boxen-to-fish.rb

#!/usr/bin/env ruby

def compile_script(file)
  compiled = File.readlines(file).map do |line|
    case line
    when /^#!/
      "#!/usr/bin/env fish"
    when /^\s*(?:export )?(.*?)=(.*)/
      name, content = $1, $2
      if !content.match(/:\/\//) # not protocol strings (eg. "http://")
        content.gsub!(/:\$/, ' $') # yay fuzzy heuristics
      end
      content.gsub!(/\$\{(.+?)\}/, '$\1') # ${VARIABLE} -> $VARIABLE
      content.gsub!(/`(.*)`/) {
        contents = $1
        contents.sub!(/^([^\s]+?)=([^\s]+)/, 'env \1=\2')
        "(#{contents})"
      }
      content.gsub!(/\$\{(.*)\}/, '(\1)')
      "set -x #{name} #{content}\n"
    when /^\s*set [\-\+][eu]/
      "# #{line.chomp}\n"
    when /^\s*eval "\$\((.+?) init -\)"/
      name = $1
      [
        "set -x PATH $BOXEN_HOME/#{name}/shims $PATH",
        "#{name} rehash 2>/dev/null"
      ].join("\n")
    when /^\s*#.*/
      line
    when /^\s*$/
      line
    else
      "###### PARSE ERR: #{line.chomp}\n"
    end
  end
  compiled.join
end

Dir.chdir("/opt/boxen") do
  boxen_fish_path = File.expand_path("~/.config/fish/boxen.fish")
  bash_scripts = ["env.sh", *Dir.glob("env.d/*.sh")]

  File.open(boxen_fish_path, "w") do |f|
    bash_scripts.each do |file|
      f.puts compile_script(file)
    end
  end
end