id(1) on Linux
The text 48f538c185df, as Debian 3.1 (Sarge) shipped it.
print real and effective UIDs and GIDs
Flags it lists
-
--group -
--groups -
--help -
--name -
--real -
--user -
--version -
-G -
-a -
-g -
-n -
-r -
-u