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标题: LR函数研究fopen [打印本页]

作者: wan_xie2007 时间: 2010-3-31 16:11
标题: LR函数研究fopen
首先，可以从LR函数帮助中查找到fopen函数定义如下，返回值是FILE *类型。FILE *fopen ( const char *filename, const char *access_mode );

我们再看看它给出的例子程序，发现将其返回值赋给长整形变量file_stream;

file_stream = fopen(filename, "r")== NULL ;

这里我不能理解，怎么不是赋给一个文件指针类型变量？望高手们回答……

Action() {

   int count, total = 0;
   char buffer[1000];
   long file_stream;
   char *filename = "c:\\readme.txt";

   /* Open the file with read access */
   if ((file_stream = fopen(filename, "r")) == NULL ) {

      lr_error_message("Cannot open %s", filename);
      return -1;
   }

   /* Read until end of file */
   while (!feof(file_stream)) {

      /* Read 1000 bytes while maintaining a running count */
      count = fread(buffer, sizeof(char), 1000, file_stream);
      lr_output_message("%3d read", count);

      /* Check for file I/O errors */
      if (ferror(file_stream)) {

            lr_output_message("Error reading file %s", filename);
            break;
      }

      total += count; /* add up actual bytes read */
   }

   /* Display final total */
   lr_output_message("Total number of bytes read = %d", total );

   /* Close the file stream */
   if (fclose(file_stream))
      lr_error_message("Error closing file %s", filename);

   return 0;
}

作者: sunzhenguo1010 时间: 2010-3-31 16:17
应该文件的句柄吧呵呵

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