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Improved mainargs code from Stefan Haubenthal

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git-svn-id: svn://svn.cc65.org/cc65/trunk@3366 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2005-01-11 07:02:43 +00:00
parent d63dc84262
commit bd2185c57b
2 changed files with 64 additions and 52 deletions
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12
doc/apple2.sgml
View File

@ -214,15 +214,17 @@ Command line arguments can be passed to <tt/main()/. Since this is not
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>

104
libsrc/apple2/mainargs.s
View File

@ -3,6 +3,7 @@
; 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.
@ -11,11 +12,11 @@
; 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.
@ -33,8 +34,9 @@ BASIC_BUF = $200
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
@ -55,68 +57,73 @@ 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 #$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.
cmp #' ' ; Skip leading spaces
beq next ;
L4: lda BASIC_BUF,x
beq point ; zero-length argument
inx
cmp #' '
beq L4 ; skip leading spaces
; 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 argument quoted?
beq L5
dex ; no, don't skip over character
clc ; (quotation-mark sets flag)
L5: ror quoted ; save it
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
; 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
; 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
asl quoted ; is argument a string-literal?
bcc next ; no, don't look for ending quotation-mark
L7: lda BASIC_BUF,x
; Search for the end of the argument
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
@ -124,10 +131,13 @@ done: lda #<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