id(1) [osx man page]

ID(1)							    BSD General Commands Manual 						     ID(1)

NAME

     id -- return user identity

SYNOPSIS

     id [user]
     id -A
     id -G [-n] [user]
     id -M
     id -P [user]
     id -g [-nr] [user]
     id -p [user]
     id -u [-nr] [user]

DESCRIPTION

     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:

     -A      Display the process audit user ID and other process audit properties, which requires privilege.

     -G      Display the different group IDs (effective, real and supplementary) as white-space separated numbers, in no particular order.

     -M      Display the MAC label of the current process.

     -P      Display the id as a password file entry.

     -a      Ignored for compatibility with other id implementations.

     -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''.  Each display is on a separate line.

     -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.

EXIT STATUS

     The id utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

     who(1)

STANDARDS

     The id function is expected to conform to IEEE Std 1003.2 (``POSIX.2'').

HISTORY

     The historic groups(1) command is equivalent to ``id -Gn [user]''.

     The historic whoami(1) command is equivalent to ``id -un''.

     The id command appeared in 4.4BSD.

BSD
								September 26, 2006							       BSD

Check Out this Related Man Page

setresuid(2)							System Calls Manual						      setresuid(2)

NAME

       setresuid, setresgid - set real, effective, and saved user and group IDs

SYNOPSIS

DESCRIPTION

       sets the real, effective and/or saved user ID of the calling process.

       If  the	current  real,	effective  or saved user ID is equal to that of a user having appropriate privileges, sets the real, effective and
       saved user IDs to ruid, euid, and suid, respectively.  Otherwise, only sets the real, effective, and saved user IDs if ruid, euid, and suid
       each match at least one of the current real, effective, or saved user IDs.

       If ruid, euid, or suid is leaves the current real, effective or saved user ID unchanged.

       sets the real, effective and/or saved group ID of the calling process.

       If  the	current  real,	effective or saved user ID is equal to that of a user having appropriate privileges, sets the real, effective, and
       saved group ID to rgid, egid, and sgid, respectively.  Otherwise, only sets the real, effective and saved group ID if rgid, egid, and  sgid
       each match at least one of the current real, effective or saved group ID.

       If rgid, egid, or sgid is leaves the current real, effective or saved group ID unchanged.

   Security Restrictions
       Some  or  all  of  the actions associated with this system call require the privilege (CHSUBJIDENT).  Processes owned by the superuser will
       have this privilege.  Processes owned by other users may have this privilege, depending on system configuration.

       See privileges(5) for more information about privileged access on systems that support fine-grained privileges.

RETURN VALUE

       Upon successful completion, and return 0; otherwise, they return -1 and set to indicate the error.

ERRORS

       and fail if any of the following conditions are encountered:

	      ruid,	     euid, or suid (rgid, egid, or sgid) is not a valid user (group) ID.

	      None of the conditions above are met.

AUTHOR

       and were developed by HP.

SEE ALSO

       exec(2), getuid(2), setuid(2), privileges(5).

																      setresuid(2)

Linux and UNIX Man Pages

id(1) [osx man page]

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