Shell script to swap knife configs

knife-config

#!/bin/sh
die () {
    echo >&2 "$@"
    exit 1
}

available_configs () {
    echo "Available configs:"
    ls -A ~ | grep .chef- | sed 's/.chef-//'
}

if [ ! "$#" == 1 ]
then
    echo "Usage: knife-config CHEF_SERVER"
    available_configs
    exit 0
fi

if [ ! -d ~/.chef-$1 ]
then
    available_configs
    die "~/.chef-$1 does not exist or is not a directory."
fi

if [ ! -L ~/.chef ]
then
    if [ -a ~/.chef ]
    then
        die "~/.chef is not a symlink."
    fi
fi

rm -f ~/.chef

if [ -a ~/.chef ]
then
    die "~/.chef not successfully deleted"
fi

if [ ! -a ~/.chef ]
then
    echo "~/.chef symlinked to ~/.chef-$1"
    ln -s ~/.chef-$1 ~/.chef
fi

Related: https://github.com/trobrock/chefvm (alternative solution)