diff --git a/helpers.inc.php b/helpers.inc.php
index 089abf7..81c188a 100644
--- a/helpers.inc.php
+++ b/helpers.inc.php
@@ -302,33 +302,43 @@ const COPY_MODE_BUILTIN  = 1;
 const COPY_MODE_SYSTEM   = 2;
 const COPY_MODE_HARDLINK = 3;
 
-function ensure_copy($src, $dst, $dir_perms = 0777, $excludes = array())
+function ensure_copy(string $src, string $dst, int $dir_perms = 0777, array $excludes = array(), array $fnmatches = array())
 {
-  recurse_copy($src, $dst, $dir_perms, COPY_MODE_BUILTIN, false, $excludes);
+  recurse_copy($src, $dst, $dir_perms, COPY_MODE_BUILTIN, false, $excludes, $fnmatches);
 }
 
-function ensure_copy_file_if_differs($src_file, $dst_file, $dir_perms = 0777)
+function ensure_copy_file_if_differs(string $src_file, string $dst_file, $dir_perms = 0777)
 {
   if(!is_file($dst_file) || filesize($src_file) != filesize($dst_file) || crc32_file($src_file) !== crc32_file($dst_file))
     ensure_copy($src_file, $dst_file, $dir_perms);
 }
 
-function ensure_sync($src, $dst, $dir_perms = 0777, $excludes = array())
+function ensure_sync(string $src, string $dst, int $dir_perms = 0777, array $excludes = array(), array $fnmatches = array())
 {
-  recurse_copy($src, $dst, $dir_perms, COPY_MODE_BUILTIN, true, $excludes);
+  recurse_copy($src, $dst, $dir_perms, COPY_MODE_BUILTIN, true, $excludes, $fnmatches);
 }
 
-function ensure_hardlink($src, $dst, $dir_perms = 0777, $excludes = array())
+function ensure_hardlink(string $src, string $dst, int $dir_perms = 0777, array $excludes = array(), array $fnmatches = array())
 {
-  recurse_copy($src, $dst, $dir_perms, COPY_MODE_HARDLINK, true, $excludes);
+  recurse_copy($src, $dst, $dir_perms, COPY_MODE_HARDLINK, true, $excludes, $fnmatches);
 }
 
-function ensure_duplicate($src, $dst, $dir_perms = 0777)
+function ensure_duplicate(string $src, string $dst, int $dir_perms = 0777)
 {
   recurse_copy($src, $dst, $dir_perms, COPY_MODE_SYSTEM);
 }
 
-function recurse_copy($src, $dst, $dir_perms = 0777, $copy_mode = COPY_MODE_BUILTIN, $mtime_check = false, $excludes = array()) 
+function recurse_copy(
+  string $src, 
+  string $dst, 
+  int $dir_perms = 0777, 
+  int $copy_mode = COPY_MODE_BUILTIN, 
+  bool $mtime_check = false, 
+  //regex expressions which check full paths
+  array $excludes = array(),
+  //fnmatch expressions which check file names only
+  array $fnmatches = array()
+) 
 {
   msg_dbg("copying $src => $dst ...\n");
 
@@ -354,12 +364,24 @@ function recurse_copy($src, $dst, $dir_perms = 0777, $copy_mode = COPY_MODE_BUIL
     if(($file != '.' ) && ($file != '..')) 
     {
       if(is_dir($src . '/' . $file))
-        recurse_copy($src . '/' . $file, $dst . '/' . $file, $dir_perms, $copy_mode, $mtime_check, $excludes);
+      {
+        recurse_copy(
+          $src . '/' . $file, 
+          $dst . '/' . $file, 
+          $dir_perms, 
+          $copy_mode, 
+          $mtime_check, 
+          $excludes, 
+          $fnmatches
+        );
+      }
       else
       {
         $excluded = false;
         foreach($excludes as $exclude_pattern)
           $excluded = $excluded || (bool)preg_match("~$exclude_pattern~", $src . '/' . $file);
+        foreach($fnmatches as $fnmatch)
+          $excluded = $excluded || !fnmatch($fnmatch, $file);
 
         if($excluded)
           continue;