| 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 10.0 |