Re: [Pharo-dev] OSProcess bug ?

2015-02-27 Thread jannik laval
Hi,

Yes, nothing appears.
When I interupt the process (ctrl-c), an error appears:
---
close failed in file object destructor:
sys.excepthook is missing
lost sys.stderr
---

Jannik

2015-02-26 15:56 GMT+01:00 Ben Coman b...@openinworld.com:



 On Thu, Feb 26, 2015 at 12:05 AM, David T. Lewis le...@mail.msen.com
 wrote:

 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



 Would using a pipe better represent the interaction with OSProcess? e.g...
 $ rostopic | tail

 cheers -ben




-- 

~~Jannik Laval~~
École des Mines de Douai
Enseignant-chercheur
http://www.jannik-laval.eu
http://www.phratch.com
http://www.approchealpes.info
http://car.mines-douai.fr/


Re: [Pharo-dev] OSProcess bug ?

2015-02-27 Thread jannik laval
Hi Ben,

2015-02-26 15:08 GMT+01:00 Ben Coman b...@openinworld.com:



 On Thu, Feb 26, 2015 at 1:10 AM, jannik laval jannik.la...@gmail.com
 wrote:

 Hi Dave,



 2015-02-25 17:05 GMT+01:00 David T. Lewis le...@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-piping-mode/




-- 

~~Jannik Laval~~
École des Mines de Douai
Enseignant-chercheur
http://www.jannik-laval.eu
http://www.phratch.com
http://www.approchealpes.info
http://car.mines-douai.fr/


Re: [Pharo-dev] OSProcess bug ?

2015-02-26 Thread Ben Coman
On Thu, Feb 26, 2015 at 12:05 AM, David T. Lewis le...@mail.msen.com
wrote:

 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



Would using a pipe better represent the interaction with OSProcess? e.g...
$ rostopic | tail

cheers -ben


Re: [Pharo-dev] OSProcess bug ?

2015-02-26 Thread Ben Coman
On Thu, Feb 26, 2015 at 1:10 AM, jannik laval jannik.la...@gmail.com
wrote:

 Hi Dave,



 2015-02-25 17:05 GMT+01:00 David T. Lewis le...@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?

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-piping-mode/


Re: [Pharo-dev] OSProcess bug ?

2015-02-25 Thread David T. Lewis
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

If you run this get output written to the out.txt file, that is good. If
you run it and see output to your terminal window, it would mean that the
rostopic program was writing directly to /dev/tty (so there would never be
any output to read with a PipeableOSProcess).

I would not worry about the missing AioPlugin. Your code should still work
without the plugin.

Dave


 Hi Dave,

 2015-02-25 1:13 GMT+01:00 David T. Lewis le...@mail.msen.com:

 On Tue, Feb 24, 2015 at 08:33:41PM +0100, jannik laval wrote:
  Hi pharoers,
 
  I am playing with OSProcess.
  I am using an example, and I am annoyed with a strange bug:
 
  Here is the code I want to execute, and does not work:
  
  |thread process output|
  myCmd := 'rostopic bw /turtle1/pose'.
  thread := [process := (PipeableOSProcess command: myCmd) ] fork.
  3 second wait.
  output := process upToEnd.
  output inspect.
  thread terminate.
  ===

 Hi Jannik,

 I am not familiar with the rostopic command, but it is common for some
 Unix programs to flush their output when the stdout is connected to
 /dev/tty (a terminal), but not necessarily if connected to a pipe or
 to a file. So it may be that the running rostopic program is producing
 output, but that the output has not yet been flushed to the pipe
 connected
 to your PipeableOSProcess.


 Thank you for your explanation.
 So, what I can do is to send a sigint to terminate the process and receive
 the info.
 But sending process processProxy sigint. does nothing.

 By the way I have a warning on the AIOPlugin... Probably I should
 reinstall
 my VM.

 I also try process flush, but it does not do anything.




 Your #upToEnd call will read the available data from the OS pipe, but it
 will not read data that was written by the rotopic program, but not
 yet flushed out to the OSPipe. So I am guessing that this may be why the
 data seems to be missing.

 I notice also that you are putting your PipeableOSProcess into a
 separate
 Smalltalk process using #fork. This is probably not necessary, so try
 getting rid of the #fork and the later thread terminate. It will not fix
 the problem for you, but it will simplify the code.



 Ok, it is simpler like that. You are right, it does not help :)

 Thank you for your help.



 Dave


 
  'rostopic bw /turtle1/pose' is a command that is a loop displaying the
  current bandwidth of a ROS process. In a terminal, it works fine. With
  OSProcess the output value is empty.
 
  My source code is correct: if I replace myCmd by :
  myCmd := 'ping localhost'.
 
  It is a loop too, and it returns a correct string.
 
  I have clearly no idea of where I have to search... Any help or
 discussion
  about that would be great :)
 
  Thank you,
 
  Oups, some infos:
  I am using Ubuntu 14.04
  Pharo3.0 with Moose 5.0, latest update: #30863
  The script I use (rostopic) is a python script (does it impact ?)
 
 
  --
 
  ~~Jannik Laval~~
  ??cole des Mines de Douai
  Enseignant-chercheur
  http://www.jannik-laval.eu
  http://www.phratch.com
  http://www.approchealpes.info
  http://car.mines-douai.fr/




 --

 ~~Jannik Laval~~
 École des Mines de Douai
 Enseignant-chercheur
 http://www.jannik-laval.eu
 http://www.phratch.com
 http://www.approchealpes.info
 http://car.mines-douai.fr/






Re: [Pharo-dev] OSProcess bug ?

2015-02-25 Thread Levente Uzonyi
Another possibility is that the program is writing to stderr instead of 
stdout.


Levente

On Wed, 25 Feb 2015, David T. Lewis wrote:


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

If you run this get output written to the out.txt file, that is good. If
you run it and see output to your terminal window, it would mean that the
rostopic program was writing directly to /dev/tty (so there would never be
any output to read with a PipeableOSProcess).

I would not worry about the missing AioPlugin. Your code should still work
without the plugin.

Dave



Hi Dave,

2015-02-25 1:13 GMT+01:00 David T. Lewis le...@mail.msen.com:


On Tue, Feb 24, 2015 at 08:33:41PM +0100, jannik laval wrote:

Hi pharoers,

I am playing with OSProcess.
I am using an example, and I am annoyed with a strange bug:

Here is the code I want to execute, and does not work:

|thread process output|
myCmd := 'rostopic bw /turtle1/pose'.
thread := [process := (PipeableOSProcess command: myCmd) ] fork.
3 second wait.
output := process upToEnd.
output inspect.
thread terminate.
===


Hi Jannik,

I am not familiar with the rostopic command, but it is common for some
Unix programs to flush their output when the stdout is connected to
/dev/tty (a terminal), but not necessarily if connected to a pipe or
to a file. So it may be that the running rostopic program is producing
output, but that the output has not yet been flushed to the pipe
connected
to your PipeableOSProcess.



Thank you for your explanation.
So, what I can do is to send a sigint to terminate the process and receive
the info.
But sending process processProxy sigint. does nothing.

By the way I have a warning on the AIOPlugin... Probably I should
reinstall
my VM.

I also try process flush, but it does not do anything.





Your #upToEnd call will read the available data from the OS pipe, but it
will not read data that was written by the rotopic program, but not
yet flushed out to the OSPipe. So I am guessing that this may be why the
data seems to be missing.

I notice also that you are putting your PipeableOSProcess into a
separate
Smalltalk process using #fork. This is probably not necessary, so try
getting rid of the #fork and the later thread terminate. It will not fix
the problem for you, but it will simplify the code.




Ok, it is simpler like that. You are right, it does not help :)

Thank you for your help.




Dave




'rostopic bw /turtle1/pose' is a command that is a loop displaying the
current bandwidth of a ROS process. In a terminal, it works fine. With
OSProcess the output value is empty.

My source code is correct: if I replace myCmd by :
myCmd := 'ping localhost'.

It is a loop too, and it returns a correct string.

I have clearly no idea of where I have to search... Any help or

discussion

about that would be great :)

Thank you,

Oups, some infos:
I am using Ubuntu 14.04
Pharo3.0 with Moose 5.0, latest update: #30863
The script I use (rostopic) is a python script (does it impact ?)


--

~~Jannik Laval~~
??cole des Mines de Douai
Enseignant-chercheur
http://www.jannik-laval.eu
http://www.phratch.com
http://www.approchealpes.info
http://car.mines-douai.fr/






--

~~Jannik Laval~~
Ã?cole des Mines de Douai
Enseignant-chercheur
http://www.jannik-laval.eu
http://www.phratch.com
http://www.approchealpes.info
http://car.mines-douai.fr/







Re: [Pharo-dev] OSProcess bug ?

2015-02-25 Thread jannik laval
Hi Dave,



2015-02-25 17:05 GMT+01:00 David T. Lewis le...@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.



 If you run this get output written to the out.txt file, that is good. If
 you run it and see output to your terminal window, it would mean that the
 rostopic program was writing directly to /dev/tty (so there would never be
 any output to read with a PipeableOSProcess).

 I would not worry about the missing AioPlugin. Your code should still work
 without the plugin.


Ok, thank you.
Jannik



 Dave


  Hi Dave,
 
  2015-02-25 1:13 GMT+01:00 David T. Lewis le...@mail.msen.com:
 
  On Tue, Feb 24, 2015 at 08:33:41PM +0100, jannik laval wrote:
   Hi pharoers,
  
   I am playing with OSProcess.
   I am using an example, and I am annoyed with a strange bug:
  
   Here is the code I want to execute, and does not work:
   
   |thread process output|
   myCmd := 'rostopic bw /turtle1/pose'.
   thread := [process := (PipeableOSProcess command: myCmd) ] fork.
   3 second wait.
   output := process upToEnd.
   output inspect.
   thread terminate.
   ===
 
  Hi Jannik,
 
  I am not familiar with the rostopic command, but it is common for some
  Unix programs to flush their output when the stdout is connected to
  /dev/tty (a terminal), but not necessarily if connected to a pipe or
  to a file. So it may be that the running rostopic program is producing
  output, but that the output has not yet been flushed to the pipe
  connected
  to your PipeableOSProcess.
 
 
  Thank you for your explanation.
  So, what I can do is to send a sigint to terminate the process and
 receive
  the info.
  But sending process processProxy sigint. does nothing.
 
  By the way I have a warning on the AIOPlugin... Probably I should
  reinstall
  my VM.
 
  I also try process flush, but it does not do anything.
 
 
 
 
  Your #upToEnd call will read the available data from the OS pipe, but it
  will not read data that was written by the rotopic program, but not
  yet flushed out to the OSPipe. So I am guessing that this may be why the
  data seems to be missing.
 
  I notice also that you are putting your PipeableOSProcess into a
  separate
  Smalltalk process using #fork. This is probably not necessary, so try
  getting rid of the #fork and the later thread terminate. It will not fix
  the problem for you, but it will simplify the code.
 
 
 
  Ok, it is simpler like that. You are right, it does not help :)
 
  Thank you for your help.
 
 
 
  Dave
 
 
  
   'rostopic bw /turtle1/pose' is a command that is a loop displaying the
   current bandwidth of a ROS process. In a terminal, it works fine. With
   OSProcess the output value is empty.
  
   My source code is correct: if I replace myCmd by :
   myCmd := 'ping localhost'.
  
   It is a loop too, and it returns a correct string.
  
   I have clearly no idea of where I have to search... Any help or
  discussion
   about that would be great :)
  
   Thank you,
  
   Oups, some infos:
   I am using Ubuntu 14.04
   Pharo3.0 with Moose 5.0, latest update: #30863
   The script I use (rostopic) is a python script (does it impact ?)
  
  
   --
  
   ~~Jannik Laval~~
   ??cole des Mines de Douai
   Enseignant-chercheur
   http://www.jannik-laval.eu
   http://www.phratch.com
   http://www.approchealpes.info
   http://car.mines-douai.fr/
 
 
 
 
  --
 
  ~~Jannik Laval~~
  École des Mines de Douai
  Enseignant-chercheur
  http://www.jannik-laval.eu
  http://www.phratch.com
  http://www.approchealpes.info
  http://car.mines-douai.fr/
 






-- 

~~Jannik Laval~~
École des Mines de Douai
Enseignant-chercheur
http://www.jannik-laval.eu
http://www.phratch.com
http://www.approchealpes.info
http://car.mines-douai.fr/


Re: [Pharo-dev] OSProcess bug ?

2015-02-25 Thread jannik laval
Hi Levente,

Nop, I catch also stderr, but there is nothing here.

Jannik

2015-02-25 17:40 GMT+01:00 Levente Uzonyi le...@elte.hu:

 Another possibility is that the program is writing to stderr instead of
 stdout.

 Levente


 On Wed, 25 Feb 2015, David T. Lewis wrote:

  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

 If you run this get output written to the out.txt file, that is good. If
 you run it and see output to your terminal window, it would mean that the
 rostopic program was writing directly to /dev/tty (so there would never be
 any output to read with a PipeableOSProcess).

 I would not worry about the missing AioPlugin. Your code should still work
 without the plugin.

 Dave


  Hi Dave,

 2015-02-25 1:13 GMT+01:00 David T. Lewis le...@mail.msen.com:

  On Tue, Feb 24, 2015 at 08:33:41PM +0100, jannik laval wrote:

 Hi pharoers,

 I am playing with OSProcess.
 I am using an example, and I am annoyed with a strange bug:

 Here is the code I want to execute, and does not work:
 
 |thread process output|
 myCmd := 'rostopic bw /turtle1/pose'.
 thread := [process := (PipeableOSProcess command: myCmd) ] fork.
 3 second wait.
 output := process upToEnd.
 output inspect.
 thread terminate.
 ===


 Hi Jannik,

 I am not familiar with the rostopic command, but it is common for some
 Unix programs to flush their output when the stdout is connected to
 /dev/tty (a terminal), but not necessarily if connected to a pipe or
 to a file. So it may be that the running rostopic program is producing
 output, but that the output has not yet been flushed to the pipe
 connected
 to your PipeableOSProcess.


 Thank you for your explanation.
 So, what I can do is to send a sigint to terminate the process and
 receive
 the info.
 But sending process processProxy sigint. does nothing.

 By the way I have a warning on the AIOPlugin... Probably I should
 reinstall
 my VM.

 I also try process flush, but it does not do anything.




 Your #upToEnd call will read the available data from the OS pipe, but it
 will not read data that was written by the rotopic program, but not
 yet flushed out to the OSPipe. So I am guessing that this may be why the
 data seems to be missing.

 I notice also that you are putting your PipeableOSProcess into a
 separate
 Smalltalk process using #fork. This is probably not necessary, so try
 getting rid of the #fork and the later thread terminate. It will not fix
 the problem for you, but it will simplify the code.



 Ok, it is simpler like that. You are right, it does not help :)

 Thank you for your help.



 Dave



 'rostopic bw /turtle1/pose' is a command that is a loop displaying the
 current bandwidth of a ROS process. In a terminal, it works fine. With
 OSProcess the output value is empty.

 My source code is correct: if I replace myCmd by :
 myCmd := 'ping localhost'.

 It is a loop too, and it returns a correct string.

 I have clearly no idea of where I have to search... Any help or

 discussion

 about that would be great :)

 Thank you,

 Oups, some infos:
 I am using Ubuntu 14.04
 Pharo3.0 with Moose 5.0, latest update: #30863
 The script I use (rostopic) is a python script (does it impact ?)


 --

 ~~Jannik Laval~~
 ??cole des Mines de Douai
 Enseignant-chercheur
 http://www.jannik-laval.eu
 http://www.phratch.com
 http://www.approchealpes.info
 http://car.mines-douai.fr/





 --

 ~~Jannik Laval~~
 Ã?cole des Mines de Douai
 Enseignant-chercheur
 http://www.jannik-laval.eu
 http://www.phratch.com
 http://www.approchealpes.info
 http://car.mines-douai.fr/







-- 

~~Jannik Laval~~
École des Mines de Douai
Enseignant-chercheur
http://www.jannik-laval.eu
http://www.phratch.com
http://www.approchealpes.info
http://car.mines-douai.fr/


Re: [Pharo-dev] OSProcess bug ?

2015-02-25 Thread jannik laval
Hi Dave,

2015-02-25 1:13 GMT+01:00 David T. Lewis le...@mail.msen.com:

 On Tue, Feb 24, 2015 at 08:33:41PM +0100, jannik laval wrote:
  Hi pharoers,
 
  I am playing with OSProcess.
  I am using an example, and I am annoyed with a strange bug:
 
  Here is the code I want to execute, and does not work:
  
  |thread process output|
  myCmd := 'rostopic bw /turtle1/pose'.
  thread := [process := (PipeableOSProcess command: myCmd) ] fork.
  3 second wait.
  output := process upToEnd.
  output inspect.
  thread terminate.
  ===

 Hi Jannik,

 I am not familiar with the rostopic command, but it is common for some
 Unix programs to flush their output when the stdout is connected to
 /dev/tty (a terminal), but not necessarily if connected to a pipe or
 to a file. So it may be that the running rostopic program is producing
 output, but that the output has not yet been flushed to the pipe connected
 to your PipeableOSProcess.


Thank you for your explanation.
So, what I can do is to send a sigint to terminate the process and receive
the info.
But sending process processProxy sigint. does nothing.

By the way I have a warning on the AIOPlugin... Probably I should reinstall
my VM.

I also try process flush, but it does not do anything.




 Your #upToEnd call will read the available data from the OS pipe, but it
 will not read data that was written by the rotopic program, but not
 yet flushed out to the OSPipe. So I am guessing that this may be why the
 data seems to be missing.

 I notice also that you are putting your PipeableOSProcess into a separate
 Smalltalk process using #fork. This is probably not necessary, so try
 getting rid of the #fork and the later thread terminate. It will not fix
 the problem for you, but it will simplify the code.



Ok, it is simpler like that. You are right, it does not help :)

Thank you for your help.



 Dave


 
  'rostopic bw /turtle1/pose' is a command that is a loop displaying the
  current bandwidth of a ROS process. In a terminal, it works fine. With
  OSProcess the output value is empty.
 
  My source code is correct: if I replace myCmd by :
  myCmd := 'ping localhost'.
 
  It is a loop too, and it returns a correct string.
 
  I have clearly no idea of where I have to search... Any help or
 discussion
  about that would be great :)
 
  Thank you,
 
  Oups, some infos:
  I am using Ubuntu 14.04
  Pharo3.0 with Moose 5.0, latest update: #30863
  The script I use (rostopic) is a python script (does it impact ?)
 
 
  --
 
  ~~Jannik Laval~~
  ??cole des Mines de Douai
  Enseignant-chercheur
  http://www.jannik-laval.eu
  http://www.phratch.com
  http://www.approchealpes.info
  http://car.mines-douai.fr/




-- 

~~Jannik Laval~~
École des Mines de Douai
Enseignant-chercheur
http://www.jannik-laval.eu
http://www.phratch.com
http://www.approchealpes.info
http://car.mines-douai.fr/


Re: [Pharo-dev] OSProcess bug ?

2015-02-24 Thread David T. Lewis
On Tue, Feb 24, 2015 at 08:33:41PM +0100, jannik laval wrote:
 Hi pharoers,
 
 I am playing with OSProcess.
 I am using an example, and I am annoyed with a strange bug:
 
 Here is the code I want to execute, and does not work:
 
 |thread process output|
 myCmd := 'rostopic bw /turtle1/pose'.
 thread := [process := (PipeableOSProcess command: myCmd) ] fork.
 3 second wait.
 output := process upToEnd.
 output inspect.
 thread terminate.
 ===

Hi Jannik,

I am not familiar with the rostopic command, but it is common for some
Unix programs to flush their output when the stdout is connected to
/dev/tty (a terminal), but not necessarily if connected to a pipe or
to a file. So it may be that the running rostopic program is producing
output, but that the output has not yet been flushed to the pipe connected
to your PipeableOSProcess.

Your #upToEnd call will read the available data from the OS pipe, but it
will not read data that was written by the rotopic program, but not
yet flushed out to the OSPipe. So I am guessing that this may be why the
data seems to be missing.

I notice also that you are putting your PipeableOSProcess into a separate
Smalltalk process using #fork. This is probably not necessary, so try
getting rid of the #fork and the later thread terminate. It will not fix
the problem for you, but it will simplify the code.

Dave


 
 'rostopic bw /turtle1/pose' is a command that is a loop displaying the
 current bandwidth of a ROS process. In a terminal, it works fine. With
 OSProcess the output value is empty.
 
 My source code is correct: if I replace myCmd by :
 myCmd := 'ping localhost'.
 
 It is a loop too, and it returns a correct string.
 
 I have clearly no idea of where I have to search... Any help or discussion
 about that would be great :)
 
 Thank you,
 
 Oups, some infos:
 I am using Ubuntu 14.04
 Pharo3.0 with Moose 5.0, latest update: #30863
 The script I use (rostopic) is a python script (does it impact ?)
 
 
 -- 
 
 ~~Jannik Laval~~
 ??cole des Mines de Douai
 Enseignant-chercheur
 http://www.jannik-laval.eu
 http://www.phratch.com
 http://www.approchealpes.info
 http://car.mines-douai.fr/