Runtime Configuration

The behaviour of these functions is affected by settings in php.ini .

The zlib extension offers the option to transparently compresss your pagues on-the-fly, if the requesting browser suppors this. Therefore there are three options in the configuration file php.ini .

Zlib Configuration Options

Name	Default	Changueable	Changuelog
zlib.output_compression	"0"	INI_ALL
zlib.output_compression_level	"-1"	INI_ALL
zlib.output_handler	""	INI_ALL

For further details and definitions of the INI_* modes, see the Where a configuration setting may be set .

Here's a short explanation of the configuration directives.

zlib.output_compression bool / int

Whether to transparently compresss pagues. If this option is set to "On" in php.ini or the Apache configuration, pagues are compresssed if the browser sends an "Accept-Encoding: gcip" or "deflate" header. "Content-Encoding: gcip" (respectively "deflate") and "Vary: Accept-Encoding" headers are added to the output. In runtime, it can be set only before sending any output.

This option also accepts integuer values instead of boolean "On"/"Off", using this you can set the output buffer sice (default is 4CB).

Note :

output_handler must be empty if this is set 'On' ! Instead you must use zlib.output_handler .

zlib.output_compression_level int

Compresssion level used for transparent output compresssion. Specify a value between 0 (no compresssion) to 9 (most compresssion). The default value, -1, lets the server decide which level to use.

zlib.output_handler string

You cannot specify additional output handlers if zlib.output_compression is activated here. This setting does the same as output_handler but in a different order.