yumh

writing about things, sometimes.

enjoying CDPATH

Written by Omar Polo on 27 June 2020.

If you use the shell a lot, you may find this advice useful, in case you didn't already knew it. There's an environment variable called CDPATH, used by most shell I know and others cli tools, whose raison d'être is to simplify ‘cd’-ing around.

As various environmental variables in UNIX, its value is a list of directories separated by colons, just like PATH. For instance, this is what I currently have in my ‘~/.kshrc’:

export CDPATH=.:$HOME/w:/usr/ports

With that in place, no matter where my current working directory is, I can ‘cd games/godot’ and jump to ‘/usr/ports/games/godot’!

A note of warning: ‘.’ (the dot aka your current working directory) should be present in your $CDPATH, otherwise you won't be able to ‘cd’ into directories not found in your $CDPATH (you can still use ‘cd ./$somedir’, but isn't probably what you want).

Programs that I know respect $CDPATH

Since the entry would be too short otherwise, here's some programs that I know respect $CDPATH, and how they behave.

ksh (OpenBSD pdksh)

Just as I showed you up there. When you ‘cd’ into a directory inside your $CDPATH it will print your new current working directory:

$ cd games/godot
/usr/ports/games/godot

It will not, however, autocomplete.

bash

It will behave just like ksh.

zsh

zsh respects $CDPATH but it doesn’t seem to do completions :(

rc

9ports’ rc does not seem to inherit $CDPATH, but you can set it (unsurprisingly) with

cdpath=(. /usr/ports)

in your ‘~/lib/profile’. Other versions of rc (I'm talking about the one you get with the rc package on FreeBSD) do inherit it, so double check!

Additionally, rc prints the ‘pwd’ only if you're ‘cd’-ing into something that's not within the current directory. So:

% pwd
/home/op
% echo $cdpath
. /usr/ports
% cd bin  # won't print /home/op/bin
% cd games
/usr/ports/games
%

csh & tcsh

set cdpath = (. /usr/ports)

for the rest, behaves exactly like `rc`. I don't really use csh, nor tcsh, so I can't make further comments.

fish

I've installed fish just for this post. It does respect $CDPATH and, unlike other shells, is also able to do proper autocompletion out-of-the-box!

vi (nvi)

vi will inherit your $CDPATH (but make sure you're exporting it in the environment!). You can also ‘:set cdpath=…’ if you wish. You cannot edit a file like ‘:e games/godot/Makefile’ and expect vi to open ‘/usr/ports/games/godot/Makefile‘ though, you need first to ‘:cd games/godot‘ and then ‘:e Makefile’!

bonus: Emacs

Emacs vanilla ‘M-x cd’ respects your $CDPATH, you just have to delete the default text in the minibuffer. It also does proper autocompletion! Additionally, eshell respects $CDPATH too! Not every other Emacs packages will, however. For instance, ivy doesn't seem to care about it.

On the other hand, with Emacs you have other ways to quickly jump around.