chroot(2) [ultrix man page]

chroot(2)							System Calls Manual							 chroot(2)

Name
       chroot - change root directory

Syntax
       chroot(dirname)
       char *dirname;

Description
       The  dirname is the address of the pathname of a directory, terminated by a null byte.  The system call causes this directory to become the
       root directory (/).

       For a directory to become the root directory, a process must have execute (search) access to the directory.

       This call is restricted to the superuser.

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.

Diagnostics
       The system call fails and the root directory is unchanged under the following conditions:

       [ENOTDIR]      A component of the dirname is not a directory.

       [ENAMETOOLONG] A component of a dirname exceeded 255 characters, or an entire dirname exceeded 1023 characters.

       [ENOENT]       The dirname argument points to the name of a directory which does not exist, or to  an  empty  string  and  the  environment
		      defined is POSIX or SYSTEM_FIVE.

       [EFAULT]       The dirname points outside the process's allocated address space.

       [ELOOP]	      Too many symbolic links were encountered in translating the pathname.

       [EIO]	      An I/O error occurred while reading from or writing to the file system.

       [ESTALE]       The  file  handle  given	in the argument is invalid.  The file referred to by that file handle no longer exists or has been
		      revoked.

       [ETIMEDOUT]    A connect request or remote file operation failed because the connected party did not properly respond  after  a	period	of
		      time that is dependent on the communications protocol.

       [EPERM]	      The effective user ID is not that of superuser.

See Also
       chdir(2)

																	 chroot(2)

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 cur-
     rent 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} characters, or an entire path name exceeded {PATH_MAX} characters.

     [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 translating 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