diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -398,6 +398,7 @@
     'phutil_escape_uri' => 'markup/render.php',
     'phutil_escape_uri_path_component' => 'markup/render.php',
     'phutil_exit' => 'utils/utils.php',
+    'phutil_fnmatch' => 'utils/utils.php',
     'phutil_format_bytes' => 'utils/viewutils.php',
     'phutil_format_relative_time' => 'utils/viewutils.php',
     'phutil_format_relative_time_detailed' => 'utils/viewutils.php',
diff --git a/src/utils/__tests__/PhutilUtilsTestCase.php b/src/utils/__tests__/PhutilUtilsTestCase.php
--- a/src/utils/__tests__/PhutilUtilsTestCase.php
+++ b/src/utils/__tests__/PhutilUtilsTestCase.php
@@ -616,4 +616,65 @@
       phutil_var_export(new PhutilTestPhobject()));
   }
 
+  public function testFnmatch() {
+    $cases = array(
+      '' => array(
+        array(''),
+        array('.', '/'),
+      ),
+      '*' => array(
+        array('file'),
+        array('dir/', '/dir'),
+      ),
+      '**' => array(
+        array('file', 'dir/', '/dir', 'dir/subdir/file'),
+        array(),
+      ),
+      '**/file' => array(
+        array('file', 'dir/file', 'dir/subdir/file', 'dir/subdir/subdir/file'),
+        array('file/', 'file/dir'),
+      ),
+      'file.*' => array(
+        array('file.php', 'file.a', 'file.'),
+        array('files.php', 'file.php/blah'),
+      ),
+      'fo?' => array(
+        array('foo', 'fot'),
+        array('fooo', 'ffoo', 'fo/', 'foo/'),
+      ),
+      'fo{o,t}' => array(
+        array('foo', 'fot'),
+        array('fob', 'fo/', 'foo/'),
+      ),
+      'fo{o,\\,}' => array(
+        array('foo', 'fo,'),
+        array('foo/', 'fo,/'),
+      ),
+      'fo{o,\\\\}' => array(
+        array('foo', 'fo\\'),
+        array('foo/', 'fo\\/'),
+      ),
+      '/foo' => array(
+        array('/foo'),
+        array('foo', '/foo/'),
+      ),
+    );
+
+    foreach ($cases as $input => $expect) {
+      list($matches, $no_matches) = $expect;
+
+      foreach ($matches as $match) {
+        $this->assertTrue(
+          phutil_fnmatch($input, $match),
+          pht('Expecting "%s" to match "%s".', $input, $match));
+      }
+
+      foreach ($no_matches as $no_match) {
+        $this->assertFalse(
+          phutil_fnmatch($input, $no_match),
+          pht('Expecting "%s" not to match "%s".', $input, $no_match));
+      }
+    }
+  }
+
 }
diff --git a/src/utils/utils.php b/src/utils/utils.php
--- a/src/utils/utils.php
+++ b/src/utils/utils.php
@@ -1121,3 +1121,68 @@
   // Let PHP handle everything else.
   return var_export($var, true);
 }
+
+
+/**
+ * An improved version of `fnmatch`.
+ *
+ * @param  string  A glob pattern.
+ * @param  string  A path.
+ * @return bool
+ */
+function phutil_fnmatch($glob, $path) {
+  // Modify the glob to allow `**/` to match files in the root directory.
+  $glob = preg_replace('@(?:(?<!\\\\)\\*){2}/@', '{,*/,**/}', $glob);
+
+  $escaping = false;
+  $in_curlies = 0;
+  $regex = '';
+
+  for ($i = 0; $i < strlen($glob); $i++) {
+    $char = $glob[$i];
+    $next_char = ($i < strlen($glob) - 1) ? $glob[$i + 1] : null;
+
+    if (in_array($char, array('.', '(', ')', '|', '+', '^', '$'))) {
+      $regex .= "\\$char";
+    } else if ($char === '*') {
+      if ($escaping) {
+        $regex .= '\\*';
+      } else {
+        if ($next_char === '*') {
+          $regex .= '.*';
+        } else {
+          $regex .= '[^/]*';
+        }
+      }
+    } else if ($char === '?') {
+      $regex .= $escaping ? '\\?' : '[^/]';
+    } else if ($char === '{') {
+      $regex .= $escaping ? '\\{' : '(';
+      if (!$escaping) {
+        ++$in_curlies;
+      }
+    } else if ($char === '}' && $in_curlies) {
+      $regex .= $escaping ? '}' : ')';
+      if (!$escaping) {
+        --$in_curlies;
+      }
+    } else if ($char === ',' && $in_curlies) {
+      $regex .= $escaping ? ',' : '|';
+    } else if ($char === '\\') {
+      if ($escaping) {
+        $regex .= '\\\\';
+        $escaping = false;
+      } else {
+        $escaping = true;
+      }
+
+      continue;
+    } else {
+      $regex .= $char;
+    }
+    $escaping = false;
+  }
+
+  $regex = '#\A'.$regex.'\z#';
+  return (bool)preg_match($regex, $path);
+}