C strcpy() - evil?

Question

Some people seem to think that C\'s strcpy() function is bad or evil. While I admit that it\'s usually better to use strncpy() in order to avoid bu

Answer 1

In the situation you describe, strcpy is a good choice. This strdup will only get into trouble if the s1 was not ended with a '\0'.

I would add a comment indicating why there are no problems with strcpy, to prevent others (and yourself one year from now) wondering about its correctness for too long.

strncpy often seems safe, but may get you into trouble. If the source "string" is shorter than count, it pads the target with '\0' until it reaches count. That may be bad for performance. If the source string is longer than count, strncpy does not append a '\0' to the target. That is bound to get you into trouble later on when you expect a '\0' terminated "string". So strncpy should also be used with caution!

I would only use memcpy if I was not working with '\0' terminated strings, but that seems to be a matter of taste.