[Newbies] PipeableOSProcess - Can't SIGINT

[Sean P. DeNigris]

I have the following:

p := PipeableOSProcess command: 'export
PYTHONPATH=$PYTHONPATH:/usr/local/lib/python3.6/site-packages;
/usr/local/bin/python3 /path/to/gst-mic.py'.

The program doesn't stop until it's "told" to, which from a command line
means CTRL-C. However, `p processProxy sigint` [1] doesn't work. I assume
because I don't have the actual python process, but rather the shell
process. This guess is based on seeing that `p processProxy programName =
'/bin/sh'` and arguments are `"#('-c' 'export
PYTHONPATH=$PYTHONPATH:/usr/local/lib/python3.6/site-packages;
/usr/local/bin/python3
/Users/sean/Dynabook/Repositories/seandenigris/DynaChef/asr/experiments/continuous/gst-mic.py')"`.

Also, if I `ps aux | grep gst-mi` on the command line, I see two processes,
and I can effectively send SIGINT to the python process via `kill -SIGINT
pid`.

Taking a step back, what's the best/easiest/cleanest way for OSP and this
little gobject-loop-based Python program to negotiate when it should stop?

Thanks!



-----
Cheers,
Sean
--
Sent from: http://forum.world.st/Squeak-Beginners-f107673.html

[David T. Lewis]

Post by Sean P. DeNigris
p := PipeableOSProcess command: 'export
PYTHONPATH=$PYTHONPATH:/usr/local/lib/python3.6/site-packages;
/usr/local/bin/python3 /path/to/gst-mic.py'.
The program doesn't stop until it's "told" to, which from a command line
means CTRL-C. However, `p processProxy sigint` [1] doesn't work. I assume
because I don't have the actual python process, but rather the shell
process. This guess is based on seeing that `p processProxy programName =
'/bin/sh'` and arguments are `"#('-c' 'export
PYTHONPATH=$PYTHONPATH:/usr/local/lib/python3.6/site-packages;
/usr/local/bin/python3
/Users/sean/Dynabook/Repositories/seandenigris/DynaChef/asr/experiments/continuous/gst-mic.py')"`.
Also, if I `ps aux | grep gst-mi` on the command line, I see two processes,
and I can effectively send SIGINT to the python process via `kill -SIGINT
pid`.
Taking a step back, what's the best/easiest/cleanest way for OSP and this
little gobject-loop-based Python program to negotiate when it should stop?
Thanks!

Hi Sean,

It looks to me like the Python interpreter has handlers for SIGINT, so I
don't know if that would be a good way to terminate it. The SIGTERM signal
seems to do the trick though (p processProxy sigterm).

I am not very familiar with Python, so I don't know if this will help.
But here are two suggestions:

1) In the command line, try putting an 'exec' before the python interpreter,
like this:

p := PipeableOSProcess command: 'export PYTHONPATH=$PYTHONPATH:/usr/local/lib/python3.6/site-packages; exec /usr/local/bin/python3 /path/to/gst-mic.py'.

This will cause the python program to directly replace the /bin/sh that
started it. From Squeak, it will still look as if your PipeableOSProcess
is running a /bin/sh program but actually the /bin/sh will have been replaced
by python, and you will therefore be directly connected to the python
interpreter with no shell in between.

2) To terminate the python interpreter, try any of these and see if it
does what you want:

p close.

p pipeToInput close.

p processProxy sigterm

Dave

[Sean P. DeNigris]

But here are two suggestions…

Thanks! I will try. Actually, googling around a bit revealed a similar
thread [1] with some great information which I collected into a wiki page
[2]. The top two solutions there were:

1. ProxyPipeline (via David T. Lewis). This looks like the first choice for
most situations.

CommandShell itself uses a ProxyPipeline to represent one or more process
proxies from a command line, so you can use that class directly to evaluate
a command line:

ProxyPipeline command: '/bin/sleep 10'

2. PipeableOSProcess - The Long Way

This gives you total control (at the obvious cost of LOC!).

env := CommandShell new environment.
pwd := '/'.
args := Array
with: '-jar'
with: '/path/with/another space/jenkins.war'.
desc := Array with: nil with: nil with: nil.
p := PipeableOSProcess
new: '/usr/bin/java'
arguments: args
environment: env
descriptors: desc
workingDir: pwd
errorPipelineStream: nil


The thing I find eery is *not* that I ask the same questions over and over,
but that it seems to be almost the same day of the year even many years
apart! (May 7th, 2012 -> April 29th, 2018)

1. http://forum.world.st/Running-in-background-with-OSProcess-tp4615534.html



-----
Cheers,
Sean
--
Sent from: http://forum.world.st/Squeak-Beginners-f107673.html

[David T. Lewis]

Post by Sean P. DeNigris

But here are two suggestions???

Thanks! I will try. Actually, googling around a bit revealed a similar
thread [1] with some great information which I collected into a wiki page
1. ProxyPipeline (via David T. Lewis). This looks like the first choice for
most situations.
CommandShell itself uses a ProxyPipeline to represent one or more process
proxies from a command line, so you can use that class directly to evaluate
ProxyPipeline command: '/bin/sleep 10'
2. PipeableOSProcess - The Long Way
This gives you total control (at the obvious cost of LOC!).
env := CommandShell new environment.
pwd := '/'.
args := Array
with: '-jar'
with: '/path/with/another space/jenkins.war'.
desc := Array with: nil with: nil with: nil.
p := PipeableOSProcess
new: '/usr/bin/java'
arguments: args
environment: env
descriptors: desc
workingDir: pwd
errorPipelineStream: nil
The thing I find eery is *not* that I ask the same questions over and over,
but that it seems to be almost the same day of the year even many years
apart! (May 7th, 2012 -> April 29th, 2018)
1. http://forum.world.st/Running-in-background-with-OSProcess-tp4615534.html

Hi Sean,

LOL!

I think you and I must both be forgetting the same amount of material every
six years, because I didn't remember it either :-)

This does point to a need to be able to something like ProxyPipeline or PipeableOSProcess
simply and with less confusion, and maybe with a class name that is not so wierd
that nobody could ever remember it.

Thanks,
Dave

[Sean P. DeNigris]

I collected into a wiki page [2]

Oops! Forgot the link: https://github.com/seandenigris/pharo/wiki/OSProcess
Feel free to harvest for OSP docs if you see anything worthwhile. I also
linked to the threads of some of our more interesting (IMHO) exchanges re
OSP over the years…



-----
Cheers,
Sean
--
Sent from: http://forum.world.st/Squeak-Beginners-f107673.html

[David T. Lewis]

Post by Sean P. DeNigris

I collected into a wiki page [2]

Oops! Forgot the link: https://github.com/seandenigris/pharo/wiki/OSProcess
Feel free to harvest for OSP docs if you see anything worthwhile. I also
linked to the threads of some of our more interesting (IMHO) exchanges re
OSP over the years???

Thank you!!!

Dave