How to create shortcuts using the terminal

One way of doing it is to use xbindkeys:

Install xbindkeys

sudo apt-get install xbindkeys

Create the default settings file:

xbindkeys --defaults > ~/.xbindkeysrc

Add the relevant lines to ~/.xbindkeysrc:

printf '"google-chrome"\nControl+Shift+Mod2 + c\n' >> .xbindkeysrc

The keycodes above make Crtl Shift C launch google-chrome.

You might need to get the right keycodes for your keys. Run xbindkeys -k and press your desired shortcut. That will print the relevant key sequence.
Run xbindkeys. To make this permanent, add a line containing xbindkeys to your ~/.Xsession:

echo xbindkeys >> ~/.Xsession

Now, once you have all that set up, and xbindkeys is running automatically every time you log in (because of step 4 above), you will be able to add new shortcut keys with this command:

printf '"ApplicationName"\n+Shortcut+Key\n' >> ~/.xbindkeysrc &&
    killall xbindkeys ; xbindkyes

For example, this will make Ctrl+Shift+X launch xclock:

printf '"xclock"\nControl+Shift+Mod2 + x\n' >> ~/.xbindkeysrc &&
    killall xbindkeys ; xbindkyes

You could then create a little script that does it for you. Save the following lines as ~/bin/keyb.sh:

#!/bin/bash
printf '"$1"\n$2\n' >>  ~/.xbindkeysrc &&
killall xbindkeys ; xbindkyes

Make the script executable with chmod a+x ~/bin/keyb.sh. You can now add a new shortcut with

keyb.sh firefox 'Control+Shift+Mod2 + x'


PHP application not running on Ubuntu server

in my opinion you upload your files to incorrect location. You write you connect using sftp, if you upload the files directly without changing the directory they will be stored in the homedirectory of the user. But your php-files must be stored in document-root of Apache Webserver. I don't know AWS Lightsail not at all, but it seems that document root is there under /opt/bitnami/apache2/htdocs.
But you should know, that those instancess are not the same as native ubuntu. So you can maybe find earlier an answer under https://aws.amazon.com/documentation/lightsail or in the forum https://forums.aws.amazon.com/forum.jspa?forumID=231


jackbenny is close...

I am running on AWS with Ubuntu here is what I did to make vsftpd behave correctly:

seccomp_sandbox=NO
allow_writeable_chroot=YES
pasv_address=<(public ip) or (AWS public domain or DNS)>
pasv_enable=Yes
pasv_min_port=30000
pasv_max_port=30100
port_enable=YES

Then you have to make sure you are allowing ports, 20,21,30000-30100 through. Keep in mind that the port choices 30000-30100 are completely arbitrary and can be whatever you want. Although, I would stick to ports above 10000 and a range of 100 or more.


How do I resolve a 401 error when setting up Juju MAAS environment?

I've actually stumbled upon this error and it was some time ago, but I'm afraid I don't remember the details and the logs AND that version of that maas test server is looong gone.

If memory serves though...I'd go for one of the next 2

1 - "Misconfigured environment" If you tried bootstrapping with a misconfigured yaml with small errors previously and it failed (such as credentials or MaaS IP), then you should delete the environment manually and retry. The file "your_environment.jenv" should be at ~/.juju/environments . There used to be a bug (or feature) that wouldn't let a new yaml configuration overwrite the old environment, which meant that whatever changes you made to correct it, wouldn't really matter.

2 - Configuration Issue. Unless MaaS is vanilla try running dpkg-reconfigure on your maas-cluster-controller & region-controller. On that note...Try talking over plain HTTP. (Adjusting the url in the environments.yaml and the maas url for the cluster & region in the reconfigure window).


awk - compare two files and print all columns from both files

You have a couple of options here:

save whole lines $0 of File2 into an array keyed on its $1; then look up $1 of File1 based on the key in its $2:
 $ awk 'NR==FNR{a[$1]=$0; next} ($2 in a){print $1,a[$2]}' File2 File1
 evm.TU.PTPU-T1. PF00808 CL0012  Histone CBFD_NFYB_HMF   Histone-like transcription factor
 evm.TU.PTP-T1 PF00498 CL0357  SMAD-FHA    FHA FHA domain
 evm.TU.PAN-T1 PF00817 CL0123  HTH Forkhead    Forkhead domain

save the $1 values of File1 keyed on its $2 then look up the corresponding whole lines of File2 based on the key in its $1
 $ awk 'NR==FNR{a[$2]=$1} ($1 in a){print a[$1], $0}' File1 File2
 evm.TU.PTPU-T1. PF00808 CL0012  Histone CBFD_NFYB_HMF   Histone-like transcription factor
 evm.TU.PTP-T1 PF00498 CL0357  SMAD-FHA    FHA FHA domain
 evm.TU.PAN-T1 PF00817 CL0123  HTH Forkhead    Forkhead domain


How could a virtual machine in Ubuntu be more secure?

Correct, the VM protects the machine it is running on, but not the virtual machine itself.  The benefit comes from having a clean clone of your virtual machine so that if the virtual machine becomes corrupt, you can destroy it, load a copy of the clean clone ans start all over.


How to shut down the S/PDIF output in my sound card?

Open a terminal with Ctrl-Alt-T keyboard shortcut and type:    alsamixer

Use the arrow keys to move around and when over S/PDIF press M to mute, this will turn the light OFF.  Hit the  escape key to leave or just close the terminal.


wifi driver for Samsung Tab Pro S Ubuntu 17.04?

There is a github page dedicated to this machine.

You need at least kernel 4.5 (Ubuntu 17.04 uses 4.10) and it has issues with wifi, brightness (both fixed) and audio (no fix). Regarding the wifi:

  The NIC is an ath10k QCA6174. The firmware support for this device is rather messy and the wrong set of files will break it. Place the contents of the ath10k/QCA6174/hw3.0 dir in /lib/firmware and be sure to delete anything else in there. This firmware works very well (30MByte/s on 5ghz without issue) on 4.7.x.


Which framework/package provides the file dialog which is used by a lot of gnome applications?

It's a part of the GTK+ toolkit. File a bug for the package libgtk-3-0


No Network Connection - ifconfig shows only lo - lshw -c network says *-network unclaimed

According to the technical specifications, the ThinkPad E460 has newer intel networking hardware that (according to intel) is only properly supported in Linux kernel versions later than 4.2.

To see your exact networking hardware, open a terminal and run:

lspci

and look for "Network Controller" or "Ethernet Controller".  Your wifi controller will either be Intel 3165 (requires kernel 4.2 or later) or Intel 8260 (requires kernel 4.1 or later).

To see your current kernel version, run

uname -r

Since you are using Ubuntu 13.10, you will have kernel 3.11 by default.

There are several ways to upgrade your kernel, but the safest way is to use packages from the Ubuntu repositories.  Unfortunately, 13.10 has already reached end of life, and there do not appear to be any 4.2 kernel packages for that release.  You could try using the 14.04 packages, but they may or may not work.  If you want to try that, I would recommend you try to install these packages and restart:

linux-headers-4.2.0-35
linux-headers-4.2.0-35-generic
linux-image-4.2.0-35-generic
linux-image-extra-4.2.0-35-generic

If the packages successfully install, but something goes wrong, and you restart and are not able to boot into the OS, hold down shift while booting up to get the Grub boot menu, and choose your old kernel version (3.11) from the menu.  You will then be able to remove the 4.2 kernel packages if they are not working.


Atom text editor gone after update to 20.10, error: Depends: gvfs-bin but it is not installable

The package gvfs-bin package has been dropped by Ubuntu in 20.10. It won't be added later. It won't be supported.
The reason is that it's deprecated. See the package description:

This package contains deprecated command-line tools such as gvfs-copy
and gvfs-rename. Please use the gio(1) tool in the libglib2.0-bin
package instead.

Since there is no atom package in the Ubuntu repositories, there was no reason to keep gvfs-bin. Contact the upstream Atom project and let them know that their software has an obsolete dependency and is no longer installable.
The gvfs-bin package remains in all supported releases before and including 20.04. Consider remaining on 20.04, or running a 20.04 VM or Container.
Alternately, you can try downloading the package and trying to install it on a newer system. However, that is unsupported. If you encounter problems, you're on your own. Our only advice will be to uninstall the wrong-version package.
...or you can skip all the deb dependencies entirely and just install the Snap instead.


What is wrong if my wired ethernet connection keeps coming up and down? (And how do I fix it?)

I would first start from external causes (Hardware) and work my way into internal causes (Software and internal hardware).

Make sure the cables are correctly plugged in and the cable connectors are correctly made (Should not disconnect if you for example try to slightly pull the cable).
Verify that the cable does not have a huge rotten chewing on it or some mutated monster dropping radiactive goo on the ethernet cable.
Check that the network cards are, if they are PCI, correctly connected. Over exaggerating this but it happened 3 times in my life experience.

After doing this 3 cases then read this post that it might solve the same problem: Sharing any Network Connection starts a connection/disconnection loop

The solution was to update Ubuntu packages and it was solved, not only for sharing connections wirelessly and wired but also for connecting to shared ones or directly to wired/wifi ones.


Is my poor wireless connection the result of a bad driver?

I suggest that you update the firmware files. With a working internet connection, open a terminal and do:

wget http://mirrors.kernel.org/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.159_all.deb
sudo dpkg -i linux-firmware*.deb

Reboot. Is there any improvement?

If there is no improvement, I recommend that you try the steps outlined here: Ubuntu 16.04 wifi Intel 7265 slow/disconnecting


Ubuntu Gnome login screen on ASUS GL552VW with closed lid

Have a look here:

https://bugzilla.redhat.com/show_bug.cgi?id=1444229
https://patchwork.kernel.org/patch/9512307

$ cat /sys/module/button/parameters/lid_init_state
$ sudo nano /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="button.lid_init_state=method"
$ sudo update-grub


How can I check if the user is logged in with a graphical session AND that the same user is executing the script

To check who is logged in you can use who.
To check which user ran the script:

ps aux | grep $0 | awk '{ print $1 }' | uniq

ps aux : Lists all the running processes including the respective user on the first column.

grep $0 : Searches for the current script

awk '{ print $1 }': Prints only what's in the first column

uniq: Removes possible duplicates
To check whether the user who ran the script is the same as the user loged in:

LOGED_USER=$(who | awk '{ print $1 }')
EXEC_USER=$(ps aux | grep $0 | awk '{ print $1 }' | uniq)

if [ $LOGED_USER == $EXEC_USER ]; then
      echo "Same USER"
else
      echo "Different USER"
fi


First a few basics:

When you run a command on your terminal, you enter the name of a file, (which should be executable): if you enter a simple name e.g. emacs, the system searches a number of directories for a file with such name. This list of directory is your PATH (i.e. it is stored in a variable named PATH). you can see its contents by typing echo $PATH. (As a side note, these commands are not built-in like you said in your question... but some are, for instance ls, which don't have any executable file, but is directly executed by the shell)

Alternatively, you can enter a more complex filename, which include the directory :  /usr/bin/emacs, or event relative pathnames ! For instance, if you want to run the program in the file myprog, residing in your user directory, enter ./myprog (. meaning current directory)

Now back to your question:

When installing software, the system has to take care of putting everthing in the right place, so you can find it later on... It is what the package manager does : it takes an archive (.deb file), open it, and basically, put the files in the right places.

In conclusion, you have to open your .deb file with the package manager.

cd ~/Downloads
dpkg -i google-chrome.deb

or, event better, install it through the software center.


USB 3.0 problem on HP ProBook 6570b with Ubuntu 12.10

Sorry I was not clear enough.

The message in French and in English is the same :

With Ubuntu 12.10/ Linux Mint 14 the usb3 didn’t worked on my ASUS Zenbook Prime UX31A :  When I plugged in my hard drive (usb3) on my computer, I couldn’t open the hard drive.
The problem comes from the kernel included in ubuntu 12.10/linux mint 14. The basic kernel in Ubuntu 12.10 is the 3.5.0.
To correct the problem I installed a newer kernel : I installed the 3.5.7 one and the problem was solved.

To change the kernel, it’s really easy: https://wiki.ubuntu.com/Kernel/MainlineBuilds

The Kernel 3.5.7 for Ubuntu 12.10/Linux mint 14: http://kernel.ubuntu.com/~kernel-ppa/mainline/linux-3.5.y.z-review/current/

Is it more clear now? =$
Really sorry for my English!... I’ll try to be better…


I have no idea about if NTP should or should not access the file /etc/ntp.leapseconds However I can tell you why you are getting the problem.

the LSM apparmor is denying the read.

If you believe that NTP should have access to that file the correct solution would be to update the apparmor profile for ntp.

sudo vim /etc/apparmor.d/usr.sbin.ntpd

add a line that permits read access to the file in question eg.

/etc/ntp.leapseconds r,

save your file then reload the NTP profile

sudo apparmor_parser -r /etc/apparmor.d/usr.sbin.ntpd

Why is this happening?

NTP has listening network sockets and has a pretty predictable behaviour , so usually ubuntu will ship a apparmor profile for it and turn it on by default.

Apparmor is a LSM ( Linux Security Module ) Its an extra layer of security called MAC ( Mandatory access control ) and its a way of telling an application what it can and cannot access via policy. It has the last say on access permissions and even if you chmod 777 a file if the policy says you are not permitted to access the file the kernel will deny access.

You can start learning here


Why can python3 not import gi.repository?

You should install the correct Python 3 packages, these are prepended with python3- instead of python- .

This will do the trick:

sudo apt-get install python3-gi

Or search this package in your favorite package manager.


How to fix error 'libxenlight failed to create a new domain'?

Maybe this will work. Yet to try.

So it looks like there is a need to add the following to a file named usr.sbin.libvirtd. In commandline, updatedb (sudo updatedb) and then use locate to find that file (locate usr.sbin.libvirtd).

Edit it with gedit or nano or vi or another applicable text editor

Under these lines:

/lib/udev/scsi_id PUx,
/lib/udev/scsi_id PUx,
/usr/lib/xen-common/bin/xen-toolstack PUx,

Add:

/usr/lib/xen-*/bin/pygrub PUx,

Taken by and large from:

https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1326003/comments/2


Yes,you can install kdevelop 4.6 via apt-get,by adding the below repository.

sudo add-apt-repository ppa:kubuntu-ppa/backports
sudo apt-get update
sudo apt-get install kdevelop


how to create shortcut for an application?

The solution to this are .desktop files.
The simplest .desktop entry looks like this but you can add many things like an icon and so on. These 3 keywords are the only one which are needed for it to work:

[Desktop Entry]
Type=Application
Name=NameOfYourApplication
Exec=CommandToExecute

You have to save it as $HOME/.local/share/applications/CustomName.desktop
But if you want it to be executable for every user, save it as /usr/share/applications/CustomName.desktop. You need root permissions to access that folder though.

Then you have to make it executable (chmod u+x /path/to/your/file.desktop).

Finally, you have to add a symbolic link to your Desktop with

ln -s /path/to/your/file.desktop $HOME/Desktop/NameItHowEverYouLike


The files appear as read-only because you don't have enough permissions to modify them. If you want to use the GUI, you run your editor from command prompt like:

sudo gedit


Ubuntu not booting after installation on Acer R5-571T 59DC

I found a good enough solution.

I enabled secure boot again in the UEFI settings and after that the option for adding the new OS to the EFI boot menu was enabled.

Now when I access it with F12 key I have both the Ubuntu & Windows options.

Thanks wjandrea for your answer


Record program and mic on two separate tracks with ffmpeg

Today I accidentely stumbled across this Youtube video. It doesn't show how to do it in Ardour. However, it shows how you can record several sources at the same time from pulseaudio (including my created virtual sinks).

Quick summary:

Find your input sources with pacmd list-source-outputs | grep source:

Use ffmpeg

This doesn't guarantee sync though!
ffmpeg -f pulse -i [Your input source 1] -map '0' 0.mp3 -f pulse -i [Your input source 2] -map '1' 1.mp3


Ubuntu Touch running on Fairphone - are there agreements?

For now both the fairphone and Ubuntu Touch are unfinished products, so it's to early say anything.

Fairphone wants their phone to be as open as possible. They also partnered-up with Canonical. I'd be surprised if there won't be a Fairphone-Ubuntu-Touch release.

  "We are planning to launch the phone with root access for the user
  (rootable), so they can decide for themselves which operating system
  they want to install after some hard coding. At this point, we really
  need the support of open-source communities – people who develop for
  Firefox and Ubuntu – to help us optimize our device for these
  operating systems."
  - Fairphone.com


I have saved a hadoop3.pem file in the downloaded section . but the chmod command cannot acces this

/path/to/hadoop3.pem isn't some magical file path that finds the hadoop3.pem file. You actually need to specify the "path to hadoop3.pem." If it's in your Downloads folder, it'll be

~/Downloads/hadoop3.pem


This was solved by copying librxtxParallel.so and librxtxSerial.so to /usr/lib/ and the details on this post: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238062036/all


Is it possible to enlarge Ubuntu desktop somehow

What you want is called panning viewport. X has supported this for many years, it was awesome with low resolution monitors and it works exactly as you described.

I haven't tried it with recent version of Ubuntu, so I'll better point you to the official documentation.

It's done with xrandr --panning, but be sure to read everything before experimenting with your resolutions.


Benefits of deploying kubernetes in juju vs deploy it directly in ubuntu

The juju provider makes it easier to scale and integrate other elements over time.


Is there an easy way to (temporarily) disable the display timeout?

Just found a possible solution:
Keep the Screen on
For this, there's the little applet caffeine:

It sits in the tray, and you click it once to de-activate screen saver etc. Click it again, and it restores it. As the screenshot of its configuration shows, you can have it started automatically on login, and even deactivate the screen automatically on configured conditions (e.g. whenever playing Flash or Quake, or whenever certain programs are running). More details can be found in this article, including detailed instructions for installation and configuration.
Though the screenshots show it in Unity, it seems to work in KDE as well. I just installed it, so I cannot give reports yet (feel free to ask if you need). To install:
sudo add-apt-repository ppa:caffeine-developers/ppa
sudo apt-get update
sudo apt-get install caffeine

Again, the article speaks of Ubuntu 11.10 -- in my case, it installed smoothly on 12.04 with above 3 steps.
Power profiles
For the other stuff (power management profiles), those interested in might want to take a look at the Jupiter Applet, which offers this and, additionally, switching between different screen modes and resolutions:

This also comes in its own PPA:
sudo add-apt-repository ppa:webupd8team/jupiter
sudo apt-get update
sudo apt-get install jupiter

Those with an EeePC might add:
sudo apt-get install jupiter-support-eee


How can I ping from specific network card on Ubuntu v16.04 LTS?

Try ip route get 8.8.8.8 from 192.168.22.51 to check your routing table. It may say enp2s0.


ubuntu indicator applet that has a dynamic menu item

In your init (or wherever you initialise stuff) set up a timer:

refreshIntervalInMinutes = 5
GLib.timeout_add_seconds( refreshIntervalInMinutes, build_menu )

Then ensure the last line of build_menu() returns True so the timer is continually called.


Accidentaly hit esc during a do-release-upgrade?

I think you'll be fine other than I would rerun apt-get on the machine before rebooting. I've accidentally borked a apt-get session that just picked where it left off.


Ubuntu 12.10 no audio via hdmi on a ASUS F1A75-V PRO AMD

Does not work on. you don't help people like this!

Ubuntu disable and hide digital audio output SPDIF in all Realtek / Nvidia Cards by default in fact it does same in all flavor of Ubuntu because no body cares the final user.

The prosedure to fixit is the same in all verssion of ubuntu and works for all sound cards Ati Nvidia Realtek Creative Bosse etc. You need to edit a file to do work get a terminal and tipe this

sintax: sudo nano /etc/modprobe.d/alsa-base.conf (enter)

then add this line to the end of the file

sintax: options snd-hda-intel model=auto (then use the end page controls to rewrite and save the file, then exit console)

At this time you need to reboot the machine, and then realize the missing digital audio spdif its work! go to task bar icon to select propper devise (its show now) to avoid get sound for all speackers at same time. if you need mute ubuntu alets or whatever you need to do enjoy.

for spanish take this link: http://www.fermu.com/es/articulos/linux/48-ubuntu/773-configurar-audio-hdmi-a-trav%C3%A9s-de-una-tarjeta-gr%C3%A1fica-nvidia-geforce-8600m-gt-en-ubuntu

Boggart Akerley NASA Space Ship Program Sofware Engineer.


My Canon LBP6020B printer doesn't forward anything from the printer queue

As mentioned in the Readme for the CAPT v2.60 driver, since you have 64 bit you will need to install 32bit versions of some files. Here is the excerpt from the Readme.

About printing from 64-bit version Ubuntu
Because a common module is installed with 64-bit Ubuntu, a 64-bit version
libglade2 library is required.
You can install the libglade2 library by executing the following command.

# apt-get install libglade2

In a 64-bit Ubuntu environment, all the 32-bit libraries required for
printing are not installed. As a result, printing will fail if 32-bit
libraries are not installed.
Before printing, it is required that you execute the following commands to
install a 32-bit library package.

# apt-get install ia32-libs
# apt-get install libpopt0:i386


a version in python (python3 to be precise).

save the program below under the name diff_filename.py (make it exectuable) and use it in the following way:

$ ./diff_filename.py the/directory/containing/the/files

the program assumes that the numbers you want to compare are always in the same position of the filename (indices 10:16).

as it is now it's pretty verbose and prints out correct filenames including the difference. as soon as it hits a filename that does not respect the minimal difference it prints that out  and stops.

here's the source code:

#!/usr/bin/python3
# -*- coding: utf-8 -*-

'''
usage: ./diff_filename.py the/directory/containing/the/files
'''

import os
import  sys

MIN_DIFF = 15

the_dir = sys.argv[1]
sorted_files = sorted(os.listdir(the_dir))

last_number = None
last_file = None
for current_file in sorted_files:
    current_number = int(current_file[10:16])
    if last_number is None:
        last_number = current_number
        last_file = current_file
        continue
    diff = current_number - last_number
    if diff < MIN_DIFF:
        print('fail! "{}" and "{}" do not respect MIN_DIFF={}'.format(
            last_file, current_file, MIN_DIFF))
        break
    else:
        print('ok! "{}" and "{}" diff={}'.format(last_file, current_file, diff))

    last_number = current_number
    last_file = current_file


Checkout this link: http://patrickmylund.com/blog/lowering-gaming-mouse-sensitivity-in-ubuntu-9-10/

Have fun!


lightdm fail to start automatically after last update

It is a long-standing bug in Ubuntu: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/969489

Most common workaround is to add

respawn

in /etc/init/lightdm.conf to ensure it stays up even it fails to start at the first try.


Solved!

Thanks to CL, above.   The key to what I was doing was the persistent change:

   $ sudo vi /etc/modprobe.d/alsa-base.conf

Then, at the bottom of the text file, comment out the line that says

    options snd-usb-audio index=-2

Then, after a reboot (or a force-reload of alsa, probably), pavucontrol lists the device normally.

The above edit is one I learned/stole from here.


for what I know, QR codes can be Text, URL, call, SMS, Email, Map, Bookmark, paypal, facebook or contact
also some qr code generator allow you to change colors and some other things to make QR beautiful :)
so you cant convert PDF to QR Code, so if you want to convert any of above to qr visit :

Online QR Code Generator


"The identity of this website has not been verified."

Nothing is wrong, if you click the "What do these mean?" you will see
https://support.google.com/chrome/bin/answer.py?hl=en&answer=95617&p=ui_security_indicator

  The site isn't using SSL. This icon displays for http:// sites. Most
  sites don’t need to use SSL because they don’t handle sensitive
  information. Avoid entering sensitive information, such as your credit
  card information or bank login information, on the page. If sensitive
  information is being requested on a site not using SSL, consider
  contacting the website owner.


The package system is broken using 12.04.2 lts

Your package management is out of sync.  The version of libefl available by that name is newer than the libefl-bin that you're trying to install. This PPA has the version of libefl-bin that matches the libefl you have (you might have to rebuild libefl-bin-blahblah and libefl-blahblah as libefl and libefl-bin though).


Does updating applications affect .desktop files?

The .desktop files is in really part of the package itself, so of course the .desktop will b updated within the package.

Indeed the .desktop files can be found in 3 different places.

/usr/share/applciations
/usr/share/app-install/desktop
~/.local/share/applications

But be care for some tips:

The .desktop in the /usr/share/applciations and those in /usr/share/app-install/desktop will be updated since those are related to system wide and those .desktop files are created when installing via apt-get or Ubuntu Software Center.

But to make sure that your file will not change you can put it in ~/.local/share/applications, as those directories are for the user himself, so it'll not be changed unless you did it.

Related question: Why are there redundant directories for .desktop files?


Cannot boot to Windows 10 in dual-boot setup with Lubuntu

I've had the same problem. To boot Windows 10 a different way, hit F12 while it is displaying the company's name, then choose Windows Boot Manager.


Upgrading from 16LTS to 18LTS broke Samba AD DC

Turns out systemd added a DNS Stub listener by default and Samba just kept running without complaining even though it's builtin DNS couldn't run.

I turned off the systemd dnsstub listener and restarted Samba. Bingo.


How do I prevent webpages from stealing focus in Webkit?

From the comments:

The 1.9.1 release of webkit (which isn't even in quantal as of this writing) claims to have fixed" Web content (except plugins) should no longer steal focus from other GTK+ widgets." (mail.gnome.org/archives/gnome-announce-list/2012-April/…) Also see bug: bugs.webkit.org/show_bug.cgi?id=77791 – andrewsomething Jun 9 at 20:32


This worked for me:

(originally posted by praseodym)

echo "blacklist acer_wmi" | sudo tee -a /etc/modprobe.d/blacklist.conf

and reboot

.. sprang into life listing available networks from the network icon (top right)


DeaDBeeF (http://deadbeef.sourceforge.net/) via this plugin can play music tracks from RAR, 7z and Gzip archives.

Visit this link for a short video showing this feature.

DeaDBeeF can be installed from this ppa


Containers are no VMs. Nothing is virtualized, it all just runs as isolated processes on the host. Even the kernel is shared.

So the kind of CPU utilization you can observe from a container process is just the same as from a host process.


How do I make `ifup wlan0` return immediately if no dhcp lease can be obtained?

I had the same problem for a while, and doing a simple :

$ systemctl enable netctl.service
$ systemctl start netctl.service

Fixed everything on my ubuntu 17.04.

Hope it helps.


Why is the 64bit 10.10 ISO labeled amd64.iso?

amd64 is a description of the chip architecture, like x86 (or i386) was for 32-bit architectures. AMD developed and released 64-bit chips before intel, and iirc, intel actually liscensed the AMD technology to use in their chips.

In short, this is the correct version for your 64-bit machine.


In Ubuntu 12.04 the package is called seahorse-nautilus.


Configuring Network with OpenVPN and GUFW for Secure Only Thought VPN Traffic. Configuring Self-made Kill Switch on Ubuntu

If the best is openvpn

You need to install it:

sudo apt-get install openvpn

sudo apt-get install network-manager-openvpn

If you have any problems with the openvpn as I had at the beginning you can run the following command to know what's happening

grep VPN /var/log/syslog

Then you can add a openvpn configuration from the Network Manager. It's also possible to set autoconnect all from the Network Manager.

However I'm still looking to a Firewall solution for dropouts (Kill Switch)

And I'm not sure if IPv6 configuration should be changed...


How do I check the file format of an usb stick?

You could use fdisk -l to get info on all mounted disks


How to install rubygems in Ubuntu 12.04 with Ruby 1.9.3

Do you also have ruby1.8 and rubygems installed?  Uninstall them, or at least rubygems ("sudo apt-get remove rubygems").  Ubuntu 12.04's ruby1.9.3 package includes a version of rubygems, no additional package needed.


How to find out why process was killed on server

If a process is consuming too much memory then the kernel "Out of Memory" (OOM) killer will automatically kill the offending process. It sounds like this may have happened to your job.  The kernel log should show OOM killer actions, so use the "dmesg" command to see what happened, e.g.

dmesg | less

You will see a OOM killer messages, something like the following:

[   54.125380] Out of memory: Kill process 8320 (stress-ng-brk) score 324 or sacrifice child
[   54.125382] Killed process 8320 (stress-ng-brk) total-vm:1309660kB, anon-rss:1287796kB, file-rss:76kB
[   54.522906] gmain invoked oom-killer: gfp_mask=0x24201ca, order=0, oom_score_adj=0
[   54.522908] gmain cpuset=accounts-daemon.service mems_allowed=0
[   54.522912] CPU: 6 PID: 1032 Comm: gmain Not tainted 4.4.0-0-generic #3-Ubuntu
[   54.522913] Hardware name: Intel Corporation Skylake Client platform/Skylake DT DDR4 RVP8, BIOS SKLSE2R1.R00.B089.B00.1506160228 06/16/2015
[   54.522914]  0000000000000000 000000002d879fe9 ffff88016d727a58 ffffffff813d8604
[   54.522915]  ffff88016d727c50 ffff88016d727ac8 ffffffff8120272e 0000000000000015
[   54.522916]  0000000000000000 ffff880080ab3600 ffff880086725880 ffff88016d727ab8
[   54.522917] Call Trace:
[   54.522921]  [<ffffffff813d8604>] dump_stack+0x44/0x60
[   54.522924]  [<ffffffff8120272e>] dump_header+0x5a/0x1c5
[   54.522926]  [<ffffffff81376bd8>] ? apparmor_capable+0xb8/0x120
[   54.522928]  [<ffffffff8118b472>] oom_kill_process+0x202/0x3b0
[   54.522929]  [<ffffffff8118b885>] out_of_memory+0x215/0x460
[   54.522931]  [<ffffffff81191740>] __alloc_pages_nodemask+0x9b0/0xb40
[   54.522933]  [<ffffffff811da7cc>] alloc_pages_current+0x8c/0x110
[   54.522934]  [<ffffffff81187d75>] __page_cache_alloc+0xb5/0xc0
[   54.522935]  [<ffffffff81189f4a>] filemap_fault+0x14a/0x3f0
[   54.522937]  [<ffffffff811b6140>] __do_fault+0x50/0xe0
[   54.522938]  [<ffffffff811b9b82>] handle_mm_fault+0xf92/0x1840
[   54.522939]  [<ffffffff812526a7>] ? eventfd_ctx_read+0x67/0x210
[   54.522941]  [<ffffffff81068517>] __do_page_fault+0x197/0x400
[   54.522942]  [<ffffffff810687a2>] do_page_fault+0x22/0x30
[   54.522944]  [<ffffffff8180e2f8>] page_fault+0x28/0x30
[   54.522945] Mem-Info:
[   54.522947] active_anon:788399 inactive_anon:33532 isolated_anon:0
                active_file:83 inactive_file:37 isolated_file:0
                unevictable:1 dirty:10 writeback:0 unstable:0
                slab_reclaimable:5166 slab_unreclaimable:13868
                mapped:5646 shmem:9752 pagetables:4476 bounce:0
                free:7576 free_pcp:0 free_cma:0
[   54.522948] Node 0 DMA free:15476kB min:28kB low:32kB high:40kB active_anon:144kB inactive_anon:216kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15984kB managed:15888kB mlocked:0kB dirty:0kB writeback:0kB mapped:80kB shmem:80kB slab_reclaimable:0kB slab_unreclaimable:48kB kernel_stack:0kB pagetables:4kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes
[   54.522951] lowmem_reserve[]: 0 2072 3862 3862
[   54.522952] Node 0 DMA32 free:11220kB min:4204kB low:5252kB high:6304kB active_anon:1711968kB inactive_anon:80964kB active_file:236kB inactive_file:100kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:2206296kB managed:2125964kB mlocked:0kB dirty:36kB writeback:0kB mapped:17948kB shmem:26240kB slab_reclaimable:8988kB slab_unreclaimable:26036kB kernel_stack:2656kB pagetables:9348kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:3776 all_unreclaimable? yes
[   54.522955] lowmem_reserve[]: 0 0 1790 1790
[   54.522956] Node 0 Normal free:3608kB min:3628kB low:4532kB high:5440kB active_anon:1441484kB inactive_anon:52948kB active_file:96kB inactive_file:48kB unevictable:4kB isolated(anon):0kB isolated(file):0kB present:1900544kB managed:1833172kB mlocked:4kB dirty:4kB writeback:0kB mapped:4556kB shmem:12688kB slab_reclaimable:11676kB slab_unreclaimable:29388kB kernel_stack:2448kB pagetables:8552kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:924 all_unreclaimable? yes
[   54.522958] lowmem_reserve[]: 0 0 0 0
[   54.522959] Node 0 DMA: 7*4kB (UME) 3*8kB (UM) 4*16kB (UME) 4*32kB (UME) 2*64kB (U) 4*128kB (UME) 1*256kB (E) 2*512kB (ME) 3*1024kB (UME) 1*2048kB (E) 2*4096kB (M) = 15476kB
[   54.522965] Node 0 DMA32: 118*4kB (UME) 36*8kB (UME) 62*16kB (UME) 94*32kB (UME) 34*64kB (UME) 24*128kB (UME) 5*256kB (UE) 1*512kB (U) 0*1024kB 0*2048kB 0*4096kB = 11800kB
[   54.522969] Node 0 Normal: 151*4kB (UME) 39*8kB (UME) 77*16kB (UME) 38*32kB (UME) 9*64kB (ME) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 3940kB
[   54.522974] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[   54.522974] Node 0 hugepages_total=256 hugepages_free=256 hugepages_surp=0 hugepages_size=2048kB
[   54.522975] 9932 total pagecache pages
[   54.522976] 0 pages in swap cache
[   54.522976] Swap cache stats: add 1831590, delete 1831590, find 5929/10969
[   54.522977] Free swap  = 0kB
[   54.522977] Total swap = 0kB
[   54.522978] 1030706 pages RAM
[   54.522978] 0 pages HighMem/MovableOnly
[   54.522979] 36950 pages reserved
[   54.522979] 0 pages cma reserved
[   54.522979] 0 pages hwpoisoned
[   54.522980] [ pid ]   uid  tgid total_vm      rss nr_ptes nr_pmds swapents oom_score_adj name
[   54.522986] [  285]     0   285    10173     1022      23       3        0             0 systemd-journal
[   54.522988] [  312]     0   312    11192      266      22       3        0         -1000 systemd-udevd
[   54.522989] [  623]   100   623    25590      569      20       4        6             0 systemd-timesyn
[   54.522990] [  823]     0   823     5859     1723      14       3        0             0 dhclient
[   54.522991] [  917]     0   917     7152       96      18       3        2             0 systemd-logind
[   54.522992] [  936]     0   936     6310      223      16       3        0             0 smartd
[   54.522993] [  943]     0   943   112847      523      72       3        9             0 NetworkManager
[   54.522993] [  952]     0   952    84334      421      68       4        0             0 ModemManager
[   54.522994] [  957]     0   957     4797       40      15       4        0             0 atd
[   54.522995] [  961]   115   961    93456      912      80       4        0             0 whoopsie
[   54.522996] [  963]     0   963     4865       65      13       3        0             0 irqbalance
[   54.522997] [  964]   104   964    65667      224      30       4        9             0 rsyslogd
[   54.522998] [  966]     0   966    23282       34      13       3        0             0 lxcfs
[   54.522999] [  971]   105   971    10926      318      26       3        8          -900 dbus-daemon
[   54.523000] [ 1008]     0  1008     9570       82      25       3        0             0 cgmanager
[   54.523001] [ 1016]     0  1016    70808      240      41       3        0             0 accounts-daemon
[   54.523002] [ 1019]     0  1019     1119       46       8       3        0             0 ondemand
[   54.523003] [ 1022]     0  1022     7233       68      20       3        0             0 cron
[   54.523004] [ 1028]   109  1028    11218       97      26       3        3             0 avahi-daemon
[   54.523005] [ 1030]     0  1030     1807       20      10       3        0             0 sleep
[   54.523006] [ 1037]   109  1037    11185       82      25       3        0             0 avahi-daemon
[   54.523007] [ 1047]     0  1047   141966     2188     156       4        3             0 libvirtd
[   54.523008] [ 1053]     0  1053    13902      163      33       3        0         -1000 sshd
[   54.523009] [ 1057]     0  1057    69683      586      40       3       12             0 polkitd
[   54.523010] [ 1072]     0  1072    10963      134      24       3        0             0 wpa_supplicant
[   54.523011] [ 1081]     0  1081    87582      696      39       3       23             0 lightdm
[   54.523012] [ 1088]     0  1088    99946     6138      97       3       15             0 Xorg
[   54.523012] [ 1111]     0  1111     1099       45       8       3        0             0 acpid
[   54.523013] [ 1125]     0  1125    56533      191      47       4       14             0 lightdm
[   54.523014] [ 1129]   114  1129    11957      850      27       3        0             0 systemd
[   54.523015] [ 1130]   114  1130    15825      501      33       3        0             0 (sd-pam)
[   54.523029] [ 1136]   114  1136    30728      108      26       4        0             0 gnome-keyring-d
[   54.523030] [ 1138]   114  1138     1119       20       8       3        0             0 lightdm-greeter
[   54.523031] [ 1143]   114  1143    10743      145      25       3       13             0 dbus-daemon
[   54.523032] [ 1144]   114  1144   227063     2039     170       4       17             0 unity-greeter
[   54.523032] [ 1146]   114  1146    84488      626      34       3        0             0 at-spi-bus-laun
[   54.523033] [ 1151]   114  1151    10680       97      27       4        0             0 dbus-daemon
[   54.523034] [ 1153]   114  1153    51706      157      37       3        3             0 at-spi2-registr
[   54.523035] [ 1159]   114  1159    68584      154      37       3        0             0 gvfsd
[   54.523036] [ 1164]   114  1164    85325      145      32       3        0             0 gvfsd-fuse
[   54.523037] [ 1174]   114  1174    44626      121      23       3        3             0 dconf-service
[   54.523038] [ 1197]     0  1197    20665      147      44       3        0             0 lightdm
[   54.523038] [ 1201]   114  1201    11465      160      27       3        0             0 upstart
[   54.523039] [ 1204]   114  1204   144936     1323     136       4        4             0 nm-applet
[   54.523040] [ 1206]   114  1206    88647      256      41       3       26             0 indicator-messa
[   54.523041] [ 1207]   114  1207    83323      127      31       3        0             0 indicator-bluet
[   54.523042] [ 1208]   114  1208   122044       98      37       4       12             0 indicator-power
[   54.523043] [ 1209]   114  1209   132868      439      75       3        0             0 indicator-datet
[   54.523044] [ 1210]   114  1210   140272     1504     127       4        1             0 indicator-keybo
[   54.523045] [ 1211]   114  1211   134142      426      68       4        8             0 indicator-sound
[   54.523045] [ 1212]   114  1212   189042      260      47       4        0             0 indicator-sessi
[   54.523046] [ 1218]   114  1218   117391      350      89       4        0             0 indicator-appli
[   54.523047] [ 1232]     0  1232     7973       81      20       3       11             0 bluetoothd
[   54.523048] [ 1238]   114  1238   152474     1084     129       3       15             0 unity-settings-
[   54.523049] [ 1261]   114  1261   104039      719      78       4        0             0 pulseaudio
[   54.523050] [ 1272]   120  1272    45874       77      24       3        1             0 rtkit-daemon
[   54.523051] [ 1293]     0  1293    68995      324      53       3       12             0 upowerd
[   54.523052] [ 1296]   114  1296    15493      366      33       3        0             0 gconfd-2
[   54.523053] [ 1342]   110  1342    75254     1170      49       3        0             0 colord
[   54.523054] [ 1429]   113  1429    12484       98      27       3        0             0 dnsmasq
[   54.523054] [ 1430]     0  1430    12477       94      27       3        0             0 dnsmasq
[   54.523055] [ 1514]     0  1514    22408      226      49       3        0             0 sshd
[   54.523056] [ 1570]  1000  1570    11958      853      26       3        0             0 systemd
[   54.523057] [ 1571]  1000  1571    15825      501      33       3        0             0 (sd-pam)
[   54.523058] [ 1631]  1000  1631    22408      244      46       3        0             0 sshd
[   54.523058] [ 1632]  1000  1632     5779      619      16       3        0             0 bash
[   54.523059] [ 1692]   118  1692    11320       77      25       3       14             0 kerneloops
[   54.523060] [ 1745]     0  1745     3964       41      13       3        0             0 agetty
[   54.523061] [ 1768]   125  1768    13192       98      27       3        0             0 dnsmasq
[   54.523062] [ 2276]   126  2276    32160      388      58       3        0             0 exim4
[   54.523062] [ 8310]  1000  8310     5508      661      14       3        0             0 stress-ng
[   54.523063] [ 8311]  1000  8311     5508       49      13       3        0             0 stress-ng-brk
[   54.523064] [ 8312]  1000  8312     5508       46      13       3        0             0 stress-ng-brk
[   54.523065] [ 8313]  1000  8313     5508       46      13       3        0             0 stress-ng-brk
[   54.523065] [ 8314]  1000  8314     5508       46      13       3        0             0 stress-ng-brk
[   54.523066] [ 8321]  1000  8321   365871   360407     717       4        0             0 stress-ng-brk
[   54.523067] [ 8322]  1000  8322   239424   233959     470       3        0             0 stress-ng-brk
[   54.523068] [ 8323]  1000  8323   143599   138152     283       3        0             0 stress-ng-brk
[   54.523069] [ 8324]  1000  8324    54613    49145     109       3        0             0 stress-ng-brk
[   54.523070] Out of memory: Kill process 8321 (stress-ng-brk) score 363 or sacrifice child
[   54.523072] Killed process 8321 (stress-ng-brk) total-vm:1463484kB, anon-rss:1441628kB, file-rss:0kB

However, this message may have been cleared from the kernel log, so one may need to inspect the kernel logs /var/log/kern.log*

The default virtual memory setting for Linux is to over-commit memory. This means the kernel will allow one to allocate more memory than is available, allowing processes to memory map large regions because normally not all the pages in the allocation are used.  However, sometimes a process will read/write to all the pages that are over committed and the kernel cannot provide enough physical memory + swap, so the OOM killer attempts to find the best candidate overcommitted process and kill it.


As requested, here is an example of using cgroups to have certain processes bypass your VPN.
Install required tools:
sudo apt-get install cgroup-lite cgroup-tools
Then on each bootup where I want this functionality I do this in a terminal shell:
sudo su
./cgroup_setup.bash
exit

Where cgroup_setup contains something like this (change myuser, mynetworkdevice and mygatewayip as appropriate):
#!/bin/bash

# Define a control group named novpn with a classid of 11:11
sudo cgcreate -a $USER:$USER -t $USER:$USER -g net_cls:novpn
echo 0x00110011 > /sys/fs/cgroup/net_cls/novpn/net_cls.classid

# Change ownership so myuser can run processes bypassing the vpn
sudo chown myuser:myuser /sys/fs/cgroup/net_cls/novpn
sudo chown myuser:myuser /sys/fs/cgroup/net_cls/novpn/*

# Add mark 11 on packets of classid 0x00110011
iptables -t mangle -A OUTPUT -m cgroup --cgroup 0x00110011 -j MARK --set-mark 11

# Force the packets to exit through my interface (mynetworkdevice) with NAT
iptables -t nat -A POSTROUTING -m cgroup --cgroup 0x00110011 -o mynetworkdevice -j MASQUERADE

# Define a new "novpn" routing table
# This is persistent so it does not actually need to be done each time in script...
echo 11 novpn >> /etc/iproute2/rt_tables

# Packets with mark 11 will use novpn
ip rule add fwmark 11 table novpn

# Add a route for default gateway for novpn
ip route add default via mygatewayip table novpn

# Unset reverse path filtering for all interfaces
for i in /proc/sys/net/ipv4/conf/*/rp_filter; do echo 0 > $i; done

# Create control group
cgcreate -t $USER:$USER -a $USER:$USER -g net_cls:novpn

Now you can use cgexec to run a process bypassing the VPN for example:
killall firefox
cgexec -g net_cls:novpn firefox

If you run firefox normally with a VPN running you should see that your public facing IP is a VPN IP. But with cgexec bypassing the VPN you can check it's your actual home IP.


install discourse with docker on ubuntu 16.04

I am not able to fully test this right now, but in theory if you change line 230 in discourse-setup file from
check_port "80" to a free port, then it should work fine according to this post


Clean uninstall of virtualenv and virtualenvwrapper

I got the same issue, but eventually found out where the problematic file was. It's

  /etc/bash_completion.d/virtualenvwrapper

Delete it and you won't see the error message again.

PS: Here's how I found out where the file was:

  grep -lir "virtualenvwrapper" /etc/


Your command has a number of issues.

Pipes connect standard output to standard input. Since you redirect the standard output of tee to a file, there's nothing to go to the input of the remainder of the pipeline. It should be
 cat file1.txt file2.txt | tee unsorted.txt | ...

xargs turns standard input into arguments of the given command. The sort and cat commands expect their arguments to be filenames. So you're asking it to run sort (and then cat) on files named as each of the lines in the original files, rather than on the lines themselves.
 cat file1.txt file2.txt | tee unsorted.txt | sort -r | cat > reversed.txt

However the final cat is superfluous, so all you need is
cat file1.txt file2.txt | tee unsorted.txt | sort -r > reversed.txt


How do I use file contents as arguments in crontab

That's because cron uses /bin/sh by default - which doesn't support the $(< file) syntax

You can either replace

$(< /home/<MYUSERNAME>/IPcontainer)

by the POSIX

$(cat /home/<MYUSERNAME>/IPcontainer)

or tell cron to use bash explicitly

SHELL=/bin/bash
0 * * * * 6tunnel 80 $(< /home/<MYUSERNAME>/IPcontainer) 80

See also

Understanding Bash's Read-a-File Command Substitution


How do I access a hard drive from a live CD?

Not sure what this has to do with shredding...

To mount a drive in this manner, first locate it using sudo fdisk -l in a terminal (within the LiveCD environment).

Then determine the drive/partition you want and mount it as usual with the mount command.


Create (for example) a file located in /etc/lightdm/lightdm.conf.d/ named 10-webkit.conf with these lines:

[Seat:*]
greeter-session=lightdm-webkit-greeter


Drivers don't get installed from the windows cds because the windows software is made only for windows. In GNU/Linux, a lot of the drivers that you'll ever need are already running with the default kernel from installation.

As for the webcam, it probably just works. I would suggest that you install the cheese webcam utility to test it out. To install cheese, either open the software center and search for/ install it from there.. Or, hit ctrl+alt+t to get the command line. Then, run this command:

sudo apt-get update && sudo apt-get install cheese -y

After the installation is complete, you can click the Ubuntu icon, then start typing cheese, then launch the "Cheese Webcam Booth".


What are the steps needed to create new keyboard layout on ubuntu?

In Ubuntu 14.04, keyboard layouts are kept in

/usr/share/X11/xkb/symbols/

Each of the files in this directory contains a series of entries of the following type:

    key <AC01> {[a, A, aacute, Aacute]};

This entry maps a key on the keyboard to a number of specific characters using the following conventions:

<A C01> The first letter A indicates we are looking in the alphanumeric key block (other options include KP [for keypad] and FK [for Function Key]);
<A C 01> The second letter C indicates the row, counting from the bottom in which the key is found. (In a standard US keyboard, the space bar is in row AA and the number keys are in row AE).
<AC 01> The numbers 01 indicates the position of the key, counting from the left and ignoring any specially named key like TAB or ~ (tilde): AC01 is in the third row up, first key over from the left (ignoring Caps Lock, if present); on a standard US keyboard, this is the key marked “a”.
The brackets enclose the list of characters assigned to each key. This contains up to four entries, separated by commas:

a - The unmodified key.
A - The Shift character.
á - The Alt Gr character. (aacute)
Á - The Shift+Alt Gr character. (Aacute)

Creating a custom keyboard map is as easy as replacing the characters you don’t want in a given line with the ones you do!

For example:

As an Anglo-Saxonist, I type á and Á much less frequently than I type æ and Æ.

To add the Anglo-Saxon characters to my list, I simply replace aacute and Aacute with the entity names or Unicode code points for æ and Æ (“aelig” or U00E6 and “AElig” or U00C6, respectively):

    key  {[a, A, aelig, AElig]};

or

    key  {[a, A, U00E6, U00C6]};

When I am finished modifying my keyboard layout, I save the file with a new name, "oe" in the same directory.

Adding a new keyboard layout to evdev.xml file.

In order to use new keyboard layout, We need to tell X11 that it exists. In Ubuntu 14.04 X11 keeps track of installed keyboards in /usr/share/X11/xkb/rules/evdev.xml file. Then lets add the new layout in it.

Open X11/xkb/rules/evdev.xml in an editor
Go to the end of the <layoutList> section (search for </layoutList>). Add the following after the last </layout> tag, where X is the file name of your keyboard layout in /usr/share/X11/xkb/symbols (in my case oe); Y a suitable short name; and Z an appropriate long name in one or more languages and aaa a legal three letter (ISO 639-2) language code (e.g. eng for English):

<layout>
 <configItem>
   <name> X </name>
   <shortDescription> Y </shortDescription>
   <description> Z </description>
   <languageList>
      <iso639Id> aaa </iso639Id>
   </languageList>
 </configItem>
 <variantList/>
</layout>

Here it is, follow complete introduction

Other related links:
http://ubuntuforums.org/showthread.php?t=188761&p=1092145#post1092145
http://www.charvolant.org/~doug/xkb/html/index.html


I had this problem too. "USB" does not have to (and may never) appear on the boot menu. As far as I can remember you should disable the fast boot and secure boot options on the Boot page in BIOS. (I think they are the last two items on the list). You may have to choose "Disable" in the boot priority menu as well. Then try booting from USB.

Now something very important. You should choose UEFI not CMS. Look here: Dual boot Ubuntu+Windows 8: Ubuntu won't show up


Is scrolling down Facebook web page causes high CPU usage normal?

In Firefox you can disable "smooth scrolling" which saves RAM and CPU. I don't use Chrome very often, so I don't know how to disable it there, but it should be possible.


Windows Subsystem for Linux: /home/user (Linux Home Directory Path) to use for ConEmu Terminal?

I stumbled upon the article "Bashing Windows" (By: Jan De Dobbeleer),
which led me to this answer.

The main trick is the ~ (tilde) when opening the bash shell.

Home (Linux)

BASH (path): C:\Windows\System32\Bash.exe ~ (has tilde ~)
STARTUP DIRECTORY (path): C:\Users\<YourUserName>\AppData\Local\lxss\home

Root (Linux)

BASH (path): C:\Windows\System32\Bash.exe (no tilde)
STARTUP DIRECTORY (path): C:\Users\<YourUserName>\AppData\Local\lxss\root

Home (Windows)

BASH (path): C:\Windows\System32\Bash.exe (no tilde)
STARTUP DIRECTORY (path): C:\Users\<YourUserName>


Samaba - where are my Win10 sahres mounted?

KDE accesses the share by talking to the remote server directly, it doesn't actually mount the remote share via the kernel. This is why it doesn't show up in mount on the standard Linux file hierarchy.

To mount the share, you need to run the mount command manually. E.g.

mount -t cifs //seven/share /mnt/samba


ssh-ing in to ubuntu comp by hostname suddenly stopped working (`Could not resolve hostname [ubuntu_comp_hostname]: Name or service not known`)

EDIT
The cause of the problem
As for why the server name is not correctly resolved to the IP, I wouldn't know, this requires diagnosis.
Please perform the following actions:

Post the contents of /etc/hosts, /etc/resolv.conf /etc/nsswitch.conf.
Post the contents of ${HOME}/.ssh/config. Try removing (for privacy issues) as little as possible.
Rename config and try ssh-ing. Post the outcome.
Try connecting not using .local, using both the IP and server name. Post the outcome.
Specify what is your network configuration... 1) Where are the connecting machines located? 2) Which is the DNS?
Try host hostname_of_ubuntu_comp. Post the outcome.
Further debug with ssh -vvv .... Post the outcome.
Post the output of netstat -plunt | grep 22 in the server.
Post the output of systemctl status ssh in the server.

Related:

What does ".local" do?
https://serverfault.com/questions/831747/why-is-ssh-not-resolving-this-hostname/831769
https://stackoverflow.com/questions/20252294/ssh-could-not-resolve-hostname-hostname-nodename-nor-servname-provided-or-n
https://docstore.mik.ua/orelly/networking_2ndEd/ssh/ch12_01.htm

A way to make it work
You say you can ssh into the server using the IP.
Let's say the command that you use to connect is
$ ssh user_at_server@10.20.10.10

Then, make sure in ${HOME}/.ssh/config in your client you have the following lines (the last two are convenient, but optional)
Host server_user
  HostName      10.20.10.10
  User          user_at_server
  ServerAliveInterval 30
  ForwardX11 yes

Then make sure the right attributes are assigned:
$ chmod 0664 ${HOME}/.ssh/config
$ chmod 0700 ${HOME}/.ssh

You should now be able to
$ ssh server_user


Canon Pixma MP640 wireless network on Ubuntu 17.10 (64bit)

so the drivers are available: http://support-asia.canon-asia.com/contents/ASIA/EN/0100236602.html coming down as cnijfilter-mp640series-3.20-1-i386-deb.tar.gz and 32bit;

If you do symbolic links, I wonder if that helps

sudo ln -s /usr/lib /usr/lib64

sudo ln -s /usr/local/lib /usr/local/lib64

that is a 10 yr old printer; you are doing well to keep it going; and Canon do well to build such long-lasting hardware!!

from here, https://ubuntuforums.org/showthread.php?t=2021854 is the justification for the links; perhaps do them first, and then download and install the drivers; from the earlier link;

it has an install script so

cd Downloads

tar -zxvf cnijfilter-mp640series-3.20-1-i386-deb.tar.gz

cd cnijfilter-mp640series-3.20-1-i386-deb

sudo ./install.sh

and the terminal should ask you some questions as the script runs ..


I have a micro sd card that can be read and written in windows, but it can't be written in VMware. How do I fix this? Thanks!

First, unmount the drive. Low-level disk utilities (like fsck) change the physical disk, which may no longer match the kernel data stored by mount. Then, since you want low-level access to the drive, you must run as root, using sudo:

 sudo umount /dev/sda1
 sudo fsck.vfat -a /dev/sda1

The -a option to fsck.vfat asks for automatic repair. See man fsck.vfat for other choices.


What to use to monitor MySQL for corrupted tables?

Corruption is tough to look for, but there are some methods.

Maatkit has some amazing tools for this. mk-table-checksum in particular is useful:

http://www.maatkit.org/doc/mk-table-checksum.html

You can restore from a backup onto another machine, and compare all the rows that you think should be the same, or just eyeball the diffs to make sure they all make sense. However, there isn't any strong checksumming built into the row formats, so if you aren't doing your own data checksums, you're at the mercy of bitrot on your disks nad weird memory corruption errors. :-P


Startup Applications didn't run my script

Enclose your commands in quotes:

gnome-terminal --command 'bash -c "sleep 30 ; export PATH=$PATH:/home/erik/Downloads/geckodriver_dir ; python ~/Dropbox/BashScripts/fjucheckin.py ; bash"'

Having "bash" at the end of the commands will keep the terminal open.


Ubuntu 18.04 configure vlc always on top

You can achieve the first with devilspie or its GUI counterpart gdevilspie. You may refer to this detailed answer by @Isaiah to learn more about how to use devilspie.

Once you're done setting up devilspie, add the following rule.

(if
  (is (window_class) "vlc")
    (begin
        (above)
    )
)


Can't mount my Ubuntu partition from Live USB

TL;DR: There is no Ubuntu installed on your computer or the partition table is incomplete or broken.

In your partition list, sda4 is listed as an extended partition. This means that it doesn't actually work as a "real" partition, but as a container for subpartitions. This is done because MBR disks can only have 4 primary partitions. By doing so, one can create more than 4 partitions by creating subpartitions inside the extended partition.

Also, your partition list, you can see where your partitions start and end. Your extended partition starts at sector 459864062 and ends at sector 625141759.

As you can see, there is only one partition with its boundaries between those two values: The Swap partition, which is 7.6GiB in size and is located at the very end of the extended partition. All other partitions are outside this range.

So you have 3 primary NTFS partitions and one extended partition, which only contains a Swap partition. There is no partition which can hold a Linux installation; you don't have Ubuntu installed on your computer.

Or you do and the Windows installer erased the partition form the partition table; in this case you should be able to recover the partition entry, e.g. with the instructions given here


I'm not sure if it can do what you are asking but compizconfig-settings-manager  can do many tricks and you might find an answer there.

By choosing Place Windows in Windows Management you are able to individually define a fixed location for windows:


Ubuntu 18.04 Thinkpad T460p w/ UltraDock 4k@60Hz Blank Screen

The problem was the monitor. There was a setting deep in the menus to switch the displayport protocol from 1.1 to 1.2. Once switched, the computer works perfectly at 60Hz.


Opencv commands are needed to be called as root using 'sudo', otherwise shows error

Most probably your OpenCV was installed as root, and hence its owner is root. Try running these commands in terminal:

Get to know yourself whoami
Locate OpenCV directory (sudo may be needed) whereis opencv
Go to OpenCV directory

cd `whereis opencv`

Change ownership recursively to yourself

sudo chown -R `whoami`


sublime text installation, and how to run it

Sublime Text 3 is available from the official Sublime Text repository. The following information was taken from the documentation available at that page.

In order to use the repository, install their signing key:

wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add -

Make sure your apt supports https:

sudo apt install apt-transport-https

Add an entry for the repository to your apt configuration:

echo "deb https://download.sublimetext.com/ apt/stable/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

Install Sublime Text using apt

sudo apt update
sudo apt install sublime-text


“error: no init found. Try passing init=bootarg” error after power failure during boot

Boot into the LiveCD again, launch GParted, and check the partition (click on the partition and choose Partition → Check). If you see any errors, save them and copy them here.


Your problem:

The problem is that echo hello world executes within milliseconds, faster than the terminal window is able to pop up.

This means your script already exits before the terminal is visible and therefore its startup is cancelled and you see nothing.

Solution 1 - modify script and add a delay:

You can add a delay (here: 5 seconds) at the end of your script so that it runs longer and you have time to view the result before the script quits and the terminal window closes itself:

#!/usr/bin/env bash
echo hello world
sleep 5

Solution 2 - modify script and wait for a keypress:

You can also add a read command to the end of your script to wait for keyboard input before the script exits.

The -s parameter causes silent input i.e. your pressed key will not be echoed to the terminal.
-n1 lets it read only one single character and returns immediately afterwards instead of waiting for Enter to be pressed.
The -p "Press any key to exit..." argument actually specifies the text to print before waiting for input.

#!/usr/bin/env bash
echo hello world
read -s -n1 -p "Press any key to exit..."

Solution 3 - change gnome-terminal's preference to keep the window open:

Launch a gnome-terminal window, open the Edit menu and select Profile preferences. Navigate to the Commands tab. You will see a drop-down menu labelled When command exits:

Pick Hold terminal open here and close the settings window.

From now on when you double-click on a script and select to run it in a terminal, the window will no longer close itself but stay open and display a banner informing you about the script's exit status:

  Warning!
  This setting also applies if you manually open a terminal window and try to close it by exiting Bash using the exit command or Ctrl+D - I find it pretty annoying that the terminal window does not close any more then as well.


Is there a way to integrate Node.js into the kernel core so that the system has this node running as a module.?

No, there is no way to do this. In general, having it as a kernel module will pose a significant security risk, because nodejs is executing a user application and if there are problems with that application, it will be very easy to exploit them. As well, kernel modules are supposed to be "very tight and tidy" in terms of their runtime behavior, many/most nodejs application certainly will not be.

I might be wrong, but I am not aware of any other software similar to nodejs that runs as a kernel module (java, django, etc.).

At the same time, I do not think you are going to gain any real benefits compared to running it as a daemon.


wired connection 1 connection established" but still there is no internet

Go to networking icon (up and down arrows near the menu you use to shutdown) and click on edit connections. Use the appropriate type of connection (sounds like dsl??) and enter username and password by clicking on the connection and hitting the edit button.


Open .bashrc using your favorite editor, for example:

gedit ~/.bashrc

Then find:

HISTCONTROL=ignoreboth

Change it to:

#HISTCONTROL=ignoreboth

And save the file.

Now duplicated commands and commands started with a space will be saved in your bash history too.


Problem with newly installed Ubuntu 13.04

This was I problem I had a while back, and using propriatary drivers instead of the open-source ones bundled with Ubuntu seems to fix it.
The way I did it was repeatedly logging in and restarting till I get in and then slowly navigating to the driver page in settings, but I now read that you can press ctrl+alt+delete and then enter to get out of the glitchy screen and back to the login screen without errors when you log in again.
Anyways, after you log in, navigate to Software Sources via the dash or settings and go to the additional drivers tab to see the drivers you can use. You should look for propriatary and tested tags on the drivers to know which one you should use.

Hope this helps, Roy~


Can't install Thunderbird 38.1 on Ubuntu 14.04

Thanks for all the tips so far.  The answer came from the hint that warci provided of asking whether I was using the 32bit version on a 64 bit system.  I am running a 64 bit system and it was the 64 bit version I was having trouble with.

However just for the hell of it, I installed the 32 bit version on my 64 bit system and lo' and behold it is now working.

I have no idea why??


Will r-base on ubuntu give me the same interface as RStudio with R on Windows?

Install r-base first using the command you mentioned; that gives you a command-line interface to R.
Then install RStudio from this page (look under "installers" and pick the .deb file that corresponds to your computer's architecture (32- or 64-bit)).
After you've downloaded the .deb file, change directory to wherever that file was downloaded to (using cd command, for example cd ~/Downloads) and install it via sudo dpkg -i rstudio-0.99.902-amd64.deb (or whatever the downloaded .deb file is called).

After successful install, you can delete the .deb file.


How to reset setting of Wine, avoiding uninstalling all applications in it?

As we have discussed various things in the comments without success, what might work is to create a new wineprefix and then install and run foobar always from that prefix. That may allow you to continue using foobar without reinstalling wine, as the corrupted settings may be present in the original .wine folder.

Create your wine prefix with:

WINEPREFIX=$HOME/.foobar winecfg

Then you can temporarily export the location to the environment:

export WINEPREFIX=$HOME/.foobar

(see my note below re using export and env)

Then cd to your newly downloaded version of Foobar2000 and run the install:

wine foobar2000_v1.1.17.exe

I had to logout and login before I launched the program, or I experienced some odd errors and heavy disk activity. That was probably my system however.

Now if you have logged out, open terminal and run the export command again and then enter

wine "c:\\Program files\\foobar2000\\foobar2000.exe"

To alter any settings in this new prefix, you can just run

winecfg

as long as the prefix is exported to the environment as above.

Note: I have specified to export the WINEPREFIX environmental variable above; an equally valid method would be to use env, and often using env is very useful as it does not rely on the variable having already been set with export. The WINEPREFIX specified with env is used for that command-line only, whereas using export means that variable becomes the default environmental variable and thus would have to be unset if a different WINEPREFIX was needed to be used.

Some example usage of env:

env WINEPREFIX=$HOME/.special <wine commands>

You will also have to modify the foobar location in the script I recently discussed in my other answer by adding the following, modified for your system, under the shebang at the top of the script:

export WINEPREFIX=$HOME/.foobar
cd /home/mike/.foobar/drive_c/Program\ Files/foobar2000/

This is definitely one way to get fresh settings without reinstalling wine and removing your .wine folder, and it should make foobar work correctly again, and can be repeated for many different wine programs: see the Wine FAQ.


How can I override the title of an X11 window running across an SSH tunnel?

Specifically for Firefox, there are add-ons that should be able to help you, e.g., firetitle. Install and configure it on the remote machine.


Can't install. I click install Ubuntu and get a black screen

did you try using  the "try ubuntu" option, I had this happen to me when I was attempting to use a flashdrive as a replacement for a hard drive


This worked for me:

sudo apt-get install systemd-shim

and then restart


If the interface is managed by the system

If your network interface (eth0 in most cases) is managed via /etc/network/interfaces you could avoid running ethtool before every shutdown by following this guide.

If the interface is managed by NetworkManager

If eth0 is managed by Network Manager, the simplest way is to add the ethtool -s eth0 wol g command in an if-up.d script.

Here is a quick example that you could put in /etc/network/if-up.d/eth0-wol and make the script executable: sudo chmod +x /etc/network/if-up.d/eth0-wol :

#!/bin/sh

ETHTOOL=/sbin/ethtool
[ -x "$ETHTOOL" ] || exit 0
[ "$IFACE" != "lo" ] || exit 0

WOL="g"
"$ETHTOOL" -s "$IFACE" wol "$WOL"
exit 0


nvidia-352 driver not working with kernel 4.2.0-29

First of all, as of writing this : the latest stable and tested kernel available is 4.2.0-27-generic.
Boot with this kernel and everything should work flawlessly ... if not reinstall the NVIDIA drivers.

Uninstall the NVIDIA drivers - open a terminal and execute :

sudo apt-get purge nvidia*
sudo reboot

Reinstall the NVIDIA drivers - open a terminal and execute :

sudo apt-get update
sudo apt-get install nvidia-352
sudo reboot

Generally it is recommended to use the NVIDIA drivers from the official Ubuntu repositories.
When there are problems with these drivers, you can install the latest official NVIDIA drivers.

Uninstall the NVIDIA drivers - open a terminal and execute :

sudo apt-get purge nvidia*
sudo reboot

Reinstall the NVIDIA drivers - open a terminal and execute :

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt-get update
sudo apt-get install nvidia-361
sudo reboot

My personal experience :

I installed these drivers shortly after the release and they are working great without any issue.
NVIDIA drivers 361.28 are the latest official drivers version from the NVIDIA long-lived branch.

Updated information :

A new kernel 4.2.0-30-generic is available in the repositories.

Ubuntu 15.10 Linux kernel -> Ubuntu Security Notice USN-2908-1

Ubuntu 14.04 Linux kernel -> Ubuntu Security Notice USN-2908-2


Is there a tool to periodically filter IMAP email messages on other folders (not Inbox)?

Depending on what exactly you're intending to do and what technologies or programming languages are at your disposal, you could whip up a short script in Ruby / Python / Perl / ... and execute this script periodically with a cronjob.
But this approach seems like tinkering with the symptoms to me, instead of actually solving your problem. If Yahoo! can't offer you what you need, I'd look into switching to another mail host. Yahoo! isn't as well regarded as it once was anymore, and I'm not sure whether I would still use something@yahoo.com to represent my business ;)
Depending on your budget (regarding money, time, technological expertise etc.), I'd even look into moving that workflow away from mail completely. As I understand, the incoming mails are generated by a software. So it might be a better solution to build an API that this software could talk to and transfer the bookings. This isn't exactly done in a day, but it might be a more reliable solution in the long run - especially if we're talking business.


Ubuntu Cleaner for Ubuntu 16.04 LTS not working Only Icon Appear

Converting the OP's comments to an answer:

A solution was posted here on Ubuntu Forums.

Installing the package python-dbus should fix the issue.


As stated on the top of /boot/grub/grub.cfg:

# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

Edit /etc/default/grub instead.

Here are details on how to configure the grub file; see the other answers there for a GUI-based method.


Try changing the owner and group of that directory to www-data and setting permissions for owner/group to rwx

sudo chown -R www-data:wwwdata /var/www/html/assets/img
sudo chmod -R 755 /var/www/html/assets/img


Are you installing from the ISO itself, or are you recording it in a CD or DVD? Because the problem might be in the recording, not in the ISO.

Try to check the MD5 for the iso file first, before burning it to disk. If that's correct, then the corrupted files happen when you build the CD. I would advice to use a bootable USB for the installation instead of a CD or DVD (you'll save time and won't waste any more discs).

Here you can get the ISO files an its corresonding hash files. To check a hash in Windows (if you have not Ubuntu installed) there are dozens of little programs around like md5sum


Swap partition under logical partitions container?

Placing the swap partition inside an extended partition is not necessary, it is just something that the installer always does.  Yes, you can remove both the swap partition and the extended partition that contains it and recreate the swap partition as a primary partition.  This probably will result in a properly aligned partition.


Run in a terminal

sudo tee /etc/modprobe.d/asus.conf <<< "options asus_nb_wmi wapf=4"

then reboot and check BIOS if the Wi-Fi is enabled there.


Ubuntu 18.04 || Remote access - remote server display not supported

This was very well answered at the following link, which worked for me: Anydesk remote server display not supported e.g Wayland

After installing Anydesk on my Ubuntu 18.04 server and trying to connect from a Mac, I would get a display_server_not_supported error. I was able to resolve this by going into the /etc/gdm3/custom.conf file and changing:
[daemon]
    # Enabling automatic login
    AutomaticLoginEnable=true
    AutomaticLogin=$USERNAME

After rebooting the Ubuntu server, Anydesk now connects and shows the login screen and I can login just
fine.


Are you using Compiz? Have you tried changing the option

CompizConfig Settings Manager → General Options → Focus & Raise Behavior → Focus Prevention Level?


Why doesn't this show the hidden files/folders?

Use

du -sch .[!.]* * |sort -h

in your home folder.

Alternatively, the command I use most frequently is

ncdu

Easy to install if needed:

sudo apt-get install ncdu


apt-get autocomplete package name is broken

As stated in the comments to the other answer, first make sure that bash-completion is installed:

sudo apt-get install bash-completion

and apparently for @diapir, it helped to reinstall it:

sudo apt-get install --reinstall bash-completion

However, for me, the problem was not that bash-completion was not installed or broken, the problem was that I had accidently deleted my .bashrc file. You can get a new one by copying it from /etc/skel:

cp /etc/skel/.bashrc ~/


How do I increase the volume beyond 100% in Kubuntu?

Left click on the KMix plasmoid then on "Configure Channels" button:

In the "General" section of the widget settings check "Volume Overdrive" checkbox.


Twitter app that supports real time updating

From your specifications, I recommend you to use Gwibber, which is default in 11.04.

Integration in Unity:

Integrates with Message Indicator
Quicklists in the launcher.
Real time updating.  How*?

Real time updating?

Not by seconds, the minimum is 5 minutes to refresh for tweets and mentions and replies, but seriously do you need it to be faster?It will bring headache:).

And tick show notifications for all messages.

Go to edit ---> preferences ---> set the minimum to 5 minutes.

Note: If you really need real time updating; you can use Tweetdeck for desktop, but you need first to install Adobe Air. But it lacks integration with Unity and Ubuntu in general.


I was not able to set up the Router using Ubuntu. The password to http://192.168.1.1 was not blank and was a random string.

I had to use a Windows machine to set it up. After it was setup, I was able to access it over http://192.168.1.1 from by Ubuntu Machine as well without the setup.

Thanks for all the help.

SB


Things to check

do you have another apache instance running?

ps aux | grep apache2

to check if you have and

pkill -9 apache

and start apache again.
if not check with ...

ls -l /var/lock/apache2.26wFR2Eely

the username and group of the file. The username and group need to match what you set apache up with. If not remove this file and start apache again.


Ubuntu itself does not limit connections. I have run the Deluge BitTorrent client and had around 1000 connections going simultaneously (on a good torrent).

It is possible that Vuze/Azurues might have a setting somewhere for throttling the numbers of connections (probably in the same place as bandwidth settings).


How do I keep the screen contents after quitting less or more?

You can use the -X switch:

-X or --no-init
          Disables  sending  the  termcap  initialization and deinitialization strings to the terminal.
          This is sometimes desirable if the deinitialization string does something  unnecessary,  like
          clearing the screen.

Or you could do the following:
For example cat myfile to display the entire file or cat myfile | grep searchterm if you want to search for something specific.

You also could use head -n X or tail-n X to display the first/last X lines of a file.


How do I "clean up" a machine after using the local provider?

LXC containers and the Juju environment need to persist through a reboot, so everything is not contained in one place.

First, ensure that you have the environment destroyed and the containers are not running. Then remove the following files and directories:

/etc/init/juju-*
/etc/lxc/auto/juju-*
/etc/rsyslog.d/25-juju*
/var/lib/juju/containers/*
/var/lib/lxc/juju-*
~/.juju/<env>
~/.juju/environments/<env>.jenv

Then you can reboostrap with a clean environment.

In certain cases you might need to list, stop, and destroy containers by hand, do this before removing the Juju files.

http://manpages.ubuntu.com/manpages/trusty/en/man1/lxc-ls.1.html
http://manpages.ubuntu.com/manpages/trusty/en/man1/lxc-stop.1.html
http://manpages.ubuntu.com/manpages/trusty/en/man1/lxc-destroy.1.html


IPv6 auto-configuration has several parts:

Routing is done with RA (Router Advertisement) messages sent out by the router(s)

The RA message may tell the client that stateless auto-configuration is allowed so the client can give itself IPv6 addresses without needing to contact a DHCPv6 server
The RA message also informs the clients about if any DHCPv6 servers are present, and of which type.
The RA can also contain an indication that the router that sent it can be used as a default gateway.
(and there are many more things that can be in an RA, but let's keep it simple for now ;)

DHCPv6 can be used in two different modes:

You can have a DHCPv6 server that does not hand out IPv6 addresses, but that does give extra information like DNS settings, time servers etc. This is called stateless DHCPv6.
You can have a 'full' DHCPv6 server that will give out addresses and any other settings. This is called stateful DHCPv6.

Do the routing part is always done by the RA. DHCPv6 does not contain any routing information. The idea behind this is that the router knows better about routing than a DHCPv6 server.

I would recommend starting with one of these scenarios:

If you don't really care which addresses each device gets and just want them to be able to access the IPv6 internet: Let the router send out RA messages that indicate that a stateless DHCPv6 server is available and that stateless auto-configuration is allowed. Configure a stateless DHCPv6 server that provides DNS settings to the clients. The clients will then configure their own addresses based on the information in the RA, use the router as default gateway and they will get their DNS settings from the stateless DHCPv6 server.
If you do care about the addresses and want to manage them, when you want to update a DNS server automatically with a client's address etc.: Let the router send out RA messages that
indicate that a stateful DHCPv6 server is available and that stateless auto-configuration is not allowed. Configure a full DHCPv6 server that hands out addresses and provides DNS settings to clients. The client will not configure its own addresses, will use the router as default gateway, and will get both addresses and DNS settings from the DHCPv6 server.


Performance tuning/diagnotics help needed... (12.04LTS 64bit, LVM, & LUKS)

The first is a known bug. There are suggested work arounds on the bug report

https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/699802

Most common is:

Commenting out GRUB_HIDDEN_TIMEOUT and GRUB_HIDDEN_TIMEOUT_QUIET in /etc/default/grub works for me.

GRUB_DEFAULT=GRUB_SAVED_DEFAULT
#GRUB_HIDDEN_TIMEOUT=10
#GRUB_HIDDEN_TIMEOUT_QUIET=
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
#GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

GRUB_TERMINAL=console

GRUB_GFXMODE=auto

I do not know the problem with nautilus, but this question has been asked with no obvious solution either. I doubt it has to do with either LVM or LUKS.

Nautilus is really slow

Nautilus is extremely slow

The most common problem is a network share (samba) that is not mounted.

Perhaps running nautilus from the command line might show an error of some kind.


After upgrading from 14.04 lts to 16.04 lts gnome terminal tabs look broken

Upgrading an operating system is a very complex procedure that involves changing thousands of components, and it's impossible to test the upgrade for every variation of hardware and software that people will use the script on.  This makes the upgrade script inherently buggy.  (The problem is not just with Ubuntu; I once ran a script to upgrade Windows Vista to Windows 7.  The script crashed and burned, and in the end I had to install Windows 7 from scratch.)  Chances are that your problem was caused by the upgrade.  Here is a Ubuntu forums thread with more information and advice.  I'm afraid that the fix will probably be to backup your files, wipe the partition clean, install Ubuntu from scratch, and restore the backup.


MySQL-server installation does not complete

I finally was able to solve the problem by removing all the dependencies and configuration files of the mysql as well as maria-db first. To do that, go to /var/lib and delete all the files related to mysql (You will have to have root permissions to delete them so dont forget to write sudo su before that). You can delete all the files by typing rm -r /var/lib/mysql*.
After that you have to delete all the files in the /etc directory by typing rm -r /etc/mysql*

Then perform the following commands and you will be set to go :

sudo apt purge mysql-client-5.7 mysql-client-core-5.7 mysql-common mysql-server-5.7 mysql-server-core-5.7 mysql-server
sudo apt update && sudo apt dist-upgrade && sudo apt autoremove && sudo apt -f install
sudo apt install mysql-server


How can I install Cinnamon on Ubuntu 12.04 and eliminate the following errors:

This PPA does not contain the latest version of Cinnamon.  It is relatively old given the rapid pace of development and the maintainer has not (as yet) updated this PPA.

As such, I would recommend you purge the PPA and install the latest version as per this Q&A:

How do I install the Cinnamon Desktop?

how to

Install ppa-purge

sudo apt-get install ppa-purge

The purge the ppa:

sudo apt-get -f install
sudo ppa-purge ppa:ppa:merlwiz79/cinnamon-ppa
sudo apt-get update


Through chat we determined this to be a corrupted partition. She was able to access her drive through terminal and knew already how to copy the files he wanted to save

I had her save all the files that were important

We then deleted the existing partition and re-created it

This was able to restore the drive to a working order.

This isn't the greatest "depth" of answer but there was a bunch of troubleshooting and stuff that  would be useless to post.


Win8 + Ubuntu 12.04: Grub loader menu is not shown any more

I had a similar problem.

My Notebook uses EFI and there are entries named HDD and Windows8 Loader.

Check if Windows8 Loader has a higher priority than your HDD.


Try these commands,

cd ~/Desktop
tar -xzvf CatlateralDamage_v4.1a_linux.tar.gz


How to set permisions for git so it runs without sudo

As you can see in your ls output, the .git directory is owned by root, and you don't have write access to it. Fix it with this command:

sudo chown -R wiktor:wiktor /var/www/html/apps/blog/.git

This will transfer file ownership of the git directory and everything in it back to you.


Server Ubuntu 20.04 move file and folder to root

Thanks I have found another good way to this
mv * .[^.]* ..

This made the trick


For wallpapers, install Wallch software,its available in software centre. Then download wallpapers from the net, open Wallch, Add the folder where the wallpapers are to wallch "Add Folder" option, set the timing and click start,and you'l get a wallpaper slideshow.For a single wallpaper, just right click on the image and select set as desktop.
There are several apps which allows you to not only paint but even photoshop like- GIMP , GNU paint . Both are available in software centre.


You can easily add appuser into the sudoers group.
First, open terminal with a user that has sudo permissions. Then, you can run sudo adduser appuser sudo to add appuser to the sudoers group. Now you can use appuser to run sudo commands.


Odd warning message when encrypting/decrypting

This means that you did not verify the key ID C8BB54DC. If it is your own key, you should issue ultimate trust (run gpg --edit-key C8BB54DC, run trust, select ultimate).

If it is another person's key and you're sure about the key's ownership (for example compared at least the long key ID with what the key's owner provided to you), issue a signature with your own key (issue a local signature if you don't want it uploaded to the key server network) by running gpg --edit-key C8BB54DC as described above, but then using the sign or lsign commands.


how to transfer files ubuntu 20.04 pc with windows pc through ethernet cable?

You can setup a samba server on your ubuntu computer, then upload your files from your pc to your ubuntu computer.

You can also use SFTP, which uses the SSH protocol. All you have to do is enable SSH on your computer.


Can I install Ubuntu along with another Linux OS?

Yes ,you can install ubuntu along with another linux distro.After installing ubuntu,boot into it ,open the terminalctrl+alt+t and run the below commands,

sudo update-grub
sudo shutdown -r now

These commands will detect if there was any os previously installed in this pc and then it update the grub to boot both the Os's.And then it restarts your pc.Now your grub will show both linux distro's.If you still facing problems on dual booting,then try boot-repair.


Trouble with size of partition (too small) after cloning disk/OS from USB flash drive to SSD

GNU Parted is a very useful tool for this kind of problem. If you are booting your image, and have a GUI, you can install it from the Ubuntu software store and it's very straightforward to use. Select the partition, right-click, select resize the partition. It will probably require a reboot to do the job.
Look for gparted in the software store.
If you can boot off the other USB drive and select the 500 GB drive in GParted, that might be helpful.


How can I properly install Nvidia driver and toolkit and samples?

Do you confirm you have pre-installation dependencies installed (check §2.3 and §2.4 of Cuda Installation Guide)?

If so, you just have to follow step by step Quick Start Guide ( starting §4.1.5.2 in your case)

Looks like you miss kernel header, xorg.conf generation and variables links ($PATH...) steps.


Ubuntu Server Netplan for Wifi and Ethernet

To use wifi with netplan.io and systemd-networkd, you need to manually install the wpasupplicant package.  It is not automatically installed as a dependency since wifi support is optional on servers.


Do I need Intel Linux Graphics Installer?

Yes you need to install Intel Graphic Driver

  The question is why ?

The answer is

It has  Intel Hardware Acceleration For Intel 3D ( VA-API ).
( VA-API ) also save battery power, I have done lots of testing so i will recommend to install Intel drivers. https://01.org/linuxgraphics/downloads
For Vmware user's 3D acceleration is ON by default and you don't need to do any tweaks for 3D acceleration

You check full details on ( VA-API ) on my answer, You can install it manually check my answer VA-API (Hardware Acceleration For Intel / AMD GPUs), But intel drivers updated VA-API package.


Getting character key code mappings in Ubuntu

Run xev from a terminal. This will give you a new window.

Place your mouse pointer in this window, type some keys and watch for results in the terminal.


mdadm system unbootable warming from update-initramfs -u

On Ubuntu 16.04, with mdadm 3.3, and all commands executed as 'root' - preceed with sudo if otherwise:

After struggling for 48 hours in the same corner, I found all my problems solved by applying this sequence, repeatedly if necessary:

cat /proc/mdstat
if any mdxxx shows up that you do not want, remove it with

mdadm --stop /dev/mdxxx
mdadm --remove /dev/mdxxx

and, most importantly, clear the corresponding disk slice(s) with

mdadm --zero-superblock /dev/sdxn

If any mdyyy is missing, add it.
Run cat /proc/mdstat again to be very sure all is as desired.
Update the config file with:

mdadm --detail --scan >>/etc/mdadm/mdadm.conf

Then remove any possible double entries with a simple edit (vi, nano, or whatever you prefer) of the same /etc/mdadm/mdadm.conf
if the config file is OK, update initramfs with it:

update-initramfs -u

Reboot and validate, until perfectly to taste.


The indicated amount seems to be .deb cache in majority. Issue this command:

sudo apt-get clean

and after that check again the disk usage.


I'm having a problem with locale and locale-gen in Ubuntu

Make sure your locale exist using:

locale -a

If you don't see your locale on the list, then use:

sudo locale-gen en_US
sudo locale-gen en_US.UTF-8

Then update your locales to existing locale by:

sudo update-locale LC_ALL=en_US.UTF-8

Apply changes by:

. /etc/default/locale

My locale:

$ locale
LANG=en_US.UTF-8
LANGUAGE=en_US
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC=uk_UA.UTF-8
LC_TIME=uk_UA.UTF-8
LC_COLLATE="en_US.UTF-8"
LC_MONETARY=uk_UA.UTF-8
LC_MESSAGES="en_US.UTF-8"
LC_PAPER=uk_UA.UTF-8
LC_NAME=uk_UA.UTF-8
LC_ADDRESS=uk_UA.UTF-8
LC_TELEPHONE=uk_UA.UTF-8
LC_MEASUREMENT=uk_UA.UTF-8
LC_IDENTIFICATION=uk_UA.UTF-8
LC_ALL=

Setting locale for current session:

$ export LC_ALL=en_US.UTF-8
$ locale
LANG=en_US.UTF-8
LANGUAGE=en_US
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=en_US.UTF-8

You could also try

$ sudo apt purge locales && sudo apt install locales


Problem solved by user....booted up in recovery mode, changed desktop background and realized login input was now available yet hidden with different desktop background. Luckily moving mouse around showed the login / password input menu.

Anyone that may have read this will realize this user is relatively new to Linux and Ubuntu. Background in Windows. Again, luckily Ubuntu appears to have some excellent support resources.

Has my floundering messed up anything critical? Time will tell, or my much younger support expert will I'm sure let me know!


My system is Ubuntu 11.10 and I was using Google earth without any problems until this morning. Last night I was using Google earth and this morning it would not start. I looked all over for a solution and came across this thread: Installed Google Earth won't launch  Then I tried to start it from the terminal as suggested and this is the output. As you can see, it shows that Google earth was already running and asks you to delete the file instance-running-lock. I deleted it and voila, it now runs again.

$ googleearth
Google Earth appears to be running already. Please kill the
 existing process, or delete /home/outlawradioinc/.googleearth/instance-running-lock if this is an error.
$ googleearth

I hope this helps some of the people out there that are having similar problems.


Android Developer Tools (ADT) installation gives GTK errors when not run as sudo

I think the reason for this is because you're running 64-bit architecture. This can hopefully be fixed quite easy. When running android on 64-bit Ubuntu you need 32-bit libs. This can be easily installed by running the following in a terminal:

sudo apt-get install ia32-libs

Give that a go. If it works without using sudo and your above edit, then happy days! If not I'll take a look around. This fixed issues I had on my 64-bit ubuntu.


Lenovo v570 ubuntu 12.04 wireless hard blocked even when ext. switch is on

This looks to be the problem:

ESSID:off/any

If so ... this will stop network-manager:

sudo service network-manager stop

and this will (manually) add the ESSID to wlan (change $id to your wireless network name):

sudo iwconfig wlan0 essid $id
sudo dhclient -v wlan0

It should result in you getting an IP address.


How do I set the representation of dates?

This page has a good walkthrough for what you want:

http://ccollins.wordpress.com/2009/01/06/how-to-change-date-formats-on-ubuntu/


I can recommend Gnumeric.
Gnumeric is an open-source spreadsheet program. Gnumeric is...

Free: Gnumeric and its source code are available free of charge,
licensed under the terms of the GNU General Public License version 2 or version 3.
Fast: Gnumeric starts up quickly and handles large spreadsheets
while remaining responsive.
Accurate: A spreadsheet should calculate the right answer.
Gnumeric's built-in functions and tools are accurate, as
several researchers have found.

To install:

sudo apt update
sudo apt install gnumeric


14.04.3 LTS Falure to start session at the login screen

According to your screen output it seems you are not entering correct usename and password . first enter your username

pocydal-CT14 login: yourusername  Enter

Password : yourpassword  Enter

then try to solve your problem using commands:

sudo apt-get install ubuntu-session
sudo apt-get install --reinstall ubuntu-session
sudo reboot

or
it might be

sudo apt-get autoremove

removed your ubuntu-desktop so try to install that using command:

sudo apt-get install ubuntu-desktop

and
reboot using command:

sudo reboot

or you can try

sudo dpkg-reconfigure -a
sudo apt-get install gnome-shell ubuntu-gnome-desktop


Cannot “Turn On” Chrome remote desktop in Ubuntu 20.04

The file dependency was messed up.
$ sudo apt-get install xbase-clients
$ sudo apt-get install python3-psutil

I got error message, so did the below as it said:
$ sudo apt --fix-broken install

Then at downloaded directory,
$ sudo dpkg -i chrome-remote-desktop_current_amd64.deb

Then I created a directory under ~/.config/chrome-remote-desktop.
After reboot (I did it for sure), access
https://remotedesktop.google.com/access
Then the set up message for hostname and pin # showed up.


Undo apt-get install with many dependencies

Open the terminal and type:
sudo apt autoremove
sudo apt remove texlive-latex-base
sudo apt remove maxima-sage maxima-sage-doc maxima-sage-share
sudo apt remove octave
sudo apt remove r-base-core
sudo apt remove python-sympy python-scipy
sudo apt remove python-flask python-flask-autoindex python-flask-babel python-flask-oldsessions python-flask-openid python-flask-silk
sudo apt remove sagemath-database-conway-polynomials sagemath-database-elliptic-curves sagemath-database-graphs sagemath-database-mutually-combinatorial-designs sagemath-database-polytopes sagemath-doc-en sagemath-jupyter sagetex
sudo apt remove sagemath # maybe you'll also have to run 'sudo dpkg --configure -a' to correct the problem
sudo apt autoremove


Using Ubuntu 12.04 LTS no sound in select apps

Well, I'll post my comment as a answer as I fixed it:

Maybe you have this configuration in silence:


Can't find fingerprint enrollment option on 18.10

I have the same problem with a Lenovo thinkpad X280. But I think is not a solution for my device right now (06cb:009a).

In your case I have read that is a solution if you install the package  fingerprint-gui.

Url: https://launchpad.net/~fingerprint/+archive/ubuntu/fingerprint-gui

I hope this information helps you.


You might have to enter a key combination.  Try holding Shift-F8 or F8 alone just after your BIOS screen goes away and before the 'loading windows' screen comes up.  You'll have to have good timing, so try at least a few times.

After that you might need to configure the boot loader, but that appears to be beyond your immediate problem for now.


Your sources are very outdated, ex. of current versions,

libpq-dev - 9.3.10-0ubuntu0.14.04

libssl-dev - 1.0.1f-1ubuntu2.16

krb5-multidev - 1.12+dfsg-2ubuntu5.2

comerr-dev - 2.1-1.42.9-3ubuntu1.3

Open Software & Updates, make sure that both trusty-security & trusty-updates are enabled under the Updates tab, then reload your sources & see if you get the current versions. If both were already enabled then open a terminal & run sudo apt-get update, then check for current versions.

If that doesn't help then again open Software & Updates & on main page switch to a different mirror in the Download from: section, reload sources, ect.