CHROOT(2) BSD Programmer's Manual CHROOT(2)
chroot - change root directory
chroot(const char *dirname);
Dirname is the address of the pathname of a directory, terminated by an
ASCII NUL. Chroot() causes dirname to become the root directory, that
is, the starting point for path searches of pathnames beginning with `/'.
In order for a directory to become the root directory a process must have
execute (search) access for that directory.
It should be noted that chroot() has no effect on the process's current
This call is restricted to the super-user.
Upon successful completion, a value of 0 is returned. Otherwise, a value
of -1 is returned and errno is set to indicate an error.
Chroot() will fail and the root directory will be unchanged if:
[ENOTDIR] A component of the path name is not a directory.
[EINVAL] The pathname contains a character with the high-order bit set.
A component of a pathname exceeded 255 characters, or an en-
tire path name exceeded 1023 characters.
[ENOENT] The named directory does not exist.
[EACCES] Search permission is denied for any component of the path
[ELOOP] Too many symbolic links were encountered in translating the
[EFAULT] Path points outside the process's allocated address space.
[EIO] An I/O error occurred while reading from or writing to the
The chroot function call appeared in 4.2BSD.
4.2 Berkeley Distribution June 4, 1993 1