1.\" $NetBSD: newgrp.1,v 1.2 2007/10/17 21:07:49 christos Exp $ 2.\" 3.\" Copyright (c) 2007, The NetBSD Foundation. 4.\" All Rights Reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Brian Ginsbach. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgment: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.Dd June 6, 2007 38.Dt NEWGRP 1 39.Os 40.Sh NAME 41.Nm newgrp 42.Nd change to a new primary group 43.Sh SYNOPSIS 44.Nm 45.Op Fl l 46.Op Ar group 47.Sh DESCRIPTION 48The 49.Nm 50command changes a user to a new primary group 51.Pq real and effective group ID 52by starting a new shell. 53The user remains logged in and the current directory 54and file creation mask remain unchanged. 55The user is always given a new shell even if 56the primary group change fails. 57.Pp 58The 59.Nm 60command accepts the following options: 61.Bl -tag -width indent 62.It Fl l 63The environment is changed to what would be expected if the user 64actually logged in again. 65This simulates a full login. 66.El 67.Pp 68The 69.Ar group 70is a group name or non-negative numeric group ID from the group database. 71The real and effective group IDs are set to 72.Ar group 73or the group ID associated with the group name. 74.Pp 75If 76.Ar group 77is not specified, 78.Nm 79restores the user's real and effective group IDs to the user's 80primary group specified in the password database. 81The user's supplementary group IDs are restored to the set specified 82for the user in the group database. 83.Pp 84If the user is not a member of the specified group, and the group 85requires a password, the user will be prompted for the group password. 86.Sh EXIT STATUS 87If a new shell is started the exit status is the exit status of the shell. 88Otherwise the exit status will be \*[Gt]0. 89.Sh FILES 90.Bl -tag -width /etc/master.passwd -compact 91.It Pa /etc/group 92The group database 93.It Pa /etc/master.passwd 94The user database 95.It Pa /etc/passwd 96A Version 7 format password file 97.El 98.Sh SEE ALSO 99.Xr csh 1 , 100.Xr groups 1 , 101.Xr login 1 , 102.Xr sh 1 , 103.Xr su 1 , 104.Xr umask 2 , 105.Xr group 5 , 106.Xr passwd 5 , 107.Xr environ 7 108.Sh STANDARDS 109The 110.Nm 111command conforms to 112.St -p1003.1-2001 . 113.Sh HISTORY 114A 115.Nm 116command appeared in 117.At v6 . 118A 119.Nm 120command appeared in 121.Nx 5.0 . 122.Sh BUGS 123There is no convenient way to enter a password into 124.Pa /etc/group . 125The use of group passwords is strongly discouraged 126since they are inherently insecure. 127It is not possible to stop users from obtaining the encrypted 128password from the group database. 129