How to create zip files on the fly w/o Tempfile

There are many articles about how to archive files from the server and send a zip-file to a client without persisting it on the server. But usually they don't literally do it, because they use temporary files.

There is a simple way to do it without creating any file though. You just have to put files directly to Zip::OutputStream and then read from it. Btw pay attention: you must rewind the stream before reading it.

 # some files objects def download(files) zip_stream = Zip::OutputStream.write_buffer do |zip| files.each.with_index(1) do |file, index| # file name must be uniq in archive zip.put_next_entry("#{file.name}--#{index}.#{file.extension}") zip.write(file.read.force_encoding('utf-8')) end end # important - rewind the steam zip_stream.rewind send_data zip_stream.read, type: 'application/zip', disposition: 'attachment', filename: 'files-archive.zip' end