#!/usr/bin/perl

use Win32::API;

use constant SPI_SETDESKWALLPAPER  => 20;
use constant SPIF_UPDATEANDSENDINI => 3;
use constant NULL                  => 0;

my $syspinf = Win32::API->new('user32','SystemParametersInfo', [I,I,P,I], I)
  or die "Could not import function.\n";

$syspinf->Call(SPI_SETDESKWALLPAPER, 0, $ARGV[0], SPIF_UPDATEANDSENDINI);