Today I have tried to install pdftk on ubuntu 18 . After search on developer site I saw that are package only for the redhat/centos.
So after a few search find out that you can install it with snap install pdftk
However this will not work .
Error: Unable to find file.
Error: Failed to open PDF file:
Errors encountered. No output created.
Done. Input errors, so no output created.
Errors like this you will see.
One solution is to download and install from other links
cd /tmp
# download packages
wget http://launchpadlibrarian.net/340410966/libgcj17_6.4.0-8ubuntu1_amd64.deb \
http://launchpadlibrarian.net/337429932/libgcj-common_6.4-3ubuntu1_all.deb \
https://launchpad.net/ubuntu/+source/pdftk/2.02-4build1/+build/10581759/+files/pdftk_2.02-4build1_amd64.deb \
https://launchpad.net/ubuntu/+source/pdftk/2.02-4build1/+build/10581759/+files/pdftk-dbg_2.02-4build1_amd64.deb
And after that you can install them with
sudo apt-get install ./libgcj17_6.4.0-8ubuntu1_amd64.deb \
./libgcj-common_6.4-3ubuntu1_all.deb \
./pdftk_2.02-4build1_amd64.deb \
./pdftk-dbg_2.02-4build1_amd64.deb
After that you can remove those from /tmp directory