Wildcard's questions

This question is similar to:

• kdenlive appimage file: how to get it to show in list of applications

However, I want to install my AppImages for ALL users on the computer (it's a family laptop), not just for me. I'd like to do this without having to modify anything inside anyone else's home directory.

In other words, just as I can install e.g. a new game via Muon Package Manager and have it immediately available to all other users if they go to "Applications -> Games" in the Application Launcher, I'd like to accomplish the same effect for packages (software) that I download as AppImages.

(I'm using Kubuntu 20.04.)

I am pretty sure I'll need to make the AppImage file executable and move it to some directory that's owned by root, but I'm not sure where. I'll also probably need to add a .desktop file in some other directory owned by root but I'm not sure where this should be either, or what needs to be in it.

How can I make an installed AppImage into a "first-class citizen" as far as showing in all users' application launchers is concerned?

From what I've read, an Appimage file is a compressed application along with all of its resources, and when run it is auto-mounted and then executed.

I want to inspect the resources and files inside an Appimage file I've downloaded, without actually running the Appimage.

How can I do this?

I thought this detail would be in the Info Center, but the only similar info I can find there (under Graphical Information -> X Server) is just showing the current resolution, not the details on what the hardware supports.

The reason I need this is because I was trying out a game (Berusky) and it set my monitor resolution extremely low, and didn't reset it when exiting. I know my native resolution is either 1366x768 or 1360x768, but the difference is small enough (six pixels) that I can't tell visually which one is "correct." (The monitor is my built-in laptop monitor, by the way.)

Where is this information available? I would like to know how to find it both via the GUI, and via the command line, if that is possible.

I'm using Kubuntu 20.04 which I know is not supported yet, but I would accept answers that only apply to 19.10. (I would be surprised if the methods for finding out this info have changed, anyway.)

Obviously I can search the internet for my particular model of hardware and look up the specs that way, but I would like to know how to do this "inside" the OS if at all possible.

Some time ago I installed a whole bunch of games on my computer (from the command line) so I could check out what sort of games are available for Linux. (Probably hundreds of games, in perhaps half a dozen software bundles.)

Now I'd like to do some cleanup. I'm also trying to stick to the GUI wherever possible in general, as I want to recommend Kubuntu to family members and friends, and would like to have an experience similar to what theirs will be and be able to answer their questions.

Going through and removing packages one by one from the "installed" tab works okay, but I have to type in my password every time. Worse, I have to wait until one package removal finishes before the next password prompt will pop up. (So I can't click "remove" for several packages and then walk away and let the computer finish.)

(As a side note, it doesn't seem possible to view the installed software by categories; only to view installed AND uninstalled software together by categories, or to view ALL installed software in one giant list. I would like to be wrong about that; please mention it if I am.)

How can I remove many applications via the GUI without having to type my password many times?

In opening a bug report for a program just now, a core dump from coredumpctl was requested. Running that command produced a message that the command wasn't available, but could be made available by installing systemd-coredump.

When I installed systemd-coredump, I saw that installing it REMOVED the packages apport and apport-kde. (I'm using Kubuntu 18.04.)

I completed the filing of that bug report, using a coredump provided from coredumpctl as requested.

Now, is there a reason to prefer coredumpctl to apport? I see from the package descriptions that apport-kde is the GUI; probably that's what I've been seeing pop up after a program crash. But it doesn't seem provide a "get coredump" button in the UI when it pops up, just a "relaunch" or "leave closed" option. Does systemd-coredump have any analogous UI tool?

Perhaps more to the point, is there a way to provide the same coredump from apport as I provided from coredumpctl (or better yet to provide it from the apport-kde GUI), or are the results qualitatively different?

Really what I'm trying to establish is whether I should leave systemd-coredump installed, or remove it by reinstalling apport-kde just to have my system closer to the "normal" setup for Kubuntu 18.04. I'd like to understand the implications of the decision.

I have just started using Okular now that I've installed Kubuntu (18.04).

Previously, when printing a PDF, I would get an option about scaling. For instance, Adobe Reader has options such as "Fit to page" and "Do not scale." I don't see options like that in the print dialog from Okular.

The PDF I have is exactly sized already, and should not be scaled during printing. The size of the PDF pages is 8 1/2" by 11", which is exactly the size of my paper.

However, when I print from Okular, the printout has extra (and uneven) margins, showing that the PDF was scaled down during printing.

How can I avoid this when printing from Okular so that the PDF prints at exactly the page size? Or is it absolutely necessary that I use another program to do my printing?

_{(I'd rather use Okular as it is the default viewer with Kubuntu and if possible I'd like to be able to recommend this distro for non-technical family and friends, and be familiar with the default applications they'll then be using.)}

What I've tried already: clicking "properties" for the printer from the print dialog, and then in the "page" tab reducing the size of all four margins from the default "0.20in" down to 0. This did not have any effect on the next printout.

I'm running Ubuntu 18.04 (Kubuntu, actually) on a Lenovo ThinkPad L540.

I installed the latest Blender from the PPA repository like so:

sudo add-apt-repository ppa:thomas-schiex/blender
sudo apt install blender

(The version string is 94552-4c0cca78eb4-0thomas~bionic0 and the description includes This is version 2.8 obtained by pulling the last version in the master branch of the blender git repository. According to the Blender website, that should be 2.82a.)

Attempting to run this new blender gives the error:

/usr/lib/blender/blender: error while loading shared libraries: libLLVM-6.0.so.1: cannot open shared object file: No such file or directory

I then discovered that my scrollback history wasn't set up right, so I don't have the list of packages installed when I ran the earlier commands.

I'd earlier (a year ago) installed Blender 2.80 manually (not from a .deb but from a tarball); that installation still opens without complaining about libraries.

I've searched the error and libLLVM online and found a suggestion to use sudo /sbin/ldconfig -v, which (after checking the man page) I tried, but it had no effect; the error on trying to run the new blender is exactly the same, including in a new Konsole window.

1. How can I get the dependencies installed correctly so the program will open, and
2. Is there somewhere I should report this as a bug?

I have just started using Kubuntu with KDE Plasma.

I wanted to look up the keyboard shortcut for switching users. Typing "switch user" in the application launcher turned up nothing. Clicking "Leave" and mousing over the "Switch User" list entry turned up nothing.

I finally found the keyboard shortcut by opening up "global keyboard shortcuts" (can be opened through system settings, or directly), and then clicking on "ksmserver" and then seeing the shortcut for "Lock Session."

As far as I can tell, there is no shorter way to find the shortcut. The search box above the list of shortcuts will ONLY search the currently selected list, which is one of: Accessibility, Audio Volume, KDE Daemon, ksmserver, KWin, Plasma, Power Management, Run Command. I don't see any way to search all of those keyboard shortcuts at the same time.

That search box also won't search the "Standard Shortcuts," which have to be opened separately unless you go in through "System Settings" in the first place. Likewise "Web Shortcuts" and "Custom Shortcuts" have to be searched separately. (A search in the application launcher for "Shortcuts" won't turn up the "System Settings Shortcuts" view either, by the way, so it was just serendipity that I found it at all rather than just the four separate views it contains.)

How can I search ALL keyboard shortcuts in KDE?

And to give a practical immediate use for this, also: when I try to close System Settings using Ctrl-Q, I get a chime and a popup message:

The key sequence Ctrl+Q is ambiguous. Use 'Configure Shortcuts' from the 'Settings' menu to solve the ambiguity. No action will be triggered.

Looking through the keyboard shortcut lists and sorting by keyboard shortcut (rather than by action name), I don't see Ctrl-Q bound to anything except "Quit." So how can I find out why this is ambiguous?

(Note that I would like a two-way search: search by action name, and search by keyboard shortcut. A complete answer would include both, but having just one or the other would still be good.)

I've just started using Kubuntu with KDE Plasma. In adding my frequently-used applications to the launcher bar, I noticed that there doesn't seem to be a way to do this using only the keyboard.

For example, I can pin the Dolphin file manager to the launcher bar using the following steps:

1. Press the OS (Windows) key.
2. Type "Dolphin."
3. Right click on the result in the launcher menu.
4. Press "P" for "Pin to Task Manager."

I want to do step 3 with the keyboard. How can I do this?

I found instructions suggesting to use Shift-F10 or Ctrl-F10, but neither of these worked. Suggestions to use the "menu" button between the right alt key and the right shift key won't work either, because this Lenovo laptop has a "print screen" key in that position. (Also, I usually plug in and use a CODE keyboard, which has a menu key - but I have it set to the "function" key option, which allows me to use the media key shortcuts built into the keyboard. So just finding the menu key on this one Lenovo keyboard wouldn't be a complete solution for me.)

Alternatively, I would like a way to pin applications to the launcher bar (task manager??) without using the mouse. (Activating the right-click menu using the keyboard would accomplish that, but even if there's no way to do that there may still be a way to pin applications with the keyboard.)

For the home Linux laptop (running Ubuntu 18.04), for the kids, I would like to be able to configure the computer to require answer(s) to randomly selected math problems to log in, rather than requiring a password. (For a specific user account only, for graphical login only.)

I've searched the internet but haven't found anything about this. It doesn't seem likely that I'm the first one to think of this idea, but internet searches do suggest that. :)

Security isn't an issue since the only people with physical access to the computer are all trusted. (If there is anything I should configure to disallow SSH access or for other security concerns, you could mention it, but I doubt my ISP would let port 22 traffic through from the internet anyway.)

The benefits should be obvious, but to be explicit about them - the point is that there could be a mild barrier to "getting screen time" that would involve something a little bit educational.

I am currently using Gnome with sddm as the display manager, but I don't know if that really matters.

For testing purposes, to ensure that the automation I am running will work on a "fresh" server, how can I clear all info downloaded via apt-get update?

apt-get clean does not appear to do this.

Example sequence:

1. Check apt show somepackage and get no results.
2. Add a new sources list in /etc/apt/sources.list.d
3. Repeat step 1 and get no results.
4. Run apt-get update
5. Repeat step 1 and the package is now shown.
6. ???? Run some command to reverse the effects of step 4.
7. Repeat step 1 and get no results.

I even removed the new sources list and did an apt-get clean and still got a result, listed as an "additional record" and only shown in full with -a.

(Forgive me for not including the actual package details, but I am working against an in-house repository so the results would not be reproducible anyway.)

What is the most complete way to clear out cached information to accomplish step 6 above?

On Ubuntu 18.04, the following commands do not turn up any man pages:

man 2 creat
man 2 ioctl
man 2 chown

There are plenty of other examples, but these illustrate the point.

I tried a bit of apt search and online searching as well, but didn't turn up any clear answer for which package(s) to install to get these and other similar man pages.

How can I install the system call man pages on Ubuntu 18.04?

I plugged in my 4K external monitor (Dell 27 inch) to my Lenovo Thinkpad l540 running Ubuntu 18.04 using a mini displayport cable, and it works perfectly when I'm in the GUI. (The scaling option I chose makes the laptop monitor have everything too large, but that would be a separate question; it's fine on the external monitor which is what I care about for now.)

However, in the virtual terminal, the bottom three lines are not displayed. The built-in monitor is automatically mirrored, so I can read the bottom three lines on the built-in monitor and the rest on the 4K monitor, but for obvious reasons I don't want to do this.

Also, the text is slightly blurry (not just pixelated but fuzzy) on the 4K monitor when showing a virtual terminal. This is less of a problem than the lines being cut off at the bottom.

How can I get all the lines of the virtual terminal to show on the external monitor, preferably sized appropriately for the screen?

This question might be overly simple, but I just want to make sure I'm not falling into some anti-pattern regarding package installation.

I found the official installation instructions; however since what's available is a tarball and I already have the golang-go package installed via apt, should I simply remove golang-go, or what?

If I leave golang-go in place and just unpack the tarball according to the instructions, then the older version of go (in /usr/bin/go) is still first in my PATH lookup, so this doesn't seem to be a workable option.

Is there any drawback to uninstalling golang-go and just using the tarball only (as per those instructions)?

I've run into this situation three times recently, prompting me to wonder if there is a general approach to handling this. However, advice on the particular examples below would also be appreciated.

• I wanted to install the upstream (development version) of the game "Supertux." I found the download page, but it doesn't give a .deb package.

• Likewise, the download page for the racing game "Supertuxkart" gives an archive file, but no .deb package.

• More recently, I wanted to install the 2.80 beta of Blender. The download file is an archive file, not a .deb package.

All of these packages are available (in an earlier version) from the default package sources, so can be installed with just apt install <packagename>. They just won't be the upstream, development versions.

I want to install them so they are available for all users of the family computer, not just me. I want to have the desktop launcher files in the usual places (so they show up in the "applications search" from the GUI) and the binaries able to be launched from the usual PATH lookup. Ideally, I would like to have the package versions recorded wherever apt usually stores that information (so that any "apt" commands will show the versions installed).

I know I could do all of this if I had .deb files for the newer versions of these packages.

Is there a usual way to install newer versions of standard packages than the versions available from the default apt sources? If not, what are some typical ways the results above can be accomplished? (Or at least how to install the three packages listed above?)

(I know that software maintainers must fulfill certain requirements to be included in the default apt sources, so it seems possible that there might be some requirement about making newer versions available in some standard way.)

I'm using 18.04 if that makes a difference.

I was upgrading my laptop from 16.04 to 18.04 using the do-release-upgrade command.

It downloaded everything and went about unpackaging things and installing them.

I was doing this in a virtual terminal (Ctrl-Alt-F6) and I had two graphical terminals open at the same time (F7 and F8).

The update froze—and I couldn't open any applications in either of my graphical terminals. The applications that were already open (Nautilus and Solitaire) worked fine, but nothing else. Switching to any other virtual terminal showed the same as F6, just a frozen update in progress with all the output there.

After attempting to get another shell (I couldn't), attempting to kill or suspend the update (I couldn't), open up Terminal in one of my GUI terminals (I couldn't), or just reboot or shut down from the GUI terminal (I couldn't), I held down the power button until the computer shut off, and started it up.

I got the Ubuntu splash screen, and a mouse that moves when I use the trackpad. Black screen otherwise. This is on terminal 7; switching to terminal 6 I get a text login prompt and can log in. /etc/os-release shows I have 18.04, but I don't have internet (of course) and running startx doesn't have any effect.

Also, the text that appears after I log in says "Welcome to Ubuntu 18.04.1 LTS" but goes on to say my Hardware Enablement Stack (HWE) is going out of support on 2023-04-30, and suggests I:

* Upgrade from Ubuntu 16.04 LTS to Ubuntu 18.04 LTS by running:
sudo do-release-upgrade -p

OR

* Switch to the current security-supported stack by running:
sudo apt-get install libwayland-egl1-mesa-hwe-18.04 xserver-xorg-hwe-18.04 linux-generic-hwe-18.04

and reboot your system.

I tried rebooting, and there was no change.

How can I get X working again and get a graphical login back? (Note: I usually use WiFi, but I do have an hard line and an Ethernet cable available if that would make things easier.)

(P.S.: I'm not sure what tags are relevant, so I only put a couple.)