Exercise php file upload, the uploaded image cannot be opened

Exercise php file download, the downloaded image cannot be opened & lt ;? Php?file_name=&quot=hello.jpg & quot; if (! File_exists ($ file_name) {echo & quot; the file does not exist & quot; return;} $ fp = fopen ($ file_name, & exercise php file download. the downloaded image cannot be opened
$ File_name = "hello.jpg ";
If (! File_exists ($ file_name ))
{
Echo "the file does not exist ";
Return;
}
$ Fp = fopen ($ file_name, "r ");
// Get the downloaded file size
$ File_size = filesize ($ file_name );
Echo $ file_size;
// Returned file
Header ("Content-type: application/octet-stream ");
// Returns the value in bytes.
Header ("Accept-Ranges: byte ");
// Returns the file size.
Header ("Accept-Length: $ file_size ");
// The pop-up dialog box on the client, with the corresponding file name
Header ("Content-Disposition: attachment; filename =". $ file_name );


$ Buffer = 1024;
// Determine whether the end of the file ends.
While (! Feof ($ fp ))
{
// Echo "1111 ";
$ File_data = fread ($ fp, $ buffer );
// Send some data back to the browser
Echo $ file_data;
}
Fclose ($ fp );
?>


The prompt that the image file cannot be opened is: the file may be damaged or too large.

------ Solution --------------------
Echo $ file_size; // comment out this sentence