CHDIR(2) System Calls Manual CHDIR(2)
chdir, chroot - change default directory
Dirname is the address of the pathname of a directory, terminated by a
null byte. Chdir causes this directory to become the current working
directory, the starting point for path names not beginning with `/'.
Chroot sets the root directory, the starting point for path names
beginning with `/'. The call is restricted to the super-user.
Zero is returned if the directory is changed; -1 is returned if the
given name is not that of a directory or is not searchable.
(chdir = 12.)
sys chdir; dirname
(chroot = 61.)
sys chroot; dirname