SIGSETOPS(3) BSD Library Functions Manual SIGSETOPS(3)NAME
sigemptyset, sigfillset, sigaddset, sigdelset, sigismember — manipulate
signal sets
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <signal.h>
int
sigemptyset(sigset_t *set);
int
sigfillset(sigset_t *set);
int
sigaddset(sigset_t *set, int signo);
int
sigdelset(sigset_t *set, int signo);
int
sigismember(sigset_t *set, int signo);
DESCRIPTION
These functions manipulate signal sets stored in a sigset_t. Either
sigemptyset() or sigfillset() must be called for every object of type
sigset_t before any other use of the object.
The sigemptyset() function initializes a signal set to be empty.
The sigfillset() function initializes a signal set to contain all sig‐
nals.
The sigaddset() function adds the specified signal signo to the signal
set.
The sigdelset() function deletes the specified signal signo from the sig‐
nal set.
The sigismember() function returns whether a specified signal signo is
contained in the signal set.
sigemptyset() and sigfillset() are provided as macros, but actual func‐
tions are available if their names are undefined (with #undef name).
RETURN VALUES
The sigismember() function returns 1 if the signal is a member of the
set, a 0 otherwise. The other functions return 0 upon success. A -1
return value indicates an error occurred and the global variable errno is
set to indicate the reason.
ERRORS
These functions could fail if one of the following occurs:
[EINVAL] signo has an invalid value.
SEE ALSOkill(2), sigaction(2), sigsuspend(2), signal(7)STANDARDS
These functions conform to ISO/IEC 9945-1:1990 (“POSIX.1”).
BSD June 4, 1993 BSD