strlcpy is a BSD-ism that isn't in posix. The official recommendation is stpecpy. Unfortunately, it is only implemented in the documentation, but not available anywhere unless you roll your own:
Who cares? Just vendor it into your project. It's a tiny string manipulation function.
(I agree with the author of the piece that strlcpy doesn't actually solve the real problem.)
strlcpy is in POSIX now, actually.
https://pubs.opengroup.org/onlinepubs/9799919799/functions/s...