sub handler {  local($sig) = @_;  print "Caught a SIG$sig -- shutting down\n";  exit(0);}$SIG{'INT'} = 'handler';$SIG{'QUIT'} = 'handler';$SIG{'ALRM'} = 'handler';print "Starting execution ...\n";alarm(10);while ( <> ) {}print "Normal exit.\n";