id —
return user identity
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:
-
-
-c- Display the login class of the real user ID or the specified
user.
-
-
-G- Display the different group IDs (effective, real and supplementary) 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 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”. 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.
-
-
-R- Display the routing table of the current process.
-
-
-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.
who(1),
login.conf(5)
The
id utility is compliant with the
IEEE Std 1003.1-2008
(“POSIX.1”) specification.
The flags [
-cpR
] are
extensions to that specification.
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.
![[OpenBSD]](/openbsd.gif){kind=small}