If you were using Perl 5.8, I'd suggest pushing an encoding layer when you opened the file (or after with binmode). As you're not, I won't.

Here's a quick script that reads a file line-by-line and uses pack to set the UTF-8 flag on each string read in. After that flag is set, character semantics work as expected for wide characters that were read in from the file:

  use utf8;
  use CGI::Carp qw(fatalsToBrowser);

  print "Content-type: text/html; charset=utf-8\n\n";

  open(FILE, "<", "/path/to/utf8/file.txt") || die "$!";

  print "<pre>\n";
  while(<FILE>) {
    chomp;
    $_ = set_utf($_);
    my $len = length($_);    # count of chars not bytes
    print "$_", ' ' x (72 - $len), "|\n";
  }
  print "</pre>\n";

  sub set_utf {
    return pack "U0a*", join '', @_;
  }

[download]

I fashioned the script as a CGI script so that you can view the output in your browser - which understands UTF-8 characters (whereas your TTY might not). Given a UTF-8 text file with lines less than 80 characters, this should pad each line out to 80 characters with spaces and then append a '|'. If character semantics are not in force, the length will count bytes rather than characters and the '|'s won't line up.

In reply to Re: Setting UTF-8 mode on filehandle reads? by grantm
in thread Setting UTF-8 mode on filehandle reads? by jkahn

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.