for (1..4) {
   if (glob($0)) {
      print("I exist\n");
   } else {
      print("I don't exist\n");
   }
}

##</code><code>##

I exist
I don't exist
I exist
I don't exist

##</code><code>##

for (1..4) {
   if (() = glob($0)) {
      print("I exist\n");
   } else {
      print("I don't exist\n");
   }
}

##</code><code>##

for (1..4) {
   if (-e $0) {
      print("I exist\n");
   } else {
      print("I don't exist\n");
   }
}

##</code><code>##

I exist
I exist
I exist
I exist