print "username: ";
chomp ($uname = <STDIN>);
print "\npassword: ";
chomp ($password = <STDIN>);
print "\nYou entered username $uname and password $password\n";

##</code><code>##

someusername
somepassword

##</code><code>##

perl script.pl < answer.txt

##</code><code>##

C:\test\scratch>perl script.pl < answer.txt
username:
password:
You entered username someusername and password somepassword