I like that you or I can write command line utilities in any language, name
it git-butterfly, or whatever you want, and then run it as though it were an
official part of the git tool, as git butterfly.
It feels a lot like magic, but it’s actually not that complicated a thing to do.
If you don’t believe me, watch this video or skip after it to the code, and make
your own extendible utility, pig.
designing your own extendible command line utility from Max Jacobson on Vimeo.
If you want your own pig command line utility, copy this code to an executable
file on your $PATH called pig. Then, try running pig. Try running
pig oink.
#!/usr/bin/env sh
subcommand=$1
bin="pig-$subcommand"
paths="${PATH//:/$'\n'}"
if [[ -z $subcommand ]]; then
echo "Gimme a subcommand"
exit 1
fi
for path in $paths; do
pathToBin="$path/$bin"
if [ -f $pathToBin ]; then
$pathToBin
exit 0
fi
done
echo "$bin is not a pig command"
exit 1
