pdf-verification-cli

# PDF Verification with Command-Line Tools When verifying PDF files during task execution, Python libraries like PyPDF2 may not be available in the environment. This skill provides a reliable alternative using standard command-line tools from the `poppler-utils` package. ## When to Use This Skill - Need to verify PDF page count - Need to inspect PDF text content - PyPDF2 or similar Python PDF libraries are unavailable - Working in minimal/containerized environments ## Core Tools ### 1. `pdfinfo` - Extract PDF Metadata Use `pdfinfo` to get page count and other metadata: ```bash # Get full PDF info pdfinfo document.pdf # Get only page count pdfinfo document.pdf | grep Pages # Extract page count as a number pdfinfo document.pdf | grep Pages | awk '{print $2}' ``` **Key metadata fields:** - `Pages`: Number of pages in the PDF - `Title`: Document title - `Author`: Document author - `Creator`: Application that created the PDF - `Producer`: Application that processed the PDF - `CreationDate`: When the PDF was created - `ModDate`: Last modification date ### 2. `pdftotext` - Extract Text Content Use `pdftotext` to inspect the actual content of the PDF: ```bash # Extract all text to stdout pdftotext document.pdf - # Extract text to a file pdftotext document.pdf output.txt # Extract text from specific page range pdftotext -f 1 -l 3 document.pdf output.txt # Preserve layout (rough formatting) pdftotext -layout document.pdf output.txt ``` ## Verification Workflow ### Step 1: Check Tool Availability ```bash # Check if tools are installed which pdfinfo which pdftotext # Or test with --help pdfinfo --help 2>&1 | head -1 ``` ### Step 2: Install if Needed ```bash # Debian/Ubuntu apt-get update && apt-get install -y poppler-utils # RHEL/CentOS/Fedora yum install -y poppler-utils # or dnf install -y poppler-utils # macOS (with Homebrew) brew install poppler ``` ### Step 3: Verify PDF Properties ```bash # Verify page count matches expected EXPECTED_PAGES=4 ACTUAL_PAGES=$(pdfinfo document.pdf | grep Pages | awk '{print $2}') if [ "$ACTUAL_PAGES" -eq "$EXPECTED_PAGES" ]; then echo "✓ Page count verified: $ACTUAL_PAGES pages" else echo "✗ Page count mismatch: expected $EXPECTED_PAGES, got $ACTUAL_PAGES" fi ``` ### Step 4: Verify PDF Content ```bash # Check for required sections/content pdftotext document.pdf - | grep -i "checklist" && echo "✓ Contains checklist section" pdftotext document.pdf - | grep -i "references" && echo "✓ Contains references section" # Count occurrences of key terms pdftotext document.pdf - | grep -ci "assessment" # Case-insensitive count ``` ## Python Integration Example ```python import subprocess def get_pdf_page_count(pdf_path): """Get page count using pdfinfo""" result = subprocess.run( ['pdfinfo', pdf_path], capture_output=True, text=True ) for line in result.stdout.split('\n'): if line.startswith('Pages:'): return int(line.split(':')[1].strip()) return None def extract_pdf_text(pdf_path): """Extract all text from PDF using pdftotext""" result = subprocess.run( ['pdftotext', pdf_path, '-'], capture_output=True, text=True ) return result.stdout def verify_pdf(pdf_path, expected_pages, required_terms): """Verify PDF has expected page count and contains required terms""" # Check page count pages = get_pdf_page_count(pdf_path) if pages != expected_pages: return False, f"Expected {expected_pages} pages, got {pages}" # Check content text = extract_pdf_text(pdf_path).lower() missing = [term for term in required_terms if term.lower() not in text] if missing: return False, f"Missing terms: {missing}" return True, "PDF verification passed" ``` ## Common Use Cases | Task | Command | |------|---------| | Count pages | `pdfinfo file.pdf \| grep Pages` | | Check if PDF has text | `pdftotext file.pdf - \| head -5` | | Search for keyword | `pdftotext file.pdf - \| grep -i "keyword"` | | Extract first page | `pdftotext -f 1 -l 1 file.pdf out.txt` | | Get PDF title | `pdfinfo file.pdf \| grep Title` | ## Troubleshooting **`pdfinfo: command not found`** - Install poppler-utils (see Step 2 above) - Ensure PATH includes the installation directory **`pdftotext` returns empty output** - PDF may be image-only (scanned) - requires OCR - PDF may be encrypted/password-protected - Try `pdftotext -layout` for better text extraction **Page count seems wrong** - Some PDFs have blank pages counted - Verify with `pdftotext` to see actual content per page ## Best Practices 1. **Always verify both structure and content** - Page count alone doesn't guarantee content quality 2. **Use case-insensitive searches** - Content may vary in capitalization 3. **Handle errors gracefully** - Tools may fail on corrupted or encrypted PDFs 4. **Combine with file existence checks** - Verify PDF exists before running tools