Mastering Go - Second Edition

A simple viper example

Before going into more advanced examples, I will present some sample Go code that uses viper. The name of the program is usingViper.go and it will be presented in three parts.

The first part of useViper.go is as follows:

package main 
 
import ( 
    "fmt" 
    "github.com/spf13/viper" 
) 

The second part of useViper.go is as follows:

func main() { 
    viper.BindEnv("GOMAXPROCS") 
    val := viper.Get("GOMAXPROCS") 
    fmt.Println("GOMAXPROCS:", val) 
    viper.Set("GOMAXPROCS", 10) 
    val = viper.Get("GOMAXPROCS") 
    fmt.Println("GOMAXPROCS:", val) 

The last part of useViper.go contains the following Go code:

 viper.BindEnv("NEW_VARIABLE") val = viper.Get("NEW_VARIABLE") if val == nil { fmt.Println("NEW_VARIABLE not defined.") return } fmt.Println(val) ...