Get notified when a long command finishes, locally or over SSH

Desktop popup with notify-send

Add notify-send after your command to get a desktop popup when it finishes. The syntax is notify-send [-u low|normal|critical] [-t ms] [-a app] [-i icon] "summary" "body", and it talks to the notification service over your desktop session's D-Bus.

How you join the two commands matters. With ; the popup appears whatever happened, && fires only after success (exit status 0) and || only after a failure. $? holds the exit status of the last command, so "exit $?" in the body tells you whether it worked before you switch windows.

make build; notify-send "Build finished" "exit $?"
make build && notify-send "Build passed"
make build || notify-send -u critical "Build failed"

A few flags worth knowing:

• -u sets the urgency: low, normal or critical.
• -t sets how long the popup stays, in milliseconds, but GNOME Shell ignores it.
• -a sets the app name and -i an icon.

Typing that every time gets old. Put a small function in ~/.bashrc or ~/.zshrc that runs any command, keeps its exit status and passes it to the popup.

notify_done() {
  "$@"
  local status=$?
  notify-send "Finished: $*" "exit $status"
  return $status
}

notify_done make build

Already running? Wait for the PID

You started a backup 20 minutes ago and forgot the notification. Open a second terminal, find the process ID with pgrep -f backup.sh, and wait for it from there.

The bash builtin wait doesn't work for this: it only waits for children of the current shell. From another terminal it fails with wait: pid 12345 is not a child of this shell and exit status 127.

Use tail --pid=PID -f /dev/null from GNU coreutils, which exits as soon as that process is gone. Without GNU tail, poll with kill -0 in a loop. Neither way can see the other process's exit status, only that it ended.

tail --pid=12345 -f /dev/null; notify-send "Process 12345 ended"

while kill -0 12345 2>/dev/null; do sleep 5; done; notify-send "Process 12345 ended"

Terminal bell and macOS

If you only want the terminal to get your attention, printf '\a' rings the bell. What that does, a sound, a flashing tab or a dock badge, depends on your terminal settings. Because it is just a character in the output, it reaches your local window over SSH too.

macOS has no notify-send. Use osascript to show a Notification Center banner, or say to have the Mac read the result out loud.

./backup.sh; printf '\a'
./backup.sh; osascript -e 'display notification "Done" with title "backup.sh"'
./backup.sh; say "backup finished"

Over SSH: send it to your phone

On a remote server over plain SSH there is usually no notification service to talk to, so notify-send exits with status 1 and an error such as Failed to show notification: Cannot autolaunch D-Bus without X11 $DISPLAY.

Send the alert over HTTPS instead, and run long jobs inside tmux so a dropped connection doesn't kill the job before it reaches the notification. ntfy needs only curl and a topic name; topics on ntfy.sh are public and capped at 250 messages a day, so pick a long random name. A Discord webhook takes JSON with content up to 2,000 characters.

./backup.sh; curl -s -H "Title: backup.sh finished" -d "exit $?" ntfy.sh/your-long-random-topic

./backup.sh; status=$?
curl -s -H "Content-Type: application/json" \
  -d "{\"content\": \"backup.sh finished with exit $status\"}" \
  "$DISCORD_WEBHOOK_URL"

For a single Python script, run PYTHONUNBUFFERED=1 tqdml run -- python job.py so its output reaches the live page as it prints.

Which method works where