| IDL Spawn command on UNIX system [message #16729] |
Sat, 21 August 1999 00:00  |
John D. Sample
Messages: 11
Registered: August 1999
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Junior Member |
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I'm using IDL to SPAWN a c program on many UNIX systems using the 'remsh'
(remote shell) command.
I would like to SPAWN these jobs in the background and forget them until
later, but, by default my IDL session stops and waits for the SPAWNed job to
be complete. The UNIT keyword almost solves the problem by sending the
output to a pipe, and allows the IDL session to continue while the process
runs in the background. The catch is that apparently my UNIX box still
counts this as an active process, and when 12 jobs or so have been launched
in this way, no new processes can be run. In fact I can't even cd to
another directory in a terminal window. I need to be able to SPAWN about 50
jobs or so at a time, some which take 12 hrs or more to run, and continue to
use my IDL session.
Another possible problem is that the documentation on pipes indicates that
the pipe, which is actually just a buffer, can fill up and cause the SPAWNed
job to stop until the buffer has been emptied.
Another possibility (I thought) was to use the keyword for No Shell, but
thus far that doesn't seem to work. Apparently the remote shell is required
in order for the program to read its input files.
Does anyone have a suggestion or work-around? The output to the pipe
contains no useful information, so I'd really like to dump it somewhere. I
suppose I could edit the programs to eliminate the myriad of printf
statements I don't really want to locate and comment them out.
Thanks in advance.
Chip
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| Re: IDL Spawn command on UNIX system [message #16863 is a reply to message #16729] |
Mon, 23 August 1999 00:00  |
steinhh
Messages: 260
Registered: June 1994
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Senior Member |
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I think the solution to your problem is to make sure your
remote shell command does terminate, while leaving the remote
job in operation. I think this should be possible if you write
a script to be run by the remsh command that goes something like
this:
--------------- remscript.csh
#/bin/csh
do_my_job >& /dev/null &
--------------- end remscript.csh
and then use the spawn command approx. like this (don't know
the syntax of your "remsh" command, but..):
spawn,"remsh machine.idcomm.com remscript.csh"
Some variations on a theme may apply here, but the key
issue is to get your remote shell command to terminate.
That means making the remote shell *script* terminate.
Regards,
Stein Vidar
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| Re: IDL Spawn command on UNIX system [message #16868 is a reply to message #16729] |
Sun, 22 August 1999 00:00 |
R.Bauer
Messages: 1424
Registered: November 1998
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Senior Member |
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"John D. Sample" wrote:
> ----------
> In article <Pine.GHP.4.05.9908212248380.14331-100000@nagik.cs.colorado.edu>,
> Kenneth Mankoff <mankoff@nagik.cs.colorado.edu> wrote:
>
>>
>> On Sat, 21 Aug 1999, Mike Schienle wrote:
>>
>>> In article <37bf3790@mindmeld.idcomm.com>, "John D. Sample"
>>> <sample@idcomm.com> wrote:
>>>
>>>> I'm using IDL to SPAWN a c program on many UNIX systems using the 'remsh'
>>>> (remote shell) command.
>>>>
>>>> I would like to SPAWN these jobs in the background and forget them until
>>>> later, but, by default my IDL session stops and waits for the SPAWNed job to
>>>> be complete.
>>> ...
>>>
>>> I hope this is something you've overlooked and I'm not sounding like an
>>> idiot for suggesting it, but how about adding an ampersand (&) to the end
>>> of the command string which is sent to the spawn command? That would
>>> background the spawned command and return to the IDL command/program
>>> without waiting for the process to complete.
>>>
>>> --
>>> Mike Schienle Interactive Visuals, Inc.
>>> mgs@ivsoftware.com Remote Sensing and Image Processing
>>> http://www.ivsoftware.com/ Analysis and Application Development
>>>
>>
>> but it wouldn't solve the problem of your process quota. Talk to your
>> sysadmin, and ask them to raise the number of processes you are allowed to
>> run at any one given time to solve that problem.
>>
>> -ken.
>>
> Thanks for both replies. I am using the ampersand, and initially assumed
> this *would* send the process to the background. Apparently this is not
> enough to return control to IDL. Even though the process runs in the
> background, IDL still stops and waits for the process to complete before
> processing the next widget event. This is consistent with the documentation
> (which I consulted later).
This is only if you are using only xmanager, if you use widget_event you will be
able to get paralell another event.
R.Bauer
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| Re: IDL Spawn command on UNIX system [message #16870 is a reply to message #16729] |
Sun, 22 August 1999 00:00 |
John D. Sample
Messages: 11
Registered: August 1999
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Junior Member |
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----------
In article <Pine.GHP.4.05.9908212248380.14331-100000@nagik.cs.colorado.edu>,
Kenneth Mankoff <mankoff@nagik.cs.colorado.edu> wrote:
>
> On Sat, 21 Aug 1999, Mike Schienle wrote:
>
>> In article <37bf3790@mindmeld.idcomm.com>, "John D. Sample"
>> <sample@idcomm.com> wrote:
>>
>>> I'm using IDL to SPAWN a c program on many UNIX systems using the 'remsh'
>>> (remote shell) command.
>>>
>>> I would like to SPAWN these jobs in the background and forget them until
>>> later, but, by default my IDL session stops and waits for the SPAWNed job to
>>> be complete.
>> ...
>>
>> I hope this is something you've overlooked and I'm not sounding like an
>> idiot for suggesting it, but how about adding an ampersand (&) to the end
>> of the command string which is sent to the spawn command? That would
>> background the spawned command and return to the IDL command/program
>> without waiting for the process to complete.
>>
>> --
>> Mike Schienle Interactive Visuals, Inc.
>> mgs@ivsoftware.com Remote Sensing and Image Processing
>> http://www.ivsoftware.com/ Analysis and Application Development
>>
>
> but it wouldn't solve the problem of your process quota. Talk to your
> sysadmin, and ask them to raise the number of processes you are allowed to
> run at any one given time to solve that problem.
>
> -ken.
>
Thanks for both replies. I am using the ampersand, and initially assumed
this *would* send the process to the background. Apparently this is not
enough to return control to IDL. Even though the process runs in the
background, IDL still stops and waits for the process to complete before
processing the next widget event. This is consistent with the documentation
(which I consulted later).
Using the pipe DOES return control to IDL.
I will check on the number of processes allowed. There must be some kind of
work around however, because I *am* able to launch 50 jobs at a time using
UNIX scripts...and maybe the answer is to learn this language well enough to
decode what is going on.
A problem still remains with the pipe used to relegate the job to the
background. If it fills up, it will bring the job to a stop (according to
the IDL documentation.) I may need to create some code which reads from the
pipe every so often to insure it doesn't fill up, and some how detect when
the job is complete so I can FREE_LUN the pipe.
Chip
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| Re: IDL Spawn command on UNIX system [message #16877 is a reply to message #16729] |
Sat, 21 August 1999 00:00 |
Kenneth Mankoff
Messages: 42
Registered: August 1999
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Member |
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On Sat, 21 Aug 1999, Mike Schienle wrote:
> In article <37bf3790@mindmeld.idcomm.com>, "John D. Sample"
> <sample@idcomm.com> wrote:
>
>> I'm using IDL to SPAWN a c program on many UNIX systems using the 'remsh'
>> (remote shell) command.
>>
>> I would like to SPAWN these jobs in the background and forget them until
>> later, but, by default my IDL session stops and waits for the SPAWNed job to
>> be complete.
> ...
>
> I hope this is something you've overlooked and I'm not sounding like an
> idiot for suggesting it, but how about adding an ampersand (&) to the end
> of the command string which is sent to the spawn command? That would
> background the spawned command and return to the IDL command/program
> without waiting for the process to complete.
>
> --
> Mike Schienle Interactive Visuals, Inc.
> mgs@ivsoftware.com Remote Sensing and Image Processing
> http://www.ivsoftware.com/ Analysis and Application Development
>
but it wouldn't solve the problem of your process quota. Talk to your
sysadmin, and ask them to raise the number of processes you are allowed to
run at any one given time to solve that problem.
-ken.
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