koaps has asked for the wisdom of the Perl Monks concerning the following question:

Hi guys,
I'm trying to figure out how to dereference something and I can't get the syntax right.
I have a hash reference I'm filling up with username => @logins basically. 

my $matches = {};
$matches->{$user} = [grep {/$user/} @logins];

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What I can't seem to get right: 
foreach my $user (keys %$matches) {
    print "$user: ". @{$matches->{$user}} . "\n";
}

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Gives me: 
user1: 1
user2: 0
user3: 0

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It should be more like: 
user1: Thu Nov  5 18:49:39 2009 [pid x] [user1] OK LOGIN: Client "127.
+0.0.1"

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How can I get at the array values in the hashref?

Replies are listed 'Best First'.
Re: Help with a dereference
by Anonymous Monk on Nov 06, 2009 at 19:39 UTC
    scalar context, see perlop
    my @stuff = 1 .. 10;
print "dot aka period  ". @stuff ."\n";
print "comma ", @stuff ,"\n";
__END__
dot aka period  10
comma 12345678910

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[d/l]
      Or even direct string interpolation: 
      >perl -wMstrict -le
"my @stuff = 1 .. 10;
 print qq{interpolate @stuff here};
"
interpolate 1 2 3 4 5 6 7 8 9 10 here

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      Update: Using something closer to the code of the OP: 
      >perl -wMstrict -le
"my $stuff = {};
 my $this  = 'here';
 $stuff->{$this} = [ qw(foo bar baz) ];
 print qq{interpolate @{ $stuff->{$this} } here};
"
interpolate foo bar baz here

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[d/l]
[select]

        Thanks guys,

        I mainly was checking that @{$matches->{$user}} was correct, because I actually was using it in an if statement then iterating through it to print to a filehandle.

        I was using print to test that the array looked right and the periods were hanging me up.

        Thanks again.

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      thanks
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