sys/setregid.2

   1 .\" Copyright (c) 1980, 1991, 1993, 1994
   2 .\"     The Regents of the University of California.  All rights reserved.
   3 .\"
   4 .\" Redistribution and use in source and binary forms, with or without
   5 .\" modification, are permitted provided that the following conditions
   6 .\" are met:
   7 .\" 1. Redistributions of source code must retain the above copyright
   8 .\"    notice, this list of conditions and the following disclaimer.
   9 .\" 2. Redistributions in binary form must reproduce the above copyright
  10 .\"    notice, this list of conditions and the following disclaimer in the
  11 .\"    documentation and/or other materials provided with the distribution.
  12 .\" 3. All advertising materials mentioning features or use of this software
  13 .\"    must display the following acknowledgement:
  14 .\"     This product includes software developed by the University of
  15 .\"     California, Berkeley and its contributors.
  16 .\" 4. Neither the name of the University nor the names of its contributors
  17 .\"    may be used to endorse or promote products derived from this software
  18 .\"    without specific prior written permission.
  19 .\"
  20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30 .\" SUCH DAMAGE.
  31 .\"
  32 .\"     @(#)setregid.2  8.2 (Berkeley) 4/16/94
  33 .\" $FreeBSD: src/lib/libc/sys/setregid.2,v 1.6.2.4 2001/12/14 18:34:01 ru Exp $
  34 .\"
  35 .Dd April 16, 1994
  36 .Dt SETREGID 2
  37 .Os
  38 .Sh NAME
  39 .Nm setregid
  40 .Nd set real and effective group ID
  41 .Sh LIBRARY
  42 .Lb libc
  43 .Sh SYNOPSIS
  44 .In unistd.h
  45 .Ft int
  46 .Fn setregid "gid_t rgid" "gid_t egid"
  47 .Sh DESCRIPTION
  48 The real and effective group ID's of the current process
  49 are set to the arguments.
  50 Unprivileged users may change the real group
  51 ID to the effective group ID and vice-versa; only the super-user may
  52 make other changes.
  53 .Pp
  54 Supplying a value of -1 for either the real or effective
  55 group ID forces the system to substitute the current
  56 ID in place of the -1 parameter.
  57 .Pp
  58 The
  59 .Fn setregid
  60 function was intended to allow swapping
  61 the real and effective group IDs
  62 in set-group-ID programs to temporarily relinquish the set-group-ID value.
  63 This function did not work correctly,
  64 and its purpose is now better served by the use of the
  65 .Fn setegid
  66 function (see
  67 .Xr setuid 2 ) .
  68 .Pp
  69 When setting the real and effective group IDs to the same value,
  70 the standard
  71 .Fn setgid
  72 function is preferred.
  73 .Sh RETURN VALUES
  74 .Rv -std setregid
  75 .Sh ERRORS
  76 .Bl -tag -width Er
  77 .It Bq Er EPERM
  78 The current process is not the super-user and a change
  79 other than changing the effective group-id to the real group-id
  80 was specified.
  81 .El
  82 .Sh SEE ALSO
  83 .Xr getgid 2 ,
  84 .Xr issetugid 2 ,
  85 .Xr setegid 2 ,
  86 .Xr setgid 2 ,
  87 .Xr setuid 2
  88 .Sh HISTORY
  89 The
  90 .Fn setregid
  91 system call appeared in
  92 .Bx 4.2 .