PDF Text Extraction Fallback

PDF Text Extraction Fallback

When to Use This Skill

Use this skill when read_file with filetype="pdf" returns binary/image data instead of readable text content. This is a common issue with PDF files that contain embedded images or complex formatting.

Steps

1. Validate Parameters First

Before attempting extraction, ensure you're using the correct parameter name:

• Use filetype (not file_type) for the read_file function
• Incorrect parameter names can cause silent failures

# Correct
read_file(filetype="pdf", file_path="document.pdf")

# Incorrect - may fail silently
read_file(file_type="pdf", file_path="document.pdf")

2. Detect Binary Data Issue

After calling read_file, check if the result contains:

• Garbled/binary characters
• Image data representations (e.g., b'...' byte strings with non-text content)
• Unreadable or corrupted-looking content

If yes, proceed with the pdftotext workaround.

3. Extract Text via pdftotext

Use run_shell to call pdftotext, which extracts text directly from PDF files:

# Extract text to stdout
result = run_shell(command="pdftotext /path/to/document.pdf -")
text_content = result.stdout

The - flag tells pdftotext to output to stdout instead of creating a file.

4. Handle Output and Errors

result = run_shell(command="pdftotext /path/to/document.pdf -")

if result.stderr:
    # Check for errors like "pdftotext not found"
    # May need to install poppler-utils
    pass

text_content = result.stdout
# text_content now contains the extracted text

Example Workflow

# Step 1: Try normal read with correct parameters
content = read_file(filetype="pdf", file_path="reference.pdf")

# Step 2: Check if content is readable
if not content or looks_like_binary(content):
    # Step 3: Fall back to pdftotext
    result = run_shell(command="pdftotext reference.pdf -")
    text_content = result.stdout
    
    # Step 4: Verify extraction succeeded
    if result.stderr:
        # Handle error (e.g., install pdftotext)
        pass

Installation Notes

pdftotext is part of the poppler-utils package:

• Debian/Ubuntu: apt-get install poppler-utils
• macOS: brew install poppler
• Many Linux environments: Pre-installed

Alternative: Output to File

If stdout approach has issues, output to a temporary file:

run_shell(command="pdftotext /path/to/document.pdf /tmp/output.txt")
text_content = read_file(filetype="txt", file_path="/tmp/output.txt")

Best Practices

1. Always validate the filetype parameter spelling before troubleshooting
2. Check both stdout and stderr from pdftotext
3. For multi-page PDFs, pdftotext preserves page breaks with form feeds
4. This method works better for text-based PDFs than image-scanned PDFs