This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

siginterrupt — allow signals to interrupt functions

#include <signal.h>
int siginterrupt(int sig, int flag);

The siginterrupt() function shall change the restart behavior when a function is interrupted by the specified signal. The function siginterrupt(sig, flag) has an effect as if implemented as:

int siginterrupt(int sig, int flag) {
    int ret;
    struct sigaction act;
    (void) sigaction(sig, NULL, &act);
    if (flag)
        act.sa_flags &= ~SA_RESTART;
        act.sa_flags |= SA_RESTART;
    ret = sigaction(sig, &act, NULL);
    return ret;

Upon successful completion, siginterrupt() shall return 0; otherwise, -1 shall be returned and errno set to indicate the error.

The siginterrupt() function shall fail if:

The sig argument is not a valid signal number.

The following sections are informative.


The siginterrupt() function supports programs written to historical system interfaces. Applications should use the sigaction() with the SA_RESTART flag instead of the obsolescent siginterrupt() function.



Section 2.4, Signal Concepts, sigaction()

The Base Definitions volume of POSIX.1‐2017, <signal.h>

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at .

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2017 IEEE/The Open Group