You are most welcome! On another point...white space is the easiest thing that you can do to enhance code readability and understandability.

Consider this re-formatted code with just white space added... Now it is clear that the "map{}sort{}map{}<>" "stack" feeds the "for" loop. The "for" is iterating on the list provided by the map { $_->[0] } which is the end result of the 4 lines in this map{}sort{}map{}<> "stack" (which is actually just one line). When that whole thing is nicely indented, it is easier to see. Human eyeballs work best vertically, not diagonally. 

for  (
         map  { $_->[0] }
         sort { $a->[1] cmp $b->[1] }
         map  { [$_, (split)[$column_number] ] }
         <>
     )
{
   print unless $_ eq $prev;
   $prev = $_;
}

[download]
This "for" statement is the same as:
for(map{$_->[0]}sort{$a->[1]cmp$b->[1]}map{[$_,(split)[$column_number]]}<>)
what do you think is easier to read?

In reply to Re^5: Emulating 'sort' command through a Perl by Marshall
in thread Emulating 'sort' command through a Perl by paragkalra

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.