complete wc exercise

Author: enjoy15

implement-shell-tools/wc/wc.js

@@ -0,0 +1,61 @@
+#!/usr/bin/env node
+
+const fs = require('fs');
+const path = require('path');
+
+function countFile(filePath, options) {
+  try {
+    const data = fs.readFileSync(filePath, 'utf8');
+
+    const lines = data.split('\n').length;
+    const words = data.split(/\s+/).filter(Boolean).length;
+    const bytes = Buffer.byteLength(data, 'utf8');
+
+    if (options.lines) {
+      console.log(`${lines}\t${filePath}`);
+    } else if (options.words) {
+      console.log(`${words}\t${filePath}`);
+    } else if (options.bytes) {
+      console.log(`${bytes}\t${filePath}`);
+    } else {
+      console.log(`${lines}\t${words}\t${bytes}\t${filePath}`);
+    }
+  } catch (err) {
+    console.error(`wc: ${filePath}: No such file or directory`);
+  }
+}
+
+function main() {
+  const args = process.argv.slice(2);
+  const options = {
+    lines: false,
+    words: false,
+    bytes: false,
+  };
+
+  const files = [];
+
+  args.forEach((arg) => {
+    if (arg === '-l') {
+      options.lines = true;
+    } else if (arg === '-w') {
+      options.words = true;
+    } else if (arg === '-c') {
+      options.bytes = true;
+    } else {
+      files.push(arg);
+    }
+  });
+
+  if (files.length === 0) {
+    console.error('Usage: wc [-l | -w | -c] <file>...');
+    process.exit(1);
+  }
+
+  files.forEach((file) => {
+    const filePath = path.resolve(file);
+    countFile(filePath, options);
+  });
+}
+
+main();