Bash Shell Automatically Creating User - Adduser

I need to automatically create a user by reading lines of a file that contains username, home directory and full name.

I am new to bash shell scripting and it is very confusing to me.

There is something wrong with my adduser command. It gives the error - adduser: Only one or two names allowed.

following is the full script -

while read line;
do 
      fieldnumbers=$(echo $line | grep - o " " | wc - l)
      username=$(echo $line | cut -d' ' -f 1)
      home=$(echo $line | cut -d' ' -f 2)
      firstname=$(echo $line | cut -d' ' -f 3)

      if [[ "$fieldnumbers" -eq b4 ]]
      then
               middlename=""
      else
               middlename=$(echo $line | rev | cut -d' ' -f 2)

      lastname=$(echo $line | rev | cut -d' ' -f 1)
      password=$(echo pwgen 7 1) #create random password
      fullname="$firstname $middlename $lastname"

      echo "username is : $username"
      sudo adduser --gecos $fullname --disabled-password --home $home $username

      echo 'username:$password' | chpasswd
       echo "Password is for $username is: $password"
done < users.txt

I am sure that this script is riddled with syntax errors. Please help. my brain is fried.