chroot − change root directory

#include <unistd.h>

int chroot(const char *path);

chroot changes the root directory to that specified in path. This directory will be used for path names beginning with /. The root directory is inherited by all children of the current process.

Only the super-user may change the root directory.

Note that this call does not change the current working directory, so that ‘.’ can be outside the tree rooted at ‘/’. In particular, the super-user can escape from a ‘chroot jail’ by doing ‘mkdir foo; chroot foo; cd ..’.

On success, zero is returned. On error, −1 is returned, and errno is set appropriately.

Depending on the file system, other errors can be returned. The more general errors are listed below:

EPERM

The effective UID is not zero.

EFAULT

path points outside your accessible address space.

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.

EACCES

Search permission is denied on a component of the path prefix.

ELOOP

Too many symbolic links were encountered in resolving path.

EIO

An I/O error occurred.

SVr4, SVID, 4.4BSD, X/OPEN. This function is not part of POSIX.1. SVr4 documents additional EINTR, ENOLINK and EMULTIHOP error conditions. X/OPEN does not document EIO, ENOMEM or EFAULT error conditions. This interface is marked as legacy by X/OPEN.

FreeBSD has a stronger jail() system call.

chdir(2)