PDF Processing Skill

When working with PDF files, follow these guidelines:

1. Reading & Extracting from PDFs

For text extraction:

bash

# Extract all text
pdftotext input.pdf output.txt

# Extract specific pages
pdftotext -f 1 -l 10 input.pdf output.txt

# Preserve layout
pdftotext -layout input.pdf output.txt

For extracting images:

bash

# Extract all images
pdfimages -all input.pdf output_prefix

# Extract as PNG
pdfimages -png input.pdf images/page

For metadata:

bash

# Get PDF info
pdfinfo document.pdf

# Get detailed metadata
exiftool document.pdf

2. Creating PDFs

From text/markdown:

bash

# From markdown using pandoc
pandoc input.md -o output.pdf

# From text with formatting
enscript input.txt -o - | ps2pdf - output.pdf

From HTML:

bash

# Using wkhtmltopdf
wkhtmltopdf input.html output.pdf

# With options
wkhtmltopdf --page-size A4 --margin-top 10mm input.html output.pdf

From images:

bash

# Convert images to PDF
convert image1.png image2.png output.pdf

# Multiple images
img2pdf img1.jpg img2.jpg -o output.pdf

3. Merging PDFs

bash

# Merge multiple PDFs (using pdftk)
pdftk file1.pdf file2.pdf file3.pdf cat output merged.pdf

# Using ghostscript
gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=merged.pdf file1.pdf file2.pdf

# Using pdfunite
pdfunite file1.pdf file2.pdf output.pdf

4. Splitting PDFs

bash

# Split into individual pages
pdftk input.pdf burst output page_%02d.pdf

# Extract specific pages
pdftk input.pdf cat 1-5 output first-5-pages.pdf

# Extract page ranges
pdftk input.pdf cat 1-10 25-30 output selected.pdf

5. Converting PDFs

PDF to Images:

bash

# To PNG (high quality)
pdftoppm -png -r 300 input.pdf output

# To JPG
pdftoppm -jpeg -r 150 input.pdf output

# Specific pages
pdftoppm -png -f 1 -l 5 input.pdf output

PDF to DOCX:

bash

# Using libreoffice
libreoffice --headless --convert-to docx input.pdf

# Using pandoc
pandoc input.pdf -o output.docx

PDF to Text:

bash

# Simple conversion
pdftotext input.pdf output.txt

# Maintain layout
pdftotext -layout input.pdf output.txt

6. PDF Analysis & Information

Get page count:

bash

pdfinfo document.pdf | grep "Pages:" | awk '{print $2}'

Check PDF version:

bash

pdfinfo document.pdf | grep "PDF version"

Analyze structure:

bash

# Get detailed structure
mutool show input.pdf outline

# Extract fonts
pdffonts input.pdf

7. PDF Optimization

Compress PDF:

bash

# Using ghostscript (screen quality - smallest)
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen \
   -dNOPAUSE -dQUIET -dBATCH -sOutputFile=compressed.pdf input.pdf

# Using ghostscript (ebook quality - medium)
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook \
   -dNOPAUSE -dQUIET -dBATCH -sOutputFile=compressed.pdf input.pdf

Remove password:

bash

# If you know the password
pdftk secured.pdf input_pw PASSWORD output unsecured.pdf

8. Common Workflows

Extract tables from PDF

bash

# Using tabula-py
tabula-py input.pdf --output-format csv --pages all

# Or use pdfplumber for complex tables

Add watermark

bash

pdftk input.pdf stamp watermark.pdf output watermarked.pdf

Rotate pages

bash

# Rotate all pages 90 degrees clockwise
pdftk input.pdf cat 1-endright output rotated.pdf

# Rotate specific pages
pdftk input.pdf cat 1-5 6right 7-end output rotated.pdf

Tools Required

Make sure these tools are installed:

•poppler-utils (pdftotext, pdfinfo, pdftoppm, pdfunite)
•pdftk or pdftk-java
•ghostscript (gs)
•imagemagick (convert)
•pandoc (for conversions)
•img2pdf (for image to PDF)
•exiftool (for metadata)

Install on Ubuntu/Debian:

bash

sudo apt-get install poppler-utils pdftk ghostscript imagemagick pandoc python3-img2pdf exiftool

Security Notes

•✅ Always validate PDF file paths before processing
•✅ Check file sizes to prevent resource exhaustion
•✅ Sanitize output filenames
•✅ Be cautious with password-protected PDFs
•✅ Scan PDFs for malicious content if from untrusted sources

When to Use This Skill

Use /pdf when the user:

•Wants to read or extract text from a PDF
•Needs to create a PDF from other formats
•Wants to merge or split PDFs
•Needs to convert PDFs to images or other formats
•Asks to analyze PDF structure or metadata
•Wants to compress or optimize PDFs

Always confirm destructive operations before executing.