Re: Reading from Many Child Processes using Pipes

I know there are a few (unrelated to the problem) issues in the code, but in the interest of getting a working solution

The major problem is that if one of your kids fails to write because its hung; then your entire sets of processes will block.

The parent will block at the readline the first time it tries to read from the blocked child; and all the other children will block once they've written a buffer full of output to their pipe that the parent is no longer reading from.

while (1) {
    foreach my $i (0..$#kids) {
        if (<$readers[$i]>) {
[download]

The solution is to use select which will prevent you from trying to read from a kid that hasn't written something for you to read.

There are lots of select loop examples on perlmonks to get you started.

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Comment on Re: Reading from Many Child Processes using Pipes Download Code

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Re^2: Reading from Many Child Processes using Pipes by sved (Novice) on Oct 31, 2015 at 18:39 UTC
Thanks BrowserUK. The child processes are designed to always be non-blocking (or block with a timeout) and so will never hang. And, yes I was indeed looking for help with select. The select syntax is what confused me.	[reply]
Re^3: Reading from Many Child Processes using Pipes by BrowserUk (Patriarch) on Oct 31, 2015 at 20:18 UTC
will never hang. That's a brave assumption. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". I knew I was on the right track :) In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]