envmnt

Environment variables utility functions.

• Overview
• Usage
• Installation
• API Documentation
• Contributing
• Release History
• License

Overview

This library has many helper functions to access/modify/check environment variables.

Usage

Simply include the library and invoke the various utility functions.

Get/Set/Remove environment variables

use envmnt::{ExpandOptions, ExpansionType};

fn main() {
    if !envmnt::exists("MY_ENV_VAR") {
        envmnt::set("MY_ENV_VAR", "SOME VALUE");
    }

    let mut value = envmnt::get_or("MY_ENV_VAR", "DEFAULT_VALUE");
    println!("Env Value: {}", &value);

    value = envmnt::get_or_panic("MY_ENV_VAR");
    println!("Env Value: {}", &value);

    let pre_value = envmnt::get_set("MY_ENV_VAR", "SOME NEW VALUE");

    let value = envmnt::get_or("MY_ENV_VAR", "DEFAULT_VALUE");
    println!("New Env Value: {}", &value);
    println!("Previous Env Value: {:?}", &pre_value);

    let var_was_set = envmnt::set_optional("MY_ENV_VAR", &Some("OPTIONAL VALUE"));
    println!("Env Was Modified: {}", var_was_set);

    let all_vars = envmnt::vars(); // returned as Vec<(String, String)>

    for (key, value) in all_vars {
        println!("{}: {}", key, value);
    }

    envmnt::set("MY_ENV_VAR2", "SOME VALUE2");

    let value = envmnt::get_any(&vec!["MY_ENV_VAR1", "MY_ENV_VAR2"], "default");
    println!("MY_ENV_VAR1 exists: {}", envmnt::exists("MY_ENV_VAR1"));
    println!("MY_ENV_VAR2 exists: {}", envmnt::exists("MY_ENV_VAR2"));
    println!("Found value: {}", value);

    let mut options = ExpandOptions::new();
    options.expansion_type = Some(ExpansionType::Unix);
    let mut value = envmnt::expand("Env: MY_ENV value is: ${MY_ENV}", Some(options));
    println!("Expanded: {}", &value);
    options.expansion_type = Some(ExpansionType::UnixBracketsWithDefaults);
    value = envmnt::expand(
        "Env: MY_ENV_NOT_FOUND value is: ${MY_ENV_NOT_FOUND:default value}",
        Some(options),
    );
    println!("Expanded: {}", &value);
}

Get/Set boolean environment variables and other comparisons

fn main() {
    envmnt::set_bool("FLAG_VAR", true);
    let mut flag_value = envmnt::is_or("FLAG_VAR", false);
    println!("Bool Flag: {}", &flag_value);

    flag_value = envmnt::is("FLAG_VAR");
    assert!(flag_value);

    envmnt::set_bool("FLAG_VAR", true);
    assert!(envmnt::is_equal("FLAG_VAR", "true"));

    envmnt::set("MY_ENV_VAR", "SOME VALUE");
    let same = envmnt::is_equal("MY_ENV_VAR", "SOME VALUE");
    println!("Value Is Same: {}", &same);
    let mut contains = envmnt::contains("MY_ENV_VAR", "_ENV_");
    println!("Value Contained: {}", &contains);
    contains = envmnt::contains_ignore_case("MY_ENV_VAR", "_env_");
    println!("Value Contained (case insensitive): {}", &contains);
}

Get/Set numeric environment variables

fn main() {
    // all numeric data types: u8/i8/u16/i16/u32/i32/u64/i64/u128/i128/f32/f64/isize/usize
    // are supported by specific set/get functions.
    // get_parse can support parsing various data types beyond the simple numeric getters.
    envmnt::set_u8("U8_TEST_ENV", 50);
    let mut value_u8 = envmnt::get_u8("U8_TEST_ENV", 5);
    assert_eq!(value_u8, 50);
    value_u8 = envmnt::get_parse_or("U8_TEST_ENV", 5).unwrap();
    assert_eq!(value_u8, 50);

    envmnt::set_isize("ISIZE_TEST_ENV", -50);
    let mut value_isize = envmnt::get_isize("ISIZE_TEST_ENV", 5);
    assert_eq!(value_isize, -50);
    value_isize = envmnt::get_parse("ISIZE_TEST_ENV").unwrap();
    assert_eq!(value_isize, -50);

    // increment/decrement values
    value_isize = envmnt::increment("U8_TEST_ENV");
    assert_eq!(value_isize, 51);
    value_u8 = envmnt::get_u8("U8_TEST_ENV", 5);
    assert_eq!(value_u8, 51);
    value_isize = envmnt::decrement("U8_TEST_ENV");
    assert_eq!(value_isize, 50);
    value_u8 = envmnt::get_u8("U8_TEST_ENV", 5);
    assert_eq!(value_u8, 50);
}

Get/Set list environment variables

fn main() {
    envmnt::set_list(
        "LIST_TEST_ENV",
        &vec!["1".to_string(), "2".to_string(), "3".to_string()],
    );

    let mut values = envmnt::get_list("LIST_TEST_ENV").unwrap();
    println!("List Values: {:?}", values);

    let mut same = envmnt::is_equal("LIST_TEST_ENV", "1;2;3");
    println!("Same: {}", same);

    let mut options = envmnt::ListOptions::new();
    options.separator = Some(",".to_string());
    envmnt::set_list_with_options(
        "LIST_TEST_ENV",
        &vec!["1".to_string(), "2".to_string(), "3".to_string()],
        &options,
    );

    values = envmnt::get_list_with_options("LIST_TEST_ENV", &options).unwrap();
    println!("List Values: {:?}", values);

    same = envmnt::is_equal("LIST_TEST_ENV", "1,2,3");
    println!("Same: {}", same);
}

Bulk Operations

use indexmap::IndexMap;

fn main() {
    let mut env: IndexMap<String, String> = IndexMap::new();
    env.insert("ENV_VAR1".to_string(), "MY VALUE".to_string());
    env.insert("ENV_VAR2".to_string(), "MY VALUE2".to_string());

    envmnt::set_all(&env);

    let value = envmnt::get_or_panic("ENV_VAR1");
    println!("Value Is: {}", &value);

    let mut found = envmnt::is_any_exists(&vec!["ENV_VAR1", "ENV_VAR2"]);

    println!("Any Found: {}", &found);

    found = envmnt::is_all_exists(&vec!["ENV_VAR1", "ENV_VAR2"]);

    println!("All Found: {}", &found);

    envmnt::remove_all(&vec!["ENV_VAR1", "ENV_VAR2"]);

    found = envmnt::is_any_exists(&vec!["ENV_VAR1", "ENV_VAR2"]);

    println!("Any Found: {}", &found);

    env = IndexMap::new();
    env.insert("ENV_VAR1".to_string(), "MY VALUE".to_string());
    env.insert("ENV_VAR2".to_string(), "MY VALUE2".to_string());

    let eval_env = |key: String, value: String| {
        let mut updated_key = String::from("KEY-");
        updated_key.push_str(&key);
        let mut updated_value = String::from("VALUE-");
        updated_value.push_str(&value);
        Some((updated_key, updated_value))
    };

    envmnt::evaluate_and_set_all(&env, eval_env);

    let value = envmnt::get_or_panic("KEY-ENV_VAR1");
    println!("Value Is: {}", &value);
}

File Operations

fn main() {
    let mut output = envmnt::load_file("./src/test/var.env");
    assert!(output.is_ok());

    let eval_env = |key: String, value: String| {
        let mut updated_key = String::from("KEY-");
        updated_key.push_str(&key);
        let mut updated_value = String::from("VALUE-");
        updated_value.push_str(&value);
        Some((updated_key, updated_value))
    };

    output = envmnt::evaluate_and_load_file("./src/test/var.env", eval_env);
    assert!(output.is_ok());
}

Installation

In order to use this library, just add it as a dependency:

[dependencies]
envmnt = "^0.10.4"

API Documentation

See full docs at: API Docs

Contributing

See contributing guide

Release History

See Changelog

License

Developed by Sagie Gur-Ari and licensed under the Apache 2 open source license.