Sstrhsrtj

 The idea is that I need to write the username and the password and the script tell me who I am.

• if:
  
  username: admin pass: admin the script echo: "you are an admin"


• if:
  
  username: user pass: user the script echo: "you are a user"


• if:
  
  username: anonymous pass: anonymous the script echo: "you are anonymous"


• if
  
  username=="admin" and password=="hello"
  echo password wrong


• if
  
  username=="hello" and password=="admin" (for example) echo username non available

I expect you do not want to write a real login script but rather
want to play a bit with scripting. The following script will do what
you ask …

#!/usr/bin/env bash



read -p "username: " username

read -p "password: " password



case $username in

    admin|user|anonymous)

        if [[ $password == $username ]]; then

            echo "you are $username"

        else

            echo "wrong password"

        fi

        ;;

    *)

        echo "username not available"

esac

… but it has some flaws:

• It shows the password in cleartext while the user is typing.
  This is usually NOT what anyone wants.


• The usernames and passwords must be equal in this case and
  are also hard coded in the script. That means: anyone who
  can execute this script can also look into it and see what
  the expected passwords are.

The script prompts for username and password and stores them in the
variables $username and $password. Then it checks whether the
$username is one of admin, user, or anonymous. If so, it
checks whether the $username and the $password match.