siginterrupt man page

siginterrupt — allow signals to interrupt system calls


#include <signal.h>

int siginterrupt(int sig, int flag);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):


   || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
   || /* Glibc versions <= 2.19: */ _BSD_SOURCE


The siginterrupt() function changes the restart behavior when a system call is interrupted by the signal sig. If the flag argument is false (0), then system calls will be restarted if interrupted by the specified signal sig. This is the default behavior in Linux.

If the flag argument is true (1) and no data has been transferred, then a system call interrupted by the signal sig will return -1 and errno will be set to EINTR.

If the flag 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.

Return Value

The siginterrupt() function returns 0 on success. It returns -1 if the signal number sig is invalid, with errno set to indicate the cause of the error.



The specified signal number is invalid.


For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
siginterrupt() Thread safety MT-Unsafe const:sigintr

Conforming to

4.3BSD, POSIX.1-2001. POSIX.1-2008 marks siginterrupt() as obsolete, recommending the use of sigaction(2) with the SA_RESTART flag instead.

See Also



This page is part of release 4.09 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at

Referenced By

sigaction(2), signal(2).

2016-03-15 Linux Programmer's Manual