If you've installed Apache 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 (or a directory containing a build.xml file).

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 -D property = 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; -debug , which causes Ant to print considerably more additional information; and -silent which makes Ant print nothing but task output and build failures (useful to capture Ant output by scripts).

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 "Other targets", then the "Default" target is listed ("Other targets" are only displayed if there are no main targets, or if Ant is invoked in -verbose or -debug mode).

Command-line Options Summary

ant [options] [target [target2 [target3] ...]]
Options:
  -help, -h              print this message and exit
  -projecthelp, -p       print project help information and exit
  -version               print the version information and exit
  -diagnostics           print information that might be helpful to
                         diagnose or report problems and exit
  -quiet, -q             be extra quiet
  -silent, -S            print nothing but task outputs and build failures
  -verbose, -v           be extra verbose
  -debug, -d             print debugging information
  -emacs, -e             produce logging information without adornments
  -lib <path>            specifies a path to search for jars and classes
  -logfile <file>        use given file for log
    -l     <file>                ''
  -logger <classname>    the class which is to perform logging
  -listener <classname>  add an instance of class as a project listener
  -noinput               do not allow interactive input
  -buildfile <file>      use given buildfile
    -file    <file>              ''
    -f       <file>              ''
  -D<property>=<value>   use value for given property
  -keep-going, -k        execute all targets that do not depend
                         on failed target(s)
  -propertyfile <name>   load all properties from file with -D
                         properties taking precedence
  -inputhandler <class>  the class which will handle input requests
  -find <file>           (s)earch for buildfile towards the root of
    -s  <file>           the filesystem and use it
  -nice  number          A niceness value for the main thread:
                         1 (lowest) to 10 (highest); 5 is the default
  -nouserlib             Run ant without using the jar files from ${user.home}/.ant/lib
  -noclasspath           Run ant without using CLASSPATH
  -autoproxy             Java 5+ : use the OS proxies
  -main <class>          override Ant's normal entry point
For more information about -logger
and -listener see Loggers &
Listeners.
For more information about -inputhandler
see InputHandler.
Easiest way of changing the exit-behaviour is subclassing the
original main class:
public class CustomExitCode extends org.apache.tools.ant.Main {
    protected void exit(int exitCode) {
        // implement your own behaviour, e.g. NOT exiting the JVM
and starting Ant with access (-lib path-to-class)
to this class.
Library Directories
Prior to Ant 1.6, all jars in the ANT_HOME/lib would
be added to the CLASSPATH used to run Ant. This was done
in the scripts that started Ant. Since Ant 1.6, two
directories are scanned by default and more can be added as
required. The default directories scanned
are ANT_HOME/lib and a user specific
directory, ${user.home}/.ant/lib. This arrangement allows
the Ant installation to be shared by many users while still allowing
each user to deploy additional jars.  Such additional jars could be
support jars for Ant's optional tasks or jars containing third-party
tasks to be used in the build. It also allows the main Ant
installation to be locked down which will please system
administrators.
Additional directories to be searched may be added by using
the -lib option.  The -lib option specifies
a search path. Any jars or classes in the directories of the path will
be added to Ant's classloader. The order in which jars are added to
the classpath is as follows:
  
jars in the order specified by the -lib options on the command line
  
jars from ${user.home}/.ant/lib (unless -nouserlib is set)
  
jars from ANT_HOME/lib
Note that the CLASSPATH environment variable is passed
to Ant using a -lib option. Ant itself is started with a
very minimalistic classpath.  Ant should work perfectly well with an
empty CLASSPATH environment variable, something the
the -noclasspath option actually enforces. We get many more
support calls related to classpath problems (especially quoting
problems) than we like.
The location of ${user.home}/.ant/lib is somewhat
dependent on the JVM. On Unix systems ${user.home} maps
to the user's home directory whilst on recent versions of Windows it
will be somewhere such
as C:\Users\username\.ant\lib. You should consult
your JVM documentation for more details.
Examples
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.
ant -lib /home/ant/extras
runs Ant picking up additional task and support jars from
the /home/ant/extras location
ant -lib one.jar;another.jar
ant -lib one.jar -lib another.jar
adds two jars to Ants classpath.
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.
Java System Properties
Some of Ant's core classes can be configured via system properties.
Here is the result of a search through the codebase. Because system
properties are available via Project instance, I searched for them with a
grep -r -n "getPropert" * > ..\grep.txt
command. After that I filtered out the often-used but
not-so-important values (most of them read-only
values): path.separator, ant.home, basedir,
user.dir, os.name, line.separator,
java.home, java.version, java.version,
user.home, java.class.path

And I filtered out the getPropertyHelper access.
  property name
  valid values/default value
  description
  ant.build.javac.source
  Source-level version number
  Default source value
  for <javac>/<javadoc>
  ant.build.javac.target
  Class-compatibility version number
  Default target value for <javac>
  ant.executor.class
  classname; default is org.apache.tools.ant.helper.DefaultExecutor
  Since Ant 1.6.3 Ant will delegate Target invocation to
  the org.apache.tools.ant.Executor
  implementation specified here.
  ant.file
  read only: full filename of the build file
  This is set to the name of the build
  file. In <import>-ed files,
  this is set to the containing build file.
  ant.file.*
  read only: full filename of the build file of Ant projects
  This is set to the name of a file by project; this lets you
  determine the location
  of <import>-ed files.
  ant.input.properties
  filename (required)
  Name of the file holding the values for
  the PropertyFileInputHandler.
  ant.logger.defaults
  filename (optional, default /org/apache/tools/ant/listener/defaults.properties)
  Name of the file holding the color mappings for
  the AnsiColorLogger.
  ant.netrexxc.*
  several formats
  Use specified values as defaults
  for netrexxc.
  ant.PropertyHelper
  Ant reference name (optional)
  Specify the PropertyHelper to use. The object must be of the
  type org.apache.tools.ant.PropertyHelper. By
  default, an object
  of org.apache.tools.ant.PropertyHelper
  will be used as PropertyHelper.
  ant.regexp.regexpimpl
  classname
  classname for a RegExp implementation; by default the java.util.regex
  implementation; RegExp
  Mapper "Choice of regular expression implementation".
  ant.reuse.loader
  boolean
  allow to reuse classloaders used
  in org.apache.tools.ant.util.ClasspathUtil.
  ant.XmlLogger.stylesheet.uri
  filename (default log.xsl)
  Name for the stylesheet to include in the logfile
  by XmlLogger.
  build.compiler
  Specify the default compiler to use;
  see javac, EJB
  Tasks (compiler
  attribute), javah.
  build.compiler.emacs
  boolean (default false)
  Enable emacs-compatible error messages;
  see javac "Jikes Notes".
  build.compiler.fulldepend
  boolean (default false)
  Enable full dependency checking;
  see javac "Jikes Notes".
  build.compiler.jvc.extensions
  Deprecated
  Enable Microsoft extensions of their Java compiler;
  see javac "Jvc Notes".
  build.compiler.pedantic
  boolean (default false)
  Enable pedantic warnings;
  see javac "Jikes Notes".
  build.compiler.warnings
  Deprecated
  See javac "Jikes Notes"
  build.rmic
  Control the rmic compiler
  build.sysclasspath
  No default value
  See its dedicated page
  file.encoding
  name of a supported character set (e.g. UTF-8, ISO-8859-1, US-ASCII)
  use as default character set of email messages; use as default
  for srcencoding, destencoding
  and bundleencoding
  in translate
 see JavaDoc
  of java.nio.charset.Charset for more information
  about character sets (not used in Ant, but has nice docs).
  jikes.class.path
  The specified path is added to the classpath if Jikes is used as compiler.
  MailLogger.properties.file, MailLogger.*
  filename (optional, defaults derived from Project instance)
  Name of the file holding properties for sending emails by
  the MailLogger. Override
  properties set inside the buildfile or via command line.
  org.apache.tools.ant.ProjectHelper
  classname (optional, default org.apache.tools.ant.ProjectHelper2)
  specifies the classname to use as ProjectHelper. The class must
  extend org.apache.tools.ant.ProjectHelper.
  org.apache.tools.ant.ArgumentProcessor
  classname (optional)
  specifies the classname to use as ArgumentProcessor. The class
  must extend org.apache.tools.ant.ArgumentProcessor.
  websphere.home
  Points to home directory of WebSphere;
  see EJB Tasks
  XmlLogger.file
  filename (default log.xml)
  Name for the logfile
  for MailLogger.
  ant.project-helper-repo.debug
  boolean (default false)
  Set it to true to enable debugging with
  Ant's ProjectHelper internal
  repository.
  ant.argument-processor-repo.debug
  boolean (default false)
  Set it to true to enable debugging with
  Ant's ArgumentProcessor
  internal repository.
  ant.tstamp.now
  number, seconds since the epoch (midnight 1970-01-01)
  The value to use as current time and date
  for <tstamp>
  ant.tstamp.now.iso
  ISO-8601 timestamp string like 1972-04-17T08:07:00Z
  java.io.tmpdir
  Some tasks need to create temporary files and will write them to
  the directory specified by this property. This property is set by
  the Java VM but can be overridden when Ant is started.

  See also Temporary Directories.
  ant.tmpdir
  Since Ant 1.10.8

  Some tasks need to create temporary files and will write them to
  the directory specified by this property. This property takes
  precedence over java.io.tmpdir if it has been
  set. Unlike java.io.tmpdir this property can be set
  from within the build file.

  See also Temporary Directories.
  ant.disable.graal.nashorn.compat
  boolean (default false)
  Since Ant 1.10.9

  By default Ant will enable GraalVM JavaScript's Nashorn
  compatibility mode for script and friends. You can
  disable this behavior by setting this property to true.

  See also the script task manual.
If new properties get added (it happens), expect them to appear under
the ant. and org.apache.tools.ant. prefixes,
unless the developers have a very good reason to use another
prefix. Accordingly, please avoid using properties that begin with
these prefixes. This protects you from future Ant releases breaking
your build file.
return code
Ant start up scripts (in their Windows and Unix version) return the
return code of the java program. So a successful build
returns 0, failed builds return other values.
Temporary Directories
Some Ant tasks and types need to create temporary files. By default
they use the default temporary directory of the Java VM they are
running in - which can be set by setting the system
property java.io.tmpdir. The default value of it depends
on the platform and the JVM implementation.
Setting a system property when invoking Ant is not straight forward
  as the corresponding command line arguments must be sent to the Java
  executable rather than Ant's main class. When using
  the ant(.cmd) wrapper scripts you can do so with the
  help of the ANT_OPTS environment variable.
Starting with Ant 1.10.8 we've introduced a new Ant
  property ant.tmpdir that takes precedence
  over java.io.tmpdir when set. As this is a normal Ant
  property it can be set via the command line or even from within a
  build file.
Tasks and types using the temporary directory will state the fact
  inside of their respective manual page. In addition every execution
  of an external command on OpenVMS will create a temporary file
  holding a DCL script that invokes the actual command.
Starting with Ant 1.10.9 Ant will try to create a build process
  specific temporary directory inside java.io.tmpdir with
  permissions set to be accessible by the current user only and use
  that if ant.tmpdir has not been set and Ant is able to
  set permissions on the filesystem in question.
Tasks not provided with the Ant distribution will ignore
  the ant.tmpdir property or the process subdirectory and
  use java.io.tmpdir unless they have been adapted to the
  changed API of Ant 1.10.8.
Security Note: Using the default temporary directory
specified by java.io.tmpdir can result in the leakage of
sensitive information or possibly allow an attacker to inject source
files into the build process. This is especially true in multi-user
environments. It is recommended that ant.tmpdir be set to
a directory owned by the user running Ant with 0700 permissions. Ant
1.10.8 and later will try to make temporary files created by it only
readable/writable by the current user but may silently fail to do so
depending on the OS and filesystem.
Cygwin Users
Unix launch script that come with Ant works correctly with Cygwin. You
should not have any problems launching Ant from the Cygwin shell. It
is important to note, however, that once Ant is running it is part of
the JDK which operates as a native Windows application. The JDK is not
a Cygwin executable, and it therefore has no knowledge of Cygwin
paths, etc. In particular when using the <exec>
task, executable names such as /bin/sh will not work, even
though these work from the Cygwin shell from which Ant was
launched. You can use an executable name such as sh and rely on
that command being available in the Windows path.
OS/2 Users
The OS/2 launch script was developed to perform complex tasks. It has
two parts: ant.cmd which calls Ant
and antenv.cmd which sets the environment for Ant.  Most
often you will just call ant.cmd using the same command
line options as described above. The behaviour can be modified by a
number of ways explained below.
Script ant.cmd first verifies whether the Ant environment
is set correctly. The requirements are:
Environment variable JAVA_HOME is set.
Environment variable ANT_HOME is set.
Environment variable CLASSPATH is set and contains at least one element from
JAVA_HOME and at least one element from ANT_HOME.
If any of these conditions is violated, script antenv.cmd
is called. This script first invokes configuration scripts if there
exist: the system-wide configuration antconf.cmd from
the %ETC% directory and then the user
configuration antrc.cmd from the %HOME%
directory. At this moment both JAVA_HOME
and ANT_HOME must be defined
because antenv.cmd now adds classes.zip
or tools.jar (depending on version of JVM) and everything
from %ANT_HOME%\lib except ant-*.jar
to CLASSPATH. Finally ant.cmd calls
per-directory configuration antrc.cmd. All settings made
by ant.cmd are local and are undone when the script
ends. The settings made by antenv.cmd are persistent
during the lifetime of the shell (of course unless called
automatically from ant.cmd). It is thus possible to
call antenv.cmd manually and modify some settings before
calling ant.cmd.
Scripts envset.cmd and runrc.cmd perform
auxiliary tasks. All scripts have some documentation inside.
Running Ant as a background process on Unix(-like) systems
If you start Ant as a background process (like in ant
&) and the build process creates another process, Ant will
immediately try to read from standard input, which in turn will most
likely suspend the process.  In order to avoid this, you must redirect
Ant's standard input or explicitly provide input to each spawned
process via the input related attributes of the corresponding tasks.
Tasks that create such new processes
include <exec>, <apply>
or <java> when the fork attribute
is true.
Running Ant via Java
If you have installed Ant in the do-it-yourself way, Ant can be
started from one of two entry points:
java -Dant.home=c:\ant org.apache.tools.ant.Main [options] [target]
java -Dant.home=c:\ant org.apache.tools.ant.launch.Launcher [options] [target]
The first method runs Ant's traditional entry point. The second method
uses the Ant Launcher introduced in Ant 1.6. The former method does
not support the -lib option and all required classes are
loaded from the CLASSPATH. You must ensure that all
required jars are available. At a minimum the CLASSPATH
should include:
ant.jar and ant-launcher.jar
jars/classes for your XML parser
the JDK's required jar/zip files
The latter method supports
the -lib, -nouserlib, -noclasspath
options and will load jars from the
specified ANT_HOME. You should start the latter with the
most minimal classpath possible, generally just
the ant-launcher.jar.
Ant can be started in Ant via the <java> command.
Here is an example:
<java classname="org.apache.tools.ant.launch.Launcher"
      fork="true"
      failonerror="true"
      dir="${sub.builddir}"
      timeout="4000000"
      taskname="startAnt">
    <classpath>
        <pathelement location="${ant.home}/lib/ant-launcher.jar"/>
    </classpath>
    <arg value="-buildfile"/>
    <arg file="${sub.buildfile}"/>
    <arg value="-Dthis=this"/>
    <arg value="-Dthat=that"/>
    <arg value="-Dbasedir=${sub.builddir}"/>
    <arg value="-Dthe.other=the.other"/>