tenv (temporary environment)

Small CLI app for running commands with temporary environment variables. Super useful on Windows/Powershell where you can't easily set temp variables inline with command being run.

Installation

Install from http://crates.io via cargo

cargo install --locked tenv

Install from source

cargo install --path .

Arg Files

Supports argfiles. see example.tenv for an example. Can be used to set up an environment across multiple projects. For instance here's one that sets up a flutter environment:

# Flutter
-p C:\dev\flutter\bin
# Android SDK Locations
-e ANDROID_SDK_ROOT=C:\Users\user1\AppData\Local\Android\Sdk
-e ANDROID_NDK_ROOT=$ANDROID_SDK_ROOT\ndk\25.0.8775105
# Android SDK binaries
-p $ANDROID_SDK_ROOT\tools\bin
-p $ANDROID_SDK_ROOT\emulator

# Spawn bash shell with flutter environment
tenv @flutter.tenv bash

# Spawn new powersehll with flutter environment (Need to escape @ in powershell with `)
tenv `@flutter.tenv powershell

Uses

Running commands

Bash

# Add ~/hugo to PATH and run `hugo` program
tenv -p ~/hugo hugo

Powershell

# Add C:\dev\hugo to PATH and run `hugo` program
tenv -p C:\dev\hugo hugo

Especially useful for RUST_BACKTRACE on Powershell

tenv -e RUST_BACKTRACE=1 "cargo run"

Shell environment

Bash

# spawn new bash shell with env vars APPLES="Red" and BANANAS="Yellow"
tenv -e APPLES=Red -e BANANAS=Yellow bash

Powershell

<# spawn new Powershell with env vars APPLES="Red" and BANANAS="Yellow" #>
tenv -e APPLES=Red -a BANANAS=Yellow powershell

Caveat

Because some shell commands aren't directly callable from Command::new() (i.e. the cat alias on Powershell), tenv runs programs directly through powershell on Windows and bash otherwise.