supported by BASIC, the following syntax was choosen:
<tscreen><verb>
- CALL2048:REM,ARG1," ARG2", ARG 3,, ARG5, ...
+]CALL2048:REM ARG1 " ARG2 IS QUOTED" ARG3 "" ARG5
</verb></tscreen>
<enum>
-<item>Arguments are separated by commas.
-<item>There must be a comma after the first <tt/REM/.
-<item>Leading spaces are ignored; trailing spaces are included unless the
- argument was quoted.
+<item>Arguments are separated by spaces.
+<item>Arguments may be quoted.
+<item>Leading and trailing spaces around an argument are ignored. Spaces within
+ a quoted argument are allowed.
<item>The first argument passed to <tt/main/ is the program name.
+<item>A maximum number of 10 arguments (including the program name) are
+ supported.
</enum>
; Ullrich von Bassewitz, 2003-03-07
; Based on code from Stefan A. Haubenthal <polluks@web.de>, 2003-11-08
; Greg King, 2003-05-18
+; Stefan Haubenthal, 2005-01-07
;
; 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 no arguments because no comma!
-; call2048:rem,arg1," arg 2" , arg 3 ,, arg5, ...
+; call2048 : rem
+; call2048:rem arg1 " arg 2 is quoted " arg3 "" arg5
;
-; "call" and "rem" are entokenned; the args. are not. Leading spaces are
-; ignored; trailing spaces are included -- unless the argument was quoted.
+; "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.
BASIC_BUF_LEN = 239
FNAM_LEN = $280
FNAM = $281
-MAXARGS = BASIC_BUF_LEN - 2 ; (don't count REM and terminating '\0')
+ .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
sta name,y
L1: dey
bpl L0
- lda #<name
- ldx #>name
- sta argv
- stx argv + 1
inc __argc ; argc always is equal to, at least, 1
; Find the "rem" token.
-;
- ldx #$00
+
+ ldx #0
L2: lda BASIC_BUF,x
- beq done ; no "rem," no args.
+ beq done ; no "rem" no args.
inx
cmp #REM
bne L2
- ldy #$01 * 2
+ ldy #1 * 2
; 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.
-
-L4: lda BASIC_BUF,x
- beq point ; zero-length argument
- inx
- cmp #' '
- beq L4 ; skip leading spaces
+ cmp #' ' ; Skip leading spaces
+ beq next ;
- cmp #'"' ; is argument quoted?
- beq L5
- dex ; no, don't skip over character
- clc ; (quotation-mark sets flag)
-L5: ror quoted ; save it
+; 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.
-; 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
+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
- asl quoted ; is argument a string-literal?
- bcc next ; no, don't look for ending quotation-mark
-L7: lda BASIC_BUF,x
+argloop: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)
+ 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
rts
; These arrays are zeroed before initmainargs is called.
-; char name[16+1];
+; char name[NAME_LEN+1];
; char* argv[MAXARGS+1]={name};
-;
- .bss
-quoted: .res 1, %00000000
+
+.bss
+term: .res 1
name: .res NAME_LEN + 1
-argv: .res (MAXARGS + 1) * 2
+
+.data
+argv: .addr name
+ .res MAXARGS * 2
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