cdenv is a little utility to help you manage the changing of
environment variables depending on your current working directory --
changing "env" when you "cd", ergo "cdenv".
Place cdenv somewhere where you can get to it via your PATH environment variable (OK to symlink it into place), and then add the following line to your shell's startup file (.zshrc, .bashrc, .profile, or the like):
eval "`cdenv -i`"
The command has a few different usage patterns, see cdenv -h for
info.
Once you have it configured (see Installation, above), you'll want to
create, in certain directories, a file called .cdenv. That file can
have one or more lines of the form (in
BNF):
<cdenv-line> ::= <command> ':' <optional-whitespace> <args>
<command> ::= "prepend_path"
<optional-whitespace> ::= " " <optional-whitespace> | ""
<args> ::= <!-- could be anything, currently -->
prepend_path is currently the only command supported. Expect more
in the future.
prepend_path : prepends the given string (which may contain colons) to your PATH. Upon exiting a directory, if that string is still at the beginning of your PATH, it will be removed.
More to come.
Inspired by some tools I've seen at companies past, cdenv is a
little utility (and some helper library code) for managing changes to
such things as environment variables upon execution of a cd command
in the shell (change directories).
This can be useful for cases where you want certain environment variables to change depending on what directory you're in. For example, if you've different source code projects that use different versions of the same set of tools, cdenv can change your PATH (and/or other relevant variables) such that when you cd into a particular project's directory heirarchy, you'll be using the correct set of tools. (I've seen this used for changing compiler versions depending on which source tree you're in, to use appropriate cross-compilers and/or toolchains. Recently, I've been motivated to finally write these tools by the release of Rails 3, while I'm also maintaining various sites that still use previous versions of rails.)
This utility is currently still in its infancy, nominally supporting thus far:
- zsh, bash, sh/ksh syntax replacement for
cd - commands as listed above
See the TODO file for the various things still needing to be done.