How to copy a string into a char array in C++ without going over the buffer

Question

I want to copy a string into a char array, and not overrun the buffer.

So if I have a char array of size 5, then I want to copy a maximum of 5 bytes from a string in

Answer 1

Some nice libc versions provide non-standard but great replacement for strcpy(3)/strncpy(3) - strlcpy(3).

If yours doesn't, the source code is freely available here from the OpenBSD repository.