#!/usr/bin/perl
use warnings;
use strict;

my $block = "cat\nman\n";
my $n = 3;

my $expected = << '__EOF__';
1 cat
man
2 cat
man
3 cat
man
__EOF__

$block =~ s/(cat\nman\n)/join "", map "$_ $1", 1 .. $n/e;

use Test::More tests => 1;
is $block, $expected, 'same';