A Node.js library which can work with PDFs, based on Ghostscript.
npm install ghostscript-node  
A fully promise-based Node.js library which can work with PDFs, based on Ghostscript and qpdf.
All PDF files that are handled by this library in the form of Buffer objects, i.e. to a user of this library, it looks like everything works only in memory. In the background though, file system access (via tempy) is needed.
Additionally, this library requires the gs command (Ghostscript) as well as qpdf to be available. The required apt dependencies on Ubuntu 20.04 can be installed via the following command:
``
sudo apt install -y python python3 build-essential ghostscript libjpeg-dev libpng-dev libcurl4-openssl-dev mupdf-tools libfreetype6-dev qpdf
`
npm install ghostscript-node
`javascript
const gs = require("ghostscript-node");
(async () => {
const pdf1 = / load first PDF as Buffer, e.g. from database /;
const pdf2 = / load second PDF as Buffer, e.g. from database /;
// get Buffer object with bytes of combined PDF
const combinedPDF = await gs.combinePDFs([pdf1, pdf2]);
// get number of pages of pdf1
const numPagesPDF1 = await gs.countPDFPages(pdf1);
// get Buffer object with bytes of specified set of pages
// page numbers begin with 1, last page is included
const partOfPDF1 = await gs.extractPDFPages(pdf1, 3, 5);
// rotate all pages of pdf1 by 90 degrees clockwise
const rotatedPDF = await gs.rotatePDF(pdf1, "90");
// returns an array of buffers containing PNG images of the desired pages
const renderedPages = await gs.renderPDFPagesToPNG(pdf1);
// checks if pdf1 is a valid PDF file
const isPDF1Valid = await gs.isValidPDF(pdf1);
})();
``
MIT