How can I merge PDF files with Perl?
CAM::PDF can do this quite easily, and has a simple command-line front end to help. Note: I'm the author of that library. Example:
appendpdf.pl file1.pdf file2.pdf outfile.pdf
From the SYNOPSIS section of the perldoc:
my $anotherpdf = CAM::PDF->new('test2.pdf');
$pdf->appendPDF($anotherpdf);
Why do you need to do it from Perl? Chris has already mentioned CAM::PDF.
If you just need to merge them, pdftk (PDF ToolKit) works just fine. It's a simple command line:
pdftk file1.pdf file2.pdf cat output merged.pdf