env-var

提供更容易访问Rust中环境变量的宏。

许可证

env-var在Apache License，版本2.0和MIT许可证下双许可。

用法

将以下内容放入您的Cargo.toml

[dependencies]
env-var = "1"
log = "0.4"

示例

#[macro_use]
extern crate env_var;

fn main() {
  // retrieving a optional value
  // var1 either contains the value or an empty string
  let var1 = env_var!(optional "TEST_OPT_1");

  // retrieving a optional value with default
  // var1 either contains the value or "default1"
  let var1 = env_var!(optional "TEST_OPT_1", default: "default1");

  // retrieving a optional value with default
  // if not found, the message will be logged as info message
  // var1 either contains the value or "default1"
  let var1 = env_var!(optional "TEST_OPT_1", default: "default1", msg: "using default");

  // retrieving a required value
  // var1 either contains the value or the programm panics
  let var1 = env_var!(required "TEST_OPT_1");

  // retrieving a required value with default
  // var1 either contains the value or "default1"
  let var1 = env_var!(required "TEST_OPT_1", default: "default1");

  // retrieving a required value with default
  // if not found, the message will be logged as warn message
  // var1 either contains the value or "default1"
  let var1 = env_var!(required "TEST_OPT_1", default: "default1", msg: "using default");

}