C ++ shared_ptr并从类中读取

Question

I have a problem with simple reading from the file that shares file pointer between a few objects (It works for me with just simple istream, but not when I am using shared pointer of istream pointers).

I am trying to read the whole file to the buffer (file itself is a few lines long.

The code compiles, but throws segmentation fault.

The class that uses shared_ptr:

RecordsSplitter::RecordsSplitter(char *filename):iStream( new ifstream(filename, ifstream::in|ifstream::binary))
{
}


string RecordsSplitter::buildRecord() {
       char *buffer;
        int buffer_length;
        iStream->seekg (0, ios::end)_
        buffer_length = iStream->tellg();
        cout << buffer_length;
        iStream->seekg(0, ios::beg);
        iStream->read(buffer,buffer_length);
        iStream->close();
        cout << buffer;

        return 0;
}







int main(int argc, char* argv[]) {
        RecordsSplitter *splitter;
        splitter = new RecordsSplitter(argv[2]);
        int return_num = splitter->buildRecord();
        return 0;
}

Answer 1

You declare your buffer but you don't initialise it anywhere. You need this in your buildRecord function or a use of malloc if you so desire.

buffer = new char[buffer_length];

Your seg fault is caused by this uninitialised pointer

Don't forget to clean up!

delete[] buffer;