SIGPROCMASK(2) | System Calls Manual | SIGPROCMASK(2) |
sigprocmask
—
#include <signal.h>
int
sigprocmask
(int
how, const sigset_t *
restrict set, sigset_t *
restrict oset);
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_BLOCK
SIG_UNBLOCK
SIG_SETMASK
If 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.
sigprocmask
() call will fail and the signal mask
will be unchanged if one of the following occurs:
EINVAL
]sigprocmask
() function conforms to
IEEE Std 1003.1-1990 (“POSIX.1”).
June 4, 1993 | NetBSD 9.2 |