The program sleeps for a specified time, and send a system notification.
Send a system-wide notification after a countdown
USAGE:
countdown [FLAGS] <time> [text]
ARGS:
<time> A float number for the countdown, unit being second, unless --minute is specified.
<text> A short message to show in the notification. [default: Timer]
FLAGS:
-h, --help Prints help information
-m, --minute Change the unit of time to minute, instead of second.
-V, --version Prints version information