; smelly.asm By Michael Kohn
; April 7,1995

; EXPECTS:  es to point to the start of video page being searched
;           si should point to a string in memory ending in either a 0
;           or a chr$(13) (CR)
; RETURNS:  nothing.. just highlights selected text (if found) on screen

.model tiny 

.code

start:
  jmp Installation

wsear:
  inc si               ; a recursive routine that checks for two words
  add di, 2            ; being similar (wow! recursion :)
  mov bl, es:[di]
  mov bh, [si]
  cmp bh, 13
  je done
  cmp bh, 0
  je done
  cmp bl, bh
  jne skipy           ; if difference, then abort recursion and cl=0
  inc cl              ; counts how many similar letters
  call wsear
  jmp done
skipy:
  mov cl, 0
done:
  ret

right:
  push di
  push si
  lea si, nwerd
highl:
  mov bl, [si]
  cmp bl, 0
  je donep
  mov es:[di], bl
  add di, 2
  inc si
  jmp highl
donep:
  pop si
  pop di
  ret

search:
  mov di, 0
again:
  mov bl, es:[di]
  mov bh, [si]
  cmp bl, bh
  jne skip
  mov cl, 1
  push si
  push di
  call wsear    ; my RECURSIVE routine  
  pop di
  pop si
  cmp cl, 0
  jz skip
  call right    ; for lack of a better name :)
skip:
  add di, 2
  cmp di, 4000
  jne again 
  ret

oldInt8 label dword
     oldIP dw ?
     oldCS dw ?

werd db  "EXE",0
nwerd db "XXX",0

.286
myIntHandler:
  sti
  pusha
  push ds
  push es
   mov ax, cs
  mov ds, ax 
  mov ax, 0b800h
  mov es, ax
  lea si, werd
  call search
  pop es
  pop ds
  popa
  jmp cs:oldInt8

Installation:
  push cs
  pop ds
  mov ax,0
  mov es, ax
  mov bx, es:[4*8]
  mov ax, es:[4*8+2]
  mov oldIP, bx
  mov oldCS, ax
  mov es:[4*8+2], cs
  lea ax, myIntHandler
  mov es:[4*8], ax
  mov dx, 100h
  mov al, 0
  mov ah, 31h
  int 21h
  ; lea dx, Installation
  ; int 27h
  
end start