Either login as the root user or type: sudo then the command you wish to run.
sudo will run a command with root privileges
When u put sudo before a command in terminal the command run with root privileges
You can obtain root permissions in Linux by using the "sudo" command before executing a command that requires elevated privileges. This allows you to temporarily act as the root user to perform administrative tasks. Alternatively, you can switch to the root user using the "su" command by entering the root user's password.
Virtually all Linux distributions will accept the "halt" command. Some also have a shutdown command, though this has additional parameters and is meant mainly to shut down the system at a certain time.
Run the command "passwd". You will have to enter your old password to change it. If you are root, you will not have to enter the old password to change a user's password.
If by simulate you mean to run command as root i.e with root privileges then sudo is the command. sudo <command name> which execute the command with root privileges.
sudo is a Linux command used to execute programs as the root, or "super user." sudo is a shortening of "super user do." One uses sudo when they need to run a command or program as root, but do not wish to log out or switch their entire shell to root privileges (like they could do with the su command). The file sudoers defines per user or per group what commands can be run with sudo. This file is edited with the command visudoers
if the file is allready runnable you can type in the terminal: ./filename
if the file is allready runnable you can type in the terminal: ./filename
sudo ... but you have to be in the sudoers list which has to be edited as root. Once you are in the sudoers file/list, you can execute a command as root by typing "sudo" (without quotations) and then a space and then the command. You will be asked for your password, enter it, and the command will be executed with root privileges. The sudoers file is in /etc.
"r" is not a standard command on Linux systems. Some systems may included or provide support for the R programming language, in which case the command would launch the "littler" program to run R commands included in the file 12.
If you want to run something on an existing X display from a console the correct syntax is: DISPLAY=":0.0" (command) Of course, it might just be easier to go to your X display and run your command from there.