基于TCP协议的进程间通信

TCP协议是应用在传输层的协议。是一种面向连接的、可靠的协议。TCP协议的特点：1）面向字节流。2）TCP是面向连接的运输层协议3) 每一条TCP链接只能有两个端点4）TCP提供可靠交付的服务5）TCP提供全双工通信根据TCP协议三次握手，server一直处于监听状态，等接受到client的请求连接（connect）信号，accept该连接。

server:
1 #include<stdio.h>
2 #include<string.h>
3 #include<unistd.h>
4 #include<stdlib.h>
5 #include<sys/socket.h>
6 #include<sys/types.h>
7 #include<netinet/in.h>
8 #include<arpa/inet.h>
9 #define _BACKLOG 5
10 void usage(char *_proc)
11 {
12     printf("usage: %s,[ip],[proc]",_proc);
13 }
14 int startup(const char *ip,const int port)
15 {
16     int sock = socket(AF_INET,SOCK_STREAM,0); //创建套接字
17     if(sock < 0)
18     {
19         perror("socket");
20         exit(1);
21     }
22     struct sockaddr_in local;
23     local.sin_family = AF_INET;
24     local.sin_port = htons(port);
25     local.sin_addr.s_addr = inet_addr(ip);
26     if(bind(sock,(struct sockaddr*)&local,sizeof(local))<0) //将IP和端口号绑定
27     {
28         perror("bind");
29         exit(2);
30     }
31     if(listen(sock,_BACKLOG)<0) //监听是否有进程与之创建连接
32     {
33         perror("listen");
34         exit(3);
35     }
36     return sock;
37 }
38 void* pthread(void * arg)
39 {
40     int sock = (int)arg;
41     char buf[1024];
42     while(1)
43     {
44         ssize_t size = read(sock,buf,sizeof(buf)-1);
45         if(size>0)
46         {
47             buf[size] = '\0';
48         }
49         else if(size==0)
50         {
51             printf("client close...\n");
52             break;
53         }
54         else
55         {
56             perror("read");
57             exit(3);
58         }
59         printf("client say: %s\n",buf);
60     }
61     close(sock);
62     return NULL;
63 }
64
65 int main(int argc,char *argv[])
66 {
67     if(argc != 3)
68     {
69         usage(argv[0]);
70         exit(1);
71     }
72     char *ip = argv[1];
73     int port = atoi(argv[2]);
74     int listen_sock = startup(ip,port);
75     struct sockaddr_in client;
76     socklen_t len = sizeof(client);
77     while(1)
78     {
79         int new_sock = accept(listen_sock,(struct sockaddr*)&client,&len);
80         if(new_sock<0)
81         {
82             perror("accept");
83             continue;
84         }
85         printf("get a client... sock %d,ip: %s,port: %d\n",new_sock,inet_nto    a(client.sin_addr),ntohs(client.sin_port));
86 #ifdef _V1_ //单进程通信
87         char buf[1024];
88         while(1)
89         {
90             ssize_t size = read(new_sock,buf,sizeof(buf)-1);
91             if(size>0)
92             {
93                 buf[size] = '\0';
94             }
95             else if(size==0)
96             {
97                 printf("client close...\n");
98                 break;
99             }
100             else
101             {
102                 perror("read");
103                 exit(3);
104             }
105             printf("client say :%s\n",buf);
106         }
107 #elif _V2_ //多进程
108         pid_t pid = fork();
109         if(pid<0)
110         {
111             perror("fork");
112             exit(4);
113         }
114         else if(pid == 0)
115         {//child
116             close(listen_sock);
117             char *_client = inet_ntoa(client.sin_addr);
118             char buf[1024];
119             while(1)
120             {
121                 memset(buf,'\0',sizeof(buf));
122                 ssize_t size = read(new_sock,buf,sizeof(buf)-1);
123                 if(size>0)
124                 {
125                     buf[size] = '\0';
126                 }
127                 else if(size==0)
128                 {
129                     printf("[ip]:%s close...\n",_client);
130                     break;
131                 }
132                 else
133                 {
134                     perror("read");
135                     exit(3);
136                 }
137                 printf("[ip]:%s say :%s\n",_client,buf);
138             }
139             close(new_sock);
140             exit(0);
141         }
142         else
143         {//father
144             close(new_sock);
145         }
146 #elif _V3_ //多线程
147         pthread_t pid;
148         pthread_create(&pid,NULL,pthread,(void*)new_sock);
149         pthread_detach(pid);
150 #else
151         printf("default");
152 #endif
153     }
154     return 0;
155 }

client:
1 #include<stdio.h>
2 #include<unistd.h>
3 #include<stdlib.h>
4 #include<sys/socket.h>
5 #include<sys/types.h>
6 #include<netinet/in.h>
7 #include<arpa/inet.h>
8
9 void usage(char *proc)
10 {
11     printf("usage:%s,[remote ip],[remote proc]",proc);
12 }
13 int main(int argc,char *argv[])
14 {
15     if(argc != 3)
16     {
17         usage(argv[0]);
18         exit(1);
19     }
20     int sock = socket(AF_INET,SOCK_STREAM,0);
21     if(sock<0)
22     {
23         perror("sock");
24         exit(1);
25     }
26     int port = atoi(argv[2]);
27     char *ip = argv[1];
28     struct sockaddr_in remote;
29     remote.sin_family = AF_INET;
30     remote.sin_port = htons(port);
31     remote.sin_addr.s_addr = inet_addr(ip);
32
33     int ret = connect(sock,(struct sockaddr*)&remote,sizeof(remote));
34     if(ret<0)
35     {
36         perror("connect");
37         exit(2);
38     }
39     char buf[1024];
40     while(1)
41     {
42         printf("please say: ");
43         scanf("%s",buf);
44         ssize_t size = write(sock,buf,sizeof(buf)-1);
45
46     }
47     return 0;
48 }

结果：
[fbl@localhost tcp]$ ./tcp_server 192.168.1.106 8080
get a client... sock 4,ip: 192.168.1.106,port: 51708
client say: hello
client say: hi
client say: nihao
client close...
^C
[fbl@localhost tcp]$
[fbl@localhost tcp]$ ./tcp_client 192.168.1.106 8080
please say: hello
please say: hi
please say: nihao
please say: ^C
[fbl@localhost tcp]$