making multiple functions work at the same time using conccurent programming

I started learning about concurrency in Go and after reading some examples i wanted to Try A system in which every second the current time will be printed out in terminal and in every moment user can input any text in terminal and the same text will be printed out in the terminal(or we can do any other stuff like if only a specific text was written that would be printed out). and basically I came up with this form to write my code:

• ShowTime: function to prints out time every second
• GetInput: function to check for user input and if the input was not empty get its value and pour it into a variable that another function is going to read
• ShowInput: function to read from a value and( if the value was not empty )
• If "done" was written in the inputs the program will end and everything will be stopped

right now i came up with this solution but i get error after putting in an input:
Code:

package main

import (
	"fmt"
	"sync"
	"time"
)

func getInputs(ch chan<- string, wg *sync.WaitGroup) {
	defer wg.Done()

	var input string
	for input != "done" {
		fmt.Scanln(&input)
		if input != "" {
			ch <- input
		}
	}
}

func showInputs(ch <-chan string, wg *sync.WaitGroup) {
	defer wg.Done()

	var msg string

	for msg != "done" {
		msg = <-ch
		if msg == "dog" {
			fmt.Println("YEP thats a dog!")
		}
	}
}

func showTime(ch <-chan string, wg *sync.WaitGroup) {
	defer wg.Done()

	var msg string
	for msg != "done" {
		msg = <-ch
		currentTime := time.Now()
		fmt.Println(currentTime.String())
		time.Sleep(time.Second)
	}
}

func main() {
	var wg sync.WaitGroup
	inChan := make(chan string)

	wg.Add(3)
	go showTime(inChan, &wg)
	go showInputs(inChan, &wg)
	go getInputs(inChan, &wg)

	close(inChan)

	wg.Wait()
	fmt.Println("The End!")
}

Error:

2022-07-07 22:40:10.928195762 +0430 +0430 m=+0.000087833
2022-07-07 22:40:11.928359701 +0430 +0430 m=+1.000251851
2022-07-07 22:40:12.928442575 +0430 +0430 m=+2.000334715
5
panic: send on closed channel
goroutine 8 [running]:
main.getInputs(0x0?, 0x0?)
/mnt/d/GoLang/BlackHat/lab/multifunc/main.go:16 +0xef
created by main.main
/mnt/d/GoLang/BlackHat/lab/multifunc/main.go:53 +0x14d
exit status 2

Would appreciate the help :))

The problem is that you close inChan shortly after (or even before, depending on the scheduler) your goroutines start running and reading/writing from it.

Typically, it would be best if the sending goroutine would close the channel when it's done, or some other coordination mechanism. For example, your getInputs function could close the channel when it gets a "done" input, before returning.

Another issue in your code is that showTime receives from the channel as well. Note that this will consume a message from the channel which can be missed by another goroutine waiting for the same message. Look up channel "fan in, fan out" patterns for how to address this.