Best way to manage y/n and password prompts through a Python script

I am creating a Python script to install AUR packages but can't figure out how to detect yes/no and root password prompts.

So far what I have managed is to get rid of yes/no prompts using yes command, like this.

cmd = r'yes y | makepkg -si'
output = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True, universal_newlines=True)

But still 2 problems persist:

1. Detect the password prompt: The password prompt appears mainly after makepkg enters in fakeroot. IDK how to detect that and supply the password from the script. There is no pattern actually. Some package evoke 1 y/n prompt while some prompt more than 1.

2. Enter actual password: Actually, I want to enter password through a GUI. So, basically, I want user to input password in a text box that I will create using Tkinter.

   tkinter.simpledialog.askstring("Password", "Enter password:", show='*')

I am confused how to implement this. I looked up this problem already and some Stackoverflow posts demonstrate the use of pexpect but I am having hard time understanding it. But if it can be done using the standsard libraries then it would be great.

Any help is appreacited. Thanks.

Solution 1:

Detect the password prompt: The password prompt appears mainly after makepkg enters in fakeroot. IDK how to detect that and supply the password from the script. There is no pattern actually. Some package evoke 1 y/n prompt while some prompt more than 1.

There is a pattern. An y/n prompt is shown when:

• makepkg invokes pacman to install build dependencies (for the -s option);
• makepkg invokes pacman to install the freshly built package (for the -i option);
• makepkg invokes pacman to remove the build dependencies (for the -r option).
• makepkg invokes pacman to...

In all cases, if makepkg is given the --noconfirm option, it will pass that to pacman as well.

Enter actual password: Actually, I want to enter password through a GUI. So, basically, I want user to input password in a text box that I will create using Tkinter.

The password prompt, if any, is shown by sudo. Sudo supports running external "askpass" tools through the SUDO_ASKPASS environment variable.

Write or install a program that shows the password prompt and outputs the password to stdout (e.g. ssh-askpass or zenity would do), then set the SUDO_ASKPASS environment variable to the program's path:

export SUDO_ASKPASS=/usr/local/bin/ssh-askpass

Finally, edit ~/.config/pacman/makepkg.conf to make makepkg run sudo -A for elevation, activating the "graphical askpass" feature:

PACMAN_AUTH=(sudo -A)