Re: Faster StrNCpy

Martijn van Oosterhout wrote:
> On Tue, Sep 26, 2006 at 04:24:51PM -0400, Tom Lane wrote:
> > David Strong points out here
> > http://archives.postgresql.org/pgsql-hackers/2006-09/msg02071.php
> > that some popular implementations of strncpy(dst,src,n) are quite
> > inefficient when strlen(src) is much less than n, because they don't
> > optimize the zero-pad step that is required by the standard.
>
> I think that's why strlcpy was invented, to deal with the issues with
> strncpy.
>
> http://www.gratisoft.us/todd/papers/strlcpy.html
>
> There's an implementation here (used in glib), though you could
> probably find more.
>
> http://mail.gnome.org/archives/gtk-devel-list/2000-May/msg00029.html

That one would be LGPL (glib's license). Here is OpenBSD's version,
linked from that one:

ftp://ftp.openbsd.org/pub/OpenBSD/src/lib/libc/string/strlcpy.c

You'll notice that it iterates once per char. Between that and the
strlen() call in Tom's version, not sure which is the lesser evil.

--
Alvaro Herrera http://www.CommandPrompt.com/
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