[Solved] how to operate on global variables in c++

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The problem is that you’re storing pointers into cstr in argv, but then you’re deleting cstr at the end of the parse() function. Get rid of:

delete[] cstr;

Also, you should pass argc by reference. Otherwise, when you update it in the parse() function it won’t update the caller’s variable. So it should be:

void parse(string str, int &argc, char *argv[])

However, you also have a memory leak. You’re creating a new cstr each time parse is called, but never deleting it. You should change the function to return cstr, and have the caller delete it when they’re done with that parsed line.

char *parse(str str, int &argv, char *argv[]) {
    ...
    return cstr;
}

Then in your main() loop, do:

int main( void ) 
{
    string theLine;

    while (true) 
        {
            cout << "myshell> ";
            getline(cin,theLine);
            cout << "Command was: " << theLine << endl;
            if ((theLine == "exit") || (cin.eof()) || (theLine == "quit"))
                exit(0); 

            char *cstr = parse(theLine, argc, argv);
            cout << "argv[0] " << argv[0] << "\n";
            delete[] cstr;
        }   
}

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solved how to operate on global variables in c++