When writing, :encoding only makes sense if you try to print "strings of chars". Perl 5.6 doesn't have string of chars, so there can be no parallel to :encoding.

To replace :encoding, you'd have to replace three things:

• The function that converts the string of encoded bytes to a string of chars, such as :encoding() on read and decode.
• Any string function used, such as regexps, substr, eq, etc.
• The function that converts the string of chars to a string of encoded bytes, such as :encoding() on write and encode.

Basically, you need a "string of chars" class for Perl 5.6 to fill in for the native one in Perl 5.8. I don't know if such a thing exists. You really should upgrade to Perl 5.8 if you're going to deal with characters sets.

(And no, Encode won't help since it allows you to do explicitly what :encoding does implicitly. You can't convert "string of chars" if in a version of Perl where they don't exist.)