Get current PHP executable from within script?

Question

I want to run a PHP cli program from within PHP cli. On some machines where this will run, both php4 and php5 are installed. If I run the outer program as

Answer 1

Unfortunately PHP_BINARY is returning the httpd binary (on windows XAMPP), so I'm back to using paths...

    if (defined('PHP_BINARY') && PHP_BINARY && in_array(PHP_SAPI, array('cli', 'cli-server')) && is_file(PHP_BINARY)) {
          return PHP_BINARY;
    } else if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
        $paths = explode(PATH_SEPARATOR, getenv('PATH'));
        foreach ($paths as $path) {
            if (substr($path, strlen($path)-1)==DIRECTORY_SEPARATOR) {
                $path=substr($path, 0, strlen($path)-1);
            }
            if ( substr($path, strlen($path) - strlen('php')) == 'php' ) {
                $response=$path.DIRECTORY_SEPARATOR.'php.exe';
                if (is_file($response)) {
                    return $response;
                }
            } else if ( substr($path, strlen($path) - strlen('php.exe')) == 'php.exe' ) {
                if (is_file($response)) {
                    return $response;
                }
            }                
        }
    } else {
        $paths = explode(PATH_SEPARATOR, getenv('PATH'));
        foreach ($paths as $path) {
            if (substr($path, strlen($path)-1)==DIRECTORY_SEPARATOR) {
                $path=substr($path, strlen($path)-1);
            }
            if ( substr($path, strlen($path) - strlen('php')) == 'php' ) {
                if (is_file($path)) {
                    return $path;
                }
                $response=$path.DIRECTORY_SEPARATOR.'php';
                if (is_file($response)) {
                    return $response;
                }
            }               
        }
    }
    return null;