Functions related to Erlang ports.
See http://www.erlang.org/doc/man/erlang.html#port_call-3
See http://www.erlang.org/doc/man/erlang.html#port_close-1
See http://www.erlang.org/doc/man/erlang.html#port_command-2
See http://www.erlang.org/doc/man/erlang.html#port_connect-2
See http://www.erlang.org/doc/man/erlang.html#port_control-3
See http://www.erlang.org/doc/man/erlang.html#port_info-1
See http://www.erlang.org/doc/man/erlang.html#port_info-2
See http://www.erlang.org/doc/man/erlang.html#ports-0
See http://www.erlang.org/doc/man/erlang.html#open_port-2
See http://www.erlang.org/doc/man/erlang.html#port_call-3.
See http://www.erlang.org/doc/man/erlang.html#port_close-1.
See http://www.erlang.org/doc/man/erlang.html#port_command-2.
See http://www.erlang.org/doc/man/erlang.html#port_connect-2.
See http://www.erlang.org/doc/man/erlang.html#port_control-3.
See http://www.erlang.org/doc/man/erlang.html#port_info-1.
See http://www.erlang.org/doc/man/erlang.html#port_info-2.
See http://www.erlang.org/doc/man/erlang.html#ports-0.
See http://www.erlang.org/doc/man/erlang.html#open_port-2.