Factorioをサーバーで動かした時のログを見てDiscordに送るnode.js

watchFactorio.js

const fs = require('fs');
const { exec } = require('child_process');
const Discord = require('discord.js');
const client = new Discord.Client();
const token = '***';
const channelId = '***';

const target = process.env['HOME'] + '/.forever/****.log';

var latest;

// Discord
client.on('ready', () => {
    /* ログ出力 */
    console.log(`Logged in as ${client.user.tag}`);

    // ログファイル監視
    fs.watch(target, (eventType, filename) => {
        exec('tail -10 ' + target + " | grep -e '\\[LEAVE\\]' -e '\\[JOIN\\]'", (error, stdout, stderr) => {
            if (error instanceof Error) {
      //          console.error(error);
            } else {
                parseGrepLog(stdout);
            }
        });

    });
});
client.login(token);


function parseGrepLog(stdout) {
    const lines = stdout.split("\n");
    lines.forEach((item, index) => {
        if (item.length > 0) {
            // ex. 2020-03-25 17:30:50 [JOIN] username joined the game
            let items = item.split(' ');
            let time = new Date(items[0] + ' ' + items[1]);
            if (!latest || latest.getTime() < time.getTime()) {
                latest = time;
                sendBot(items[3], items[2]);
            }
        }
    });
}

function sendBot(username, command) {
    let message;
    const channel = client.channels.fetch(channelId);
    if (command.indexOf('JOIN') > 0) {
        // login
        message = username + 'さんがログインしました。';
    } else {
        // logout
        message = username + 'さんがログアウトしました。';
    }
    channel.then(ch => ch.send(message));
    console.log(message);
}