CODEWITHSUNDEEP
c++
user3091765
user3091765

Reputation: 13

Delete file and record in C++

I'm new to C++. I have written a program that allow user to add in file to my data folder. But now I want to also allow user to delete the files. So in the case below, it will displayed a list of available files from the data folder. The user chooses the file by entering the number, for example, [i] to delete the file from the list and also delete in the data folder. I have tried writing codes to delete it, but I got this error "Debug Assertion Failed". Is there something wrong with my delete?

case 'D':
case 'd':
    myfiles = getFiles();
    cout << "Current available objects:" << endl;
    for (int i = 0; i < myfiles.size(); i++)
        cout << '[' << i << ']' << ' ' << myfiles[i] << endl;
    cout << endl << "Enter file number to delete or \"end\" to exit:";
    while (cin >> str)
    {
        if (str == "end")
            break;
        input = str2int(str);
        if (input >= 0 && input < myfiles.size())
        {
            //Delete object
            newname = ExePath() + "/data/" + myfiles[input];
            name = new char[newname.size() - 1];
            strcpy(name, newname.c_str());
            remove(name);

            //Print out the available objects
            cout << "\nCurrent available objects:" << endl;
            for (int i = 0; i < myfiles.size(); i++)
                cout << '[' << i << ']' << ' ' << myfiles[i-1] << endl;
            cout << endl << "Enter file number to delete or \"end\" to exit:";
        }
        else cout << "Invalid input." << endl;
    }
    break;

Upvotes: 1

Views: 580

Answers (2)

Christian Hackl
Christian Hackl

Reputation: 27518

I think it's this loop:

 for (int i = 0; i < myfiles.size(); i++)
                cout << '[' << i << ']' << ' ' << myfiles[i-1] << endl;

When i is 0, then you are trying to access myfiles[-1]. If myfiles is not an object of a very strange class which overloads operator[] in an unusual way, but is instead just a normal std::vector (99% more likely :)), then this is undefined behaviour, i.e. anything can happen (including the error message you see).

As a side note, you are performing pointer operations instead of using real C++ strings (i.e. std::string objects) consistently. Which is surprising, because you already seem to have a std::string there (newname), and you seem to know how to use it together with (old / legacy / C) functions requiring a char const *, namely with its c_str() member function. Why don't you just write remove(newname.c_str()) ?

Upvotes: 2

honk
honk

Reputation: 9743

At least you should use

name = new char[newname.size() + 1];

instead of

name = new char[newname.size() - 1];

Anyway, I don't see the need to copy the string. What will also fail is:

myfiles[i-1]

in your second loop, because it starts from 0.

Upvotes: 1

Related Questions