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    <p>If you just want to slurp input to output, this should do the trick. </p> <pre><code>use Carp (); { #Lexical For FileHandle and $/ open my $fh, '&lt;' , '/path/to/file.txt' or Carp::croak("File Open Failed"); local $/ = undef; print scalar &lt;$fh&gt;; close $fh or Carp::carp("File Close Failed"); } </code></pre> <p>I guess in response to the "Does Perl have a PHP ReadFile Equivelant" , and I guess my answer would be "But it doesn't really need one". </p> <p>I've used PHP's manual File IO controls and they're a pain, Perls are just so easy to use by comparison that shelling out for a one-size-fits-all function seems over-kill. </p> <p>Also, you might want to look at <code>X-SendFile</code> support, and basically send a header to your webserver to tell it what file to send: <a href="http://john.guen.in/past/2007/4/17/send_files_faster_with_xsendfile/" rel="nofollow noreferrer">http://john.guen.in/past/2007/4/17/send_files_faster_with_xsendfile/</a> ( assuming of course it has permissions enough to access the file, but the file is just NOT normally accessible via a standard URI ) </p> <p><em>Edit</em> Noted, it <em>is</em> better to do it in a loop, I tested the above code with a hard-drive and it does implicitly try store the whole thing in an invisible temporary variable and eat all your ram. </p> <h2>Alternative using blocks</h2> <p>The following improved code reads the given file in blocks of 8192 chars, which is much more memory efficient, and gets a throughput respectably comparable with my disk raw read rate. ( I also pointed it at /dev/full for fits and giggles and got a healthy 500mb/s throughput, and it didn't eat all my rams, so that must be good ) </p> <pre><code>{ open my $fh , '&lt;', '/dev/sda' ; local $/ = \8192; # this tells IO to use 8192 char chunks. print $_ while defined ( $_ = scalar &lt;$fh&gt; ); close $fh; } </code></pre> <h2>Applying jrockways suggestions</h2> <pre><code>{ open my $fh , '&lt;', '/dev/sda5' ; print $_ while ( sysread $fh, $_ , 8192 ); close $fh; } </code></pre> <p>This literally doubles performance, ... and in some cases, gets me better throughput than DD does O_o. </p>
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    1. POHow do I serve a large file for download with Perl?
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    1. COFWIW, you should use "sysread" instead of changing $INPUT_RECORD_SEPARATOR.
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    2. COOut of curiosity, where did 8192 come from?
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    3. COno, 8192 *bytes*. Its just a handy unit. 4096 is usally the filesystem block size, and 8192 fits conveniently with most drives disk-cache these days, so its a convenient transfer unit. You can use any number, but powers of 2 are best.
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