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Digital-Research-Source-Code/MPM OPERATING SYSTEMS/MPM-86/MPM-86 2.0 SOURCES/02/PARSE.SUP
Sepp J Morris 31738079c4 Upload
Digital Research
2020-11-06 18:50:37 +01:00

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;*****************************************************
;*
;* Parse Filename Function
;*
;*****************************************************
;=========== =========================
parse_entry: ; Parse filename into FCB
;=========== =========================
; input: DX -> PCB in u_wrkseg
; output: BX = 0ffffh on error
; = 0 on last name in string
; = offset of delimiter following name
; CX = Error Code
;
; PCB: +----+----+----+----+
; | NAMEADR | FCBADR |
; +----+----+----+----+
;
; NAMEADR = offset of String to parse
; FCBADR = offset of FCB in u_wrkseg
;
; Parsed FCB:
; 0 => drive, 0=default, 1=A, 2=B, ...
; 1- 8 => name, converted to upper case,
; padded w/blanks
; 9-11 => type, converted to upper case,
; padded w/blanks
; 12-15 => set to zero
; 16-23 => password, convered to upper case,
; padded w/blanks
; 24-25 => address of password field in 'filename',
; set to zero if password length=0
; 26 => length of password (0-8)
; 27-31 => left as is
mov ax,u_wrkseg
push ds ! mov ds,ax ;DS->u_wrkseg
push es ! mov es,ax ;ES->u_wrkseg for string ops
mov bx,dx ! mov si,pcb_flnmptr[bx] ;SI->nxt char in parse string
mov bx,pcb_fcbptr[bx] ;BX -> FCB
call fcbinit ! call deblank ;init FCB, deblank parse str
mov bp,e_badfname ;BAD FILENAME
;BP=error code if error
call delim ! jnz parse1 ;chk 1st char
jmp pfn_endp
parse1: mov ch,al ! inc si ! mov al,[si] ;see if Disk spec
cmp al,':' ! jne parse2
mov bp,e_illdisk ;drive specified
mov al,ch ! sub al,'A' ! jc pfn_err ;see if legal
cmp al,16 ! jge pfn_err
inc al ! mov fcb_dr[bx],al ;good drv, set fcb_dr field
mov bp,e_badfname
inc si ! call delim ! jnz parse3 ;check nxt char
cmp al,'.' ! je pfn_err ;hit delim
cmp al,':' ! je pfn_err ; see if legal
cmp al,';' ! je pfn_err
jmp parse3
parse2: dec si ;use default disk
parse3: ;parse filename
mov di,bx ! lea bx,fcb_name[di]
mov ch,8 ! call setfld ;fill in FCB
cmp ch,0 ! jne parse4
call delim ! jz parse4 ;see if more than 8 chars
pfn_err: mov cx,bp
mov bx,0ffffh ! pop es ! pop ds ! ret
parse4: cmp al,'.' ! jnz parse5 ;see if filetype
mov bp,e_badftype
mov ch,3 ! lea bx,fcb_type[di]
inc si ! call setfld ;fill in FCB
cmp ch,0 ! jne parse5
call delim ! jz parse5
jmp pfn_err
;parse passwd
parse5:
cmp al,';' ! jnz parse8 ;see if password delim
mov bp,e_ill_passwd
mov ch,8 ! lea bx,fcb_passwd[di]
inc si ! call setfld ;yes
mov cl,8 ! sub cl,ch
mov fcb_plen[di],cl
cmp ch,0 ! jne parse8
call delim ! jz parse8
jmp pfn_err
parse8: mov bx,si ! call deblank ;see if more to parse
call delim ! jnz pfn_out ;if yes,exit
mov bx,si
cmp al,0 ! je pfn_endp
cmp al,cr ! jne pfn_out
pfn_endp: mov bx,0 ;NOPE
pfn_out:sub cx,cx ! pop es ! pop ds ! ret ;exit
setfld: ; fill in a field until end of field or delim
;------
pop dx ! call delim ! push dx
jz setret
cmp al,'*' ! jnz setfld1
mov byte ptr [bx],'?'
inc bx ! dec ch ! jnz setfld
jmp setfld2
setfld1: mov [bx],al ! inc bx ! dec ch
setfld2: inc si ! cmp ch,0 ! jne setfld
setret: ret
delim: ; see if char is delim, if not UPPER it, err if illegal
;-----
; input: SI -> next char in parse string
; output: 'z' flag on if delimiter found
; character converted to UPPER if 'a'-'z'
; AL = converted char
mov cl,ndelims ! mov al,[si] ;See if Delimiter
push di ! mov di,offset delims ;look at delim string
delnxt: cmp cl,0 ! je no_del ;if end of delims,not delim
cmp cs:[di],al ! je delret ;if delim, ret w/ z set
dec cl ! inc di ! jmps delnxt ;try next delim
no_del: cmp al,' ' ! ja del_up ;not delim, check graphic
pop di ! pop bx ! mov cx,e_badfname ;not graphic, err
jmp pfn_err ;go directly out, bypass ret
del_up: cmp al,'a' ! jb delret ;if below 'a', no high bit,ret
cmp al,'z' ! ja del_noup ;if above 'z',
and al,05fh ;make 'a'-'z' UPPER CASE
del_noup: and al,07fh ;strip high bit
delret: pop di ! ret
delims db 0,tab,cr,'.:;=,/[]<> '
ndelims equ (offset $)-(offset delims)
deblank: ;strip leading blanks
;-------
; input: SI -> parse string
; output: SI -> first non-blank or tab char
cmp byte ptr [si],' ' ! je blnk
cmp byte ptr [si],tab ! je blnk
ret
blnk: inc si ! jmps deblank
fcbinit: ; Initialize FCB
;-------
mov di,bx ! sub ax,ax
sub cx,cx ! stosb ; 0 =0
mov al,' ' ! mov cl,11 ! rep stosb ; 1-11=' '
mov al,0 ! mov cl,2 ! rep stosw ;12-15=0
mov al,' ' ! mov cl,8 ! rep stosb ;16-23=' '
mov al,0 ! mov cl,3 ! rep stosb ;24-26=0
ret