Segfaults are Cool: Compressed Output from Bash CGI Scripts

Monday, May 16, 2011

Compressed Output from Bash CGI Scripts

I have blogged before on how to compress the output of Per CGIs. As I've started to use and Android phone I learned that some of my status pages dump a heck of a lot of output. A few are written ad Bash CGI scripts.

So here's how to repeat the trick in Bash:

#!/bin/sh

gz_pipe='cat';
echo $HTTP_ACCEPT_ENCODING | grep -qw gzip && {
  gz='ok'; gz_pipe='gzip -9f';
}

echo "Content-Type: text/html";
[ ! -z "$gz" ] && echo "Content-Encoding: gzip";
echo '';

{
  echo '<html><PRE>';
  set
  ps axf
  echo '</PRE></html>';
} | $gz_pipe

For user agents that do not accept gzip-encoded output we use cat(1) as a straight pass-thru as there is no 'nice way' to put nil afer a pipe sign (|) in Bash.

-ulianov