CHDIR(2)                                                 CHDIR(2)

     NAME
          chdir, chroot - change working or root directory

     SYNOPSIS
          chdir(dirname)
          char *dirname;

          chroot(dirname)
          char *dirname;

     DESCRIPTION
          Chdir changes the working directory of the invoking process
          to dirname; chroot changes its root directory.

          The root directory is the starting point when searching for
          pathnames beginning with `/'.  The working directory is the
          starting point for pathnames that don't.  The root directory
          normally points to the system root, defined when the system
          is built.  Login(1) initially sets the working directory as
          specified in the password file, passwd(5).

          After chroot, it is impossible to name a file outside the
          subtree rooted at the current root, provided that the cur-
          rent directory is located within the subtree and there are
          no links pointing outside the subtree (except for the entry
          `..'  in the root directory).

          Chroot may only be used by the super-user.

     SEE ALSO
          sh(1)

     DIAGNOSTICS
          Zero is returned if the directory was changed; -1 is
          returned if the given pathname doesn't exist, isn't a direc-
          tory or can't be searched, or if chroot is used by other
          than the super-user.

     BUGS
          Using chroot, it is quite easy to fool set-UID programs
          about the contents of the password file (for example).