PDF Appender - Append a page to multiple PDF files in a directory using pdftk

pdf_append.sh

#!/bin/bash

# Check if pdftk is installed
if ! command -v pdftk &> /dev/null; then
    echo "pdftk is not installed."
    echo "Please install pdftk for your operating system."
    echo ""
    case "$(uname -s)" in
        Linux*)
            echo "To install on Ubuntu/Debian, run: sudo apt-get install pdftk"
            echo "To install on CentOS/Fedora, run: sudo yum install pdftk"
            ;;
        Darwin*)
            echo "To install on macOS, run: brew install pdftk"
            ;;
        *)
            echo "Unsupported operating system. Please install pdftk manually."
            ;;
    esac
    exit 1
fi

# Set the default directory containing the PDF files
pdf_dir="pdf-folder"

# Set the default filename of the page you want to append to each PDF
page_file="cover/cover.pdf"

# Set the default output directory
output_dir="out"

# Print usage message function
function usage {
    echo "Usage: $0 [-d PDF_DIRECTORY] [-p PAGE_FILE] [-o OUTPUT_DIRECTORY] [--help]" 1>&2
    echo ""
    echo "This script relies that you have "
    echo ""
    echo "Append a page to each PDF file in a directory."
    echo ""
    echo "Options:"
    echo "  -d PDF_DIRECTORY    Directory containing the PDF files (default: $pdf_dir)"
    echo "  -p PAGE_FILE        Filename of the page to append (default: $page_file)"
    echo "  -o OUTPUT_DIRECTORY Directory to save the modified PDF files (default: $output_dir)"
    echo "  --help              Display this help message"
    echo ""
    exit 1
}

# Parse command line arguments
while getopts ":d:p:o:-:" opt; do
  case ${opt} in
    d ) pdf_dir="$OPTARG"
      ;;
    p ) page_file="$OPTARG"
      ;;
    o ) output_dir="$OPTARG"
      ;;
    - )
        case "${OPTARG}" in
            help)
                usage
                ;;
            *)
                echo "Invalid option: --$OPTARG" 1>&2
                exit 1
                ;;
        esac
        ;;
    \? ) echo "Invalid option: -$OPTARG" 1>&2
         usage
      ;;
    : ) echo "Option -$OPTARG requires an argument." 1>&2
         usage
      ;;
  esac
done

# Count the number of PDF files in the directory
num_files=$(ls -1q "$pdf_dir"/*.pdf | wc -l)

# Initialize a counter for the number of processed files
count=0

# Loop through each PDF file in the directory
for file in "$pdf_dir"/*.pdf; do
  # Print the name of the PDF file being processed
  echo "Processing $file..."
  
  # Append the page to the PDF using pdftk
  pdftk "$page_file" "$file" cat output "$output_dir"/"${file##*/}"
  
  # Increment the counter
  count=$((count+1))
  
  # Calculate the progress percentage and print it
  progress=$((count * 100 / num_files))
  echo "----> Progress: $progress%"
done