I asked a similar question yesterday, but recognize that i need to rephase it in a different way.
In short:
In C++ on Windows, how do I do a case-insensitive search for a string (inside another string) when the strings are in unicode format (wide char, wchar_t), and I don’t know the language of the strings. I just want to know whether the needle exists in the haystack. Location of the needle isn’t relevant to me.
Background:
I have a repository containing a lot of email bodies. The messages are in different languages (japanese, german, russian, finnish; you name it). All the data is in Unicode format, and I load it to wide strings (wchar_t) in my C++ application (the bodies have been MIME decoded, so in my debugger I can see the actual japanese, german characters). I don’t know the language of the messages since email messages doensn’t contain that detail, also a single email body may contain characters from several languages.
I’m looking for something like wcsstr, but with the ability to do the search in a case insensitve manner. I know that it’s not possible to do a 100% proper conversion from upper case to lower case, without knowing the language of the text. I want a solution which works in the 99% cases where it’s possible.
I’m using Visual Studio 2008 with C++, STL and Boost.
Boost String Algorithms has an icontains() function template which may do what you need.