End of Life Ruby 3.0 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

instance method

Kconv#guess

Kconv.guess(str) => encoding

# File tmp/rubies/ruby-3.0.5/ext/nkf/lib/kconv.rb, line 141
def guess(str)
  ::NKF::guess(str)
end

Guess input encoding by NKF.guess

See also .guess .toutf8 #iseuc .toutf32 also in 3.3 · 3.2 · 3.1