Installing PHP extensions in Debian

I'm trying to install the PECL extension pecl_http so that I can use PHP's http_negotiate_language() function.

I'm running PHP5 on Apache2 and Debian Lenny. I installed the php_http package from the debian repo, however, I still can't use that function in m开发者_如何学Cy php scripts! The package also doesn't show up under phpinfo(). I tried installing it from PECL, but I could not.

Is there some procedure for enabling these extensions in PHP? Kind of like a2enmod for apache?

Note: This is a repost from http://forum.slicehost.com/comments.php?DiscussionID=4650

I also tried adding extension=pecl_http.so to my apache2/php.ini with no effect.

Any guesses?

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I ended up installing the extension with PECL.

For the record, the correct addition to php.ini to enable pecl_http under Linux is:

extension=http.so