find_latest_gem_versions_per_Gemfile.sh

#!/bin/bash --login
export rvmsudo_secure_path=1
rvmsudo gem update --system

cat Gemfile | awk '{print $2}' | grep -E "^'.+$" | grep -v -e rubygems.org | while read gem; do 
  this_gem=`echo $gem | sed "s/'//g" | sed 's/\,//g'`
  latest_version=`gem search -r $this_gem | grep -E "^${this_gem}\s.+$" | awk '{print $2}' | sed 's/(//g' | sed 's/)//g' | sed 's/,//g'`
  echo "${this_gem} => $latest_version"
  if [[ $this_gem == 'bundler' ]]; then
    sed -i "s/^gem '${this_gem}'.*$/gem '${this_gem}', '>=${latest_version}'/g" Gemfile
  else
    sed -i "s/^gem '${this_gem}'.*$/gem '${this_gem}', '${latest_version}'/g" Gemfile
  fi
done