DK Bose's questions

Xubuntu 20.04 (in a VM)

I've installed ksnip as a snap but I noticed that

Automatically connect eligible plugs and slots of snap "ksnip"

took a long time (5-10 min) after ksnip was downloaded.

Installing okular as a snap took even longer (after okular itself was downloaded).

$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            1.9G     0  1.9G   0% /dev
tmpfs           394M  1.2M  393M   1% /run
/dev/sda5        20G  6.2G   12G  35% /
tmpfs           2.0G     0  2.0G   0% /dev/shm
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           2.0G     0  2.0G   0% /sys/fs/cgroup
/dev/sda1       511M  4.0K  511M   1% /boot/efi
tmpfs           394M   16K  394M   1% /run/user/1000
/dev/loop0       28M   28M     0 100% /snap/snapd/7264
/dev/loop1       55M   55M     0 100% /snap/core18/1705
/dev/loop2      1.0M  1.0M     0 100% /snap/ksnip/3
/dev/loop3       63M   63M     0 100% /snap/gtk-common-themes/1506
/dev/loop4      261M  261M     0 100% /snap/kde-frameworks-5-core18/32
/dev/loop5       20M   20M     0 100% /snap/okular/98
/dev/loop6      291M  291M     0 100% /snap/kde-frameworks-5-qt-5-14-core18/4
$ 

So what is happening during this process? Is it normally time-consuming?

Is it that the other "supporting" snaps were being downloaded with the less-than-meaningful (to me) "Automatically connect eligible plugs …" nessage? ksnip is a qt-based program and pulled in /snap/kde-frameworks-5-core18/32. And okular, also a qt-based program, pulled in /snap/kde-frameworks-5-qt-5-14-core18/4 both of which are much, much larger than ksnip and okular. In which case, the delay would just be a network issue?

OS: Ubuntu 19.10

When I ran locate plymouth, I got

dkb@dkb-uee:~$ locate plymouth

Command 'locate' not found, but can be installed with:

sudo apt install mlocate

dkb@dkb-uee:~$ 

So I installed mlocate and now locate works.

As far as I can remember, since Ubuntu 11.04, locate has always been there.

Why was it excluded in Ubuntu 19.10?

Kubuntu 19.10

I can't say when this began, but the output of sudo apt update has lines with c-n-f Metadata.

...                                                       
Hit:11 http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu eoan InRelease                                                  
Get:12 http://security.ubuntu.com/ubuntu eoan-security/main amd64 c-n-f Metadata [232 B]               
Get:13 http://security.ubuntu.com/ubuntu eoan-security/universe amd64 Packages [2,404 B]
Get:14 http://security.ubuntu.com/ubuntu eoan-security/universe amd64 c-n-f Metadata [288 B]
Fetched 445 kB in 2s (195 kB/s)                         
Reading package lists... Done
...

I found please add cnf support to debmirror indicating that cnf expands to "Command not found" but after reading that I'm none the wiser in understanding its purpose in sudo apt update. What is it's purpose?

I have several applications open. Running wmctrl and piping the output to awk lists the window IDs (excluding "sticky" windows) like this:

$ wmctrl -l | awk ' !/-1/ { print $1 } '
0x00a00018
0x04800005
0x04e00005
0x04400003
0x05000003
0x0540002b
0x05a00012
0x05800002
0x05c00003
$ 

I can send this output to wmctrl to close all these windows:

• windows without content that needs to be saved and windows that don't need a response will be closed without asking me but

• windows such as those of editors with unsaved content or terminals running a process will be closed "gracefully": the respective application will present a window allowing me to save changes or discard changes or to inform me of a process that's still running.

The following script, assigned to a suitable shortcut, works:

#!/bin/bash

list=$(wmctrl -l | awk ' !/-1/ { print $1 } ')

for i in ${list[@]}
do
    wmctrl -i -a $i
    wmctrl -i -c $i
done

I found that the simpler (to me) for i in $list also works.

Is there any reason to prefer one over the other?

"sticky" and "gracefully" are terms from man wmctrl.

Is it possible to select a column or block of text in Gedit 3.28.1?

The following image is with Kate 17.12.3 but shows what I want:

By default, Firefox uses the GTK file selection dialog when you press, for example, Control+O to open a local file.

How does a Kubuntu user make Firefox use the KDE file selection dialog?

I have Google Chrome Version 70.0.3538.77 (Official Build) (64-bit).

Today, after running sudo apt update and sudo apt full-upgrade, I saw:

E: Repository 'http://dl.google.com/linux/chrome/deb stable Release' changed its 'Origin' value from 'Google, Inc.' to 'Google LLC'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.

I looked at the man page for apt-secure but it's pretty technical and difficult, at least for me, to follow.

So how do I fix this issue?

Edit: for now, I've removed the existing Google Chrome ppa from Software Sources and then ran sudo apt update and sudo apt full-upgrade successfully with the following being installed/upgraded successfully:

The following NEW packages will be installed:
  python3-netifaces
The following packages will be upgraded:
  netplan.io nplan ppp
3 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.

There are several questions and answers here that include the output of inxi. What can inxi be used for?

I have read What classifies an application as 'installed' in Ubuntu? but it does not address the following issue:

When I runapt list --installed on Kubuntu 16.04, I see that all my listed packages have [installed] or [installed,automatic]. Yet, I've see reports where users have a few or even the majority of their packages being described as [installed,local]. And in this, last, case, their packages seem to be outdated.

Is [installed,local] the equivalent of what the Synaptic Package Manager would describe as "local or obsolete" as discussed in What does “local or obsolete” mean in Synaptic?

The Debian mailing list has a post relevant to some Skylake and Kaby Lake users: [WARNING] Intel Skylake/Kaby Lake processors: broken hyper-threading

Users are to run

grep name /proc/cpuinfo | sort -u

to obtain their processor details and then to check http://ark.intel.com/products/codename/37572/Skylake or http://ark.intel.com/products/codename/82879/Kaby-Lake as appropriate.

If their processor is listed, they should next run

grep -q '^flags.*[[:space:]]ht[[:space:]]' /proc/cpuinfo && \
echo "Hyper-threading is supported"

According to a follow-up post, the above command which I've struck through is not reliable and users need to run lscpu and check if

the lscpu output reports: "Thread(s) per core: 2", that means hyper-threading is enabled and supported.

If hyper-threading is supported, advice is provided for both Skylake and Kaby Lake.

I have an affected Skylake processor on 16.04 which can be fixed because

grep -E 'model|stepping' /proc/cpuinfo | sort -u

returns

model       : 78
model name  : Intel(R) Core(TM) i3-6006U CPU @ 2.00GHz
stepping    : 3

For such processors the fix suggested is to install

the non-free "intel-microcode" package with base version 3.20170511.1, and reboot the system. THIS IS THE RECOMMENDED SOLUTION FOR THESE SYSTEMS, AS IT FIXES OTHER PROCESSOR ISSUES AS WELL.

But the 16.04 repo shows me an older version:

apt policy intel-microcode
intel-microcode:
Installed: (none)
Candidate: 3.20151106.1
Version table:
3.20151106.1 500
500 http://archive.ubuntu.com/ubuntu xenial/restricted amd64 Packages

Is it possible to get the recommended version and, if it is possible, how can I do so?

Edit: I found https://launchpad.net/ubuntu/xenial/+package/intel-microcode but they all seem to be older versions.

Second edit: https://launchpad.net/ubuntu/+source/intel-microcode has the relevant update but it is for Artful Aadvark.

How does ls -l format its output so that column contents line up neatly?

I just read Meet Etcher, A Stylish Open-Source USB Image Writer Tool. It talks about downloading an AppImage.

Yes, Linux; the Linux packages are distributed as a .appimage for 32-bit and 64-bit distributions, and should run across all major Linux distributions without any issues. The team currently has no plan to provide a native .deb (or .rpm) installer.

What are AppImages? How do they differ from snaps?

I came across this wiki page: Package Manager Troubleshooting Procedure.

In it, there were commands such as:

LANG=C;sudo apt-get clean
LANG=C;sudo apt-get autoclean
LANG=C;sudo apt-get -f install
LANG=C;sudo apt-get --fix-missing install
LANG=C;sudo apt-get --purge autoremove
LANG=C;sudo apt-get --fix-missing update -o APT::Cache-Limit=100000000
LANG=C;sudo apt-get update -o APT::Cache-Limit=100000000 && sudo apt-get dist-upgrade

So what is the purpose of LANG=C;?

If I run diff -q on two files and they are identical, the exit code generated by echo $? is 0; if the files differ, the exit code is 1. Why is that? In what way is the first diff a success and the second a failure?

I used the terms "success" and "failure" based on my reading and limited understanding of http://mywiki.wooledge.org/BashGuide/TestsAndConditionals:

1. Exit Status
   Every command results in an exit code whenever it terminates.
   This exit code is used by whatever application started it to evaluate
   whether everything went OK. This exit code is like a return value from
   functions. It's an integer between 0 and 255 (inclusive). Convention
   dictates that we use 0 to denote success, and any other number to denote
   failure of some sort. The specific number is entirely application-specific,
   and is used to hint as to what exactly went wrong.

I should have read man diff right to the end where the convention used by the developers is clear.

Sorry for the confusing title!

Suppose I run

apt-cache depends kde-window-manager > ~/Desktop/kwin-depends

I'll get a file named "kwin-depends" in my Desktop folder.

Is there some trick to include the command I issued as part of the file, preferably at the start of the file?

So, at least in 14.04 LTS, the first few lines would look like this:

apt-cache depends kde-window-manager > ~/Desktop/kwin-depends

kde-window-manager
  Depends: kde-runtime
  Depends: libc6
 |Depends: libegl1-mesa
  Depends: <libegl1-x11>

Instead of just like this:

kde-window-manager
  Depends: kde-runtime
  Depends: libc6
 |Depends: libegl1-mesa
  Depends: <libegl1-x11>

I have youtube-dl version 2015.07.04. While downloading a video, I see this message:

Your copy of avconv is outdated and unable to properly mux separate video and audio files, youtube-dl will download single file media. Update avconv to version 10-0 or newer to fix this.

Apparently, the drawback of an outdated avconv is that youtube-dl won't be able to download bestvideo and bestaudio separately and mux them together into a single file giving the best overall quality available.

How can I find my currently installed avconv's version number? How can I get a newer version than what is provided by libav-tools 6:9.18-0ubuntu0.14.04.1?

Is there a ppa available for 14.04 with avconv version 10.0 or higher?

Please look at these commands:

$ notify-send SYNC TIME!
$ notify-send 'SYNC TIME!'
$ notify-send "SYNC TIME!"
bash: !": event not found
$

The first two commands produce a notification bubble as expected. The third gives the error shown.

and

$ echo SYNC TIME!
SYNC TIME!
$ echo 'SYNC TIME!'
SYNC TIME!
$ echo "SYNC TIME!"
bash: !": event not found
$

Here as well, the echo works for first two commands but not in the third.

More problems here (although I was not planning on using this): both notify-send "SYNC!TIME" and echo "SYNC!TIME" give bash: !TIME": event not found.

But both notify-send and echo work with "SYNC! TIME"

Can someone please explain why the bash: !": event not found error appears?

I have my references as a text file with a long list of entries and each has two (or more) fields.

The first column is the reference's url; the second column is the title which may vary a bit depending on how the entry was made. Same for third field which may or may not be present.

I want to identify but not remove entries that have the first field (reference url) identical. I know about sort -k1,1 -u but that will automatically (non-interactively) remove all but the first hit. Is there a way to just let me know so I can choose which to retain?

In the extract below of three lines that have the same first field (http://unix.stackexchange.com/questions/49569/), I would like to keep line 2 because it has additional tags (sort, CLI) and delete lines #1 and #3:

http://unix.stackexchange.com/questions/49569/  unique-lines-based-on-the-first-field
http://unix.stackexchange.com/questions/49569/  Unique lines based on the first field   sort, CLI
http://unix.stackexchange.com/questions/49569/  Unique lines based on the first field

Is there a program to help identify such "duplicates"? Then, I can manually clean up by personally deleting lines #1 and #3?

In this answer, I came across this command:

aptitude why firefox

aptitude whylooks like an useful command but I don't want to install aptitude just for that. What is the apt-get equivalent of aptitude why?

Can I directly download audio from a YouTube video instead of first downloading audio+video and then extracting the audio?