# Running Ant

## Command Line

If you've installed Ant as described in the Installing Ant section, running Ant from the command-line is simple: just type `ant`.

When no arguments are specified, Ant looks for a `build.xml` file in the current directory and, if found, uses that file as the build file and runs the target specified in the `default` attribute of the `<project>` tag. To make Ant use a build file other than `build.xml`, use the command-line option `-buildfile file`, where file is the name of the build file you want to use.

If you use the `-find [file]` option, Ant will search for a build file first in the current directory, then in the parent directory, and so on, until either a build file is found or the root of the filesystem has been reached. By default, it will look for a build file called `build.xml`. To have it search for a build file other than `build.xml`, specify a file argument. Note: If you include any other flags or arguments on the command line after the `-find` flag, you must include the file argument for the `-find` flag, even if the name of the build file you want to find is `build.xml`.

You can also set properties on the command line. This can be done with the `-Dproperty=value` option, where property is the name of the property, and value is the value for that property. If you specify a property that is also set in the build file (see the property task), the value specified on the command line will override the value specified in the build file. Defining properties on the command line can also be used to pass in the value of environment variables - just pass `-DMYVAR=%MYVAR%` (Windows) or `-DMYVAR=$MYVAR` (Unix) to Ant. You can then access these variables inside your build file as `${MYVAR}`. You can also access environment variables using the property task's `environment` attribute.

Options that affect the amount of logging output by Ant are: `-quiet`, which instructs Ant to print less information to the console; `-verbose`, which causes Ant to print additional information to the console; and `-debug`, which causes Ant to print considerably more additional information.

It is also possible to specify one or more targets that should be executed. When omitted, the target that is specified in the `default` attribute of the `project` tag is used.

The `-projecthelp` option prints out a list of the build file's targets. Targets that include a `description` attribute are listed as "Main targets", those without a `description` are listed as "Subtargets", then the "Default" target is listed.

### Command-line Options Summary

    ant [options] [target [target2 [target3] ...]]
    Options:
      -help                  print this message
      -projecthelp           print project help information
      -version               print the version information and exit
      -quiet                 be extra quiet
      -verbose               be extra verbose
      -debug                 print debugging information
      -emacs                 produce logging information without adornments
      -logfile <file>        write logging output to given file
      -logger <classname>    the class that is to perform logging
      -listener <classname>  add an instance of classname as a project listener
      -buildfile <file>      use given build file
      -D<property>=<value>   use value for given property
      -propertyfile <file>   load all properties from file (with -D taking precedence)
      -inputhandler <class>  the class that will handle input requests
      -find [<file>]         search for build.xml, or file, towards the root of the
                             filesystem

For more information about `-logger` and `-listener` see Loggers & Listeners.

For more information about `-inputhandler` see InputHandler.

### Examples

>     ant

runs Ant using the `build.xml` file in the current directory, on the default target.

>     ant -buildfile test.xml

runs Ant using the `test.xml` file in the current directory, on the default target.

>     ant -buildfile test.xml dist

runs Ant using the `test.xml` file in the current directory, on the target called `dist`.

>     ant -buildfile test.xml -Dbuild=build/classes dist

runs Ant using the `test.xml` file in the current directory, on the target called `dist`, setting the `build` property to the value `build/classes`.

### Files

The Ant wrapper script for Unix will source (read and evaluate) the file `~/.antrc` before it does anything. On Windows, the Ant wrapper batch-file invokes `%HOME%\antrc_pre.bat` at the start and `%HOME%\antrc_post.bat` at the end. You can use these files, for example, to set/unset environment variables that should only be visible during the execution of Ant. See the next section for examples.

### Environment Variables

The wrapper scripts use the following environment variables (if set):

- `JAVACMD` - full path of the Java executable. Use this to invoke a different JVM than `JAVA_HOME/bin/java(.exe)`.
- `ANT_OPTS` - command-line arguments that should be passed to the JVM. For example, you can define system properties or set the maximum Java heap size here.
- `ANT_ARGS` - Ant command-line arguments. For example, set `ANT_ARGS` to point to a different logger, include a listener, and to include the `-find` flag.
Note: If you include `-find` in `ANT_ARGS`, you should include the name of the build file to find, even if the file is called `build.xml`.

## Running Ant via Java

If you have installed Ant in the do-it-yourself way, Ant can be started with:

>     java -Dant.home=c:\ant org.apache.tools.ant.Main [options] [target]

These instructions actually do exactly the same as the `ant` command. The options and target are the same as when running Ant with the `ant` command. This example assumes you have set your classpath to include:

- `ant.jar`
- jars/classes for your XML parser
- the JDK's required jar/zip files

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