— return user
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:
- Display the login class of the real user ID or the
- Display the different group IDs (effective, real and
supplementary) as whitespace separated numbers, in no particular
- Display the effective group ID as a number.
- 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
- 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”. If there is a login class
specified for the user in the
passwd(5) database, it is
displayed, preceded by the keyword “class”. Each display is on
a separate line.
- Display the routing table of the current process.
- Display the real ID for the -g
and -u options instead of the effective
- Display the effective user ID as a number.
utility exits 0 on success,
and >0 if an error occurs.
utility is compliant with the
IEEE Std 1003.1-2008
The flags [-cpR
extensions to that specification.
The historic groups(1)
equivalent to id -Gn
The historic whoami(1)
equivalent to id
command first appeared in