如何在Ubuntu 18.04及更高版本中安装pdftk？

 sudo snap install pdftk

 sudo ln -s /snap/pdftk/current/usr/bin/pdftk /usr/bin/pdftk

lsb_release -a && pdftk --version
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04 LTS
Release:        18.04
Codename:       bionic

pdftk 2.02 a Handy Tool for Manipulating PDF Documents
Copyright (c) 2003-13 Steward and Lee, LLC - Please Visit: www.pdftk.com

deb http://no.archive.ubuntu.com/ubuntu/ artful main restricted
deb http://no.archive.ubuntu.com/ubuntu/ artful-updates main restricted
deb http://no.archive.ubuntu.com/ubuntu/ artful universe
deb http://no.archive.ubuntu.com/ubuntu/ artful-updates universe
deb http://no.archive.ubuntu.com/ubuntu/ artful multiverse
deb http://no.archive.ubuntu.com/ubuntu/ artful-updates multiverse
deb http://no.archive.ubuntu.com/ubuntu/ artful-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu artful-security main restricted
deb http://security.ubuntu.com/ubuntu artful-security universe
deb http://security.ubuntu.com/ubuntu artful-security multiverse

# Generate the Singularity container to run pdftk from Ubuntu 16.04.
Bootstrap: docker
From: ubuntu:16.04

%help
    pdftk was removed from Ubuntu 18.04, so this container packages up the old
    version.

%post
    apt-get update -qq
    apt-get install -qq pdftk

%runscript
    pdftk "$@"

sudo singularity build pdftk.simg Singularity

sudo mv pdftk.simg /usr/bin/
echo 'singularity run --home $PWD /usr/bin/pdftk.simg "$@"' > pdftk
sudo chown root:root pdftk
sudo chmod +x pdftk
sudo mv pdftk /usr/bin

$ pdftk --version

pdftk 2.02 a Handy Tool for Manipulating PDF Documents
Copyright (c) 2003-13 Steward and Lee, LLC - Please Visit: www.pdftk.com
This is free software; see the source code for copying conditions. There is
NO warranty, not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ ls -lh /usr/bin/pdftk*
-rwxr-xr-x 1 root root  53 Jul 23 12:32 /usr/bin/pdftk
-rwxr-xr-x 1 root root 88M Jul 23 12:06 /usr/bin/pdftk.simg

#!/bin/bash

# Build or use cached image and tag with "local/local/ubuntu_pdftk", suppress 
# output to maintain compatibility in case you are parsing the pdftk output.
# It will build the image if it's absent or use the cached one.
echo "FROM ubuntu:16.04
RUN apt-get update && \
    apt-get install -y pdftk && \
    rm -rf /var/lib/apt/lists/*" | docker build -t local/local/ubuntu_pdftk - 2>&1 > /dev/null

# Run the pdftk as current user
set -eu
docker run --name pdftk -it --user $(id -u):$(id -g) --rm -v "$PWD:/workdir$PWD" -w "/workdir$PWD" local/local/ubuntu_pdftk pdftk "$@"

#!/bin/bash
#
# author: abu
# date:   May 12 2018
# description: bash script to install pdftk on Ubuntu 18.04 for amd64 machines
##############################################################################
#
# change to /tmp directory
cd /tmp
# download packages
wget http://mirrors.edge.kernel.org/ubuntu/pool/main/g/gcc-5/libgcj16_5.4.0-6ubuntu1~16.04.10_amd64.deb \
    http://mirrors.edge.kernel.org/ubuntu/pool/main/g/gcc-defaults/libgcj-common_4.9.3-9ubuntu1_all.deb \
    http://mirrors.edge.kernel.org/ubuntu/pool/universe/p/pdftk/pdftk_2.02-4_amd64.deb \
    http://mirrors.edge.kernel.org/ubuntu/pool/universe/p/pdftk/pdftk-dbg_2.02-4_amd64.deb

echo -e "Packages for pdftk downloaded\n\n"
# install packages 
echo -e "\n\n Installing pdftk: \n\n"
sudo apt-get install ./libgcj16_5.4.0-6ubuntu1~16.04.10_amd64.deb \
    ./libgcj-common_4.9.3-9ubuntu1_all.deb \
    ./pdftk_2.02-4_amd64.deb \
    ./pdftk-dbg_2.02-4_amd64.deb
echo -e "\n\n pdftk installed\n"
echo -e "   try it in shell with: > pdftk \n"
# delete deb files in /tmp directory
rm ./libgcj16_5.4.0-6ubuntu1~16.04.10_amd64.deb
rm ./libgcj-common_4.9.3-9ubuntu1_all.deb
rm ./pdftk_2.02-4_amd64.deb
rm ./pdftk-dbg_2.02-4_amd64.deb

$ wget wget http://launchpadlibrarian.net/383018194/pdftk-java_0.0.0+20180723.1-1_all.deb
$ sudo apt install default-jre-headless libcommons-lang3-java libbcprov-java
$ sudo dpkg -i pdftk-java_0.0.0+20180723.1-1_all.deb

sudo apt install gcc-6-base

sudo dpkg -i libgcj*

wget http://ftp.us.debian.org/debian/pool/main/p/pdftk/pdftk_2.02-4+b2_amd64.deb
sudo dpkg -i pdftk_2.02-4+b2_amd64.deb