resizing an image to get a thumbnail - php

Question

I am trying to create a thumbnail of an image. I got the php code from the php.net website, but it returns this error:
Warning: imagejpeg(/Users/michelebrizzi/Sites/htdocs/blogmichele/immagini/ragazza_thumb.jpg): failed to open stream: Permission denied in /Users/michelebrizzi/Sites/htdocs/blogmichele/prova/imagescale.php on line 19
What did I make a mistake?
This is the php code I've used:
<?php
// File and new size
$filename = $_SERVER['DOCUMENT_ROOT'].'/cartella_sito/immagini/image.jpg';
$percent = 0.5;
// Content type
// header('Content-Type: image/jpeg');
// Get new sizes
list($width, $height) = getimagesize($filename);
$newwidth = $width * $percent;
$newheight = $height * $percent;
// Load
$thumb = imagecreatetruecolor($newwidth, $newheight);
$source = imagecreatefromjpeg($filename);
// Resize
imagecopyresized($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
// Output
imagejpeg($thumb, $_SERVER['DOCUMENT_ROOT']."/cartella_sito/immagini/image_thumb.jpg", 75);
?>

Answer 1

read error messages again. The error message itself says permission denied.
That is pretty routine - getting permission denied. Check the unix level file permissions and make sure the user under which PHP runs has read access. just to test chmod to 777. Then revert to more restrictive settings. Make sure that the entire path chain can be accessed.
It could also be that PHP does not have the directive/permission to go into that directory. I am forgetting the setting. But there is this thing; that for directories outside htdocs/webroot you need to explicitly permit that. See this - Make XAMPP/Apache serve file outside of htdocs. But it appears that this does not apply, as you are trying to access files inside of htdocs.

Answer 2

Try putting some error handling in:
From my experience there are two options why this won't work
1) The file doesn't exist
<?php
// File and new size
$filename = $_SERVER['DOCUMENT_ROOT'].'/cartella_sito/immagini/image.jpg';
if(!file_exists($filename)) {
die("The file does not exist");
}
$percent = 0.5;
// Content type
// header('Content-Type: image/jpeg');
// Get new sizes
list($width, $height) = getimagesize($filename);
$newwidth = $width * $percent;
$newheight = $height * $percent;
// Load
$thumb = imagecreatetruecolor($newwidth, $newheight);
$source = imagecreatefromjpeg($filename);
// Resize
imagecopyresized($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
// Output
imagejpeg($thumb, $_SERVER['DOCUMENT_ROOT']."/cartella_sito/immagini/image_thumb.jpg", 75);
?>
2) You do not have the correct permissions
Assuming you are using a client such as FileZilla, right click on the folder of the image and ensure you at least have read access to the file (by going to Folder Permissions)