#!/usr/bin/perl

# http://perlmonks.org/?node_id=1200077

use strict;
use warnings;

my $string = 'Titles consisting of a single word are discouraged, and in most cases are disallowed outright.';

my @tags = split /\n/, <<END;
consisting of: cat1: id1: 7: 20
discouraged: cat1: id2: 39: 50
most cases: cat2: id3: 59: 69
END

print "$string\n";

for (reverse @tags)
  {
  my ($text, $cat, $id, $start, $end) = split /: /;
  substr $string, $start, $end - $start, "($cat: $id)$text($cat)";
  }

print "$string\n";