This Blog primarily focus on providing solutions for administering Linux Operating system in Enterprise environment. I have put my best effort to ensure the solutions provided in this are accurate, easy to follow, effective, and helpful for Linux Users & System Administrators.
When you execute an useradd command (# useradd <username>”), the following happens.
1.Add the new user entry in the following files:/etc/passwdand/etc/shadow
2.A group will be created with the same username and it will be updated in the following files:/etc/groupand/etc/gshadow.
3.Home folder for the user will be created (/home/<username>) and the default profile settings will be copied from/etc/skelto it.
# ls -la /etc/skel/
drwxr-xr-x 3 root root 4096 Aug 16 13:03 .
drwxr-xr-x 111 root root 12288 Oct 6 15:10 ..
-rw-r--r-- 1 root root 33 Jan 21 2009 .bash_logout
-rw-r--r-- 1 root root 176 Jan 21 2009 .bash_profile
-rw-r--r-- 1 root root 124 Jan 21 2009 .bashrc
-rw-r--r-- 1 root root 515 May 24 2008 .emacs
drwxr-xr-x 4 root root 4096 Jul 26 18:19 .mozilla
-rw-r--r-- 1 root root 658 Sep 21 2009 .zshrc
Please note in the case, if you happen to accidently delete either /etc/passwd or /etc/shadow files, you can restore it from its corresponding backup files (i.e/etc/passwd- , /etc/shadow-) respectively. These files are updated upon the system reboot. So you can’t expect these files to be having the entries for user accounts which are added after the system reboot.