freebsd-skq/usr.bin/id/id.1

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.\"	@(#)id.1	8.1 (Berkeley) 6/6/93
.\" $FreeBSD$
.\"
.Dd March 5, 2011
.Dt ID 1
.Os
.Sh NAME
.Nm id
.Nd return user identity
.Sh SYNOPSIS
.Nm
.Op Ar user
.Nm
.Fl A
.Nm
.Fl G Op Fl n
.Op Ar user
.Nm
.Fl M
.Nm
.Fl P
.Op Ar user
.Nm
.Fl c
.Nm
.Fl g Op Fl nr
.Op Ar user
.Nm
.Fl p
.Op Ar user
.Nm
.Fl u Op Fl nr
.Op Ar user
.Sh DESCRIPTION
The
.Nm
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.
.Pp
If a
.Ar 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.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl A
Display the process audit user ID and other process audit properties, which
requires privilege.
.It Fl G
Display the different group IDs (effective, real and supplementary)
as white-space separated numbers, in no particular order.
.It Fl M
Display the MAC label of the current process.
.It Fl P
Display the id as a password file entry.
.It Fl a
Ignored for compatibility with other
.Nm
implementations.
.It Fl c
Display current login class.
.It Fl g
Display the effective group ID as a number.
.It Fl n
Display the name of the user or group ID for the
.Fl G ,
.Fl g
and
.Fl u
options instead of the number.
If any of the ID numbers cannot be mapped into names, the number will be
displayed as usual.
.It Fl p
Make the output human-readable.
If the user name returned by
.Xr getlogin 2
is different from the login name referenced by the user ID, the name
returned by
.Xr getlogin 2
is displayed, preceded by the keyword
.Dq login .
The user ID as a name is displayed, preceded by the keyword
.Dq 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
.Dq 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
.Dq rgid .
The list of groups to which the user belongs is then displayed as names,
preceded by the keyword
.Dq groups .
Each display is on a separate line.
.It Fl r
Display the real ID for the
.Fl g
and
.Fl u
options instead of the effective ID.
.It Fl u
Display the effective user ID as a number.
.El
.Sh EXIT STATUS
.Ex -std
.Sh EXAMPLES
Show information for the user
.Ql bob
as a password file entry:
.Bd -literal -offset indent
$ id -P bob
bob:*:0:0::0:0:Robert:/bob:/usr/local/bin/bash
.Ed
.Pp
Same output as
.Xr groups 1 for the root user:
.Bd -literal -offset indent
$ id -Gn root
wheel operator
.Ed
.Pp
Show human readable information about
.Ql alice :
.Bd -literal -offset indent
$ id -p alice
uid     alice
groups  alice webcamd vboxusers
.Ed
.Pp
Assuming the user
.Ql bob
executed
.Dq Nm su Fl l
to simulate a root login, compare the result of the following commands:
.Bd -literal -offset indent
# id -un
root
# who am i
bob          pts/5        Dec  4 19:51
.Ed
.Sh SEE ALSO
.Xr groups 1 ,
.Xr who 1
.Sh STANDARDS
The
.Nm
function is expected to conform to
.St -p1003.2 .
.Sh HISTORY
The
historic
.Xr groups 1
command is equivalent to
.Dq Nm id Fl Gn Op Ar user .
.Pp
The
historic
.Xr whoami 1
command is equivalent to
.Dq Nm id Fl un .
.Pp
The
.Nm
command appeared in
.Bx 4.4 .