Name
chroot — change root directory
Synopsis
#include <unistd.h>
int
chroot( |
const char * |
path); |
DESCRIPTION
chroot() changes the root
directory to that specified in path. This directory will be
used for pathnames beginning with /. The root directory is
inherited by all children of the current process.
Only a privileged process (Linux: one with the
CAP_SYS_CHROOT capability) may
call chroot(2).
This call changes an ingredient in the pathname resolution
process and does nothing else.
This call does not change the current working directory,
so that after the call `.' can be outside the tree rooted at
`/'. In particular, the superuser can escape from a `chroot
jail' by doing `mkdir foo; chroot foo; cd ..'.
This call does not close open file descriptors, and such
file descriptors may allow access to files outside the chroot
tree.
RETURN VALUE
On success, zero is returned. On error, −1 is
returned, and errno is set
appropriately.
ERRORS
Depending on the file system, other errors can be
returned. The more general errors are listed below:
- EACCES
-
Search permission is denied on a component of the
path prefix. (See also path_resolution(7).)
- EFAULT
-
path points
outside your accessible address space.
- EIO
-
An I/O error occurred.
- ELOOP
-
Too many symbolic links were encountered in
resolving path.
- ENAMETOOLONG
-
path is too
long.
- ENOENT
-
The file does not exist.
- ENOMEM
-
Insufficient kernel memory was available.
- ENOTDIR
-
A component of path is not a
directory.
- EPERM
-
The caller has insufficient privilege.
CONFORMING TO
SVr4, 4.4BSD, SUSv2 (marked LEGACY). This function is not
part of POSIX.1-2001.
NOTES
A child process created via fork(2) inherits its
parent's root directory. The root directory is left unchanged
by execve(2).
FreeBSD has a stronger jail() system call.
SEE ALSO
chdir(2), path_resolution(7)
Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
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Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
Modified by Michael Haardt <michael@moria.de>
Modified 1993-07-21 by Rik Faith <faith@cs.unc.edu>
Modified 1994-08-21 by Michael Chastain <mec@shell.portal.com>
Modified 1996-06-13 by aeb
Modified 1996-11-06 by Eric S. Raymond <esr@thyrsus.com>
Modified 1997-08-21 by Joseph S. Myers <jsm28@cam.ac.uk>
Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
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