diff --git a/aria2_to_magnet.py b/aria2_to_magnet.py
index c250c24..a365237 100755
--- a/aria2_to_magnet.py
+++ b/aria2_to_magnet.py
@@ -1,14 +1,42 @@
 #!/usr/bin/env python
-import struct
-import binascii
 import argparse
+import os
+import glob
 
-parser = argparse.ArgumentParser()
-parser.add_argument("file", nargs='+',
-                    help="input file XXX.aria2")
+"""
+Usage:
+command line
+python aria2_to_magnet.py -e .aria2 .
+"""
 
-args = parser.parse_args()
 
+def main():
+    # codes from gist
+    # https://gist.github.com/89465127/5273149
+    parser = argparse.ArgumentParser(
+        description='Read in a file or set of files, and return the result.',
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+    parser.add_argument('path',
+                        nargs='+',
+                        help='Path of a file or a folder of files.')
+    parser.add_argument('-e',
+                        '--extension',
+                        default='',
+                        help='File extension to filter by.')
+    args = parser.parse_args()
+
+    # Parse paths
+    full_paths = [os.path.join(os.getcwd(), path) for path in args.path]
+    files = set()
+    for path in full_paths:
+        if os.path.isfile(path):
+            files.add(path)
+        else:
+            files |= set(glob.glob(path + '/*' + args.extension))
+
+    for f in files:
+        magnet = parse_aria_control_file(f)
+        print(f'file name: {os.path.basename(f)}, {magnet}')
 
 # ================================================================
 #  0                   1                   2                   3
@@ -40,6 +68,7 @@ args = parser.parse_args()
 # https://aria2.github.io/manual/en/html/technical-notes.html
 # ================================================================
 
+
 def parse_aria_control_file(file_name):
     with open(file_name, "rb") as f:
         try:
@@ -47,28 +76,23 @@ def parse_aria_control_file(file_name):
             f.seek(0)  # Go to beginning, read VER
             version = f.read(2)
 
-            i = int(version.encode('hex'), 16)
-            # print "version is " + str(i)
+            i = int.from_bytes(version, 'big')
+            # print("version is " + str(i))
 
             # skip  EXT, find info  hash_binary length
             f.seek(6)
 
             length = f.read(4)
-            hash_length = int(length.encode('hex'), 16)
+            hash_length = int.from_bytes(length, 'big')
             # print "hash length is " + str(hash_length)
 
             # read next hash_length
             f.seek(10)  # Go to info hash
             hash_binary = f.read(hash_length)
-            info_hash = ""
-            for ch in hash_binary:
-                hex_word = hex(ord(ch))[2:].zfill(2)
-                # print hex_word
-
-                info_hash += hex_word.upper()
+            info_hash = hash_binary.hex().upper()
 
             magnet_link = "magnet:?xt=urn:btih:" + info_hash
-            print magnet_link
+            return magnet_link
         except:
             pass
         finally:
@@ -76,9 +100,10 @@ def parse_aria_control_file(file_name):
 
 
 if __name__ == '__main__':
-    file_list = args.file
-    for file_name in file_list:
-        parse_aria_control_file(file_name)
+    # file_list = args.file
+    # for file_name in file_list:
+    #     parse_aria_control_file(file_name)
     # version is 1
     # hash length is 20
     # magnet:?xt=urn:btih:959E2ECEB954313D38690EFF7924CA7CD80DE739
+    main()