The Perforce SCMClient now supports the -X flag for diff and post

operations. The -X parameter specifies a pattern to match against.

To specify a pattern against a depot, use -X //depot/... and to

specify a relative (to the current working directory) pattern, use

-X pattern. A pattern that beings with a single slash is

interpreted as an absolute path.

Generated diffs via rbt diff -X that excluded files. This was tested

using numbered changesets (both submitted and pending) and the default

changeset (i.e., open files)