Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!hc!hi!erikj
From: erikj@hi.unm.edu (Erik Johannes)
Newsgroups: comp.sys.amiga
Subject: Add to VT100 v2.8 a script NULL character transmission command.
Message-ID: <23565@hi.unm.edu>
Date: 6 Apr 88 06:30:08 GMT
Reply-To: erikj@hi.unm.edu ()
Organization: U. of New Mexico, Albuquerque
Lines: 61


	This posting is two fold.  First a question about compiling VT100 2.8
with Manx 3.6A followed by a modification to add the ability to transmit the
NULL character from a script.

	When I try to compile the stock VT100 2.8 I get an error on vt100.c
saying that ConsoleDevice is multipluly defined.  ConsoleDevice is defined in
the two include files : functions.h (defined as a function) and 
intuition/intuitionbase.h (defined as an APTR ).  Renaming ConsoleDevice
in the vt100 would result in the linker not being able to find _ConsoleDevice.
The only solution I could come up with is to comment out ConsoleDevice from
the include files.  Modifying the Manx include files is not the kind of 
solution I like.  Has anybody come up with a better solution for this problem?
At any point I managed to finally compile the vt100 and confirm that my
modification does work.
 
	When trying to write a script that would log onto the library computer
at the university I noticed that there was a problem with trying to send a NULL
from a script.  The SEND command performs the conversion turning "^@" into
the NULL character.  However this NULL ends up terminating the string that
is to be sent and thus SEND is unable to send a NULL character.  Inorder to
keep my modifications as little as possible I decided to add a new script
command instead of modifying the SEND code.  The new command is the NULL 
command.  The manual entry would look like this :

------------------------------------------------------------
NULL	Sends a NULL character to the host			(SCRIPT)
   Format:
	NULL	
------------------------------------------------------------

	The implementation involves very little modification of the vt100
code.  Below are the diffs for the two file that had to be modified.  The
diff program I used is the one that comes with Manx C.  The first diff says
to change line 227 in the original file to the second line preceded by >.
The second diff says to add at line 103 the line that is shown.  It also
says to add at line 695 the new cmd_snull() function.

*******************************************************************************
File :	vt100.h

227c227
< 		cmd_sendf(), cmd_wait(), cmd_xr(), cmd_xs(),
---
> 		cmd_sendf(), cmd_snull(), cmd_wait(), cmd_xr(), cmd_xs(),

*******************************************************************************
File :	script.c

103a104
>     cmd_snull,	"null",		/* send a NULL			*/
695a697,702
> void cmd_snull(str)
> char *str;
> {
>     sendchar('\0');
> }
> 
*******************************************************************************


		-Erik