CHROOT(2) Linux Programmer's Manual CHROOT(2)
NAME
chroot(1,2) - change root directory
SYNOPSIS
#include <unistd.h>
int chroot(1,2)(const char *path);
DESCRIPTION
chroot(1,2) changes the root directory to that specified in(1,8) path. This
directory will be used for path names 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 capabil-
ity) may call chroot(1,2)(2).
This call changes an ingredient in(1,8) 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
super-user can escape from a `chroot(1,2) jail' by doing `mkdir(1,2) foo; chroot(1,2)
foo; cd ..'.
This call does not close(2,7,n) open(2,3,n) file(1,n) descriptors, and such file(1,n) descrip-
tors may allow access(2,5) to files outside the chroot(1,2) tree.
RETURN VALUE
On success, zero is returned. On error(8,n), -1 is returned, and errno is
set(7,n,1 builtins) appropriately.
ERRORS
Depending on the file(1,n) 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(2).)
EFAULT path points outside your accessible address space.
EIO An I/O error(8,n) occurred.
ELOOP Too many symbolic links were encountered in(1,8) resolving path.
ENAMETOOLONG
path is too long.
ENOENT The file(1,n) 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, SVID, 4.4BSD, X/OPEN. This function is not part of POSIX.1.
SVr4 documents additional EINTR, ENOLINK and EMULTIHOP error(8,n) condi-
tions. X/OPEN does not document EIO, ENOMEM or EFAULT error(8,n) condi-
tions. This interface is marked as legacy by X/OPEN.
NOTES
FreeBSD has a stronger jail() system call.
SEE ALSO
chdir(2), path_resolution(2)
Linux 2.6.7 2004-06-23 CHROOT(2)