CStringT to char[]

Question

I'm trying to make changes to some legacy code. I need to fill a char[] ext with a file extension gotten using filename.Right(3). Problem is that I don't know how to convert from a CStringT to a char[].

There has to be a really easy solution that I'm just not realizing...

TIA.

Answer 1

If you have access to ATL, which I imagine you do if you're using CString, then you can look into the ATL conversion classes like CT2CA.

CString fileExt = _T ("txt");
CT2CA fileExtA (fileExt);

If a conversion needs to be performed (as when compiling for Unicode), then CT2CA allocates some internal memory and performs the conversion, destroying the memory in its destructor. If compiling for ANSI, no conversion needs to be performed, so it just hangs on to a pointer to the original string. It also provides an implicit conversion to const char * so you can use it like any C-style string.

This makes conversions really easy, with the caveat that if you need to hang on to the string after the CT2CA goes out of scope, then you need to copy the string into a buffer under your control (not just store a pointer to it). Otherwise, the CT2CA cleans up the converted buffer and you have a dangling reference.