Golang : Get absolute path to binary for os.Exec function with exec.LookPath

Sometimes it is good to tell our Golang program to execute exactly which binary file based on the path. For instance, there will be situation where due to poor system administration on client's machine....possible...duplicate binaries might caused unwanted/weird result due to different versions.

Before we can execute a binary with os.Exec(), Go needs to know the absolute path to the binary. This can be accomplish with the exec.LookPath() function.

If the path returned by exec.LookPath() function is not what you after, then you want to change the path variable before executing.

For example :

 package main

 import (
 "fmt"
 "os/exec"
 )

 func main() {
 path, err := exec.LookPath("dig")

 if err != nil {
 panic(err)
 }

 fmt.Println("Will be executing the binary at :", path)

 // if path is not what you after, assign new string value to path

 cmd := exec.Command(path, "any", "google.com")

 out, err := cmd.Output()

 if err != nil {
 fmt.Println(err.Error())
 return
 }

 fmt.Print(string(out))
 }

Sample output :

Will be executing the binary at : /usr/bin/dig

Reference :

http://golang.org/pkg/os/exec/#LookPath