BASH script to add username, password and multiple groups

Question

ASSUMPTIONS:

I have a file called users.txt

username:password:groups
user1:password:group1,group2,group3
user2:password:group3
user3:password:group1,group3
user4:password:group2,group3

CODE

#!/bin/bash
FILENAME="users.txt"

while IFS=':' read USERNAME PASSWORD GROUPS
do

    echo "USERNAME" $USERNAME "PASSWORD" $PASSWORD "GROUPS" $GROUPS

done < "$FILENAME"

I want to be able to add a bunch of users to be able to do a samba share. I have a full list of users to input. I am having difficulty mostly with the groups.

Two biggest questions are, how to I get the groups as one string and how do I encrypt the password.

I have been through all tutorials on this site and none of them are working.

Simple to understand code would really help. Thanks.

UPDATED FINISHED WORKING EXAMPLE

#!/bin/bash
# set filename
FILENAME="users.txt"

# loop through file 
while IFS=':' read USERNAME PASSWORD GROUPNAMES
do

    # add user and assign groups
    echo " "
    echo "ADDING USER: " $USERNAME
    useradd $USERNAME -G $GROUPNAMES

    # add password
    echo -e "$PASSWORD\n$PASSWORD\n" | passwd $USERNAME

    # add user to samba
    echo -e "$PASSWORD\n$PASSWORD\n" | smbpasswd -a $USERNAME

done < "$FILENAME"

Answer 1

Don't use GROUPS as a variable name : it's a read-only variable already used by the system. Just change the name of this variable.

Answer 2

I'm not sure about the password encryption part but I can give a suggestion about the groups. Inside of your loop, you could do this:

read -ra groups_array -d, <<<"$groups"

Now you have an array containing each group as an element. You can pass them as separate arguments to a command using the expansion "${groups_array[@]}" or access them individually using "${groups_array[0]}" , "${groups_array[1]}" , etc.

Note that I am using lowercase variable names - this is intentional. Uppercase names should be reserved for use by the shell, as otherwise you run the risk of overwriting important ones.

Answer 3

Excellent script above: I used the code co create this working version.

#!/bin/bash

This method includes the bash code and data in just one file

Install this file, run it and remove it immediately for future use with a new server etc.

function setupUser()
{

first, remove old instance of user in both linux and samba

echo "remove user: " $1 smbpasswd -d $1 userdel $1

Now add new user in both linux and samba

echo "adding user: "$1 useradd $1 -G nogroup echo -e "$2\\n$2\\n" | passwd $1 echo -e "$2\\n$2\\n" | smbpasswd -a $1 }

#---------------------------------------------------------------------------

setupUser tom secret setupUser dick secret setupUser harry secret