Question

所以当我使用这个'保存'功能时，它似乎改变了我的结构中的数据，随机数字和图标。如果我不保存文件，那么结构内数据的完整性将保持原始输入。

我不确定错误的位置或者如何开始修复此错误，感谢您的帮助。

这是我的结构;

struct packet{ // declare structure for packet creation
        int source;
        int destination;
        int type;
        int port;
        char data[51];
    };

这是函数;

//Save the records to a file: follows the same principle as list but uses a file handle (pointer to a file)
//and fprintf to write to the file
void save(int rCount, struct packet *records){
      FILE *recordFile;                 //file handle
      char fileName[30] = { '\0'};      //string to store the file name
      int i;

      puts("Enter a filename to save the records :");   //ask the user for the filename
      scanf("%s", fileName);                            //store the filename: data input should be checked
                                                        //here in your program

      //try and open the file for writing and react accordingly if there is a problem
      if((recordFile = fopen(fileName,"w"))==NULL){
          printf("Couldn't open the file: %s\n",fileName);
          exit(1);
      }
      else{ //the file opened so print the records array of packet to it
          for(i=0;i<rCount;i++){
                fprintf(recordFile,"%04d:%04d:%04d:%04d:%s\n",records[i].source,
                                                              records[i].destination,
                                                              records[i].type,
                                                              records[i].port,
                                                              records[i].data);
                }
                fclose(recordFile);   //close the file

          }


}

Answer 1

您如何知道结构数据已损坏？根据您的代码，我可以看到您的输出到文件将是错误的基于这一行：

fprintf(recordFile,"%04d:%04d:%04d:%04d:%s\n",&records[i].source,
                                                          &records[i].destination,
                                                          &records[i].type,
                                                          &records[i].port,
                                                          &records[i].data);

您的指针引用已关闭。假设你的程序的其余部分是正确的，只需删除领先＆amp; s，我猜这解决了大部分问题，如果不是全部你的问题：

fprintf(recordFile,"%04d:%04d:%04d:%04d:%s\n",records[i].source,
                                                          records[i].destination,
                                                          records[i].type,
                                                          records[i].port,
                                                          records[i].data);

每次我保存到文件，结构中的数据都被覆盖/编辑 - C编程

1 个答案: