Install PDFTk without touching up the permissions

install_pdftk.sh

#!/usr/bin/env bash

# This is based on this excellent gist https://gist.github.com/jvenator/9672772a631c117da151
# Nothing of this is my original work, except that I made the download link an argument
# to this script, so it installs on OSX 10.11
#
# Thank you jvenator & sethetter
set -e

error() { info "$1"; exit 1; }
have() { command -v "$1" >/dev/null; }
usage() { echo "usage: $0 LINK_TO_SETUP_PKG"; }

have "brew" || error "Need homebrew to be installed"
[[ "$1" ]] || { usage; exit 1; }
[[ "$1" == "--help" || "$1" == "-h" ]] && { usage; exit; }

BASE_TMP_DIR=`mktemp -d -t pdftk`
TMP_DIR="$BASE_TMP_DIR/pdftk_package"
PKG_FILE="$BASE_TMP_DIR/pdftk_download.pkg"
BREW_DIR="/usr/local/Cellar/pdftk"

if [ -d $BREW_DIR ]; then
    echo -n "$BREW_DIR exists, remove? (y/n) "
    read answer
    if echo "$answer" | grep -iq "^y" ;then
        brew unlink pdftk
        rm -rf $BREW_DIR
    else
        echo "$BREW_DIR was not removed, exiting."
        exit 1
    fi
fi

# OSX <10.11: https://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/pdftk_server-2.02-mac_osx-10.6-setup.pkg
# OSX  10.11: https://www.pdflabs.com/tools/pdftk-the-pdf-toolkit/pdftk_server-2.02-mac_osx-10.11-setup.pkg
echo "Downloading to $PKG_FILE"
curl -o $PKG_FILE $1

# Extract the Mac OS X server install package
pkgutil --expand $PKG_FILE $TMP_DIR

# Give the Payload file the proper gzip file extension and unzip it
mv $TMP_DIR/pdftk.pkg/Payload $TMP_DIR/pdftk.pkg/Payload.gz
gunzip $TMP_DIR/pdftk.pkg/Payload.gz

# List the contents of the archive to stdout; do not restore the contents to disk.
# cpio -i -t < $TMP_DIR/pdftk.pkg/Payload

# Use cpio to unarchive the resulting file
cd $TMP_DIR
cpio -iv < $TMP_DIR/pdftk.pkg/Payload

# Create Homebrew directories
mkdir -p $BREW_DIR/2.02/bin
mkdir -p $BREW_DIR/2.02/lib
mkdir -p $BREW_DIR/2.02/share/man/man1

# Move the relevant extracted files to their appropriate locations
mv $TMP_DIR/bin/pdftk    $BREW_DIR/2.02/bin/pdftk
mv $TMP_DIR/lib/*        $BREW_DIR/2.02/lib/
mv $TMP_DIR/man/pdftk.1  $BREW_DIR/2.02/share/man/man1/pdftk.1

brew link pdftk

echo "Done. You might wanna run 'brew doctor' to make sure everything is fine with your brew install"

Replacing BREW_DIR="/usr/local/Cellar/pdftk" by BREW_DIR="$(brew --cellar)/pdftk" will make sure the script works regardless of the location of your Homebrew installation.