mirror of https://github.com/GnoConsortium/gno.git
56 lines
1.3 KiB
Groff
56 lines
1.3 KiB
Groff
.\"
|
|
.\" $Id: sigblock.2,v 1.2 1997/09/15 19:15:26 gdr Exp $
|
|
.\"
|
|
.TH SIGBLOCK 2 "19 January 1997" GNO "System Calls"
|
|
.SH NAME
|
|
.BR sigblock,
|
|
.BR sigmask
|
|
\- temporarily block signals
|
|
.SH SYNOPSIS
|
|
#include <signal.h>
|
|
.sp 1
|
|
long
|
|
\fBsigblock\fR(long \fImask\fR);
|
|
.br
|
|
#define \fBsigmask\fR(\fIsignum\fR)
|
|
.SH DESCRIPTION
|
|
.BR sigblock
|
|
is used to temporarily block the reception of signals. The input parameter
|
|
.IR mask
|
|
is a bit vector that specifies which signals are to be blocked; a 1 in bit
|
|
.I n
|
|
will block signal
|
|
.IR n +1.
|
|
The
|
|
.IR mask
|
|
is bitwise-or'd with the current signal mask to create the new
|
|
signal mask.
|
|
.LP
|
|
.BR sigmask
|
|
is a macro that can be used to calculate signal masks for
|
|
.BR sigsetmask .
|
|
It takes a signal number
|
|
.IR signum ,
|
|
as listed in
|
|
.BR signal (2),
|
|
as an argument and returns a mask corresponding to that signal.
|
|
.LP
|
|
If a signal is sent to a process but is blocked, the event is recorded
|
|
for later release by
|
|
.BR sigsetmask (2).
|
|
blocked signals are not stacked; further occurrences of a blocked signal
|
|
will overwrite any previous pending signal of the same
|
|
.IR signum .
|
|
.LP
|
|
It is not possible to block
|
|
.BR SIGKILL ,
|
|
.BR SIGCONT ,
|
|
or
|
|
.BR SIGSTOP .
|
|
This restriction is silently enforced by the kernel.
|
|
.SH RETURN VALUE
|
|
The previous value of the signal mask is returned.
|
|
.SH SEE ALSO
|
|
.BR kill (2),
|
|
.BR sigsetmask (2),
|
|
.BR signal (2) |