1. what exactly is the difference between :utf8 and :encoding(UTF8)

As Juerd says:

What exactly isn't clear about that?

Properly decoding/validating of course takes time.  OTOH, if you let perl work with unvalidated 'UTF-8' strings, nasty things can happen (including segfaults), because Perl's unicode internals have not been implemented to handle this safely in each and every case... Strings which are not properly encoded in UTF-8 should not have the utf8 flag on.

In reply to Re: :utf8 I/O layer vs encoding(UTF8), segfault and speed by almut
in thread :utf8 I/O layer vs encoding(UTF8), segfault and speed by mje

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