Here are 179 basic Linux utilities...

    rpm -ql binutils coreutils moreutils moreutils-parallel \
        findutils diffutils sharutils psutils \
        pciutils iputils elfutils | grep -E /usr/s?bin

...some of which likely have parsing bugs which can be automatically identified with this fuzzer discussed on HN recently:

http://lcamtuf.coredump.cx/afl/

Also, an exciting opportunity to discover what the 'pee' and 'sponge' commands do.