redis-scan.js

var _ = require('highland'),
    redis = require('redis'),
    client = redis.createClient();

var pattern = process.argv[2],
    count = process.argv[3] || 10

client.on('error', function(err) {
  throw err
});

function createScanStream(cursor) {
  return _(function(push, next) {
    client.scan(cursor, 'MATCH', pattern, 'COUNT', count, function(err, reply) {
      if (err) return push(err);

      var _cursor = Number(reply.shift());

      if (reply[0].length) reply[0].forEach(function(key) {
        push(null, key);
      });

      if (_cursor) return next(createScanStream(_cursor));

      push(null, _.nil);
    })
  })
}

createScanStream(0)
  .consume(function(err, key, push, next) {
    // Close redis client when stream is finished
    if (key === _.nil) return client.quit()

    push(err, key + '\n')
    next()
  })
  .pipe(process.stdout)