#!/usr/bin/perl
use Modern::Perl;
use Data::Dumper;

#945627  Workaround if the distinction among elements in each data 
#        segment need not be retained; if retention
#        is required, read DATA into a HoA with the 
#        separator-and-its-following-digit(s) as keys.

say "\n\t \$/ is a string, not a regex," .  
    "\n\t so, using an input_separator without any regex metachar \n";
$/ = "FOO";

my @newarr;
my @arr = <DATA>;


for my $item(@arr) {
    $item =~ s/\n//sg;
    if ( $item =~ /^\d+(.+?)(?:FOO)*$/s ) {
        my $out = $1;
        push @newarr, $out;
    } else {
        say "\t Disgarding $item (ie, \$arr[1])";  # discarding the initial "FOO" in $arr[1]
    }
}

print Dumper @newarr;

=head OUTPUT


        $/ is a string, not a regex,
         so, using an input_separator without any regex metachar

         Disgarding FOO (ie, $arr[1])
$VAR1 = 'abcdefghi';
$VAR2 = 'jkl-123-';
$VAR3 = 'mnopqrstu';
$VAR4 = 'vwxyz';

=cut

__DATA__
FOO0
abc
def
ghi
FOO1
jkl
-123-

FOO2
mno
pqr
stu
FOO3
vwxy
z