Allow users to shutdown

Using systemd-logind

If you're using systemd (which is default in Arch Linux), users with non-remote session can issue power-related commands as long as polkit is installed and the session is not broken.

To shutdown:

# systemctl poweroff

The suspend, poweroff and hibernate button presses and lid close events are also handled by logind as described in Power Management#ACPI events.

Using sudo

First install sudo:

# pacman -S sudo

Then, as root, add the following to the end of /etc/sudoers using the visudo command. Substitute user for your username and hostname for the machine's hostname.

user hostname =NOPASSWD: /usr/bin/shutdown -h now,/usr/bin/halt,/usr/bin/poweroff,/usr/bin/reboot

Now your user can shutdown with sudo shutdown -h now, and reboot with sudo reboot. Users wishing to power down a system can also use poweroff or halt. Use the NOPASSWD: tag only if you do not want to be prompted for your password.

For convenience, you can add these aliases to your user's ~/.bashrc if you have it enabled (or to /etc/bash.bashrc for system-wide settings):

alias reboot="sudo reboot"
alias poweroff="sudo poweroff"
alias halt="sudo halt"

Using acpid

acpid can be used to allow anyone with physical access to cleanly shut down the computer by using this power button.