Hi Ben, 2015-02-26 15:08 GMT+01:00 Ben Coman <btc@openinworld.com>:
On Thu, Feb 26, 2015 at 1:10 AM, jannik laval <jannik.laval@gmail.com> wrote:
Hi Dave,
2015-02-25 17:05 GMT+01:00 David T. Lewis <lewis@mail.msen.com>:
Hi Jannik,
One other thing I just thought of: Check and see if your rostopic program is actually writing to standard output, as opposed to writing directly to /dev/tty. From a terminal window, I think you could do this:
$ rostopic > out.txt
Yes, it writes on the file after a ctrl-c.
Is that a hint? So if in one terminal you run $ rostopic > out.txt then without hitting ctrl-c, in another terminal view the contents of out.txt, is it empty?
Yes, it is empty. So, the best way I have is: I run the script > I kill it after a while > I receive the infos. But when I want to terminate it , nothing happens: the process is not killed, and I have no error. Jannik
Do you get different behaviour with this between each of these mode [1]?...
-
*Latching mode* -
rostopic will publish a message to /topic_name and keep it *latched* -- any new subscribers that come online after you start rostopic will hear this message. You can stop this at any time by pressing ctrl-C.
*Once mode* -
If you don't want to have to stop rostopic with ctrl-C, you can publish in *once mode*. rostopic will keep the message latched for 3 seconds, then quit.
*Rate mode*. -
In rate mode, rostopic will publish your message at a specific rate. For example, -r 10 will publish at 10hz. For file and piped input, this defaults to 10hz.
Options:
-
-l, --latch New in Diamondback -
Enable latch mode. Latching mode is the *default* when using command-line arguments.
-r RATE -
Enable *rate mode*. Rate mode is the *default* (10hz) when using piped or file input.
-1, --once -
Enable *once mode*.
cheers -ben
[1] http://wiki.ros.org/rostopic#rostopic_pub [2] http://answers.ros.org/question/59070/disable-latching-for-rostopic-in-pipin...
-- ~~Jannik Laval~~ Ãcole des Mines de Douai Enseignant-chercheur http://www.jannik-laval.eu http://www.phratch.com http://www.approchealpes.info http://car.mines-douai.fr/