Fix STDIN pipe detection logic

main.py

@@ -1,6 +1,5 @@
 from sys import argv, stdin
 from sys import exit as sysexit
-from select import select
 from hashlib import blake2b
 from io import BytesIO
 
@@ -24,15 +23,11 @@ def get_input_stream():
     io = None
     if len(argv) == 2:
         io = BytesIO(argv[1].encode())
-    elif stdin_has_data():
+    elif not stdin.isatty():
         io = stdin.buffer
     return io
 
 
-def stdin_has_data():
-    return bool(select([stdin], [], [], 0.0)[0])
-
-
 def print_usage_and_exit():
     print('Usage: identicon [TEXT]')
     print('Print OpenSSH style randomart identicon for arbitrary data.\n')