+/**
+ * g_keyfile_settings_backend_new:
+ * @filename: the filename of the keyfile
+ * @root_path: the path under which all settings keys appear
+ * @root_group: (allow-none): the group name corresponding to
+ * @root_path, or %NULL
+ *
+ * Creates a keyfile-backed #GSettingsBackend.
+ *
+ * The filename of the keyfile to use is given by @filename.
+ *
+ * All settings read to or written from the backend must fall under the
+ * path given in @root_path (which must start and end with a slash and
+ * not contain two consecutive slashes). @root_path may be "/".
+ *
+ * If @root_group is non-%NULL then it specifies the name of the keyfile
+ * group used for keys that are written directly below @root_path. For
+ * example, if @root_path is "/apps/example/" and @root_group is
+ * "toplevel", then settings the key "/apps/example/enabled" to a value
+ * of %TRUE will cause the following to appear in the keyfile:
+ *
+ * |[
+ * [toplevel]
+ * enabled=true
+ * ]|
+ *
+ * If @root_group is %NULL then it is not permitted to store keys
+ * directly below the @root_path.
+ *
+ * For keys not stored directly below @root_path (ie: in a sub-path),
+ * the name of the subpath (with the final slash stripped) is used as
+ * the name of the keyfile group. To continue the example, if
+ * "/apps/example/profiles/default/font-size" were set to
+ * 12 then the following would appear in the keyfile:
+ *
+ * |[
+ * [profiles/default]
+ * font-size=12
+ * ]|
+ *
+ * The backend will refuse writes (and return writability as being
+ * %FALSE) for keys outside of @root_path and, in the event that
+ * @root_group is %NULL, also for keys directly under @root_path.
+ * Writes will also be refused if the backend detects that it has the
+ * inability to rewrite the keyfile (ie: the containing directory is not
+ * writable).
+ *
+ * There is no checking done for your key namespace clashing with the
+ * syntax of the key file format. For example, if you have '[' or ']'
+ * characters in your path names or '=' in your key names you may be in
+ * trouble.
+ *
+ * Returns: (transfer full): a keyfile-backed #GSettingsBackend
+ **/