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Assembly Source File  |  1994-10-27  |  2KB  |  111 lines
  1.     page    66,132
  2. ;******************************* COMPARF.ASM ********************************
  3.  
  4. LIBSEG           segment byte public "LIB"
  5.         assume cs:LIBSEG , ds:nothing
  6.  
  7. ;----------------------------------------------------------------------------
  8. .xlist
  9.     include  mac.inc
  10.     include  common.inc
  11.  
  12.     extrn    dos_mem_allocate:far
  13.     extrn    dos_mem_release:far
  14. .list
  15. comment 
  16. ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -( COMPARE )
  17. ;COMPARE_FILES - compares two files
  18. ;
  19. ; inputs:   DS:[SI] = address of file1 asciiz
  20. ;           DS:[DI] = address of file2 asciiz
  21. ; 
  22. ; output:  AX = 0 if successful compare
  23. ;* * * * * * * * * * * * * *
  24. 
  25.  
  26. file1_handle    dw    0
  27. file2_handle    dw    0
  28.  
  29. read_amount1    dw    0
  30.  
  31. file1_name    db    30 dup (0)
  32. file2_name    db    30 dup (0)
  33.  
  34. buffer_length    equ    4000h
  35. file1_buf    equ    0        ;
  36. file2_buf    equ    4000h        ;
  37.  
  38.     public    compare_files
  39. compare_files    proc    far
  40.    apush   bx,cx,dx,si,di,ds,es
  41.    mov       dx,0
  42.    mov     ax,8000h
  43.    call    dos_mem_allocate
  44.    
  45.    cld    
  46.    MOV     DX,si
  47.    MOV       AX,3D00h            ;open file
  48.    INT     21h
  49.    JB      error
  50.    mov       cs:file1_handle,ax
  51.  
  52.    mov       dx,di
  53.    MOV       AX,3D00h            ;open file
  54.    INT     21h
  55.    JB      error
  56.    mov       cs:file2_handle,ax
  57.  
  58.    push    es
  59.    pop     ds                ;point at buffers
  60.  
  61. cmp_loop:   
  62.    MOV       AH,3Fh            ;read file
  63.    MOV     BX,cs:file1_handle
  64.    mov       dx,file1_buf
  65.    mov       cx,buffer_length
  66.    int       21h
  67.    mov     cs:read_amount1,ax
  68.    OR      AX,AX
  69.    JZ      done_ok
  70.  
  71.    MOV       AH,3Fh            ;read file
  72.    MOV     BX,cs:file2_handle
  73.    mov       dx,file2_buf
  74.    mov       cx,buffer_length
  75.    INT     21h
  76.    cmp       cs:read_amount1,ax
  77.    jne     error            ;jmp if different length files
  78.    OR      AX,AX
  79.    JZ      done_ok
  80.  
  81.     mov    si,offset file1_buf
  82.     mov    di,offset file2_buf
  83.     mov    cx,ax
  84.     cld
  85.     rep    cmpsb
  86.     jne    error
  87.     jmp    cmp_loop
  88.     
  89. done_ok:
  90.     mov    ax,0
  91.     jmp    exit
  92. error:
  93.     mov    ax,1    
  94. exit:
  95.     push    ax            ;save error code (al)
  96.         MOV     BX,file1_handle
  97.         MOV    AH,3Eh            ;close file
  98.         INT     21h
  99.         MOV     BX,file2_handle
  100.         MOV    AH,3Eh            ;close file
  101.         INT     21h
  102.         call    dos_mem_release
  103.     pop    ax
  104.     apop    es,ds,di,si,dx,cx,bx
  105.     retf
  106. compare_files    ENDP
  107. ;------------------------------------------------------------------------
  108.  
  109. LIBSEG    ENDS
  110.     end
  111.