#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


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.


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.


Multithreading (see pthreads(7))

The siginterrupt() function uses a global variable that is not protected, so it is not thread-safe.


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

RELATED TO siginterrupt…


This page is part of release 3.74 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