'\" te
.\" Copyright (c) 2007, Sun Microsystems, Inc. All Rights Reserved.
.\" Copyright (c) 1985 Regents of the University of California.  All rights reserved.  The Berkeley software License Agreement specifies the terms and conditions for redistribution.
.TH SIGINTERRUPT 3UCB "Oct 30, 2007"
.SH NAME
siginterrupt \- allow signals to interrupt functions
.SH SYNOPSIS
.LP
.nf
\fB/usr/ucb/cc\fR [ \fIflag\fR ... ] \fIfile\fR ...

\fBint\fR \fBsiginterrupt\fR(\fIsig\fR, \fIflag\fR)
\fBint\fR \fIsig\fR, \fIflag\fR;
.fi

.SH DESCRIPTION
.sp
.LP
\fBsiginterrupt()\fR is used to change the function restart behavior when a
function is interrupted by the specified signal. If the flag is false
(\fB0\fR), then functions will be restarted if they are interrupted by the
specified signal and no data has been transferred yet. System call restart is
the default behavior when the \fBsignal\fR(3C) routine is used.
.sp
.LP
If the flag is true,   (\fB1\fR), then restarting of functions is disabled.  If
a function is interrupted by the specified signal and no data has been
transferred, the function will return  \fB\(mi1\fR with \fBerrno\fR set to
\fBEINTR\fR. Interrupted functions that have started transferring data will
return the amount of data actually transferred.
.sp
.LP
Issuing a \fBsiginterrupt()\fR call during the execution of a signal handler
will cause the new action to take place on the next signal to be caught.
.SH RETURN VALUES
.sp
.LP
A  \fB0\fR value indicates that the call succeeded. A  \fB\(mi1\fR value
indicates that the call failed and  \fBerrno\fR is set to indicate the error.
.SH ERRORS
.sp
.LP
\fBsiginterrupt()\fR may return the following error:
.sp
.ne 2
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 10n
\fIsig\fR is not a valid signal.
.RE

.SH SEE ALSO
.sp
.LP
\fBsigblock\fR(3UCB), \fBsigvec\fR(3UCB), \fBsignal\fR(3C)
.SH NOTES
.sp
.LP
Use of these interfaces should be restricted to only applications written on
BSD platforms.  Use of these interfaces with any of the system libraries or in
multi-threaded applications is unsupported.
.sp
.LP
This library routine uses an extension of the \fBsigvec\fR(3UCB) function that
is not available in 4.2 BSD, hence it should not be used if backward
compatibility is needed.