A subdirectory is a directory within another directory.
Therefore, when instructing users to create a subdirectory, use “within” not “in”.
Create a subdirectory named yesitis within the current directory as follows:
$ mkdir /path/to/dir yesitis
A file in a directory is simply this. A file in a directory.
Therefore, when instructing users to create a file in a directory, use “in” not “within”.
Create a file named inlikeflynn in the current directory as follows:
$ nano filename
nano is a modeless editor. This means you can type immediately. We recommend nano for command line work over something like gedit.