Home » Golang » Golang Programs

Golang program to print the value of environment variable using os.LookupEnv()

Here, we are going to learn how to print the value of environment variable using os.LookupEnv() in Golang (Go Language)?
Submitted by Nidhi, on April 20, 2021 [Last updated : March 05, 2023]

Printing the value of environment variable in Golang

Problem Solution:

In this program, we will use os.LookupEnv() function to get the value of specified environment variable. The os.LookupEnv() function returns two values first the value of the specified environment variable and the second is a Boolean value that specifies the given environment variable exists or not.

Program/Source Code:

The source code to print the value of the environment variable using os.LookupEnv() is given below. The given program is compiled and executed on the ubuntu 18.04 operating system successfully.

Golang code to print the value of environment variable

// Golang program to print the value of
// environment variable using os.LookupEnv()

package main

import "fmt"
import "os"

func main() {

	val, flag := os.LookupEnv("USER")

	if flag == true {
		fmt.Printf("Username: %s\n", val)
	} else {
		fmt.Printf("Specified environment variable does not exist\n")
	}
}

Output:

Username: Nidhi

Explanation:

In the above program, we declare the package main. The main package is used to tell the Go language compiler that the package must be compiled and produced the executable file. Here, we imported the "fmt" package to use the Printf() function and we also imported the "os" package to use the LookupEnv() function.

In the main() function, we got the username using the LookupEnv() function and printed the result on the console screen.