PHP function to try and find the php executable on the current system. Kind of redundant now 5.4 has PHP_BINARY, but this is good for backwards compatibility

findPHP

function findPHP() {
    if (defined('PHP_BINARY') && is_executable(PHP_BINARY)) {
        $res = PHP_BINARY;
    } else {
        $which       = (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') ? 'where' : 'which';
        $outputArr   = [];
        $whichReturn = false;
        $res         = exec($which . " php 2>&1", $outputArr, $whichReturn);
        if ($whichReturn !== 0) {
            $res        = false;
            $lookIn     = array(
                defined('PHP_BINDIR') ? PHP_BINDIR : '',
                'c:\xampp',
                'd:\xampp',
                getenv('ProgramFiles'),
                getenv('ProgramFiles(x86)'),
                getenv('ProgramW6432')
            );
            $suffixes   = array(
                'php',
                '/php/php',
                '/php/bin/php',
            );
            $extensions = array(
                "",
                ".exe"
            );
            foreach ($lookIn as $folder) {
                foreach ($suffixes as $suffix) {
                    foreach ($extensions as $extension) {
                        $php = $folder . $suffix . $extension;
                        if (is_executable($php)) {
                            $res = realpath($php);
                            break 3;
                        }
                    }
                }
            }
        }
    }
    return $res;
}