write.c

#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/ip.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void
handler(int signal)
{
	const char message[] = "Signal handler!\n";
	write(2, message, sizeof(message));
}

int
main(void)
{
	struct sigaction action = {
		.sa_handler = handler,
		.sa_mask = 0,
		.sa_flags = 0,
	};
	sigaction(SIGUSR1, &action, NULL);
	int fd = socket(AF_INET, SOCK_STREAM, 0);
	union {struct sockaddr sa; struct sockaddr_in sin;} addr = {
		.sin = {
			.sin_family = AF_INET,
			.sin_port = htons(54321),
			.sin_addr.s_addr = htonl(0x7F000001),
		}
	};
	char *buffer = malloc(104857600);
	connect(fd, &addr.sa, sizeof(addr.sa));
	printf("Connection established -- please drop packets\n");
	getchar();
	memset(buffer, 'a', sizeof(buffer));
	int ret = write(fd, buffer, 104857600);
	printf("write returned %d\n", ret);
}