$ perl -E'
   $SIG{INT} = sub {
      if ($i++) {
         say "You were sure.";
         exit(1);
      } else {
         say "Are you sure?";
      }
   };

   for (;;) {
      say "Waiting...";
      if (select(undef, undef, undef, undef) < 0) {
         if ($!{EINTR}) {
            say "Interrupted";
         } else {
            die $!;
         }
      } else {
         say "select returned without an error???";
      }
   }
'
Waiting...
^CAre you sure?
Interrupted
Waiting...
^CYou were sure.
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