Linux urgent question please answer ASAP

Question

1. Your menu will be surrounded by a loop, either the until or while loop, so that when one option is concluded it will go back to the main menu until the user selects an option x to exit. Try  NOT TO USE THE EXIT command to quit the script, use the proper logic of the loop control to exit the program. Also using while : or while true or until true, etc. is not a good loop logic. You have a menu so, the exit should be an option in the menu such as, when option <> q, etc.
2. Program in one file
3. 
   
4. Menu example:
5. email:~> bash menu_script.sh
6. Command Menu
7. 
   
8. a. Emailer Program
9. b. Users Currently Logged On
10. c. Current Date and Time
11. d. This months Calendar
12. e. name of the Working Directory
13. f. Contents of the Working Directory
14. g. Find the IP of a Web Address
15. h. See your Fortune
16. i. Print a file (on the screen)
17. j. Exit
18. 
    
19. Please select a letter:
20. Here is samples interaction with the emailer portion of the program. There is no need to display the calendar or show a list of available files to attach.
21. Please select a letter: a (this would go to the option for the emailer program that you created)
22. 
    
23. Welcome user
24. 
    
25. Today is: date
26. 
    
27. This is this months Calendar:
28. 
    
29. February 2005
30. Su Mo Tu We Th Fr Sa
31. 1 2 3 4 5
32. 6 7 8 9 10 11 12
33. 13 14 15 16 17 18 19
34. 20 21 22 23 24 25 26
35. 27 28
36. 
    
37. 
    
38. This program will allow you to send a message,
39. with a file attachment, to any selected user.
40. 
    
41. Please enter the subject of your message and press <enter>: Test message
42. 
    
43. Please enter the email address of the recipient and hit <enter>:
44. 
    
45. Please enter the file to be attached to this message and press <enter>.
46. 
    
47. please choose a file: testfile
48. Then it would got back to the main menu

1) Lack of comments on your program

2) Use of meaningful variable names

3) #!/bin/bash should be the first line of our program.

4) Using the option read -n1 varname allows you to tap on “one key to continue”

5) Many commands might produce a full screen of output and you will not be able to see the what was on the top, always | more

6) Use the command clear to clear the screen and have a non-cluttered output. =======================

7) Use the logic of the loop to get out of the loop, using exit 1 or exit 0 still terminates the program but you are forcing the end of the program instead of using the logic of a loop

8) There are many ways to implement the until loop, but you need to make sure to use the proper operator and initialize the variable before it is checked in the until loop. Otherwise the comparison condition may always be true or false. Same not as above, use the logic of the loop to end it.

9) Consider using functions. They will be easier to troubleshoot if your program does not work and it organizes your program

10) Initialize your variables to a value.

11) Test you emailer.

12) Binary logic. Remember that when you do binary logic you are always comparing two items. For instance if a > b then .. you do not use if a > b > c, you need to break it down into if a > b and a > c

Answer 1

$ cat command_menu

#! /bin/bash

# menu interface to simple commands

echo -e "\n" COMMAND MENU\n"

echo " a. Current date and time"

echo " b. Users currently logged in"

echo " c. Name of the working directory"

echo - e " d. Contents of the working directory\n"

echo -n "Enter a, b, c, or d: "

read answer

echo

###############################

# Problem #1

#---------------------------------

# copies the specified file into

# your KEEP directory and opens

# it up in VI

####################################

if test $# = 1 # IF the number of command line arguments is 1

then

if test -f $1 # IF the file is a regular file and not a system file

then

cp $1 $HOME/keep # moves the file to your KEEP folder

vi $1 # and opens it in VI

else

echo "file not found try again

fi

else

echo "You must specify a file name. Try again"

fi

###############################

# Problem #2

#---------------------------------

# checks every 30 seconds

# for the specified user

# to log on

####################################

# pipes the output of who is currently loggeed on

# to grep, which fileters for the username specified;

# if present, gets returned while the remaining output

# gets wasted;

until who | grep "$1" > /dev/null

do sleep 30 # sleeps/waits for 30 seconds

done

echo "$1 is logged on." exit 0 # bails once condition is

# met and loop stops

#Problem 3

case answer in

"a")

date

;;

"b")

who

;;

"c")

pwd

;;

"d")

ls

;;