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cc65/libsrc/apple2/mainargs.s
cuz 1c5c974200 mainargs rewrite by Oliver Schmidt
git-svn-id: svn://svn.cc65.org/cc65/trunk@3453 b7a2c559-68d2-44c3-8de9-860c34a00d81
2005-04-05 21:11:10 +00:00

140 lines
3.6 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
; 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.
; Send, to main(), that array and the count of the arguments.
; Command-lines look like these lines:
;
; call2048
; call2048 : rem
; call2048:rem arg1 " arg 2 is quoted " arg3 "" arg5
;
; "call" and "rem" are entokenned; the args. are not. Leading and trailing
; spaces outside of quotes are ignored.
; TO-DO:
; Add a control-character quoting mechanism.
.constructor initmainargs, 24
.import __argc, __argv, __dos_type
.include "zeropage.inc"
.include "apple2.inc"
; Maximum number of arguments allowed in the argument table.
; (An argument contains a comma, at least.)
MAXARGS = 10
BASIC_BUF = $200
FNAM_LEN = $280
FNAM = $281
REM = $B2 ; BASIC token-code
; Get possible command-line arguments. Goes into the special INIT segment,
; which may be reused after the startup code is run
.segment "INIT"
initmainargs:
; Assume that the program was loaded, a moment ago, by the traditional BLOAD
; statement of BASIC.SYSTEM. Save the "most-recent filename" as argument #0.
ldx __dos_type ; No ProDOS -> argv[0] = ""
beq :+
; Terminate the filename with a zero to make it a valid C string.
ldx FNAM_LEN
: lda #$00
sta FNAM,x
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 :-
ldy #$01 * 2 ; Start with argv[1]
; Find the next argument.
next: lda BASIC_BUF,x
beq 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.
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 tmp1 ; 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 tmp1
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 #$00
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
; This array is zeroed before initmainargs is called.
; char* argv[MAXARGS+1] = {FNAM};
.data
argv: .addr FNAM
.res MAXARGS * 2