Manual browser: sigblock(3)
|SIGBLOCK(3)||Library Functions Manual||SIGBLOCK(3)|
NAMEsigblock — block signals
LIBRARYStandard C Library (libc, -lc)
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.
RETURN VALUESThe previous set of masked signals is returned.
EXAMPLESThe following example using sigblock():
int omask; omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));
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);
HISTORYThe sigblock() function call appeared in 4.2BSD and has been deprecated.
|August 10, 2002||NetBSD 7.0|