diff --git a/scripts/jantoran.py b/scripts/jantoran.py
index df30f35..98dbc42 100755
--- a/scripts/jantoran.py
+++ b/scripts/jantoran.py
@@ -46,11 +46,16 @@ def extract_info(inf, s):
   with open(inf) as f:
     full = ''.join(f.readlines())
     x = re.search(r'orig-server (\d+) (\d+) \d+', full)
-    s['current']['npkt'] = int(x.groups()[0])
-    s['current']['interval'] = int(x.groups()[1])
+    if x:
+      s['current']['npkt'] = int(x.groups()[0])
+      s['current']['interval'] = int(x.groups()[1])
+      return True
+    else:
+      print("read error for",inf)
+      return False
 
 def extract_folder(p, s):
-  extract_info(p + '/info.txt', s)
+  if not extract_info(p + '/info.txt', s): return False
   extract_measlat(p + '/log/client-measlat-stdout.log', s)
 
   compute_failure(s)
@@ -70,8 +75,7 @@ def extract(p, s):
   print("extracting...")
   for folder in os.listdir(p):
     s['current'] = {}
-    extract_folder(p + '/' + folder, s)
-    categorize(folder, s)
+    extract_folder(p + '/' + folder, s) and categorize(folder, s)
     counter += 1
     progress = round(counter / item_count * 100)
     print(f"{progress}%", end="\r")