Function is_binary

src/ugrep.cpp:702–714

return true if s[0..n-1] contains a \0 (NUL) or a non-displayable invalid UTF-8 encoding

// return true if s[0..n-1] contains a \0 (NUL) or a non-displayable invalid UTF-8 encoding
inline bool is_binary(const char *s, size_t n)
{
  // not --null-data or --encoding=null-data that permit NUL in the input and non-UTF-8 like GNU grep
  if (flag_encoding_type == reflex::Input::file_encoding::null_data)
    return false;

  // not -a and -U or -W: file is binary if it has a \0 (NUL) or an invalid UTF-8 encoding when --encoding is unset
  if (!flag_text && (!flag_binary || flag_with_hex) && flag_encoding_type == reflex::Input::file_encoding::plain)
    return !reflex::isutf8(s, s + n);

  // otherwise, file is binary if it contains a \0 (NUL) which is what GNU grep checks
  return memchr(s, '\0', n) != NULL;
}

// return true if -X or if -W and match s[0..n-1] is binary
inline bool check_binary(const char *s, size_t n)