汇编语言实现DOS下的文件目录清单（DIR）

  1 data segment
  2     org 80h
  3     psp     dw 0ffh dup(?)
  4     ddd     db ‘diretory:$‘
  5     head    db ‘name           size      type      date       time    ‘,0dh,0ah,24h
  6     space   db ‘        ‘,24h
  7     dir     db ‘xxx       <dir>   ‘,24h
  8     fn    db 200h dup(?)
  9     dta     db 128 dup(?)
 10     msg     db ‘press any key to continue...‘,0dh,0ah,24h
 11     newline db 0dh,0ah,24h
 12     count   db ?
 13     show    db 0
 14     base_10     dw      10
 15     used_32bits_high    dw      0
 16     used_32bits_low     dw      0
 17     var_32bits_high     dw      0
 18     var_32bits_low     dw      0
 19     quotidient_32bits_high      dw      0
 20     quotidient_32bits_low       dw      0
 21     negate_mask         equ      0FFFFh
 22     lowest_signed_32bits_high        dw     8000h
 23     lowest_signed_32bits_low         dw     0000h
 24     lowest_signed_32bits_string      db     ‘-2147483648$‘
 25     qhigh       dw      0
 26     rhigh       dw      0
 27     qlow        dw      0
 28     rlow        dw      0
 29     qhigh_redundant     dw      0
 30     rhigh_redundant     dw      0
 31     q_0         dw      0
 32     qhigh0      equ     0h
 33     rhigh0      equ     0h
 34     qhigh1      equ     1999h
 35     rhigh1      equ     6h
 36     qhigh2      equ     3333h
 37     rhigh2      equ     2h
 38     qhigh3      equ     4CCCh
 39     rhigh3      equ     8h
 40     qhigh4      equ     6666h
 41     rhigh4      equ     4h
 42     qhigh5      equ     8000h
 43     rhigh5      equ     0h
 44     qhigh6      equ     9999h
 45     rhigh6      equ     6h
 46     qhigh7      equ     0B333h
 47     rhigh7      equ     2h
 48     qhigh8      equ     0CCCCh
 49     rhigh8      equ     8h
 50     qhigh9      equ     0E666h
 51     rhigh9      equ     4h
 52     filenum     db      0
 53     dirnum      db      0
 54     filespace   db      ‘ File(s)    $‘
 55     dirspace    db      ‘ Dir(s)     $‘
 56     bytes       db      ‘ Bytes.‘,0dh,0ah,24h
 57     bytesfree   db      ‘ Bytes free.‘,0dh,0ah,24h
 58 data ends
 59 
 60 stack1  segment   stack
 61        dw  0ffh  dup(0)
 62 stack1  ends
 63 
 64 main    segment
 65         assume cs:main,ds:data,ss:stack1
 66         org 100h
 67 cmdln equ byte ptr es:[82h] ;command line data
 68 
 69 ;-------------------------------------------------------------------------------
 70 p1      proc near
 71         push ds
 72         mov ax,data
 73         mov ds,ax
 74         pop psp
 75         mov es,psp
 76         mov ax,stack1
 77         mov ss,ax
 78         mov cl,byte ptr es:[80h]
 79         cmp cl,0               ;command line?
 80         jne l4                 ;yes
 81 no_dir:
 82         mov ah,19h             ;no
 83         int 21h
 84         add al,‘a‘
 85         mov byte ptr[fn],al
 86         mov word ptr[fn+1],5c3ah
 87         mov ah,47h             ;current directory but no driver,so have to
 88         lea si,fn[3]           ;use 19h to add myself
 89         sub al,‘a‘
 90         mov dl,al
 91         int 21h
 92 
 93         lea di,fn[3]      ;to point di to the end of the diretory
 94 
 95 l7:
 96         mov al,[di]
 97         cmp al,0
 98         je l6
 99         inc di
100         jmp l7
101 
102 l4:
103         lea si,cmdln              
104         lea di,fn
105         cld
106         xor ch,ch
107         dec cl
108         ;rep movsb
109 
110         lea di,fn
111         lea bx,cmdln
112         lea bp,fn
113 
114 repeat:
115 
116         mov al,es:[bx]
117         mov ds:[bp],al
118         inc bx
119         inc bp
120         inc di
121         dec cl
122         jnz repeat
123 
124 l6:
125         mov cl,[di-1]                ;end by ‘\‘ ?
126         cmp cl,92                   ;92-->‘\‘
127         je l8                        ;yes
128         ;mov byte ptr[di],92         ;no
129         ;inc di
130 
131         cmp byte ptr[di-1],‘W‘
132         jne notW
133         mov al,1
134         mov [show],al
135 notW:
136         cmp byte ptr[di-1],92           ;‘\‘
137         je l8
138         dec di
139         jz no_dir
140         jmp notW
141 
142 l8:
143         mov word ptr[di],0a0dh       ;end by $ for printing
144         mov byte ptr[di+2],24h
145         mov ah,09h                   ;print "directory:*:\*\*\"
146         ;lea dx,ddd
147         mov dx,offset ddd
148         int 21h
149         mov ah,09h
150         lea dx,fn
151         int 21h
152         mov ah,09h
153         mov al,[show]
154         cmp al,1
155         je  w_head
156         lea dx,head
157         int 21h
158 w_head:
159         
160 
161         mov word ptr[di],2e2ah        ;add ‘*.* ‘ at the end
162         mov word ptr[di+2],002ah
163 
164 l5:
165         lea dx,dta
166         mov ah,1ah
167         int 21h
168         mov ah,4eh                   ;first fdt matched
169         mov cx,16h                   ;all file
170         lea dx,fn
171         int 21h
172         
173         call outp              ;print first file imformation
174         mov cl,1
175         mov count,cl
176         ;-------------
177         ;mov ah,4ch
178         ;int 21h 
179         ;-----------
180 l2:
181         mov ah,4fh                   ;next fdt
182         int 21h
183         jc l0                        ;end when no file any more
184 
185         call outp              ;print next file imformation
186         mov cl,count
187         inc cl
188         mov count,cl
189 
190         cmp cl,14h
191         ja pause
192 pause_end:
193         jmp l2
194 
195 pause:
196         mov dl,[show]
197         cmp dl,1
198         je pause_end
199         mov   ah,9h;move 9 into ah (9 is the interrupt for output)
200         lea   dx,msg;move the message into dx
201         int   21h  ;call dos function
202         mov   ah,7h;move 7 into ah (7 is the interrupt for input)
203         mov   dx,00h;get the actual input
204         int   21h  ;dos interrupt
205         mov cl,0
206         mov count,cl
207         jmp pause_end
208 
209 l0:     ;int 20h                       ;end
210         mov dl,[show]
211         cmp dl,0
212         je not_newline
213 
214         mov ah,2                     ;new line
215         mov dl,0dh
216         int 21h
217         mov ah,2
218         mov dl,0ah
219         int 21h
220 
221 not_newline:
222         lea dx,[space]
223         mov ah,09h
224         int 21h
225         mov al,[filenum]
226         xor ah,ah
227         mov [var_32bits_low],ax
228         xor al,al
229         mov [var_32bits_high],ax
230         call showspace
231 
232         lea dx,filespace
233         mov ah,09h
234         int 21h
235 
236         mov ax,[used_32bits_high]
237         mov [var_32bits_high],ax
238         mov ax,[used_32bits_low]
239         mov [var_32bits_low],ax
240         call showspace
241         lea dx,bytes
242         mov ah,09h
243         int 21h
244 
245 
246         lea dx,[space]
247         mov ah,09h
248         int 21h
249 
250         mov al,[dirnum]
251         xor ah,ah
252         mov [var_32bits_low],ax
253         xor al,al
254         mov [var_32bits_high],ax
255         call showspace
256 
257         lea dx,[dirspace]
258         mov ah,09h
259         int 21h
260         ;-----------------------get free space
261         mov dl,fn[0]
262 
263         sub dl,‘a‘
264         mov ah,36h
265         int 21h
266 
267         mul bx
268         mov bx,cx
269         xor cx,cx
270 
271         call mymul32
272 
273         mov var_32bits_high,cx
274         mov [var_32bits_low],bx
275         call showspace
276 
277         lea dx,bytesfree
278         mov ah,09h
279         int 21h
280 
281         mov ah,4ch
282         int 21h
283 
284 
285 p1      endp
286 
287 pspace proc near
288         push dx
289         push ax
290         mov dl, ‘ ‘
291         mov ah, 2h
292         int 21h
293         pop ax
294         pop dx
295 pspace endp
296 
297 printax proc near
298         cmp ax,0
299         je pret
300         push bx
301         push cx
302         push ax
303         push dx
304 
305         xor cx,cx
306         ;jmp lable1
307 b11:    xor dx,dx
308 lable1: mov si,10
309         div si
310 
311         push dx
312         inc cx
313         cmp ax,0
314         jne b11
315 
316 b22:     pop dx
317         add dl,30h
318         mov ah,2
319         int 21h
320         loop b22
321 
322         pop dx
323         pop ax
324         pop cx
325         pop bx
326 pret:        ret
327 printax endp
328 
329 printax_hex proc near
330         mov cx,4        ; print 4 hex digits (= 16 bits)
331 .print_digit:
332         rol ax,4   ; move the currently left-most digit into the least significant 4 bits
333         mov dl,al
334         and dl,0Fh  ; isolate the hex digit we want to print
335         add dl,‘0‘  ; and convert it into a character..
336         cmp dl,‘9‘  ; ...
337         jbe .ok     ; ...
338         add dl,7    ; ... (for ‘A‘..‘F‘)
339 .ok:            ; ...
340         push ax    ; save EAX on the stack temporarily
341         mov ah,2    ; INT 21H / AH=2: write character to stdout
342         int 21h
343         pop ax     ; restore EAX
344         loop .print_digit
345         ret
346 printax_hex endp
347 
348 ;----------------------------print the file imfomation--------------------
349 outp    proc near
350         push bx
351         push dx
352         push ax
353         push cx
354         mov cx,16
355         lea bx,dta[1eh]       ;print name
356 o0:
357         mov dl,[bx]
358         cmp dl,0
359         je o1
360         mov ah,2
361         int 21h
362         dec cx
363         inc bx
364         jmp o0
365 
366 
367 o1:
368         mov ah,02h            ;print space between name and size
369         mov dl,20h
370         int 21h
371         loop o1
372         call b2d              ;print size and dir type
373         ;----judge is W
374         mov dl,[show]
375         cmp dl,1
376         je w_file
377         call datm             ;print date and time
378 
379 
380         mov ah,2                     ;new line
381         mov dl,0dh
382         int 21h
383         mov ah,2
384         mov dl,0ah
385         int 21h
386 w_file:
387         pop cx
388         pop ax
389         pop dx
390         pop bx
391         ret
392 outp    endp
393 ;------------------------------print size-------------------------------------
394 b2d     proc near
395         push cx
396         push ax
397         push dx
398         push si
399 
400 
401         xor cx,cx
402         lea si,dta[1ah]
403         mov ax,[si]
404         call add_used_space
405         call add_filenum
406         cmp ax,0
407         je b4
408         ;----judge is W
409         mov dl,[show]
410         cmp dl,1
411         je b5
412         xor cx,cx
413 b1:
414         xor dx,dx
415         mov si,10
416         div si
417 
418         push dx
419         inc cx
420         cmp ax,0
421         jne b1
422         mov si,cx
423 
424 b2:
425         pop dx
426         add dl,30h
427         mov ah,2
428         int 21h
429         loop b2
430 
431         mov cx,10
432         sub cx,si
433 b3:
434         mov ah,02h
435         mov dl,20h
436         int 21h
437         loop b3
438 
439         ;----judge is W
440         mov dl,[show]
441         cmp dl,1
442         je b5
443 
444         mov ah,9
445         lea dx,space
446         int 21h
447         jmp b5
448 
449 b4:
450         call add_dirnum
451         call sub_filenum
452         ;----judge is W
453         mov dl,[show]
454         cmp dl,1
455         je b5
456         mov ah,09h
457         lea dx,dir
458         int 21h
459 
460 b5:
461         pop si
462         pop dx
463         pop ax
464         pop cx
465     ret
466 b2d     endp
467 
468 add_filenum proc near
469         push ax
470         mov al,[filenum]
471         inc al
472         mov [filenum],al
473         pop ax
474         ret
475 add_filenum endp
476 
477 add_dirnum proc near
478         push ax
479         mov al,[dirnum]
480         inc al
481         mov [dirnum],al
482         pop ax
483         ret
484 add_dirnum endp
485 
486 sub_filenum proc near
487         push ax
488         mov al,[filenum]
489         dec al
490         mov [filenum],al
491         pop ax
492         ret
493 sub_filenum endp
494 
495 ;------------------------------print date and time-----------------------------------------------
496 datm    proc near
497         push ax
498         push bx
499         push cx
500         push dx
501         push di
502 
503 
504         lea bx,dta[18h];data
505         mov di,[bx]
506         mov cx,7;year
507         xor bx,bx
508 d1:
509         shl di,1
510         rcl bx,1
511         loop d1
512         add bx,1980
513         call bi2de
514         mov ah,2
515         mov dl,"."
516         int 21h
517 
518         mov cx,4;month
519         xor bx,bx
520 d2:
521         shl di,1
522         rcl bx,1
523         loop d2
524         call bi2de
525         mov ah,2
526         mov dl,"."
527         int 21h
528 
529         mov cx,5;day
530         xor bx,bx
531 d3:
532         shl di,1
533         rcl bx,1
534         loop d3
535         call bi2de
536         mov cx,3
537 d7:
538         mov ah,2
539         mov dl," "
540         int 21h
541         loop d7
542 
543 ;time
544         lea bx,dta[16h]
545         mov di,[bx]
546         mov cx,5;hour
547         xor bx,bx
548 d5:
549         shl di,1
550         rcl bx,1
551         loop d5
552         call bi2de
553         mov ah,2
554         mov dl,":"
555         int 21h
556         mov cx,6;min
557         xor bx,bx
558 d6:
559         shl di,1
560         rcl bx,1
561         loop d6
562         call bi2de
563 
564 
565     pop di
566     pop dx
567     pop cx
568     pop bx
569     pop ax
570     ret
571 datm    endp
572 
573 ;---------------------------------binary2decimal-----------------------------
574 bi2de    proc near
575         push ax
576 
577         cmp bx,9
578         ja bi0
579         mov ah,2
580         mov dl,‘0‘
581         int 21h
582 bi0:
583         xor cx,cx
584         mov ax,bx
585 bi1:
586         xor dx,dx
587         mov si,10
588         div si
589 
590         push dx
591         inc cx
592         cmp ax,0
593         jne bi1
594 
595 bi2:
596         pop dx
597         add dl,30h
598         mov ah,2
599         int 21h
600         loop bi2
601 
602         pop ax
603         ret
604 bi2de    endp
605 
606 ;----------------multiplies dx:ax x cx:bx return dx:ax:cx:bx
607 mymul32    proc     near
608 
609          push si
610          push di
611          mov      si,dx       ;save op1hi in si
612          mov      di,ax       ;save op1lo in di
613          mul      bx          ;op1l0 x op2lo
614          push     ax          ;save 1st (32 bit) pp. on stack
615          push     dx
616 ;
617          mov      ax,si       ;op1hi in ax
618          mul      bx          ;op1hi x op2l0
619          pop      bx          ;add 2nd (48 bit) pp. to pp1
620          add      ax,bx
621          adc      dx,0
622          push     ax
623          mov      bx,dx       ;pp1 + pp2 in bx:tos:tos+2
624 ;
625          mov      ax,di       ;op1lo in ax
626          mul      cx          ;op1lo x op2hi
627          pop      di          ;add 3rd (48 bit) pp. to pp1 + pp2
628          add      di,ax
629          push     di
630          mov      di,0
631          adc      bx,dx
632          adc      di,0        ;pp1+pp2+pp3 in di:bx:tos:tos+2
633 ;
634          mov      ax,si       ;op1hi in ax
635          mul      cx          ;op1hi x op2hi
636          add      ax,bx       ;add 4th (64 bit) pp. to pp1+pp2+pp3
637          adc      dx,di
638          pop      cx
639          pop      bx          ;final product in dx:ax:cx:bx
640 ;
641          pop      di
642          pop      si
643          ret
644 mymul32    endp
645 
646 showspace proc near
647     push ax
648     push bx
649     push dx
650     push cx
651     mov     ax,0
652     mov     bx,0        ;bx: quotidient_32bits_high
653     mov     dx,0        ;dx: quotidient_32bits_low
654     mov     cx,0        ;counter = 0
655 ;16bits or 32bits ?
656     mov     ax,var_32bits_high
657     cmp     ax,0
658     jne     _32bits_routine
659     jmp     _16bits_routine
660 
661 ;;;
662 _32bits_routine:
663     mov     cx,0
664 ;if == -2147483648 (-2^31)
665     mov     ax,var_32bits_high
666     cmp     ax,lowest_signed_32bits_high
667     jne     check_if_neg
668     mov     ax,var_32bits_low
669     cmp     ax,lowest_signed_32bits_low
670     jne     check_if_neg
671 ;then
672     lea     dx,lowest_signed_32bits_string
673     mov     ah,9
674     int     21h
675     jmp     return_to_dos
676 ;if < 0
677 check_if_neg:
678     mov     ax,var_32bits_high
679     cmp     ax,0
680     jnl      preparations
681 ;then print "-" ...
682     mov     ah,2
683     mov     dl,‘-‘
684     int     21h
685 ;... and negate number
686     ;---------xor 0ffffffff , + 1----------
687     mov     ax,var_32bits_high
688     xor     ax,negate_mask
689     mov     var_32bits_high,ax
690     mov     ax,var_32bits_low
691     xor     ax,negate_mask
692     inc     ax
693     mov     var_32bits_low,ax
694     jnc     preparations
695     mov     ax,var_32bits_high
696     inc     ax
697     mov     var_32bits_high,ax
698 preparations:
699     mov     ax,var_32bits_high
700     mov     quotidient_32bits_high,ax
701     mov     ax,var_32bits_low
702     mov     quotidient_32bits_low,ax
703 while_32bits:
704 ; while >0 do
705     mov     ax,quotidient_32bits_high
706     cmp     ax,0
707     jne     div_high_part
708     mov     ax,quotidient_32bits_low
709     cmp     ax,0
710     jne     div_high_part
711     jmp     print_char
712 div_high_part:
713 ;divide high part
714     mov     dx,0
715     mov     ax,quotidient_32bits_high
716     div     base_10
717     mov     qhigh,ax
718     mov     rhigh,dx
719 ;case rhigh
720     mov     ax,rhigh
721     cmp     ax,0
722     je      _rhigh0
723     cmp     ax,1
724     je      _rhigh1
725     cmp     ax,2
726     je      _rhigh2
727     cmp     ax,3
728     je      _rhigh3
729     cmp     ax,4
730     je      _rhigh4
731     cmp     ax,5
732     je      _rhigh5
733     cmp     ax,6
734     je      _rhigh6
735     cmp     ax,7
736     je      _rhigh7
737     cmp     ax,8
738     je      __rhigh8
739     cmp     ax,9
740     je      __rhigh9
741 _rhigh0:
742     mov     ax,qhigh0
743     mov     qhigh_redundant,ax
744     mov     ax,rhigh0
745     mov     rhigh_redundant,ax
746     jmp     _aftercase
747 
748 _rhigh1:
749     mov     ax,qhigh1
750     mov     qhigh_redundant,ax
751     mov     ax,rhigh1
752     mov     rhigh_redundant,ax
753     jmp     _aftercase
754 __rhigh8:
755     jmp _rhigh8
756 __rhigh9:
757     jmp _rhigh9
758 _rhigh2:
759     mov     ax,qhigh2
760     mov     qhigh_redundant,ax
761     mov     ax,rhigh2
762     mov     rhigh_redundant,ax
763     jmp     _aftercase
764 _rhigh3:
765     mov     ax,qhigh3
766     mov     qhigh_redundant,ax
767     mov     ax,rhigh3
768     mov     rhigh_redundant,ax
769     jmp     _aftercase
770 _rhigh4:
771     mov     ax,qhigh4
772     mov     qhigh_redundant,ax
773     mov     ax,rhigh4
774     mov     rhigh_redundant,ax
775     jmp     _aftercase
776 _rhigh5:
777     mov     ax,qhigh5
778     mov     qhigh_redundant,ax
779     mov     ax,rhigh5
780     mov     rhigh_redundant,ax
781     jmp     _aftercase
782 _rhigh6:
783     mov     ax,qhigh6
784     mov     qhigh_redundant,ax
785     mov     ax,rhigh6
786     mov     rhigh_redundant,ax
787     jmp     _aftercase
788 _rhigh7:
789     mov     ax,qhigh7
790     mov     qhigh_redundant,ax
791     mov     ax,rhigh7
792     mov     rhigh_redundant,ax
793     jmp     _aftercase
794 _rhigh8:
795     mov     ax,qhigh8
796     mov     qhigh_redundant,ax
797     mov     ax,rhigh8
798     mov     rhigh_redundant,ax
799     jmp     _aftercase
800 _rhigh9:
801     mov     ax,qhigh9
802     mov     qhigh_redundant,ax
803     mov     ax,rhigh9
804     mov     rhigh_redundant,ax
805     jmp     _aftercase
806 _aftercase:
807 ;divide low part
808     mov     ax,0
809     mov     q_0,ax
810     mov     dx,0
811     mov     ax,quotidient_32bits_low
812     div     base_10
813     mov     qlow,ax
814     mov     rlow,dx
815     mov     ax,rlow
816     add     ax,rhigh_redundant
817 ;if remainder >= 10
818     cmp     ax,base_10
819     jl      after_if
820     sub     ax,base_10
821     mov     dx,1
822     mov     q_0,dx
823 after_if:
824     mov     rlow,ax
825     mov     ax,q_0
826     add     ax,qlow
827     mov     qlow,ax
828     jnc     label1
829     mov     ax,qhigh
830     inc     ax
831     mov     qhigh,ax
832 label1:
833     mov     ax,qlow
834     add     ax,qhigh_redundant
835     mov     qlow,ax
836     jnc     label2
837     mov     ax,qhigh
838     inc     ax
839     mov     qhigh,ax
840 label2:
841 ;push remainder to stack
842     mov     ax,rlow
843     push    ax
844     inc     cx
845     mov     ax,qhigh
846     mov     quotidient_32bits_high,ax
847     mov     ax,qlow
848     mov     quotidient_32bits_low,ax
849     jmp     while_32bits
850 
851 ;;;
852 _16bits_routine:
853     mov     ax,var_32bits_low
854     mov     bx,0   ;bx: quotient
855     mov     cx,0
856 while_loop:
857     cmp     ax,0
858     je      print_char
859     mov     dx,0
860     div     base_10
861     mov     bx,ax ;ax stores quotidient
862     mov     ax,dx ;dx stores remainder
863 ;push remainder
864     push    ax
865 ;counter = counter + 1
866     inc     cx
867 ;numerator = quotidient
868     mov     ax,bx
869     jmp     while_loop
870 print_char:
871     cmp     cx,0
872     je      return_to_dos
873     pop     ax
874 ;because at this point 0 <= ax <= 9, setting ah = 2 does not change the results
875     mov     ah,2
876     mov     dl,al
877     add     dl,30h   ;0-> ‘0‘,1->‘1‘,....
878     int     21h
879     dec     cx
880     jmp     print_char
881 
882 return_to_dos:
883 
884     pop cx
885     pop dx
886     pop bx
887     pop ax
888     ret
889 showspace endp
890 
891 ;--------input:ax----------
892 add_used_space proc near
893         push ax
894         push bx
895         push cx
896         push dx
897 
898         mov dx,[used_32bits_low]
899         add dx,ax
900         jnc add_finish
901         mov bx,[used_32bits_high]
902         inc bx
903         mov [used_32bits_high],bx
904 
905 add_finish:
906         mov [used_32bits_low],dx
907 
908         pop dx
909         pop cx
910         pop bx
911         pop ax
912         ret
913 add_used_space endp
914 
915 main    ends
916         end p1