Microsoft Programmer's Library 1.3

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Assembly Source File | 1989-11-20 | 14.9 KB | 679 lines

; Created by Microsoft Corp. 1986 name cpgrepsub retlen equ 2 ; Size of return address on stack dgroup group _data extrn _casesen: word ; Case-sensitivity flag extrn _stringlist: word ; Table of string lists extrn _target: byte ; Target string extrn _targetlen: word ; Length of target string extrn _transtab: byte ; Translation table for _findlist ; This segment is puposely word-aligned. See note ; in _findlist below. _text segment word public 'code' assume cs:_text, ds:dgroup, es:nothing, ss:dgroup ; char *findone(buffer,bufend) ; char *buffer /* Buffer in which to search */ ; char *bufend; /* End of buffer */ ; ; NOTE: targetlen MUST BE greater than zero buffer equ word ptr [bp+retlen+2] bufend equ word ptr [bp+retlen+4] EVEN public _findone _findone proc near push bp mov bp,sp push di push si push es push ds ; ES = DS pop es mov cx,bufend ; CX = end of buffer mov di,buffer ; ES:DI = buffer sub cx,di ; CX = length of buffer jbe sfnomatch ; length less than or equal to zero mov dx,_targetlen ; DX = length of target dec dx ; Decrement it sub cx,dx ; target must fit in buffer jbe sfnomatch ; (no match if buffer too short) ; CX = buffer length ; DX = target length (minus first character) ; ES:DI = buffer pointer sf0: jcxz sfnomatch ; No match if count zero mov si,offset dgroup:_target ; DS:SI = target lodsb ; AL = first byte of target repne scasb ; Look for first character jne sfnomatch ; jump if not found mov bx,cx ; BX = buffer length mov ax,di ; AX = buffer pointer mov cx,dx ; Get count for cmpsb or cx,cx ; Zero? (JCXZ doesn't set flag) je sf1 ; yes, skip compare repe cmpsb ; Do string compare sf1: mov di,ax ; DI = buffer pointer mov cx,bx ; CX = buffer length jne sf0 ; Loop if no match dec ax ; AX = offset of start of match jmp short sf4 sfnomatch: xor ax,ax ; No match sf4: pop es pop si pop di pop bp ret _findone endp ; int revfind(s,c,slen) ; char *s; /* String to search */ ; int c; /* Char to search for */ ; int slen; /* Length of s */ s equ [bp+retlen+2] c equ [bp+retlen+4] slen equ [bp+retlen+6] EVEN public _revfind _revfind proc near push bp mov bp,sp push di push es push ds pop es mov di,s mov ax,c mov cx,slen jcxz rf1 std repne scasb cld mov cx,s jne rf0 inc di rf0: sub cx,di rf1: mov ax,cx pop es pop di pop bp ret _revfind endp ; int countlines(start,finish) ; char *start; ; char *finish; start equ [bp+retlen+2] finish equ [bp+retlen+4] EVEN public _countlines _countlines proc near push bp mov bp,sp push di push es push ds pop es xor dx,dx ; Accumulate count in DX mov di,start ; ES:DI points to start mov cx,finish ; Put length in CX sub cx,di jbe cl1 ; branch if no bytes mov al,0Ah ; Search for linefeeds cl0: jcxz cl1 ; Exit loop if count zero repne scasb ; Do search jne cl1 ; branch if none found inc dx ; Increment count jmp short cl0 ; Loop cl1: mov ax,dx ; Return line count in AX pop es pop di pop bp ret _countlines endp ; char *findlist(buffer,bufend) ; char *buffer; /* Buffer to search */ ; char *bufend; /* End of buffer */ savesi equ word ptr [bp-2] endbyte equ byte ptr [bp-4] stringnode struc s_alt dw ? ; List of alternate portions s_suf dw ? ; Pointer to suffix string list s_must dw ? ; Length of portion that must match stringnode ends EVEN flworker dw findsubi, findsub ; Worker dispatch table public _findlist _findlist proc near ASSUME DS:DGROUP, ES:NOTHING, SS:DGROUP push bp mov bp,sp sub sp,4 ; Make room for local vars push di push si push ds pop es ASSUME ES:DGROUP ; We mark the end of our search buffer with 0FFh so that ; any comparisons that might run past the end of the buffer ; will fail on the 0FFh. We choose 0FFh so that if the ; comparison fails on it, it will always appear as though ; the string in the buffer is greater that the string in ; the search list. This will prevent us from stopping ; the search too soon. Of course, we must restore the byte ; when we're done. mov bx,bufend ; BX = end of buffer mov al,0FFh ; End marker xchg byte ptr [bx],al ; AL = byte after end of buffer mov endbyte,al ; Save the byte mov cx,bx ; CX = end of buffer mov si,buffer ; SI = buffer sub cx,si ; CX = buffer length jbe fl1 ; no match if empty buffer mov bx,offset dgroup:_transtab ; BX = translation table address mov di,_casesen ; Get flag shl di,1 ; Scale to word index call cs:flworker[di] ; Call helper jc fl1 ; branch if no match ; We have a match ; ; SI = offset of first character past end of matched string ; savesi = offset of first character past start of matched string mov ax,savesi ; AX = 1st char past start dec ax ; AX = start of matched string jmp short fl2 ; We did not find a match fl1: xor ax,ax ; Return NULL ; Restore end byte before leaving fl2: mov bx,bufend ; BX = end of buffer mov dl,endbyte ; DL = end byte mov [bx],dl ; Restore byte pop si pop di mov sp,bp pop bp ret _findlist endp ;*** findsub - case-sensitive worker for _findlist ; ; This function does most of the work for ; case-sensitive multi-string searches. ; ; ENTRY BX = address of translation table ; CX = number of bytes left in buffer ; DS:SI = buffer pointer ; SS:BP = pointer to stack frame for _findlist ; EXIT Carry set ; No match ; Carry clear ; DS:SI = pointer to first character after match ; USES AX, CX, DX, DI, SI, Flags EVEN public findsub, fs0, fs1, fs2, fs3, fs4, fs5, fs6 findsub proc near ASSUME DS:DGROUP, ES:DGROUP, SS:DGROUP fs0: xor ax,ax ; AH = 0 ; AH = 0 ; BX = address of translation table ; CX = number of bytes left in buffer ; SI = buffer pointer ; DS = ES = SS = DGROUP fs1: lodsb ; Character in AL xlat byte ptr [bx] ; Translate character to index or al,al ; Zero means invalid 1st byte loopz fs1 ; if so, try next character ; Either the zero bit is set, meaning the buffer is empty, ; or the zero bit is clear, meaning we have a valid first ; character. Either way, CX has been decremented. jz fs6 ; branch if buffer empty mov savesi,si ; Save buffer pointer shl ax,1 ; Scale to word index mov di,ax mov di,_stringlist[di] ; DI points to string record or di,di ; One byte match? (OR clears carry) jz fs3 ; yes, skip ahead ; Loop to search for match. ; BX = address of translation table ; DI = pointer to string record ; SI = pointer into buffer fs2: mov cx,[di].s_must ; CX = length of string sub di,cx ; DI = pointer to string mov dx,si ; Save pointer to start of suffix repe cmpsb ; Strings match? ja fs4 ; no, try alternate if follows jb fs5 ; no, cannot be in this list add di,cx ; DI = pointer to string record mov di,[di].s_suf ; Get pointer to suffix string list or di,di ; Is there one? (OR clears carry) jnz fs2 ; yes, keep looking ; Match found fs3: ret ; no, we have a match ; Try alternate suffix fs4: add di,cx ; DI = pointer to string record mov di,[di].s_alt ; Get pointer to alternate mov si,dx ; Restore SI to start of suffix or di,di ; Is there one? jnz fs2 ; yes, loop ; Try new first character fs5: mov cx,bufend ; CX = end of buffer mov si,savesi ; Restore SI to saved value sub cx,si ; CX = length of buffer ja short fs0 ; Try next character in buffer ; No match fs6: stc ; No match ret findsub endp ;*** findsubi - case-insensitive worker for _findlist ; ; This function does most of the work for ; case-insensitive multi-string searches. ; ; ENTRY BX = address of translation table ; CX = number of bytes left in buffer ; DS:SI = buffer pointer ; SS:BP = pointer to stack frame for _findlist ; EXIT Carry set ; No match ; Carry clear ; DS:SI = pointer to first character after match ; USES AX, CX, DX, DI, SI, Flags EVEN public findsubi findsubi proc near ASSUME DS:DGROUP, ES:DGROUP, SS:DGROUP fsi0: xor ax,ax ; AH = 0 ; AH = 0 ; BX = address of translation table ; CX = number of bytes left in buffer ; SI = buffer pointer ; DS = ES = SS = DGROUP fsi1: lodsb ; Character in AL xlat byte ptr [bx] ; Translate character to index or al,al ; Zero means invalid 1st byte loopz fsi1 ; if so, try next character ; Either the zero bit is set, meaning the buffer is empty, ; or the zero bit is clear, meaning we have a valid first ; character. Either way, CX has been decremented. jz fsi7 ; branch if buffer empty mov savesi,si ; Save buffer pointer shl ax,1 ; Scale to word index mov di,ax mov di,_stringlist[di] ; DI points to string record or di,di ; One byte match? (OR clears carry) jz fsi4 ; yes, skip ahead ; Loop to search for match. ; BX = address of translation table ; DI = pointer to string record ; SI = pointer into buffer fsi2: mov cx,[di].s_must ; CX = length of string sub di,cx ; DI = pointer to string mov dx,si ; Save pointer to start of suffix fsi3: lodsb ; Byte in AL, SI = SI + 1 mov ah,[di] ; Byte in AH, DI = DI + 1 inc di or ax,2020h ; Fold bytes onto lower case cmp al,ah ; Compare bytes loope fsi3 ; Loop while same ja fsi5 ; no, try alternate if follows jb fsi6 ; no, cannot be in this list add di,cx ; DI = pointer to string record mov di,[di].s_suf ; Get pointer to suffix string list or di,di ; Is there one? (OR clears carry) jnz fsi2 ; yes, keep looking ; Match found fsi4: ret ; no, we have a match ; Try alternate suffix fsi5: add di,cx ; DI = pointer to string record mov di,[di].s_alt ; Get pointer to alternate mov si,dx ; Restore SI to start of suffix or di,di ; Is there one? jnz fsi2 ; yes, loop ; Try new first character fsi6: mov cx,bufend ; CX = end of buffer mov si,savesi ; Restore SI to saved value sub cx,si ; CX = length of buffer ja short fsi0 ; Try next character in buffer ; No match fsi7: stc ; No match ret findsubi endp ; int strnspn(s,t,n) ; char *s; /* String to search */ ; char *t; /* Target list */ ; int n; /* Length of s */ s equ word ptr [bp+retlen+2] t equ word ptr [bp+retlen+4] n equ word ptr [bp+retlen+6] EVEN public _strnspn _strnspn proc near push bp mov bp,sp push di push si push ds pop es cld mov bx,t ; BX = t mov di,bx ; DI = t xor al,al ; Search for 0 byte mov cx,0FFFFh repne scasb dec di ; Back up to 0 sub di,bx ; DI = length of t jz spn1 ; Done if length of t is 0 mov dx,di ; DX = length of t mov si,s ; SI = s mov cx,n ; CX = length of s jcxz spn1 ; Check for null string push bp spn0: lodsb ; AL = next char in s mov bp,cx ; BP = length of s mov cx,dx ; CX = length of t mov di,bx ; DI = t repne scasb ; Scan until match found mov cx,bp ; CX = length of s loope spn0 ; Loop if match found pop bp je spn1 ; Skip ahead if end of s reached dec si ; Back up one char spn1: sub si,s ; SI = length of prefix mov ax,si ; AX = length of prefix pop si pop di pop bp ret _strnspn endp ; int strncspn(s,t,n) ; char *s; /* String to search */ ; char *t; /* Target list */ ; int n; /* Length of s */ EVEN public _strncspn _strncspn proc near push bp mov bp,sp push di push si push ds pop es cld mov bx,t ; BX = t mov di,bx ; DI = t xor al,al ; Search for 0 byte mov cx,0FFFFh repne scasb dec di ; Back up to 0 sub di,bx ; DI = length of t mov ax,n ; Assume length of t is 0 jz cspn2 ; Done if length of t is 0 mov dx,di ; DX = length of t mov si,s ; SI = s mov cx,ax ; CX = length of s jcxz cspn1 ; Check for null string push bp cspn0: lodsb ; AL = next char in s mov bp,cx ; BP = length of s mov cx,dx ; CX = length of t mov di,bx ; DI = t repne scasb ; Scan until match found mov cx,bp ; CX = length of s loopne cspn0 ; Loop if match not found pop bp jne cspn1 ; Skip ahead if end of s reached dec si ; Back up one char cspn1: sub si,s ; SI = length of prefix mov ax,si ; AX = length of prefix cspn2: pop si pop di pop bp ret _strncspn endp ; cmpsen - case-sensitive comparison ; ; ENTRY DS:SI = buffer ; ES:DI = string ; CX = length of string ; EXIT CX = length of string unused ; DI = unused portion of string ; Z set ; match found ; Z clear ; no match ; USES CX, DI, SI, Flags EVEN cmpsen proc near repe cmpsb ret cmpsen endp ; cmpinsen - case-insensitive comparison ; ; ENTRY DS:SI = buffer ; ES:DI = string ; CX = length of string ; EXIT CX = length of string unused ; DI = unused portion of string ; Z set ; match found ; Z clear ; no match ; USES AX, CX, DI, SI, Flags EVEN cmpinsen proc near cmpi0: lodsb ; Byte in AL, SI = SI + 1 mov ah,[di] ; Byte in AH, DI = DI + 1 inc di or ax,2020h ; Fold bytes onto lower case cmp al,ah ; Compare bytes loope cmpi0 ; Loop while same ret cmpinsen endp ; void matchstrings(s1,s2,len,nmatched,leg) ; char *s1; /* First string */ ; char *s2; /* Second string */ ; int len; /* Length */ ; int *nmatched; /* Number of bytes matched */ ; int *leg; /* Less than, equal, greater than */ cm_s1 equ word ptr [bp+retlen+2] cm_s2 equ word ptr [bp+retlen+4] cm_len equ word ptr [bp+retlen+6] cm_nmatched equ word ptr [bp+retlen+8] cm_leg equ word ptr [bp+retlen+10] EVEN public _matchstrings _matchstrings proc near ASSUME DS:DGROUP, ES:NOTHING, SS:DGROUP push bp mov bp,sp push di push si push ds pop es ASSUME ES:DGROUP mov di,cm_s2 mov si,cm_s1 mov cx,cm_len cmp _casesen,0 je cm0 call cmpsen jmp short cm1 cm0: call cmpinsen cm1: mov bx,cm_leg mov word ptr [bx],0 ; Assume equal jz cm2 ; yes, skip ahead mov word ptr [bx],1 ; Assume greater than jg cm1a ; yes, skip ahead mov word ptr [bx],-1 ; Less than cm1a: dec si cm2: sub si,cm_s1 mov bx,cm_nmatched mov [bx],si pop si pop di pop bp ret _matchstrings endp ; int strcmp(s1,s2) ; char *s1; /* First string */ ; char *s2; /* Second string */ public _strcmp _strcmp proc near push bp mov bp,sp push di push si push ds pop es mov si,[bp+4] ; DS:SI = s1 mov di,[bp+6] ; ES:DI = s2 sc0: lodsb ; AL = *s1++ scasb ; AL - *s2++ jne sc1 ; branch if no match or al,al ; End of s1? jne sc0 ; no, loop cbw ; AX = 0 jmp short sc2 ; Exit sc1: mov ax,1 ; Assume s1 > s2 jg sc2 ; yes, branch neg ax ; s1 < s2 sc2: pop si pop di pop bp ret _strcmp endp public _bpt _bpt proc near int 3 ret _bpt endp _text ends _data segment word public 'data' _data ends end