Given an extension or media type, return the full Content-Type header string. Returns undefined if not resolvable.

Test whether or not the given path exists by checking with the file system

Parse or format the given val.

Create a HTTP server

Create an HTTPS server with given options

Converts and format a variable number of args as is specified by format. sprintf returns the formatted string.

Interface of HTTP server response. If body is a Reader, response would be chunked. If body is a string, it would be UTF-8 encoded by default.