Add check_php_build.php from phpipam/phpipam repository

We are re-using code from phpipam/phpipam that requires php5.4+ and 64bit OS.

Author: GaryAllan

README.md

@@ -5,7 +5,7 @@ phpipam-agent is a scanning agent for phpipam server to be deployed to remote se
 phpipam is released under the GPL v3 license, see misc/gpl-3.0.txt.
 
 ## Requirements
- - PHP version 5.3+ with following modules
+ - 64bit PHP version 5.4+ with following modules
     - pdo, pdo_mysql : Adds support for mysql connections (if type=mysql)
     - gmp            : Adds support for dev-libs/gmp (GNU MP library) -> to calculate IPv6 networks
     - json           : Adds supports for JSON data-interexchange format

functions/checks/check_php_build.php

@@ -0,0 +1,68 @@
+<?php
+
+/**
+ *
+ * Script to check if all required extensions are compiled and loaded in PHP
+ *
+ *
+ * We need the following mudules:
+ *      - session
+ *      - gmp
+ *      - json
+ *      - gettext
+ *      - PDO
+ *      - pdo_mysql
+ *
+ ************************************/
+
+
+# Required extensions
+$requiredExt  = array("PDO", "pdo_mysql", "mbstring", "iconv", "ctype", "gettext", "gmp", "json", "filter");
+
+# Available extensions
+$availableExt = get_loaded_extensions();
+
+# Empty missing array to prevent errors
+$missingExt[0] = "";
+
+# if not all are present create array of missing ones
+foreach ($requiredExt as $extension) {
+    if (!in_array($extension, $availableExt)) {
+        $missingExt[] = $extension;
+    }
+}
+
+# check for PEAR functions
+if ((@include_once 'PEAR.php') != true) {
+	$missingExt[] = "php PEAR support";
+}
+
+# if any extension is missing print error and die!
+if (sizeof($missingExt) != 1 || (phpversion() < "5.4") || PHP_INT_SIZE==4) {
+
+    /* remove dummy 0 line */
+    unset($missingExt[0]);
+
+    /* Extensions error */
+    if(sizeof($missingExt)>0) {
+        $error[] = _('The following required PHP extensions are missing');
+        foreach ($missingExt as $missing) {
+            $error[] = $missing;
+        }
+        $error[] = _('Please recompile PHP to include missing extensions.');
+    }
+    /* php version error */
+    elseif(phpversion() < "5.4") {
+        $error[] = _('Unsupported PHP version');
+        $error[] = _('From release 1.3.2+, at least PHP version 5.4 is required!');
+        $error[] = _("Detected PHP version: ").phpversion();
+    }
+    /* 32-bit systems */
+    else {
+        $error[] = _('From phpIPAM release 1.4 onwards, 64bit system is required!');
+    }
+
+    $error[] = "";
+
+    die(implode("\n", $error));
+}

functions/functions.php

@@ -1,5 +1,7 @@
 <?php
 
+require( dirname(__FILE__) .  '/checks/check_php_build.php' );
+
 /* @config file ------------------ */
 require_once( dirname(__FILE__) . '/classes/class.Config.php' );
 $config = Config::ValueOf('config');