Image resizer and uploader

Question

I've written an image resizer / uploader, that takes an incoming image, resizes it, and uploads it to the server, under the /usericons/ folder.

However, the code is sloppy. Can somebody suggest a better method / improvements?

define ("MAX_SIZE","400");
$errors = 0;
if ($_SERVER["REQUEST_METHOD"] == "POST") {
 $image = $_FILES["icon"]["name"];
 $uploadedfile = $_FILES['icon']['tmp_name'];
 if ($image) {
 $filename = stripslashes($_FILES['icon']['name']);
 $extension = getExtension($filename);
 $extension = strtolower($extension);
 if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png") && ($extension != "gif")) {
 echo ' Unknown Image extension ';
 $errors = 1;
 } else {
 $size=filesize($_FILES['icon']['tmp_name']);
 if ($size > MAX_SIZE*1024) {
 echo "You have exceeded the size limit";
 $errors = 1;
 }
 if ($extension == "jpg" || $extension == "jpeg" ) {
 $uploadedfile = $_FILES['icon']['tmp_name'];
 $src = imagecreatefromjpeg($uploadedfile);
 } else if($extension=="png") {
 $uploadedfile = $_FILES['icon']['tmp_name'];
 $src = imagecreatefrompng($uploadedfile);
 } else {
 $src = imagecreatefromgif($uploadedfile);
 }
 list($width,$height)=getimagesize($uploadedfile);
 $newwidth = 500;
 $newheight = ($height/$width)*$newwidth;
 $tmp = imagecreatetruecolor($newwidth,$newheight);
 $newwidth1 = 300;
 $newheight1 = ($height/$width)*$newwidth1;
 $tmp1 = imagecreatetruecolor($newwidth1,$newheight1);
 imagecopyresampled($tmp, $src, 0,0,0,0, $newwidth, $newheight, $width, $height);
 imagecopyresampled($tmp1, $src, 0,0,0,0, $newwidth1, $newheight1, $width, $height);
 $filename = "usericons/500-". $_SESSION['username'] . '.png';
 $filename1 = "usericons/300-". $_SESSION['username'] . '.png';
 imagejpeg($tmp,$filename,100);
 imagejpeg($tmp1,$filename1,100);
 hasIcon($_SESSION['username']);
 imagedestroy($src);
 imagedestroy($tmp);
 imagedestroy($tmp1);
 echo '<script>window.location = "/Users/";</script>';
 }
 }
}
 //If no errors registred, print the success message
if (isset($_POST['Submit']) && !$errors) {
 echo "Image Upload Fail!";
}
function getExtension($str) {
 $i = strrpos($str,".");
 if (!$i) { return ""; } 
 $l = strlen($str) - $i;
 $ext = substr($str,$i+1,$l);
 return $ext;
 }

Answer 1

Couple of things I've done to your code:

• Early exits
• Redundant code removal
• Readability improvement

Keep in mind that I have not tested this, but it should work. And also, the code will only work on PHP 5.4 and greater.

Cleaned up version:

<?php
if ($_SERVER['REQUEST_METHOD'] !== 'POST' || !isset($_FILES['icon'])) {
 echo 'Image upload failed.';
 return;
}
$file = [
 'name' => stripslashes($_FILES['icon']['name']),
 'path' => $_FILES['icon']['tmp_name'],
 'ext' => strtolower(pathinfo($_FILES['icon']['name'], PATHINFO_EXTENSION)),
 'size' => filesize($_FILES['icon']['tmp_name'])
];
$supportedExts = [
 'jpg',
 'jpeg',
 'png',
 'gif'
];
if (!in_array($file['ext'], $supportedExts)) {
 echo 'Extension not supported.';
 return;
}
if ($file['size'] > 400 * 1024) {
 echo 'You have exceeded the image size limit.';
 return;
}
list($image['x'], $image['y']) = getimagesize($file['path']);
switch ($file['ext']) {
 case 'jpg':
 case 'jpeg':
 $imgResrc1 = imagecreatefromjpeg($file['path']);
 break;
 case 'png':
 $imgResrc1 = imagecreatefrompng($file['path']);
 break;
 default:
 $imgResrc1 = imagecreatefromgif($file['path']);
}
$imageSizes = array(
 [
 'x' => 300,
 'y' => $image['y'] / $image['x'] * 300
 ],
 [
 'x' => 500,
 'y' => $image['y'] / $image['x'] * 500
 ]
);
foreach ($imageSizes as $size) {
 $imgResrc2 = imagecreatetruecolor($size['x'], $size['y']);
 imagecopyresampled($imgResrc2, $imgResrc1, 0, 0, 0, 0, $size['x'], $size['y'], $image['x'], $image['y']);
 // Shouldn't the extension be .jpg / .jpeg since you're using imagejpeg()?
 $filePath = 'usericons/' . $size['x'] . '-'. $_SESSION['username'] . '.png';
 imagejpeg($imgResrc2, $filePath, 100);
 imagedestroy($imgResrc2);
}
imagedestroy($imgResrc1);
hasIcon($_SESSION['username']);
echo '<script>window.location = \'/Users/\';</script>';
// TODO: Print success message

Answer 2

function getExtension() replacement

you can replace it with this code

$filename = stripslashes($_FILES['icon']['name']);
$extension = pathinfo($filename, PATHINFO_EXTENSION);

so you can safely remove function getExtension() because you don't need it anymore.