File option.
This field lets you to specify whether you want to create a new
file, modify an existing file, or view the data in an existing file.
If you enter either M (Modify)
or V (View), information from the
file entered in the Terminal type file name
field is copied into the work area of the utility. To modify the
file, you must have write access for this file. However, to view
a file, you only need read access.
If you specify C (Create),
a new file is created and saved. The file is then automatically
reopened when the modify option is specified.