Problems with spawn on Linux

[ftjec(at)uaf.edu]

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.

Thanks --
  Jay
  ftjec@uaf.edu

I wrote a simple test program to trick this problem:

pro foo
   tmpstr = "the quick brown fox jumped over the lazy dog"
   unit = 69

   on_ioerror, io_err
   i = 0

   while ( 1 eq 1 ) do begin
     i = i + 1
     print, "Working on " + string(i)
     spawn, 'ls ', unit=unit, /SH


		;-- EOF of a pipe appears to be always FALSE.  Strange.
		;-- Just used to check that output was generated.
     while ( EOF(unit) eq 0) do begin
        readf, unit, tmpstr, format='(a)'
        print, tmpstr
     end

     goto, done
     io_err:
        free_lun, unit

     done:
     if ( i > 10 ) then goto, finished
   end


Here is the output on the sun machine:
Working on        1
foo.pro
init
status_watch.pro
Working on        2
foo.pro
init
status_watch.pro
Working on        3
foo.pro
init
status_watch.pro
Working on        4
foo.pro
init
status_watch.pro
Working on        5
foo.pro
init
status_watch.pro
Working on        6
foo.pro
init
status_watch.pro
Working on        7
foo.pro
init
status_watch.pro
Working on        8
foo.pro
init
status_watch.pro
Working on        9
foo.pro
init
status_watch.pro
Working on       10
foo.pro
init
status_watch.pro
Working on       11
foo.pro
init
status_watch.pro


On the linux box -- Note that everything after the 4th spawn is just
failing and not generating any output.  It always appears to fail, but
not always at the same spot.  Some times idl just crashes and dumps me
back to my shell.

Working on        1
foo.pro
init
status_watch.pro
Working on        2
foo.pro
init
status_watch.pro
Working on        3
foo.pro
init
status_watch.pro
Working on        4
foo.pro
init
status_watch.pro
Working on        5
Working on        6
Working on        7
Working on        8
Working on        9
Working on       10
Working on       11






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