Script for running Ruby apps. See http://null-terminated.org/blog/2011/10/12/a-simple-ruby-runner-script/

ruby-runner.sh

#!/usr/bin/env zsh

# Set up RVM
if [[ -f $HOME/.rvm/scripts/rvm ]]; then
    source "$HOME/.rvm/scripts/rvm"
elif [[ -f /etc/profile.d/rvm.sh ]]; then
    source /etc/profile.d/rvm.sh
else
    echo RVM not found
    exit
fi

# Get the directory we're running in
DIR=$(dirname $(perl -e 'use Cwd "abs_path";print abs_path(shift)' $0))

rvm $(cat $DIR/.ruby-version)@$(cat $DIR/.ruby-gemset)

# Find some Ruby script to run based on the name of this script
if [[ -f $DIR/bin/$(basename $0).rb ]] then
    ruby -I $DIR/lib $DIR/bin/$(basename $0).rb $@
elif [[ -f $DIR/bin/$(basename $0) ]] then
    ruby -I $DIR/lib $DIR/bin/$(basename $0) $@
else
    echo 'so, um...?'
fi

Second revision allows target Ruby script to either have a .rb file extension, or not.