program quits when using getline..

This is a discussion on program quits when using getline.. within the C++ Programming forums, part of the General Programming Boards category; Code: /************************/ /**** GetEntries ****/ /************************/ void Phonebook::GetEntries(fstream &fFile) { int i=0; string test1; if(getline(fFile,test1,'|')==NULL) { return; } else { ...

  1. #1
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    program quits when using getline..

    Code:
    /************************/
    /****   GetEntries   ****/
    /************************/
    void Phonebook::GetEntries(fstream &fFile)
    {
         int i=0;
         string test1;
         if(getline(fFile,test1,'|')==NULL)
         {
                        return;
         }
         else
         {
             while(getline(fFile,vEntries[i].name,'|') != NULL) //ERROR
             {
                       i++;
                       getline(fFile,vEntries[i].cnumber,'|');
                       getline(fFile,vEntries[i].hnumber,'|');
                       getline(fFile,vEntries[i].address);
             }
         }
    }
    The above code is suppose to take a .txt file and read in strings and set them to variables...Yes, for testing, I made sure there was a text file to open before actually trying it.

    It seems that when I get to the while loop with getline... this is when the program decides to quit and send a stupid windows error report. I know for a fact that it gets to the while loop because just to test it, I set up an if-conditional statement right before the while loop just to output a simple string "yep" and cin.get(); After pressing enter, the program crashes, obviously from the while loop? What could be wrong with it?

  2. #2
    and the hat of wrongness Salem's Avatar
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    Is ventries an array of sufficient size?

    > i++
    Why are you incrementing the index between reading the name and reading the address.
    Won't that screw up the data?
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  3. #3
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    ventries is a vector... and i will move the increment down to the bottom of the data

  4. #4
    For Narnia! Sentral's Avatar
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    Why not just use a linked list?

  5. #5
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    I'm not very familiar with linked lists... and this program is suppose to get me more familiar with Vectors.

  6. #6
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    invalid floating point operation error ?
    overflow?
    be carefull this

  7. #7
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    invalid floating point operation error ?
    overflow?
    I am not familiar with these terms...could you describe?

    Maybe if I posted where the function is located in the code, it would be easier to understand whats going on.

    Code:
    /*********************/
    /****  MOpenFile  ****/
    /*********************/
    void MOpenFile()
    {
        Phonebook pbEntry;
         
        string filename;
        string directory = "Data/";
        string dirfile;
        
        CLEARSCREEN;
        
        cout<<"\t\t\tPlease enter the filename: ";
        cin>>filename;
        filename.append(".txt");
        
        dirfile=directory+filename;
        
        fstream File(dirfile.c_str(), ios::in);
        if(File.fail())
        {
             cout<<"\n\t\t\t   Error opening file!";
             return;
        }
        else if(File.good())
        {
            cout<<"\n\t\t\t\'"<<filename<<"\' was opened!!"<<endl<<endl;
            cin.ignore();
            cin.get();
            CLEARSCREEN;
        }
          
        int entrymenu;
        bool done=false;
        
        pbEntry.GetEntries(File);   // Right here <<<<<<<<<<<<<<
        
       while(done==false)
       {
        cout<<setfill('-')<<setw(80)<<"-";
        cout<<"\t\t\t\t    "<<filename<<endl;
        cout<<setfill('-')<<setw(80)<<"-";
        
        pbEntry.DisplayEntries();
        
        cout<<"\t\t\t\t-(1)Add Entry"<<endl;
        cout<<"\t\t\t\t-(2)Delete Entry"<<endl;
        cout<<"\t\t\t\t-(3)Edit Entry"<<endl;
        cout<<"\t\t\t\t-(4)Save and Quit"<<endl;
        cout<<"\t\t\t->: ";
        cin>>entrymenu;
        switch(entrymenu)
        {
                         case 1:
                              pbEntry.Add();
                              break;
                         case 2:
                              pbEntry.Delete();
                              break;
                         case 3:
                              pbEntry.Edit();
                              break;
                         case 4:
                              done=true;
                              File.close(); //Erase once WriteEntries is called
                              return;
                              break;
                         default:
                                cout<<"\t\t\tNot Valid!";
        }
       }
        
        //WriteEntries(File);
    }
    Last edited by gL_nEwB; 05-20-2006 at 11:36 AM.

  8. #8
    and the hat of wrongness Salem's Avatar
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    My guess is you're accessing elements of the vector which don't exist yet.

    Say
    Code:
    <some type, same a ventries> temp;
             while(getline(fFile,temp.name,'|') != NULL) //ERROR
             {
                       getline(fFile,temp.cnumber,'|');
                       getline(fFile,temp.hnumber,'|');
                       getline(fFile,temp.address);
                       vEntries.push_back( temp );
             }
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  9. #9
    ZuK
    ZuK is offline
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    I don't like this line
    Code:
    while(getline(fFile,vEntries[i].name,'|') != NULL) //ERROR
    It shouldn't be the cause of your problem but you actually compare the return of getline ( a reference to the input stream that evaluates to a boolean ) to a null pointer.
    I would prefer
    Code:
    while( getline(fFile,vEntries[i].name,'|') )
    Kurt

  10. #10
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    Salem, you were very correct! LOL, I treated the GetEntries as the DisplayEntries function, thinking that there were already entries in the vector... thank you very much.

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