Creating a large number of users
http://www.cyberciti.biz/tips/linux-how-to-create-multiple-users-accounts-in-batch.html
http://www.thegeekstuff.com/2009/06/useradd-adduser-newuser-how-to-create-linux-users/
newusers command reads a file of user name and clear-text password pairs and uses this information to update a group of existing users or to create new users. Each line is in the same format as the standard password file.
This command is intended to be used in a large system environment where many accounts are updated at a single time (batch mode). Since username and passwords are stored in clear text format make sure only root can read/write the file. Use chmod command:
# touch /root/batch-user-add.txt # chmod 0600 /root/batch-user-add.txt
Create a user list as follows. Open file:
# vi /root/batch-user-add.txt
Append username and password:
user1:password:1001:513:Student Account:/home/user1:/bin/bash user2:password:1002:513:Sales user:/home/user2:/bin/bash user100:password:1100:513:Sales user:/home/user100:/bin/bash tom:password:1110:501:Guest Account:/home/guest:/bin/menu jerry:password:1120:501:Guest Account:/home/guest:/bin/menu
Now, create users in batch:
# newusers /root/batch-user-add.txt