which cd prints nothing. Same for
whatis cd and
whereis cd. How can I find out if cd is an alias, function, or bash built-in? I'm using Ubuntu 12.04.
Builtins don't have a man page of their own (unless they also exist as an external utility, but then you get the documentation of the external utility, which may support different options). They are documented in the bash manual.
To list all bash aliases:
To list all defined function names:
To see the list of bash builtins, check the bash manpage.
You can probably hack together a single script to grep through the output of each command above.