使用 readdir 或 readdirSync 列出目錄內容

const fs = require('fs');

// Read the contents of the directory /usr/local/bin asynchronously.
// The callback will be invoked once the operation has either completed
// or failed.
fs.readdir('/usr/local/bin', (err, files) => {
  // On error, show it and return
  if(err) return console.error(err);

  // files is an array containing the names of all entries
  // in the directory, excluding '.' (the directory itself)
  // and '..' (the parent directory).

  // Display directory entries
  console.log(files.join(' '));
});

同步變體可用作 readdirSync，它可以阻塞主執行緒，因此可以防止非同步程式碼同時執行。大多數開發人員都避免使用同步 IO 功能來提高效能。

let files;

try {
  files = fs.readdirSync('/var/tmp');
} catch(err) {
  // An error occurred
  console.error(err);
}

使用發電機

const fs = require('fs');

// Iterate through all items obtained via
// 'yield' statements
// A callback is passed to the generator function because it is required by
// the 'readdir' method
function run(gen) {
  var iter = gen((err, data) => {
    if (err) { iter.throw(err); }

    return iter.next(data);
  });

  iter.next();
}

const dirPath = '/usr/local/bin';

// Execute the generator function
run(function* (resume) {
  // Emit the list of files in the directory from the generator
  var contents = yield fs.readdir(dirPath, resume);
  console.log(contents);
});