Reads a file and writes it to standard output.
Returns the number of bytes read from the file. If an error occurs, FALSE is returned and unless the function was called as @readfile, an error message is printed.
If filename begins with "http://" (not case sensitive), an HTTP 1.0 connection is opened to the specified server and the text of the response is written to standard output.
Versions prior to PHP 4.0.5 do not handle HTTP redirects. Because of this, directories must include trailing slashes.
If filename begins with "ftp://" (not case sensitive), an ftp connection to the specified server is opened and the requested file is written to standard output. If the server does not support passive mode ftp, this will fail.
If filename begins with neither of these strings, the file will be opened from the filesystem and its contents written to standard output.
You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too.