+bool check_id(const char *id) {
+ if(!id || !*id)
+ return false;
+
+ for(; *id; id++)
+ if(!isalnum(*id) && *id != '_')
+ return false;
+
+ return true;
+}
+
+/* Windows doesn't define HOST_NAME_MAX. */
+#ifndef HOST_NAME_MAX
+#define HOST_NAME_MAX 255
+#endif
+