gifdiff --version (return code: 0)
gifdiff (LCDF Gifsicle) 1.90 Copyright (C) 1998-2017 Eddie Kohler This is free software; see the source for copying conditions. There is NO warranty, not even for merchantability or fitness for a particular purpose.
gifdiff --help (return code: 0)
'Gifdiff' compares two GIF files (either images or animations) for identical visual appearance. An animation and an optimized version of the same animation should compare as the same. Gifdiff exits with status 0 if the images are the same, 1 if they're different, and 2 if there was some error. Usage: gifdiff [OPTION]... FILE1 FILE2 Options: -q, --brief Don't report detailed differences. -w, --ignore-redundancy Ignore differences in redundant frames. -B, --ignore-background Ignore differences in background colors. -h, --help Print this message and exit. -v, --version Print version number and exit. Report bugs to <email@example.com>.