ctype_alnum( $text)
ctype_alpha( $text)
ctype_cntrl( $text)
ctype_digit( $text)
ctype_graph( $text)
ctype_lower( $text)
ctype_print( $text)
ctype_punct( $text)
ctype_space( $text)
ctype_upper( $text)
ctype_xdigit( $text)