This is not possible.
But you can use the "Grub Customizer".

Features:
* move, remove or rename menuentries (they stey updatable by update-grub)
* edit the contents of menuentries or create new ones (internally it edits the 40_custom)
* settings like default operating system, kernel params, background image and text colors etc.

Open the terminal and run the following commands

sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt-get update
sudo apt-get install grub-customizer


Driver for printer Fuji Xerox DocuPrint C3360?

It finally worked! Here is the full procedure:

Download the official RPM, it is the big button at the bottom of this page.
Open it with Archive Manager.
As root, copy all files found in the RPM to their respective directories.
Reboot.
In Unity's Add Printer dialog, select "Network printer" then "LDP", and type the printer's IP address.
It looks for a driver but can't find it, so you are presented with a large list of manufacturers.
Above this list, click the PPD addition button.
Select the fxlinuxprint.ppd you have copied into /usr
In Text Editor, open the Print dialog, in Page setup set Paper source to Tray1, set Paper size to A4.
Press Print, it should print the document after a few minutes, even though "Media tray needs to be filled" errors appear.

UPDATE: If you get a message saying There was an error during the CUPS operation: 'server-error-internal-error', then try with the web interface which runs at http://localhost:631 by default. It worked in my case on Ubuntu 2012.04.


Wi-fi stops after a while working. Issues related to supplicant network-manager

I tried every solution in the web. I even wiped my hard disk and reinstalled Ubuntu. The problem persisted.

So. I changed the wifi chipset and now the wi-fi is working again. It seems like it was a problem more related to the hardware than the software.


Ubuntu 12.04.2 hangs during boot on a pink screen, console mode is blank

If you are installing on a disk with GPT partition table, you will need EFI-partition. Take a look at "Creating an EFI partition" in here:

https://help.ubuntu.com/community/UEFI

You may also install boot loader on a different disk with legacy MBR partition table (e.g. USB flash drive).


Can't see my Nexus 4 with fastboot on Ubuntu 12.10

You can update your gvfs file to enable your computer to see Nexus 4 files. Use the ppa

sudo add-apt-repository ppa:langdalepl/gvfs-mtp
sudo apt-get update && sudo apt-get upgrade

After you update, reboot your computer. When you connect the Nexus 4 to the PC, make sure its unlocked. This should help you. :)

If you are trying to use adb and cannot see your device, change the ownership of your ~/.android folder to the current user .

sudo chown -R $USER:$GROUP ~/.android

For more details see here.


How can I install my printer by terminal?

Test this:

Download this file for 32 bits:

http://download.ebz.epson.net/dsc/op/stable/debian/dists/lsb3.2/main/binary-i386/epson-inkjet-printer-stylus-nx110-series_1.0.0-1lsb3.2_i386.deb

Or this file for 64 bits:

http://download.ebz.epson.net/dsc/op/stable/debian/dists/lsb3.2/main/binary-amd64/epson-inkjet-printer-stylus-nx110-series_1.0.0-1lsb3.2_amd64.deb

Install the file using gdebi, requires some dependencies.

Use your distribution's printer setup tool or the CUPS web interface at:

http://localhost:631/admin

And go through the steps of the add printer wizard.


The problem comes from the graphics card drivers, reinstall it by following this thread :Graphics issues after/while installing Ubuntu 16.04/16.10 with NVIDIA graphics (It's for 16.04 but works for 14.04)
For the install step, make sure you install the correct version of the driver (you can check which one you need for your GPU on Nvidia's website)


Determine if current login is first for the month in Bash

Why not simplify life for yourself and note in a file at each login the current
month, and test its previous value?

When you login and your shell is bash it will read the files
~/.bash_profile, ~/.bash_login, and ~/.profile.

So, for example, add to any of these the lines:

now=$(date +%m)
last=$(<~/.mylastlogin)
if [ $now != "$last" ]
then notify-send "first login!!!!"
     echo $now >~/.mylastlogin
fi
unset now last

To avoid the use of a temporary file, you can use any existing file,
eg the ~/.profile file itself.  Just touch it at every login after
comparing its ls -l time output. Eg:

now=$(date +%m)
last=$(ls -ld --time-style=+%m ~/.profile | awk '{print $6}')
if [ $now != "$last" ]
then notify-send "first login!!!!"
     touch ~/.profile
fi
unset now last


How to install shellcheck 0.7.0 version in Ubuntu 18.04

You can install the precompiled binary directly from their GitHub page.

wget -qO- https://github.com/koalaman/shellcheck/releases/download/v0.7.0/shellcheck-v0.7.0.linux.x86_64.tar.xz | tar -xJf -
cd shellcheck-v0.7.0/
sudo cp shellcheck /usr/local/bin

Finally you can check the version.

$ shellcheck --version
ShellCheck - shell script analysis tool
version: 0.7.0
license: GNU General Public License, version 3
website: https://www.shellcheck.net

https://github.com/koalaman/shellcheck#installing-a-pre-compiled-binary


Unable to activate wireless card on Vostro 3360 running 13.04

In order to correct your wireless, hook up the ethernet temporarily and do:

sudo dpkg -P  wireless-bcm43142-dkms
sudo apt-get install bcmwl-kernel-source

After a reboot, your wireless should be working.


How can I delete all folders of a specific name without deleting Contents in it?

First move all MP3 files up one level by the command as following:

find MP3_SONGS -type f -name '*.mp3' -execdir echo mv -v '{}' .. \;

The -type f option looks for all files
The -name '*.mp3' filter files which end with .mp3
The command mv -v '{}' .. will be run for each subdirectory containing the matched file, which is not normally the directory in which you started find (action of the -execdir).
The string '{}' specifies the current file name being processed everywhere it occurs in the arguments to the command.

Note: After running above command, remove the echo command to perform running actual mv command.

Then try to delete all empty directories (128Kbps_Songs directories):

find MP3_SONGS -empty -type d -name '128Kbps_Songs' -delete

The -empty : File is empty and is either a regular file or a directory.
The -type d option as the same as -type f but this looks for all directories instead.
The -delete, deletes the found file or directory.

See man find for more info.


Need ia32-libs to run 32bit app on 64 bit OS

The app is the same with skype i think. So the workaround is to install first your app(topdrawer), better if its .deb file. It will not run after installation. You need to run sudo apt-get install -f and let apt-get automatically detect and install the dependencies. This procedure is based on installation of skype on my system that also requires ia32-libs.


It is possible, but there would need to be an extra bit of code to bind together the background services which search in various pots of data and the lens front end you'd like these delivered to.

This would be an 'all in one' lens. And you can learn about making them here: http://developer.ubuntu.com/resources/technologies/lenses-and-scopes/

The alternative method is to hack the existing lens definitions so they all appear in the home menu when you search there. There is work here though, so look for someone else who might have done with job for you already. (and post it here!)


How do I write an application install shell script?

I would assume the script would look something like this:

#!/bin/sh
apt-get update  # To get the latest package lists
apt-get install <package name> -y
#etc.

Just save that as something like install_my_apps.sh, change the file's properties to make it executable, and run it from the command line as root.

(Edit: The -y tells apt-get not to prompt you and just get on with installing)


I had the same problem and installing libnss-winbind resolved the problem.

sudo apt-get install libnss-winbind


EC2 ephemeral drives missing on 11.10 AMI? (ami-21f53948)

The block device mapping is wrong.  The ephemeral drives can be found at /dev/xvd[b-e], following the virtualized block device naming scheme.


You must clear the unknown Cmos/Bios password and reinstall Ubuntu from live-usb.

On the motherboard locate the BIOS clear jumperand change its position.

This jumper is often labeled Clear, Clear Cmos, CLR, CLRPWD.

To clear, remove the jumper from the two pins currently covers the replace it over the other two.

Once the appropriate jumper or dips switch has been located and toggled, the password should be cleared.

Turn your machine on to verify that the password has bee reset.

Once cleared, turn the computer off and return the jumper or dip switch to its original position.

If your computer is a laptop and you are the original owner of the laptop, we highly recommend contacting the manufacturer of the laptop. Companies can reset the password if you are the original owner.


How do I install the ethernet drivers in ubuntu 10.04

I found the solution for this problem,

just run these following commands

sudo apt-get update

sudo apt-get install linux-backports-modules-wireless-lucid-generic


VirtualBox host-only networking on Ubuntu 18.04.2 LTS

The problem was that I forgot to turn off the firewall on both of the Windows VMs.

This is how to solve the problem:

Go to the Windows Security Center. You can find the Windows Security Center in an obscure corner of the Windows infrastructure: Choose Start→All Programs→Accessories→System Tools→Security Center.
You will get this window:
Click on Windows Firewall on the bottom right. Then, choose the Off (not recommended) option, and then click the OK button.
Do the same thing for both of your VMs and you are good to go.


How do I modify the session such that closing Chromium logs out of the session?

Just add this script to your startup programs (Run simple bash script to start applications at login), only for that specific session:

#!/bin/bash
while true; do
   if ! pidof chromium-browser ; then
      gnome-session-quit --no-prompt
      exit
   fi
   sleep 1;
done

it will check if chromium is running every second, and, if it is not, then it logs you out...

If you want to prompt before logout (to ask you first), then remove the --no-prompt argument...

Also be careful this script to run after chromium-browser (it may need a timeout before the while loop so as to let the chromium-browser start (with the sleep command)), otherwise it will log you out immediately...


How can I see the fancy prompt in Byobu on Windows?

Anna.

I have no exact solution to your issue (looks like bug with some unicode symbols support in PuTTY/KiTTY), but you can change this symbol to any you like. For example this: ».

See the file /usr/share/byobu/profiles/bashrc. There are the next strings:

# MATHEMATICAL RIGHT DOUBLE ANGLE BRACKET (U+27EB, Pe): ⟫
printf "%s" "⟫"

Change the symbol and restart you terminal session.


Should I file a bug report if the USB audio quits working after a kernel upgrade?

Updating the kernel can cause problems that sometimes are bugs and sometimes are not. For example, updating the kernel in an Ubuntu guest OS running in VirtualBox can cause fullscreen to stop working, but this is not a bug and it is easily fixed. Report the bug and leave it to the subscribers to the bug's notifications to decide whether your problem with USB headphones not working after a kernel upgrade is a confirmed bug. If it is a confirmed bug, reporting it will help it to be fixed in future package updates.

When reporting the bug it might be relevant to provide information about the proprietary graphics driver if you have one installed.


How come no one outside my network can connect to my Owncloud server?

That is because you are giving your internal IP address, which means that users would have to be in your LAN to use it. If you want to allow outside access you'll have to port-forward the proper port (Most likely 80) to your machine. This can be done in the settings for your router.


Open URL in Chromium and switching to existing tab open if URL already open

The Chrome extension, Clutter Free, does exactly what you asked:

switches to already open duplicate tab, when a new one is opened,
works on redirects as long as the final redirected url is already open

Disclaimer: I'm the author for this extension. I too was looking for this solution, and ended up making the extension.


Activation of network connection failed in Ubuntu 18.04LTS

You would need to go over router settings and then match Ubuntu network settings with them.
You can also try using BSSID to connect instead of network name.
more here: https://help.ubuntu.com/stable/ubuntu-help/net-wireless-hidden.html.en
I am note sure what is the benefit of hiding the network. See also the note in official documentation in the link i posted.
Can you connect to any other wi-fi network? That way at least you would know that wi-fi driver is not the issue. though based on bluetooth/flight mode behaviour i would say something is off.
newer version of Ubuntu would bring in new kernel that might have this driver built in or a newer tested version of driver (i am assuming here you had to patch 18.04 kernel to get the chip working.). but if you use 18.04 HWE stack you will get new kernel that was ported to 18.04.
you can read more about HWE here: https://wiki.ubuntu.com/Kernel/LTSEnablementStack


how to upgrade pip to version >> 9.0.1 ? (pip install --upgrade pip gives 'cannot import name main' error)

The issue here is that the pip installed by apt conflicts with the standard pip package

The easiest solution is to only install the standard pip:

Uninstall pip by running the following until nothing happens:

sudo python -m pip uninstall pip

Uninstall apt pip

sudo apt-get remove python-pip

Download the pip boot-strap from https://bootstrap.pypa.io/get-pip.py
Install standard pip

python get-pip.py

NB: replace python with python3 if you're using Python 3, but the OP wants matplotlib for Python 2

The main difference between the apt pip and the standard pip is that --user is the default on apt, meaning packages will be installed to the user's packages directory: eg "~/.local/lib/python2.7/site-packages". Standard pip will default to installing to the system packages directory. Edit: pip v20 will install to the user directory if it doesn't have permissions to edit the system directory

Also, the apt pip tends to be many versions behind, lacking many features and bug-fixes that are in the current standard pip (such as installation from private repositories, PEP-517 support, command-line autocompletion)


How to make a simple ubuntu GUI application from shell script code?

Yad is a fork of Zenity with many
  improvements.


Contributing to the package or the upstream branch?

You need to conceptually separate Ubuntu from upstream, even when the upstream branch is hosted on Launchpad. The vast majority of packages in Ubuntu have their upstream branch hosted somewhere else completely (i.e. GitHub or SourceForge). An upstream project that is hosted on Launchpad might have a closer relationship with Ubuntu, but it should be treated essentially like any other upstream project.

Ubuntu redistributes upstream software usually only making changes when necessary for integrating with all the other software we ship. In most cases, the best option is to fix bugs upstream. That way the fix reach the most people. This also reduces the burden in Ubuntu by not having to maintain the local modifications.

So ideally, the process looks like your first option. You fix the bug upstream, upstream makes a new release, and Ubuntu updates to that version. As you've noticed, things don't always work that way.

Sometimes the release schedules of Ubuntu and an upstream project might not be aligned. Say you've found and fixed a bug that you'd like to see in the next Ubuntu release, but Ubuntu is releasing in three months and upstream has no idea when its next release will be. In a situation like this, the best approach is to fix the bug upstream but backport it to the release in Ubuntu as an Ubuntu specific patch. This is also the case when making a fix in a stable release of Ubuntu where we will most likely not be able to include a new upstream release.

Sometimes Ubuntu carries changes to upstream. If the bug lies in those changes, the fix should go directly to Ubuntu. This includes issues in things like the packaging.

New features are extremely unlikely to be accepted in Ubuntu unless it has already been accepted upstream. We will often accept patches fixing a specific problem before its been applied upstream for the sake of the larger project, but we normally don't like to deviate from upstream in terms of design or functionality.

I know that I'm basically just saying it depends, but it does!


May be that not all the required certs were downloaded on your computer.  Bring up terminal and type the following command to refresh your SSL certificates:

$ sudo apt-get install --reinstall ca-certificates

Once you re-install the certs, restart your computer and try again.


Google Chrome not retaining default browser selection in Ubuntu 15.10

Just click the "Don't Ask Any More" button in Google Chrome, it's a bug that has existed in Chrome for a long time.  I've experienced this with Google Chrome through several versions of both Chrome and Ubuntu.


This link ended weeks of frustration for me:
https://ubuntuforums.org/showthread.php?t=571188

I used the WPA (not WPA2, though I'm not sure it matters) instructions. I am working with a 2006-era dell with a Broadcomm driver. The key for me was altering the recommended configuration of wpa_supplicant as follows:

in wpa_supplicant.conf, do everything that link says except:

  proto=RSN
  pairwise=CCMP
  group=CCMP

and then use the nl80211 driver, like so:

sudo wpa_supplicant -Dnl80211 -iyour interface, e.g. wlp4rb1l -c/etc/wpa_supplicant.conf -dd

Good luck! No idea why this is so easy in desktop Ubuntu, but so very, very difficult with server.


Alternative to LibreOffice Base for Ubuntu

Try Kexi.

Kexi is an open source visual database creator, a long-awaited competitor for programs like MS Access or Filemaker.

It is part of the Calligra Suite (but can be used completely independently).
To install from the software center:
Kexi
From the command line:

Press Ctrl+Alt+T on your keyboard to open Terminal.

When it opens, run the following command:
 sudo apt-get install kexi

For more information, or to download Kexi, see the Kexi website


accidently overwritten the ~/.bashrc file

If you haven't made any significant modifications, copying the skeleton bashrc is enough. It doesn't affect the boot or GUI login process.


"airmon-ng start wlan0" will not create mon0

You need to specify what channel you want your wireless card to operate on while in monitor mode.

Your command should read
    airmon-ng start wlan0 wireless-channel 1 to 11

For example airmon-ng start wlan0 11 will put your wireless card in monitor mode on channel 11.

For more information check out the man page for airmon-ng

http://linux.die.net/man/1/airmon-ng


Xorg/Compiz is using massive amounts of CPU. What to do?

I used "Compiz Config Settings Manager" to resolve the same issue. Though it wasn't using nearly as much of my CPU, just enough to annoy me from time to time.

  sudo apt-get install compizconfig-settings-manager

After installation, press the Super/Windows key, and begin to type "Compiz", after which you can select the tool. (There is a warning upon opening the application, stating to be wary of changes made.) Click "Ok" and click on "OpenGL" (The actual words)

Uncheck "Sync to VBlank", and depending on your system, change the "Texture Filter" accordingly. (I personally have mine set to "Fast" and have not experienced any issues.)

Afterwards I exited the application, and restarted my computer without any further problems.


[I see you have asked this question on both SO and AskUbuntu, so I answer here too, but don't know if one of these shouldn't be closed]

I asked me the same question today, seeing the txmt protocol with "better_errors" gem for Rails.

I search a long time but found nothing, so I tried to make it by myself.

I write an article and my blog, but I copy it here, for "future-proofness" :

Step 1

Create the file /usr/share/applications/sublime-handler.desktop

[Desktop Entry]
Name=Sublime Text 2 URL Handler
GenericName=Text Editor
Comment=Handle URL Scheme txmt://
Exec=/home/<your_user>/bin/sublime-handler %u
Terminal=false
Type=Application
MimeType=x-scheme-handler/txmt;
Icon=sublime-text-2
Categories=TextEditor;Development;Utility;
Name[en_US]=Sublime Text 2 URL Handler

Step 2: Update the MIME-types database

$ sudo update-desktop-database

Step 3: Create the ~/bin/sublime-handler file

#!/usr/bin/env bash

request=${1:23}               # Delete the first 23 characters
request=${request//%2F//}     # Replace %2F with /
request=${request/&line=/:}   # Replace &line= with :
request=${request/&column=/:} # Replace &column= with :
sublime-text-2 $request       # Launch ST2

Then make it executable : $ chmod +x sublime-handler

Step 4: Test a txmt:// file

If that dosen't work, say me, I'll try to help you.


Ubuntu 12.04 LTS - HP Probook 4515s - WLAN Problem

With an Ethernet connection, open a terminal and write:

sudo apt-get install firmware-b43-installer

Restart your computer and see if it works then.


"Add to Startup" program is available in Ubuntu. You can use the same to achieve this.

Here is an article where I explained how to add a file to start up in details.
http://www.crappy3.com/home/index/make-your-ubuntu-desktop-look-stunning-with-conky


Unable to change Brightness Ubuntu 13.04 Toshiba Satellite A105

Well, after quite a while BYEAskUbuntu's answer solved it for me as per his answer here: How to change LCD brightness from command line (or via script)? (scroll down to his answer.)

I ran xrandr -q | grep " connected" and then xrandr --output LVDS1 --brightness [VALUE] and it worked!

Thanks to BYEAskUbuntu!


Things scroll by themselves, and in terminal certain text appears by itself ~~~~~

You've got a stuck key on your keyboard, or a defective keyboard. Unplug the keyboard to see if the problem stops.


Will I have any trouble dual-booting an HP 250 G1

Ubuntu supports UEFI if I remember correctly. You shouldn't have any problem with it. http://www.instructables.com/id/Dual-Boot-Ubuntu-and-Windows-8-UEFI/


Problem installing Ubuntu 13.04 alongside Windows 8

Make a clean install of ubuntu again in your system. But before doing that take a look at the following link. It might help you out solcing the problem:

Installing Ubuntu Alongside a Pre-Installed Windows with UEFI


I wrote a small bash script to do the job.

#!/bin/bash

# Variables
extension='mobi'
report='report.log'

if [ -f $report ];
then
    rm -rf $report
fi

echo $'renaming files . . .\n'

for filename in *.$extension
do
    temp=$(echo $filename | tr '_' ' ' | tr '%20' ' ' | tr '[]' '()' | tr -s ' ' | sed 's/\.[^.]*$//' )

    part1=$(echo $temp | cut -f1 -d-)
    part2=$(echo $temp | cut -f2 -d-)
    new_filename=$(echo "${part2#?} - ${part1%?}.$extension")
    echo $(mv -v "$filename" "$new_filename") | tee -a $report
    if [ $? -ne 0 ]; then
        echo $'\n\nScript FAILED'
        exit 1
    fi
done

echo $'\n\nScript SUCCESSFUL'
exit 0

Create a .bsh file inside the directory in which your .mobi files are stored and paste the above code :

Open a Terminal with Ctrl + Alt + T and navigate to the directory in which your script is stored :

cd /path/to/directory/

To change the permissions of the script :

chmod +x <filename>.bsh

To execute the script :

bash <filename>.bsh

If for some reason the mv fails you will receive an error 'Script FAILED', otherwise you'll get 'Script SUCCESSFUL'.

Explanation

tr '_' ' ' replace underscores with whitespace

tr '%20' ' ' replace %20 with whitespace

tr '[]' '()' replace square brackets with parentheses

tr -s ' ' replace multiple spaces with one

sed 's/\.[^.]*$//' extracts only the name of the file without the extension

${string#?} remove first character of a string

${string%?} remove last character of a string

mv -v this will show in the terminal which files are being moved. -v stands for verbose.

tee -a changelog.log By default tee command reads from standard input, and writes to standard output and files. -a stands for append.

if [ $? -ne 0 ] checks if the previous command was successful.

report.log stores the previous and latest name of each file.

Note

The script assumes that the filename contains only one dash -


Why can't I access this Facebook game in Ubuntu?

The problem is that Adobe Flash (where all the FB games are build on), has it's own flash-plugin for ubuntu, but sometimes you also have a 3-party plugin for flash on Firefox.

Try the following;

open up a terminal
sudo apt-get autoremove flashplugin-installer
sudo apt-get install flashplugin-installer

restart Firefox and check again. should be working now.


I don't know if ubuntu does kernel optimizations during install, so I will not comment if this is a good idea or not. Maybe someone more knowledgeable can explain this for us :)
Device name is arbitrary as far as I know.
First thing I would do is find out if the motherboard has bios reset jumper or some sort of switch. Some older boards had this I think.
If not see if your board has quick boot select. For my PC I think it is F12. This feature might not be locked with bios password.
Another sugestion for you to try is booting usb from grub, since you have an ubuntu drive already booting:
https://help.ubuntu.com/community/BootFromUSB#:~:text=initial%20Linux%20system.-,Booting%20via%20GRUB,key%20to%20enter%20command%20mode.


Why adb and fastboot command not included in Android SDK?

After installing Android Studio (the IDE) you need to install an SDK (At least one) & the tools before you can jump into building Android apps.

Click on Configure -> SDK Manager to open Android SDK Manager.

Select the latest API in order to test against target build, e.g. API 19 (Android 4.4.2), and the Android Support Library and Android Support Repository packages in Extras. There you'll find the adb and fastboot tools.

You can also use apt to install adb and fastboot independently:

 sudo apt update
 sudo apt-get install android-tools-adb android-tools-fastboot

You can check if it is working using:

 adb version

And check connectend devices using:

adb devices


veracrypt: error while loading shared libraries: libgtk-x11-2.0.so.0

According to the search on packages.ubuntu.com you need to install one package:

sudo apt install libgtk2.0-0

Your results from locate command are correct, but these libraries are used locally by their parent Snaps.


Problems with updates due to dependencies

issue these in a terminal ( ctrl+alt+t )

sudo dpkg --configure -a
sudo apt-get -f install
sudo apt-get --fix-missing install
sudo dpkg --configure --pending
sudo dpkg -C  # audit - check for broken packages

it should comb out any tangles in the dependency manager ... post errors if this fails to fully resolve

UPDATE - issue this to see what you have installed

dpkg  -l|grep  update-notifier

now get them  re-installed

sudo apt-get --reinstall install  update-notifier update-notifier-common

Tell us if that runs OK ... if good then go back and run the original set of commands above


It does not seem to be your problem. But there are missing info.
- Check your logs (syslog, dmesg, /var/log/messages, journatctl -xe, whatever) to see if you have some problems system-wide.
- Check you .profile, .bashrc, /etc/profile[.d] and /etc/bash.bashrc to see what those load with bash.
- Try ksh or any other to see if the problem is more generic than bash.
  -- If it is only bash, you better start with clean profile and bashrc for checking.


FIXED! The answer is the full 7zip.

sudo apt install p7zip-full

did the trick. See [https://www.ibm.com/developerworks/community/blogs/6e6f6d1b-95c3-46df-8a26-b7efd8ee4b57/entry/how_to_use_7zip_on_linux_command_line144?lang=en] is where I got the idea to try this.


I had similar problem and find answer.first I install windows and boot live ubuntu cd then ubuntu 15.04 automatically divided hdd two part one ntfs and else ext4 and install on ext4 and boot both os normally


"Gave Up waiting for root device. Alert! /dev/disk/by-uuid/ does not exist. Dropping to a shell" while booting

Since the root filesystem is detected after some time, you can add a rootdelay or a rootwait. From the kernel documentation:

rootdelay=  [KNL] Delay (in seconds) to pause before attempting to
        mount the root filesystem
...
rootwait    [KNL] Wait (indefinitely) for root device to show up.
        Useful for devices that are detected asynchronously
        (e.g. USB and MMC devices).

To set either, edit /etc/default/grub, and change the value of GRUB_CMDLINE_LINUX. Use your preferred editor, like nano or gedit, with sudo or gksudo as needed:

sudo nano /etc/default/grub

Add rootdelay=10 inside the quotes. If you'd rather not edit manually, then run this command:

sudo sed -i.bak 's/^GRUB_CMDLINE_LINUX="/& rootdelay=10 /' /etc/default/grub

Then run:

sudo update-grub

This will tell the kernel to wait 10 seconds before proceeding to mount the root filesystem.
To see if this change was applied, run

grep rootdelay /boot/grub/grub.cfg

If some output was shown, then it was applied. Now reboot.

If it still threw an error, press CtrlAltDel to reboot, wait for the GRUB OS selection menu to show up and press e. Edit the value of rootdelay, and increase it. Press F10 to boot. Repeat.

If it booted correctly, try the above process, and decrease the value.


relationship between device name and mount point

TL;DR: Because /dev/ filesystem and mountpoint of a device have very minimal relation, and they differ in their purpose.

What is the purpose of /dev filesystem?

To quote Gilles's answer:

  Almost all the files under /dev are device files. Whereas reading and writing to a regular file stores data on a disk or other filesystem, accessing a device file communicates with a driver in the kernel, which generally in turn communicates with a piece of hardware (a hardware device, hence the name).

Have you ever heard the saying "everything is a file on *nix" ? Well, that's somewhat how /dev filesystem works - it allows you to have a "file" representing a specific piece of hardware connected to your computer. If you have a mouse connected, it will show up as /dev/input/mouse0, for example; if you have hard drive connected, it likely will show up as /dev/sd<LETTER><NUMBER> (and it should be noted, typically is used to represent block devices which allow you reading data in blocks of some number of bytes and typically make use of SCSI protocol, although for new NVM drives can show up as /dev/nvme0n1).

And it's possible to interact with devices just like that. It's common for people to make backups with dd if=/dev/sda1 of=/dev/sdc1 or something a long the lines. When you have Arduino or Raspberry Pi connected via serial port, they'll show up as serial consoles /dev/ttyUSB0 or /dev/ttyACM0, and you can write bytes to it to communicate with the device, although more practical is to use something like screen or byobu or PuTTY software. But that's about it - you can't really view files on device in a simple way.

What is a filesystem?

A filesystem is how  data is organized on a storage device of some form. And there's many filesystems.If you have hard drive from Mac, data was organized on that drive with HPFS or APFS types of filesystem; if it comes from Windows - that may use NTFS filesystem; it if comes from Linux - typically would be a form  of ext filesystem; BSD or Solaris might use zfs, and so on and so forth. You could even mount iso file of a backup and bind it to a folder. They all have their own advantages, but the key idea is that data is organized in certain logical manner and allow a user do deal with individual files, rather than dealing with bytes or blocks of data. And the common trait is that all filesystems should have a mount point, the logical root of the filesystem tree of folders and files.

And that's where /dev comes in. The /dev is actually a virtual filesystem mounted on /dev folder, in a sense that it exists only when your machine is running; once you shut down, everything in that directory is gone. Same with /proc and /sys directories - the representations of processes and physical devices exist only for the uptime of the system. That's why you can't make /dev a mountpoint for your USB drive or hard drive - it is already a mount point for something else, and besides doing that would violate Unix filesystem hierarchy standard.

Although, it is possible to create directory in /dev/my_mountpoint and mount a hard drive there ( with root privileges ), but it's redundant and against the already mentioned Unix filesystem hierarchy standard.

How are devices and mountpoints related?

We could make comparison between websites and disks. With a website, you have set of links to specific pages. But website is technically a collection of data stored somewhere on a server. Same idea here - /dev/sda1 may contain data and files, but mount point allows you to interface with those things in a logical way, and knowing path of a file, you can easily navigate to it just like with links on website you navigate to pages you need.

On technical side of things, mountpoint and device are managed by couple files. /etc/fstab will allow you to specify device (either by /dev reference or via UUID number ) and where to mount it at boot time. /etc/mtab, /proc/mounts, /proc/self/mountinfo, and /proc/self/mountstats will tell you where devices are currently mounted. Now, on Ubuntu the GUI allows automatic mounting ( in the past that was Unity, now GNOME , but in either case that should be still managed by the same GSettings schema). That in turn interfaces with UDisks2 system, which then mounts your USB or hard drive to /media folder; in other words, there's software in place that relates your USB drive with mountpoint automatically.

It should also be noted, that  certain programs such as df can operate on only mounted filesystems, i.e. df will show you usage only for those drives and partitions that are mounted. By contrast, in a lot of cases it is desirable to have filesystem unmounted for fsck filesystem checking utility or parted/Gparted utilities (since those are used for resizing, and resizing a partition that is mounted can lead to loss of data). Such utilities as findmnt will allow you to find where a specific device is mounted (which I personally use in my shell prompt to know which disk drive I'm currently in).

Conclusion

Probably this still doesn't make whole lot of sense, and it's understandable. Let's just say, that this is a convention. Not necessarily a Unix thing, because Windows does that in a similar way, with similar terminology. It's just how computers are built and what made sense to engineers when they were designing the systems years and years ago. But hey - it works, right ?


How to disable apt key checking for private repositories under Ubuntu 14.04?

Disabling signature verification because you installed a local repository is like removing the door locks because you fenced your garden. Don't do this, especially not in environments requiring enhanced security!

You don't need access to a key server to install the public key used for signing packets in reprepro. Simply copy the key file to the respective machine, and import it using a command like

sudo apt-key add [publickey]

while [publickey] is the file containing the key with ID 082BCA0181FE8E68. You can generate such a file on the computer you generated the key on with

gpg --armor --export 082BCA0181FE8E68 >082BCA0181FE8E68.asc

The public key can be shared arbitrarily, as it can only be used to verify signatures issued using the private key. Adding the key only needs to be performed once per machine using the repository.


How to uninstall Ubuntu from inside itself

If you just begin the 11.10 install, you can choose to overwrite the old partition with 10.04. No need to uninstall it first.


Hide padlock symbols in Thunar (Xubuntu)

I didn't found a way to hide the icons but solved the problem differently.

Give back the write permission to the shortcuts. Desktop folder is still owned by another account and has no write permission.
Change desktop settings to your needs
Copy $HOME/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-desktop.xml to /etc/xdg/xfce4/xfconf/xfce-perchannel-xml/
Edit the file and add the 'unlocked' attribute to the channel tag. For example:

<channel name="xfce4-desktop" version="1.0" unlocked="@wheel;rvb">

This will only allow members of wheel and the user rvb to change their desktop settings. Other users will use the config file you just copied.


Changing workspace shortcuts do not work

For the shortcuts to work you need at the minimum the workspaces setting enabled:

  Settings - appearance - behaviour tab and tick the workspaces checkbox

Assuming that this is correct, the next step is to confirm if this is account specific or system wide.  Login to another account to confirm.

If you dont have access to another account, then look at account specific stuff.

You could try resetting Unity as per our canonical Q&A:

If this still doesn't work, then you can use the ultimate "correct everything" method of clearing down all Gnome settings:


Moving root from LVM to standard ext4 partition

The steps I would follow, in a nutshell, are as thus:

Boot from a liveUSB
Install Boot-Repair:

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair

Install and mount LVM drives as described here

sudo apt-get install software-properties-common
sudo apt-get install lvm2   #This step may or may not be required.
sudo pvscan                 #Use this to verify your LVM partition(s) is/are detected.
sudo vgscan                 #Scans for LVM Volume Group(s)
sudo vgchange -ay           #Activates LVM Volume Group(s)
sudo lvscan                 #Scans for available Logical Volumes
sudo mount /dev/YourVolGroup00/YourLogVol00 /YourMountPoint

Mount the drive where you are moving the data
Copy data from the old to the new drive:

Copy the boot partition:

sudo dd if=/dev/sda1 of=/dev/sdb1 bs=4096

Copy the root partition:¹

sudo dd if=/dev/beta/root | pv -s 300G | dd of=/dev/sdb2 bs=4096

Run Boot-Repair on the new drive:

sudo boot-repair

Reboot

Note 1: This could take a very long time.


cd to the directory where the downloaded file is then:

sudo sh NVIDIA-Linux-x86-310.44.run

You may want to read up on the full process here:

http://us.download.nvidia.com/XFree86/Linux-x86/310.44/README/installdriver.html#BeforeYouBegin89f39


I have a similar problem on Lubuntu 14.04, with the added nuisance of a bunch of error boxes popping up on booting. After a bit of digging, I have concluded that the following might be relevant:

/usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1 is not running (not listed when I run ps aux | grep pol). Attempting to start it throws:

Cannot register authentication agent: GDBus.Error:org.freedesktop.PolicyKit1.Error.NotSupported: Operation not supported

pkexec has segfaulted at some point during the boot, and is broken. Running pkexec echo 'test' results in a segfault.
This line in my auth.log:

gnome-keyring-daemon[1255]: couldn't set environment variable in session: The name org.gnome.SessionManager was not provided by any .service files

I have tried the solutions listed here, without success.
I have tried reinstalling policykit-1-gnome and gnome-keyring, without success.

Lastly, the only workaround I've found is running sudo shutdown now from a terminal.


On boot menu I pressed 'e' to edit the way 14.04 starts, deleted "quiet splash" and pressed F10 to start ubuntu in onscreen verbose mode (so to speak).

Soon enough it hanged on a kernel sort of panic which was due to a usb mouse in a different usb plug than usual (it was plugged in a usb 3.0 plug instead of the usb 2.0 that doesn't give any problems with the linux 3.13 kernels used on ubuntu 14.04). Problem solved.
The laptop is a Dell Vostro, by the way.


Audio Driver for Lenovo G500 DOLBY ADVANCED AUDIO v2

I also have the Dolby Advanced Audio v2 in my Lenovo laptop. I understand that you do not have the Dolby 'feel' because louder music tends to 'feel' of being of better quality, of course there is some difference that it makes, but I have the idea not much.

You can increase the volume in the audio settings with allowing volume to go beyond 100% then it amplifies up to 150% I think. You click on the speaker icon in the bar and then click sound settings and then you'll see where you can enable the volume-increase


I had to find this out the hard way, as there's little to no information about this on the web, only questions;

If you boot from an MBR formatted drive, you will not be able to install Linux successfully to a GPT formatted drive!  (Not without a lot of customisation of setting up your own boot partition etc.)

This can happen when you have multiple drives installed in your PC - you may even be booting from an MBR drive which then points to some other drive where Windows is installed - and you won't even know it!  I found this out the hard was as well, when I removed an old drive which only had data on it (so I thought) and then the computer wouldn't boot - even though Windows was on a separate drive!

This is an insidious problem since the Linux dual boot installs don't check for this, and things seem to go well - and then your computer doesn't boot.

To check if this is the case for you - you can go back into Windows, and in Drive Manager, right click on the physical Drive - not the partitions.  So right click on, Drive0, Drive1 etc. and for each, click Properties, then click Volumes.  Note the “Partition style” for each drive, so go back and write either MBR or GPT next to each drive.

You can find out which drive you’re booting from in Windows, open Computer Management, Drive Management, and look for the partition that says “System”, that is the boot drive.

To be safe, if you have any MBR drives, just install Linux to an MBR drive.  It shouldn’t be a problem if you have a huge GPT drive with a lot of space free - just move some stuff off one of the MBR drives onto it.


Ubuntu 16.04.1 : shutdown/reboot stuck on "[ok] stopped thermal daemon service"

I've found a fix for my problem.

*I don't know why the last time I try to wait it out it took more than an hour to shutdown.

What I did was I recorded the shutdown process with my phone in Slow-mo Mode.

Like before, it stucks at

[ok] stopped thermal daemon service

After around 10 minutes, I see something like this

[ok] stopped thermal daemon service
[ok] stopped mysql community server

right before a bunch of text very quickly fill the screen and my laptop shuts down.

So the problem turns out that mysql community server is not shutting down on it's own. but even after the timeout (10 minutes) ran out, it doesn't give me a single error or anything.

Here's the solution

type the following in terminal

 systemctl show mysql

it will return the location of mysql service configuration in one of the lines. for example mine says

 Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: en

edit the file (/lib/systemd/system/mysql.service) find a line that contain the word "timeout". change the value.

TimeoutSec=600

to

TimeoutSec=5

What this does is change the timeout of mysql community server from 10 minutes to 5 seconds, if stopping/starting the service took more than the timeout value, it will force close/stop the service. Making my ubuntu shuts down faster.


GNOME Terminal in 18.04: Visual bell only?

Apparently, the sound is coming from Ubuntu's alert system. In Ubuntu 18.04, you need to go Setting > Sound > Sound Effects > Alert Volume > Off.

I got this answer from:
Turn off error sound on Ubuntu 18.04


WARNING I have NOT tried this in real life, and it may confuse your thumbnail-using applications. Please use the man command to understand the commands before execution, and adapt them to your environment.

This is a command-line solution, to be run in a Terminal.

# Ensure no process has any thumbnails open
sudo lsof +D $HOME/.cache/thumbnails
# If there are any processes listed, either exit them, or
# Terminate them with SIGKILL
sudo lsof -t +D $HOME/.cache/thumbnails | xargs --no-run-if-empty sudo kill -9
# Create a directory on the NAS, owned by me, readable by Group and Other
sudo mkdir --parents --mode=0755 /NAS/thumbnails
sudo chown $(id -u):$(id -g) /NAS/thumbnails/
sudo chmod 755 /NAS/thumbnails
# Populate the NAS
cp -r -v $HOME/.cache/thumbnails/* /NAS/thumbnails
# Hide $HOME/.cache/thumbnails, but keep a copy in case this doesn't work
mv $HOME/.cache/thumbnails $HOME/.cache/Local_thumbnails
# Now, create a symbolic link (man ln) as $HOME/.cache/thumbnails that points to /NAS/thumbnails
ln --symbolic /NAS/thumbnails $HOME/.cache/thumbnails
ls -ld $HOME/.cache/thumbnails
ls -lR $HOME/.cache/thumbnails
#
#
# **If it fails**
# If your GUI app doesn't work with symbolic links, undo this by
# Ensure no process has any thumbnails open
sudo lsof +D $HOME/.cache/thumbnails
# If there are any processes listed, either exit them, or
# Terminate them with SIGKILL
sudo lsof -t +D $HOME/.cache/thumbnails | xargs --no-run-if-empty sudo kill -9
# delete the link
rm $HOME/.cache/thumbnails
# put the old way back
mv $HOME/.cache/Local_thumbnails $HOME/.cache/thumbnails
# clean up the NAS
sudo rm -rf /NAS/thumbnails

Use at your own risk.


Graphic issue 'only' in UEFI mode on Kubuntu 15.x on i5 6600k Skylake

I just installed Kernel 4.3 from Ubuntu Mainline kernel

and my graphic issue is resolved.


How do I stop my computer form disconnecting from my WiFi adapter?

I think the problem may be related more to an excessive distance from the WiFi router than to real issues with Ubuntu.

Anyway, you could try to "force" your WiFi line in a constantly active state with this simple command:

sudo nano /etc/cron.d/wifi-on

adding as file text the following one:

SHELL=/bin/bash
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
MAILTO = ""

* * * * * root ping resolver1.opendns.com -w60 >/dev/null;

This procedure will force your WiFi to run a Ping to the OpenDns server every second, maintain your line in constant activity.

If this will not work, you can undo all this work with this simple command:

sudo rm -f /etc/cron.d/wifi-on

PS: It is more a workaround than a definitive solution, but I think it's still worth trying.


How do I show the paths of a package in aptitude?

dpkg is a lower-level tool that needs to know where files are extracted and such, but aptitude and apt handle packages as a whole (using package names) and therefore don't provide a method for showing filenames.


Is there a way to find out the current volume level?

One way I found to get the volume level is to use the command line program alsamixer.

In the screenshot below, 65 is the current global volume level.


Error "Cannot utime: Operation not supported" when restoring a tar archive on an android device

You get this error when you do not have proper permissions in the target directory, in this case /tmp , or if you are extracting to an non-linux file system (vfat or ntfs).

Extract or make the archive to a location you own, such as your home directory.


How do I get pbutils on Ubuntu 18.04 and 19.04, a required dependency of gstreamer?

Visit https://packages.ubuntu.com next time first.

For current query see two relevant search results for your question -  gstreamer-pbutils-1.0.pc and for gstreamer-1.0.pc.

So you need to install two development packages with needed pkg-config files:

sudo apt-get install libgstreamer-plugins-base1.0-dev libgstreamer1.0-dev

If you want to build GStreamer by yourself you may be also interested with installing full list of its dependencies with:

sudo apt-get build-dep gstreamer1.0

and then do what you want to do.


Sounds like you need to reinstall grub (or at least have it embedded on the MBR). Grub does usually work fine in a 64bit environment (at least it works here).

There are a lot of guides out there for doing this but most concern Grub v1. Ubuntu has been on Grub v2 (confusingly the actual version number is 1.9x) for a while and the repair instructions are slightly different.

If I were you, I'd follow this guide and see where you get.


Is there any recommended partition layout for Ubuntu 16.04 aimed to be the only OS for a production environment machine?

It depends on what your using or how your using it. Are you using a live cd/usb? Are you using it as your main OS? Is there any other OS(s) in the HDD/cd/usb/(....ext) you are placing it? Any other files your trying to put on said medium that you want to keep? If not then just let the installer handle it. If you want to increase size needed later, or maybe downsize/modify the partitions' later, then they have a box to check otherwise let it handle it from there.
If you are adding it alongside another OS, then partitioning from the other OS, should make that partition space show up as a separate drive, so you will be able to see which one to let the auto install loose on. If you are just trying to go for the bare minimum then follow the recommended settings for your version on Ubuntu. Then add half as much swap space, and leave free space separating all the partitions.
Personally I prefer my 2Tb removable hard drive to take with me. /*the only issue I had with that is I use OSX and windows on my macbook pro 11.3 with bootcamp, but with rEFInd and a couple driver issues that got resolved.  everything works out smoothly with a nice boot screen to boot... pardon the pun  */
But anyway it is severely user dependent on what they use, I've provided the recommended requirements and minimum, with the minimum linking to the installation guide. Hope it helps, if not then please add more specifics of what your wanting to do, or use it for.
~
2.3. Memory and Disk Space Requirements
You must have at least 20MB of memory and 680MB of hard disk space to perform a normal installation. Note that these are fairly minimal numbers. For more realistic figures, see Section 3.4, “Meeting Minimum Hardware Requirements”.
Installation on systems with less memory or disk space available may be possible but is only advised for experienced users
~
// and yes I know grammar is atrocious


Finally , fixed .

I searched in /lib and found an other "libreadline.so.6" and replaced it and problem fixed.

Thank you for your attention.


How can I fix phpMyAdmin, broken after Ubuntu update?

Remove PHPMyAdmin

sudo apt-get purge phpmyadmin
sudo apt-get autoremove
sudo apt-get clean

Reinstall it

sudo apt-get install phpmyadmin


You probably have a typo in your ~/.bashrc or ~/.profile file - at a guess, you typed expert rather than export in a command like export PATH=$PATH:/some/prog/path


Is there a way to install KDE Neon on Kubuntu without formatting my disk?

From https://neon.kde.org/faq

  Can I turn Kubuntu into KDE neon with a PPA?

  We recommend that you install a fresh KDE neon from the provided ISO
  images. But you can indeed add an APT repository to switch from
  Kubuntu to KDE neon. This is absolutely not tested or supported. If
  things take a turn for the worse you are expected to be knowledgable
  enough to repair your system on your own. A web search should quickly
  give you relevant information on how to do this.

There is a ppa here:

https://launchpad.net/~project-neon/+archive/ubuntu/ppa

Directions from the above page:

  Adding this PPA to your system

  You can update your system with unsupported packages from this
  untrusted PPA by adding ppa:project-neon/ppa to your system's Software
  Sources. (Read about installing)

sudo add-apt-repository ppa:project-neon/ppa
sudo apt-get update

I highly advise you download the developers edition from here : https://neon.kde.org/download

They have both a stable and unstable developers branch.


How to diagnose hard drive space problem with df, du and/or Disk Usage Analyzer

To search for files and folders that take up a lot of space on the hard drive - I ran the command:

root# du -h / > list-disk.txt

The file (list-disk.txt) will contain the contents of your disk with the size. Then it is already possible - to decide what to remove.


How to set up an ethernet and wireless network using /etc/network/interfaces?

Set managed=false in /etc/NetworkManager/NetworkManager.conf to remove network interfaces control to interfaces file.

Command to stop network manager:

/etc/init.d/network-manager stop

For detailed documentation, please refer to:

http://wiki.debian.org/NetworkManager, section #Wired Networks are Unmanaged

And for WiFi management please refer to:

http://wiki.debian.org/WiFi/HowToUse#SwitchingConnections


What is a snapshot?

snapshots are a facility which makes us able to create a new block device (like /dev/My-vg/snapshot_home ) which presents an exact copy of a logical volume frozen at some point in time. After we are done with what we are doing, we can simply remove the snapshot device.

Important to note while creating a snapshot:
While creating a snapshot we should consider enough disk space for our changes, if our changes makes snapshot device space full then it will be dropped and becomes unusable.

When to use it?
Some times we need to install an application or run a program we don't know what it's going to happens or in any situations that makes any changes to our files we can setup a snapshot device, if we were not happy with the change we can simply make everything same as the time we created our snapshot.

How to create a snapshot

To create a snapshot we can use a command like:

lvcreate -s -n  home_snap -L 1G /dev/My-vg/home

-s is for snapshot
-n home_snap is the name of our new logical volume (snapshot device)
L 1G is the size of our snapshot, so it supports to 1GB of changes (remember the above important note).
/dev/mapper/my--vg-home is the logical volume that I want to create a snapshot of.

then use sudo lvs to get a list of your logical volumes you should see your newly created snapshot device.

Note that you should have enough free space on your volume group to create a new snapshot.

sources: 1, 2


Data Loss when Switching media server from Server to Desktop

You don't need to reinstall anything. Just installing the ubuntu-desktop package (if you like unity) or any other of the *-desktop packages should be enough.


How to add a GRUB2 menu entry for booting installed Ubuntu on a USB drive?

Each time you upgrade kernel on external, you can run this to update boot stanza in grub on the internal drive.

sudo update-grub

But you can also add a boot stanza to grub2's 40_custom that boots the partition, not the specific kernel. Ubuntu installs links in / (root) to boot the most recent install. Adjust example below if necessary to your drive & partition. Boot drive with grub is always hd0, but then other drives are in BIOS reported order which may vary.

Edit with:

gksudo gedit /etc/grub.d/40_custom

then, add:

menuentry "Install on sdb1" {
    set root=(hd1,1)
    linux /vmlinuz root=/dev/sdb1 ro quiet splash
    initrd /initrd.img
}

While above works, I find the drive may change when plugging in a flash drive or any other USB device. So I am converting to use labels.

menuentry "Cosmic 18.10 on sdb12 test" {
    search --set=root --label cosmic_b --hint hd2,gpt12
    configfile /boot/grub/grub.cfg
}


Ubuntu 16.04 GLib-GIO-Message: Using the 'memory' GSettings backend. Your settings will not be saved or shared with other applications

I get that message when I try to use gsettings directly (seems unrelated to Nvidia driver), and it looks like it is caused by anaconda or miniconda installing their own version of glib.  For me, which gsettings shows gsettings within the conda folder tree.  If I change my commands from, for example:

gsettings set org.gnome.Evince.Default show-sidebar false

to explicitly calling the system version of gsettings:

/usr/bin/gsettings set org.gnome.Evince.Default show-sidebar false

they don't give that using "memory" backend message, and the setting sticks.


Get process ids of all spawned processes from xargs

The PID you get with $! is xargs's own PID (because this is xargs that you are sending to the background...), not the one of your processes. If you terminate it it will terminate all its children (i.e., any of your processes still running).
If you want the pids of the child processes you can use pgrep -P {parent} where {parent} is xargs PID.
Edit:
When you run a command (pid=Y) in a script (pid=X), and send a signal to the script (to pid=X), the signal is not forwarded to the command (so pid=Y doesn't see it).
You can write a contrived script that starts the command in the background, grabs its pid (Y), traps signals send to pid=X and forwards them to pid=Y.
But in many cases, the command is the last significant bit of code to run (the script exits with the command's return code). When this is so instead of using:
some_initialization_code
the_command and the command args
exit $?

you write your script as:
some_initialization_code
exec the_command and the command args

In the first case the script is the process with pid=X and the command is the process with pid=Y. With exec, process with pid=X becomes the command, and everything happens as if you called the_command directly: there is no pid=Y, and signals sent to process X (the script) are received by the the_command when it runs.


How do I install qps from repositories on ubuntu 13?

qps is a visual process status monitor that displays the status of the processes currently  in existence, much like top or ps. The qps package isn't in the Ubuntu Software Center for Ubuntu 13.04. In order to find the repository that contains qps, visit the Ubuntu Packages Search website and search for qps for Any Distribution. Alternatively you can open the terminal and run:

apt-cache show qps

...and then check if there are any results for qps for your version of Ubuntu. qps is found in the universe repository for Ubuntu 12.04.


How do I properly access Windows software RAID 0?

I finally got this working thanks to this Stack Overflow post: Windows Spanned Disks (LDM) restoration with Linux?

It was extremely difficult to uncover this elusive information. It took days of searching, and I guess I wasn't finding it because the post makes no mention of RAID, so it wasn't coming up in my search results. It definitely works for my Windows software RAID 0, though.

The solution:

The solution is actually quite simple. There's a wonderful tool built specifically for this purpose, called ldmtool. It is capable of reading and working with Windows dynamic disks which use LDM (Logical Disk Manager). It is not installed by default, but is included in the Ubuntu repositories. All I had to do was execute two commands:

sudo apt-get install ldmtool
sudo ldmtool create all

The first command installs ldmtool, and the second has it automagically create device mappings for all of the connected Windows dynamic disks. These mappings are located in /dev/mapper/ and can be mounted manually with mount -t ntfs /dev/mapper/mapfilename, but I didn't need to do that - Ubuntu mounted them for me automatically after I ran the above two commands. That's all I had to do, and I could immediately access them from the file browser!

The linked post includes a suggestion for doing this automatically every boot. Just open the file /etc/init/mountall.conf and add the line [ -x /usr/bin/ldmtool ] && ldmtool create all >/dev/null || true immediately before the exec mountall ... line near the end of the file.

Full credit for this solution goes to Christian Hudon, the guy who posted it as an answer over on Stack Overflow. Thanks!

To add some further information to this, I used some other ldmtool commands to query my volumes for information:

sudo ldmtool scan /dev/sdd
[
  "e856a65f-e558-11e1-ae19-bc5ff435f790"
]

sudo ldmtool show diskgroup e856a65f-e558-11e1-ae19-bc5ff435f790
{
  "name" : "Dan-PC-Dg0",
  "guid" : "e856a65f-e558-11e1-ae19-bc5ff435f790",
  "volumes" : [
    "Volume1",
    "Volume2"
  ],
  "disks" : [
    "Disk1",
    "Disk2",
    "Disk3"
  ]
}

sudo ldmtool show volume e856a65f-e558-11e1-ae19-bc5ff435f790 Volume1
{
  "name" : "Volume1",
  "type" : "striped",
  "size" : 1048578048,
  "chunk-size" : 128,
  "hint" : "D:",
  "partitions" : [
    "Disk1-01",
    "Disk2-01",
    "Disk3-01"
  ]
}

sudo ldmtool show volume e856a65f-e558-11e1-ae19-bc5ff435f790 Volume2
{
  "name" : "Volume2",
  "type" : "striped",
  "size" : 4811194368,
  "chunk-size" : 128,
  "hint" : "E:",
  "partitions" : [
    "Disk1-02",
    "Disk2-02",
    "Disk3-02"
  ]
}

It isn't necessary to run the above commands, as ldmtool create all does all the necessary work to create the mappings. I just included them because I already included information about my setup in the question, so this information might be helpful for anyone coming across this post later. In particular, we can see that according to ldmtool, both of my dynamic volumes use a chunk size of 128, despite being created with different block sizes in Windows. I guess this means that block size and chunk size are not synonymous terms. The commands ldmtool show disk and ldmtool show partition can be used to display further information.


Resume from suspend not working and Rhythmbox loses all files on reboot

There were two questions in my original post having to do with:

Resuming from a suspend
Rhythmbox losing library after reboot

I was able to setup hibernate to work using the simple instructions found here: https://help.ubuntu.com/14.04/ubuntu-help/power-hibernate.html
Suspend, technically is still not working, however, I found that Hibernate is an equivalent for my purposes so I am satisfied with this alternative. The helpful link above I followed pretty much verbatim.
First, I did have to setup my swap file to be sure it would be used to store files during a hibernate in order for it to resume later.  For that I used the info in this link:
https://help.ubuntu.com/community/SwapFaq
As far as Rhythmbox losing its library after reboot I was able to overcome this issue as well.  I believe the main issue here was the linked files becoming unlinked during the reboot, an issue that really has nothing to do with Rhythmbox or any other music player/manager.
However the issue is related to a dual boot Win7/Linux system. I did not have the NTFS volume, where the library (actual music files) were located configured or set to mount upon reboot.  There were a few other things I learned along the way.
In order to solve this issue I followed some helpful links:
https://help.ubuntu.com/community/MountingWindowsPartitions
I created a shared partition in Windows and named it Data.  I then moved my music, pictures, documents, downloads, and videos to this NTFS volume.  I used Gparted Live cd to add a /home and a new swap volume.  I then configured the ftsab, grub, and initramfs files to setup the new swap for a resume state per the swapfaq link above.  Then I created a mountpoint

sudo mkdir /media/Data

where the Data volume would mount on reboot. I added

UUID=F0EAFE30EAFDF2A8                     /media/Data     ntfs-3g defaults,windows_names,locale=en_US.utf8  0       0

To fstab to actually mount the volume per the info in the Mounting Windows Partitions help wiki above.
My volumes look like this now:

/dev/sda1: LABEL="System Reserved" UUID="1E98FB2198FAF5DD" TYPE="ntfs" PARTUUID="a287a9ef-01"
/dev/sda2: LABEL="Win7OS" UUID="6016FE5E16FE349E" TYPE="ntfs" PARTUUID="a287a9ef-02"
/dev/sda3: LABEL="Data" UUID="F0EAFE30EAFDF2A8" TYPE="ntfs" PARTUUID="a287a9ef-03"
/dev/sda5: LABEL="Ubuntu" UUID="b010e611-6efb-49a9-bff0-59b9533d659b" TYPE="ext4" PARTUUID="a287a9ef-05"
/dev/sda6: LABEL="HOME" UUID="3cd8964d-59e2-43e3-8f15-bee9600f95b3" TYPE="ext4" PARTUUID="a287a9ef-06"
/dev/sda7: LABEL="Swap" UUID="8bcb4169-f5ab-4ab6-b644-23e528088d41" TYPE="swap" PARTUUID="a287a9ef-07"

My Hibernate works and my Rhythmbox does not lose any of the library files after rebooting.  Thanks to those that made comments and helped me direct my attention where it needed to be.  I hope this helps others in future.


Using the "dash" from Unity interface in classic mode?

It won't be completely similar in appearance and it won't have the "More Apps" functionality, but Cardapio has the ability to search for applications by typing, among other things.


I would use a ppa to provide your application and add a dependency to include the qt5 packages available in the "Ubuntu SDK team" ppa.

You can easily add a ppa dependency to your own ppa using edit PPA dependencies:

The SDK ppa mentions this for 12.04:

  Ubuntu 12.04 LTS has older versions of packages offered in this PPA,
  but the SDK support has moved to the new 14.04 LTS release. It's
  however usable for example for general Qt 5 usage.


Steeldriver, you saved my weekend. Thanks a lot! I had the same problem as the bug in

http://savannah.gnu.org/bugs/?41390

and it was sufficient to remove the package

sudo apt remove octave-strings

from the Ubuntu package repository. It seems like the default GNU Octave package is not compatible with all of the Octave-Forge "add-on" packages in the default repository. Are you able to reproduce the bug by installing that package? Maybe this inconsistency should be reported somewhere.

Btw, the output of

apt-cache policy octave-strings

was

>> octave-strings:
>> Installé : 1.1.0-1build1
>> Candidat : 1.1.0-1build1
>> Table de version :
>> *** 1.1.0-1build1 0
>>     500 http://fr.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
>>     100 /var/lib/dpkg/status

and the output of

apt-cache policy octave

is

>> octave:
>> Installé : 3.8.1-1ubuntu1
>> Candidat : 3.8.1-1ubuntu1
>> Table de version :
>> *** 3.8.1-1ubuntu1 0
>>    500 http://fr.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages
>>    100 /var/lib/dpkg/status


In Natulius press "CTRL + F", and search for '.[extension]'.

For example, to locate all the MP3s in a folder you'd type '.mp3'.


How to uninstall software installed via Terminal?

Use

sudo apt-get remove nameOfProgram

Or if you want to uninstall the program and also associated data:

sudo apt-get purge nameOfProgram

That will remove the program. It doesn't always remove the dependencies that were installed to make the program work. To clean up those package you can run this after:

sudo apt-get autoremove


As  Abu Ahmed Al Khatiri comment in question, is working for me so here is the commands how these needs to run.

To remove all mosquitto packages like mosquitto, mosquitto-clients and mosquitto-dev below command will be used:-

sudo apt-get purge --remove mosquitto*

After this we need to remove repository type so need to run this command too on terminal:-

sudo apt-add-repository --remove ppa:mosquitto-dev/mosquitto-ppa

This works for me perfectly. So this may help any one.


Tabs {
    id: tabs
    Tab {
        title: i18n.tr("Welcome")
        page: Page {
            Label {
                id: label
                anchors.centerIn: parent
                text: "Welcome To The Premier Duty Gear WebApp for Ubuntu Devices"
            }
            tools: ToolbarItems {
                ToolbarButton {
                    text: "About"
                    onTriggered: print("action triggered")
                }
            }
        }
    }
    Tab {
        id: externalTab
        title: i18n.tr("Web App")
        iconSource: "call_icon.png"
        page: Loader {
            parent: externalTab
            anchors.fill: parent
            source: (tabs.selectedTab === externalTab) ? Qt.resolvedUrl("webapp.qml") : ""

This is a snippet from a webapp i'm working on. You just need to call another qml file. it'll run in the same window.

also do not define window dimensions for the qml filed called or it won't display. It has to use the same dimensions as the parent app.


XRDP - Connect to the same session (multiple users)

Based on your Ubuntu version, you can achieve your requirement easily.  if you are running ubuntu 14.10 or later, the xrdp package has been updated to version 0.6.1-1 which allows users to reconnect to existing session. (out of the box no need to change xrdp.ini file)

Another option is to perform a custom installation (using x11vnc). This type of installation allow the system to reconnect to existing sessions

Finally, you can configure your ubuntu system to have multiple users and have the xrdp solution working. to ensure that all users that needs access to xrdp sessions, you have create the ~/.xession file for each users or you configure your system to handle this process.

whatever the option you select, each user will create their own session and they will be able to reconnect to their own existing session

Reference links

Custom installation xrdp on ubuntu 15.04 and later

Custom installation xrdp on ubuntu between 12.10 and 14.10

configure xrdp for multiple users


Canon Multifunctional MG3150 - printer OK, but scanning is NOT

try this MG3100 series IJ Printer Driver Ver. 3.60 for Linux
its a deb package

hope it helps.


How to get internal sounds working with Macbook

You probably need newer sound drivers.  Please see https://wiki.ubuntu.com/Audio/InstallingLinuxAlsaDriverModules.


Why is extended partition option is grayed out in GParted?

This is a GPT disk. There are no extended partitions on GPT.
You can create almost unlimited number of primary partitions.

So create as many primary partitions as you need.


Keyboard Layout indicator doesn't display current layout in Ubuntu 18.04 (empty drop down box)

A fix was released, already verified on Cosmic and Bionic.

EnableProposed

Until is added to normal repos, to enable them on Bionic (18.04) as said here, follow these instructions to enable the proposed archive, which basically say:

Enable pre-release updates:
Add to /etc/apt/preferences.d/proposed-updates

Package: *
Pin: release a=bionic-proposed
Pin-Priority: 400

If sudo apt-get upgrade -s return any package, something went wrong.
Run sudo aptitude -t bionic-proposed
Update with u
Select the proposed related packages:

gnome-shell-common 3.28.3+git20190124-0ubuntu18.04.1
gnome-shell 3.28.3+git20190124-0ubuntu18.04.1

Upgrade with g
Restart GNOME.

Please test it and eventually suggest changes to this post. If everything went OK upvote and share your love with the developers.


Change login screens with Flat-Remix shell theme on Ubuntu 18.04

So, obviously the title changed for obvious reasons : I have Flat-Remix installed as the shell theme.
First, here is the redirections shown by ll :
$ ll /etc/alternatives/gdm3.css
lrwxrwxrwx 1 root root 56 3月   1 20:30 /etc/alternatives/gdm3.css -> /usr/share/themes/Flat-Remix/gnome-shell/gnome-shell.css
$ ll /usr/share/gnome-shell/theme/ubuntu.css
-rw-r--r-- 1 root root 51510 3月  15 13:28 /usr/share/gnome-shell/theme/ubuntu.css

If other files need to know their redirections, I'd gladly know.
Since the gnome-shell.css show these lines for lockDialogGroup, I choose not to change it, and rather change the image in the assets folder.
#lockDialogGroup {
    background: url("assets/login-background");
    background-size: cover; }

After a reboot, nothing has changed, two reboots, nothing : the colour I set in ubuntu.css still takes on both the login and the unlock screen.
Hence I decided to comment the lockDialogGroup line in the ubuntu.css file.
The result is a still only colored login screen (color #FDF030) and a bugging black/shield_screen for the unlock screen.
I checked the pages mentioned int he commentaries above, but none helped.


Why are some packages unfindable in new non-LTS releases of Ubuntu?

It looks like netbeans is not ready for vivid as of now. You can however, install it by running the following commands:

sudo apt-get install gdebi
wget http://us.archive.ubuntu.com/ubuntu/pool/universe/n/netbeans/netbeans_7.0.1+dfsg1-5ubuntu2_all.deb
sudo gdebi netbeans_7.0.1+dfsg1-5ubuntu2_all.deb

Review any changes before confirming to accept.

You will have to keep up on any security updates or newer versions untill the vivid version is released. These versions can be found here http://packages.ubuntu.com/search?suite=utopic&keywords=netbeans

done


Wireless stopped working on Dell Inspiron mini

I had the same problem with my Dell Inspiron 3000, which has the same wifi card by Realtek. (Windows users are complaining of the same problem!)

I clicked on the wifi networking button on the top right of the screen, and then clicked edit and selected my connection. Then select the ipv6 network tab and select ignore from the method drop-down menu.

Then I ran the following line in the terminal:

echo "options rtl8723be fwlps=N ips=N" | sudo tee /etc/modprobe.d/rtl8723be.conf

Reboot and it worked like magic.

It took me 3 days to figure it out, but now my internet connection is stable :)


Virt-Manager (QEMU/KVM) install internal error when using UEFI x86_64 OVMF firmware

First of all (you did already, but others finding this might wonder as it isn't auto-installed as dependency in 18.04 - it is on later releases) you need to install ovmf

$ apt install ovmf

I tried the same on 18.04 and 20.04 and both worked fine.
Note: A common reason for this error is to use arm64 EFI roms on x86 (example 1, example 2, but your config LGTM (we can see the x86 in the path).

Finally I saw that your system is complaining about your VARS file .../kubuntu-18.04.3-lts_VARS.fd and not the actual rom which ends in CODE.fd.

When I create such a guest in virt-manager the XML it creates looks like:

<loader readonly='yes' type='pflash'>/usr/share/OVMF/OVMF_CODE.fd</loader>
<nvram>/var/lib/libvirt/qemu/nvram/ubuntu18.04_VARS.fd</nvram>

The latter was auto-created and usually is a copy from /usr/share/OVMF/OVMF_VARS.fd. The error you mention would occur if these file sizes are off (8MB max, 128KB is the usual size).

Here how they'd look on a normal system:

-rw-r--r-- 1 root         root 128K Jul  8 16:07 /usr/share/OVMF/OVMF_VARS.fd
-rw------- 1 libvirt-qemu kvm  128K Nov 12 08:05 /var/lib/libvirt/qemu/nvram/ubuntu18.04_VARS.fd

Most likely this copy from the empty template went wrong, or your base copy is broken/oversized. Could you please check this?


Have you tried to disable the wayland support in gdm3

sudo gedit /etc/gdm3/custom.conf

find the following line

#WaylandEnable=false

change to

WaylandEnable=false

reboot computer

then run the autoinstall command

sudo ubuntu-drivers autoinstall

or

sudo apt install nvidia-driver-(driver number to install)


Do comboboxes support keyboard input in Gtk+ 3?

No, this hasn't changed in gtk+ 3.

Back in 2001, a bug was reported that dropdown comboboxes couldn't be navigated using the keyboard (even the arrow keys and Enter).  All parts of this bug were fixed except the part about typing text while the combobox has focus and having the list select the correct item alphabetically.

More recently, a new bug was filed requesting that combobox lists respond to all keyboard input by selecting items alphabetically.  This issue is still open.


Have you tried pressing the power button for a second or so?

I have a Lenovo X1 Carbon that has the same issue: it won't wake via any keypresses, or pressing the power button for a short time, but seems to wake fine with a long press.

Not sure if that is a bug or a feature...


How to get Avast! Running on Ubuntu 13.10

This doesn't seem to be supported any longer by Avast. As the package itself is broken, your only options are to force the install, use a different scanner such as clamav, not use a virus scanner at all, or contact Avast support to complain about the issue.


Is there any 3rd party keyboard layout indicator software for GNOME?

Founded excellent solution but looks like just for En/Ru keyboard layouts and product just in sources. But I think this idea is more than brilliant: The idea is to add a keyboard layout flag to the mouse cursor.

Software name: X Cursor Flag

Screenshot:


Taskbar and Tray on Lubuntu gone missing but not on guest account

Have you tried restarting lxpanel from the terminal that is available to launch from the openbox menu?

lxpanelctl restart

or

killall lxpanel && lxpanel --profile Lubuntu

source:
https://help.ubuntu.com/community/Lubuntu/Documentation/FAQ/Guides#Restart_lxpanel


How to mount smb share on Ubuntu 18.04 with read-write from the terminal

ajgringo619 corrected your sytax. The only thing remaining is to take possession of the mounted share with a uid=user:

sudo mount -t cifs -o rw,user=user,uid=user //ServerIP/share /home/user/documents/share

The user in user=user is the user name you pass to the server as credentials. The user in uid=user is the user name on the client that is mounting the share.

CIFS is a virtual filesystem. When you mount a share on the client it creates a "view" of the remote share on the client and by default sets the owner to root since he is the one mounting it. uid=user replaces root as the owner of the mounted share with "user".

EDIT: BTW, how do I enable access to everyone?

sudo mount -t cifs -o rw,user=user,uid=user,nounix,dir_mode=0777,file_mode=0777 //ServerIP/share /home/user/documents/share


nvidia-driver-450 Resolution & 2nd GPU Problem on Ubuntu 20.04

I have same problem with Ubuntu 20.04(In my case, dual ASUS GTX 1070)
This is my question asked to DELL-community.
https://www.dell.com/community/Precision-Fixed-Workstations/How-to-set-up-dual-monitor-with-dual-GTX-on-Ubuntu-20-04-or/m-p/7670304
Some people soleved issue like this.
Gnome ignoring second monitor Ubuntu 19.10
I've tried everything I could bunt I couldn't solved my problem.
So, I re-installed Ubuntu 20.04 (Then NOT checked "install proprietary-driver")
I hope it helps you.


Can't use Brother MFC-J625DW scanner as normal user

So I cannot test this as no access to USB scanner but I have seen a group in /etc/groups called scanner

can you try adding a user to this group then logout and back in as that user and test?

sudo usermod -a -G scanner usernamehere


'No medium found' after issuing dd on an old external hard drive

Most of the times the "No medium found" error which is same as "No media" label shown on some GUIs means that the hdd is damaged. I tried to "repair" such disks once, I followed every guide I found on the web, I used several OS but nothing could be done...

So, my advice is "throw it in the recycle bin" (not from the window) and spend your time with something else!


The answer, looking at the link you gave appears to be either the capitalisation of the key words, TO or the fact that you have placed a space either side of the @ in line 3.

Present:

-> to 'guest' @ 'localhost'

Correct syntax

-> TO 'guest'@'localhost'


how do I convert a non gui user into a gui user

AFAIK there's no distinction between GUI users and non-GUI users: instead, there's conventionally a distinction between system users and non-system users.

System users have low numeric UID: specifically, the /etc/login.defs file defines

#
# Min/max values for automatic uid selection in useradd
#
UID_MIN                  1000
UID_MAX                 60000
# System accounts
#SYS_UID_MIN              100
#SYS_UID_MAX              999

GUI display managers like lightdm are typically configured to ignore system accounts: in lightdm, that's done using a configuration option minimum-uid:

[UserList]
minimum-uid=500
hidden-users=nobody nobody4 noaccess
hidden-shells=/bin/false /usr/sbin/nologin

Why is minimum-uid 500 not 1000? AFAIK that's for compatibility with other systems, in particular OSX which uses a UID_MIN of 500

To actually log in, the user will also need a valid login shell (as specified in the /etc/shells file) and to log in with a GUI session, they also need a writeable home directory.


How do I set up Codename One in Eclipse?

There's a regression in Eclipse Oxygen 4.7.1a that broke the simulator/debugger in Codename One, so install the latest version of Eclipse 4.8 instead.

Install the latest version of Eclipse.

sudo snap install eclipse --classic

This command will install the latest Photon Release 4.8 version of Eclipse IDE for Java Developers.
In the menu option Help -> Eclipse Marketplace -> search for Codename One -> click the Install button (marked by the mouse cursor in the below screenshot), and follow the installation process.

openjdk-8-jdk should work for the Codename One 5.0 release coming out in September 2018.


Emulating Xbox 360 controller using xboxdrv not working for Dualshock controller on 14.04

I finally found out what the problem was. Recently, this Ubuntu Launchpad bug report came to light. It states that the kernel regressed from .24 to .25.

What I did then was go to the mainline kernel builds of Ubuntu and installed 3.13.11 as that's what the bug report stated as a fix:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.13.11-trusty/

You download the all package, headers package and the image package of the type "generic". Choose the correct packages for your OS (32/64 bit).

Once you download those 3 packages, go to the folder and run:

sudo dpkg -i linux*.deb

And it will install the new kernel. Finally reboot it and it should be default in your GRUB config.

If you really can't figure it out, I used this tutorial to do the upgrade.


Okay, you probably mixed something up there. "nVidia Corporation MCP61 High Definition Audio" isn't a graphics card but your sound card. What graphics card you really have is displayed in the "system details" panel. Just type "details" into the dash and it should show up.

If you do have a nvidia or AMD graphics card you probably haven't installed the right graphics driver. Just run the driver installation tool and try installing the proprietary driver for your card. The app should show up when you type "jockey" into the dash.


Removing a program in Ubuntu--unable to find package name

Now the problem is moot, but for the future:

Always use the same removal method as the installation method.

Therefore, use the following priority in installing software

Install/remove from the standard Ubuntu repositories using the GUI of the Ubuntu Software center.
Use the TUI of aptitude
apt-get install szPackageName to install and apt-get purge szPackageName to completely remove and apt-get remove szPackageName to remove the application, but not its configuration files.
Download and install a .deb file: use dpgk --install szPackageName and dpgk --purge szPackageName and dpgk --remove szPackageName as above.
So if you do download and build from source, use CheckInstall to be able to remove more easily in the future.


Ubuntu 18.04 stuck at purple screen after update on March-2020

Found the package. It was grub-efi-amd64-signed 1.93.16+2.02-2ubuntu8.15. Just downgraded to grub-efi-amd64-signed 1.93.15+2.02-2ubuntu8.14. Couldn't find the packages on the repositories, so I used the packages found at the ubuntu 18.04.4 iso.


How can I give two users access to a folder?

Create a custom group. Folder is a Windows term for directory.  Set the group associated with the directory to be the custom group.  Add the group to the two IDs.  Make sure any files already in the directory are associated with the group.  Perhaps examples would be better - for the examples the users are thing1 and thing2.  the custom group chosen is vroom. Remember much of this is done with the root ID (ie use sudo) The full name of the folder is /home/bigshare/house  (think of the name of the directory as house)
sudo addgroup vroom
sudo adduser thing1 vroom
sudo adduser thing2 vroom
sudo chgrp vroom /home/bigshare/house
sudo chgrp -R vroom /home/bigshare/house/*
sudo chmod 770 /home/bigshare/house
sudo chmod -R 770 /home/bigshare/house/*

What did we do?

made the group (addgroup)
allowed thing1 and thing2 to be associated with the group (adduser)
made the directory be associated with the group (chgrp)
made everything within that directory and beyond be associated with the group (chgrp)
set permissions on the directory itself so that only people associated with the directory could work with it (chmod)
set permissions of everything under that directory such that only the owner (first 7) or IDs in the group (second 7) can read, write or run the files, as for nobody else can read, write or run files (final digit 0).


Library error while Installing .Net Core

Using the discussion at https://github.com/dotnet/cli/issues/3657, I would suggest the following to install a newer version of .NET Core that fixes the problem:

From Step 2 of the tutorial you linked, there is a link to a script that removes all previous versions of .NET Core. Run that script.
Run sudo apt-get install dotnet-dev-1.0.0-preview2-003118.


Dual boot partition accessibility problem

Yes... This should work just fine. The problem is that Windows can not read Ext4 formatted partitions.


Can't shut down the computer. It only reboots

Shutdown ubuntu

sudo shutdown -h

reboot

sudo reboot


bcbc answered this in comments; here and in related bug reports.

  Yes there are two bugs at play and different workarounds required...
  one for Lubuntu (pad.lv/1043607), and another for Xubuntu/Kubuntu
  etc. (pad.lv/1067833).

– bcbc Oct 17 '12 at 19:58

Lubuntu workaround (bug 1043607, comment #1):

  Use the 12.04 version of Wubi.exe for Lubuntu. You can get it off the
  Lubuntu 12.04 ISO or download it from here:
  http://people.canonical.com/~evand/wubi/precise/wubi-r266-signed.exe

Workaround for other official Ubuntu derivatives -- Kubuntu, Xubuntu, Edubuntu, Mythbuntu, Ubuntu Studio, etc. (bug 1067833, comment #1, subject to correction in comment #2):

  Download the 12.04.1 desktop CD ISO into the same folder as Wubi.exe
  (12.04.1).

  Disconnect from internet.

  Run wubi.exe to install.

  Reconnect to internet prior to rebooting.

  When 12.10 is released (shortly), then it will work again (for the
  12.10 releases) but it will still be broken if you use Wubi.exe for 12.04.1. And PS 12.10 Wubi will no longer support Xubuntu.

– bcbc Oct 17 '12 at 20:03


Thanks to @Yvain comments, I have solved the issue.

While being in the login screen, I have pressed Ctrl+Alt+F5 that let me access to a terminal. In this terminal the keyboard worked fine and I could remap keys that weren't functioning properly.

In order to remap keys I have used the second answer that you can find in this thread
How can I remap keyboard keys?

Hope it can help.


What is a good alternative to the sux command?

I've been very sad too to see that there were no easy alternative to sux at first, but ended with this:

In /etc/pam.d/su, to forward xauth keys between users when calling su, add:

session  optional  pam_xauth.so

In ~olivier/.bashrc:

export $(dbus-launch)

(Not sure it is actually needed.)
And then a simple su olivier from my logged-in user.


Is LAMP strictly for development purposes?

LAMP is definitely production ready, of course with any IP accessible service(s) you have to follow Security Best Practices.

Secure LAMP server for production use

Basics;

hide all version numbers and debug/informations pages
create a mysql user for each application with hardened passwords
use regular user accounts (using sudo if needing root permissions)
use a firewall (iptables) and open specific ports
do not load modules you don't explicitly need
apply latest patches/keep packages up to date


How do I install ChomiumOS and run it as a separate X ession?

Virtualization is the easiest way There are even virtual disk images prebuilt.

Install Virtualbox from the terminal with sudo apt-get install virtualbox or through the Software Center:

Install Chromium OS on a VM under Virtualbox.

There are builds here and a step by step installation.

If something isn't clear drop me a comment and I'll expand the answer to sort it out.


Kernel source for Ubuntu 14.04 on Raspberry Pi 2?

I was able to compile Linux kernel 3.18.0-29-rpi2 with fbtft modules for Ubuntu 14.04 on Raspberry Pi 2.

This GitHub Gist contains the steps I followed:

https://gist.github.com/pdp7/440f522ff7060ab9ae72

Linux kernel .deb package with fbtft modules:

linux-image-3.18.0-29-rpi2_3.18.0-29.30_armhf.deb

https://drive.google.com/open?id=0B_NI2VDamOOfakYwV3NESF81TWM


I have followed the below steps and my problem solved.

Remove dnsmasq:

apt-get remove --purge dnsmasq

Comment out dns=dnsmasq by putting # in /etc/NetworkManager/NetworkManager.conf.
Comment out the local DNS address.
Comment out prepend domain-name-servers 127.0.0.1; by putting # in /etc/dhcp/dhclient.conf
Update resolvconf:

resolvconf -u

Restart network-manager or reboot system:

service network-manager restart


Proper way to remove an active / inactive LVM snapshot

If you have not already, please ensure that your snapshot lv is NOT mounted prior to removing it. Just add an extra line to your ruby script to unmount the snapshot lv prior to performing the lvremove. It may also be wise to add a condition to the lvremove that requires the parition to NOT be mounted in order for the lvremove to proceed.

Hope this was helpful,

MG


Resized VirtualBox VM disk, but when partitioning can't use all new available space

If you're doing all this in a vm, then you're needlessly making work for yourself.  Let me answer this in 3 parts.
Firstly following the approach you've taken, something very strange is going on with your partition table.  In my experience when you 'grow' a physical disk (normally by block copying from one small real disk to a larger one), the partition table needs recreating, as even with the same disk parameters, you'll have alignment issues.  That said, I don't see why fdisk can't recreate a new partition table, if the disk has actually grown (as would happen in a real disk).
Secondly, LVM was created to abstract between the physical drives and partitions, and the volumes contained on them.  Hence when using a virtual machine, without the problem of physical space (normally when upgrading a real disk, you do get rid of the old one), you can just create a new 11Gb virtual disk, and join it to your volume, without having to go through the grief of messing with your old vmfs file.

If you're intent on the approach you're taking, something has clearly gone wrong.  As @daniel suggested, try rebooting, but personally, I'd consider creating a new image, with a new set of partitions and volumes, and copying everything across.  What time you spend in copying, you'll save from trying to figure out how you managed to get your partition table out of order.


You need to fix several issues:

... is configured multiple times in /etc/apt/sources.list:51 and /etc/apt/sources.list:54 - by manual editing of /etc/apt/sources.list and commenting out duplicate 54 line.
manually remove packages lists:

sudo rm -rf /var/lib/apt/lists/*

disable PPAs without Xenial packages:

sudo add-apt-repository -r ppa:picaso/octave
sudo add-apt-repository -r ppa:samuellb/fribid
sudo add-apt-repository -r ppa:tomahawk/ppa
sudo add-apt-repository -r ppa:yorba/ppa

add fresh Spotify GPG key:

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 931FF8E79F0876134EDDBDCCA87FF9DF48BF1C90

update package lists

sudo apt-get update

install all upgrades

sudo apt-get upgrade


This is a common error that indicates you did not install a driver that supports it:

From a bugreport on netflix:

Go to the power/config menu in the upper right and choose "System Settings".
Open "Additional Drivers"
Choose the most up-to-date proprietary driver it lists that is not labeled "experimental"
Click "Activate"
Wait for it to download and activate the driver
Try again. If it does not work then reboot and try again ;)


The best way to install an application is from repositories
In general the Windows executables don't work on Ubuntu. Some Windows software works through Wine. See How to install and configure Wine? for more on how to use Wine. But this is the last resort. You should try to find and install the native version if available.
See How do I install applications in Ubuntu? for general instructions regarding how to install software in Ubuntu.
Install gnome-twitch from the repositories
Gnome-twitch is available in the Ubuntu Universe repository. To make sure the Universe repository is enabled, Open Software & Update app and mark the check box next to universe.

See How do I enable the "Universe" repository?
Open a terminal by pressing Ctrl+Alt+T and enter:
sudo apt install gnome-twitch

Alternatively, install the snap version of gnome-twitch
The version of software such as gnome-twitch is often not the latest in the repositories. snap is a different method of software installation and management for Ubuntu that often contains the most recent version. There is a beta version of gnome-twitch available via snap. To install this version, enter the following command in the open terminal:
sudo snap install --beta gnome-twitch

On my Ubuntu 16.04 LTS this is the only thing I needed to do. If you have not used a snap version of any software before, you may need to install snapd and associated software with the following command before installing gnome-twitch:
sudo apt install snapd snapd-xdg-open

On my computer I did not need to install Gnome 3.24 and you shouldn't need to install the snap version of Gnome 3.24 for Ubuntu 18.04, as it comes with Gnome 3.28 by default.
To start gnome-twitch search for it in the Dash and click on it:

Reference: Ubuntu Handbook


Removes all but config files.

sudo apt-get remove nginx nginx-common

Removes everything.

sudo apt-get purge nginx nginx-common

After using any of the above commands, use this in order to remove dependencies used by nginx which are no longer required.

sudo apt-get autoremove


Last hour, I installed Lubuntu 14.04.4 with Wubi on a preinstalled Windows 8.1 for a friend. It worked without problems. These were the neccessary steps for me, which could be also a guide for you.

Download

I downloaded lubuntu-14.04.4-desktop-amd64.iso from official release site and wubi14044r302.exe from the community supported Wubi site

Run Wubi

I ran wubi14044r302.exe from my Windows download folder. In the same folder was the downloaded iso. I chose Lubuntu, user name and password and because there was only one Windows drive, I selected "C:"

Installation

I pressed button "Install" and because I downloaded iso manually, no further download was needed and only few minutes later, I rebooted the system.

UEFI firmware

I pressed the function key I read in the online manual of the notebook. Then I saw a menu entry with "Windows Boot Manager" and "Lubuntu". I selected "Lubuntu".

Secure Boot

I saw an error message "access denied" but I could perform MokManager and imported the MOK key. After that I selected "continue" but it booted into Windows. After a second reboot I selected again "Lubuntu" and now the installation was completed.

Completing installation

No further issues, I just waited about 10 minutes until a third reboot. I selected again "Lubuntu" and now I saw the freshly installed system.


Why can't I connect to an ad-hoc wireless network on a Windows 7 system?

based on my experience in windows ad hoc network types are weak and unstable . if you want to create a wireless network that other computers or devices be able to connect to it and use internet I mean if you want to share internet via wireless in windows use connectify .
it's a software that you are able to create wire or wireless network and share internet via this networks . I hope this answer was helpfull


Advice for multiple remote access to Ubuntu system for students

On the server side

Install the openssh server if not already installed. In a terminal enter:

sudo apt install openssh-server

Add 25 usernames for 25 students and respective passwords. Make sure the passwords are not easy to guess. You may want to restrict the student users in various ways. See How to create a restricted SSH user for port forwarding? for a very detailed example of using restrictions within ssh server. See configuring the ssh server instructions for security related information.

On the Windows 7 clients

Install PuTTy or another Windows ssh client, such as 10 best PuTTY alternatives.

Finally...

If all the Windows clients and the Ubuntu server are on the same network, and the students don't need to access the ssh server from outside, you are done. If not, you may need NAT or some other configuration.

Try to login from a Windows PuTTy client and if it works, distribute the userID and password to each students along with login instructions.

The students should be able to take screenshots of the PuTTy window in Windows using the standard screenshot taking mechanism in Windows.

Hope this helps


Selecting nvidia graphics card with Prime results in black screen

Solved the issue through the following steps:

Booted into login screen and switched to console via Ctrl+Alt+F1
Ran sudo service lightdm stop to stop lightdm
Purged all nvidia packages along with intel-microcode, tlp, and thermald
Rebooted machine, repeated steps 1-2, then reinstalled intel-microcode, nvidia-384, tlp, and thermald in that order
Deleted all XOrg .conf files in /etc/X11
Ran nvidia-xconfig and sudo prime-select intel
Rebooted machine, logged in as normal, then switched to nvidia graphics via PRIME GUI
Machine has been working as normal


How to connect Java and MySQL on Ubuntu 16.04?

You will need to add the mysql connector to your project.

There are plenty of ways and tools to do it, I suggest you one here.

The connector can be downloaded on mysql website. Choose the "Platform independant" to get an archive that will contain a JAR file.

Then extract the downloaded archive and move the JAR file with your project source.

Then adding it to your project can be done with your IDE. For example, this is the procedure to follow with Eclipse (2018-09 - More details on this post):

In project explorer, right click on your project
Select Properties
In the Properties window, click on "Java Build Path" in the left panel
In the Java Build Path, click on "Librairies" tab
Select Classpath and use the button "Add JARs" on the right


I have loaded up my older desktop with Ubuntu 12.04 and changed the administrator from myself, michael, to my son, Tony! I also changed the administrator password to one I knew he would always use from the one I normally use for myself.

I now get a keyring authentication banner which comes up asking to authenticate but none of the passwords will work, either my own old password, nor his, nor 'none'!

I now have a computer which is fixed in time and space as I cannot update or add or remove software.

How can I annul the password requirements and start afresh?

Do I wipe the computer clean with a hard drive eraser and start again??