1!		LAWRENCE UNIVERSITY
		COMPUTER CENTER
		APPLETON, WISCONSIN 54911
		(414) 739-3681, EXT 564

    PROGRAM NAME, VERSION AND DATE:
	XREF, VERSION 1A, 18-JUN-74

    PROGRAM AUTHORSHIP:
2!	XREF WAS WRITTEN AND DESIGNED BY PAUL KONING OF THE LAWRENCE
	UNIVERSITY COMPUTER CENTER.

    PURPOSE OF PROGRAM:
	XREF IS A PROGRAM FOR MAKING A CROSS REFERENCE TABLE OF A BASIC-
	PLUS PROGRAM.
3!
    LANGUAGE AND OPERATING SYSTEM:
XREF IS WRITTEN IN BASIC-PLUS FOR OPERATION UNDER RSTS V4A-12
	ON A PDP11/20 OR PDP11/35 WITH 28K OF CORE. IT WILL
	ALSO OPERATE UNDER RSTS/E, SINCE IT DOES NOT USE ANY FUNCTIONS
4!	PECULIAR TO RSTS V4A-12.
10!
    AVAILABILITY:
	XREF IS A NON-PROPRIETARY PROGRAM PRODUCT OF LAWRENCE
	UNIVERSITY. IT IS DISTRIBUTED AT COST FOR EDUCATIONAL USE, ON
	THE CONDITION THAT IT NOT BE SOLD, RENTED OR LEASED FOR PROFIT.

    LIMITATIONS:
11!	XREF ASSUMES THAT THE PROGRAM IT CROSS-REFERENCES IS
	SYNTACTICALLY CORRECT AND THAT 'ERL' ONLY OCCURS IN EXPRESSIONS
	OF THE FORM: ERL=10 OR ERL<>35.

    FURTHER DOCUMENTATION:
12!	XREF IS STARTED (ASSUMING IT IS SAVED ON [1,2]) BY TYPING:
	RUN $XREF. XREF WILL ASK: WHICH PROGRAM DO YOU WANT CROSS-
	REFERENCED? . TYPE IN THE PROGRAM NAME, WITHOUT EXTENSION, BUT
13!	IF DESIRED WITH DEVICE SPECIFICATION OR ACCOUNT NUMBER. XREF
	WILL PRINT OUT 'PASS 1' AND  WHILE LATER 'PASS 2'. THEN IT WILL
	PRINT OUT A HEADER AND ALL LINE NUMBERS OCCURRING IN THE PROGRAM
14!	FOLLOWED BY THE NUMBERS OF THE LINES THAT REFERENCE THAT LINE.
	LINES THAT ARE REFERENCED BUT DO NOT EXIST IN THE PROGRAM ARE
	MARKED 'UNDEF' (FOR UNDEFINED). NO FURTHER OPERATOR INTERACTION
	IS NEEDED.
15!	XREF CAN BE SAVED IN COMPILED OR SOURCE FORM ON THE SYSTEM
	LIBRARY [1,2] WITH A PROTECTION CODE OF <40>.
20!
    DISCLAIMER:
	NEITHER THE AUTHORS OF THIS PROGRAM NOR LAWRENCE UNIVERSITY
	ASSUME ANY LIABILITY, EXPRESSED OR IMPLIED, WITH RESPECT TO
	THE CORRECTNESS OR PERFORMANCE OF THIS PROGRAM.

95 PRINT "XREF V1A -- BASIC-PLUS CROSS REFERENCE PROGRAM -- LAWRENCE"
100 &"WHICH PROGRAM DO YOU WANT CROSS-REFERENCED";:INPUTLINE F$:F$=F$+".BAS":
	OPEN F$ FOR INPUT AS FILE 1%:ON ERROR GOTO 200 :
	OPEN"CREF"+NUM$(ASCII(SYS(CHR$(6%)+CHR$(9%)))/2%)+".TMP"
	FOR OUTPUT AS FILE 2%
110 DIM P%(200%),N%(200%),S1%(100%),S2%(400%):DIM #2%,L%(200%,50%):
	MAT P%=ZER:MAT N%=ZER:I%=0%:&"PASS 1"
120 GOSUB 220 :I%=I%+1%:P%(I%)=VAL(LEFT(S2$,INSTR(1%,S2$,CHR$(255%))-1%)):
	GOTO 120 IF I%<200%:&"TOO MANY LINES IN FILE":GOTO 400 
130 CLOSE 1%:OPEN F$ FOR INPUT AS FILE 1%:ON ERROR GOTO 210 :&"PASS 2"
140 GOSUB 220 :W%=VAL(LEFT(S2$,INSTR(1%,S2$,CHR$(255%))-1%)):Q%=1%:
	O%=FNM%(INSTR(1%,S2$,"!"),INSTR(1%,S2$,"DATA")):O%=32767% UNLESS O%
150 GOSUB 290 :IF R% THEN GOSUB 390 :L%(S%,N%(S%))=W%:Q%=R%:
	N%(S%)=N%(S%)+1%:GOTO 150 
160 GOTO 140 
170 CLOSE 1%:&CHR$(13%);CHR$(12%),"CROSS REFERENCE TABLE":
	&:&"LINE #",,"REFERENCES":&:FOR J%=1% TO I%
180 &ABS(P%(J%));:&" UNDEF"; IF P%(J%)<0%:&,:FOR K%=1% TO N%(J%):
	&USING"#####   ",L%(J%,K%-1%);:IF K%/7%*7%=K% THEN &:&,
190 NEXT K%:&"*** NOT REFERENCED ***" UNLESS N%(J%):& IF POS(0%):
	NEXT J%:GOTO 400 
200 IF ERR=11% THEN RESUME 130 ELSE ON ERROR GOTO 0
210 IF ERR=11% THEN RESUME 170 ELSE ON ERROR GOTO 0
220 Z%=1%:N1%=0%
230 INPUT LINE #1%,S1$:CHANGE S1$ TO S1%:FOR S1%=1% TO S1%(0%):S9%=S1%(S1%):
	IF S9%<33% THEN 250 ELSE IF S9%>47%
	AND S9%<58% THEN N1%=-1% ELSE IF S9%>96% AND S9%<123% 
	THEN S9%=S9%-32% ELSE IF S9%=34% OR S9%=39% THEN S3%=
	INSTR(S1%+1%,S1$,CHR$(S9%)):IF S3%=0% THEN 250 ELSE S1%=S3%:GOTO 250 
240 S2%(Z%)=S9%:Z%=Z%+1%:IF (S9%>57% OR S9%<48%) AND N1% THEN S2%(Z%-1%)=255%:
	S2%(Z%)=S9%:Z%=Z%+1%:N1%=0%
250 NEXT S1%:IF INSTR(1%,S1$,CHR$(10%))<INSTR(1%,S1$,CHR$(13%)) THEN 230 
260 IF N1% THEN S2%(Z%)=255%:Z%=Z%+1%
270 S2%(0%)=Z%-1%:CHANGE S2% TO S2$:S1%=INSTR(1%,S2$,"DATA"):
	S2$=LEFT(S2$,S1%-2%) IF S1%:S1%=INSTR(1%,S2$,"!"):
	S2$=LEFT(S2$,S1%-2%) IF S1%:S1%=INSTR(1%,S2$,"REM")
280 S2$=LEFT(S2$,S1%-2%) IF S1%:GOTO 220 UNLESS INSTR(1%,S2$,CHR$(255%)):
	RETURN
290 R%=FNM%(FNM%(FNM%(FNM%(FNM%(FNM%(FNM%(FNI%("ERL<>"),FNI%("ERL=")),
	FNI%("GOSUB")),FNJ%),FNK%("GOTO")),FNK%("RESUME")),
	FNK%("THEN")),FNK%("ELSE")):RETURN
300 DEF FNM%(A1%,A2%):A1%=A2% IF A2% AND A2%<A1% OR A1%=0%:FNM%=A1%:FNEND
310 DEF FNI%(Z$)=FNL%(Q%,Z$)
320 DEF FNJ%:Z2%=Q%
330 IF S2%(Z2%)>47% AND S2%(Z2%)<58% THEN Z2%=Z2%+1%:GOTO 330 
340 IF S2%(Z2%)=255% AND S2%(Z2%+1%)=44% THEN FNJ%=Z2%+2% ELSE FNJ%=0%
350 FNEND
360 DEF FNK%(Z$)=FNO%(Q%,Z$)
370 DEF FNL%(A%,A$):Z1%=INSTR(A%,S2$,A$):Z1%=Z1%+LEN(A$) IF Z1%:
	FNL%=Z1%:FNEND
380 DEF FNO%(A%,A$):X%=FNL%(A%,A$):X%=FNO%(X%,A$) IF X% AND (S2%(X%)<48%
	OR S2%(X%)>57%):FNO%=X%:FNEND
390 Z1%=VAL(MID(S2$,R%,INSTR(R%,S2$,CHR$(255%))-R%)):RETURN
	IF Z1%=ABS(P%(S%)) FOR S%=1% TO I%:S%,I%=I%+1%:P%(I%)=-Z1%:RETURN
400 CLOSE 1%,2%:KILL "CREF"+NUM$(ASCII(SYS(CHR$(6%)+CHR$(9%)))/2%)+".TMP"
32767 END