下载和合并的脚本[关闭]

Question

i want to a script for downloading file . below example work well

<?php

if ( isset($_POST['downloadButton'] )) {

    $filename = ( isset($_POST["filename"]) ?
    $_POST["filename"] : null );


   if ( file_exists( $filename )) {

        header("Content-Type: application/octet-stream");
        header("Content-Disposition: attachment; filename=filename here");
        header("Content-Length: " . filesize( $filename) );
        header("Cache-Control: must-revalidate");
        readfile( $filename );
        exit;
     }
  }
?>

but i want download file chunk ! for example i download file and stop it in 4th byte and then download it from 5th byte to end and at the end merge it . how can i do?

actually my Q is how to send this file from any byte that i want for example 5 to end or 3 to 10 or ...

Answer 1

You can download a chunk of the file by reading the file into a variable and then writing a substring. So replace readfile($filename); with:

$contents = file_get_contents($filename);
echo substr($contents, $start, $length);

You'll also need to adjust the Content-length::

header("Content-Length: " . min(filesize($filename)-$start, $length));

There's nothing you can do to automatically merge them. You can only download one file at a time, and the user will have to do that by hand after they download all the pieces.