Much cleaner! Putting the increment back in and not skipping a line at the end yields a "more intresting"* result (63 chars):

perl -ln0e's/\s+/ /g;print$"x(40-($c=2+length$&)/2),$&while/.{0$c,}? |
+.+/g' a.txt w.txt
                                      a 
                                    a a a 
                                  a a a a a 
                                a a a a a a a 
                              a a a a a a a a a 
                             a a a a a a a a a a 
                          The same principle applies 
                    to any text file, basically splitting 
                      words only on spaces or new lines 


perl -ln0e's/\s+/ /g;print$"x(40-($c=2+length$&)/2),$&while/.{0$c,}? |
+.+/g' w.txt a.txt
                                     The 
                                same principle 
                             applies to any text 
                          file, basically splitting 
                      words only on spaces or new lines 
                    a a a a a a a a a a a a a a a a a a a 
                       a a a a a a a a a a a a a a a a
[download]

(I know, I know. I'm the only one who could possibly still be interested at this point.)

* update "more interesting" meaning more <|triangular|>  (than the original challenge).

And, moving even deeper into 'useless use of code in void context':

print($"x(40-($c=2+length$&)/2),$&),$c*=($c<80)while...
[download]

will make triangles of files of any length (a step towards automated obfusification?).

p

---

---

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! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

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:
	&		&
	<		&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.