- NetBSD Manual Pages
SIGBLOCK(3) NetBSD Library Functions Manual SIGBLOCK(3)
Powered by man-cgi (2020-09-24).
Maintained for NetBSD
by Kimmo Suominen.
Based on man-cgi by Panagiotis Christias.
sigblock -- block signals
Standard C Library (libc, -lc)
This interface is made obsolete by: sigprocmask(2).
sigblock() adds the signals specified in mask to the set of signals cur-
rently being blocked from delivery. Signals are blocked if the corre-
sponding 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.
The previous set of masked signals is returned.
The following example using sigblock():
omask = sigblock(sigmask(SIGINT) | sigmask(SIGHUP));
sigset_t set, oset;
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:
set = sigblock(0);
Use the following:
sigprocmask(SIG_BLOCK, NULL, &set);
kill(2), sigaction(2), sigprocmask(2), sigsetmask(3), sigsetops(3)
The sigblock() function call appeared in 4.2BSD and has been deprecated.
NetBSD 8.1 August 10, 2002 NetBSD 8.1