Re: [PATCH v2 1/3] add strnncmp() function

[Jeremiah Mahler <jmmahler@gmail.com>]

Erik,

On Tue, Jun 17, 2014 at 11:09:59AM +0200, Erik Faye-Lund wrote:
> On Tue, Jun 17, 2014 at 9:34 AM, Jeremiah Mahler <jmmahler@gmail.com> wrote:
> > Add a strnncmp() function which behaves like strncmp() except it takes
> > the length of both strings instead of just one.  It behaves the same as
> > strncmp() up to the minimum common length between the strings.  When the
> > strings are identical up to this minimum common length, the length
> > difference is returned.
> >
> > Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
> > ---
> >  strbuf.c | 9 +++++++++
> >  strbuf.h | 2 ++
> >  2 files changed, 11 insertions(+)
> >
> > diff --git a/strbuf.c b/strbuf.c
> > index ac62982..4eb7954 100644
> > --- a/strbuf.c
> > +++ b/strbuf.c
> > @@ -600,3 +600,12 @@ char *xstrdup_tolower(const char *string)
> >         result[i] = '\0';
> >         return result;
> >  }
> > +
> > +int strnncmp(const char *a, int len_a, const char *b, int len_b)
> > +{
> > +       int min_len = (len_a < len_b) ? len_a : len_b;
> > +       int cmp = strncmp(a, b, min_len);
> > +       if (cmp)
> > +               return cmp;
> > +       return (len_a - len_b);
> > +}
> 
> Using a name that sounds like it's from the stdlib makes me cringe a
> little bit. Names that start with "str" reserved for stdlib[1][2], but
> we already ignore this for strbuf (and perhaps some other functions).
> However, in this case it doesn't seem *that* unlikely that we might
> collide with some stdlib-extensions.
> 
> [1]: http://pubs.opengroup.org/onlinepubs/007904975/functions/xsh_chap02_02.html#tag_02_02_02
> [2]: http://www.gnu.org/software/libc/manual/html_node/Reserved-Names.html

I chose strnncmp() to try and emphasize its similarity to strncmp().
But you have a good point about potential name conflicts.  That could be
a problem.  I will change the name.

-- 
Jeremiah Mahler
jmmahler@gmail.com
http://github.com/jmahler