Getting the right result even if you misspell an input

[Confessions]

I was wondering how one could code it so that when a user misspells his searches, he would still get to the right result.

So if one writes "phpbilderr" into a search form, it would bring up the correct "phpbuilder" instead.

Is there some predefined function in PHP or MySQL already, or do you have to create some sort of an algorithm for this?

[rsmith]

PHP doesn't have any built in functions but using the MySQL Pattern Matching techniques might be of some assistance: http://dev.mysql.com/doc/refman/5.0/en/pattern-matching.html

[Weedpacket]

You can have a look at the various approximate string matching or phonetic-hashing functions PHP provides (such as [man]similar_text[/man] and others cited on that page).

For these to be useful, you'd need a dictionary of correct words for the functions to compare the submitted term against and find those that are "close enough".