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Groups > comp.lang.c > #111711
| From | Ben Bacarisse <ben.usenet@bsb.me.uk> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: memscan() function or equivalent |
| Date | 2017-06-07 16:50 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <878tl3g5jw.fsf@bsb.me.uk> (permalink) |
| References | <fc95db66-ccd5-4fbc-83bf-84cb17257d41@googlegroups.com> <20170607154705.f161b2807eb2b1a8dc12d389@gmail.com> <12fb0e96-0ac3-442d-8d04-baaef4234a85@googlegroups.com> <20170607164800.a6fba9d07170ec5d056d25a0@gmail.com> |
GOTHIER Nathan <nathan.gothier@gmail.com> writes:
> On Wed, 7 Jun 2017 07:15:04 -0700 (PDT)
> "Rick C. Hodgin" <rick.c.hodgin@gmail.com> wrote:
>
>> On Wednesday, June 7, 2017 at 9:50:27 AM UTC-4, GOTHIER Nathan wrote:
>> > /* count the occurrence number of c */
>> > size_t memfrq(const void *s, int c, size_t n);
>>
>> What do these parameters equate to? What are s, c, and n? Can you
>> include the function body so I can see it at work?
>
>
> /*
> The "memfrq" function
>
> Description:
>
> The memfrq function count the occurrence number of c (converted as an
> unsigned char) in the initial n characters (each interpreted as unsigned
> char) of the object pointed to by s.
>
> Returns:
>
> The memfrq function returns the number of c occurences found.
> */
>
> #include <stddef.h>
>
> typedef unsigned char uchar_t;
>
> size_t memfrq(const void *s, int c, size_t n)
> {
> uchar_t *s0 = (uchar_t *) s;
> uchar_t c0 = (uchar_t) c;
> size_t k = 0U;
That looks fussy to me. If you don't keep repeating the type you don't
need to typedef it. I'd also keep the const:
const unsigned char *s0 = s, c0 = c;
size_t k = 0;
> scan:
> {
> if (n > 1)
What do you have against n == 1?!!
> {
> if (*s0 == c0)
> {
> k++;
> }
>
> s0++;
> n--;
>
> goto scan;
> }
Seriously? That's a wind-up, surely?
> return k;
> }
> }
What is the general view of writing things like
k += *s0 == c0;
? I find it compact and natural with no extra cost, at least with
modern compilers.
Anyway, an alternative version (keeping the names):
size_t memfrqBB(const void *s, int c, size_t n)
{
const unsigned char *s0 = s, c0 = c;
size_t k = 0;
while (n-- > 0)
k += *s0++ == c0;
return k;
}
--
Ben.
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memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 06:16 -0700
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 15:47 +0200
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 07:15 -0700
Re: memscan() function or equivalent scott@slp53.sl.home (Scott Lurndal) - 2017-06-07 14:34 +0000
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 07:42 -0700
Re: memscan() function or equivalent scott@slp53.sl.home (Scott Lurndal) - 2017-06-07 14:45 +0000
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 08:07 -0700
Re: memscan() function or equivalent jameskuyper@verizon.net - 2017-06-07 09:14 -0700
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 09:33 -0700
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 16:48 +0200
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 08:31 -0700
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 17:37 +0200
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 08:47 -0700
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 18:02 +0200
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 09:09 -0700
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 18:34 +0200
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 09:54 -0700
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 19:01 +0200
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 10:17 -0700
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 19:53 +0200
Re: memscan() function or equivalent asetofsymbols@gmail.com - 2017-06-07 22:15 -0700
Re: memscan() function or equivalent asetofsymbols@gmail.com - 2017-06-07 22:26 -0700
Re: memscan() function or equivalent asetofsymbols@gmail.com - 2017-06-07 22:56 -0700
Re: memscan() function or equivalent asetofsymbols@gmail.com - 2017-06-07 23:03 -0700
Re: memscan() function or equivalent scott@slp53.sl.home (Scott Lurndal) - 2017-06-07 16:10 +0000
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 09:30 -0700
Re: memscan() function or equivalent Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-07 16:50 +0100
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 08:58 -0700
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 09:03 -0700
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 09:07 -0700
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-07 17:30 +0100
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 09:36 -0700
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-07 17:48 +0100
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 09:57 -0700
Re: memscan() function or equivalent Ike Naar <ike@iceland.freeshell.org> - 2017-06-12 05:54 +0000
Re: memscan() function or equivalent Keith Thompson <kst-u@mib.org> - 2017-06-07 09:48 -0700
Re: memscan() function or equivalent Gareth Owen <gwowen@gmail.com> - 2017-06-07 20:55 +0100
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-07 22:13 +0100
Re: memscan() function or equivalent Keith Thompson <kst-u@mib.org> - 2017-06-07 16:02 -0700
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-08 01:26 +0100
Re: memscan() function or equivalent Ian Collins <ian-news@hotmail.com> - 2017-06-08 13:00 +1200
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-08 09:48 +0100
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-10 08:52 +0200
Re: memscan() function or equivalent supercat@casperkitty.com - 2017-06-07 10:00 -0700
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 10:13 -0700
Re: memscan() function or equivalent supercat@casperkitty.com - 2017-06-07 11:19 -0700
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-07 11:27 -0700
Re: memscan() function or equivalent Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-07 21:18 +0100
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 18:18 +0200
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-07 21:15 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 21:16 +0200
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-10 09:08 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-10 09:56 +0200
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-10 17:14 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-10 17:38 +0200
Re: memscan() function or equivalent David Kleinecke <dkleinecke@gmail.com> - 2017-06-10 11:52 -0700
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-10 20:03 +0100
Re: memscan() function or equivalent Keith Thompson <kst-u@mib.org> - 2017-06-10 13:32 -0700
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-10 23:40 +0200
Re: memscan() function or equivalent Anton Shepelev <anton.txt@gmail.com> - 2017-06-11 00:53 +0300
Re: memscan() function or equivalent Anton Shepelev <anton.txt@gmail.com> - 2017-06-11 01:11 +0300
Re: memscan() function or equivalent Ian Collins <ian-news@hotmail.com> - 2017-06-11 10:26 +1200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-11 00:32 +0200
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-11 10:05 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-11 10:06 +0200
Re: memscan() function or equivalent Keith Thompson <kst-u@mib.org> - 2017-06-11 13:19 -0700
Re: memscan() function or equivalent Anton Shepelev <anton.txt@gmail.com> - 2017-06-11 02:17 +0300
Re: memscan() function or equivalent supercat@casperkitty.com - 2017-06-10 15:21 -0700
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-11 00:19 +0200
Re: memscan() function or equivalent Anton Shepelev <anton.txt@gmail.com> - 2017-06-11 02:15 +0300
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-11 10:36 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-11 10:46 +0200
Re: memscan() function or equivalent asetofsymbols@gmail.com - 2017-06-10 22:25 -0700
Re: memscan() function or equivalent "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-06-10 15:13 -0700
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-10 23:21 +0100
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-11 00:28 +0200
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-11 10:56 +0100
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-11 13:27 +0200
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-11 13:19 +0100
Re: memscan() function or equivalent Ike Naar <ike@iceland.freeshell.org> - 2017-06-11 18:36 +0000
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-11 20:22 +0100
Re: memscan() function or equivalent Ike Naar <ike@iceland.freeshell.org> - 2017-06-12 06:09 +0000
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-12 10:38 +0100
Re: memscan() function or equivalent asetofsymbols@gmail.com - 2017-06-12 05:30 -0700
Re: memscan() function or equivalent Ike Naar <ike@iceland.freeshell.org> - 2017-06-12 13:51 +0000
Re: memscan() function or equivalent bartc <bc@freeuk.com> - 2017-06-12 15:04 +0100
Re: memscan() function or equivalent Ike Naar <ike@iceland.freeshell.org> - 2017-06-12 21:26 +0000
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-11 10:04 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-11 10:13 +0200
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-11 13:38 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-11 14:18 +0200
Re: memscan() function or equivalent supercat@casperkitty.com - 2017-06-11 09:57 -0700
Re: memscan() function or equivalent Melzzzzz <Melzzzzz@zzzzz.com> - 2017-06-11 17:18 +0000
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-11 09:53 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-11 10:00 +0200
Re: memscan() function or equivalent "Patrick.Schluter" <Patrick.Schluter@free.fr> - 2017-06-11 13:41 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 21:24 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 21:55 +0200
Re: memscan() function or equivalent Gareth Owen <gwowen@gmail.com> - 2017-06-07 20:54 +0100
Re: memscan() function or equivalent David Brown <david.brown@hesbynett.no> - 2017-06-07 23:00 +0200
Re: memscan() function or equivalent Gareth Owen <gwowen@gmail.com> - 2017-06-08 08:16 +0100
Re: memscan() function or equivalent David Brown <david.brown@hesbynett.no> - 2017-06-08 10:55 +0200
Re: memscan() function or equivalent Gareth Owen <gwowen@gmail.com> - 2017-06-08 11:44 +0100
Re: memscan() function or equivalent David Brown <david.brown@hesbynett.no> - 2017-06-08 13:11 +0200
Re: memscan() function or equivalent Gareth Owen <gwowen@gmail.com> - 2017-06-08 13:45 +0100
Re: memscan() function or equivalent David Brown <david.brown@hesbynett.no> - 2017-06-08 14:51 +0200
Re: memscan() function or equivalent supercat@casperkitty.com - 2017-06-08 08:00 -0700
Re: memscan() function or equivalent Tim Rentsch <txr@alumni.caltech.edu> - 2017-06-09 12:26 -0700
Re: memscan() function or equivalent Gareth Owen <gwowen@gmail.com> - 2017-06-10 07:24 +0100
Re: memscan() function or equivalent Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-10 13:17 +0100
Re: memscan() function or equivalent Gareth Owen <gwowen@gmail.com> - 2017-06-10 17:18 +0100
Re: memscan() function or equivalent Ike Naar <ike@iceland.freeshell.org> - 2017-06-11 18:11 +0000
Re: memscan() function or equivalent Tim Rentsch <txr@alumni.caltech.edu> - 2017-06-11 15:08 -0700
Re: memscan() function or equivalent Gareth Owen <gwowen@gmail.com> - 2017-06-12 18:34 +0100
Re: memscan() function or equivalent Tim Rentsch <txr@alumni.caltech.edu> - 2017-06-14 09:52 -0700
Re: memscan() function or equivalent Gareth Owen <gwowen@gmail.com> - 2017-06-14 19:56 +0100
Re: memscan() function or equivalent Keith Thompson <kst-u@mib.org> - 2017-06-14 12:20 -0700
Re: memscan() function or equivalent Tim Rentsch <txr@alumni.caltech.edu> - 2017-06-17 06:37 -0700
Re: memscan() function or equivalent supercat@casperkitty.com - 2017-06-17 10:02 -0700
Re: memscan() function or equivalent David Brown <david.brown@hesbynett.no> - 2017-06-07 16:51 +0200
Re: memscan() function or equivalent GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-07 17:00 +0200
Re: memscan() function or equivalent supercat@casperkitty.com - 2017-06-07 08:53 -0700
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