+static char *
+show_n (const struct dataset *ds)
+{
+ casenumber n;
+ size_t l;
+
+ const struct casereader *reader = dataset_source (ds);
+
+ if (reader == NULL)
+ return strdup (_("Unknown"));
+
+ n = casereader_count_cases (reader);
+
+ return asnprintf (NULL, &l, "%ld", n);
+}
+
+