linuxvfs.c: replace strncpy by strlcpy”

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strncpy is my least favorite C function. Not terminating with NULL when the destination length is exhausted is bad enough. But when you give it a large enough buffer, it wastes cycles padding the destination with NULLs to the full length. If that's what I wanted I'd have just called memset ahead of time!

I ended up getting in the (probably bad) habit of using strlen+memcpy for all my string management needs. That is, until I realized I shouldn't be wasting my time with such tedious bit-twiddling and moved on to C++ with std::string.

strncpy()'s NUL-padding behaviour is the right thing for its niche, which is copying to fixed-length buffers such as the 14-character filenames in ancient filesystem directory entries. See http://stackoverflow.com/a/1454071

That niche doesn't particularly exist anymore, so strncpy() isn't often a good fit for what people need these days. Hence they don't like strncpy(), but what they really mean is that they shouldn't have been considering strncpy() in the first place.

strncat() on the other hand... now that's a weird function!

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