SETREGID(3P)                                        POSIX Programmer's Manual                                       SETREGID(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
       setregid - set real and effective group IDs

SYNOPSIS
       #include <unistd.h>

       int setregid(gid_t rgid, gid_t egid);


DESCRIPTION
       The setregid() function shall set the real and effective group IDs of the calling process.

       If rgid is -1, the real group ID shall not be changed; if egid is -1, the effective group ID shall not be changed.

       The real and effective group IDs may be set to different values in the same call.

       Only a process with appropriate privileges can set the real group ID and the effective group ID to any valid value.

       A  non-privileged process can set either the real group ID to the saved set-group-ID from one of the exec family of func-
       tions, or the effective group ID to the saved set-group-ID or the real group ID.

       Any supplementary group IDs of the calling process remain unchanged.

RETURN VALUE
       Upon successful completion, 0 shall be returned. Otherwise, -1 shall be returned and errno set to indicate the error, and
       neither of the group IDs are changed.

ERRORS
       The setregid() function shall fail if:

       EINVAL The value of the rgid or egid argument is invalid or out-of-range.

       EPERM  The  process  does not have appropriate privileges and a change other than changing the real group ID to the saved
              set-group-ID, or changing the effective group ID to the real group ID or the saved set-group-ID, was requested.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       If a set-group-ID process sets its effective group ID to its real group ID, it can still set its effective group ID  back
       to the saved set-group-ID.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       exec(),  getegid(), geteuid(), getgid(), getuid(), setegid(), seteuid(), setgid(), setreuid(), setuid(), the Base Defini-
       tions volume of IEEE Std 1003.1-2001, <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                                                  SETREGID(3P)