Create physical link recursively

lnr.ts

#!/usr/bin/env -S deno run --allow-read --allow-write
import {
  walk,
  type WalkEntry,
  type WalkOptions,
} from "https://deno.land/[email protected]/fs/walk.ts";
import * as path from "https://deno.land/[email protected]/path/mod.ts";

async function* multiWalk(roots: string[], options?: WalkOptions) {
  for (const root of roots) {
    const dirname = path.dirname(root);
    for await (const entry of walk(root, options)) {
      yield {
        entry,
        relative: path.relative(dirname, entry.path),
      };
    }
  }
}

async function link(src: WalkEntry, dest: string) {
  if (src.isFile) {
    try {
      await Deno.link(src.path, dest);
    } catch (error) {
      console.warn(error);
    }
    console.log(src.path, "=>", dest);
    return;
  }
  console.log("Make directory", dest);
  return Deno.mkdir(dest, {
    recursive: true,
  });
}

function usage(): number {
  console.error(
    "Usage:",
    import.meta.filename ?? import.meta.url,
    "SRC",
    "[...SRC]",
    "OUTDIR",
  );
  return 1;
}

async function main(args: string[]): Promise<number> {
  const outdir = args.pop();
  if (outdir === undefined) {
    console.error("OUTDIR is required.");
    return usage();
  }
  if (args.length === 0) {
    console.error("At least one INDIR is required.");
    return usage();
  }
  for await (const { entry, relative } of multiWalk(args)) {
    await link(entry, path.resolve(outdir, relative));
  }
  return 0;
}

if (import.meta.main) {
  main(Deno.args.slice())
    .then(Deno.exit)
    .catch((e) => {
      console.error(e);
      Deno.exit(2);
    });
}