This would be hard to do automatically, as there is no standard chapter label in a PDF file. However, if you do not mind some manual work, write down the pages for each chapter, and use pdftk to select the pages and save them into a new pdf file. For example, if chapter 2 is pages 23-45, do

pdftk A=input.pdf cat A23-45 output chapter_2.pdf

You need to install pdftk first:

sudo apt-get install pdftk

You can also use ghostscript (which comes preinstalled) directly:

gs -sDEVICE=pdfwrite -dNOPAUSE -dBATCH -dSAFER -dFirstPage=23 -dLastPage=45 -sOutputFile=chapter_2.pdf input.pdf

This is quite easy to convert a script that runs things semi-automatically. First, create an input file; on each line, put the desired output pdf file title, the starting page, the ending page -- like that:

chapter1 1 23

chapter2 24 56

Save this, using a text editor, to file pdfchaps.in.

Now, create a script -- save the following to a file called pdfchaps.sh:

#!/bin/bash



function pdfextr() { 

  echo "Chapter $2"

  pdftk A=$1 cat A$3-$4 output $2.pdf 

}



chapters=$1

pdffile=$2



echo "Splitting pdf file $pdffile by chapters from $chapters"

cat $chapters | while read line ; do  pdfextr $pdffile $line ; done

Make the script executable:

chmod a+x pdfchaps.sh

And run it:

pdfchaps chaps.in mybook.pdf