Bash Shell Scripting - Select Case Menu Not Working - bash

Question

i'm quite new to shell programming.. and working on project
am doing Select Menu using the Select Case
below is the scripting
#! /usr/bin/bash
echo "1) Add new book"
echo "2) Remove existing book info"
echo "3) Update book info and quantity"
echo "4) Search for book by title/author"
echo "5) Process a book sold"
echo "6) Inventory summary report"
echo "7) Quit"
PS3="Please enter your option: "
select book in Add Remove update search process inventory quit
#read book
do
case $book in
1) echo "Add new book"
echo "Title: "
read title
echo $title > BookDB.txt
echo "Author: "
read name
echo $name > BookDB.txt
echo "$title successfully added!"
break
;;
2) echo "Remove existing book info"
sed '$NAME' BookDB.txt
break
;;
3) echo "Update book info and quantity"
echo "Title: "
read title
echo $title < BookDB.txt
echo "Author: "
read name
echo $name < BookDB.txt
break
;;
4) echo "Search for book by title/author"
break
;;
5) echo "Process a book sold"
break
;;
6) echo "Inventory summary report"
break
;;
7) echo "Quit"
exit
;;
esac
done
and below is the shell commands in the Ubuntu terminal
1) Add new book
2) Remove existing book info
3) Update book info and quantity
4) Search for book by title/author
5) Process a book sold
6) Inventory summary report
7) Quit
1) Add 3) update 5) process 7) quit
2) Remove 4) search 6) inventory
Please enter your option: 1
Please enter your option:
the words in the echo do not appear after i entered 1.and even if i I choose Quit, it doesn't go back to the menu. how do i get it to work? :(
Any help is greatly appreciated. thanks! :)

Answer 1

From the bash manpage (my italics and bold):
select name [ in word ] ; do list ; done
The list of words following in is expanded, generating a list of items. The set of expanded words is printed on the standard error, each preceded by a number. If the in word is omitted, the positional parameters are printed (see PARAMETERS below).
The PS3 prompt is then displayed and a line read from the standard input.
If the line consists of a number corresponding to one of the displayed words, then the value of name is set to that word.
If the line is empty, the words and prompt are displayed again. If EOF is read, the command completes.
Any other value read causes name to be set to null. The line read is saved in the variable REPLY. The list is executed after each selection until a break command is executed.
The exit status of select is the exit status of the last command executed in list, or zero if no commands were executed.
Hence, in your case statement, you need "Add" rather than 1, ditto for the others.
You should also look into what you're actually doing in each case. Obviously the latter ones are empty because you haven't yet gotten around to them, but your use of sed in the second case will not remove anything from the file as it stands. And, for the third case:
echo $title < BookDB.txt
in ... interesting. If it were output redirection, I could understand the beginnings of a plan but the line as you have it will simply output $title and totally ignore the content of your input redirection.
No doubt you'll fix them in time, I just thought I'd bring them to your attention as something that needs looking at.

Answer 2

Try this:
PS3="Please enter your option: "
select book in Add Remove Update Search Process Inventory Quit
do
case $book in
"Add")
...
;;
"Remove")
...
;;
"Update")
...
;;
etc...
esac
done

Answer 3

Under select statement, in case you should use the string stated in select. Here you should do it like this:
select book in Add Remove update search process inventory quit
do
case $book in
Add) echo "Add new book"
echo "Title: "
read title
echo $title > BookDB.txt
echo "Author: "
read name
echo $name > BookDB.txt
echo "$title successfully added!"
break
;;
Remove) echo "Remove existing book info"
sed '$NAME' BookDB.txt
break
;;
update) echo "Update book info and quantity"
echo "Title: "
read title
echo $title < BookDB.txt
echo "Author: "
read name
echo $name < BookDB.txt
break
;;
search) echo "Search for book by title/author"
break
;;
process) echo "Process a book sold"
break
;;
inventory) echo "Inventory summary report"
break
;;
quit) echo "Quit"
exit
;;
esac
done
You can understand the code as below:
select prepare many values for book, and which value assigned is due to what we input. The input should be integer indexed begin from 1.
For further understanding, you should learn much about bash and select system call.

Answer 4

Replace
select book in Add Remove update search process inventory quit
With:
select book in 1 2 3 4 5 6 7