1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<sys/types.h>
4 #include<sys/socket.h>
5 #include<string.h>
6 #include<strings.h>
7 #include<ctype.h>
8 #include<arpa/inet.h>
9 #include<unistd.h>
10
11 #define SERV_PORT 8888
12
13 int std_err(const char* name)
14 {
15 perror(name);
16 exit(1);
17 }
18
19 int main(void)
20 {
21 int sfd, cfd, ret;
22 int len;
23 socklen_t clie_len;
24 char buf[BUFSIZ];
25 //创建服务器套节字
26 sfd = socket(AF_INET, SOCK_STREAM, 0);
27 if(sfd == -1)
28 std_err("socket");
29 //定义地址类型
30 struct sockaddr_in serv_addr, clie_addr;
31 serv_addr.sin_family = AF_INET;
32 serv_addr.sin_port = htons(SERV_PORT);
33 serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
34
35 //绑定服务器的IP、端口；
36 ret = bind(sfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr));
37 if(ret == -1)
38 std_err("bind");
39
40 //监听链接服务器的客户数量
41 ret = listen(sfd, 99);
42 if(ret == -1)
43 std_err("listen");
44 clie_len = sizeof(clie_addr);
45 //阻塞等待客户端发起链接请求
46 cfd = accept(sfd, (struct sockaddr*)&clie_addr, &clie_len);
47 if(cfd == -1)
48 std_err("accept");
49
50 //传输数据
51 while(1)
52 {
53 len = read(cfd, buf, sizeof(buf));
54 printf("server: %s\n", buf);
55 int i;
56 for(i = 0; i < len; i++)
57 buf[i] = toupper(buf[i]);
58 write(cfd, buf, len);
59 }
60 close(sfd);
61 close(cfd);
62 return 0;
63 }
2.单客户端
1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<sys/types.h>
4 #include<sys/socket.h>
5 #include<string.h>
6 #include<strings.h>
7 #include<ctype.h>
8 #include<arpa/inet.h>
9 #include<unistd.h>
10
11 #define SERV_PORT 8888
12
13 int std_err(const char* name)
14 {
15 perror(name);
16 exit(1);
17 }
18
19 int main(void)
20 {
21 int cfd, ret, serv_IP;
22 char buf[BUFSIZ];
23 //创建套节字
24 cfd = socket(AF_INET, SOCK_STREAM, 0);
25 if(cfd == -1)
26 std_err("socket");
27 //定义IP ， 端口
28 struct sockaddr_in clie_addr;
29 clie_addr.sin_family = AF_INET;
30 clie_addr.sin_port = htons(SERV_PORT);
31 //转换IP 字符串的地址
32 ret = inet_pton(AF_INET, "192.168.22.251", &serv_IP);
33 if(ret != 1)
34 std_err("inet_pton");
35 clie_addr.sin_addr.s_addr = serv_IP;
36 //链接服务器
37 ret = connect(cfd, (struct sockaddr*)&clie_addr, sizeof(clie_addr));
38 if(ret == -1)
39 std_err("connect");
40 // 传输数据
41 while(1)
42 {
43 int len = read(STDIN_FILENO, buf, sizeof(buf));
44 printf("cliet_len: %d\n", len);
45
46 write(cfd, buf, len);
47 len = read(cfd, buf, sizeof(buf));
48 printf("serve_len: %d\n", len);
49 printf("%s",buf);
50 //write(STDOUT_FILENO, buf, len);
51 }
52 //关闭套节字
53 close(cfd);
54 return 0;
55
56 }
3.多进程服务器
1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<sys/types.h>
4 #include<sys/socket.h>
5 #include<string.h>
6 #include<strings.h>
7 #include<ctype.h>
8 #include<arpa/inet.h>
9 #include<unistd.h>
10 #include<errno.h>
11 #include<sys/wait.h>
12 #include<errno.h>
13
14 #define SERV_PORT 8883
15
16 int std_err(const char* name)
17 {
18 perror(name);
19 exit(1);
20 }
21
22 void do_sth_child(int signum)
23 {
24
25 while(waitpid(0, NULL, WNOHANG) < 0)
26 ;
27
28 }
29
30 int main(void)
31 {
32 int sfd, cfd, ret;
33 int len;
34 pid_t pid;
35 socklen_t clie_len;
36 char buf[BUFSIZ], clibuf[32];
37 //创建服务器套节字
38 sfd = socket(AF_INET, SOCK_STREAM, 0);
39 if(sfd == -1)
40 std_err("socket");
41 //定义地址类型
42 struct sockaddr_in serv_addr, clie_addr;
43 serv_addr.sin_family = AF_INET;
44 serv_addr.sin_port = htons(SERV_PORT);
45 serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
46
47 //绑定服务器的IP、端口；
48 ret = bind(sfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr));
49 if(ret == -1)
50 std_err("bind");
51
52 //监听链接服务器的客户数量
53 ret = listen(sfd, 99);
54 if(ret == -1)
55 std_err("listen");
56 clie_len = sizeof(clie_addr);
57 while(1)
58 {
59 //阻塞等待客户端发起链接请求
60 cfd = accept(sfd, (struct sockaddr*)&clie_addr, &clie_len);
61 printf("client IP :%s, port: %d\n",
62 inet_ntop(sfd, &clie_addr.sin_addr.s_addr, clibuf, sizeof(clibuf)),
63 ntohs(clie_addr.sin_port) );
64 if(cfd == -1)
65 std_err("accept");
66 pid = fork();
67 if(pid < 0)
68 std_err("fork:");
69 else if(pid == 0)
70 {
71 close(sfd);
72 break;
73 }
74 else //住进程实现逻辑；1.回收子进程，2，关闭不必要的文件描述父 3,继续等待客户端链接，如果有，则继续创建子进程
75 {
76 close(cfd);
77 signal(SIGCHLD, do_sth_child);
78 }
79 }
80 if(pid == 0)
81 {
82 agian:
83 //子进程传输数据
84 while(1)
85 {
86 len = read(cfd, buf, sizeof(buf));
87 if(len == 0) //即客户端关闭通信，
88 {
89 close(cfd);
90 exit(1);
91 }
92 else if( len == -1)
93 {
94 if(errno == EINTR)
95 {
96 goto agian;
97 }
98 else
99 {
100 std_err("read:");
101 }
102 }
103 else
104 {
105 int i;
106 for(i = 0; i < len; i++)
107 buf[i] = toupper(buf[i]);
108 write(cfd, buf, len);
109 write(STDOUT_FILENO, buf, len);
110 }
111 }
112 }
113
114 return 0;
115 }
4.多个客户端(一段代码产生多个客户端)
1.当时编写这段代码的作用是撑爆老师的服务器
1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<sys/types.h>
4 #include<sys/socket.h>
5 #include<string.h>
6 #include<strings.h>
7 #include<ctype.h>
8 #include<arpa/inet.h>
9 #include<unistd.h>
10 #include<sys/wait.h>
11 #include<signal.h>
12 #include<errno.h>
13 #include<pthread.h>
14 #include <pthread.h>
15
16
17 #define SERV_PORT 8883
18 #define SERV_IP "127.0.0.1"
19 int std_err(const char* name)
20 {
21 perror(name);
22 exit(1);
23 }
24 void do_sth_child(int signum)
25 {
26 while(waitpid(0, NULL, WNOHANG) > 0);
27 }
28
29 int main(void)
30 {
31 int cfd, ret;
32 char buf[BUFSIZ];
33 pid_t pid;
34 //pthread_mutexattr_t mattr;
35 //pthread_mutexattr_init(&mattr);
36 //pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
37 //pthread_mutex_t mutex;
38 //pthread_mutex_init(&mutex, &mattr);
39
40 int i;
41 for(i = 0; i < 6; i++){
42 pid = fork();
43 if(pid == 0)
44 break;
45 else if(pid < 0)
46 std_err("fork");
47 else
48 {
49 // close(cfd);
50 signal(SIGCHLD, do_sth_child);
51 }
52 }
53
54 //子进程逻辑
55 if(pid == 0)
56 {
57 //创建套节字
58 cfd = socket(AF_INET, SOCK_STREAM, 0);
59 if(cfd == -1)
60 std_err("socket");
61 //定义IP ， 端口
62 struct sockaddr_in clie_addr;
63 clie_addr.sin_family = AF_INET;
64 clie_addr.sin_port = htons(SERV_PORT);
65 //转换IP 字符串的地址
66 ret = inet_pton(AF_INET, SERV_IP, &clie_addr.sin_addr.s_addr);
67 if(ret != 1)
68 std_err("inet_pton");
69 //pthread_mutex_lock(&mutex);
70 //链接服务器
71 ret = connect(cfd, (struct sockaddr*)&clie_addr, sizeof(clie_addr));
72 if(ret == -1)
73 std_err("connect");
74 // 传输数据
75 // while(1)
76 {
77 int len;
78 again:
79 //char bufstr[10] = "sdasdasd";
80 len = read(STDIN_FILENO, buf, sizeof(buf));
81 if(len < 0)
82 {
83 if(errno == EAGAIN || errno == EINTR)
84 goto again;
85 else
86 std_err("read");
87 }
88 write(cfd, buf, len);
89 //write(cfd, bufstr, sizeof(bufstr));
90 //len = read(cfd, buf, sizeof(buf));
91 //printf("serve_len: %d\n", len);
92 //printf("%s",buf);
93 write(STDOUT_FILENO, buf, len);
94 }
95 //pthread_mutex_unlock(&mutex);
96 }
97 while(1);
98 //关闭套节字
99 close(cfd);
100 return 0;
101
102 }