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Posted by Curtis on 02/07/07 08:50
On Mon, 05 Feb 2007 11:24:30 -0800, yawnmoth <terra1024@yahoo.com> wrote=
:
> Say I have the following script:
>
> <?php
> $contents =3D file_get_contents('preg_test.txt');
> echo preg_match("#(.*?)[\r\n]+ddddddddddddd#s",$contents) ? 'is
> equal' : 'is not equal';
> ?>
>
> Here's preg_test.txt:
>
> http://www.geocities.com/terra1024/preg_test.txt
>
> (it's a malformed part of a postscript file, in case you're curious)
>
> My question is... when I remove the s modifier, preg_match returns
> true. When the s modifier is there, it returns false. I'm not really=
> sure why this is. The s modifier means that . includes new lines and
> carriage returns. In either case, it seems like it should match.
>
> Any ideas as to why it doesn't?
>
This is a very inefficient regex for a large amount of data. Since you a=
re =
using the lazy asterisk with the dot, the regex engine immediately start=
s =
backtracking throughout the search. It would be easier to specify the =
amount of d's through the {} quantifier, not hardcoding.
Is there a reason you capture all the content before the CRLF and d =
portion of the pattern? It looks like you're merely testing if any =
whitespace and 13 d's exist. If that's the case, you could just use the =
=
strstr() function. If you want everything except the whitespace and d's,=
=
then use substr().
-- =
Curtis, http://dyersweb.com
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