Cream of the Crop 1/Cream of the Crop 1.iso/PROGRAM/PCCP024.ARJ/MANUAL

Text File | 1992-05-18 | 5KB | 129 lines

          Pete Cann's Communication Package

        Portions Copyright (C) 1992 Peter Edward Cann

         (Please see the file README for legal junk)

This is a set of programs and data files for communication between a
PC and something external, possibly over a modem. It is drastically
different from most other communications programs, in that it is
highly modular and generally requires the user to write batch files
and/or scripts to make use of it. This is what you might call a
"hacker style" paradigm (not to be confused with "cracker", generally
an infantile individual who feels so insignificant that they screw
other people in a desperate attempt to feel powerful). Hackers are
people who are very comfortable with computers, and like to have a
lot of control and to know what's going on. The source code for all
of these programs is included in the distribution, so if you know C
you have all the information I do now.

All of the programs give USAGE: information if invoked without
arguments.

The centerpiece of the package is TERM. This is a terminal emulator.
It takes an emulation file, which you create or modify with EMUED.
EMUED lets you specify strings to send for any programmable key, and
lets you enter strings of characters and substitution tokens to
invoke functions. These would be the "escape sequences", although
they need not begin with Escape. The token codes are in EMU.H. The
emulation facility also provides a graphics character substitution
table for graphics character commands. TERM and EMUED look in the
directory named by the PCCPPATH environment variable for emulation
files, if PCCPPATH is set. The program CCODES types a hex listing of
display character codes for use when assigning graphics characters in
EMUED.

The program MASTERM invokes term with the three or four arguments,
but if you exit term you get a menu for file transfers or beginning a
dribble file. The file transfer programs are three variations on
XMODEM in each direction, and have fairly clear names.

The program HOST is a simple one-password host. It is hard-coded for
8n1 bits. It expects the modem to be in AT&C1&D2 mode, that is,
Carrier Detect conveys information and Data Terminal Ready controls
hookswitch. The shell has no extra protection, because calling the
FTP protocols creates a potential trap-door situation anyway. The
host program presently only operates at the specified speed, because
I don't off-hand know a neat way to autobaud. Lots of modems these
days speed-buffer anyway. The environment of any subschell contains
REMOTE=YES, so you can do IF NOT "%REMOTE%"=="YES" THING in a batch
file, where THING is something that would be bad to do from a
comport, such as run a display editor.

The program COMSCRPT runs scripts. It is very powerful, with multiple
branching look-fors, timeouts and retry limits.

The script file must have the extension ".SCR". If the PCCPPATH
environment variable is set, the program looks for the script there.
The program loads the script into RAM and then executes it. Lines are
limited to 80 characters. The number of lines is limited to 255.

The characters '|' and '~' are special. '|' means CR in < lines and >
lines (LF is stripped for > processing); and newline in ! lines. '~'
means 0.4 second delay in < lines and bell in ! lines. (In > lines it
means itself.) Also, in < lines, `xx (backquote followed by two hex
digits) expands to the specified character code.

The first line of the script file is the first three arguments as for
TERM, space-delimited. In subsequent lines, the first character of
each line is the command; the rest of the line (after the delimiting
space) is argument(s). A final string argument may include spaces,
and begins after the delimiting space. Blank lines are ignored.

The command characters are as follows:

;
    {introduces comment; line ignored; space not required}

: <decimal number 0-255>
    {label for conditional or unconditional goto}

g <label #>
    {goto label #}

r <label #> <retries>
    {resets retry count and goes to label if hit more than retries}

p <seconds>
    {processes pending look-fors; falls through upon timeout}
    {clears pending look-for list upon completion}

> <label #> <string>
    {look for string upon p command; if hit goto label}
    {incoming linefeeds ignored}

? <label #>
    {goto label if Clear To Send or Tx Hold Reg Empty is false}

< <string>
    {send string to port}

! <string>
    {send string to console}

s <label #> <command line string>
    {run system command line and wait for termination}
    {goto label # if error in running command.com}
    {will not report errors within command string}

q <exit code>
    {quit with exit code}
    {codes other than zero under 128 are reserved to internals}

When scripting modem commands, which is how you're intended to
configure and dial the modem, try a ~ before and after the at, for
instance:

    < ~at~&f&c1&d2|

The program SCRCHK types a listing of the argument script file giving
statement numbers, which are not the same as line numbers. It leaves
out blank lines for some reason. It also detects some errors.

All of the I/O programs except TERM pay attention to CTS. None of
them do XON/XOFF. The computer is assumed to be fast enough to keep
up. However, since DOS video is very slow, TERM will suspend display
if a buffer overrun threatens.