Implement ls in JavaScript

Author: Konvaly

implement-shell-tools/ls/ls.mjs

@@ -0,0 +1,74 @@
+import process from "node:process";
+import { promises as fs } from "node:fs";
+import { parseArgs } from "node:util";
+
+const { values, positionals } = parseArgs({
+  options: {
+    one: { type: "boolean", short: "1", default: false },
+    all: { type: "boolean", short: "a", default: false },
+  },
+  allowPositionals: true,
+});
+
+const showAll = values.all;
+const paths = positionals.length > 0 ? positionals : ["."];
+
+function stripPunctuation(name) {
+  return name.replace(/[^\p{L}\p{N}]/gu, "");
+}
+
+function compareNames(a, b) {
+  const result = stripPunctuation(a).localeCompare(stripPunctuation(b));
+  return result !== 0 ? result : a.localeCompare(b);
+}
+
+const files = [];
+const directories = [];
+
+for (const path of paths) {
+  try {
+    const stats = await fs.stat(path);
+    if (stats.isDirectory()) {
+      directories.push(path);
+    } else {
+      files.push(path);
+    }
+  } catch {
+    console.error(`ls: cannot access '${path}': No such file or directory`);
+    process.exitCode = 2;
+  }
+}
+
+files.sort(compareNames);
+directories.sort(compareNames);
+
+const needHeaders = directories.length > 1 || files.length > 0;
+let printedSomething = false;
+
+for (const file of files) {
+  console.log(file);
+  printedSomething = true;
+}
+
+for (const dir of directories) {
+  let entries = await fs.readdir(dir);
+
+  if (showAll) {
+    entries = [".", "..", ...entries];
+  } else {
+    entries = entries.filter((entry) => !entry.startsWith("."));
+  }
+  entries.sort(compareNames);
+
+  if (needHeaders) {
+    if (printedSomething) {
+      console.log("");
+    }
+    console.log(`${dir}:`);
+  }
+
+  for (const entry of entries) {
+    console.log(entry);
+  }
+  printedSomething = true;
+}