Linux单用户CS模型TCP通讯完全注释手册
server
描述
- 实现一个简单的Linux单用户CS通讯,客户端发送一串字符串,服务器将其转换为大写后返回。
server 代码
```
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <ctype.h>
#include <arpa/inet.h>
#define SERV_PORT 6666
int main(int argc,char *argv[])
{
int sfd, cfd;
int len, i;
char buf[BUFSIZ], clie_IP[BUFSIZ];
struct sockaddr_in serv_addr, clie_addr;
socklen_t clie_addr_len;
sfd = socket(AF_INET, SOCK_STREAM, 0);
bzero(&serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
serv_addr.sin_port = htons(SERV_PORT);
bind(sfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
listen(sfd, 2);
printf("Wait for client connect ...\n");
while(1)
{
clie_addr_len= sizeof(clie_addr);
cfd = accept(sfd, (struct sockaddr *)&clie_addr, &clie_addr_len);
printf("cfd = ----------%d\n", cfd);
printf("client IP : %s, port : %d\n",
inet_ntop(AF_INET, &clie_addr.sin_addr.s_addr, clie_IP, sizeof(clie_IP)),
ntohs(clie_addr.sin_port)
);
do
{
len = read(cfd, buf, sizeof(buf));
write(STDOUT_FILENO, buf, len);
for(i = 0; i< len; ++i)
{
buf[i] = toupper(buf[i]);
}
write(cfd, buf, len);
}while(len);
close(cfd);
}
close(sfd);
return 0;
}
```
client代码实现
```
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#define SERV_IP "127.0.0.1"
#define SERV_PORT 6666
int main(int argc,char *argv[])
{
int sfd, len;
struct sockaddr_in serv_addr;
char buf[BUFSIZ];
sfd = socket(AF_INET, SOCK_STREAM, 0);
bzero(&serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
inet_pton(AF_INET, SERV_IP, &serv_addr.sin_addr.s_addr);
serv_addr.sin_port = htons(SERV_PORT);
connect(sfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
while(1)
{
fgets(buf, sizeof(buf), stdin);
int ret = write(sfd, buf, strlen(buf));
printf("write ret = %d\n", ret);
len = read(sfd, buf, sizeof(buf));
printf("read len = %d\n", len);
write(STDOUT_FILENO, buf, len);
}
close(sfd);
return 0;
}
```
运行效果
- 客户端输入:hello,world
- 服务端转换为大写后返回,客户端收到服务器发回的数据后进行打印:HELLO,WORLD
如图
存在问题
- 仅作学习建立TCP连接使用,不支持多用户,未进行错误处理。