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    <p><code>parse(*ARGV)</code> is the simplest solution: the explanation is a bit long, but an important part of learning how to use Perl effectively is to learn Perl.</p> <p>When you use a null filehandle (<code>&lt;&gt;</code>), it actually reads from the magical <code>ARGV</code> filehandle, which has special semantics: it reads from all the files named in <code>@ARGV</code>, or <code>STDIN</code> if <code>@ARGV</code> is empty.</p> <p>From <code>perldoc perlop</code>:</p> <blockquote> <p>The null filehandle <code>&lt;&gt;</code> is special: it can be used to emulate the behavior of sed and awk. Input from <code>&lt;&gt;</code> comes either from standard input, or from each file listed on the command line. Here’s how it works: the first time <code>&lt;&gt;</code> is evaluated, the <code>@ARGV</code> array is checked, and if it is empty, <code>$ARGV[0]</code> is set to <code>"-"</code>, which when opened gives you standard input. The <code>@ARGV</code> array is then processed as a list of filenames. The loop</p> <pre><code>while (&lt;&gt;) { ... # code for each line } </code></pre> <p>is equivalent to the following Perl-like pseudo code:</p> <pre><code>unshift(@ARGV, '-') unless @ARGV; while ($ARGV = shift) { open(ARGV, $ARGV); while (&lt;ARGV&gt;) { ... # code for each line } } </code></pre> <p>except that it isn’t so cumbersome to say, and will actually work. It really does shift the <code>@ARGV</code> array and put the current filename into the <code>$ARGV</code> variable. It also uses filehandle <code>ARGV</code> internally--<code>&lt;&gt;</code> is just a synonym for <code>&lt;ARGV&gt;</code>, which is magical. (The pseudo code above doesn’t work because it treats <code>&lt;ARGV&gt;</code> as non-magical.)</p> </blockquote> <p>You don't have to use <code>&lt;&gt;</code> in a <code>while</code> loop -- <code>my $data = &lt;&gt;</code> will read one line from the first non-empty file, <code>my @data = &lt;&gt;;</code> will slurp it all up at once, and you can pass <code>*ARGV</code> around as if it were a normal filehandle.</p>
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    1. POHow do I get a filehandle from the command line?
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    1. COIt doesn't quite answer the question directly... but suggesting, based on this, that the OP pass the ARGV filehandle to his function would. (Assuming, of course, that doing so would work - I haven't tried it.)
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    2. COClarified this answer to say that parse(*ARGV) does work, instead of putting it in a comment on the question.
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