Heap Corruption Detected

[imwan]

I have written this code which reads a file and stores it in a struct. and from struct it saves the data in a new file. The file name is inserted by the user and new file name is also generated dynamically.
But it is giving error.

HEAP CORRUPTION DETECTED: After Normal Block (#142) at 0x008620C8
CRT detected that the application wrote to memory after end of Heap buffer.

Here is my code

#include<iostream>
#include<fstream>
#include<string>
#include<iomanip>

using namespace std;

struct Data{
	string ticker;
	double	date;
	float open;
	float high;
	float low;
	float close;
	long volume;
};

int main()
{
	Data data;
	int i=0;
	string name;
	ifstream isf;
	ofstream osf;
	string sline;
	char* cline = NULL;
	char* chr = NULL;
	char* jDate = NULL;
	char* aChr = NULL;
	char* d = NULL;
	int day;
	int month;
	int year;
	int intRes1;
	int intRes2;
	int intRes3;
	//int jdn1;
	int flag = 0;
	long numlines = 0;
	//int openFileCheck = 0;
	string fileName;

	cout << "Please enter a file name: \n";
	cin >> name;

	try{
		isf.open(name.data()); 

		while (! isf.eof() )
		{
			getline(isf,sline);
			numlines++;

			if(numlines == 1)
				continue;

			cline = new char[sline.length()+1];
			strcpy(cline, sline.c_str());

			chr = strtok(cline,",");
			data.ticker +=string(chr);
			fileName +=string(chr);

			aChr = chr;
			strcat(aChr, ".txt");
			fileName =string(aChr);

			osf.open(fileName.data());
			osf<<data.ticker<<"	";

			strcpy(cline, sline.c_str());
			chr = strtok(cline,",");

			while(chr != NULL && ! isf.eof()){

				if(flag == 1){
					data.ticker =string(chr);
					osf<<data.ticker<<"	";
					flag = 0;
				}

				chr = strtok(NULL,",");

				if(i==0){
					d= chr;	
					jDate = strtok(d,"/");
					day = atoi(jDate);
					jDate = strtok(NULL,"/");
					month = atoi(jDate);
					jDate = strtok(NULL,"/");
					year = atoi(jDate);

					intRes1 = ((2 - year / 100) + (year / 400));
					intRes2 = int(365.25 * year);
					intRes3 = int(30.6001 * (month + 1));
					data.date = (intRes1 + intRes2 + intRes3 + day + 1720994.5);

					osf<<data.date<<"	";
					i++;

					strcpy(cline, sline.c_str());
					chr = strtok(cline, ",");
					chr = strtok(NULL,",");
				}

				else if(i==1){
					data.open = atof(chr);
					osf<<data.open<<"	";
					i++;
				}

				else if(i==2){
					data.high = atof(chr);
					osf<<data.high<<"	";
					i++;
				}

				else if(i==3){
					data.low = atof(chr);
					osf<<data.low<<"	";
					i++;
				}

				else if(i==4){
					data.close = atof(chr);
					osf<<data.close<<"	";
					i++;
				}

				else if(i==5){
					data.volume = atol(chr);
					osf<<data.volume<<'\n';
					flag = 1;
					i = 0;
					getline(isf,sline);
					strcpy(cline, sline.c_str());
					chr = strtok(cline,",");
				}

			}//end of while(chr != NULL)
			osf.close();
		}//end of while (! isf.eof() )

	}//end of Try
	catch(...){
		cout<< "Can't find the file!\n";
	}

	delete [] cline;
	delete chr;
	delete d;
	delete aChr;
	delete jDate;

	cin.clear();
	cin.get();

	return 0;
}

[Protuberance]

I think you have to try place freeing memory code into the "try{...}catch()" block.
Because you allocate memory inside the try{}catch block, and free the memory outside of it.
If you raised an exception in allocating memory, and then try to free that memory you have raise the new exception.

And second - you try to free the memory, which was not allocated dinamically.
In your code it's

delete chr;
delete d;
delete aChr;
delete jDate;

lines.

[Salem]

cline = new char[sline.length()+1];
			strcpy(cline, sline.c_str());

			chr = strtok(cline,",");
			data.ticker +=string(chr);
			fileName +=string(chr);

			aChr = chr;
			strcat(aChr, ".txt");
			fileName =string(aChr);

This happens on your char array, where there is only just room for the characters you read, nevermind adding .txt to it.

1. You're always doing fileName += something
it gets longer and longer.

2. Add the suffix with
fileName += ".txt";
rather than messing with the char array.

IMO, you should learn how to do this kind of thing with a std::string, rather than running to c-style strtok() for short-term convenience. You only typed a few lines, and it blew up anyway.

> And second - you try to free the memory, which was not allocated dinamically.
True, but deleting NULL is harmless.

[imwan]

I have changed my code exactly the way both the replies have said. But the problem persists.

chr = strtok(cline,",");
data.ticker =string(chr);
fileName =string(chr);

//      aChr = chr;
//	strcat(aChr, ".txt");
fileName +=".txt";

and i have put

delete [] cline

in try{}..

[mrnutty]

strcpy(cline, sline.c_str());
chr = strtok(cline,",");
data.ticker +=string(chr);

You problem is probably there. whats sline.c_str() ? Its not
initialized to anything.

[imwan]

still the problem is there =(

[Dave Sinkula]

IMO, you should learn how to do this kind of thing with a std::string, rather than running to c-style strtok() for short-term convenience. You only typed a few lines, and it blew up anyway.

I have changed my code exactly the way both the replies have said.

still the problem is there =(

Why not show us the code you're attempted with the std::string version?

[DdoubleD]

still the problem is there =(

Repost your code changes (complete code) so it can be examined with the changes.