uhd: paths: Harmonize around XDG Base Directory specification

Up until now, we completely ignore the XDG specification.

This commit does the following to change that:

- It uses XDG_DATA_HOME and XDG_CONFIG_HOME for cal and config data,
  respectively.
- If config data is in ~/.uhd/uhd.conf, that is still accepted, but if
  it conflicts with $XDG_CONFIG_HOME/uhd.conf, it is ignored and a
  warning is displayed
- The default location for cal data is thus ${HOME}/.local/share/uhd/cal
  on Unix, and %LOCALAPPDATA%\uhd\cal on Windows. This is a change in
  location!
- The UHD_CONFIG_DIR environment variable was confusingly named and is
  now removed. It provided an alternative location than the home
  directory. The same purpose is now much better served by XDG_DATA_HOME
  and XDG_CONFIG_HOME.

The specification can be found here:
specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html

1 files changed, 2 insertions, 2 deletions

diff --git a/host/lib/utils/paths_python.hpp b/host/lib/utils/paths_python.hpp
index fb91ec373..f738904ca 100644
--- a/host/lib/utils/paths_python.hpp
+++ b/host/lib/utils/paths_python.hpp
@@ -12,9 +12,9 @@
 void export_paths(py::module& m)
 {
     m.def("get_tmp_path", &uhd::get_tmp_path);
-    m.def("get_app_path", &uhd::get_app_path);
-    m.def("get_pkg_path", &uhd::get_pkg_path);
     m.def("get_lib_path", &uhd::get_lib_path);
+    m.def("get_pkg_path", &uhd::get_pkg_path);
+    m.def("get_cal_data_path", &uhd::get_cal_data_path);
     m.def("get_images_dir", &uhd::get_images_dir);
     m.def("find_image_path", &uhd::find_image_path);
     m.def("find_utility", &uhd::find_utility);