Update to Drupal 8.2.0. For more information, see https://www.drupal.org/project/drupal/releases/8.2.0

core/lib/Drupal/Component/FileSystem/FileSystem.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace Drupal\Component\FileSystem;
+
+/**
+ * Provides file system functions.
+ */
+class FileSystem {
+
+  /**
+   * Discovers a writable system-appropriate temporary directory.
+   *
+   * @return string|false
+   *   A string containing the path to the temporary directory, or FALSE if no
+   *   suitable temporary directory can be found.
+   */
+  public static function getOsTemporaryDirectory() {
+    $directories = array();
+
+    // Has PHP been set with an upload_tmp_dir?
+    if (ini_get('upload_tmp_dir')) {
+      $directories[] = ini_get('upload_tmp_dir');
+    }
+
+    // Operating system specific dirs.
+    if (substr(PHP_OS, 0, 3) == 'WIN') {
+      $directories[] = 'c:\\windows\\temp';
+      $directories[] = 'c:\\winnt\\temp';
+    }
+    else {
+      $directories[] = '/tmp';
+    }
+    // PHP may be able to find an alternative tmp directory.
+    $directories[] = sys_get_temp_dir();
+
+    foreach ($directories as $directory) {
+      if (is_dir($directory) && is_writable($directory)) {
+        // Both sys_get_temp_dir() and ini_get('upload_tmp_dir') can return paths
+        // with a trailing directory separator.
+        return rtrim($directory, DIRECTORY_SEPARATOR);
+      }
+    }
+    return FALSE;
+  }
+
+}