#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>

int main()
{
	int i, optlen;
	const int fd = socket(AF_INET, SOCK_STREAM, 0);
	getsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &i, &optlen);
	printf("TCP maximum segment size: %d\n", i);
	return EXIT_SUCCESS;
}