dont write unchanged files

fgs/writer.py

@@ -61,6 +61,14 @@ class Writer:
         # write to file
         fullpath = self.output_dir + '/' + path
         directory = os.path.dirname(fullpath)
+        if os.path.exists(fullpath):
+            readmode = 'r'
+            if 'b' in mode:
+                readmode = 'rb'
+            with open(fullpath, readmode) as f:
+                if out == f.read():
+                    print("skipping writing file: ", fullpath)
+                    return
         print("writing file: ", fullpath)
         #print("dir: ", directory)
         os.makedirs(directory, exist_ok=True)