Copyright (C) 1992, 1993 Signum Support AB Copyright (C) 1993, 1994
Free Software Foundation, Inc.

   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the section entitled "GNU General Public License" is included
exactly as in the original, and provided that the entire resulting
derived work is distributed under the terms of a permission notice
identical to this one.

   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the section entitled "GNU General Public License"
and this permission notice may be included in translations approved by
the Free Software Foundation instead of in the original English.



   This info manual describes how to use and administer CVS version
1.9.

About this manual
*****************

   Up to this point, one of the weakest parts of CVS has been the
documentation.  CVS is a complex program.  Previous versions of the
manual were written in the manual page format, which is not really well
suited for such a complex program.

   When writing this manual, I had several goals in mind:

   * No knowledge of RCS should be necessary.

   * No previous knowledge of revision control software should be
     necessary.  All terms, such as "revision numbers", "revision
     trees" and "merging" are explained as they are introduced.

   * The manual should concentrate on the things CVS users want to do,
     instead of what the CVS commands can do.  The first part of this
     manual leads you through things you might want to do while doing
     development, and introduces the relevant CVS commands as they are
     needed.

   * Information should be easy to find.  In the reference manual in
     the appendices almost all information about every CVS command is
     gathered together.  There is also an extensive index, and a lot of
     cross references.

   This manual was contributed by Signum Support AB in Sweden.  Signum
is yet another in the growing list of companies that support free
software.  You are free to copy both this manual and the CVS program.
*Note Copying::, for the details.  Signum Support offers support
contracts and binary distribution for many programs, such as CVS, GNU
Emacs, the GNU C compiler and others.  Write to us for more information.

     Signum Support AB
     Box 2044
     S-580 02  Linkoping
     Sweden
     
     Email: info@signum.se
     Phone: +46 (0)13 - 21 46 00
     Fax:   +46 (0)13 - 21 47 00

   Another company selling support for CVS is Cyclic Software, web:
`http://www.cyclic.com/', email: `info@cyclic.com'.

Checklist for the impatient reader
==================================

   CVS is a complex system.  You will need to read the manual to be
able to use all of its capabilities.  There are dangers that can easily
be avoided if you know about them, and this manual tries to warn you
about them.  This checklist is intended to help you avoid the dangers
without reading the entire manual.  If you intend to read the entire
manual you can skip this table.

Binary files
     CVS can handle binary files, but you must have RCS release 5.5 or
     later and a release of GNU diff that supports the `-a' flag
     (release 1.15 and later are OK).  You must also configure both RCS
     and CVS to handle binary files when you install them.

     Keword substitution can be a source of trouble with binary files.
     *Note Keyword substitution::, for solutions.

The `admin' command
     Careless use of the `admin' command can cause CVS to cease
     working.  *Note admin::, before trying to use it.

Credits
=======

   Roland Pesch, Cygnus Support <pesch@cygnus.com> wrote the manual
pages which were distributed with CVS 1.3.  Appendix A and B contain
much text that was extracted from them.  He also read an early draft of
this manual and contributed many ideas and corrections.

   The mailing-list `info-cvs' is sometimes informative. I have
included information from postings made by the following persons: David
G. Grubbs <dgg@think.com>.

   Some text has been extracted from the man pages for RCS.

   The CVS FAQ by David G. Grubbs has provided useful material.  The
FAQ is no longer maintained, however, and this manual about the closest
thing there is to a successor (with respect to documenting how to use
CVS, at least).

   In addition, the following persons have helped by telling me about
mistakes I've made: Roxanne Brunskill <rbrunski@datap.ca>, Kathy Dyer
<dyer@phoenix.ocf.llnl.gov>, Karl Pingle <pingle@acuson.com>, Thomas A
Peterson <tap@src.honeywell.com>, Inge Wallin <ingwa@signum.se>, Dirk
Koschuetzki <koschuet@fmi.uni-passau.de> and Michael Brown
<brown@wi.extrel.com>.

BUGS
====

   This manual is known to have room for improvement.  Here is a list
of known deficiencies:

   * In the examples, the output from CVS is sometimes displayed,
     sometimes not.

   * The input that you are supposed to type in the examples should
     have a different font than the output from the computer.

   * This manual should be clearer about what file permissions you
     should set up in the repository, and about setuid/setgid.

   * Some of the chapters are not yet complete.  They are noted by
     comments in the `cvs.texinfo' file.

   * This list is not complete.  If you notice any error, omission, or
     something that is unclear, please send mail to
     bug-cvs@prep.ai.mit.edu.

   I hope that you will find this manual useful, despite the
above-mentioned shortcomings.


                                                Linkoping, October 1993
                                                         Per Cederqvist

What is CVS?
************

   CVS is a version control system.  Using it, you can record the
history of your source files.

   For example, bugs sometimes creep in when software is modified, and
you might not detect the bug until a long time after you make the
modification.  With CVS, you can easily retrieve old versions to see
exactly which change caused the bug.  This can sometimes be a big help.

   You could of course save every version of every file you have ever
created.  This would however waste an enormous amount of disk space.
CVS stores all the versions of a file in a single file in a clever way
that only stores the differences between versions.

   CVS also helps you if you are part of a group of people working on
the same project.  It is all too easy to overwrite each others' changes
unless you are extremely careful.  Some editors, like GNU Emacs, try to
make sure that the same file is never modified by two people at the
same time.  Unfortunately, if someone is using another editor, that
safeguard will not work.  CVS solves this problem by insulating the
different developers from each other.  Every developer works in his own
directory, and CVS merges the work when each developer is done.

   CVS started out as a bunch of shell scripts written by Dick Grune,
posted to `comp.sources.unix' in the volume 6 release of December,
1986.  While no actual code from these shell scripts is present in the
current version of CVS much of the CVS conflict resolution algorithms
come from them.

   In April, 1989, Brian Berliner designed and coded CVS.  Jeff Polk
later helped Brian with the design of the CVS module and vendor branch
support.

   You can get CVS via anonymous ftp from a number of sites, for
instance prep.ai.mit.edu in `pub/gnu'.

   There is a mailing list, known as `info-cvs', devoted to CVS.  To
subscribe or unsubscribe send a message to
`info-cvs-request@prep.ai.mit.edu'.  Please be specific about your
email address.  As of May 1996, subscription requests are handled by a
busy human being, so you cannot expect to be added or removed
immediately.  The usenet group `comp.software.config-mgmt' is also a
suitable place for CVS discussions (along with other configuration
management systems).

CVS is not...
=============

   CVS can do a lot of things for you, but it does not try to be
everything for everyone.

CVS is not a build system.
     Though the structure of your repository and modules file interact
     with your build system (e.g. `Makefile's), they are essentially
     independent.

     CVS does not dictate how you build anything.  It merely stores
     files for retrieval in a tree structure you devise.

     CVS does not dictate how to use disk space in the checked out
     working directories.  If you write your `Makefile's or scripts in
     every directory so they have to know the relative positions of
     everything else, you wind up requiring the entire repository to be
     checked out.

     If you modularize your work, and construct a build system that
     will share files (via links, mounts, `VPATH' in `Makefile's,
     etc.), you can arrange your disk usage however you like.

     But you have to remember that *any* such system is a lot of work
     to construct and maintain.  CVS does not address the issues
     involved.

     Of course, you should place the tools created to support such a
     build system (scripts, `Makefile's, etc) under CVS.

     Figuring out what files need to be rebuilt when something changes
     is, again, something to be handled outside the scope of CVS.  One
     traditional approach is to use `make' for building, and use some
     automated tool for generating the depencies which `make' uses.

CVS is not a substitute for management.
     Your managers and project leaders are expected to talk to you
     frequently enough to make certain you are aware of schedules,
     merge points, branch names and release dates.  If they don't, CVS
     can't help.

     CVS is an instrument for making sources dance to your tune.  But
     you are the piper and the composer.  No instrument plays itself or
     writes its own music.

CVS is not a substitute for developer communication.
     When faced with conflicts within a single file, most developers
     manage to resolve them without too much effort.  But a more
     general definition of "conflict" includes problems too difficult
     to solve without communication between developers.

     CVS cannot determine when simultaneous changes within a single
     file, or across a whole collection of files, will logically
     conflict with one another.  Its concept of a "conflict" is purely
     textual, arising when two changes to the same base file are near
     enough to spook the merge (i.e. `diff3') command.

     CVS does not claim to help at all in figuring out non-textual or
     distributed conflicts in program logic.

     For example: Say you change the arguments to function `X' defined
     in file `A'.  At the same time, someone edits file `B', adding new
     calls to function `X' using the old arguments.  You are outside
     the realm of CVS's competence.

     Acquire the habit of reading specs and talking to your peers.

CVS does not have change control
     Change control refers to a number of things.  First of all it can
     mean "bug-tracking", that is being able to keep a database of
     reported bugs and the status of each one (is it fixed?  in what
     release?  has the bug submitter agreed that it is fixed?).  For
     interfacing CVS to an external bug-tracking system, see the
     `rcsinfo' and `editinfo' files (*note Administrative files::.).

     Another aspect of change control is keeping track of the fact that
     changes to several files were in fact changed together as one
     logical change.  If you check in several files in a single `cvs
     commit' operation, CVS then forgets that those files were checked
     in together, and the fact that they have the same log message is
     the only thing tying them together.  Keeping a GNU style
     `ChangeLog' can help somewhat.

     Another aspect of change control, in some systems, is the ability
     to keep track of the status of each change.  Some changes have
     been written by a developer, others have been reviewed by a second
     developer, and so on.  Generally, the way to do this with CVS is to
     generate a diff (using `cvs diff' or `diff') and email it to
     someone who can then apply it using the `patch' utility.  This is
     very flexible, but depends on mechanisms outside CVS to make sure
     nothing falls through the cracks.

CVS is not an automated testing program
     It should be possible to enforce mandatory use of a testsuite
     using the `commitinfo' file.  I haven't heard a lot about projects
     trying to do that or whether there are subtle gotchas, however.

CVS does not have a builtin process model
     Some systems provide ways to ensure that changes or releases go
     through various steps, with various approvals as needed.
     Generally, one can accomplish this with CVS but it might be a
     little more work.  In some cases you'll want to use the
     `commitinfo', `loginfo', `rcsinfo', or `editinfo' files, to
     require that certain steps be performed before cvs will allow a
     checkin.  Also consider whether features such as branches and tags
     can be used to perform tasks such as doing work in a development
     tree and then merging certain changes over to a stable tree only
     once they have been proven.

Basic concepts
**************

   CVS stores all files in a centralized "repository" (*note
Repository::.).

   The repository contains directories and files, in an arbitrary tree.
The "modules" feature can be used to group together a set of
directories or files into a single entity (*note modules::.).  A
typical usage is to define one module per project.

Revision numbers
================

   Each version of a file has a unique "revision number".  Revision
numbers look like `1.1', `1.2', `1.3.2.2' or even `1.3.2.2.4.5'.  A
revision number always has an even number of period-separated decimal
integers.  By default revision 1.1 is the first revision of a file.
Each successive revision is given a new number by increasing the
rightmost number by one.  The following figure displays a few
revisions, with newer revisions to the right.

            +-----+    +-----+    +-----+    +-----+    +-----+
            ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !
            +-----+    +-----+    +-----+    +-----+    +-----+

   CVS is not limited to linear development.  The "revision tree" can
be split into "branches", where each branch is a self-maintained line of
development.  Changes made on one branch can easily be moved back to
the main trunk.

   Each branch has a "branch number", consisting of an odd number of
period-separated decimal integers.  The branch number is created by
appending an integer to the revision number where the corresponding
branch forked off.  Having branch numbers allows more than one branch
to be forked off from a certain revision.

   All revisions on a branch have revision numbers formed by appending
an ordinal number to the branch number.  The following figure
illustrates branching with an example.

                                                          +-------------+
                               Branch 1.2.2.3.2 ->        ! 1.2.2.3.2.1 !
                                                        / +-------------+
                                                       /
                                                      /
                      +---------+    +---------+    +---------+    +---------+
     Branch 1.2.2 -> _! 1.2.2.1 !----! 1.2.2.2 !----! 1.2.2.3 !----! 1.2.2.4 !
                    / +---------+    +---------+    +---------+    +---------+
                   /
                  /
     +-----+    +-----+    +-----+    +-----+    +-----+
     ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !      <- The main trunk
     +-----+    +-----+    +-----+    +-----+    +-----+
                     !
                     !
                     !   +---------+    +---------+    +---------+
     Branch 1.2.4 -> +---! 1.2.4.1 !----! 1.2.4.2 !----! 1.2.4.3 !
                         +---------+    +---------+    +---------+

   The exact details of how the branch number is constructed is not
something you normally need to be concerned about, but here is how it
works: When CVS creates a branch number it picks the first unused even
integer, starting with 2.  So when you want to create a branch from
revision 6.4 it will be numbered 6.4.2.  All branch numbers ending in a
zero (such as 6.4.0) are used internally by CVS (*note Magic branch
numbers::.).  The branch 1.1.1 has a special meaning.  *Note Tracking
sources::.

Versions, revisions and releases
================================

   A file can have several versions, as described above.  Likewise, a
software product can have several versions.  A software product is
often given a version number such as `4.1.1'.

   Versions in the first sense are called "revisions" in this document,
and versions in the second sense are called "releases".  To avoid
confusion, the word "version" is almost never used in this document.

A sample session
****************

   This section describes a typical work-session using CVS.  It assumes
that a repository is set up (*note Repository::.).

   Suppose you are working on a simple compiler.  The source consists
of a handful of C files and a `Makefile'.  The compiler is called `tc'
(Trivial Compiler), and the repository is set up so that there is a
module called `tc'.

Getting the source
==================

   The first thing you must do is to get your own working copy of the
source for `tc'.  For this, you use the `checkout' command:

     $ cvs checkout tc

This will create a new directory called `tc' and populate it with the
source files.

     $ cd tc
     $ ls
     CVS         Makefile    backend.c   driver.c    frontend.c  parser.c

   The `CVS' directory is used internally by CVS.  Normally, you should
not modify or remove any of the files in it.

   You start your favorite editor, hack away at `backend.c', and a
couple of hours later you have added an optimization pass to the
compiler.  A note to RCS and SCCS users: There is no need to lock the
files that you want to edit.  *Note Multiple developers:: for an
explanation.

Committing your changes
=======================

   When you have checked that the compiler is still compilable you
decide to make a new version of `backend.c'.

     $ cvs commit backend.c

CVS starts an editor, to allow you to enter a log message.  You type in
"Added an optimization pass.", save the temporary file, and exit the
editor.

   The environment variable `$CVSEDITOR' determines which editor is
started.  If `$CVSEDITOR' is not set, then if the environment variable
`$EDITOR' is set, it will be used. If both `$CVSEDITOR' and `$EDITOR'
are not set then the editor defaults to `vi'.  If you want to avoid the
overhead of starting an editor you can specify the log message on the
command line using the `-m' flag instead, like this:

     $ cvs commit -m "Added an optimization pass" backend.c

Cleaning up
===========

   Before you turn to other tasks you decide to remove your working
copy of tc.  One acceptable way to do that is of course

     $ cd ..
     $ rm -r tc

but a better way is to use the `release' command (*note release::.):

     $ cd ..
     $ cvs release -d tc
     M driver.c
     ? tc
     You have [1] altered files in this repository.
     Are you sure you want to release (and delete) module `tc': n
     ** `release' aborted by user choice.

   The `release' command checks that all your modifications have been
committed.  If history logging is enabled it also makes a note in the
history file.  *Note history file::.

   When you use the `-d' flag with `release', it also removes your
working copy.

   In the example above, the `release' command wrote a couple of lines
of output.  `? tc' means that the file `tc' is unknown to CVS.  That is
nothing to worry about: `tc' is the executable compiler, and it should
not be stored in the repository.  *Note cvsignore::, for information
about how to make that warning go away.  *Note release output::, for a
complete explanation of all possible output from `release'.

   `M driver.c' is more serious.  It means that the file `driver.c' has
been modified since it was checked out.

   The `release' command always finishes by telling you how many
modified files you have in your working copy of the sources, and then
asks you for confirmation before deleting any files or making any note
in the history file.

   You decide to play it safe and answer `n <RET>' when `release' asks
for confirmation.

Viewing differences
===================

   You do not remember modifying `driver.c', so you want to see what
has happened to that file.

     $ cd tc
     $ cvs diff driver.c

   This command runs `diff' to compare the version of `driver.c' that
you checked out with your working copy.  When you see the output you
remember that you added a command line option that enabled the
optimization pass.  You check it in, and release the module.

     $ cvs commit -m "Added an optimization pass" driver.c
     Checking in driver.c;
     /usr/local/cvsroot/tc/driver.c,v  <--  driver.c
     new revision: 1.2; previous revision: 1.1
     done
     $ cd ..
     $ cvs release -d tc
     ? tc
     You have [0] altered files in this repository.
     Are you sure you want to release (and delete) module `tc': y

The Repository
**************

   The CVS "repository" stores a complete copy of all the files and
directories which are under version control.

   Normally, you never access any of the files in the repository
directly.  Instead, you use CVS commands to get your own copy of the
files, and then work on that copy.  When you've finished a set of
changes, you check (or "commit") them back into the repository.  The
repository then contains the changes which you have made, as well as
recording exactly what you changed, when you changed it, and other such
information.

   CVS can access a repository by a variety of means.  It might be on
the local computer, or it might be on a computer across the room or
across the world.  To distinguish various ways to access a repository,
the repository name can start with an "access method".  For example,
the access method `:local:' means to access a repository directory, so
the repository `:local:/usr/local/cvsroot' means that the repository is
in `/usr/local/cvsroot' on the computer running CVS.  For information
on other access methods, see *Note Remote repositories::.

   If the access method is omitted, then if the repository does not
contain `:', then `:local:' is assumed.  If it does contain `:' than
either `:ext:' or `:server:' is assumed.  For example, if you have a
local repository in `/usr/local/cvsroot', you can use
`/usr/local/cvsroot' instead of `:local:/usr/local/cvsroot'.  But if
(under Windows NT, for example) your local repository is
`c:\src\cvsroot', then you must specify the access method, as in
`:local:c:\src\cvsroot'.

   The repository is split in two parts.  `$CVSROOT/CVSROOT' contains
administrative files for CVS.  The other directories contain the actual
user-defined modules.

Telling CVS where your repository is
====================================

   There are a couple of different ways to tell CVS where to find the
repository.  You can name the repository on the command line
explicitly, with the `-d' (for "directory") option:

     cvs -d /usr/local/cvsroot checkout yoyodyne/tc

   Or you can set the `$CVSROOT' environment variable to an absolute
path to the root of the repository, `/usr/local/cvsroot' in this
example.  To set `$CVSROOT', all `csh' and `tcsh' users should have
this line in their `.cshrc' or `.tcshrc' files:

     setenv CVSROOT /usr/local/cvsroot

`sh' and `bash' users should instead have these lines in their
`.profile' or `.bashrc':

     CVSROOT=/usr/local/cvsroot
     export CVSROOT

   A repository specified with `-d' will override the `$CVSROOT'
environment variable.  Once you've checked a working copy out from the
repository, it will remember where its repository is (the information
is recorded in the `CVS/Root' file in the working copy).

   The `-d' option and the `CVS/Root' file both override the `$CVSROOT'
environment variable.  If `-d' option differs from `CVS/Root', the
former is used (and specifying `-d' will cause `CVS/Root' to be
updated).  Of course, for proper operation they should be two ways of
referring to the same repository.

How data is stored in the repository
====================================

   For most purposes it isn't important *how* CVS stores information in
the repository.  In fact, the format has changed in the past, and is
likely to change in the future.  Since in almost all cases one accesses
the repository via CVS commands; such changes need not be disruptive.

   However, in some cases it may be necessary to understand how CVS
stores data in the repository, for example you might need to track down
CVS locks (*note Concurrency::.) or you might need to deal with the
file permissions appropriate for the repository.

Where files are stored within the repository
--------------------------------------------

   The overall structure of the repository is a directory tree
corresponding to the directories in the working directory.  For
example, supposing the repository is in `/usr/local/cvsroot', here is a
possible directory tree (showing only the directories):

     /usr
      |
      +--local
      |   |
      |   +--cvsroot
      |   |    |
      |   |    +--CVSROOT
               |      (administrative files)
               |
               +--gnu
               |   |
               |   +--diff
               |   |   (source code to GNU diff)
               |   |
               |   +--rcs
               |   |   (source code to RCS)
               |   |
               |   +--cvs
               |       (source code to CVS)
               |
               +--yoyodyne
                   |
                   +--tc
                   |    |
                   |    +--man
                   |    |
                   |    +--testing
                   |
                   +--(other Yoyodyne software)

   With the directories are "history files" for each file under version
control.  The name of the history file is the name of the corresponding
file with `,v' appended to the end.  Here is what the repository for
the `yoyodyne/tc' directory might look like:

       `$CVSROOT'
         |
         +--yoyodyne
         |   |
         |   +--tc
         |   |   |
                 +--Makefile,v
                 +--backend.c,v
                 +--driver.c,v
                 +--frontend.c,v
                 +--parser.c,v
                 +--man
                 |    |
                 |    +--tc.1,v
                 |
                 +--testing
                      |
                      +--testpgm.t,v
                      +--test2.t,v

   The history files contain, among other things, enough information to
recreate any revision of the file, a log of all commit messages and the
user-name of the person who committed the revision.  The history files
are known as "RCS files", because the first program to store files in
that format was a version control system known as RCS.  For a full
description of the file format, see the `man' page `rcsfile(5)',
distributed with RCS.  This file format has become very common--many
systems other than CVS or RCS can at least import history files in this
format.

File permissions
----------------

   All `,v' files are created read-only, and you should not change the
permission of those files.  The directories inside the repository
should be writable by the persons that have permission to modify the
files in each directory.  This normally means that you must create a
UNIX group (see group(5)) consisting of the persons that are to edit
the files in a project, and set up the repository so that it is that
group that owns the directory.

   This means that you can only control access to files on a
per-directory basis.

   Note that users must also have write access to check out files,
because CVS needs to create lock files (*note Concurrency::.).

   Also note that users must have write access to the
`CVSROOT/val-tags' file.  CVS uses it to keep track of what tags are
valid tag names (it is sometimes updated when tags are used, as well as
when they are created, though).

   CVS tries to set up reasonable file permissions for new directories
that are added inside the tree, but you must fix the permissions
manually when a new directory should have different permissions than its
parent directory.  If you set the `CVSUMASK' environment variable that
will control the file permissions which CVS uses in creating directories
and/or files in the repository.  `CVSUMASK' does not affect the file
permissions in the working directory; such files have the permissions
which are typical for newly created files, except that sometimes CVS
creates them read-only (see the sections on watches, *Note Setting a
watch::; -r, *Note Global options::; or CVSREAD, *Note Environment
variables::).

   Since CVS was not written to be run setuid, it is unsafe to try to
run it setuid.  You cannot use the setuid features of RCS together with
CVS.

The administrative files
========================

   The directory `$CVSROOT/CVSROOT' contains some "administrative
files".  *Note Administrative files::, for a complete description.  You
can use CVS without any of these files, but some commands work better
when at least the `modules' file is properly set up.

   The most important of these files is the `modules' file.  It defines
all modules in the repository.  This is a sample `modules' file.

     CVSROOT         CVSROOT
     modules         CVSROOT modules
     cvs             gnu/cvs
     rcs             gnu/rcs
     diff            gnu/diff
     tc              yoyodyne/tc

   The `modules' file is line oriented.  In its simplest form each line
contains the name of the module, whitespace, and the directory where
the module resides.  The directory is a path relative to `$CVSROOT'.
The last four lines in the example above are examples of such lines.

   The line that defines the module called `modules' uses features that
are not explained here.  *Note modules::, for a full explanation of all
the available features.

Editing administrative files
----------------------------

   You edit the administrative files in the same way that you would edit
any other module.  Use `cvs checkout CVSROOT' to get a working copy,
edit it, and commit your changes in the normal way.

   It is possible to commit an erroneous administrative file.  You can
often fix the error and check in a new revision, but sometimes a
particularly bad error in the administrative file makes it impossible
to commit new revisions.

Multiple repositories
=====================

   In some situations it is a good idea to have more than one
repository, for instance if you have two development groups that work
on separate projects without sharing any code.  All you have to do to
have several repositories is to specify the appropriate repository,
using the `CVSROOT' environment variable, the `-d' option to CVS, or
(once you have checked out a working directory) by simply allowing CVS
to use the repository that was used to check out the working directory
(*note Specifying a repository::.).

   The big advantage of having multiple repositories is that they can
reside on different servers.  The big disadvantage is that you cannot
have a single CVS command recurse into directories which comes from
different repositories.  Generally speaking, if you are thinking of
setting up several repositories on the same machine, you might want to
consider using several directories within the same repository.

   None of the examples in this manual show multiple repositories.

Creating a repository
=====================

   To set up a CVS repository, choose a directory with ample disk space
available for the revision history of the source files.  It should be
accessable (directly or via a networked file system) from all machines
which want to use CVS in server or local mode; the client machines need
not have any access to it other than via the CVS protocol.  It is not
possible to use CVS to read from a repository which one only has read
access to; CVS needs to be able to create lock files (*note
Concurrency::.).

   To create a repository, run the `cvs init' command.  It will set up
an empty repository in the CVS root specified in the usual way (*note
Repository::.).  For example,

     cvs -d /usr/local/cvsroot init

   `cvs init' is careful to never overwrite any existing files in the
repository, so no harm is done if you run `cvs init' on an already
set-up repository.

   `cvs init' will enable history logging; if you don't want that,
remove the history file after running `cvs init'.  *Note history file::.

Remote repositories
===================

   Your working copy of the sources can be on a different machine than
the repository.  Generally, using a remote repository is just like
using a local one, except that the format of the repository name is:

     :METHOD:USER@HOSTNAME:/path/to/repository

   The details of exactly what needs to be set up depend on how you are
connecting to the server.

   If METHOD is not specified, and the repository name contains `:',
then the default is `ext' or `server', depending on your platform; both
are described in *Note Connecting via rsh::.

Connecting with rsh
-------------------

   CVS uses the `rsh' protocol to perform these operations, so the
remote user host needs to have a `.rhosts' file which grants access to
the local user.

   For example, suppose you are the user `mozart' on the local machine
`anklet.grunge.com', and the server machine is
`chainsaw.brickyard.com'.  On chainsaw, put the following line into the
file `.rhosts' in `bach''s home directory:

     anklet.grunge.com  mozart

   Then test that `rsh' is working with

     rsh -l bach chainsaw.brickyard.com 'echo $PATH'

   Next you have to make sure that `rsh' will be able to find the
server.  Make sure that the path which `rsh' printed in the above
example includes the directory containing a program named `cvs' which
is the server.  You need to set the path in `.bashrc', `.cshrc', etc.,
not `.login' or `.profile'.  Alternately, you can set the environment
variable `CVS_SERVER' on the client machine to the filename of the
server you want to use, for example `/usr/local/bin/cvs-1.6'.

   There is no need to edit `inetd.conf' or start a CVS server daemon.

   There are two access methods that you use in CVSROOT for rsh.
`:server:' specifies an internal rsh client, which is supported only by
some CVS ports.  `:ext:' specifies an external rsh program.  By default
this is `rsh' but you may set the `CVS_RSH' environment variable to
invoke another program which can access the remote server (for example,
`remsh' on HP-UX 9 because `rsh' is something different).  It must be a
program which can transmit data to and from the server without modifying
it; for example the Windows NT `rsh' is not suitable since it by
default translates between CRLF and LF.  The OS/2 CVS port has a hack
to pass `-b' to `rsh' to get around this, but since this could
potentially cause programs for programs other than the standard `rsh',
it may change in the future.  If you set `CVS_RSH' to `SSH' or some
other rsh replacement, the instructions in the rest of this section
concerning `.rhosts' and so on are likely to be incorrect; consult the
documentation for your rsh replacement.

   Continuing our example, supposing you want to access the module
`foo' in the repository `/usr/local/cvsroot/', on machine
`chainsaw.brickyard.com', you are ready to go:

     cvs -d :ext:bach@chainsaw.brickyard.com:/usr/local/cvsroot checkout foo

   (The `bach@' can be omitted if the username is the same on both the
local and remote hosts.)

Direct connection with password authentication
----------------------------------------------

   The CVS client can also connect to the server using a password
protocol.  This is particularly useful if using `rsh' is not feasible
(for example, the server is behind a firewall), and Kerberos also is
not available.

   To use this method, it is necessary to make some adjustments on both
the server and client sides.

Setting up the server for password authentication
.................................................

   On the server side, the file `/etc/inetd.conf' needs to be edited so
`inetd' knows to run the command `cvs pserver' when it receives a
connection on the right port.  By default, the port number is 2401; it
would be different if your client were compiled with `CVS_AUTH_PORT'
defined to something else, though.

   If your `inetd' allows raw port numbers in `/etc/inetd.conf', then
the following (all on a single line in `inetd.conf') should be
sufficient:

     2401  stream  tcp  nowait  root  /usr/local/bin/cvs
     cvs -b /usr/local/bin pserver

   The `-b' option specifies the directory which contains the RCS
binaries on the server.  You could also use the `-T' option to specify
a temporary directory.

   If your `inetd' wants a symbolic service name instead of a raw port
number, then put this in `/etc/services':

     cvspserver      2401/tcp

   and put `cvspserver' instead of `2401' in `inetd.conf'.

   Once the above is taken care of, restart your `inetd', or do
whatever is necessary to force it to reread its initialization files.

   Because the client stores and transmits passwords in cleartext
(almost--see *Note Password authentication security:: for details), a
separate CVS password file may be used, so people don't compromise their
regular passwords when they access the repository.  This file is
`$CVSROOT/CVSROOT/passwd' (*note Intro administrative files::.).  Its
format is similar to `/etc/passwd', except that it only has two fields,
username and password.  For example:

     bach:ULtgRLXo7NRxs
     cwang:1sOp854gDF3DY

   The password is encrypted according to the standard Unix `crypt()'
function, so it is possible to paste in passwords directly from regular
Unix `passwd' files.

   When authenticating a password, the server first checks for the user
in the CVS `passwd' file.  If it finds the user, it compares against
that password.  If it does not find the user, or if the CVS `passwd'
file does not exist, then the server tries to match the password using
the system's user-lookup routine.  When using the CVS `passwd' file,
the server runs under as the username specified in the the third
argument in the entry, or as the first argument if there is no third
argument (in this way CVS allows imaginary usernames provided the CVS
`passwd' file indicates corresponding valid system usernames).  In any
case, CVS will have no privileges which the (valid) user would not have.

   Right now, the only way to put a password in the CVS `passwd' file
is to paste it there from somewhere else.  Someday, there may be a `cvs
passwd' command.

Using the client with password authentication
.............................................

   Before connecting to the server, the client must "log in" with the
command `cvs login'.  Logging in verifies a password with the server,
and also records the password for later transactions with the server.
The `cvs login' command needs to know the username, server hostname,
and full repository path, and it gets this information from the
repository argument or the `CVSROOT' environment variable.

   `cvs login' is interactive -- it prompts for a password:

     cvs -d :pserver:bach@chainsaw.brickyard.com:/usr/local/cvsroot login
     CVS password:

   The password is checked with the server; if it is correct, the
`login' succeeds, else it fails, complaining that the password was
incorrect.

   Once you have logged in, you can force CVS to connect directly to
the server and authenticate with the stored password:

     cvs -d :pserver:bach@chainsaw.brickyard.com:/usr/local/cvsroot checkout foo

   The `:pserver:' is necessary because without it, CVS will assume it
should use `rsh' to connect with the server (*note Connecting via
rsh::.).  (Once you have a working copy checked out and are running CVS
commands from within it, there is no longer any need to specify the
repository explicitly, because CVS records it in the working copy's
`CVS' subdirectory.)

   Passwords are stored by default in the file `$HOME/.cvspass'.  Its
format is human-readable, but don't edit it unless you know what you
are doing.  The passwords are not stored in cleartext, but are
trivially encoded to protect them from "innocent" compromise (i.e.,
inadvertently being seen by a system administrator who happens to look
at that file).

   The `CVS_PASSFILE' environment variable overrides this default.  If
you use this variable, make sure you set it *before* `cvs login' is
run.  If you were to set it after running `cvs login', then later CVS
commands would be unable to look up the password for transmission to
the server.

   The `CVS_PASSWORD' environment variable overrides *all* stored
passwords.  If it is set, CVS will use it for all password-authenticated
connections.

Security considerations with password authentication
....................................................

   The passwords are stored on the client side in a trivial encoding of
the cleartext, and transmitted in the same encoding.  The encoding is
done only to prevent inadvertent password compromises (i.e., a system
administrator accidentally looking at the file), and will not prevent
even a naive attacker from gaining the password.

   The separate CVS password file (*note Password authentication
server::.) allows people to use a different password for repository
access than for login access.  On the other hand, once a user has
access to the repository, she can execute programs on the server system
through a variety of means.  Thus, repository access implies fairly
broad system access as well.  It might be possible to modify CVS to
prevent that, but no one has done so as of this writing.  Furthermore,
there may be other ways in which having access to CVS allows people to
gain more general access to the system; noone has done a careful audit.

   In summary, anyone who gets the password gets repository access, and
some measure of general system access as well.  The password is
available to anyone who can sniff network packets or read a protected
(i.e., user read-only) file.  If you want real security, get Kerberos.

Direct connection with kerberos
-------------------------------

   The main disadvantage of using rsh is that all the data needs to
pass through additional programs, so it may be slower.  So if you have
kerberos installed you can connect via a direct TCP connection,
authenticating with kerberos.

   To do this, CVS needs to be compiled with kerberos support; when
configuring CVS it tries to detect whether kerberos is present or you
can use the `--with-krb4' flag to configure.

   The data transmitted is *not* encrypted by default.  Encryption
support must be compiled into both the client and server; use the
`--enable-encryption' configure option to turn it on.  You must then
use the `-x' global option to request encryption.

   You need to edit `inetd.conf' on the server machine to run `cvs
kserver'.  The client uses port 1999 by default; if you want to use
another port specify it in the `CVS_CLIENT_PORT' environment variable
on the client.

   When you want to use CVS, get a ticket in the usual way (generally
`kinit'); it must be a ticket which allows you to log into the server
machine.  Then you are ready to go:

     cvs -d :kserver:chainsaw.brickyard.com:/user/local/cvsroot checkout foo

   Previous versions of CVS would fall back to a connection via rsh;
this version will not do so.

Starting a project with CVS
***************************

   Because renaming files and moving them between directories is
somewhat inconvenient, the first thing you do when you start a new
project should be to think through your file organization.  It is not
impossible to rename or move files, but it does increase the potential
for confusion and CVS does have some quirks particularly in the area of
renaming directories.  *Note Moving files::.

   What to do next depends on the situation at hand.

Setting up the files
====================

   The first step is to create the files inside the repository.  This
can be done in a couple of different ways.

Creating a directory tree from a number of files
------------------------------------------------

   When you begin using CVS, you will probably already have several
projects that can be put under CVS control.  In these cases the easiest
way is to use the `import' command.  An example is probably the easiest
way to explain how to use it.  If the files you want to install in CVS
reside in `WDIR', and you want them to appear in the repository as
`$CVSROOT/yoyodyne/RDIR', you can do this:

     $ cd WDIR
     $ cvs import -m "Imported sources" yoyodyne/RDIR yoyo start

   Unless you supply a log message with the `-m' flag, CVS starts an
editor and prompts for a message.  The string `yoyo' is a "vendor tag",
and `start' is a "release tag".  They may fill no purpose in this
context, but since CVS requires them they must be present.  *Note
Tracking sources::, for more information about them.

   You can now verify that it worked, and remove your original source
directory.

     $ cd ..
     $ mv DIR DIR.orig
     $ cvs checkout yoyodyne/DIR       # Explanation below
     $ ls -R yoyodyne
     $ rm -r DIR.orig

Erasing the original sources is a good idea, to make sure that you do
not accidentally edit them in DIR, bypassing CVS.  Of course, it would
be wise to make sure that you have a backup of the sources before you
remove them.

   The `checkout' command can either take a module name as argument (as
it has done in all previous examples) or a path name relative to
`$CVSROOT', as it did in the example above.

   It is a good idea to check that the permissions CVS sets on the
directories inside `$CVSROOT' are reasonable, and that they belong to
the proper groups.  *Note File permissions::.

   If some of the files you want to import are binary, you may want to
use the wrappers features to specify which files are binary and which
are not.  *Note Wrappers::.

Creating Files From Other Version Control Systems
-------------------------------------------------

   If you have a project which you are maintaining with another version
control system, such as RCS, you may wish to put the files from that
project into CVS, and preserve the revision history of the files.

From RCS
     If you have been using RCS, find the RCS files--usually a file
     named `foo.c' will have its RCS file in `RCS/foo.c,v' (but it
     could be other places; consult the RCS documentation for details).
     Then create the appropriate directories in CVS if they do not
     already exist.  Then copy the files into the appropriate
     directories in the CVS repository (the name in the repository must
     be the name of the source file with `,v' added; the files go
     directly in the appopriate directory of the repository, not in an
     `RCS' subdirectory).  This is one of the few times when it is a
     good idea to access the CVS repository directly, rather than using
     CVS commands.  Then you are ready to check out a new working
     directory.

     The RCS file should not be locked when you move it into CVS; if it
     is, CVS will have trouble letting you operate on it.

From another version control system
     Many version control systems have the ability to export RCS files
     in the standard format.  If yours does, export the RCS files and
     then follow the above instructions.

From SCCS
     There is a script in the `contrib' directory of the CVS source
     distribution called `sccs2rcs' which converts SCCS files to RCS
     files.  Note: you must run it on a machine which has both SCCS and
     RCS installed, and like everything else in contrib it is
     unsupported (your mileage may vary).

Creating a directory tree from scratch
--------------------------------------

   For a new project, the easiest thing to do is probably to create an
empty directory structure, like this:

     $ mkdir tc
     $ mkdir tc/man
     $ mkdir tc/testing

   After that, you use the `import' command to create the corresponding
(empty) directory structure inside the repository:

     $ cd tc
     $ cvs import -m "Created directory structure" yoyodyne/DIR yoyo start

   Then, use `add' to add files (and new directories) as they appear.

   Check that the permissions CVS sets on the directories inside
`$CVSROOT' are reasonable.

Defining the module
===================

   The next step is to define the module in the `modules' file.  This
is not strictly necessary, but modules can be convenient in grouping
together related files and directories.

   In simple cases these steps are sufficient to define a module.

  1. Get a working copy of the modules file.

          $ cvs checkout CVSROOT/modules
          $ cd CVSROOT

  2. Edit the file and insert a line that defines the module.  *Note
     Intro administrative files::, for an introduction.  *Note
     modules::, for a full description of the modules file.  You can
     use the following line to define the module `tc':

          tc   yoyodyne/tc

  3. Commit your changes to the modules file.

          $ cvs commit -m "Added the tc module." modules

  4. Release the modules module.

          $ cd ..
          $ cvs release -d CVSROOT

Multiple developers
*******************

   When more than one person works on a software project things often
get complicated.  Often, two people try to edit the same file
simultaneously.  One solution, known as "file locking" or "reserved
checkouts", is to allow only one person to edit each file at a time.
This is the only solution with some version control systems, including
RCS and SCCS.  CVS doesn't have a very nice implementation of reserved
checkouts (yet) but there are ways to get it working (for example, see
the `cvs admin -l' command in *Note admin options::).  It also may be
possible to use the watches features described below, together with
suitable procedures (not enforced by software), to avoid having two
people edit at the same time.

   The default model with CVS is known as "unreserved checkouts".  In
this model, developers can edit their own "working copy" of a file
simultaneously.  The first person that commits his changes has no
automatic way of knowing that another has started to edit it.  Others
will get an error message when they try to commit the file.  They must
then use CVS commands to bring their working copy up to date with the
repository revision.  This process is almost automatic.

   CVS also supports mechanisms which facilitate various kinds of
communcation, without actually enforcing rules like reserved checkouts
do.

   The rest of this chapter describes how these various models work,
and some of the issues involved in choosing between them.

File status
===========

   Based on what operations you have performed on a checked out file,
and what operations others have performed to that file in the
repository, one can classify a file in a number of states.  The states,
as reported by the `status' command, are:

Up-to-date
     The file is identical with the latest revision in the repository
     for the branch in use.

Locally Modified
     You have edited the file, and not yet committed your changes.

Locally Added
     You have added the file with `add', and not yet committed your
     changes.

Locally Removed
     You have removed the file with `remove', and not yet committed
     your changes.

Needs Checkout
     Someone else has committed a newer revision to the repository.
     The name is slightly misleading; you will ordinarily use `update'
     rather than `checkout' to get that newer revision.

Needs Patch
     Like Needs Checkout, but the CVS server will send a patch rather
     than the entire file.  Sending a patch or sending an entire file
     accomplishes the same thing.

Needs Merge
     Someone else has committed a newer revision to the repository, and
     you have also made modifications to the file.

Unresolved Conflict
     This is like Locally Modified, except that a previous `update'
     command gave a conflict.  You need to resolve the conflict as
     described in *Note Conflicts example::.

Unknown
     CVS doesn't know anything about this file.  For example, you have
     created a new file and have not run `add'.

   To help clarify the file status, `status' also reports the `Working
revision' which is the revision that the file in the working directory
derives from, and the `Repository revision' which is the latest
revision in the repository for the branch in use.

   For information on the options to `status', see *Note status::.  For
information on its `Sticky tag' and `Sticky date' output, see *Note
Sticky tags::.  For information on its `Sticky options' output, see the
`-k' option in *Note update options::.

Bringing a file up to date
==========================

   When you want to update or merge a file, use the `update' command.
For files that are not up to date this is roughly equivalent to a
`checkout' command: the newest revision of the file is extracted from
the repository and put in your working copy of the module.

   Your modifications to a file are never lost when you use `update'.
If no newer revision exists, running `update' has no effect.  If you
have edited the file, and a newer revision is available, CVS will merge
all changes into your working copy.

   For instance, imagine that you checked out revision 1.4 and started
editing it.  In the meantime someone else committed revision 1.5, and
shortly after that revision 1.6.  If you run `update' on the file now,
CVS will incorporate all changes between revision 1.4 and 1.6 into your
file.

   If any of the changes between 1.4 and 1.6 were made too close to any
of the changes you have made, an "overlap" occurs.  In such cases a
warning is printed, and the resulting file includes both versions of
the lines that overlap, delimited by special markers.  *Note update::,
for a complete description of the `update' command.

Conflicts example
=================

   Suppose revision 1.4 of `driver.c' contains this:

     #include <stdio.h>
     
     void main()
     {
         parse();
         if (nerr == 0)
             gencode();
         else
             fprintf(stderr, "No code generated.\n");
         exit(nerr == 0 ? 0 : 1);
     }

Revision 1.6 of `driver.c' contains this:

     #include <stdio.h>
     
     int main(int argc,
              char **argv)
     {
         parse();
         if (argc != 1)
         {
             fprintf(stderr, "tc: No args expected.\n");
             exit(1);
         }
         if (nerr == 0)
             gencode();
         else
             fprintf(stderr, "No code generated.\n");
         exit(!!nerr);
     }

Your working copy of `driver.c', based on revision 1.4, contains this
before you run `cvs update':

     #include <stdlib.h>
     #include <stdio.h>
     
     void main()
     {
         init_scanner();
         parse();
         if (nerr == 0)
             gencode();
         else
             fprintf(stderr, "No code generated.\n");
         exit(nerr == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
     }

You run `cvs update':

     $ cvs update driver.c
     RCS file: /usr/local/cvsroot/yoyodyne/tc/driver.c,v
     retrieving revision 1.4
     retrieving revision 1.6
     Merging differences between 1.4 and 1.6 into driver.c
     rcsmerge warning: overlaps during merge
     cvs update: conflicts found in driver.c
     C driver.c

CVS tells you that there were some conflicts.  Your original working
file is saved unmodified in `.#driver.c.1.4'.  The new version of
`driver.c' contains this:

     #include <stdlib.h>
     #include <stdio.h>
     
     int main(int argc,
              char **argv)
     {
         init_scanner();
         parse();
         if (argc != 1)
         {
             fprintf(stderr, "tc: No args expected.\n");
             exit(1);
         }
         if (nerr == 0)
             gencode();
         else
             fprintf(stderr, "No code generated.\n");
     <<<<<<< driver.c
         exit(nerr == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
     =======
         exit(!!nerr);
     >>>>>>> 1.6
     }

Note how all non-overlapping modifications are incorporated in your
working copy, and that the overlapping section is clearly marked with
`<<<<<<<', `=======' and `>>>>>>>'.

   You resolve the conflict by editing the file, removing the markers
and the erroneous line.  Suppose you end up with this file:
     #include <stdlib.h>
     #include <stdio.h>
     
     int main(int argc,
              char **argv)
     {
         init_scanner();
         parse();
         if (argc != 1)
         {
             fprintf(stderr, "tc: No args expected.\n");
             exit(1);
         }
         if (nerr == 0)
             gencode();
         else
             fprintf(stderr, "No code generated.\n");
         exit(nerr == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
     }

You can now go ahead and commit this as revision 1.7.

     $ cvs commit -m "Initialize scanner. Use symbolic exit values." driver.c
     Checking in driver.c;
     /usr/local/cvsroot/yoyodyne/tc/driver.c,v  <--  driver.c
     new revision: 1.7; previous revision: 1.6
     done

   For your protection, CVS will refuse to check in a file if a
conflict occurred and you have not resolved the conflict.  Currently to
resolve a conflict, you must change the timestamp on the file, and must
also insure that the file contains no conflict markers.  If your file
legitimately contains conflict markers (that is, occurrences of
`>>>>>>> ' at the start of a line that don't mark a conflict), then CVS
has trouble handling this and you need to start hacking on the
`CVS/Entries' file or other such workarounds.

   If you use release 1.04 or later of pcl-cvs (a GNU Emacs front-end
for CVS) you can use an Emacs package called emerge to help you resolve
conflicts.  See the documentation for pcl-cvs.

Informing others about commits
==============================

   It is often useful to inform others when you commit a new revision
of a file.  The `-i' option of the `modules' file, or the `loginfo'
file, can be used to automate this process.  *Note modules::.  *Note
loginfo::.  You can use these features of CVS to, for instance,
instruct CVS to mail a message to all developers, or post a message to
a local newsgroup.

Several developers simultaneously attempting to run CVS
=======================================================

   If several developers try to run CVS at the same time, one may get
the following message:

     [11:43:23] waiting for bach's lock in /usr/local/cvsroot/foo

   CVS will try again every 30 seconds, and either continue with the
operation or print the message again, if it still needs to wait.  If a
lock seems to stick around for an undue amount of time, find the person
holding the lock and ask them about the cvs command they are running.
If they aren't running a cvs command, look for and remove files
starting with `#cvs.tfl', `#cvs.rfl', or `#cvs.wfl' from the repository.

   Note that these locks are to protect CVS's internal data structures
and have no relationship to the word "lock" in the sense used by
RCS--which refers to reserved checkouts (*note Multiple developers::.).

   Any number of people can be reading from a given repository at a
time; only when someone is writing do the locks prevent other people
from reading or writing.

   One might hope for the following property

     If someone commits some changes in one cvs command,
     then an update by someone else will either get all the
     changes, or none of them.

   but CVS does *not* have this property.  For example, given the files

     a/one.c
     a/two.c
     b/three.c
     b/four.c

   if someone runs

     cvs ci a/two.c b/three.c

   and someone else runs `cvs update' at the same time, the person
running `update' might get only the change to `b/three.c' and not the
change to `a/two.c'.

Mechanisms to track who is editing files
========================================

   For many groups, use of CVS in its default mode is perfectly
satisfactory.  Users may sometimes go to check in a modification only
to find that another modification has intervened, but they deal with it
and proceed with their check in.  Other groups prefer to be able to
know who is editing what files, so that if two people try to edit the
same file they can choose to talk about who is doing what when rather
than be surprised at check in time.  The features in this section allow
such coordination, while retaining the ability of two developers to
edit the same file at the same time.

   For maximum benefit developers should use `cvs edit' (not `chmod')
to make files read-write to edit them, and `cvs release' (not `rm') to
discard a working directory which is no longer in use, but CVS is not
able to enforce this behavior.

Telling CVS to watch certain files
----------------------------------

   To enable the watch features, you first specify that certain files
are to be watched.

 - Command: cvs watch on [`-l'] FILES ...
     Specify that developers should run `cvs edit' before editing
     FILES.  CVS will create working copies of FILES read-only, to
     remind developers to run the `cvs edit' command before working on
     them.

     If FILES includes the name of a directory, CVS arranges to watch
     all files added to the corresponding repository directory, and
     sets a default for files added in the future; this allows the user
     to set notification policies on a per-directory basis.  The
     contents of the directory are processed recursively, unless the
     `-l' option is given.

     If FILES is omitted, it defaults to the current directory.


 - Command: cvs watch off [`-l'] FILES ...
     Do not provide notification about work on FILES.  CVS will create
     working copies of FILES read-write.

     The FILES and `-l' arguments are processed as for `cvs watch on'.


Telling CVS to notify you
-------------------------

   You can tell CVS that you want to receive notifications about
various actions taken on a file.  You can do this without using `cvs
watch on' for the file, but generally you will want to use `cvs watch
on', so that developers use the `cvs edit' command.

 - Command: cvs watch add [`-a' ACTION] [`-l'] FILES ...
     Add the current user to the list of people to receive notification
     of work done on FILES.

     The `-a' option specifies what kinds of events CVS should notify
     the user about.  ACTION is one of the following:

    `edit'
          Another user has applied the `cvs edit' command (described
          below) to a file.

    `unedit'
          Another user has applied the `cvs unedit' command (described
          below) or the `cvs release' command to a file, or has deleted
          the file and allowed `cvs update' to recreate it.

    `commit'
          Another user has committed changes to a file.

    `all'
          All of the above.

    `none'
          None of the above.  (This is useful with `cvs edit',
          described below.)

     The `-a' option may appear more than once, or not at all.  If
     omitted, the action defaults to `all'.

     The FILES and `-l' option are processed as for the `cvs watch'
     commands.


 - Command: cvs watch remove [`-a' ACTION] [`-l'] FILES ...
     Remove a notification request established using `cvs watch add';
     the arguments are the same.  If the `-a' option is present, only
     watches for the specified actions are removed.


   When the conditions exist for notification, CVS calls the `notify'
administrative file.  Edit `notify' as one edits the other
administrative files (*note Intro administrative files::.).  This file
follows the usual conventions for administrative files (*note
syntax::.), where each line is a regular expression followed by a
command to execute.  The command should contain a single ocurrence of
`%s' which will be replaced by the user to notify; the rest of the
information regarding the notification will be supplied to the command
on standard input.  The standard thing to put in the `notify' file is
the single line:

     ALL mail %s -s \"CVS notification\"

   This causes users to be notified by electronic mail.

   Note that if you set this up in the straightforward way, users
receive notifications on the server machine.  One could of course write
a `notify' script which directed notifications elsewhere, but to make
this easy, CVS allows you to associate a notification address for each
user.  To do so create a file `users' in `CVSROOT' with a line for each
user in the format USER:VALUE.  Then instead of passing the name of the
user to be notified to `notify', CVS will pass the VALUE (normally an
email address on some other machine).

How to edit a file which is being watched
-----------------------------------------

   Since a file which is being watched is checked out read-only, you
cannot simply edit it.  To make it read-write, and inform others that
you are planning to edit it, use the `cvs edit' command.  Some systems
call this a "checkout", but CVS uses that term for obtaining a copy of
the sources (*note Getting the source::.), an operation which those
systems call a "get" or a "fetch".

 - Command: cvs edit [OPTIONS] FILES ...
     Prepare to edit the working files FILES.  CVS makes the FILES
     read-write, and notifies users who have requested `edit'
     notification for any of FILES.

     The `cvs edit' command accepts the same OPTIONS as the `cvs watch
     add' command, and establishes a temporary watch for the user on
     FILES; CVS will remove the watch when FILES are `unedit'ed or
     `commit'ted.  If the user does not wish to receive notifications,
     she should specify `-a none'.

     The FILES and `-l' option are processed as for the `cvs watch'
     commands.


   Normally when you are done with a set of changes, you use the `cvs
commit' command, which checks in your changes and returns the watched
files to their usual read-only state.  But if you instead decide to
abandon your changes, or not to make any changes, you can use the `cvs
unedit' command.

 - Command: cvs unedit [`-l'] FILES ...
     Abandon work on the working files FILES, and revert them to the
     repository versions on which they are based.  CVS makes those
     FILES read-only for which users have requested notification using
     `cvs watch on'.  CVS notifies users who have requested `unedit'
     notification for any of FILES.

     The FILES and `-l' option are processed as for the `cvs watch'
     commands.

     If watches are not in use, the `unedit' command probably does not
     work, and the way to revert to the repository version is to remove
     the file and then use `cvs update' to get a new copy.  The meaning
     is not precisely the same; removing and updating may also bring in
     some changes which have been made in the repository since the last
     time you updated.

   When using client/server CVS, you can use the `cvs edit' and `cvs
unedit' commands even if CVS is unable to succesfully communicate with
the server; the notifications will be sent upon the next successful CVS
command.

Information about who is watching and editing
---------------------------------------------

 - Command: cvs watchers [`-l'] FILES ...
     List the users currently watching changes to FILES.  The report
     includes the files being watched, and the mail address of each
     watcher.

     The FILES and `-l' arguments are processed as for the `cvs watch'
     commands.


 - Command: cvs editors [`-l'] FILES ...
     List the users currently working on FILES.  The report includes
     the mail address of each user, the time when the user began
     working with the file, and the host and path of the working
     directory containing the file.

     The FILES and `-l' arguments are processed as for the `cvs watch'
     commands.


Using watches with old versions of CVS
--------------------------------------

   If you use the watch features on a repository, it creates `CVS'
directories in the repository and stores the information about watches
in that directory.  If you attempt to use CVS 1.6 or earlier with the
repository, you get an error message such as

     cvs update: cannot open CVS/Entries for reading: No such file or directory

   and your operation will likely be aborted.  To use the watch
features, you must upgrade all copies of CVS which use that repository
in local or server mode.  If you cannot upgrade, use the `watch off' and
`watch remove' commands to remove all watches, and that will restore
the repository to a state which CVS 1.6 can cope with.

Choosing between reserved or unreserved checkouts
=================================================

   Reserved and unreserved checkouts each have pros and cons.  Let it
be said that a lot of this is a matter of opinion or what works given
different groups' working styles, but here is an attempt to briefly
describe the issues.  There are many ways to organize a team of
developers.  CVS does not try to enforce a certain organization.  It is
a tool that can be used in several ways.

   Reserved checkouts can be very counter-productive.  If two persons
want to edit different parts of a file, there may be no reason to
prevent either of them from doing so.  Also, it is common for someone
to take out a lock on a file, because they are planning to edit it, but
then forget to release the lock.

   People, especially people who are familiar with reserved checkouts,
often wonder how often conflicts occur if unreserved checkouts are
used, and how difficult they are to resolve.  The experience with many
groups is that they occur rarely and usually are relatively
straightforward to resolve.

   The rarity of serious conflicts may be surprising, until one realizes
that they occur only when two developers disagree on the proper design
for a given section of code; such a disagreement suggests that the team
has not been communicating properly in the first place.  In order to
collaborate under *any* source management regimen, developers must
agree on the general design of the system; given this agreement,
overlapping changes are usually straightforward to merge.

   In some cases unreserved checkouts are clearly inappropriate.  If no
merge tool exists for the kind of file you are managing (for example
word processor files or files edited by Computer Aided Design
programs), and it is not desirable to change to a program which uses a
mergeable data format, then resolving conflicts is going to be
unpleasant enough that you generally will be better off to simply avoid
the conflicts instead, by using reserved checkouts.

   The watches features described above in *Note Watches:: can be
considered to be an intermediate model between reserved checkouts and
unreserved checkouts.  When you go to edit a file, it is possible to
find out who else is editing it.  And rather than having the system
simply forbid both people editing the file, it can tell you what the
situation is and let you figure out whether it is a problem in that
particular case or not.  Therefore, for some groups it can be
considered the best of both the reserved checkout and unreserved
checkout worlds.

Branches
********

   So far, all revisions shown in this manual have been on the "main
trunk" of the revision tree, i.e., all revision numbers have been of
the form X.Y.  One useful feature, especially when maintaining several
releases of a software product at once, is the ability to make branches
on the revision tree.  "Tags", symbolic names for revisions, will also
be introduced in this chapter.

Tags-Symbolic revisions
=======================

   The revision numbers live a life of their own.  They need not have
anything at all to do with the release numbers of your software
product.  Depending on how you use CVS the revision numbers might
change several times between two releases.  As an example, some of the
source files that make up RCS 5.6 have the following revision numbers:

     ci.c            5.21
     co.c            5.9
     ident.c         5.3
     rcs.c           5.12
     rcsbase.h       5.11
     rcsdiff.c       5.10
     rcsedit.c       5.11
     rcsfcmp.c       5.9
     rcsgen.c        5.10
     rcslex.c        5.11
     rcsmap.c        5.2
     rcsutil.c       5.10

   You can use the `tag' command to give a symbolic name to a certain
revision of a file.  You can use the `-v' flag to the `status' command
to see all tags that a file has, and which revision numbers they
represent.  Tag names can contain uppercase and lowercase letters,
digits, `-', and `_'.  The two tag names `BASE' and `HEAD' are reserved
for use by CVS.  It is expected that future names which are special to
CVS will contain characters such as `%' or `=', rather than being named
analogously to `BASE' and `HEAD', to avoid conflicts with actual tag
names.

   The following example shows how you can add a tag to a file.  The
commands must be issued inside your working copy of the module.  That
is, you should issue the command in the directory where `backend.c'
resides.

     $ cvs tag release-0-4 backend.c
     T backend.c
     $ cvs status -v backend.c
     ===================================================================
     File: backend.c         Status: Up-to-date
     
         Version:            1.4     Tue Dec  1 14:39:01 1992
         RCS Version:        1.4     /usr/local/cvsroot/yoyodyne/tc/backend.c,v
         Sticky Tag:         (none)
         Sticky Date:        (none)
         Sticky Options:     (none)
     
         Existing Tags:
             release-0-4                     (revision: 1.4)

   There is seldom reason to tag a file in isolation.  A more common
use is to tag all the files that constitute a module with the same tag
at strategic points in the development life-cycle, such as when a
release is made.

     $ cvs tag release-1-0 .
     cvs tag: Tagging .
     T Makefile
     T backend.c
     T driver.c
     T frontend.c
     T parser.c

   (When you give CVS a directory as argument, it generally applies the
operation to all the files in that directory, and (recursively), to any
subdirectories that it may contain.  *Note Recursive behavior::.)

   The `checkout' command has a flag, `-r', that lets you check out a
certain revision of a module.  This flag makes it easy to retrieve the
sources that make up release 1.0 of the module `tc' at any time in the
future:

     $ cvs checkout -r release-1-0 tc

This is useful, for instance, if someone claims that there is a bug in
that release, but you cannot find the bug in the current working copy.

   You can also check out a module as it was at any given date.  *Note
checkout options::.

   When you tag more than one file with the same tag you can think
about the tag as "a curve drawn through a matrix of filename vs.
revision number."  Say we have 5 files with the following revisions:

             file1   file2   file3   file4   file5
     
             1.1     1.1     1.1     1.1  /--1.1*      <-*-  TAG
             1.2*-   1.2     1.2    -1.2*-
             1.3  \- 1.3*-   1.3   / 1.3
             1.4          \  1.4  /  1.4
                           \-1.5*-   1.5
                             1.6

   At some time in the past, the `*' versions were tagged.  You can
think of the tag as a handle attached to the curve drawn through the
tagged revisions.  When you pull on the handle, you get all the tagged
revisions.  Another way to look at it is that you "sight" through a set
of revisions that is "flat" along the tagged revisions, like this:

             file1   file2   file3   file4   file5
     
                             1.1
                             1.2
                     1.1     1.3                       _
             1.1     1.2     1.4     1.1              /
             1.2*----1.3*----1.5*----1.2*----1.1     (--- <--- Look here
             1.3             1.6     1.3              \_
             1.4                     1.4
                                     1.5

What branches are good for
==========================

   Suppose that release 1.0 of tc has been made.  You are continuing to
develop tc, planning to create release 1.1 in a couple of months.
After a while your customers start to complain about a fatal bug.  You
check out release 1.0 (*note Tags::.) and find the bug (which turns out
to have a trivial fix).  However, the current revision of the sources
are in a state of flux and are not expected to be stable for at least
another month.  There is no way to make a bugfix release based on the
newest sources.

   The thing to do in a situation like this is to create a "branch" on
the revision trees for all the files that make up release 1.0 of tc.
You can then make modifications to the branch without disturbing the
main trunk.  When the modifications are finished you can select to
either incorporate them on the main trunk, or leave them on the branch.

Creating a branch
=================

   The `rtag' command can be used to create a branch.  The `rtag'
command is much like `tag', but it does not require that you have a
working copy of the module.  *Note rtag::.  (You can also use the `tag'
command; *note tag::.).

     $ cvs rtag -b -r release-1-0 release-1-0-patches tc

   The `-b' flag makes `rtag' create a branch (rather than just a
symbolic revision name).  `-r release-1-0' says that this branch should
be rooted at the node (in the revision tree) that corresponds to the tag
`release-1-0'.  Note that the numeric revision number that matches
`release-1-0' will probably be different from file to file.  The name
of the new branch is `release-1-0-patches', and the module affected is
`tc'.

   To fix the problem in release 1.0, you need a working copy of the
branch you just created.

     $ cvs checkout -r release-1-0-patches tc
     $ cvs status -v driver.c backend.c
     ===================================================================
     File: driver.c          Status: Up-to-date
     
         Version:            1.7     Sat Dec  5 18:25:54 1992
         RCS Version:        1.7     /usr/local/cvsroot/yoyodyne/tc/driver.c,v
         Sticky Tag:         release-1-0-patches (branch: 1.7.2)
         Sticky Date:        (none)
         Sticky Options:     (none)
     
         Existing Tags:
             release-1-0-patches             (branch: 1.7.2)
             release-1-0                     (revision: 1.7)
     
     ===================================================================
     File: backend.c         Status: Up-to-date
     
         Version:            1.4     Tue Dec  1 14:39:01 1992
         RCS Version:        1.4     /usr/local/cvsroot/yoyodyne/tc/backend.c,v
         Sticky Tag:         release-1-0-patches (branch: 1.4.2)
         Sticky Date:        (none)
         Sticky Options:     (none)
     
         Existing Tags:
             release-1-0-patches             (branch: 1.4.2)
             release-1-0                     (revision: 1.4)
             release-0-4                     (revision: 1.4)

   As the output from the `status' command shows the branch number is
created by adding a digit at the tail of the revision number it is
based on.  (If `release-1-0' corresponds to revision 1.4, the branch's
revision number will be 1.4.2.  For obscure reasons CVS always gives
branches even numbers, starting at 2.  *Note Revision numbers::).

Sticky tags
===========

   The `-r release-1-0-patches' flag that was given to `checkout' in
the previous example is "sticky", that is, it will apply to subsequent
commands in this directory.  If you commit any modifications, they are
committed on the branch.  You can later merge the modifications into
the main trunk.  *Note Merging::.

   You can use the `status' command to see what sticky tags or dates
are set:

     $ vi driver.c   # Fix the bugs
     $ cvs commit -m "Fixed initialization bug" driver.c
     Checking in driver.c;
     /usr/local/cvsroot/yoyodyne/tc/driver.c,v  <--  driver.c
     new revision: 1.7.2.1; previous revision: 1.7
     done
     $ cvs status -v driver.c
     ===================================================================
     File: driver.c          Status: Up-to-date
     
         Version:            1.7.2.1 Sat Dec  5 19:35:03 1992
         RCS Version:        1.7.2.1 /usr/local/cvsroot/yoyodyne/tc/driver.c,v
         Sticky Tag:         release-1-0-patches (branch: 1.7.2)
         Sticky Date:        (none)
         Sticky Options:     (none)
     
         Existing Tags:
             release-1-0-patches             (branch: 1.7.2)
             release-1-0                     (revision: 1.7)

   The sticky tags will remain on your working files until you delete
them with `cvs update -A'.  The `-A' option retrieves the version of
the file from the head of the trunk, and forgets any sticky tags,
dates, or options.

   Sticky tags are not just for branches.  For example, suppose that
you want to avoid updating your working directory, to isolate yourself
from possibly destabilizing changes other people are making.  You can,
of course, just refrain from running `cvs update'.  But if you want to
avoid updating only a portion of a larger tree, then sticky tags can
help.  If you check out a certain revision (such as 1.4) it will become
sticky.  Subsequent `cvs update' will not retrieve the latest revision
until you reset the tag with `cvs update -A'.  Likewise, use of the
`-D' option to `update' or `checkout' sets a "sticky date", which,
similarly, causes that date to be used for future retrievals.

   Many times you will want to retrieve an old version of a file
without setting a sticky tag.  The way to do that is with the `-p'
option to `checkout' or `update', which sends the contents of the file
to standard output.  For example, suppose you have a file named `file1'
which existed as revision 1.1, and you then removed it (thus adding a
dead revision 1.2).  Now suppose you want to add it again, with the same
contents it had previously.  Here is how to do it:

     $ cvs update -p -r 1.1 file1 >file1
     ===================================================================
     Checking out file1
     RCS:  /tmp/cvs-sanity/cvsroot/first-dir/Attic/file1,v
     VERS: 1.1
     ***************
     $ cvs add file1
     cvs add: re-adding file file1 (in place of dead revision 1.2)
     cvs add: use 'cvs commit' to add this file permanently
     $ cvs commit -m test
     Checking in file1;
     /tmp/cvs-sanity/cvsroot/first-dir/file1,v  <--  file1
     new revision: 1.3; previous revision: 1.2
     done
     $

Merging
*******

   You can include the changes made between any two revisions into your
working copy, by "merging".  You can then commit that revision, and
thus effectively copy the changes onto another branch.

Merging an entire branch
========================

   You can merge changes made on a branch into your working copy by
giving the `-j BRANCH' flag to the `update' command.  With one `-j
BRANCH' option it merges the changes made between the point where the
branch forked and newest revision on that branch (into your working
copy).

   The `-j' stands for "join".

   Consider this revision tree:

     +-----+    +-----+    +-----+    +-----+
     ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !      <- The main trunk
     +-----+    +-----+    +-----+    +-----+
                     !
                     !
                     !   +---------+    +---------+
     Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 !
                         +---------+    +---------+

The branch 1.2.2 has been given the tag (symbolic name) `R1fix'.  The
following example assumes that the module `mod' contains only one file,
`m.c'.

     $ cvs checkout mod               # Retrieve the latest revision, 1.4
     
     $ cvs update -j R1fix m.c        # Merge all changes made on the branch,
                                      # i.e. the changes between revision 1.2
                                      # and 1.2.2.2, into your working copy
                                      # of the file.
     
     $ cvs commit -m "Included R1fix" # Create revision 1.5.

   A conflict can result from a merge operation.  If that happens, you
should resolve it before committing the new revision.  *Note Conflicts
example::.

   The `checkout' command also supports the `-j BRANCH' flag.  The same
effect as above could be achieved with this:

     $ cvs checkout -j R1fix mod
     $ cvs commit -m "Included R1fix"

Merging from a branch several times
===================================

   Continuing our example, the revision tree now looks like this:

     +-----+    +-----+    +-----+    +-----+    +-----+
     ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !      <- The main trunk
     +-----+    +-----+    +-----+    +-----+    +-----+
                     !                           *
                     !                          *
                     !   +---------+    +---------+
     Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 !
                         +---------+    +---------+

   where the starred line represents the merge from the `R1fix' branch
to the main trunk, as just discussed.

   Now suppose that development continues on the `R1fix' branch:

     +-----+    +-----+    +-----+    +-----+    +-----+
     ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !      <- The main trunk
     +-----+    +-----+    +-----+    +-----+    +-----+
                     !                           *
                     !                          *
                     !   +---------+    +---------+    +---------+
     Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 !----! 1.2.2.3 !
                         +---------+    +---------+    +---------+

   and then you want to merge those new changes onto the main trunk.
If you just use the `cvs update -j R1fix m.c' command again, CVS will
attempt to merge again the changes which you have already merged, which
can have undesirable side effects.

   So instead you need to specify that you only want to merge the
changes on the branch which have not yet been merged into the trunk.
To do that you specify two `-j' options, and CVS merges the changes from
the first revision to the second revision.  For example, in this case
the simplest way would be

     cvs update -j 1.2.2.2 -j R1fix m.c    # Merge changes from 1.2.2.2 to the
                                           # head of the R1fix branch

   The problem with this is that you need to specify the 1.2.2.2
revision manually.  A slightly better approach might be to use the date
the last merge was done:

     cvs update -j R1fix:yesterday -j R1fix m.c

   Better yet, tag the R1fix branch after every merge into the trunk,
and then use that tag for subsequent merges:

     cvs update -j merged_from_R1fix_to_trunk -j R1fix m.c

Merging differences between any two revisions
=============================================

   With two `-j REVISION' flags, the `update' (and `checkout') command
can merge the differences between any two revisions into your working
file.

     $ cvs update -j 1.5 -j 1.3 backend.c

will *remove* all changes made between revision 1.3 and 1.5.  Note the
order of the revisions!

   If you try to use this option when operating on multiple files,
remember that the numeric revisions will probably be very different
between the various files that make up a module.  You almost always use
symbolic tags rather than revision numbers when operating on multiple
files.

Merging can add or remove files
===============================

   If the changes which you are merging involve removing or adding some
files, `update -j' will reflect such additions or removals.

   For example:
     cvs update -A
     touch a b c
     cvs add a b c ; cvs ci -m "added" a b c
     cvs tag -b branchtag
     cvs update -r branchtag
     touch d ; cvs add d
     rm a ; cvs rm a
     cvs ci -m "added d, removed a"
     cvs update -A
     cvs update -jbranchtag

Recursive behavior
******************

   Almost all of the subcommands of CVS work recursively when you
specify a directory as an argument.  For instance, consider this
directory structure:

           `$HOME'
             |
             +--tc
             |   |
                 +--CVS
                 |      (internal CVS files)
                 +--Makefile
                 +--backend.c
                 +--driver.c
                 +--frontend.c
                 +--parser.c
                 +--man
                 |    |
                 |    +--CVS
                 |    |  (internal CVS files)
                 |    +--tc.1
                 |
                 +--testing
                      |
                      +--CVS
                      |  (internal CVS files)
                      +--testpgm.t
                      +--test2.t

If `tc' is the current working directory, the following is true:

   * `cvs update testing' is equivalent to `cvs update
     testing/testpgm.t testing/test2.t'

   * `cvs update testing man' updates all files in the subdirectories

   * `cvs update .' or just `cvs update' updates all files in the `tc'
     module

   If no arguments are given to `update' it will update all files in
the current working directory and all its subdirectories.  In other
words, `.' is a default argument to `update'.  This is also true for
most of the CVS subcommands, not only the `update' command.

   The recursive behavior of the CVS subcommands can be turned off with
the `-l' option.

     $ cvs update -l         # Don't update files in subdirectories

Adding files to a directory
***************************

   To add a new file to a directory, follow these steps.

   * You must have a working copy of the directory.  *Note Getting the
     source::.

   * Create the new file inside your working copy of the directory.

   * Use `cvs add FILENAME' to tell CVS that you want to version
     control the file.  If the file contains binary data, specify `-kb'
     (*note Binary files::.).

   * Use `cvs commit FILENAME' to actually check in the file into the
     repository.  Other developers cannot see the file until you
     perform this step.

   You can also use the `add' command to add a new directory.

   Unlike most other commands, the `add' command is not recursive.  You
cannot even type `cvs add foo/bar'!  Instead, you have to

     $ cd foo
     $ cvs add bar

 - Command: cvs add [`-k' KFLAG] [`-m' MESSAGE] FILES ...
     Schedule FILES to be added to the repository.  The files or
     directories specified with `add' must already exist in the current
     directory.  To add a whole new directory hierarchy to the source
     repository (for example, files received from a third-party
     vendor), use the `import' command instead.  *Note import::.

     The added files are not placed in the source repository until you
     use `commit' to make the change permanent.  Doing an `add' on a
     file that was removed with the `remove' command will undo the
     effect of the `remove', unless a `commit' command intervened.
     *Note Removing files::, for an example.

     The `-k' option specifies the default way that this file will be
     checked out; for more information see *Note Substitution modes::.

     The `-m' option specifies a description for the file.  This
     description appears in the history log (if it is enabled, *note
     history file::.).  It will also be saved in the version history
     inside the repository when the file is committed.  The `log'
     command displays this description.  The description can be changed
     using `admin -t'.  *Note admin::.  If you omit the `-m
     DESCRIPTION' flag, an empty string will be used.  You will not be
     prompted for a description.

   For example, the following commands add the file `backend.c' to the
repository:

     $ cvs add backend.c
     $ cvs commit -m "Early version. Not yet compilable." backend.c

   When you add a file it is added only on the branch which you are
working on (*note Branches::.).  You can later merge the additions to
another branch if you want (*note Merging adds and removals::.).

Removing files from a module
****************************

   Modules change.  New files are added, and old files disappear.
Still, you want to be able to retrieve an exact copy of old releases of
the module.

   Here is what you can do to remove a file from a module, but remain
able to retrieve old revisions:

   * Make sure that you have not made any uncommitted modifications to
     the file.  *Note Viewing differences::, for one way to do that.
     You can also use the `status' or `update' command.  If you remove
     the file without committing your changes, you will of course not
     be able to retrieve the file as it was immediately before you
     deleted it.

   * Remove the file from your working copy of the module.  You can for
     instance use `rm'.

   * Use `cvs remove FILENAME' to tell CVS that you really want to
     delete the file.

   * Use `cvs commit FILENAME' to actually perform the removal of the
     file from the repository.

   When you commit the removal of the file, CVS records the fact that
the file no longer exists.  It is possible for a file to exist on only
some branches and not on others, or to re-add another file with the same
name later.  CVS will correctly create or not create the file, based on
the `-r' and `-D' options specified to `checkout' or `update'.

 - Command: cvs remove [`-lR'] FILES ...
     Schedule file(s) to be removed from the repository (files which
     have not already been removed from the working directory are not
     processed).  This command does not actually remove the file from
     the repository until you commit the removal.  The `-R' option (the
     default) specifies that it will recurse into subdirectories; `-l'
     specifies that it will not.

   Here is an example of removing several files:

     $ cd test
     $ rm ?.c
     $ cvs remove
     cvs remove: Removing .
     cvs remove: scheduling a.c for removal
     cvs remove: scheduling b.c for removal
     cvs remove: use 'cvs commit' to remove these files permanently
     $ cvs ci -m "Removed unneeded files"
     cvs commit: Examining .
     cvs commit: Committing .

   If you change your mind you can easily resurrect the file before you
commit it, using the `add' command.

     $ ls
     CVS   ja.h  oj.c
     $ rm oj.c
     $ cvs remove oj.c
     cvs remove: scheduling oj.c for removal
     cvs remove: use 'cvs commit' to remove this file permanently
     $ cvs add oj.c
     U oj.c
     cvs add: oj.c, version 1.1.1.1, resurrected

   If you realize your mistake before you run the `remove' command you
can use `update' to resurrect the file:

     $ rm oj.c
     $ cvs update oj.c
     cvs update: warning: oj.c was lost
     U oj.c

   When you remove a file it is added only on the branch which you are
working on (*note Branches::.).  You can later merge the additions to
another branch if you want (*note Merging adds and removals::.).

Tracking third-party sources
****************************

   If you modify a program to better fit your site, you probably want
to include your modifications when the next release of the program
arrives.  CVS can help you with this task.

   In the terminology used in CVS, the supplier of the program is
called a "vendor".  The unmodified distribution from the vendor is
checked in on its own branch, the "vendor branch".  CVS reserves branch
1.1.1 for this use.

   When you modify the source and commit it, your revision will end up
on the main trunk.  When a new release is made by the vendor, you
commit it on the vendor branch and copy the modifications onto the main
trunk.

   Use the `import' command to create and update the vendor branch.
After a successful `import' the vendor branch is made the `head'
revision, so anyone that checks out a copy of the file gets that
revision.  When a local modification is committed it is placed on the
main trunk, and made the `head' revision.

Importing a module for the first time
=====================================

   Use the `import' command to check in the sources for the first time.
When you use the `import' command to track third-party sources, the
"vendor tag" and "release tags" are useful.  The "vendor tag" is a
symbolic name for the branch (which is always 1.1.1, unless you use the
`-b BRANCH' flag--*Note import options::).  The "release tags" are
symbolic names for a particular release, such as `FSF_0_04'.

   Suppose you use `wdiff' (a variant of `diff' that ignores changes
that only involve whitespace), and are going to make private
modifications that you want to be able to use even when new releases
are made in the future.  You start by importing the source to your
repository:

     $ tar xfz wdiff-0.04.tar.gz
     $ cd wdiff-0.04
     $ cvs import -m "Import of FSF v. 0.04" fsf/wdiff FSF_DIST WDIFF_0_04

   The vendor tag is named `FSF_DIST' in the above example, and the
only release tag assigned is `WDIFF_0_04'.

Updating a module with the import command
=========================================

   When a new release of the source arrives, you import it into the
repository with the same `import' command that you used to set up the
repository in the first place.  The only difference is that you specify
a different release tag this time.

     $ tar xfz wdiff-0.05.tar.gz
     $ cd wdiff-0.05
     $ cvs import -m "Import of FSF v. 0.05" fsf/wdiff FSF_DIST WDIFF_0_05

   For files that have not been modified locally, the newly created
revision becomes the head revision.  If you have made local changes,
`import' will warn you that you must merge the changes into the main
trunk, and tell you to use `checkout -j' to do so.

     $ cvs checkout -jFSF_DIST:yesterday -jFSF_DIST wdiff

The above command will check out the latest revision of `wdiff',
merging the changes made on the vendor branch `FSF_DIST' since
yesterday into the working copy.  If any conflicts arise during the
merge they should be resolved in the normal way (*note Conflicts
example::.).  Then, the modified files may be committed.

   Using a date, as suggested above, assumes that you do not import
more than one release of a product per day. If you do, you can always
use something like this instead:

     $ cvs checkout -jWDIFF_0_04 -jWDIFF_0_05 wdiff

In this case, the two above commands are equivalent.

How to handle binary files with cvs import
==========================================

   Use the `-k' wrapper option to tell import which files are binary.
*Note Wrappers::.

Moving and renaming files
*************************

   Moving files to a different directory or renaming them is not
difficult, but some of the ways in which this works may be non-obvious.
(Moving or renaming a directory is even harder.  *Note Moving
directories::).

   The examples below assume that the file OLD is renamed to NEW.

The Normal way to Rename
========================

   The normal way to move a file is to copy OLD to NEW, and then issue
the normal CVS commands to remove OLD from the repository, and add NEW
to it.  (Both OLD and NEW could contain relative paths, for example
`foo/bar.c').

     $ mv OLD NEW
     $ cvs remove OLD
     $ cvs add NEW
     $ cvs commit -m "Renamed OLD to NEW" OLD NEW

   This is the simplest way to move a file, it is not error-prone, and
it preserves the history of what was done.  Note that to access the
history of the file you must specify the old or the new name, depending
on what portion of the history you are accessing.  For example, `cvs
log OLD' will give the log up until the time of the rename.

   When NEW is committed its revision numbers will start at 1.0 again,
so if that bothers you, use the `-r rev' option to commit (*note commit
options::.)

Moving the history file
=======================

   This method is more dangerous, since it involves moving files inside
the repository.  Read this entire section before trying it out!

     $ cd $CVSROOT/MODULE
     $ mv OLD,v NEW,v

Advantages:

   * The log of changes is maintained intact.

   * The revision numbers are not affected.

Disadvantages:

   * Old releases of the module cannot easily be fetched from the
     repository.  (The file will show up as NEW even in revisions from
     the time before it was renamed).

   * There is no log information of when the file was renamed.

   * Nasty things might happen if someone accesses the history file
     while you are moving it.  Make sure no one else runs any of the CVS
     commands while you move it.

Copying the history file
========================

   This way also involves direct modifications to the repository.  It
is safe, but not without drawbacks.

     # Copy the RCS file inside the repository
     $ cd $CVSROOT/MODULE
     $ cp OLD,v NEW,v
     # Remove the old file
     $ cd ~/MODULE
     $ rm OLD
     $ cvs remove OLD
     $ cvs commit OLD
     # Remove all tags from NEW
     $ cvs update NEW
     $ cvs log NEW             # Remember the non-branch tag names
     $ cvs tag -d TAG1 NEW
     $ cvs tag -d TAG2 NEW
     ...

   By removing the tags you will be able to check out old revisions of
the module.

Advantages:

   * Checking out old revisions works correctly, as long as you use
     `-rTAG' and not `-DDATE' to retrieve the revisions.

   * The log of changes is maintained intact.

   * The revision numbers are not affected.

Disadvantages:

   * You cannot easily see the history of the file across the rename.

   * Unless you use the `-r rev' (*note commit options::.) flag when
     NEW is committed its revision numbers will start at 1.0 again.

Moving and renaming directories
*******************************

   If you want to be able to retrieve old versions of the module, you
must move each file in the directory with the CVS commands.  *Note
Outside::.  The old, empty directory will remain inside the repository,
but it will not appear in your workspace when you check out the module
in the future.

   If you really want to rename or delete a directory, you can do it
like this:

  1. Inform everyone who has a copy of the module that the directory
     will be renamed.  They should commit all their changes, and remove
     their working copies of the module, before you take the steps
     below.

  2. Rename the directory inside the repository.

          $ cd $CVSROOT/MODULE
          $ mv OLD-DIR NEW-DIR

  3. Fix the CVS administrative files, if necessary (for instance if
     you renamed an entire module).

  4. Tell everyone that they can check out the module and continue
     working.


   If someone had a working copy of the module the CVS commands will
cease to work for him, until he removes the directory that disappeared
inside the repository.

   It is almost always better to move the files in the directory
instead of moving the directory.  If you move the directory you are
unlikely to be able to retrieve old releases correctly, since they
probably depend on the name of the directories.

History browsing
****************

   Once you have used CVS to store a version control history--what
files have changed when, how, and by whom, there are a variety of
mechanisms for looking through the history.

Log messages
============

   Whenever you commit a file you specify a log message.

   To look through the log messages which have been specified for every
revision which has been committed, use the `cvs log' command (*note
log::.).

The history database
====================

   You can use the history file (*note history file::.) to log various
CVS actions.  To retrieve the information from the history file, use
the `cvs history' command (*note history::.).

User-defined logging
====================

   You can customize CVS to log various kinds of actions, in whatever
manner you choose.  These mechanisms operate by executing a script at
various times.  The script might append a message to a file listing the
information and the programmer who created it, or send mail to a group
of developers, or, perhaps, post a message to a particular newsgroup.
To log commits, use the `loginfo' file (*note loginfo::.).  To log
commits, checkouts, exports, and tags, respectively, you can also use
the `-i', `-o', `-e', and `-t' options in the modules file.  For a more
flexible way of giving notifications to various users, which requires
less in the way of keeping centralized scripts up to date, use the `cvs
watch add' command (*note Getting Notified::.); this command is useful
even if you are not using `cvs watch on'.

   The `taginfo' file defines programs to execute when someone executes
a `tag' or `rtag' command.  The `taginfo' file has the standard form
for administrative files (*note Administrative files::.), where each
line is a regular expression followed by a command to execute.  The
arguments passed to the command are, in order, the TAGNAME, OPERATION
(`add' for `tag', `mov' for `tag -F', and `del' for `tag -d'),
REPOSITORY, and any remaining are pairs of FILENAME REVISION.  A
non-zero exit of the filter program will cause the tag to be aborted.

Annotate command
================

 - Command: cvs annotate [`-lf'] [`-r rev'|`-D date'] FILES ...
     For each file in FILES, print the head revision of the trunk,
     together with information on the last modification for each line.
     For example:

          $ cvs annotate ssfile
          Annotations for ssfile
          ***************
          1.1          (mary     27-Mar-96): ssfile line 1
          1.2          (joe      28-Mar-96): ssfile line 2

     The file `ssfile' currently contains two lines.  The `ssfile line
     1' line was checked in by `mary' on March 27.  Then, on March 28,
     `joe' added a line `ssfile line 2', without modifying the `ssfile
     line 1' line.  This report doesn't tell you anything about lines
     which have been deleted or replaced; you need to use `cvs diff'
     for that (*note diff::.).


   These standard options are available with `annotate' (*note Common
options::., for a complete description of them):

`-D DATE'
     Annotate the most recent revision no later than DATE.

`-f'
     Only useful with the `-D DATE' or `-r TAG' flags.  If no matching
     revision is found, annotate the most recent revision (instead of
     ignoring the file).

`-l'
     Local; run only in current working directory.  *Note Recursive
     behavior::.

`-r TAG'
     Annotate revision TAG.

Keyword substitution
********************

   As long as you edit source files inside your working copy of a
module you can always find out the state of your files via `cvs status'
and `cvs log'.  But as soon as you export the files from your
development environment it becomes harder to identify which revisions
they are.

   RCS uses a mechanism known as "keyword substitution" (or "keyword
expansion") to help identifying the files.  Embedded strings of the form
`$KEYWORD$' and `$KEYWORD:...$' in a file are replaced with strings of
the form `$KEYWORD:VALUE$' whenever you obtain a new revision of the
file.

RCS Keywords
============

   This is a list of the keywords that RCS currently (in release
5.6.0.1) supports:

`$Author$'
     The login name of the user who checked in the revision.

`$Date$'
     The date and time (UTC) the revision was checked in.

`$Header$'
     A standard header containing the full pathname of the RCS file,
     the revision number, the date (UTC), the author, the state, and
     the locker (if locked).  Files will normally never be locked when
     you use CVS.

`$Id$'
     Same as `$Header$', except that the RCS filename is without a path.

`$Name$'
     Tag name used to check out this file.

`$Locker$'
     The login name of the user who locked the revision (empty if not
     locked, and thus almost always useless when you are using CVS).

`$Log$'
     The log message supplied during commit, preceded by a header
     containing the RCS filename, the revision number, the author, and
     the date (UTC).  Existing log messages are *not* replaced.
     Instead, the new log message is inserted after `$Log:...$'.  Each
     new line is prefixed with a "comment leader" which RCS guesses
     from the file name extension.  It can be changed with `cvs admin
     -c'.  *Note admin options::.  This keyword is useful for
     accumulating a complete change log in a source file, but for
     several reasons it can be problematic.  *Note Log keyword::.

`$RCSfile$'
     The name of the RCS file without a path.

`$Revision$'
     The revision number assigned to the revision.

`$Source$'
     The full pathname of the RCS file.

`$State$'
     The state assigned to the revision.  States can be assigned with
     `cvs admin -s'--*Note admin options::.

Using keywords
==============

   To include a keyword string you simply include the relevant text
string, such as `$Id$', inside the file, and commit the file.  CVS will
automatically expand the string as part of the commit operation.

   It is common to embed `$Id$' string in the C source code.  This
example shows the first few lines of a typical file, after keyword
substitution has been performed:

     static char *rcsid="$Id: samp.c,v 1.5 1993/10/19 14:57:32 ceder Exp $";
     /* The following lines will prevent `gcc' version 2.X
        from issuing an "unused variable" warning. */
     #if __GNUC__ == 2
     #define USE(var) static void * use_##var = (&use_##var, (void *) &var)
     USE (rcsid);
     #endif

   Even though a clever optimizing compiler could remove the unused
variable `rcsid', most compilers tend to include the string in the
binary.  Some compilers have a `#pragma' directive to include literal
text in the binary.

   The `ident' command (which is part of the RCS package) can be used
to extract keywords and their values from a file.  This can be handy
for text files, but it is even more useful for extracting keywords from
binary files.

     $ ident samp.c
     samp.c:
          $Id: samp.c,v 1.5 1993/10/19 14:57:32 ceder Exp $
     $ gcc samp.c
     $ ident a.out
     a.out:
          $Id: samp.c,v 1.5 1993/10/19 14:57:32 ceder Exp $

   SCCS is another popular revision control system.  It has a command,
`what', which is very similar to `ident' and used for the same purpose.
Many sites without RCS have SCCS.  Since `what' looks for the
character sequence `@(#)' it is easy to include keywords that are
detected by either command.  Simply prefix the RCS keyword with the
magic SCCS phrase, like this:

     static char *id="@(#) $Id: ab.c,v 1.5 1993/10/19 14:57:32 ceder Exp $";

Avoiding substitution
=====================

   Keyword substitution has its disadvantages.  Sometimes you might
want the literal text string `$Author$' to appear inside a file without
RCS interpreting it as a keyword and expanding it into something like
`$Author: ceder $'.

   There is unfortunately no way to selectively turn off keyword
substitution.  You can use `-ko' (*note Substitution modes::.) to turn
off keyword substitution entirely.

   In many cases you can avoid using RCS keywords in the source, even
though they appear in the final product.  For example, the source for
this manual contains `$@asis{}Author$' whenever the text `$Author$'
should appear.  In `nroff' and `troff' you can embed the null-character
`\&' inside the keyword for a similar effect.

Substitution modes
==================

   Each file has a stored default substitution mode, and each working
directory copy of a file also has a substitution mode.  The former is
set by the `-k' option to `cvs add' and `cvs admin'; the latter is set
by the -k or -A options to `cvs checkout' or `cvs update'.  `cvs diff'
also has a `-k' option.  For some examples, *Note Binary files::.

   The modes available are:

`-kkv'
     Generate keyword strings using the default form, e.g.  `$Revision:
     5.7 $' for the `Revision' keyword.

`-kkvl'
     Like `-kkv', except that a locker's name is always inserted if the
     given revision is currently locked.  This option is normally not
     useful when CVS is used.

`-kk'
     Generate only keyword names in keyword strings; omit their values.
     For example, for the `Revision' keyword, generate the string
     `$Revision$' instead of `$Revision: 5.7 $'.  This option is useful
     to ignore differences due to keyword substitution when comparing
     different revisions of a file.

`-ko'
     Generate the old keyword string, present in the working file just
     before it was checked in.  For example, for the `Revision'
     keyword, generate the string `$Revision: 1.1 $' instead of
     `$Revision: 5.7 $' if that is how the string appeared when the
     file was checked in.

`-kb'
     Like `-ko', but also inhibit conversion of line endings between
     the canonical form in which they are stored in the repository
     (linefeed only), and the form appropriate to the operating system
     in use on the client.  For systems, like unix, which use linefeed
     only to terminate lines, this is the same as `-ko'.  For more
     information on binary files, see *Note Binary files::.

`-kv'
     Generate only keyword values for keyword strings.  For example,
     for the `Revision' keyword, generate the string `5.7' instead of
     `$Revision: 5.7 $'.  This can help generate files in programming
     languages where it is hard to strip keyword delimiters like
     `$Revision: $' from a string.  However, further keyword
     substitution cannot be performed once the keyword names are
     removed, so this option should be used with care.

     One often would like to use `-kv' with `cvs export'--*note
     export::..  But be aware that doesn't handle an export containing
     binary files correctly.

Problems with the $Log$ keyword.
================================

   The `$Log$' keyword is somewhat controversial.  As long as you are
working on your development system the information is easily accessible
even if you do not use the `$Log$' keyword--just do a `cvs log'.  Once
you export the file the history information might be useless anyhow.

   A more serious concern is that RCS is not good at handling `$Log$'
entries when a branch is merged onto the main trunk.  Conflicts often
result from the merging operation.

   People also tend to "fix" the log entries in the file (correcting
spelling mistakes and maybe even factual errors).  If that is done the
information from `cvs log' will not be consistent with the information
inside the file.  This may or may not be a problem in real life.

   It has been suggested that the `$Log$' keyword should be inserted
*last* in the file, and not in the files header, if it is to be used at
all.  That way the long list of change messages will not interfere with
everyday source file browsing.

Handling binary files
*********************

   There are two issues with using CVS to store binary files.  The
first is that CVS by default convert line endings between the canonical
form in which they are stored in the repository (linefeed only), and
the form appropriate to the operating system in use on the client (for
example, carriage return followed by line feed for Windows NT).

   The second is that a binary file might happen to contain data which
looks like a keyword (*note Keyword substitution::.), so keyword
expansion must be turned off.

   The `-kb' option available with some CVS commands insures that
neither line ending conversion nor keyword expansion will be done.  If
you are using an old version of RCS without this option, and you are
using an operating system, such as unix, which terminates lines with
linefeeds only, you can use `-ko' instead; if you are on another
operating system, upgrade to a version of RCS, such as 5.7 or later,
which supports `-kb'.

   Here is an example of how you can create a new file using the `-kb'
flag:

     $ echo '$Id$' > kotest
     $ cvs add -kb -m"A test file" kotest
     $ cvs ci -m"First checkin; contains a keyword" kotest

   If a file accidentally gets added without `-kb', one can use the
`cvs admin' command to recover.  For example:

     $ echo '$Id$' > kotest
     $ cvs add -m"A test file" kotest
     $ cvs ci -m"First checkin; contains a keyword" kotest
     $ cvs admin -kb kotest
     $ cvs update -A kotest
     $ cvs commit -m "make it binary" kotest  # For non-unix systems

   When you check in the file `kotest' the keywords are expanded.  (Try
the above example, and do a `cat kotest' after every command).  The `cvs
admin -kb' command sets the default keyword substitution method for
this file, but it does not alter the working copy of the file that you
have.  The easiest way to get the unexpanded version of `kotest' is
`cvs update -A'.  If you need to cope with line endings (that is, you
are using a CVS client on a non-unix system), then you need to check in
a new copy of the file, as shown by the `cvs commit' command above.

   However, in using `cvs admin -k' to change the keyword expansion, be
aware that the keyword expansion mode is not version controlled.  This
means that, for example, that if you have a text file in old releases,
and a binary file with the same name in new releases, CVS provides no
way to check out the file in text or binary mode depending on what
version you are checking out.  There is no good workaround for this
problem.

   You can also set a default for whether `cvs add' and `cvs import'
treat a file as binary based on its name; for example you could say
that files who names end in `.exe' are binary.  *Note Wrappers::.

Revision management
*******************

   If you have read this far, you probably have a pretty good grasp on
what CVS can do for you.  This chapter talks a little about things that
you still have to decide.

   If you are doing development on your own using CVS you could
probably skip this chapter.  The questions this chapter takes up become
more important when more than one person is working in a repository.

When to commit?
===============

   Your group should decide which policy to use regarding commits.
Several policies are possible, and as your experience with CVS grows
you will probably find out what works for you.

   If you commit files too quickly you might commit files that do not
even compile.  If your partner updates his working sources to include
your buggy file, he will be unable to compile the code.  On the other
hand, other persons will not be able to benefit from the improvements
you make to the code if you commit very seldom, and conflicts will
probably be more common.

   It is common to only commit files after making sure that they can be
compiled.  Some sites require that the files pass a test suite.
Policies like this can be enforced using the commitinfo file (*note
commitinfo::.), but you should think twice before you enforce such a
convention.  By making the development environment too controlled it
might become too regimented and thus counter-productive to the real
goal, which is to get software written.

Reference manual for CVS commands
*********************************

   This appendix describes how to invoke CVS, and describes in detail
those subcommands of CVS which are not fully described elsewhere.  To
look up a particular subcommand, see *Note Index::.

Overall structure of CVS commands
=================================

   The overall format of all CVS commands is:

     cvs [ cvs_options ] cvs_command [ command_options ] [ command_args ]

`cvs'
     The name of the CVS program.

`cvs_options'
     Some options that affect all sub-commands of CVS.  These are
     described below.

`cvs_command'
     One of several different sub-commands.  Some of the commands have
     aliases that can be used instead; those aliases are noted in the
     reference manual for that command.  There are only two situations
     where you may omit `cvs_command': `cvs -H' elicits a list of
     available commands, and `cvs -v' displays version information on
     CVS itself.

`command_options'
     Options that are specific for the command.

`command_args'
     Arguments to the commands.

   There is unfortunately some confusion between `cvs_options' and
`command_options'.  `-l', when given as a `cvs_option', only affects
some of the commands.  When it is given as a `command_option' is has a
different meaning, and is accepted by more commands.  In other words,
do not take the above categorization too seriously.  Look at the
documentation instead.

Default options and the ~/.cvsrc file
=====================================

   There are some `command_options' that are used so often that you
might have set up an alias or some other means to make sure you always
specify that option.  One example (the one that drove the
implementation of the .cvsrc support, actually) is that many people
find the default output of the `diff' command to be very hard to read,
and that either context diffs or unidiffs are much easier to understand.

   The `~/.cvsrc' file is a way that you can add default options to
`cvs_commands' within cvs, instead of relying on aliases or other shell
scripts.

   The format of the `~/.cvsrc' file is simple.  The file is searched
for a line that begins with the same name as the `cvs_command' being
executed.  If a match is found, then the remainder of the line is split
up (at whitespace characters) into separate options and added to the
command arguments *before* any options from the command line.

   If a command has two names (e.g., `checkout' and `co'), the official
name, not necessarily the one used on the command line, will be used to
match against the file.  So if this is the contents of the user's
`~/.cvsrc' file:

     log -N
     diff -u
     update -P
     co -P

the command `cvs checkout foo' would have the `-P' option added to the
arguments, as well as `cvs co foo'.

   With the example file above, the output from `cvs diff foobar' will
be in unidiff format.  `cvs diff -c foobar' will provide context diffs,
as usual.  Getting "old" format diffs would be slightly more
complicated, because `diff' doesn't have an option to specify use of
the "old" format, so you would need `cvs -f diff foobar'.

   In place of the command name you can use `cvs' to specify global
options (*note Global options::.).  For example the following line in
`.cvsrc'

     cvs -z6

   causes CVS to use compression level 6

Global options
==============

   The available `cvs_options' (that are given to the left of
`cvs_command') are:

`-b BINDIR'
     Use BINDIR as the directory where RCS programs are located.
     Overrides the setting of the `$RCSBIN' environment variable and
     any precompiled directory.  This parameter should be specified as
     an absolute pathname.

`-T TEMPDIR'
     Use TEMPDIR as the directory where temporary files are located.
     Overrides the setting of the `$TMPDIR' environment variable and
     any precompiled directory.  This parameter should be specified as
     an absolute pathname.

`-d CVS_ROOT_DIRECTORY'
     Use CVS_ROOT_DIRECTORY as the root directory pathname of the
     repository.  Overrides the setting of the `$CVSROOT' environment
     variable.  *Note Repository::.

`-e EDITOR'
     Use EDITOR to enter revision log information.  Overrides the
     setting of the `$CVSEDITOR' and `$EDITOR' environment variables.

`-f'
     Do not read the `~/.cvsrc' file.  This option is most often used
     because of the non-orthogonality of the CVS option set.  For
     example, the `cvs log' option `-N' (turn off display of tag names)
     does not have a corresponding option to turn the display on.  So
     if you have `-N' in the `~/.cvsrc' entry for `log', you may need
     to use `-f' to show the tag names.

`-H'
     Display usage information about the specified `cvs_command' (but
     do not actually execute the command).  If you don't specify a
     command name, `cvs -H' displays a summary of all the commands
     available.

`-l'
     Do not log the cvs_command in the command history (but execute it
     anyway).  *Note history::, for information on command history.

`-n'
     Do not change any files.  Attempt to execute the `cvs_command',
     but only to issue reports; do not remove, update, or merge any
     existing files, or create any new files.

`-Q'
     Cause the command to be really quiet; the command will only
     generate output for serious problems.

`-q'
     Cause the command to be somewhat quiet; informational messages,
     such as reports of recursion through subdirectories, are
     suppressed.

`-r'
     Make new working files files read-only.  Same effect as if the
     `$CVSREAD' environment variable is set (*note Environment
     variables::.).  The default is to make working files writable,
     unless watches are on (*note Watches::.).

`-s VARIABLE=VALUE'
     Set a user variable (*note Variables::.).

`-t'
     Trace program execution; display messages showing the steps of CVS
     activity.  Particularly useful with `-n' to explore the potential
     impact of an unfamiliar command.

`-v'
     Display version and copyright information for CVS.

`-w'
     Make new working files read-write.  Overrides the setting of the
     `$CVSREAD' environment variable.  Files are created read-write by
     default, unless `$CVSREAD' is set or `-r' is given.

`-x'
     Encrypt all communication between the client and the server.  Only
     has an effect on the CVS client.  As of this writing, this is only
     implemented when using a Kerberos connection (*note Kerberos
     authenticated::.).  Encryption support is not available by
     default; it must be enabled using a special configure option,
     `--enable-encryption', when you build CVS.

`-z GZIP-LEVEL'
     Set the compression level.  Only has an effect on the CVS client.

Common command options
======================

   This section describes the `command_options' that are available
across several CVS commands.  These options are always given to the
right of `cvs_command'. Not all commands support all of these options;
each option is only supported for commands where it makes sense.
However, when a command has one of these options you can almost always
count on the same behavior of the option as in other commands.  (Other
command options, which are listed with the individual commands, may have
different behavior from one CVS command to the other).

   *Warning:* the `history' command is an exception; it supports many
options that conflict even with these standard options.

`-D DATE_SPEC'
     Use the most recent revision no later than DATE_SPEC.  DATE_SPEC
     is a single argument, a date description specifying a date in the
     past.

     The specification is "sticky" when you use it to make a private
     copy of a source file; that is, when you get a working file using
     `-D', CVS records the date you specified, so that further updates
     in the same directory will use the same date (for more information
     on sticky tags/dates, *note Sticky tags::.).

     A wide variety of date formats are supported by CVS.  The
     DATE_SPEC is interpreted as being in the local timezone, unless a
     specific timezone is specified.  Examples of valid date
     specifications include:

                              1 month ago
                              2 hours ago
                              400000 seconds ago
                              last year
                              last Monday
                              yesterday
                              a fortnight ago
                              3/31/92 10:00:07 PST
                              January 23, 1987 10:05pm
                              22:00 GMT

     `-D' is available with the `checkout', `diff', `export', `history',
     `rdiff', `rtag', and `update' commands.  (The `history' command
     uses this option in a slightly different way; *note history
     options::.).  Note that when specifying a date like `3/31/92' it is
     `MONTH/DAY/YEAR'.  So `1/4/96' is January 4, not March 1.

     Remember to quote the argument to the `-D' flag so that your shell
     doesn't interpret spaces as argument separators.  A command using
     the `-D' flag can look like this:

          $ cvs diff -D "1 hour ago" cvs.texinfo

`-f'
     When you specify a particular date or tag to CVS commands, they
     normally ignore files that do not contain the tag (or did not
     exist prior to the date) that you specified.  Use the `-f' option
     if you want files retrieved even when there is no match for the
     tag or date.  (The most recent revision of the file will be used).

     `-f' is available with these commands: `checkout', `export',
     `rdiff', `rtag', and `update'.

     *Warning:*  The `commit' command also has a `-f' option, but it
     has a different behavior for that command.  *Note commit options::.

`-H'
     Help; describe the options available for this command.  This is
     the only option supported for all CVS commands.

`-k KFLAG'
     Alter the default RCS processing of keywords.  *Note Keyword
     substitution::, for the meaning of KFLAG.  Your KFLAG
     specification is "sticky" when you use it to create a private copy
     of a source file; that is, when you use this option with the
     `checkout' or `update' commands, CVS associates your selected
     KFLAG with the file, and continues to use it with future update
     commands on the same file until you specify otherwise.

     The `-k' option is available with the `add', `checkout', `diff' and
     `update' commands.

`-l'
     Local; run only in current working directory, rather than
     recursing through subdirectories.

     *Warning:* this is not the same as the overall `cvs -l' option,
     which you can specify to the left of a cvs command!

     Available with the following commands: `checkout', `commit',
     `diff', `export', `log', `remove', `rdiff', `rtag', `status',
     `tag', and `update'.

`-m MESSAGE'
     Use MESSAGE as log information, instead of invoking an editor.

     Available with the following commands: `add', `commit' and
     `import'.

`-n'
     Do not run any checkout/commit/tag program.  (A program can be
     specified to run on each of these activities, in the modules
     database (*note modules::.); this option bypasses it).

     *Warning:* this is not the same as the overall `cvs -n' option,
     which you can specify to the left of a cvs command!

     Available with the `checkout', `commit', `export', and `rtag'
     commands.

`-P'
     Prune (remove) directories that are empty after being updated, on
     `checkout', or `update'.  Normally, an empty directory (one that
     is void of revision-controlled files) is left alone.  Specifying
     `-P' will cause these directories to be silently removed from your
     checked-out sources.  This does not remove the directory from the
     repository, only from your checked out copy.  Note that this
     option is implied by the `-r' or `-D' options of `checkout' and
     `export'.

`-p'
     Pipe the files retrieved from the repository to standard output,
     rather than writing them in the current directory.  Available with
     the `checkout' and `update' commands.

`-W'
     Specify file names that should be filtered.  You can use this
     option repeatedly.  The spec can be a file name pattern of the
     same type that you can specify in the `.cvswrappers' file.
     Avaliable with the following commands: `import', and `update'.

`-r TAG'
     Use the revision specified by the TAG argument instead of the
     default "head" revision.  As well as arbitrary tags defined with
     the `tag' or `rtag' command, two special tags are always
     available: `HEAD' refers to the most recent version available in
     the repository, and `BASE' refers to the revision you last checked
     out into the current working directory.

     The tag specification is sticky when you use this with `checkout'
     or `update' to make your own copy of a file: CVS remembers the tag
     and continues to use it on future update commands, until you
     specify otherwise (for more information on sticky tags/dates,
     *note Sticky tags::.).  The tag can be either a symbolic or
     numeric tag.  *Note Tags::.

     Specifying the `-q' global option along with the `-r' command
     option is often useful, to suppress the warning messages when the
     RCS history file does not contain the specified tag.

     *Warning:* this is not the same as the overall `cvs -r' option,
     which you can specify to the left of a cvs command!

     `-r' is available with the `checkout', `commit', `diff',
     `history', `export', `rdiff', `rtag', and `update' commands.

admin--Administration front end for rcs
=======================================

   * Requires: repository, working directory.

   * Changes: repository.

   * Synonym: rcs

   This is the CVS interface to assorted administrative RCS facilities,
documented in rcs(1).  `admin' simply passes all its options and
arguments to the `rcs' command; it does no filtering or other
processing.  This command *does* work recursively, however, so extreme
care should be used.

   If there is a group whose name matches a compiled in value which
defaults to `cvsadmin', only members of that group can use `cvs admin'.
To disallow `cvs admin' for all users, create a group with no users in
it.

admin options
-------------

   Not all valid `rcs' options are useful together with CVS.  Some even
makes it impossible to use CVS until you undo the effect!

   This description of the available options is based on the `rcs(1)'
man page, but modified to suit readers that are more interrested in CVS
than RCS.

`-AOLDFILE'
     Might not work together with CVS.  Append the access list of
     OLDFILE to the access list of the RCS file.

`-aLOGINS'
     Might not work together with CVS.  Append the login names
     appearing in the comma-separated list LOGINS to the access list of
     the RCS file.

`-b[REV]'
     When used with bare RCS, this option sets the default branch to
     REV; in CVS sticky tags (*note Sticky tags::.) are a better way to
     decide which branch you want to work on.  With CVS, this option
     can be used to control behavior with respect to the vendor branch.

`-cSTRING'
     Useful with CVS.  Sets the comment leader to STRING.  The comment
     leader is printed before every log message line generated by the
     keyword `$Log$' (*note Keyword substitution::.).  This is useful
     for programming languages without multi-line comments.  RCS
     initially guesses the value of the comment leader from the file
     name extension when the file is first committed.

`-e[LOGINS]'
     Might not work together with CVS.  Erase the login names appearing
     in the comma-separated list LOGINS from the access list of the RCS
     file.  If LOGINS is omitted, erase the entire access list.

`-I'
     Run interactively, even if the standard input is not a terminal.

`-i'
     Useless with CVS.  When using bare RCS, this is used to create and
     initialize a new RCS file, without depositing a revision.

`-kSUBST'
     Useful with CVS.  Set the default keyword substitution to SUBST.
     *Note Keyword substitution::.  Giving an explicit `-k' option to
     `cvs update', `cvs export', or `cvs checkout' overrides this
     default.

`-l[REV]'
     Lock the revision with number REV.  If a branch is given, lock the
     latest revision on that branch.  If REV is omitted, lock the
     latest revision on the default branch.

     This can be used in conjunction with the `rcslock.pl' script in
     the `contrib' directory of the CVS source distribution to provide
     reserved checkouts (where only one user can be editing a given
     file at a time).  See the comments in that file for details (and
     see the `README' file in that directory for disclaimers about the
     unsupported nature of contrib).  According to comments in that
     file, locking must set to strict (which is the default).

`-L'
     Set locking to strict.  Strict locking means that the owner of an
     RCS file is not exempt from locking for checkin.  For use with
     CVS, strict locking must be set; see the discussion under the `-l'
     option above.

`-mREV:MSG'
     Replace the log message of revision REV with MSG.

`-NNAME[:[REV]]'
     Act like `-n', except override any previous assignment of NAME.

`-nNAME[:[REV]]'
     Associate the symbolic name NAME with the branch or revision REV.
     It is normally better to use `cvs tag' or `cvs rtag' instead.
     Delete the symbolic name if both `:' and REV are omitted;
     otherwise, print an error message if NAME is already associated
     with another number.  If REV is symbolic, it is expanded before
     association.  A REV consisting of a branch number followed by a
     `.' stands for the current latest revision in the branch.  A `:'
     with an empty REV stands for the current latest revision on the
     default branch, normally the trunk.  For example, `rcs -nNAME:
     RCS/*' associates NAME with the current latest revision of all the
     named RCS files; this contrasts with `rcs -nNAME:$ RCS/*' which
     associates NAME with the revision numbers extracted from keyword
     strings in the corresponding working files.

`-oRANGE'
     Potentially useful, but dangerous, with CVS (see below).  Deletes
     ("outdates") the revisions given by RANGE.  A range consisting of
     a single revision number means that revision.  A range consisting
     of a branch number means the latest revision on that branch.  A
     range of the form `REV1:REV2' means revisions REV1 to REV2 on the
     same branch, `:REV' means from the beginning of the branch
     containing REV up to and including REV, and `REV:' means from
     revision REV to the end of the branch containing REV.  None of the
     outdated revisions may have branches or locks.

     Due to the way CVS handles branches REV cannot be specified
     symbolically if it is a branch.  *Note Magic branch numbers::, for
     an explanation.

     Make sure that no-one has checked out a copy of the revision you
     outdate.  Strange things will happen if he starts to edit it and
     tries to check it back in.  For this reason, this option is not a
     good way to take back a bogus commit; commit a new revision
     undoing the bogus change instead (*note Merging two revisions::.).

`-q'
     Run quietly; do not print diagnostics.

`-sSTATE[:REV]'
     Useful with CVS.  Set the state attribute of the revision REV to
     STATE.  If REV is a branch number, assume the latest revision on
     that branch.  If REV is omitted, assume the latest revision on the
     default branch.  Any identifier is acceptable for STATE.  A useful
     set of states is `Exp' (for experimental), `Stab' (for stable),
     and `Rel' (for released).  By default, the state of a new revision
     is set to `Exp' when it is created.  The state is visible in the
     output from CVS LOG (*note log::.), and in the `$Log$' and
     `$State$' keywords (*note Keyword substitution::.).  Note that CVS
     uses the `dead' state for its own purposes; to take a file to or
     from the `dead' state use commands like `cvs remove' and `cvs
     add', not `cvs admin -s'.

`-t[FILE]'
     Useful with CVS.  Write descriptive text from the contents of the
     named FILE into the RCS file, deleting the existing text.  The
     FILE pathname may not begin with `-'.  If FILE is omitted, obtain
     the text from standard input, terminated by end-of-file or by a
     line containing `.' by itself.  Prompt for the text if interaction
     is possible; see `-I'.  The descriptive text can be seen in the
     output from `cvs log' (*note log::.).

`-t-STRING'
     Similar to `-tFILE'. Write descriptive text from the STRING into
     the RCS file, deleting the existing text.

`-U'
     Set locking to non-strict.  Non-strict locking means that the
     owner of a file need not lock a revision for checkin.  For use
     with CVS, strict locking must be set; see the discussion under the
     `-l' option above.

`-u[REV]'
     See the option `-l' above, for a discussion of using this option
     with CVS.  Unlock the revision with number REV.  If a branch is
     given, unlock the latest revision on that branch.  If REV is
     omitted, remove the latest lock held by the caller.  Normally,
     only the locker of a revision may unlock it.  Somebody else
     unlocking a revision breaks the lock.  This causes a mail message
     to be sent to the original locker.  The message contains a
     commentary solicited from the breaker.  The commentary is
     terminated by end-of-file or by a line containing `.' by itself.

`-VN'
     Emulate RCS version N. Use -VN to make an RCS file acceptable to
     RCS version N by discarding information that would confuse version
     N.

`-xSUFFIXES'
     Useless with CVS. Use SUFFIXES to characterize RCS files.

admin examples
--------------

Outdating is dangerous
......................

   First, an example of how *not* to use the `admin' command.  It is
included to stress the fact that this command can be quite dangerous
unless you know *exactly* what you are doing.

   The `-o' option can be used to "outdate" old revisions from the
history file.  If you are short on disc this option might help you.
But think twice before using it--there is no way short of restoring the
latest backup to undo this command!

   The next line is an example of a command that you would *not* like
to execute.

     $ cvs admin -o:R_1_02 .

   The above command will delete all revisions up to, and including,
the revision that corresponds to the tag R_1_02.  But beware!  If there
are files that have not changed between R_1_02 and R_1_03 the file will
have *the same* numerical revision number assigned to the tags R_1_02
and R_1_03.  So not only will it be impossible to retrieve R_1_02;
R_1_03 will also have to be restored from the tapes!

Comment leaders
...............

   If you use the `$Log$' keyword and you do not agree with the guess
for comment leader that CVS has done, you can enforce your will with
`cvs admin -c'.  This might be suitable for `nroff' source:

     $ cvs admin -c'.\" ' *.man
     $ rm *.man
     $ cvs update

   The two last steps are to make sure that you get the versions with
correct comment leaders in your working files.

checkout--Check out sources for editing
=======================================

   * Synopsis: checkout [options] modules...

   * Requires: repository.

   * Changes: working directory.

   * Synonyms: co, get

   Make a working directory containing copies of the source files
specified by MODULES.  You must execute `checkout' before using most of
the other CVS commands, since most of them operate on your working
directory.

   The MODULES part of the command are either symbolic names for some
collection of source directories and files, or paths to directories or
files in the repository.  The symbolic names are defined in the
`modules' file.  *Note modules::.

   Depending on the modules you specify, `checkout' may recursively
create directories and populate them with the appropriate source files.
You can then edit these source files at any time (regardless of
whether other software developers are editing their own copies of the
sources); update them to include new changes applied by others to the
source repository; or commit your work as a permanent change to the
source repository.

   Note that `checkout' is used to create directories.  The top-level
directory created is always added to the directory where `checkout' is
invoked, and usually has the same name as the specified module.  In the
case of a module alias, the created sub-directory may have a different
name, but you can be sure that it will be a sub-directory, and that
`checkout' will show the relative path leading to each file as it is
extracted into your private work area (unless you specify the `-Q'
global option).

   The files created by `checkout' are created read-write, unless the
`-r' option to CVS (*note Global options::.) is specified, the
`CVSREAD' environment variable is specified (*note Environment
variables::.), or a watch is in effect for that file (*note Watches::.).

   Running `checkout' on a directory that was already built by a prior
`checkout' is also permitted, and has the same effect as specifying the
`-d' option to the `update' command, that is, any new directories that
have been created in the repository will appear in your work area.
*Note update::.

   For the output produced by the `checkout' command see *Note update
output::.

checkout options
----------------

   These standard options are supported by `checkout' (*note Common
options::., for a complete description of them):

`-D DATE'
     Use the most recent revision no later than DATE.  This option is
     sticky, and implies `-P'.  See *Note Sticky tags::, for more
     information on sticky tags/dates.

`-f'
     Only useful with the `-D DATE' or `-r TAG' flags.  If no matching
     revision is found, retrieve the most recent revision (instead of
     ignoring the file).

`-k KFLAG'
     Process RCS keywords according to KFLAG.  See co(1).  This option
     is sticky; future updates of this file in this working directory
     will use the same KFLAG.  The `status' command can be viewed to
     see the sticky options.  *Note status::.

`-l'
     Local; run only in current working directory.

`-n'
     Do not run any checkout program (as specified with the `-o' option
     in the modules file; *note modules::.).

`-P'
     Prune empty directories.

`-p'
     Pipe files to the standard output.

`-r TAG'
     Use revision TAG.  This option is sticky, and implies `-P'.  See
     *Note Sticky tags::, for more information on sticky tags/dates.

   In addition to those, you can use these special command options with
`checkout':

`-A'
     Reset any sticky tags, dates, or `-k' options.  See *Note Sticky
     tags::, for more information on sticky tags/dates.

`-c'
     Copy the module file, sorted, to the standard output, instead of
     creating or modifying any files or directories in your working
     directory.

`-d DIR'
     Create a directory called DIR for the working files, instead of
     using the module name.  Unless you also use `-N', the paths
     created under DIR will be as short as possible.

`-j TAG'
     With two `-j' options, merge changes from the revision specified
     with the first `-j' option to the revision specified with the
     second `j' option, into the working directory.

     With one `-j' option, merge changes from the ancestor revision to
     the revision specified with the `-j' option, into the working
     directory.  The ancestor revision is the common ancestor of the
     revision which the working directory is based on, and the revision
     specified in the `-j' option.

     In addition, each -j option can contain an optional date
     specification which, when used with branches, can limit the chosen
     revision to one within a specific date.  An optional date is
     specified by adding a colon (:) to the tag:
     `-jSYMBOLIC_TAG:DATE_SPECIFIER'.

     *Note Merging::.

`-N'
     Only useful together with `-d DIR'.  With this option, CVS will
     not shorten module paths in your working directory.  (Normally,
     CVS shortens paths as much as possible when you specify an
     explicit target directory).

`-s'
     Like `-c', but include the status of all modules, and sort it by
     the status string.  *Note modules::, for info about the `-s'
     option that is used inside the modules file to set the module
     status.

checkout examples
-----------------

   Get a copy of the module `tc':

     $ cvs checkout tc

   Get a copy of the module `tc' as it looked one day ago:

     $ cvs checkout -D yesterday tc

commit--Check files into the repository
=======================================

   * Version 1.3 Synopsis: commit [-lnR] [-m 'log_message' | -f file]
     [-r revision] [files...]

   * Version 1.3.1 Synopsis: commit [-lnRf] [-m 'log_message' | -F
     file] [-r revision] [files...]

   * Requires: working directory, repository.

   * Changes: repository.

   * Synonym: ci

   *Warning:* The `-f FILE' option will probably be renamed to `-F
FILE', and `-f' will be given a new behavior in future releases of CVS.

   Use `commit' when you want to incorporate changes from your working
source files into the source repository.

   If you don't specify particular files to commit, all of the files in
your working current directory are examined.  `commit' is careful to
change in the repository only those files that you have really changed.
By default (or if you explicitly specify the `-R' option), files in
subdirectories are also examined and committed if they have changed;
you can use the `-l' option to limit `commit' to the current directory
only.

   `commit' verifies that the selected files are up to date with the
current revisions in the source repository; it will notify you, and
exit without committing, if any of the specified files must be made
current first with `update' (*note update::.).  `commit' does not call
the `update' command for you, but rather leaves that for you to do when
the time is right.

   When all is well, an editor is invoked to allow you to enter a log
message that will be written to one or more logging programs (*note
modules::., and *note loginfo::.)  and placed in the RCS history file
inside the repository.  This log message can be retrieved with the
`log' command; *Note log::.  You can specify the log message on the
command line with the `-m MESSAGE' option, and thus avoid the editor
invocation, or use the `-f FILE' option to specify that the argument
file contains the log message.

commit options
--------------

   These standard options are supported by `commit' (*note Common
options::., for a complete description of them):

`-l'
     Local; run only in current working directory.

`-n'
     Do not run any module program.

`-R'
     Commit directories recursively.  This is on by default.

`-r REVISION'
     Commit to REVISION.  REVISION must be either a branch, or a
     revision on the main trunk that is higher than any existing
     revision number.  You cannot commit to a specific revision on a
     branch.

   `commit' also supports these options:

`-F FILE'
     This option is present in CVS releases 1.3-s3 and later.  Read the
     log message from FILE, instead of invoking an editor.

`-f'
     This option is present in CVS 1.3-s3 and later releases of CVS.
     Note that this is not the standard behavior of the `-f' option as
     defined in *Note Common options::.

     Force CVS to commit a new revision even if you haven't made any
     changes to the file.  If the current revision of FILE is 1.7, then
     the following two commands are equivalent:

          $ cvs commit -f FILE
          $ cvs commit -r 1.8 FILE

`-f FILE'
     This option is present in CVS releases 1.3, 1.3-s1 and 1.3-s2.
     Note that this is not the standard behavior of the `-f' option as
     defined in *Note Common options::.

     Read the log message from FILE, instead of invoking an editor.

`-m MESSAGE'
     Use MESSAGE as the log message, instead of invoking an editor.

commit examples
---------------

New major release number
........................

   When you make a major release of your product, you might want the
revision numbers to track your major release number.  You should
normally not care about the revision numbers, but this is a thing that
many people want to do, and it can be done without doing any harm.

   To bring all your files up to the RCS revision 3.0 (including those
that haven't changed), you might do:

     $ cvs commit -r 3.0

   Note that it is generally a bad idea to try to make the RCS revision
number equal to the current release number of your product.  You should
think of the revision number as an internal number that the CVS package
maintains, and that you generally never need to care much about.  Using
the `tag' and `rtag' commands you can give symbolic names to the
releases instead.  *Note tag:: and *Note rtag::.

   Note that the number you specify with `-r' must be larger than any
existing revision number.  That is, if revision 3.0 exists, you cannot
`cvs commit -r 1.3'.

Committing to a branch
......................

   You can commit to a branch revision (one that has an even number of
dots) with the `-r' option.  To create a branch revision, use the `-b'
option of the `rtag' or `tag' commands (*note tag::.  or *note
rtag::.).  Then, either `checkout' or `update' can be used to base your
sources on the newly created branch.  From that point on, all `commit'
changes made within these working sources will be automatically added
to a branch revision, thereby not disturbing main-line development in
any way.  For example, if you had to create a patch to the 1.2 version
of the product, even though the 2.0 version is already under
development, you might do:

     $ cvs rtag -b -r FCS1_2 FCS1_2_Patch product_module
     $ cvs checkout -r FCS1_2_Patch product_module
     $ cd product_module
     [[ hack away ]]
     $ cvs commit

This works automatically since the `-r' option is sticky.

Creating the branch after editing
.................................

   Say you have been working on some extremely experimental software,
based on whatever revision you happened to checkout last week.  If
others in your group would like to work on this software with you, but
without disturbing main-line development, you could commit your change
to a new branch.  Others can then checkout your experimental stuff and
utilize the full benefit of CVS conflict resolution.  The scenario might
look like:

     [[ hacked sources are present ]]
     $ cvs tag -b EXPR1
     $ cvs update -r EXPR1
     $ cvs commit

   The `update' command will make the `-r EXPR1' option sticky on all
files.  Note that your changes to the files will never be removed by the
`update' command.  The `commit' will automatically commit to the
correct branch, because the `-r' is sticky.  You could also do like
this:

     [[ hacked sources are present ]]
     $ cvs tag -b EXPR1
     $ cvs commit -r EXPR1

but then, only those files that were changed by you will have the `-r
EXPR1' sticky flag.  If you hack away, and commit without specifying
the `-r EXPR1' flag, some files may accidentally end up on the main
trunk.

   To work with you on the experimental change, others would simply do

     $ cvs checkout -r EXPR1 whatever_module

diff--Run diffs between revisions
=================================

   * Synopsis: diff [-l] [rcsdiff_options] [[-r rev1 | -D date1] [-r
     rev2 |  -D date2]] [files...]

   * Requires: working directory, repository.

   * Changes: nothing.

   The `diff' command is used to compare different revisions of files.
The default action is to compare your working files with the revisions
they were based on, and report any differences that are found.

   If any file names are given, only those files are compared.  If any
directories are given, all files under them will be compared.

   The exit status will be 0 if no differences were found, 1 if some
differences were found, and 2 if any error occurred.

diff options
------------

   These standard options are supported by `diff' (*note Common
options::., for a complete description of them):

`-D DATE'
     Use the most recent revision no later than DATE.  See `-r' for how
     this affects the comparison.

     CVS can be configured to pass the `-D' option through to `rcsdiff'
     (which in turn passes it on to `diff'.  GNU diff uses `-D' as a
     way to put `cpp'-style `#define' statements around the output
     differences.  There is no way short of testing to figure out how
     CVS was configured.  In the default configuration CVS will use the
     `-D DATE' option.

`-k KFLAG'
     Process RCS keywords according to KFLAG.  See co(1).

`-l'
     Local; run only in current working directory.

`-R'
     Examine directories recursively.  This option is on by default.

`-r TAG'
     Compare with revision TAG.  Zero, one or two `-r' options can be
     present.  With no `-r' option, the working file will be compared
     with the revision it was based on.  With one `-r', that revision
     will be compared to your current working file.  With two `-r'
     options those two revisions will be compared (and your working
     file will not affect the outcome in any way).

     One or both `-r' options can be replaced by a `-D DATE' option,
     described above.

   Any other options that are found are passed through to `rcsdiff',
which in turn passes them to `diff'.  The exact meaning of the options
depends on which `diff' you are using.  The long options introduced in
GNU diff 2.0 are not yet supported in CVS.  See the documentation for
your `diff' to see which options are supported.

diff examples
-------------

   The following line produces a Unidiff (`-u' flag) between revision
1.14 and 1.19 of `backend.c'.  Due to the `-kk' flag no keywords are
substituted, so differences that only depend on keyword substitution
are ignored.

     $ cvs diff -kk -u -r 1.14 -r 1.19 backend.c

   Suppose the experimental branch EXPR1 was based on a set of files
tagged RELEASE_1_0.  To see what has happened on that branch, the
following can be used:

     $ cvs diff -r RELEASE_1_0 -r EXPR1

   A command like this can be used to produce a context diff between
two releases:

     $ cvs diff -c -r RELEASE_1_0 -r RELEASE_1_1 > diffs

   If you are maintaining ChangeLogs, a command like the following just
before you commit your changes may help you write the ChangeLog entry.
All local modifications that have not yet been committed will be
printed.

     $ cvs diff -u | less

export--Export sources from CVS, similar to checkout
====================================================

   * Synopsis: export [-flNn] [-r rev|-D date] [-k subst] [-d dir]
     module...

   * Requires: repository.

   * Changes: current directory.

   This command is a variant of `checkout'; use it when you want a copy
of the source for module without the CVS administrative directories.
For example, you might use `export' to prepare source for shipment
off-site.  This command requires that you specify a date or tag (with
`-D' or `-r'), so that you can count on reproducing the source you ship
to others.

   One often would like to use `-kv' with `cvs export'.  This causes
any RCS keywords to be expanded such that an import done at some other
site will not lose the keyword revision information.  But be aware that
doesn't handle an export containing binary files correctly.  Also be
aware that after having used `-kv', one can no longer use the `ident'
command (which is part of the RCS suite--see ident(1)) which looks for
RCS keyword strings.  If you want to be able to use `ident' you must not
use `-kv'.

export options
--------------

   These standard options are supported by `export' (*note Common
options::., for a complete description of them):

`-D DATE'
     Use the most recent revision no later than DATE.

`-f'
     If no matching revision is found, retrieve the most recent
     revision (instead of ignoring the file).

`-l'
     Local; run only in current working directory.

`-n'
     Do not run any checkout program.

`-R'
     Export directories recursively.  This is on by default.

`-r TAG'
     Use revision TAG.

   In addition, these options (that are common to `checkout' and
`export') are also supported:

`-d DIR'
     Create a directory called DIR for the working files, instead of
     using the module name.  Unless you also use `-N', the paths
     created under DIR will be as short as possible.

`-k SUBST'
     Set keyword expansion mode (*note Substitution modes::.).

`-N'
     Only useful together with `-d DIR'.  With this option, CVS will
     not shorten module paths in your working directory.  (Normally,
     CVS shortens paths as much as possible when you specify an
     explicit target directory.)

history--Show status of files and users
=======================================

   * Synopsis:     history [-report] [-flags] [-options args] [files...]

   * Requires: the file `$CVSROOT/CVSROOT/history'

   * Changes: nothing.

   CVS can keep a history file that tracks each use of the `checkout',
`commit', `rtag', `update', and `release' commands.  You can use
`history' to display this information in various formats.

   Logging must be enabled by creating the file
`$CVSROOT/CVSROOT/history'.

   *Warning:* `history' uses `-f', `-l', `-n', and `-p' in ways that
conflict with the normal use inside CVS (*note Common options::.).

history options
---------------

   Several options (shown above as `-report')  control  what kind of
report is generated:

`-c'
     Report on each time commit was used (i.e., each time the
     repository was modified).

`-e'
     Everything (all record types); equivalent to specifying
     `-xMACFROGWUT'.

`-m MODULE'
     Report on a particular module.  (You can meaningfully use `-m'
     more than once on the command line.)

`-o'
     Report on checked-out modules.

`-T'
     Report on all tags.

`-x TYPE'
     Extract a particular set of record types TYPE from the CVS
     history.  The types are indicated by single letters, which you may
     specify in combination.

     Certain commands have a single record type:

    `F'
          release

    `O'
          checkout

    `T'
          rtag

     One of four record types may result from an update:

    `C'
          A merge was necessary but collisions were detected (requiring
          manual merging).

    `G'
          A merge was necessary and it succeeded.

    `U'
          A working file was copied from the repository.

    `W'
          The working copy of a file was deleted during update (because
          it was gone from the repository).

     One of three record types results from commit:

    `A'
          A file was added for the first time.

    `M'
          A file was modified.

    `R'
          A file was removed.

   The options shown as `-flags' constrain or expand the report without
requiring option arguments:

`-a'
     Show data for all users (the default is to show data only for the
     user executing `history').

`-l'
     Show last modification only.

`-w'
     Show only the records for modifications done from the same working
     directory where `history' is executing.

   The options shown as `-options ARGS' constrain the report based on
an argument:

`-b STR'
     Show data back to a record containing  the  string STR  in  either
     the module name, the file name, or the repository path.

`-D DATE'
     Show data since DATE.  This is slightly different from the normal
     use of `-D DATE', which selects the newest revision older than
     DATE.

`-p REPOSITORY'
     Show data for a particular source repository  (you can specify
     several `-p' options on the same command line).

`-r REV'
     Show records referring to revisions since the revision or tag
     named REV appears in individual RCS files.  Each RCS file is
     searched for the revision or tag.

`-t TAG'
     Show records since tag TAG was last added to the the history file.
     This differs from the `-r' flag above in that it reads only the
     history file, not the RCS files, and is much faster.

`-u NAME'
     Show records for user NAME.

import--Import sources into CVS, using vendor branches
======================================================

   * Synopsis: import [-options] repository vendortag releasetag...

   * Requires: Repository, source distribution directory.

   * Changes: repository.

   Use `import' to incorporate an entire source distribution from an
outside source (e.g., a source vendor) into your source repository
directory.  You can use this command both for initial creation of a
repository, and for wholesale updates to the module from the outside
source.  *Note Tracking sources::, for a discussion on this subject.

   The REPOSITORY argument gives a directory name (or a path to a
directory) under the CVS root directory for repositories; if the
directory did not exist, import creates it.

   When you use import for updates to source that has been modified in
your source repository (since a prior import), it will notify you of
any files that conflict in the two branches of development; use
`checkout -j' to reconcile the differences, as import instructs you to
do.

   If CVS decides a file should be ignored (*note cvsignore::.), it
does not import it and prints `I ' followed by the filename (*note
import output::., for a complete description of the output).

   If the file `$CVSROOT/CVSROOT/cvswrappers' exists, any file whose
names match the specifications in that file will be treated as packages
and the appropriate filtering will be performed on the file/directory
before being imported, *Note Wrappers::.

   The outside source is saved in a first-level RCS branch, by default
1.1.1.  Updates are leaves of this branch; for example, files from the
first imported collection of source will be revision 1.1.1.1, then
files from the first imported update will be revision 1.1.1.2, and so
on.

   At least three arguments are required.  REPOSITORY is needed to
identify the collection of source.  VENDORTAG is a tag for the entire
branch (e.g., for 1.1.1).  You must also specify at least one
RELEASETAG to identify the files at the leaves created each time you
execute `import'.

import options
--------------

   This standard option is supported by `import' (*note Common
options::., for a complete description):

`-m MESSAGE'
     Use MESSAGE as log information, instead of invoking an editor.

   There are three additional special options.

`-b BRANCH'
     Specify a first-level branch other than 1.1.1.  Unless the `-b
     BRANCH' flag is given, revisions will *always* be made to the
     branch 1.1.1--even if a VENDORTAG that matches another branch is
     given!  What happens in that case, is that the tag will be reset
     to 1.1.1.  Warning: This behavior might change in the future.

`-k SUBST'
     Indicate the RCS keyword expansion mode desired.  This setting
     will apply to all files created during the import, but not to any
     files that previously existed in the repository.  See *Note
     Substitution modes:: for a list of valid `-k' settings.

`-I NAME'
     Specify file names that should be ignored during import.  You can
     use this option repeatedly.  To avoid ignoring any files at all
     (even those ignored by default), specify `-I !'.

     NAME can be a file name pattern of the same type that you can
     specify in the `.cvsignore' file.  *Note cvsignore::.

`-W SPEC'
     Specify file names that should be filtered during import.  You can
     use this option repeatedly.

     SPEC can be a file name pattern of the same type that you can
     specify in the `.cvswrappers' file. *Note Wrappers::.

import output
-------------

   `import' keeps you informed of its progress by printing a line for
each file, preceded by one character indicating the status of the file:

`U FILE'
     The file already exists in the repository and has not been locally
     modified; a new revision has been created (if necessary).

`N FILE'
     The file is a new file which has been added to the repository.

`C FILE'
     The file already exists in the repository but has been locally
     modified; you will have to merge the changes.

`I FILE'
     The file is being ignored (*note cvsignore::.).

`L FILE'
     The file is a symbolic link; at the moment (and for the forseeable
     future), symbolic links are ignored.  (Various options in the
     `modules' file can be used to recreate symbolic links on checkout,
     update, etc.; *note modules::..)

import examples
---------------

   *Note Tracking sources::, and *Note From files::.

log--Print out log information for files
========================================

   * Synopsis: log [options] [files...]

   * Requires: repository, working directory.

   * Changes: nothing.

   Display log information for files.  `log' used to call the RCS
utility `rlog'.  Although this is no longer true in the current
sources, this history determines the format of the output and the
options, which are not quite in the style of the other CVS commands.

   The output includes the location of the RCS file, the "head"
revision (the latest revision on the trunk), all symbolic names (tags)
and some other things.  For each revision, the revision number, the
author, the number of lines added/deleted and the log message are
printed.  All times are displayed in Coordinated Universal Time (UTC).
(Other parts of CVS print times in the local timezone).

log options
-----------

   By default, `log' prints all information that is available.  All
other options restrict the output.

`-b'
     Print information about the revisions on the default branch,
     normally the highest branch on the trunk.

`-d DATES'
     Print information about revisions with a checkin date/time in the
     range given by the semicolon-separated list of dates.  The date
     formats accepted are those accepted by the `-D' option to many
     other CVS commands (*note Common options::.).  Dates can be
     combined into ranges as follows:

    `D1<D2'
    `D2>D1'
          Select the revisions that were deposited between D1 and D2.

    `<D'
    `D>'
          Select all revisions dated D or earlier.

    `D<'
    `>D'
          Select all revisions dated D or later.

    `D'
          Select the single, latest revision dated D or earlier.

     The `>' or `<' characters may be followed by `=' to indicate an
     inclusive range rather than an exclusive one.

     Note that the separator is a semicolon (;).

`-h'
     Print only the RCS pathname, working pathname, head, default
     branch, access list, locks, symbolic names, and suffix.

`-l'
     Local; run only in current working directory.  (Default is to run
     recursively).

`-N'
     Do not print the list of tags for this file.  This option can be
     very useful when your site uses a lot of tags, so rather than
     "more"'ing over 3 pages of tag information, the log information is
     presented without tags at all.

`-R'
     Print only the name of the RCS history file.

`-rREVISIONS'
     Print information about revisions given in the comma-separated
     list REVISIONS of revisions and ranges.  The following table
     explains the available range formats:

    `REV1:REV2'
          Revisions REV1 to REV2 (which must be on the same branch).

    `:REV'
          Revisions from the beginning of the branch up to and
          including REV.

    `REV:'
          Revisions starting with REV to the end of the branch
          containing REV.

    `BRANCH'
          An argument that is a branch means all revisions on that
          branch.

    `BRANCH1:BRANCH2'
          A range of branches means all revisions on the branches in
          that range.

    `BRANCH.'
          The latest revision in BRANCH.

     A bare `-r' with no revisions means the latest revision on the
     default branch, normally the trunk.  There can be no space between
     the `-r' option and its argument.

`-s STATES'
     Print information about revisions whose state attributes match one
     of the states given in the comma-separated list STATES.

`-t'
     Print the same as `-h', plus the descriptive text.

`-wLOGINS'
     Print information about revisions checked in by users with login
     names appearing in the comma-separated list LOGINS.  If LOGINS is
     omitted, the user's login is assumed.  There can be no space
     between the `-w' option and its argument.

   `log' prints the intersection of the revisions selected with the
options `-d', `-s', and `-w', intersected with the union of the
revisions selected by `-b' and `-r'.

log examples
------------

   Contributed examples are gratefully accepted.

rdiff--'patch' format diffs between releases
============================================

   * rdiff [-flags] [-V vn] [-r t|-D d [-r t2|-D d2]] modules...

   * Requires: repository.

   * Changes: nothing.

   * Synonym: patch

   Builds a Larry Wall format patch(1) file between two releases, that
can be fed directly into the patch program to bring an old release
up-to-date with the new release.  (This is one of the few CVS commands
that operates directly from the repository, and doesn't require a prior
checkout.) The diff output is sent to the standard output device.

   You can specify (using the standard `-r' and `-D' options) any
combination of one or two revisions or dates.  If only one revision or
date is specified, the patch file reflects differences between that
revision or date and the current head revisions in the RCS file.

   Note that if the software release affected is contained in more than
one directory, then it may be necessary to specify the `-p' option to
the patch command when patching the old sources, so that patch is able
to find the files that are located in other directories.

rdiff options
-------------

   These standard options are supported by `rdiff' (*note Common
options::., for a complete description of them):

`-D DATE'
     Use the most recent revision no later than DATE.

`-f'
     If no matching revision is found, retrieve the most recent
     revision (instead of ignoring the file).

`-l'
     Local; don't descend subdirectories.

`-r TAG'
     Use revision TAG.

   In addition to the above, these options are available:

`-c'
     Use the context diff format.  This is the default format.

`-s'
     Create a summary change report instead of a patch.  The summary
     includes information about files that were changed or added
     between the releases.  It is sent to the standard output device.
     This is useful for finding out, for example, which files have
     changed between two dates or revisions.

`-t'
     A diff of the top two revisions is sent to the standard output
     device.  This is most useful for seeing what the last change to a
     file was.

`-u'
     Use the unidiff format for the context diffs.  This option is not
     available if your diff does not support the unidiff format.
     Remember that old versions of the `patch' program can't handle the
     unidiff format, so if you plan to post this patch to the net you
     should probably not use `-u'.

`-V VN'
     Expand RCS keywords according to the rules current in RCS version
     VN (the expansion format changed with RCS version 5).

rdiff examples
--------------

   Suppose you receive mail from foo@bar.com asking for an update from
release 1.2 to 1.4 of the tc compiler.  You have no such patches on
hand, but with CVS that can easily be fixed with a command such as this:

     $ cvs rdiff -c -r FOO1_2 -r FOO1_4 tc | \
     $$ Mail -s 'The patches you asked for' foo@bar.com

   Suppose you have made release 1.3, and forked a branch called
`R_1_3fix' for bugfixes.  `R_1_3_1' corresponds to release 1.3.1, which
was made some time ago.  Now, you want to see how much development has
been done on the branch.  This command can be used:

     $ cvs patch -s -r R_1_3_1 -r R_1_3fix module-name
     cvs rdiff: Diffing module-name
     File ChangeLog,v changed from revision 1.52.2.5 to 1.52.2.6
     File foo.c,v changed from revision 1.52.2.3 to 1.52.2.4
     File bar.h,v changed from revision 1.29.2.1 to 1.2

release--Indicate that a Module is no longer in use
===================================================

   * release [-d] directories...

   * Requires: Working directory.

   * Changes: Working directory, history log.

   This command is meant to safely cancel the effect of `cvs checkout'.
Since CVS doesn't lock files, it isn't strictly necessary to use this
command.  You can always simply delete your working directory, if you
like; but you risk losing changes you may have forgotten, and you leave
no trace in the CVS history file (*note history file::.) that you've
abandoned your checkout.

   Use `cvs release' to avoid these problems.  This command checks that
no uncommitted changes are present; that you are executing it from
immediately above a CVS working directory; and that the repository
recorded for your files is the same as the repository defined in the
module database.

   If all these conditions are true, `cvs release' leaves a record of
its execution (attesting to your intentionally abandoning your
checkout) in the CVS history log.

release options
---------------

   The `release' command supports one command option:

`-d'
     Delete your working copy of the file if the release succeeds.  If
     this flag is not given your files will remain in your working
     directory.

     *Warning:*  The `release' command deletes all directories and
     files recursively.  This has the very serious side-effect that any
     directory that you have created inside your checked-out sources,
     and not added to the repository (using the `add' command; *note
     Adding files::.) will be silently deleted--even if it is non-empty!

release output
--------------

   Before `release' releases your sources it will print a one-line
message for any file that is not up-to-date.

   *Warning:*  Any new directories that you have created, but not added
to the CVS directory hierarchy with the `add' command (*note Adding
files::.) will be silently ignored (and deleted, if `-d' is specified),
even if they contain files.

`U FILE'
     There exists a newer revision of this file in the repository, and
     you have not modified your local copy of the file.

`A FILE'
     The file has been added to your private copy of the sources, but
     has not yet been committed to the repository.  If you delete your
     copy of the sources this file will be lost.

`R FILE'
     The file has been removed from your private copy of the sources,
     but has not yet been removed from the repository, since you have
     not yet committed the removal.  *Note commit::.

`M FILE'
     The file is modified in your working directory.  There might also
     be a newer revision inside the repository.

`? FILE'
     FILE is in your working directory, but does not correspond to
     anything in the source repository, and is not in the list of files
     for CVS to ignore (see the description of the `-I' option, and
     *note cvsignore::.).  If you remove your working sources, this
     file will be lost.

     Note that no warning message like this is printed for spurious
     directories that CVS encounters.  The directory, and all its
     contents, are silently ignored.

release examples
----------------

   Release the module, and delete your local working copy of the files.

     $ cd ..         # You must stand immediately above the
                     # sources when you issue `cvs release'.
     $ cvs release -d tc
     You have [0] altered files in this repository.
     Are you sure you want to release (and delete) module `tc': y
     $

rtag--Add a symbolic tag to a module
====================================

   * rtag [-falnR] [-b] [-d] [-r tag | -Ddate] symbolic_tag modules...

   * Requires: repository.

   * Changes: repository.

   * Synonym: rfreeze

   You can use this command to assign symbolic tags to particular,
explicitly specified source revisions in the repository.  `rtag' works
directly on the repository contents (and requires no prior checkout).
Use `tag' instead (*note tag::.), to base the selection of revisions on
the contents of your working directory.

   If you attempt to use a tag name that already exists, CVS will
complain and not overwrite that tag.  Use the `-F' option to force the
new tag value.

rtag options
------------

   These standard options are supported by `rtag' (*note Common
options::., for a complete description of them):

`-D DATE'
     Tag the most recent revision no later than DATE.

`-f'
     Only useful with the `-D DATE' or `-r TAG' flags.  If no matching
     revision is found, use the most recent revision (instead of
     ignoring the file).

`-F'
     Overwrite an existing tag of the same name on a different
     revision.  This option is new in CVS 1.4.  The old behavior is
     matched by `cvs tag -F'.

`-l'
     Local; run only in current working directory.

`-n'
     Do not run any tag program that was specified with the `-t' flag
     inside the `modules' file.  (*note modules::.).

`-R'
     Commit directories recursively.  This is on by default.

`-r TAG'
     Only tag those files that contain TAG.  This can be used to rename
     a tag: tag only the files identified by the old tag, then delete
     the old tag, leaving the new tag on exactly the same files as the
     old tag.

   In addition to the above common options, these options are available:

`-a'
     Use the `-a' option to have `rtag' look in the `Attic' (*note
     Removing files::.) for removed files that contain the specified
     tag.  The tag is removed from these files, which makes it
     convenient to re-use a symbolic tag as development continues (and
     files get removed from the up-coming distribution).

`-b'
     Make the tag a branch tag.  *Note Branches::.

`-d'
     Delete the tag instead of creating it.

     In general, tags (often the symbolic names of software
     distributions) should not be removed, but the `-d' option is
     available as a means to remove completely obsolete symbolic names
     if necessary (as might be the case for an Alpha release, or if you
     mistagged a module).

status--Display status information on checked out files
=======================================================

   * status [-lR] [-v] [files...]

   * Requires: working directory, repository.

   * Changes: nothing.

   Display a brief report on the current status of files with respect
to the source repository.  For information on the basic output see
*Note File status::.  For information on the `Sticky tag' and `Sticky
date' output, see *Note Sticky tags::.  For information on the `Sticky
options' output, see the `-k' option in *Note update options::.

   You can also use this command to determine the potential impact of a
`cvs update' on your working source directory--but remember that things
might change in the repository before you run `update'.

status options
--------------

   These standard options are supported by `status' (*note Common
options::., for a complete description of them):

`-l'
     Local; run only in current working directory.

`-R'
     Commit directories recursively.  This is on by default.

   There is one additional option:

`-v'
     Verbose.  In addition to the information normally displayed, print
     all symbolic tags, together with the numerical value of the
     revision or branch they refer to.  For more information, see *Note
     Tags::

tag--Add a symbolic tag to checked out versions of files
========================================================

   * tag [-lR] [-b] [-c] [-d] symbolic_tag [files...]

   * Requires: working directory, repository.

   * Changes: repository.

   * Synonym: freeze

   Use this command to assign symbolic tags to the nearest repository
versions to your working sources.  The tags are applied immediately to
the repository, as with `rtag', but the versions are supplied
implicitly by the CVS records of your working files' history rather than
applied explicitly.

   One use for tags is to record a snapshot of the current sources when
the software freeze date of a project arrives.  As bugs are fixed after
the freeze date, only those changed sources that are to be part of the
release need be re-tagged.

   The symbolic tags are meant to permanently record which revisions of
which files were used in creating a software distribution.  The
`checkout' and `update' commands allow you to extract an exact copy of
a tagged release at any time in the future, regardless of whether files
have been changed, added, or removed since the release was tagged.

   This command can also be used to delete a symbolic tag, or to create
a branch.  See the options section below.

   If you attempt to use a tag name that already exists, CVS will
complain and not overwrite that tag.  Use the `-F' option to force the
new tag value.

tag options
-----------

   These standard options are supported by `tag' (*note Common
options::., for a complete description of them):

`-F'
     Overwrite an existing tag of the same name on a different
     revision.  This option is new in CVS 1.4.  The old behavior is
     matched by `cvs tag -F'.

`-l'
     Local; run only in current working directory.

`-R'
     Commit directories recursively.  This is on by default.

   Two special options are available:

`-b'
     The -b option makes the tag a branch tag (*note Branches::.),
     allowing concurrent, isolated development.  This is most useful
     for creating a patch to a previously released software
     distribution.

`-c'
     The -c option checks that all files which are to be tagged are
     unmodified.  This can be used to make sure that you can
     reconstruct the current file contents.

`-d'
     Delete a tag.

     If you use `cvs tag -d symbolic_tag', the symbolic tag you specify
     is deleted instead of being added.  Warning: Be very certain of
     your ground before you delete a tag; doing this permanently
     discards some historical information, which may later turn out to
     be valuable.

update--Bring work tree in sync with repository
===============================================

   * update [-AdflPpR] [-d] [-r tag|-D date] files...

   * Requires: repository, working directory.

   * Changes: working directory.

   After you've run checkout to create your private copy of source from
the common repository, other developers will continue changing the
central source.  From time to time, when it is convenient in your
development process, you can use the `update' command from within your
working directory to reconcile your work with any revisions applied to
the source repository since your last checkout or update.

update options
--------------

   These standard options are available with `update' (*note Common
options::., for a complete description of them):

`-D date'
     Use the most recent revision no later than DATE.  This option is
     sticky, and implies `-P'.  See *Note Sticky tags::, for more
     information on sticky tags/dates.

`-f'
     Only useful with the `-D DATE' or `-r TAG' flags.  If no matching
     revision is found, retrieve the most recent revision (instead of
     ignoring the file).

`-k KFLAG'
     Process RCS keywords according to KFLAG.  See co(1).  This option
     is sticky; future updates of this file in this working directory
     will use the same KFLAG.  The `status' command can be viewed to
     see the sticky options.  *Note status::.

`-l'
     Local; run only in current working directory.  *Note Recursive
     behavior::.

`-P'
     Prune empty directories.

`-p'
     Pipe files to the standard output.

`-R'
     Operate recursively.  This is on by default.  *Note Recursive
     behavior::.

`-r tag'
     Retrieve revision TAG.  This option is sticky, and implies `-P'.
     See *Note Sticky tags::, for more information on sticky tags/dates.

   These special options are also available with `update'.

`-A'
     Reset any sticky tags, dates, or `-k' options.  See *Note Sticky
     tags::, for more information on sticky tags/dates.

`-d'
     Create any directories that exist in the repository if they're
     missing from the working directory.  Normally, `update' acts only
     on directories and files that were already enrolled in your
     working directory.

     This is useful for updating directories that were created in the
     repository since the initial checkout; but it has an unfortunate
     side effect.  If you deliberately avoided certain directories in
     the repository when you created your working directory (either
     through use of a module name or by listing explicitly the files
     and directories you wanted on the command line), then updating
     with `-d' will create those directories, which may not be what you
     want.

`-I NAME'
     Ignore files whose names match NAME (in your working directory)
     during the update.  You can specify `-I' more than once on the
     command line to specify several files to ignore.  Use `-I !' to
     avoid ignoring any files at all.  *Note cvsignore::, for other
     ways to make CVS ignore some files.

`-WSPEC'
     Specify file names that should be filtered during update.  You can
     use this option repeatedly.

     SPEC can be a file name pattern of the same type that you can
     specify in the `.cvswrappers' file. *Note Wrappers::.

`-jREVISION'
     With two `-j' options, merge changes from the revision specified
     with the first `-j' option to the revision specified with the
     second `j' option, into the working directory.

     With one `-j' option, merge changes from the ancestor revision to
     the revision specified with the `-j' option, into the working
     directory.  The ancestor revision is the common ancestor of the
     revision which the working directory is based on, and the revision
     specified in the `-j' option.

     In addition, each -j option can contain an optional date
     specification which, when used with branches, can limit the chosen
     revision to one within a specific date.  An optional date is
     specified by adding a colon (:) to the tag:
     `-jSYMBOLIC_TAG:DATE_SPECIFIER'.

     *Note Merging::.

update output
-------------

   `update' and `checkout' keep you informed of its progress by
printing a line for each file, preceded by one character indicating the
status of the file:

`U FILE'
     The file was brought up to date with respect to the repository.
     This is done for any file that exists in the repository but not in
     your source, and for files that you haven't changed but are not
     the most recent versions available in the repository.

`A FILE'
     The file has been added to your private copy of the sources, and
     will be added to the source repository when you run `commit' on
     the file.  This is a reminder to you that the file needs to be
     committed.

`R FILE'
     The file has been removed from your private copy of the sources,
     and will be removed from the source repository when you run
     `commit' on the file.  This is a reminder to you that the file
     needs to be committed.

`M FILE'
     The file is modified in  your  working  directory.

     `M' can indicate one of two states for a file you're working on:
     either there were no modifications to the same file in the
     repository, so that your file remains as you last saw it; or there
     were modifications in the repository as well as in your copy, but
     they were merged successfully, without conflict, in your working
     directory.

     CVS will print some messages if it merges your work, and a backup
     copy of your working file (as it looked before you ran `update')
     will be made.  The exact name of that file is printed while
     `update' runs.

`C FILE'
     A conflict was detected while trying to merge your changes to FILE
     with changes from the source repository.  FILE (the copy in your
     working directory) is now the output of the rcsmerge(1) command on
     the two revisions; an unmodified copy of your file is also in your
     working directory, with the name `.#FILE.REVISION' where REVISION
     is the RCS revision that your modified file started from.  Resolve
     the conflict as described in *Note Conflicts example:: (Note that
     some systems automatically purge files that begin with `.#' if
     they have not been accessed for a few days.  If you intend to keep
     a copy of your original file, it is a very good idea to rename
     it.)  Under VMS, the file name starts with `__' rather than `.#'.

`? FILE'
     FILE is in your working directory, but does not correspond to
     anything in the source repository, and is not in the list of files
     for CVS to ignore (see the description of the `-I' option, and
     *note cvsignore::.).

     Note that no warning message like this is printed for spurious
     directories that CVS encounters.  The directory, and all its
     contents, are silently ignored.

update examples
---------------

   The following line will display all files which are not up-to-date
without actually change anything in your working directory.  It can be
used to check what has been going on with the project.

     $ cvs -n -q update

Reference manual for the Administrative files
*********************************************

   Inside the repository, in the directory `$CVSROOT/CVSROOT', there
are a number of supportive files for CVS.  You can use CVS in a limited
fashion without any of them, but if they are set up properly they can
help make life easier.  For a discussion of how to edit them, *Note
Intro administrative files::.

   The most important of these files is the `modules' file, which
defines the modules inside the repository.

The modules file
================

   The `modules' file records your definitions of names for collections
of source code.  CVS will use these definitions if you use CVS to
update the modules file (use normal commands like `add', `commit', etc).

   The `modules' file may contain blank lines and comments (lines
beginning with `#') as well as module definitions.  Long lines can be
continued on the next line by specifying a backslash (`\') as the last
character on the line.

   A module definition is a single line of the `modules' file, in
either of two formats.  In both cases, MNAME represents the symbolic
module name, and the remainder of the line is its definition.

`MNAME -a ALIASES...'
     This represents the simplest way of defining a module MNAME.  The
     `-a' flags the definition as a simple alias: CVS will treat any
     use of MNAME (as a command argument) as if the list of names
     ALIASES had been specified instead.  ALIASES may contain either
     other module names or paths.  When you use paths in aliases,
     `checkout' creates all intermediate directories in the working
     directory, just as if the path had been specified explicitly in
     the CVS arguments.

`MNAME [ options ] DIR [ FILES... ] [ &MODULE... ]'
     In the simplest case, this form of module definition reduces to
     `MNAME DIR'.  This defines all the files in directory DIR as
     module mname.  DIR is a relative path (from `$CVSROOT') to a
     directory of source in the source repository.  In this case, on
     checkout, a single directory called MNAME is created as a working
     directory; no intermediate directory levels are used by default,
     even if DIR was a path involving several directory levels.

     By explicitly specifying files in the module definition after DIR,
     you can select particular files from directory DIR.  The sample
     definition for `modules' is an example of a module defined with a
     single file from a particular directory.  Here is another example:

          m4test  unsupported/gnu/m4 foreach.m4 forloop.m4

     With this definition, executing `cvs checkout m4test' will create
     a single working directory `m4test' containing the two files
     listed, which both come from a common directory several levels deep
     in the CVS source repository.

     A module definition can refer to other modules by including
     `&MODULE' in its definition.  `checkout' creates a subdirectory
     for each such module, in your working directory.

    `-d NAME'
          Name the working directory something other than the module
          name.

    `-e PROG'
          Specify a program PROG to run whenever files in a module are
          exported.  PROG runs with a single argument, the module name.

    `-i PROG'
          Specify a program PROG to run whenever files in a module are
          committed.  PROG runs with a single argument, the full
          pathname of the affected directory in a source repository.
          The `commitinfo', `loginfo', and `editinfo' files provide
          other ways to call a program on commit.

    `-o PROG'
          Specify a program PROG to run whenever files in a module are
          checked out.  PROG runs with a single argument, the module
          name.

    `-s STATUS'
          Assign a status to the module.  When the module file is
          printed with `cvs checkout -s' the modules are sorted
          according to primarily module status, and secondarily
          according to the module name.  This option has no other
          meaning.  You can use this option for several things besides
          status: for instance, list the person that is responsible for
          this module.

    `-t PROG'
          Specify a program PROG to run whenever files in a module are
          tagged with `rtag'.  PROG runs with two arguments: the module
          name and the symbolic tag specified to `rtag'.  There is no
          way to specify a program to run when `tag' is executed.

    `-u PROG'
          Specify a program PROG to run whenever `cvs update' is
          executed from the top-level directory of the checked-out
          module.  PROG runs with a single argument, the full path to
          the source repository for this module.

The cvswrappers file
====================

   Wrappers allow you to set a hook which transforms files on their way
in and out of CVS.  Most or all of the wrappers features do not work
with client/server CVS.

   The file `cvswrappers' defines the script that will be run on a file
when its name matches a regular expresion. There are two scripts that
can be run on a file or directory. One script is executed on the
file/directory before being checked into the repository (this is denoted
with the `-t' flag) and the other when the file is checked out of the
repository (this is denoted with the `-f' flag)

   The `cvswrappers' also has a `-m' option to specify the merge
methodology that should be used when the file is updated.  `MERGE'
means the usual CVS behavior: try to merge the files (this generally
will not work for binary files).  `COPY' means that `cvs update' will
merely copy one version over the other, and require the user using
mechanisms outside CVS, to insert any necessary changes.  The `-m'
wrapper option only affects behavior when merging is done on update; it
does not affect how files are stored.  See *Note Binary files::, for
more on binary files.

   The basic format of the file `cvswrappers' is:

     wildcard     [option value][option value]...
     
     where option is one of
     -f           from cvs filter         value: path to filter
     -t           to cvs filter           value: path to filter
     -m           update methodology      value: MERGE or COPY
     -k           keyword expansion       value: expansion mode
     
     and value is a single-quote delimited value.

     *.nib    -f 'unwrap %s' -t 'wrap %s %s' -m 'COPY'
     *.c      -t 'indent %s %s'

The above example of a `cvswrappers' file states that all
files/directories that end with a `.nib' should be filtered with the
`wrap' program before checking the file into the repository. The file
should be filtered though the `unwrap' program when the file is checked
out of the repository. The `cvswrappers' file also states that a `COPY'
methodology should be used when updating the files in the repository
(that is no merging should be performed).

   The last example line says that all files that end with a `*.c'
should be filtered with `indent' before being checked into the
repository. Unlike the previous example no filtering of the `*.c' file
is done when it is checked out of the repository.

The `-t' filter is called with two arguments, the first is the name of
the file/directory to filter and the second is the pathname to where
the resulting filtered file should be placed.

The `-f' filter is called with one argument, which is the name of the
file to filter from. The end result of this filter will be a file in
the users directory that they can work on as they normally would.

   For another example, the following command imports a directory,
treating files whose name ends in `.exe' as binary:

     cvs import -I ! -W "*.exe -k 'b'" first-dir vendortag reltag

The commit support files
========================

   The `-i' flag in the `modules' file can be used to run a certain
program whenever files are committed (*note modules::.).  The files
described in this section provide other, more flexible, ways to run
programs whenever something is committed.

   There are three kind of programs that can be run on commit.  They
are specified in files in the repository, as described below.  The
following table summarizes the file names and the purpose of the
corresponding programs.

`commitinfo'
     The program is responsible for checking that the commit is
     allowed.  If it exits with a non-zero exit status the commit will
     be aborted.

`editinfo'
     The specified program is used to edit the log message, and
     possibly verify that it contains all required fields.  This is
     most useful in combination with the `rcsinfo' file, which can hold
     a log message template (*note rcsinfo::.).

`loginfo'
     The specified program is called when the commit is complete.  It
     receives the log message and some additional information and can
     store the log message in a file, or mail it to appropriate
     persons, or maybe post it to a local newsgroup, or...  Your
     imagination is the limit!

The common syntax
-----------------

   The four files `commitinfo', `loginfo', `rcsinfo' and `editinfo' all
have a common format.  The purpose of the files are described later on.
The common syntax is described here.

   Each line contains the following:
   * A regular expression

   * A whitespace separator--one or more spaces and/or tabs.

   * A file name or command-line template.

Blank lines are ignored.  Lines that start with the character `#' are
treated as comments.  Long lines unfortunately can *not* be broken in
two parts in any way.

   The first regular expression that matches the current directory name
in the repository is used.  The rest of the line is used as a file name
or command-line as appropriate.

Commitinfo
==========

   The `commitinfo' file defines programs to execute whenever `cvs
commit' is about to execute.  These programs are used for pre-commit
checking to verify that the modified, added and removed files are really
ready to be committed.  This could be used, for instance, to verify
that the changed files conform to to your site's standards for coding
practice.

   As mentioned earlier, each line in the `commitinfo' file consists of
a regular expression and a command-line template.  The template can
include a program name and any number of arguments you wish to supply
to it.  The full path to the current source repository is appended to
the template, followed by the file names of any files involved in the
commit (added, removed, and modified files).

   The first line with a regular expression matching the relative path
to the module will be used.  If the command returns a non-zero exit
status the commit will be aborted.

   If the repository name does not match any of the regular expressions
in this file, the `DEFAULT' line is used, if it is specified.

   All occurances of the name `ALL' appearing as a regular expression
are used in addition to the first matching regular expression or the
name `DEFAULT'.

   Note: when CVS is accessing a remote repository, `commitinfo' will
be run on the *remote* (i.e., server) side, not the client side (*note
Remote repositories::.).

Editinfo
========

   If you want to make sure that all log messages look the same way,
you can use the `editinfo' file to specify a program that is used to
edit the log message.  This program could be a custom-made editor that
always enforces a certain style of the log message, or maybe a simple
shell script that calls an editor, and checks that the entered message
contains the required fields.

   If no matching line is found in the `editinfo' file, the editor
specified in the environment variable `$CVSEDITOR' is used instead.  If
that variable is not set, then the environment variable `$EDITOR' is
used instead.  If that variable is not set a precompiled default,
normally `vi', will be used.

   The `editinfo' file is often most useful together with the `rcsinfo'
file, which can be used to specify a log message template.

   Each line in the `editinfo' file consists of a regular expression
and a command-line template.  The template must include a program name,
and can include any number of arguments.  The full path to the current
log message template file is appended to the template.

   One thing that should be noted is that the `ALL' keyword is not
supported.  If more than one matching line is found, the first one is
used.  This can be useful for specifying a default edit script in a
module, and then overriding it in a subdirectory.

   If the repository name does not match any of the regular expressions
in this file, the `DEFAULT' line is used, if it is specified.

   If the edit script exits with a non-zero exit status, the commit is
aborted.

   Note: when CVS is accessing a remote repository, or when the `-m' or
`-F' options to `cvs commit' are used, `editinfo' will not be consulted.
There is no good workaround for this.

Editinfo example
----------------

   The following is a little silly example of a `editinfo' file,
together with the corresponding `rcsinfo' file, the log message
template and an editor script.  We begin with the log message template.
We want to always record a bug-id number on the first line of the log
message.  The rest of log message is free text.  The following template
is found in the file `/usr/cvssupport/tc.template'.

     BugId:

   The script `/usr/cvssupport/bugid.edit' is used to edit the log
message.

     #!/bin/sh
     #
     #       bugid.edit filename
     #
     #  Call $EDITOR on FILENAME, and verify that the
     #  resulting file contains a valid bugid on the first
     #  line.
     if [ "x$EDITOR" = "x" ]; then EDITOR=vi; fi
     if [ "x$CVSEDITOR" = "x" ]; then CVSEDITOR=$EDITOR; fi
     $CVSEDITOR $1
     until head -1|grep '^BugId:[ ]*[0-9][0-9]*$' < $1
     do  echo -n  "No BugId found.  Edit again? ([y]/n)"
         read ans
         case ${ans} in
             n*) exit 1;;
         esac
         $CVSEDITOR $1
     done

   The `editinfo' file contains this line:

     ^tc     /usr/cvssupport/bugid.edit

   The `rcsinfo' file contains this line:

     ^tc     /usr/cvssupport/tc.template

Loginfo
=======

   The `loginfo' file is used to control where `cvs commit' log
information is sent.  The first entry on a line is a regular expression
which is tested against the directory that the change is being made to,
relative to the `$CVSROOT'.  If a match is found, then the remainder of
the line is a filter program that should expect log information on its
standard input.

   The filter program may use one and only one % modifier (a la
printf).  If `%s' is specified in the filter program, a brief title is
included (enclosed in single quotes) showing the modified file names.

   If the repository name does not match any of the regular expressions
in this file, the `DEFAULT' line is used, if it is specified.

   All occurances of the name `ALL' appearing as a regular expression
are used in addition to the first matching regular expression or
`DEFAULT'.

   The first matching regular expression is used.

   *Note commit files::, for a description of the syntax of the
`loginfo' file.

   Note: when CVS is accessing a remote repository, `loginfo' will be
run on the *remote* (i.e., server) side, not the client side (*note
Remote repositories::.).

Loginfo example
---------------

   The following `loginfo' file, together with the tiny shell-script
below, appends all log messages to the file
`$CVSROOT/CVSROOT/commitlog', and any commits to the administrative
files (inside the `CVSROOT' directory) are also logged in
`/usr/adm/cvsroot-log'.

     ALL             /usr/local/bin/cvs-log $CVSROOT/CVSROOT/commitlog
     ^CVSROOT        /usr/local/bin/cvs-log /usr/adm/cvsroot-log

   The shell-script `/usr/local/bin/cvs-log' looks like this:

     #!/bin/sh
     (echo "-----------------------------------------------------------------";
      echo -n $USER"  ";
      date;
      echo;
      sed '1s+'${CVSROOT}'++') >> $1

Keeping a checked out copy
--------------------------

   It is often useful to maintain a directory tree which contains files
which correspond to the latest version in the repository.  For example,
other developers might want to refer to the latest sources without
having to check them out, or you might be maintaining a web site with
CVS and want every checkin to cause the files used by the web server to
be updated.

   The way to do this is by having loginfo invoke `cvs update'.  Doing
so in the naive way will cause a problem with locks, so the `cvs update'
must be run in the background.  Here is an example (this should all be
on one line):

     ^cyclic-pages		(date; cat; (sleep 2; cd /u/www/local-docs;
      cvs -q update -d) &) >> $CVSROOT/CVSROOT/updatelog 2>&1

   This will cause checkins to repository directories starting with
`cyclic-pages' to update the checked out tree in `/u/www/local-docs'.

Rcsinfo
=======

   The `rcsinfo' file can be used to specify a form to edit when
filling out the commit log.  The `rcsinfo' file has a syntax similar to
the `editinfo', `commitinfo' and `loginfo' files.  *Note syntax::.
Unlike the other files the second part is *not* a command-line
template.  Instead, the part after the regular expression should be a
full pathname to a file containing the log message template.

   If the repository name does not match any of the regular expressions
in this file, the `DEFAULT' line is used, if it is specified.

   All occurances of the name `ALL' appearing as a regular expression
are used in addition to the first matching regular expression or
`DEFAULT'.

   The log message template will be used as a default log message.  If
you specify a log message with `cvs commit -m MESSAGE' or `cvs commit -f
FILE' that log message will override the template.

   *Note editinfo example::, for an example `rcsinfo' file.

   When CVS is accessing a remote repository, the contents of `rcsinfo'
at the time a directory is first checked out will specify a template
which does not then change.  If you edit `rcsinfo' or its templates,
you may need to check out a new working directory.

Ignoring files via cvsignore
============================

   There are certain file names that frequently occur inside your
working copy, but that you don't want to put under CVS control.
Examples are all the object files that you get while you compile your
sources.  Normally, when you run `cvs update', it prints a line for
each file it encounters that it doesn't know about (*note update
output::.).

   CVS has a list of files (or sh(1) file name patterns) that it should
ignore while running `update', `import' and `release'.  This list is
constructed in the following way.

   * The list is initialized to include certain file name patterns:
     names associated with CVS administration, or with other common
     source control systems; common names for patch files, object files,
     archive files, and editor backup files; and other names that are
     usually artifacts of assorted utilities.  Currently, the default
     list of ignored file name patterns is:

              RCS     SCCS    CVS     CVS.adm
              RCSLOG  cvslog.*
              tags    TAGS
              .make.state     .nse_depinfo
              *~      #*      .#*     ,*      _$*     *$
              *.old   *.bak   *.BAK   *.orig  *.rej   .del-*
              *.a     *.olb   *.o     *.obj   *.so    *.exe
              *.Z     *.elc   *.ln
              core

   * The per-repository list in `$CVSROOT/CVSROOT/cvsignore' is
     appended to the list, if that file exists.

   * The per-user list in `.cvsignore' in your home directory is
     appended to the list, if it exists.

   * Any entries in the environment variable `$CVSIGNORE' is appended
     to the list.

   * Any `-I' options given to CVS is appended.

   * As CVS traverses through your directories, the contents of any
     `.cvsignore' will be appended to the list.  The patterns found in
     `.cvsignore' are only valid for the directory that contains them,
     not for any sub-directories.

   In any of the 5 places listed above, a single exclamation mark (`!')
clears the ignore list.  This can be used if you want to store any file
which normally is ignored by CVS.

The history file
================

   The file `$CVSROOT/CVSROOT/history' is used to log information for
the `history' command (*note history::.).  This file must be created to
turn on logging.  This is done automatically if the `cvs init' command
is used to set up the repository (*note Creating a repository::.).

   The file format of the `history' file is documented only in comments
in the CVS source code, but generally programs should use the `cvs
history' command to access it anyway, in case the format changes with
future releases of CVS.

Expansions in administrative files
==================================

   Sometimes in writing an administrative file, you might want the file
to be able to know various things based on environment CVS is running
in.  There are several mechanisms to do that.

   To find the home directory of the user running CVS (from the `HOME'
environment variable), use `~' followed by `/' or the end of the line.
Likewise for the home directory of USER, use `~USER'.  These variables
are expanded on the server machine, and don't get any resonable
expansion if pserver (*note Password authenticated::.)  is in used;
therefore user variables (see below) may be a better choice to
customize behavior based on the user running CVS.

   One may want to know about various pieces of information internal to
CVS.  A CVS internal variable has the syntax `${VARIABLE}', where
VARIABLE starts with a letter and consists of alphanumberic characters
and `_'.  If the character following VARIABLE is a non-alphanumeric
character other than `_', the `{' and `}' can be omitted.  The CVS
internal variables are:

`CVSROOT'
     This is the value of the CVS root in use.  *Note Repository::, for
     a description of the various ways to specify this.

`RCSBIN'
     This is the value CVS is using for where to find RCS binaries.
     *Note Global options::, for a description of how to specify this.

`CVSEDITOR'
`VISUAL'
`EDITOR'
     These all expand to the same value, which is the editor that CVS
     is using.  *Note Global options::, for how to specify this.

`USER'
     Username of the user running CVS (on the CVS server machine).

   If you want to pass a value to the administrative files which the
user that is running CVS can specify, use a user variable.  To expand a
user variable, the administrative file contains `${=VARIABLE}'.  To set
a user variable, specify the global option `-s' to CVS, with argument
`VARIABLE=VALUE'.  It may be particularly useful to specify this option
via `.cvsrc' (*note ~/.cvsrc::.).

   For example, if you want the administrative file to refer to a test
directory you might create a user variable `TESTDIR'.  Then if CVS is
invoked as `cvs -s TESTDIR=/work/local/tests', and the administrative
file contains `sh ${=TESTDIR}/runtests', then that string is expanded
to `sh /work/local/tests/runtests'.

   All other strings containing `$' are reserved; there is no way to
quote a `$' character so that `$' represents itself.

All environment variables which affect CVS
******************************************

   This is a complete list of all environment variables that affect CVS.

`$CVSIGNORE'
     A whitespace-separated list of file name patterns that CVS should
     ignore. *Note cvsignore::.

`$CVSWRAPPERS'
     A whitespace-separated list of file name patterns that CVS should
     treat as wrappers. *Note Wrappers::.

`$CVSREAD'
     If this is set, `checkout' and `update' will try hard to make the
     files in your working directory read-only.  When this is not set,
     the default behavior is to permit modification of your working
     files.

`$CVSROOT'
     Should contain the full pathname to the root of the CVS source
     repository (where the RCS history files are kept).  This
     information must be available to CVS for most commands to execute;
     if `$CVSROOT' is not set, or if you wish to override it for one
     invocation, you can supply it on the command line: `cvs -d cvsroot
     cvs_command...' Once you have checked out a working directory, CVS
     stores the appropriate root (in the file `CVS/Root'), so normally
     you only need to worry about this when initially checking out a
     working directory.

`$EDITOR'
`$CVSEDITOR'
     Specifies the program to use for recording log messages during
     commit.  If not set, the default is `/usr/ucb/vi'.  `$CVSEDITOR'
     overrides `$EDITOR'.  `$CVSEDITOR' does not exist in CVS 1.3, but
     the next release will probably include it.

`$PATH'
     If `$RCSBIN' is not set, and no path is compiled into CVS, it will
     use `$PATH' to try to find all programs it uses.

`$RCSBIN'
     This is the value CVS is using for where to find RCS binaries.
     *Note Global options::, for a description of how to specify this.
     If not set, a compiled-in value is used, or your `$PATH' is
     searched.

`$HOME'

`$HOMEPATH'
     Used to locate the directory where the `.cvsrc' file is searched
     (`$HOMEPATH' is used for Windows-NT).  *note ~/.cvsrc::.

`$CVS_RSH'
     Specifies the external program which CVS connects with, when
     `:ext:' access method is specified.  *note Connecting via rsh::..

`$CVS_SERVER'
     Used in client-server mode when accessing a remote repository
     using RSH.  It specifies the name of the program to start on the
     server side when accessing a remote repository using RSH.  The
     default value is `cvs'.  *note Connecting via rsh::.

`$CVS_PASSFILE'
     Used in client-server mode when accessing the `cvs login server'.
     Default value is `$HOME/.cvspass'.  *note Password authentication
     client::.

`$CVS_PASSWORD'
     Used in client-server mode when accessing the `cvs login server'.
     *note Password authentication client::.

`$CVS_CLIENT_PORT'
     Used in client-server mode when accessing the server via Kerberos.
     *note Kerberos authenticated::.

`$CVS_RCMD_PORT'
     Used in client-server mode.  If set, specifies the port number to
     be used when accessing the RCMD demon on the server side.
     (Currently not used for Unix clients).

`$CVS_CLIENT_LOG'
     Used for debugging only in client-server mode.  If set, everything
     send to the server is logged into ``$CVS_CLIENT_LOG'.in' and
     everything send from the server is logged into
     ``$CVS_CLIENT_LOG'.out'.

`$CVS_SERVER_SLEEP'
     Used only for debugging the server side in client-server mode.  If
     set, delays the start of the server child process the the
     specified amount of seconds so that you can attach to it with a
     debugger.

`$CVS_IGNORE_REMOTE_ROOT'
     (What is the purpose of this variable?)

`$COMSPEC'
     Used under OS/2 only.  It specifies the name of the command
     interpreter and defaults to CMD.EXE.

`$TMPDIR'
`$TMP'
`$TEMP'
     Directory in which temporary files are located.  Those parts of
     CVS which are implemented using RCS inspect the above variables in
     the order they appear above and the first value found is taken; if
     none of them are set, a host-dependent default is used, typically
     `/tmp'.  The CVS server uses `TMPDIR'.  *Note Global options::,
     for a description of how to specify this.  Some parts of CVS will
     always use `/tmp' (via the `tmpnam' function provided by the
     system).

     On Windows NT, `TMP' is used (via the `_tempnam' function provided
     by the system).

     The `patch' program which is used by the CVS client uses `TMPDIR',
     and if it is not set, uses `/tmp' (at least with GNU patch 2.1).

   CVS invokes RCS to perform certain operations.  The following
environment variables affect RCS.  Note that if you are using the
client/server CVS, these variables need to be set on the server side
(which may or not may be possible depending on how you are connecting).
There is probably not any need to set any of them, however.

`$LOGNAME'
`$USER'
     If set, they affect who RCS thinks you are.  If you have trouble
     checking in files it might be because your login name differs from
     the setting of e.g.  `$LOGNAME'.

`$RCSINIT'
     Options prepended to the argument list, separated by spaces.  A
     backslash escapes spaces within an option.  The `$RCSINIT' options
     are prepended to the argument lists of most RCS commands.

Troubleshooting
***************

Magic branch numbers
====================

   Externally, branch numbers consist of an odd number of dot-separated
decimal integers.  *Note Revision numbers::.  That is not the whole
truth, however.  For efficiency reasons CVS sometimes inserts an extra 0
in the second rightmost position (1.2.3 becomes 1.2.0.3, 8.9.10.11.12
becomes 8.9.10.11.0.12 and so on).

   CVS does a pretty good job at hiding these so called magic branches,
but in a few places the hiding is incomplete:

   * The magic branch number appears in the output from `cvs log'.

   * You cannot specify a symbolic branch name to `cvs admin'.

   You can use the `admin' command to reassign a symbolic name to a
branch the way RCS expects it to be.  If `R4patches' is assigned to the
branch 1.4.2 (magic branch number 1.4.0.2) in file `numbers.c' you can
do this:

     $ cvs admin -NR4patches:1.4.2 numbers.c

   It only works if at least one revision is already committed on the
branch.  Be very careful so that you do not assign the tag to the wrong
number.  (There is no way to see how the tag was assigned yesterday).

GNU GENERAL PUBLIC LICENSE
**************************

Index
*****

* Menu:

* -j (merging branches):                 Merging a branch.
* -k (RCS kflags):                       Substitution modes.
* .# files:                              update output.
* .bashrc, setting CVSROOT in:           Specifying a repository.
* .cshrc, setting CVSROOT in:            Specifying a repository.
* .cvsrc file:                           ~/.cvsrc.
* .profile, setting CVSROOT in:          Specifying a repository.
* .tcshrc, setting CVSROOT in:           Specifying a repository.
* /usr/local/cvsroot, as example repository: Repository.
* :ext::                                 Connecting via rsh.
* :kserver::                             Kerberos authenticated.
* :local::                               Repository.
* :pserver::                             Password authentication client.
* :server::                              Connecting via rsh.
* <<<<<<<:                               Conflicts example.
* =======:                               Conflicts example.
* >>>>>>>:                               Conflicts example.
* __ files (VMS):                        update output.
* A sample session:                      A sample session.
* abandoning work:                       Editing files.
* About this manual:                     Preface.
* add (subcommand):                      Adding files.
* Adding a tag:                          Tags.
* Adding files:                          Adding files.
* Admin (subcommand):                    admin.
* Administrative files (intro):          Intro administrative files.
* Administrative files (reference):      Administrative files.
* Administrative files, editing them:    Intro administrative files.
* ALL in commitinfo:                     commitinfo.
* annotate (subcommand):                 annotate.
* Atomic transactions, lack of:          Concurrency.
* authenticated client, using:           Password authentication client.
* authenticating server, setting up:     Password authentication server.
* Author keyword:                        Keyword list.
* Automatically ignored files:           cvsignore.
* Avoiding editor invocation:            Common options.
* Binary files:                          Binary files.
* Branch merge example:                  Merging a branch.
* Branch number:                         Revision numbers.
* Branch numbers:                        Creating a branch.
* Branch, creating a:                    Creating a branch.
* Branch, vendor-:                       Tracking sources.
* Branches:                              Branches.
* Branches motivation:                   Branches motivation.
* Branches, copying changes between:     Merging.
* Branches, sticky:                      Sticky tags.
* Bringing a file up to date:            Updating a file.
* Bugs, known in this manual:            BUGS.
* Bugs, reporting (manual):              BUGS.
* Changes, copying between branches:     Merging.
* Changing a log message:                admin options.
* checked out copy, keeping:             Keeping a checked out copy.
* Checkin program:                       modules.
* Checking commits:                      commitinfo.
* Checking out source:                   Getting the source.
* Checkout (subcommand):                 checkout.
* Checkout program:                      modules.
* checkout, as term for getting ready to edit: Editing files.
* Checkout, example:                     Getting the source.
* choosing, reserved or unreserved checkouts: Choosing a model.
* Cleaning up:                           Cleaning up.
* Client/Server Operation:               Remote repositories.
* Co (subcommand):                       checkout.
* Command reference:                     Invoking CVS.
* Command structure:                     Structure.
* Comment leader:                        admin examples.
* Commit (subcommand):                   commit.
* Commit files:                          commit files.
* Commit, when to:                       When to commit.
* Commitinfo:                            commitinfo.
* Committing changes:                    Committing your changes.
* Common options:                        Common options.
* Common syntax of info files:           syntax.
* COMSPEC:                               Environment variables.
* Conflict markers:                      Conflicts example.
* Conflict resolution:                   Conflicts example.
* Conflicts (merge example):             Conflicts example.
* Contributors (CVS program):            What is CVS?.
* Contributors (manual):                 Credits.
* Copying changes:                       Merging.
* Correcting a log message:              admin options.
* Creating a branch:                     Creating a branch.
* Creating a project:                    Starting a new project.
* Creating a repository:                 Creating a repository.
* Credits (CVS program):                 What is CVS?.
* Credits (manual):                      Credits.
* CVS 1.6, and watches:                  Watches Compatibility.
* CVS command structure:                 Structure.
* CVS passwd file:                       Password authentication server.
* CVS, history of:                       What is CVS?.
* CVS, introduction to:                  What is CVS?.
* CVS_CLIENT_LOG:                        Environment variables.
* CVS_CLIENT_PORT:                       Kerberos authenticated.
* CVS_IGNORE_REMOTE_ROOT:                Environment variables.
* CVS_PASSFILE, environment variable:    Password authentication client.
* CVS_PASSWORD, environment variable:    Password authentication client.
* CVS_RCMD_PORT:                         Environment variables.
* CVS_RSH:                               Environment variables.
* CVS_SERVER:                            Connecting via rsh.
* CVS_SERVER_SLEEP:                      Environment variables.
* CVSEDITOR:                             Environment variables.
* CVSEDITOR, environment variable:       Committing your changes.
* CVSIGNORE:                             Environment variables.
* cvsignore (admin file), global:        cvsignore.
* CVSREAD:                               Environment variables.
* CVSREAD, overriding:                   Global options.
* CVSROOT:                               Environment variables.
* cvsroot:                               Repository.
* CVSROOT (file):                        Administrative files.
* CVSROOT, environment variable:         Specifying a repository.
* CVSROOT, module name:                  Intro administrative files.
* CVSROOT, multiple repositories:        Multiple repositories.
* CVSROOT, overriding:                   Global options.
* CVSUMASK:                              File permissions.
* CVSWRAPPERS:                           Environment variables.
* cvswrappers (admin file):              Wrappers.
* CVSWRAPPERS, environment variable:     Wrappers.
* Date keyword:                          Keyword list.
* Dates:                                 Common options.
* Decimal revision number:               Revision numbers.
* DEFAULT in commitinfo:                 commitinfo.
* DEFAULT in editinfo:                   editinfo.
* Defining a module:                     Defining the module.
* Defining modules (intro):              Intro administrative files.
* Defining modules (reference manual):   modules.
* Deleting files:                        Removing files.
* Deleting revisions:                    admin options.
* Deleting sticky tags:                  Sticky tags.
* Descending directories:                Recursive behavior.
* Diff:                                  Viewing differences.
* Diff (subcommand):                     diff.
* Differences, merging:                  Merging two revisions.
* Directories, moving:                   Moving directories.
* Directory, descending:                 Recursive behavior.
* Disjoint repositories:                 Multiple repositories.
* Distributing log messages:             loginfo.
* driver.c (merge example):              Conflicts example.
* edit (subcommand):                     Editing files.
* editinfo (admin file):                 editinfo.
* Editing administrative files:          Intro administrative files.
* Editing the modules file:              Defining the module.
* EDITOR:                                Environment variables.
* Editor, avoiding invocation of:        Common options.
* EDITOR, environment variable:          Committing your changes.
* EDITOR, overriding:                    Global options.
* Editor, specifying per module:         editinfo.
* editors (subcommand):                  Watch information.
* emerge:                                Conflicts example.
* Environment variables:                 Environment variables.
* Errors, reporting (manual):            BUGS.
* Example of a work-session:             A sample session.
* Example of merge:                      Conflicts example.
* Example, branch merge:                 Merging a branch.
* Export (subcommand):                   export.
* Export program:                        modules.
* Fetching source:                       Getting the source.
* File locking:                          Multiple developers.
* File permissions:                      File permissions.
* File status:                           File status.
* Files, moving:                         Moving files.
* Files, reference manual:               Administrative files.
* Fixing a log message:                  admin options.
* Forcing a tag match:                   Common options.
* Form for log message:                  rcsinfo.
* Format of CVS commands:                Structure.
* Getting started:                       A sample session.
* Getting the source:                    Getting the source.
* Global cvsignore:                      cvsignore.
* Global options:                        Global options.
* Group:                                 File permissions.
* Header keyword:                        Keyword list.
* History (subcommand):                  history.
* History browsing:                      History browsing.
* History file:                          history file.
* History files:                         Repository files.
* History of CVS:                        What is CVS?.
* HOME:                                  Environment variables.
* HOMEPATH:                              Environment variables.
* Id keyword:                            Keyword list.
* Ident (shell command):                 Using keywords.
* Identifying files:                     Keyword substitution.
* Ignored files:                         cvsignore.
* Ignoring files:                        cvsignore.
* Import (subcommand):                   import.
* Importing files:                       From files.
* Importing files, from other version control systesm: From other version control systems.
* Importing modules:                     First import.
* Index:                                 Index.
* Info files (syntax):                   syntax.
* Informing others:                      Informing others.
* init (subcommand):                     Creating a repository.
* Introduction to CVS:                   What is CVS?.
* Invoking CVS:                          Invoking CVS.
* Isolation:                             History browsing.
* Join:                                  Merging a branch.
* keeping a checked out copy:            Keeping a checked out copy.
* kerberos:                              Kerberos authenticated.
* Keyword expansion:                     Keyword substitution.
* Keyword substitution:                  Keyword substitution.
* Kflag:                                 Substitution modes.
* kinit:                                 Kerberos authenticated.
* Known bugs in this manual:             BUGS.
* Layout of repository:                  Repository.
* Left-hand options:                     Global options.
* Linear development:                    Revision numbers.
* List, mailing list:                    What is CVS?.
* Locally Added:                         File status.
* Locally Modified:                      File status.
* Locally Removed:                       File status.
* Locker keyword:                        Keyword list.
* Locking files:                         Multiple developers.
* locks, cvs:                            Concurrency.
* Log (subcommand):                      log.
* Log information, saving:               history file.
* Log keyword:                           Keyword list.
* Log keyword, selecting comment leader: admin examples.
* Log message entry:                     Committing your changes.
* Log message template:                  rcsinfo.
* Log message, correcting:               admin options.
* Log messages:                          loginfo.
* Log messages, editing:                 editinfo.
* Login (subcommand):                    Password authentication client.
* loginfo (admin file):                  loginfo.
* LOGNAME:                               Environment variables.
* Mail, automatic mail on commit:        Informing others.
* Mailing list:                          What is CVS?.
* Mailing log messages:                  loginfo.
* Main trunk (intro):                    Revision numbers.
* Main trunk and branches:               Branches.
* Many repositories:                     Multiple repositories.
* Markers, conflict:                     Conflicts example.
* Merge, an example:                     Conflicts example.
* Merge, branch example:                 Merging a branch.
* Merging:                               Merging.
* Merging a branch:                      Merging a branch.
* Merging a file:                        Updating a file.
* Merging two revisions:                 Merging two revisions.
* Modifications, copying between branches: Merging.
* Module status:                         modules.
* Module, defining:                      Defining the module.
* Modules (admin file):                  modules.
* Modules (intro):                       Basic concepts.
* Modules file:                          Intro administrative files.
* Modules file, changing:                Defining the module.
* Motivation for branches:               Branches motivation.
* Moving directories:                    Moving directories.
* Moving files:                          Moving files.
* Multiple developers:                   Multiple developers.
* Multiple repositories:                 Multiple repositories.
* Name keyword:                          Keyword list.
* Name, symbolic (tag):                  Tags.
* Needs Checkout:                        File status.
* Needs Merge:                           File status.
* Needs Patch:                           File status.
* Newsgroups:                            What is CVS?.
* notify (admin file):                   Getting Notified.
* Nroff (selecting comment leader):      admin examples.
* Number, branch:                        Revision numbers.
* Number, revision-:                     Revision numbers.
* option defaults:                       ~/.cvsrc.
* Options, global:                       Global options.
* Outdating revisions:                   admin options.
* Overlap:                               Updating a file.
* Overriding CVSREAD:                    Global options.
* Overriding CVSROOT:                    Global options.
* Overriding EDITOR:                     Global options.
* Overriding RCSBIN:                     Global options.
* Overriding TMPDIR:                     Global options.
* Parallel repositories:                 Multiple repositories.
* passwd (admin file):                   Password authentication server.
* password client, using:                Password authentication client.
* password server, setting up:           Password authentication server.
* PATH:                                  Environment variables.
* Per-module editor:                     editinfo.
* Policy:                                When to commit.
* Precommit checking:                    commitinfo.
* Preface:                               Preface.
* Pserver (subcommand):                  Password authentication server.
* RCS history files:                     Repository files.
* RCS keywords:                          Keyword list.
* RCS revision numbers:                  Tags.
* RCS, importing files from:             From other version control systems.
* RCS-style locking:                     Multiple developers.
* RCSBIN:                                Environment variables.
* RCSBIN, overriding:                    Global options.
* RCSfile keyword:                       Keyword list.
* rcsinfo (admin file):                  rcsinfo.
* RCSINIT:                               Environment variables.
* Rdiff (subcommand):                    rdiff.
* read-only files, and -r:               Global options.
* read-only files, and CVSREAD:          Environment variables.
* read-only files, and watches:          Setting a watch.
* read-only files, in repository:        File permissions.
* Read-only mode:                        Global options.
* Recursive (directory descending):      Recursive behavior.
* Reference manual (files):              Administrative files.
* Reference manual for variables:        Environment variables.
* Reference, commands:                   Invoking CVS.
* Release (subcommand):                  release.
* Releases, revisions and versions:      Versions revisions releases.
* Releasing your working copy:           Cleaning up.
* Remote repositories:                   Remote repositories.
* Remove (subcommand):                   Removing files.
* Removing a change:                     Merging two revisions.
* Removing files:                        Removing files.
* Removing your working copy:            Cleaning up.
* Renaming directories:                  Moving directories.
* Renaming files:                        Moving files.
* Replacing a log message:               admin options.
* Reporting bugs (manual):               BUGS.
* Repositories, multiple:                Multiple repositories.
* Repositories, remote:                  Remote repositories.
* Repository (intro):                    Repository.
* Repository, example:                   Repository.
* Repository, how data is stored:        Repository storage.
* Repository, setting up:                Creating a repository.
* reserved checkouts:                    Multiple developers.
* Resetting sticky tags:                 Sticky tags.
* Resolving a conflict:                  Conflicts example.
* Restoring old version of removed file: Sticky tags.
* Resurrecting old version of dead file: Sticky tags.
* Retrieving an old revision using tags: Tags.
* reverting to repository version:       Editing files.
* Revision keyword:                      Keyword list.
* Revision management:                   Revision management.
* Revision numbers:                      Revision numbers.
* Revision tree:                         Revision numbers.
* Revision tree, making branches:        Branches.
* Revisions, merging differences between: Merging two revisions.
* Revisions, versions and releases:      Versions revisions releases.
* Right-hand options:                    Common options.
* rsh:                                   Connecting via rsh.
* Rtag (subcommand):                     rtag.
* rtag, creating a branch using:         Creating a branch.
* Saving space:                          admin options.
* SCCS, importing files from:            From other version control systems.
* Security:                              File permissions.
* setgid:                                File permissions.
* Setting up a repository:               Creating a repository.
* setuid:                                File permissions.
* Signum Support:                        Preface.
* Source keyword:                        Keyword list.
* Source, getting CVS source:            What is CVS?.
* Source, getting from CVS:              Getting the source.
* Specifying dates:                      Common options.
* Spreading information:                 Informing others.
* Starting a project with CVS:           Starting a new project.
* State keyword:                         Keyword list.
* Status (subcommand):                   status.
* Status of a file:                      File status.
* Status of a module:                    modules.
* sticky date:                           Sticky tags.
* Sticky tags:                           Sticky tags.
* Sticky tags, resetting:                Sticky tags.
* Storing log messages:                  loginfo.
* Structure:                             Structure.
* Subdirectories:                        Recursive behavior.
* Support, getting CVS support:          Preface.
* Symbolic name (tag):                   Tags.
* Syntax of info files:                  syntax.
* Tag (subcommand):                      tag.
* Tag program:                           modules.
* tag, command, introduction:            Tags.
* tag, example:                          Tags.
* Tag, retrieving old revisions:         Tags.
* Tag, symbolic name:                    Tags.
* taginfo:                               user-defined logging.
* Tags:                                  Tags.
* Tags, sticky:                          Sticky tags.
* tc, Trivial Compiler (example):        A sample session.
* Team of developers:                    Multiple developers.
* TEMP:                                  Environment variables.
* Template for log message:              rcsinfo.
* temporary files, location of:          Environment variables.
* Third-party sources:                   Tracking sources.
* Time:                                  Common options.
* timezone, in input:                    Common options.
* timezone, in output:                   log.
* TMP:                                   Environment variables.
* TMPDIR:                                Environment variables.
* TMPDIR, overriding:                    Global options.
* Trace:                                 Global options.
* Traceability:                          History browsing.
* Tracking sources:                      Tracking sources.
* Transactions, atomic, lack of:         Concurrency.
* Trivial Compiler (example):            A sample session.
* Typical repository:                    Repository.
* umask, for repository files:           File permissions.
* Undoing a change:                      Merging two revisions.
* unedit (subcommand):                   Editing files.
* Unknown:                               File status.
* unreserved checkouts:                  Multiple developers.
* Unresolved Conflict:                   File status.
* Up-to-date:                            File status.
* Update (subcommand):                   update.
* Update program:                        modules.
* update, introduction:                  Updating a file.
* Updating a file:                       Updating a file.
* USER:                                  Environment variables.
* users (admin file):                    Getting Notified.
* Vendor:                                Tracking sources.
* Vendor branch:                         Tracking sources.
* Versions, revisions and releases:      Versions revisions releases.
* Viewing differences:                   Viewing differences.
* watch add (subcommand):                Getting Notified.
* watch off (subcommand):                Setting a watch.
* watch on (subcommand):                 Setting a watch.
* watch remove (subcommand):             Getting Notified.
* watchers (subcommand):                 Watch information.
* Watches:                               Watches.
* Wdiff (import example):                First import.
* What (shell command):                  Using keywords.
* What branches are good for:            Branches motivation.
* What is CVS?:                          What is CVS?.
* When to commit:                        When to commit.
* Work-session, example of:              A sample session.
* Working copy:                          Multiple developers.
* Working copy, removing:                Cleaning up.
* Wrappers:                              Wrappers.
* zone, time, in input:                  Common options.
* zone, time, in output:                 log.

