3. Library calls (functions within program libraries)

STRSIGNAL

Section: Linux Programmer's Manual (3)
Updated: 2020-11-01
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NAME

strsignal, sigdescr_np, sigdescr_np, sys_siglist - return string describing signal

SYNOPSIS

#include <string.h>

char *strsignal(int sig);
char *sigdescr_np(int sig);
char *sigabbrev_np(int sig);

extern const char * const sys_siglist[];

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

sigabbrev_np(), sigdescr_np():

_GNU_SOURCE

strsignal():

From glibc 2.10 to 2.31:: _POSIX_C_SOURCE >= 200809L
Before glibc 2.10:: _GNU_SOURCE

sys_siglist:
    Since glibc 2.19:
        _DEFAULT_SOURCE
    Glibc 2.19 and earlier:
        _BSD_SOURCE

DESCRIPTION

The strsignal() function returns a string describing the signal number passed in the argument sig. The string can be used only until the next call to strsignal(). The string returned by strsignal() is localized according to the LC_MESSAGES category in the current locale.

The sigdescr_np() function returns a string describing the signal number passed in the argument sig. Unlike strsignal() this string is not influenced by the current locale.

The sigabbrev_np() function returns the abbreviated name of the signal, sig. For example, given the value SIGINT, it returns the string "INT".

The (deprecated) array sys_siglist holds the signal description strings indexed by signal number. The strsignal() or the sigdescr_np() function should be used instead of this array; see also VERSIONS.

RETURN VALUE

The strsignal() function returns the appropriate description string, or an unknown signal message if the signal number is invalid. On some systems (but not on Linux), NULL may instead be returned for an invalid signal number.

The sigdescr_np() and sigdabbrev_np() functions return the appropriate description string. The returned string is statically allocated and valid for the lifetime of the program. These functions return NULL for an invalid signal number.

VERSIONS

sigdescr_np() and sigdabbrev_np() first appeared in glibc 2.32.

Starting with version 2.32, the sys_siglist symbol is no longer exported by glibc.

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
strsignal()	Thread safety	MT-Unsafe race:strsignal locale
sigdescr_np(), sigabbrev_np()	Thread safety	MT-Safe

CONFORMING TO

strsignal(): POSIX.1-2008. Present on Solaris and the BSDs.

sigdescr_np() and sigdabbrev_np() are GNU extensions.

sys_siglist is nonstandard, but present on many other systems.

NOTES

sigdescr_np() and sigdabbrev_np() are thread-safe and async-signal-safe.

COLOPHON

This page is part of release 5.10 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

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