README.telnet

Last updated Mon Sep 16 08:08:40 EDT 1996

INSTALLATION DETAIL
-------------------
For SCO, Linux or SunOS, you need do nothing special at installation
time. (If the SCO Development System does not have inet support,
namely libsocket.a, no attempt will be made to include the
telenet option);

To enable the feature otherwise, you must add (or add to) a file
in the ecu distribution directory named 'config.local' as follows:

1. The file must contain the line:
LOCAL_CFLAGS = -DCFG_TelnetOption

2. On SCO or similar, you must add the line (or similar)
LOCAL_LIBS = -lsocket
LOCAL_LIBS = -lsocket -lnsl
LOCAL_LIBS = -lsocket -ldl

EXECUTION NOTES
---------------

From the command line, you may start an internet connection
by specifying a logical "telephone number" with a period in it.
For instance,

    ecu blah.org
    ecu 127.0.0.1
    ecu kepler.
	ecu localhost.:25

The next to last example shows how to call a host with a simple name like
"kepler": suffix the simple name with a period.
The last example shows how to call a host with port number
other than 23 (telnet).

The -z switch enables display of telnet option negotiation.  The
interactive and procedure 'telopt' commands also control the
display, but the show is mostly over by the time you get a login
prompt, so consider using-z or putting 'telopt yes' in an _rc.ep
file.

While connected, try using the HOME stat command: it is different.

FILE TRANSFER
-------------

You may use ZMODEM for file transfer.

For file transmission, no special action is required.
ECU's sz command causes proper transmission using an
"escape control character" feature of ZMODEM.

For file reception, no special action is required in your
remote sz command complies with the ZMODEM standard.  That is:

1. ECU's rz receiver requests "escape control character" of
the sz transmitter. A compliant sz will properly interpret
this request.

2. Some sz programs or functions do not properly escape the 0xFF
(255 decimal, octal 377) character.  This is the telnet IAC
character and it must be "escaped" like other control characters.
That is, 0xFF characters in the data stream must be replaced with
0x18 followed by 0x6D (ZDLE + ZRUB1).

No other control characters actually need escaping over telnet,
but to buy the one you must accept the others.

You may wish to try the program "tsz.c" supplied in the ECU distribution.
It is a quickly hacked version of Chuck Forsberg's sz 1.44 public
domain effort.  Follow the compilation instructions in the file.

PROCEDURE LANGUAGE SUPPORT
--------------------------

%telnet is a procedure integer function which returns zero
if the current connection is a serial connection, 1 if an
internet connection.