core: apply config files under XDG_CONFIG_DIRS

src/build/mdgen/ghostty_1_footer.md

@@ -2,7 +2,11 @@
 
 _\$XDG_CONFIG_HOME/ghostty/config_
 
-: Location of the default configuration file.
+: Location of the default user configuration file.
+
+_\$XDG_CONFIG_DIRS/ghostty/config_
+
+: Location of the default system configuration files.
 
 _\$LOCALAPPDATA/ghostty/config_
 
@@ -23,6 +27,10 @@ for configuration files.
 
 : Default location for configuration files.
 
+**XDG_CONFIG_DIRS**
+
+: Colon separated list of paths to load configuration files.
+
 **LOCALAPPDATA**
 
 : **WINDOWS ONLY:** alternate location to search for configuration files.

src/build/mdgen/ghostty_5_footer.md

@@ -2,7 +2,11 @@
 
 _\$XDG_CONFIG_HOME/ghostty/config_
 
-: Location of the default configuration file.
+: Location of the default user configuration file.
+
+_\$XDG_CONFIG_DIRS/ghostty/config_
+
+: Location of the default system configuration files.
 
 _\$LOCALAPPDATA/ghostty/config_
 
@@ -15,6 +19,10 @@ for configuration files.
 
 : Default location for configuration files.
 
+**XDG_CONFIG_DIRS**
+
+: Colon separated list of paths to load configuration files.
+
 **LOCALAPPDATA**
 
 : **WINDOWS ONLY:** alternate location to search for configuration files.

src/config/Config.zig

@@ -1439,8 +1439,10 @@ keybind: Keybinds = .{},
 @"config-file": RepeatablePath = .{},
 
 /// When this is true, the default configuration file paths will be loaded.
-/// The default configuration file paths are currently only the XDG
+/// The default configuration files are at ./ghostty/config,
-/// config path ($XDG_CONFIG_HOME/ghostty/config).
+/// in each of the colon seperated directories in $XDG_CONFIG_DIRS, and,
+/// the xdg user config directory $XDG_CONFIG_HOME
+/// (/etc/xdg and ~/.config if these environment variables are not set).
 ///
 /// If this is false, the default configuration paths will not be loaded.
 /// This is targeted directly at using Ghostty from the CLI in a way
@@ -2921,20 +2923,36 @@ fn writeConfigTemplate(path: []const u8) !void {
     );
 }
 
-/// Load configurations from the default configuration files. The default
+/// Load configurations from the default configuration files.
-/// configuration file is at `$XDG_CONFIG_HOME/ghostty/config`.
+/// The default system configuration files are at `$XDG_CONFIG_DIRS/ghostty/config`.
+/// The default user configuration file is at `$XDG_CONFIG_HOME/ghostty/config`.
 ///
 /// On macOS, `$HOME/Library/Application Support/$CFBundleIdentifier/config`
 /// is also loaded.
 pub fn loadDefaultFiles(self: *Config, alloc: Allocator) !void {
-    // Load XDG first
+    const config_subdir = "ghostty";
-    const xdg_path = try internal_os.xdg.config(alloc, .{ .subdir = "ghostty/config" });
+    const config_file = "config";
+    // Load XDG system config first
+    var it = internal_os.xdg.DirIterator.init(.config);
+    while (it.next()) |xdg_dir| {
+        const config_path = try std.fs.path.join(alloc, &[_][]const u8{
+            xdg_dir,
+            config_subdir,
+            config_file,
+        });
+        defer alloc.free(config_path);
+        _ = self.loadOptionalFile(alloc, config_path);
+    }
+    // Load XDG user config next
+    const xdg_config_dir = try internal_os.xdg.config(alloc, .{ .subdir = config_subdir });
+    defer alloc.free(xdg_config_dir);
+    const xdg_path = try std.fs.path.join(alloc, &[_][]const u8{ xdg_config_dir, config_file });
     defer alloc.free(xdg_path);
     const xdg_action = self.loadOptionalFile(alloc, xdg_path);
 
     // On macOS load the app support directory as well
     if (comptime builtin.os.tag == .macos) {
-        const app_support_path = try internal_os.macos.appSupportDir(alloc, "config");
+        const app_support_path = try internal_os.macos.appSupportDir(alloc, config_file);
         defer alloc.free(app_support_path);
         const app_support_action = self.loadOptionalFile(alloc, app_support_path);