pdf_page_rotation.pl

#!/usr/bin/env perl
use strict;
use warnings;
use PDF::API2;

for my $file (@ARGV) {
  print "$file page rotation.¥n";
  my $pdf = PDF::API2->open($file);
  for my $page_number (1..$pdf->pages) {
    $pdf->openpage($page_number)
      ->rotate($page_number % 2 ? 270 : 90);
  }
  $pdf->update;
}