In a new post to his blog Danne Lundqvist looks at a common pitfall that could trip you up if you're not careful with your UTF-8 data - not looking for the UTF byte order mark that tells the application if it needs to be handled as UTF content.
One such thing is the occurrence of the UTF byte order mark, or BOM. [...] For UTF-8, especially on Windows, it has become more and more common to use it to indicate that the file is indeed UTF. Most text editors handle this well and you won't ever see these bytes. As it should be.
He points out what could cause an issue - using strcmp or substr but it can be prevented by looking at and removing those first three bytes if needed. He includes a snippet of code that does just that.