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/ Programming Languages Suite / ProgramD2.iso / Languages / Masm V6.11 / SAMPLES / SHOW / SHOW.AS$ / SHOW.bin

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Text File | 1993-07-16 | 15.3 KB | 453 lines

;* SHOW.ASM - Text file displayer for DOS. TITLE Show .MODEL small, pascal ; This code also works in tiny model .DOSSEG INCLUDE show.inc INCLUDE dos.inc INCLUDE bios.inc .STACK .DATA ; Status line stLine BYTE "Line: 12345 " stFile BYTE "File: 12345678.123 " BYTE "Quit: Q Next: ESC Move: PGUP PGDN HOME END" ; Variables for screen handling yCur WORD 1 yMax WORD 24 ; Number of rows - status line takes one more iMode BYTE 0 ; Initial mode iPage BYTE 0 ; Initial display page atInit BYTE 0 ; Initial attribute shCsr WORD 0 ; Initial cursor shape bCsrSta BYTE 0 ; 0 = cursor visible, position unchanged ; 1 = cursor invisible, position unchanged ; 2 = cursor invisible, position changed fNewVid BYTE 0 ; Video change flag fCGA BYTE 1 ; CGA flag - default yes segVid WORD SEG_CLR ; Video buffer address - default color atSta BYTE STAT_CLR ; Status line color celScr LABEL WORD ; Cell (character and attribute) chScr BYTE ' ' ; Initialize to space atScr BYTE SCRN_CLR ; Screen color ; Buffer variables fpBuf LABEL FAR PTR offBuf WORD 0 ; Position in buffer (offset) segBuf WORD 0 ; Base of buffer (segment) cbBuf WORD 0 ; Length of buffer ; File information hFileIn WORD 0 ; Holds file handle on open ; Buffer for file spec and structure for file info achBuf BYTE NAME_MAX, ? ; Buffer format for string input stFiles BYTE NAME_MAX DUP (0); File spec string fiFiles FILEINFO <> ; Wild card entry structure cFiles WORD 0 ; Count of 1 or 0 files remaining ; Messages stMsg1 BYTE 13, 10, 13, 10, "Enter filename: $" stMsg2 BYTE 13, 10, "File problem. Try again? $" stMsg3 BYTE 13, 10, "File too large: $" stMsg4 BYTE 13, 10, "Memory problem.", 13, 10, "$" stMsg5 BYTE 13, 10, "Must have DOS 2.0 or higher", 13, 10, "$" ; Call table achKeys BYTE 71, 72, 73, 79, 80, 81, 'q', 'Q'; Key table afnKeys WORD HomeKey ; Corresponding procedures WORD UpKey WORD PgUpKey WORD EndKey WORD DownKey WORD PgDnKey WORD Quit WORD Quit WORD UnknownKey .CODE .STARTUP ; Adjust memory allocation (works for tiny or small model) mov bx, sp ; Convert stack pointer to paragraphs mov cl, 4 ; to get stack size shr bx, cl mov ax, ss ; Add SS to get end of program add ax, bx mov bx, es ; Get start of program sub ax, bx ; Subtract start from end inc ax @ModBlock ax ; Release memory after program ; Check DOS @GetVer ; Get DOS version .IF al < 2 ; Requires DOS 2.0 @ShowStr stMsg5 ; else error and quit int 20h .ENDIF ; Get command line and copy to filename buffer mov di, 80h ; PSP offset of command line mov bl, es:[di] ; Get length from first byte sub bh, bh or bx, bx je Prompter mov WORD PTR es:[bx+81h], 0 ; Convert to ASCIIZ mov al, ' ' ; Character to check for inc di ; Advance beyond count mov cx, 0FFFFh ; Don't let count interfere repe scasb ; Find first nonspace dec di ; Adjust mov si, di ; Filename source mov di, OFFSET stFiles ; Name buffer destination mov bx, ds ; Save segment registers mov dx, es mov ds, dx ; DS = ES mov es, bx ; ES = DS mov cx, NAME_MAX ; Count = max filename allowed .REPEAT lodsb ; Copy characters .BREAK .IF (al == ' ') || (al == 0) ; Stop at space or null stosb .UNTILCXZ ; Until name exceeds max mov ds, bx ; Restore segments mov es, dx mov BYTE PTR [di], 0 jmp FindFile NoFile: @ShowStr stMsg2 ; Prompt to try again @GetChar 0, 1, 0 and al, 11011111y ; Convert key to upper case .IF al != 'Y' ; If not yes, jmp quit ; quit .ENDIF ; Prompt for file Prompter: @ShowStr stMsg1 ; Prompt for file @GetStr achBuf, 0 ; Get response as ASCIIZ ; Find first (or only) file in file spec FindFile: @SetDTA <OFFSET fiFiles> ; Set DTA to file info structure ; Don't need DTA for anything else, ; so no need to restore it @GetFirst stFiles,0 ; Find a matching file jc NoFile ; If not found, prompt for new inc cFiles ; Some files remaining INVOKE GetVid ; Main program loop to process files .REPEAT ; Copy filename to file spec mov bCsrSta, 2 ; Cursor hidden, position unchanged INVOKE GetNamePos, ; Get filename position in file spec ADDR stFiles mov si, OFFSET fiFiles.fiFileName ; Point to source name push ds ; ES = DS pop es mov di, ax ; Load address from return value .REPEAT ; Copy to (and including) null movsb .UNTIL BYTE PTR [si-1] == 0 ; Copy filename to status line mov si, OFFSET fiFiles.fiFileName ; Point to source name mov di, OFFSET stFile[FILE_POS] ; Point to status line sub cx, cx ; Count characters .REPEAT lodsb ; Copy to (but excluding) null .BREAK .IF al == 0 stosb inc cx .UNTIL 0 mov bx, 12 ; Calculate blank spaces to fill sub bx, cx mov al, ' ' ; Fill rest of name space with blanks mov cx, bx rep stosb ; Skip any file that is larger than 64K .IF WORD PTR fiFiles.fiSize[2] != 0 ; Error if high word isn't 0 mov bCsrSta, 1 ; Cursor hidden, position unchanged @ShowStr stMsg3 ; Display error string and filename @Write fiFiles.fiFileName, cx, 1 .IF cFiles ; If files remaining, @GetChar 0 ; get a key .ENDIF .ENDIF ; Allocate dynamic memory for file buffer mov ax, WORD PTR fiFiles.fiSize[0] ; Get length mov cbBuf, ax ; Save mov offBuf, 0 mov cl, 4 ; Convert to paragraphs shr ax, cl inc ax ; Zero adjust @GetBlock ax ; Try to allocate 64K .IF carry? ; Display error and quit if @ShowStr stMsg4 ; request failed jmp Quit .ENDIF mov segBuf, ax ; Save buffer segment ; Open file and read contents into buffer @OpenFile stFiles, 0 ; Try to open jc NoFile ; If fail, get a new file mov hFileIn, ax ; Save handle push ds @Read fpBuf, cbBuf, hFileIn ; Read file pop ds .IF carry? jmp NoFile ; If read error try again .ENDIF ; Search back for EOF marker and adjust if necessary mov di, cbBuf ; Load file length dec di ; and adjust mov es, segBuf std ; Look backward for 255 characters mov cx, 0FFh .IF cx >= di mov cx, di .ENDIF mov al, 1Ah ; Search for EOF marker repne scasb cld .IF cx != 0 ; If found, inc di ; adjust and save file size mov cbBuf, di .ENDIF ; Show a screen of text and allow commands INVOKE Show @CloseFile hFileIn ; Yes? Close file @FreeBlock segBuf ; Release buffer @GetNext .IF carry? dec cFiles .ENDIF .UNTIL !cFiles ; Fall through to Quit Quit PROC cmp bCsrSta, 1 ; Check cursor status jg csrvislast ; 2 - Make cursor visible on last line je csrvis ; 1 - Make cursor visible jmp csrasis ; 0 - Leave cursor as is csrvislast: mov dx, yMax ; Load last row and first column xchg dl, dh mov cx, dx ; Make row the same mov dl, 79 @Scroll 0, atInit ; Clear last line to original color sub dl, dl ; Column 0 @SetCsrPos ; Set cursor csrvis: ; Fall through ; Restore cursor attribute @SetCsrSize <BYTE PTR shCsr[1]>, <BYTE PTR shCsr[0]> csrasis: .IF fNewVid == 1 @SetMode iMode ; Restore video mode, page, and cursor @SetPage iPage .ENDIF .EXIT 0 ; Quit Quit ENDP Show PROC ; Display first page mov yCur, 1 ; Reinitialize INVOKE Pager, ; Start at 0 0 ; Handle keys .REPEAT @GetChar 0, 0, 0 ; Get a key .BREAK .IF al == 27 ; If ESC get out for next file ; If null or E0 (for extended keyboard), it's an extended key .IF (al == 0) || (al == 0E0h) @GetChar 0, 0, 0 ; Get extended code .ENDIF push ds ; ES = DS pop es mov di, OFFSET achKeys ; Load address and length of key list mov cx, LENGTHOF achKeys + 1 repne scasb ; Find position and point to key sub di, OFFSET achKeys + 1 shl di, 1 ; Adjust pointer for word addresses call afnKeys[di] ; Call procedure .UNTIL 0 ret Show ENDP HomeKey: mov offBuf, 0 ; HOME - set position to 0 mov yCur, 1 INVOKE Pager, offBuf retn UpKey: INVOKE Pager, -1 ; UP - scroll backward 1 line retn PgUpKey: mov ax, yMax ; PGUP - Page back neg ax INVOKE Pager, ax retn EndKey: mov ax, cbBuf ; END - Get last byte of file dec ax ; Zero adjust mov offBuf, ax ; Make it the file position mov yCur, -1 ; Set illegal line number as flag mov ax, yMax ; Page back neg ax INVOKE Pager, ax retn DownKey: INVOKE Pager, 1 ; DOWN - scroll forward 1 line retn PgDnKey: INVOKE Pager, yMax ; PGDN - page forward retn UnknownKey: retn ; Ignore unknown key ;* GetVid - Gets the video mode and sets related global variables. ;* ;* Params: None ;* ;* Return: Number of lines in current mode (25, 43, or 50) GetVid PROC ; Adjust for current mode and and video adapter INVOKE IsEGA ; EGA (or VGA)? .IF ax != 0 ; If 0 must be CGA or MA mov yMax, ax ; Load rows dec fCGA ; Not CGA .ENDIF @GetMode ; Get video mode mov iMode, al ; Save initial mode and page mov iPage, bh mov dl, al ; Work on copy cmp dl, 7 ; Is it mono 7? je loadmono ; Yes? Set mono cmp dl, 15 ; Is it mono 15? jne graphchk ; No? Check graphics loadmono: mov segVid, SEG_MONO ; Load mono address mov atSta, STAT_BW ; Set B&W defaults for status line mov atScr, SCRN_BW ; and screen background dec fCGA ; Not CGA cmp al, 15 ; Is it mono 15? jne exit ; No? Done mov dl, 7 ; Yes? Set standard mono jmp chmode graphchk: cmp dl, 7 ; 7 or higher? jg color ; 8 to 14 are color (7 and 15 done) cmp dl, 4 ; 4 or higher? jg bnw ; 5 and 6 are probably black and white je color ; 4 is color test dl, 1 ; Even? jz bnw ; 0 and 2 are black and white color: ; 1 and 3 are color cmp dl, 3 ; 3? je exit ; Yes? Done mov dl, 3 ; Change mode to 3 jmp chmode bnw: mov atSta, STAT_BW ; Set B&W defaults for status line mov atScr, SCRN_BW ; and screen background cmp dl, 2 ; 2? je exit ; Yes? Done mov dl, 2 ; Make it 2 chmode: @SetMode dl ; Set video mode @SetPage 0 ; Set video page mov fNewVid, 1 ; Set flag exit: @GetCsr ; Get cursor shape (ignore position) mov shCsr, cx ; Save shape @GetCharAtr ; Read the cell at the cursor mov atInit, ah ; Save attribute @SetCsrSize 20h, 20h ; Turn off cursor (invisible shape) ret GetVid ENDP END