; Based on code from Stefan A. Haubenthal <polluks@web.de>, 2003-11-08
; Greg King, 2003-05-18
; Stefan Haubenthal, 2005-01-07
+; Oliver Schmidt, 2005-04-05
;
; Scan a group of arguments that are in BASIC's input-buffer.
; Build an array that points to the beginning of each argument.
; Command-lines look like these lines:
;
-; call2048
-; call2048 : rem
-; call2048:rem arg1 " arg 2 is quoted " arg3 "" arg5
+; call2051
+; call2051 : rem
+; call2051:rem arg1 " arg 2 is quoted " arg3 "" arg5
;
-; "call" and "rem" are entokenned; the args. are not. Leading and trailing
+; "call" 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.
+; Add a control-character quoting mechanism.
- .constructor initmainargs, 24
- .import __argc, __argv
+ .constructor initmainargs, 24
+ .import __argc, __argv, __dos_type
- .include "apple2.inc"
+ .include "zeropage.inc"
+ .include "apple2.inc"
; Maximum number of arguments allowed in the argument table.
; (An argument contains a comma, at least.)
-;
+
+MAXARGS = 10
+
+; ProDOS stores the filename in the second half of BASIC's input buffer, so
+; there are 128 characters left. At least 1 character is necessary for the
+; REM so 127 characters (including the terminating zero) may be used before
+; overwriting the ProDOS filename. As we don't want to further restrict the
+; command-line length we reserve those 127 characters.
+
+BUF_LEN = 127
+
BASIC_BUF = $200
-BASIC_BUF_LEN = 239
-FNAM_LEN = $280
-FNAM = $281
+FNAM_LEN = $280
+FNAM = $281
+REM = $B2 ; BASIC token-code
- .assert MAXARGS <= (BASIC_BUF_LEN - 2)/2, error, "Too many arguments"
-MAXARGS = 10 ; Maximum number of arguments allowed
-REM = $B2 ; BASIC token-code
-NAME_LEN = 15 ; maximum length of command-name
+; Get possible command-line arguments. Goes into the special INIT segment,
+; which may be reused after the startup code is run.
+
+ .segment "INIT"
-; 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
+; Assume that the program was loaded, a moment ago, by the traditional BLOAD
+; statement of BASIC.SYSTEM. Save the filename as argument #0 if available.
-; Find the "rem" token.
+ ldx __dos_type ; No ProDOS -> argv[0] = ""
+ beq :+
- ldx #0
-L2: lda BASIC_BUF,x
- beq done ; no "rem" no args.
- inx
- cmp #REM
- bne L2
- ldy #1 * 2
+; Terminate the filename with a zero to make it a valid C string.
-; Find the next argument.
+ ldx FNAM_LEN
+: lda #$00
+ sta FNAM,x
-next: lda BASIC_BUF,x
- beq done
- inx
- cmp #' ' ; Skip leading spaces
- beq next ;
+ inc __argc ; argc always is equal to, at least, 1
+
+; Find the "rem" token.
+
+ ldx #$00
+: lda BASIC_BUF,x
+ beq done ; No "rem" -> no args
+ inx
+ cmp #REM
+ bne :-
+
+; If a clock is present it is called by ProDOS on file operations. On machines
+; with a slot-based clock (like the Thunder Clock) the clock firmware places
+; the current date in BASIC's input buffer. Therefore we have to create a copy
+; of the command-line in a different buffer before the original is potentially
+; destroyed.
+
+ ldy #$00
+: lda BASIC_BUF,x
+ sta buffer,y
+ inx
+ iny
+ cpy #BUF_LEN - 1 ; Keep the terminating zero intact
+ bcc :-
+
+; Start processing the arguments.
+
+ ldx #$00
+ ldy #$01 * 2 ; Start with argv[1]
+
+; Find the next argument. Stop if the end of the string or a character with the
+; hibit set is reached. The later is true if the string isn't already parsed by
+; BASIC (as expected) but is a still unprocessed input string. In this case the
+; string isn't the expected command-line at all. We found this out the hard way
+; by BRUNing the program with ProDOS on a machine with a slot-based clock (like
+; the Thunder Clock). ProDOS called the clock firmware which places the current
+; date as BASIC input string with hibits set in the input buffer. While looking
+; for the REM token we stumbled across the first '2' character ($32+$80 = $B2)
+; and interpreted the rest of the date as a spurious command-line parameter.
+
+next: lda buffer,x
+ beq done
+ bmi done
+ inx
+ cmp #' ' ; Skip leading spaces
+ beq next
; 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.
-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
-
-; 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
+ cmp #'"' ; Is the argument quoted?
+ beq :+ ; Jump if so
+ dex ; Reset pointer to first argument character
+ lda #' ' ; A space ends the argument
+: sta tmp1 ; Set end of argument marker
+
+; Now store a pointer to the argument into the next slot.
+
+ txa ; Get low byte
+ clc
+ adc #<buffer
+ sta argv,y ; argv[y] = &arg
+ iny
+ lda #$00
+ adc #>buffer
+ sta argv,y
+ iny
+ inc __argc ; Found another arg
+
+; Search for the end of the argument.
+
+: lda buffer,x
+ beq done
+ inx
+ cmp tmp1
+ bne :-
; 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
+ lda #$00
+ sta buffer-1,x
-; Check if the maximum number of command line arguments is reached. If not,
+; 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
+ 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
+done: lda #<argv
+ ldx #>argv
+ sta __argv
+ stx __argv+1
+ rts
+
+; This array is zeroed before initmainargs is called.
+; char* argv[MAXARGS+1] = {FNAM};
+
+ .data
-; These arrays are zeroed before initmainargs is called.
-; char name[NAME_LEN+1];
-; char* argv[MAXARGS+1]={name};
+argv: .addr FNAM
+ .res MAXARGS * 2
-.bss
-term: .res 1
-name: .res NAME_LEN + 1
+ .bss
-.data
-argv: .addr name
- .res MAXARGS * 2
+buffer: .res BUF_LEN
projects / cc65 / blobdiff