c - 如何将数据从数组发送到指针变量并从指针变量返回到数组？

Question

#include "MAIN.h"
#include "xcpip_callbacks.h"
typedef unsigned _int16 uint16;
typedef unsigned _int8 uint8;

uint16 port = 18017;
void XcpApp_IpTransmit( uint16 port, Xcp_StatePtr8 pBytes, uint16 numBytes )

{
        WSADATA wsa;
        SOCKET s;
        uint8 bytes_recieved;
        uint8 send_data[1024],recv_data[1024];

        struct sockaddr_in server;  // creating a socket address structure: structure contains ip address and port number

        printf("Initializing Winsock\n");
        if(WSAStartup(MAKEWORD(2,2), &wsa)!=0)
        {
            printf("Failed Error Code: %d", WSAGetLastError());
            return 1;
        }
        printf("Initialised\n");



        //int sock, bytes_recieved;  
        //char send_data[1024],recv_data[1024];
        //struct hostent *host;
        //struct sockaddr_in server_addr;  

        //host = gethostbyname("127.0.0.1");

        /*if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
            perror("Socket");
            exit(1);
        }*/


        //CREATING a SOCKET

        if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1)
        {
            printf("Could not Create Socket\n");
            return 0;
        }
        printf("Socket Created\n");

        server.sin_addr.s_addr = inet_addr("192.168.0.1");
        server.sin_family = AF_INET;     
        server.sin_port = htons("port");   

        //Connect to a remote server
        if(connect(s, (struct sockaddr *)&server, sizeof(server))<0)
        {
        puts("Connect Error\n");
        return 1;
        }

        puts("Connected\n");


        //SENDING a data


        /* bzero(&(server_addr.sin_zero),8); 

        if (connect(sock, (struct sockaddr *)&server_addr,
                    sizeof(struct sockaddr)) == -1) 
        {
            perror("Connect");
            exit(1);
        }*/

        while(1)
        {
        /*
            s- socket
            recv_data - receive data buffer and size of it (1024)
        */
          bytes_recieved=recv(s,recv_data,1024,0);
          recv_data[bytes_recieved] = '\0';

          if(strcmp(recv_data , "q") == 0 || strcmp(recv_data , "Q") == 0)
          {
           close(s);
           break;
          }

          else
           printf("\nRecieved data = %s " , recv_data);

          /*
          port For TCP: the port which listened for the connection which
                        was used to transmit the data. Note that this may not be
                        the same as the port which actually transmitted the data.
          For UDP:      the port which transmitted the data.
                        numTxBytes The number of bytes which were transmitted during the
                        latest call to XcpApp_IpTransmit(). For TCP, this may
                        be less than the total number of bytes which were supplied
                        to XcpApp_IpTransmit().*/


          XcpIp_TxCallback(uint16 port, uint16 numTxBytes );

           printf("\nSEND (q or Q to quit) : ");
           gets(send_data);

          if (strcmp(send_data , "q") != 0 && strcmp(send_data , "Q") != 0)
           send(s,send_data,strlen(send_data), 0); 

          else
          {
           send(s,send_data,strlen(send_data), 0); 

           /*
         chunkLen :  The number of bytes at pChunkData.
         pChunkData : The payload of the received IP frame. The caller does not
                      need to interpret the payload: the entire payload should be
                      passed to XcpIp_RxCallback().
                      The caller can discard this data after the function returns.
        port For TCP:  the port which listened for the connection which
                       received the data. Note that this may not be the same as
                       the port which actually received the data.
        For UDP:       the port which received the data. */

          XcpIp_RxCallback(uint16 chunkLen, uint8* pChunkData, uint16 port);

           closesocket(s);
           WSACleanup();
           break;
          }

        }   

}

我已经创建了一个 TCP 层，用于在特定端口上发送和接收数据，并调用一些特定的 XCP 协议(protocol)来执行一些事件。我已经创建了一个套接字并指定了端口号和ip地址来发送和接收数据。我在 recv_data[1024] 上收到了一些数据；我可以从 send_data[1024] 发送数据；

我需要一些帮助:在写入或发送该数据之前:我应该将数据从 send_data[1024] 发送到 Xcp_StatePtr8 pBytes(指针指向地址空间中的内存)。稍后我必须将数据从 Xcp_StatePtr8 pBytes 写入 recv_data[1024];

有人可以给我一些想法吗？？

Answer 1

您可以使用 memcpy 将数据从数组写入指针，反之亦然，就像我在下面创建的这个示例:

#include <stdio.h>
#include <cstring>

#define MAX_SIZE 20

int main()
{
    int anTest[MAX_SIZE] = {200, 200, 200, 200};
    int anTest2[MAX_SIZE];
    int* pnTest = new int[MAX_SIZE];

    // Initializing array and pointer to 0
    memset(anTest2, 0, sizeof(anTest2));
    memset(pnTest, 0, sizeof(pnTest));

    //Outputting anTest values and exiting loop when
    //an element contains 0, just because.
    puts("anTest values: ");
    for(int nIndex = 0; nIndex < MAX_SIZE; nIndex++)
    {
        if (0 == anTest[nIndex])
        {
            break;
        }

        printf("%d: %d\n", nIndex, anTest[nIndex]);
    }

    //Copying array to pointer
    memcpy(pnTest, anTest, MAX_SIZE * sizeof(int));

    //Copying pointer to array
    memcpy(anTest2, pnTest, MAX_SIZE * sizeof(int));

    //Outputting anTest2 values and exiting loop when
    //an element contains 0, just because.
    puts("\nanTest2 values: ");
    for(int nIndex = 0; nIndex < MAX_SIZE; nIndex++)
    {
        if (0 == anTest2[nIndex])
        {
            break;
        }

        printf("%d: %d\n", nIndex, anTest2[nIndex]);
    }

    //Deleting pointer since it's no longer needed.
    delete pnTest;
    pnTest = NULL;

    return 0;
}

[编辑] 我忘记添加代码来证明它有效(我总是通过遍历代码而不是输出值来检查我的代码，哈哈)。我编辑了我的代码以包括打印输出值。