Bash Parameter "timestamp"

#!/bin/sh

HOT_FOLDER="$1"  # Folder to watch  
SAFE_FOLDER="$2" # Folder for the safe file  
OCR="$3"         # OCR language (or empty for no OCR)  

timestamp=$(date +%d-%m-%Y_%H-%M-%S)



if [ -z "${HOT_FOLDER}" ]; then  
    echo "Please specify which folder to check as first parameter."  
    exit
fi

if [ -z "${SAFE_FOLDER}" ]; then  
    echo "Please specify which folder to write the results to as second parameter."  
    exit
fi

if [ -z "${OCR}" ]; then  
    echo "No OCR-language specified, will not perform OCR. (Specify a string like 'deu' as third parameter for OCR.)"  
fi

printf "\nThis programm will check the folder '%s' for files to convert with cli. Results will be written to '%s', the original files will be deleted after conversion. Press Ctrl+C to cancel.\n\n" "${HOT_FOLDER}" "${SAFE_FOLDER}"  

inotifywait --monitor "${HOT_FOLDER}" \  
            --event moved_to \
            --event create \
            --format '%f' |  
    while read -r file; do
        input="${HOT_FOLDER}/${file}"  
        output="${SAFE_FOLDER}/${file}-safe.pdf"  

        if [ -z "${file}" ]; then  
            echo "ERROR: Received empty string."  
        elif [ ! -r "${input}" ]; then  
            echo "ERROR: File '${input}' is not readable."  
        elif [ -e "${output}" ]; then  
            echo "File '${file}' already converted ('${output}' exists)."  
        else
            if [ -z "${OCR}" ]; then  
                appzone-cli --output-filename "${output}" "${input}"  
            else
                appzone-cli --output-filename "${output}" --ocr-lang "$OCR" "${input}"  
            fi
            rm "${input}"  
        fi
printf "\n ###### $timestamp ######\n\n"  


        printf '\nWaiting for files to convert (press Ctrl+C to cancel) ...\n\n'  
    done