Category: Node.js

$ node -v
v10.24.1
$ sudo npm install n -g
$ sudo n stable
$ sudo apt purge -y nodejs npm
$ exec $SHELL -l
$ node -v
v16.13.2
$ npm -v
8.1.2

うおおおおおおおおおおおおおおおお

$ npm install
$ npm run dev

OK

Node.jsでは実行時に渡される引数の情報はprocess.argvにまとめられている
process.argv[0] = nodeコマンドのパス
process.argv[1] = スクリプトファイルのパス
process.argv[2]以降 = コマンド実行時に渡される引数

src/index.ts

console.log("Node path = " + process.argv[0])
console.log("Script file path = " + process.argv[1])

const data: number[] = []
for(var i = 2; i < process.argv.length; i++){
	data.push(Number(process.argv[i]))
}
console.log(data)

for (let item of data){
	const res = primeFactor(item)
	console.log(item + '= ' + res)
}

function primeFactor(a: number): number[] {
	const v: number[ ] = []
	let x = a
	let n = 2
	while(x > n){
	  if(x % n == 0){
	  	x = x / n
	  	v.push(n)
	  } else {
	  	n += n == 2 ? 1 : 2
	  }
	}
	v.push(x)
	return v
}

$ npm run build
$ node dist/main.js 100 1234 9876
Node path = /usr/bin/node
Script file path = /home/vagrant/dev/hands-on/dist/main.js
[ 100, 1234, 9876 ]
100= 2,2,5,5
1234= 2,617
9876= 2,2,3,823

console.log("Node path = " + process.argv[0])
console.log("Script file path = " + process.argv[1])

const data: number[] = []
for(var i = 2; i < process.argv.length; i++){
	data.push(Number(process.argv[i]))
}
console.log('parameters: ' + data)

const f = aggregate()


for (let item of data){
	const res = f(item)
	console.log(res)
}

function aggregate(): (n:number) => [number, number, number, number, number] {
	let total = 0
	let totalp = 0
	let totalt = 0
	return (n:number):[number, number, number, number, number] => {
		total += n
		let tax = Math.floor(n - n / 1.1)
		totalp += n - tax
		totalt += tax
		return [n, tax, total, totalp, totalt]
	}
}

$ node dist/main.js 1200 1870 3058 2765 1875
Node path = /usr/bin/node
Script file path = /home/vagrant/dev/hands-on/dist/main.js
parameters: 1200,1870,3058,2765,1875
[ 1200, 109, 1200, 1091, 109 ]
[ 1870, 170, 3070, 2791, 279 ]
[ 3058, 278, 6128, 5571, 557 ]
[ 2765, 251, 8893, 8085, 808 ]
[ 1875, 170, 10768, 9790, 978 ]

なるほど、ここまでの知識を使って何か作ってみたいですね

S3から複数のjsonをdownloadして、一つのjsonにまとめたい。
※後にgraphQLで出力する

objectを配列([])で宣言して、pushする

		var object = [];
		const s3Client = new AWS.S3({
				accessKeyId: 'fuga',
				secretAccessKey: 'hoge',
				region: 'ap-northeast-1'
			})
		
		function getObject(params){
			s3Client.getObject(params, function(err, data){
				if(err){
					console.log(err, err.stack);
				} else {
					object.push(JSON.parse(data.Body.toString()|| "null"));
					console.log(object)
					fs.writeFile('speech.json', JSON.stringify(object), function(err, result){
						if(err) console.log('error', err);
					});
				}
			})
		}

		const params1 = {
			Bucket: 'speech-dnn',
			Key: 'speech.json',
		}

		const params2 = {
			Bucket: 'speech-dnn',
			Key: 'speech2.json',
		}
		
		getObject(params1);
		getObject(params2);

$ node test.js
Server Now Running
$ node test.js
Server Now Running
[ { id: 1, text: ‘ 凄い技術ですね。\n’ } ]
[ { id: 1, text: ‘ 凄い技術ですね。\n’ }, { id: 2, text: ‘ びっくりしました。\n’ } ]

なるほど、これをgraphQLに入れる
※timeを追加
$ node server5.js
Express GraphQL Server Now Running On 192.168.34.10:8000/graphql
[ { id: 1, text: ‘ 凄い技術ですね。\n’, time: ‘2021/12/10 15:04:10’ } ]
[
{ id: 1, text: ‘ 凄い技術ですね。\n’, time: ‘2021/12/10 15:04:10’ },
{ id: 2, text: ‘ びっくりしました。\n’, time: ‘2021/12/10 15:04:12’ }

http://192.168.34.10:8000/graphql

OK、

$ npm install mysql2

接続

var express = require('express');
const mysql = require('mysql2');

const app = express();

const db_setting = {
	host: 'localhost',
	user: 'root',
	password: 'hoge',
	database: 'test'
}
let mycon = null;

(async() => {
	try {
		mycon = await mysql.createConnection(db_setting);
		mycon.connect(function(err){
			if(err){
				console.log(err);
			} else {
				console.log("success");
			}
		});
	} catch(e){
		console.log(e);
	}
	if(mycon){
		mycon.end();
	}
})();

app.listen(8000);

うーむ、asyncの外で使いたいんだよなあ

1. mysqlパッケージをインストール
$ npm install mysql

var express = require('express');
var mysql = require('mysql');

const app = express();

const connection = mysql.createConnection({
	host: 'localhost',
	user: 'root',
	password: 'hoge',
	database: 'test'
});

connection.connect((err) => {
	if(err){
		console.log('error connecting:' + err.stack);
		return;
	}
	console.log('success');
});

app.get('/', (req, res) => {
	connection.query(
		'SELECT * FROM master_zip',
		(error, results) => {
			console.log(results);
		}
	);
});

app.listen(8000);

$ node app.js
success
[
RowDataPacket {
zip_code: ‘1690075’,
pref_name: ‘東京都’,
city_name: ‘新宿区’,
town_name: ”,
area_name: ‘高田馬場’
},
// 省略
]

mysql.createConnectionで接続して、connection.queryでqueryを実行するのね
基本はわかりました。

ただ、これをconnection.queryの外に変数を出そうとするとできない。

var getAddress = function(args){

	var zip_code = args.zip_code;

	const connection = mysql.createConnection({
		host: 'localhost',
		user: 'root',
		password: 'password',
		database: 'test'
	});
	// conection.queryは非同期関数なので外に出せない
	connection.query(
		'SELECT * FROM master_zip',
		(error, results) => {
			var db_results = JSON.parse(JSON.stringify(results));
			}
	);
	return db_results.filter(address => {
 			return address.zip_code == zip_code;
	})[0];
}

なかなか複雑…