[BNE-PM] you lot have all gone quiet again? (Fwd)

[Derek Thomson]

Anthony Thyssen wrote:
> ------- Forwarded Message
> 
> From:    Anthony Thyssen <anthony at wumpus.cit.gu.edu.au>
> To:      "David Bussenschutt" <d.bussenschutt at mailbox.gu.edu.au>
> Subject: Re: [BNE-PM] you lot have all gone quiet again? 
> Date:    Tue, 17 Sep 2002 18:00:19 +1000
> Reply-to: Anthony Thyssen <anthony at cit.gu.edu.au>
> 
> "David Bussenschutt" on  wrote...
> | Is it just me... or have you lot out there on this list all gone quiet 
> | again.    We'll be having none of that!. 
> | 
 > | Ok, here's my challenge to you all:   I want one-liners.    useful,
 > | useless, fun,necessary,unique,quirky, whatever I don't care. Let's
 > | see
 > | what interesting one-liner perl programs you lot have come up with.
 > | Send-em to the list, and we'll all become a little wiser as a
 > | result.

I didn't know about the "-l" option. Handy, that!

> 
> As the co-worker... How about this perl chalange...
> 
> Write a print one-linter that can take the place of either
> the "column" or "pr" command above :-)

Horizontal columns is easy:

perl -le 'print for 1..100' | perl -ne 'chomp; print "$_\t"; print "\n" 
unless $. % 10'

(it's less than 80 columns if you disregard the separate program that 
generates the numbers, so it's a valid one-liner)

Vertical columns are much harder. Here's a start:

perl -le 'print for 1..104' | perl -e '@a=<>; chomp @a; 
$c=int(@a/10)+(@a%10>0); for $i (0..$c-1) { for ($j=0; $j<@a; $j+=$c) { 
printf "%6d", $a[$i+$j] } print "\n"; }'

This is too long by far, and has a bug - "filler" values in the final 
column are printed as "0". I could fix that, but it's too long already 
:( Suggestions?

Possibly the best solution for vertical columns is to get the 
Array::PrintCols module from CPAN, and use that:

perl -le 'print for 1..104' | perl -MArray::PrintCols -e '@a=<>; chomp 
@a; print_cols \@a'

Yes, that's breaking the rules for one-liners - no modules (*everything* 
can be done in one line if you've got CPAN!)

--
D.