How do I open a file in read-only mode?

You can open a file in read-only mode using the “:view” command:

    :view 

This command sets the ‘readonly’ option for the opened buffer. You can also use the “-R” command-line option to open a file in read-only mode:

    $ vim -R 

You can also use the symbolic link executable “view” to open a file in read-only mode from the command-line:

    $ view