How to convert special unicode character to it's closet ASCII in PHP

Question

I have a problem when user input a string in special Unicode like and my system cannot distinguish it with the string "tuyendung" that is written in ASCII. The question is how can I normalize the input string to ASCII before storing it in the database?

Sample Input:

(Char code: 0xd835, 0xde01, 0xd835, 0xde02, 0xd835, 0xde06, 0xd835, 0xddf2, 0xd835, 0xddfb, 0xd835, 0xddf1, 0xd835, 0xde02, 0xd835, 0xddfb, 0xd835, 0xddf4)

Expected output:

tuyendung

(Char code: 0x74, 0x75, 0x79, 0x65, 0x6e, 0x64, 0x75, 0x6e, 0x67)

Answer 1

It looks like the //TRANSLIT option can do the trick here.

<?php

$input = '𝘁𝘂𝘆𝗲𝗻𝗱𝘂𝗻𝗴';
echo iconv('UTF-8', 'US-ASCII//TRANSLIT', $input);

This turns (what I think are?) math symbols like to t

Answer 2

I don't know what "tuyendung" is.

But in php, you can convert the character sets with the "iconv" function or you can keep the original form in a blob field in the database. You can make any transformation you want in the screening.

Maybe it gives an idea.