If your script is in latin-1, decode('iso-8859-1',$string) will work too. As far as I know decode() will always upgrade to utf8 (or ascii, which is a byte-compatible subset of utf-8)

If $string = 'ρα'; is a literal in a utf-8 encoded script, you should use the utf8 pragma to set the utf-8 markers correctly on literals. And then decode('iso-8859-1') probably won't work correctly on it. But utf8::upgrade() will still work.

By default, there is a fundamental asymmetry in Perl's unicode model: implicit upgrading from byte strings to Unicode strings assumes that they were encoded in *ISO 8859-1 (Latin-1)*, but Unicode strings are downgraded with UTF-8 encoding. This happens because the first 256 codepoints in Unicode happens to agree with Latin-1.
I don't know what "Unicode strings are downgraded with UTF-8 encoding" means. Also the line below that paragraph in perlunicode says 

If you wish to interpret byte strings as UTF-8 instead, use the "encod
+ing" pragma:

      use encoding 'utf8';

[download]

Don't believe it. You should use utf8; instead. use encoding 'utf8' is broken.

"What should it profit a man, if he should win a flame war, yet lose his cool?"

In reply to Re^7: A UTF8 round trip with MySQL by Joost
in thread A UTF8 round trip with MySQL by clinton

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.