Linux

sudo adduser userName, add a single user and create the home directory with default bash

sudo useradd -d homeDirectory -u userID -g groupID -s loginShell

#!/bin/bash
# add a single user

# read username and password
read -p "Enter user name: " username

# add the user and create the home directory
useradd -m $username -s /bin/bash

# create password for the user
passwd $username

# switch to the created user
# copy a .bashrc template to the home directory of the created user
sudo -u $username cp -f /home/lchen/.bashrc /home/$username

#!/bin/bash
# add multiple users

for i in `more namelist.txt`
do
        useradd -m $i -s /bin/bash
        echo -e "$i\n$i" | passwd $i
done

whoami, check the current username

sudo -u userName bash, switch to a specific user

sudo -u userName command; command; carry out commands with permission of a specific user

cat /etc/passwd, username, password, user ID, group ID, user info, home directory, bash shell

sudo userdel -r userName, remove a user and the home directory

#!/bin/bash
# remove multiple users

for i in `more namelist.txt`
do
        userdel -r $i
done

sudo adduser userName sudo

Add User