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  • question on reading console screen buffer by a different program

    before i do a lot of work, maybe some of you know the answer.
    can i store the location in memory of the console screen buffer in a file and a different program start by other means, say in a batch file using the command "start filename.exe" or even start by other means not from inside the console and have that other program read the memory location of the console screen buffer stored as data in a file, then in the other program retreive the console screen's buffer.
    i am using windows 2000 and the attachconsole api is not in that version,
    so i am having to do something else.

    thanks in advance
    p purvis

  • #2
    Using PB/DOS? Just BSAVE the screen in one program and BLOAD it in the other.

    Or do you mean have one Windows program interact with another Windows program in real time via something like a console interface? If so this question should probably be in one of the other forums, but there is no user-accessible "move thread" function. But that's very doable, but you wouldn't do it that way.... at least I wouldn't.

    (Disk IS memory!)

    [EDIT]
    Woo, for some reason I thought this was the PB/DOS forum. Never mind the PB/DOS comments.
    [/EDIT]

    MCM
    Last edited by Michael Mattias; 18 Jul 2008, 06:22 AM. Reason: Had second cup of coffee and realized I had the forum wrong
    Michael Mattias
    Tal Systems (retired)
    Port Washington WI USA
    [email protected]
    http://www.talsystems.com

    Comment


    • #3
      Paul --

      It sounds like my company's DOSBox Tools* product can do exactly what you are describing. There's even a free version that you can download.

      -- Eric Pearson, Perfect Sync, Inc.

      *No relation to DOSBox by SourceForge.
      "Not my circus, not my monkeys."

      Comment


      • #4
        this question could of gone inside a previous thread i started but i wanted high attraction to question.

        the second program does not have to interact with the console program but if it had that would be great.
        i have no control over the console program and prefer to run the console program.
        i was thinking of having a program run and record the console screen buffer location from a batch file just prior to running this third party console program.
        my windows program could then read the file to get the console screen buffer, then read the location from memory.
        Last edited by Paul Purvis; 18 Jul 2008, 06:32 AM.
        p purvis

        Comment


        • #5
          Recording a memory location (address) in one process and trying to use it in another process is a non-starter, as all addresses are private to a process.

          What is it you want from this program over which you have no control? The contents of the screen at some point in time?

          From the doc it appears you can do lots of stuff by obtaining a handle to the target process' screen buffer, but I don't know how to do that.

          (Can you even get a handle to another process' STDIN or STDOUT? I know you can pass a handle to another process and that target process can duplicate it for its own use, but I don't know how you'd get a handle from an unsuspecting process).

          MCM
          Michael Mattias
          Tal Systems (retired)
          Port Washington WI USA
          [email protected]
          http://www.talsystems.com

          Comment


          • #6
            thanks Eric
            i was in the hopes i could get want i wanted without having the console program run as a child to another process, because the console program is being supported by a third party and it runs our large database which i am not willing to make much changes to the environment under which it runs.
            when problems come up, i do not want the third party to not be pointing fingers to others.
            it is a shame that people do that when they know conditions exist where their programs have problems, but i cannot afford for the third party to point fingers.
            p purvis

            Comment


            • #7
              i was in the hopes i could get want i wanted ....
              Which was ...?
              ... without having the console program run as a child to another process....
              Now THAT you can do; and if that console program is properly respecting standard handles you can now do lots of stuff in a supported fashion.

              But what was it you wanted? "save screen buffer address to disk" is a "how" not a "what."
              Michael Mattias
              Tal Systems (retired)
              Port Washington WI USA
              [email protected]
              http://www.talsystems.com

              Comment


              • #8
                MCM
                thanks for responding
                i would hope child process is the term that best fit.
                i was able to write a test program about 12 months ago where i used the api functions allocconsole and createfile to spin off console program and capture the screen then sent the screen buffer to the a file every so much of a second and it appears everything when fine there.

                is that what you where to referring to MCM.

                the programs i wanted to take screen shots of are both DOS and CONSOLE programs.

                i will put up my example program
                this was a windowed program as i look back now
                Code:
                'consoletofile
                'pbwin 8.03
                '
                #COMPILE EXE
                '#Dim All
                #REGISTER NONE
                #INCLUDE "WIN32API.INC"
                
                FUNCTION GetConsoleWindow AS LONG
                        DIM lpConsName1 AS ASCIIZ * 256, lpConsName2 AS ASCIIZ * 256, hWndConsole1 AS LONG, hWndConsole2 AS LONG
                        DIM temp AS STRING
                        GetConsoleTitle lpConsName1, SIZEOF(lpConsName1)
                        DO
                           IF LEN(lpConsName2) >= SIZEOF(lpConsName2) THEN EXIT FUNCTION
                           lpConsName2 = lpConsName2 + " "
                           SetConsoleTitle lpConsName2
                           DO
                              hWndConsole1 = FindWindow(BYVAL %NULL, lpConsName2)
                              IF hWndConsole1 THEN EXIT DO ELSE ApiSleep 40
                           LOOP
                           IF hWndConsole1 = hWndConsole2 THEN EXIT DO
                           hWndConsole2 = hWndConsole1
                        LOOP
                        FUNCTION = hWndConsole1
                        SetConsoleTitle lpConsName1
                END FUNCTION
                
                FUNCTION PBMAIN
                
                  DIM Buf AS STRING, i AS LONG, j AS LONG, sBuf AS STRING
                  DIM hFile AS LONG
                
                  commandline$=TRIM$(COMMAND$)
                  TEMP&=INSTR(commandline$," ")
                  IF TEMP&=0& THEN
                        MSGBOX "a bad command line was given, see examples below"+_
                        $CRLF+_
                        "consoletofile.exe <space> drive:directory\outputfile directory without any spaces <space> consoleprogram"+_
                        $CRLF+_
                        "consoletofile c:\temp\consoleoutput.txt program.exe"+_
                        $CRLF+_
                        "the drive and directory of the consoleoutput.txt file must already exist before running this program",_
                        %MB_TASKMODAL OR %MB_OK,"consoletofile.exe":_
                        EXIT FUNCTION
                
                  END IF
                
                REM test for bad characters in the commandline
                  filetestchar$="ABCDEFGHIJKLMNOPQRSTUVWXYZ 0123456789_.:\[email protected]        "
                  FOR CHECK&=1& TO LEN(commandline$)
                    IF INSTR(filetestchar$,UCASE$(MID$(commandline$,CHECK&,1&)))=0 THEN
                         MSGBOX "there seems to be an unaccepted character on the command line check for bad characters"+_
                                $CRLF+_
                                "only use the following characters "+filetestchar$+_
                                $CRLF+_
                                "the command tail given is listed below, found a bad character at position"+STR$(check&)+_
                                $CRLF+_
                                commandline$,_
                                %MB_TASKMODAL OR %MB_OK,"consoletofile.exe":_
                                EXIT FUNCTION
                     END IF
                
                   NEXT CHECK&
                
                
                
                        outputtofile&=0&
                        SCREENTOFILE$=""
                        cmdline$ = ""
                        SCREENTOFILE$=TRIM$(MID$(commandline$,1,TEMP&))
                        cmdline$=RIGHT$(commandline$,LEN(commandline$)-TEMP&)
                        cmdline$=TRIM$(cmdline$)
                
                        REM test to see if output file exist, and if it does exist no console output will be saved
                        ofile%=FREEFILE
                        ERRCLEAR
                        OPEN SCREENTOFILE$ FOR INPUT AS #ofile%
                        IF ERR=53 THEN
                             outputtofile&=0&
                        END IF
                        IF ERR=76 THEN
                             outputtofile&=1&
                             MSGBOX "There is no directory for "+screentofile$+", therefore no console output will be saved"+_
                             $CRLF+_
                             "press anykey to continue",_
                             %MB_TASKMODAL OR %MB_OK,"consoletofile.exe"
                        END IF
                        IF ERR=0 THEN
                             CLOSE #ofile%
                             outputtofile&=1&
                             MSGBOX "The file "+screentofile$+" already exist, therefore no console output will be saved to this file",_
                             %MB_TASKMODAL OR %MB_OK,"consoletofile.exe"
                        END IF
                
                        ERRCLEAR
                
                        IF  outputtofile&=0&  THEN
                        ofile%=FREEFILE
                        OPEN SCREENTOFILE$ FOR OUTPUT LOCK READ WRITE AS #ofile%
                           IF ERR=76 THEN
                               outputtofile&=1&
                               MSGBOX "testthere is no directory for "+screentofile$+", therefore no console output will be saved",_
                               %MB_TASKMODAL OR %MB_OK,"consoletofile.exe":_
                           END IF
                
                           IF ERR<>0 THEN
                               outputtofile&=1&
                               MSGBOX "There is somekind of error using the file "+screentofile$+", therefore no console output will be saved",_
                               %MB_TASKMODAL OR %MB_OK,"consoletofile.exe"
                           END IF
                
                           IF ERR=0 THEN
                             WRITE #ofile%,SPACE$(4000)
                             CLOSE #ofile%
                           END IF
                
                        END IF
                
                       ERRCLEAR
                
                        AllocConsole
                        pid???=SHELL (cmdline$,1)
                        SLEEP 500
                        i = GetConsoleWindow
                
                
                         READSCREENSTART:
                        hFile = CreateFile("CONOUT$", %GENERIC_READ OR %GENERIC_WRITE, _
                            %FILE_SHARE_READ OR %FILE_SHARE_WRITE, BYVAL 0&, %OPEN_ALWAYS, _
                            %FILE_ATTRIBUTE_NORMAL, BYVAL 0&)
                
                             IF hFile = %INVALID_HANDLE_VALUE THEN
                                 i = GetConsoleWindow
                                 freeconsole
                                 KILL SCREENTOFILE$
                                 SendMessage i, %WM_SYSCOMMAND, %SC_CLOSE, 0
                                  KILL SCREENTOFILE$
                                  EXIT FUNCTION
                             END IF
                
                        DIM sb AS CONSOLE_SCREEN_BUFFER_INFO
                        GetConsoleScreenBufferInfo hFile, sb
                
                        BUF=""
                        SBUF=""
                
                        Buf = SPACE$(sb.dwsize.x * sb.dwsize.y)
                        ReadConsoleOutputCharacter hFile, BYVAL STRPTR(Buf), LEN(Buf), BYVAL MAKDWD(0, 0), i
                        CloseHandle hFile
                
                        OemToCharBuff BYVAL STRPTR(Buf), BYVAL STRPTR(Buf), LEN(Buf)
                        FOR i = 0 TO sb.dwsize.y - 1
                           sBuf = SBuf + MID$(Buf, i * sb.dwsize.x + 1, sb.dwsize.x) + $CRLF
                        NEXT
                
                
                        temp$=TRIM$(sbuf)
                        REPLACE $CR WITH " " IN TEMP$
                        REPLACE $LF WITH " " IN TEMP$
                        temp$=TRIM$(temp$)
                
                        IF LEN (temp$)=0 THEN
                                i = GetConsoleWindow
                                freeconsole
                                SendMessage i, %WM_SYSCOMMAND, %SC_CLOSE, 0
                                EXIT FUNCTION
                         END IF
                
                        REM IF outputtofile&=1& then sleep 4000:goto readscreenstart
                        ofile%=FREEFILE
                        producefile:
                        ERRCLEAR
                
                        OPEN SCREENTOFILE$ FOR OUTPUT LOCK READ WRITE AS #ofile%
                        IF ERR THEN SLEEP 1250:GOTO producefile
                        ERRCLEAR
                        WRITE #ofile%,sb.dwsize.x,sb.dwsize.y
                        WRITE #ofile%,temp$
                        CLOSE #ofile%
                        ERRCLEAR
                
                        SLEEP 1250
                        GOTO READSCREENSTART
                
                         END FUNCTION
                p purvis

                Comment


                • #9
                  You want a screen shot of target console/MS-DOS program - excuse me, a non-cooperating console/MS-DOS program - saved to disk every four seconds?

                  Well, why didn't you just say so?

                  I don't know how to do that but at least we know your goal now.

                  MCM
                  Michael Mattias
                  Tal Systems (retired)
                  Port Washington WI USA
                  [email protected]
                  http://www.talsystems.com

                  Comment


                  • #10
                    MCM
                    i am after the text
                    the program above program was just a test
                    i had to start somewhere
                    Last edited by Paul Purvis; 18 Jul 2008, 04:07 PM.
                    p purvis

                    Comment


                    • #11
                      Oh, you want the text on the screen of a target non-cooperating console or MS-DOS program saved to disk every four seconds.

                      I don't know how to do that, either.
                      Michael Mattias
                      Tal Systems (retired)
                      Port Washington WI USA
                      [email protected]
                      http://www.talsystems.com

                      Comment


                      • #12
                        Michael,
                        if you want to chit chat, there is a cafe section.
                        if you cannot help why bother with a response.
                        p purvis

                        Comment


                        • #13
                          I don't think this is possible with existing consoles, due to handle inheritance. Now if you wrote a "shell" program that used CreateProcess with both the main console and your "addon" utility (to inherit both handles), that might work. Failing that, try Google to see if anyone has the same requirement. This forum is but a bright star in the Win32 development universe
                          kgpsoftware.com | Slam DBMS | PrpT Control | Other Downloads | Contact Me

                          Comment


                          • #14
                            >if you cannot help why bother with a response

                            As a Real Life demonstration of the importance of communications skills to applications developers.

                            You must be able to elicit from the user what it is he really wants.

                            I have seen far too many systems which were technical home runs but user strikeouts for lack of mutual undestanding.
                            Michael Mattias
                            Tal Systems (retired)
                            Port Washington WI USA
                            [email protected]
                            http://www.talsystems.com

                            Comment


                            • #15
                              [quote=kev peel;291082]i don't think this is possible with [i]existing</i> consoles.

                              Sure you can, screen readers for the blind do it all the time.
                              Take a look at nvda (opensource) and there's another one I can't remember at the moment.
                              They're not written in powerbasic, and they use msaa for the work, but they do read the screens of dos applications quite well.
                              I've not made any headway in porting the window bridge screen reader to powerbasic, but I'll go look at it's source, and see if I can find anything refering to how it grabs content from other programs, and perhaps post something here explaining the process, even if I can't code it directly. That may help.
                              http://www.softcon.com]


                              for hosting/internet


                              access.

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