.\" $OpenBSD: chroot.8,v 1.8 2002/10/29 23:12:06 millert Exp $ .\" $NetBSD: chroot.8,v 1.9 2000/08/17 12:36:32 mrg Exp $ .\" .\" 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 .\" .Dd October 25, 2002 .Dt CHROOT 8 .Os .Sh NAME .Nm chroot .Nd change root directory .Sh SYNOPSIS .Nm chroot .Op Fl u Ar user .Op Fl U Ar user .Op Fl g Ar group .Op Fl G Ar group,group,... .Ar newroot .Op Ar command .Sh DESCRIPTION The .Nm command changes its root directory to the supplied directory .Ar newroot and executes .Ar command , if supplied, or an interactive copy of the user's shell. .Pp The .Nm command is restricted to the superuser. .Pp The options are as follows: .Bl -tag -width Ds .It Fl u Ar user Set user ID to .Ar user (a user name or user ID). .It Fl U Ar user Set user, group and supplemental group IDs based on the .Xr passwd 5 database entry for .Ar user . The .Fl U option may not be specified in conjunction with any other options. .It Fl g Ar group Set group ID to .Ar group (a group name or group ID). If supplemental groups are specified via the .Fl G flag, .Ar group will be the used as the first entry in the group vector. .It Fl G Ar group,group,... Set the supplemental group IDs to a comma-separated list of group names or group IDs. If neither the .Fl G nor the .Fl U option is specified, the supplemental group list remains unchanged. .El .Sh ENVIRONMENT .Bl -tag -width SHELL .It Ev SHELL If set, the string specified by .Ev SHELL is interpreted as the name of the shell to execute. If the variable .Ev SHELL is not set, .Pa /bin/sh is used. .El .Sh SEE ALSO .Xr chdir 2 , .Xr chroot 2 , .Xr setgid 2 , .Xr setgroups 2 , .Xr setuid 2 , .Xr getgrnam 3 , .Xr getpwnam 3 , .Xr environ 7 .Sh HISTORY The .Nm utility first appeared in .Bx 4.4 . .Sh CAVEATS .Nm should never be installed setuid root, as it would then be possible to exploit the program to gain root privileges.