OK,

First, I create the @fields array, using the split function with default args (i.e. splits $_ into fields separated by whitespace).

Then, I use the pop function to remove (and get) the rightmost element of the fields array. (push and pop manipulate the right hand side; shift and unshift manipulate the left). So after the $key has been popped, @fields is an array of all fields, except the rightmost.

To push a list onto a list of arrays, I need an array reference. I could have used \@fields; but there are subtle ways that can go wrong when you're new to perl data-structures. So instead, I create a new anonymous array reference (using square brackets).

Later, when I want convert the array-reference back into an array, I need to use the array dereferencing operator: @{$line}. I appologise for using a standard shorthand here: perl interprets @$line as @{$line}.

Your last question is how to format you colmns more nicely. The easiest way (might work) is to join the elements of the array using a tab, instead of a space:

    my $text = join("\t", @fields);
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If this doesn't work, then there are many alternatives: you could define a format (see books); or you could write some clever padding functions; or you could store the original input text in the hash-of-lines; or you could get a CPAN module such as Data::ShowTable or Text::FormatTable. Personally, I usually don't bother: if I really need to view something as neat tables, then I use a table viewing application (or output as html). --Dave.