int :str-bytes ( string $STR )

Returns length of given string, in bytes. For ASCII strings, this is identical to :str-len.

# :str-bytes example
:set &UTF u''
:readln &UTF

:writeln s'$UTF = ' $UTF
:writeln s'Codepoints: ' :str-len $UTF
:writeln s'Bytes: ' :str-bytes $UTF