Initiates an SSL/TLS handshake with a server. The handshake may be started after unencrypted data has been sent over the socket.
Connect to IO tcp, with context of the current certificate configuration
Returns true if the directory may be entered by CWD/CDUP.
Parses the received response and separates the reply code and the human readable reply text
Raises an exception if any arguments given.
Raises an exception if argument is not present.
Parses argument if given, or uses default value.
Returns nil if argument is not present or begins with ‘-’.