src/log4php/helpers/LoggerOptionConverter.php
public static function getSystemProperty($key, $def) {
		if(defined($key)) {
			return (string)constant($key);
		} else if(isset($_SERVER[$key])) {
			return (string)$_SERVER[$key];
		} else if(isset($_ENV[$key])) {
			return (string)$_ENV[$key];
		} else {
			return $def;
		}
	}
public static function getSystemProperty($key, $def) {
		if(defined($key)) {
			return (string)constant($key);
		} else if(isset($_SERVER[$key])) {
			return (string)$_SERVER[$key];
		} else if(isset($_ENV[$key])) {
			return (string)$_ENV[$key];
		} else {
			return $def;
		}
	}
Read a predefined var.

It returns a value referenced by <var>$key</var> using this search criteria:
- if <var>$key</var> is a constant then return it. Else
- if <var>$key</var> is set in <var>$_ENV</var> then return it. Else
- return <var>$def</var>.

@param string $key The key to search for.
@param string $def The default value to return.
@return string	the string value of the system property, or the default
value if there is no property with that key.