packages/utils/head.js

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Return the first num lines of an array.
 * @param lines An array of strings.
 * @param num Number of lines to return.
 */
function main(msg) {
    var lines = msg.lines || [];
    var num = msg.num || 1;
    var head = lines.slice(0, num);
    console.log('head get first ' + num + ' lines of ' + lines + ': ' + head);
    return {lines: head, num: num};
}