libobs: Add XDG config directory support

Adding XDG Base Directory Specification support for config dir

http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html

Closes jp9000/obs-studio#348

CMakeLists.txt

@@ -70,8 +70,15 @@ if(APPLE)
 	set(CMAKE_MACOSX_RPATH TRUE)
 	set(CMAKE_BUILD_WITH_INSTALL_RPATH TRUE)
 	list(APPEND CMAKE_INSTALL_RPATH "@loader_path/" "@executable_path/")
-elseif(UNIX AND NOT UNIX_STRUCTURE)
-	list(APPEND CMAKE_INSTALL_RPATH "$ORIGIN")
+elseif(UNIX)
+	option(USE_XDG "Utilize XDG Base Directory Specification" ON)
+	if(USE_XDG)
+		add_definitions(-DUSE_XDG)
+	endif()
+
+	if(NOT UNIX_STRUCTURE)
+		list(APPEND CMAKE_INSTALL_RPATH "$ORIGIN")
+	endif()
 endif()
 
 option(BUILD_TESTS "Build test directory (includes test sources and possibly a platform test executable)" FALSE)

libobs/util/platform-nix.c

@@ -153,18 +153,58 @@ uint64_t os_gettime_ns(void)
 	return ((uint64_t) ts.tv_sec * 1000000000ULL + (uint64_t) ts.tv_nsec);
 }
 
-/* should return $HOME/.[name] */
+/* should return $HOME/.[name], or when using XDG,
+ * should return $HOME/.config/[name] as default */
 int os_get_config_path(char *dst, size_t size, const char *name)
 {
+#ifdef USE_XDG
+	char *xdg_ptr = getenv("XDG_CONFIG_HOME");
+
+	// If XDG_CONFIG_HOME is unset,
+	// we use the default $HOME/.config/[name] instead
+	if (xdg_ptr == NULL) {
+		char *home_ptr = getenv("HOME");
+		if (home_ptr == NULL)
+			bcrash("Could not get $HOME\n");
+
+		return snprintf(dst, size, "%s/.config/%s", home_ptr, name);
+	} else {
+		return snprintf(dst, size, "%s/%s", xdg_ptr, name);
+	}
+#else
 	char *path_ptr = getenv("HOME");
 	if (path_ptr == NULL)
 		bcrash("Could not get $HOME\n");
 
 	return snprintf(dst, size, "%s/.%s", path_ptr, name);
+#endif
 }
 
+/* should return $HOME/.[name], or when using XDG,
+ * should return $HOME/.config/[name] as default */
 char *os_get_config_path_ptr(const char *name)
 {
+#ifdef USE_XDG
+	struct dstr path;
+	char *xdg_ptr = getenv("XDG_CONFIG_HOME");
+
+	/* If XDG_CONFIG_HOME is unset,
+	 * we use the default $HOME/.config/[name] instead */
+	if (xdg_ptr == NULL) {
+		char *home_ptr = getenv("HOME");
+		if (home_ptr == NULL)
+			bcrash("Could not get $HOME\n");
+
+		dstr_init_copy(&path, home_ptr);
+		dstr_cat(&path, "/.config/");
+		dstr_cat(&path, name);
+	} else {
+		dstr_init_copy(&path, xdg_ptr);
+		dstr_cat(&path, "/");
+		dstr_cat(&path, name);
+	}
+	return path.array;
+#else
 	char *path_ptr = getenv("HOME");
 	if (path_ptr == NULL)
 		bcrash("Could not get $HOME\n");
@@ -174,6 +214,7 @@ char *os_get_config_path_ptr(const char *name)
 	dstr_cat(&path, "/.");
 	dstr_cat(&path, name);
 	return path.array;
+#endif
 }
 
 #endif

obs/obs-app.cpp

@@ -1058,6 +1058,32 @@ static inline bool arg_is(const char *arg,
 	       (short_form && strcmp(arg, short_form) == 0);
 }
 
+#if !defined(_WIN32) && !defined(__APPLE__)
+#define IS_UNIX 1
+#endif
+
+/* if using XDG and was previously using an older build of OBS, move config
+ * files to XDG directory */
+#if defined(USE_XDG) && defined(IS_UNIX)
+static void move_to_xdg(void)
+{
+	char old_path[512];
+	char new_path[512];
+	char *home = getenv("HOME");
+	if (!home)
+		return;
+
+	if (snprintf(old_path, 512, "%s/.obs-studio", home) <= 0)
+		return;
+	if (GetConfigPath(new_path, 512, "obs-studio") <= 0)
+		return;
+
+	if (os_file_exists(old_path) && !os_file_exists(new_path)) {
+		rename(old_path, new_path);
+	}
+}
+#endif
+
 int main(int argc, char *argv[])
 {
 #ifndef _WIN32
@@ -1071,6 +1097,10 @@ int main(int argc, char *argv[])
 
 	base_get_log_handler(&def_log_handler, nullptr);
 
+#if defined(USE_XDG) && defined(IS_UNIX)
+	move_to_xdg();
+#endif
+
 	for (int i = 1; i < argc; i++) {
 		if (arg_is(argv[i], "--portable", "-p")) {
 			portable_mode = true;