NAME

sigemptyset, sigfillset, sigaddset, sigdelset, sigismember − manipulate sets of signals

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 sigset_t data types, representing the set of signals supported by the implementation. 

sigemptyset initializes the set pointed to by set to exclude all signals defined by the system. 

sigfillset initializes the set pointed to by set to include all signals defined by the system. 

sigaddset adds the individual signal specified by the value of signo to the set pointed to by set. 

sigdelset deletes the individual signal specified by the value of signo from the set pointed to by set. 

sigismember checks whether the signal specified by the value of signo is a member of the set pointed to by set. 

Any object of type sigset_t must be initialized by applying either sigemptyset or sigfillset before applying any other operation. 

sigaddset, sigdelset and sigismember will fail if the following is true:

EINVAL The value of the signo argument is not a valid signal number. 

sigfillset will dump a core file if the set argument specifies an invalid address. 

SEE ALSO

sigaction(2), sigprocmask(2), sigpending(2), sigsuspend(2), signal(5)

DIAGNOSTICS

Upon successful completion, the sigismember function returns a value of one if the specified signal is a member of the specified set, or a value of zero if it is not.  Upon successful completion, the other functions return a value of zero.  Otherwise a value of -1 is returned and errno is set to indicate the error.