Добавить в текстовый редактор функцию открытия файла - Assembler - Ответ 8671633

;-----------------------------------------------------------------------
; This routine prints the marked text.  If printer fails, it is cancelled.
;-----------------------------------------------------------------------
PRINT       PROC    NEAR
        CMP MARK_MODE,0 ;is mark mode on?
        JE  PRINT_RET   ;if not, nothing to print
        MOV CX,MARK_END ;end of marked region
        MOV SI,MARK_START   ;start of marked region
        SUB CX,SI       ;number of bytes selected
        JCXZ    PRINT_DONE  ;if nothing to print, return
DO_FF_CHAR:
        XOR DX,DX       ;select printer 0
        MOV AH,2
        INT 17H     ;get printer status
        TEST    AH,10000000B    ;is busy bit set?
        JZ  PRINT_DONE
        TEST    AH,00100000B    ;is printer out of paper?
        JNZ PRINT_DONE
PRINT_LOOP:
        LODSB
        XOR AH,AH
        INT 17H     ;print the character
        ROR AH,1        ;check the time out bit
        JC  PRINT_DONE  ;if set, quit printing
        LOOP    PRINT_LOOP
        MOV AL,CR
;------ [typographical error in article]
;**nop!     XOR AH,0        ;[would be No-Operation]
        XOR AH,AH
;------
        INT 17H     ;finish with a CR
PRINT_DONE:
        CALL    MARK        ;turn off the mark status
PRINT_RET:
        RET
PRINT       ENDP
 
;=======================================================================
; CHARACTER STRING SEARCH and SEARCH AGAIN services; HELP screen
;=======================================================================
; from TEDPLUS
; This routine is used to search or search again for a character string.
;-----------------------------------------------------------------------
FIND_STR    PROC    NEAR
        PUSH    DS
        MOV BX,CS
        MOV DS,BX
        ASSUME  DS:CSEG
;---------------------------------------
;** now ShftF6  CMP AH,66H      ;Is it shift F9
        CMP AH,89       ;Is it shift-F6 (JEG)
;---------------------------------------
        JE  RPT_FIND
        MOV DH,ROWS
        INC DH      ;Last row on the screen
        XOR DL,DL       ;First column
        MOV SI,OFFSET SRCH_PROMPT
        CALL    TTY_STRING  ;Display search prompt
        MOV DX, OFFSET SRCH_MAX
        MOV AH,0AH
        INT 21H     ;Read input string
RPT_FIND:
        XOR DX,DX
        MOV DL,BYTE PTR SRCH_SIZ
        ADD DX,OFFSET SRCH_STR
        MOV DI,DX
        DEC DI
        MOV SRCH_END,DI
        XOR DX,DX
        MOV SI,CURSOR
        INC SI
        MOV SRCH_BASE,SI
S_REDO:
        MOV DI,OFFSET SRCH_STR
        MOV BX,SRCH_BASE
S_CYCLE:    MOV AL,[DI]
        MOV AH,AL       ;CONVERT AL TO OPPOSITE AND PUT IN AH
        CMP AL,'A'
        JB  S_CMP
        CMP AL,'Z'
        JA  TSTLO
        XOR AH,20H      ;toggle letter case
        JMP SHORT S_CMP
TSTLO:      CMP AL,'a'
        JB  S_CMP
        CMP AL,'z'
        JA  S_CMP
        XOR AH,20H      ;toggle letter case
S_CMP:      CMP BX,LAST_CHAR
        JA  END_MCH
        CMP AL,ES:[BX]
        JE  S_MCH
        CMP AH,ES:[BX]
        JE  S_MCH
        CMP DI,OFFSET SRCH_STR
        JNE S_REDO
        INC BX
        CMP WORD PTR ES:[BX-1],CRLF ;test for EOL marker
        JNE S_BX1
        INC DL
S_BX1:      JMP SHORT S_CMP
        
S_MCH:      INC BX
        CMP DI,OFFSET SRCH_STR
        JNE NO_BSE
        MOV SRCH_BASE,BX
NO_BSE:     ADD DH,DL
        XOR DL,DL
        CMP DI,SRCH_END
        JE  YEA_MCH
        INC DI
        JMP SHORT S_CYCLE
YEA_MCH:    
        MOV SRCH_FLG,1
        MOV SI,SRCH_BASE
        DEC SI
        MOV SRCH_BASE,SI
        MOV CURSOR,SI
        XOR BX,BX
        MOV BL,BYTE PTR SRCH_SIZ
        ADD BX,SI
        MOV SRCH_END,BX
        XOR DL,DL
        ADD DX,CURS_POSN
        CMP DH,ROWS
        JBE NEW_S
        XOR DX,DX
NEW_S:
        POP DS      ;ASSUME is no longer valid
        CALL    LOCATE
                JMP     SHORT END_MCH2
END_MCH:                
        POP DS
END_MCH2:
                CALL    REDO_PROMPT     ;redraw the prompt and the screen
        RET
FIND_STR    ENDP
 
;=======================================================================
; This routine displays a user help screen
;-----------------------------------------------------------------------
HELP        PROC    NEAR
        PUSH    DS
        PUSH    CS
        POP DS
        ASSUME  DS:CSEG     ;for func-9, display message
        CALL    CLR_SCREEN
 
        MOV DX,OFFSET HELP_SCREEN   ;message is at DS:DX in CSEG
        MOV AH,9        ;display message
        INT 21H
HELP_WAIT_KEY:
        MOV AH,1        ;wait for any key pressed
        INT 16H
        JZ  HELP_WAIT_KEY
        MOV AH,0
        INT 16H
 
        POP DS
        ASSUME  DS:NOTHING
        JMP REDO_PROMPT ;redraw the prompt and the screen
        ;(CALL/RETurn)
HELP        ENDP
 
;=======================================================================
; This routine prompts for a filename then writes the file.  The original 
; file is renamed to filename.BAK.  If an invalid filename is entered, the 
; speaker is beeped.  If the file has not been altered, the edit file is 
; abandoned and control is immediately returned to DOS.  
;-----------------------------------------------------------------------
EXIT        PROC    NEAR
        PUSH    DS      ;save in case ESC key
        PUSH    ES
        MOV AX,CS
        MOV DS,AX
        MOV ES,AX
        ASSUME  DS:CSEG, ES:CSEG
        TEST    BYTE PTR DIRTY_FILE,0FFH ;is the file altered?
        JNZ NEXT_LETTER ;(jump was out of range)
        JMP FINISHED    ;file has not been altered, no save.
        ;-----------------------
IS_BACKSPACE:
        CMP DI,NAME_POINTER ;at first letter?
        JLE NEXT_LETTER ;if yes, don't erase it
        MOV BYTE PTR [DI-1],0
        DEC NAME_END
 
NEXT_LETTER:
        MOV DH,ROWS
        INC DH      ;last row on the screen
        XOR DL,DL       ;first column
        MOV SI,OFFSET SAVE_MESS
        PUSH    DX
        CALL    TTY_STRING  ;display a prompt
        POP DX
        ADD DL,9        ;move right 9 spaces
        MOV SI,NAME_POINTER
        CALL    TTY_STRING  ;display the filename
 
        XOR AH,AH       ;read the next key
        INT 16H
        MOV DI,NAME_END ;this points to the last letter
        OR  AL,AL       ;is it a real character?
;       JZ  NEXT_LETTER ;ignore special keys
        JZ  IS_ESCAPE   ;special keys return to edit mode
        CMP AL,1BH      ;is it ESCape?
        JE  IS_ESCAPE   ;continue with exit procedure
        CMP AL,CR       ;is it CR?
        JE  GOT_NAME
        CMP AL,08H      ;is it a backspace?
        JE  IS_BACKSPACE
        CMP DI,81H + 65 ;too many letters?
        JG  NEXT_LETTER ;if yes, ignore them
        XOR AH,AH       ;for new terminal 0 to string
        STOSW           ;store the new letter and 0
        INC NAME_END    ;name is one character longer
        JMP NEXT_LETTER ;read another keystroke
        ;-----------------------
IS_ESCAPE:
        POP ES      ;get back file segment
        POP DS
        JMP REDO_PROMPT ;redraw the prompt and the screen
        ;(CALL/RETurn)      ;return to edit mode
        ;-----------------------
GOT_NAME:
        MOV DX,NAME_POINTER ;point to the filename
        MOV AX,4300H    ;get the file attribute
        INT 21H     ;DOS call
        JNC NAME_OK     ;if no error, filename is OK
        CMP AX,3        ;was it "path not found" error?
        JE  BAD_NAME    ;if yes, filename was bad
NAME_OK:
        MOV SI,OFFSET DOT_$$$   ;point to the ".$$$"
        MOV DI,OFFSET NAME_DOT_$$$
        CALL    CHG_EXTENSION       ;add the new extension
 
        MOV DX,OFFSET NAME_DOT_$$$  ;point to temp filename
        MOV CX,0020H        ;attribute for new file
        MOV AH,3CH          ;function to create file
        INT 21H         ;DOS call
        JNC NAME_WAS_OK     ;continue if name was OK
BAD_NAME:
        MOV AX,0E07H    ;write a bell character
        INT 10H     ;BIOS TTY service
        JMP NEXT_LETTER ;get another letter
        ;-----------------------
WRITE_ERROR:
        MOV AH,3EH      ;close the file
        INT 21H     ;DOS call
        JMP BAD_NAME    ;filename must be bad
        ;-----------------------
NAME_WAS_OK:
        XOR DX,DX       ;this is the file buffer
        MOV CX,LAST_CHAR    ;number of chars in file
        MOV BX,AX       ;this is the handle
        MOV AH,40H      ;write to the file
        POP DS      ;recover the buffer segment
        INT 21H     ;write the buffer contents
        POP DS
        JC  WRITE_ERROR ;exit on a write error
        CMP AX,CX       ;was entire file written?
        JNE WRITE_ERROR ;if not, exit
 
        PUSH    CS
        POP DS          ;get the code segment
        MOV AH,3EH          ;close the temp file
        INT 21H         ;DOS call
        MOV SI,OFFSET DOT_BAK   ;point to the ".BAK"
        MOV DI,OFFSET NAME_DOT_BAK
        CALL    CHG_EXTENSION       ;make the backup filename
 
        MOV DX,OFFSET NAME_DOT_BAK  ;point to the backup name
        MOV AH,41H          ;delete existing backup file
        INT 21H         ;DOS call
        MOV DI,OFFSET NAME_DOT_BAK
        MOV DX,NAME_POINTER
        MOV AH,56H
        INT 21H         ;DOS call
 
        MOV DI,NAME_POINTER ;point to new filename
        MOV DX,OFFSET NAME_DOT_$$$ ;point to temporary file
        MOV AH,56H      ;rename temp to new file
        INT 21H     ;DOS call, rename
        POP AX      ;restore the stack
        POP AX
        JMP SHORT FINISHED
        ;(To return to DOS)
EXIT        ENDP
 
;-----------------------------------------------------------------------
; This routine prompts for a verify keystroke then exits without saving 
; the file.  If the file has not been altered, the edit file is abandoned 
; and control is immediately returned to DOS.  
;-----------------------------------------------------------------------
ABORT       PROC    NEAR
        PUSH    CS
        POP DS
        ASSUME  DS:CSEG
        TEST    BYTE PTR DIRTY_FILE,0FFH ;is the file altered?
        JZ  FINISHED    ;file has not been altered.
 
        MOV DH,ROWS     ;last row on display
        INC DH      ;bottom row on screen
        XOR DL,DL       ;first column
        MOV SI,OFFSET VERIFY_MESS
        CALL    TTY_STRING  ;display verify message
 
        XOR AH,AH       ;read the next key
        INT 16H     ;BIOS read key routine
        CMP AL,CR       ;is it CR?
        JE  FINISHED
        OR  AL,20H      ;convert to lower case
        CMP AL,"y"      ;was answer Yes?
        JE  FINISHED    ;if yes, then we're finished
        CALL    REDO_PROMPT ;redraw the prompt and the screen
        PUSH    ES
        POP DS      ;set DS back to file segment
        RET         ;return to edit mode
        ;-----------------------
FINISHED:
        MOV DX,OFFSET COPYRIGHT
        ;-----------------------
EXIT_TO_DOS:                ;External entry point (DX, message)
        PUSH    CS
        POP DS      ;point to code segment
        ASSUME  DS:CSEG
        CALL    CLR_SCREEN  ;clear the screen (passes DX through)
        MOV AH,9        ;display error/exit message DS:DX
        INT 21H     ;DOS call
        MOV AX,EXIT_CODE    ;Exit to DOS with exit code
        INT 21H     ;DOS call
 
ABORT       ENDP
 
;=======================================================================
; This routine copies the input filename to CS:DI and changes the extension.
;-----------------------------------------------------------------------
CHG_EXTENSION   PROC    NEAR
        ASSUME  DS:CSEG, ES:CSEG
        PUSH    SI
        MOV SI,NAME_POINTER
CHG_LOOP:
        LODSB
        CMP AL,"."      ;look for the extension
        JE  FOUND_DOT
        OR  AL,AL
        JZ  FOUND_DOT
        STOSB           ;copy a character
        JMP CHG_LOOP
        ;-----------------------
FOUND_DOT:
        MOV CX,5        ;five characters in extension
        POP SI
        REP MOVSB       ;move new extension in
        RET
CHG_EXTENSION   ENDP
 
;=======================================================================
; This routine displays the string at CS:SI at the location in DX.  The 
; remainder of the row is erased.  Cursor is put at the end of the line.
;-----------------------------------------------------------------------
TTY_STRING  PROC    NEAR
        ASSUME  DS:CSEG
        PUSH    DX
        CALL    POSITION    ;compute offset into video
        POP DX
TTY_LOOP:
        LODSB           ;load DS:SI to AL
        OR  AL,AL       ;at end of string yet?
        JZ  TTY_DONE
        INC DL
        PUSH    DX
        CALL    WRITE_INVERSE   ;write in inverse video
        POP DX
        JMP TTY_LOOP
        ;-----------------------
TTY_DONE:
        CALL    SET_CURSOR  ;move cursor to end of string
        JMP ERASE_EOL   ;erase the rest of the line
        ;(CALL/RETurn)
TTY_STRING  ENDP
 
;=======================================================================
; This routine clears the screen, leaves registers unaltered.
;-----------------------------------------------------------------------
CLR_SCREEN  PROC    NEAR
        ASSUME  DS:NOTHING
        PUSH    AX      ;save registers (for INT-24)
        PUSH    BX
        PUSH    CX
        PUSH    DX      ;save DX for message address
        MOV DL,79       ;DL = right column
        MOV DH,CS:ROWS  ;DH = lower row
        INC DH      ;to clear the last line on the screen
        MOV CX,0        ;CH = upper row, CL = left column
        MOV BH,CS:NORMAL    ;BH is blank line attribute, 07 = normal video
        MOV AX,0600H    ;scroll the cursor up (blank line)
        INT 10H
        XOR DX,DX       ;set cursor to top left of screen
        CALL    SET_CURSOR
        POP DX
        POP CX
        POP BX
        POP AX
        RET
CLR_SCREEN  ENDP
 
;=======================================================================
; This is the control break handler for MS-DOS.  It ignores the break.
; TED then responds by entering a <Ctrl-C> in the file.
;-----------------------------------------------------------------------
NEWINT23    PROC    FAR
        ASSUME  DS:NOTHING, ES:NOTHING
        MOV CS:DIRTY_BITS,1 ;to redraw the screen
        CLC         ;tell DOS to ignore break
        IRET
NEWINT23    ENDP
 
;=======================================================================
; This is the severe error handler.  It homes the cursor before 
; processing the error.
;-----------------------------------------------------------------------
NEWINT24    PROC    FAR
        ASSUME  DS:NOTHING, ES:NOTHING
        PUSHF
        CALL    CLR_SCREEN  ;clear the screen and home the cursor
        POPF
        JMP CS:OLDINT24
        ;(chain to old INT 24 handler)
NEWINT24    ENDP
 
;=======================================================================
; This is the location of the character string search buffer.  It occupies 
; the last three bytes in the program file.  The following 64-bytes are used 
; for the buffer area.  The third byte is also used as the program code 
; check-sum compensation byte.
;-----------------------------------------------------------------------
        EVEN
SRCH_MAX    DB  66      ;42H, maximum size of buffer
SRCH_SIZ    DB  0       ;number of char's actually in buffer
SRCH_STR    DB  0       ;start of buffer block
 
        ;This is the correction byte for the check-sum test
CHEK_SUM_BYT    DB      0103
 
;=======================================================================
 
NAME_DOT_$$$    EQU $ +64       ;128 bytes
NAME_DOT_BAK    EQU $+80H +64   ;128 bytes
UNDO_BUFFER EQU $+100H +64  ;256 bytes, Del key buffer
LINE_BUFFER EQU $+200H +64  ;256 bytes, Delete line, EOL
 
END_BUFFER  EQU $+300H +64 +15  ;end of buffers, file segment follows
                    ; +15 is for paragraph rounding
 
 
CSEG    ENDS
 
;-----------------------------------------------------------------------
 
FILE_SEG    SEGMENT
FILE_SEG    ENDS
 
END     START