[TAG] Two-cent tip for Linux Gazette

Fri Sep 12 18:05:13 MSD 2008

A quick "download whole directory as zip file" CGI

If you have a large collection of files, and you put them on your
webserver without any special index, then it's likely that the
server will generate its own index HTML for you.  This is all very
well, but I recently had the tedious experience of downloading 46
separate small files from my webserver, using somebody's Windows
box with Internet Explorer and a "download manager" that took me
through 3 dialog boxes per click in a foreign language.  Wouldn't
it be nice if I could tell the web server to zip them all up and
send me the zip file.

You can do this because the Unix "zip" utility (package "zip" on
most distributions) is capable of writing to standard output.  At a
minimum, you can create a CGI script like this:

#!/bin/bash
echo Content-Type: application/zip
echo "Content-Disposition: attachment; filename=files.zip"
echo
zip -9r - *

This zips the content of the current directory, sending the result
to standard output (that's what the dash - is for) and telling the
Web browser that it's a zip file called files.zip.

But we can go one up on that - the following short script will list
the contents of the directory, with an optional "download as zip"
link that sets the filename appropriately.  If you're using the
small Mathopd webserver, you can edit /etc/mathopd.conf and set
AutoIndexCommand to the path of this script:

export Filename="$(pwd|sed -e 's,.*/,,').zip"
if test "$QUERY_STRING" == zip; then
  echo Content-type: application/zip
  echo "Content-Disposition: attachment; filename=$Filename"
  echo
  zip -9r - *
else
  echo "Content-type: text/html; charset=utf-8"
  echo
  echo "<HTML><BODY><A HREF=\"..\">Parent directory</A> |"
  echo "<A HREF=\"./?zip\">Download $Filename</A>"
  echo "<h2>Contents of $Filename</h2><UL>"
  for N in *; do
    echo "<LI><A HREF=\"$N\">$N</A> ($(du -h "$N"|cut -f1))</LI>"
  done
  echo "</UL></BODY></HTML>"
fi

This assumes that any non-ASCII filenames will be listed in UTF-8
(otherwise change the charset).

-- 
Silas S Brown http://people.pwf.cam.ac.uk/ssb22