KILLPG(3P)

🌸 PROLOG 🌸

Okay bestie, before literally anything else, real talk: this page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (so like, go check the corresponding Linux manual page for the deets on Linux behavior), or honestly? The interface may not even be implemented on Linux. Vibe check accordingly. 💅

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✨ NAME ✨

killpg — send a signal to a process group 💌

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🎀 SYNOPSIS 🎀

#include <signal.h>

int killpg(pid_t pgrp, int sig);

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💖 DESCRIPTION 💖

So the killpg() function shall send the signal specified by sig to the process group specified by pgrp. That's the whole thing. Iconic, simple, slays. 🫶

And here's the tea: if pgrp is greater than 1, then killpg(pgrp, sig) shall be equivalent to kill(-pgrp, sig).

If pgrp is less than or equal to 1, the behavior of killpg() is undefined. Not "undefined" like quirky, undefined like 🚫 don't do it. The spec is literally not gonna tell you what happens, because it's not a valid move.

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⭐ RETURN VALUE ⭐

Refer to kill(). (Yes bestie, go read that one, it's got the receipts.) 📜

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💀 ERRORS 💀

Refer to kill().

The following sections are informative. (Which is fancy-speak for "the actual requirements are done, this is the commentary track 🎧".)

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🌈 EXAMPLES 🌈

Sending a Signal to All Other Members of a Process Group 🦋

The following example shows how the calling process could send a signal to all other members of its process group. And the clever part — to prevent itself from receiving the signal, it first makes itself immune to the signal by ignoring it. Main character behavior, honestly. 👑

#include <signal.h>
#include <unistd.h>
...
    if (signal(SIGUSR1, SIG_IGN) == SIG_ERR)
        /* Handle error */;

    if (killpg(getpgrp(), SIGUSR1) == -1)
        /* Handle error */;"

Note: that trailing " at the very end is exactly what's in the original, so we're keeping it. Character for character, no cap. 🙈

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💅 APPLICATION USAGE 💅

None.

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🧚 RATIONALE 🧚

None.

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🌸 FUTURE DIRECTIONS 🌸

None.

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🔥 SEE ALSO 🔥

• getpgid()
• getpid()
• kill()
• raise()

The Base Definitions volume of POSIX.1‐2017, <signal.h>

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👑 COPYRIGHT 👑

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

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Okay and that's the whole page, bestie!! 💜 This one's from IEEE/The Open Group, dated 2017, and it's the KILLPG(3P) girlies' moment. Go forth and signal your process group responsibly. Mwah 🎀✨🦋