This would work, You'll get hash of arrays

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my $HASH;
my $Title;
while ( <DATA> ) {
    chomp;
    next if ! $_;
    if ( /^\d+\.(.*)/sg ) {
        $Title = $1;        
        $HASH->{$Title} = [];
        next;
    }
    if ( exists $HASH->{$Title} ) {
        push @{$HASH->{$Title}} , $_;
    }

}

print Dumper($HASH);

__DATA__
1.TITLE OF FIRST RECIPE

abstract

Recipe 1.
Recipe 2.
Recipe ...

Procedure...


2.TITLE OF SECOND RECIPE
...

[download]

In reply to Re: Regexp and reading a file n-lines at time by ahmad
in thread Regexp and reading a file n-lines at time by epimenidecretese

Title:
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