Misleading Zlib Configuration Options info

JdS · #1 09-Apr-2003, 15:49

Please disregard this post, the information is useless - see this post.

At the time of posting, this page at php.net lists the following in their

Table 1. Configuration options list:

Code:

zlib.output_compression "0" PHP_INI_SYSTEM|PHP_INI_PERDIR

This is misleading and most likely an error on the page.

If you look at this other page, you'll notice that the correct configuration option is listed under

Runtime Configuration as:

Code:

zlib.output_compression "Off" PHP_INI_ALL

I had the misfortune of reading the wrong info first and wasted a few hours worth of useless code

For anyone wondering what all this means, here's code that you can use at the top of your scripts (or in a global functions.php file) to http://www.desilva.biz/php/zlib.html "compress your PHP-driven web pages" even better than ob_start( ' ob_gzhandler' ) can:

PHP Code:


<?php

// compression
$c = ini_get( 'zlib.output_compression' );
if( empty($c) ):
  ini_set( 'zlib.output_compression', '1' );
  ini_set( 'zlib.output_compression_level', '9' ); /* levels, I think
    are between 0 (no compression) - 9 (maximum compression). 
    Meanwhile there's the '-1', which I think is the default
    compression level, whichever that is! */
endif;

/// the rest of your PHP code / script...
?>

With a little bit more thought you can make this into a sort of a compression switch for each of your scripts (and / or 3rd party scripts)!

jrobbio · #2 09-Apr-2003, 16:37

Wow that's cool JDS I searched for ages trying to find the line to insert for the compression level. The php.net help files were really ambigious and I ended up leaving them. Looks really useful. Not sure how a server would perform on level 9 though.

JdS · #3 09-Apr-2003, 20:00

Quote:

Originally posted by jrobbio
Not sure how a server would perform on level 9 though.

If I were you, I wouldn't worry so much about how the server would perform with max compression - you don't need to, your web host will take care of that for you

Seriously? My new sites will use this and it will be at 9 until I find information to the contrary.

JdS · #4 11-Apr-2003, 11:24

I was SO wrong, zlib.output_compression cannot be set using ini_set() after all!

It does change the (local) value in your phpinfo() (when ini_set() is used) but the page is NOT compressed!

So the only thing one can do is use the .htaccess file adding the following lines to it:

Code:

php_flag zlib.output_compression on
php_value zlib.output_compression_level 9

This is what I have done for this site today...

jrobbio · #5 11-Apr-2003, 11:30

PHP Code:


php_value zlib.output_compression_level 9

This is what I have been looking for. I'm going to try it in my .htaccess file. It makes things so much easier than having to try and change the code on my pages. Woo!

Garth Farley · #6 12-Apr-2003, 12:44

I think ini_set() isn't very useful, as most of the ini file options that you actually want to use are already applied before you call ini_set().

For instance, trying to set register_globals to of using ini_set() just doesn't work, as the the PHP predefined variables are already set before the script is even looked at.

Similarily with output compression setting, the php.ini's file will set up whatever compression is to be used, before the first line of the script is even looked at.

But I suppose it's handy for some settings, like you can change the colours that the syntax_highlight function uses, and other little things too. But nothing major.

GF

JdS · #7 12-Apr-2003, 21:55

au contraire, there are many 'useful' uses for ini_set() at least I think they are useful - just not in the case of :

register_globals and zlib.output_compression

The reason was I think, because there was initial confusion when many of us looking to manipulate these very same settings found misleading information in the PHP Manual. i.e. for a while back then, the PHP manual stated that register_globals configuration was PHP_INI_ALL when this was clearly not the case.

BobbyDouglas · #8 06-Sep-2003, 13:38

Isn't there a way to do this in your .htaccess? Maybe I missed t he post about it, I thought I saw it on here tho.

jrobbio · #9 06-Sep-2003, 16:17

You can place

Code:

php_flag zlib.output_compression on
php_value zlib.output_compression_level 9

within your .htaccess so you don't have to place it in every page yes. However, if you have the ob_gzhandler code on any page with this it'll cause all sorts of messed up rubbish being sent as it can't do it twice.

Also its important that you place all your flash files in a seperate folder with php_flag zlib.output_compression off so that it doesn't cause problems since it can't handle it.

There is a way to prevent gzip attempting different mime types but I can't find the resource at the moment.

Rob

zpeek · #10 11-Jul-2004, 18:26

Is there a better way too see if it is compressing the page then just timeing it?

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Misleading Zlib Configuration Options info

zlib.output_compression != PHP_INI_ALL after all!