join or split pdf files - pdftk

join

pdftk file1.pdf file2.pdf cat output file12.pdf

split

ex) in.pdf has 10 page total. We want split it in two files.
out1.pdf has page 1 to 5, and out2.pdf has 6 to 10.

pdftk in.pdf cat 1-5 output out1.pdf
pdftk in.pdf cat 6-end output out2.pdf

very simple and elegance !!

detailed manual :

pdftk --help

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