vb.org Archive - help with a regular expression please

Page 1 of 2

Show 40 post(s) from this thread on one page

vb.org Archive (https://vborg.vbsupport.ru/index.php)

- vB3 Programming Discussions (https://vborg.vbsupport.ru/forumdisplay.php?f=15)

- - help with a regular expression please (https://vborg.vbsupport.ru/showthread.php?t=102207)

akanevsky

12-04-2005 02:14 PM

help with a regular expression please

Say I have a string:
x!!x bbbbbdddd x!!x bbbbaaaaddddd x!!x bbbbcccccddddd
How do I match the bbbb(.*)dddd that do NOT have an "x!!x" substring between them? Don't ask what for, just tell me how do to such regex. explode() is not an option for my purposes. Thanks.

Ideally, it would be something like ([^x!!x]*), but that won't work for some reason.

Andreas

12-04-2005 02:36 PM

lookahead/lookbehind assertions

akanevsky

12-04-2005 02:45 PM

Example plz?

Andreas

12-04-2005 02:50 PM

> x!!x bbbbbdddd x!!x bbbbaaaaddddd x!!x bbbbcccccddddd
From this string, what would be your desired match(es)?

akanevsky

12-04-2005 08:06 PM

Hmm..
I just want to end up having bbbb moved as towards the closest ddddd, so that the result would be:

x!!x bbbbdddd x!!x aaaabbbbddddd x!!x cccccbbbbddddd

EDIT: Actually, nevermind. That won't work as desired because the corresponding bbbb and dddd could have inner pairs of x!!x between them, which would give an undesired result. So nvm... :P

Andreas

12-04-2005 09:32 PM

PHP Code:


		
			
preg_replace('/bbbb(.*)dddd/U', '$1bbbbdddd', 'x!!x bbbbbdddd x!!x bbbbaaaaddddd x!!x bbbbcccccddddd');

akanevsky

12-04-2005 09:41 PM

Yes, that works. However, as I said, it could happen like.. let me explain.

<bbbb <bbbbaaaadddd> dddd>

So here, my result would have to be:
< <aaaabbbbdddd> bbbbdddd>
However, because there is another <....> inside the outer <....>, there is no way to see the the first bbbb belongs to the latest dddd. Or is there? :P

Andreas

12-04-2005 10:04 PM

<Disclaimer>
This Code is utterly bad
</Disclaimer>

PHP Code:


		
			
function recurse_replace($str)

{

    if (preg_match('/bbbb(.*)dddd/', $str))

    {

        return preg_replace('/bbbb(.*)dddd/eS', "recurse_replace('\\1') . 'bbbbdddd'", $str);

    }

    else

    {

        return $str;

    }

}

akanevsky

12-04-2005 10:15 PM

Why is it utterly bad? Because of performance?

Andreas

12-04-2005 10:24 PM

Because it is recursive and not checked ;)

All times are GMT. The time now is 03:15 AM.

Page 1 of 2

Show 40 post(s) from this thread on one page

X vBulletin 3.8.12 by vBS Debug Information
Page Generation 0.01839 seconds Memory Usage 1,728KB Queries Executed 10 (?)
More Information
Template Usage: (1)ad_footer_end (1)ad_footer_start (1)ad_header_end (1)ad_header_logo (1)ad_navbar_below (2)bbcode_php_printable (1)footer (1)gobutton (1)header (1)headinclude (6)option (1)pagenav (1)pagenav_curpage (1)pagenav_pagelink (1)post_thanks_navbar_search (1)printthread (10)printthreadbit (1)spacer_close (1)spacer_open Phrase Groups Available: global postbit showthread	Included Files: ./printthread.php ./global.php ./includes/init.php ./includes/class_core.php ./includes/config.php ./includes/functions.php ./includes/class_hook.php ./includes/modsystem_functions.php ./includes/class_bbcode_alt.php ./includes/class_bbcode.php ./includes/functions_bigthree.php Hooks Called: init_startup init_startup_session_setup_start init_startup_session_setup_complete cache_permissions fetch_threadinfo_query fetch_threadinfo fetch_foruminfo style_fetch cache_templates global_start parse_templates global_setup_complete printthread_start pagenav_page pagenav_complete bbcode_fetch_tags bbcode_create bbcode_parse_start bbcode_parse_complete_precache bbcode_parse_complete printthread_post printthread_complete
Messages: