#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <signal.h>
#include <stdio.h>

int main()
{
	int sockfd;

	socklen_t i;
	socklen_t len;
	size_t t1, t2;

	sockfd = socket(AF_INET, SOCK_STREAM, 0);

	i = sizeof(len);
	if (getsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, (void *)&len, &i) < 0) {
		perror(": getsockopt");
	}

	printf("receive buffer size = %d\n", len);

	if (getsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &len, &i) < 0) {
		perror(": getsockopt");
	}

	printf("send buffer size = %d\n", len);

	if (getsockopt(sockfd, SOL_SOCKET, SO_RCVLOWAT, &len, &i) < 0) {
		perror(": getsockopt");
	}

	printf("rcv low watermark= %d\n", len);

	if (getsockopt(sockfd, SOL_SOCKET, SO_SNDLOWAT, &len, &i) < 0) {
		perror(": getsockopt");
	}

	printf("snd low watermark = %d\n", len);


	t1 =1000000; t2 = sizeof(int);
	if (setsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &t1, t2) < 0) {
		perror(": setsockopt");
	}

	i = sizeof(len);
	if (getsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &len, &i) < 0) {
		perror(": getsockopt");
	}

	printf("modified receive buffer size = %d\n", len);


	t1 = 2; t2 = sizeof(int);
	if (setsockopt(sockfd, SOL_SOCKET, SO_RCVLOWAT, &t1, t2) < 0) {
		perror(": setsockopt");
	}

	if (getsockopt(sockfd, SOL_SOCKET, SO_RCVLOWAT, &len, &i) < 0) {
		perror(": getsockopt");
	}

	printf("modified rcv low watermark= %d\n", len);

	return 0;
}