Ghostscript notes

Using Ghostscript to manipulate PDF files

Join PDF files with just a simple command:

    $ gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=finished.pdf file1.pdf file2.pdf

Reference: Putting together PDF files

To generate a file with a subset of its pages, use gs as well::

    $ gs -dBATCH -dSAFER -dNOPAUSE -dFirstPage=5 -dLastPage=10 -sDEVICE=pdfwrite -o output.pdf input.pdf

To compress a PDF (resizing the file size)::

    $ gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dPDFSETTINGS=/ebook -dCompatibilityLevel=1.4 -sOutputFile=output.pdf input.pdf

Settings can be /screen, /ebook, /printer and /prepress, ranging from low quality images resolution to better quality. I like to use /ebook. I could turn a 8 MB PDF into a 276 KB file suitable to be sent to e-mail.

Editing PDF metadata

(2018-09-27)

There are many ways to edit a PDF metadata, using other programs. See the following two links about simple ways to do that.

How to edit pdf metadata from command line?

Ghostcript PDF Reference & Tips

First, create a file with the desired information. Let's call this file pdfmarks::

    [ /Title (Document title)
      /Author (Author name)
      /Subject (Subject description)
      /Keywords (comma, separated, keywords)
      /ModDate (D:20061204092842)
      /CreationDate (D:20061204092842)
      /Creator (application name or creator note)
      /Producer (PDF producer name or note)
      /DOCINFO pdfmark

Now, just call Ghostscript passing both PDF file and the pdfmarks file as parameters::

    gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=pdfwrite -sOutputFile=output.pdf no_marks.pdf pdfmarks

Your output.pdf file will be created with the metadata. :-)