Re: Problems with spawn on Linux

[Craig Markwardt <craigmnet(at)cow.physics.wisc.edu>]

ftjec@uaf.edu writes:
> Hello,
> I am having problems with the spawn command on Linux.  I am using the
> unit parameter to spawn to obtain a pipe to the child process and use
> this pipe to moniter the child's progress.  The code I have works fine
> on the sun I coded it for originally -- but on linux I get very
> unpredictable results.  Sometimes the process is spawned, yet no output
> is generated, sometimes it works fine, and sometimes it crashes idl
> completely with a "bus error" message.
> 
> Does anyone know of a solution to this problem?
> 
> Also any advice on the general state of idl on Linux would be greatly
> apprecated.

I can't reproduce your problem either:

RedHat 6.1
IDL> print, !version
{ x86 linux unix 5.2.1 Jun  4 1999}

What you describe is very strange.

However, I did discover that the ON_IOERROR procedure interferes with
reads from SPAWNed pipes.  In particular, ON_IOERROR occasionally
causes the input buffer to be lost (along with your data of course).
Usually this can be solved by moving ON_IOERROR outside of your read
loop, which in your case you have done already.  Perhaps you could try
CATCH just to see if anything different happens.

Craig

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Craig B. Markwardt, Ph.D.         EMAIL:    craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
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