xref: /freebsd/usr.bin/newgrp/newgrp.1 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)
129f48d62STim J. Robbins.\" Copyright (c) 2002 Tim J. Robbins.
229f48d62STim J. Robbins.\" All rights reserved.
329f48d62STim J. Robbins.\"
429f48d62STim J. Robbins.\" Redistribution and use in source and binary forms, with or without
529f48d62STim J. Robbins.\" modification, are permitted provided that the following conditions
629f48d62STim J. Robbins.\" are met:
729f48d62STim J. Robbins.\" 1. Redistributions of source code must retain the above copyright
829f48d62STim J. Robbins.\"    notice, this list of conditions and the following disclaimer.
929f48d62STim J. Robbins.\" 2. Redistributions in binary form must reproduce the above copyright
1029f48d62STim J. Robbins.\"    notice, this list of conditions and the following disclaimer in the
1129f48d62STim J. Robbins.\"    documentation and/or other materials provided with the distribution.
1229f48d62STim J. Robbins.\"
1329f48d62STim J. Robbins.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
1429f48d62STim J. Robbins.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1529f48d62STim J. Robbins.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1629f48d62STim J. Robbins.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
1729f48d62STim J. Robbins.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
1829f48d62STim J. Robbins.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
1929f48d62STim J. Robbins.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2029f48d62STim J. Robbins.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2129f48d62STim J. Robbins.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2229f48d62STim J. Robbins.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2329f48d62STim J. Robbins.\" SUCH DAMAGE.
2429f48d62STim J. Robbins.\"
25*30c4fc7cSDag-Erling Smørgrav.Dd February 8, 2013
2629f48d62STim J. Robbins.Dt NEWGRP 1
2729f48d62STim J. Robbins.Os
2829f48d62STim J. Robbins.Sh NAME
2929f48d62STim J. Robbins.Nm newgrp
3029f48d62STim J. Robbins.Nd change to a new group
3129f48d62STim J. Robbins.Sh SYNOPSIS
3229f48d62STim J. Robbins.Nm
3329f48d62STim J. Robbins.Op Fl l
3429f48d62STim J. Robbins.Op Ar group
3529f48d62STim J. Robbins.Sh DESCRIPTION
3629f48d62STim J. RobbinsThe
3729f48d62STim J. Robbins.Nm
3829f48d62STim J. Robbinsutility creates a new shell execution environment with modified
3929f48d62STim J. Robbinsreal and effective group IDs.
4029f48d62STim J. Robbins.Pp
4129f48d62STim J. RobbinsThe options are as follows:
4229f48d62STim J. Robbins.Bl -tag -width indent
4329f48d62STim J. Robbins.It Fl l
4429f48d62STim J. RobbinsSimulate a full login.
4529f48d62STim J. RobbinsThe environment and umask are set to what would be expected if the user
4629f48d62STim J. Robbinsactually logged in again.
4729f48d62STim J. Robbins.El
4829f48d62STim J. Robbins.Pp
4929f48d62STim J. RobbinsIf the
5029f48d62STim J. Robbins.Ar group
5129f48d62STim J. Robbinsoperand is present, a new shell is started with the specified effective
5229f48d62STim J. Robbinsand real group IDs.
5329f48d62STim J. RobbinsThe user will be prompted for a password if they are not a member of the
5429f48d62STim J. Robbinsspecified group.
5529f48d62STim J. Robbins.Pp
5629f48d62STim J. RobbinsOtherwise, the real, effective and supplementary group IDs are restored to
5729f48d62STim J. Robbinsthose from the current user's password database entry.
58a866e170SRuslan Ermilov.Sh EXIT STATUS
5929f48d62STim J. RobbinsThe
6029f48d62STim J. Robbins.Nm
618bf118edSRuslan Ermilovutility attempts to start the shell regardless of whether group IDs
6229f48d62STim J. Robbinswere successfully changed.
6329f48d62STim J. Robbins.Pp
6429f48d62STim J. RobbinsIf an error occurs and the shell cannot be started,
6529f48d62STim J. Robbins.Nm
6629f48d62STim J. Robbinsexits >0.
6729f48d62STim J. RobbinsOtherwise, the exit status of
6829f48d62STim J. Robbins.Nm
6929f48d62STim J. Robbinsis the exit status of the shell.
7029f48d62STim J. Robbins.Sh SEE ALSO
7129f48d62STim J. Robbins.Xr csh 1 ,
7229f48d62STim J. Robbins.Xr groups 1 ,
7329f48d62STim J. Robbins.Xr login 1 ,
7429f48d62STim J. Robbins.Xr sh 1 ,
7529f48d62STim J. Robbins.Xr su 1 ,
7629f48d62STim J. Robbins.Xr umask 1 ,
7729f48d62STim J. Robbins.Xr group 5 ,
7829f48d62STim J. Robbins.Xr passwd 5 ,
7929f48d62STim J. Robbins.Xr environ 7
8029f48d62STim J. Robbins.Sh STANDARDS
8129f48d62STim J. RobbinsThe
8229f48d62STim J. Robbins.Nm
8329f48d62STim J. Robbinsutility conforms to
8429f48d62STim J. Robbins.St -p1003.1-2001 .
8529f48d62STim J. Robbins.Sh HISTORY
8629f48d62STim J. RobbinsA
8729f48d62STim J. Robbins.Nm
8829f48d62STim J. Robbinsutility appeared in
8929f48d62STim J. Robbins.At v6 .
9029f48d62STim J. Robbins.Sh BUGS
91*30c4fc7cSDag-Erling SmørgravFor security reasons, the
92*30c4fc7cSDag-Erling Smørgrav.Nm
93*30c4fc7cSDag-Erling Smørgravutility is normally installed without the setuid bit.
94*30c4fc7cSDag-Erling SmørgravTo enable it, run the following command:
95*30c4fc7cSDag-Erling Smørgrav.Bd -literal -offset indent
96*30c4fc7cSDag-Erling Smørgravchmod u+s /usr/bin/newgrp
97*30c4fc7cSDag-Erling Smørgrav.Ed
98*30c4fc7cSDag-Erling Smørgrav.Pp
9929f48d62STim J. RobbinsGroup passwords are inherently insecure as there is no way to stop
100*30c4fc7cSDag-Erling Smørgravusers obtaining the password hash from the group database.
10129f48d62STim J. RobbinsTheir use is discouraged.
102*30c4fc7cSDag-Erling SmørgravInstead, users should simply be added to the necessary groups.
103