Tag Archives: sudo

hot to bypass requiretty in sudo

You can execute it a command without password from the commande line


$ sudo -l
User lsc may run the following commands on this host:
    (root) NOPASSWD: /usr/local/bin/helloworld
$ sudo /usr/local/bin/helloworld
Hello World!

Now you try to run it via cron and you get


sudo: sorry, you must have a tty to run sudo

The message is clear, you need a terminal.

Either you edit your sudoers files to disable requiretty, or you just get yourself a terminal.

Maybe you tried to assign a pseudo terminal with ssh -t, but you may get an error if ssh has no local tty


Pseudo-terminal will not be allocated because stdin is not a terminal.

Don’t despair, read man ssh


Multiple -t options force tty allocation, even if ssh has no local tty.

Let’s try


* * * * * ssh -t -t sudo /usr/local/bin/helloworld >> /tmp/txt

This should work, providing you configured ssh keys :)