I am assuming you want to slurp the whole file into the variable $info. It might be easier to do this as follows:
{
local $/ = undef;
$info = <DATA>;
}

[download]
For more info on $\ look at perlvar

Apart from this, I have changed the regex a little bit to do more of what I think you want it to do. Here is the code. 

use strict;
use warnings;
use Data::Dumper;
my $info;

{
local $/ = undef;
$info = <DATA>;
}

my %lines;

while ($info =~ m/(\d+)\: (.+?)\n(?=\d)/gs) {
    $lines{$1} = $2;
}

print Dumper (%lines);

__DATA__
3: Tag <test> found
Tag <test> found
5: Tag <test> found
7: Tag <test> found
14: Tag <test> found
16: Tag <test> found
18: Tag <test> found
21: Tag <test> found
25: Tag <test> found
27: Tag <test> found
29: Tag <test> found
32: Tag <test> found
34: Tag <test> found
49: Tag <test> found
80: Tag <test> found
98: Tag <test> found
Tag <test> found

[download]
and here is the output:
$VAR1 = '29';
$VAR2 = 'Tag <test> found';
$VAR3 = '21';
$VAR4 = 'Tag <test> found';
$VAR5 = '7';
$VAR6 = 'Tag <test> found';
$VAR7 = '14';
$VAR8 = 'Tag <test> found';
$VAR9 = '80';
$VAR10 = 'Tag <test> found';
$VAR11 = '32';
$VAR12 = 'Tag <test> found';
$VAR13 = '16';
$VAR14 = 'Tag <test> found';
$VAR15 = '49';
$VAR16 = 'Tag <test> found';
$VAR17 = '25';
$VAR18 = 'Tag <test> found';
$VAR19 = '3';
$VAR20 = 'Tag <test> found
Tag <test> found';
$VAR21 = '34';
$VAR22 = 'Tag <test> found';
$VAR23 = '18';
$VAR24 = 'Tag <test> found';
$VAR25 = '27';
$VAR26 = 'Tag <test> found';
$VAR27 = '5';
$VAR28 = 'Tag <test> found';

[download]
. The regex: m/(\d+)\: (.+?)\n(?=\d)/gs
looks for a number then lazily matches up to where the next thing is a new line, but only if the first thing after that new line is a digit.

Well, I think this is what you want.

UPDATE: I meant to have placed the Dumper(\%lines) as BrowserUK has done below, instead of just Dumper(%lines). Don't know what I was thinking.

-enlil

In reply to Re: Matching over multiple lines in a scalar by Enlil
in thread Matching over multiple lines in a scalar by Rich36

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