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    <p>On the topic of manipulating @ARGV - that's definitely working code, Perl certainly allows you to do that. I don't think it's a good coding habit though. Most of the code I've seen that uses the "while (&lt;>)" idiom is using it to read from standard input, and that's what I initially expect your code to do. A more readable pattern might be to open/close each input file individually:</p> <pre><code>foreach my $file (@files) { open FILE, "&lt;$file" or die "Error opening file $file ($!)"; my @lines = &lt;FILE&gt;; close FILE or die $!; foreach my $line (@file) { if ( $line =~ /$pattern/ ) { # do something here! } } } </code></pre> <p>That would read more easily to me, although it is a few more lines of code. Perl allows you a lot of flexibility, but I think that makes it that much more important to develop your own style in Perl that's readable and understandable to you (and your co-workers, if that's important for your code/career).</p> <p>Putting subroutines in the main function or in a subroutine is also mostly a stylistic decision that you should play around with and think about. Modern computers are so fast at this stuff that style and readability is much more important for scripts like this, as you're not likely to encounter situations in which such a script over-taxes your hardware.</p> <p>Good luck! Perl is fun. :)</p> <p>Edit: It's of course true that if he had a very large file, he should do something smarter than slurping the entire file into an array. In that case, something like this would definitely be better:</p> <pre><code>while ( my $line = &lt;FILE&gt; ) { if ( $line =~ /$pattern/ ) { # do something here! } } </code></pre> <p>The point when I wrote "you're not likely to encounter situations in which such a script over-taxes your hardware" was meant to cover that, sorry for not being more specific. Besides, who even has 4GB hard drives, let alone 4GB <em>files</em>? :P</p> <p>Another Edit: After perusing the Internet on the advice of commenters, I've realized that there are hard drives that are much larger than 4GB available for purchase. I thank the commenters for pointing this out, and promise in the future to never-ever-<em>ever</em> try to write a sarcastic comment on the internet.</p>
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    1. POShould I manually set Perl's @ARGV so I can use <> to open, scan, and close files?
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    1. COIt's not necessary to store the whole file in memory first and go through it in a separate loop. Imagine he had a 4GB file, for example!
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    2. CO"Who even has 4GB hard drives?" - what decade are you in? My hard drive is 150GB. Perhaps you meant 4GB of memory, which is slightly more believable. But my computer has 2GB of memory. So what exactly are you talking about?
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