feat(env): Allow exporting env vars as dotenv format

docs/cli/env.md

@@ -1,6 +1,6 @@
 # `mise env`
 
-- **Usage**: `mise env [-J --json] [-s --shell <SHELL>] [TOOL@VERSION]...`
+- **Usage**: `mise env [FLAGS] [TOOL@VERSION]...`
 - **Aliases**: `e`
 - **Source code**: [`src/cli/env.rs`](https://github.com/jdx/mise/blob/main/src/cli/env.rs)
 
@@ -21,6 +21,10 @@ Tool(s) to use
 
 Output in JSON format
 
+### `-D --dotenv`
+
+Output in dotenv format
+
 ### `-s --shell <SHELL>`
 
 Shell type to generate environment variables for

docs/cli/index.md

@@ -50,7 +50,7 @@ Answer yes to all confirmation prompts
 - [`mise direnv <SUBCOMMAND>`](/cli/direnv.md)
 - [`mise direnv activate`](/cli/direnv/activate.md)
 - [`mise doctor`](/cli/doctor.md)
-- [`mise env [-J --json] [-s --shell <SHELL>] [TOOL@VERSION]...`](/cli/env.md)
+- [`mise env [FLAGS] [TOOL@VERSION]...`](/cli/env.md)
 - [`mise exec [FLAGS] [TOOL@VERSION]... [COMMAND]...`](/cli/exec.md)
 - [`mise generate <SUBCOMMAND>`](/cli/generate.md)
 - [`mise generate git-pre-commit [FLAGS]`](/cli/generate/git-pre-commit.md)

e2e/cli/test_env_dotenv

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+cat >.mise.toml <<EOF
+[env]
+FOO = "bar"
+EOF
+
+assert "mise env --dotenv | grep FOO" "FOO=bar"

mise.usage.kdl

@@ -334,6 +334,7 @@ use this if you have `mise activate` in your shell rc file."
     $ execx($(mise env -s xonsh))
 "#
     flag "-J --json" help="Output in JSON format"
+    flag "-D --dotenv" help="Output in dotenv format"
     flag "-s --shell" help="Shell type to generate environment variables for" {
         arg "<SHELL>" {
             choices "bash" "elvish" "fish" "nu" "xonsh" "zsh"

src/cli/env.rs

@@ -20,6 +20,10 @@ pub struct Env {
     #[clap(long, short = 'J', overrides_with = "shell")]
     json: bool,
 
+    /// Output in dotenv format
+    #[clap(long, short = 'D', overrides_with = "shell")]
+    dotenv: bool,
+
     /// Shell type to generate environment variables for
     #[clap(long, short, overrides_with = "json")]
     shell: Option<ShellType>,
@@ -34,6 +38,8 @@ impl Env {
 
         if self.json {
             self.output_json(&config, ts)
+        } else if self.dotenv {
+            self.output_dotenv(&config, ts)
         } else {
             self.output_shell(&config, ts)
         }
@@ -55,6 +61,15 @@ impl Env {
         }
         Ok(())
     }
+
+    fn output_dotenv(&self, config: &Config, ts: Toolset) -> Result<()> {
+        for (k, v) in ts.env(config)? {
+            let k = k.to_string();
+            let v = v.to_string();
+            miseprint!("{}={}\n", k, v)?;
+        }
+        Ok(())
+    }
 }
 
 static AFTER_LONG_HELP: &str = color_print::cstr!(

tasks/fig/src/mise.ts

@@ -849,6 +849,14 @@ const completionSpec: Fig.Spec = {
                     "description": "Output in JSON format",
                     "isRepeatable": false
                 },
+                {
+                    "name": [
+                        "-D",
+                        "--dotenv"
+                    ],
+                    "description": "Output in dotenv format",
+                    "isRepeatable": false
+                },
                 {
                     "name": [
                         "-s",