local $/;
my $data = <DATA>;
my @img = $data =~ m/<\s*img[^>]*?src\s*=\s*['"]?([^"' >\n]+)/gi;
my @css = $data =~ m/<\s*link[^>]*?href\s*=\s*['"]?([^"' >\n]+)/gi;
my @lnk = $data =~ m/<\s*a[^>]*?href\s*=\s*['"]?([^"' >\n]+)/gi;
use Data::Dumper;
print Dumper \@img, \@css, \@lnk;
__DATA__
<img src="img.link1">
<img src="img.link2" alt="foo">
<img height=20 width=25 src=img.link3 >
<IMG src='img.link4'>
<link href="css.link1">
<a class=foo href="normal.link1">
<A href=normal.link2 class="foo" >
<a href="normal.link3">
<a class=foo href='normal.link4'>
<a Href='normal.link5'>
__END__
$VAR1 = [
          'img.link1',
          'img.link2',
          'img.link3',
          'img.link4'
        ];
$VAR2 = [
          'css.link1'
        ];
$VAR3 = [
          'normal.link1',
          'normal.link2',
          'normal.link3',
          'normal.link4',
          'normal.link5'
        ];