CODEWITHSUNDEEP
c++windowsmsdn
mboronin
mboronin

Reputation: 925

Heap error in VS2010

I'm trying to implement the program, which recognizes Windows file attributes. I have a code, but sometimes, I receive heap error after passing return in the main block. Thank you for your attention and help!

#include "stdafx.h"
#include <Windows.h>
#include <conio.h>

_TCHAR* getStringAttributes(int value, _TCHAR* str[])
{
    DWORD d = GetFileAttributes(str[value]);
    _TCHAR* temp;

    switch(d)
    {
        case 2048: temp = L"Compressed\n"; break;
        case 32: temp = L"Archive\n"; break;
        case 16: temp = L"Directory\n"; break;
        case 16384: temp = L"Encrypted\n"; break;
        case 2: temp = L"Hidden\n"; break;
        case 128: temp = L"Normal\n"; break;
        case 1: temp = L"Readonly\n"; break;
        case 4: temp = L"System\n"; break;
        case 256: temp = L"Temporary\n"; break;
        default: temp = L"Error or unsupported attribute\n"; break;
    }

    return temp;
}

int _tmain(int argc, _TCHAR* argv[])
{
    _TCHAR* attString = new _TCHAR();
    char* ynAnswer = new char();

    if(argv[1] == NULL)
    {
        printf("%s\n","You didn't type file path. Try again?[Y/N]");
        gets_s(ynAnswer,10);

        if(*ynAnswer == 'y' || *ynAnswer == 'Y')
        {
            printf("%s\n","Type in a path to the file");
            argv[1] = new _TCHAR();
            _getws(argv[1]);

            if(argv[1] != L"")
            {
                printf("%s","Attribute: ");
                attString = getStringAttributes(1,argv);

                _tprintf(attString);
                printf("%s","for\n");
                _tprintf(argv[1]);
            }
        }
    }
    else
    {
        printf("%s","Attribute: ");
        attString = getStringAttributes(1,argv);
        _tprintf(attString);
    }

    printf("%s","Goodbye");
    getch();

    delete[] ynAnswer;
    delete[] attString;

    return 0;
}

Upvotes: 0

Views: 79

Answers (1)

SHR
SHR

Reputation: 8313

you input whole string into 1 or 2 bytes strings. These allocations:

_TCHAR* attString = new _TCHAR();
char* ynAnswer = new char();

Allocate only 1 item array.

it should be:

_TCHAR* attString = new _TCHAR[MAX_SIZE];
char* ynAnswer = new char[MAX_SIZE];

When MAX_SIZE must beeb defuned as macro.

even better is to use: 

 wstring attString ;
 string  ynAnswer;

 wcin>> attString;
 cin>>  ynAnswer;

More problem is the allocation in the line:

 argv[1] = new _TCHAR();

in addition to the previous answered problem, in this line argv[1] may not even exists. You should input to other buffer.

it can be like this:

wstring argv1;
if(argc <2){
   wcin>>argv1;
}else{
   argv1=argv[1]; 
}

now use argv1 instead of argv[1]

One more thing:

You are using _TCHAR as WCHAR.

when you use _TCHAR strings should be decalared as:

_T("some string")

not as:

L"some string".

Upvotes: 1

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