#!/usr/bin/perl
use strict;
use warnings;
my $issue  = qr/^ [[] [A-Z][A-Z0-9]+ - \d+ .* [\]]/xms;
my $merge  = qr/^ Merge /xms;
my $revert = qr/^ Revert /xms;
my $regen  = qr/^ Regen /xms;
my $pom    = qr/^ POM /xms;
my $good   = qr/ $issue | $merge | $revert | $regen | $pom /xms;
open my $fh, "<", $ARGV[0] or die "Can't read commit message!: $!\n";
my $msg = do { local $/; <$fh> };
if ( $msg !~ /$good/xms ) {
    warn <<"MESSAGE";
Bad message! '$ARGV[0]'
Messages should be:
    [JIRA-NNN]
    Merge ...
    Revert ...
    Regen ...
    POM ...
MESSAGE
    exit 1;
}
exit 0;