$ perl -E '
    use strict;
    use warnings;
    use PDF::API2;
    my $pdf = PDF::API2->new();
    my $font = $pdf->font("Helvetica-Bold");
    for my $p (1 .. 10) {
        my $page = $pdf->page();
        my $text = $page->text();
        $text->font($font, 20);
        $text->position(200, 700);
        $text->text("Page: $p");
    }
    $pdf->save("test.pdf");
'

$ file test.pdf
test.pdf: PDF document, version 1.4, 10 pages

$ perl -E '
    use strict;
    use warnings;
    use PDF::API2;
    my $pdf = PDF::API2->open("test.pdf");
    say "Page count: ", $pdf->page_count();
'
Page count: 10

##</code><code>##

$ perl -E '
    use strict;
    use warnings;
    use PDF::Builder;
    my $pdf = PDF::Builder->new();
    my $font = $pdf->font("Helvetica-Bold");
    for my $p (1 .. 10) {
        my $page = $pdf->page();
        my $text = $page->text();
        $text->font($font, 20);
        $text->position(200, 700);
        $text->text("Page: $p");
    }
    $pdf->save("test2.pdf");
'

$ file test2.pdf
test2.pdf: PDF document, version 1.4, 10 pages

perl -E '
    use strict;
    use warnings;
    use PDF::Builder;
    my $pdf = PDF::Builder->open("test2.pdf");
    say "Page count: ", $pdf->page_count();
'
Page count: 10

##</code><code>##

ken@titan ~/tmp/pm_11152014_pdf
$ ls -l
total 16
-rw-r--r-- 1 ken None 4272 May  7 00:50 test.pdf
-rw-r--r-- 1 ken None 7024 May  7 01:05 test2.pdf