Golang flag.VisitAll() function example

package flag

VisitAll visits the command-line flags in lexicographical order, calling fn for each. It visits all flags, even those not set.

Golang flag.VisitAll() function usage example

 package main

 import (
 "flag"
 "fmt"
 )



 func main() {
 f := flag.NewFlagSet("flag", flag.ExitOnError)
 f.Int("int", 0, "int flag with value")
 f.Int("int2", 0, "second int flag with value")

 visitor := func(a *flag.Flag) {
 fmt.Println(">", a.Name, "value=", a.Value)
 }


 fmt.Println("First visit")
 f.Visit(visitor) // no value assigned

 f.Parse([]string{"-int", "108"}) // visit flag set earlier and assign value

 fmt.Println("Second visit")
 f.Visit(visitor)

 fmt.Println("Visit All")
 f.VisitAll(visitor) // this will display the int2 flag

 }

Output :

First visit

Second visit

> int value= 108

Visit All

> int value= 108

> int2 value= 0

See https://www.socketloop.com/references/golang-flag-visit-function-example for comparison

Reference :

http://golang.org/pkg/flag/#VisitAll