Stop using "which" to find binaries. Create system::find_binary()

which traverses the $PATH and returns any executable binary of the
appropriate name that it can find.  Fixes #1555.

1 files changed, 43 insertions, 0 deletions

diff --git a/modules/gallery/helpers/system.php b/modules/gallery/helpers/system.php
new file mode 100644
index 00000000..4a6a3c0f
--- /dev/null
+++ b/modules/gallery/helpers/system.php
@@ -0,0 +1,43 @@
+<?php defined("SYSPATH") or die("No direct script access.");
+/**
+ * Gallery - a web based photo album viewer and editor
+ * Copyright (C) 2000-2010 Bharat Mediratta
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+class system_Core {
+  /**
+   * Return the path to an executable version of the named binary, or null.
+   * Traverse the PATH environment variable looking for the given file.  If
+   * the $priority_path variable is set, check that path first.
+   */
+  static function find_binary($binary, $priority_path=null) {
+    $paths = array_merge(
+      explode(":", getenv("PATH")),
+      explode(":", module::get_var("gallery", "extra_binary_paths")));
+    if ($priority_path) {
+      array_unshift($paths, $priority_path);
+    }
+
+    foreach ($paths as $path) {
+      $candidate = "$path/$binary";
+      // @suppress errors below to avoid open_basedir issues
+      if (@file_exists($candidate) && @is_executable($candidate)) {
+        return $candidate;
+      }
+    }
+    return null;
+  }
+}
\ No newline at end of file