The Single UNIX ® Specification, Version 2
Copyright © 1997 The Open Group


sigismember - test for a signal in a signal set


#include <signal.h>

int sigismember(const sigset_t *set, int signo);


The sigismember() function tests whether the signal specified by signo is a member of the set pointed to by set.

Applications should call either sigemptyset() or sigfillset() at least once for each object of type sigset_t prior to any other use of that object. If such an object is not initialised in this way, but is nonetheless supplied as an argument to any of sigaction(), sigaddset(), sigdelset(), sigismember(), sigpending() or sigprocmask(), the results are undefined.


Upon successful completion, sigismember() returns 1 if the specified signal is a member of the specified set, or 0 if it is not. Otherwise, it returns -1 and sets errno to indicate the error.


The sigismember() function may fail if:
The signo argument is not a valid signal number, or is an unsupported signal number.








sigaction(), sigaddset(), sigdelset(), sigfillset(), sigemptyset(), sigpending(), sigprocmask(), sigsuspend(), <signal.h>.


Derived from the POSIX.1-1988 standard.

UNIX ® is a registered Trademark of The Open Group.
Copyright © 1997 The Open Group
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