Simple file manipulation Ruby snippets

ruby grep

File.open(fname).read.match(/\"accepted_fields\":\s+\[((\d(,)?)+)\]/)

ruby sed

Dir.glob(fnames).each do |fname|
        convertFile = File.open(fname).read.match(/\"accepted_fields\":\s+\[((\d(,)?)+)\]/)
        next unless convertFile
        tempfile = "#{fname}.tmp"
        File.open(tempfile, 'w') do |f|
          IO.foreach(fname) do |line|
            if(line =~ /\"accepted_fields\":\s+\[((\d(,)?)+)\]/)
              ids = line.match(/\[(.*)\]/)[1].split(",").map{|x| x.to_i}
              names = ContentType.where(id: ids).pluck(:name)
              f.puts line.sub(/\[.*\]/, names.to_s)
            else
              f.puts line
            end
          end
        end