Introduction: Sending Desktop Notifications Sometimes it's useful to get visual feedback from a script. For example, when script or cron job completes or when a long-running build fails, or when there is an urgent problem during script execution. Desktop applications can do this with popup notifications. But it can be done from a script too! You can use script commands to send yourself desktop notifications and reminders. The below code has been written and tested on Linux. What about MacOS? Well... it can be done too, with a bit of effort. Sending notifications from Linux terminal To send notifications from the Linux terminal, use the command. Run to see if it's present. If not, install it with your package manager of choice, for example notify-send which at sudo apt install notify-send A few examples of simple notifications: notify-send "Dinner ready!" notify-send "Tip of the Day" "How about a nap?" You can customize the notification with options such as urgency level, custom icon, etc. Find out more with . You can use a small set of HTML tags in the notification body, to give your notifications nice touch. On top of that, URLs are rendered as clickable, for example: man notify-send notify-send -u critical \ "Build failed!" \ "There were <b>123</b> errors. Click to see the results: http://buildserver/latest" Sent notifications are picked up by the desktop environment and displayed just like any other notification. They will have the same consistent look, feel, and behaviour. Combine notify-send with AT We all know cron, used to schedule commands at regular intervals. Command is used to schedule single execution of a command at a specified time. If you run it like this: AT at 12:00 it will start in interactive mode, where you can enter commands to execute at given time. This isn't useful for scripts. Luckily, accepts parameters from standard input, so we can use it this way: at echo "npm run build" | at now + 1 minute echo "backup-db" | at 13:00 There are many ways of specifying time. From absolute time such as through relative time such as to special times such as or . We can combine it with to show ourselves reminders at some time in future, for example: 10:00 now + 2 hours noon midnight notify-send echo "notify-send 'Stop it and go home now' 'Enough for today.' -u critical" | at now REMIND command Now, let's build a custom bash command for sending ourselves reminders. How about something as simple and human-friendly as: remind "I'm still here" now remind "Time to wake up!" in 5 minutes remind "Dinner" in 1 hour remind "Take a break" at noon remind "It's Friday pints time!" at 17:00 This is better than Alexa! How to get this goodness? See the code below. It defined bash function called which supports the above syntax. The actual work is done in the last two lines. The rest is responsible for help, parameter validation etc. which rougly matches the proportion of useful code vs necessary white-noise in any large application 😉 Save the code somewhere, for example in file and load the function in your profile: remind ~/bin/remind .bashrc source ~/bin/remind Reload the terminal, then type to see the syntax. Enjoy! remind #!/usr/bin/env bash function remind () { local COUNT="$#" local COMMAND="$1" local MESSAGE="$1" local OP="$2" shift 2 local WHEN="$@" # Display help if no parameters or help command if [[ $COUNT -eq 0 || "$COMMAND" == "help" || "$COMMAND" == "--help" || "$COMMAND" == "-h" ]]; then echo "COMMAND" echo " remind <message> <time>" echo " remind <command>" echo echo "DESCRIPTION" echo " Displays notification at specified time" echo echo "EXAMPLES" echo ' remind "Hi there" now' echo ' remind "Time to wake up" in 5 minutes' echo ' remind "Dinner" in 1 hour' echo ' remind "Take a break" at noon' echo ' remind "Are you ready?" at 13:00' echo ' remind list' echo ' remind clear' echo ' remind help' echo return fi # Check presence of AT command if ! which at >/dev/null; then echo "remind: AT utility is required but not installed on your system. Install it with your package manager of choice, for example 'sudo apt install at'." return fi # Run commands: list, clear if [[ $COUNT -eq 1 ]]; then if [[ "$COMMAND" == "list" ]]; then at -l elif [[ "$COMMAND" == "clear" ]]; then at -r $(atq | cut -f1) else echo "remind: unknown command $COMMAND. Type 'remind' without any parameters to see syntax." fi return fi # Determine time of notification if [[ "$OP" == "in" ]]; then local TIME="now + $WHEN" elif [[ "$OP" == "at" ]]; then local TIME="$WHEN" elif [[ "$OP" == "now" ]]; then local TIME="now" else echo "remind: invalid time operator $OP" return fi # Schedule the notification echo "notify-send '$MESSAGE' 'Reminder' -u critical" | at $TIME 2>/dev/null echo "Notification scheduled at $TIME" } Script Notifications on MacOS Although there is no on MacOS, notifications can be sent with ActionScript. For example: notify-send osascript -e 'display notification "Wake up!" with title "Reminder"' Also, there's available, so things should be easy? Well, not so. Sadly, MacOS is makes it increasingly difficult for power users to use their powers ... at First, command is disabled by default. Even if you run it, nothing will happen at scheduled time, because daemon is disabled, and no user account is allowed to use it by default. at atrun To allow yourself to use the command, edit file and add your user name. /var/at/at.allow sudo open -a textedit /var/at/at.allow Then enable daemon: atrun sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.atrun.plist Let's try sending a notification: osascript -e 'display notification "Wake up!" with title "Reminder"' | at now ... and nothing happens. Why? The daemon is not allowed to interact with the desktop, nor anything else for that matter. To fix this, go to System Preferences / Security & Privacy / Privacy / Full Disk Access and add to the list. The file is found at path. You want to see this: atrun /usr/libexec/atrun ... only how to select this file? MacOS won't display system folders in the file selector, even if you've been asked to authenticate as admin just a minute ago. I managed to circumvent it by adding my `/usr` folder to list of favourite folders in Finder: Last but not least, for some even this won't work. AT will not send these pesky notifications, period. It has something to do with script executing not in userspace. You can find more information and solution here: . This is what helps: https://github.com/ChrisJohnsen/tmux-MacOSX-pasteboard # Install reattach-to-user-namespace utility brew install reattach-to-user-namespace # Run notification command as follows reattach-to-user-namespace osascript -e 'display notification "Wake up!" with title "Reminder"' | at now Phew. Hopefully, it works for you too, and you can use script on your Mac as well! Happy weekend! remind Software License Permission is hereby granted, free of charge, to any person obtaining a copy of software published on this website and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions, unless stated explicitly otherwise: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. The software is provided “as is”, without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement. In no event shall the authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings in the software.