问如何将文件指针( FILE* fp )转换为文件描述符(int fd)？

EN

  fd = _fileno(fp);  // Probably the best way
       fd = fp->_file;     // direct from the FILE structure, member 

   
    typedef struct _iobuf  {
       char*   _ptr;
       int     _cnt;
       char*   _base;
       int     _flag;
       int     _file;
       int     _charbuf;
       int     _bufsiz;
       char*   _tmpfname; } FILE;