+uint8_t
+ao_getnibble(void)
+{
+ char c;
+
+ c = getchar();
+ if ('0' <= c && c <= '9')
+ return c - '0';
+ if ('a' <= c && c <= 'f')
+ return c - ('a' - 10);
+ if ('A' <= c && c <= 'F')
+ return c - ('A' - 10);
+ ao_cmd_status = ao_cmd_lex_error;
+ return 0;
+}
+