4.6 Editor -- vi

4.6 Editor -- vi

In this lab we will look at some of the features of the vi text editor. This can be a very good text editor for touch typists. The only special key that is needed is the "escape" key. For a full description of the vi text editor look at the manual pages.

1. Copy the file ~cis137/flatpara.text

   username@gort ~ $ cp ~cis137/flatpara.text .
   

   (Did you notice the trailing period? You need it.) If you are not using gort you can get the file with anonymous ftp from from
   ftp://lt.tucson.az.us/pub/flatpara.text. The file is a paragraph from the book Flatland by Edwin A. Abbott.
2. Bring up the file in vi.

   username@gort ~ $ vi flatpara.text
   

3. Insert your name, the current date, and TABER CIS137 as the first line of the file.
4. Number each line in the file. Number the line with your name as 1. Place a space after each number. You should have 19 numbered lines. This needs to be placed into the file by hand. You may want to use the command :set number to check your numbers. In some versions of vi you will need to get out of insert mode with the esc key to move from one line to the next.
5. With the ":" command move to line 11. :11<cr>.
6. Move to the end of the line with the "$" in command mode. Delete the ";" with the x command. Move to the beginning of the line with a "0" (zero). Replace the "1" with a "4" using the "r" command. If you are on an X system, try positioning the cursor with the mouse.
7. On lines 15 through the end of the file change all of the "t"s to "**". Use the ":" command ":15,$s/t/**/g". In this command "t" is a regular expression.
8. Read the manual pages of ed or ex. If ed is not on your system try ex. This is where regular expressions may be documented. Read the section on regular expressions. On gort man uses less to help the user view the manual pages. less uses regular expressions for searching, like vi. So the "/" and "?" work for forward and backward searches. You may need to look at the vi manual pages. You can use regular expressions in many UNIX commands. We will come back to regular expressions in several future labs.
9. Go to line 4 of the file with a ":4". Once you have done this, forward search for "land" with the "/" command "/land". The display should now highlight the first "/land" found. Repeat the search twice with two "n" commands. Each time you type an "n", the highlight and the cursor will advance. At this point take note of the line that the cursor is on. Go back to line four (4), the blank line, and on this line place (insert) the line number that has the third "/land". The "?" is used to search backwards. An "N" searches again, but in the other direction.
10. Swap all adjacent vowels and enclose them in parentheses. The command to do this.

    :5,10s/\([aeiou]\)\([aeiou]\)/(\2\1)/g
    

    This needs an explanation. The "5,10s" indicates what area of the file. Between the first two forward slashes "/" are two regular expressions. They are marked off with "\(" and "\)". They both specify vowels, [aeiou]. These regular expressions are referred to later by "\1" and "\2". The "g" at the end is for global, all of the occurrences on a line. You may want to copy this command from the web page.
11. Exit the vi editor with the command "ZZ" (Upper case). This will save your file.
12. Print out your resulting file.

    username@gort ~ $ lpr flatpara.text
    

Turn in your output from step 4.6 marked as follows:

your-name
Lab 4.6: vi Part 2
TABER CIS137

Please turn your lab to Louis Taber or to Pima Community College employee in room A-115 of the Santa Rita Building. Ask them to place it in the dark blue folder in Louis Taber's mailbox.  

4.6 Editor -- vi