パラメータ付きbashスクリプトを使用したユーザーの作成

（s）ftpユーザーを生成するスクリプトを作成しようとしていますが、失敗し続け、理由がわかりません。コマンドをエコーすれば大丈夫です。コピーして貼り付けてユーザーを作成できますが、bashスクリプトでコマンドを実行するとユーザーを作成できません。

私が得る唯一のエラーは、useraddコマンドのヘルプセクションで発生します。

私が間違っていることを知っている人はいますか？

#!/bin/bash
# at the top are all the functions  at the bottem is the execution order
username() 
{
echo Enter the username.
read USERNAME
echo 
echo 
echo 

if [ -n "$USERNAME" ]; then
        :
        else
            echo "You didn't supply a username"
            username
         exit 1
fi
echo "the username you have selected is " $USERNAME
read -p "Is this the username you would like to use? Yy/Nn  " yn
case $yn in
    [Yy]* ) echo ;;
    [Nn]* ) username;;
    * ) echo "Please answer yes or no."; username;;
 esac
  }
groups()
{
groeps=($(cat /etc/group | grep ftponly))  #productie
#groeps=($(cat group | grep ftponly))  #local test
read -p "$(
         f=0
        for groepname in "${groeps[@]}" ; do
            # echo "$((++f)): $groepname"
     echo "$((++f)): ${groepname:0:8}"
    done


    echo -ne 'Please select the groep you would like to use > '   
 )" selection

selected_groep="${groeps[$((selection-1))]}"
echo "you have selected " ${selected_groep:0:8}
read -p "is this the right group? Yy/Nn  " yn
case $yn in
[Yy]* ) echo " " ;;
[Nn]* ) groups;;
* ) echo "Please answer yes or no."; groups;;
esac
}

 ticket()
{
echo "Enter the ticket number"
read TICKET
echo 
echo 
if [ -n "$TICKET" ]; then
    :
        else
    echo "you didnt supply a ticket number, to execute this you need to have a ticket number."
    ticket
fi
}
endcommand() 

{
echo  
echo 
DIR=/data/xchangeremote
final="/usr/sbin/useradd -g ${selected_groep:10:4} -c \"$USERNAME + $TICKET\" -d $DIR/./\"$USERNAME\" -s /usr/sbin/nologin \"$USERNAME\""
echo $final
echo "To check if the command is correct see example on: "

read -p "is the command correct now? Answer with: Yy/Nn " yn
    case $yn in
            [Yy]* ) echo ;;
            [Nn]* ) echo "please enter the correct username"; username; groups; ticket; endcommand;; 
            * ) echo "Please answer yes or no."; endcommand;;
     esac
PASSWORD=$(< /dev/urandom tr -dc '1234567890!@#$%qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM' | head -c12; echo "")
echo " the password for this account will be" $PASSWORD 
$final
$USERNAME:$PASSWORD | chpasswd
}
#here are the functions called
username
groups
ticket
endcommand