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Viswa
Asked: 2013-03-23 02:59:25 +0800 CST

How do I resolve the tty problem?

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I am developing project by using python script in Ubuntu 10.04. In my project,I need to reboot the system automatically at particular time period. So that,I was wrote the below command in my python script.

passwd = "my system password"
os.system('echo %(passwd)s | sudo reboot -f' %locals())

It was working fine but today when I run my script it throws the below error.

sudo no tty present and no askpass program specified
How to resolve this problem.I need to reboot my system through python script.If you know let me, your answer is very useful to me.

10.04

2 Answers

  1. You can restart your computer through dbus, no password required.

    (Taken from a previous answer of mine)

    #!/usr/bin/env python

import dbus

def main():
    answer = raw_input("Do you really want to shutdown your computer? (Y/n): ")
    if answer in ('y', 'Y', ''):
        bus = dbus.SystemBus()
        bus_object = bus.get_object("org.freedesktop.Hal", "/org/freedesktop/Hal/devices/computer")
        bus_object.Shutdown(dbus_interface="org.freedesktop.Hal.Device.SystemPowerManagement")

if __name__ == "__main__":
    main()
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  2. I've found very interesting information that could help your problem.

    sudo will only run a program as a different user if one of these 3 conditions has been met (as far as passwords are concerned):

    1. the NOPASSWD option is specified
    2. the user entered the correct target password
    3. the user entered the correct source password

    Since options 2 and 3 require a TTY (sudo won't read from a pipe) it won't run if it can't find one. Check your script if at any point you're running a script remotely using ssh, as it's possible that it won't allocate a TTY for a non-interactive remote command.

    Source: Post #2 (by pludi) on sudo: no tty present and no askpass program specified (by linuxgeek)

    For more information about this solution, see that forum discussion.

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