Async execution in Win32

herby1620 has asked for the wisdom of the Perl Monks concerning the following question:

This is probably pretty simple, but... I desire to start another process from a Win32 perl script. If I were in unix, I'd just write

system "ls -l 2>Xerr >Xout &";
[download]

And go from there. Well, I'm in (Yuck!) Win32 and that doesn't work, thus the question. Oh, yes I'd like the sub process to get specific file descriptors that I specify like the example above. This may be the hard part. Eventually I'll wait for the process to end, and that may be another call. Yes, I'm using XP/2000/NT (not 95/98/Me), because they are the ones that can have tasks like this.

Update...... Well, I tried:

system 1, "program 2>Xerr >Xout";
[download]

and that works, BUT... Windows desires to put up an empty command window (yuck!) and there is a rare instance where I might want to abort 'program'. What to do now? Also, where is the "system 1," thing documented? I also tried the "start /b" goodie, but it put up a command window as well. The information so far will allow me to do my deeds, but (as usual) I need a bit more (*SIGH*).

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Re: Async execution in Win32 by ikegami (Patriarch) on Mar 15, 2006 at 01:21 UTC
`system "start program 2>Xerr >Xout";` [download] Update: Doh! In the above, the redirections apply to `start`, but not to `program`. Here is something that works (tested): `system 1, 'program 2>Xerr >Xout';` [download]	[reply] [d/l] [select]
Re^2: Async execution in Win32 by BrowserUk (Patriarch) on Mar 15, 2006 at 02:15 UTC
Your start version seems to work for me? `[0] Perl> system q[cmd /c del errors output];; [0] Perl> system q[start /b perl -le"print for 1..10; die 'An error';" + 2>errors 1>output];; [0] Perl> system q[cmd /c type errors output];; errors An error at -e line 1. output 1 2 3 4 5 6 7 8 9 10` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]
Re^3: Async execution in Win32 by ikegami (Patriarch) on Mar 15, 2006 at 02:44 UTC
You added "/b". That made a difference.	[reply]
Re: Async execution in Win32 by adamk (Chaplain) on Mar 15, 2006 at 10:29 UTC
I know you have your answer, but if the async stuff is a Perl program, you might also be interested in the Process:: family of modules, specifically Process::Backgroundable in this case.	[reply]


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