Basics of System Administration in Linux

Ubuntu 10.10

Objective 

adduser

sudo
su
sudo -i
usermod
userdel
id
du
df

Summary

 adduser command to create a new user account
 su command to switch from one user to another
 sudo -i  command to change root password 
 usermod command for changing the user account setting
 userdel command to delete the account
 id command to know the information about user ids and group ids
 df command to check the file system size and its availability
 du command to check the space occupied by a file



adduser
 
   The adduser command will create a new user login for us along with authentication
    we can add any user account with the help of sudo command

sudo

   sudo command allows the administrative user to execute a command as a super user.
   The sudo command has many options.

Su
 
   su stands for 'Switch User'
   This commands is useful in switching from current user to another user.




sudo -i

  sudo -i command which is user to change a root password




usermod
 
  usermod Enables a super user or root user to modify the setting of others
  user accounts:
       change the password to no password or empty password
       show the date on which the user
       account will be disabled



userdel

 we can delete the user account permanently with the help of  the userdel command



id

id command is used to check the identities of all the users and groups on the system
To know about the identity of the user, we use id -u
To know about the identity of the group users,it is id -g



df / du

 The df command gives a report on the free space available on the disk.
 The du command gives a report on how much space a file has occupied.