The following code counts how many times a given password occurs in a list:

my $passwdkey = 'bob';
my $passcount = 0;
while (<DATA>) {
   chomp;
   if ($_ eq $passwdkey) {
      $passcount++;
      print "ok\n";
   }
}
print "final '$passwdkey' count = $passcount\n";
__DATA__
ted
bob
carol
alice
bob
hank
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A fancier way to do this is to use grep:

my $passcount = grep {$_ eq "$passwdkey\n") <DATA>;
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