groff does it with the help of its preconv(1), also invoked with groff's -k option. $ printf 'Hello ①②③\n' | preconv .lf 1 - Hello \[u2460]\[u2461]

groff does it with the help of its preconv(1), also invoked with groff's -k option. $ printf 'Hello ①②③\n' | preconv .lf 1 - Hello \[u2460]\[u2461]\[u2462] $ printf 'Hello ①②③\n' | groff -k -Tutf8 | grep . Hello ①②③ $