So? Did you actually bother to look up what perldoc -f crypt displays? Or did it give you more satisfaction to write a stupid reply than to do some trivial research. Let me quote it for you:

               Here's an example that makes sure that whoever
               runs this program knows their own password:

                   $pwd = (getpwuid($<))[1];

                   system "stty -echo";
                   print "Password: ";
                   chomp($word = <STDIN>);
                   print "\n";
                   system "stty echo";

                   if (crypt($word, $pwd) ne $pwd) {
                       die "Sorry...\n";
                   } else {
                       print "ok\n";
                   }
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Abigail