1START   ACCOUNTA     XXXXXMA      12345     XYZ111          1START   ACCOUNTB     XXXXXBR      12345     XYZ191          1START   ACCOUNTA     XXXXXNY      54321     XYZ131

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

use Data::Dumper;

$| = 1;
srand();
$Data::Dumper::Sortkeys = 1;

my $fn = q{test.dat};
open my $df, $fn or die $!;
$/ = q{1START};
while ( my $line = <$df> ) {
    chomp $line;
    next if ( $line =~ m/^\s*$/ );

    if ( substr( $line, 3, 8 ) eq q{ACCOUNTA} ) {
        print $/, $line, qq{\n};
    }
}
close $df;

##</code><code>##

1START   ACCOUNTA     XXXXXMA      12345     XYZ111
1START   ACCOUNTA     XXXXXNY      54321     XYZ131