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

chrootchange root directory

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

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:

group[,group ...]
Run the command with the permissions of the specified groups.
group
Run the command with the permissions of the specified group.
user
Run the command as the user.

The following environment variable is referenced by chroot:

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.

Chrooting into a New Root Directory

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

# chroot / /bin/csh
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

chdir(2), chroot(2), setgid(2), setgroups(2), setuid(2), getgrnam(3), environ(7)

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

July 20, 2021 Mac OS X 12