Re: Writing portable code

Coming as I do from an OO background, I would approach the problem like this:

#! perl
use strict;
use warnings;

{
    package FunctionsFactory;

    my $class = ($^O =~ /Win/) ? 'WinFunctions' :
                                 'LinuxFunctions';
    sub new { return $class->new(); }
}

{
    package WinFunctions;

    sub new { return bless {}, shift; }
    sub f   { print "Windows f()\n"; }
    sub g   { print "Windows g()\n"; }
}

{
    package LinuxFunctions;

    sub new { return bless {}, shift; }
    sub f   { print "Linux f()\n"; }
    sub g   { print "Linux g()\n"; }
}

my $funcs = FunctionsFactory->new();

$funcs->f();
$funcs->g();
[download]

Output (on my system!):

19:49 >perl 564_SoPW.pl
Windows f()
Windows g()

19:53 >
[download]

This scheme allows you to keep all the code in one file, and gives a clean/transparent interface to the functions concerned.

Hope that helps,

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

Comment on Re: Writing portable code Select or Download Code

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Re^2: Writing portable code by tobyink (Canon) on Mar 08, 2013 at 10:08 UTC
The disadvantage here is that the `WinFunctions` package is still parsed and compiled on Linux machines, and the symbol table still exists using up memory, even if it never gets used. For a handful of small functions this is unlikely to cause many performance problems. What you need to look out for though are cases where, say, `WinFunctions` not only will not run on Linux, but won't even compile on Linux (e.g. because it `use`s some Win32::* module). Careful use of run-time `require` should generally solve this. `package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name`	[reply] [d/l] [select]
Re^3: Writing portable code by DrHyde (Prior) on Mar 11, 2013 at 11:34 UTC
Even thinking about having a few unused entries in the symbol table is a ridiculous micro-optimisation. If you want to keep the code clean and in one file, then I suggest something like this ... `use Devel::CheckOS; setup_for_platform(); ... application code goes here ... # decide what platform-specific code to use sub setup_for_platform { if(os_is('MicrosoftWindows')) { do_stuff = \&do_stuff_for_windows; } elsif(os_is('Unix')) { do_stuff = \&do_stuff_for_unix; } else { die("Don't know about $^O\n"); } } # platform-specific function implementations sub do_stuff_for_unix { ... } sub do_stuff_for_windows { ... }` [download]	[reply] [d/l]