diff [-ru] file1 file2

id [-ruGgn] username

tr:
	support for character classes [:alnum:]

od/hd

uuencode, uudecode:
	missing options for base64

sed

patch

ed

awk

bc/dc

fmt

install

find (bare minimum)

at

For more commands that might need to be implemented
refer to: http://pubs.opengroup.org/onlinepubs/9699919799/idx/utilities.html