You just need to capture the output of the regexp match, which Perl makes available in $1.

See Extracting matches.

(Update: added link to docs)

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

my $book= "^\\s\*book ref \#";
my $book_res = $book =~ "/^\\s\*owner \#/";

my $title = "^\\s\*title ";
my $title_res = $title =~ "/^\\s\*title /";

my %keepers;

foreach (<DATA>) {
  #next unless /$book|$title/ip;
  chomp;

  if ( /($book|$title)/ip ) {
    $keepers{ $_ } = $1;
  }
   #print ;
}

# here i would like to access the regex matches as scalers

for (keys %keepers ) {
  print "Here's your scalar: <<$_>> has value <<$keepers{ $_ }>>\n";
}

__DATA__

Book ref #4346
Lent: Sun Jul 12 03:26:43 BST 2015
status Lent
Description: classic
title blah blah blah
last used: 2
color red
Pages 238
Publisher Bca
Type Hardback
Location: N/a
Author R jones
[download]

Commonly, we use hashes for doing this sort of work, where you want to have a key (book ref) that holds information about the thing (the book's title). In this specific case, I've used a hash of hashes (HoH), and used regex capture groups (()) to grab the relevant parts of the regex to store. Here's a basic example. This assumes that the book's ref will always be in the same position (above the line containing the title, and any other items you want to store)

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

my %books;
my $book_ref;

while (<DATA>) {
    chomp;

    if (/^\s*book ref #(\d+)/i and $1){
        $book_ref = $1;
        $books{$book_ref} = {};
    }
    if (/^title\s+(.*)$/i and $1){
        $books{$book_ref}{Title} = $1;
    }
}

# print the whole shebang

for my $ref (keys %books){
    for my $book_element (keys $books{$ref}){
        print "Book ref: $ref, $book_element: $books{$ref}{$book_eleme
+nt}\n";
    }
}

# print one of the book's titles

print "$books{9969}{Title}\n";

__DATA__

Book ref #4346
Lent: Sun Jul 12 03:26:43 BST 2015
status Lent
Description: classic
title blah blah blah
last used: 2
color red
Pages 238
Publisher Bca
Type Hardback
Location: N/a
Author R jones

Book ref #9969
Lent: Sun Jul 12 03:26:43 BST 2015
status Lent
Description: classic
title My Little Pony
last used: 2
color red
Pages 238
Publisher Bca
Type Hardback
Location: N/a
Author R jones


__END__
Book ref: 4346, Title: blah blah blah
Book ref: 9969, Title: My Little Pony
My Little Pony
[download]

-stevieb

you've been given good answers (use of $1 for retrieving the capture, etc.), I would just add a couple of comments on your code.

If I understand what you are trying to do, your regex matching attempts should be within the loop over the DATA section, not before.

Then, for a regex to capture what it matches or part thereof, you need to use parentheses around the part of the match that you want to capture.

Finally, and less importantly, you might want to consider using the qr// operator (see http://perldoc.perl.org/perlop.html#Quote-and-Quote-like-Operators) rather than simple quote marks for defining your regex patterns.

Putting it together, you might end up with something like this:

my $book_regex = qr/^Book ref #(\d+)/; # (\d+) will capture the ref in
+to $1
my ($ref, $title, ...);
while (<DATA>) {
    # you may need to chomp the lines
    $ref = $1 if /$book_regex/;
    $title = $1 if /^title\s+(.*)/;
    # other regexes for title, etc.
}
# now you can use $ref and $title
[download]

Regarding matching numbers ... I have recently gone back to using the old-school

/[0-9]+/
[download]

because of (in Using character classes)

Since the introduction of Unicode, unless the //a modifier is in effec
+t, these character classes match more than just a few characters in t
+he ASCII range.

\d matches a digit, not just [0-9] but also digits from non-roman scri
+pts
[download]

There are a lot of characters flying around out there. But some stuff still needs to be limited to ASCII -- for example book ref numbers, even if your book titles may have non-Roman characters; or a primary key from a database table in a multilingual CMS ...

So if you want to make sure you are matching only Roman script digits, and you need to work on perls older than 5.14, you should probably use the old [0-9]. If you have a new perl, you can do:

/\d+/a
[download]

which will limit the match to ASCII characters ...

Remember: Ne dederis in spiritu molere illegitimi!

Yes, 1nickt, you're absolutely right, we have to be quite careful about these things nowadays. I am not dealing too often with Unicode or UTF8 data, and mostly with pure ASCII or sometimes with an extended ASCII Latin character set, so that I don't always think about the possibility of character classes matching more than I usually expect. Thank you for reminding.

Having said that, I was not presenting production code, not even a complete working program, but just trying to identify some of the errors in the OP code and show some ways to correct them.

foreach (<DATA>) {
    my $re = qr/($book|$title)/;
    next unless /$re/;
    push @matches, [$1, $_, $re];
    print;
}
[download]

This saves the portion of the string that was captured, the string that matched, and the regexp that succeeded.