How to split/join pdf files

Ghostscript is a very useful tool in this situation.

• Install ghostscript (the gs command line).

sudo apt install -yq ghostscript

• To extract pages from the 3rd page to the 5th page in in.pdf , write output to out.pdf

gs -sDEVICE=pdfwrite -dNOPAUSE -dBATCH -dSAFER -dFirstPage=3 -dLastPage=5 -sOutputFile=out.pdf in.pdf

By default -dFirstPage is 1,  -dLastPage is the last page number.

• To combine 2 pdf files in1.pdf in2.pdf, write output to out.pdf.

gs -sDEVICE=pdfwrite -dNOPAUSE -dBATCH -dSAFER -sOutputFile=out.pdf in1.pdf in2.pdf