Golang : Get command line arguments



Tags : golang flag os

Basically there are two ways to get arguments from the command line in Go.

The first way is via the flag package

flag.go

 package main

  import (
 "flag"
 "fmt"
  )

  func main() {
 flag.Parse() // get the arguments from command line

 arg := flag.Arg(0) // get the source directory from 1st argument

 fmt.Println("The first argument is " + arg)
 }

the output :

go run flag.go here

The first argument is here

go run flag.go there

The first argument is there

The second way is via the os package

osarg.go

 package main

 import (
 "os"
 "fmt"
 )

 func main () {


 if len(os.Args) != 3 {
 fmt.Printf("Usage : %s argument1 argument2 \n ", os.Args[0]) // return the program name back to %s
 os.Exit(1) // graceful exit
 }

 fmt.Println("First argument is : " + os.Args[1] + "\n")
 fmt.Println("Second argument is : " + os.Args[2] + "\n")
 }

Ok, this should cover the needs to get arguments from command line. Did I miss anything ? Leave your comment below.

  See also : Golang : Check if a directory exist or not



Tags : golang flag os

By Adam Ng

IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.


Advertisement