cksum: Added cksum
multiple: Closed open files
cp: Added cp
cp: Updated usage message
cmp: Fixed compiler error
basename: Removed extra space
cat: Changed c from char to int
cut: Added cut
date: Added date
dd: Added dd
dirname: Added dirname
date: Added custom date format
echo: Added echo
env: Added env
basename: Made POSIX compliant
cat: Added (ignored) "-u" option