Add uv tool dir --bin to show executable directory (#5160)

## Summary

Closes https://github.com/astral-sh/uv/issues/5159.

crates/uv-cli/src/lib.rs

@@ -2067,7 +2067,7 @@ pub enum ToolCommand {
     #[command(alias = "ensurepath")]
     UpdateShell,
     /// Show the tools directory.
-    Dir,
+    Dir(ToolDirArgs),
 }
 
 #[derive(Args)]
@@ -2168,6 +2168,17 @@ pub struct ToolInstallArgs {
 #[allow(clippy::struct_excessive_bools)]
 pub struct ToolListArgs;
 
+#[derive(Args)]
+#[allow(clippy::struct_excessive_bools)]
+pub struct ToolDirArgs {
+    /// Show the directory into which `uv tool` will install executables.
+    ///
+    /// By default, `uv tool dir` shows the directory into which the tool Python environments
+    /// themselves are installed, rather than the directory containing the linked executables.
+    #[arg(long, alias = "executable")]
+    pub bin: bool,
+}
+
 #[derive(Args)]
 #[allow(clippy::struct_excessive_bools)]
 pub struct ToolUninstallArgs {

crates/uv/src/commands/tool/dir.rs

@@ -3,16 +3,23 @@ use owo_colors::OwoColorize;
 
 use uv_configuration::PreviewMode;
 use uv_fs::Simplified;
-use uv_tool::InstalledTools;
+use uv_tool::{find_executable_directory, InstalledTools};
 use uv_warnings::warn_user_once;
 
 /// Show the tool directory.
-pub(crate) fn dir(preview: PreviewMode) -> anyhow::Result<()> {
+pub(crate) fn dir(bin: bool, preview: PreviewMode) -> anyhow::Result<()> {
     if preview.is_disabled() {
         warn_user_once!("`uv tool dir` is experimental and may change without warning.");
     }
-    let installed_tools =
-        InstalledTools::from_settings().context("Failed to initialize tools settings")?;
-    anstream::println!("{}", installed_tools.root().simplified_display().cyan());
+
+    if bin {
+        let executable_directory = find_executable_directory()?;
+        anstream::println!("{}", executable_directory.simplified_display().cyan());
+    } else {
+        let installed_tools =
+            InstalledTools::from_settings().context("Failed to initialize tools settings")?;
+        anstream::println!("{}", installed_tools.root().simplified_display().cyan());
+    }
+
     Ok(())
 }

crates/uv/src/lib.rs

@@ -689,9 +689,13 @@ async fn run(cli: Cli) -> Result<ExitStatus> {
             Ok(ExitStatus::Success)
         }
         Commands::Tool(ToolNamespace {
-            command: ToolCommand::Dir,
+            command: ToolCommand::Dir(args),
         }) => {
-            commands::tool_dir(globals.preview)?;
+            // Resolve the settings from the command-line arguments and workspace configuration.
+            let args = settings::ToolDirSettings::resolve(args, filesystem);
+            show_settings!(args);
+
+            commands::tool_dir(args.bin, globals.preview)?;
             Ok(ExitStatus::Success)
         }
         Commands::Python(PythonNamespace {

crates/uv/src/settings.rs

@@ -14,8 +14,8 @@ use uv_cli::{
     AddArgs, ColorChoice, Commands, ExternalCommand, GlobalArgs, ListFormat, LockArgs, Maybe,
     PipCheckArgs, PipCompileArgs, PipFreezeArgs, PipInstallArgs, PipListArgs, PipShowArgs,
     PipSyncArgs, PipTreeArgs, PipUninstallArgs, PythonFindArgs, PythonInstallArgs, PythonListArgs,
-    PythonPinArgs, PythonUninstallArgs, RemoveArgs, RunArgs, SyncArgs, ToolInstallArgs,
-    ToolListArgs, ToolRunArgs, ToolUninstallArgs, TreeArgs, VenvArgs,
+    PythonPinArgs, PythonUninstallArgs, RemoveArgs, RunArgs, SyncArgs, ToolDirArgs,
+    ToolInstallArgs, ToolListArgs, ToolRunArgs, ToolUninstallArgs, TreeArgs, VenvArgs,
 };
 use uv_client::Connectivity;
 use uv_configuration::{
@@ -316,6 +316,23 @@ impl ToolUninstallSettings {
     }
 }
 
+/// The resolved settings to use for a `tool dir` invocation.
+#[allow(clippy::struct_excessive_bools)]
+#[derive(Debug, Clone)]
+pub(crate) struct ToolDirSettings {
+    pub(crate) bin: bool,
+}
+
+impl ToolDirSettings {
+    /// Resolve the [`ToolDirSettings`] from the CLI and filesystem configuration.
+    #[allow(clippy::needless_pass_by_value)]
+    pub(crate) fn resolve(args: ToolDirArgs, _filesystem: Option<FilesystemOptions>) -> Self {
+        let ToolDirArgs { bin } = args;
+
+        Self { bin }
+    }
+}
+
 #[derive(Debug, Clone, Default)]
 pub(crate) enum PythonListKinds {
     #[default]

crates/uv/tests/tool_dir.rs

@@ -24,3 +24,22 @@ fn tool_dir() {
     warning: `uv tool dir` is experimental and may change without warning.
     "###);
 }
+
+#[test]
+fn tool_dir_bin() {
+    let context = TestContext::new("3.12");
+    let tool_dir = context.temp_dir.child("tools");
+    let bin_dir = context.temp_dir.child("bin");
+
+    uv_snapshot!(context.filters(), context.tool_dir().arg("--bin")
+    .env("UV_TOOL_DIR", tool_dir.as_os_str())
+    .env("XDG_BIN_HOME", bin_dir.as_os_str()), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    [TEMP_DIR]/bin
+
+    ----- stderr -----
+    warning: `uv tool dir` is experimental and may change without warning.
+    "###);
+}