create user from JAVA application in LINUX OS

Java code to create a user in linux

public static void main(String[] args) {
    try {

        ProcessBuilder pb = new ProcessBuilder("sudo useradd username",
                "sudo mkdir /home/username", "sudo passwd username",
                "sudo chown username /home/username",
                "sudo chgrp username /home/username",
                "sudo adduser username", "sudo adduser username sudo");
        pb.redirectErrorStream();
        Process process = pb.start();
        InputStream inputStream = process.getInputStream();
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                inputStream));
        String line = null;
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }
        process.waitFor();

    } catch (Exception ex) {
        ex.printStackTrace();
    }
}

create/remove user accounts using the terminal

1. Adding A User Account

   • You can add a user account from the terminal with this command:

   sudo useradd username

Replace username with any name of your choice.

• Create the home directory for this new user with this command:

  sudo mkdir /home/username

Assign now a password for this user with this command:

sudo passwd username

Grant this user ownership and access to its home directory with these two commands:

sudo chown username /home/username

sudo chgrp username /home/username

You can also create a new user account with this command:

sudo adduser username

Grant Root Priviliges To A User Account (Optional)

If you want to give a user account root privileges so that it can execute "sudo" commands, run this command:

sudo adduser username sudo

Execute all commands using java Process class

Process p = Runtime.getRuntime().exec("////command////");

Sample shell script to add a user Based upon above discussion here is a sample shell script

#!/bin/bash
# Script to add a user to Linux system
if [ $(id -u) -eq 0 ]; then
read -p "Enter username : " username
read -s -p "Enter password : " password
egrep "^$username" /etc/passwd >/dev/null
if [ $? -eq 0 ]; then
    echo "$username exists!"
    exit 1
else
    pass=$(perl -e 'print crypt($ARGV[0], "password")' $password)
    useradd -m -p $pass $username
    [ $? -eq 0 ] && echo "User has been added to system!" || echo "Failed    to add a user!"
    fi
else
echo "Only root may add a user to the system"
exit 2
fi

Close and save the script: $ ./adduser.sh

Only root may add a user to the system

Run as root:

./adduser

Output:

Enter username : manaf
Enter password : HIDDEN
User has been added to system!