where to find php.ini document code example

Example 1: how to find php.ini

php -i | grep "Loaded Configuration File"

Example 2: find which php.ini is used

for cmd : php --ini
  
for code : use php_ini_loaded_file() as :=

$inipath = php_ini_loaded_file();
if ($inipath) {
    echo 'Loaded php.ini: ' . $inipath;
} else {
    echo 'A php.ini file is not loaded';
}