PHP: How to check whether a library has been properly installed and enabled?

Question

Following another question on SO (I am no PHP expert), I am wondering whether the Zlib library has been properly installed on my local laptop. Documentation says there should be no need to manually install this library, but code using this library does not work.

Documentation mentions a need to configure PHP --with-zlib[=DIR], but for versions below 4.3. I am on 5.2.17. I have checked php.ini, but I see no reference to it. My PHP system has been installed with Acquia Dev Desktop.

How can I check whether the Zlib library has been properly installed and enabled on my local PC? Where should I take a look at? What should I look for? Thanks.

Answer 1

You can use phpinfo() to get full information about libraries

<?php
   phpinfo();
?>

or in your PHP code test for a given function

if (function_exists("gzcompress")) {
  echo "OK";
} else {
  die("zlib missing");
}

Answer 2

Unless I'm missing something:

var_dump(function_exists('gzclose')); // or any gz-related functions

Or to be more specific and correct

if(extension_loaded('zlib'))

http://sg.php.net/manual/en/function.extension-loaded.php