New mainargs.s from Greg King

git-svn-id: svn://svn.cc65.org/cc65/trunk@2168 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/c64/c64.inc

@@ -24,6 +24,9 @@ CURS_X		= $D3		; Cursor column
 CURS_Y		= $D6		; Cursor row
 CRAM_PTR	= $F3		; Pointer to current char in color RAM
 
+BASIC_BUF	= $200		; Location of command-line
+BASIC_BUF_LEN	= 89		; Maximum length of command-line
+
 CHARCOLOR       = $286
 CURS_COLOR      = $287		; Color under the cursor
 PALFLAG		= $2A6		; $01 = PAL, $00 = NTSC

libsrc/c64/mainargs.s

@@ -1,72 +1,129 @@
+; mainargs.s
 ;
 ; Ullrich von Bassewitz, 2003-03-07
-;
-; Setup arguments for main.
 ; Based on code from Stefan A. Haubenthal, <polluks@web.de>
+; 2003-05-18, Greg King
 ;
+; Scan a group of arguments that are in BASIC's input-buffer.
+; Build an array that points to the beginning of each argument.
+; Send, to main(), that array and the count of the arguments.
 
+; Command-lines look like these lines:
+;
+; run
+; run : rem  no arguments because no comma!
+; run:rem,arg1," arg 2" , arg 3 ,, arg5, ...
+;
+; "run" and "rem" are entokenned; the args. are not.  Leading spaces are
+; ignored; trailing spaces are included -- unless the argument was quoted.
+
+; TO-DO:
+; - The "file-name" might be a path-name; don't copy the directory-components.
+; - Add a control-character quoting mechanism.
 
 	.constructor	initmainargs, 24
 	.import		__argc, __argv
 
 	.include	"c64.inc"
 
-;---------------------------------------------------------------------------
+; Maximum number of arguments allowed in the argument table.
-; Setup arguments for main
+; (An argument contains a comma, at least.)
+;
+MAXARGS	 = BASIC_BUF_LEN - 2	; (don't count REM and terminating '\0')
 
-.proc   initmainargs
+REM	 = $8f			; BASIC token-code
+NAME_LEN = 16			; maximum length of command-name
 
-; Setup a pointer to our argv vector
+; Get possible command-line arguments.
-
+;
-        lda     #<argv
+initmainargs:
-        sta     __argv
-        lda     #>argv
-        sta     __argv+1
-
-; Save the last filename as argument #0. Since the buffer we're copying into
-; is zeroed out, we don't need to add a NUL character.
 
+; Assume that the program was loaded, a moment ago, by the traditional LOAD
+; statement.  Save the "most-recent filename" as argument #0.
+; Because the buffer, that we're copying into, was zeroed out,
+; we don't need to add a NUL character.
+;
 	ldy	FNAM_LEN
-        cpy     #16+1
+	cpy	#NAME_LEN + 1
-        bcc     L0
+	bcc	L1
-        ldy     #16             ; Limit the length
+	ldy	#NAME_LEN - 1	; limit the length
-L0:     dey
+L0:	lda	(FNAM),y
-L1:     lda     (FNAM),y
+	sta	name,y
-        sta     argv0,y
+L1:	dey
-        dey
+	bpl	L0
-        bpl     L1
+	lda	#<name
-        inc     __argc          ; __argc = 1
+	ldx	#>name
+	sta	argv
+	stx	argv + 1
+	inc	__argc		; argc always is equal to, at least, 1
 
-; Find argument in BASIC buffer, if found, use it as arg #1
+; Find the "rem" token.
-
+;
-        ldy     #0
+	ldx	#0
-L2:     lda     $200,y
+L2:	lda	BASIC_BUF,x
-        beq     L9
+	beq	done		; no "rem," no args.
-        iny
+	inx
-        cmp     #$8F            ; REM token
+	cmp	#REM
 	bne	L2
-        sty     argv+2          ; Store offset
+	ldy	#1 * 2
-        ldy     #>$200
-        sty     argv+3
-        inc     __argc          ; argc = 2
 
-; Done
+; Find the next argument.
+;
+next:	lda	BASIC_BUF,x
+	beq	done
+	inx
+	cmp	#','		; look for argument-list separator
+	bne	next
+	lda	#$00
+	sta	BASIC_BUF-1,x	; make the previous arg. be a legal C string
+	inc	__argc		; found another arg.
 
-L9:     rts
+L4:	lda	BASIC_BUF,x
+	beq	point		; zero-length argument
+	inx
+	cmp	#' '
+	beq	L4		; skip leading spaces
 
-.endproc
+	cmp	#'"'		; is argument quoted?
+	beq	L5
+	dex			; no, don't skip over character
+	clc			; (quotation-mark sets flag)
+L5:	ror	quoted		; save it
 
+; BASIC's input-buffer starts at the beginning of a RAM page.
+; So, we don't need to add the offset -- just store it.
+;
+point:	txa
+	sta	argv,y		; argv[y]= &arg
+	iny
+	lda	#>BASIC_BUF
+	sta	argv,y
+	iny
 
-;---------------------------------------------------------------------------
+	asl	quoted		; is argument a string-literal?
-; Data
+	bcc	next		; no, don't look for ending quotation-mark
+L7:	lda	BASIC_BUF,x
+	beq	done
+	inx
+	cmp	#'"'
+	bne	L7
+	lda	#$00
+	sta	BASIC_BUF-1,x	; make this arg. be a legal C string
+	beq	next		;(bra)
 
-.data
+; (The last vector in argv[] already is NULL.)
-
+;
-argv:   .word   argv0           ; Pointer to program name
+done:	lda	#<argv
-        .word   $0000           ; Optional second argument
+	ldx	#>argv
-        .word   $0000           ; Last vector must always be NULL
+	sta	__argv
+	stx	__argv + 1
+	rts
 
+; These arrays are zeroed before initmainargs is called.
+; char	name[16+1];
+; char* argv[MAXARGS+1]={name};
+;
 	.bss
-argv0:  .res    17              ; Program name
+quoted:	.res	1, %00000000
-
+name:	.res	NAME_LEN + 1
-
+argv:	.res	(MAXARGS + 1) * 2