FreeBSD manual

download PDF document: chroot.8.pdf

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