zforce forces a .gz extension on all gzip files so that gzip will not compress them twice. This can be useful for files with names truncated after a file transfer. On systems with a 14 char limitation on file names, the original name is truncated to make room for the .gz suffix. For example, 12345678901234 is renamed to 12345678901.gz. A file name such as foo.tgz is left intact.