Like a lot of monks, I am not one to completley write code for someone. Especially since it sounds like an assignment (since you are specifying the exact number of lines you need it in). However, to open the file up, check out IO::File, read in the line, put the vars into an array and then sort them:

for my $line (<FH>) { 
  my @unsorted = split / /, $line;
  # sort ascending
  my @sorted = sort @unsorted;
  # sort descending
  my @desc_sort = reverse @sorted;
}
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Check out the pages on sort, reverse, and split for more information. There are certainly shorter ways to do this, but you need to understand what's going on before you can condense it.