Git branch del by prefix

git-branch-del

#! /usr/bin/env ruby

# Ruby wrapper script to filter git branches by prefix, provide a confirmation
# prompt, then delete those branches. Without confirmation prompt you can easily
# do something like `git branch -D (git branch | egrep "^\s+core-" | tr -d ' ')`
# or `(git branch | egrep "^\s+core-") | xargs git branch -D`. This could be
# done with a bash script, but Ruby is pleasant to use.

prefix = ARGV.first

raise 'No prefix specified' if prefix.nil?

branches = `git branch`
filtered = branches.split.select { |b| b =~ %r{^\s*#{prefix}} }

puts 'Matched branches:'
puts ''
puts filtered
puts ''

prompt = 'confirm? [y/n]: '.freeze

print prompt

# Create a loop that we break out of on 'y'/'n' only.
while input = STDIN.gets.chomp.downcase
  case input
  when 'y'
    # Just break, deal with branch deletion below.
    break
  when 'n'
    # Exit the script on 'n'.
    exit
  else
    # Was not 'y' or 'n', retry.
    print prompt
  end
end

puts ''

system('git', 'branch', '-D', *filtered)