+/**
+ * Check if the directory in the specified search path is a valid PD dir.
+ *
+ * A valid sigrok protocol decoder consists of a directory, which contains
+ * at least two .py files (the special __init__.py and at least one additional
+ * .py file which contains the actual PD code).
+ *
+ * TODO: We should also check that this is not a random other Python module,
+ * but really a sigrok PD module by some means.
+ *
+ * @param search_path A string containing the (absolute) path to the directory
+ * where 'entry' resides in.
+ * @param entry A string containing the (relative) directory name of the
+ * sigrok PD module. E.g. "i2c" for the I2C protocol decoder.
+ * @return SRD_OK, if the directory is a valid sigrok PD, a negative error
+ * code, such as SRD_ERR, otherwise.
+ */
+int srd_is_valid_pd_dir(const gchar *search_path, const gchar *entry)
+{
+ GDir *dir;
+ int py_files = 0, has_init_py = 0;
+ gchar *path1, *path2, *file;
+ GError *error;
+
+ /* TODO: Error handling. */
+ path1 = g_build_filename(search_path, entry, NULL);
+
+ /* Check that it is a directory (and exists). */
+ if (!g_file_test(path1, G_FILE_TEST_IS_DIR)) {
+ srd_dbg("decoder: %s: '%s' not a directory or doesn't exist",
+ __func__, entry);
+ return SRD_ERR;
+ }
+
+ if (!(dir = g_dir_open(path1, 0, &error))) { /* TODO: flags? */
+ srd_dbg("decoder: %s: '%s' failed to open directory",
+ __func__, entry);
+ return SRD_ERR;
+ }
+
+ /* Check the contents of the directory. */
+ while ((file = g_dir_read_name(dir)) != NULL) {
+ /* TODO: Error handling. */
+ path2 = g_build_filename(path1, file, NULL);
+
+ /* Ignore non-files. */
+ if (!g_file_test(path2, G_FILE_TEST_IS_REGULAR)) {
+ srd_spew("decoder: %s: '%s' not a file, ignoring",
+ __func__, file);
+ continue;
+ }
+
+ /* Count number of .py files. */
+ if (g_str_has_suffix(path2, ".py")) {
+ srd_spew("decoder: %s: found .py file: '%s'",
+ __func__, file);
+ py_files++;
+ }
+
+ /* Check if it's an __init__.py file. */
+ if (g_str_has_suffix(path2, "__init__.py")) {
+ srd_spew("decoder: %s: found __init__.py file: '%s'",
+ __func__, path2);
+ has_init_py = 1;
+ }
+ }
+ g_dir_close(dir);
+
+ /* Check if the directory contains >= 2 *.py files. */
+ if (py_files < 2) {
+ srd_dbg("decoder: %s: '%s' is not a valid PD dir, it doesn't "
+ "contain >= 2 .py files", __func__, entry);
+ return SRD_ERR;
+ }
+
+ /* Check if the directory contains an __init__.py file. */
+ if (!has_init_py) {
+ srd_dbg("decoder: %s: '%s' is not a valid PD dir, it doesn't "
+ "contain an __init__.py file", __func__, entry);
+ return SRD_ERR;
+ }
+
+ /* TODO: Check if it's a PD, not a random other Python module. */
+
+ return SRD_OK;
+}