my @coordinates_unsorted; while ( ) { push @coordinates_unsorted, [ m/([\d.]+)/g ]; } my( @coordinates_sorted ) = sort { $a->[1] <=> $b->[1] or $a->[2] <=> $b->[2] or $a->[0] <=> $b->[0] or $a->[3] <=> $b->[3] } @coordinates_unsorted; foreach my $coordinate_ref ( @coordinates_sorted ) { printf "((%2.1f %2.1f) (%2.1f %2.1f))\n", @{$coordinate_ref}; }