Slash Boxes
NOTE: use Perl; is on undef hiatus. You can read content, but you can't post it. More info will be forthcoming forthcomingly.

All the Perl that's Practical to Extract and Report

use Perl Log In

Log In

[ Create a new account ]

Ovid (2709)

  (email not shown publicly)
AOL IM: ovidperl (Add Buddy, Send Message)

Stuff with the Perl Foundation. A couple of patches in the Perl core. A few CPAN modules. That about sums it up.

Journal of Ovid (2709)

Monday August 20, 2007
04:37 PM

The Logic of Programs

[ #34163 ]

A program, to my mind, is basically code which does something. A module or class on its own doesn't do anything. It's not a program. You need a program to use them and do something. However, the problem which I see all too often is programs which try to do too much. As a result, when I wrote grepl, I did not want any logic in there which belong in the App::Grepl class. Though grepl is powerful and does a lot, here's the entire program:


use strict;
use warnings;
use App::Grepl;
use Pod::Usage 1.12;

use Getopt::Long;
    "pattern=s" => \my $pattern,
    "search=s"  => \my $lookfor,
    "warnings"  => \my $warnings,
    "l"         => \my $filename_only,
    'h|help|?'  => sub { pod2usage( { -verbose => 1 } ); exit },
    'H|man'     => sub { pod2usage( { -verbose => 2 } ); exit },

$lookfor = [ split ',' => ( $lookfor || '' ) ];
$pattern ||= '';

my @search_in;

if ( !@ARGV ) {
    @search_in = ( dir => '.' );
elsif ( 1 == @ARGV && -d $ARGV[0] ) {
    @search_in = ( dir => $ARGV[0] );
else {
    @search_in = ( files => [ @ARGV ] );

my $grepl = App::Grepl->new(
        look_for      => $lookfor,
        pattern       => $pattern,
        warnings      => $warnings,
        filename_only => $filename_only,

Now that's how you write a program. The only logic is processing command line arguments and passing them to the application.

Yes, the constructor is doing a lot, but even that's fairly easy to manage. I have about 96% test coverage and I'm not worried about having code in my program which is difficult to test (unlike in, say, runtests).

The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
More | Login | Reply
Loading... please wait.