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[Shell] [Bash Script] Go back to menu, when an option is selected - Printable Version

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+---- Thread: [Shell] [Bash Script] Go back to menu, when an option is selected (/showthread.php?tid=6022986)

[Bash Script] Go back to menu, when an option is selected - friiz1337 - Nov 7, 2019

Hello guys

Down here I have a code that lets a user login into a system, as well as create an account. My question is: How can I loop this same code every time the user creates an account (chooses option 2, specifies username and password, and then shows the same menu(in case the user wants to create another account)).
I know bash doesn't have a goto option so I tried wrapping this whole piece of code into a function, but without luck (I miss something) . :/

Thanks for the help.

Code
echo
echo
welcomeMessage                  #welcome message function
echo
echo 1: Login                   #login option
echo 2: Create account          #create account option
echo
echo Enter your option:
read options                    #read option
case $options in
   "1")                                #login
       echo Enter Username
       read username           #read username entered
       grabUser                        #function to check if username exists and return 1 if he exists
       if [ "$userResult" == 1 ]; then
           enterPass           #prompt password field

       else
           userResult=0
           while [ "$userResult" == 0 ]; do
               echo -n Try again:
               read username
               grabUser
   done
           enterPass
       fi
grabPass                        #function to check if password exists and return 1 if it exists
       if [ "$passResult" == 1 ]; then
           echo
           echo
           welcomeASCII
       else
           passResult=0
           while [ "$passResult" == 0 ]; do
               echo Try again:
               read -s password
               grabPass
           done
           echo
           echo
           welcomeASCII                #welcome screen ASCII function
       fi
echo
echo
;;
   "2")                                #create user option
       echo Create Username:
       read username
       grabUser
       while true; do          #while grabUser grabs username
           if [ "$userResult" == 0 ]; then             #if username doesn't exist
               insertUser                              #add user to db
enterPass                               #prompt password field
               insertPass                              #add password to db
           else
               userResult=1
               while [ "$userResult" == 1 ]; do #loop until user doesn't exist
                   echo Try Again
                   read username
                   grabUser
               done
               insertUser
               enterPass
               insertPass
           fi
       done
esac


RE: [Bash Script] Go back to menu, when an option is selected - m3rkill - Nov 8, 2019

how about making the script start itself again instead of quit?

RE: [Bash Script] Go back to menu, when an option is selected - netWalker - Nov 12, 2019

Here's how I'd do it.

Code
#!/bin/bash
make_account() {
  do stuff...
  do more stuff...
}

while true
do
  make_account
done

Of course you could also just make the entire thing a while loop. Something like this:
Code
#!/bin/bash
while true
do
  make account commands...
  make account commands....
done

A few side notes unrelated to your question. Do what you want with this, just my opinion.
1) The "echo" commands
There's an unnecessary number of them. It makes it not very pretty to read. I'm not judging, I used to do the same thing. Instead you should use something like this:
Code
echo -e "Make account\n\n"
It's the same thing as
Code
echo "Make account"
echo
echo
But it calls echo less, which makes things marginally faster. And it's easier on the eyes.
2) Make a prompt for "read."
You can give the read command a prompt by using this: read -p "Select an option: " option. Just a cosmetic thing really. Purely optional.

3) Might as well make that "case" statement an if-else. You really only have 3 possible options. Login, make account, and wtf ever else the retarded user could put in. This is again a personal preference thing, but it just seems a bit unnecessary. You could just make it a if-else.
Code
#!/bin/bash
if [ $option == 1 ]; then
  code...
  code...
elif [ $option == 2 ]; then
  code...
  code...
else
  echo "$option is an invalid option"
fi


RE: [Bash Script] Go back to menu, when an option is selected - friiz1337 - Nov 13, 2019

(Nov 12, 2019 02:52 PM)netWalker Wrote:  Here's how I'd do it.

Code
#!/bin/bash
make_account() {
 do stuff...
 do more stuff...
}

while true
do
 make_account
done

Of course you could also just make the entire thing a while loop. Something like this:
Code
#!/bin/bash
while true
do
 make account commands...
 make account commands....
done

A few side notes unrelated to your question. Do what you want with this, just my opinion.
1) The "echo" commands
 There's an unnecessary number of them. It makes it not very pretty to read. I'm not judging, I used to do the same thing. Instead you should use something like this:
Code
echo -e "Make account\n\n"
It's the same thing as
Code
echo "Make account"
echo
echo
But it calls echo less, which makes things marginally faster. And it's easier on the eyes.
2) Make a prompt for "read."
 You can give the read command a prompt by using this: read -p "Select an option: " option. Just a cosmetic thing really. Purely optional.

3) Might as well make that "case" statement an if-else. You really only have 3 possible options. Login, make account, and wtf ever else the retarded user could put in. This is again a personal preference thing, but it just seems a bit unnecessary. You could just make it a if-else.
Code
#!/bin/bash
if [ $option == 1 ]; then
 code...
 code...
elif [ $option == 2 ]; then
 code...
 code...
else
 echo "$option is an invalid option"
fi

Wow, thanks for the great answer, I will modify my code and get back to this thread. As for the tips, thank you, I'm sort of new to programming so anything is helpful.

RE: [Bash Script] Go back to menu, when an option is selected - netWalker - Nov 14, 2019

(Nov 13, 2019 10:26 AM)friiz1337 Wrote:  Wow, thanks for the great answer, I will modify my code and get back to this thread. As for the tips, thank you, I'm sort of new to programming so anything is helpful.

Glad I could help. Good luck with your script.

RE: [Bash Script] Go back to menu, when an option is selected - friiz1337 - Jan 11, 2020

So, it's been a while since my last reply, however I managed to solve my problem. I just used the exec "$0" command right after my "register" option loop. This allows the program to restart without creating additional processes, after the user has created an account. I also changed the case with if-elif's.
Another option that was pretty close to solving my problem was using break 2/3 (depending on your loops).

Thank you for the help.

RE: [Bash Script] Go back to menu, when an option is selected - FantaŠec - Feb 3, 2020

If you’re still looking to improve this, can you post an updated version? You shouldn’t have to use exec at all to leverage this functionality (exec isn’t usually ideal for a case like this too).

RE: [Bash Script] Go back to menu, when an option is selected - AnonMouse - Feb 6, 2020

this would be cool to use if you could make it smaller

RE: [Bash Script] Go back to menu, when an option is selected - friiz1337 - Feb 6, 2020

(Jan 11, 2020 03:34 AM)friiz1337 Wrote:  So, it's been a while since my last reply, however I managed to solve my problem. I just used the exec "$0" command right after my "register" option loop. This allows the program to restart without creating additional processes, after the user has created an account. I also changed the case with if-elif's.
Another option that was pretty close to solving my problem was using break 2/3 (depending on your loops).

Thank you for the help.

I actually updated this by using functions lol. Calling a function works like a charm