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cc65/libsrc/apple2/mainargs.s
cuz cf49ca3d0a New mainargs module from Stefan Haubenthal
git-svn-id: svn://svn.cc65.org/cc65/trunk@2804 b7a2c559-68d2-44c3-8de9-860c34a00d81
2003-12-21 10:56:34 +00:00

134 lines
3.0 KiB
ArmAsm

; mainargs.s
;
; Ullrich von Bassewitz, 2003-03-07
; Based on code from Stefan A. Haubenthal <polluks@web.de>, 2003-11-08
; Greg King, 2003-05-18
;
; 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:
;
; call2048
; call2048 : rem no arguments because no comma!
; call2048:rem,arg1," arg 2" , arg 3 ,, arg5, ...
;
; "call" 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 "apple2.inc"
; Maximum number of arguments allowed in the argument table.
; (An argument contains a comma, at least.)
;
BASIC_BUF = $200
BASIC_BUF_LEN = 239
FNAM_LEN = $280
FNAM = $281
MAXARGS = BASIC_BUF_LEN - 2 ; (don't count REM and terminating '\0')
REM = $b2 ; BASIC token-code
NAME_LEN = 15 ; 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
lda #<name
ldx #>name
sta argv
stx argv + 1
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.
;
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 #'"' ; 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?
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)
; (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
quoted: .res 1, %00000000
name: .res NAME_LEN + 1
argv: .res (MAXARGS + 1) * 2