Concatenates different pdf files into one single file (with GUI)

catPdf.sh

#!/bin/bash

# ========================================================================
# Author: Milchreis
# Description: Concatenates different pdf files into one single file with GUI
# Date: 2016-05-13
# Dependencies: zenity, pdftk
# Tested and used on ubuntu and linux mint
# ========================================================================

# Check dependencies
command -v zenity >/dev/null 2>&1 || { echo >&2 "Require 'zenity' package, install it please. Aborting."; exit 1; }
command -v pdftk >/dev/null 2>&1 || { echo >&2 "Require 'pdftk' package, install it please. Aborting."; exit 1; }

# Array for PDF filepaths
PDFS=()

# Inform the user
zenity --info --text="Choose a set of pdf-files to concatenating them."

# Choose a PDF file
FILE=`zenity --file-selection --title="Choose a pdf-file"`

# If a file is choosen add to array
if [ $? -eq 0 ] ; then
	PDFS+=("$FILE")
fi

# Ask for more files
if QUESTION=$(zenity --question --text="Do you want choose next file?"); then

	# Add and ask while the user want more
	while $QUESTION; do
		F=`zenity --file-selection --title="Choose a pdf-file"`
		if [ $? -eq 0 ] ; then
			PDFS+=($F)
		fi

		# If the dialog returns false break the loop
		if ! Q=$(zenity --question --text="Do you want choose next file?"); then
			break
		fi
	done
fi

# Convert the array content into a string in a single line
LIST=`printf '%s\n' "${PDFS[@]}"`
# Choose the target directory
OUTPUTDIR=`zenity --file-selection --directory --title="Choose the target path"`
# Choose a name for the target file
OUTPUTNAME=$(zenity --entry --title="Name for the new pdf-file" \
--text="Name of the file:" \
--entry-text "Output.pdf")

# Create the new big pdf file
pdftk $LIST cat output $OUTPUTDIR/$OUTPUTNAME