id(1) on Linux
The text 167a2c85bb49, as Debian 7 (Wheezy) shipped it.
print real and effective user and group IDs
Flags it lists
-
--context -
--group -
--groups -
--help -
--name -
--real -
--user -
--version -
-G -
-Z -
-a -
-g -
-n -
-r -
-u