string htmlspecialchars(string string);
Certain characters have special significance in HTML, and should be represented by HTML entities if they are to preserve their meanings. This function returns a string with these conversions made.
This function is useful in preventing user-supplied text from containing HTML markup, such as in a message board or guest book application.
At present, the translations that are done are:
'&' (ampersand) becomes '&'
'"' (double quote) becomes '"'
'<' (less than) becomes '<'
'>' (greater than) becomes '>'
Note that this functions does not translate anything beyond what is listed above. For full entity translation, see htmlentities().
See also htmlentities() and nl2br().