Correct. unicode_strings affects things that care whether characters in the U+80 to U+FF range are letters or not, or whitespace or not. This includes uc, split and the regex engine. It doesn't affect I/O. 

$ t() {
   perl -e'
      use open ":std", ":encoding(UTF-8)";
      use if $ARGV[0], feature => "unicode_strings";
      CORE::say uc "\xE9";
   ' -- "$@"
}

$ t 0
é

$ t 1
É

[download]
$ t() {
   perl -e'
      use open ":std", ":encoding(UTF-8)";
      use if $ARGV[0], feature => "unicode_strings";
      CORE::say join "|", split " ", "a\x20b\xA0c";
   ' -- "$@"
}

$ t 0
a|b c

$ t 1
a|b|c

[download]

In reply to Re^2: FCGI, tied handles and wide characters by ikegami
in thread FCGI, tied handles and wide characters by Maelstrom

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.