perl -MFile::Basename -le"print for fileparse('/path/to/foo.txt.bak')"
perl -MFile::Basename -le"print for fileparse('/path/to/foo.txt.bak','.bak')"
perl -MFile::Basename -le"print for fileparse('/path/to/foo.txt.bak','.txt')"
perl -MFile::Basename -le"print for fileparse('/path/to/foo.txt.bak','.txt.bak')"