PHP code to implement download function_PHP tutorial

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You will definitely laugh at me. Is it worth saying that "downloading files" is so simple? Of course it's not as simple as you think. For example, if you want customers to fill out a form before they can download a certain file, your first idea must be to use the "Redirect" method. First check whether the form has been filled in and complete, and then point the URL to the file. , so that customers can download, for example, the following code written by the author:

Copy code The code is as follows:

<?
// Check whether the FORM is completely filled out...
if ($form_completed) {
Header("Location: http://www.jb51.net/download/info_check.exe");
exit;
}
?>

Or the following situation:

Copy code The code is as follows:

<a href="http://www.yourwebl.com/users/download.php?id=124524">Start downloading file</a>

Here, the ID method is used to receive the number of the file to be downloaded, and then the "Redirect" method is used to connect to the actual URL.

If you want to make an e-commerce website about "online shopping" and consider security issues, you don't want users to directly copy the URL to download the file. The author recommends that you use PHP to directly read the actual file and then download it. Do it. The program is as follows:

Copy code The code is as follows:

<?
$file_name = "info_check.exe";
$file_dir = "/public/www/download/";
if (!file_exists($file_dir . $file_name)) { //Check whether the file exists
echo "File not found";
exit;
} else {
$file = fopen($file_dir . $file_name,"r"); // Open the file
// Enter the file tag
Header("Content-type : application/octet-stream"); ​​
Header("Accept-Ranges: bytes");
Header("Accept-Length: ".filesize($file_dir . $file_name));
Header( "Content-Disposition: attachment; filename=" . $file_name);
// Output file content
echo fread($file,filesize($file_dir . $file_name));
fclose($file) ;
exit;}
?>

And if the file path is an "http" or "ftp" URL, the source code will change slightly. The procedure is as follows:

Copy code The code is as follows:

＜?
$file_name = "info_check.exe";
$file_dir = "http://www.jb51.net/";
$file = @ fopen($file_dir . $file_name,"r");
if (!$file) {
echo "File search Less than ";
} else {
Header("Content-type: application/octet-stream"); ​​
Header("Content-Disposition: attachment; filename=" . $file_name);
while (!feof ($file)) {
echo fread($file,50000);
}
fclose ($file);
}
?＞

In this way, you can directly output the file using PHP.

Achieve safe downloading of php files!

Copy code The code is as follows:

public function downloads($name){
$name_tmp = explode("_ ",$name);
$type = $name_tmp[0];
$file_time = explode(".",$name_tmp[3]);
$file_time = $file_time[0];
$file_date = date("Y/md",$file_time);
$file_dir = SITE_PATH."/data/uploads/$type/$file_date/";

if (!file_exists( $file_dir.$name)){
header("Content-type: text/html; charset=utf-8");
echo "File not found!";
exit;
} else {
$file = fopen($file_dir.$name,"r");
Header("Content-type: application/octet-stream"); ​​
Header("Accept-Ranges: bytes ");
Header("Accept-Length: ".filesize($file_dir . $name));
Header("Content-Disposition: attachment; filename=".$name);
echo fread ($file, filesize($file_dir.$name));
fclose($file);
}
}

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