Variable: shell-pushd-regexp
shell-pushd-regexp is a customizable variable defined in shell.el.gz.
Value
"pushd"
Documentation
Regexp to match subshell commands equivalent to pushd.
Probably introduced at or before Emacs version 17.
Source Code
;; Defined in /usr/src/emacs/lisp/shell.el.gz
(defcustom shell-pushd-regexp "pushd"
"Regexp to match subshell commands equivalent to pushd."
:type 'regexp
:group 'shell-directories)