id - return user identity
id -G [-n] [user]
id -g [-nr] [user]
id -u [-nr] [user]
The id utility displays the user and group names and numeric
IDs, of the
calling process, to the standard output. If the real and
are different, both are displayed, otherwise only the real
ID is displayed.
If a user (login name or user ID) is specified, the user and
group IDs of
that user are displayed. In this case, the real and effective IDs are
assumed to be the same.
The options are as follows:
-G Display the different group IDs (effective, real and
as whitespace separated numbers, in no particular order.
-g Display the effective group ID as a number.
-n Display the name of the user or group ID for the -G,
-g and -u
options instead of the number. If any of the ID
be mapped into names, the number will be displayed
-p Make the output human-readable. If the user name
getlogin(2) is different from the login name referenced by the
user ID, the name returned by getlogin(2) is displayed, preceded
by the keyword ``login''. The user ID as a name is
preceded by the keyword ``uid''. If the effective
user ID is
different from the real user ID, the real user ID is
a name, preceded by the keyword ``euid''. If the
ID is different from the real group ID, the real
group ID is displayed
as a name, preceded by the keyword ``rgid''.
The list of
groups to which the user belongs is then displayed
as names, preceded
by the keyword ``groups''. Each display is on
-r Display the real ID for the -g and -u options instead of the effective
-u Display the effective user ID as a number.
The id utility exits 0 on success or >0 if an error occurred.
The id function is expected to conform to IEEE Std 1003.2
The historic groups(1) command is equivalent to id -Gn
The historic whoami(1) command is equivalent to id -un.
The id command first appeared in 4.4BSD.
OpenBSD 3.6 May 5, 1994
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