Git script to change a repo's push/pull URLs to point to another Github owner

git-switch-github-owner.rb

#!/usr/bin/env ruby

def run(s)
  puts "[#{s}]"
  result = `#{s}`
  unless $?.exited? and $?.exitstatus == 0
    abort "Failed to run: #{s}"
  end
  result
end

new_owner = ARGV.shift
unless new_owner
  abort "Usage: #{$0} <new-owner>"
end

unless run("git remote show -n origin") =~ /Fetch URL: (.*?)$/m
  abort "Could not read remote"
end
old_url = $1 

unless old_url =~ %r{git@github\.com:([^/]+)/(.*)$}
  abort "Remote must be Github path"
end
old_owner = $1
if old_owner == new_owner
  abort "Owner is already #{new_owner}"
end

repo_name = $2

new_url = "git@github.com:#{new_owner}/#{repo_name}"
puts "Writing new origin #{new_url}"
run("git remote set-url origin #{new_url}")
run("git remote set-url --push origin #{new_url}")