if (isdigit (s[1]) && isdigit (s[2]) && isdigit (s[3]) && s[4] == '>')
if (isdigit ((unsigned char) s[1]) && isdigit ((unsigned char) s[2]) && isdigit ((unsigned char) s[3]) && s[4] == '>')
static int parse_keycode (const char *s){  if (isdigit (s[1]) && isdigit (s[2]) && isdigit (s[3]) && s[4] == '>')  {    return (s[3] - '0') + (s[2] - '0') * 8 + (s[1] - '0') * 64;  }  return -1;}