erreur upload image php

Question

I have the following error:

Warning: move_uploaded_file(avatar/essai.jpg): failed to open stream:
... Permission not granted in /opt/lampp/htdocs/site/submitfunc.php ...

Warning: move_uploaded_file(): Unable to move '/opt/lampp/temp/php2FwMbY' to 'avatar/essai.jpg' in /opt/lampp/htdocs/site/submitfunc.php on line 3

when I press confirm to load the image

Here is my function submitfunc.php:

<?php
//la fonction qui va changer l'image de profil
//function that will change the profile picture
move_uploaded_file($avatar_tmp,'avatar/'.$avatar);
mysql_query("

UPDATE membres SET avatar='{$_FILES['avatar']['name']}' WHERE nom='{$_SESSION['nom']}'

");

?>

I use xampp on ubuntu

Answer 1

Reading the documentation on the function is always a good place to start:
fr.php.net/manual/fr/function.move-uploaded-file.php
www.php.net/move_uploaded_file

Si filename n'est pas valide, rien ne se passe, et move_uploaded_file() retournera FALSE.

Si filename est un fichier téléchargé, mais que pour une raison quelconque, il ne peut être déplacé, rien ne se passe, et move_uploaded_file() retourne FALSE. De plus, une alerte sera affichée.

If filename is not a valid upload file, then no action will occur, and move_uploaded_file() will return FALSE.

If filename is a valid upload file, but cannot be moved for some reason, no action will occur, and move_uploaded_file() will return FALSE. Additionally, a warning will be issued.

The warning message indicates that your Apache process does not have permission to access/write to your destination folder. Use the Linux command chmod to adjust the folder's permission settings to allow apache access.