CHROOT(8)               FreeBSD System Manager's Manual              CHROOT(8)

NAME
     chroot - change root directory

SYNOPSIS
     chroot [-G group[,group ...]] [-g group] [-u user] [-n] newroot
            [command [arg ...]]

DESCRIPTION
     The chroot utility changes its current and root directories to the
     supplied directory newroot and then exec's command with provided
     arguments, if supplied, or an interactive copy of the user's login shell.

     The options are as follows:

     -G group[,group ...]  Run the command with the permissions of the
                           specified groups.

     -g group              Run the command with the permissions of the
                           specified group.

     -u user               Run the command as the user.

     -n                    Use the PROC_NO_NEW_PRIVS_CTL procctl(2) command
                           before chrooting, effectively disabling SUID/SGID
                           bits for the calling process and its descendants.
                           If security.bsd.unprivileged_chroot sysctl is set
                           to 1, it will make it possible to chroot without
                           superuser privileges.

ENVIRONMENT
     The following environment variable is referenced by chroot:

     SHELL  If set, the string specified by SHELL is interpreted as the name
            of the shell to exec.  If the variable SHELL is not set, /bin/sh
            is used.

EXAMPLES
     Example 1: Chrooting into a New Root Directory

       The following command opens the csh(1) shell after chrooting to the
       standard root directory.

         # chroot / /bin/csh

     Example 2: Execution of a Command with a Changed Root Directory

       The following command changes a root directory with chroot and then
       runs ls(1) to list the contents of /sbin.

         # chroot /tmp/testroot ls /sbin

SEE ALSO
     chdir(2), chroot(2), setgid(2), setgroups(2), setuid(2), getgrnam(3),
     environ(7), jail(8)

HISTORY
     The chroot utility first appeared in AT&T System III UNIX and
     4.3BSD-Reno.

FreeBSD 13.1-RELEASE-p6          July 20, 2021         FreeBSD 13.1-RELEASE-p6