PDF Compression Script

This script scans a specified directory for PDF files and compresses them using Ghostscript on a Linux system. The compressed PDFs are saved in a separate subdirectory.

Features

Batch Compression: Automatically compresses all PDF files in a folder.
Customizable Output: Compressed files are saved in a separate compressed folder within the original directory.
Multiple Compression Levels: Uses the /screen preset by default, with options to customize.

Prerequisites

Ghostscript: Ensure that Ghostscript is installed on your system. You can install it using the following command:
```
sudo apt-get install ghostscript
```

Usage

Clone or Download the Script:

Save the script as compress_pdfs.sh or any name you prefer.
Edit the Script:

Open the script in a text editor and replace the path in the PDF_DIR variable with the path to your folder containing PDF files.
```
PDF_DIR="/path/to/your/pdf/folder"
```
Make the Script Executable:

Run the following command to give the script execute permissions:
```
chmod +x compress_pdfs.sh
```
Run the Script:

Execute the script with:
```
./compress_pdfs.sh
```
The script will scan the specified directory for PDF files, compress them, and save the compressed versions in a subdirectory named compressed.

Customization

The script uses the /screen preset for compression by default, which is suitable for on-screen viewing. If you want to change the compression level, modify the -dPDFSETTINGS option in the script:

/screen: Low resolution, suitable for screen-view only.
/ebook: Medium resolution, suitable for eBooks.
/printer: High resolution, suitable for printing.
/prepress: High quality, suitable for prepress.

Example:

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook \
   -dNOPAUSE -dQUIET -dBATCH -sOutputFile="$output_pdf" "$pdf"

Troubleshooting

Ghostscript Not Installed: If you encounter a "command not found" error, ensure that Ghostscript is installed and properly configured in your system's PATH.
File Not Found: Make sure the PDF_DIR variable is correctly set to the directory containing your PDF files.

License

This script is released under the MIT License. You are free to use, modify, and distribute it.

Author: Joseph Gakah
Date: August 2024