Ruby source installation manager

opt-ruby.sh

#!/bin/bash
CONF=/etc/profile.d/optruby.sh
INSTALLED=/opt/ruby


do_status() {
    current=$(OPTRUBY=system ; [ -f $CONF ] && . $CONF ; echo $OPTRUBY )
    echo "Currently enabled version via profile.d: $current"
    echo "Currently selected by this shell: $(ruby -v)"
}

do_list() {
    echo "Available rubies:"
    find "$INSTALLED" -mindepth 1 -maxdepth 1 -execdir test -f "{}/bin/ruby" \; -ls
}

do_set() {
    set_ruby=$1
    if [ -z $set_ruby ]; then
        echo "Usage: $0 set {VERSION|system}" >&2
        exit 3
    fi
    if [ "$set_ruby" == "system" ] ; then
	echo "Using system ruby"
	[ -f "$CONF" ] && rm -f "$CONF"
    else
	tee $CONF <<-EOF 
	OPTRUBY=$set_ruby
	export PATH="$INSTALLED/\$OPTRUBY/bin:\$PATH"
	EOF
    fi
}

do_install() {
    install_ruby=$1
    if [ -z $install_ruby ]; then
        echo "Usage: $0 install VERSION" >&2
        exit 3
    fi
    ruby-build $install_ruby "$INSTALLED/$install_ruby"
}

case "$1" in
    status)
        shift
        do_status $*
        ;;
    list)
        shift
        do_list $*
        ;;
    set)
        shift
        do_set $*
        ;;
    install)
        shift
        do_install $*
        ;;
    *)
        echo "Usage: $0 {status|list|set|install}" >&2
        exit 3
        ;;
esac