Home Accessibility Courses Twitter The Mouth Facebook Resources Site Map About Us Contact
 
Python and Tcl - public course schedule [here]
Private courses on your site - see [here]
Please ask about maintenance training for Perl, PHP, Lua, etc
 
A short Perl example

#!/usr/bin/perl -pa
$_ = "$F[0] $F[-2]\n";


What does that Perl code do?

Although it's very short, it's also somewhat obscure, and my delegates yesterday were not at all sure that they would wish to be given code like this to maintain ... but then they admitted that they have seen things like this around ...

There are some Perl programmers who take what I feel is a perverse delight in writing their code as short as possible, even to the extent that it looses clarity; for sure, you should make good use of the Perl language and its facilities to avoid needless loops - use a grep in place of a foreach loop with a regular expression check and a push, and slurp a file into a list by all means rather that reading in through a while loop - but the above takes it just too far!

Oh - I asked you what it does, didn't I? It reads the file named on the command line in line by line, and prints out the first and next-to-last field on each line, throwing away the rest of the data.
(written 2008-07-30)

 
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
P210 - Perl - Topicalization and Special Variables
  [4700] Obfurscated code - it might work, but is it maintainable? - (2016-07-02)
  [4682] One line scripts - Awk, Perl and Ruby - (2016-05-20)
  [4395] Preparing data through a little bit of Perl - (2015-01-15)
  [4301] Perl - still a very effective language indeed for extracting and reporting - (2014-09-20)
  [3449] Apache Internal Dummy Connection - what is it and what should I do with it? - (2011-09-19)
  [2972] Some more advanced Perl examples from a recent course - (2010-09-27)
  [2876] Different perl examples - some corners I rarely explore - (2010-07-18)
  [2833] Fresh Perl Teaching Examples - part 2 of 3 - (2010-06-27)
  [1922] Flurinci knows Raby Lae PHP and Jeve - (2008-12-04)
  [1860] Seven new intermediate Perl examples - (2008-10-30)
  [1829] Dont bother to write a Perl program - (2008-10-10)
  [1705] Environment variables in Perl / use Env - (2008-07-11)
  [1704] Finding operating system settings in Perl - (2008-07-10)
  [1508] How not to write Perl? - (2008-01-15)
  [1444] Using English can slow you right down! - (2007-11-25)
  [1289] Pure Perl - (2007-08-03)
  [1232] Bathtub example - (2007-06-14)
  [1221] Bathtubs and pecking birds - (2007-06-07)
  [1136] Buffering output - why it is done and issues raised in Tcl, Perl, Python and PHP - (2007-04-06)
  [969] Perl - $_ and @_ - (2006-12-07)
  [639] Progress bars and other dynamic reports - (2006-03-09)
  [493] Running a Perl script within a PHP page - (2005-11-12)

P711 - An Introduction to Standards in Perl
  [4326] Learning to program - comments, documentation and test code - (2014-11-22)
  [3398] Perl - making best use of the flexibility, but also using good coding standards - (2011-08-19)
  [2875] A long day in Melksham ... - (2010-07-17)
  [2688] Security considerations in programming - what do we teach? - (2010-03-22)
  [2375] Designing your data structures for a robust Perl application - (2009-08-25)
  [1863] About dieing and exiting in Perl - (2008-11-01)
  [1853] Well structured coding in Perl - (2008-10-24)
  [1555] Advanced Python, Perl, PHP and Tcl training courses / classes - (2008-02-25)
  [1395] Dont just convert to Perl - re-engineer! - (2007-10-18)
  [1345] Perl and Shell coding standards / costs of an IT project - (2007-09-11)
  [1047] Maintainable code - some positive advice - (2007-01-21)
  [965] KISS - one action per statement please - Perl - (2006-12-05)
  [945] Code quality counts - (2006-11-26)
  [743] How to debug a Perl program - (2006-06-04)
  [668] Python - block insets help with documentation - (2006-04-04)
  [242] Satisfaction of training - (2005-03-11)


Back to
Equality and looks like tests - Perl
Previous and next
or
Horse's mouth home
Forward to
Back from the future
Some other Articles
Old pictures and comparisons
Apache httpd, MySQL, PHP - installation procedure
Punting on the Cam
Back from the future
A short Perl example
Equality and looks like tests - Perl
Hot Courses - Perl
A future vision for Melksham
addslashes v mysql_real_escape_string in PHP
Bath - Melksham - Devizes. Bus route changes, new timetable
4759 posts, page by page
Link to page ... 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96 at 50 posts per page


This is a page archived from The Horse's Mouth at http://www.wellho.net/horse/ - the diary and writings of Graham Ellis. Every attempt was made to provide current information at the time the page was written, but things do move forward in our business - new software releases, price changes, new techniques. Please check back via our main site for current courses, prices, versions, etc - any mention of a price in "The Horse's Mouth" cannot be taken as an offer to supply at that price.

Link to Ezine home page (for reading).
Link to Blogging home page (to add comments).

You can Add a comment or ranking to this page

© WELL HOUSE CONSULTANTS LTD., 2019: 404 The Spa • Melksham, Wiltshire • United Kingdom • SN12 6QL
PH: 01225 708225 • EMAIL: info@wellho.net • WEB: http://www.wellho.net • SKYPE: wellho

PAGE: http://www.wellho.net/mouth/1728_A-s ... ample.html • PAGE BUILT: Sat May 27 16:49:10 2017 • BUILD SYSTEM: WomanWithCat