Very simple regex

[Dotan Cohen]

Now, I know that this is easy, but I am embarassed to say that I can't
find a regex tutorial that will show me how to match any occurances of
x and replace them with one x:

xxxxx >x
xx > x
x > x

$string="I have xxxxxxxx apples!";
$string=preg_replace("-regex here-","x", $string);
print "$string";

I have x apples!

I searched marc because I know that I've seen this, but I don't know
on what keywords to search. I know that php uses perl-compatable
regular expressions, but in no tutorial did I find this. I know that *
matches any amount of occurances of a string, but formulating it to do
it in the middle of a string of text I could not get.

Dotan
http://lyricslist.com/lyrics/artist_albums/19/adams_bryan.php
Bryan Adams Lyrics