How do I pass my password to sudo from an environment variable through stdin without the sudo prompt appearing?
I have tried $ echo $PASSWORD | sudo -S echo foo but that returns [sudo] password for mithic: foo.
Using the -n flag just always returns sudo: a password is required (unless I have recently inputted the correct password).
If it's really in the environment, I would recommend using the -A option instead of -S. Write a very small script that writes the value to standard output.
#!/bin/sh
printf '%s' "$PASSWORD"
Call it something like asker and make it executable
chmod +x asker
The do the following:
SUDO_ASKPASS=./asker sudo -A echo foo
-A makes sudo run the executable named by SUDO_ASKPASS and read the password from its output.