#!/usr/bin/env ruby
# encoding: utf-8
exceptBranches = ['master', 'pre', 'develop']
for branch in `cd #{ARGV[0]} && git branch -l`.split(' ') - ['*']
    next if exceptBranches.include? branch
    system("git branch -d #{branch}")
end

ruby removeMergedBranches.rb your_git_project

warning: deleting branch 'custom' that has been merged to
         'refs/remotes/origin/custom', but not yet merged to HEAD.
Deleted branch custom (was b63ab7d).
Deleted branch hotfix (was 340cca0).
Deleted branch mgit (was 86b4004).
error: The branch 'develop_rtl' is not fully merged.
If you are sure you want to delete it, run 'git branch -D develop_rtl'.