iconv -f euc-jp -t utf-8 filename

node.js iconv sample.js

var spawn = require('child_process').spawn,
    iconv = spawn('iconv', ['-f', 'euc-jp', '-t', 'utf-8']),
    fs = require('fs');

var filename = __dirname + '/eucjp.html';

var stream = fs.createReadStream(filename);
stream.pipe(iconv.stdin);

iconv.stdout.on('data', function(data) {
  process.stdout.write(data.toString());
});

iconv.stdout.on('error', function(e) {
  console.log("err");
  process.stderr.write(e);
});