use strict;
use warnings;

my $szUser = 'any_user';
my $szPassword = 'for_me_to_know';

my ($szOther, $szEncryptedPwd) = getpwnam($szUser);
my $bValid = (crypt($szPassword, $szEncryptedPwd) eq $szEncryptedPwd);

print $bValid ? 'Yes' : 'No';
print "\n";