.\" Copyright (c) 1980, 1991, 1993, 1994 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)setregid.2 8.2 (Berkeley) 4/16/94 .\" $FreeBSD: src/lib/libc/sys/setregid.2,v 126.96.36.199 2001/12/14 18:34:01 ru Exp $ .\" .Dd April 16, 1994 .Dt SETREGID 2 .Os .Sh NAME .Nm setregid .Nd set real and effective group ID .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In unistd.h .Ft int .Fn setregid "gid_t rgid" "gid_t egid" .Sh 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 effective group ID and vice-versa; only the super-user may make other changes. .Pp 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. .Pp The .Fn 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; its purpose is now better served by the use of the .Fn setegid function (see .Xr setuid 2 ) . .Pp When setting the real and effective group IDs to the same value, the standard .Fn setgid function is preferred. .Sh RETURN VALUES .Rv -std setregid .Sh ERRORS .Bl -tag -width Er .It Bq Er 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. .El .Sh SEE ALSO .Xr getgid 2 , .Xr issetugid 2 , .Xr setegid 2 , .Xr setgid 2 , .Xr setuid 2 .Sh HISTORY The .Fn setregid system call appeared in .Bx 4.2 .