Very simple file upload script for private use

upload.php

<?php
	// Very simple file upload script
	// ----------------------------------------------
	// I'm a shitty coder, so this is a shitty script
	
	/////////////////////////////////////////////////////////////
	// Fill these three variables
	$allowedip = '1.2.3.4'; // IP address allowed to upload
	$serveurl = 'https://uploads.example.com/';
	$uploaddir = '/srv/uploads.example.com/htdocs/';
	// No need to edit from here
	/////////////////////////////////////////////////////////////
	
	if ($_SERVER['REMOTE_ADDR'] == "$allowedip"){
		
		if (isset($_FILES['userfile'])){
			$fullfilename = basename($_FILES['userfile']['name']);
			$dirtyfilename = pathinfo($fullfilename) ['filename'];
			$cleanfilename = preg_replace("/[^A-Za-z0-9 _.-]/", "", $dirtyfilename);
			$nospacesfilename = str_replace(' ', '-', $cleanfilename);
			$extension = pathinfo($fullfilename) ['extension'];
			$randomstring = substr(str_shuffle(md5(time())) , 0, 10);
			$finalfilename = $nospacesfilename . '-' . $randomstring . '.' . $extension;
			$finalfilepath = $uploaddir . $finalfilename;
			
			if (move_uploaded_file($_FILES['userfile']['tmp_name'], $finalfilepath)){
				echo "<a href='$serveurl$finalfilename'>$serveurl$finalfilename</a>";
			} else {
				echo 'Error';
			}

		} else {
			echo '<form enctype="multipart/form-data" action="" method="POST">
	<input name="userfile" type="file" />
	<input type="submit" value="Upload" />
	</form>';
		}

	} else {
		echo '&#xAF;&#x5C;&#x5F;&#x28;&#x30C4;&#x29;&#x5F;&#x2F;&#xAF;';
	}

?>