how do I create multiple CRON function by looping through a list


import (
    "fmt"

    "gopkg.in/robfig/cron.v3"
)

func test(x int) {
    fmt.Println("acessesing device", x)
}
func main() {
    c := cron.New()
    x := make(chan bool)
    devices := [10]int{1,2,3,4,5,6,7,8,9,10}
    for _, va := range devices {
        c.AddFunc("@every 30s", func() { test(va) })
    }

    c.Start()
    <-x
}

output got by the above program:

acessesing gateway 13

I like run the same function with different input

Expected output for every 30s

acessesing gateway 1

acessesing gateway 2

acessesing gateway 3

acessesing gateway 4

acessesing gateway 5

acessesing gateway 6

acessesing gateway 7

acessesing gateway 8

acessesing gateway 9

acessesing gateway 10

Solution

Problem in your code is equivalent to the one described here:

https://github.com/golang/go/wiki/CommonMistakes#using-goroutines-on-loop-iterator-variables

To fix it:

for _, va := range devices {
    va := va // create a new "va" variable on each iteration
    c.AddFunc("@every 30s", func() { test(va) })
}