The <different> selector will select a file if it is deemed to be
'different' from an equivalent file in another location. The rules for determining difference
between the two files are as follows:
If a file is only present in the resource collection you apply the selector to but not in targetdir (or after applying the mapper) the file is selected.
If a file is only present in targetdir (or after applying the mapper) it is ignored.
Files with different lengths are different.
If ignoreFileTimes is turned off, then differing file timestamps will cause files to be regarded as different.
Unless ignoreContents is set to true, a byte-for-byte check is run against the two files.
This is a useful selector to work with programs and tasks that don't handle dependency checking properly; even if a predecessor task always creates its output files, followup tasks can be driven off copies made with a different selector, so their dependencies are driven on the absolute state of the files, not just a timestamp. For example: anything fetched from a web site, or the output of some program. To reduce the amount of checking, when using this task inside a <copy> task, set preservelastmodified to true to propagate the timestamp from the source file to the destination file.
The <different> selector supports the use of a contained <mapper> element to define the location of the file to be compared against. If no <mapper> element is specified, the identity type mapper is used.
<fileset dir="${phing.1.5}/classes" includes="**/*.php">
<different targetdir="${phing.1.4.1}/classes"
ignoreFileTimes="true"/>
</fileset>
Table G.5: Attributes for the <different> selector
| Name | Description | Default | Required |
|---|---|---|---|
targetdir | The base directory to look for the files to compare against. The
precise location depends on a combination of this attribute and the
mapper element, if any. | n/a | Yes |
ignoreFileTimes | Whether to use file times in the comparison or not. | true | No |
ignoreContents | Whether to do a byte per byte compare. | false | No |