sig.3

.fp 5 CW
.de Af
.ds ;G \\*(;G\\f\\$1\\$3\\f\\$2
.if !\\$4 .Af \\$2 \\$1 "\\$4" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9"
..
.de aF
.ie \\$3 .ft \\$1
.el \{\
.ds ;G \&
.nr ;G \\n(.f
.Af "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7" "\\$8" "\\$9"
\\*(;G
.ft \\n(;G \}
..
.de L
.aF 5 \\n(.f "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"
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.de LR
.aF 5 1 "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"
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.de RL
.aF 1 5 "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6" "\\$7"
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.de EX		\" start example
.ta 1i 2i 3i 4i 5i 6i
.PP
.RS
.PD 0
.ft 5
.nf
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.de EE		\" end example
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.PD
.RE
.PP
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.TH SIG 3
.SH NAME
sig \- signal interface routines
.SH SYNOPSIS
.EX
.L "#include <ast.h>"
.L "#include <sig.h>"
.sp
.L "int sigunblock(int sig);"
.L "int sigcritical(int op);"
.SH DESCRIPTION
.B sigunblock
is called to
unblock the signal
.B sig
from within a handler currently servicing
.BR sig .
.PP
.B sigcritical
controls a critical region for the
.BR SIGINT ,
.B SIGQUIT
and
.B SIGHUP
signals.
.B "op > 0"
pushes the region,
.B "op == 0"
pops the region, and
.B "op < 0"
returns non-zero if any signals are being held in the current
critical region.
Signal critical regions may be nested.
The current critical region level is returned,
.B \-1
on error.
.SH "SEE ALSO"
signal(2)