Возьми 1024 байта в буфер в коде: package main import ( "bufio" "bytes" "io" ) func Contains(r io.Reader, seq []byte) (bool, error) { br := bufio.NewReader(r) buf := make([]byte, len(seq)) for { n, err := br.Read (buf) if err == io.EOF { break } if err != nil { return false, err } for i := 0; i < n; i++ { if bytes.Contains(buf[i:], seq) { return true, nil } } } return false, nil }

func main() { buffer := make([]byte, 1024) reader := bytes.NewReader(buffer)

seq := []byte{1, 2, 3, 4}

found, err := Contains(reader, seq)
if err != nil {
	fmt.Println("Error:", err)
} else {
	fmt.Println("Sequence found:", found)
}

}