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:
Your comment makes no sense. If it was designed for non-null terminated strings, why would it specifically pad after a null terminator?
I looked up the actual reason for its inception:
---
Rationale for the ANSI C Programming Language", Silicon Press 1990.
4.11.2.4 The strncpy function
strncpy was initially introduced into the C library to deal with fixed-length name fields in structures such as directory entries. Such fields are not used in the same way as strings: the trailing null is unnecessary for a maximum-length field, and setting trailing bytes for shorter names to null assures efficient field-wise comparisons. strncpy is not by origin a "bounded strcpy," and the Committee has preferred to recognize existing practice rather than alter the function to better suit it to such use.
Yep, the "shortlived" (6-day) profile will be available to the general public later this week. But at this time we explicitly encourage only mature organizations with stable infrastructure and an oncall rotation to adopt that profile, as the risks associated with a renewal failing at the beginning of a holiday long weekend are just too high for many sites.
Well if you bother looking up that it's originally created for non null-terminated strings, then it kinda makes sense.
The real problem begun when static analyzers started to recommend using it instead of strcpy (the real alternative used to be snprintf, now strlcpy).