NAME

sigwait — select a set of signals

SYNOPSIS

#include <signal.h>

int
sigwait(const sigset_t *restrict set, int *restrict sig);

DESCRIPTION

The sigwait() function selects a set of signals, specified by set. If none of the selected signals are pending, sigwait() waits until one or more of the selected signals has been generated. Then sigwait() atomically clears one of the selected signals from the set of pending signals for the process and sets the location pointed to by sig to the signal number that was cleared.

The signals specified by set should be blocked, but not ignored, at the time of the call to sigwait().

Processes which call sigwait() on ignored signals will wait indefinitely. Ignored signals are dropped immediately by the system, before delivery to a waiting process.

RETURN VALUES

If successful, sigwait() returns 0 and sets the location pointed to by sig to the cleared signal number. Otherwise, an error number is returned.

ERRORS

sigwait() will fail if:

[EINVAL]

set specifies one or more invalid signal numbers.

SEE ALSO

pthread_sigmask(2), sigaction(2), sigpending(2), sigsuspend(2), pause(3)

STANDARDS

sigwait() conforms to ISO/IEC 9945-1:1996 (``POSIX.1'')