文件操作

    //以只写方式打开文件,并写入数字100,关闭
    //以只读方式打开文件,并读出数字100,并闭
    char *filename = "D:\\test.txt";
    long filestream;
    int num_w = 100;
    int num_r;
    if((filestream = fopen(filename,"w")) == NULL)
       lr_error_message("cannot open %s",filename);
    else
       lr_error_message("open success");
    fprintf(filestream,"%d",num_w);  
    if(fclose(filestream) == 0)
       lr_output_message("close success %s",filename);
    else
       lr_output_message("close error %s",filename);
    fopen(filename,"r");
    fscanf(filestream,"%d",&num_r);
    lr_output_message("%d",num_r);
    fclose(filestream);