| SIGPROCMASK(2) | System Calls Manual | SIGPROCMASK(2) |
sigprocmask —
manipulate current signal mask
Standard C Library (libc, -lc)
#include
<signal.h>
int
sigprocmask(int
how, const sigset_t *
restrict set, sigset_t *
restrict oset);
The
sigprocmask()
function examines and/or changes the current signal mask (those signals that
are blocked from delivery). Signals are blocked if they are members of the
current signal mask set.
If set is not null, the
action of
sigprocmask()
depends on the value of the parameter how. The signal
mask is changed as a function of the specified set and
the current mask. The function is specified by how
using one of the following values:
SIG_BLOCKSIG_UNBLOCKSIG_SETMASKIf oset is not null, it is set to the previous value of the signal mask.
When set is null, the value of how is insignificant and the mask remains unset providing a way to examine the signal mask without modification.
The system quietly disallows SIGKILL or
SIGSTOP to be blocked.
A 0 value indicates that the call succeeded. A -1 return value indicates an error occurred and errno is set to indicate the reason.
The sigprocmask() call will fail and the
signal mask will be unchanged if one of the following occurs:
EINVAL]kill(2), sigaction(2), sigsuspend(2), pthread_sigmask(3), sigsetops(3), signal(7)
The sigprocmask() function conforms to
IEEE Std 1003.1-1990 (“POSIX.1”).
| June 4, 1993 | NetBSD 11.0 |