mb_ereg() executes the regular expression
match with multibyte support, and returns 1 if matches are found.
If the optional third parameter was specified, the function
returns the byte length of matched part, and the array
regs will contain the substring of matched
string. The functions returns 1 if it matches with the empty
string. If no matches found or error happend, FALSE will be
The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.