wc implementation exercise

Author: Priscilla-EM

implement-shell-tools/wc/mywc.js

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+import { program } from "commander";
+import { promises as fs } from "node:fs";
+
+program
+  .name("mywc")
+  .description(
+    "Counts lines, words, and bytes in files like the Unix wc command"
+  )
+  .option("-l", "counts the number of lines")
+  .option("-w", "counts words")
+  .option("-c", "counts bytes")
+  .argument("<files...>", "Files to count");
+
+program.parse();
+
+const options = program.opts();
+const files = program.args; 
+
+// If there are no given flags, default to counting lines, words and bytes like the Unix wc command
+if (!options.l && !options.w && !options.c) {
+  options.l = true;
+  options.w = true;
+  options.c = true;
+}
+
+const showLines = options.l;
+const showWords = options.w;
+const showBytes = options.c;
+
+// To support multiple files and a total
+let totalLines = 0;
+let totalWords = 0;
+let totalBytes = 0;
+
+for (const file of files) {
+  try {
+    const content = await fs.readFile(file, "utf-8");
+
+    const lineCount = content.split("\n").length - 1;
+    const wordCount = content.trim().split(/\s+/).filter(Boolean).length;
+    const byteCount = Buffer.byteLength(content, "utf-8");
+
+    totalLines += lineCount;
+    totalWords += wordCount;
+    totalBytes += byteCount;
+
+    let output = "";
+    if (showLines) output += `${lineCount.toString().padStart(8)}`;
+    if (showWords) output += `${wordCount.toString().padStart(8)}`;
+    if (showBytes) output += `${byteCount.toString().padStart(8)}`;
+    output += ` ${file}`;
+
+    console.log(output);
+  } catch (err) {
+    console.error(`Error reading file ${file}: ${err.message}`);
+  }
+}
+
+// If multiple files were given, show the total
+if (files.length > 1) {
+  let totalOutput = "";
+  if (showLines) totalOutput += `${totalLines.toString().padStart(8)}`;
+  if (showWords) totalOutput += `${totalWords.toString().padStart(8)}`;
+  if (showBytes) totalOutput += `${totalBytes.toString().padStart(8)}`;
+  totalOutput += " total";
+
+  console.log(totalOutput);
+}

implement-shell-tools/wc/package-lock.json

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+{
+  "name": "wc",
+  "version": "1.0.0",
+  "description": "You should already be familiar with the `wc` command line tool.",
+  "main": "index.js",
+  "type": "module",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "commander": "^14.0.0"
+  }
+}