mov	ax,ds
	mov	es,ax
;
;	find the end of the string
;
	xor	ax,ax
	mov	cx,-1
	repne scasb
	mov	si,di
	pop	es
	pop	di
	not	cx
	dec	cx
	jnz	has_fnp		; continue if there's more in the string
	add	sp,2
	stosb			; terminate path string
	jmp	check_fname	; exit if no path or filename
;
;	search from the end for slash/backslash
;
has_fnp:
	sub	si,2		; last char of string
	mov	bx,5c2fh	; the two slashes
	std			; backwards scan
;
spath:
	lodsb
	cmp	al,bl
	je	pfound
	cmp	al,bh
	je	pfound
	loop	spath
;
;	no slash/backslash -> no path given
;
	cld
	pop	si
	xor	cx,cx
	jmp	short cfname
;
longpath:
	mov	ax,ERR_PATHLEN
	jmp	error_exit
;
;	copy the path (note: CX has length of path including slash)
;
pfound:
	cld
	pop	si
	cmp	cx,MAXPATH
	ja	longpath
	or	flags,HAS_PATH		; we have a path
	ldes	di,path
	IFDEF	PASCAL
	inc	di
	ENDIF
	push	cx
	rep movsb
	pop	cx
;
;	check for special filenames '.' and '..', and add them to
;	the path if present.
;	The special form that adds a '.' for every level further down
;	the tree is recognized, and translated into the DOS-form '..\'
;
cfname:
	cmp	byte ptr [si],'.'
	jne	path_finished
	cmp	byte ptr [si+1],'.'
	je	is_special
	cmp	byte ptr [si+1],0
	jne	path_finished
;
is_special:
	or	flags,HAS_PATH		; we have a path
	mov	bx,MAXPATH
	sub	bx,cx
	mov	cx,2
	lodsb
;
copy_special:
	or	bx,bx
	jz	longpath
	dec	bx
	stosb
	lodsb
	or	al,al
	jz	special_finished
	cmp	al,'.'
	jne	badname
	loop	copy_special
;
add_special:
	sub	bx,3
	jle	longpath
	mov	al,'\'
	stosb
	mov	al,'.'
	stosb
	stosb
	lodsb
	or	al,al
	jz	special_finished
	cmp	al,'.'
	jne	badname
	jmp	add_special
;
badname:
	mov	ax,ERR_FNAME
	jmp	error_exit
;
special_finished:
	dec	si
	mov	al,'\'
	stosb
;
;	now copy the filename and extension (limited to 8/3 chars)
;
path_finished:
	xor	al,al			; terminate path
	stosb
;
	mov	bx,2a3fh		; the two wildcards '*' and '?'
	ldes	di,fname
	IFDEF	PASCAL
	inc	di
	ENDIF
	mov	cx,8			; max 8 for name
;
cfnloop:
	lodsb
	or	al,al			; end of string?
	jz	cfndot
	cmp	al,'.'
	je	cfndot
	jcxz	cfnloop			; skip if 8 chars copied
	stosb
	dec	cx
	or	flags,HAS_FNAME
	cmp	al,bl			; check for wildcards	
	je	fnwild
	cmp	al,bh
	jne	cfnloop
;
fnwild:
	or	flags,HAS_WILD
	jmp	cfnloop
;
cfndot:
	mov	ah,al			; save terminator (0 or '.')
	xor	al,al
	stosb				; terminate filename
	or	ah,ah
	jz	no_ext			; jump if at end of string
;
;	extension present, copy it.
;
	or	flags,HAS_EXT
	ldes	di,ext
	IFDEF	PASCAL
	inc	di
	ENDIF
	mov	cx,3
	mov	al,ah
	stosb				; store '.' as first ext char
;
cextloop:
	lodsb
	or	al,al
	jz	cextend
	stosb
	cmp	al,bl			; check for wildcards	
	je	extwild
	cmp	al,bh
	jne	cextcont
;
extwild:
	or	flags,HAS_WILD
;
cextcont:
	loop	cextloop
;
cextend:
	xor	al,al
	stosb				; terminate extension
;
;
no_ext:
	test	flags,HAS_PATH
	jz	check_fname
;
;	A path was specified, check it:
;	Change the current directory to the one specified. 
;	If valid, read back the new directory string 
;	(which has '.' and '..' resolved).
;	In any case, restore the current directory.
;
	ldes	di,fullpath	; make path string from drive and path
	IFDEF	PASCAL
	inc	di
	ENDIF
	ldds	si,drive
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
	ldds	si,path
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
	cmp	byte ptr es:[di-2],':'	; root dir ?
	je	no_slstrip		; then don't strip backslash
	mov	byte ptr es:[di-1],0	; else remove trailing '\'
;
no_slstrip:
	xor	cx,cx		; cx is 'path ok' flag (init to not ok)
	ldds	dx,fullpath
	IFDEF	PASCAL
	inc	dx
	ENDIF
	ldes	di,path
	IFDEF	PASCAL
	inc	di
	ENDIF
	mov	ah,3bh		; change current directory
	int	21h
	mov	ds,dseg
	jc	rest_path	; skip dir reading if invalid
	cmp	fail,0
	jne	rest_path
;
;	read back path
;
	ldds	si,path
	IFDEF	PASCAL
	inc	si
	ENDIF
	inc	si		; leave space for leading '\'
	mov	ah,47h		; get current directory
	mov	dx,drv		; drive number
	int	21h
	mov	ds,dseg
	jc	rest_path	; shouldn't happen, but...
	cmp	fail,0
	jne	rest_path
;
	mov	byte ptr es:[di],'\'	; prefix with '\'
	xor	ax,ax
	mov	cx,-1
	repne scasb			; find end of string
	not	cx
	cmp	cx,2
	je	rest_path		; don't append trailing '\' if root
	mov	byte ptr es:[di-1],'\'
	stosb				; terminate
;
rest_path:
	mov	dx,offset dfltpath
	mov	ah,3bh
	int	21h
;
;	was the path ok?
;
	or	cx,cx
	jnz	check_fname
;
;	exit if not
;
	mov	ax,ERR_PATH
	jmp	error_exit
;
;	the path was ok, now check the filename if it doesn't contain
;	wildcard chars.
;
check_fname:
	test	flags,HAS_WILD
	jz	checkfn1
	jmp	ready
;
checkfn1:
	ldesf	di,fullpath	; make full path string
	IFDEF	PASCAL
	inc	di
	ENDIF
	lddsf	si,drive
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
	ldds	si,path
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
	test	flags,HAS_FNAME OR HAS_EXT
	jnz	checkfn2
;
;	No filename, get the attribute of the directory
;
	or	flags,IS_DIR
	dec	di
	mov	byte ptr es:[di],0	; clear trailing '\'
	dec	di
	cmp	byte ptr es:[di],':'	; root dir?
	je	no_dirchk		; then don't get attribute
	ldds	dx,fullpath
	IFDEF	PASCAL
	inc	dx
	ENDIF
	mov	ax,4300h	; get attribute
	int	21h
	mov	ds,dseg
	jc	no_attrib	; shouldn't happen
	cmp	fail,0
	jne	no_attrib
	mov	ax,flags
	mov	ah,cl
	and	ah,7fh
	mov	flags,ax
no_dirchk:
	jmp	ready
;
no_attrib:
	mov	ax,ERR_PATH
	jmp	error_exit
;
checkfn2:
	ldds	si,fname
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
	ldds	si,ext
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
;
	mov	ah,2fh		; get current DTA
	int	21h		; ES:BX has current DTA
	push	bx
	push	es
;
	mov	ds,dseg
	mov	dx,offset dfltpath
	mov	ah,1ah		; set DTA
	int	21h
;
	ldds	dx,fullpath
	IFDEF	PASCAL
	inc	dx
	ENDIF
	mov	cx,10110B	; search all except label
	mov	ah,4eh		; search for first
	int	21h
	mov	ds,dseg
	jc	no_file
	cmp	fail,0
	jne	no_file
;
	mov	ax,flags
	mov	ah,dfltpath+15h	; file attributes into upper byte of flags
	test	ah,10h		; subdirectory?
	jz	no_subdir
;
;	The filename specifies a subdirectory. Append it to the path.
;
	test	inflags,INF_NODIR
	jnz	no_file
	ldesf	di,path
	IFDEF	PASCAL
	inc	di
	ENDIF
	mov	cx,-1
	xor	ax,ax
	repne scasb
	dec	di
	mov	si,offset dfltpath+1eh
	call	@strcpy
	mov	al,'\'
	stosb
	xor	al,al
	stosb
	ldes	di,fname
	IFDEF	PASCAL
	inc	di
	ENDIF
	stosb
	ldes	di,ext
	IFDEF	PASCAL
	inc	di
	ENDIF
	stosb
	mov	ax,flags
	mov	ah,dfltpath+15h	; file attributes into upper byte of flags
	and	ah,7fh		; make sure it's positive
	and	al,NOT (HAS_FNAME OR HAS_EXT)
	or	al,HAS_PATH
	mov	flags,ax
	jmp	short no_file
;
no_subdir:
	or	al,FILE_EXISTS
	and	ah,7fh		; make sure it's positive
	mov	flags,ax
;
no_file:
	pop	ds
	pop	dx
	mov	ah,1ah
	int	21h		; restore DTA
;
ready:
	ldesf	di,fullpath	; make full path string
	IFDEF	PASCAL
	inc	di
	ENDIF
	lddsf	si,drive
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
	ldds	si,path
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
	ldds	si,fname
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
	ldds	si,ext
	IFDEF	PASCAL
	inc	si
	ENDIF
	call	@strcpy
	mov	ds,dseg
	mov	ax,flags
;
error_exit:
	mov	ds,dseg
	cmp	fail,0
	je	nofail
	mov	ax,ERR_CRITICAL
;
nofail:
	push	ax
	cmp	ax,0
	jge	no_error
	ldesf	di,fullpath
	mov	word ptr es:[di],0
;
no_error:
	lds	dx,save24
	mov	ax,2524h
	int	21h
	IFDEF	PASCAL
	ldesf	di,drive
	call	@strlen
	ldes	di,path
	call	@strlen
	ldes	di,fname
	call	@strlen
	ldes	di,ext
	call	@strlen
	ldes	di,fullpath
	call	@strlen
	ENDIF
	pop	ax
;
	ret
;
checkpath endp
;
;
;e Returns TRUE if a file with name 'fname' exists.
;d Liefert TRUE wenn eine Datei mit dem Namen 'fname' existiert.
;
	IFDEF	PASCAL
	IFDEF	FARCALL
exists	PROC far uses ds, fname: dword
	ELSE
exists	PROC near uses ds, fname: dword
	ENDIF
	ELSE
exists	PROC	uses ds, fname: ptr byte
	ENDIF
;
	IFDEF	TC_HUGE
	mov	ax,SEG my_data
	mov	ds,ax
	ENDIF
;
	IFDEF	PASCAL
	ldds	si,fname
; for pascal, zero-terminate input string
	lodsb
	mov	bl,al
	xor	bh,bh
	mov	[si+bx],bh
	mov	dx,si
	ELSE
	ldds	dx,fname
	ENDIF
;
	mov	ax,4300h	; get file attributes
	int	21h
	mov	ax,0
	jc	exists_end
	test	cx,10h		; directory?
	jnz	exists_end
	inc	ax
;
exists_end:
	ret
;
exists	endp
;
	end