How do I create a zero-length file using the Ubuntu terminal?

Question

I'm using Ubuntu for the first time and I have to create a directory and then create a zero-length file inside that directory. After that, apparently I have to do a long listing of the file to show it has zero bytes. I'm not sure how to do this.

Answer 1

 mkdir directory_name
 cd directory_name
 touch file_name_to_create
 ls -l file_name_to_create

If the file already exists, then touch will not change its length to zero. But if the file does not exist, then it will be created with zero length.