Liberating GrandFather's example and twiddling it to use hostname and /etc/hosts: 
#!/usr/bin/perl

use strict;
use warnings;

chomp(my $HN = `hostname`);

if (open(HOSTS, "</etc/hosts")) {
  while (<HOSTS>) {
    next if ! /^((?:\d{1,3}\.){3}\d{1,3})\s+($HN)\b/;
    print "$2: $1\n";
    last;
  }
  close HOSTS;
} else {
  die "Could not open /etc/hosts for reading: $!\n";
}

[download]

... might save a few minutes of head scratching for someone.

In reply to Re: Passing variables into regular expressions by gloryhack
in thread Passing variables into regular expressions by wanderer

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