html_entity_decode() and htmlspecialchars() for XML

[lawrence]

Using the conversion to char sets described for these functions, is it
possible to get a whole string into some charset? I'm trying to figure
out a way to take invalid character sets from idiot users, and
translate the string so that in the end I have a string that won't
cause my XML to test invalid.

html_entity_dec ode()
htmlspecialchar s()
htmlentities()

http://www.php.net/manual/en/function.html-entity-decode.php