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Re: memmem()

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puppi <fabricio.puppi@gmail.com> writes:
> On May 8, 1:03 pm, barcaroller <barcarol...@music.net> wrote:
>> On 2011-05-08 11:56:23 -0400, Angel said:
>>
>> > You might want to be careful with that, memmem() is broken in several
>> > versions of libc.
>>
>> I know that it was broken at some point in the past (in fact, it says
>> so in the manpage) but my understanding is that it has now been fixed.  
>> If you know otherwise, please let me know (or point me to a source).
>
> You could also bitwise AND with 0x01 each byte of the sequences to be
> compared, filtering out the low bits (and preferably packing them 8 by
> 8 in a single byte), then bitwise OR the original sequences with 0x01,
> put a sentinel 0x00 at the end and use 2 strstr()s (or 1 strstr() and
> 1 plain equality test for each possible match). Of course it wouldn't
> be as efficient, but at least it's as alternative.

Or you could use memcmp() in a loop.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Nokia
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

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memmem() barcaroller <barcaroller@music.net> - 2011-05-07 22:53 -0400
  Re: memmem() "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-08 02:33 -0400
  Re: memmem() puppi <fabricio.puppi@gmail.com> - 2011-05-08 00:11 -0700
    Re: memmem() "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-08 04:36 -0400
    Re: memmem() James Kuyper <jameskuyper@verizon.net> - 2011-05-08 09:33 -0400
      Re: memmem() barcaroller <barcaroller@music.net> - 2011-05-08 10:48 -0400
    Re: memmem() barcaroller <barcaroller@gmail.com> - 2011-05-08 10:46 -0400
      Re: memmem() Angel <angel+news@spamcop.net> - 2011-05-08 15:56 +0000
        Re: memmem() barcaroller <barcaroller@music.net> - 2011-05-08 12:03 -0400
          Re: memmem() puppi <fabricio.puppi@gmail.com> - 2011-05-09 04:58 -0700
            Re: memmem() Keith Thompson <kst-u@mib.org> - 2011-05-09 08:45 -0700
      Re: memmem() puppi <fabricio.puppi@gmail.com> - 2011-05-09 04:47 -0700
  Re: memmem() blp@cs.stanford.edu (Ben Pfaff) - 2011-05-09 09:45 -0700
    Re: memmem() Nobody <nobody@nowhere.com> - 2011-05-10 07:19 +0100
      Re: memmem() Dr Nick <3-nospam@temporary-address.org.uk> - 2011-05-10 07:35 +0100
        Re: memmem() pete <pfiland@mindspring.com> - 2011-05-10 04:27 -0400
      Re: memmem() Ben Pfaff <blp@cs.stanford.edu> - 2011-05-10 07:16 -0700
        Re: memmem() Nobody <nobody@nowhere.com> - 2011-05-10 21:07 +0100

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