diff --git a/min_unit_tests/test_realpath.php b/min_unit_tests/test_realpath.php
new file mode 100644
index 0000000..9ed6666
--- /dev/null
+++ b/min_unit_tests/test_realpath.php
@@ -0,0 +1,64 @@
+<?php
+
+$tests = array(
+    '$_SERVER["DOCUMENT_ROOT"]'    => $_SERVER["DOCUMENT_ROOT"]
+    ,'__FILE__'                    => __FILE__
+    ,'$_SERVER["SCRIPT_FILENAME"]' => $_SERVER["SCRIPT_FILENAME"]
+);
+
+function e($txt) {
+    if (is_string($txt)) {
+        return htmlspecialchars($txt, ENT_QUOTES, 'UTF-8');
+    } else {
+        return '<em>' . htmlspecialchars(var_export($txt, true), ENT_QUOTES, 'UTF-8') . '</em>';
+    }
+}
+function rp() {
+    if (! isset($_POST['rp']) || ! is_string($_POST['rp'])) {
+        return '';
+    }
+    return get_magic_quotes_gpc()
+        ? stripslashes($_POST['rp'])
+        : $_POST['rp'];
+}
+
+header('Content-Type: text/html; charset=utf-8');
+
+?><!doctype html>
+<head>
+<title>Test of $_SERVER and realpath()</title>
+<style>
+h2, td {font:80% monospace}
+h2 {margin:1em 0 0}
+table {margin-left:2em}
+th {text-align:right; padding-right:.5em}
+</style>
+</head>
+<body>
+<h1>Test of $_SERVER and realpath()</h1>
+
+<?php foreach ($tests as $key => $value): ?>
+<h2><?= e($key) ?> </h2>
+<table>
+  <tr><th>value</th><td><?= e($value) ?></td></tr>
+  <tr><th>realpath(value)</th><td><?= e(realpath($value)) ?></td></tr>
+</table>
+<?php endForeach; ?>
+<h2>$_SERVER['REQUEST_URI'] </h2>
+<table>
+  <tr><th>value</th><td><?= e($_SERVER['REQUEST_URI']) ?></td></tr>
+</table>
+
+<h3>Test realpath()</h3>
+
+
+<form action="" method="post"><p>
+ <label style="font:80% monospace">realpath(<input type="text" name="rp" size="80" value="<?= e(rp()) ?>">)<label> 
+ <input type="submit" value="evaluate...">
+ </p>
+<?php if (rp() !== ''): ?>
+<pre>= <?= e(realpath(rp())) ?></pre>
+<?php endIf; ?>
+</form>
+
+</body>
\ No newline at end of file
