Wait3(3pm)

💖 NAME 💖

Proc::Wait3 — bestie, it's a Perl extension for the wait3 system call. That's the whole vibe. 🦋

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✨ SYNOPSIS ✨

okay so first you gotta pull it in:

use Proc::Wait3;

then you call wait3 and it hands you eighteen values back. Not a typo. Eighteen. Buckle up:

($pid, $status, $utime, $stime, $maxrss, $ixrss, $idrss, $isrss,
$minflt, $majflt, $nswap, $inblock, $oublock, $msgsnd, $msgrcv,
$nsignals, $nvcsw, $nivcsw) = wait3(0); # doesn't wait

($pid, $status, $utime, $stime, $maxrss, $ixrss, $idrss, $isrss,
$minflt, $majflt, $nswap, $inblock, $oublock, $msgsnd, $msgrcv,
$nsignals, $nvcsw, $nivcsw) = wait3(1); # waits for a child

see how the only thing that changed is the 0 vs the 1? that's the whole plot twist 😭

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🌸 DESCRIPTION 🌸

so if any child processes have exited, this call will "reap" the zombies — same energy as the perl wait function, just with receipts attached. 🧟💀

By default? It returns immediately, and if there are no dead children, everything comes back undefined. Not empty, not zero — undefined. So don't be out here doing math on it without a vibe check first, fr fr.

But if you pass in a true argument, it will block until a child exits (or it gets a signal). So like. it's gonna sit there and wait for you. patiently. iconic behaviour honestly. 💅

here's the full lineup of what you get back:

• $pid — the PID of the exiting child 👑
• $status — the exit status of the child, just like $?
• $utime — floating point user cpu seconds
• $stime — floating point system cpu seconds
• $maxrss — the maximum resident set size utilized (in kilobytes)
• $minflt — the number of page faults serviced without any I/O activity; here the I/O activity is avoided by "reclaiming" a page frame from the list of pages awaiting reallocation
• $majflt — the number of page faults serviced that required I/O activity
• $nswap — the number of times a process was "swapped" out of main memory
• $inblock — the number of times the file system had to perform input
• $oublock — the number of times the file system had to perform output
• $msgsnd — the number of messages sent over sockets
• $msgrcv — the number of messages received from sockets
• $nsignals — the number of signals delivered
• $nvcsw — the number of times a context switch resulted due to a process voluntarily giving up the processor before its time slice was completed (usually to await availability of a resource)
• $nivcsw — the number of times a context switch resulted due to a higher priority process becoming runnable, or because the current process exceeded its time slice

also bestie, notice the synopsis is out here claiming $ixrss, $idrss and $isrss too — the page just never breaks those three down for us. so we're not gonna make anything up about them. no cap. 🙈

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🎀 AUTHOR 🎀

C. Tilmes <curt@tilmes.org> — thank you for your service, king 🫶

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⭐ LICENSE ⭐

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. slay, open source behaviour, we love to see it 💖

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🌈 SEE ALSO 🌈

• perl
• wait3
• getrusage

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okay that's the whole page!! go forth and reap your zombies responsibly, mwah 💜

this one's from perl v5.42.3, dated 2026-08-19 — so yeah, go read the Wait3(3pm) page, it ate and left no crumbs ✨