Launchpad could not import your OpenPGP key

Before you can import your key to Launchpad, it must be available on the Ubuntu keyserver.

  Publishing your key

  Your key is useful only if other people can verify items that you
  sign. By publishing your key to a keyserver, which acts as a directory
  of people's public keys, you can make your public key available to
  anyone else.

  Before you add your key to Launchpad, you need to push it to the
  Ubuntu keyserver.

  Using Passwords and Encryption Keys

  Step 1 Open Passwords and Encryption Keys.

  Step 2 Select the My Personal Keys tab, select your key.

  Step 3 Select Remote > Sync and Publish Keys from the menu. Choose the
  Sync button. (You may need to add hkp://keyserver.ubuntu.com to your
  key servers if you are not using Ubuntu.)

  It can take up to thirty minutes before your key is available to
  Launchpad. After that time, you're ready to import your new key into
  Launchpad!

From: https://launchpad.net/+help-registry/openpgp-keys.html#publish


How do you mount a hard drive in RW mode?

First, when it's auto-mounted, run mount and look for the /dev/sdb1 and see how it's mounted now. If there's a ro it's read-only, or a rw means you're almost done :)

And a lsblk is a prettier way to see if & where drives are mounted too. sudo blkid may show some more useful info as well, possibly about FS types.

It may be mounted rw now, but the permissions won't let you write to it. May need to chown to get write permissions.

Or if it is ro, try a basic sudo mount -o remount,rw /dev/sdb1, maybe it's erroring on the other options.

If that doesn't work, then my only other idea now is - is it a writeable filesystem? Or a ro-only system like squashfs or iso9660/cd format? gparted should show what partitions & FS's are what.


Until they get perl bindings for app indicator, you can whitelist Shutter systray as per the one-line command posted in this question,

  gsettings set com.canonical.Unity.Panel systray-whitelist "$(gsettings get com.canonical.Unity.Panel systray-whitelist | sed -e "s/]$/, 'shutter']/")"

GUI Editor method

Install dconf-tools
Open dconf-editor

Run Command Alt+F2 and type dconf-editor
Navigate to desktop => unity => panel

Add the text ,'shutter' to the end of the list (inside the square bracket).
Close dconf-editor and restart Unity (Run Command Alt+F2 and type unity)


How to install seafile within libertine container

It looks like you are using an outdated syntax for adding a repository with the configure subcommand. Try this instead:

$ libertine-container-manager configure --archive add \
          --archive-name ppa:seafile/seafile-client --id myContainerID

This is the correct syntax in python3-libertine>=1.3.1 and possibly earlier than that. When in doubt, you can always check libertine-container-manager configure --help for more information.


Finally found the solution.

Had to use:

apt-cache policy icedtea-6-jre-cacao

To find the right version string to perform a downgrade. For some reason apt-cache showpkg and apt-show-versions didn't show it.

So the final commands to fix this problem where:

apt-cache showpkg openjdk-6-jre
apt-cache policy icedtea-6-jre-cacao

To find the right version to downgrade to. And:

apt-get install openjdk-6-jre=6b24-1.11.1-4ubuntu2 openjdk-6-jre-headless=6b24-1.11.1-4ubuntu2 icedtea-6-jre-cacao=6b24-1.11.1-4ubuntu2

To perform the downgrade.

After downgrading from 6b27 to 6b24 the problems in NetBeans are resolved for me on both PCs.


changed the iptables configuration by mistake and want to revoke it

The command:

iptables --flush

is only temporary. To make it permanent your do:

iptables-save

Since you haven't done so it's ok


Errors were encountered while processing: install-info

Copy the following in a file and save it in your Desktop as askubuntu.

#!/bin/sh
# update-info-dir
# create a dir file from all installed info files
# Copyright 2009, 2014 Norbert Preining
# GPLv2

INFODIR=/usr/share/info

set -e

#
# since user's environment is taken over into root account when sudo-ing
# we don't want that one's user LANGUAGE setting changes the messages in
# the dir file. Unset LANGUAGE and reload /etc/environment to get
# the system wide settings. See bug #536476
unset LANGUAGE
unset LANG
if [ -r /etc/environment ] ; then
  . /etc/environment
fi
if [ -r /etc/default/locale ] ; then
  . /etc/default/locale
fi

Help ()
{
    echo "\
SYNOPSIS: update-info-dir [-h,--help] [info-directory]

(re-)creates the index of available documentation in info format
(the file /usr/share/info/dir) which is usually presented by info browsers
on startup."

    exit 0
}

if [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
    Help
fi

if [ -n "$1" ] ; then
  INFODIR="$1"
fi

if [ ! -d "$INFODIR" ] ; then
  echo "Not a directory: $INFODIR." >&2
  exit 1
fi

if [ -r "$INFODIR/dir" ] ; then
  rm -f "$INFODIR/dir.old"
  cp $INFODIR/dir $INFODIR/dir.old
fi

# we have to remove the dir file not make install-info being surprised
rm -f "$INFODIR/dir"

errors=0
find "$INFODIR" -type f | while read file ; do
  case $file in
    */dir|*/dir.gz|*/dir.old|*/dir.old.gz|*-[0-9]|*-[0-9].gz|*-[1-9][0-9]|*-[1-9][0-9].gz|*.png|*.jpg)
      # these files are ignored
      continue
      ;;
    *)
      install-info "$file" "$INFODIR/dir" || {
        errors=$((errors+1))
      }
      ;;
  esac
done

if [ $errors -gt 0 ] ; then
  exec >&2
  echo
  echo "Updating the index of info documentation produced $errors errors."
fi

exit 0

# vim:set expandtab tabstop=2: #

Open a terminal and run:

sudo cp /usr/sbin/update-info-dir /usr/sbin/update-info-dir-backup
sudo rm /usr/sbin/update-info-dir
sudo cat ~/Desktop/askubuntu >> /usr/sbin/update-info-dir
sudo chmod +x /usr/sbin/update-info-dir


Open the terminal and type:

sudo dpkg -r isomaster:i386

Check in the Ubuntu Software Center to make sure that the exact spelling of the package's name is isomaster:i386.


I removed python2 and python3; Terminal won't launch now!

open your Xterm terminal

sudo apt-get remove gnome-terminal

then reinstall it with

sudo apt-get install gnome-terminal


User password rejected on login screen but accepted on text console login

Try resetting your account's password from the command prompt. If you are able to gain root access, just use CTRL-ALT-F2 to access the terminal and login as root. If you are unable to gain root access, reboot and select the recovery mode option in grub, then select the option to drop to the root shell prompt.

Once you have the root command prompt, you can change your users password with the following:

# passwd usr

Where usr is replaced with your account name. You should then be prompted to enter the new password for that account. You may want to try changing it to something else entirely, then changing it back. After that, reboot and try logging in properly again.


I want to set up FAUmachine virtual machine, please help

As far I can understand Ubuntu 14.04 LTS and 16.04 LTS have faumachine 20120707-3.

According to official site, it is latest version.

You can install it with:

sudo apt-get install faumachine

Then you can launch it with faum or from launcher FAUMachine.


bash-completion: how to select among different alternatives

Bash works the next way:

$ touch file1.txt file2.txt file3.txt video1.avi video2.avi
$ ls
file1.txt  file2.txt  file3.txt  video1.avi  video2.avi

If you input the first letter f and hit TAB the first time, it autocompletes it to file. If you hit TAB the second time, it shows all available variants starting with file. There're three files starting with file prefix and bash does not know which of them you want.

$ vim.tiny file                    # the second tab
file1.txt  file2.txt  file3.txt

Then, if you input the next symbol and there's no other files starting with it, it autocompletes it fully:

$ vim.tiny file1#   1 added to 'file' word
$ vim.tiny file1
TAB
$ vim.tiny file1.txt  #   result

If you want it to work similarly as it is in zsh, you could execute the next commands:

bind 'set show-all-if-ambiguous on'
bind 'TAB:menu-complete'

It will behave the next way:

$ vim.tiny f
TAB
Result:

file1.txt  file2.txt  file3.txt
$ vim.tiny file1.txt

TAB
Result: $ vim.tiny file2.txt


What should I know about networking before I use rsync?

You should know:

to access remote systems rsync uses SSH protocol by default
SSH protocol implementations (by default) verify the identify of both: the server and the client

to verify server, client uses Trust On First Use trust model and by default it remembers the servers it connected to in -/.ssh/known_hosts file
if you replace the server with another one (at the same name or IP address), the client will complain and require you to manually remove the entry from the -/.ssh/known_hosts file

client can be authenticated using a password-based or key-based authentication

password-based authentication is considered less secure (although it is not inherently insecure)
for key-based authentication you use two keys: public and private (you generate them with ssh-keygen command usually on the client)
you add the public key (contents of the -/.ssh/id_rsa.pub fileon the client) to the -/.ssh/authorized_keys file in the account home directory on the server (again by default) or you can use ssh-copy-id command to do it for you
you store the private key usually in -/.ssh/id_rsa on the client
you should consider protecting the private key with a passphrase (you can further configure GPG keychain to remember the passphrase for you for a specified time)

server SSH daemon configuration is stored in /etc/ssh/sshd_config
SSH client configuration can be stored in ~/.ssh/config
majority of problems with SSH are related to authentication, if you encounter any, you should try connecting to the remote machine with ssh command and add -vvv option to display detailed messages, try to unstated the reason, and include the results in questions on StackExchange or AskUbuntu, if you cannot identify the problem yourself
all above describes the defaults or typical scenario, rsync might be configured to use different transport protocol or used directly over TCP with rsync:// addresses; SSH can be configured with a myriad of settings influencing the operations


Those commands are correct as they are.

You can get the respective error only if you have a space character inside ACL spec (in your case u:www-data:rwx or u:`whoami`:rwx). An wrong example:

sudo setfacl -dR -m u:www-data :rwx -m u: `whoami`:rwx app/cache app/logs
#                             ↑          ↑

So, please check again more carefully!


Nautilus is theme-less unless I run it as root

Well, after searching around. Adding a delay to gnome-settings-daemon when logging in corrected the problem


You disable it from the (xfce) preferences

Click on the icon and select preferences ;)

See http://docs.xfce.org/xfce/xfce4-power-manager/getting-started and http://docs.xfce.org/xfce/xfce4-power-manager/preferences


That is a method to do this. You can also do this from /etc/cron.d or /etc/crontab

But it depends on what test.php does. If the result of this is to print something to the screen or to a website... not going to work. If this sets a setting on the Ubuntu server sure it will work.

I would advice to add a log behind the command. That will make tracing problems easier.

*/5 * * * * /var/www/example.com/public_html/test.php >> /var/log/test.log 2>&1


Can I keep my files on Windows XP if I install Ubuntu side by side with it?

If, by "windows installer", you mean to say you want to install Ubuntu "inside" Windows, then no files will be deleted and you will be able to access your files and folders even in Ubuntu. However, you won't be able to run your windows applications directly in Ubuntu. You can run some of those, if not all, using applications like wine.

All files which are stored in the virtual disk where Ubuntu is installed are stored in a folder /host, which you will be able to see when after you install Ubuntu and boot into Ubuntu. For your information, you can also install Ubuntu alongside Ubuntu, which is usually considered to be more common and better for long-term uses, since crashing of Windows does not affect Ubuntu, which is not the case if you install it inside Windows, i.e. like an application.

For more information, read this. If you have trouble installing Ubuntu, please refer to the above link or you can also post your queries or problems here, if they are not already posted.


When multitasking a fullscreen app, cant get mouse to lock back in the application: Ex. SPAZ game

Try disabling mouse capture on the option menu that comes up when you start the game. Then you can wiggle the mouse when you get kicked out and it will re-focus on the game. Worked twice for me when I was playing last night. This also fixes the double mouse icon I was getting.

Still not sure why it looses focus on the full screen, that seems like a bug but I am not sure if it is with SPAZ or Ubuntu.


How to reassigns language settings and launcher shortcuts in Ubuntu 19.10

Note:

Tried this in Ubuntu 18.04.3.. similar to 19.10 Also.. (If you find difficulty.. I shall Install 19.10 and test it)

Workaround:

  Alt+CapsLock switches to the next (without toggling the caps lock)

use gnome-tweak tool to choose this.. It will not toggle caps_lock.
If you dont have gnome-tweak tool. Install it by below command.

sudo apt install gnome-tweaks

  Alt+Space opens the launcher menu

go to keyboard shortcuts..
disable the default keyboard shortcut Alt+Space

Create a Custom Shortcut with below details

Name: Toggle Overview
Command: /bin/bash /home/<yourusername>/tgov.sh
{ example: /bin/bash /home/pratap/tgov.sh }

create a script in your home folder tgov.sh (toggle overview) with below content

#!/bin/bash

status=`gdbus call --session --dest org.gnome.Shell --object-path /org/gnome/Shell --method org.gnome.Shell.Eval 'Main.overview.visible'`

if [ "$status" == "(true, 'false')" ]; then

dbus-send --session --type=method_call --dest=org.gnome.Shell /org/gnome/Shell org.gnome.Shell.Eval string:'Main.overview.show()'
else
dbus-send --session --type=method_call --dest=org.gnome.Shell /org/gnome/Shell org.gnome.Shell.Eval string:'Main.overview.hide()'
fi

  Win key switches to the first layout

Disable the overlay function from Super key..

gsettings set org.gnome.mutter overlay-key ''

Create a Custom Shortcut key Super+F with below details

Name: Switch to First Language
Command:

gdbus call --session --dest org.gnome.Shell --object-path /org/gnome/Shell --method org.gnome.Shell.Eval "imports.ui.status.keyboard.getInputSourceManager().inputSources[0].activate()"

Install the package xcape with below command.

sudo apt install xcape

Make the Super_L key behave like pressing two keys Super_L+F

xcape -e 'Super_L=Super_L|f'

Create a startup applications preferences like below

  Language settings valid per window

use system settings to configure like below


This is, unfortunately, a feature of Gnome 3.4 and above.

See the release notes here: http://library.gnome.org/misc/release-notes/3.4/#rnusers.gnome-3-applications

I've searched hard and haven't found a way to restore the old style menu bars.

So far the Gnome developers have, in their infinite wisdom, managed to destroy Epiphany, Baobab, Nautilus and others in this way. From a usability perspective it's a complete disaster - I now need to click, move the mouse and click again just to close a window! I shudder to think what "innovations" they'll come up with next..


Has anyone tried installing Ubuntu (or any linux distro) on an Eluktronics (N850HK1) laptop?

So I bought it, installed Ubuntu. Everything ran pretty smoothly as far as installation goes but there are a few problems such as brightness keys not working, but nothing that can't be worked around. Haven't has any issues with random hanging during shutdown, sleep, etc. So an in all, this laptop is pretty compatible with Ubuntu!

EDIT: After a bit more use, there's a lot of problems. It's usable but just little annoying things like you can't change the color of keyboard (which may or may not be the cause of it heating so fast), the brightness keys do not work and all work-arounds I've tried have not fixed them, cinnamon battery applet does not update, and there's not much documentation on the fixes for these so they're just little annoying things you have to deal with.


How can I change camera image details (metadata)?

digiKam incorporates a fast Image Editor with many image editing tools.
   You can use the Image Editor to view your photographs, comment and rate
   them, correct, enhance and alter them. The editing power can be easily
   extended by a set of plugins, the KDE Image Plugins Interface (manual)
   While digiKam remains easy to use, it provides professional level features
   by the dozens. It is fully 16 bit enabled including all available plugins,
   supports RAW format conversion through libraw, DNG export and ICC color
   management work flow.
   digiKam can also make use of the KIPI image handling plugins to
   extend its capabilities even further for photo manipulations,
   import and export, etc. The kipi-plugins package contains many
   very useful extensions.

First of all nstall digikam using

sudo apt install digikam

To edit details or metadata of image:

Open digiKam and add the folder as Album by clicking on  Album→New

Then click on the desired image and go to Tools→Image Editor

A new dialog will be opened with all editing options for the image. In order to edit the details/metadata, click on Tools→Edit Metadata

Again a new window will popup like below. There you can edit all details such as EXIF, IPTC, and XMP.


It is quite annoying where this setting is. When "Show at top. . " is unchecked it goes to the bottom.


Unfortunately the way it is done for testing is plugging in usb sticks to all nodes.  You have to get small ones so they clear the housing when it's closed.


Strange blocky/interlaced textures on Ubuntu MATE 20.04 games

Disable texture compression, enable lowest quality settings, make it fullscreen, and fit the screen to your resolution.


How do I purge Pantheon desktop?/Why does this window appear?

ppa-purge is unneffective with that ppa, (elementary-os/daily) & the same with autoremove.

Open Synaptic,

click Settings, Repositories

Click Add
and add back the ppa you used previously & update sources.

Click the Reload button in the upper left corner, then  Origin. Click on the entry for that ppa/now similar (entry highlighted above). With shift+click highlight all the packages & mark for removal, and remove them.

Then remove the PPA from your software sources Under Settings, Repositories.

Source: comment from @doug


Open the Dash and launch a Terminal and enter:

sudo apt-get install ubuntu-restricted-extras && sudo apt-get install gstreamer0.10-plugins-good

Enter your password to complete the installation.

More info HERE


apache doesn't restart on Ubuntu 14.04 server reboot

I had this problem consistently and it was the .pid file for the process before the reboot still being there.  These are RedHat examples, but the concept is the same.  A "service tomcat stop" both stops the apache process and the deletes the accompanying .pid file.  A reboot was not removing the .pid file.  What I ended up doing at first was manually stop and restart tomcat after the server came back up.  Later I modified the startup script to do an automatic shutdown first.  It would give me an error if it tried to stop something already down, but the webserver started up afterwards just fine.


External usb mouse and keyboard stop working all of a sudden

Cambiando el dispositivo de USB a otro USB trabaja de nuevo, si es el ratón a mi me funciona hacer desde la terminal (control+alt+t):

echo -n "0000:00:1d.0" | sudo tee /sys/bus/pci/drivers/ehci-pci/unbind
echo -n "0000:00:1d.0" | sudo tee /sys/bus/pci/drivers/ehci-pci/bind

Para no escribir tanto me hice un script bash (simplemente copia y pega en un editor de texto simple como xed, gedit, nano...):

#!/bin/bash

echo -n "0000:00:1d.0" | tee /sys/bus/pci/drivers/ehci-pci/unbind
echo -n "0000:00:1d.0" | tee /sys/bus/pci/drivers/ehci-pci/bind

Lo guardas en tu carpeta personal /home/TUUSUARIO con un nombre, por ejemplo ponraton.sh y lo haces ejecutable con el botón derecho de ratón sobre el mismo, en propiedades u Opciones - Permisos y marcas lo de ejectuar, en terminal sería:
    $ chmod 755 ponraton.sh
Y ahora puedes ejecutar con sudo: primero Control+Alt+T en el teclado te abre la terminal y usas sudo ./ponraton.sh

Con teclado no sé porque uso portátil y no teclado USB. Me pasa de hace poco para acá, igual desde el paso del kernel al 4.13 desde 4.4 por culpa del fallo de los procesadores.

Google translates the above post to:
Changing the USB device to another USB works again, if the mouse is working for me from the terminal (control + alt + t):

echo -n "0000:00:1d.0" | sudo tee/sys/bus/pci/drivers/ehci-pci/unbind
echo -n "0000:00:1d.0" | sudo tee/sys/bus/pci/drivers/ehci-pci/bind

To not write so much I made a bash script (simply copy and paste in a simple text editor such as xed, gedit, nano ...):

#!/bin/bash

echo -n "0000:00:1d.0" | tee/sys/bus/pci/drivers/ehci-pci/unbind
echo -n "0000:00:1d.0" | tee/sys/bus/pci/drivers/ehci-pci/bind

You save it in your personal folder /home/YOUR_USER with a name, for example switchmouse.sh and you do it executable with the right mouse button on it, in properties or Options - Permissions and marks what to execute, in terminal it would be: $ chmod 755 switchmouse.sh And now you can run with sudo: first Control + Alt + T on the keyboard opens the terminal and you use sudo ./switchmouse.sh


Switch from GUI to the command line interface/console temporarily

(First, a hint to avoid confusion: the way how to solve that has changed in Ubuntu not long ago. When you look around, you will find much information refering to 'changing runlevels', and init or telinit. That's about the outdated method and not useful any more.)

With the current system, there seems to be no direct replacemet for this, as it does not use the concept of runlevels that way.

I'll propose two ways how to do it, let me know which of them works best for you:

If you want to switch off the GUI screen showing the login dialog, sometimes with wallpaper image ( - which is called a greeter in X11 terminology - ), try to shut down the display manager service. It is usually either gdm or lightdm, so
sudo service lightdm stop might work (use start instead of stop to restore)

The second way may be obvious for someone who has used it, but I am not sure from the question whether you took that one into account:

If it is acceptable for what you want to do, you could keep the GUI running, but hide it while not needed: You have multiple text consoles, and at least one GUI screen that you can use. Use Ctrl+Alt+F1 to switch to the first text console, and get back later using F7 of F8 instead.


You renamed myFile.jar to ..myFile.jar. As the file name starts with a dot the file is hidden by default.

You can use

mv ..myFile.jar ../myFile

to move it to ../myFile


How can I figure out which theme is used by the user?

You can type in terminal:

gsettings get org.gnome.desktop.interface gtk-theme

Or in Python:

from gi.repository import Gio
theme=Gio.Settings.new('org.gnome.desktop.interface').get_string('gtk-theme')


Customization for quicklists of Unity is reverted after reboot

First step is to copy the .desktop file over to ~/.local/share/applications and to edit that version. ~/.local/share/applications overrules the .desktop from /usr/share/applications.

The ones in /usr/share/applications get recreated probably to prevent malformed desktop files to crash Unity: in case of a crash it can fallback to the unchanged version.


Cannot boot after upgrade to 18.04 grub-probe: error: cannot find a GRUB drive for /dev/sdb1

I fixed it by disabling SecureBoot from UEFI. I don't know why after the update this had become a problem (since with Ubuntu 16.04 SecureBoot has always remained activated) and currently I do not have too much time to investigate.

In any case, thanks to GabrielaGarcia for the clarifications.


Ubuntu 18.04 install on an old Intel motherboard

The Ubuntu 64-bit iso files with amd64 in the file name should work in your Dell Latitude E6420 laptops. (There is no download specifically for Intel motherboards, the same iso files work for all brands of motherboards for Intel type PCs (typically with Intel and AMD processors).)

Even if the computer's name and model numbers are the same, there can be different hardware components inside. In this case I would guess that there are different hardware for wifi. For example, if the wifi hardware is made by Broadcom, you need a proprietary driver.

Try the following command line in order to identify the wifi hardware,

lspci|grep -i net

You can expect to see

one line for Ethernet (wired network) and
one line for wireless network (the brand name and model should be found here)

You should also check that the wireless hardware is turned on. See the picture.

If you find wireless hardware by Broadcom, you can get more specific information about the version of Broadcom (the model number) via the command

lspci -nn -d 14e4:

and then you can select driver from the list in the following 'AskUbuntu answer',

Installing Broadcom Wireless Drivers

The switch for wifi on Dell Latitude E6420:


unity-greeter: missing indicators on login screen after logout

The bug has been confirmed, in this Launchpad tracker. There is a fix committed to the lightdm package, version 1.18.2-0ubuntu2.

It's currently in the proposed repo for Xenial (16.04) - I've enabled the proposed repo from the instructions here and installed the updated version. (I also followed the selective upgrades instructions, so that only packages I choose update to the proposed versions.)

If you don't want to play around with the proposed repository, that's OK - the updated package should make its way into the normal updates soon enough.


Why doesn't tty7 show a prompt with no display manager?

As far as I know this is all just tradition. "tty" is just a historical hangover from mainframes. 1-6 exist as login prompts because that's how they're defined in /etc/default/console-setup (and executed by /etc/init/console-setup.conf). This is how those TTYs get their login prompts and by extension, why tty7 does not have one.

But why 6 text ttys? And why tty7 for graphics? I have no idea.


32 bit Wine in 64 bit PC running Ubuntu 64 bit Precise

You can install several wine versions including 64 and 32bit ones easily by using playonlinux. Playonlinux is a simple program providing you with as many wineprefixes as you like and for each of them you can choose a different version of wine.

You can install it via the Ubuntu software center or via command line (sudo apt-get install playonlinux) [or via any package management program you prefer].


How to open a graphical file exporer in a home dir of a different user?

Since there is no gksudo anymore, we'll use pkexec, which is part of polkit.

The following shell script will run nautilus as user xyz on the current display:

#!/bin/sh
xhost +SI:localuser:xyz
pkexec --user xyz env DISPLAY=$DISPLAY nautilus
xhost -SI:localuser:xyz

The pkexec line executes env DISPLAY=$DISPLAY nautilus as user xyz. We need to specify the $DISPLAY variable, because pkexec explicitly doesn't (see man pkexec for more information).

xhost +SI:localuser:xyz permits user xyz to use the current display, the last command revokes that permission.

Now you can either run the script on its own or specify it in a .desktop file.


Avahi is a zeroconf/bonjour DNS responder, which is not available per default on Windows since its an Apple invention. It may help if you install 'Bonjour for Windows' on the W 7 machine.

If you don't like this, the Windows laptop can resolve your linux desktop if the desktop runs samba, the nmbd daemon there will advertise the hostname and the corresponding IP-Address by means of NetBIOS over TCP/IP, which is just a checkbox somewhere in the Windows networking preferences.

The router may do IPV4 only, perhaps disable IPV6 on both, reboot Windows, retry.
Also, avahi may not pick up config changes immediately, do a restart avahi as root.


It works for me, I get those two keys (into a test operating system, which was not used for this purpose before). My language is Swedish, but I think it is obvious that two keys were imported.

tester@tester-SATELLITE-PRO-C850-19W:~$ gpg --keyid-format long --keyserver hkp://keyserver.ubuntu.com --recv-keys 0x46181433FBB75451 0xD94AA3F0EFE21092
gpg: keybox '/home/tester/.gnupg/pubring.kbx' created
gpg: key D94AA3F0EFE21092: 2 duplicate signatures removed
gpg: key D94AA3F0EFE21092: 59 signatures not checked due to missing keys
gpg: /home/tester/.gnupg/trustdb.gpg: tillitsdatabas skapad
gpg: nyckel D94AA3F0EFE21092: publika nyckeln "Ubuntu CD Image Automatic Signing Key (2012) <cdimage@ubuntu.com>" importerades
gpg: key 46181433FBB75451: 2 duplicate signatures removed
gpg: key 46181433FBB75451: 106 signatures not checked due to missing keys
gpg: nyckel 46181433FBB75451: publika nyckeln "Ubuntu CD Image Automatic Signing Key <cdimage@ubuntu.com>" importerades
gpg: hittade inga nycklar med förbehållslöst förtroende
gpg: Totalt antal behandlade enheter: 2
gpg:               importerade: 2
tester@tester-SATELLITE-PRO-C850-19W:~$

If you tell me which iso file you have, I can check it and verify that the checksum is correct. I know that it is not a perfect way to verify that the checksum and the iso file are correct, but since you cannot get the keys, it is better than nothing.


rhythmbox-scope consuming lots of memory

If you are using rhythmbox-scope from https://launchpad.net/~markjtully/+archive/ppa, then you may be using something you do not actually require.  The main music lens includes support for rhythmbox by default in 12.04.

rhythmbox-scope may be removed from your system using the Software Centre, or by entering

sudo apt-get remove rhythmbox-scope

Log out and log back in again to complete the process.  You should still be able to search your music using the music lens's included rhythmbox support, hopefully with lower memory usage (look for unity-music-daemon in System Monitor).

rhythmbox-scope is a holdover from Ubuntu 11.10 (where it was required to search Rhythmbox) and the early development of Ubuntu 12.04, before it was included in the main music lens by default, rewritten using vala rather than python.  I suspect it uses so much memory because it maintained its own list of music in memory (though 700-800 Mb still seems excessive, even for 34,000 songs).  It may also be conflicting with the main music lens (as both are essentially trying to do the same thing).  I have stopped development of this scope of this scope since it is now redundant.  I really should also remove it from my ppa.


The lines "for: DISK=/dev/mmcblk0" and "for: DISK=/dev/sdX" are for your eyes only, not command lines. "for:"only points to the following instructions in the tutorial, which are command lines and should be run.

The following command lines set the environment variable DISK

for a card connected via a PCI card reader

DISK=/dev/mmcblk0

for a card connected via a USB card reader,

DISK=/dev/sdX

In this case you should replace X with the actual drive letter (a, b, c ...), so for example /dev/sdb, that you can identify with the commands

sudo lsblk --fs     # Output info about filesystems
sudo lsblk --perms  # Output info about device owner, group and mode
sudo parted -ls     # --list: lists partition layout on all block devices; --script: never prompts for user intervention

In general, you can use the commands above to find out how the card is connected and identified.

This environment variable is used in the next command in the tutorial as ${DISK}, for example (depending on the version of mkfs.ext4),

when connected via PCI

sudo mkfs.ext4 -L rootfs -O ^metadata_csum,^64bit ${DISK}p1

or when connected via USB

sudo mkfs.ext4 -L rootfs -O ^metadata_csum,^64bit ${DISK}1

${DISK}p1 and ${DISK}1 specify the partition where you want to create an ext4 file system.


Software for capturing of selected text from any place (browser, text editor, etc)

If you highlight text and then press  Ctrl  +  C  It will copy all selected text. Then you can paste it again with  Ctrl  +  V  You can also cut text which is copying and removing with  Ctrl  +  X  And then paste it with  Ctrl  +  V


This sounds like an issue beyond the grub in the Windows boot process.
I would suggest to boot with your Windows installation DVD or with a Windows recovery USB (You can make one in Windows 10, if you have another PC with Windows 10) an do a repair/recovery (F8) .

You will probably need to reinstall grub afterwards since the repair process will most likely "repair" the masterboot record and remove grub.

Alternatively: This might be a sign that your way should rather go via free open source  GNU/Linux than via proprietary  Windows. Just continue to use Ubuntu. ;-)


How to install VM tools in Ubuntu 18.04 desktop on Synology

According to this answer, you must enable the universe repository, since the package is in that repository.

sudo add-apt-repository universe
sudo apt install qemu-guest-agent


Intermittent freezing on a Macbook Pro 7,1

I think this is related to a known bug when the proprietary Nvidia driver is installed.
They forgot to add linux-headers-generic as a dependency for installing the nvidia driver.

Try to get into a virtual terminal, I don't have a MAC, but on the PC you get to one by using CTRL+ALT+F1 .

Once you get there, log in, get root privileges  (sudo -i),  and do

sudo apt-get install linux-headers-generic

Once that's done, try to reinstall the nvidia driver.

sudo apt-get purge nvidia-current
sudo apt-get install nvidia-current

Reboot and hopefully it should work then for you.


Now the snap has been published you can obtain the snap via:-

snap install firefox

Alternatively search for Firefox in GNOME Software.


Still stable version is ubuntu 12.10, I thing it's good for beginner, otherwise you can use Ubuntu 13.04 but it's a testing version, while you are using it may be appear some bug, Ubuntu 13.04 is now latest version, and now have to download Ubuntu 13.10 Daily Build, I will recommend for you Ubuntu 12.10


Ubuntu 18.10, Samba 4.8.4 smb.conf - what are the valid values for fruit:model?

There are plenty of other model strings that should work as values; I believe they are directly read from /System/Library/CoreServices/CoreTypes.bundle/Contents/Info.plist.

Browsing through that file, you should be able to intuit valid values. For example, from the line

UTTypeTagSpecification = { com.apple.device-model-code = ( "Macmini", "Macmini5", "Macmini6", "Macmini7" ); };

I deduced that the proper string for the Mac Mini is Macmini (no CamelCase). MacBook should work, though. As should AppleTV, MacBook5,2, and many more appearing in the aforementioned file.


As royalsampler suggested above use nethogs for Realtime network usage viewing through terminal . Install it using

sudo apt-get install nethogs

and run it

sudo nethogs

For example you can see as here

NetHogs version 0.8.0

  PID USER     PROGRAM                      DEV        SENT      RECEIVED
2652  user     /usr/lib/firefox/firefox     eth0       2.318      48.183 KB/sec

And for a GUI preferred interface use Firestarter , approximately 500 KB's download.


Broadcom bcm4318 airforce one 54g, can't connect to WiFi

Yeah, it's frustrating. Especially here where instead of getting answers you get more questions. Anyway, see below for what worked for me. I had the same problem. The LAST option is what worked for me. I tried about 50 different methods to get the g-d wifi working, and finally did using the below: Make sure you do the update and upgrade before though. I did not write this, this was taken from another part of this forum.

You can fix wifi problems using two methods:

Either connect to the internet via wired connection and run this command:

sudo apt-get update && sudo apt-get upgrade

Then reboot your system.

Or use the following commands:

sudo apt-get install linux linux-headers-generic kernel-package
sudo apt-get install --reinstall bcmwl* firmware-b43-lpphy-installer b43-fwcutter

Finally, reboot your system.

If that didn't help, try these commands:

sudo apt-get remove bcmwl-kernel-source
sudo apt-get install firmware-b43-installer b43-fwcutter
sudo reboot


GIMP 2.10.18 in Ubuntu 20.04 unable to maximize screen

Figure out that after resetting every setting in the interface section of preferences can reset the window and recover the maximize button. Which one, I don't know. If you are facing the same issue try with everyone of them.


Duplicate application icons in Ubuntu dock upon launch

You need to add a proper StartupWMClass line to the .desktop launcher corresponding to the application (refer to this). Follow these steps:

Open Files and go to your /usr/share/applications folder. Look for the "Nightly" file (i.e. the launcher for the application you want to fix) and copy it.
Paste the file in ~/.local/share/applications. It should look like a file with the name <filename>.desktop.
Right click on this .desktop file and open with Text Editor.
Launch "Nightly" (i.e. the application you want to fix) from "Activities".
Run xprop WM_CLASS in Terminal.
Place the cursor over the opened "Nightly" window. The cursor should turn into a crosshair already. Click. You should get a WM_CLASS string for "Nightly" in Terminal.
In the .desktop file opened in Text Editor add the following line

StartupWMClass=OBTAINED-VALUE

In place of OBTAINED-VALUE put a value you got from step 6 without any quotes.
Save the .desktop file.


You BIOS may be corrupt. For now, use a DVD, and/or burn PLoP Boot Manager  to boot from usb in the future. Or try the UNIX utility dd instead of Unetbootin, then it may boot natively.


Try this,

for i in $(cat ~/jlog/"$2"); do
        grep "$1" ~/jlog/"$2" |
        awk '/\([a-zA-Z0-9.]+/ {print $7; exit}'
done;

exit in the awk command exits after printing the first match.

OR

Just pipe the output of for command to the below awk command,

for .... | awk -F'[(/]' '{print $2;exit}'


Your script doesn't have a shebang line

#!/bin/sh
...

Without that line the script can only be run from a shell and
that shell will guess that the script is to be executed
as a shell script. Basically the order is as follows:

the shell tries to execute the script as a binary and
the kernel may or may not look for a magic number
(with #! counting as magic number)
if that doesn't work then the shell executes the script as
a shell script.

That's why it works when you invoke the script from a shell
even though it lacks the shebang line.

If you run the script from cron, then there is no parent shell
that could guess how to execute the script. To avoid this, add a
shebang line like so:

#!/bin/sh
# Swap clear
# 03.08.2017
swapoff -a ;
swapon /tmp/swap

Further reading:

Shell script working fine without shebang line? Why? (Question on SO)
Section - Why do some scripts start with #! ... ?


How to configure locales to Unicode in a Docker Ubuntu 14.04 container?

I use this in my Dockerfile:

# Set the locale
RUN locale-gen en_US.UTF-8
ENV LANG en_US.UTF-8
ENV LANGUAGE en_US:en
ENV LC_ALL en_US.UTF-8

One can also use the ENV one-liner:

RUN locale-gen en_US.UTF-8
ENV LANG='en_US.UTF-8' LANGUAGE='en_US:en' LC_ALL='en_US.UTF-8'


As final resort I would go to Synaptic Package manager and try its "Fix broken packages" menu item under Edit menu. If that fails I will, in same program do check all broken packages and remove them (if it fails in synaptic just do it in terminal sudo apt-get remove) and then I do sudo apt-get autoremove and sudo apt-get autoclean

Before you try installing them you need to run sudo apt-get update

By the way what was the last package you tried to install that broke things? That is important and should be part of your question!


I found another solution that suited me.
In fact I realised that I did not really need to simulate an USB drive, but rather any type of storage device (my app watches HAL or UDisks for "DeviceAdded" events).

So I did the following:

create a filesytem image, for example with the "virt-make-fs" command
sudo virt-make-fs --type=ntfs -- fs.tar.gz fs-test.img
upload the img file on the test machine
setup the image as a loop device: sudo losetup /dev/loop0 fs-test.img

And that's it, UDisks just triggered the "DeviceAdded" DBus event!
(however, HAL does not trigger anything in this case, so it's a good opportunity to drop it since it is deprecated)

If you want, you can manually mount the image with something like sudo mount /dev/loop0 /mnt/fs.

If you need to use pmount, don't forget to add /dev/loop0 to /etc/pmount.allow.

To unset the loop device, just use sudo losetup -d /dev/loop0.


I faced the same issue and it was caused by nearby devices. The signals of my WiFi device were less than the other device and channel was also same. You need to change it's channel.

Follow these steps to solve your issue:

Connect your mobile with Wifi by going near to your Wifi or connect laptop with eathernet cable.
Open any web browser and go to device configuration menu by typing default gateway address(that is usually written on the back side of WiFi device).
Go to wireless settings>advanced-settings and find the option to change WiFi channel.
You can also search how to change channel for your WiFi model.
Change WiFi Channel and apply.
Forget WiFi from laptop and reconnect.
enjoy:)


ubuntu 20.04 - mouse right button not working in gnome

My bad.

I thought I had tested with another mouse, but I must have just thought I had. The old logitech mouse is dead, right button functioing normally with a new device I got.

Please delete this thread,


Firefox becomes very slow, showing spinning circle "connecting" for ages, ipv6 is disabled, no proxy, and disabling addons doesn't work

Have you tried to reset your Firefox ???

If not, you have to go to Firefox --> Troubleshooting Information --> Reset Firefox...


How can an internal hard drive be made completely inaccessible for the system?

The only way to "to pretend as if I had physically removed" a disk is to disconnect it:

Power down your system
Open your system, wearing a grounded anti-static strap.
Physically remove the Power cable from the disk. Be very careful, and remember how to replace the cable. Removing the Data cable is not needed. Leave the disk in place.
Put your system back together.

If the disk is powered, and physically connected to the bus, it MUST be visible to the BIOS, and, when it is booted, Ubuntu. Otherwise, you would complain "Ubuntu cannot see my disk!".


rsync from local folder to mounted nfs share causes permission denied errors and nothing is copied

One of the "security" measures in NFS is rootsquash being a default option. With rootsquash, root on a client system has the same privileges as the nobody user (or some other assigned, impotent, account depending on the exact configuration). Accordingly, using sudo on NFS actually weakens your access privileges. So, don't use sudo on NFS. Set your permissions properly.


Correct password fails to login (login loop) in Ubuntu 16.04

OK! I figured out what my problem is and now I can login!!! Here how I solved it:

Press Ctrl+Alt+F3 to enter terminal then login with your username and password.

Firstly, run nano ~/bash_history. This will show you the commands you used before. (Notice that the command at the top of the list is the oldest one). Then, look at your commands line by line, try to figure out which one can cause this problem. Pass unimportant commands like cd or cat. Try to focus on commands that makes effect on your system or environment. If you find anything, undo what you did.

In my case, it was sudo nano etc/environment command. When I inspected that file, there wasn't even any typo. But still, I removed all the lines
that I added before to revert my changes. Now it includes only $PATH variable which is:
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"

Then I ran source etc/environment. After that I was able to login!

P.S: Never edit your etc/environment file. Instead use export command to set an environment variable. Besides, check if there is a typo in your ~/.profile and ~/.bash_profile files, as well.


Blank screen after TV turns off in Xubuntu 15.10

Ok I have found a "dirty" work around for this.

When having black screen do:

xrandr --output HDMI-0 --mode 1920x1080 --pos 0x0 --rotate normal --output VGA-0 --off

HDMI-0 = the output where your TV is connected
1920x1080 = The mode you want to have (desktop resolution)
VGA-0 = other outputs which should be disconnected

To find your output name and supported modes do:

xrandr --current

This will give you a list of disconnected and connected outputs and their supported modes (for those who are connected).

But this is just a work around, not a solution in my optinion


Wine + PlayOnLinux + SelfExtractingArchive.exe

I have tested two exe-files with File Roller and Engrampa (fork of file-roller). They were extracted normally. All we need is to have p7zip-full package installed (as @karel already noted).

The file utility reports that they have two file-types:

PE32 executable (GUI) Intel 80386, for MS Windows, Nullsoft Installer self-extracting archive
PE32 executable (GUI) Intel 80386, for MS Windows (for example 7-Zip and WinRAR from Windows create such files when SFX ZIP or SFX RAR was chosen).

Note: the SFX RAR archive could not be opened with this method on Ubuntu 16.04 LTS. You can use Wine for this purpose here.


How do I get my network drivers working?

Instead of doing the manual compile and install, install the package linux-generic-lts-quantal. This will activate the LTS Enablement Stack, which will upgrade the Linux kernel in your 12.04 LTS to the version in Quantal (12.10). That kernel (3.5.0) has built-in support for the drivers you need.

You will find the package linux-generic-lts-quantal in your package manager, or from a command shell do:

sudo apt-get update
sudo apt-get install linux-generic-lts-quantal

You will find some background info on this solution in my reponse to this question.


Nvidia GT 710 overscan issue w/ Ubuntu 16.04

I was able to get it working with the new nVidia Settings GUI


How to display all windows names in the Gnome overview screen without mouse over - Ubtuntu 20.04.1

Try the Gnome Shell extension Always Show Titles In Overview by 5q0Fw.


unattended-upgrades stopped updating on Dec 17 2020

Nothing is wrong with your systems, at least that is causing this.
Updates have resumed as of 1/4/21. If you do not receive any updates in the next day or so, please report back.
There haven't been any updates since then to the 18.04 repositories.  I suspect they're taking the last two weeks of the year off.  I got a google-chrome-unstable update on the 18th, but that is from a PPA.
The "stuff downloaded" is the index files that your systems use to determine if there have been updates or not.

Source: Ubuntu Updates


What are the names of the icons that LightDM uses?

Turns out that this was a simple matter of giving the wrong permissions to my icon set. There was nothing wrong with my theme, it just couldn't be read. Odds are, if you're modifying an existing icon theme, it has all the required icons. Permissions just need to be set as 755 for directories, and 644 for files.

Lesson from this: Always check permissions!!


It's because the Java Console is hidden by default.

To change this:

First start the Java Control Panel.

From the command line run: ControlPanel (if not in PATH, you may have to run something like /usr/lib/jvm/jre1.7.0_51/bin/ControlPanel )

Or, choose from the Dash like the screenshot below

In the Java Control Panel go to the Advanced Tab, expand Java Console and choose Show Console. Screenshot below:

Now the console will pop up whenever you execute ANY Java Applet.

Fix INFO from this bug.


What is the root cause of ppa, source list errors because I keep getting them?

Simply put, it it ain't broke, you cannot fix it...

That said, sometimes there are issues with the way that packages add their sources to the apt source list. Opera has a bug where it is added with the https// rather than https:// and apart from inspecting the entries when you notice them added, there is no way but the error to know that something went wrong. It is not your doing so much, but it IS up to you to fix it if you do not want to get the error (do not wait for someone else to fix or you might be waiting a while).

Now, if you have a specific error message which is troubling you, then you can post the output and someone can help with that. Otherwise, as Byte Commander said, we would be shooting in the dark to give you a list of all possible things which could go wrong.


Module imap.ini missing PHP Ubuntu 16.04

You have not installed the php-imap package correctly.

Prior installing, ensure that your system is upgraded and all dependencies are resolved:

sudo apt-get update
sudo apt-get -f install
sudo apt-get dist-upgrade

Run the following commands to install and enable it for Ubuntu 16.04 or later:

sudo apt-get install php-imap
sudo phpenmod imap

To install and enable it for Ubuntu 14.04:

sudo apt-get install php5-imap
sudo php5enmod imap


Cannot get rid of nvidia drivers, restore nouveau driver and get desktop working

Had the same problem.

sudo apt-get install --reinstall xserver-xorg-core libgl1-mesa-glx

This actually fixed it. Ubuntu 13.10 x64 + nVidia 740M. Thank you very much!

You did not mention your GPU. If you've had that problem on a laptop, I'd suggest its because of the so-called "Fusion" system (which uses your integrated GPU in lieu of discrete one when you don't need it).


For the cases about Ubuntu 11.04 and up here are some of the steps to find out what is wrong. We will assume the following:

You are using a wired connection (Not wirelessly. This will avoid other problems).
You have already tested the connection using, either another Distro, an older version of Ubuntu or Windows. When testing the speed it was much better than when using Ubuntu 11.04+. So we assume that the problem is ONLY on Ubuntu 11.04+. If the problem is the same in Windows or with another Os/Distro then this is not an Ubuntu problem so much as a network problem. Maybe your ISP, Router, ADSL connection, etc..
You installed the default Ubuntu using the LiveCD and not Wubi from inside Windows. There has been several cases where installing Ubuntu via Wubi somehow slowed the network speed. I can only confirm for myself 1 case but I have heard of several. So I will assume you have installed Ubuntu using the LiveCD (Does not matter if you are sharing the hard drive with another distro or with Windows, the important part here is installing Ubuntu using the LiveCD).
You have updated your Ubuntu version to the latest. I recommend activating the multiverse, universe and restricted repos and also activate the proposed and backports updates. All of which can be done using the software sources.
Optional - You have installed Ubuntu from Scratch and not updated from an older version. In the past i have trouble after upgrading from a previous one. Do not know right now but this is "just in case".
You have already rebooted the PC at least once after installing ALL the updates.
You do not have a Firewall that limits anything. Just in case you have a pro-windows firewall device.

So now we can begin...

In each case I will give an answer that works for some but not for others. If one works, do not test the rest. We will also open several files with the terminal tool NANO. After editing or changing anything with it, to exit and save just press CTRL+X and then press Y. That should quit nano and tell it to save the file.

The IPv6 Issue

There has been some issues with having IPv6 for some users. For this let us go step by step with this:

Check to see if IPv6 is ENABLED - Type the following in a terminal: lsmod | grep ipv6. If you see anything mentioning IPv6, then you have it enabled. If not then you can proceed with the next issue mentioned.
Disable IPv6 - There are several ways to accomplish this (Do only one):

2.1 - Edit the file sudo nano /etc/sysctl.conf and add the following lines at the end of the file:

net.ipv6.conf.all.accept_ra = 0
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

Save and reboot.

2.2 - Edit the file sudo nano /etc/default/grub and find the line that says GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" and add to it ipv6.disable=1.
It should look like this afterwards: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash ipv6.disable=1". Save it and type sudo update-grub. After this reboot the PC.

2.3 - Edit the file sudo nano /etc/modprobe.d/blacklist.conf and at the end add the line: blacklist ipv6. Save and reboot.

2.4 - Via the GUI version of NetworkManager in the Upper Panel (The network icon that appears when you install Ubuntu in the upper right corner next to the volume icon) select the network icon and select Edit Settings. Select the network connection you are using and in the IPv6 Settings select Ignore. This option can be mixed with the 3 previous mentioned above.

Configuration Issue

In some cases it may be some misconfiguration gone wild. Try this:

1.1 - Type ifconfig and look for the txqueuelen option. Normally it says 1000. Lower it to 500, 200, 100 or 50 just to test if it gets better: sudo ifconfig eth0 txqueuelen 50. In this case we have set txqueuelen to 50. To go back to 1000 just change the 50 to 1000.

1.2 - Edit the file /etc/sysctl.conf and add at the end: net.ipv4.tcp_window_scaling=0 to the file. Save and reboot.

Network Card Issues

In some cases the actual network card is the problem. Maybe a confusion between the drivers and the NIC or the actual NIC. In any case here are some examples depending on the network card:

1. Realtek 8166 - Slow wired internet connection on Realtek RTL8168-8111 (Rev 6)

2. Broadcom BCM5721 - Slow Internet connection with 11.04

3. e1000e 82579V - Ubuntu 11.04 and slow internet experience

Askubuntu Issues

If all else fails Askubuntu has an exaggerating amount of info about "Slow Internet". Mose cases are 11.04 and 11.10. All of which you can see here: https://askubuntu.com/search?q=slow+internet


connect to VM Ubuntu from win cmd on the same machine

You should try out Vagrant, simply download Vagrant and Virtualbox and you can then spin up an Ubuntu VM with no GUI in 4 simple steps:

mkdir ubuntu-vm
cd ubuntu-vm
vagrant init ubuntu/trusty64 # Create the Vagrantfile and specify the image to use in one command
vagrant up && vagrant ssh # Start up the VM and connect to it via SSH

Obviously remove the comments I put in from #


Can't run Vidalia due to an AppArmor policy error

I tried it:

sudo ln -s /etc/apparmor.d/usr.bin.vidalia /etc/apparmor.d/disable/
sudo apparmor_parser -R /etc/apparmor.d/usr.bin.vidalia
sudo /etc/init.d/tor start

Ok , now vidalia works fine:

$ vidalia


Ubuntu 20.04 lags when extensions using GLib spawn command with pgrep

pgrep in Ubuntu 20.04 is extremely slow. The run time is linear to your stack limit (ulimit -S -s to check), it can easily reach 30 sec even on fast machines. If you have no stack limit, any pgrep call will fail:

cannot allocate 4611686018427387903 bytes

Bug reports are open for Ubuntu (Debian, Archlinux), but see no traffic. Please consider marking that you are affected too: https://bugs.launchpad.net/ubuntu/+source/procps/+bug/1874824

The bug is fixed in procps, but distributions are not picking it up ...


oracle-jdk9-installer fails with HTTP 404

Alternative, what worked for me was using SDKMAN to install, assuming you have SDKMAN installed it's as simple as:

sdk install java

At the time for me it installed java 9.0.0-zulu


What's the right terminology for Unity's UI elements?

Ubuntu 11.04

Launcher
Launcher Items
Workspace Switcher

Menu Bar:
Window Title
Application Menus
Status Menus (Indicators)

Network Menu
Sound Menu
Messaging Menu
Clock
Me Menu
Session Menu

And others

This region also contains the Notification Area, disabled by default.
Window Decoration
Window Buttons
Toolbar
Status Bar
Desktop
Ubuntu Button (Home Button or BFB, "Big Freakin' Button")
Dash
Run Command (Alt+F2)


Maybe the GPG-key is not there (anymore).
If you want to install CFEngine Community Linux Packages:
from(http://cfengine.com/cfengine-linux-distros)
exerpt:
CFEngine 3 Linux Distributions:
Download and install the CFEngine GPG key(changed # to sudo because of formating):

sudo wget http://cfengine.com/pub/gpg.key
sudo apt-key add gpg.key
sudo rm gpg.key

Add the repository to the apt list of sources. If the add-apt-repository utility is installed on your system, you may simply run:

sudo add-apt-repository http://cfengine.com/pub/apt

... follow instructions on the website.


Sure just reverse it:

mv ~/a/b/c/typoedFolder ~/a/b/c/myFile.py

The files has only changed its name. So you're fine in this case to simply rename it back.


How exactly do files get opened from Nautilus?

There are two directories that contain .desctop files: /usr/share/applications/ (global list for all users) and ~/.local/share/applications/ (for a particular user). Both directories contain a list of file type associations (defaults.list and mimeapps.list correspondingly).

When you click a file, Nautilus finds the appropriate .desctop file and launches your program. Each .desctop file contains the Exec key which specifies the command line (the program and its parameters). See this document for details on the Exec key.

If a .desctop file specifies a program without the full path, it will be looked up on your $PATH. In a default installation, $PATH usually includes the following directories: /usr/local/sbin, /usr/local/bin, /usr/sbin, /usr/bin, /sbin, /bin.


Unable to find a medium containing a live file system on second boot

Okay I found the error, Since I partitioned the pen drive into two equal parts somewhat around 3850 MB each in windows but space calculations on Linux are done differently so, when I repartitioned the pen drive this time into 4-equal parts the bootable pen drive worked just fine.


No clue on the graphics but using the mediainfo program on the command line would do what you want. Use it in a bash script and you could process ever file you have in a loop outputting to a file of your choosing for importation into some kind of spreadsheet program, that can give you what you wish with charts and things like this in OpenOffice or whatever it is called now. I used this idea to build myself a website with all my files once upon a time, run the script and it produced the entire thing for me.
zeus@zeus-H370M:~$ mediainfo 38_Special-Rockin_Into_The_Night-01-Rockin_Into_The_Night.m4a | grep Track
Track name                               : Rockin' Into The Night
Track name/Position                      : 1


What is the best AntiVirus application available for non-technical users?

avast! Linux Home Edition ofc! Simple the best interface and virus detection available for a home user.

But, I have to agree on the comments, if you are not running a server an AV is a bit overkill for linux. On servers were files are hosted for users, using different operative systems, etc and AV can detect and eliminate virus for the user, for home linux installations? Not really something you need a lot.

Don't forget that most these AV for home users are not licensed for server use or even organizations so be careful with that.


Strange symbols shown in terminal, font missing

In the terminal emulator profile settings, either check the box Use the system fixed width font (red highlight), or select a font, that is currently installed on your system, through the button underneath (green highlight). Close and re-open the terminal emulator.

I'm not entirely sure, whether this is the (only) reason for the broken font glyphs, but the selection of a non-installed font most likely causes some problem down the road.


Is there any way a can buy on iTunes Store?

Unless Apple release a web-based version, the only method is to use Itunes. I discuss methods of using itunes in another question: Run iTunes without virtualizing Windows?

Wine currently doesn't deliver that awesome an experience and given you only want to buy one album, VirtualBox might take too much time to bother with for just one album.

You might have the best luck just writing directly to the artist and explaining your woe. Let them know what you're happy to pay and see if they can sell you a CD directly. It might prompt them to add their music to more than one online store.


How to use sed with file path variables AND regex callbacks AND arithmetic expressions

sed and arithmetic do not mix.  The right tool for jobs like this is awk.

Consider this test file:

$ cat test.txt
/nonmatching/line 1
/home/username/Pictures/properties/wallpaper/span/tree.jpg 2
/another/non/matching/line 5

We can increment the number of the line that you want with:

$ line="/home/username/Pictures/properties/wallpaper/span/tree.jpg"
$ awk -v f="$line" '$0~f {$NF++} 1' test.txt
/nonmatching/line 1
/home/username/Pictures/properties/wallpaper/span/tree.jpg 3
/another/non/matching/line 5

As you can see, this incremented the number on the line that matched $line.

One limitation is that this code, as written, will not preserve multiple blanks on lines for which the number is incremented.  If whitespace is important, we would need more definition of the input format.

How it works

-v f="$line"

This assigns the value of the shell variable line to the awk variable f.
$0~f {$NF++}

Here, $0~f is a condition.  It is true if the input line, denoted $0, matches the regex f as defined above.  If it matches, then the statement $NF++ is executed.  This increments the last field on the line which, for your input, is the number.
1

This is awk's cryptic shorthand for print-the-line.

Editing a file in-place with awk

If you have a modern GNU awk, you can edit the file in place with:

gawk -i inplace -v f="$line" '$0~f {$NF++} 1' test.txt

With other awks, use:

awk -v f="$line" '$0~f {$NF++} 1' test.txt > tmp.txt && mv -f tmp.txt test.txt

Creating text.txt if it doesn't exist

In the case that the file test.txt is does not contain a line matching $line, this version will such a line with 1 as the count:

gawk -i inplace -v f="$line" '$0~f {n=1; $NF++} 1; END{if(!n) print f,1>>FILENAME}' test.txt

This code adds a variable n.  If $line is in the file, n is set to 1.  If it isn't, n stays at the default value of 0.  At the END of the input file, the value of n is tested.  If n is still zero, the line is added.


The test suite is packaged separately, as package maxima-test:
$ apt show maxima-test
Package: maxima-test
Version: 5.43.2-3
Priority: optional
Section: universe/math
Source: maxima
Origin: Ubuntu
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Camm Maguire <camm@debian.org>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 1955 kB
Depends: maxima (>= 5.43.2-3), maxima-src (>= 5.43.2-3), maxima-share (>= 5.43.2-3), tex-common (>= 6.13)
Download-Size: 320 kB
APT-Sources: http://archive.ubuntu.com/ubuntu focal/universe amd64 Packages
Description: Computer algebra system -- test suite
 Maxima is a fully symbolic computation program.  It is full featured
 doing symbolic manipulation of polynomials, matrices, rational
 functions, integration, Todd-coxeter methods for finite group
 analysis, graphing, multiple precision floating point computation.
 It has a symbolic source level debugger for maxima code.  Maxima is
 based on the original Macsyma developed at MIT in the 1970s.  It is
 quite reliable, and has good garbage collection, and no memory leaks.
 It comes with hundreds of self tests.
 .
 This package contains a build integrity test suite.


No internet access when I'm connect to my company's VPN

First, look at the company's policy on VPN connections. What you're trying to do may be disallowed. If you have a VPN to the company, and use the internet to get subverted by a Black Hat, then the Black Hat has a VPN to the company with your identity. If you access the internet through the VPN and whatever else the company requires, if you get subverted, they bear some responsibility.

Take a look at the route you have when connected and not connected to the VPN, with netstat -rn. Read man route. Be aware - when you fiddle with routes, you can end up with nowhere to send packets, if you're not careful.


I finally uninstall MySQL completely, and reinstall it using these lines :

Remove all files related to MySQL

sudo apt-get purge mysql*

sudo apt-get autoremove

sudo apt-get autoclean

Then upgrade my distribution

sudo apt-get dist-upgrade

Then install MySQL

sudo apt-get install mysql-server

That's all.


Random patches on the screen after upgradeing to Ubuntu 20.04

This is what works for me:

Create /usr/share/X11/xorg.conf.d/20-intel.conf:

Section "Device"
  Identifier  "Intel Graphics"
  Driver      "intel"
  Option      "AccelMethod"  "uxa"
EndSection

Reboot

However, I found that the system is somewhat sluggish with above modification.

Much better results with:

Section "Device"
  Identifier  "Intel Graphics"
  Driver      "intel"
  Option      "DRI"  "3"
EndSection

One can experiment with values "FALSE", "1", "2", "3" for "DRI".
On my system, "2" gives the patches again, and glxgears won't run.


How to bind Ctrl+arrows to Home and End keys? xmodmap does not work

AutoKey can do bindings like this, but it requires running a service in the background (like ahk, but unlike xmodmap).

Configure a "phrase" where the text is <home>, the paste method is Keyboard, and the hotkey is <ctrl>-<left>:


How to launch bugzilla after installation?

You were so close to making it work :) the URL to visit after the installation is http://localhost/bugzilla3 :)

I tried it on a virtualbox instance and it does work flawlessly.

All the dependencies are installed automatically along with bugzilla (apache, mysql, perl modules) - as always happening when you use apt-get/synaptic/Software Center, that's the whole point of package management.

Post-install scripts create databases, it asks you for passwords for Mysql's root user and for bugzilla user. Even Apache is restarted with new configuration.

Absolutely no need to install everything manually, unless you're an experienced admin and have very specific requirements.


The only solution I found so far was rebooting as root in recovery mode and starting  networking service for it to download required packages and after all it's back to normal, but unfortunately 1.8.27 version


Ubuntu 15.04: Change KDE application's icons

So, I was looking for over an hour befor I decided to post here, and five minutes later I find a question. Well, I guess others can use it. Just launch this in a shell:

kcmshell4 icons


Any chance you're using a NVidia GPU? If yes, open nvidia-settings and try test between the 3 profiles.
I lose the blur (and usually all dialogs shading) when I try the "NVIDIA On-Demand" profile.
Later I realized this was happening because the NVidia drivers were not properly updated (I was facing an apt divert error like described on this answer.


How do I file a bug on a PPA upstream with the maintainers using Launchpad?

Launchpad doesn't have the facility to host bug trackers for PPAs, except in informal ways (some PPAs have an associated project for the purpose of bug reporting).  If you aren't told otherwise, the only thing you can do is contact the owner of the PPA directly.


How to make Ubuntu remember forever the password after the first time

There is also the sudo configuration file, where you can allow applications to be started without password-query. How to use it, is described here: http://www.gratisoft.us/sudo/man/1.8.0/sudoers.man.html

Warning: Though very unlikely, messing with sudoers configuration could lock you out of your system or open doors for others. Always double check and be sure of what you're doing.

As a safety precaution you can open a root shell and keep it open until you have tested your changes. Open a shell and type sudo su, you will be asked for your password. Your shell is now a root shell. Also you can make a backup of your /etc/sudoers file to be able revert changes.

The basic use is you edit it by invoking visudo in shell:

sudo select-editor # this is optional. it will allow you to select your default editor in shell
sudo visudo

The latter of wich will open your shell default editor with the file. Normal syntax is:

username machine=(usernameToRunCommandAs) command1,command2,...

as in:

confus confusion=(root) NOPASSWD:/sbin/halt,/sbin/reboot/usr/sbin/synaptic   #allows user confus to run "sudo synaptic" as root on confusion without password querry
confus ALL=(ALL) NOPASSWD:/sbin/halt,/sbin/reboot #allows confus to shutdown and reboot as all users on all machines without pw

As the $PATH variable is user dependent and sudo is not, the full path to the command is needed in sodoers list (note it says '/sbin/halt' not just 'halt'). You can find out the full path using the whereis command - as in whereis halt which will most likely return '/sbin/halt'.

Generelly speaking that's bad practise. You are asked for a reason. Installing software with synaptic ist potentially harmfull. As is tempering with partitions which can lead to an unbootable system and massive data loss. It also makes a hackers job much easier. But you're free to do it on your own risk.


This solution was helpful for me: https://bugs.launchpad.net/ubuntu/+source/cheese/+bug/838739/comments/16

sudo add-apt-repository ppa:libv4l
sudo apt-get update
sudo apt-get install libv4l-0 libv4l-dev

  In my case it solved all my problems (cheese, gst-launch-0.10) except
  one. Since I'm running a 64 bits system, I keep having a problem with
  Skype, even after updating the i386 libraries (sudo apt-get install
  libv4l-0:i386). However, with the help of v4l2ucp you can change the
  saturation pattern and get a much more reasonable output.


Dual-boot Windows 7 and Ubuntu on two SSDs with UEFI

Your problem may be related to UEFI. Follow the procedure of the 1st paragraph of the UEFI Community Documentation: https://help.ubuntu.com/community/UEFI


Should I run "dpkg -i" after running "apt-get install -f" in case of unmet dependencies?

No. apt-get install -f, if it succeeded in installing dependencies, will run all remaining steps left in the installation of the new package (and any other pending installations). dpkg -i will just be repeating that work. If apt-get failed, then running dpkg -i isn't going to do anything useful.

Note that you shouldn't have to do this if you have the Ubuntu Software Center installed. It can handle deb files and install dependencies as needed.


How to Install AMD graphics in ubuntu 13.10 in HP probook 440G1 with haswell integrated

I got it working. In fact I had to wait.after logging in It takes upto 2 minutes to load the unity desktop, till then it is black screen with pointer.
ia32-libs is not required for Ubuntu 13.10 and the open source drivers don't detect the 8750M hardware.(not yet). So, downloading the driver binary and installing as mentioned in the post above worked.


how to adjust window decoration *and* font size settings in xenial

Objects of your interface are too big because your resolution is too low. You've got large 30'' monitor and only 1920x1200 resolution (as I can see on your screenshot).

Open the "Resolution" dropdown menu - it should contain 2560x1600 setting (which has the same size ratio as your current one, i.e. 16:10). Select it and press "Apply". If the dropdown menu line with 2560x1600 is not the last, and your monitor is able to sustain even greater resolution, use it.

And then, when your resolution will fit the native resolution of your monitor, you can use the advice you've mentioned in your question to adjust the DPI of your monitor properly.

Different GUI aspire to achieve resolution independence. This will ensure that all interface elements will look the same and have the same size on different device types be it phone, tablet or PC monitor. If you check the mentioned link, you'll see that GNOME isn't resolution independent yet. 1920x1200 fits well the 22-23'' monitor. If you use it on 15'' screen, all objects will be too small and you'll need to increase font size to get improved readability. In your case the screen is 7'' bigger than the proper one for this resolution, that's why you've got an opposite problem - everything looks too big.

If you wish to alter your font sizes, this may also decrease the sizes of your interface objects. Use GSettings configuration tool to achieve that. Run this command in your terminal:

gsettings list-recursively | grep desktop | grep font

In my case it returns:

org.gnome.desktop.wm.preferences titlebar-font 'Ubuntu Bold 10'
org.gnome.desktop.wm.preferences titlebar-uses-system-font false
org.gnome.desktop.interface document-font-name 'Ubuntu 10'
org.gnome.desktop.interface font-name 'Ubuntu 10'
org.gnome.desktop.interface monospace-font-name 'Liberation Mono 10'
org.gnome.nautilus.desktop font 'Ubuntu 10'

First key affects the window titlebar, third key sets Document font name/size, fourth key sets Font name/size which affects all interface elements (i.e. menus, panels, etc.), fifth key sets Monospace font/name which is used in your terminal. And the sixth setting affects the name/size of the font of your desktop icons (if any).

So, if I wish to decrease, say, the size of the font used on the panels by one (in my case 'Ubuntu 10' will become 'Ubuntu 9'), then I should run the command:

gsettings set org.gnome.desktop.interface font-name 'Ubuntu 9'

Adjust the sizes of your fonts as you see fit, selecting the proper schemes and keys with GSettings. If you prefer GUI tools, you can try Unity Tweak Tool, which can be found here.


None of the nvidia drivers works on ubuntu 4.15 18.04

Do you use Secure Boot? If so it might prevent the Nvidia drivers to load. You can try disabling it in the boot menu.

You could try the nouveau.modeset boot option as well, just press 'e' while in grub-menu and add nouveau.modeset=0 after the line which starts with "linux" then press f10.


Are ubuntu 20.10 packages compatible with ubuntu 20.04

No, most are not re-usable in other release.
The odd package has no conflicts, for example wallpaper packages have no dependencies that will create issues with other systems, but most packages contain more complex things inside than just wallpapers.
If you look at the requirements of gnome-shell
https://packages.ubuntu.com/groovy-updates/gnome-shell
compared with
https://packages.ubuntu.com/focal-updates/gnome-shell
You'll note many rules are the same, but that doesn't apply to all. You've have to check all rules for all dependencies... which is why wallpaper package examples are easy (they have minimal to no dependencies usually, eg. https://packages.ubuntu.com/groovy/ubuntu-wallpapers).


18.04 - Cannot change the background color of the LOCK screen, not the Login screen

Edit the file /usr/share/xsessions/ubuntu-communitheme-snap.desktop and change the "ubuntu-communitheme" text to "myct" (change anything, not necessarily "myct") in the line starting with Exec=

sudo -H gedit /usr/share/xsessions/ubuntu-communitheme-snap.desktop

[Desktop Entry]
Name=Ubuntu with communitheme snap
Comment=This session logs you into Ubuntu
Exec=env GNOME_SHELL_SESSION_MODE=myct /snap/communitheme/current/session
TryExec=/snap/communitheme/current/session
Type=Application
DesktopNames=communitheme:ubuntu:GNOME
X-Ubuntu-Gettext-Domain=gnome-session-3.0

create a file named myct.json in the directory /usr/share/gnome-shell/modes/ with below content.

{
    "parentMode": "user",
    "stylesheetName": "myct.css",
    "enabledExtensions": ["ubuntu-dock@ubuntu.com", "ubuntu-appindicators@ubuntu.com"]
}

Create a text file named myct.css in the directory /usr/share/gnome-shell/theme/

sudo touch /usr/share/gnome-shell/theme/myct.css

Open the file and paste the below content

sudo -H gedit /usr/share/gnome-shell/theme/myct.css

Content:

@import url("/snap/communitheme/current/share/gnome-shell/theme/Communitheme/gnome-shell.css");

#lockDialogGroup {
  background-color: magenta; }

Reboot and then lock the screen to see your preferred color.


How to clear old update installation files?

There is a program called Ubuntu Tweak [1,2].  It allows you to clear those files.  The "janitor" function is the one you need.

A note, even though it says that it only have the download for 11.04, you can still download it for the later versions of Ubuntu.  It still works.  You can also get the PPA for updates.

Select "Apt Cache" "Old Kernel" "Package Configs" and "Uneeded Packages to clean these for free space.  "Old Kernel" one clears the boot since these sit in that partition.  You can also select the others to gain more space.

[1]http://ubuntu-tweak.com/

[2]https://launchpad.net/ubuntu-tweak


How to treat supposed chkrootkit false positive

You can verify your packages (somewhat) with debsums

sudo apt install debsums

Then

sudo debsums

By default it skips config files, to include them

sudo debsums -a

To show only errors use the -s flag

sudo debsums -as

For details and additional options see man debsums

http://manpages.ubuntu.com/manpages/zesty/en/man1/debsums.1.html

If  you  are  looking  for  an integrity checker that can run from safe
       media, do integrity checks on checksum  databases  and  can  be  easily
       configured  to  run periodically to warn the admin of changes see other
       tools such as: aide, integrit, samhain, or tripwire.

Those tools (aide, integrit, samhain, or tripwire) should be installed / initialized on a fresh install / known good system and preferably run from a live media as come cracking tools can defeat these tools on a cracked system.


How to connect to Ubuntu Server 16.04 from Chrome Browser?

The default Ubuntu GNOME torrent client - Transmission - already provides the functionally you want but not enabled by default.

In order to enable it open Edit > Preferences > Remote

and select the options as pictured above. Authentication is optional.

After this you'll be able to connect to its web interface, from Google Chrome or any other web browser, by typing IP_ADDRESS:9091 where IP_ADDRESS is the "torrenting servers"' IP address. If you changed the default port (9091) then also change the above accordingly.


Ununtu is not booting, I have ubuntu installed in my laptop and then I installed windows 8.1 after it

Check your boot order in BIOS (usually by hitting F1 or F2, check here) and make sure that the ubuntu boot manager is the first device under boot priority or boot order, and make sure that the other drive is recognized under that same tab. Once you have those in order save your bios and restart, it should bring up the usual boot manager page.

It would be helpful to know the make of your laptop to be more specific.


For wired / wireless adapters

ifconfig |grep HWaddr

For bluetooth adapters:

hciconfig


Why is wireless to wireless transfer so slow?

The 54Mbps is the upper bound, and in that 54Mbps, a percentage is overhead even with no other devices.

Full duplex wired networks can also have all devices connected to a router communicating at once...on a wireless network, only one device can talk at a time, and the way they do it is by checking to see if there is anything else signalling, and if so, they wait for a random length of time before trying again.

So with your laptop and an access point, that is already two devices sharing the bandwidth. Anything else on that frequency, or even near it, and you will get increased retries, collisions etc.

Even turning your microwave on may affect it, depending on just how good the shielding is.

You also should realise that bps is not the same as B/s - a Byte is 8 bits, so 300KB/s is 2.4MB/s of data, plus a few hunderd K of overhead - so it isn't quite as bad as you think:-)


Need help with IP Tables rule to filter by Hex

According to the string section of the iptables-extensions manual page, there are two options for controlling which part of a packet the pattern is tested against:

   --from offset
          Set the offset from which it starts looking for any matching. If
          not passed, default is 0.

   --to offset
          Set the offset up to which should be scanned. That is, byte off‐
          set-1 (counting from 0) is the last one that is scanned.  If not
          passed, default is the packet size.

Have you tried --to 2 argument, which supposedly should limit matching range length to that value?


For those looking in the future for this same problem as Pastie doesn't help any at all! :)

The answer was hinted on by SirCharlo. By looking through the code I found that Pastie uses a clipboard history file in XML, the code for this is in the main Pastie file and protector.py.

Running a find in my home directory I found that Pastie stores this history file in ~/.local/share/pastie, it's called clipboard_history.

Basically something that was copied in the past had a character that Python didn't like or wasn't escaped right by the software code. So it was choking on that line of XML in the history file.

So just go to that directory and erase the file completely and restart pastie, works like a charm.  If your using an older version of Pastie the file is located at ~/.clipboard_history


Slow boot time on fresh minimal install of 18.04

As answered in this similar question, it may be possible to workaround/resolve this issue by passing the noresume option to the kernel.
To update GRUB so that it passes this option to the kernel automatically on boot:

edit the /etc/default/grub file so that the string noresume is included in the GRUB_CMDLINE_LINUX_DEFAULT variable:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash noresume"

run this command to update grub: sudo update-grub

reboot the computer


Ubuntu 14.04 does not detect my WiFi SSID

Switch to a lower channel. Since channels above 11 are illegal in some countries, not all the drivers support them.


What is the way to update to the next kernel?

You're asking if you install an updated mainline kernel today, will this be replaced in future by official kernel if there is a release with kernel version greater than this mainline kernel?

The answer is NO. Because each kernel is packaged independently and kernel's version number is part of the package name. That is why you can run multiple kernels in the same system. So, when I install kernel-3.23, It won't be replaced when kernel-3.24 is available in update path. I have to manually install the later/updated one.

But Ubuntu partially handles this problem by using an empty linux-image-generic package. This package's description says

  This package will always depend on the latest generic kernel image
   available.

So, when you update this package, this will bring newer 3-24 kernel in my system. But the older one will still be there. And those will accumulate until you removed them manually. That's why so many people have insufficient space problem in /boot.

This is true only for Ubuntu maintained generic kernel only. Mainline kernels don't even have this kind of upgrade mechanism. So, You're the person responsible for maintaining the versions.


Global application menus implemented for LibreOffice in stable release?

It's available but not by default, you need to install this package:

sudo apt-get install lo-menubar


Problems after dual booting Ubuntu and Windows 10

You need to change where the boot loader is in your BIOS settings. This will be different based on the machine, but generally there will be a "Boot Options" tab or menu in the BIOS settings, and in there you can specify the boot device or boot device order - specify the boot partition (or UEFI image) of your Ubuntu installation or whatever drive/partition GRUB is installed on.


GPG error: The following signatures couldn't be verified because the public key is not available

Run the following in your terminal,

 sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3C962022012520A0
 sudo apt-get update

References: How do I fix the GPG error "NO_PUBKEY"?

You need to replace the key (3C962022...) with the one that is displayed in the error message in the terminal.


Change Ubuntu Server 14.04 Screen Resolution

1. Get supported video mode info
(to achieve this, I had to install hwinfo)

>sudo apt-get install hwinfo

Then check supported modes (I was interested in setting the resolution to 1280x1024 and set the highest color depth available, so I'm going to check this.)

    sudo hwinfo --framebuffer |grep 1280x1024

The best available mode was shown like this

    > Mode 0x031b: 1280x1024 (+3840), 24 bits
    > Mode 0x0345: 1280x1024 (+5120), 24 bits

Strange as it is, 0x0345 worked from the above two modes only.

2. Edit /etc/default/grub

    sudo nano /etc/default/grub

Uncomment #GRUB_GFXMODE="some value", and change it to your resolution, also add GRUB_GFXPAYLOAD_LINUX line, like in the example below. Also modify GRUB_CMDLINE_LINUX_DEFAULT to reflect the video mode chosen.

    GRUB_CMDLINE_LINUX_DEFAULT="video=0x0345"
    GRUB_GFXMODE=1280x1024x24
    GRUB_GFXPAYLOAD_LINUX=1280x1024x24

Save the changes you have done.

3. Update grub

    sudo update-grub

4. Reboot:

    sudo reboot

If all went smooth, Ubuntu will boot in the resolution you set, for me 1280x1024x24 was fine.

Finally I managed to refine this solution, it's not partial any more.

If connecting with putty, cygwin,  you will not experience this issue and the settings above will not change your terminal experience.


Cannot get to BIOS to Install New Lubuntu over Xubuntu on Microsoft Surface Pro 1st Gen 128GB

Google says these are the steps to access the bios on a surface pro

Make sure the Surface Pro device is turned off.
Hold the volume-up button.
Press and release the power button.
When the Surface logo appears, release the volume-up button.


where does gnome-display-properties save the different configurations?

Adding to htorque's answer and converting JohanSJA's comment to an answer:

  Where is this information saved?

In ~/.config/monitors.xml.


Orange Nura phone not recognized on ubuntu 14.04

Okay at the begining it was not an ubuntu issue but it became one :
First You have to enable MTP in the storage setting when the phone is connected with USB cable :

Storage > Options > USB connexion

But ubuntu still can't recognize the phone as a MTP device.

I edited the /lib/udev/rules.d/69-libmtp.rules and saw that there was not the idVendor 1bbb with product af00. So I added the line :

# Nura phone
ATTR{idVendor}=="1bbb", ATTR{idProduct}=="af00", SYMLINK+="libmtp-%k", MODE="660", GROUP="audio", ENV{ID_MTP_DEVICE}="1", ENV{ID_MEDIA_PLAYER}="1"

Then ubuntu sees the phone. Note that there is still the automatic mount of a USB driver directory but when you close it, the android phone is mounted normally.


Dual-boot OSx (El Capitan) and Ubuntu 16.04 doesn't work after updates Ubuntu

Chances are the update (re-)installed GRUB, which has overridden rEFInd. This issue is covered in the rEFInd documentation, on the page entitled "Keeping rEFInd Booting." That page covers several recovery options. Since you don't say to what (if any) OS you can boot right now, I can't be more precise in my answer here. If the system isn't booting at all, then I recommend you download the USB flash drive or CD-R image of rEFInd from its downloads page, prepare that boot medium, and use it to boot to OS X or Ubuntu to fix the problem. Alternatively, you may be able to boot into OS X by holding down the Option (or Alt) key while you power on the system, from where you can fix the problem.


https://bugs.kde.org/show_bug.cgi?id=411584
I've been having issues with night color the whole time I have been using Kubuntu 20.04 - I have been fully unable to change Night Color in the normal settings window since I very first set it up when I installed the OS. This is a documented bug that only occurs on some systems - KDE has repeatedly stated it is resolved as of Plasma 5.18 or 5.19 despite users still continuously complaining that it is still around.
Today though was the first time I also experienced the inability to manually turn it off using the taskbar control button when I signed in this morning.
You can edit night color settings in /home/yourusernamehere/.config/kwinrc. You can then apply changes in that file, including forcing it to be active or inactive, by restarting kwin using the terminal command:

kwin_x11 --replace & disown


where symbols there are and what they are saying?

As far as I know,

[ + ] means the service is running
[ - ] means the service is stopped
[ ? ] means the status of the service cannot be determined

I don't know exactly the circumstances in which a service's status cannot be determined, but in some cases it's because the service control has been moved from a traditional init script to an upstart job - in which case you can see its status using initctl instead e.g.

$ service --status-all 2>&1 | grep mysql
 [ ? ]  mysql

$ initctl status mysql
mysql start/running, process 1182

The equivalent to service --status-all for upstart jobs is initctl list


How to setup partitions on my boot disk with cloud-config?

To close that task I post here my answer:
Important to know is, that resize_rootfs has to be false
I also ended up using mbr instead of gpt only because I couldn't figure out how to evolve with gpt. Maybe someone could post that example too.

#cloud-config
resize_rootfs: false

disk_setup:
  /dev/sda:
    table_type: 'mbr'
    layout:
      - 25
      - 75
    overwrite: true

fs_setup:
  - label: root_fs
    filesystem: 'ext4'
    device: /dev/sda
    partition: sda1
    overwrite: true
  - label: data_disk
    filesystem: 'xfs'
    device: /dev/sda
    partition: sda2
    overwrite: true

# now we attach the settings
runcmd:
  - [ partx, --update, /dev/sda ]
  - [ mkfs.xfs, /dev/sda2 ]
  - [ partprobe ]
  - parted /dev/sda set 1 boot on p

mounts:
  - ["/dev/sda1", "/"]
  - ["/dev/sda2", "/data-disk"]


Does Ubuntu support the OpenBSD Crypto Framework?

Ubuntu definitely uses the Linux Crypto API (which is available for kernels from 2.6.4)

I think for OCF, you need to use the OCF-Linux port


Conditional file and directory installation in `.deb` Packages

In order to interactively ask questions during package installation you should use debconf. To dynamically create and manage configuration files (and files in /etc/init.d/ are considered configuration files) ucf can be used.

A tutorial, on how to use debconf, may be found here:
http://www.fifi.org/doc/debconf-doc/tutorial.html

Minimal example

debconf template

Put this in the file debian/templates. It contains the text that is shown to the user during installation. Just be sure to replace demo-pkg with you actually package name!

Template: demo-pkg/install-init.d
Type: boolean
Default: false
Description: Would you like to install a service for this package?
 Services are really cool! They allow stuff to be started in the
 background without you having to start them manually!!!

Package configuration script

This is where you ask the user (interactively) about the things you need to know. This script is special since, when installing more than one package, all of these files of all packages are run before dpkg begins the actual installation process. This means that, if more than one package wants to ask the user something, all questions are asked at the beginning of installation for all packages, instead of later on for each package individually.

Just put the following stuff into a file named debian/config and mark it as executable (remember to replace demo-pkg with the correct package name):

#!/bin/sh

# Make sure this script fails if any unexpected errors happen
set -e

# Load debconf library
. /usr/share/debconf/confmodule

# Should an init job be installed?
db_input high demo-pkg/install-init.d || true
db_go

# You can also act upon the user's answers using `db_get`
#db_get demo-pkg/install-init.d
#[ "${RET}" = "false"] && echo "I don't think that was a wise decision..."

Maintainer scripts (postinst, prerm and postrm)

Here we do the actual magic and dynamically add and remove the configuration file/init script. For this to work you have to install your init script as regular file along with your package (I assumed /usr/share/demo-pkg/init-service in this example).

The debian/postinst file (called after all files were extracted by dpkg):

#!/bin/sh

# Make sure this script fails if any unexpected errors happen
set -e

# Load debconf library
. /usr/share/debconf/confmodule

if [ "$1" = "configure" ];
then
    # Check if the user decided the enable the service using `db_get`
    db_get demo-pkg/install-init.d
    if [ "${RET}" != "false" ];
    then
        # Install init script using `ucf`
        ucf /usr/share/demo-pkg/init-service /etc/init.d/demo-service

        # Register init script as service
        update-rc.d demo-service defaults

        # Start service
        invoke-rc.d demo-service start
    fi
fi

The debian/prerm file (called before files are removed by dpkg or the package is upgraded to a newer version):

#!/bin/sh

# Make sure this script fails if any unexpected errors happen
set -e

# Load debconf library
. /usr/share/debconf/confmodule

# Check if the user decided the enable the service using `db_get`
db_get demo-pkg/install-init.d
if [ "${RET}" != "false" ];
then
    # Stop the service before upgrade or removal
    invoke-rc.d demo-service stop

    if [ "$1" = "remove" ] || [ "$1" = "deconfigure" ];
    then
        # Unregister service prior to removal
        update-rc.d -f demo-service remove
    fi
fi

The debian/postrm file (called after all files were removed by dpkg):

#!/bin/sh

# Make sure this script fails if any unexpected errors happen
set -e

if [ "$1" = "purge" ];
then
    # Remove service file using `ucf` (checking whether `ucf` is still available first)
    if type ucf >/dev/null 2>&1;
    then
        ucf --purge "/etc/init.d/demo-service"
    fi

    # Remove service file by hand (in case the above failed somehow)
    rm -f "/etc/init.d/demo-service"
fi

Final steps

Add a Pre-Depends: dependency on debconf in the file debian/control
Add a normal Depends: dependency on ucf in the file debian/control
Make sure the file /usr/share/demo-pkg/init-service (or whatever you call it) gets installed properly


what should next step?? to run apt-get update , in 16.04

The next step is to see if there are updated or new packages. There are a few ways to do this.

The apt-get command will upgrade packages, but doesn't tell you about new packages. It is also all or nothing, unless you already know which packages have updates. If there is a lot of packages to update, it is preferable to do upgrade first then dist-upgrade/full-upgrade in order to reduce the load on the package resolver and reduce the possibility of erroneously removing packages.

sudo apt-get upgrade #This updates packages that do not require updating others
sudo apt-get dist-upgrade #This updates all packages. apt-get full-upgrade is the same command
sudo apt-get install --only-upgrade <packagename> #This will upgrade a specific package

aptitude is a text based package manager. It will give a list of packages broken into categories. Security Updates, Upgradeable Packages, and New Packages will be at the top. This gives you the option to selectively upgrade packages. It uses the resolver to handle dependencies, and shows what it is going to do before you commit. If you don't already have it, the following command will install it.

sudo apt-get install aptitude

The GUI package manager. The package manager supplied with your desktop will usually filter by upgradeable packages and new packages.

No matter which method you use, it is recommend to apply all updates unless there is a specific reason not to; especially the security updates.


Brightness Control not working Acer Aspire e1-531 ubuntu 14.04

You need to install gedit first with:

sudo apt-get install gedit

Then you should be able to use:

sudo gedit /etc/default/grub

Ideally though, you should use gksudo or similar to run GUI stuff as root so bits of your home directory don't accidentally end up being owned by root. You can use a command line editor such as nano instead:

sudo nano /etc/default/grub

To use it simply edit stuff, then save with Ctrl+O and exit with  Ctrl+X. You may need to install it first with sudo apt-get install nano.

After any apply changes, you should be able them by running sudo update-grub and rebooting.


First, check your BIOS for a USB setting. It may have choices like "legacy", or "compatibility", or "USB 3 enable". Adjust as required.

Second, your BIOS is very old. You have version A3KT36AUS, from 2014.

The current BIOS is version A3KT68A, from Feb 25, 2020.

Note: Make sure to perform important data backups before flashing a new BIOS.

Note: Make sure that the web site covers your specific model D30. The BIOS update at the links given below covers D30 (type 4353, 4354).

Download the new version here, or here.


Failed to download package files. Check your internet connection

Try to install playonlinux package through apt-get

sudo apt-get install playonlinux

Sometimes Software center fails to detect the internet connection but terminal does.


Changing the target directory of command cd ~

Check your /etc/passwd file and change directory location for tensineer user but for this, you must have sudo privileges.

Hope this will work for you.


How can I find my Internet Service Provider (ISP) using a bash script?

You could use e.g. the services of ipinfo.io to determine your public IP including some additional information like the provider company name.

The site can be normally visited in your browser, but if you query it from the command-line with e.g. curl, they respond in a clean and well-defined JSON format so that you don't need to parse any HTML:

$ curl ipinfo.io
{
  "ip": "xxx.xxx.xxx.xxx",
  "hostname": "xxxxxxxxxxxxxxxxxxxxxxxxxxx.xx",
  "city": "xxxxxxxx",
  "region": "xxxxxxxxxx",
  "country": "xx",
  "loc": "xxx.xxxx,xxx.xxxx",
  "org": "xxxxxxxxxxxx",
  "postal": "xxxxx"
}

To only show one value, you can directly send a request to the respective path. E.g. for the ISP name (org), try this:

curl ipinfo.io/org

Inspired by this answer.


Why does ssh-key work on one server but not on another?

No supported authentication methods available: Server sent public key.

This says that server is able to use pubkey authentication, but you didn't provide any key. Make sure that the key is configured in the client.


How do I configure Apache to run multiple instances?

see https://serverfault.com/a/397236

alternatively, is it possible to solve your problem with different vhosts?