+; mainargs.s
;
; Ullrich von Bassewitz, 2003-03-07
+; Based on code from Stefan A. Haubenthal, <polluks@web.de>
+; 2003-05-18, Greg King
+; 2004-04-28, Ullrich von Bassewitz
;
-; Setup arguments for main
+; 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
+; run:rem arg1 " arg 2 is quoted " arg3 "" arg5
+;
+; "run" and "rem" are entokenned; the args. are not. Leading and trailing
+; spaces outside of quotes are ignored.
+;
+; 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 "vic20.inc"
+
- .constructor initmainargs, 24
- .import __argc, __argv
+MAXARGS = 10 ; Maximum number of arguments allowed
+REM = $8f ; BASIC token-code
+NAME_LEN = 16 ; maximum length of command-name
+
+; Get possible command-line arguments.
+;
+initmainargs:
+
+; 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 #NAME_LEN + 1
+ bcc L1
+ ldy #NAME_LEN - 1 ; limit the length
+L0: lda (FNAM),y
+ sta name,y
+L1: dey
+ bpl L0
+ inc __argc ; argc always is equal to, at least, 1
+
+; Find the "rem" token.
+;
+ ldx #0
+L2: lda BASIC_BUF,x
+ beq done ; no "rem," no args.
+ inx
+ cmp #REM
+ bne L2
+ ldy #1 * 2
+; Find the next argument
-;---------------------------------------------------------------------------
-; Setup arguments for main
+next: lda BASIC_BUF,x
+ beq done ; End of line reached
+ inx
+ cmp #' ' ; Skip leading spaces
+ beq next ;
-.proc initmainargs
+; Found start of next argument. We've incremented the pointer in X already, so
+; it points to the second character of the argument. This is useful since we
+; will check now for a quoted argument, in which case we will have to skip this
+; first character.
- rts
+found: cmp #'"' ; Is the argument quoted?
+ beq setterm ; Jump if so
+ dex ; Reset pointer to first argument character
+ lda #' ' ; A space ends the argument
+setterm:sta term ; Set end of argument marker
-.endproc
+; Now store a pointer to the argument into the next slot. Since the BASIC
+; input buffer is located at the start of a RAM page, no calculations are
+; necessary.
+
+ txa ; Get low byte
+ sta argv,y ; argv[y]= &arg
+ iny
+ lda #>BASIC_BUF
+ sta argv,y
+ iny
+ inc __argc ; Found another arg
+
+; Search for the end of the argument
+
+argloop:lda BASIC_BUF,x
+ beq done
+ inx
+ cmp term
+ bne argloop
+
+; We've found the end of the argument. X points one character behind it, and
+; A contains the terminating character. To make the argument a valid C string,
+; replace the terminating character by a zero.
+
+ lda #0
+ sta BASIC_BUF-1,x
+
+; Check if the maximum number of command line arguments is reached. If not,
+; parse the next one.
+
+ lda __argc ; Get low byte of argument count
+ cmp #MAXARGS ; Maximum number of arguments reached?
+ bcc next ; Parse next one if not
+
+; (The last vector in argv[] already is NULL.)
+
+done: lda #<argv
+ ldx #>argv
+ sta __argv
+ stx __argv + 1
+ rts
+
+; These arrays are zeroed before initmainargs is called.
+; char name[16+1];
+; char* argv[MAXARGS+1]={name};
+;
+.bss
+term: .res 1
+name: .res NAME_LEN + 1
+.data
+argv: .addr name
+ .res MAXARGS * 2
; ---------------------------------------------------------------------------
; Zero page, Commodore stuff
-ST = $90 ; IEC status byte
-
-TIME = $A0 ; 60HZ clock
-FNAM_LEN = $B7 ; Length of filename
-SECADR = $B9 ; Secondary address
-DEVNUM = $BA ; Device number
-KEY_COUNT = $C6 ; Number of keys in input buffer
-RVS = $C7 ; Reverse flag
-CURS_FLAG = $CC ; 1 = cursor off
-CURS_BLINK = $CD ; Blink counter
-CURS_CHAR = $CE ; Character under the cursor
-CURS_STATE = $CF ; Cursor blink state
-SCREEN_PTR = $D1 ; Pointer to current char in text screen
-CURS_X = $D3 ; Cursor column
-CURS_Y = $D6 ; Cursor row
-CRAM_PTR = $F3 ; Pointer to current char in color RAM
-
-CHARCOLOR = $286
-CURS_COLOR = $287 ; Color under the cursor
-PALFLAG = $2A6 ; $01 = PAL, $00 = NTSC
+ST := $90 ; IEC status byte
+
+TIME := $A0 ; 60HZ clock
+FNAM_LEN := $B7 ; Length of filename
+SECADR := $B9 ; Secondary address
+DEVNUM := $BA ; Device number
+FNAM := $BB ; Pointer to filename
+KEY_COUNT := $C6 ; Number of keys in input buffer
+RVS := $C7 ; Reverse flag
+CURS_FLAG := $CC ; 1 = cursor off
+CURS_BLINK := $CD ; Blink counter
+CURS_CHAR := $CE ; Character under the cursor
+CURS_STATE := $CF ; Cursor blink state
+SCREEN_PTR := $D1 ; Pointer to current char in text screen
+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
; ---------------------------------------------------------------------------
; Screen size
XSIZE = 22
-YSIZE = 23
+YSIZE = 23
; ---------------------------------------------------------------------------
; Kernal routines
; Direct entries
-CLRSCR = $E55F
-KBDREAD = $E5CF
+CLRSCR := $E55F
+KBDREAD := $E5CF
; ---------------------------------------------------------------------------
; Vector and other locations
-IRQVec = $0314
-BRKVec = $0316
-NMIVec = $0318
+IRQVec := $0314
+BRKVec := $0316
+NMIVec := $0318
; ---------------------------------------------------------------------------
; I/O: 6560 VIC
-VIC = $9000
-VIC_LINES = $9003 ; Screen lines, bit 7 is bit 0 from VIC_HLINE
-VIC_HLINE = $9004 ; Rasterline, bits 1-8
-VIC_COLOR = $900F ; Border and background color
+VIC := $9000
+VIC_LINES := $9003 ; Screen lines, bit 7 is bit 0 from VIC_HLINE
+VIC_HLINE := $9004 ; Rasterline, bits 1-8
+VIC_COLOR := $900F ; Border and background color
; ---------------------------------------------------------------------------
; I/O: 6522 VIA1
-VIA1 = $9110
-VIA1_JOY = $9111
-VIA1_DDRB = $9112
-VIA1_DDRA = $9113
+VIA1 := $9110
+VIA1_JOY := $9111
+VIA1_DDRB := $9112
+VIA1_DDRA := $9113
; ---------------------------------------------------------------------------
; I/O: 6522 VIA2
-VIA2 = $9120
-VIA2_JOY = $9120
-VIA2_DDRB = $9122
-VIA2_DDRA = $9123
+VIA2 := $9120
+VIA2_JOY := $9120
+VIA2_DDRB := $9122
+VIA2_DDRA := $9123
projects / cc65 / commitdiff