Exception in two line Xerces program

Question

The following code gives me an exception on the XMLFormatTarget line, but if I change the string from "C:/test.xml" to "test.xml" it works fine.

// test.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#include <xercesc/util/XMLString.hpp>
#include <xercesc/framework/LocalFileFormatTarget.hpp>

using namespace xercesc;

int main()
{
    XMLPlatformUtils::Initialize();

    XMLFormatTarget *formatTarget = new LocalFileFormatTarget("C:/test.xml"); 

    return 0;
}

[edit] Xerces exception is:

Error Message: unable to open file 'C:\test.xml'

Windows exception is:

Access is denied

Answer 1

It could be that you don't have sufficient permissions to write to C:\. In such a case, Xerces might report the error throwing an exception.

An Access Denied exception is typically what we could expect if you try to write to a system directory without administrator credentials.

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Maybe it has also something to do with the directory separators:

XMLFormatTarget *formatTarget = new LocalFileFormatTarget("C:\\test.xml");

On Windows, directory separators are backslashes "\". Some libraries don't care (and I never used Xerces, so I can't tell). In C and C++, backslash is also an escape character and so you must double it if you want a litteral "\" in your string.

Also, telling us what was the exception you got would help us even more.

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Not directly related, but from your code, it seems you never delete formatTarget. I assume this is sample code, but if it is not, you should add the following line to your code:

delete formatTarget;

Or use a scoped pointer instead:

boost::scoped_ptr<XMLFormatTarget> formatTarget(new LocalFileFormatTarget("C:\\test.xml"));

To avoid memory leaks.