Ubuntu Linux: Edit and Open Files That Require Administrator Privileges

1. sudo command : Execute a command as another user using command line method.
2. gksudo or gksu command : Execute a command as another user using graphical tool.

Requirements

The normal user needs to be a member of the admin group to raise privileges either via the sudo or gksudo/gksu command. By default, the first user account on a Ubuntu Linux is a member of the admin group. You can verify this by typing the following commands:

## find out your user name ##
who am i 
 
## verify that you are part of either sudo or admin group ##
id 
 
## Or use /etc/group file to verify that you are part of either sudo or admin group ##
egrep -i 'sudo|admin' /etc/group

Sample outputs:

Fig.01: The normal user needs to be a member of the admin or sudo group.

Examples

The nixcraft user is part of the admin or sudo group. All members of the admin group may gain root privileges or allow members of group sudo to execute any command using either CLI or graphical method.

Command line method

The syntax is:

sudo command
sudo command arg1 arg2

Open the Terminal app and edit file called /etc/resolv.conf either using with nano or vi text editor:
sudo nano /etc/resolv.conf
OR
sudo vi /etc/resolv.conf
You need to provide normal user’s password when prompted:

Gif 01: sudo command demo

sudo -K

Graphical method

The syntax is as follows to edit the file /etc/resolv.conf using the gksudo command. First, press ALT-F2 and type the following command in the box (open the terminal app and type the following command):

gksudo gedit /etc/resolv.conf

Sample outputs:

Fig. 02: Press ALT+F2 and type gksudo command

Fig.03: Type normal user account password i.e. your own password when promoted to perform admin task

Fig. 04: gedit editing files with administrator privileges

See also

• Linux Run Command As Another User – explains use of su and runuser commands on a Linux bases systems.
• Man pages – gksu(1)