how to get root's right in my program

icoming · 09-02-2004, 10:17 AM

there is the function of system("/sbin/poweroff") in my program.
When i run the program,it tells me i must be 'root' if i execute 'poweroff'.
But i execute 'poweroff' in my xterm,when i am not 'root',it doesn't tell me that i am not root.
why?

lone_nut · 09-02-2004, 11:03 AM

Setuid
It is a special atribut you can set to files, so when executed you can run it as the owner of the file, nearly always root. try
man chmod
for how to turn it on. cant remember.

icoming · 09-02-2004, 09:54 PM

But there are such softwares:when i am not 'root',and run them,they will ask me for the root's password.
how can i do that?

mirradric · 09-03-2004, 12:09 AM

Quote:

Originally posted by icoming
But there are such softwares:when i am not 'root',and run them,they will ask me for the root's password.
how can i do that?

are you refering to su?

2mcm · 09-03-2004, 02:14 AM

or sudo ?

heluani · 09-03-2004, 11:43 AM

The syntax to change the setuid flag is chmod +s /sbin/halt or +s /sbin/poweroff (I assume that poweroff is a link to halt in your system, and both of them call shutdown). Anyways this doesn't answer your original question as to why you can't run them from a program but you can call them from a Console. I believe that the answer lies in that you may have configured permissions to console users. For instance, if you're using Fedora Core/Red Hat, by default you'll have files /etc/security/console.apps/poweroff and so on, if you remove these files then you won't be able to call poweroff from console. Another thing that could be set up in your box is the line

%users localhost=/sbin/shutdown -h now

in your /etc/sudoers file, which grant access also...

Hope this answers your question.

R.

phoenix7 · 09-04-2004, 11:00 AM

hi
first you can run in the shell:

you add this line

Code:

visudo

this also as the same as

Code:

vim /etc/sudoers

you can copy the line I think that is

Code:

root ALL ALL=(ALL)

and add a line almost seems to this line

Code:

yourusername  ALL ALL=(ALL)

after that your account has root permissons to all resources in the system.
and you can run programs with this syntax

Code:

sudo yourprogram

in this case your program has root permissons.

Have a time with Linux!,
Mohammad

KneeLess · 09-05-2004, 03:03 PM

$ chmod u+s yourprogram

gizmo_thunder · 09-06-2004, 02:29 AM

There is a pam module which can be used to get the roots' password
from the user and execute something in roots' permissions.
I think that would be helpful to you.
Try searching for 'pam' in this df i saw a url posted with tutorials..
in this df could be helpful to you.