Oct 25
Combining two or more PDFs into one, on Linux
Most elegant, open-source and completely free solution: ghostscript.
gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=finished.pdf inputfile1.pdf inputfile2.pdf
ghostscript (gs) is pre-installed in most linux distributions.
Note:
Find our in Merging multiple pdf files and jpg files into one PDF how to merge JPGs and PDFs into one PDF.