From 7c7d720f8e9f3bdc53f5d189787d90f055fa4602 Mon Sep 17 00:00:00 2001
From: Valerie Wolfe <sleeplessval@gmail.com>
Date: Mon, 8 Jul 2024 10:12:46 -0400
Subject: [PATCH] env-share: initial implementation

---
 env-share/.gitignore            |  2 ++
 env-share/Cargo.toml            |  8 ++++++++
 env-share/scripts/env-share.ps1 | 18 ++++++++++++++++++
 env-share/src/error.rs          | 18 ++++++++++++++++++
 env-share/src/main.rs           | 31 +++++++++++++++++++++++++++++++
 man/env-share.1                 | 30 ++++++++++++++++++++++++++++++
 6 files changed, 107 insertions(+)
 create mode 100644 env-share/.gitignore
 create mode 100644 env-share/Cargo.toml
 create mode 100644 env-share/scripts/env-share.ps1
 create mode 100644 env-share/src/error.rs
 create mode 100644 env-share/src/main.rs
 create mode 100644 man/env-share.1

diff --git a/env-share/.gitignore b/env-share/.gitignore
new file mode 100644
index 0000000..96ef6c0
--- /dev/null
+++ b/env-share/.gitignore
@@ -0,0 +1,2 @@
+/target
+Cargo.lock
diff --git a/env-share/Cargo.toml b/env-share/Cargo.toml
new file mode 100644
index 0000000..91f0407
--- /dev/null
+++ b/env-share/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "env-share"
+version = "0.0.1"
+edition = "2021"
+
+[dependencies]
+pico-args = "0.5.0"
+
diff --git a/env-share/scripts/env-share.ps1 b/env-share/scripts/env-share.ps1
new file mode 100644
index 0000000..87fdf9c
--- /dev/null
+++ b/env-share/scripts/env-share.ps1
@@ -0,0 +1,18 @@
+
+#	make sure the file exists
+$file = $env:ENV_SHARE_FILE
+if -not (Test-Path $file) {
+	exit
+}
+
+#	insert values into env
+foreach($line in Get-Content $file) {
+	$parts = $line -split ' = '
+	$var = $parts[0]
+	$value = $parts[1]
+	Set-Item env:$var -Value $value
+}
+
+#	delete the file
+Remove-Item $file
+
diff --git a/env-share/src/error.rs b/env-share/src/error.rs
new file mode 100644
index 0000000..a073c47
--- /dev/null
+++ b/env-share/src/error.rs
@@ -0,0 +1,18 @@
+use std::process::exit;
+
+pub fn file_unset() {
+	println!("env-share: ENV_SHARE_FILE is unset");
+	exit(1);
+}
+
+pub fn vars_unset() {
+	println!("env-share: ENV_SHARE_VARS is unset");
+	exit(1);
+}
+
+
+pub fn write_fail(file: &String) {
+	println!("env-share: failed to write to '{file}'");
+	exit(2);
+}
+
diff --git a/env-share/src/main.rs b/env-share/src/main.rs
new file mode 100644
index 0000000..a925ee3
--- /dev/null
+++ b/env-share/src/main.rs
@@ -0,0 +1,31 @@
+use std::{
+	env,
+	fs::write
+};
+
+mod error;
+
+fn main() {
+	//	try to get share file variable
+	if let Ok(file) = env::var("ENV_SHARE_FILE") {
+		if let Ok(var_string) = env::var("ENV_SHARE_VARS") {
+			//	build output
+			let mut output = String::new();
+			let vars = var_string.split(':');
+			for var in vars {
+				let value = env::var(var).unwrap_or(String::new());
+				if value.is_empty() { continue; }
+
+				output += &format!("{var} = {value}\n");
+			}
+
+			//	write to file
+			let result = write(&file, output);
+			match result {
+				Err(_)	=>	error::write_fail(&file),
+				_		=>	{ }
+			}
+		} else { error::vars_unset(); }
+	} else { error::file_unset(); }
+}
+
diff --git a/man/env-share.1 b/man/env-share.1
new file mode 100644
index 0000000..607b6d3
--- /dev/null
+++ b/man/env-share.1
@@ -0,0 +1,30 @@
+.Dd $Mdocdate$
+.Dt ENV-SHARE 1
+.Os
+.Sh NAME
+.Nm env-share
+.Nd share environment variables back to Windows from WSL
+.Sh SYNOPSIS
+.Nm env-share
+.Sh DESCRIPTION
+The
+.Nm
+utility writes environment variables to a file to be loaded by a script in the target process.
+.Sh ENVIRONMENT
+.Bl -tag -width Ds
+.It Ev ENV_SHARE_FILE
+The file to write variables to.
+.It Ev ENV_SHARE_VARS
+A colon-separated list of variables to copy.
+.El
+.Sh EXIT STATUS
+.Bl -tag -width Ds
+.It 1
+An environment variable is unset.
+.It 2
+Failed to write to the file at
+.Ev ENV_SHARE_FILE
+.El
+.Sh AUTHORS
+.An -nosplit
+.An Valerie Wolfe Aq Mt sleeplessval@gmail.com