Hướng dẫn php chdir not working

I'm developing a PHP cron script to check if a server is up or not (Ping).

Here is my code :

// Remonte d'un dossier
chdir('../');

// Inclusion du header pour avoir les infos de connexion à la db, fonctions, etc ...
require_once('./includes/header.php');

// Requête pour récupérer toutes les IP à pinger (Non-exclues donc)
$sReqGetAllServers = "  SELECT
                            *
                        FROM
                            host
                        WHERE
                            exclude_machine = :exclude_machine";

// Préparation de la requête
$oDatabase->Prepare($sReqGetAllServers);

// On bind la valeur au paramètre dans le WHERE
$oDatabase->BindValue(':exclude_machine', 'n', PDO::PARAM_STR);

// Exécution de la requête
$oDatabase->Execute();

// On associe les données dans un tableau à deux dimensions associatif
$aServers = $oDatabase->Assoc();

So at the first line, I need to make a chdir('../'); to include the necessary files (header.php).

I tested the script with Chrome and all worked fine but when I execute the script with command-line, PHP drop this error :

[14:40]  / >> php -f /web/dev/company/public_html/dasPing/cron/cron.php 
PHP Warning:  require_once(./includes/header.php): failed to open stream: No such file or directory in /var/www/html/dev/diadeis/public_html/dasPing/cron/cron.php on line 7

Warning: require_once(./includes/header.php): failed to open stream: No such file or directory in /var/www/html/dev/diadeis/public_html/dasPing/cron/cron.php on line 7
PHP Fatal error:  require_once(): Failed opening required './includes/header.php' (include_path='/usr/share/php') in /var/www/html/dev/diadeis/public_html/dasPing/cron/cron.php on line 7

Fatal error: require_once(): Failed opening required './includes/header.php' (include_path='/usr/share/php') in /var/www/html/dev/diadeis/public_html/dasPing/cron/cron.php on line 7

I searched why PHP drop this but I can't find any answer.

Do anyone knows why this is happening ?

Thank you !!

/home/vincent
/home/vincent/public_html

How do I move up a directory in PHP?

If you are using PHP 7.0 and above then the best way to navigate from your current directory or file path is to use dirname(). This function will return the parent directory of whatever path we pass to it.

How do I view a directory in PHP?

PHP scandir() Function $b = scandir($dir,1);

What is chdir in PHP?

The chdir() function changes the current directory.

What is __ DIR __ in PHP?

The __DIR__ can be used to obtain the current code working directory. It has been introduced in PHP beginning from version 5.3. It is similar to using dirname(__FILE__). Usually, it is used to include other files that is present in an included file.