feat(daemon): follow XDG_RUNTIME_DIR if set

If XDG_RUNTIME_DIR is set, put the socket file there.

If not, default to storing it in our data dir. We cannot default to a
path such as /run/user/$UID/ because it does not exist on all systems.
Any system running systemd will set this var by default, and ensure that
the directory it points to is correctly setup.

Author: ellie

crates/atuin-client/src/settings.rs

@@ -667,7 +667,7 @@ impl Settings {
         let data_dir = atuin_common::utils::data_dir();
         let db_path = data_dir.join("history.db");
         let record_store_path = data_dir.join("records.db");
-        let socket_path = data_dir.join("atuin.sock");
+        let socket_path = atuin_common::utils::runtime_dir().join("atuin.sock");
 
         let key_path = data_dir.join("key");
         let session_path = data_dir.join("session");

crates/atuin-common/src/dirs.rs

@@ -0,0 +1,106 @@
+use std::path::PathBuf;
+
+// Where do we store things? The following makes sense.
+//
+// 1. If set by ATUIN_<config>, follow the env.
+// 2. If not set, check for existence of XDG_*. Follow if set.
+// 3. If not set, platform-specific defaults:
+//  Linux: XDG spec, as much as it makes sense anyway
+//  Mac: ~/.atuin/* for everything
+//
+//  Mac is tricky. we can either follow the spec exactly and put things in ~/Library/blah, follow
+//  the spec for linux which people may expect, or just put it one place so everything is easy to
+//  find. I'd rather not follow it, than half follow it.
+
+pub fn data_dir() -> PathBuf {
+    let data_dir = std::env::var("XDG_DATA_HOME")
+        .map_or_else(|_| home_dir().join(".local").join("share"), PathBuf::from);
+
+    data_dir.join("atuin")
+}
+
+#[cfg(not(target_os = "windows"))]
+pub fn home_dir() -> PathBuf {
+    let home = std::env::var("HOME").expect("$HOME not found");
+    PathBuf::from(home)
+}
+
+#[cfg(target_os = "windows")]
+pub fn home_dir() -> PathBuf {
+    let home = std::env::var("USERPROFILE").expect("%userprofile% not found");
+    PathBuf::from(home)
+}
+
+pub fn config_dir() -> PathBuf {
+    let config_dir =
+        std::env::var("XDG_CONFIG_HOME").map_or_else(|_| home_dir().join(".config"), PathBuf::from);
+    config_dir.join("atuin")
+}
+
+pub fn dotfiles_cache_dir() -> PathBuf {
+    // In most cases, this will be  ~/.local/share/atuin/dotfiles/cache
+    let data_dir = std::env::var("XDG_DATA_HOME")
+        .map_or_else(|_| home_dir().join(".local").join("share"), PathBuf::from);
+
+    data_dir.join("atuin").join("dotfiles").join("cache")
+}
+
+pub fn get_current_dir() -> String {
+    // Prefer PWD environment variable over cwd if available to better support symbolic links
+    match std::env::var("PWD") {
+        Ok(v) => v,
+        Err(_) => match std::env::current_dir() {
+            Ok(dir) => dir.display().to_string(),
+            Err(_) => String::from(""),
+        },
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::env;
+
+    #[cfg(not(windows))]
+    #[test]
+    fn test_dirs() {
+        // these tests need to be run sequentially to prevent race condition
+        test_config_dir_xdg();
+        test_config_dir();
+        test_data_dir_xdg();
+        test_data_dir();
+    }
+
+    fn test_config_dir_xdg() {
+        env::remove_var("HOME");
+        env::set_var("XDG_CONFIG_HOME", "/home/user/custom_config");
+        assert_eq!(
+            config_dir(),
+            PathBuf::from("/home/user/custom_config/atuin")
+        );
+        env::remove_var("XDG_CONFIG_HOME");
+    }
+
+    fn test_config_dir() {
+        env::set_var("HOME", "/home/user");
+        env::remove_var("XDG_CONFIG_HOME");
+
+        assert_eq!(config_dir(), PathBuf::from("/home/user/.config/atuin"));
+
+        env::remove_var("HOME");
+    }
+
+    fn test_data_dir_xdg() {
+        env::remove_var("HOME");
+        env::set_var("XDG_DATA_HOME", "/home/user/custom_data");
+        assert_eq!(data_dir(), PathBuf::from("/home/user/custom_data/atuin"));
+        env::remove_var("XDG_DATA_HOME");
+    }
+
+    fn test_data_dir() {
+        env::set_var("HOME", "/home/user");
+        env::remove_var("XDG_DATA_HOME");
+        assert_eq!(data_dir(), PathBuf::from("/home/user/.local/share/atuin"));
+        env::remove_var("HOME");
+    }
+}

crates/atuin-common/src/utils.rs

@@ -77,6 +77,10 @@ pub fn data_dir() -> PathBuf {
     data_dir.join("atuin")
 }
 
+pub fn runtime_dir() -> PathBuf {
+    std::env::var("XDG_RUNTIME_DIR").map_or_else(|_| data_dir(), PathBuf::from)
+}
+
 pub fn dotfiles_cache_dir() -> PathBuf {
     // In most cases, this will be  ~/.local/share/atuin/dotfiles/cache
     let data_dir = std::env::var("XDG_DATA_HOME")