Bash Script add, delete, users, directories and files

Question

hi guys I need to create a bash scrip for my class and I haven't taken any classes that teach how to this yet. The bash script menu has to have the following:

Please choose one of the following option:
a- Create a File
b- Create a Directory
c- Delete a File
d- Delete a Directory
e- Create a User
f- Delete a User
q- Quit 


Enter your choice: a
     What would you like to name your file (including the path to the location to where you want the file to be): ~/Data
     ~/Data: File Created successfully.
Enter your choice: q

I've try to do search on my own but since I've never done it before I don't know where to start. I know how to execute it at least and i know how to do all of this with the commands but I have no idea how to create the bash script file. I would appreciate the help and some explanation so I can at least try to understand this. My class is using the newest version of fedora if that helps. Also the professor wants us to use nano for it

Answer 1

What's wrong with a 10-15 page report? Research and writing included, your looking at an hour-per-page. Piece of cake... Or,

You owe a lotta beer:

#!/bin/bash

while [ "$SEL" != q ]; do
cat >&2 << MENU

  Enter a number to launch:
    a - Create a File
    b - Create a Directory
    c - Delete a File
    d - Delete a Directory
    e - Create a User
    f - Delete a User
    q - Exit
MENU
    printf "\n  Enter your choice: "
    read SEL
    SEL=${SEL,,}
    case $SEL in
        a ) printf "\nWhat would you like to name your File?\n"
            printf "(including the path to the file location): "
            read -r fname
            [ -n $fname ] && touch "$fname" || \
            printf "error: invalid filename.\n"
            unset fname
            ;;
        b ) printf "\nWhat would you like to name your Directory?\n"
            printf "(including the path to the directory location): "
            read -r dname
            [ -n $dname ] && mkdir -p "$dname" || \
            printf "error: invalid directory name.\n"
            unset dname
            ;;
        c ) printf "\nWhat File would you lime to delete?\n"
            printf "(including path): "
            read -r fname
            [ -w "$fname" ] && rm "$fname" || \
            printf "error: invalid filename or insufficent permission.\n"
            unset fname
            ;;
        d ) printf "\nWhat Directory would you lime to delete?\n"
            printf "(including path): "
            read -r dname
            [ -d "$dname" -a -w "$dname" ] && rm -r "$dname" || \
            printf "error: invalid directory or insufficent permission.\n"
            unset dname
            ;;
        e ) printf "\nEnter user name to add: "
            read -r uname
            [ -n $uname ] && useradd $uname
            unset uname
            ;;
        f ) printf "\nEnter user name to delete: "
            read -r uname
            [ -n $uname ] && userdel $uname
            unset uname
            ;;
        q ) exit 0
            ;;
        * ) printf "\nError. Please enter a valid selection.\n"
            ;;
    esac
done

Note: you make sure you return the favor to someone in need in the future...

Answer 2

I wish your teaching assistants or professors provided a little more assistance. This is a rudimentary program that might help you. This is not a means for you to submit as an answer, but for you to learn (note that I know little about bash). I do like that you took the opportunity to tackle the bash problem instead of writing a report.

Start with copying this into nano. Remove the line numbers though. That'll be a painful process. Save the file as test.sh. From command line type: chmod 755 test.sh . To run the program, type ./test.sh

I'll write comments inline.

 1  #!/bin/bash
 2
 3  # create a function that will have echo statements
 4  # to print instructions on the screen
 5  function print_menu() {
 6  echo Please choose on of the following option:
 7  echo a - Create a file
 8  echo b - Create a directory
 9  echo c - Delete a file
10  echo d - Delete a directory
11  echo e - Create a user
12  echo f - Delete a user
13  echo q - quit
14  }

At this point we have written a function that can be reused by calling it using print_menu . You'll see as you read further.

15
16  # keep on looping until user presses q
17  while true; do
18

We want to show the print menu, then ask the user questions, based on the answer we'll do some work and then repeat the loop of showing print menu and yada yada.

19      # print the menu
20      print_menu
21      # ask user to choose an option
22      read -p "Enter your choice: " choice

So far we have shown the user the menu and asked to enter a choice. We should ideally do error checking from user input and such, but we'll cover those concepts some other time. choice is a variable (or bucket) that will store whatever user typed. If user typed a , then choice bucket will contain a . To retrieve information from that bucket, we use $choice

23      # based on user's choice, do variety of things
24      case $choice in
25          a)  read -p "Name of file to create: " file
26              touch $file
27              echo Created file $file
28              echo ----
29              ;;

Check out http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_07_03.html for more information on how to write case statements in bash. We use this case statement to evaluate contents of bucket $choice .

Then we tell bash, if the choice was a , ask another question about file to create. Store the answer in bucket called file. And use the value contained in bucket called file by using $file

touch command creates the file. Then we provide some feedback to the user and then close out that case by typing ;;

30
31          b)  read -p "Name of directory to create: " dir
32              mkdir -p $dir
33              echo Created directory $dir
34              echo ---
35              ;;
36
37          c)  read -p "Name of file to delete: " file
38              rm $file
39              echo Deleted file $file
40              echo ---
41              ;;
42
43          d)  read -p "Name of directory to delete: " dir
44              rm -rf $dir
45              echo Deleted directory $dir
46              ;;

All the above is just the same as choice a . You can add more code to handle rest of the cases.

47
48          q)  echo Goodbye
49              break;;

If the user typed q , we give feedback and we break out from the while loop.

50
51          *)  echo Nothing selected. Try again
52              ;;

If none of the above choices were given by the user, we will just provide feedback and go back to the top of the while loop.

53      esac
54      # sleep 3 seconds to give user time to digest the output
55      sleep 3
56  done
57

We sleep for 3 seconds and then go back to the top of while loop.

Hope this helps out.