interrupt_read.c

#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <errno.h>

void on_signal(int sig) {
	printf("\nIN handler\n");
	//nothing
}

int main(int argc, char const *argv[])
{
	struct sigaction act;
	memset(&act, 0, sizeof(act));
	act.sa_handler = on_signal;
	// no SA_RESTART here
	// act.sa_flags = SA_RESTART;
	if (sigaction(SIGINT, &act, NULL) < 0) {
		perror("sigaction");
		return 1;
	}

	while (1) {
		char c;
		int ret = read(STDIN_FILENO, &c, 1);
		printf("%d: >%c<\n", ret, c);

		if (ret == 0) {
			break;
		} else if (ret == -1) {
			printf("IS EINTR: %d\n", errno == EINTR);
			perror("read");
			break;
		}
	}

	return 0;
}