Newsgroups: comp.lang.apl
Path: utzoo!utgpu!watserv1!maytag!watdragon!daisy.waterloo.edu!ljdickey
From: ljdickey@daisy.waterloo.edu (Lee Dickey)
Subject: Re: script file in J
Message-ID: <1990Dec1.171214.10761@watdragon.waterloo.edu>
Sender: daemon@watdragon.waterloo.edu (Owner of Many System Processes)
Organization: University of Waterloo
References: <1990Nov29.032733.7810@nas.nasa.gov>
Date: Sat, 1 Dec 90 17:12:14 GMT
Lines: 43

In article <1990Nov29.032733.7810@nas.nasa.gov> freedman@amelia
	(Richard S. Freedman) writes:

>I am using J on a Vax with BSD unix. When I create an output "log" file
>using the )script command this file is empty upon exiting J.  What is the
>definition of the session "log" and what should be on this file ?

The command

	)script - 'somefile'

is intended to create a file with the given name that contains a
transcript of all characters into and out of the interpreter.

There is a feature that distinguishes between input lines and output
lines.  It can be seen in this little example:

% J
J Version 1.2   Copyright (c) 1990, Iverson Software Inc.

   )script - 'temp'
   i. 3 4
0 1  2  3
4 5  6  7
8 9 10 11
   )script -
   )off
% cat -v temp
   i. 3 4
^@0 1  2  3
^@4 5  6  7
^@8 9 10 11
   )script -
% 

Upon input, lines of files that begin with ^@ are not executed.
This allows you to re-execute the commands that you gave during
a session, without re-executing the output.

In the above example the line ")script -" seems to be necessary
to write and close the file.  However, I think it is intended
that the ")off" command do the same thing.

