[Update:solution] thx everyone, especially RiaD for the IT idea, which is what I've done:
edited my. htaccess file at the root of my website and added the following line,
#Loads an init php located at <fullpath>/<path-to-folder-with-php-files-to-include>/init.phpphp_value auto_prepend_file /home/a7503679/public_html/bin/res/include/init.php
Now all my HTML files would include that init.php file and so should (as I do) put there all the common PHP code you ll n Eed on every HTML page, which in my case was:
<?phpdefine("PHP_ROOT", "/home/a7503679/public_html/bin/res/include/"); #this solves the probleminclude ‘lang.php‘; #translations file?>
Before I needed to include this on lang.php every page and now it's automatically done. If I need to include any other PHP file with the using its absolute path, I just typeinclude PHP_ROOT.‘filename.php‘;
Add an automatically loaded PHP file in PHP. htaccess