added "en" command

Fixes #1655

completions/_mise

@@ -27,6 +27,7 @@ _mise() {
         (deactivate) __mise_deactivate_cmd && ret=0 ;;
         (direnv) __mise_direnv_cmd && ret=0 ;;
         (dr|doctor) __mise_doctor_cmd && ret=0 ;;
+        (en) __mise_en_cmd && ret=0 ;;
         (e|env) __mise_env_cmd && ret=0 ;;
         (x|exec) __mise_exec_cmd && ret=0 ;;
         (g|global) __mise_global_cmd && ret=0 ;;
@@ -313,6 +314,16 @@ __mise_doctor_cmd() {
     '*'{-v,--verbose}'[Show extra output (use -vv for even more)]' \
     '(-y --yes)'{-y,--yes}'[Answer yes to all confirmation prompts]'
 }
+(( $+functions[__mise_en_cmd] )) ||
+__mise_en_cmd() {
+  _arguments -s -S \
+    '::dir:_files' \
+    '(-s --shell)'{-s,--shell}'=[Shell to start]:shell:' \
+    '(-C --cd)'{-C,--cd}'=[Change directory before running command]:cd:_directories' \
+    '(-q --quiet)'{-q,--quiet}'[Suppress non-error messages]' \
+    '*'{-v,--verbose}'[Show extra output (use -vv for even more)]' \
+    '(-y --yes)'{-y,--yes}'[Answer yes to all confirmation prompts]'
+}
 (( $+functions[__mise_env_cmd] )) ||
 __mise_env_cmd() {
   _arguments -s -S \
@@ -928,6 +939,7 @@ __mise_cmds() {
     'deactivate:Disable mise for current shell session'
     'direnv:Output direnv function to use mise inside direnv'
     {dr,doctor}':Check mise installation for possible problems'
+    'en:\[experimental\] starts a new shell with the mise environment built from the current configuration'
     {e,env}':Exports env vars to activate mise a single time'
     {x,exec}':Execute a command with tool(s) set'
     'implode:Removes mise CLI and all related data'

docs/cli-reference.md

@@ -319,6 +319,42 @@ Examples:
     [WARN] plugin node is not installed
 ```
 
+## `mise en [OPTIONS] [DIR]`
+
+```text
+[experimental] starts a new shell with the mise environment built from the current configuration
+
+This is an alternative to `mise activate` that allows you to explicitly start a mise session.
+It will have the tools and environment variables in the configs loaded.
+Note that changing directories will not update the mise environment.
+
+Usage: en [OPTIONS] [DIR]
+
+Arguments:
+  [DIR]
+          Directory to start the shell in
+
+          [default: .]
+
+Options:
+  -s, --shell <SHELL>
+          Shell to start
+
+          Defaults to $SHELL
+
+Examples:
+
+    $ mise en .
+    $ node -v
+    v20.0.0
+
+    Skip loading bashrc:
+    $ mise en -s "bash --norc"
+
+    Skip loading zshrc:
+    $ mise en -s "zsh -f"
+```
+
 ## `mise env [OPTIONS] [TOOL@VERSION]...`
 
 **Aliases:** `e`

man/man1/mise.1

@@ -65,6 +65,9 @@ Output direnv function to use mise inside direnv
 mise\-doctor(1)
 Check mise installation for possible problems
 .TP
+mise\-en(1)
+[experimental] starts a new shell with the mise environment built from the current configuration
+.TP
 mise\-env(1)
 Exports env vars to activate mise a single time
 .TP

mise.usage.kdl

@@ -239,6 +239,30 @@ cmd "doctor" help="Check mise installation for possible problems" {
     [WARN] plugin node is not installed
 "
 }
+cmd "en" help="[experimental] starts a new shell with the mise environment built from the current configuration" {
+    long_help r"[experimental] starts a new shell with the mise environment built from the current configuration
+
+This is an alternative to `mise activate` that allows you to explicitly start a mise session.
+It will have the tools and environment variables in the configs loaded.
+Note that changing directories will not update the mise environment."
+    after_long_help r#"Examples:
+
+    $ mise en .
+    $ node -v
+    v20.0.0
+
+    Skip loading bashrc:
+    $ mise en -s "bash --norc"
+
+    Skip loading zshrc:
+    $ mise en -s "zsh -f"
+"#
+    flag "-s --shell" help="Shell to start" {
+        long_help "Shell to start\n\nDefaults to $SHELL"
+        arg "<SHELL>"
+    }
+    arg "[DIR]" help="Directory to start the shell in" default="."
+}
 cmd "env" help="Exports env vars to activate mise a single time" {
     alias "e"
     long_help r"Exports env vars to activate mise a single time

src/cli/en.rs

@@ -0,0 +1,60 @@
+use crate::cli::exec::Exec;
+use crate::config::Settings;
+use std::ffi::OsString;
+use std::path::PathBuf;
+
+use crate::env;
+
+/// [experimental] starts a new shell with the mise environment built from the current configuration
+///
+/// This is an alternative to `mise activate` that allows you to explicitly start a mise session.
+/// It will have the tools and environment variables in the configs loaded.
+/// Note that changing directories will not update the mise environment.
+#[derive(Debug, clap::Args)]
+#[clap(verbatim_doc_comment, after_long_help = AFTER_LONG_HELP)]
+pub struct En {
+    /// Directory to start the shell in
+    #[clap(default_value = ".", verbatim_doc_comment)]
+    pub dir: PathBuf,
+
+    /// Shell to start
+    ///
+    /// Defaults to $SHELL
+    #[clap(verbatim_doc_comment, long, short = 's')]
+    pub shell: Option<String>,
+}
+
+impl En {
+    pub fn run(self) -> eyre::Result<()> {
+        let settings = Settings::get();
+        settings.ensure_experimental("en")?;
+
+        env::set_current_dir(&self.dir)?;
+        let shell = self.shell.or(env::var("SHELL").ok()).unwrap_or("sh".into());
+        let command = vec!["sh".into(), "-c".into(), OsString::from(shell)];
+
+        Exec {
+            tool: vec![],
+            raw: false,
+            jobs: None,
+            c: None,
+            command: Some(command),
+        }
+        .run()
+    }
+}
+
+static AFTER_LONG_HELP: &str = color_print::cstr!(
+    r#"<bold><underline>Examples:</underline></bold>
+
+    $ <bold>mise en .</bold>
+    $ <bold>node -v</bold>
+    v20.0.0
+
+    Skip loading bashrc:
+    $ <bold>mise en -s "bash --norc"</bold>
+
+    Skip loading zshrc:
+    $ <bold>mise en -s "zsh -f"</bold>
+"#
+);

src/cli/mod.rs

@@ -16,6 +16,7 @@ mod current;
 mod deactivate;
 mod direnv;
 mod doctor;
+mod en;
 mod env;
 pub mod exec;
 mod external;
@@ -70,6 +71,7 @@ pub enum Commands {
     Deactivate(deactivate::Deactivate),
     Direnv(direnv::Direnv),
     Doctor(doctor::Doctor),
+    En(en::En),
     Env(env::Env),
     Exec(exec::Exec),
     Global(global::Global),
@@ -125,6 +127,7 @@ impl Commands {
             Self::Deactivate(cmd) => cmd.run(),
             Self::Direnv(cmd) => cmd.run(),
             Self::Doctor(cmd) => cmd.run(),
+            Self::En(cmd) => cmd.run(),
             Self::Env(cmd) => cmd.run(),
             Self::Exec(cmd) => cmd.run(),
             Self::Global(cmd) => cmd.run(),