SETREGID(2)                 BSD Programmer's Manual                SETREGID(2)

NAME
     setregid - set real and effective group ID

SYNOPSIS
     #include <unistd.h>

     int
     setregid(int rgid, int egid)

DESCRIPTION
     The real and effective group ID's of the current process are set to the
     arguments.  Unprivileged users may change the real group ID to the effec-
     tive group ID and vice-versa; only the super-user may make other changes.

     Supplying a value of -1 for either the real or effective group ID forces
     the system to substitute the current ID in place of the -1 parameter.

     The setregid(function, was, intended, to, allow, swapping) the real and
     effective group IDs in set-group-ID programs to temporarily relinquish
     the set-group-ID value.  This function did not work correctly, and its
     purpose is now better served by the use of the setegid() function (see
     setuid(2)).

     When setting the real and effective group IDs to the same value, the
     standard setgid() function is preferred.

RETURN VALUES
     Upon successful completion, a value of 0 is returned.  Otherwise, a value
     of -1 is returned and errno is set to indicate the error.

ERRORS
     [EPERM]  The current process is not the super-user and a change other
              than changing the effective group-id to the real group-id was
              specified.

SEE ALSO
     getgid(2),  setegid(2),  setgid(2),  setuid(2)

HISTORY
     The setregid function call appeared in 4.2BSD.

4.2 Berkeley Distribution       March 26, 1993                               1