Socket发送和接收变长结构体

//Server端代码

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1. #include<stdio.h>   
2. #include<stdlib.h>   
3. #include<string.h>   
4. #include<sys/types.h>   
5. #include<netinet/in.h>   
6. #include<sys/socket.h>   
7.   
8.   
9. #include<unistd.h>   
10. //使用不定长的结构体发送数据的关键在于：结构体变量必须分配到堆中，而不是栈中   
11. //即只能用malloc或者new来给结构体分配空间   
12. typedef struct Node  
13. {  
14.     int nodeSize;  
15.     int bufSize;  
16.     char buf[0];             //用0字节表示该结构体不定长  
17. } Node;  
18.   
19. int main()  
20. {  
21.     int sockfd,new_fd;  
22.     struct sockaddr_in server_addr;  
23.     struct sockaddr_in client_addr;  
24.   
25.     if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1)  
26.     {  
27.         printf("socket error!\n");  
28.         exit(1);  
29.     }  
30.     server_addr.sin_family = AF_INET;  
31.     server_addr.sin_port = htons(5050);  
32.     server_addr.sin_addr.s_addr = INADDR_ANY;  
33.     bzero(&(server_addr.sin_zero),8);  
34.   
35.     if(bind(sockfd,(struct sockaddr *)&server_addr,sizeof(server_addr)) == -1)  
36.     {  
37.         printf("bind error!\n");  
38.         exit(1);  
39.     }  
40.     if(listen(sockfd,100) == -1)  
41.     {  
42.         printf("listen error!\n");  
43.         exit(1);  
44.     }  
45.     printf("Server is listening:\n");  
46.     while(1)  
47.     {  
48.         int sin_size = sizeof(struct sockaddr_in);  
49.         if((new_fd = accept(sockfd,(struct sockaddr *)&client_addr,(socklen_t *)&sin_size)) == -1)  
50.         {  
51.             printf("accept error!\n");  
52.             exit(1);  
53.         }  
54.         int recvSize = 0;//data total length  
55.         if(recv(new_fd,(char *)&recvSize,sizeof(recvSize),0) == -1)  
56.         {  
57.             printf("recv error!\n");  
58.             exit(1);  
59.         }  
60.         int leftSize = sizeof(char) * (recvSize - sizeof(int));  
61.         char *dataBuf = (char *)malloc(leftSize);  
62.         memset(dataBuf,0,leftSize);  
63.         if(recv(new_fd,dataBuf,leftSize,0) == -1)  
64.         {  
65.             printf("recv error!\n");  
66.             exit(1);  
67.         }  
68.         close(new_fd);  
69.         Node *p = (Node *)malloc(sizeof(char) * recvSize);  
70.         p->nodeSize = recvSize;  
71.         memcpy((char *)(&p->bufSize),dataBuf,leftSize);  
72.         printf("nodeSize = %d\n",p->nodeSize);  
73.         printf("bufSize = %d\n",p->bufSize);  
74.         printf("buf = %s\n",p->buf);  
75.     }  
76.   
77.     return 0;  
78. }  

#include<stdio.h>#include<stdlib.h>#include<string.h>#include<sys/types.h>#include<netinet/in.h>#include<sys/socket.h>#include<unistd.h>//使用不定长的结构体发送数据的关键在于：结构体变量必须分配到堆中，而不是栈中//即只能用malloc或者new来给结构体分配空间typedef struct Node{int nodeSize;int bufSize;char buf[0];             //用0字节表示该结构体不定长} Node;int main(){int sockfd,new_fd;struct sockaddr_in server_addr;struct sockaddr_in client_addr;if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){printf("socket error!\n");exit(1);}server_addr.sin_family = AF_INET;server_addr.sin_port = htons(5050);server_addr.sin_addr.s_addr = INADDR_ANY;bzero(&(server_addr.sin_zero),8);if(bind(sockfd,(struct sockaddr *)&server_addr,sizeof(server_addr)) == -1){printf("bind error!\n");exit(1);}if(listen(sockfd,100) == -1){printf("listen error!\n");exit(1);}printf("Server is listening:\n");while(1){int sin_size = sizeof(struct sockaddr_in);if((new_fd = accept(sockfd,(struct sockaddr *)&client_addr,(socklen_t *)&sin_size)) == -1){printf("accept error!\n");exit(1);}int recvSize = 0;//data total lengthif(recv(new_fd,(char *)&recvSize,sizeof(recvSize),0) == -1){printf("recv error!\n");exit(1);}int leftSize = sizeof(char) * (recvSize - sizeof(int));char *dataBuf = (char *)malloc(leftSize);memset(dataBuf,0,leftSize);if(recv(new_fd,dataBuf,leftSize,0) == -1){printf("recv error!\n");exit(1);}close(new_fd);Node *p = (Node *)malloc(sizeof(char) * recvSize);p->nodeSize = recvSize;memcpy((char *)(&p->bufSize),dataBuf,leftSize);printf("nodeSize = %d\n",p->nodeSize);printf("bufSize = %d\n",p->bufSize);printf("buf = %s\n",p->buf);}return 0;}

//Client端代码

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1. #include<stdio.h>   
2. #include<stdlib.h>   
3. #include<string.h>   
4. #include<sys/types.h>   
5. #include<arpa/inet.h>   
6. #include<netinet/in.h>   
7. #include<sys/socket.h>   
8.   
9.   
10. #include<unistd.h>   
11.   
12. typedef struct Node  
13. {  
14.     int nodeSize;  
15.     int bufSize;  
16.     char buf[0];  
17. } Node;  
18.   
19. int main()  
20. {  
21.     int sockfd,new_fd;  
22.     struct sockaddr_in server_addr;  
23.   
24.     if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1)  
25.     {  
26.         printf("socket error!\n");  
27.         exit(1);  
28.     }  
29.     server_addr.sin_family = AF_INET;  
30.     server_addr.sin_port = htons(5050);  
31.     server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");  
32.     bzero(&(server_addr.sin_zero),8);  
33.   
34.     if(connect(sockfd,(struct sockaddr *)&server_addr,sizeof(server_addr)) == -1)  
35.     {  
36.         printf("connect error!\n");  
37.         exit(1);  
38.     }  
39.     printf("Client is connecting\n");  
40.     const char *tmp = "this is a test!";  
41.     int tmpLen = strlen(tmp);  
42.     Node *dataBuf = (Node *)malloc(sizeof(Node) + tmpLen + 1);  
43.     dataBuf->nodeSize = sizeof(Node) + tmpLen + 1;  
44.     dataBuf->bufSize = tmpLen;  
45.     memset(dataBuf->buf,0,tmpLen + 1);  
46.     memcpy(dataBuf->buf,tmp,tmpLen + 1);  
47.     printf("nodeSize = %d\n",dataBuf->nodeSize);  
48.     printf("bufSize = %d\n",dataBuf->bufSize);  
49.     printf("buf = %s\n",dataBuf->buf);  
50.     if(send(sockfd,(char *)dataBuf,dataBuf->nodeSize,0) == -1)  
51.     {  
52.         printf("send error!\n");  
53.         exit(1);  
54.     }  
55.     close(sockfd);  
56.     return 0;  
57. }  

#include<stdio.h>#include<stdlib.h>#include<string.h>#include<sys/types.h>#include<arpa/inet.h>#include<netinet/in.h>#include<sys/socket.h>#include<unistd.h>typedef struct Node{int nodeSize;int bufSize;char buf[0];} Node;int main(){int sockfd,new_fd;struct sockaddr_in server_addr;if((sockfd = socket(AF_INET,SOCK_STREAM,0)) == -1){printf("socket error!\n");exit(1);}server_addr.sin_family = AF_INET;server_addr.sin_port = htons(5050);server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");bzero(&(server_addr.sin_zero),8);if(connect(sockfd,(struct sockaddr *)&server_addr,sizeof(server_addr)) == -1){printf("connect error!\n");exit(1);}printf("Client is connecting\n");const char *tmp = "this is a test!";int tmpLen = strlen(tmp);Node *dataBuf = (Node *)malloc(sizeof(Node) + tmpLen + 1);dataBuf->nodeSize = sizeof(Node) + tmpLen + 1;dataBuf->bufSize = tmpLen;memset(dataBuf->buf,0,tmpLen + 1);memcpy(dataBuf->buf,tmp,tmpLen + 1);printf("nodeSize = %d\n",dataBuf->nodeSize);printf("bufSize = %d\n",dataBuf->bufSize);printf("buf = %s\n",dataBuf->buf);if(send(sockfd,(char *)dataBuf,dataBuf->nodeSize,0) == -1){printf("send error!\n");exit(1);}close(sockfd);return 0;}