CMarkup uses an ignorecase string comparison function for two purposes. The first one is to match the encoding name in the XML declaration:

<?xml version="1.0" encoding="UTF-8"?>

CMarkup matches "utf-8" and "UTF-8" with an ignorecase string comparison. The other purpose CMarkup has for this function is to support HTML:

CMarkup html
html.SetDocFlags( CMarkup::MDF_IGNORECASE );
html.Load( "test.htm" );
while ( html.FindElem("//a") )
  ...

This will find all of the hyperlink tags whether the HTML file uses upper or lower case "A" tags or a mixture of cases.

Unfortunately the ignorecase string comparison function is not standardized across platforms. Different C++ compilers have different function names such as strncasecmp _strnicmp strnicmp and strncmpi. In wide char builds too you have these variations: wcsncasecmp _wcsnicmp wcsnicmp and wcsncmpi (and the same issue occurs with the stricmp variant without the "n" in it, but CMarkup never used it).

strncasecmp for CMarkup on OSX/Xcode	Geoff 22-Jul-2008
Hi, I am evaluating CMarkup on OSX/Xcode. I have had to change the strnicmp to strncasecmp. Will this work? So far it has compiled after this change.

Yes it will work. But ideally you shouldn't be bothered with making this modification.

I spent a long time researching how I could safely determine which function name to use based on compiler defines so for example I could say:

#if defined(LINUX)
#define MCD_PSZNICMP strncasecmp
#elif defined(_MSC_VER)
#define MCD_PSZNICMP _strnicmp
#elif...

The good news is that it appears all of the variations take the same arguments and work the same way. But the bad news is that I cannot hope to reliably figure out all of the compilers and versions of compilers. UNIX, LINUX and OS X compilers among others tend to use strncasecmp, while Visual C++ uses _strnicmp (or strnicmp if you link oldnames.lib), and others use strnicmp and strncmpi.

What does CMarkup actually need out of this function anyway? Sometimes you need to match and sort strings outside of the ASCII range containing characters like É and é. CMarkup doesn't need this. In unicode, the case mappings can differ slightly based on the case table version in your operating system (Michael Kaplan has an eye opening post illustrating the complexities of Unicode casing). But CMarkup only needs to ignore ASCII case.

So instead of traveling any further down the road of trying to use an existing function supplied by the compiler or operating system platform, I simply wrote a small efficient function to do a string compare ignoring ASCII case. In other words, if a non-ASCII character is encountered, then the strings must be identical (do not ignore case).

static int x_StrNIACMP( MCD_PCSZ p1, MCD_PCSZ p2, int n )
{
  bool bNonAsciiFound = false;
  MCD_CHAR c1, c2;
  while ( n-- )
  {
    c1 = *p1++;
    c2 = *p2++;
    if ( c1 != c2 )
    {
      if ( bNonAsciiFound ||
          ! ( (c1 >= 'a' && c1 <= 'z' && c1 == c2 + ('a'-'A'))
            || (c2 >= 'a' && c2 <= 'z' && c2 == c1 + ('a'-'A')) ) )
        return c1 - c2;
    }
    else if ( (unsigned int)c1 > 127 )
      bNonAsciiFound = true;
  }
  return 0;
}

This works for char and wide char wchar_t strings (MCD_PCSZ and MCD_CHAR are defined accordingly). In far eastern double byte a lead byte is non-ASCII, so it will work too. Feel free to use it if you need a string compare ignore ASCII case function in C/C++. This will be in the next release of CMarkup after release 9.0.

I created a demo screencast about the C++ XML parser CMarkup. This is a C++ class I wrote in 1999. Since then I put a lot of energy into making it better and have been selling the developer version here since 2001. It makes XML simple for a lot of people. But it doesn't do everything. Try out the evaluation version I demonstrated in this video and see if you get the results thousands of others have. And check out the articles and free C++ XML resources on this site.

And the video shows my high performance free firstobject XML Editor which is especially useful with big UTF-8 files.

You can see it took a minute to download CMarkup, add it to the project, and configure it. Then it took about a minute and a half to add simple code to extract data out of the XML file.

Give CMarkup a try and let me know how it goes.