Basically I cant use os.Mkdir or os.MkdirAll because it will create the directories as root. I know I can go the exec.Cmd route and set the syscall.Credential{}. But thats a bit cumbersome and I have to remove and replace a lot of code.
I was wondering if there was anything global I can set so calls to the os package will be ran as a specified user.
Thanks in advance.
In general, a process will make system calls as the user that ran the process. Maybe seteuid is what you're looking for?
Related
I managed to install windows based network printer with python3 on ubuntu.
For better coding, I want to check first if the file with the drivers in it exists after the download. I know it is possible with os.path.isfile or something like that but I would like to do that with subprocess although os will not be supported in the future anymore.
So how do I do it? With subprocess.call or something like that?
to check for a file to be present, You ideally use pathlib, which is the pythonic and portable way to interact with the filesystem.
But to avoid Time of Check to Time of Use Errors (TOCTTOU) You should consider:
Instead of :
if check_printer_present():
# now, after checking the printer is present,
# the printer might go offline
use_printer()
better use:
try:
use_printer()
except PrinterError():
printer_error_cleanup()
see:
https://de.wikipedia.org/wiki/Time-of-Check-to-Time-of-Use-Problem
You might remember that idiom as :
it's better to ask forgiveness than permission
(t is better to act decisively and apologize for it later
than to seek approval to act and risk delay, objections, etc.)
We have a python script that needs to trigger the open of the Microsoft Store. We believe that the easiest way to do that is to use the ms-windows-store:// protocol.
We're currently doing that like this
import subprocess
ret = subprocess.call(["start", "ms-windows-store://pdp/?ProductId=9WZDNCRFHVJL"], shell=True)
Is that the recommended way to do this? I'm not sure if using start is correct here, or if there's something better?
Use os.startfile("ms-windows-store://pdp/?ProductId=9WZDNCRFHVJL"). This calls WINAPI ShellExecuteW directly. If you use subprocess, you have the expense of starting a child process. Plus CMD's start command will first search PATH to find a file that it can execute. Presuming nothing is found (and nothing likely will be, given this name), it hands the request off to ShellExecuteExW to let the OS shell handle it.
What I mean by this is:
I have a program. The end user is currently using it. I submit a new piece of source code and expect it to run as if it were always there?
I can't find an answer that specifically answers the point.
I'd like to be able to say, "extend" or add new features (rather than fix something that's already there on the fly) to the program without requiring a termination of the program (eg. Restart or exit).
Yes, you can definitely do that in python.
Although, it opens a security hole, so be very careful.
You can easily do this by setting up a "loader" class that can collect the source code you want it to use and then call the exec builtin function, just pass some python source code in and it will be evaluated.
Check the package
http://opensourcehacker.com/2011/11/08/sauna-reload-the-most-awesomely-named-python-package-ever/ . It allows to overcome certain raw edges of plain exec. Also it may be worth to check Dynamically reload a class definition in Python
Context
I'm building my complete debian system configuration,
so I'm modifying the keyboard and console setups.
I prefer not to modify the base files to keep a maximum
commpatibility and modularity. So I want to use VARIANT
(see setupcon (5)) and load them at init.
But not sure I'm doing it right.
Desired Architecture
I will only use keyboard file for the following example.
There is the base file /etc/default/keyboard
And two possible custom files (according to setupcon (5))
~/.keyboard
/etc/default/keyboard.variant
~/.keyboard
It provides a custom behaviour per $HOME (user)
/etc/default/keyboard.variant
A global and default keyboard setup
I would like to use the three at a time.
Problem
The daemon calling setupcon are console-setup and console-setup-mini
(according to the coments in their initd scripts). They are started
before login shell, so won't know ~/.keyboard.
setupcon needs to be called
setupcon variant
or, looking at the sources, with a variable $VARIANT
VARIANT=variant
What is the best solution to adopt, saving a maximum modularity.
Thank you,
How can I get the current user path in Linux? It can be either with the GTK+ framework APIs, or plain C++.
Assuming you mean the current directory of the process:
The plain POSIX C function is getcwd().
In glib, there's also g_get_current_dir().
If you want to get home directory use getenv("HOME")
g_get_home_dir() from Glib is more cross-platform than getenv("HOME"). It also prefers /etc/passwd entries over the HOME variable for various reasons discussed at the aforementioned link.
Not sure whether you're wanting the contents of $PATH or the user's current working directory. However to cover both options...
PATH is an environment variable, so you can access this with getenv(), in this instance getenv("PATH"), and is defined in <stdlib.h>.
The current working directory can be obtained with getcwd(), and is defined in <unistd.h>.