Determines the directory name of the specified file.
This task can accept the following attributes:
file
property
Both file and property are required.
When this task executes, it will set the specified property to the
value of the specified file up to, but not including, the last path
element. If file is a file, the directory will be the current
directory.
Called by the project to let the task do its work. This method may be
called more than once, if the task is invoked more than once.
For example,
if target1 and target2 both depend on target3, then running
"ant target1 target2" will run all tasks in target3 twice.