Function: shell-dirtrack-toggle

Toggle directory tracking in this shell buffer (Shell Dirtrack mode).
With a prefix argument ARG, enable Shell Dirtrack mode if ARG is
positive, and disable it otherwise. If called from Lisp, enable
the mode if ARG is omitted or nil.

The `dirtrack' package provides an alternative implementation of
this feature; see the function `dirtrack-mode'. (fn &optional ARG)