pfSense

/****f* pkg-utils/compare_pkg_versions

 * NAME

 *   compare_pkg_versions - Decide if the installed package is newer, the same or older than the available package.

 * INPUTS

 *   $installed_pkg_ver - the package version installed on the system.

 *   $available_pkg_ver - the package version available from the package server.

 * RESULT

 *   -1 - the installed package is older (an upgrade is available)

 *   0 - the package versions are the same

 *   1 - the installed package is newer (somebody has installed a newer version than is officially available)

 ******/

function compare_pkg_versions($installed_pkg_ver, $available_pkg_ver) {

	// If the strings are the same then short-cut all the processing.

	if (strcmp($installed_pkg_ver, $available_pkg_ver) == 0) {

		return 0;

	}

	// Split into pieces that are groups of digits and groups of non-digits.

	$installed_arr = preg_split( '/([0-9]+)/', $installed_pkg_ver, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);

	$available_arr = preg_split( '/([0-9]+)/', $available_pkg_ver, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);

	foreach ($installed_arr as $n => $val) {

		if (array_key_exists($n, $available_arr)) {

			// Check if this piece looks like a genuine integer like "123", "0" rather than "05", "005", "1a", "abc".

			// Note: At this point the pieces cannot be like "-1", "+1" so we do not need to worry about those possibilities that filter_var() will see as "genuine integers".

			$val1_as_int = filter_var($val, FILTER_VALIDATE_INT);

			$val2_as_int = filter_var($available_arr[$n], FILTER_VALIDATE_INT);

			if (($val1_as_int === false) || ($val2_as_int === false)) {

				// One of them does not look like a genuine integer so use string comparison.

				if (strcmp($val, $available_arr[$n]) > 0) {

					return 1;

				} elseif (strcmp($val, $available_arr[$n]) < 0) {

					return -1;

				}

			} else {

				// Both look like genuine integers so compare as numbers.

				if ($val1_as_int > $val2_as_int) {

					return 1;

				} elseif ($val1_as_int < $val2_as_int) {

					return -1;

				}

			}

		} else {

			// The installed package version is greater, since all components have matched up to this point

			// and available_arr doesn't have any more data.

			return 1;

		}

	}

	if (count($available_arr) > count($installed_arr)) {

		// All the installed package components matched the corresponding available package components.

		// The available package is longer than the installed package, so the installed package is old.

		return -1;

	} else {

		// Both versions are of equal length and value.

		return 0;

	}

	return $resp ? $resp : array();

}