Thanks for that link, it was helpful for sure. Here's how I did it. The first subroutine gets the tuples from the file, splits them into an array, and writes them all into one array.

sub get_links {
    my @links;
    open(my $fh, "<", "links.alpha.sorted.25sample")
        or die "cannot open < links.alpha.sorted.25sample: $!";
    while(<$fh>) {
        chomp;
        my $tuple;
        @$tuple = split(/\s+/, $_);
        push(@links, $tuple);
    }
    return @links;
}

[download]

Then I sort by the second value and write it to another file:

sub sort_and_store {
    my @links = get_links();
    my @sorted_links = sort { $a->[1] cmp $b->[1] } @links;
    open(my $fh, ">", "sorted.by.destination")
        or die "cannot open > sorted.by.destination: $!";
    foreach my $tuple (@sorted_links) {
        print $fh "@$tuple\n";
    }
}

[download]

I've never used the @$blah variable type before, and I couldn't find any information about it. I'm guessing that's how you refer to the arrays in an array of arrays?

In reply to Re^2: Sorting a "tuple" by the second value by thmsdrew
in thread Sorting a "tuple" by the second value by thmsdrew

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