简单的tcp服务端/客户端代码例一

客户端：(client1.c)

 1 include<unistd.h>
 2 #include<stdlib.h>
 3 #include<sys/socket.h>
 4 #include<arpa/inet.h>
 5 #include<string.h>
 6 
 7 #define BUFSIZE 1024
 8 #define SERV_IP "127.0.0.1"
 9 #define SERV_PORT 6666
10 int main()
11 {
12         int cfd;
13         int n;
14         char buf[BUFSIZE];
15         struct sockaddr_in serv_addr;
16         //socklen_t serv_addr_len;
17         cfd = socket(AF_INET, SOCK_STREAM, 0);
18 
19         memset(&serv_addr, 0, sizeof(serv_addr));
20         serv_addr.sin_family = AF_INET;
21         serv_addr.sin_port = htons(SERV_PORT);
22         inet_pton(AF_INET, SERV_IP, &serv_addr.sin_addr.s_addr);
23         if(connect(cfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr))<0)
24         {
25                 perror("connect");
26                 exit(1);
27         }
28 
29         while(1)
30         {
31                 fgets(buf, sizeof(buf), stdin);
32                 write(cfd, buf, strlen(buf));
33                 n = read(cfd, buf, sizeof(buf));
34                 write(STDOUT_FILENO, buf, n);
35         }
36 
37         close(cfd);
38         return 0;
39 }

服务端：(server1.c)

 1 #include<stdio.h>
 2 #include<unistd.h>
 3 #include<sys/socket.h>
 4 #include<stdlib.h>
 5 #include<arpa/inet.h>
 6 #include<ctype.h>
 7 #include<string.h>
 8 #define SERV_PORT 6666
 9 #define BUFSIZE 1024
10 #define SERV_IP "127.0.0.1"
11 
12 int main()
13 {
14     int lfd,cfd;
15     int n;
16     char buf[BUFSIZE];
17     struct sockaddr_in serv_addr,clie_addr;
18     socklen_t clie_addr_len;
19     lfd=socket(AF_INET,SOCK_STREAM,0);
20     
21     serv_addr.sin_family = AF_INET;
22     serv_addr.sin_port = htons(SERV_PORT);
23     serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
24     //memset(&serv_addr, 0, sizeof(serv_addr));
25         //inet_pton(AF_INET, SERV_IP, &serv_addr.sin_addr.s_addr);
26 
27 
28     if(bind(lfd,(struct sockaddr *) &serv_addr, sizeof(serv_addr))==-1)
29     {
30         perror("bind");
31         exit(1);
32     }
33 
34     if(listen(lfd,128)==-1)
35     {
36         perror("listen");
37         exit(1);
38     }
39 
40     clie_addr_len = sizeof(clie_addr);
41     cfd = accept(lfd, (struct sockaddr *) & clie_addr, &clie_addr_len);
42     if(cfd<0)
43     {
44         perror("accept");
45         exit(1);
46     }
47     while(1)
48     {
49         n = read (cfd, buf, sizeof(buf));
50         for (int i = 0; i < n; i++)
51             buf[i] = toupper(buf[i]);
52         write (cfd, buf, n);
53 
54     }
55     close(cfd);
56     close(lfd);
57     return 0;
58 }