The PHP http_response_code() function sets or returns the HTTP response status code.

The PHP inet_ntop() function converts a 32bit IPv4 or 128bit IPv6 address into a readable format.

The PHP inet_pton() function converts a readable IP address into a packed 32bit IPv4 or 128bit IPv6 format.

The PHP ip2long() function converts an IPv4 address into a long integer.

The PHP long2ip() function converts a long integer address into a string in IPv4 format.

The PHP openlog() function opens the connection of system logger.

The PHP pfsockopen() function opens a persistent internet or Unix domain socket connection.

The PHP setcookie() function defines a cookie to be sent along with the rest of the HTTP headers.

The PHP setrawcookie() function defines a cookie (without URL encoding) to be sent along with the rest of the HTTP headers.

The PHP syslog() function generates a system log message.