catpdf

README

catpdf

A command-line utility written in Go that concatenates (catenates) PDF files.

Installation

go install github.com/Michael-F-Ellis/catpdf@latest

Or build from source:

git clone https://github.com/Michael-F-Ellis/catpdf.git
cd catpdf
go build -o catpdf main.go
sudo mv catpdf /usr/local/bin/

Usage

catpdf file1.pdf file2.pdf file3.pdf > combined.pdf

The utility reads PDF files in the order they are provided as command-line arguments and writes the concatenated PDF to standard output.

Examples

Concatenate two PDFs:

catpdf chapter1.pdf chapter2.pdf > book.pdf

Concatenate multiple PDFs:

catpdf *.pdf > all.pdf

Use in a pipeline (though direct file arguments are preferred):

find . -name "*.pdf" -print0 | xargs -0 catpdf > combined.pdf

Requirements

• Go 1.16 or later (for building from source)
• The pdfcpu library is used internally for PDF processing

How it works

catpdf uses the pdfcpu library to merge PDF files. It opens each input file, reads them as streams, and merges them directly to standard output without creating intermediate files on disk (except in memory).

Error handling

• If no arguments are provided, usage instructions are displayed
• If a file cannot be opened, an error is printed and the program exits
• If a file is not a valid PDF, an error is printed and the program exits
• The program exits with a non-zero status on error

License

See LICENSE file.

Contributing

Contributions are welcome! Please open an issue or pull request on GitHub.