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

Thanks to all who have helped me out with this one; my first "real" program!
Code snippet: 
  foreach $element_priv(@priv) {
       open FILE, "$as_dir/$element_priv" or warn ("Can't open $as_dir
+/$element_priv: $!\n"), next;
       while ($compare_lines = <FILE>) {
           chomp $compare_lines;
           next if ($compare_lines =~ /unknown|shutdown/);
           ($as,$as_name,$neighbor,$router,$interface,$address,$interf
+ace_name,$ifindex,$vpi,$vci) = split(' ',$compare_lines);
           push @{$HoL_compare_priv{$router}}, $interface_name;
       }
   }

 my %no_priv_matches;
   
   foreach my $key (keys %HoL_compare_priv) {
       push @{$no_priv_matches{$key}}, $HoL_compare_priv{$key}
       unless exists $HoL_priv{$key};
   }


   foreach my $group (keys %no_priv_matches) {
       print "New interconnects for $group are:\n";
      foreach (@{$no_priv_matches{$group}}) {
           print "\t@{$no_priv_matches{$group}}\n";
       }
   }

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When run, prints: 
New interconnects for vienna1-nbr2 are:
        ARRAY(0x1e9184)
New interconnects for crtntx1-cr8 are:
        ARRAY(0x1df388)
New interconnects for washdc3-br1 are:
        ARRAY(0x1e91e4)
New interconnects for chcgil2-cr1 are:
        ARRAY(0x207358)

[download]
How can I dereference those array references?

Replies are listed 'Best First'.
(jeffa) Re: Dereferencing Hash of Array
by jeffa (Bishop) on Feb 20, 2001 at 20:53 UTC
    In your last chunk: 
    foreach my $group (keys %no_priv_matches) {
    print "New interconnects for $group are:\n";
    foreach (@{$no_priv_matches{$group}}) {
        print "\t@{$no_priv_matches{$group}}\n";
    }
}

    [download]
    That inner foreach is not doing anything usefull, that's like saying this: 
    foreach (@array) {
    print @array;
}

    [download]
    Do you really mean: 
    foreach (@array) {
    print $_;
}

    [download]
    If that's the case, then maybe this will work: 
    foreach my $group (keys %np_matches) {
    print "blah $group:\n";
    foreach (@{$np_matches{$group}}) {
        print "\t@{$_}\n";
    }
}

    [download]
    Hope this helps

    Jeff 

    R-R-R--R-R-R--R-R-R--R-R-R--R-R-R--
L-L--L-L--L-L--L-L--L-L--L-L--L-L--
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[d/l]
[select]
Re: Dereferencing Hash of Array
by TheoPetersen (Priest) on Feb 20, 2001 at 20:53 UTC
    Is this really what you want? 
    foreach (@{$no_priv_matches{$group}}) {
    print "\t@{$no_priv_matches{$group}}\n";
}

    [download]
    For each member of the array, you're printing the entire array? Seems like you'd want a dereferencing expression inside the loop there.
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[d/l]
Re: Dereferencing Hash of Array
by mr.nick (Chaplain) on Feb 20, 2001 at 20:40 UTC
    You just need to use join or something similiar. 

    foreach my $group (keys %no_priv_matches) {
       print "New interconnects for $group are:\n";
      foreach (@{$no_priv_matches{$group}}) {

           print "\t".join(",",@{$no_priv_matches{$group}})."\n";
       }
   }

    [download]
[reply]
[d/l]
      Thanks for the reply, but that returns the same result as the code that I posted.
[reply]
        Sorry, my mistake, I didn't see the double arrays. Something like this will work: 
        foreach (@{$no_priv_matches{$group}}) {
 for my $x (@$_) {
   print "$x ";
 }
}

        [download]
[reply]
[d/l]

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