run command as root from shell script

[luishi07]

Hello people, i'm new to this linux business and i really need your help.
I'm running ubuntu 7.04
I need to run a script that will be executed in cron.
This script must shutdown the linux box.
The problem i have is that i can't run the shutdown because i don't have root permissions in this user.
I don't want to modify my user's permissions, i just want to enter a script with the username and password of root that turns off the linux box
thanks a lot

[Juan Pablo]

I'm afraid it's not possible to just 'store' in a file the root password, it's not a good idea either. The best I can think of is using a password-less sudo that just works for shutdown

[anomie]

As another option, see this blurb from the manpages for shutdown(8 )
(in code tags to preserve formatting):

ACCESS CONTROL
       shutdown  can  be called from init(8) when the magic keys CTRL-ALT-DEL
       are pressed, by creating an appropriate entry  in  /etc/inittab.  This
       means  that  everyone  who has physical access to the console keyboard
       can shut the system down. To prevent this, shutdown can check  to  see
       if  an authorized user is logged in on one of the virtual consoles. If
       shutdown is called with the -a argument (add this to the invocation of
       shutdown  in  /etc/inittab),  it  checks to see if the file /etc/shut-
       down.allow is present.  It then compares the login names in that  file
       with  the list of people that are logged in on a virtual console (from
       /var/run/utmp). Only if one of  those  authorized  users  or  root  is
       logged in, it will proceed. Otherwise it will write the message

       shutdown: no authorized users logged in

       to the (physical) system console. The format of /etc/shutdown.allow is
       one user name per line. Empty lines and comment lines (prefixed  by  a
       #) are allowed. Currently there is a limit of 32 users in this file.

       Note  that  if  /etc/shutdown.allow is not present, the -a argument is
       ignored.

So with some modifications to /etc/inittab and additions to /etc/shutdown.allow you may be able to produce the functionality you want.

Caveat: This is a CentOS 4.5 box. You'll need to check if the same rules apply for your ubuntu box.

[luishi07]

thanks people for your help, you are the very best linux has to offer.
I think the linux software rocks but the comunity of users, experienced users and programmers that are willingly helping each other is the real linux spirit and POWER.
Im gonna tell you how i´ve solved this problem of mine. (this probably is a way to stupid way to do it but is the one that is working now for me)
I just made a crontab file for the user root which im certain that has shutdown permissions.
1- open terminal
2- log as root (su)
3- crontab -u root -e
4- 15 15 * * * /sbin/shutdown -r now
minute hour dom dow command to execute.
Now your computer will automatically shut down every day at 15:15 hours.

It works like a charm in ubuntu linux 7.04 feisty feast 64 bit edition

HOPE THIS HELPS SOMEONE.
THANKS A LOT FOR YOUR HELP

Pd: do you know any firewall out of the box for linux (with gui and ms windows like stuff like kerio for example) im new to linux i was a pretty good windows user

[Juan Pablo]

Try firestarter, it's a frontend to IPtables, the default Linux firewall