[apple/shell_cmds.git] / chroot / chroot.8

.\" Copyright (c) 1988, 1991, 1993
.\"	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.
.\"
.\"     from: @(#)chroot.8	8.1 (Berkeley) 6/9/93
.\"	$NetBSD: chroot.8,v 1.7 1998/10/06 03:47:50 mrg Exp $
.\"
.Dd October 6, 1998
.Dt CHROOT 8
.Os BSD 4.3
.Sh NAME
.Nm chroot
.Nd change root directory
.Sh SYNOPSIS
.Nm
.Op Fl u user
.Op Fl g group
.Op Fl G group,group,...
.Ar newroot
.Op Ar command
.Sh DESCRIPTION
The
.Nm
command changes its root directory to the supplied directory
.Ar newroot
and exec's
.Ar command ,
if supplied, or an interactive copy of your shell.
.Pp
If the
.Fl u ,
.Fl g
or
.Fl G
options are given, the user, group and group list of the process are
set to these values after the chroot has taken place.  See
.Xr setgid 2 ,
.Xr setgroups 2 ,
.Xr setuid 2 ,
.Xr getgrnam 3
and
.Xr getpwnam 3 .
.Pp
Note,
.Ar command
or the shell are run as your real-user-id.
.Sh ENVIRONMENT
The following environment variable is referenced by
.Nm :
.Bl -tag -width SHELL
.It Ev SHELL
If set,
the string specified by
.Ev SHELL
is interpreted as the name of
the shell to exec.
If the variable
.Ev SHELL
is not set,
.Pa /bin/sh
is used.
.El
.Sh SEE ALSO
.Xr chdir 2 ,
.Xr chroot 2 ,
.Xr environ 7
.Sh HISTORY
The
.Nm
utility first appeared in
.Bx 4.4 .
.Sh SECURITY CONSIDERATIONS
.Nm
should never be installed setuid root, as it would then be possible
to exploit the program to gain root privileges.
Commit	Line	Data
44bd5ea7 A	1	.\" Copyright (c) 1988, 1991, 1993
	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	.\" from: @(#)chroot.8 8.1 (Berkeley) 6/9/93
	33	.\" $NetBSD: chroot.8,v 1.7 1998/10/06 03:47:50 mrg Exp $
	34	.\"
	35	.Dd October 6, 1998
	36	.Dt CHROOT 8
	37	.Os BSD 4.3
	38	.Sh NAME
	39	.Nm chroot
	40	.Nd change root directory
	41	.Sh SYNOPSIS
	42	.Nm
	43	.Op Fl u user
	44	.Op Fl g group
	45	.Op Fl G group,group,...
	46	.Ar newroot
	47	.Op Ar command
	48	.Sh DESCRIPTION
	49	The
	50	.Nm
	51	command changes its root directory to the supplied directory
	52	.Ar newroot
	53	and exec's
	54	.Ar command ,
	55	if supplied, or an interactive copy of your shell.
	56	.Pp
	57	If the
	58	.Fl u ,
	59	.Fl g
	60	or
	61	.Fl G
	62	options are given, the user, group and group list of the process are
	63	set to these values after the chroot has taken place. See
	64	.Xr setgid 2 ,
65	.Xr setgroups 2 ,
66	.Xr setuid 2 ,
67	.Xr getgrnam 3
68	and
69	.Xr getpwnam 3 .
70	.Pp
71	Note,
72	.Ar command
73	or the shell are run as your real-user-id.
74	.Sh ENVIRONMENT
75	The following environment variable is referenced by
daf87b50	76	.Nm :
44bd5ea7 A	77	.Bl -tag -width SHELL
	78	.It Ev SHELL
	79	If set,
	80	the string specified by
	81	.Ev SHELL
	82	is interpreted as the name of
	83	the shell to exec.
	84	If the variable
	85	.Ev SHELL
	86	is not set,
	87	.Pa /bin/sh
	88	is used.
	89	.El
	90	.Sh SEE ALSO
	91	.Xr chdir 2 ,
	92	.Xr chroot 2 ,
	93	.Xr environ 7
	94	.Sh HISTORY
	95	The
	96	.Nm
	97	utility first appeared in
	98	.Bx 4.4 .
	99	.Sh SECURITY CONSIDERATIONS
	100	.Nm
	101	should never be installed setuid root, as it would then be possible
	102	to exploit the program to gain root privileges.