The name execon
is deprecated and only kept for backwards
compatibility.
Executes a system command. When the os attribute is specified, then the command is only executed when Apache Ant is run on one of the specified operating systems.
The files and/or directories of a number of Resource Collections –- including but not restricted to FileSets, DirSets (since Ant 1.6) or FileLists (since Ant 1.6) –- are passed as arguments to the system command.
If you specify a nested mapper, the timestamp of each source
file is compared to the timestamp of a target file which is defined by the
nested mapper
element and searched for in the given dest, if specified.
At least one fileset
or filelist
is required, and you must not specify
more than one mapper
.
Note that you cannot interact with the forked program, the only way to send input to it is via the input and inputstring attributes.
If you run Ant as a background process (like ant &) and use
the <apply>
task with spawn set to false
, you must provide
explicit input to the forked process or Ant will be suspended because it tries to read from the
standard input.
Attribute | Description | Required |
---|---|---|
executable | the command to execute without any command line arguments. | Yes |
dest | the directory where the command is expected to place target files when it is executed. | No; ignored unless a nested mapper is specified; by default, the target filenames returned by the mapper will be interpreted as absolute paths |
spawn | whether or not you want the commands to be spawned. If you spawn a command, its output will not be logged by Ant. The input, output, error, and result property settings are not active when spawning a process. since Ant 1.6 |
No; default is false |
dir | the directory in which the command should be executed. | No; if vmlauncher is true, defaults to the current working directory, otherwise the project's basedir |
relative | whether the filenames should be passed on the command line as relative pathnames (relative to the base directory of the corresponding fileset/list for source files or the dest attribute for target files). | No; default is false |
forwardslash | whether the file names should be passed with forward slashes even if the operating system requires other file separator. The option is ignored if the system file separator is a forward slash. | No; default is false |
os | list of Operating Systems on which the command may be executed. | No |
osfamily | OS family as used in the <os> condition.
since Ant 1.7 |
No |
output | the file to which the output of the command should be redirected. If the error stream is not also redirected to a file or property, it will appear in this output. | No |
error | The file to which the standard error of the command should be redirected. since Ant 1.6 | No |
logError | This attribute is used when you wish to see error output in Ant's log and you are redirecting output to a file/property. The error output will not be included in the output file/property. If you redirect error with the error or errorProperty attributes, this will have no effect. since Ant 1.6 | No |
append | whether output should be appended to or overwrite an existing file. If you
set parallel to false, you will probably want to set this one to true. |
No; default is false |
outputproperty | the name of a property in which the output of the command should be stored. Unless the error stream is redirected to a separate file or stream, this property will include the error output. | No |
errorproperty | The name of a property in which the standard error of the command should be stored. since Ant 1.6 | No |
input | A file from which the executed command's standard input is taken. This attribute is mutually exclusive with the inputstring attribute. since Ant 1.6 | No |
inputstring | A string which serves as the input stream for the executed command. This attribute is mutually exclusive with the input attribute. since Ant 1.6 | No |
resultproperty | the name of a property in which the return code of the command should be stored. Only of
interest if failonerror is false. If you set parallel to false, only the result of the first execution will be stored. |
No |
timeout | Stop the command if it doesn't finish within the specified time (given in milliseconds). | No |
failonerror | Stop the build process if the command exits with a return code other than 0. |
No; defaults to false |
failifexecutionfails | Stop the build if we can't start the program. | No; defaults to true |
skipemptyfilesets | Don't run the command, if no source files have been found or are newer than their corresponding target files. Despite its name, this attribute applies to filelists as well. | No; default is false |
parallel | Run the command only once, appending all files as arguments. If false, command will be executed once for every file. |
No; default is false |
type | One of file, diror both. If set to file, only the names of plain files will be sent to the command. If set to dir, only the names of directories are considered. Note: The type attribute does not apply to nested dirset s—dirset s always implicitly assume type to
be dir. |
No; default is file |
newenvironment | Do not propagate old environment when new environment variables are specified. | No; default is false |
vmlauncher | Run command using the JVM's execution facilities where available. If set to falsethe underlying OS's shell, either directly or through the antRun scripts, will be used. Under some operating systems, this gives access to facilities not normally available through JVM including, under Windows, being able to execute scripts, rather than their associated interpreter. If you want to specify the name of the executable as a relative path to the directory given by the dir attribute, it may become necessary to set vmlauncher to falseas well. |
No; default is true |
resolveExecutable | When this attribute is true, the name of the executable if resolved firstly against the project basedir and if that does not exist, against the execution directory if specified. On Unix systems, if you only want to allow execution of commands in the user's path, set this to false. since Ant 1.6 |
No; default is false |
maxparallel | Limit the amount of parallelism by passing at most this many sourcefiles at once. Set it to negative integer for unlimited. Since Ant 1.6. | No, unlimited by default |
addsourcefile | Whether source file names should be added to the command automatically. Since Ant 1.6. | No; default is true |
verbose | Whether to print a summary after execution or not. Since Ant 1.6. | No; default is false |
ignoremissing | Whether to ignore nonexistent files specified via filelists. Since Ant 1.6.2. | No; default is true |
force | Whether to bypass timestamp comparisons for target files. Since Ant 1.6.3. | No; default is false |
discardOutput | Whether output should completely be discarded. This setting is
incompatible with any setting that redirects output to files or
properties. If you set this to trueerror output will be discared as well unless you redirect error output to files, properties or enable logError. Since Ant 1.10.10 |
No; defaults to false |
discardError | Whether error output should completely be discarded. This
setting is incompatible with any setting that redirects error
output to files or properties as well as logError. Since Ant 1.10.10 |
No; defaults to false |
You can use any number of nested <fileset>
elements to define the files for
this task and refer to <fileset>
s defined elsewhere.
Since Ant 1.6
You can use any number of nested <filelist>
elements to define the files for
this task and refer to <filelist>
s defined elsewhere.
Since Ant 1.6
You can use any number of nested <dirset>
elements to define the directories
for this task and refer to <dirset>
s defined elsewhere.
Since Ant 1.7
You can use any number of nested resource collections.
A single <mapper>
specifies the target files relative to the dest
attribute for dependency checking. If the dest attribute is specified it will be used as
a base directory for resolving relative pathnames returned by the mapper. At least one
<fileset>
or <filelist>
is required.
Command line arguments should be specified as nested <arg>
elements. See Command line arguments.
By default the file names of the source files will be added to the end of the command line
(unless you set addsourcefile to false
). If you need to place it somewhere
different, use a nested <srcfile>
element between your <arg>
elements to mark the insertion point.
Attribute | Description | Required |
---|---|---|
prefix | a prefix to place in front of the file name when building the command line argument. Since Ant 1.8.0 | No |
suffix | a suffix to append to the file name when building the command line argument. Since Ant 1.8.0 | No |
<targetfile>
is similar to <srcfile>
and marks the position
of the target filename on the command line. If omitted, the target filenames will not be added to
the command line at all. This element can only be specified if you also define a nested mapper.
Attribute | Description | Required |
---|---|---|
prefix | a prefix to place in front of the file name when building the command line argument. Since Ant 1.8.0 | No |
suffix | a suffix to append to the file name when building the command line argument. Since Ant 1.8.0 | No |
It is possible to specify environment variables to pass to the system command via
nested <env>
elements. See the description in the section
about exec
A nested I/O Redirector can be specified. <apply>'s behavior is like that of exec with regard to redirectors, with the exception that, in non-parallel mode, file mapping will take place with each iteration. This grants the user the capacity to receive input from, and send output to, different files for each sourcefile.
In parallel mode the redirector will be reset for each batch of executions
(with maxparallel > 0) and null will be used a source file just like it is in the case
of exec
.
Invoke ls -l, adding the absolute filenames of all files below /tmp not ending in .txt and all files of the FileSet with id other.files to the command line.
<apply executable="ls"> <arg value="-l"/> <fileset dir="/tmp"> <patternset> <exclude name="**/*.txt"/> </patternset> </fileset> <fileset refid="other.files"/> </apply>
Invoke somecommand arg1 SOURCEFILENAME arg2 for each file in /tmp
replacing SOURCEFILENAME
with the absolute filename of each file in
turn. If parallel had been set to true
, SOURCEFILENAME
would be
replaced with the absolute filenames of all files separated by spaces.
<apply executable="somecommand" parallel="false"> <arg value="arg1"/> <srcfile/> <arg value="arg2"/> <fileset dir="/tmp"/> </apply>
Invoke cc -c -o TARGETFILE SOURCEFILE for each .c file that is newer than
the corresponding .o, replacing TARGETFILE
with the absolute filename of
the .o and SOURCEFILE
with the absolute name of the .c
file.
<apply executable="cc" dest="src/C" parallel="false"> <arg value="-c"/> <arg value="-o"/> <targetfile/> <srcfile/> <fileset dir="src/C" includes="*.c"/> <mapper type="glob" from="*.c" to="*.o"/> </apply>
Apply the fictitious processfile executable to all files matching *.file
in the src directory. The out <mapper>
has been set up
to map *.file to *.out, then this <mapper>
is used to
specify targetfile
s for this <apply>
task. A reference
to out is then used as an <outputmapper>
nested in
a <redirector>
, which in turn is nested beneath this <apply>
instance. This allows us to perform dependency checking against output files—the target files
in this case.
<mapper id="out" type="glob" from="src${file.separator}*.file" to="dest${file.separator}*.out"/> <apply executable="processfile" dest="dest"> <fileset dir="src" includes="*.file"/> <mapper refid="out"/> <redirector> <outputmapper refid="out"/> </redirector> </apply>
Apply the ls executable to all directories in the PATH
, effectively
listing all executables that are available on the PATH
.
<apply executable="ls" parallel="true" force="true" dest="${basedir}" append="true" type="both"> <path> <pathelement path="${env.PATH}"/> </path> <identitymapper/> </apply>
Convert all JavaScript files in the src directory using the command jsmin <
src/a.js > dest/a.js. Because the filename itself should not be passed to
the jsmin
program, the addsourcefile is set to false
.
<apply executable="jsmin" addsourcefile="false"> <!-- Collect the JS-files --> <fileset dir="src" includes="*.js"/> <redirector> <!-- redirect STDIN; fileset collects relative to its dir, but we need --> <!-- relative to basedir --> <inputmapper type="glob" from="*" to="src/*"/> <!-- redirect STDOUT to file in dest-dir --> <outputmapper id="out" type="glob" from="*.js" to="dest/*.js"/> </redirector> </apply>