c++ command to shutdown ubuntu computer?

Okay ...

First to shutdown Linux you have to invoke a command to the shell

Many commands can do like: $ init 0

So we look for a way to call a terminal shell from inside our c++ application then send this command to that shell.

Many functions in c++ allow this. Lets use popen():

#include <stdio.h>

int main() {

extern FILE *popen();

/* popen creates a pipe so we can read the output

of the program we are invoking in terminal*/

if (!(popen("init 0", "r"))) {

exit(1);

}

Here we create a pointer to a file that will hold the output of the command (we don't need the output for the purpose in our hand). Then we use the method popen() to send the command as the first parameter as you see.

Notes:

1.This command (init) may need a root privilege to be executed. I don't know how to do this maybe you need to run your c++ application as root?

2.I didn't try this myself, i just did some search for my idea and this is what i came up with.

I hope this help you.

Shutdown Ubuntu Command

I don't believe there is one... What you want to do is call the program shutdown with root privileges and attribute now (sudo shutdown now) or hook into GDM and get it to do it. But I personally have no idea how to hook into GDM to spare you the sudo so I'm afraid you will have to ask someone from gnome...