Convert 'C' function to SQL

I want to convert the PHP function "SIMILAR_TEXT" into an SQL (preferably MYSQL) Function that returns a % match. SIMILAR_TEXT is a fuzzy string matching function, but I want to use it via MYSQL, and to also return a % match. You can try it out here : [login to view URL] The function is very small, and written in 'C'. The original C code is attached within the 'string.c' file. A simpler version in pure 'C' in the attached '[login to view URL]' file. The end result should be a MYSQL (or SQL) FUNCTION of the type FN_SIMILAR_TEXT(str1, str2) RETURNS FLOAT; that returns the % match between the two strings.