Searching a string for a character and all the characters till the next whitespace?

[eluser]sophistry[/eluser]
happy birthday! here's a present for you...

preg_replace() is the function you need.

regex pattern for the preg_replace() function (assumes whitespace before pound sign #):

Code:

'/#([a-z0-9]+)\s/i'

replacement:

Code:

'<a href="http://example.com/tags/$1">$1</a>'

give that a try.

EDIT: added i switch to the regex pattern to make it case insensitive.