[Go to CFHT Home Page] Man Pages
Back to Software Index  BORDER=0Manpage Top Level
    id(1M) manual page Table of Contents

Name

id - return user identity

Synopsis

/usr/bin/id [ user ]
/usr/bin/id -a [ user ]

/usr/xpg4/bin/id [ user ]
/usr/xpg4/bin/id -G [ -n ] [ user ]
/usr/xpg4/bin/id -g [ -nr ] [ user ]
/usr/xpg4/bin/id -u [ -nr ] [ user ]

Availability

/usr/bin/id

SUNWcsu, SUNWcar

/usr/xpg4/bin/id

SUNWxcu4

Description

If no user operand is provided, the id utility will write the user and group ID s and the corresponding user and group names of the invoking process to standard output. If the effective and real ID s do not match, both will be written. If multiple groups are supported by the underlying system, the supplementary group affiliations of the invoking process also will be written.

If a user operand is provided and the process has the appropriate privileges, the user and group ID s of the selected user will be written. In this case, effective ID s will be assumed to be identical to real ID s. If the selected user has more than one allowable group membership listed in the group database, these will be written in the same manner as the supplementary groups described in the preceding paragraph.

Formats

The following formats will be used when the LC_MESSAGES locale category specifies the "C" locale. In other locales, the strings uid, gid, euid, egid, and groups may be replaced with more appropriate strings corresponding to the locale.

"uid=%u(%s) gid=%u(%s)\n" <real user ID >, <user-name>, <real group ID >, <group-name>

If the effective and real user ID s do not match, the following will be inserted immediately before the \n character in the previous format:

" euid=%u(%s)"

with the following arguments added at the end of the argument list:

<effective user ID >, <effective user-name>

If the effective and real group ID s do not match, the following will be inserted directly before the \n character in the format string (and after any addition resulting from the effective and real user ID s not matching):

" egid=%u(%s)"

with the following arguments added at the end of the argument list:

<effective group-ID >, <effective group name>

If the process has supplementary group affiliations or the selected user is allowed to belong to multiple groups, the first will be added directly before the NEWLINE character in the format string:

" groups=%u(%s)"

with the following arguments added at the end of the argument list:

<supplementary group ID >, <supplementary group name>

and the necessary number of the following added after that for any remaining supplementary group ID s:

",%u(%s)"

and the necessary number of the following arguments added at the end of the argument list:

<supplementary group ID >, <supplementary group name>

If any of the user ID , group ID , effective user ID , effective group ID or supplementary/multiple group ID s cannot be mapped by the system into printable user or group names, the corresponding (%s) and name argument will be omitted from the corresponding format string.

When any of the options are specified, the output format will be as described under OPTIONS.

Options

The following options are supported:
-a
Reports user name, user ID and all the groups to which the user belongs.
-G
Output all different group ID s (effective, real and supplementary) only, using the format "%u\n". If there is more than one distinct group affiliation, output each such affiliation, using the format " %u", before the newline character is output.
-g
Output only the effective group ID , using the format "%u\n".
-n
Output the name in the format "%s" instead of the numeric ID using the format "%u".
-r
Output the real ID instead of the effective ID .
-u
Output only the effective user ID , using the format "%u\n".

Operands

The following operand is supported:
user
The user (login) name for which information is to be written.

Environment

See environ(5) for descriptions of the following environment variables that affect the execution of id: LC_CTYPE , LC_MESSAGES , and NLSPATH .

Exit Status

The following exit values are returned:
  1. Successful completion.
    >0
    An error occurred.

    See Also

    fold(1) , logname(1) , who(1) , getgid(2) , getgroups(2) , getuid(2) , environ(5)

    Notes

    Output produced by the -G option and by the default case could potentially produce very long lines on systems that support large numbers of supplementary groups.

    Table of Contents