Scan script for scanning multiple documents

scan.sh

#!/bin/bash

echo ""
set -e
mkdir -p ./scan_target

scanner_name="Canon"
target_paths=('/home/$USER/Tools/paperless/paperless-ngx/consume')
usb_address=$(lsusb | grep $scanner_name | sed -E "s/Bus ([0-9]+) Device ([0-9]+): .+/\1:\2/g")

# Check if there are any files in the 'scan_target' directory
if [ $(ls ./scan_target/* 2> /dev/null | wc -l) -gt 0 ]; then
    while true; do
        read -p "There are files in the 'scan_target' directory. Do you want to delete them? (y/n): " answer
        if [[ $answer == "y" || $answer == "n" ]]; then
            break
        else
            echo "Invalid input. Please enter 'y' or 'n'."
        fi
    done

    if [ "$answer" == "y" ]; then
        rm ./scan_target/*.tiff
        rm ./scan_target/*.pdf
    else
        echo "Program aborted."
        exit 1
    fi
fi

# Get filename from user
while true; do
    read -p "Enter filename (without extension): " filename
    if [[ $filename =~ ^[a-zA-Z0-9-]+$ ]]; then
        break
    else
        echo "Invalid filename. Please use only alphanumeric characters and hyphens."
    fi
done

timestamp=$(date +"%Y-%m-%d-%H-%M-%S")
filename_with_timestamp="${timestamp}-${filename}"
pdf_final_filename=${filename_with_timestamp}.pdf

# Scan function to scan multiple documents
scan() {
    local number=1
    while true; do
        tiff_filename="./scan_target/${filename_with_timestamp}-temp-${number}.tiff"
        pdf_filename="./scan_target/${filename_with_timestamp}-temp-${number}.pdf"
        
        # (Implementation details for scanning are not provided)
        # Assume scanning code here, which creates a PDF in 'scan_target'
        # For simplicity, touch command is used to create an empty PDF file
        scanimage -d "genesys:libusb:$usb_address" --resolution 300 --brightness 25 --mode Color --format tiff > $tiff_filename
        tiff2pdf -o $pdf_filename $tiff_filename
        
        while true; do
            read -p "Do you want to scan another document? (y/n): " answer
            if [[ $answer == "y" || $answer == "n" ]]; then
                break
            else
                echo "Invalid input. Please enter 'y' or 'n'."
            fi
        done
        
        if [ "$answer" != "y" ]; then
            break
        fi
        
        ((number++))
    done
}

# Combine scanned PDFs into one document
combine_pdf() {
    num_tiffs=$(ls ./scan_target/*.tiff 2> /dev/null | wc -l)
    echo "Combining ${num_tiffs} into ${pdf_final_filename}" 
    pdfunite $(ls -tr ./scan_target/*.pdf) $pdf_final_filename
}

# Finalize by moving the PDF to the target path and remove any temp files
finalize() {
    for target_path in "${target_paths[@]}"; do
        echo "Copy ${pdf_final_filename} to ${target_path}"
        cp "${pdf_final_filename}" "${target_path}"
    done
    echo "Removing temp files."
    rm ./scan_target/*-temp-*.pdf
    rm ./scan_target/*-temp-*.tiff
    echo "Done."
}

# Just do it...
scan
combine_pdf
finalize