What's Go's equivalent of argv[0]?

Question

How can I get my own program's name at runtime? What's Go's equivalent of C/C++'s argv[0]? To me it is useful to generate the usage with the right name.

Update: added some code.

package main  import (     "flag"     "fmt"     "os" )  func usage() {     fmt.Fprintf(os.Stderr, "usage: myprog [inputfile]\n")     flag.PrintDefaults()     os.Exit(2) }  func main() {     flag.Usage = usage     flag.Parse()      args := flag.Args()     if len(args) < 1 {         fmt.Println("Input file is missing.");         os.Exit(1);     }     fmt.Printf("opening %s\n", args[0]);     // ... } 

Answer 1

import "os" os.Args[0] // name of the command that it is running as os.Args[1] // first command line parameter, ... 

Arguments are exposed in the os package http://golang.org/pkg/os/#Variables

If you're going to do argument handling, the flag package http://golang.org/pkg/flag is the preferred way. Specifically for your case flag.Usage

Update for the example you gave:

func usage() {     fmt.Fprintf(os.Stderr, "usage: %s [inputfile]\n", os.Args[0])     flag.PrintDefaults()     os.Exit(2) } 

should do the trick

Answer 2

use os.Args[0] from the os package

package main import "os" func main() {     println("I am ", os.Args[0]) }