set_environment_variable.rs

use std::env;
use std::path::Path;
use std::error::Error;
use std::fs;

fn set_env(filename: String) -> Result<(), Box<dyn Error>> {
  
  let data = fs::read_to_string(Path::new(&filename))?;
  for x in data.split("\n") {
    let v = x.split("=").collect::<Vec<&str>>();
    println!("Setting {} to {}", v[0], v[1]);
    env::set_var(v[0], v[1]);
  };
  
  Ok(())
}

This gist showcases how environment variables can be set in the process. The env variables which are set are temporal and will be erased once the program concludes. Use cases for this include reading from .env files in the project root in projects involving web-development, game development and CLI programming.