my $interrupted = 0;
my @signals = qw/INT TERM USR2 HUP/;
for my $sig (@signals) {
    $SIG{$sig} = sub {
        $interrupted = 1;
    }
}

#... then, throughout the code test for it ...

#main loop:
while (not $interrupted) { ...
  ... blah blah ...
  last if $interrupted;
  ... or ...
  exit(1) if $interrupted;
}