id(1) General Commands Manual id(1)
NAME
id - Displays the user's system identity
SYNOPSIS
id [user]
id -G [-n] [user]
id -g [-nr] [user]
id -u [-nr] [user]
id -a
STANDARDS
Interfaces documented on this reference page conform to industry standards as follows:
id: XCU5.0
Refer to the standards(5) reference page for more information about industry standards and associated tags.
OPTIONS
Displays all groups ids (real, effective, and supplementary) only, as unsigned decimal numbers. Displays only the effective group id as an
unsigned decimal number. Displays user and group names as strings rather than as numbers. Displays only the real ID. Displays only the
effective user ID as an unsigned decimal number. [Tru64 UNIX] Displays user and all group IDs and names if the environment variable
CMD_ENV is set to the string svr4.
OPERANDS
The user for whom information is to be written.
If this parameter is omitted, the user and group names associated with the invoking process are used.
DESCRIPTION
The id command writes to standard output a message containing the user and group IDs and corresponding names of the invoking process. If
effective names and IDs do not match the real ones, the id command writes both.
If user is specified and the invoking process has sufficient privileges, the IDs and names in the message are for user rather than for the
invoking process. Effective IDs are assumed identical to real IDs.
Your real user and group ids are specified in the /etc/passwd file and are your user and group ids on login. You can change your active
group with the newgrp shell command (see newgrp(1)) if additional groups are specified for you in the /etc/group file. Such groups are
called supplementary .
A process can also have an effective user or group id set when a set-user- or set-group-identifier program is executed. See setuid(2),
setgid(2).
SVID Conformance
[Tru64 UNIX] When the environment variable CMD_ENV is set to the string svr4, the command syntax and output is compatible with the SVID
standard. In particular, the id command with no options displays the user's name and id and the real and effective group names and ids.
The -a option adds any supplementary group names and ids to the display.
EXIT STATUS
The following exit values are returned: Successful completion. An error occurred.
EXAMPLES
To display your user and group IDs, enter: id
Information is displayed similar to: uid=200(thomas) gid=1(staff)
In the case where a user belongs to a supplementary group, information is displayed similar to: uid=200(thomas) gid=1(staff)
groups=0(system)
However, if the environment variable CMD_ENV is set to the string svr4, the command id with no options does not display any supple-
mentary groups and results in a display similar to: uid=200(thomas) gid=1(staff) To display supplementary groups with CMD_ENV set to
svr4, use the command id -a. The display is then similar to: uid=200(thomas) gid=1(staff) groups=1(users),0(system)
ENVIRONMENT VARIABLES
The following environment variables affect the execution of id: [Tru64 UNIX] When this environment variable CMD_ENV is set to the string
svr4, the command syntax and output is compatible with the SVID standard. The -a option is only available in this condition. Provides a
default value for the internationalization variables that are unset or null. If LANG is unset or null, the corresponding value from the
default locale is used. If any of the internationalization variables contain an invalid setting, the utility behaves as if none of the
variables had been defined. If set to a non-empty string value, overrides the values of all the other internationalization variables.
Determines the locale for the interpretation of sequences of bytes of text data as characters (for example, single-byte as opposed to
multibyte characters in arguments). Determines the locale for the format and contents of diagnostic messages written to standard error.
Determines the location of message catalogues for the processing of LC_MESSAGES.
FILES
Group names declared on the system. Password file.
SEE ALSO
Commands: groups(1), logname(1), newgrp(1), who(1)
Functions: getgid(2), getuid(2), setgid(2), setuid(2)
Files: group(4), passwd(4)
Environment: environ(5)
Standards: standards(5)
id(1)