Re: How do you get PID of a program called using system call?

Thank you all for your reply, I found it very helpful. However, when I mention about having 4 system calls that resulted in 4 pids, I mean the following(having them runnning in background):

my $cmd = "process_file -c arg1 -d arg2";
for(1..40)
{
    if(!WINDOWS)
    {
        system("$cmd > /dev/null &");
    }
    else
    {
        system("sh -c \"$cmd > /tmp/null \"&");
    }
}
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as you can see, the above code will gives me 4 processes running in the back ground, but I have no control over those pids

Comment on Re: How do you get PID of a program called using system call? Download Code

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Re: Re: How do you get PID of a program called using system call? by rob_au (Abbot) on Oct 09, 2001 at 06:55 UTC
With this approach in mind, your best solution would be to iteration through the process table following execution of your system processes. Under NIX, you would want to use Proc::ProcessTable (which I have written about before here). For Windows, you should take a look at either Win32::Process or Win32::ProcFarm. Even so, I still think that you would find the best solution from pre-forking within your script, rather than launching system processes and detaching yourself from the controlling tty. This pre-forking approach would give you greater control, without the need to extraneous loops and control structures, of your spawned processes. Ooohhh, Rob no beer function well without!*	[reply]

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Re: Re: How do you get PID of a program called using system call?
by rob_au (Abbot) on Oct 09, 2001 at 06:55 UTC

Even so, I still think that you would find the best solution from pre-forking within your script, rather than launching system processes and detaching yourself from the controlling tty. This pre-forking approach would give you greater control, without the need to extraneous loops and control structures, of your spawned processes.

Ooohhh, Rob no beer function well without!

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