.TITLE	PRV
	.IDENT	/V1.00/

;*******************************************************************
;
; PRV.TSK
;
;		PRV /ON -- MAKES ANY TERMINAL PRIVILEGED
;		 OR
;		PRV /OFF -- MAKES ANY TERMINAL NONPRIVILEGED
;
;	*NOTE*	COMMAND DETAILS NOT TO BE DISTRIBUTED
;
; VERSION:	V1	JAN 81
;
;	STEVE THOMPSON
;	SCHOOL OF CHEMICAL ENGINEERING
;	OLIN HALL
;	CORNELL UNIVERSITY
;	ITHACA NY 14853
;
;*******************************************************************

	.MCALL	GMCR$,EXIT$S,DIR$,QIOW$
	.MCALL	EXST$

CR=15				; CARRIAGE RETURN
LUN=1				; TI: I/O LUN
EFN=1				; EVENT FLAG FOR I/O

;
; MACROS
;

	.MACRO	PRINT	ERR
	MOV	ERR,ODPB+Q.IOPL
	MOV	ERR'SZ,ODPB+Q.IOPL+2
	DIR$	#ODPB
	.ENDM

;
; ERROR MESSAGES
;

	.NLIST	BEX

	.ENABL	LC

ERR1:	.ASCII	/PRV -- Command input error/
ERR1SZ=.-ERR1
ERR2:	.ASCII	/PRV -- Syntax error/
ERR2SZ=.-ERR2
ERR3:	.ASCII	/PRV -- Bad switch/
ERR3SZ=.-ERR3

	.EVEN

FLAG:	.WORD	0		; ON/OFF FLAG

GMCR:	GMCR$			; GET COMMAND LINE DPB
BUF=GMCR+2

ODPB:	QIOW$	IO.WVB,LUN,EFN,,,,<0,0,40>	; OUTPUT DPB

EXST:	EXST$	EX$SUC		; EXIT WITH STATUS DPB

$PRVEP:				; ENTRY POINT

;
; PARSE COMMAND LINE
;
	DIR$	#GMCR		; GET THE COMMAND LINE
	BCC	10$		; OK
	PRINT	#ERR1		; ERROR, NONE THERE
5$:	JMP	EXIT		; EXIT
10$:	MOV	#1,FLAG		; ASSUME SWITCH IS "/ON"
	MOV	#BUF,R0		; GET BUFFER ADDRESS
15$:	CALL	$GNBLK		; GET NEXT NON-BLANK
	BCC	25$		; OK
20$:	PRINT	#ERR2		; ERROR, NULL COMMAND LINE
	BR	5$		; EXIT
25$:	CMPB	R2,#'/		; SWITCH COMING BEFORE SPACE?
	BEQ	26$		; IF EQ YES
	TST	R1		; ANY BLANKS SEEN?
	BEQ	15$		; IF EQ NO, CONTINUE SCAN
	CMPB	R2,#'/		; SWITCH COMING?
	BNE	20$		; IF NE NO
26$:	CALL	$GNBLK		; GET FIRST CHAR. OF SWITCH
	BCS	30$		; EOL IS BAD SWITCH
	CMPB	R2,#'O		; LETTER O?
	BEQ	35$		; IF EQ YES
30$:	PRINT	#ERR3		; NO, ILLEGAL PARAMETER
	BR	5$		; EXIT
35$:	CALL	$GNBLK		; GET NEXT NON-BLANK
	BCS	30$		; EOL IS ERROR
	CMPB	R2,#'N		; IS THIS THE 'ON' PARAMETER?
	BEQ	40$		; IF EQ YES
	CMPB	R2,#'F		; IS THIS THE 'OFF' PARAMETER?
	BNE	30$		; ONLY 'F' IS LEGAL
	CALL	$GNBLK		; LOOK FOR SECOND F
	BCS	30$		; ILLEGAL IF NOTHING THERE
	CMPB	R2,#'F		; GOT ONE, IS IT F?
	BNE	30$		; ONLY F IS LEGAL
	CLR	FLAG		; SET FLAG FOR "OFF"
40$:	CALL	$GNBLK		; CHECK FOR END OF SWITCH
	BCC	30$		; ONLY CARRY SET IS GOOD

;
; PROCESS COMMAND FUNCTION
;

	MOV	$TKTCB,R0	; GET OUR TCB ADDRESS
	MOV	T.UCB(R0),R0	; THEN TI: UCB ADDRESS
	TST	FLAG		; MAKE TERMINAL PRIVILEGED?
	BNE	50$		; IF NE YES
	BIC	#U2.PRV,U.CW2(R0) ; NO, SET NON-PRIVILEGED
	BR	EXIT		; AND EXIT
50$:	BIS	#U2.PRV,U.CW2(R0) ; MAKE US PRIVILEGED
				; FALL THROUGH AND EXIT

EXIT:	DIR$	#EXST		; EXIT WITH CORRECT STATUS

	.END	$PRVEP