Re: how to use regex library

Newsgroups	comp.lang.c
From	Seebs <usenet-nospam@seebs.net>
Subject	Re: how to use regex library
References	(3 earlier) <ir0eii$6t7$1@dont-email.me> <pan.2011.05.19.02.13.27.514000@Owner-PC.com> <ir2ifv$111$1@dont-email.me> <pan.2011.05.19.11.59.30.927000@Owner-PC.com> <pan.2011.05.19.19.12.48.713000@Owner-PC.com>
Message-ID	<slrnitarbh.pff.usenet-nospam@guild.seebs.net> (permalink)
Date	2011-05-19 19:40 +0000
Organization	Megabitz - More USENET, Faster USENET

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On 2011-05-19, Owner <Owner@Owner-PC.com> wrote:
> I got one more problem.  I dont' think Man page mentioned
> about second matching on the same string, when I read it.
> I tried call "i = regexec(r, argv[2]);" twice, but didn't move
> forward after first match.  I did found however
> "i = regexec(r, r->endp[0]);" matches the second substring.
> but I don't think it's meant to be used this way.
> How do you match same pattern more than twice on the same line?

Well, typically, you would find a point in the line after the first
match, and use regexec to match there.

Why don't you think it's meant to be used this way?  What seems unusual
to you about using the endpoint of a previous match as the starting place
to look to see whether there are any more matches?  Why would you think
that it would "move forward" after the first match?

Let's translate this all into plain language.

Consider this string.  We need a name for it, let's call it "Bob".
	"hello, world, hello, dolly, hello, sailor".

Now, I ask you:  Does Bob contain the word hello?  If so, where?

You respond with something like:
	Yes: ">hello<, world, hello, dolly, hello, sailor".

Okay.  Now I ask you:  Does Bob contain the word hello?  If so, where?

Why would your answer be different?  I didn't ask you a different
question.  Nothing changed.  The string isn't different from what it
used to be.  It would be ridiculous for your answer to be different.

Now, imagine instead that I asked you "Does Bob contain the word hello
somewhere after the 5th character?  If so, where?", then you might
respond:
	Yes: ", world, >hello<, dolly, hello, sailor".

Computers do exactly what you ask them to.  They do not do what you
meant, and they don't care whether you just asked them that two seconds
ago; they're just going to keep answering the question you asked.

-s
-- 
Copyright 2011, all wrongs reversed.  Peter Seebach / usenet-nospam@seebs.net
http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures
http://en.wikipedia.org/wiki/Fair_Game_(Scientology) <-- get educated!
I am not speaking for my employer, although they do rent some of my opinions.

Thread

how to use regex library Owner <Owner@Owner-PC.com> - 2011-05-17 23:11 -0400
  Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-18 03:33 +0000
    Re: how to use regex library Owner <Owner@Owner-PC.com> - 2011-05-18 06:41 -0400
      Re: how to use regex library James Kuyper <jameskuyper@verizon.net> - 2011-05-18 08:00 -0400
        Re: how to use regex library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-18 20:00 +0100
          Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-18 19:44 +0000
            Re: how to use regex library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-19 00:43 +0100
              Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 00:52 +0000
                Re: how to use regex library Owner <Owner@Owner-PC.com> - 2011-05-18 22:04 -0400
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 02:21 +0000
                Re: how to use regex library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-19 04:04 +0100
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 03:14 +0000
                Re: how to use regex library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-19 12:03 +0100
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 14:37 +0000
                Re: how to use regex library Geoff <geoff@invalid.invalid> - 2011-05-19 11:29 -0700
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 19:08 +0000
                Re: how to use regex library Geoff <geoff@invalid.invalid> - 2011-05-19 12:11 -0700
                Re: how to use regex library Kenneth Brody <kenbrody@spamcop.net> - 2011-05-20 12:55 -0400
                Re: how to use regex library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-19 04:01 +0100
            Re: how to use regex library cri@tiac.net (Richard Harter) - 2011-05-19 16:02 +0000
              Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 16:34 +0000
                Re: how to use regex library Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-19 13:59 -0700
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 22:06 +0000
                Re: how to use regex library Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-24 02:03 -0700
                Re: how to use regex library Kenneth Brody <kenbrody@spamcop.net> - 2011-05-20 13:14 -0400
                Re: how to use regex library Tim Rentsch <txr@alumni.caltech.edu> - 2011-05-24 02:16 -0700
            Re: how to use regex library Kenneth Brody <kenbrody@spamcop.net> - 2011-05-19 14:37 -0400
          Re: how to use regex library James Kuyper <jameskuyper@verizon.net> - 2011-05-18 19:44 -0400
            Re: how to use regex library Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-19 03:49 +0100
              Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 03:03 +0000
                Re: how to use regex library Ike Naar <ike@iceland.freeshell.org> - 2011-05-19 06:48 +0000
                Re: how to use regex library James Kuyper <jameskuyper@verizon.net> - 2011-05-19 05:58 -0400
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 14:37 +0000
            Re: how to use regex library Kenneth Brody <kenbrody@spamcop.net> - 2011-05-19 14:48 -0400
              Re: how to use regex library Shao Miller <sha0.miller@gmail.com> - 2011-05-19 15:05 -0400
      Re: how to use regex library Mark Bluemel <mark_bluemel@pobox.com> - 2011-05-18 13:36 +0100
        Re: how to use regex library Owner <Owner@Owner-PC.com> - 2011-05-18 13:13 -0400
        Re: how to use regex library Owner <Owner@Owner-PC.com> - 2011-05-18 22:13 -0400
          Re: how to use regex library Mark Bluemel <mark_bluemel@pobox.com> - 2011-05-19 08:55 +0100
            Re: how to use regex library Owner <Owner@Owner-PC.com> - 2011-05-19 07:59 -0400
              Re: how to use regex library Keith Thompson <kst-u@mib.org> - 2011-05-19 08:50 -0700
              Re: how to use regex library Owner <Owner@Owner-PC.com> - 2011-05-19 15:12 -0400
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 19:40 +0000
                Re: how to use regex library cri@tiac.net (Richard Harter) - 2011-05-19 20:58 +0000
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-19 22:06 +0000
                Re: how to use regex library cri@tiac.net (Richard Harter) - 2011-05-20 01:01 +0000
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-20 01:57 +0000
                Re: how to use regex library Kenneth Brody <kenbrody@spamcop.net> - 2011-05-20 13:27 -0400
                Re: how to use regex library Kenneth Brody <kenbrody@spamcop.net> - 2011-05-20 13:08 -0400
                Re: how to use regex library Dr Nick <3-nospam@temporary-address.org.uk> - 2011-05-20 18:54 +0100
                Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-20 19:14 +0000
                Re: how to use regex library Dr Nick <3-nospam@temporary-address.org.uk> - 2011-05-21 00:04 +0100
                Re: how to use regex library Kenneth Brody <kenbrody@spamcop.net> - 2011-05-23 12:42 -0400
                Re: how to use regex library Dr Nick <3-nospam@temporary-address.org.uk> - 2011-05-23 20:16 +0100
                Re: how to use regex library cri@tiac.net (Richard Harter) - 2011-05-23 21:16 +0000
                Re: how to use regex library Kenneth Brody <kenbrody@spamcop.net> - 2011-05-24 12:08 -0400
                Re: how to use regex library cri@tiac.net (Richard Harter) - 2011-05-25 05:27 +0000
                Re: how to use regex library Michael Press <rubrum@pacbell.net> - 2011-05-22 21:41 -0700
                Re: how to use regex library cri@tiac.net (Richard Harter) - 2011-05-23 21:33 +0000
      Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-18 16:03 +0000
    Re: how to use regex library Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-05-18 14:05 +0000
  Re: how to use regex library Owner <Owner@Owner-PC.com> - 2011-05-20 22:06 -0400
    Re: how to use regex library Seebs <usenet-nospam@seebs.net> - 2011-05-21 03:49 +0000
      Re: how to use regex library Owner <Owner@Owner-PC.com> - 2011-05-21 20:25 -0400
    Re: how to use regex library Shao Miller <sha0.miller@gmail.com> - 2011-05-21 13:17 -0500

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