Timer in Golang

Goal

This project is a command-line timer written in Golang.
The program starts a countdown from a number of seconds given as an argument, then displays the remaining time every second until it reaches zero.

What I used

• fmt for displaying the timer
• os for reading command-line arguments and exiting on error
• strconv for converting the argument to an integer
• time for handling the countdown
• loops and integers to make the timer work

You need Golang

If you do not have Golang installed, run:

sudo apt update
sudo apt install golang-go

How to use it

Run the program with one argument:

go run . <seconds>

• <seconds>: number of seconds for the timer, must be a strictly positive integer

Example

go run . 5

You should see something like:

Timer: 5s
Timer: 4s
Timer: 3s
Timer: 2s
Timer: 1s
Timer: 0s

Error handling

If you provide an invalid argument, the program prints an error message and exits.

Examples of invalid input:

go run .
go run . abc
go run . 0
go run . -3

Notes

• The timer decreases by one second on each loop.
• The program expects exactly one argument.
• The value must be a positive non-zero integer.

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Enjoy using the timer!