SIGLONGJMP(3P)

📦 version 2017a, in alpine 3.22, alpine 3.23, alpine 3.24, arch rolling, nixpkgs unstable, opensuse-leap 16.0

🦋 siglongjmp(3P) — POSIX Programmer's Manual 🦋

okay so bestie, we're reading from the POSIX Programmer's Manual today, and this little page is all about siglongjmp. ✨

💌 PROLOG (the lil' disclaimer)

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ — so if you're on Linux, pls consult the corresponding Linux manual page for the deets on Linux behavior. 🫶

Also, lowkey important: the interface may not be implemented on Linux at all. Not me warning you twice. 💀

👑 NAME

siglongjmp — non-local goto, but make it signal-handling. 💅

✨ SYNOPSIS

#include <setjmp.h>

void siglongjmp(sigjmp_buf env, int val);

that's it. two args. iconic. 🎀

🧚 DESCRIPTION

So here's the tea: siglongjmp() shall be equivalent to the longjmp() function, except for these two little plot twists:

  • References to setjmp() shall be equivalent to sigsetjmp(). 💖
  • The siglongjmp() function shall restore the saved signal mask if and only if the env argument was initialized by a call to sigsetjmp() with a non-zero savemask argument. 👑
ngl that "if and only if" is doing so much heavy lifting. read it twice. fr fr.

🌈 RETURN VALUE

After siglongjmp() is completed, program execution shall continue as if the corresponding invocation of sigsetjmp() had just returned the value specified by val. 🦋

And here's the lil' gotcha: the siglongjmp() function shall not cause sigsetjmp() to return 0. So if val is 0, sigsetjmp() shall return the value 1. No zeros allowed, periodt. 💀

🍓 ERRORS

No errors are defined. ✨

The following sections are informative. (so like, chill reading, not the rules-rules)

🎀 EXAMPLES

None. 😭 she said no examples, bestie. we cope.

💜 APPLICATION USAGE

The distinction between setjmp() or longjmp() and sigsetjmp() or siglongjmp() is only significant for programs which use sigaction(), sigprocmask(), or sigsuspend(). 🌸

so if you're not touching those three, you're honestly just vibing with the regular version. iykyk.

⭐ RATIONALE

None. 🫶

🧊 FUTURE DIRECTIONS

None. 💅

👀 SEE ALSO

  • longjmp()
  • pthread_sigmask()
  • setjmp()
  • sigsetjmp()
  • sigsuspend()

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

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 . 🐛

and that's the whole page, bestie — brought to you by IEEE/The Open Group, dated 2017. mwah, go forth and jump non-locally. 💋💖

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