( string buffer, int mode )
ob_gzhandler() requires the zlib
ob_gzhandler() is intended to be used as a
callback function for ob_start() to help
facilitate sending gz-encoded data to web browsers that support
compressed web pages. Before ob_gzhandler()
actually sends compressed data, it determines what type of
content encoding the browser will accept ("gzip", "deflate" or
none at all) and will return its output accordingly. All
browsers are supported since it's up to the browser to send the
correct header saying that it accepts compressed web pages.
If a browser doesn't support compressed pages this function returns
mode was added in PHP 4.0.5.
Example 1. ob_gzhandler() example
<p>This should be a compressed page.</p>