sigsetops, sigaddset, sigdelset, sigfillset, sigemptyset, sigismember -
manipulate signal sets
int sigaddset(set, signo)
int sigdelset(set, signo)
int sigismember(set, signo)
The sigsetops primitives manipulate sets of signals. They operate on
data objects addressable by the application. They do not operate on
any set of signals known to the system, such as the set blocked from
delivery to a process or the set pending for a process.
sigaddset() and sigdelset() respectively add and delete the individual
signal specified by the value of signo from the signal set pointed to
sigemptyset() initializes the signal set pointed to by set such that
all signals defined in this standard are excluded.
sigfillset() initializes the signal set pointed to by set such that all
signals defined in this standard are included.
Applications shall 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 initialized in this way, but is none-
theless supplied as an argument to any of sigaddset(), sigdelset(),
sigismember(), sigaction(), sigprocmask(), sigpending(), or sigsus-
pend() the results are undefined.
sigismember() tests whether the signal specified by the value of signo
is a member of the set pointed to by set.
1 if the specified signal is a member of set.
0 if the specified signal is not a member of set.
-1 if an error is detected, and sets errno to indicate the error.
The other functions return:
0 on success.
-1 on failure and set errno to indicate the error.
For each of the following conditions, if the condition is detected,
sigaddset(), sigdelset(), and sigismember() set errno to:
EINVAL signo is an invalid or unsupported signal number.
sigaction(3V), sigpending(2V), sigprocmask(2V)
21 January 1990 SIGSETOPS(3V)