客户端向服务器发送普通数据和紧急数据的实例

/*************************************************************************
> File Name: client.c
> Author: yxk
> Mail:
> Created Time: 2015年10月29日 星期四 20时23分35秒
************************************************************************/

#include <stdio.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>

int main(int argc, char ** argv)
{
if (argc <= 2){
printf("argc is less than 3");
exit(1);
}
const char * ip =  argv[1];
int port = atoi(argv[2]);

struct sockaddr_in server_address;
bzero(&server_address, sizeof(server_address));
server_address.sin_family = AF_INET;
inet_pton(AF_INET, ip, &server_address.sin_addr);
server_address.sin_port = htons(port);

int sockfd = socket(AF_INET, SOCK_STREAM, 0);
assert(sockfd >= 0);
if(connect(sockfd, (struct sockaddr *)&server_address, sizeof(server_address)) < 0){
printf("connection failed\n");
}
else{
const char * oob_data = "abc";
const char * normal_data = "123";
send(sockfd, normal_data, strlen(normal_data), 0);
send(sockfd, oob_data, strlen(oob_data), MSG_OOB);
send(sockfd, normal_data, strlen(normal_data), 0);
}
close(sockfd);
exit(0);
}

/*************************************************************************
> File Name: server.c
> Author: yxk
> Mail:
> Created Time: 2015年10月29日 星期四 20时33分31秒
************************************************************************/

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>

#define BUF_SIZE 1024

int main(int argc, char ** argv)
{
if (argc <= 2){
printf("argc is less than 3");
exit(EXIT_FAILURE);
}

const char *ip = argv[1];
int port = atoi(argv[2]);

struct sockaddr_in address;
bzero(&address, sizeof(address));
address.sin_family = AF_INET;
inet_pton(AF_INET, ip, &address.sin_addr);
address.sin_port = htons(port);

int sock = socket(AF_INET, SOCK_STREAM, 0);
assert(sock >= 0);

int ret = bind(sock, (struct sockaddr *)&address, sizeof(address));
assert(ret != -1);

ret = listen(sock, 5);
assert(ret != -1);

struct sockaddr_in client;
int client_addrlen = sizeof(client);
int connfd = accept(sock, (struct sockaddr *)&client, &client_addrlen);
if (connfd < 0)
printf("connfd error.\n");
else{
char buffer[BUF_SIZE];
memset(buffer, '\0', BUF_SIZE);
ret = recv(connfd, buffer, BUF_SIZE-1, 0);
printf("got %d bytes of ormal data %s.\n", ret, buffer);

memset(buffer, '\0', BUF_SIZE);
ret = recv(connfd, buffer, BUF_SIZE-1, MSG_OOB);
printf("got %d bytes of oob data %s.\n", ret, buffer);

memset(buffer, '\0', BUF_SIZE);
ret = recv(connfd, buffer, BUF_SIZE-1, 0);
printf("got %d bytes of ormal data %s.\n", ret, buffer);
close(connfd);
}
close(sock);
exit(EXIT_SUCCESS);
}