regex question: replace things ONCE

[Giakko]

Dear readers,
i need help on a regular expression:
i have to apply 100 different replaces to an article, but i don't want
that a portion of text already replaced is replaced another time by
another text. the php function strtr() does this but for other reasons
i have to use ereg_replace or preg_replace

to make you understand what i need i paste a portion of the strtr()
function documentation:
-------------------------------------------------------
strtr() will always look for the longest possible match first and will
*NOT* try to replace stuff that it has already worked on.
-------------------------------------------------------


so if i have the following replaces:

[cat]=<a href="#cat">cat </a>
[catalitic] =<a href="#cataliti c">catalitic </a>

for the following text= "my cat is catalitic"
so the result should be: my <a href="#cat">cat </ais <a
href="#cataliti c">catalitic </a>
and not: <a href="#cat">cat </ais <a href="#<a href="#cat">cat </
a>alitic"><a href="#cat">cat </a>alitic</a>

i can't use strtr() for a reason that's too long to explain

thank you very much! simone

[AnrDaemon]

Greetings, Giakko.
In reply to Your message dated Tuesday, May 13, 2008, 16:03:28,

so if i have the following replaces:

[cat]=><a href="#cat">cat </a>
[catalitic] =><a href="#cataliti c">catalitic </a>

for the following text= "my cat is catalitic"
so the result should be:
my <a href="#cat">cat </ais <a href="#cataliti c">catalitic </a>
and not:
<a href="#cat">cat </ais <a href="#<a href="#cat">cat </a>alitic"><a href="#cat">cat </a>alitic</a>

There's a simple way to solve Your problem.
Use regexp modifiers to point that You have the whole word to replace, not a
part of word.
One of them are \b - word boundary.
something like

<?php

$text = 'my cat is catalitic';

$replace = array(
'#\bcat\b#',
'#\bcatalitic\b #'
);

echo preg_replace($r eplace, '<a href="#$0">$0</a>', $text);

?>
--
Sincerely Yours, AnrDaemon <an*******@free mail.ru>

[Alexey Kulentsov]

Giakko wrote:

Dear readers,
i need help on a regular expression:
i have to apply 100 different replaces to an article, but i don't want
that a portion of text already replaced is replaced another time by
another text.

Just do it in one pass. preg_replace() don't check again already
processed part of string.