Mastering Go - Second Edition

From flag to viper

There is a chance that you have a Go program that already uses the flag package and that you want to convert to using the viper package. Let us say that we have the following Go code that uses the flag package:

package main 
 
import ( 
    "flag" 
    "fmt" 
) 
 
func main() { 
    minusI := flag.Int("i", 100, "i parameter") 
    flag.Parse() 
    i := *minusI 
    fmt.Println(i) 
} 

The new version of that program, which is going to be saved in flagToViper.go, is going to use the viper package and will be presented in three parts. The first part of flagToViper.go is as follows:

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

You will need to import the pflag package in order to work with command-line arguments in