| SIGBLOCK(3) | Library Functions Manual | SIGBLOCK(3) |
sigblock —
#include <signal.h>
int
sigblock(int
mask);
int
sigmask(signum);
sigblock() adds the signals specified in
mask to the set of signals currently being blocked
from delivery. Signals are blocked if the corresponding bit in
mask is a 1; the macro
sigmask() is provided to construct the mask for a
given signum.
It is not possible to block SIGKILL or
SIGSTOP; this restriction is silently imposed by the
system.
sigblock():
int omask; omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));
Becomes:
sigset_t set, oset; sigemptyset(&set); sigaddset(&set, SIGINT); sigaddset(&set, SIGHUP); sigprocmask(SIG_BLOCK, &set, &oset);
Another use of sigblock() is to get the
current set of masked signals without changing what is actually blocked.
Instead of:
int set; set = sigblock(0);
Use the following:
sigset_t set; sigprocmask(SIG_BLOCK, NULL, &set);
sigblock() function call appeared in
4.2BSD and has been deprecated.
| August 10, 2002 | NetBSD 9.4 |