remove_all_gems.rb

#        ___         ___         ___                   ___         ___         ___         ___         ___     
#       /\  \       /\  \       /\__\                 /\  \       /\  \       /\  \       /\__\       |\__\    
#      /::\  \     /::\  \     /::|  |               /::\  \     /::\  \     /::\  \     /:/  /       |:|  |   
#     /:/\:\  \   /:/\:\  \   /:|:|  |              /:/\:\  \   /:/\:\  \   /:/\:\  \   /:/  /        |:|  |   
#    /:/  \:\  \ /::\~\:\  \ /:/|:|__|__           /::\~\:\  \ /::\~\:\  \ /:/  \:\__\ /:/  /  ___    |:|__|__ 
#   /:/__/_\:\__/:/\:\ \:\__/:/ |::::\__\         /:/\:\ \:\__/:/\:\ \:\__/:/__/ \:|__/:/__/  /\______/::::\__\
#   \:\  /\ \/__\:\~\:\ \/__\/__/~~/:/  /         \/_|::\/:/  \:\~\:\ \/__\:\  \ /:/  \:\  \ /:/  \::::/~~/~   
#    \:\ \:\__\  \:\ \:\__\       /:/  /             |:|::/  / \:\ \:\__\  \:\  /:/  / \:\  /:/  / ~~|:|~~|    
#     \:\/:/  /   \:\ \/__/      /:/  /              |:|\/__/   \:\ \/__/   \:\/:/  /   \:\/:/  /    |:|  |    
#      \::/  /     \:\__\       /:/  /               |:|  |      \:\__\      \::/__/     \::/  /     |:|  |    
#       \/__/       \/__/       \/__/                 \|__|       \/__/       ~~          \/__/       \|__|    
#
# Simple script to remove all installed gems
# without having to type gem uninstall 'gem_name'
# for each one of them
#
# Usage:
#  gem list | ruby remove_all_gems.rb
#
# Notes:
#  you might get some warning in the form of cannot
#  remove default gem
ARGF.readlines[1..-1].each do |line|
  gem = line.split(' ')
  puts "Trying to remove #{gem[0]}"
  output = `gem uninstall --executables --all --force #{gem[0].gsub(/\(|\)/, "")} 2>&1`
  puts output unless (output.to_s =~ /because it is a default gem/)
end

puts "Gems removed / check status with gem list"