system/readline: check the control ascii only to support multi-languages
@@ -733,11 +733,11 @@ ssize_t readline_common(FAR struct rl_common_s *vtbl, FAR char *buf,
return nch;
}
- /* Otherwise, check if the character is printable and, if so, put the
- * character in the line buffer
+ /* Otherwise, put the character in the line buffer if the
+ * character is not a control byte
*/
- else if (isprint(ch))
+ else if (!iscntrl(ch & 0xff))
{
buf[nch++] = ch;
