note 72150 modified in function.getenv by danbrown

You need also to know that $_SERVER['SERVER_NAME'] and surely $_SERVER['PHP_SELF'] are fakeable by sending wrong HTTP headers (hint: "Host:" will become SERVER_NAME in your PHP scripts). For PHP_SELF you may want to use SCRIPT_NAME instead. [EDIT by danbrown AT php DOT net: Just keep in mind, PHP_SELF and SCRIPT_NAME are not the exact same variable, and may differ depending on server and site configuration.] You may want to use this little code to continue using PHP_SELF: $_SERVER['PHP_SELF'] = $_SERVER['SCRIPT_NAME']; $PHP_SELF = $_SERVER['PHP_SELF'] The last one is for people who cannot switch "register_global" off. There is now "secure" replacement for SERVER_NAME available. Sometimes SERVER_ADDR (which not fakeable) might be handy but in some situations not. If you need a valid entry in SERVER_NAME validate it with a regular expressions. See regexlib.com for such expressions. --was-- You need also to know that $_SERVER['SERVER_NAME'] and surely $_SERVER['PHP_SELF'] are fakeable by sending wrong HTTP headers (hint: "Host:" will become SERVER_NAME in your PHP scripts). For PHP_SELF you may want to use SCRIPT_NAME instead. You may want to use this little code to continue using PHP_SELF: $_SERVER['PHP_SELF'] = $_SERVER['SCRIPT_NAME']; $PHP_SELF = $_SERVER['PHP_SELF'] The last one is for people who cannot switch "register_global" off. There is now "secure" replacement for SERVER_NAME available. Sometimes SERVER_ADDR (which not fakeable) might be handy but in some situations not. If you need a valid entry in SERVER_NAME validate it with a regular expressions. See regexlib.com for such expressions. http://php.net/manual/en/function.getenv.php