switch-ruby

switch-ruby

#!/bin/bash

#
# switch-ruby - Simple Ruby switcher
#
# The MIT License (MIT)
#
# Copyright (c) 2014 Jun SAITO <jun.saito@u-cast.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#

RUBIES_HOME=$HOME/.rubies
CURRENT=$RUBIES_HOME/current

AVAILABLE_RUBIES=($(find $RUBIES_HOME -maxdepth 1 -type d | grep -v "^$RUBIES_HOME$"))

function show_rubies() {
    current=$(readlink -f $CURRENT)
    i=0
    for ruby in ${AVAILABLE_RUBIES[@]}; do
        if [ $ruby == $current ]; then
            echo "--> " \($i\) $ruby
        else
            echo "    " \($i\) $ruby
        fi
        i=$((i+1))
    done
}

function switch_ruby()
{
    if [ -z $1 ]; then
        usage
        exit 1
    fi
    len=${#AVAILABLE_RUBIES[*]}
    if [ $1 -lt 0 -o $(expr $len - 1) -lt $1 ]; then
        echo "Error: Invalid number."
        exit 1
    fi
    if [ -e $CURRENT ]; then
        unlink $CURRENT
    fi
    ln -sv ${AVAILABLE_RUBIES[$1]} $CURRENT
}

function usage()
{
    cat <<EOF
Usage: $(basename $0) <command>

Available commands:

list                List installed rubies.
switch <number>     Switch ruby.

EOF
}

case $1 in
    ls | list)   show_rubies ;;
    sw | switch) switch_ruby $2 ;;
    *)           usage ;;
esac