util.string.isvalid

local valid = util.string.isvalid(
    input
)

Type	Name	Description
`string`	input	String to validate

Type	Name	Description
`bool`	valid	`true` if input is well-formed UTF-8

Check a valid UTF-8 string

local valid = util.string.isvalid("hello")

core.engine.print("info", valid) -- true

Check a string with multi-byte characters

local valid = util.string.isvalid("héllo 中文")

core.engine.print("info", valid) -- true

Check a string containing a malformed byte sequence

local valid = util.string.isvalid("hello\xFF")

core.engine.print("info", valid) -- false

Validate input before passing it to other utf8 functions

local user_input = "\xC0\x80"

if not util.string.isvalid(user_input) then
    core.engine.print("info", "Rejecting malformed input")
end