Schedule a Nightly Reboot

Untuk membuat penjadwalan reboot secara otomatis, dapat menggunakan crontab.

  1. Edit crontab.
    sudo crontab -e
  2. Tambahkan line seperti berikut ini:
    0 1 * * *    /sbin/shutdown -r +0

    Server akan reboot secara otomatis setiap jam 1 malam.
    Untuk penjelasannya sebagai berikut:

    m h dom mon dow command
    minute hour dayOfMonth Month dayOfWeek commandToRun
  3. Reboot

Install Apache, MySQL dan PHP pada Ubuntu 16.04

  1. Update package manager.
    sudo apt-get update
  2. Install dan jalankan apache.
    sudo apt-get install apache2
    sudo systemctl start apache2.service
  3. Install MySQL.
    sudo apt-get install mysql-server
    sudo /usr/bin/mysql_secure_installation
  4. Install php.
    sudo apt-get install php

    Install PHP extensions GD, MySQL.

    sudo apt-get install -y php-{bcmath,bz2,intl,gd,mbstring,mcrypt,mysql,zip} && sudo apt-get install libapache2-mod-php -y
  5. Setting auto start untuk Apache dan MySQL.
    sudo systemctl enable apache2.service
    sudo systemctl enable mysql.service

    Restart Apache untuk menjalankan PHP.

    systemctl restart apache2.service

QtMQTT on Windows 10

Pada tutorial berikut ini, menggunakan QT versi 5.10.1 dengan mingw53_32.

Pada QT versi 5.10 atau lebih tinggi, tidak perlu menggunakan modul tambahan, cukup menambahkan baris berikut pada file project.

QT += mqtt

Untuk menggunakan MQTT pada QT, diperlukan QtMQTT module yang terinstall pada QT lib directory. Untuk memeriksa apakah module sudah terinstall, bisa dicek dengan melihat pada folder QT lib directory. Untuk mengetahui posisi QT lib directory, dapat menggunakan perintah berikut:

qmake -query QT_INSTALL_LIBS

Cek folder yang ditunjukkan, apakah file Qt5Mqtt.dll ada atau tidak. Jika belum ada, perlu install QtMQTT module tersebut. Download source code QT MQTT  dengan menggunakan git command:

git clone git://

Setelah selesai, pindah ke folder file dengan menggunakan perintah cd, kemudian jalankan command berikut:

mingw32-make install

Jika sudah selesai, cek lagi folder QT lib directory.

Kubuntu on Windows 10

Install ubuntu dari windows store.

Buka bash ubuntu, kemudian jalankan command berikut:

sudo add-apt-repository ppa:kubuntu-ppa/backports
sudo apt update
sudo apt install kubuntu-desktopx

Tunggu sampai proses instalasi selesai.

Untuk menggunakan GUI, install xserver pada windows. Sebagai contoh adalah xming.

Jalankan xming, kemudian konfigurasi bash ubuntu agar menggunakan local x server dengan mengetikkan:

export DISPLAY=:0

Jalankan aplikasi yang ingin dibuka dengan mengetikkan pada bash ubuntu.

Berikut adalah contoh program firefox yang saya buka.


Client does not support any combination of challenges that will satisfy the CA

It is because Let’s Encrypt has currently disabled the TLS-SNI-01 challenge due to an identified security issue.


If you’re serving files for that domain out of a directory on that server, you can run the following command:

certbot --authenticator webroot --webroot-path --installer nginx -d

If you’re not serving files out of a directory on the server, you can temporarily stop your server while you obtain the certificate and restart it after Certbot has obtained the certificate. This would look like:

certbot --authenticator standalone --installer nginx -d --pre-hook "service nginx stop" --post-hook "service nginx start"

If using apache:

certbot --authenticator standalone --installer apache -d --pre-hook "systemctl stop apache2" --post-hook "systemctl start apache2"


apache2ctl stop
letsencrypt --authenticator standalone --installer apache -d your.domain

OpenMandriva Commands

To install packages, use: urpmi

# urmpi vim

To uninstall packages (with dependencies), use urpme

# urmpe vim

To query the package database (see if a package is installed or not) use: urmpq

# urpmq vim

To find package that contains a file, use : urpmf

# urpmf .vimrc

To find package by a part of the name: urpmq –fuzzy

# urpmq --fuzzy vim

To find a package by its partial name, with the alias use:

# search vim

To update the local repositories, use: urpmi.update -a

# urpmi.update -a

To update the system, use: urpmi –auto-select

# urpmi –auto-select

Windows 10 Keyboard Shortcuts 1

Windows 10 Keyboard Shortcut Description
Windows Show the Windows 10 Start Menu
Windows + Tab Launch Windows 10 Task View
Windows + C Search the web and Windows with Cortana (speech)
Windows + S Search the web and Windows with Cortana (keyboard input)
Windows + I Open Windows 10 settings
Windows + A Open Windows 10 Action Center (e.g. to display notifications and customizable quick actions)
Windows + Ctrl + D Create new virtual desktop
Windows + Ctrl + F4 Close current virtual desktop
Windows + Ctrl + [Left][Right] Switch between virtual desktops
Windows + [Left][Right][Up][Down] Position windows on your screen

E.g. Windows + [Left] moves the current window to the left half of your screen. If you use Windows + [Up] afterwards, the current window will be placed in the upper left quarter of your screen.

And, what’s very handy in my opinion: If you release the Windows key after positioning a window, Task View shows up on the opposite side of the positioned window to select and position another app.

Windows + H Share content (if supported by current app)
Windows + K Connect to wireless displays and audio devices
Windows + X Open Start button context menu
Windows + G Opens the Windows 10 Game Bar to take game screenshots and record gaming videos of Windows 10 games (works in any game app, e.g. Microsoft Solitaire Collection)


Windows 10 Keyboard Shortcut Description
Windows + D Show Windows desktop
Windows + E Open Windows Explorer
Windows + L Lock your Windows 10 device
Windows + Space Switch keyboard input language (if you have added at least a second one)
Windows + Shift + [Left][Right] Move current Window from one monitor to another (when using a multiple monitor setup)
Windows + [1][2][3][…] Open programs that are pinned to task bar

E.g. if first pinned program on your task bar is Windows Explorer (from left to right), the shortcut Windows + 1 opens Windows Explorer for you.

Windows + R Run a command
Windows + P Project a screen
Alt + Tab Switch to previous window
Alt + Space Restore, move, size, minimize, maximize or close current window. Also works like a charm for Windows 10 modern apps.
Alt + F4 a) Close current window

b) If you’re on your Windows 10 desktop, open Power dialogue to shut down or restart Windows, put your device in sleep mode, sign out or switch the current user