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Assembly Source File | 1988-03-23 | 29.8 KB | 992 lines

;------------------------------------------------ ; FSB.ASM -- "File Search and Browse" for OS/2 ; (c) 1988, Ziff Communications Co. ; PC Magazine * Charles Petzold, 3/88 ;------------------------------------------------ .286P ;----------------------------------------------------------- ; Macro to call OS/2 functions without declaring them first ;----------------------------------------------------------- OS2Call MACRO fnctname IFNDEF fnctname EXTRN fnctname:FAR ENDIF Call Far Ptr fnctname ENDM ;----------------------------------- ; Structures used in OS/2 functions ;----------------------------------- FileFindBufStr STRUC create_date dw ? create_time dw ? access_date dw ? access_time dw ? write_date dw ? write_time dw ? file_size dd ? falloc_size dd ? attributes dw ? string_len db ? file_name db 13 dup (?) FileFindBufStr ENDS KeyDataStruc STRUC char_code db ? scan_code db ? status db ? nls_shift db ? shift_state dw ? time dd ? KeyDataStruc ENDS ModeDataStruc STRUC md_length dw ? md_type db ? color db ? col dw ? row dw ? hres dw ? vres dw ? ModeDataStruc ENDS ;-------------------------------- ; Define all segments and DGROUP ;-------------------------------- _TEXT SEGMENT WORD PUBLIC 'CODE' _TEXT ENDS _DATA SEGMENT WORD PUBLIC 'DATA' _DATA ENDS _BSS SEGMENT WORD PUBLIC 'BSS' _BSS ENDS STACK SEGMENT PARA STACK 'STACK' dw 1024 dup (?) STACK ENDS DGROUP GROUP _DATA, _BSS, STACK ASSUME CS:_TEXT, DS:DGROUP, SS:DGROUP, ES:DGROUP ;-------------------------- ; Initialized Data Segment ;-------------------------- _DATA SEGMENT SyntaxMsg db 13, 10, "Syntax: FSB filespec" db 13, 10 db 13, 10, "File Search and Browse " db "(c) 1988, Ziff Communications Co." db 13, 10, "PC Magazine ", 254," Charles Petzold, 3/88" CRLF db 13, 10, 0 DriveError db "FSB: Invalid disk drive", 0 StartDirError db "FSB: Invalid directory", 0 FileFindError db "FSB: Invalid file spec", 0 PipeError db "FSB: Cannot not create pipe", 0 ThreadError db "FSB: Cannot not create second thread", 0 FileOpenError db 9, "FSB: Cannot open file for reading", 13, 10, 0 VideoModeError db 9, "FSB: Unsupported video mode", 13, 10, 0 RootDir db "\", 0 Delimiters db 9, ' ,;=', 0 DoBrowse db 1 _DATA ENDS ;---------------------------- ; Uninitialized Data Segment ;---------------------------- _BSS SEGMENT FileSpec dw ?, ? LastBackSlash dw ? PipeReadHandle dw ? PipeWriteHandle dw ? ThreadID dw ? ThreadStack dw 1024 dup (?) FullFileName db 80 dup (?) BytesRead dw ? BytesWritten dw ? _BSS ENDS ;-------------- ; Code Segment ;-------------- _TEXT SEGMENT ;---------------------------------------------- ; Parse command line to get file specification ;---------------------------------------------- Entry: Push DS ; Data segment selector Pop ES ; Transfer it to ES Mov DS, AX ; DS = Environment selector Mov SI, BX ; SI = Start of command line SkipProgName: Lodsb ; Pull a command line byte Or AL, AL ; Check if it's zero Jnz SkipProgName ; If not, continue SkipDelim: Lodsb ; Get command line byte Or AL, AL ; See if it's zero Jnz CheckDelim ; If not, check for delimiter Jmp DoSyntaxMsg ; If so, display message CheckDelim: Mov CX, 5 ; Five delimiters Mov DI, Offset Delimiters ; pointer to them Repne Scasb ; scan for delimiter Jz SkipDelim ; if delimiter, loop around Cmp Byte Ptr [SI], ':' ; Check if a drive present Jnz NoDiskDrive ; If not, skip section And AL, 0DFh ; Capitalize it Sub AL, '@' ; Change from A to 1, etc Sub AH, AH ; Zero out top byte Push AX ; Change to that drive OS2Call DosSelectDisk ; by calling OS/2 Mov DX, Offset DriveError Or AX, AX ; If AX not zero, Jnz ErrorExit ; display message and exit Add SI, 2 ; Skip past drive NoDiskDrive: Dec SI ; First character of rest Mov ES:[FileSpec], SI ; Save the address Mov ES:[FileSpec + 2], DS FindEnd: Lodsb ; Get a byte Cmp AL, '\' ; Check if it's a backslash Jnz NotBackSlash ; If not, continue Mov ES:[LastBackSlash], SI ; If so, save the address NotBackSlash: Mov CX, 6 ; now six delimiters Mov DI, Offset Delimiters ; pointer to delimiters Repne Scasb ; scan them Jnz FindEnd ; if not delimiter, loop around Mov Byte Ptr [SI-1], 0 ; terminate with zero DoChangeDir: Mov SI, ES:[LastBackSlash] ; Address of last back slash Or SI, SI ; See if any at all Jz NoChangeDir ; If none, skip this section Dec SI ; Points to last backslash now Cmp SI, ES:[FileSpec] ; Check if at beginning Jnz ChangeToDir ; If not, use directory Inc Word Ptr ES:[FileSpec] ; Skip past initial backslash Push DGROUP ; Segment of new dir Push Offset RootDir ; Offset of new dir Jmp Short CallChangeDir ; Change to root directory ChangeToDir: Mov Byte Ptr [SI], 0 ; Terinate dir name with zero Push Word Ptr ES:[FileSpec + 2] ; This is segment Push Word Ptr ES:[FileSpec] ; This is offset Inc SI ; Save address of filename Mov ES:[FileSpec], SI ; in FileSpec CallChangeDir: Push 0 ; Reserved bytes Push 0 OS2Call DosChdir ; Change directory Mov DX, Offset StartDirError Or AX, AX ; If non-zero return code, Jnz ErrorExit ; display message and leave NoChangeDir: Push ES ; Set DS to data segment Pop DS Call MainRoutine ; Go! Push 1 ; All threads to terminate Push 0 ; Return code OS2Call DosExit ; End the program ;------------------------------------- ; Error Exit: DX is pointer to string ;------------------------------------- DoSyntaxMsg: Mov DX, Offset SyntaxMsg ErrorExit: Mov AX, DGROUP ; Set DS to data segment Mov DS, AX Mov BX, 2 ; Standard Error handle Call StringLen ; Get length of DX string Mov CX, AX ; Move it to CX Call MyDosWrite ; Display error message Push 1 ; All threads to terminate Push 1 ; Error return code OS2Call DosExit ; End the program ;---------------------------------------------------------------- ; Main Routine, create pipe, start second thread, and do browses ;---------------------------------------------------------------- MainRoutine: Push DS ; Address for read handle Push Offset PipeReadHandle Push DS ; Address for write handle Push Offset PipeWriteHandle Push 16384 ; Size of pipe OS2Call DosMakePipe ; Create it Mov DX, Offset PipeError Or AX, AX ; If non-zero return code, Jnz ErrorExit ; depart from program Push CS ; Address of second thread Push Offset SecondThread Push DS ; Address for thread ID Push Offset ThreadID Push DS ; Top of thread stack Push Offset ThreadStack + 2048 OS2Call DosCreateThread ; Create the thread Mov DX, Offset ThreadError Or AX, AX ; Again, if error code, Jnz ErrorExit ; get out of this place StartPipeRead: Mov CX, 80 ; Read 80 chars from pipe Mov DX, Offset FullFileName ; Store it here ReadPipe: Mov BX, [PipeReadHandle] ; Pipe handle Call MyDosRead ; Read it Cmp [BytesRead], 0 ; Check if read no bytes Jz NothingLeft ; If so, pipe is empty Add DX, [BytesRead] ; Increment destination ptr Sub CX, [BytesRead] ; Decrement counter Jnz ReadPipe ; If not 80 bytes, read again Mov DX, Offset FileFindError Cmp [FullFileName], 0 ; See if file name present Jz ErrorExit ; If not, thread had problem NoErrFromThread:Mov BX, 1 ; Standard output handle Mov DX, Offset FullFileName ; Full file name Call StringLen ; Get its length Mov CX, AX ; Store in CX Call MyDosWrite ; Write to standard output Mov CX, 2 ; Two bytes Mov DX, Offset CRLF ; for carriage ret/line feed Call MyDosWrite ; Write that out also Cmp [DoBrowse], 1 ; See if still doing browse Jnz StartPipeRead ; If not, skip the call Call Browse ; Browse the file Or AX, AX ; If zero returned, continue Jz StartPipeRead Cmp AX, -1 ; If -1, Esc pressed --> Jz NothingLeft ; terminate gracefully Cmp AX, Offset VideoModeError Jnz ShowBrowseErr ; If video mode error, Mov [DoBrowse], 0 ; don't try browse again ShowBrowseErr: Mov BX, 2 ; Standard error output Mov DX, AX ; Address of error message Call StringLen ; Find length Mov CX, AX ; and save in CX Call MyDosWrite ; Dispay the string Jmp StartPipeRead ; And get another file name NothingLeft: Ret ; Return when all done ;-------------------------------------------------------------------------- ; DosRead and DosWrite routines (BX is handle, DX is buffer, CX is length) ;-------------------------------------------------------------------------- MyDosRead: Push BX ; Input handle Push DS ; Segment of buffer Push DX ; Offset of buffer Push CX ; Number of bytes to write Push DS ; Segment for bytes read Push Offset BytesRead ; Offset for bytes read OS2Call DosRead ; Read Ret MyDosWrite: Push BX ; Output handle Push DS ; Segment of buffer Push DX ; Offset of buffer Push CX ; Number of bytes to write Push DS ; Segment for bytes written Push Offset BytesWritten ; Offset for bytes written OS2Call DosWrite ; Write Ret ;------------------------------------------------------------ ; StringLen routine (DS:DX points to string, AX is returned) ;------------------------------------------------------------ StringLen: Push ES ; Save some registers Push DI Push CX Push DS Pop ES ; Set ES to DS Mov DI, DX ; Set DI to address of string Mov CX, -1 ; Initialize CX to big number Sub AL, AL ; Search for zero Repnz Scasb ; Do the scan Not CX ; Invert CX Dec CX ; Take away one Mov AX, CX ; That's the length Pop CX ; Restore saved registers Pop DI Pop ES Ret _TEXT ENDS ;----------------------------------------------------------------------- ;----------------------------------------------------------------------- ; SECOND THREAD section to search for files and write to pipe ;----------------------------------------------------------------------- ;----------------------------------------------------------------------- _DATA SEGMENT BackDir db "..", 0 StarDotStar db "*.*", 0 _DATA ENDS _BSS SEGMENT FileFindBuf FileFindBufStr <> FileFindBufLen equ $ - FileFindBuf FullPathName Label Byte CurrentDisk db ?, ?, ? CurrentDir db 64 dup (?) CurrDirLen dw ? Zeroes db 80 dup (?) DriveMap dd ? _BSS ENDS ;--------------------------------------------------------- ; Second Thread -- Calls FindThem, closes pipe, and exits ;--------------------------------------------------------- _TEXT SEGMENT SecondThread: Push DS ; Variable to receive Push Offset CurrentDisk ; current drive Push DS ; Variable to receive Push Offset DriveMap ; drive map OS2Call DosQCurDisk Add [CurrentDisk], '@' ; Convert to letter Mov [CurrentDisk + 1], ':' ; Follow by colon Mov [CurrentDisk + 2], '\' ; and backslash Call FindThem ; Do the finds TerminateThread:Push [PipeWriteHandle] ; Close the pipe for writing OS2Call DosClose Push 0 ; Terminate this thread only Push 0 ; Result code (ignored) OS2Call DosExit SearchError: Mov BX, [PipeWriteHandle] ; If error, Mov DX, Offset Zeroes ; write zeroes to Mov CX, 80 ; pipe Call MyDosWrite Jmp TerminateThread ; and terminate ;---------------------------------------------------------------- ; Find Them -- Recursive routine to find files fitting file spec ;---------------------------------------------------------------- FindThem: Enter 4, 0 ; Dir Handle is [BP - 2] ; Search Count is [BP - 4] ;------------------------------------ ; Get current directory for printing ;------------------------------------ Mov [CurrDirLen], 64 ; Len for current dir Push 0 ; Current disk drive Push DS Push Offset CurrentDir ; Space for current dir Push DS Push Offset CurrDirLen OS2Call DosQCurDir ; Get current dir Mov DX, Offset FullPathName ; Find length of it Call StringLen Cmp AX, 3 ; See if root Jz NoMoreSlashes ; If so, skip next part Mov SI, DX ; Add a slash Add SI, AX ; at end of directory Mov Byte Ptr [SI], '\' Mov Byte Ptr [SI + 1], 0 Inc AX NoMoreSlashes: Mov [CurrDirLen], AX ; Save total length ;---------------------- ; Search for the files ;---------------------- Mov Word Ptr [BP - 2], -1 ; Initial directory Handle Mov Word Ptr [BP - 4], 1 ; Search for one file Push [FileSpec + 2] ; segment of find file name Push [FileSpec] ; offset of find file name Push SS ; segment of directory handle Lea AX, [BP - 2] ; offset of directory handle Push AX Push 07h ; attribute Push DS ; segment of buffer Push Offset FileFindBuf ; offset of buffer Push FileFindBufLen ; length of buffer Push DS ; segment of search count Lea AX, [BP - 4] ; offset of search count Push AX Push 0 ; Reserved Push 0 OS2Call DosFindFirst ; Find first file FindResult1: Or AX, AX ; See if error Jz NoFindError1 ; If not skip next Cmp AX, 18 ; See if no more files Jz FindAllDone1 ; If so, done with search Jmp SearchError ; Process error NoFindError1: Cmp Word Ptr [BP - 4], 0 ; See if zero files found Jz FindAllDone1 ; If so, done with search Mov BX, [PipeWriteHandle] ; Write drive and Mov DX, Offset FullPathName ; directory path Mov CX, [CurrDirLen] ; to pipe Mov SI, CX Call MyDosWrite Mov DX, Offset FileFindBuf.file_name Mov CL, [FileFindBuf.string_len] ; Write file name Sub CH, CH ; to pipe Add SI, CX Call MyDosWrite Mov DX, Offset Zeroes ; Pad with zeroes Mov CX, 80 ; written to pipe Sub CX, SI Call MyDosWrite Push [BP - 2] ; Directory Handle Push DS ; segment of buffer Push Offset FileFindBuf ; offset of buffer Push FileFindBufLen ; length of buffer Push DS ; segment of count Lea AX, [BP - 4] ; offset of count Push AX OS2Call DosFindNext ; Find next file Jmp FindResult1 ; Loop around FindAllDone1: Push [BP - 2] ; directory handle OS2Call DosFindClose ; close it ;------------------------------- ; Now search for subdirectories ;------------------------------- Mov Word Ptr [BP - 2], -1 ; Initial directory handle Mov Word Ptr [BP - 4], 1 ; Search for one directory Push DS ; segment of spec Push Offset StarDotStar ; offset of spec Push SS ; segment of handle Lea AX, [BP - 2] ; offset of handle Push AX Push 10h ; attribute (dirs only) Push DS ; segment of buffer Push Offset FileFindBuf ; offset of buffer Push FileFindBufLen ; length of buffer Push DS ; segment of count Lea AX, [BP - 4] ; offset of count Push AX Push 0 ; reserved Push 0 OS2Call DosFindFirst ; Find first dir FindResult2: Or AX, AX ; Check if error Jz NoFindError2 Cmp AX, 18 ; Check if all finished Jz FindAllDone2 Jmp SearchError NoFindError2: Cmp Word Ptr [BP - 4], 0 ; Check if no dirs found Jz FindAllDone2 Test [FileFindBuf.attributes], 10h ; See if directory Jz FindTheNext Cmp [FileFindBuf.file_name], '.' ; Exclude '.' and '..' Jz FindTheNext Push DS ; Change the directory Push Offset FileFindBuf.file_name Push 0 Push 0 OS2Call DosChdir Call FindThem ; Recursive call Push DS ; Change to '..' directory Push Offset BackDir Push 0 Push 0 OS2Call DosChdir FindTheNext: Push [BP - 2] ; search handle Push DS ; segment of buffer Push Offset FileFindBuf ; offset of buffer Push FileFindBufLen ; length of buffer Push DS ; segment of count Lea AX, [BP - 4] ; offset of count Push AX OS2Call DosFindNext ; Find next directory Jmp FindResult2 FindAllDone2: Push [BP - 2] ; directory handle OS2Call DosFindClose ; close it Leave Ret _TEXT ENDS ;----------------------------------------------------------------------- ;----------------------------------------------------------------------- ; BROWSE section to display files after names are read from pipe ;----------------------------------------------------------------------- ;----------------------------------------------------------------------- _DATA SEGMENT db 'ATTR1=' Attribute1 db 1Eh ; Attribute for file text db 'ATTR2=' Attribute2 db 4Fh ; Attribute for file name db 'SHIFT=' ShiftHoriz db 8 ; Horizontal shift screen default FileOffset dw -1, -1 Dispatch dw Home, Up, PgUp, Dummy, Left dw Dummy, Right, Dummy, EndKey, Down, PgDn _DATA ENDS _BSS SEGMENT ModeData ModeDataStruc <> KeyData KeyDataStruc <> Buffer db 16384 dup (?) BufferMid db 16384 dup (?) BufferEnd Label Byte ScreenSize dw ? ScreenStart dw ? EndOfFile dw ? HorizOffset dw ? RightMargin dw ? ScreenAddr Label DWord ScreenOff dw ? ScreenSeg dw ? FileHandle dw ? OpenAction dw ? NewPointer dd ? ScreenSaveSel dw ? _BSS ENDS ;--------------------------- ; Open the File for reading ;--------------------------- _TEXT SEGMENT Browse: Mov [FileOffset], -1 ; Initialize these pointers Mov [FileOffset + 2], -1 Push DS ; segment of name Push Offset FullFileName ; offset of name Push DS ; segment for handle Push Offset FileHandle ; offset for handle Push DS ; segment for 'action' Push Offset OpenAction ; offset for 'acton' Sub AX, AX Push AX ; high size (ignored) Push AX ; low size (ignored) Push AX ; attribute (ignored) Push 1 ; open if file exists Push 0A0h ; read only / deny write Push AX ; reserved Push AX ; reserved OS2Call DosOpen ; Open File Or AX, AX ; Check if error Jz GotTheFile ; If not, continue Mov AX, Offset FileOpenError Ret GotTheFile: ;----------------------------- ; Get Screen Mode Information ;----------------------------- Mov [ModeData.md_length], 12 ; length of structure Push DS ; segment of structure Push Offset ModeData ; offset of structure Push 0 ; reserved OS2Call VioGetMode ; get video mode Or AX, AX ; See if error (only if Jz NotDetached ; program is detached) VideoError: Mov AX, Offset VideoModeError Ret NotDetached: Test [ModeData.md_type], 2 ; See if graphics mode Jnz VideoError ; If so, do not continue Mov AX, [ModeData.col] ; character columns Mul [ModeData.row] ; character rows Jc VideoError ; Leave if exceeds 64K Add AX, AX ; Ditto here Jc VideoError Mov [ScreenSize], AX ; Save screen size in bytes Push DS ; Segment for address Push Offset ScreenAddr ; Offset for address Push DS ; Segment for size Push Offset ScreenSize ; Offset for size Push 0 ; Reserved OS2Call VioGetBuf ; Get logical video buffer Or AX, AX ; Leave if an error Jnz VideoError ;--------------------------------------- ; Allocate memory and save screen in it ;--------------------------------------- Push [ScreenSize] ; Size of segment Push DS ; Segment for selector Push Offset ScreenSaveSel ; Offset for selector Push 0 ; No sharing OS2Call DosAllocSeg ; Allocate segment Or AX, AX ; If error, leave Jnz VideoError Push [ScreenSaveSel] ; Segment for destination Sub AX, AX Push AX ; Offset for destination Push DS ; Segment of screen size Push Offset ScreenSize ; Offset of screen size Push AX ; Starting row Push AX ; Starting column Push AX ; Reserved OS2Call VioReadCellStr ; Save the screen Call SetExitList ; Will restore on exit ;--------------------------------------- ; Get keyboard key and decide on action ;--------------------------------------- Call Home ; Read file in Mov [ScreenStart],SI ; Set buffer address KeyLoop: Push ThreadID ; Don't let the search OS2Call DosSuspendThread ; slow down the update Call UpDateScreen ; Update the screen Push ThreadID OS2Call DosResumeThread ; Let the search resume GetKey: Push DS ; Segment of structure Push Offset KeyData ; Offset of structure Push 0 ; Wait for key Push 0 ; Reserved OS2Call KbdCharIn ; Read key Mov AL, [KeyData.char_code] ; Get character code Cmp AL, ' ' ; A space means do next Je SpaceLeave ; file Cmp AL,27 ; Check if ESC Je EscLeave ; If so, terminate Cmp AL, 0E0h ; E0 for enhanced keyboard Jz ScanCode ; extended keys Or AL, AL ; Check if extended Jnz GetKey ; If not, try again ScanCode: Mov AL, [KeyData.scan_code] ; Get scan code Sub AL,71 ; Subtract Home key value Jb GetKey ; If below that, not valid Cmp AL,(81 - 71) ; Check if above PgDn Ja GetKey ; If so, ignore it Sub AH,AH ; Zero out top byte Add AX,AX ; Double for word access Mov BX,AX ; Offset in dispatch table Mov SI,[ScreenStart] ; Set current buffer pointer Call [Dispatch + BX] ; Do the call Mov [ScreenStart],SI ; Set new buffer pointer Jmp KeyLoop ; And update the screen ;-------------------------------------------- ; Terminate -- Restore screen and close file ;-------------------------------------------- SpaceLeave: Call ExitRoutine ; Restore screen Call UnsetExitList ; Take away exit list Sub AX, AX ; 0 means continue with files Ret ; Return EscLeave: Call ExitRoutine ; Restore screen Call UnsetExitList ; Take away exit list Mov AX, -1 ; -1 means stop program Ret ; Return ;------------------------------------- ; Exit List Processing for Ctrl-Break ;------------------------------------- SetExitList: Push 1 ; Set an exit list Push CS ; Segment of routine Push Offset ExitList ; Offset of routine OS2Call DosExitList Ret UnsetExitList: Push 2 ; Unset an exit list Push CS ; Segment of routine Push Offset ExitList ; Offset of routine OS2Call DosExitList Ret ExitRoutine: Push [ScreenSaveSel] ; Segment of saved screen Push 0 ; Offset of saved screen Push [ScreenSize] ; Length of saved screen Push 0 ; Starting row Push 0 ; Starting column Push 0 ; Reserved OS2Call VioWrtCellStr ; Restore screen Push [FileHandle] ; File handle OS2Call DosClose ; Close it Ret ExitList: Call ExitRoutine ; Do exit routine Push 3 ; Then continue exiting Push 0 Push 0 OS2Call DosExitList ;--------------------- ; Cursor Key Routines ;--------------------- Home: Sub BX,BX ; For zeroing out values Mov AX,[FileOffset] ; Check if read in file Or AX,[FileOffset + 2] Mov [FileOffset],BX ; Zero out file address Mov [FileOffset + 2],BX Mov [HorizOffset],BX ; Zero out horizontal offset Mov SI,Offset Buffer ; Reset buffer pointer Jz Dummy ; Skip file read if in already Mov DX,Offset Buffer ; Area to read file in Mov CX,32768 ; Number of bytes to read Call FileRead ; Read in file Dummy: Ret Up: Call GetPrevChar ; Get previous char in buffer Jc UpDone ; If none available, finish UpLoop: Call GetPrevChar ; Get previous char again Jc UpDone ; if none, we're done Cmp AL,10 ; Check if line feed Jnz UpLoop ; If not, try again Call GetNextChar ; Get char after line feed UpDone: Ret PgUp: Mov CX,Word Ptr [ModeData.row] ; Number of lines Dec CX ; less title line PgUpLoop: Call Up ; Do UP that many times Loop PgUpLoop Ret Left: Mov [HorizOffset],0 ; Reset Horizontal Offset Ret Right: Mov AL,[ShiftHoriz] ; Get places to shift Sub AH,AH Add [HorizOffset],AX ; Move that many right Ret EndKey: Mov BX,SI ; Save buffer pointer Call PgDn ; Go page down Cmp BX,SI ; Check if we did so Jnz EndKey ; If so, do it again Ret Down: Call GetNextChar ; Get next character Jc NoMoreDown ; If no more, we're done DownLoop: Call GetNextChar ; Get one again Jc UpLoop ; If no more, find prev LF Cmp AL,10 ; See if line feed Jnz DownLoop ; If not, continue NoMoreDown: Ret PgDn: Mov CX,Word Ptr [ModeData.row] ; Number of lines Dec CX ; less title line PgDnLoop: Call Down ; Do DOWN that many times Loop PgDnLoop Ret ;--------------- ; Update Screen ;--------------- UpdateScreen: Push ES Les DI,[ScreenAddr] ; Address of display Mov CX,ScreenSize ; Number of bytes in screen Shr CX,1 ; Half for number of chars Mov AL,' ' ; Will blank screen Mov AH,[Attribute1] ; With screen attribute Rep Stosw ; Blank it Mov CX, [ModeData.col] ; Number of character cols Mov DI, [ScreenOff] ; Offset of screen Mov SI, Offset FullFileName ; File name DisplayName: Lodsb ; Get character Or AL, AL ; See if end Jz EndOfName Mov AH, [Attribute2] ; Use second attribute Stosw ; Display it Loop DisplayName EndOfName: Mov SI,[ScreenStart] ; Address of data in buffer Mov DL, 1 ; Start with second line Mov AL, Byte Ptr [ModeData.col] ; Length of row Sub AH,AH Add AX,[HorizOffset] ; Add Horizontal Offset Mov [RightMargin],AX ; That's right display margin LineLoop: Sub BX,BX ; Column Number Mov AL, Byte Ptr [ModeData.col] ; Use Line Length Mul DL ; and Line Number Add AX,AX ; to recalculate Mov DI,AX ; display destination Add DI,[ScreenOff] ; Add beginning address CharLoop: Call GetNextChar ; Get next character Jc EndOfScreen ; If no more, we're done Cmp AL,13 ; Check for carriage return Je CharLoop ; Do nothing if so Cmp AL,10 ; Check for line feed Je LineFeed ; Do routine if so Cmp AL,9 ; Check for tab Je Tab ; Do routine if so Mov CX,1 ; Just 1 char to display PrintChar: Cmp BX,[HorizOffset] ; See if we can print it Jb NoPrint Cmp BX,[RightMargin] ; See if within margin Jae NoPrint Mov AH,[Attribute1] ; Attribute for display WriteIt: Stosw ; Write without retrace wait NoPrint: Inc BX ; Bump up line counter Loop PrintChar ; Do it CX times Jmp CharLoop ; Then go back to top Tab: Mov AX,BX ; Current column number And AX,07h ; Take lower three bits Mov CX,8 Sub CX,AX ; Subtract from 8 Mov AL,' ' ; Will print CX blanks Jmp PrintChar LineFeed: Inc DL ; Next line Cmp DL,Byte Ptr [ModeData.row] ; See if down at bottom Jb LineLoop ; If not, continue EndOfScreen: Push 0 ; Offset of buffer Push [ScreenSize] ; Size of buffer Push 0 ; Reserved OS2Call VioShowBuf ; Update the screen Pop ES ; All done -- leave Ret ;-------------------------------- ; Get Next Character from buffer ;-------------------------------- ; (Input is SI pointing to buffer, Returns AL, CY if no more) GetNextChar: Cmp SI, [EndOfFile] ; See if at end of file Jae NoMoreNext ; If so, no more chars Cmp SI, Offset BufferEnd ; See if at end of buffer Jb CanGetNext ; If not, just get character Push CX ; Otherwise save registers Push DX Push DI Push ES Push DS ; Set ES to DS Pop ES ; (could be different) Mov SI,Offset BufferMid ; Move 2nd buffer half Mov DI,Offset Buffer ; to 1st buffer half Mov CX,16384 Sub [ScreenStart],CX ; New buffer pointer Rep Movsb ; Move them Mov SI,DI ; SI also buffer pointer Add [FileOffset],32768 ; Adjust file addr to read Adc [FileOffset + 2],0 Mov DX,Offset BufferMid ; Place to read file Mov CX,16384 ; Number of bytes Call FileRead ; Read the file Sub [FileOffset],16384 ; Now adjust so reflects Sbb [FileOffset + 2],0 ; 1st half of buffer Pop ES ; Get back registers Pop DI Pop DX Pop CX Jmp GetNextChar ; And try again to get char CanGetNext: Lodsb ; Get the character And AL, 7Fh Stc NoMoreNext: Cmc ; So CY set if no more Ret ;------------------------------------ ; Get Previous Character from buffer ;------------------------------------ GetPrevChar: Cmp SI,Offset Buffer ; See if at top of buffer Ja CanGetPrev ; If not, just get character Mov AX,[FileOffset] ; See if at top of file Or AX,[FileOffset + 2] Jz AtTopAlready ; If so, can't get anymore Push CX ; Save some registers Push DX Push ES Push DS Pop ES Mov SI,Offset Buffer ; Move 1st half of buffer Mov DI,Offset BufferMid ; to 2nd half of buffer Mov CX, 16384 Add [ScreenStart], CX ; New buffer pointer Rep Movsb ; Do the move Sub [FileOffset], 16384 ; Adjust file addr for read Sbb [FileOffset + 2], 0 Mov DX, Offset Buffer ; Area to read file into Mov CX, 16384 ; Number of bytes Call FileRead ; Read the file Pop ES Pop DX ; Get back registers Pop CX CanGetPrev: Dec SI ; Move pointer back Mov AL,[SI] ; Get the character And AL, 7Fh ; Wipe out high byte Stc ; CY flag reset for success AtTopAlready: Cmc ; CY flag set for no more Ret ;-------------------------------------------- ; Read CX bytes from the file into DX buffer ;-------------------------------------------- FileRead: Push AX ; Save some registers Push BX Mov [EndOfFile], -1 ; Initialize this Push [FileHandle] ; File handle Push [FileOffset + 2] ; New pointer (high) Push [FileOffset] ; New pointer (low) Push 0 ; Action Push DS ; Segment for new pointer Push Offset NewPointer ; Offset for new pointer OS2Call DosChgFilePtr Mov BX, [FileHandle] ; Read from the file Call MyDosRead Or AX, AX ; See if error Mov AX, [BytesRead] Jz NoReadError ; If no error, continue Sub AX, AX ; Otherwise read zero bytes NoReadError: Cmp AX,CX ; See if 32K has been read Je GotItAll ; If so, we're home free Add AX,DX ; Otherwise add to buffer addr Mov [EndOfFile],AX ; And save as end of file GotItAll: Pop BX Pop AX Ret _TEXT ENDS END Entry