+/* handle "[$SUBSYSTEM/$KERNEL]<attribute>" lookup */
+static int attr_get_by_subsys_id(const char *attrstr, char *devpath, size_t len, char **attr)
+{
+ char subsys[NAME_SIZE];
+ char *attrib;
+ char *id;
+ int found = 0;
+
+ if (attrstr[0] != '[')
+ goto out;
+
+ strlcpy(subsys, &attrstr[1], sizeof(subsys));
+
+ attrib = strchr(subsys, ']');
+ if (attrib == NULL)
+ goto out;
+ attrib[0] = '\0';
+ attrib = &attrib[1];
+
+ id = strchr(subsys, '/');
+ if (id == NULL)
+ goto out;
+ id[0] = '\0';
+ id = &id[1];
+
+ if (sysfs_lookup_devpath_by_subsys_id(devpath, len, subsys, id)) {
+ if (attr != NULL) {
+ if (attrib[0] != '\0')
+ *attr = attrib;
+ else
+ *attr = NULL;
+ }
+ found = 1;
+ }
+out:
+ return found;
+}
+