[seq] return 1 when too few/many arguments are provided
[vis] add vis
[cmp] add cmp
[chgrp] add chgrp
[chgrp] add check for too few arguments
[misc] rename current argument variable to 'arg'
[misc] normalize help message formatting
[chown] add chown
[chroot] add chroot
[basename] add basename
[cksum] add cksum
[misc] close open files
[cp] add cp
[cp] update usage message
[cmp] fix compiler error
[cat] change c from char to int
[cut] add cut
[date] add date
[dd] add dd
[dirname] add dirname