Mac OS X in a Nutshell

Name

id

Synopsis

id [options] [username]

Displays information about yourself or another user: user ID, group ID, effective user ID and group ID if relevant, and additional group IDs.

Options

-g

Print group ID only.

-G

Print supplementary groups only.

-n

With -u, -g, or -G, print user or group name, not number.

-p

Print the output in a more easily read format. Not used with other options.

-r

With -u, -g, or -G, print real, not effective, user ID or group ID.

-u

Print user ID only.