hash - Perl: Get key value -

i'm trying key values hash inside module:

module.pm

... $logins_dump = "tmp/logins-output.txt"; system("cat /var/log/secure | grep -n -e 'accepted password for' > $logins_dump"); open (my $fh, "<", $logins_dump) or die "could not open file '$logins_dump': $!";  sub userlogins {     %user_logins;     while (my $array = <$fh>) {         if ($array =~ /accepted\s+password\s+for\s+(\s+)/) {             $user_logins{$1}++;          }     }     return \%user_logins; }  sub checkuserlogins {     $logincounter;     $userstocheck = shift @_;     if (exists %{userlogins()}{$userstocheck}){         $logincounter = %{userlogins{$userstocheck}}; #how many logins?     }     else {         $logincounter = "0";     }     return \$logincounter; } 

script.pl

$userlogincounter = module::checkuserlogins($userstopass); 

i pass usernames script , check if username in hash, if is, need return number of logins, i'm trying $logincounter. reason scripts returns 0 or undef.

well, starters - you've got checkuserlogins not checkloginattempts.

assuming that's typo - userlogins returns hash reference - single scalar value. you're getting 0 if exists check fails presumably.

if does exist though, you're doing this:

$logincounter = %{userlogins{$userstocheck}}; 

which isn't valid. have strict , warnings turned on? because you're trying assign hash scalar, isn't going want.

you mean:

$logincounter = ${userlogins()} -> {$userstocheck}; 

which dereferences reference userlogins , looks key.

i might however, approach problem little differently - it'll work once when you're doing, because each time call userlogins creates new hash, don't rewind $fh.

so i'd suggest:

use strict; use warnings;  {     %userlogins;      sub inituserlogins {         open( $fh, "<", '/var/log/secure' )             or die "could not open file: $!";         while ( $array = <$fh> ) {             if ( $array =~ /accepted\s+password\s+for\s+(\s+)/ ) {                 $userlogins{$1}++;             }         }         close($fh);     }      sub checkuserlogins {         ($userstocheck) = @_;         inituserlogins() unless %userlogins;         return $userlogins{$userstocheck} ? $userlogins{$userstocheck} : 0;     } }