server-scripts/scripts/script-system-scheduled-restart

#!/usr/bin/env bash
# Update and restart the system
# Copyright 2021-2025 Bryan C. Roessler
# Licensed under the Apache License, Version 2.0
p="${BASH_SOURCE[0]%/*}"; [[ -r $p/script-functions ]] && . "$p"/script-functions || exit 1

is_root

[[ $# -eq 0 ]] && time='*-*-* 01:30:00' # 1:30AM
[[ $# -gt 1 ]] && time="$*"

script-system-update

ask_ok "Set a scheduled reboot for $time?" || exit 1

cat <<- EOF > "/usr/lib/systemd/system/scheduled-reboot.timer"
	[Unit]
	Description=Scheduled reboot

	[Timer]
	OnCalendar=$time
	Unit=reboot.target

	[Install]
	WantedBy=timers.target
EOF

systemctl daemon-reload
systemctl start scheduled-reboot.timer

# Current date
dt=$(date '+%d/%m/%Y %H:%M:%S');

msg_part1="System restart scheduled for $time."
msg_part2="The current time is $dt."
msg_part3="Make sure all changes are saved."
message="$msg_part1 $msg_part2 $msg_part3"

# Graphical notification
IFS=$'\n'
for LINE in $(w -hs); do
    USER=$(echo "$LINE" | awk '{print $1}')
    USER_ID=$(id -u "$USER")
    DISP_ID=$(echo "$LINE" | awk '{print $8}')
    sudo -u "$USER" DISPLAY="$DISP_ID" DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/"$USER_ID"/bus notify-send "$message" --icon=dialog-warning
done

# Wall notification
wall -n "$message"