$ perl -e" binmode STDOUT,q!:encoding(UTF-8)!; print qq!\N{U+00E9}!" |od -tx1
0000000 c3 a9
0000002

$ perl -e" binmode STDOUT,q!:encoding(UTF-8)!; print qq!\xE9!" |od -tx1
0000000 c3 a9
0000002

$ perl -e" binmode STDOUT,q!:encoding(UTF-8)!; print qq!\x{00E9}!" |od -tx1
0000000 c3 a9
0000002

$ perl -e" binmode STDOUT,q!:encoding(UTF-8)!; print qq!\x{C3A9}!" |od -tx1
0000000 ec 8e a9
0000003