zidane/pixiv picture downloader, simple script

#!/usr/bin/perl

$tmp=$ARGV[0];
$tmp=~s/\D//g;

system("wget \"http://www.pixiv.net/member_illust.php?mode=medium&illust_id=".$tmp."\" --output-document=/tmp/pixiv-tmp");


$dtm=`grep $tmp /tmp/pixiv-tmp | grep "href"`;


$start=index $dtm,"http";
$end=index $dtm,$tmp;
$reg_st=(index $dtm,".",$end) ;
$reg_end=index $dtm,"\"",$reg_st;

$exp=substr($dtm,$reg_st,$reg_end-$reg_st);

system("rm /tmp/pixiv-tmp");

$url=substr($dtm,$start,$end-$start).$tmp.$exp;

system("wget ".$url." --referer=http://www.pixiv.net/");