First, show the code you tried. You'll learn faster on your own code than someone else's.

Looks like you need a hash of hashes instead. Something like this (untested): 

my %master;
while (<>)
{
  my @line = split ' ';
  foreach my $alias ( @line[1..$#line] )
  {
    $master{$line[0]}{$alias}++;
  }
}
foreach my $ip ( sort keys %master )
{
  print "$ip ", 
        +join( ' ', sort keys %{$master{$ip}}), 
        "\n";
}

[download]
You can use an array for the top level instead, and have an array of hashes. But if you have duplicate aliases, you'll want the hashes at the second level.

-QM
--
Quantum Mechanics: The dreams stuff is made of

In reply to Re: Perl and arrays of arrays? by QM
in thread Perl and arrays of arrays? by Anonymous Monk

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