SETREGID(3)               OpenBSD Programmer's Manual              SETREGID(3)

NAME
     setregid - set real and effective group IDs



SYNOPSIS
     #include <unistd.h>

     int
     setregid(int rgid, int egid);

DESCRIPTION
     The real and effective group IDs 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 ef-
     fective group IDs in set-group-ID programs to temporarily relinquish the
     set-group-ID value.  This function did not work correctly, and its pur-
     pose 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 oth-
                   er 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 and was dropped in
     4.4BSD.

OpenBSD 2.6                     March 10, 1991                               1