+static guint
+pref_check(pref_t *pref, gpointer user_data)
+{
+ const char *str_val;
+ char *p;
+ guint uval;
+ pref_t **badpref = user_data;
+
+ /* Fetch the value of the preference, and check whether it's valid. */
+ switch (pref->type) {
+
+ case PREF_UINT:
+ str_val = gtk_entry_get_text(GTK_ENTRY(pref->control));
+ uval = strtoul(str_val, &p, pref->info.base);
+ if (p == str_val || *p != '\0') {
+ *badpref = pref;
+ return PREFS_SET_SYNTAX_ERR; /* number was bad */
+ }
+ break;
+
+ case PREF_BOOL:
+ /* Value can't be bad. */
+ break;
+
+ case PREF_ENUM:
+ /* Value can't be bad. */
+ break;
+
+ case PREF_STRING:
+ /* Value can't be bad. */
+ break;
+
+ case PREF_OBSOLETE:
+ g_assert_not_reached();
+ break;
+ }
+ return 0;
+}
+
+static guint
+module_prefs_check(module_t *module, gpointer user_data)
+{
+ /* For all preferences in this module, fetch its value from this
+ module's notebook page and check whether it's valid. */
+ return prefs_pref_foreach(module, pref_check, user_data);
+}
+