utf8 decode

[AlexProfi]

hello how to use it like I do it in python
s=b"\xD0\x9C\xD0\xBE\xD1\x81\xD0\xBA\xD0\xB2\xD0\xB0"

print(s.decode("utf-8"))
Москва
lua 5.2 works similary
lua5.2
Lua 5.2.4 Copyright (C) 1994-2015 Lua.org, PUC-Rio
s="\xD0\x9C\xD0\xBE\xD1\x81\xD0\xBA\xD0\xB2\xD0\xB0"
print(s)
Москва

but lua 5.1
lua5.1
Lua 5.1.5 Copyright (C) 1994-2012 Lua.org, PUC-Rio

s="\xD0\x9C\xD0\xBE\xD1\x81\xD0\xBA\xD0\xB2\xD0\xB0"
print(s)
xD0x9CxD0xBExD1x81xD0xBAxD0xB2xD0xB0

how to make similar as in python or lua 5.2 with this lib?
what function I need to use?

[starwing]

You could try utf8.escape()

[AlexProfi]

I use make with this Makefile

lua-utf8.so:lutf8lib.c
	gcc -shared -o lua-utf8.so  -I/usr/local/include/luajit-2.1  ./lutf8lib.c -fPIC

then i add this module to cpath in nginx config

I use lua-nginx-module
Then in my code I wrote
local utf8 = require 'lua-utf8'
local i_dn = ngx.var.ssl_client_i_dn_legacy
local sprintf = string.format
local response = sprintf(" ISSUER: %s ,
    utf8.escape(i_dn))
ngx.say(response)

i_dn="\U0433.\U041C\U043E\U0441\U043A\U0432\U0430"
in above example

And in the logs nginx I get error
attempt to index local 'utf8' (a function value)
How to fix this

[ghost]

try local utf8 = require("lua-utf8") instead

[AlexProfi]

Thanks errors desappered but I also get this result in output
\xD0\xB3.\xD0\x9C\xD0\xBE\xD1\x81\xD0\xBA\xD0\xB2\xD0\xB0/
I change src of nginx and it resolve issue