title: What does the cat command in quotes in a string in perl do?
body: <pre><code>#tf.pl
  #!/usr/local/bin/perl
  use Util;
  $file = shift;
  $text = `cat $file`;
  my @words = split_words ($text);
  my @words = lc_words (@words);
  my %count = count_hash(@words);
  while (my ($w, $c) = each %count) {
      print "$w\t$c\n";
      $df{$w} = 1;
  }
  </code></pre>
  
  <p>I came across that code on a website. On line 3 $file is given the name of the file that would have been supplied with the command line argument (correct me if I am wrong, I'm a Perl rookie)</p>
  
  <p>On line 4 you see:</p>
  
  <pre><code>$text = `cat $file`;
  </code></pre>
  
  <p>I want to know what does this line do exactly? I know <code>cat filename</code> in shows you the content of the files in the terminal (again, correct me if wrong. Linux rookie too)</p>
  
  <p>I asked this on IRC and someone said this was a bad way of doing something but I really want to know what this does more than knowing the better alternative of it</p>