Vi Editor Exercise 1

Preparation

WARNING:

In this exercise /etc/passwd is used, as it exists in every UNIX system.
However it is not advised to use “vi” for user management!

Copy the file /etc/passwd to your HOME-directory.
Name your copy mypasswd
Hint: your HOME-directory is the base directory for you as a user.

HINTS:

Above the first line of this new file, add the line: This is just a test file!
Hint: O (capital o)
Add a new user to your test file.
Hint: yyp
See to it that the last line becomes the last line but one.
Hint: ddp
For the last 5 user accounts add the comment: UNIX user
Hint: The comment field is the 5th field in the passwd file.
Hint: Use the vi repeat command to make things painless.
Make each line start with one TAB.
Hint: Regular Expression characters ^ $
Hint: :1,$s/ / /
Try to undo your last change.
Hint: u
Use vi to copy all administrative users to a file called passwd.adm
Hint: Administrative users are users like “root” and “lp”.
This example shows how to copy lines to another file:
```
"a5yy
"b3yy
..
..
:e passwd.adm
"ap
"bp
```
Quit vi.
Check if you have a file named .exrc in your HOME-directory. Make a backup copy of your existing .exrc
Create the file $HOME/.exrc containing the following two lines:
```
:set showmode
:set list
```
Use vi to reopen your test file and check which vi-options are available.
Hint: :set all
In your test file, pick one of the user accounts and use <space> to add a blank at the end of the login shell field.
Is this blank visible?
Which vi-option will make it visible?
What do you think? Would it stll be possible to login with a blank after the shell in the real /etc/passwd?
Remember this option! It's an invaluable option in debugging a non functioning config file!