OpenEuphoria

2. Re: How can a program know whether it is running in superuser mode?

• Posted by rkdavis Jan 15, 2010
• 934 views

not sure if it will work but in bash you'd check the env var EUID so perhaps you can check that.

4. Re: How can a program know whether it is running in superuser mode?

• Posted by JerryStory Jan 16, 2010
• 957 views

if [[ $EUID -ne 0 ]]; then 
   echo "This script must be run as root" 1>&2 
   exit 1 
fi 

Thanks. But now I have difficulty putting that in system() or system_exec() in a way that works.

6. Re: How can a program know whether it is running in superuser mode?

• Posted by jimcbrown (admin) Jan 16, 2010
• 933 views

 
sequence env 
env = getenv("USER") 
puts(1, env & "\n") 
 
--and 
if equal(env, "ROOT") = 1 then 
  --do stuff 
else 
  --don't do stuff 
end if 
 

This is a BAD idea. I believe any user can set the USER variable to whatever they want.

This is actually not as dangerous as changing the USER variable won't change the permissions, so there is not really a security violation, but this method isn't very accurate to determine if you really are root or not.

On bash, UID is a read-only variable, but a simple C program could override the value of the UID environment variable as well. (But again, if done this is not a security breach.)

There is no way in Euphoria to do this. The only chance is to use dll.e and wrap the "getuid()" and "geteuid()" functions from the C library.

8. Re: How can a program know whether it is running in superuser mode?

• Posted by rkdavis Jan 16, 2010
• 917 views

Using $EUID is only a quick and dirty check. It can be fiddled with but it's not going to do anyone trying to fool your program any good as the system()/system_exec() would still fail anyway when they themselves try to do something they don't have the pivs to do

so personally i'd still use $EUID if all i wanted to do was warn the user they'd need to sudo (or run as root) and then exit out if they weren't

another quick and dirty method that is more system()/system_exec() friendly is id as you could pipe it's result into something else

however if you are going to be doing stuff like that alot i'd say jim's method would be the correct way

10. Re: How can a program know whether it is running in superuser mode?

• Posted by alanjohnoxley Jan 18, 2010
• 886 views

Some id's can have root permissions via the sudo'ers file, while not being the root id themselves.
How about trying to touch a garbage file in the /tmp folder, then chown it to root.
If thats successful, then you do have root permissions even if you are not the root user.
Normally you want to know if you have root permissions.