File remove-pdf-password of Package kimi-utils-ubuntu

#!/usr/bin/env bash

THIS_FILE_NAME="${0##*/}"
FULL_PATH_TO_THIS_FILE="${0}"

function Usage {
        echo "Usage: $(basename $0) PDF-file.pdf" 2>&1
        echo 'Removes password from PDF-file.'
        exit 1
}


# Check if there is an argument
if [ $# -eq 0 ]; then
    echo "No PDF-file name provided."
    echo
    Usage
    exit 1
fi

# PDF_FILE is first argument
PDF_FILE="$1"

# Check if PDF-file exists
if [ ! -f "$PDF_FILE" ]; then
    echo "No PDF-file with that path or name exist."
    echo "Check your spelling."
    exit 1 
fi

DIRECTORY_OF_FILE=`dirname "$PDF_FILE"`
EXTENSION="${PDF_FILE##*.}"
FILENAME="${PDF_FILE%.*}"

# Every PDF file starts with %PDF. You can compare the first 4 characters of a specified file in order to make sure it's a PDF.
if [ ! $(head -c 4 "$PDF_FILE") = "%PDF" ]; then
    echo "It's not a PDF-file!"
fi

# Check that it is a PDF-file
type="$(file -b "$1")"
if [ ! "${type%%,*}" == "PDF document" ]; then
    echo "$PDF_FILE is not a PDF file."
    exit 1
fi

SaveAs ()
{
    echo "Saving file:" 
    echo "    $PDF_FILE" 
    echo "without password as a new file name:"
    echo "    ${FILENAME}_unlocked.${EXTENSION}"
    echo "in directory:"
    echo "   $DIRECTORY_OF_FILE"
}

NEW_FULL_FILE_NAME="$DIRECTORY_OF_FILE/${FILENAME}"_unlocked.${EXTENSION}

# Check if qpdf is installed
checkForQpdf() {
    if hash qpdf 2>/dev/null; then
        # qpdf is installed on the system
        true
    else
        # install qpdf
        echo "qpdf is not installed on the system."
        echo "I need qpdf for this task."
        #echo "I will now install package qpdf for you."
        #sudo apt-get -y install qpdf
        exit
    fi
}

checkForQpdf

echo "Enter PDF password to open locked PDF-file"
echo "(you wont see what you type)"
IFS= read -s  -p "Enter PDF password:" pwd
echo
echo

qpdf --decrypt --password="$pwd" "$PDF_FILE" "$NEW_FULL_FILE_NAME"

SaveAs

sleep 5
xdg-open "$NEW_FULL_FILE_NAME"
sleep 5

echo "Done."

exit 0