#!/usr/bin/perl

# http://perlmonks.org/?node_id=1194202

use strict;
use warnings;

my %totals;
local $/ = 'violation';

/^([A-Z])(?:_\d+).* (\d+) violation/sm and $totals{$1} += $2 while <DA
+TA>;

print "$_ number of violations = $totals{$_};\n" for sort keys %totals
+;

__DATA__
A_01: xxxxxxx
xxxxxxxxxx
xxx......... 1 violation

A_02: xxxxxxx
xxxxxxxxxx
xxx......... 4 violations
B_02: xxxxxxxx
xxxxxxxxxx
xxx......... 3 violations
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