The <different>
tag selects files
- who are deemed to be 'different' from another, equivalent file in
- another location. The rules for determining difference between two
- files are as follows:
+
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:
<copy>
task, set the preservelastmodified to propagate the timestamp
- from source file to destintaion file.
-
-
-
-
- The <different>
tag supports the use of a
+ 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