I'm using NixOS with XMonad as a window manager, which was enabled via the configurations.nix. This works fine.
After booting, the initial login is done via the NixOS login gui.
On a Debian system for instance systemd can be configured to boot only to the terminal and not directly to a desktop environment. One can setup an .xinit file then to start the chosen window manager or desktop environment without using any display manager (like lightdm, kdm...). It's started then by calling startx.
How would described effect be done in Nix? I guess there's an
declarative way to do so.
Another question, partly related to this, is: After changing
xserver settings in the configurations.nix (e.g. in
services.xserver.synaptics) and rebuilding via nixos-rebuild
switch/test, what do I have to do in order to take them in effect?
Those are 2 separate questions, thus I believe you'd be much better splitting them into 2 StackOverflow questions (it's much harder now to answer e.g. only one of them). That said:
AFAIK, people building the NixOS are not aware of a way to do this in systemd. If you know of such method, I believe there might be interested to learn about it!
I suppose you want:
$ systemctl start display-manager.service # CAUTION: see NOTE below!!!
NOTE: this will kill any open X session! (I guess that this might be the reason why it's not done automatically on nixos-rebuild switch...)
By the way, you may have noticed that after nixos-rebuild switch, a message is shown, something like: "display-manager.service is not restarted". That's what led me to find the answer to this question when I needed it myself.
One way to do it is to enable startx, which will be treated as a display manager:
services.xserver.displayManager.startx.enable = true;
Another way to accomplish this is to bypass the display manager by logging in automatically from the TTY login prompt. NixOS default display manager being lightdm, you do that by adding the following lines to your configuration:
lightdm = {
enable = true;
autoLogin.enable = true;
autoLogin.user = "username";
};
Related
I'm coding a Rust app and since it's fairly small and there don't appear to be any stable UI frameworks, I've made it run in the console using println! and whatnot for input/output. However since this program is intended to be used by people directly after downloading from the internet (due to its use case), they're likely to just double click on it instead of navigating to their downloads directory in a terminal and running it from there.
This is a problem because on Linux, it runs in the background waiting for input and looks like it's not working. On Windows, Rust programs do open in CMD by default. (and in fact many of the search results for my question were about disabling this behavior - the exact opposite of what I want!).
So is it possible to somehow make my application open in the system's default terminal? My preferred way would be to somehow embed in the executable to open in terminal (similar to the -mconsole compiler flag on MinGW). Otherwise would it be possible to detect it's in the background and fork it into a terminal? If that's not possible then is it at least possible to detect that the app is not running in a terminal and throw up a message box telling the user to run in a terminal?
My app is cross-platform but I'm OK with writing code conditionally compiled on one OS.
One typical way would be to distribute a program.sh along with your executable. If .sh extension is bound to opening a terminal in their window manager of choice, it would open automatically. If not - it is enough of a hint for running it from the shell.
Without this file you could:
Detect if the program is already running inside a terminal can be done with isatty(). There's a crate for it.
If not, spawn the terminal app process (see process::Command) and relaunch the program with it by passing its path to the terminal command line options. As #Caesar mentioned there's a bunch of popular terminals that you might want to check for presence on Linux. If nothing is found, xterm could sometimes be a fallback.
I'm using this very simple .screenrc:
logtstamp on
logfile /tmp/screenlog-%S.log
I tried launching screens with these two methods:
screen -L -S testing
screen -S tester -L
but the filename used is /tmp/screenlog.0S.log. What am I doing wrong? Using Screen version 4.00.03jw4 (FAU) 2-May-06, and according to the manual I should be able to name the log file using the session name
If you look at the man page (man screen) for your (8-year-old?) version of screen, you'll see it's missing the %S specifier. They must have added it since your version. I'm not sure why Ubuntu 12.04 shipped screen from 2006..
P.S. I'd advocate looking into tmux. It's a little bit harder to learn, but a lot more flexible: You can move windows between sessions, You can see multiple windows at once, You can nest sessions inside of other sessions, etc.
Also, if you are just looking to log the output of long-running processes, take a look at nohup.
EDIT, the question might have not been totally clear, short version:
How to popup a dialog asking for user input if the script is running in the background and not in an active console?
/EDIT
When I run a bash script from udev or cron, it usually runs quietly somewhere in the background. Example could be plugging in an external harddrive runs rsync for data backup. So not every time I plug in the harddrive do I want to launch this action.
What is the most minimal way to fire up some user input dialog and ask yes or no? I could write some interface with PyQt but I want as little dependencies as possible, ideally cross window manager and maybe even without window manager.
Thanks!
EDIT 2: The lightweight (and hence as ugly as expected) version is xmessage, this would probably be the answer to the question, unless you have a better one:
xmessage "Do you want to run the backup script?" -buttons yes,no
http://linux.byexamples.com/archives/87/using-gui-dialog-box/
EDIT: So there's KDialog for kde, is there something really lightweight for X?
http://www.linux-magazine.com/Issues/2009/99/Zenity-and-KDialog
kdialog --title "Do you want to run the backup script?"
--yesno "Do you want to run the backup script?"
I'm currently leaning towards zenity, only trouble is it pulls in a whole array of gtk dependencies on kde, but is cross platform and works on windows. In essence, this is exaclty what I was looking for:
if zenity --question --text="Please press a button."; then
zenity --info --text="You pressed Yes\!"
else
zenity --error --text="You pressed No\!"
fi
But was hoping it would be a lot lighter on the resources / dependencies. Any alternative suggestions?
A simple approach would be for the automated script to simply email you, or perhaps alert with wall with instructions (containing the location of the real script).
Another approach would be for the automated script to touch a file in /var/lib and proceed if the file is still present after 5 minutes. This gives the user the option to stop the process (by removing the file), but maintains some automation.
This is not something you should have cron or udev handling in the first place. Write a userland daemon that listens for the appropriate D-Bus messages and performs the appropriate actions.
This should be post in linux or superuser or serverfault.
But, the number one google search on linux read user input links back here to StackOverflow:
https://www.google.com/search?q=linux+read+user+input&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=fflb
so I guess it's not too off base.
Again, the third or so google result for linux invoke command usb device plugin links to ServerFault:
https://serverfault.com/questions/399698/execute-a-command-when-a-device-is-connected-via-usb
I'll leave combining those two as an exercise.
I have laptop-desktop setup at home and I have successfully cloned my Archlinux installation from one to another. However, I would like to avoid having to {install all new software, edit settings, update} twice, so I was wondering if it'd be possible to log over ssh from laptop to desktop, do something in terminal and have linux copy everything I type into second terminal with ssh logged in?
Thanks for ideas!
You could type the commands into one terminal then edit ~/.bash_history and save the commands into a script. Copy the script onto the machine with the second terminal and execute it. The advantage of this is now you have a script that saved your setup so you can reuse it whenever you need to.
You can use clusterssh, which duplicates your typed input across multiple systems. It is designed for situations in which the exact same tasks, such as software installation or configuration commands, are needed to be performed exactly the same on multiple systems. See http://sourceforge.net/projects/clusterssh/. Also, the KDE Konsole terminal has similar functionality.
I am writing a script on Red Hat Linux (I forget the version) that needs a header, but the banner command is not there for me to use and I won't be able to get it installed. I read via Google that it may well have been deprecated.
So is there a new version of the command that produces similar results, or a way I can replicate the command, or even just temporarily change the script output so that characters are a different size?
I've tried looking at stty but we don't access via xterm, we log in directly via putty.
In its simplest form, 'banner' is less than a few pages of code (e.g. this one). Perhaps you could just compile and run it from your home directory?
Use some web site, for example http://patorjk.com/software/taag/.
If you need it frequently you can create a script to scrap the result.
BTW, stty has nothing to do with your problem, I don't know why you mentioned it.