使用 PHP 点击下载图片

Question

This code is pretty clear and neat, but for some reason it is not finding the image, so the message 'File Not Found' is being displayed after the PHP download file is reached. What is the reason for not finding the image neither by relative or by absolute path?

<?php

$file = $_GET['file'];

download_file($file);

function download_file( $fullPath ){

// Must be fresh start
if( headers_sent() )
die('Headers Sent');

// Required for some browsers
if(ini_get('zlib.output_compression'))
ini_set('zlib.output_compression', 'Off');

// File Exists?
if( file_exists($fullPath) ){


// Parse Info / Get Extension
$fsize = filesize($fullPath);
$path_parts = pathinfo($fullPath);
$ext = strtolower($path_parts["extension"]);

// Determine Content Type
switch ($ext) {
  case "pdf": $ctype="application/pdf"; break;
  case "exe": $ctype="application/octet-stream"; break;
  case "zip": $ctype="application/zip"; break;
  case "doc": $ctype="application/msword"; break;
  case "xls": $ctype="application/vnd.ms-excel"; break;
  case "ppt": $ctype="application/vnd.ms-powerpoint"; break;
  case "gif": $ctype="image/gif"; break;
  case "png": $ctype="image/png"; break;
  case "jpeg":
  case "jpg": $ctype="image/jpg"; break;
  default: $ctype="application/force-download";
}

header("Pragma: public"); // required
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private",false); // required for certain browsers
header("Content-Type: $ctype");
header("Content-Disposition: attachment; filename=\"".basename($fullPath)."\";" );
header("Content-Transfer-Encoding: binary");
header("Content-Length: ".$fsize);
ob_clean();
flush();
readfile( $fullPath );

} else
die('File Not Found');

}
?>

HTML

I've used relative path, and absolute path and it is not getting the image yet

<a href="/php/download.php?file=path/<?=$row['/images/image01.jpg']?>">Download</a>

<a href="/php/download.php?file=path/<?=$row['http://***.com/images/image01.jpg']?>">Download</a>

Answer 1

Name the following code as download.php

<?php

$file = $_GET['f'];

header("Expires: 0");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");

$ext = pathinfo($file, PATHINFO_EXTENSION);
$basename = pathinfo($file, PATHINFO_BASENAME);

header("Content-type: application/".$ext);
// tell file size
header('Content-length: '.filesize($file));
// set file name
header("Content-Disposition: attachment; filename=\"$basename\"");
readfile($file);
// Exit script. So that no useless data is output.
exit;
?>

and save it with your other files.

For downloading:

Say you put the file download.php in root folder then just give the relative path to the image/file:

<a href="download.php?f=images/image.jpg">Download</a>

or if you put download.php in say php folder inside the root folder and the images folder is also in root folder then:

<a href="download.php?f=../images/image.jpg">Download</a>

This code will work just fine for force downloading files of any extension.

I have used pathinfo (manual http://php.net/manual/en/function.pathinfo.php ) so as to get the extension and hence it reduces the code by removing the switch case you have used also it makes it more generic (ie, the code can be used for any file type).

Answer 2

This code works great, just delete

path/<?=$row['/images/image01.jpg']?>

and just add the name file: image01.jpg like

<a href="/php/download.php?file=image01.jpg">Download1</a>

Then move your php file to the directory where your images are uploaded.

Hope this help to somebody. Greetings.