merge pdf pdfunite pdfunite in 1 pdf in…

merge pdf

pdfunite

pdfunite in-1.pdf in-2.pdf in-n.pdf out.pdf

post script

gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=merged.pdf mine1.pdf mine2.pdf

or

gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -dPDFSETTINGS=/prepress -sOutputFile=merged.pdf mine1.pdf mine2.pdf

or

gs -q -sPAPERSIZE=letter -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=out.pdf in1.pdf in2.pdf in3.pdf ...

sets landscape orientation;, add the flag

-c "<</Orientation 3>> setpagedevice"

pdftk

pdftk file1.pdf file2.pdf cat output -