wp_diviser_telecharger.php

<?php
/*
$root: Path to your file
$filename: Name of file to read
$ext: Your file extension
*/
private function download_big_text_file ($root, $filename, $ext) {
	//Max file size
	$max_file_size = 10*1024*1024;
	//Calculate file size
	$filesize = filesize($root.$filename.$ext);
	//Determine a number of file to divide
	$num =  intval($filesize / $max_file_size) + ((($filesize % $max_file_size) == 0) ? 0 : 1);
	$buffer = '';

	//Open file
	$handle = fopen($root.$filename.$ext, 'rb');
	if ($handle === false) {
		return false;
	}
	
	//Create zip package to store all files divided
	$zip = new ZipArchive;
	$zipname = "{$filename}.zip";
	//Delete file if exists
	if(file_exists($root.$zipname)){
		unlink($root.$zipname);
	}
	
	//Create zip package
	if(!$zip->open($root.$zipname, ZIPARCHIVE::CREATE)){
    		echo 'Could not open archive<br />';
    		return;
	}
	
	//Read big file and insert in zip file
	$num -= 1;
	$total = 0;
	for($i = 0; $i < $num; $i++){
		//Create new file content with WRITE mode. Ex: example_p1.txt
		$newfile = "{$root}{$filename}_p$i{$ext}";
		$fnewfile = fopen($newfile, 'w');
		
		//Copy data by MAX_FILE_SIZE
		stream_copy_to_stream($handle, $fnewfile, $max_file_size);
		
		//Push to zip
		$zip->addFile($newfile, "{$filename}_p$i{$ext}");
	}
	
	//Repeat for the last file
	$newfile = "{$root}{$filename}_p$num{$ext}";
	$fnewfile = fopen($newfile, 'w');
	stream_copy_to_stream($handle, $fnewfile, $max_file_size);
	$zip->addFile($newfile, "{$filename}_p$num{$ext}");
	
	//Close zip handler
	$zip->close();
	fclose($handle);
	
	//-----------------
	//Download zip file
	//-----------------
	header("Cache-Control: public");
	header("Content-Description: File Transfer");
	header('Content-Type: text/html; charset=UTF-8');
	header("Content-Disposition: attachment; filename={$filename}.zip");
	header("Content-Type: application/zip");
	header("Content-Transfer-Encoding: binary");
	
	$this->readfile_chunked($root, $zipname);
}