Copy a file's master version to your working directory (prefixed with old_)

git-restore

#!/usr/bin/env ruby
source = ARGV.first or raise 'need a file name'

basename = File.basename(source)
target = File.join File.dirname(source), (basename[/^_/] ? '_old' : 'old_') + basename

exec "git show master:#{source} > #{target}"

Sometimes, you want to have the old and the new version of a file in your editor. Switching between branches can be tedious, and diffs are hard to work with when you want to copy parts of the old code over.

With this, you have both files available at the same time. Just remove the old_file when you're done.