# Bash environment for Nushell

Historically Bash environment for Nushell was provided via the `nu_plugin_bash_env` plugin in this repo.

That plugin is now deprecated in favour of the `bash-env` module, which is more feature rich and also embarrassingly simpler than the plugin.

## bash-env module

### Examples

#### Simple Usage
```
> bash-env ./tests/simple.env
╭───┬───╮
│ B │ b │
│ A │ a │
╰───┴───╯
> echo $env.A
Error: nu::shell::column_not_found

  × Cannot find column 'A'
   ╭─[entry #77:1:6]
 1 │ echo $env.A
   ·      ───┬──┬
   ·         │  ╰── value originates here
   ·         ╰── cannot find column 'A'
   ╰────

> bash-env ./tests/simple.env | load-env
> echo $env.A
a
> echo $env.B
b


> bash-env tests/simple.env
╭──────────────╮
│ empty record │
╰──────────────╯

# no new or changed environment variables, so nothing returned

> ssh-agent | bash-env
╭───────────────┬─────────────────────────────────────╮
│ SSH_AUTH_SOCK │ /tmp/ssh-XXXXXXOjZtSh/agent.1612713 │
│ SSH_AGENT_PID │ 1612715                             │
╰───────────────┴─────────────────────────────────────╯
```

#### Shell Variables

Rather than folding shell variables in with the environment variables as was done by the plugin, the `-s` or `--shellvars` option results in structured output with separate `env` and `shellvars`.

```
> echo "ABC=123" | bash-env
╭──────────────╮
│ empty record │
╰──────────────╯

> echo "ABC=123" | bash-env -s
╭───────────┬───────────────────╮
│ env       │ {record 0 fields} │
│           │ ╭─────┬─────╮     │
│ shellvars │ │ ABC │ 123 │     │
│           │ ╰─────┴─────╯     │
╰───────────┴───────────────────╯
> (echo "ABC=123" | bash-env -s).shellvars
╭─────┬─────╮
│ ABC │ 123 │
╰─────┴─────╯

> bash-env /etc/os-release
╭──────────────╮
│ empty record │
╰──────────────╯

> (bash-env /etc/os-release -s).shellvars
╭───────────────────┬─────────────────────────────────────────╮
│ LOGO              │ nix-snowflake                           │
│ NAME              │ NixOS                                   │
│ BUG_REPORT_URL    │ https://github.com/NixOS/nixpkgs/issues │
│ HOME_URL          │ https://nixos.org/                      │
│ VERSION_CODENAME  │ vicuna                                  │
│ ANSI_COLOR        │ 1;34                                    │
│ ID                │ nixos                                   │
│ PRETTY_NAME       │ NixOS 24.11 (Vicuna)                    │
│ DOCUMENTATION_URL │ https://nixos.org/learn.html            │
│ SUPPORT_URL       │ https://nixos.org/community.html        │
│ IMAGE_ID          │                                         │
│ VERSION_ID        │ 24.11                                   │
│ VERSION           │ 24.11 (Vicuna)                          │
│ IMAGE_VERSION     │                                         │
│ BUILD_ID          │ 24.11.20240916.99dc878                  │
╰───────────────────┴─────────────────────────────────────────╯
```

### Shell Functions

Shell functions may be run and their effect on the environment captured.

```
> cat ./tests/shell-functions.env
export A=1
export B=1

function f2() {
        export A=2
        export B=2
        C2="I am shell variable C2"
}

function f3() {
        export A=3
        export B=3
        C3="I am shell variable C3"
}
> bash-env ./tests/shell-functions.env
╭───┬───╮
│ B │ 1 │
│ A │ 1 │
╰───┴───╯
> bash-env -f [f2 f3] ./tests/shell-functions.env
╭───────────┬──────────────────────────────────────────────────────────╮
│           │ ╭───┬───╮                                                │
│ env       │ │ B │ 1 │                                                │
│           │ │ A │ 1 │                                                │
│           │ ╰───┴───╯                                                │
│ shellvars │ {record 0 fields}                                        │
│           │ ╭────┬─────────────────────────────────────────────────╮ │
│ fn        │ │    │ ╭───────────┬─────────────────────────────────╮ │ │
│           │ │ f2 │ │           │ ╭───┬───╮                       │ │ │
│           │ │    │ │ env       │ │ B │ 2 │                       │ │ │
│           │ │    │ │           │ │ A │ 2 │                       │ │ │
│           │ │    │ │           │ ╰───┴───╯                       │ │ │
│           │ │    │ │           │ ╭────┬────────────────────────╮ │ │ │
│           │ │    │ │ shellvars │ │ C2 │ I am shell variable C2 │ │ │ │
│           │ │    │ │           │ ╰────┴────────────────────────╯ │ │ │
│           │ │    │ ╰───────────┴─────────────────────────────────╯ │ │
│           │ │    │ ╭───────────┬─────────────────────────────────╮ │ │
│           │ │ f3 │ │           │ ╭───┬───╮                       │ │ │
│           │ │    │ │ env       │ │ B │ 3 │                       │ │ │
│           │ │    │ │           │ │ A │ 3 │                       │ │ │
│           │ │    │ │           │ ╰───┴───╯                       │ │ │
│           │ │    │ │           │ ╭────┬────────────────────────╮ │ │ │
│           │ │    │ │ shellvars │ │ C3 │ I am shell variable C3 │ │ │ │
│           │ │    │ │           │ ╰────┴────────────────────────╯ │ │ │
│           │ │    │ ╰───────────┴─────────────────────────────────╯ │ │
│           │ ╰────┴─────────────────────────────────────────────────╯ │
╰───────────┴──────────────────────────────────────────────────────────╯

> (bash-env -f [f2 f3] ./tests/shell-functions.env).fn.f2.env
╭───┬───╮
│ B │ 2 │
│ A │ 2 │
╰───┴───╯
> (bash-env -f [f2 f3] ./tests/shell-functions.env).fn.f2.env | load-env
> echo $env.B
2

```

### Installation

Download the module, and add to `config.nu`:

```
use /path/to/bash-env.nu
```

In contrast to the plugin, the module requires [`bash-env-json`](https://github.com/tesujimath/bash-env-json) to be separately downloaded and installed as an executable on the `$PATH`.

## nu_plugin_bash_env (deprecated)

The plugin is unlikely to be maintained beyond the next plugin protocol change in Nushell.  It is recommended to switch to the `bash-env` module instead.

For instructions on how to use this plugin, see the [Nushell book](https://www.nushell.sh/book/plugins.html).

In summary, build the crate and add the resulting `nu_plugin_bash_env` executable as a plugin using `plugin add`, then `plugin use`.

For users of Nix, this is now installable as a flake (see below).

The plugin reads the specified environment file (if any) and evaluates variables from `stdin` (if any) and returns any new or changed environment variables as a record, suitable for passing to Nu's `load-env`.

### Plugin Version Compatability

Since Nushell 0.91.0 the plugin protocol was enhanced and now requires version compatability between plugins and Nushell itself.

The following versions are compatible.

| Nushell | bash-env plugin |
| ------- | --------------- |
|    0.89 |           0.5.0 |
|    0.90 |           0.5.0 |
|    0.91 |           0.6.2 |
|    0.92 |           0.7.1 |
|    0.93 |           0.8.0 |
|    0.93 |           0.9.0 |
|    0.94 |          0.10.0 |
|    0.95 |          0.11.0 |
|    0.96 |          0.12.1 |
|    0.97 |          0.13.0 |
|    0.98 |          0.14.2 |
|    0.98 |          0.15.1 |
|    0.99 |          0.16.1 |
|   0.100 |          0.17.3 |

If you find a new version of Nushell rejects this plugin as incompatible, please report an [issue](https://github.com/tesujimath/nu_plugin_bash_env/issues).

### Dependencies

The script uses `jq` for output formatting. Previous versions required at least `jq` version `1.7`, but that may be no longer the case.

Also I suspect at least Bash version `5.1`.

Since version `0.15.0`, this plugin uses [`bash-env-json`](https://github.com/tesujimath/bash-env-json) instead of the previously bundled `bash_env.sh` script.  However, this is fetched and embedded at build time, so there is no difference at runtime.

### Examples

#### Simple Usage
```
> bash-env tests/simple.env
╭───┬───╮
│ B │ b │
│ A │ a │
╰───┴───╯

> echo $env.A
Error: nu::shell::name_not_found

  × Name not found


> bash-env tests/simple.env | load-env

> echo $env.A
a
> echo $env.B
b


> bash-env tests/simple.env
╭──────────────╮
│ empty record │
╰──────────────╯

# no new or changed environment variables, so nothing returned

> ssh-agent | bash-env
Agent pid 98985
╭───────────────┬───────────────────────────────────╮
│ SSH_AUTH_SOCK │ /tmp/ssh-XXXXXXFIMT9y/agent.98982 │
│ SSH_AGENT_PID │ 98985                             │
╰───────────────┴───────────────────────────────────╯
```

#### Exporting Shell Variables

The plugin supports `--export` for exporting shell variables into the environment.

```
> echo "ABC=123" | bash-env
╭──────────────╮
│ empty record │
╰──────────────╯

> echo "export ABC=123" | bash-env
╭─────┬─────╮
│ ABC │ 123 │
╰─────┴─────╯

> echo "ABC=123" | bash-env --export [ABC]
╭─────┬─────╮
│ ABC │ 123 │
╰─────┴─────╯

> bash-env /etc/os-release
╭──────────────╮
│ empty record │
╰──────────────╯

> bash-env --export [ID PRETTY_NAME] /etc/os-release
╭─────────────┬──────────────────────╮
│ ID          │ nixos                │
│ PRETTY_NAME │ NixOS 24.05 (Uakari) │
╰─────────────┴──────────────────────╯
```

#### Escaping Special Characters

Care has been taken to escape any special characters.

```
> bash-env `tests/Ming's "menu" of (merciless) monstrosities.env`
╭───────────┬──────────────────────────────────────────────────────╮
│ QUOTE     │ "Well done!" is better than "Well said!"             │
│ SPACEMAN  │ One small step for a man ...                         │
│ MIXED_BAG │ Did the sixth sheik's sixth sheep say "baa", or not? │
╰───────────┴──────────────────────────────────────────────────────╯

> bash-env `tests/Ming's "menu" of (merciless) monstrosities.env` | load-env
> echo $env.QUOTE
"Well done!" is better than "Well said!"
```

### Implementation

Prior to 0.13.0 this plugin was written in Bash, with the Nu plugin protocol done by hand using `jq`, with insights from the [api](api) sub-directory which contained a Rust program to produce what is required, using the official Nu plugin library.  This was too onerous to maintain through the evolution of the protocol, so was abandoned.

Since 0.13.0, the plugin is written in Rust, with the much simplified Bash script embedded.

By default the embedded Bash script is extracted at runtime into a temporary directory.  This behaviour may be overridden by setting the ``NU_PLUGIN_BASH_ENV_JSON` environment variable, which is then expected to resolve to the path of the pre-installed script.

### Logging

Logging is supported via the Rust `tracing-subscriber` crate, with log-level defined by the environment variable `NU_PLUGIN_BASH_ENV_LOG`.

## Nix flake

Both the module and the plugin are installable from its flake using Nix Home Manager.

See my own [Home Manager flake](https://github.com/tesujimath/home.nix/blob/main/flake.nix#L12) and [nushell module](https://github.com/tesujimath/home.nix/blob/main/modules/nushell/default.nix) for hints how to achieve this.  Note in particular the requirement for [each-time plugin registration](https://github.com/tesujimath/home.nix/blob/main/modules/nushell/config.nu#L761).

## Future work

- unsetting an environment variable ought to be possible