diff --git a/src/python/devtest/os/misc.py b/src/python/devtest/os/misc.py
index e67d2dc..de20a93 100644
--- a/src/python/devtest/os/misc.py
+++ b/src/python/devtest/os/misc.py
@@ -24,12 +24,13 @@ def consume_readbuffer(buf, carry, cmd, log_act=None, caller=None):
             caller = get_caller_pos(2)
         for line in lines:
             slog(log_act, line, caller=caller)
+    stripped_cmd = cmd.strip() if isinstance(cmd, str) else None
     for line in lines:
-        if line.find(cmd) != -1:
-            slog(DEBUG, "ignoring echoed command >{}<".format(cmd))
-        else:
-            r.append(line)
-    if not buf.endswith(('\n', '\r')):
+        if stripped_cmd is not None and stripped_cmd == line:
+            slog(DEBUG, "ignoring echoed command >{}<".format(stripped_cmd))
+            continue
+        r.append(line)
+    if len(r) and not buf.endswith(('\n', '\r')):
        carry = r.pop(-1)
     return r, carry
 
@@ -43,22 +44,21 @@ async def cmd_exec(conn, cmd, act_timeout=0.1, total_timeout=None, newlines=Fals
         if isinstance(cmd, str) and not cmd.endswith('\n'):
             cmd += '\n'
         slog_m(DEBUG, 'connection {}, timemout {}/{}: writing command "{}"'.format(
-            conn, act_timeout, total_timeout, cmd), only_printable=True)
+            conn, act_timeout, total_timeout, cmd.strip()), only_printable=True)
         await conn.write(cmd)
         end = datetime.now() + timedelta(seconds=total_timeout) if total_timeout else None
         carry = ''
         while True:
-            rest = min((end - datetime.now()).total_seconds(), act_timeout) if end else act_timeout
+            rest = min((end - datetime.now()).total_seconds(), act_timeout) if end is not None else act_timeout
             if rest >= 0:
+                slog(DEBUG, 'connection {}: starting read() with timeout {}'.format(conn, rest))
                 buf = await conn.read(act_timeout=rest)
                 slog_m(DEBUG, 'connection {}: read response "{}"'.format(conn, buf))
                 if buf is not None and end and len(buf) == 0 and datetime.now() < end:
                     raise Exception("connection {} reset while reading command response".format(conn))
-                ret, carry = consume_readbuffer(buf, carry, cmd, log_act=log_act, caller=caller)
+                ret, carry = consume_readbuffer(buf, carry, None if echo_cmd else cmd, log_act=log_act, caller=caller)
                 r.extend(ret)
             if rest < 0 or not buf:
-                if not echo_cmd and cmd in r:
-                    r.remove(cmd)
                 d = os.getenv("JW_DEVTEST_RESPONSE_DIR")
                 if d is not None:
                     path = d + '/' + re.sub('[^a-zA-Z0-9]+', '_', cmd)