$ LANG=C ./script
printing to /tmp/foo
printing to STDOUT
Wide character in print at t5 line 13.
Ҋ
printing to duped STDOUT
Ҋ

$ LANG=en_US.UTF-8 ./script
printing to /tmp/foo
printing to STDOUT
Ҋ
printing to duped STDOUT
Ҋ

$ LANG=C ./script > /tmp/out
printing to /tmp/foo
printing to STDOUT
Wide character in print at t5 line 13.
printing to duped STDOUT
Wide character in print at t5 line 18.

$ LANG=en_US.UTF-8 ./script > /tmp/out
printing to /tmp/foo
printing to STDOUT
printing to duped STDOUT
Wide character in print at t5 line 18.