Rar4 (.rar)

def is_rar(file_path: str) -> bool:
    """Check if file is a valid RAR by magic bytes."""
    signature = bytes([0x52, 0x61, 0x72, 0x21, 0x1A, 0x07, 0x00])
    with open(file_path, "rb") as f:
        return f.read(7) == signature

function isRAR(buffer: Buffer): boolean {
  const signature = Buffer.from([0x52, 0x61, 0x72, 0x21, 0x1A, 0x07, 0x00]);
  return buffer.subarray(0, 7).equals(signature);
}

func IsRAR(data []byte) bool {
    signature := []byte{0x52, 0x61, 0x72, 0x21, 0x1A, 0x07, 0x00}
    if len(data) < 7 {
        return false
    }
    return bytes.Equal(data[:7], signature)
}