NAME
sigemptyset, sigfillset, sigaddset, sigdelset, sigismember - POSIX sig‐ nal set operations. SYNOPSIS
#include
int sigemptyset(sigsett *set); int sigfillset(sigsett *set); int sigaddset(sigsett *set, int signum); int sigdelset(sigsett *set, int signum); int sigismember(const sigsett *set, int signum); Feature Test Macro Requirements for glibc (see featuretestmacros(7)): sigemptyset(), sigfillset(), sigaddset(), sigdelset(), sigismember(): POSIXCSOURCE >= 1 || XOPENSOURCE || POSIXSOURCE DESCRIPTION These functions allow the manipulation of POSIX signal sets. sigemptyset() initializes the signal set given by set to empty, with all signals excluded from the set. sigfillset() initializes set to full, including all signals. sigaddset() and sigdelset() add and delete respectively signal signum from set. sigismember() tests whether signum is a member of set. Objects of type sigsett must be initialized by a call to either sigemptyset() or sigfillset() before being passed to the functions sigaddset(), sigdelset() and sigismember() or the additional glibc functions described below (sigisemptyset(), sigandset(), and sig‐ orset()). The results are undefined if this is not done. RETURN VALUE sigemptyset(), sigfillset(), sigaddset(), and sigdelset() return 0 on success and -1 on error. sigismember() returns 1 if signum is a member of set, 0 if signum is
not a member, and -1 on error. On error, these functions set errno to indicate the cause. ERRORS EINVAL sig is not a valid signal. ATTRIBUTES For an explanation of the terms used in this section, see attributes(7). ┌────────────────────────────────┬───────────────┬─────────┐ │Interface │ Attribute │ Value │ ├────────────────────────────────┼───────────────┼─────────┤
│sigemptyset(), sigfillset(), │ Thread safety │ MT-Safe │ │sigaddset(), sigdelset(), │ │ │ │sigismember(), sigisemptyset(), │ │ │ │sigorset(), sigandset() │ │ │ └────────────────────────────────┴───────────────┴─────────┘ CONFORMING TO
POSIX.1-2001. NOTES Glibc notes If the GNUSOURCE feature test macro is defined, then
exposes three other functions for manipulating signal sets. int sigisemptyset(sigsett *set); returns 1 if set contains no signals, and 0 otherwise. int sigorset(sigsett *dest, sigsett *left, sigsett *right); places the union of the sets left and right in dest. int sigandset(sigsett *dest, sigsett *left, sigsett *right); places the intersection of the sets left and right in dest. sigorset() and sigandset() return 0 on success, and -1 on failure. These functions are nonstandard (a few other systems provide similar functions) and their use should be avoided in portable applications. SEE ALSO sigaction(2), sigpending(2), sigprocmask(2), sigsuspend(2) COLOPHON
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Linux 2013-04-19 SIGSETOPS(3)