NAME
id —
return user identity
SYNOPSIS
DESCRIPTION
The
id utility displays the user and group names and numeric
IDs, of the calling process, to the standard output. If the real and effective
IDs 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
supplementary) as white-space 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 numbers cannot be mapped
into names, the number will be displayed as usual.
-
-
- -p
- Make the output human-readable. If the user name returned
by 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
displayed, preceded by the keyword ``uid''. If the effective user ID is
different from the real user ID, the real user ID is displayed as a name,
preceded by the keyword ``euid''. If the effective group 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 a separate line.
-
-
- -r
- Display the real ID for the -g and
-u options instead of the effective ID.
-
-
- -u
- Display the effective user ID as a number.
The
id utility exits 0 on success, and >0 if an error
occurs.
SEE ALSO
who(1)
STANDARDS
The
id function is expected to conform to
IEEE Std 1003.2 (“POSIX.2”).
HISTORY
The historic
groups(1) command is
equivalent to “
id -Gn
[
user]”.
The historic
whoami(1) command is
equivalent to “
id -un”.
The
id command first appeared in
4.4BSD.