ebusctl errors without error message

[Mathadon]

Description

Calling ebusctl hex b5110101 works when calling it manually but only works sometimes (about once in three times) when calling it from a cron job.

I'm using an ebuzzz adapter.

Actual behavior

When it does not work:

• nothing is printed to std::cout.
• no error message is shown

Expected behavior

Expected behavior:

• the requested data should be printed
• or a clear error message

I debugged the source code and the problem is resolved most of the time using

diff --git a/src/tools/ebusctl.cpp b/src/tools/ebusctl.cpp
index 9539c5c2..8131dc9f 100755
--- a/src/tools/ebusctl.cpp
+++ b/src/tools/ebusctl.cpp
@@ -22,6 +22,7 @@
 
 #include <argp.h>
 #include <string.h>
+#include <unistd.h>
 #ifdef HAVE_PPOLL
 #  include <poll.h>
 #endif
@@ -202,6 +203,7 @@ string fetchData(ebusd::TCPSocket* socket, bool &listening, uint16_t timeout, bo
     }
     if (ret > 0 && (fds[IDX_STDIN].revents & (POLLHUP | POLLRDHUP))) {
       inputClosed = true;  // wait once more for data to arrive
+      usleep(100000);
       nfds = 1;  // stop polling stdin
     } else if (inputClosed && !errored) {
       errored = true;

So it seems that somehow the data is not received correctly, or too late.

ebusd version

current source from git

ebusd arguments

-d /dev/ttyUSB0 --enablehex --scanconfig=full --latency=20000

I'm getting the same behaviour without the latency option.

Operating system

Debian 11 (Bullseye) / Ubuntu 20-21 / Raspbian 11 / Raspberry Pi OS 11 (including lite)

CPU architecture

arm64

Dockerized

None

Hardware interface

other

Related integration

No response

Logs

2023-03-12 12:33:07.333 [main notice] hex cmd: 3108b5110101
2023-03-12 12:33:07.506 [update notice] sent read bai Status01 QQ=31: 29.5;29.0;-;-;-;off

[john30]

does it work with netcat?? i.e. when using echo "hex b5110101"|nc localhost 8888 instead

[Mathadon]

It works when manually calling netcat. I.e. I get the following result:

$ echo "hex 08b5110101" | nc localhost 8888
0934330080ffff0000ff

^C
$ ebusctl hex 08b5110101
0934330080ffff0000ff

Or did you intend that I'd integrate it in cron job too?

In any case, netcat does not return (or at least not before 15 minutes). I have to kill it using ctrl+C. So it doesn't look like a good idea to use it in a cron job since the cron jobs would never end. Perhaps that this is in fact related to the root cause?

[john30]

yes, I meant by using nc in the cronjob. you need to give an extra param to nc to not wait forever

[Mathadon]

Edit: also netcat seems to return an empty result occasionally. I used the following command.

echo hex <hexcommand> | nc localhost 8888 -N

[john30]

in this case please check the ebus logging for anything unusual when the result is empty. maybe need to increase the log level