chroot(8) [netbsd man page]

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

NAME

     chroot -- change root directory

SYNOPSIS

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

DESCRIPTION

     The chroot command changes its root directory to the supplied directory newroot and exec's command, or, if not supplied, an interactive copy
     of your shell.

     If the -u, -g, or -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 setgid(2), setgroups(2), setuid(2), getgrnam(3), and getpwnam(3).

     Note: command or the shell are run as your real-user-id.

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.

SEE ALSO

     ldd(1), chdir(2), chroot(2), environ(7)

HISTORY

     The chroot utility first appeared in 4.4BSD.

SECURITY CONSIDERATIONS

     chroot should never be installed setuid root, as it would then be possible to exploit the program to gain root privileges.

BSD
								  August 13, 2011							       BSD

chroot(1M)						  System Administration Commands						chroot(1M)

NAME

       chroot - change root directory for a command

SYNOPSIS

       /usr/sbin/chroot newroot command

DESCRIPTION

       The  chroot  utility causes command to be executed relative to newroot. The meaning of any initial slashes (/) in the path names is changed
       to newroot for command and any of its child processes. Upon execution, the initial working directory is newroot.

       Notice that redirecting the output of command to a file,

	 chroot newroot command >x

       will create the file x relative to the original root of command, not the new one.

       The new root path name is always relative to the current root. Even if a chroot is currently in effect, the newroot argument is relative to
       the current root of the running process.

       This command can be run only by the super-user.

RETURN VALUES

       The exit status of chroot is the return value of command.

EXAMPLES

       Example 1 Using the chroot Utility

       The  chroot  utility  provides an easy way to extract tar files (see tar(1)) written with absolute filenames to a different location. It is
       necessary to copy the shared libraries used by tar (see ldd(1)) to the newroot filesystem.

	 example# mkdir /tmp/lib; cd /lib
	 example# cp ld.so.1 libc.so.1 libcmd.so.1 libdl.so.1 
		  libsec.so.1 /tmp/lib
	 example# cp /usr/bin/tar /tmp
	 example# dd if=/dev/rmt/0 | chroot /tmp tar xvf -

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       cd(1), tar(1), chroot(2), ttyname(3C), attributes(5)

NOTES

       Exercise extreme caution when referencing device files in the new root file system.

       References by routines such as ttyname(3C) to stdin, stdout, and stderr will find that the device associated with the  file  descriptor	is
       unknown after chroot is run.

SunOS 5.11							    15 Dec 2003 							chroot(1M)