concat.ts

import { expandGlob } from "https://deno.land/std@0.165.0/fs/expand_glob.ts";

main().catch(console.error);

async function main() {
  const osEscaper = Deno.build.os === "windows" ? "`" : "\\";
  const readPromises: Promise<string>[] = [];
  for await (const path of Deno.args) {
    const escaped = path.replace(/(\[|\])/g, (_, arg) => `${osEscaper}${arg}`);
    for await (const entry of expandGlob(escaped, { extended: false })) {
      if (entry.isFile) {
        readPromises.push(Deno.readTextFile(entry.name));
      }
    }
  }

  const reads = await Promise.all(readPromises);
  await Deno.writeTextFile("out.txt", reads.join("\n\n\n"));
  console.log("done");
}