********************************************************************************
*
*	Support of PR1ME INFORMATION Subroutine '!AMLC'
*
*	Module	%M%	Version	%I% 	Date	%H%
*
*	(c) Copyright 1998 Ardent Software Inc. - All Rights Reserved
*	This is unpublished proprietary source code of Ardent Software Inc.
*	The copyright notice above does not evidence any actual or intended
*	publication of such source code.
*
*******************************************************************************
*
*	Maintenence log - insert most recent change descriptions at top
*
*	Date.... GTAR# WHO Description.........................................
*	06/16/99 17755 RJE Fix functionality of key = 4 and key = 5
*	10/14/98 23801 SAP Change copyrights. 
*	10/08/91 8338  LPC Fixed assignment to variable "filestat".
*	07/25/88   -    -  Maintenence log purged at 5.2.1, see release 5.1.10.
*
*******************************************************************************

$OPTIONS DEFAULT

subroutine PR1ME(key , line , buffer , count , carrier)

*************************************************************************
*									*
*	Support of PR1ME INFORMATION subroutine !AMLC			*
*									*
*	This subroutine maintans a named common segment called 'AMLC%'	*
*	to keep a file descriptor for each terminal opened using	*
*	!AMLC (This name cannot possibly conflict with existing		*
*	INFORMATION programs cause the character '%' is illegal		*
*	on INFORMATION).						*
*									*
*	This subroutine produced error messages on the controling	*
*	terminal. If users wish to suppress the messages, change	*
*	the definition of ERROR.MESSAGE, re-compile and re-catalog	*
*	this subroutine.						*
*									*
*	Users wishing more efficient code might want to convert		*
*	existing programs using !AMLC to use the more effieicnt		*
*	uni*Verse statments: OPENDEV, READSEQ, WRITESEQ, READBLK,	*
*	WRITEBLK, STATUS, NOBUF, and FLUSH.				*
*									*
*************************************************************************

equ ERROR.MESSAGE lit '$TRUE'

common	/AMLC%/	init,AMLC(128),open(128)

if not(init) then mat open = 0; init = 1
if line < 0 or line > 128 then
	if ERROR.MESSAGE then
		crt '!AMLC: Illegal terminal line number'
	end
	return
end

if not(open(line)) then
	dev = fmt(line,if line>99 then "r(TTY%3)" else "r(TTY%2)")
	opendev dev to AMLC(line) then
		nobuf AMLC(line) then null
		open(line) = 1
	end else
		if ERROR.MESSAGE then
			crt "!AMLC: can't open ":dev
		end
		return
	end
end

begin case
case key = 1

*************************************************************************
*									*
*	KEY = 1								*
*									*
*	1)	Input <count> characters				*
*									*
*	Since readblk will terminate input when a buffer is sent	*
*	from the tty to the system (on each character when terminal	*
*	is in CBREAK or RAW mode, at the end of each line otherwise)	*
*	we have to loop and read until the number of characters		*
*	desired have been read.						*
*									*
*************************************************************************
	buffer = ''
	loop
	while count > 0 do
		readblk buf0 from AMLC(line),count then
			count -= len(buf0)
		end else
			if ERROR.MESSAGE then
				crt '!AMLC: unable to read from TTY':line
			end
			return
		end
		buffer := buf0
	repeat
	for i=1 to count; buffer[1,i] = char(bitand(seq(buffer[1,i]),127)); next
	return

case key = 2

*************************************************************************
*									*
*	KEY = 2								*
*									*
*	1)	Input <count> characters, or until a LINE FEED		*
*		(ASCII 10) or CARRIAGE RETURN (ASCII 13) is		*
*		encountered, whichever occurs first.			*
*									*
*	NOTE: if the terminal is NOT in CBREAK or RAW mode,		*
*	a buffer is automatically termiated by NL (or the EOF/BRK)	*
*	character, thus this key can be replaced by the code:		*
*		READBLK buffer FROM AMLC(line),count			*
*									*
*************************************************************************

	buffer = ''
	for i=1 to count
		readblk buf0 from AMLC(line),1 then
			s = bitand(seq(buf0),127); buf0 = char(s)
			if s=10 or s=13 then
				return
			end else
				buffer := buf0
			end
		end else
			if ERROR.MESSAGE then
				crt '!AMLC: Unable to read from TTY':line
			end
			return
		end
	next i
	return

case key = 3

*************************************************************************
*									*
*	KEY = 3								*
*									*
*	1)	Output <count> characters				*
*									*
*	PR1ME maximum of 80 does not apply to uni*Verse			*
*									*
*************************************************************************
	writeblk buffer[1,count] on AMLC(line) else
		if ERROR.MESSAGE then
			crt '!AMLC: Unable to write to TTY':line
		end
	end
	return

case key = 4

*************************************************************************
*									*
*	KEY = 4								*
*									*
*	1)	Return the number of characters waiting for input	*
*		in <count>						*
*	2)	Determine the carrier status and return result		*
*		in <carrier>						*
*									*
*	Uni*Verse is currently unable to determine the carrier		*
*	status of a TTY, thus result is also always 1			*
*									*
*************************************************************************
	status filestat from AMLC(line) else
		if ERROR.MESSAGE then
			crt '!AMLC: Unable to determine status of TTY':line
		end
		return
	end
	count = filestat<4>
	carrier = 1
	return

case key = 5

*************************************************************************
*									*
*	KEY = 5								*
*									*
*	1)	Determine if there is enough room in buffer for		*
*		<count> characters and return the result in <count>	*
*	2)	Determine the carrier status and return result		*
*		in <carrier>						*
*									*
*	Uni*Verse is currently unable to determine the carrier		*
*	status of a TTY, thus result is also always 1			*
*									*
*************************************************************************

	status filestat from AMLC(line) else
		if ERROR.MESSAGE then
			crt '!AMLC: Unable to determine status of TTY':line
		end
		return
	end
	count   = (count <= filestat<19>)
	carrier = 1
	return

case key=6

*************************************************************************
*									*
*	KEY = 6								*
*									*
*	1)	Input all available characters in the input buffer	*
*		maximum = <count>, return in <count> actual number	*
*		of characters input					*
*									*
*************************************************************************

	status filestat from AMLC(line) else
		if ERROR.MESSAGE then
			crt '!AMLC: Unable to determine status of TTY':line
		end
		return
	end

	if count > filestat<19> then count = filestat<19>
	readblk buffer from AMLC(line),count else
		if ERROR.MESSAGE then
			crt '!AMLC: Unable to read from TTY':line
		end
	end
	return

case key=7
*************************************************************************
*									*
*	KEY = 7								*
*									*
*	1)	Return in <count> the amount of output buffer space	*
*		available.						*
*									*
*************************************************************************

	status filestat from AMLC(line) else
		if ERROR.MESSAGE then
			crt '!AMLC: Unable to determine status of TTY':line
		end
		return
	end
	count = filestat<4>
	return

case key=8
*************************************************************************
*									*
*	KEY = 8								*
*									*
*	1)	Flush the input buffer					*
*									*
*	Since uni*Verse does not support seperate flushing of input	*
*	and output buffers, fall into KEY# 10				*
*									*
*************************************************************************
case key=9
*************************************************************************
*									*
*	KEY = 9								*
*									*
*	1)	Flush the output buffer					*
*									*
*	Since uni*Verse does not support seperate flushing of input	*
*	and output buffers, fall into KEY# 10				*
*									*
*************************************************************************
case key=10
*************************************************************************
*									*
*	KEY = 10							*
*									*
*	1)	Flush both the input & output buffers			*
*									*
*************************************************************************
	ttyctl AMLC(line),9 else
		if ERROR.MESSAGE then
			crt '!AMLC: Unable to flush buffer on TTY':line
		end
	end
	return
case key=11
*************************************************************************
*									*
*	KEY = 11							*
*									*
*	1)	Output characters to available room in output buffer	*
*		return in <count> the number of character NOT output	*
*									*
*************************************************************************


	status filestat from AMLC(line) else
		if ERROR.MESSAGE then
			crt '!AMLC: Unable to determine status of TTY':line
		end
		return
	end
	cnt = filestat<4>
	if cnt > count then cnt = count
	writeblk buffer[1,cnt] on AMLC(line) else
		if ERROR.MESSAGE then
			crt '!AMLC: Unable to write to TTY':line
		end
		return
	end
	count -= cnt
	return

case 1

	if ERROR.MESSAGE then
		crt '!AMLC: Illegal argument'
	end
	return

end case