linux环境下搭建一个基于tcp的客户端和服务器

客户端

//TCP 客户端代码
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <string.h>
#include <unistd.h>
#include <netinet/in.h>
#include <fcntl.h>

#define MAXLINE 4096
#define SERVER_PORT 8000

/* 这里的多有函数没有作出错判断 */

int main(int argc, char *argv[])
{
struct sockaddr_in serveraddr;
int confd, len;
char ipstr[] = "192.168.1.253";
char buf[MAXLINE];

if(argc < 2) {
printf("./client str\n");
exit(1);
}

//1.创建一个socket
confd = socket(AF_INET, SOCK_STREAM, 0);
//2.初始化服务器地址
bzero(&serveraddr, sizeof(serveraddr));
serveraddr.sin_family = AF_INET;

//"192.168.1.253"
inet_pton(AF_INET, ipstr, &serveraddr.sin_addr.s_addr);
serveraddr.sin_port = htons(SERVER_PORT);

//3.链接服务器
connect(confd, (struct sockaddr *)&serveraddr, sizeof(serveraddr));

//4.请求服务器处理数据
write(confd, argv[1], strlen(argv[1]));
len = read(confd, buf, sizeof(buf));
write(STDOUT_FILENO, buf, len);

//5.关闭socket
close(confd);

return 0;

}


服务器

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

#define SERVER_PORT 8000
#define MAXLINE 4096

int main(void)
{
struct sockaddr_in serveraddr, clientaddr;
int sockfd, addrlen, confd, len, i;
char ipstr[128];
char buf[MAXLINE];

//1.socket
sockfd = socket(AF_INET, SOCK_STREAM, 0); <span style="white-space:pre"> </span>//参数含义 IPV4,默认TCP
//暂时不做出错检测

//2. bind
bzero(&serveraddr, sizeof(serveraddr));<span style="white-space:pre"> </span>//绑定之前服务器地址清零
serveraddr.sin_family = AF_INET; <span style="white-space:pre"> </span>/* 地址族协议 IPV4 */
serveraddr.sin_addr.s_addr = htonl(INADDR_ANY)<span style="white-space:pre"> </span>// IP地址 主机字节序转成网络字节序
serveraddr.sin_port = htons(SERVER_PORT);<span style="white-space:pre"> </span>//端口号转换
bind(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr));<span style="white-space:pre"> </span>//将SOCKET描述符绑定到服务器地址

//3. listen
listen(sockfd, 128);
while (1) {
//4. accept 阻塞监听客户端连接器请求
addrlen = sizeof(clientaddr);
confd = accept(sockfd, (struct sockaddr *)&clientaddr, &addrlen);<span style="white-space:pre"> </span>//调用成功传回SOCKET描述符，

/* 输出客户端IP地址和端口号 */
inet_ntop(AF_INET, &clientaddr.sin_addr.s_addr, ipstr, sizeof(ipstr));
printf("client ip %s\tport %d\n",
inet_ntop(AF_INET, &clientaddr.sin_addr.s_addr, ipstr, sizeof(ipstr)), ntohs(clientaddr.sin_port));
//客户端交互数据操作 confd
//5. 处理客户端请求
len = read(confd, buf, sizeof(buf[i]));
i = 0;
while (i < len) {
buf[i] = toupper(buf[i]);
i++;
}
write(confd, buf, len);

close(confd);
}
close(sockfd);

return 0;
}