SETGID(3P)                                          POSIX Programmer's Manual                                         SETGID(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       setgid - set-group-ID

SYNOPSIS
       #include <unistd.h>

       int setgid(gid_t gid);


DESCRIPTION
       If  the  process has appropriate privileges, setgid() shall set the real group ID, effective group ID, and the saved set-
       group-ID of the calling process to gid.

       If the process does not have appropriate privileges, but gid is equal to the real group ID  or  the  saved  set-group-ID,
       setgid() shall set the effective group ID to gid; the real group ID and saved set-group-ID shall remain unchanged.

       The setgid() function shall not affect the supplementary group list in any way.

       Any supplementary group IDs of the calling process shall remain unchanged.

RETURN VALUE
       Upon successful completion, 0 is returned. Otherwise, -1 shall be returned and errno set to indicate the error.

ERRORS
       The setgid() function shall fail if:

       EINVAL The value of the gid argument is invalid and is not supported by the implementation.

       EPERM  The  process does not have appropriate privileges and gid does not match the real group ID or the saved set-group-
              ID.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       Refer to the RATIONALE section in setuid().

FUTURE DIRECTIONS
       None.

SEE ALSO
       exec(), getegid(), geteuid(), getgid(), getuid(), setegid(), seteuid(), setregid(), setreuid(), setuid(), the Base  Defi-
       nitions volume of IEEE Std 1003.1-2001, <sys/types.h>, <unistd.h>

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open  Group
       Standard   is   the   referee   document.   The   original   Standard   can   be   obtained  online  at  http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                    SETGID(3P)