GNU programs are not a reference. They must have usage(), and handle --help and --version. Even /bin/true.
coreutils-8.25$ wc -l src/true.c
80 src/true.c coreutils-8.25$ wc -l src/true.c
80 src/true.cTo be honest, a big chunk of it is just handling user input and attempting to provide useful error messages.