Download file server to server

server_to_server.php

<?php

set_time_limit(0);
file_put_contents( 'progress.txt', '' );

$targetFile = fopen( 'filename.zip', 'w' );

$ch = curl_init( 'URL to File' );
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt( $ch, CURLOPT_NOPROGRESS, false );
curl_setopt( $ch, CURLOPT_PROGRESSFUNCTION, 'progressCallback' );
curl_setopt( $ch, CURLOPT_FILE, $targetFile );
curl_exec( $ch );
fclose( $ch );
function progressCallback( $download_size, $downloaded_size, $upload_size, $uploaded_size )
{
    static $previousProgress = 0;
    
    if ( $download_size == 0 )
        $progress = 0;
    else
        $progress = round( $downloaded_size * 100 / $download_size );
    
    if ( $progress > $previousProgress)
    {
        $previousProgress = $progress;
        $fp = fopen( 'progress.txt', 'a' );
        fputs( $fp, "$progress\n" );
        fclose( $fp );
    }
}