id(1) — Linux manual pages

Linux manual pages	Section 1

Name

id — print real and effective user and group IDs

id [OPTION...] [USER]

Print user and group information for the specified USER, or (when USER omitted) for the current user.

−a

ignore, for compatibility with other versions

−Z, −−context

print only the security context of the process

−g, −−group

print only the effective group ID

−G, −−groups

print all group IDs

−n, −−name

print a name instead of a number, for −ugG

−r, −−real

print the real ID instead of the effective ID, with −ugG

−u, −−user

print only the effective user ID

−z, −−zero

delimit entries with NUL characters, not whitespace;

not permitted in default format

−−help

display this help and exit

−−version

output version information and exit

Without any OPTION, print some useful set of identified information.

Written by Arnold Robbins and David MacKenzie.