chroot(2) BSD System Calls Manual chroot(2)
NAME
chroot -- change root directory
SYNOPSIS
#include <unistd.h>
int
chroot(const char *dirname);
DESCRIPTION
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.
If the program is not currently running with an altered root directory,
it should be noted that chroot() has no effect on the process's current
directory.
If the program is already running with an altered root directory, the
process's current directory is changed to the same new root directory.
This prevents the current directory from being further up the directory
tree than the altered root directory.
This call is restricted to the super-user.
RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value
of -1 is returned and errno is set to indicate an error.
ERRORS
Chroot() will fail and the root directory will be unchanged if:
[ENOTDIR] A component of the path name is not a directory.
[ENAMETOOLONG] A component of a pathname exceeded {NAME_MAX} charac-
ters, or an entire path name exceeded {PATH_MAX} char-
acters.
[ENOENT] The named directory does not exist.
[EACCES] Search permission is denied for any component of the
path name.
[ELOOP] Too many symbolic links were encountered in translat-
ing the pathname.
[EFAULT] Path points outside the process's allocated address
space.
[EIO] An I/O error occurred while reading from or writing to
the file system.
SEE ALSO
chdir(2)
WARNINGS
There are ways for a root process to escape from the chroot jail.
HISTORY
The chroot() function call appeared in 4.2BSD.
4.2 Berkeley Distribution June 4, 1993 4.2 Berkeley Distribution
Mac OS X 10.9.1 - Generated Sun Jan 5 19:41:32 CST 2014