To merge multiple pdf files using the most current qpdf (instead of the older pdftk) you can use the following:
qpdf --empty --pages file1.pdf file2.pdf file3.pdf -- output.pdf
To merge multiple pdf files using the most current qpdf (instead of the older pdftk) you can use the following:
qpdf --empty --pages file1.pdf file2.pdf file3.pdf -- output.pdf
If you would like to convert an epub file to pdf in Linux, you can use calibre.
First install it using
sudo apt-get install calibre
and then you should be able to use it to convert the file like
ebook-convert file.epub file.pdf
Problem
You have a pdf file with sensitive information and you want to protect it with a password.
Solution
Install the pdftk if you haven’t already in your system:
sudo apt-get install pdftk
And then run the following to prompt for a password before opening the file:
pdftk original.pdf output pswd_protected.pdf user_pw PROMPT