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 (consult the correspond-
       ing 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 functions, or the effec-
       tive 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  Definitions	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 Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (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.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003							      SETREGID(3P)