Access violation with CFtpFileFind ::FindFile

Following is a correspondence with Mr. Newcomer (thanks allot for the
serious reference and remarks).
Following your remarks I tried to pinpoint the access violation error by
eliminating codes and trial & error. I noticed that the following code may
cause the problem -

 CFtpFileFind finder(pConnect);
bWorking = finder.FindFile(NULL);

It may not be obvious but the target machine on which the connection is
established is a VMS machine and not a PC. Remarking out the following line
stoped the debugger error:

bWorking = finder.FindFile(NULL);
Can you farther advise?

Thanks

Gil

Hint: when posting code for a problem, post the RELEVANT code. For example,
remove
multiple blank lines, all code that is commented out, useless comments, etc.
Make it
single spaced. Indicate where the error occurred (the posting was so long
and tedious
that if you did identify the line on which the error occurred, I missed it).
You have to
show us the RELEVANT code, not just an entire .cpp file! You gave us a ton
of code, and
not the slightest hint as to which line was being executed when the problem
occurred.

It is hard to figure out what you are trying to accomplish here. You bring
up a dialog,
and then no matter what the user does, you go into some loop with a dead GUI
(as in really
dead) with sleeps of 20 minutes built in. You are using printf in a Windows
app, which is
pointless. If you want a console app, then write a console app that has MFC
in it. If
you want a Windows app, write a Windows app. This is neither.

You are declaring static variables with local scope, which is exceptionally
bad style in
Windows programs, and apparently a throwback to bad programming habits from
MS-DOS or Unix
or some other primitive operating system. Do not do this, particularly when
it serves no
detectably useful purpose.

Can you perhaps expalin why your GetCurDirectory specifies a buffer one
character larger
than the actual buffer? Do you enjoy buffer overrun bugs?

You did not specify where LOCAL_DISK_FTP is defined, and why are you
comparing it to
integers like 0, 1 and 2 when you should be using names that actually have
meaning? Have
you heard of #define?

There are so many things wrong with the fundamental structure of this code
that I would
suggest a major restructuring before attempting to solve any problems.

You also have a weird mixture of Unicode-aware code (TCHARs) and 8-bit only
code (e.g.,
char data type, quoted strings without _T() around them, printf). I doubt
this is the
problem, but it's bad style. So is using commas in declaration lists.

Next time, post the relvant code, and ONLY the relevant code; and indicate
where the error
occurred. A call stack backtrace to your code is useful, and when it is in
your code,
show us in the listing what line failed. We cannot learn what is going on
by virbrations
in the psychic ether; you have to give us the data we need, and most
importantly,
eliminate the noise (which this code is full of).
joe

On Thu, 27 Jul 2006 09:25:44 +0200, "Gil" <gil@mandat.com> wrote:


Joseph M. Newcomer [MVP]
email: newcomer@flounder.com
Web: http://www.flounder.com
MVP Tips: http://www.flounder.com/mvp_tips.htm

Yesterday I posted the following, but I didn't supply the code. Here is the
problem and the code follows.
Thanks in advance for all

I use try catch mechanism and notice (in the debugger) that whenever the
control arrives to the catch section, I get an access violation (error
0xC0000005)even though it skips this section immediately.

I pass compilation without any problems and the program runs fine but
crashes every few hours.

the relevant code

// mfc_concol.cpp : Defines the class behaviors for the application.

//

#include "stdafx.h"

#include "mfc_concol.h"

#include "mfc_concolDlg.h"

#include <afxinet.h>

#include "tests.h"

#ifdef _DEBUG

#define new DEBUG_NEW

#undef THIS_FILE

static char THIS_FILE[] = __FILE__;

#endif

////////////////////////////////////////////////////////////////////////////
/

// CMfc_concolApp

BEGIN_MESSAGE_MAP(CMfc_concolApp, CWinApp)

      //{{AFX_MSG_MAP(CMfc_concolApp)

            // NOTE - the ClassWizard will add and remove mapping macros
here.

            // DO NOT EDIT what you see in these blocks of generated
code!

      //}}AFX_MSG

      ON_COMMAND(ID_HELP, CWinApp::OnHelp)

END_MESSAGE_MAP()

////////////////////////////////////////////////////////////////////////////
/

// CMfc_concolApp construction

CMfc_concolApp::CMfc_concolApp()

{

      // TODO: add construction code here,

      // Place all significant initialization in InitInstance

}

extern BOOL Calculate_Average(CString LastFile);

extern BOOL Calculate_Average_CFile(CString LastFile);

////////////////////////////////////////////////////////////////////////////
/

// The one and only CMfc_concolApp object

CMfc_concolApp theApp;

////////////////////////////////////////////////////////////////////////////
/

// CMfc_concolApp initialization

BOOL CMfc_concolApp::InitInstance()

{

      // Standard initialization

      // If you are not using these features and wish to reduce the size

      // of your final executable, you should remove from the following

      // the specific initialization routines you do not need.

      /* delet dlg popup

      CMfc_concolDlg dlg;

      m_pMainWnd = &dlg;

      int nResponse = dlg.DoModal();

      if (nResponse == IDOK)

      {

            // TODO: Place code here to handle when the dialog is

            // dismissed with OK

      }

      else if (nResponse == IDCANCEL)

      {

            // TODO: Place code here to handle when the dialog is

            // dismissed with Cancel

      }

      */

   CString SubString;

   CString curdir("C:\\");;

   char CurDirectory[100];

   static CString FileName, LastFile,prev_run_last_file;

   CTime CreateTime, LastFileTime;

   CInternetSession sess(_T("MyProgram/1.0"));

   CFtpConnection* pConnect = NULL;

   ::GetCurrentDirectory((sizeof(CurDirectory) +1), CurDirectory);

      while (1)

      {

      // find out the last file from the seria and bring it

      //system("c:\\temp\\ActivateBringFile.bat");

  try

   {

        // debug

            if (LOCAL_DISK_FTP == 1)

             pConnect =
sess.GetFtpConnection("8.30.0.165","mbt-domain\\66711","JKjk8304");

            else if (LOCAL_DISK_FTP == 2)//release amsim

            pConnect =
sess.GetFtpConnection("8.8.16.120","system","geler42");

            else if (LOCAL_DISK_FTP == 0 || LOCAL_DISK_FTP == 3)//release
amrt2

            pConnect =
sess.GetFtpConnection("8.8.16.132","system","HtggFR76");

       // test local pc

       //GetCurrentDirectory((sizeof(CurDirectory) +1), CurDirectory);

       //BOOL res1 = pConnect->SetCurrentDirectory("..\\");

       //res1 = pConnect->SetCurrentDirectory("..\\");

       //res1 = pConnect->SetCurrentDirectory("..\\");

       //res1 = pConnect->SetCurrentDirectory(".\????? T????\mfc_consol");

       pConnect->GetCurrentDirectory(curdir);

       //res1 = pConnect->SetCurrentDirectory(curdir);

      // use a file find object to enumerate files

      CFtpFileFind finder(pConnect);

        // check if we know the last file name

       //res1 = pConnect->SetCurrentDirectory("..\\");

        //4-6-06 add going to the right place

            BOOL res1;

            if (LOCAL_DISK_FTP == 1)

            res1 = pConnect->SetCurrentDirectory(".\?????
T????\mfc_consol");

            else if (LOCAL_DISK_FTP == 2)//release amsim

            res1 = pConnect->SetCurrentDirectory(".\?????
T????\mfc_consol");

            else if (LOCAL_DISK_FTP == 3)//release amrt2

            res1 =
pConnect->SetCurrentDirectory("SYS$COMMON:[SYSMGR.LESHER]");

            else if (LOCAL_DISK_FTP == 0)//release amrt2

            res1 =
pConnect->SetCurrentDirectory("DSA2:[USERS.GCS_DATA.TRACK.ON_LINE_MONITOR]")
;

            //res1 =
pConnect->SetCurrentDirectory("SYS$COMMON:[SYSMGR.TEMP]");

            //res1 = pConnect->SetCurrentDirectory("dsa2:[users_gcs_data]");

            pConnect->GetCurrentDirectory(curdir);

            //Last file 5-6-06

            //{"AM1_MBT1_20060227_2259.MAG;1"}

        // start looping

        BOOL bWorking;

// if (LastFile == "")// at the beginning

// bWorking = finder.FindFile(NULL);

// else // after ther first run

// bWorking = finder.FindFile(LastFile);

        bWorking = finder.FindFile(NULL);

      //1BOOL bWorking = finder.FindFile("AM1_MBT1_20061205_1456.MAG");

      bWorking = finder.FindNextFile();

      //CString BeforeLastFile = (LPCTSTR) finder.GetFileURL());

        //LastFile = finder.GetFileName();

        //LastFile = "AM1_MBT1_20060000_0000.MAG";

        LastFile = "AM1_MBT1_20063131_0000.MAG";

        //CString monthstring, datestring

        while (bWorking)

      {

      // LastFile = "AM1_MBT1_20063131_0000.MAG";

             FileName = finder.GetFileName();

             //GetCurrentDirectory((sizeof(CurDirectory) +1),
CurDirectory);

             //SetCurrentDirectory(CurDirectory);

             // TEST

             //FileName = "AM1_MBT1_20061205_1456.MAG";

           SubString = FileName.Left(9);

                  if(FileName.Left(9) == "AM1_MBT1_")

                  {

                    CString monthstring = FileName.Mid(13,2);

                    int month = atoi(monthstring);

                    //if (month >= atoi(LastFile.Mid(13,2)))

                    if (month <= atoi(LastFile.Mid(13,2)))

                    {

                        if (month < atoi(LastFile.Mid(13,2)))

                        LastFile = FileName;

                        //continue;

                        // check date

                          CString datestring = FileName.Mid(15,2);

                          int date = atoi(datestring);

                          //if (date >= atoi(LastFile.Mid(15,2)))

                          if (date <= atoi(LastFile.Mid(15,2)))

                          {

                        if (date < atoi(LastFile.Mid(15,2)))

                              LastFile = FileName;

                              //continue;

                           // check hour

                             CString hourstring = FileName.Mid(18,2);

                     int hour = atoi(hourstring);

                               //if (hour >= atoi(LastFile.Mid(18,2)))

                               if (hour <= atoi(LastFile.Mid(18,2)))

                               {

                                    if (hour < atoi(LastFile.Mid(18,2)))

                                    LastFile = FileName;

                                    //continue;

                                 // check minutes

                                   CString minuitstring =
FileName.Mid(20,2);

                           int minuit = atoi(minuitstring);

                                     //if (minuit >=
atoi(LastFile.Mid(20,2)))

                                     if (minuit <= atoi(LastFile.Mid(20,2)))

                                     {

                                          LastFile = FileName;

      //Bring the file to the PC

      if (LOCAL_DISK_FTP == 0 || LOCAL_DISK_FTP == 3)// only in debug

      BOOL res = pConnect->GetFile(LastFile,LastFile,

      TRUE,FILE_ATTRIBUTE_ARCHIVE,

      INTERNET_FLAG_TRANSFER_ASCII,

      1);

      //open file and read lines 10-16

      //4-7-06 remove file at source

      BOOL res = pConnect->Remove(LastFile);

      //Calculate_Average(LastFile);

      if ( prev_run_last_file != LastFile ) // calculate only if new file

      Calculate_Average_CFile(LastFile);

      prev_run_last_file = LastFile; // calculate only if new file

      DeleteFile(LastFile);

      LastFile = "AM1_MBT1_20063131_0000.MAG";

                                     }

                               }

                          }

                    }

                  }

             bWorking = finder.FindNextFile();

         //CString LastFile = (LPCTSTR) finder.GetFileURL());

      }// while (working)

      /*

      //Bring the file to the PC

      if (LOCAL_DISK_FTP == 0 || LOCAL_DISK_FTP == 3)// only in debug

      BOOL res = pConnect->GetFile(LastFile,LastFile,

      TRUE,FILE_ATTRIBUTE_ARCHIVE,

      INTERNET_FLAG_TRANSFER_ASCII,

      1);

      //open file and read lines 10-16

      //4-7-06 remove file at source

      BOOL res = pConnect->Remove(LastFile);

      //release

      //Calculate_Average(LastFile);

      if ( prev_run_last_file != LastFile ) // calculate only if new file

      Calculate_Average_CFile(LastFile);

      prev_run_last_file = LastFile; // calculate only if new file

      //BOOL res = pConnect->Remove(LastFile);

      */

      pConnect->Close();

  }// try

      //read lines 10 - 16

   catch (CInternetException* pEx)

   {

      TCHAR sz[1024];

      pEx->GetErrorMessage(sz, 1024);

      printf("ERROR! %s\n", sz);

      pEx->Delete();

   }

      // sleep 20 minuits

      if (LOCAL_DISK_FTP == 0)

      Sleep(20*60*1000);

      else if (LOCAL_DISK_FTP == 3)

      Sleep(20*60*10);

      }// while (1)

      // open file GCS$DATA:[TRACK.MEASR]AM1_MBT1_2006014_1240.MAG

      // Since the dialog has been closed, return FALSE so that we exit the

      // application, rather than start the application's message pump.

      return FALSE;

}