eregi_replace and Regular Expression Quandry

[saiena]

Is there a way in my regular expression syntax to cause alternating
occurences of the search string to be replaced?

Here's my code:

$item[content] = eregi_replace($ search_string, $replace_string ,
$item[content]);

This successfully replaces all occurences of $search_string.

Any way to reaplce every other?

[Andy Hassall]

Re: eregi_replace and Regular Expression Quandry

On Mon, 29 Aug 2005 20:55:46 GMT, "saiena" <saiena@nospam_ thetellingtree. com>
wrote:
[color=blue]
>Is there a way in my regular expression syntax to cause alternating
>occurences of the search string to be replaced?
>
>Here's my code:
>
>$item[content] = eregi_replace($ search_string, $replace_string ,
>$item[content]);
>
>This successfully replaces all occurences of $search_string.
>
>Any way to reaplce every other?[/color]

The solutions I can think of all need non-greedy expressions, at which point
you need to use the PCRE (preg_*) functions - which IMHO is worth switching to
anyway unless you're really tied to the more basic ereg syntax.

At which point you can either use a clever expression, or just do it with
preg_replace_ca llback and a Boolean flag or counter accessed by the callback to
work out whether it's an odd or even call, and so whether to replace or not.

--
Andy Hassall :: andy@andyh.co.u k :: http://www.andyh.co.uk
http://www.andyhsoftware.co.uk/space :: disk and FTP usage analysis tool

[Csaba Gabor]

Re: eregi_replace and Regular Expression Quandry

saiena wrote:[color=blue]
> Is there a way in my regular expression syntax to cause alternating
> occurences of the search string to be replaced?
>
> $item[content] = eregi_replace($ search_string, $replace_string ,
> $item[content]);
>[/color]

How about using:
$string = preg_replace("/$search_string( .*?($search_str ing|$))/",
"$replace_strin g\$1",$string);

where I wrote $string instead of $item[content] cause I didn't
like the looks of that content. This assumes your $search_string
doesn't have unusual characters (in which case you'd need to read up on
regular expressions and escaping characters).

Csaba Gabor from New York