Macro_env：环境变量搜索crate

Macro_env是一个用于查找环境变量的crate。
最初设计用于轻松地从不同位置获取环境变量，而无需更改大量代码。
只需更改宏或函数中的SearchType，就可以从不同位置获取变量。

使用方法

首先添加

[dependencies]
macro_env = "0.1.*"

宏

// Import the crate, importing the whole crate is the easiest
// You can also manually import the function you need, for .env search for example:
// `use macro_env::{dotenvreader, macro_env};`
use macro_env::*;

// Fetch the environment variable "OS" from the .env file at the cargo.toml level
macro_env!(File, "OS");

// Fetch the environment variable "OS" from the system environment variables
macro_env!(System, "OS");

// Asks the user for enter the input through the terminal
macro_env!(Input);

// All, without specifying the searchtype, will try to find the variable through all 3 methods:
// First it checks for a .env file
// Then by searching for a system variable
// And if both fail, it will ask the user for input
macro_env!(All, "OS");
macro_env!("OS");

EnvSeeker()

use macro_env::*;
use macro_env::SearchType::*;
// You can use envseeker() when you prefer using a function over a macro
envseeker(Envfile, "OS")