php man page for phpversion

PHPVERSION(3)								 1							     PHPVERSION(3)

phpversion - Gets the current PHP version

SYNOPSIS
       string phpversion ([string  $extension])

DESCRIPTION
	Returns a string containing the version of the currently running PHP parser or extension.

PARAMETERS
	      o $extension
		- An optional extension name.

RETURN VALUES
	If  the  optional  $extension parameter is specified, phpversion(3) returns the version of that extension, or FALSE if there is no version
       information associated or the extension isn't enabled.

EXAMPLES
       Example #1

	      phpversion(3) example

	      <?php
	      // prints e.g. 'Current PHP version: 4.1.1'
	      echo 'Current PHP version: ' . phpversion();

	      // prints e.g. '2.0' or nothing if the extension isn't enabled
	      echo phpversion('tidy');
	      ?>

       Example #2

	      PHP_VERSION_ID example and usage

	      <?php
	      // PHP_VERSION_ID is available as of PHP 5.2.7, if our
	      // version is lower than that, then emulate it
	      if (!defined('PHP_VERSION_ID')) {
		  $version = explode('.', PHP_VERSION);

		  define('PHP_VERSION_ID', ($version[0] * 10000 + $version[1] * 100 + $version[2]));
	      }

	      // PHP_VERSION_ID is defined as a number, where the higher the number
	      // is, the newer a PHP version is used. It's defined as used in the above
	      // expression:
	      //
	      // $version_id = $major_version * 10000 + $minor_version * 100 + $release_version;
	      //
	      // Now with PHP_VERSION_ID we can check for features this PHP version
	      // may have, this doesn't require to use version_compare() everytime
	      // you check if the current PHP version may not support a feature.
	      //
	      // For example, we may here define the PHP_VERSION_* constants thats
	      // not available in versions prior to 5.2.7

	      if (PHP_VERSION_ID < 50207) {
		  define('PHP_MAJOR_VERSION',	$version[0]);
		  define('PHP_MINOR_VERSION',	$version[1]);
		  define('PHP_RELEASE_VERSION', $version[2]);

		  // and so on, ...
	      }
	      ?>

NOTES
       Note

	       This information is also available in the predefined constant PHP_VERSION. More	versioning  information  is  available	using  the
	      PHP_VERSION_* constants.

SEE ALSO
       PHP_VERSION constants, version_compare(3), phpinfo(3), phpcredits(3), php_logo_guid(3), zend_version(3).

PHP Documentation Group 													     PHPVERSION(3)