Split PDF by bookmark (pdftk)

pdf_split_by_bookmark.pl

#!/usr/bin/env perl
use 5.013;
use warnings;
use Data::Dumper;
use File::Basename;
use File::Spec::Functions;
use File::Path qw(make_path);

my $pdftk = `/usr/bin/which pdftk`;

my $file = $ARGV[0];
say ("\n$0 <FILENAME>") && exit 1 unless $file;
my $dir  = dirname( $file ) || '.';
my $output_dir = $ARGV[1] || $dir;

unless( -e $output_dir ) {
    make_path $output_dir, { mode => 0755 } unless -e $output_dir;
    die "mkdir failed: $!" unless -e $output_dir;
}

my $string = `$pdftk "$file" dump_data output -`;

my( $last_page ) = $string =~ m/NumberOfPages: (\d+)/;
say "last page is $last_page";

my $regex = qr/
BookmarkTitle:      \s+ (?<title>.*?) \s+
BookmarkLevel:      \s+ (?<level>\d+) \s+
BookmarkPageNumber: \s+ (?<page>\d+)
/x;

my @page_numbers;
while( $string =~ /$regex/g ) {
    next unless $+{level} == 1;
    push @page_numbers, [ @+{ qw(title page) } ];
}

say "Last index is $#page_numbers";

# Chapter&#160;1.&#160;Introduction
while( my( $index, $elem ) = each @page_numbers ) {
    last if $index == $#page_numbers;
    $page_numbers[$index]->[0] =~ s/&#160;/ /g;
    unshift @$elem,
    $page_numbers[$index]->[0] =~ s/(?:Chapter|Appendix)\s+(\d+|[ABC]|).?\s+//g
    ?
    $1
    :
    'XX';
    last if $index == $#page_numbers;

    push @$elem, $page_numbers[$index+1]->[-1] - 1;
}
unshift @{ $page_numbers[-1] }, 'XX';
push @{ $page_numbers[-1] }, $last_page;

print Dumper( \@page_numbers );
# pdftk A=one.pdf B=two.pdf cat A1-7 B1-5 A8 output combined.pdf
foreach my $elem ( @page_numbers ) {
    my $chapter = $elem->[1] =~ s/\s+/_/rg;
    my $filename = catfile( $output_dir, "$elem->[0].$chapter.pdf" );
    say "Splitting Chapter $elem->[0] $elem->[1]";
    print "Running ", join ' ', $pdftk, $file, 'cat', "$elem->[2]-$elem->[3]", 'output', $filename, "\n";
    system $pdftk, $file, 'cat', "$elem->[2]-$elem->[3]", 'output', $filename;
}

Borrowed from http://stackoverflow.com/questions/5657495/how-to-split-multidocument-pdf-based-on-bookmark-using-pdfapi2/5659735#5659735 .

se of uninitialized value $last_page in concatenation (.) or string at ./pdf_split_by_bookmark.pl line 24.
last page is
Last index is -1
Modification of non-creatable array value attempted, subscript -1 at ./pdf_split_by_bookmark.pl line 54.