; Program: ERRSET
; Author: Jay Sage
; Version: 1.3
; Date: June 1, 1987


;			* * *   IMPORTANT NOTE   * * *
;
; This program is copyrighted 1987 by NAOG/ZSIG.  It may be copied and
; modified freely for personal use but may not be sold or distributed for a
; fee.  Modified versions must be submitted to and approved by NAOG/ZSIG
; before they may be distributed.  See the file ZSIGPOL1.DOC on Z-Nodes for
; the ZSIG policy on signing out and modifying programs.

version	equ	13

; This program displays, clears, or sets the error handler command line.
; Error messages are given if there is no message buffer (and hence no
; external error handling) or if an attempt is made to load an error command
; line that is too long.  For the sake of neatness, ERRSET clears extraneous
; bytes in the the message buffer beyond the terminating null of the new
; command line.  The built-in help screen describes the syntax.

; UPDATE HISTORY

; Version 1.3
;	Updated to ZCPR33 compatibility using Z33LIB routines.

; Version 1.2
;	Corrected mistake resulting from misconception that error handler
;	command line buffer was only 16 bytes long.  It was originally 32
;	bytes long, but ZCPR33 has taken some of that space.  ERRSET now
;	allows a number set by the CMDLEN equate.  A value of 25 is
;	recommended.  A value of 28 is the largest allowed with ZCPR33.

;=============================================================================

;			E Q U A T E S

no	equ	0
yes	equ	not no

usedseg	equ	no		; If yes, uses separate data segment and
				; ..requires special linking

cmdlen	equ	25

tbuff	equ	80h
fcb	equ	5ch
cr	equ	0dh
lf	equ	0ah
tab	equ	09h
bell	equ	07h
eot	equ	1ah

;=============================================================================

;		E X T E R N A L    R E F E R E N C E S


	ext z3init,print,pstr,getmsg,sksp,z33chk,geterc,puterc


;=============================================================================

;		Z C P R    I N I T I A L I Z A T I O N


; External ZCPR3 Environment Descriptor

entry:
	jp	start
	defb	'Z3ENV'		; This is a ZCPR3 utility
	defb	3		; zcpr33 type 3 environment
z3eadr:
	defw	0		; Filled in by CPR or install program
	defw	entry		; Load address for ZCPR33 type 3 environment


;=============================================================================

;		M A I N    P R O G R A M    C O D E

start:
	ld	hl,(z3eadr)	; Pt to ZCPR3 environment
	call	z3init		; Initialize Z3 system

				; Check for option or help request

	call	getfirst	; Get first non-space character in tail
	jp	z,display	; Branch if null command line

	cp	'/'		; Branch if not an option request
	jr	nz,start1

	inc	hl		; Point to next character
	ld	a,(hl)		; ..and get it
	cp	'C'		; Clear option?
	jr	z,cancel
	cp	'Z'		; Zero option?
	jp	nz,help		; If not, branch to help message

cancel:
	call	getmsg		; Get pointer to message buffer
	ld	(hl),0		; Reset error-handler-installed flag (ZCPR30)
	call	geterc		; Get pointer to error command line
	ld	b,cmdlen	; Zero out error command line
	xor	a
cancel1:
	ld	(hl),a
	inc	hl
	djnz	cancel1	

	call	print
	defb	cr,lf
	defb	' External error handling turned off'
	defb	0
	jp	quit

start1:
	call	puterc		; Copy user's command line to error line
	jr	nz,start2	; If successful, branch to START2

	call	print		; Otherwise report error
	defb	cr,lf,bell,' Command line too long',0
	jr	cancel

start2:
	call	getmsg		; Get pointer to message buffer
	ld	(hl),0ffh	; Set error-handler-installed flag (ZCPR30)

display:
	call	z33chk		; See if ZCPR33 is running (Z set if so)
	jr	z,dsp33		; If so, skip over ZCPR30-style checking

	call	getmsg		; Get pointer to first byte of message buffer
	ld	a,(hl)		; See if error handler is engaged
	or	a
	jr	z,noerrh	; Case for error handler not engaged

dsp33:
	call	geterc		; Get pointer to error command line
	ld	a,(hl)		; Get first byte
	or	a		; Check for null line
	jr	nz,errh		; If not null, branch

noerrh:
	call	print
	defb	cr,lf
	defb	' No error handler loaded'
	defb	0
	jr	quit

errh:
	call	print
	defb	cr,lf
	defb	' Error handler command line set to: '
	defb	0

	call	pstr		; Print error handling command line

quit:
	call	print
	defb	cr,lf
	defb	0

	ret

;-----------------------------------------------------------------------------

; Get the first non-space character in the command line tail and set the
; zero flag to reflect end-of-line status.

getfirst:
	ld	hl,tbuff+1	; Point to command tail
	call	sksp		; Skip over leading spaces
	ld	a,(hl)		; Get first character
	or	a
	ret

;-----------------------------------------------------------------------------

; Copy characters from HL to DE up to number allowed in error command line.

copy:
	ld	b,cmdlen	; Maximum characters to copy
copy1:
	ld	a,(hl)		; Get next character from command tail
	or	a		; End of tail?
	ret	z
	ld	(de),a		; Copy the character
	inc	hl		; Increment pointers
	inc	de
	djnz	copy1		; Continue copying
	ret

;-----------------------------------------------------------------------------

help:
	call	print
	defb	cr,lf,lf
	defb	tab,tab,'ERRSET Version '
	defb	version	/ 10 + '0'
	defb	'.'
	defb	version	mod 10 + '0'
	defb	' [ZSIG]'
	defb	cr,lf,lf
	defb	'  Syntax:'
	defb	cr,lf,lf
	defb	tab,'ERRSET',tab,tab,'display current error command line'
	defb	cr,lf
	defb	tab,'ERRSET CMDLINE',tab,'set new error command line'
	defb	cr,lf
	defb	tab,'ERRSET /C',tab,'clear external error handling'
	defb	cr,lf
	defb	tab,'ERRSET /Z',tab,'zero out external error handling'
	defb	cr,lf,lf
	defb	'  Example:  ERRSET A15:VERROR'
	defb	cr,lf,lf
	defb	tab,'An explicit DU: or DIR: prefix can speed error handling.'
	defb	cr,lf
	defb	tab,'NOTE: the command line entered is not checked '
	defb	'for validity.'
	defb	cr,lf,lf
	defb	0
	ret

;-----------------------------------------------------------------------------

	 if	usedseg
	dseg
	 endif

dummybuf:
	defs	cmdlen

	end