To get the "visual size" (my term, don't know if there's an official one) of a string, you need two pieces of information:

(And that's assuming your input has no control characters such as a newline.)

The first is actually pretty easy: 

my @graphemes = $text =~ /\X/g;
my $count = () = $text =~ /\X/g;

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NFC is definitely not the way to go as it doesn't work for every character-mark combination.

The catch is knowing the width of characters. Some characters are zero-width, and others are double-width. For that, you really a need the help of a module. Unicode::GCString is such a module. 

my $size = Unicode::GCString->new($text)->columns();

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In reply to Re: Trying to determine the output length of a Unicode string by ikegami
in thread Trying to determine the output length of a Unicode string by pierswalter

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