Touch

Touch

Description

Changes the modification time of a resource and possibly creates itat the same time. In addition to working with a single file, this Taskcan also work on resources andresource collections (which also includes directories). Prior to Apache Ant1.7 only FileSet or Filelist(since Ant 1.6) have been supported.

Ant uses the API of java.io.File to set the last modification time which has some limitations. For example the timestamp granularity depends on the operating system and sometimes the operating system may allow a granularity smaller than milliseconds. If you need more control you have to fall back to the <exec> task and native commands.

Starting with Ant 1.8.2 Ant will log a warning message if it fails to change the file modification time. This will happen if you try to change the modification time of a file you do not own on many Unix systems, for example.

Parameters

Parameters specified as nested elements

any resource collection

You can use any number of nested resource collection elements todefine the resources for this task and refer to resources definedelsewhere. Note: resources passed to this task must implementthe org.apache.tools.ant.types.resources.Touchableinterface, this is true for all filesystem-based resources like thosereturned by path, fileset ot filelist.

For backwards compatibility directories matched by nested filesetswill be "touched" as well, use a <type> selector to suppressthis. This only applies to filesets nested into the task directly,not to filesets nested into a path or any other resourcecollection.

mapper

Since Ant 1.6.3, a nested mapper can be specified. Files specified via nested filesets, filelists, or the file attribute are mapped using the specified mapper. For each file mapped, the resulting files are touched. If no time has been specified and the original file exists its timestamp will be used. If no time has been specified and the original file does not exist the current time is used. Since Ant 1.8 the task settings (millis, and datetime) have priority over the timestamp of the original file.

Examples

  <touch file="myfile"/>

creates myfile if it doesn't exist and changes themodification time to the current time.

  <touch file="myfile" datetime="06/28/2000 2:02 pm"/>

creates myfile if it doesn't exist and changes themodification time to Jun, 28 2000 2:02 pm (14:02 for those used to 24hour times).

  <touch datetime="09/10/1974 4:30 pm"> <fileset dir="src_dir"/>  </touch>

changes the modification time to Oct, 09 1974 4:30 pm of all files and directories found in src_dir.

  <touch file="myfile" datetime="06/28/2000 2:02:17 pm"/>

creates myfile if it doesn't exist and changes themodification time to Jun, 28 2000 2:02:17 pm (14:02:17 for those used to 24hour times), if the filesystem allows a precision of one second - atime close to it otherwise.

  <touch file="foo"> <mapper type="glob" from="foo" to="bar" />  </touch>

creates bar if it doesn't exist and changes themodification time to that of foo.

  <touch file="foo" datetime="now"> <mapper type="regexp" from="^src(.*).java" to="shadow1.empty" />  </touch>

creates files in the shadow directory for every java file in the src directory if it doesn't exist and changes the modification time of those files to the current time.