How to get system updates automatically in Arch

You've already installed Arch and you miss the way the system reminded you about available updates. Also, what good are Arch's hyper-updated repositories if users don't know those updates are available? Anyway ... here are some alternatives ...

The famous cron

In case you don't have it installed (very unlikely):

pacman -S dcron

Cron should now work without problems. To use crontab, you need to add the user to the users group. It is very possible that your user is already added to this group, otherwise, use the following command:

gpasswd -a username users

where username is the name of the user in question.

The rest of the instructions can be found in this another post.

System bar notifiers

I have to admit that I'm really liking Arch, but I still can't figure out how something as basic as this (a system update notifier) ​​is still not available in the official repositories. All, absolutely all, are available only via AUR.

Arch-up
archup is a small tool written in C that informs Arch users when updates are available.
Official Website: http://www.nongnu.org/archup/
AUR package details: http://aur.archlinux.org/packages.php?ID=35792
Screenshots: http://www.nongnu.org/archup/

pacman notifier
Written in Ruby, uses Gtk. Show an icon in the system panel and notify about new updates through fancy pop-up windows (using libnotify).
Official page: https://github.com/valeth/pacman-notifier
AUR package details: http://aur.archlinux.org/packages.php?ID=15193
Screenshots: https://github.com/valeth/pacman-notifier

pacify
Pacupdate is a small application that notifies users of new updates to Arch's repositories.
Official Website: http://code.google.com/p/pacupdate/
AUR package details: https://aur.archlinux.org/packages/pacupdate/

ZenMan
It is designed to work under GTK / GNOME / zenity / libnotify.
AUR package details: http://aur.archlinux.org/packages.php?ID=25948
Screenshots: https://blog.desdelinux.net/wp-content/uploads/2011/01/zenman-screenshot-2.png

Yaourt-Dzen Notifier
A simple 14-line script that shows the number of available updates. Use yaourt, dzen2, and inotify-tools.
Official Website: http://andreasbwagner.tumblr.com/post/853471635/arch-linux-update-notifier-for-dzen2

Source: Arch Wiki