.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)

.\"

.\" %%%LICENSE_START(VERBATIM)

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.\" References consulted:

.\"     Linux libc source code

.\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)

.\"     386BSD man pages

.\" Modified Sun Jul 25 10:40:51 1993 by Rik Faith (faith@cs.unc.edu)

.\" Modified Sun Apr 14 16:20:34 1996 by Andries Brouwer (aeb@cwi.nl)

.TH SIGINTERRUPT 3 2016-03-15 "" "Linux Programmer's Manual"

.SH NAME

siginterrupt \- allow signals to interrupt system calls

.SH SYNOPSIS

.nf

.B #include <signal.h>

.PP

.BI "int siginterrupt(int " sig ", int " flag );

.fi

.PP

.in -4n

Feature Test Macro Requirements for glibc (see

.BR feature_test_macros (7)):

.in

.PP

.BR siginterrupt ():

.ad l

.RS 4

_XOPEN_SOURCE\ >=\ 500

.\"    || _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED

    || /* Since glibc 2.12: */ _POSIX_C_SOURCE\ >=\ 200809L

    || /* Glibc versions <= 2.19: */ _BSD_SOURCE

.RE

.ad

.SH DESCRIPTION

The

.BR siginterrupt ()

function changes the restart behavior when

a system call is interrupted by the signal \fIsig\fP.

If the \fIflag\fP

argument is false (0), then system calls will be restarted if interrupted

by the specified signal \fIsig\fP.

This is the default behavior in Linux.

.PP

If the \fIflag\fP argument is true (1) and no data has been transferred,

then a system call interrupted by the signal \fIsig\fP will return \-1

and \fIerrno\fP will be set to

.BR EINTR .

.PP

If the \fIflag\fP argument is true (1) and data transfer has started,

then the system call will be interrupted and will return the actual

amount of data transferred.

.SH RETURN VALUE

The

.BR siginterrupt ()

function returns 0 on success.

It returns \-1 if the

signal number

.I sig

is invalid, with

.I errno

set to indicate the cause of the error.

.SH ERRORS

.TP

.B EINVAL

The specified signal number is invalid.

.SH ATTRIBUTES

For an explanation of the terms used in this section, see

.BR attributes (7).

.TS

allbox;

lb lb lb

l l l.

Interface	Attribute	Value

T{

.BR siginterrupt ()

T}	Thread safety	MT-Unsafe const:sigintr

.TE

.SH CONFORMING TO

4.3BSD, POSIX.1-2001.

POSIX.1-2008 marks

.BR siginterrupt ()

as obsolete, recommending the use of

.BR sigaction (2)

with the

.B SA_RESTART

flag instead.

.SH SEE ALSO

.BR signal (2)

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I man-pages

project.

A description of the project,

information about reporting bugs,

and the latest version of this page,

can be found at

\%https://www.kernel.org/doc/man\-pages/.