QPDF is a command-line program that does structural, content-preserving
transformations on PDF files. It also provides many useful capabilities
to developers of PDF-producing software or for people who just want to
look at the innards of a PDF file to learn more about how they work.
QPDF is capable of creating linearized (also known as web-optimized)
files and encrypted files. QPDF also supports a special mode designed
to allow you to edit the content of PDF files in a text editor.
QPDF includes support for merging and splitting PDFs through the
ability to copy objects from one PDF file into another and to manipulate
the list of pages in a PDF file. The QPDF library also makes it possible
for you to create PDF files from scratch.