erc-compute-port
erc-compute-port is a compiled Lisp function in `erc.el
'.
(erc-compute-port &optional PORT)
Return a port for an IRC server.
This tries a number of increasingly more default methods until a
non-nil value is found.
- PORT (the argument passed to this function)
- The `erc-port' option
- The `erc-default-port' variable