rustWhat is an environment variable in Rust?

An environment variable in Rust is a global variable that can be accessed from any part of the program. It is used to store information that can be used by multiple parts of the program. Environment variables are set using the std::env::set_var function.

Example code

use std::env;

fn main() {
    env::set_var("MY_VAR", "my_value");
    println!("MY_VAR is set to: {}", env::var("MY_VAR").unwrap());
}

Output example

MY_VAR is set to: my_value

Code explanation

1. use std::env;: This imports the env module from the std library, which provides functions for setting and getting environment variables.
2. env::set_var("MY_VAR", "my_value");: This sets the environment variable MY_VAR to the value my_value.
3. env::var("MY_VAR").unwrap();: This retrieves the value of the environment variable MY_VAR. The unwrap() function is used to convert the Option type returned by env::var into a String.

Helpful links

• std::env

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