Running python script as root

Question

I have the following script:

#!/usr/bin/env python                                                           

import sys                                                                      
import pyttsx                                                                   

def main():                                                                     
        print 'running speech-text.py...'                                       
        engine = pyttsx.init()                                                  
        str = "Hi..."                                    
        if len(sys.argv) > 1:                                                   
                str = sys.argv[1]                                               
        engine.say(str)                                                         
        engine.runAndWait()                                                     

if __name__ == '__main__':                                                      
        main() 

and I have placed it in /usr/bin/speech-test.py

I have also given it executable permissions and ownership to root:

sudo chown root:root /usr/bin/speech-test.py
sudo chmod 4755 /usr/bin/speech-test.py

However, this script will only run correctly if I run as sudo speec-test.py. If I try to run it as just speech-test.py it complains about not finding a bunch of ALSA lib files.

Am I missing something to have my script run with root privileges?

Solution

So you want the script to run as root, even without sudo? For that you would need to set the setuid bit on the script with sudo chmod u+s program. However, most Unix distributions allow this only for binaries, and not for scripts, for security reasons. In general it's really not a good idea to do that.

If you want to run this script as root, you will have to run as sudo. Or, you have to create a binary that runs your script, so that you can set the setuid bit on this binary wrapper. This related question explains more.

It's also a good idea to check the effective uid, and if it's not root then stop running. For that, add this near the top (thanks @efirvida for the tip!)

if not os.geteuid() == 0:
    sys.exit("\nOnly root can run this script\n")

ORIGINAL ANSWER

Maybe your user and root use a different version of python, with different python path, and different set of libraries.

Try this:

command -v python
sudo command -v python

If the two commands don't give the same result then you either need to change the setup of the users to use the same version of python (the one that has the ALSA libs), or hardcode the python version the first line of the script.

Also try adding a print sys.path line in the script, and run with your user and with sudo and compare. Probably you'll get different results. You may need to tweak the PYTHONPATH variable of your user.

It shouldn't be necessary to make the owner of the script root, and to run it with sudo. You just need to configure python and PYTHONPATH correctly.

Comments

[m.wasowski]

That's not true if you have sticky bit set, as OP tries.

[Hot.PxL]

Oh yeah I forgot about that... Sorry

[jww]

which was changed to command -v. There are several reasons to use command -v over which. Please revert if you don't want the change. Also see How to check if command exists in a shell script? and How to check if a program exists from a Bash script?

[PeterT]

Unless packages are installed globally (accessible to sudo) this won't work, and there is a trend to keep packages local.

[Admin]

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[lonelyjoe]

(Ubuntu 22.04) This didn't work for me. I get the same "Permission Denied" error.

[hDmtP]

Do you have multiple python interpreters? If yes, then u may need to specify the version like python3