$ perl -e"print qq!\x{C3A9}!
Wide character in print at -e line 1.
쎩
$ perl -Mopen=:std,:encoding(UTF-8) -e"print qq!\x{C3A9}!" |hexdump
00000000: EC 8E A9                -                         |   |
00000003;

$ perl -Mopen=:std,:encoding(UTF-16LE) -e"print qq!\x{C3A9}!" |hexdump
00000000: A9 C3                   -                         |  |
00000002;

$ perl -Mopen=:std,:encoding(UTF-16BE) -e"print qq!\x{C3A9}!" |hexdump
00000000: C3 A9                   -                         |  |
00000002;

$