GNU Info

(sh-utils.info)chroot invocation

---

Next: env invocation Up: Modified command invocation

---

Enter node , (file) or (file)node

`chroot': Run a command with a different root directory
=======================================================

   `chroot' runs a command with a specified root directory.  On many
systems, only the super-user can do this.  Synopses:

     chroot NEWROOT [COMMAND [ARGS]...]
     chroot OPTION

   Ordinarily, filenames are looked up starting at the root of the
directory structure, i.e., `/'.  `chroot' changes the root to the
directory NEWROOT (which must exist) and then runs COMMAND with
optional ARGS.  If COMMAND is not specified, the default is the value
of the `SHELL' environment variable or `/bin/sh' if not set, invoked
with the `-i' option.

   The only options are `--help' and `--version'.  Note: Common
options.

   Here are a few tips to help avoid common problems in using chroot.
To start with a simple example, make COMMAND refer to a statically
linked binary.  If you were to use a dynamically linked executable, then
you'd have to arrange to have the shared libraries in the right place
under your new root directory.

   For example, if you create a statically linked `ls' executable, and
put it in /tmp/empty, you can run this command as root:

     $ chroot /tmp/empty /ls -Rl /

   Then you'll see output like this:

     /:
     total 1023
     -rwxr-xr-x    1 0        0         1041745 Aug 16 11:17 ls

   If you want to use a dynamically linked executable, say `bash', then
first run `ldd bash' to see what shared objects it needs.  Then, in
addition to copying the actual binary, also copy the listed files to
the required positions under your intended new root directory.
Finally, if the executable requires any other files (e.g., data, state,
device files), copy them into place, too.