Problem with File Handling in C++

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Hey,

I am having some problem in the code given below, why "line" parameter is not working?
//////////////////////////////Code//////////////////////////////////////////

C#

#include<iostream>
#include<fstream>
using namespace std;

void Edit_Line(string path,int Delimer,int line,string sLine)  

 //Parameter "line" is giving large values"
{
    char* temp;
    temp=new char[50];
    temp[49]='\0';
    bool Loopbrk=false,isWritten=false;
    int iCounter=0,iDelimer=0,i=0,count=0;
    fstream myfile(path);
    char keystroke;
    while(myfile.good())
    {
        myfile.get(keystroke);
        if(keystroke=='\n')
            iCounter++;
        while(iCounter==line)
        {
            myfile.get(keystroke);
            if(keystroke=='$')
                iDelimer++;
            while(iDelimer==Delimer)
            {
                if(isWritten==false)
                {
                    int iCounter=0;
                    int size=sLine.length();
                    while(iCounter<=size)
                    {
                        myfile<<sLine[iCounter];
                        iCounter++;
                    }
                    isWritten=true;
                }
                myfile.get(keystroke);
                myfile<<" ";
                i++;
                if(keystroke=='$')
                {
                    Loopbrk=true;
                    break;
                }
            }
            if(Loopbrk==true)
                break;
        }
        if(Loopbrk==true)
                break;
    }
    myfile.close();
    delete []temp;
}
void main()
{
    Edit_Line("student.txt",2,4,"Hello");
}

///////////////////////////student.txt//////////////////////////

l114443$Talha Jamil$samsung$12$17$2004$UnderGraduate$!
l114445$Kamran Javed$jannat123$12$12$2009$UnderGraduate$!
l114093$Imran Khan$pluto123$11$4$2009$UnderGraduate$!
l114444$Jamil Ahmed$origin123$11$12$2009$UnderGraduate$!
l114606$Zain Malik$samsung$9$16$2009$Graduate$!
l114441$Saad Kamran$samsung$11$4$2004$Graduate$!

Posted 12-Dec-12 5:44am

saad_lah

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saad_lah 12-Dec-12 11:49am

While Debugging the problem is in
temp=new char[50];
temp[49]='\0';

after these lines parameter "line" acquire some garbage value, something like dynamic memory is erasing parameter "line" value

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chaau · Answer 1 · 2012-12-12T11:56:00

I can see a few problems here.

1. Get rid of these lines:

C++

char* temp;
temp=new char[50];
temp[49]='\0';
delete []temp;

Explanation: variable temp is not used anywhere in the code

2. Rename iCounter to a different name in this chunk of code:

C++

int iCounter=0;
int size=sLine.length();
while(iCounter<=size)
{
    myfile<<sLine[iCounter];
    iCounter++;
}

Explanation: the same variable is used in the main loop to count the number of lines

3. In the loop above (see #2), you need to change (provided you have renamed the variable to iCounter1):

C++

while(iCounter1<size)>

Explanation: You are accessing past the address of the sLine string.

4. Just a cosmetic change: get rid of variable i. It is not used.

Other than that, I believe the program should work. Did not test it