example/README.md

pdfrx_engine Examples #

This directory contains example applications demonstrating the capabilities of pdfrx_engine.

Examples #

pdf2image.dart #

Converts PDF pages to PNG images and extracts text from each page.

Usage:

dart run example/main.dart <pdf_file> [output_dir]

Example:

dart run example/main.dart document.pdf ./output

pdfcombine.dart #

Combines multiple PDF files into a single PDF, with flexible page selection and ordering.

Usage:

dart run example/pdfcombine.dart [<input_pdf>...] -o <output_pdf> [<input_pdf>...] -- <page_spec>...

Input PDF files are automatically assigned IDs: a, b, c, etc. in order. The -o flag can appear anywhere before the -- separator.

Arguments:

• -o <output_pdf> - Output PDF file path (can appear anywhere before --)
• <input_pdf>... - Input PDF file(s) (assigned IDs a, b, c, ... in order)
• -- - Separator between input files and page specifications
• <page_spec>... - Page specification (e.g., a, b[1-3], c[1,2,3])

Page specification formats:

• a - All pages from file a
• a[1-10] - Pages 1-10 from file a
• a[1,2,3,4] - Pages 1,2,3,4 from file a
• a[1-3,5,6,7,10] - Pages 1,2,3,5,6,7,10 from file a (hybrid of ranges and individual pages)

Examples:

Combine all pages from three PDFs in order (files are assigned IDs a, b, c):

dart run example/pdfcombine.dart -o output.pdf doc1.pdf doc2.pdf doc3.pdf -- a b c

Combine specific pages from multiple PDFs (-o at the beginning):

dart run example/pdfcombine.dart -o output.pdf doc1.pdf doc2.pdf doc3.pdf -- a b[1-3] c b[4,5,6]

Same command with -o in the middle (files can be split around -o flag):

dart run example/pdfcombine.dart doc1.pdf doc2.pdf -o output.pdf doc3.pdf -- a b[1-3] c b[4,5,6]

This will:

1. doc1.pdf is assigned ID a, doc2.pdf is assigned ID b, doc3.pdf is assigned ID c
2. Add all pages from a (doc1.pdf)
3. Add pages 1-3 from b (doc2.pdf)
4. Add all pages from c (doc3.pdf)
5. Add pages 4,5,6 from b (doc2.pdf)

Split and reorder pages from a single file:

dart run example/pdfcombine.dart -o output.pdf input.pdf -- a[1-10] a[20-30] a[11-19]

Merge two PDFs with custom ordering:

dart run example/pdfcombine.dart -o merged.pdf input1.pdf input2.pdf -- a[1-10] b a[11-20]

Use hybrid page specifications (ranges and individual pages):

dart run example/pdfcombine.dart -o output.pdf doc.pdf -- a[1-3,5,6,7,10]

This extracts pages 1,2,3,5,6,7,10 from doc.pdf.

Running Examples #

From the repository root:

# Run pdf2image example
dart run packages/pdfrx_engine/example/main.dart <pdf_file> [output_dir]

# Run pdfcombine example
dart run packages/pdfrx_engine/example/pdfcombine.dart <args>

From the packages/pdfrx_engine directory:

# Run pdf2image example
dart run example/main.dart <pdf_file> [output_dir]

# Run pdfcombine example
dart run example/pdfcombine.dart <args>