implement wc command

Author: Fatma Degirmenci

implement-shell-tools/wc/wc.js

@@ -0,0 +1,53 @@
+
+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .option("-l", "Print only the line count")
+  .option("-w", "Print only the word count")
+  .option("-c", "Print only the byte count")
+  .argument("<paths...>", "One or more file paths");
+
+program.parse();
+
+const opts = program.opts();
+const paths = program.args;
+
+async function wcFile(path) {
+  const content = await fs.readFile(path, "utf8");
+
+  const lines = content.split("\n").length;
+  const words = content.trim().split(/\s+/).filter(Boolean).length;
+  const bytes = Buffer.byteLength(content, "utf8");
+
+  return { lines, words, bytes };
+}
+
+function formatOutput(counts, filename, opts) {
+  if (opts.l) return `${counts.lines} ${filename}`;
+  if (opts.w) return `${counts.words} ${filename}`;
+  if (opts.c) return `${counts.bytes} ${filename}`;
+
+  return `${counts.lines} ${counts.words} ${counts.bytes} ${filename}`;
+}
+
+async function main() {
+  let total = { lines: 0, words: 0, bytes: 0 };
+  let multipleFiles = paths.length > 1;
+
+  for (const path of paths) {
+    const counts = await wcFile(path);
+
+    total.lines += counts.lines;
+    total.words += counts.words;
+    total.bytes += counts.bytes;
+
+    console.log(formatOutput(counts, path, opts));
+  }
+
+  if (multipleFiles) {
+    console.log(formatOutput(total, "total", opts));
+  }
+}
+
+main();