PSIGNAL(3)

💖 PSIGNAL(3) — system signal messages, bestie 💖

okay so this is the PSIGNAL(3) page from the Library Functions Manual, and it is literally all about system signal messages. Buckle up, bestie. 🎀

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✨ NAME ✨

psignal, psiginfo, strsignal, sys_siglist, sys_signame, sig2str, str2sig — system signal messages. That's the whole squad. 👑

🧚 LIBRARY 🧚

Standard C Library (libc, -lc). It lives there. Slay.

🌸 SYNOPSIS 🌸

#include <signal.h>

void
psignal(int sig, const char *s);

void
psiginfo(const siginfo_t *si, const char *s);

extern const char * const sys_siglist[];
extern const char * const sys_signame[];

#include <string.h>

char *
strsignal(int sig);

int
sig2str(int signum, char *str);

int
str2sig(char *str, int *pnum);

🦋 DESCRIPTION 🦋

Both psignal() and strsignal() locate the descriptive message string for a signal number. strsignal() accepts the signal number argument sig and returns a pointer to the corresponding message string. Iconic behavior, honestly. ✨

psignal() accepts a signal number argument sig and writes it to the standard error. If the argument s is non-NULL and does not point to the null character, s is written to the standard error file descriptor prior to the message string, immediately followed by a colon and a space. If the signal number is not recognized (sigaction(2)), the string “Unknown signal” is produced. No cap. 💅

psiginfo() is similar to psignal(), except that the signal number information is taken from the si argument, which is a siginfo_t structure. Main character energy, but for structs. 🫶

The message strings can be accessed directly through the external array sys_siglist, indexed by recognized signal numbers. The external array sys_signame is used similarly and contains short, upper-case abbreviations for signals which are useful for recognizing signal names in user input. The defined variable NSIG contains a count of the strings in sys_siglist and sys_signame. iykyk. 🌟

sig2str() translates the signal number signum to the signal name, without the “SIG” prefix, and stores it at the location specified by str, which should be large enough to hold the name and the terminating NUL byte. The symbol SIG2STR_MAX gives the maximum size in bytes required. Don't skimp on the buffer, bestie. 🍓

str2sig() translates the signal name str to a signal number and stores it in the location referenced by pnum. The name in str can be either the name of the signal, with or without the “SIG” prefix, or a decimal number. Flexible queen. 👑

💅 SEE ALSO 💅

• sigaction(2)
• perror(3)
• strerror(3)

go read those too, they're part of the lore. 📚

🌈 STANDARDS 🌈

psignal() and psiginfo() are defined by IEEE Std 1003.1-2008 (“POSIX.1”), while the sig2str() and str2sig() functions are defined by . (yes, the page literally leaves that one blank, bestie — not me projecting 💀).

⭐ HISTORY ⭐

psignal() appeared in 4.2BSD. psiginfo() appeared in FreeBSD 14.3, NetBSD 6.0, and DragonFly 4.1. sig2str() and str2sig() appeared in FreeBSD 15.0. Periodt. 🔥

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xoxo, this PSIGNAL(3) page is from the Debian edition, dated May 10, 2025 — catch you in the signal chat 💖🫶