Because you admitted unabashedly you're new to Perl, and because you pleaded very graciously for our help, I've taken the liberty of refactoring your script a tiny bit. I've incorporated idioms of Modern Perl and a few Perl best practices gleaned from Perl Best Practices.

#!perl
#
# hiragana2romaji.pl - Convert hiragana text to romaji text

use strict;
use warnings;
use autodie;

use Lingua::JA::Moji qw( kana2romaji );

@ARGV == 2
    or die "Usage: perl $0 <hiragana file> <romaji file>\n";

my $hiragana_file = shift @ARGV;
my $romaji_file   = shift @ARGV;

open my $hiragana_fh, '<:encoding(UTF-8)', $hiragana_file;
open my $romaji_fh,   '>:encoding(UTF-8)', $romaji_file;

while (my $hiragana_text = <$hiragana_fh>) {
    chomp $hiragana_text;
    my $romaji_text = kana2romaji($hiragana_text);
    print {$romaji_fh} "$romaji_text\n";
}

close $hiragana_fh;
close $romaji_fh;

exit 0;

[download]

In reply to Re: UTF8 issues by Jim
in thread UTF8 issues by kemuri

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.