remove error message for Ctrl+C

tests/rateLimiter.py

@@ -23,8 +23,11 @@ rate *= 1.4   # compensation for excluding i/o time (experimentally determined)
 start = time.time()
 total_read = 0
 
-buf = " "
-while len(buf):
+sys.stderr.close()  # remove error message, for Ctrl+C
+
+try:
+  buf = " "
+  while len(buf):
     now = time.time()
     to_read = max(int(rate * (now - start) - total_read), 1)
     max_buf_size = 1 * MB
@@ -40,3 +43,6 @@ while len(buf):
     wait_time = max(read_end - read_start, write_end - write_start)
     start += wait_time   # exclude delay of the slowest
     total_read += len(buf)
+
+except (KeyboardInterrupt, BrokenPipeError) as e:
+    pass