Linux C Socket编程发送结构体、文件详解及实例

利用Socket发送文件、结构体、数字等,是在Socket编程中经常需要用到的。由于Socket只能发送字符串,所以可以使用发送字符串的方式发送文件、结构体、数字等等。

本文:http://www.cnblogs.com/xudong-bupt/p/3496741.html

1.memcpy

  Copy block of memory。内存块拷贝函数,该函数是标准库函数,可以进行二进制拷贝数据。

  函数原型: void * memcpy ( void * destination, const void * source, size_t num );

  函数说明:从source指向的地址开始拷贝num个字节到以destination开始的地址。其中destination与source指向的数据类型无关。

2.Socket传输

  使用memcpy将文件、结构体、数字等,可以转换为char数组,之后进行传输,接收方在使用memcpy将char数组转换为相应的数据。

 

下面的程序使用Socket传输结构体数据,由客户端传输给服务器端。

传输的结构体为:

typedef struct
{
    int ab;
    int num[1000000];
}Node;

服务器代码:

 1 #include<netinet/in.h>
 2 #include<sys/types.h>
 3 #include<sys/socket.h>
 4 #include<stdio.h>
 5 #include<stdlib.h>
 6 #include<string.h>
 7 
 8 #define HELLO_WORLD_SERVER_PORT    6666
 9 #define LENGTH_OF_LISTEN_QUEUE     20
10 #define BUFFER_SIZE                1024
11 
12 typedef struct
13 {
14     int ab;
15     int num[1000000];
16 }Node;
17 
18 int main(int argc, char **argv)
19 {
20     // set socket's address information
21     struct sockaddr_in   server_addr;
22     bzero(&server_addr, sizeof(server_addr));
23     server_addr.sin_family = AF_INET;
24     server_addr.sin_addr.s_addr = htons(INADDR_ANY);
25     server_addr.sin_port = htons(HELLO_WORLD_SERVER_PORT);
26 
27     // create a stream socket
28     int server_socket = socket(PF_INET, SOCK_STREAM, 0);
29     if (server_socket < 0)
30     {
31         printf("Create Socket Failed!\n");
32         exit(1);
33     }
34 
35     //bind
36     if (bind(server_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)))
37     {
38         printf("Server Bind Port: %d Failed!\n", HELLO_WORLD_SERVER_PORT);
39         exit(1);
40     }
41 
42     // listen
43     if (listen(server_socket, LENGTH_OF_LISTEN_QUEUE))
44     {
45         printf("Server Listen Failed!\n");
46         exit(1);
47     }
48 
49     while(1)
50     {
51         struct sockaddr_in client_addr;
52         socklen_t          length = sizeof(client_addr);
53 
54         int new_server_socket = accept(server_socket, (struct sockaddr*)&client_addr, &length);
55         if (new_server_socket < 0)
56         {
57             printf("Server Accept Failed!\n");
58             break;
59         }
60 
61         Node *myNode=(Node*)malloc(sizeof(Node));
62 
63         int needRecv=sizeof(Node);
64         char *buffer=(char*)malloc(needRecv);
65         int pos=0;
66         int len;
67         while(pos < needRecv)
68         {
69             len = recv(new_server_socket, buffer+pos, BUFFER_SIZE, 0);
70             if (len < 0)
71             {
72                 printf("Server Recieve Data Failed!\n");
73                 break;
74             }
75             pos+=len;
76 
77         }
78         close(new_server_socket);
79         memcpy(myNode,buffer,needRecv);
80         printf("recv over ab=%d num[0]=%d num[999999]=%d\n",myNode->ab,myNode->num[0],myNode->num[999999]);
81         free(buffer);
82         free(myNode);
83     }
84     close(server_socket);
85 
86     return 0;
87 }
View Code

客户端代码:

 1 #include <sys/types.h>
 2 #include <sys/socket.h>                         // 包含套接字函数库
 3 #include <stdio.h>
 4 #include <netinet/in.h>                         // 包含AF_INET相关结构
 5 #include <arpa/inet.h>                      // 包含AF_INET相关操作的函数
 6 #include <unistd.h>
 7 #include <string.h>
 8 #include <stdlib.h>
 9 #include <fcntl.h>
10 #include <sys/shm.h>
11 #include <pthread.h>
12 
13 #define MYPORT  6666
14 #define BUFFER_SIZE 1024
15 
16 typedef struct
17 {
18     int ab;
19     int num[1000000];
20 }Node;
21 
22 int main()
23 {
24         ///sockfd
25     int sock_cli = socket(AF_INET,SOCK_STREAM, 0);
26 
27     struct sockaddr_in servaddr;
28     memset(&servaddr, 0, sizeof(servaddr));
29     servaddr.sin_family = AF_INET;
30        servaddr.sin_port = htons(MYPORT);
31     servaddr.sin_addr.s_addr = inet_addr("127.0.0.1");
32 
33     if (connect(sock_cli, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0)
34     {
35         perror("connect");
36         exit(1);
37     }
38 
39     Node *myNode=(Node*)malloc(sizeof(Node));
40     myNode->ab=123;
41     myNode->num[0]=110;
42     myNode->num[999999]=99;
43 
44     int needSend=sizeof(Node);
45     char *buffer=(char*)malloc(needSend);
46     memcpy(buffer,myNode,needSend);
47 
48     int pos=0;
49     int len=0;
50     while(pos < needSend)
51     {
52         len=send(sock_cli, buffer+pos, BUFFER_SIZE,0);
53         if(len <= 0)
54         {
55             perror("ERRPR");
56             break;
57         }
58         pos+=len;
59     }
60     free(buffer);
61     free(myNode);
62     close(sock_cli);
63     printf("Send over!!!\n");
64     return 0;
65 }
View Code

服务器端执行输出:

posted on 2014-01-04 19:21  旭东的博客  阅读(22842)  评论(1编辑  收藏  举报

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