magic

define bash functions on a per-directory basis

Installation

make install installs into /usr/lib/magic by default.

make PREFIX=/your/prefix install to install to a different prefix.

make DESTDIR=stage install for a staged install.

Add the following line to your .bashrc or .zshrc:

source /usr/lib/magic/magic

If you used a different PREFIX, adjust the path accordingly.

Usage

Define some bash functions in a script named .spells and place it into the directory below which these functions shall be defined. Be sure to echo the name of each function you define at the end of the script.

Upon entering the directory the .spells file will be sourced and the functions defined in it will be available at the prompt. Upon leaving the directory all functions will be unset again (provided the .spells script correctly echoes their names).

Examples

A simple get command for github

Assume you have a directory ~/workspace under which you store your git repositories. Create a .spells file in this directory, defining a function called get:

function get() {
   local author="$1"
   local project="$2"

   git clone "https://github.com/${author}/${project}"
}
echo get

Now you can clone a repository from github by cd'ing into ~/workspace and typing

$ get hbekel magic

This function will only be defined below the ~/workspace directory.

Multiple .spells in the current path

Assume that ~/.spells reads

function play {
    echo "THE ONLY WINNING MOVE IS NOT TO PLAY"
}
echo play

And that ~/music/.spells reads

function play {
    mplayer "$@"
}
echo play

Anywhere in your home directory play will echo THE ONLY WINNING MOVE IS NOT TO PLAY, except below the music directory, where play foo.mp3 will instead call mplayer foo.mp3.

More specifically, whenever you change into a directory, the current path will be searched top down, starting at the root of the filesystem. Every readable .spells files encountered along the way will be sourced immediately. This means that .spells files further down the hierarchy can effectively override functions defined in .spells files residing higher up in the hierarchy.

Feedback

If you do something interesting with this, please let me know :)