tenenv

tenenv (Japanese 点 + env) is a dotenv CLI that loads a .env file and runs a command with those environment variables set.

tenenv [OPTIONS] [--] COMMAND [ARGS...]

Installation

Via Cargo

If you have Rust installed, install tenenv from crates.io:

cargo install tenenv

Via mise

If you use mise, install tenenv as a global tool (downloads a pre-built binary from GitHub releases):

mise use -g github:dahlia/tenenv

Binary releases

Pre-built binaries for Linux (x86_64, aarch64), macOS (x86_64, aarch64), and Windows (x86_64, aarch64) are available on the releases page.

From source

Clone the repository and build with Cargo:

cargo build --release

The binary is placed at target/release/tenenv.

Usage

tenenv [OPTIONS] [--] COMMAND [ARGS...]

Options:

Without --strict, a missing env file produces a warning on stderr and the command runs with the unmodified environment.

Without --override, variables already set in the environment take priority over definitions in the env file. When the same key appears more than once in the file, the last definition wins.

On Unix, tenenv replaces its own process image with the command (execvp), so the command appears directly in the process list and inherits signals properly. On other platforms, tenenv spawns a child process and waits for it to finish.

Exit status: tenenv exits with the same code as the command. If the command is not found, it exits 127; if the command is found but not executable (Unix only), it exits 126.

Examples

Run a server with production settings:

tenenv -f .env.production -- node server.js

Override an already-set variable for a single invocation:

tenenv --override -- cargo test

Use a strict mode to catch a missing env file in CI:

tenenv --strict -f /etc/app/.env -- ./start.sh

Env file format

tenenv supports a subset of POSIX shell variable assignment syntax.

Basic assignments

Variable names must start with an ASCII letter or underscore, followed by ASCII letters, digits, or underscores.

HOST=localhost
PORT=5432
_PRIVATE=value

Bare (unquoted) values may not contain spaces, tabs, or other whitespace. Use quoting for values that contain whitespace or shell metacharacters. NUL bytes (\0) in values are a parse error.

Comments

Lines starting with # are comments. An inline comment can follow a value if it is preceded by whitespace:

HOST=localhost  # this is a comment
PORT=5432#this is NOT a comment; the hash is part of the value

The export keyword

The export prefix is accepted and ignored (all loaded variables are exported to the child process):

export HOST=localhost

Quoting

Single quotes preserve the literal value of every character inside them. No escape sequences are processed:

MSG='hello $USER'  # value is:  hello $USER

Double quotes support escape sequences and variable expansion. The recognised escape sequences are \", \\, \$, and \`. A backslash at the end of a line inside double quotes continues the string on the next physical line (the backslash and newline are removed):

GREETING="hello \"world\""
MULTILINE="first line\
second line"

Any other \X sequence inside double quotes is a parse error.

Variable expansion

Inside double-quoted values, $VAR and ${VAR} are expanded. Variables defined earlier in the same file take priority over the current environment. If a variable is not defined anywhere, it expands to an empty string:

BASE=/opt/app
DATA="${BASE}/data"       # expands to /opt/app/data
MISSING="${UNDEFINED}x"   # expands to x

A bare $ not followed by a letter or underscore is treated literally:

PRICE="$100"  # value is:  $100

License

Copyright (C) Hong Minhee and contributors.

tenenv is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

See the LICENSE file for the full license text.