Linux
Bash
shell
http://manpages.ubuntu.com/manpages/disco/en/man1/cd.1posix.html
http://manpages.ubuntu.com/manpages/disco/en/man1/mkdir.1.html
http://manpages.ubuntu.com/manpages/disco/en/man1/pwd.1.html
http://manpages.ubuntu.com/manpages/disco/en/man1/vim.1.html