ruby-wrapper

#!/bin/sh
# ruby-wrapper - a tiny Ruby selector that sets up meaningful paths
#
# Written by Christian Neukirchen <purl.org/net/chneukirchen>, 2010.
# To the extent possible under law, the creator of this work has waived
# all copyright and related or neighboring rights to this work.
# http://creativecommons.org/publicdomain/zero/1.0/
#
# This script is meant to be installed as "ruby" in your path.
# It also should work with dash.  You should adjust DEFAULT_RUBY.
DEFAULT_RUBY=/usr/bin/ruby-1.8

RUBY=${RUBY:-$DEFAULT_RUBY}
PRJ=.
BIN=

until [ -d $PRJ/bin -o -d $PRJ/lib -o "$(readlink -f $PRJ)" = / ]; do
  PRJ=$PRJ/..
done

for path in ~/.ruby/bin $PRJ/.ruby/bin $PRJ/vendor/*/bin $PRJ/bin; do
  [ -d $path ] && export RUBYPATH=$path:$RUBYPATH
  [ -x $path/$RUBY ] && BIN=$path/$RUBY
done

for path in ~/.ruby/lib $PRJ/.ruby/lib $PRJ/vendor/*/lib $PRJ/lib; do
  [ -d $path ] && export RUBYLIB=$path:$RUBYLIB
done

BIN=${BIN:-$RUBY}
[ -L $BIN ] && BIN=$(readlink $BIN)
exec $BIN "$@"