bash shell automatically creating user - adduser

Question

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.

You are missing a `fi` to start with. There are better ways of splitting those fields than by using external programs like `grep` and `cut`. What's `b4` all about? — cdarke, Sep 04 '18 at 07:13
its supposed to be 4. thats a mistake. ty for the fi correction. — DazedNConfused, Sep 04 '18 at 07:23
Also see [How to use Shellcheck](https://github.com/koalaman/shellcheck), [How to debug a bash script?](https://unix.stackexchange.com/q/155551/56041) (U&L.SE), [How to debug a bash script?](https://stackoverflow.com/q/951336/608639) (SO), [How to debug bash script?](https://askubuntu.com/q/21136) (AskU), [Debugging Bash scripts](http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_02_03.html), etc. — jww, Sep 04 '18 at 08:15

score 3 · Accepted Answer · answered Sep 04 '18 at 07:11

3

Always quote your variables unless you deliberately want to split the value into separate words.

sudo adduser --gecos "$fullname" --disabled-password --home "$home" "$username"

Also, you have to use double quotes around strings containing variables, not single quotes, if you want the variables to be expanded.

Difference between single and double quotes in Bash

So this line:

echo 'username:$password' | chpasswd

should be:

echo "username:$password" | chpasswd

answered Sep 04 '18 at 07:11

Barmar

741,623
53
500
612

one more problem. What is wrong with the echo commands that show the generated password? – DazedNConfused Sep 04 '18 at 07:22
You mean the last echo command? It looks fine to me. What does shellcheck.net say about it? – Barmar Sep 04 '18 at 07:37
BTW, is there a reason you're doing all that echoing and cutting instead of just `while read username home fullname`? – Barmar Sep 04 '18 at 07:39

bash shell automatically creating user - adduser

1 Answers1