Run X11 GUI application from browser (apache - php)

There's an X server running on the same computer as PHP? If that's the case you could* run the PHP process as the same user as the owner of the X server (by editing /etc/apache2/apache2.conf) and then chain in the display identifier onto the command:

shell_exec("DISPLAY=:0 vlc ....");

You can also use putenv (IIRC) to set the environment variables from PHP.

*But consider the security ramifications of doing this before you do. If something PHP was running was compromised (happens all the time), what damage could that do?


How to change the position of docky notifications?

There is a tweaking tool just for this purpose. However, it seems to involve installing a different version of notify-osd. This is from the link above:

Install the patched (configurable) NotifyOSD in Ubuntu 11.10 or 11.04:
sudo add-apt-repository ppa:leolik/leolik
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install libnotify-bin
pkill notify-osd

Install NotifyOSD Config:
sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install notifyosdconfig


Package listed in .manifest is not installed with OS

The manifest says what's on the CD. Some things are removed after the install but I haven't found a reliable way to work out what they are short of downloading the ISO.

if you have the ISO in front of you, compare /casper/filesystem.manifest and /casper/filesystem-remove.manifest.

It's that second file that contains packages that are on the CD that are removed after installation, unless they have other dependencies — which some of those things do.


Bootproblems after second OS installation

Try booting a Ubuntu live CD and installing and running boot-repair.  Saved me from booting problems many times.  Hope this helps!

http://www.howtogeek.com/114884/how-to-repair-grub2-when-ubuntu-wont-boot/


Which is the default Python version supported in Ubuntu 15.04 and 15.10?

From the Ubuntu Package Index, the default version of:

Python 2 is 2.7.9 for both 15.04 and 15.10.
Python 3 is 3.4.3 for both 15.04 and 15.10.


Offline charging usb port doesn't work in ubuntu 14.04

This forum may help. It advises that you:

Look in the BIOS, as that is often the place it is controled and
Make sure that the device is plugged in before shutting down / putting to sleep.

Finally (and this is completely a workaound, you could buy one of these: UK and US


ImportError: cannot import name Eog, introspection typelib not found

I'm not sure, but it seems that path of Eog-3.0.typelib on 18.04 LTS was wrong.

So I created symbolic link to move it one level higher:

sudo ln -s /usr/lib/x86_64-linux-gnu/eog/girepository-1.0/Eog-3.0.typelib /usr/lib/x86_64-linux-gnu/girepository-1.0/Eog-3.0.typelib

And then I can run python3 -c "from gi.repository import Eog".

Also I have found "fallback" method.

We can install eog-plugin-python-console and use it as development console:

sudo apt install eog-plugin-python-console

Then enable it in Eye of GNOME Preferences → Plugins and launch from menu by clicking on Python Console:

I think that you can get the source code of actual Eog plugins with apt-get source eog-plugins and then try to read and/or change it.


OK, so all I had to do was alias ls='ls --color'. Thanks to the folks in comments for pointing out that I'm being an idiot. :-)

(But why have I not had to do this before? I had always thought that ls by default is in color mode...)


Error showing url: Error when getting information for file when gnome-open

You have to either remove the quotes or remove the backslash.  You can use either/or but not both when specifying a file.

When you use the quotes you are telling the system, in this case, that the backslash is part of the file name.  If you didn't use quote, the backslash would function as an escape character that would prevent the space in the filename from being separated as multiple words.


Here's the situation as I understand it, though I'm no expert. After 2 decades of being standard on laptops, touchpads are finally supported in the kernel. Therefore, the synaptics driver isn't automatically installed. However, if you open the muon packagae manager, search on synaptic and install this driver, you may find that missing options return in KDE. I did. -GEF


Open the terminal and type:
sudo ifconfig wlan0 up
If this doesnt fix it try the steps from this link:
http://ubuntuforums.org/showthread.php?t=1778094&highlight=dell-laptop


Not enough free disk space on disk '/boot' but I don't have old kenels

sudo apt purge $(dpkg -l | egrep '^rc' | awk '{print $2}')

if apt is blocked sudo dpkg -P $(dpkg -l | egrep '^rc' | awk '{print $2}')

The problem by sudo autoremove is , it let configurations-file on system. Sometimes in /var/lib/initramfs-tools/ so update-initramfs always build initramfs for removed Kernel.

But the /boot partition is really small.


Can't connect to a specific WiFi network (Ubuntu 20.04)

open
 nm-connection-editor

forget all connections and then edit your connection and choose specific band and channel number of your connection
worked for me check for yours


Error: could not set EFI variable 'OsIndications'

The EFI partition is fine, the problem is in firmware; however, there is a fix.

edit /etc/grub.d/30_uefi-firmware and remove the if/then/fi statement. I changed mine to read:

gettext_printf "Adding boot menu entry for EFI firmware configuration\n" >&2

cat << EOF
menuentry 'uefi-firmware' {
fwsetup
}
EOF

Then sudo update-grub, you should now have a UEFI firmware option in grub.


Go to your terminal and type openssl after that a prompt will come up and just type in version. The OpenSSL version should print to the console.


Empathy Google Talk with Non Google Account

Empathy should automatically realize talk.google.com is your domain. Have you tried entering in your email address and password anyways?


18.04: Is it possible to have a two-row panel (taskbar)?

In short: no.

Gnome shell, the desktop environment used by Ubuntu, will not be quite suited for this. It is a desktop that by design moves away from the presence of a plentitute of icons and controls in plain sight. By default, extensions are needed to have a task bar in Gnome. Unless some day an extension allows to have a two or multiple row layout on the bar, it won't be possible with the shell.

You could ass a lightweight taskbar such as Tint2 to your Gnome desktop.You can have multiple tint panels running.

However, it looks more that you will be better served with another desktop environment. Ubuntu Mate is based on the classic Gnome 2 desktop, and allows to freely add panes and controls everywhere, including doubling the height of the pane. Also the XFCE and KDE desktops (defaults in Xubuntu and Kubuntu)  are extremely customizable and may better adapt to your needs.


Unable to locate package with apt-get remove

Because you have pip3, you need to uninstall python3-pip.


OMG Ubuntu's solution worked for me:

sudo add-apt-repository ppa:mjblenner/ppa-hal
sudo apt-get update && sudo apt-get install hal

Once the PPA package was added I was able to play Google Play purchased TV and films using Chromium.


Upgrade problem - "dependency problems prevent configuration of libnih-dbus1"

This happened to me, hence finding this post. I had started an upgrade then my pc had been turned off.

Fixed it with

apt-get -f install

Seemed that libc6 wanted to ask if it was OK to stop services to continue - I was upgrading headless using screen. The upgrade didn't get an answer to that question thus libc6 wasn't installed.

Carrying on the do-release-upgrade now.


Can I enable bash-completion for the new apt command?

This is an omission in the bash-complete package, not apt. It just seems a completion doesn't exist yet, so I've scrapped together what I can for the apt command (it's not the best documented command that's ever existed!)

The following is an adaptation from the existing apt-get completion (with elements stripped out and bits added from apt-cache's completion). Run sudoedit /usr/share/bash-completion/completions/apt and paste in the following:

# Debian apt(8) completion                             -*- shell-script -*-

_apt()
{
    local cur prev words cword
    _init_completion || return

    local special i
    for (( i=0; i < ${#words[@]}-1; i++ )); do
        if [[ ${words[i]} == @(list|search|show|update|install|remove|upgrade|full-upgrade|edit-sources|dist-upgrade|purge) ]]; then
            special=${words[i]}
        fi
    done

    if [[ -n $special ]]; then
        case $special in
            remove|purge)
                if [[ -f /etc/debian_version ]]; then
                    # Debian system
                    COMPREPLY=( $( \
                        _xfunc dpkg _comp_dpkg_installed_packages $cur ) )
                else
                    # assume RPM based
                    _xfunc rpm _rpm_installed_packages
                fi
                return 0
                ;;
            *)
                COMPREPLY=( $( apt-cache --no-generate pkgnames "$cur" \
                    2> /dev/null ) )
                return 0
                ;;
        esac
    fi

    case $prev in
        -c|--config-file)
             _filedir
             return 0
             ;;
        -t|--target-release|--default-release)
             COMPREPLY=( $( apt-cache policy | \
                 command grep "release.o=Debian,a=$cur" | \
                 sed -e "s/.*a=\(\w*\).*/\1/" | uniq 2> /dev/null) )
             return 0
             ;;
    esac

    if [[ "$cur" == -* ]]; then
        COMPREPLY=( $( compgen -W '-d -f -h -v -m -q -s -y -u -t -b -c -o
            --download-only --fix-broken --help --version --ignore-missing
            --fix-missing --no-download --quiet --simulate --just-print
            --dry-run --recon --no-act --yes --assume-yes --show-upgraded
            --only-source --compile --build --ignore-hold --target-release
            --no-upgrade --force-yes --print-uris --purge --reinstall
            --list-cleanup --default-release --trivial-only --no-remove
            --diff-only --no-install-recommends --tar-only --config-file
            --option --auto-remove' -- "$cur" ) )
    else
        COMPREPLY=( $( compgen -W 'list search show update install
            remove upgrade full-upgrade edit-sources dist-upgrade
            purge' -- "$cur" ) )
    fi

    return 0
} &&
complete -F _apt apt

# ex: ts=4 sw=4 et filetype=sh

Then run source ~/.bashrc to load the completion. Then apt show firef + Tab should complete.

This may offer you options that just don't exist any more. I think I've nailed the main commands (which might change in time) but at the very least it'll help you with the common commands: list search show update install remove upgrade full-upgrade edit-sources dist-upgrade purge.

Obviously, if a bash-completion maintainer wants to nab the above, you're welcome to it under GPL (though I'd be tempted to start from fresh once apt is documented!)


Use the --gecos option to skip the chfn interactive part.

adduser --disabled-password --gecos "" username

It's all in the man page. Not the most obvious formulation tho.

--gecos GECOS
          Set  the  gecos field for the new entry generated.  adduser will
          not ask for finger information if this option is given.

The GECOS field is a comma separated list as such: Full name,Room number,Work phone,Home phone, despite that man page mentions finger information Details - Wikipedia

Hope this helps you.


19.10 hangs for a few seconds every minute or so

I was having the same problem after upgrading to Ubuntu 19.10.

I checked out my /var/log/syslog for clues and I noticed there were a lot of lines regarding iwlwifi even if I was not connected to any Wifi networks.

I disabled my wifi and I had no hangs after that.


Change this:

deb http://rodeo-deb.yhat.com/ rodeo main
# deb-src http://rodeo-deb.yhat.com/ rodeo main

to this:

deb [arch=amd64] http://rodeo-deb.yhat.com/ rodeo main
# deb-src [arch=amd64] http://rodeo-deb.yhat.com/ rodeo main

Source: https://github.com/yhat/rodeo/issues/615


How to resize table heights in LibreOffice Writer?

Right-clik on the row you want to modify, go to Row and select Height...

Deselect "Dynamic adjustment" and enter the desired height. (Please note that actual English terms may differ).

Tried it just now with LibreOffice 4.0.


Cannot hear sounds on Ubuntu 18.04 anymore

try  installing pulseaudio :   sudo apt-get install pulseaudio
then run : pactl -- set-sink-volume 0 210%
Inform me if that works or not!


You can save as the image as pdf from inkscape directly using the highest
resolution (dpi), say 600, of the printer you plan to use for printing.

Afterwards, you can use imagemagick (command convert) to crop the upper and lower parts of the image independently into two different pdf files. For instance (typed on a terminal):

convert askUbuntu.pdf -crop 100%x50% +repage askUbuntuSplit.pdf

You can then split it into individual pdf files using:

pdftk filename.pdf burst

I presume imagemagick and pdftk are already installed.


I faced the same problem today after an update. I have an Lenovo G50-70  (i7-4500U CPU @ 1.80GHz), also without a dedicated GPU.

The only thing I did was change OpenGL2 to XRender and I now I'm able to use Yakuake propertly (also, some Firefox menus were broken and now work.)

Please go to SystemSettings→Display and Monitor→Compositor→Rendering backend.

You may find these in the configuration file: ~/.config/kwinrc.


Can I manage dpkg-installed package with apt-get?

In short: the answer to your question is just in the page you posted.

If you like to install and update Webmin via APT, edit the /etc/apt/sources.list file on your system and add the lines :

deb http://download.webmin.com/download/repository sarge contrib
deb http://webmin.mirror.somersettechsolutions.co.uk/repository sarge contrib

You should also fetch and install my GPG key with which the repository is signed, with the commands :

cd /root
wget http://www.webmin.com/jcameron-key.asc
apt-key add jcameron-key.asc

You will now be able to install with the commands :

apt-get update
apt-get install webmin

Long version. If the package was installed with dpkg then it is installed. Once installed apt-get can handle it, i.e. you may run sudo apt-get remove webmin to uninstall it, or sudo apt-get install -f to fix the dependencies.

Just to be clear, apt-get USES dpkg. In a very short simplified way, dpkg is the engine behind apt-get (and aptitude), it's the guy leading with the actual installation of packages directly and, of course, is potentially harmful to your system if you mess up, whilst apt-get really takes care of you trying to avoid any disturbance that dpkg may generate. :)

Going to the point, the first part of my answer reply to you directly, the alternative to install a .deb with dpkg is to add a repository. Why, well in the repository you will catch every update of the program, while with dpkg your version is fixed. Also, in theory, the repo may solve all your dependencies automatically. In dpkg is allways convenient check for broken packages afeter the installation with sudo apt-get install -f.

Adding a repo consist on four steps: add the address of the software source, add the key to make ubuntu able to trust the source, update the database, and install. All of them are above. Adding a ppa saves you the steps 1 and 2! Cheers!


If I need a specific library -- what package to install?

As is stated by @edwinksl in comments and by @jbowtie in the second answer to this quite similar question the command line tool is apt-file. In this case the full solution is like:

$ sudo apt install apt-file
$ apt-file update
$ apt-file find libglut.so.3
freeglut3: [... ]
freeglut3-dev: [...]
[...]
$ sudo apt install freeglut3


Cannot boot into Windows 8.1 after "Trying Ubuntu" from a USB stick

The best and safest way to fix it is to create a bootstick with Windows 8 installer, from which you can run Windows' boot fix.

Boot Repair sometimes does strange stuff, like replacing Windows' boot loader with GRUB2. As the GRUB EFI only loads the normal GRUB2, which is located on the stick, it won't work.


you most certainly can move these directories whereever you want. You just have to create a symbolic link. For example if you want to move /var/lib/docker to /home/var/lib/docker you have to create a link by executing

ln -s /home/var/lib/docker /var/lib/docker


How can I build Aura Wm from Chrome OS in Ubuntu?

UPDATE

Found this project on GitHub which claims to do exactly what is required in the question.

From the README

lightdm-login-chromiumos

Installs Chromium OS Aura window manager to Ubuntu(64bit only), with embedded
Chromium browser(canary snapshot). Binaries are downloaded from
http://commondatastorage.googleapis.com/chromium-browser-snapshots/index.html

Project Home Page

Since aura has just been released, I don't think there is a separate package available.

But, since aura is part of the Chromium project which is open source, you can always download the source code.

You can checkout the source code using

svn checkout http://chromium.googlecode.com/svn/trunk/ chromium-read-only

The code for aura lies in src/ui/aura folder.

You can find the build instructions at http://code.google.com/p/chromium/wiki/Aura

Aura Design Document


What's the difference between desktop managers and display managers?

Display manager

Is a graphical user interface that is displayed at the end of the boot process in place of the default shell.

There are various implementations of display managers:

GDM — Gnome display manager.
LightDM — Cross-desktop display manager.
LXDM — Lxde display manager.
SDDM — QML-based display manager and successor to KDE4's kdm.
SLiM — Lightweight graphical login solution.
XDM — X display manager with support for XDMCP

Desktop environment

Is an implementation of the desktop metaphor made of a bundle of programs running on top of a computer operating system, which share a common graphical user interface.

A desktop environment typically consists of icons, windows, toolbars, folders, wallpapers and desktop widgets, might also provide drag and drop functionality and other features that make the desktop metaphor more complete.

There are various implementations of desktop environments:

Unity is the default desktop for Ubuntu, and is one of the major desktop environments.
Gnome is other of the major desktop environments.
KDE is other of the major desktop environments.
Xfce is a much lighter desktop environment.
LXDE is arguably the lightest option available for a desktop environment.
Cinnamon is another alternative to Gnome.
MATE is a continuation of the Gnome 2 codebase.
Budgie is the default desktop of Solus Operating System.
Moksha is a continuation of the Enlightenment 17 desktop.
Enlightenment started as a project to build a desktop environment.
Pantheon is the project developed by the elementaryOS team.
Trinity is a continuation of the KDE 3 series.

A desktop environment can be broken up into several components that function independently and interact with one another to provide the look and feel and functionality of the desktop environment.

A fundamental part of a desktop environment is the window manager.

A window manager creates a certain way for application windows to present themselves to the user. It manages the various application windows, keeping track of which ones are open and providing features to switch between them.

Another important element of a desktop environment is the file manager. This application manages files/ folders and presents them in a way that the user finds convenient. It provides file operations like viewing, copying or moving, changing permissions and deleting.

Desktop environments usually provide utilities to set wallpapers and screensavers, display icons on the desktop, and perform some administrative tasks.

They may optionally include word processors, CD/DVD writing applications, web browsers and e-mail clients.

The X Window System is usually started as an X session which is the combination of an X server and connecting X clients.
For the normal desktop system, both of them are executed on a workstation.

Xorg is the most popular display server among Linux users. Its ubiquity has led to making it an ever-present requisite for GUI applications, resulting in massive adoption from most distributions.

The X Window System is a windowing system for bitmap displays, common on UNIX-like computer operating systems.

X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting with a mouse and keyboard.

X does not mandate the user interface – this is handled by individual programs. As such, the visual styling of X-based environments varies greatly; different programs may present radically different interfaces.


Simulation

At here, new 14.04 installation with the KDE desktop.

Running a simulation - what will happen if I remove the 'libnepomuk4':

apt-get purge -s libnepomuk4

The result:

  The following packages will be REMOVED:

  adobe-flash-properties-kde*
  apport-kde* apturl-kde* ark* audiocd-kio* baloo*   bluedevil* dolphin*
  dolphin+* ffmpegthumbs* filelight* freespacenotifier*

  ...

  sweeper* systemsettings* usb-creator-kde* user-manager*

  The following NEW packages will be installed:

  at-spi2-core
  libatk-bridge2.0-0 libatspi2.0-0 libgtk-3-0 libgtk-3-bin
  libgtk-3-common libwayland-cursor0 policykit-1-gnome xterm

  0 upgraded,
  9 newly installed, 211 to remove and 3 not upgraded.

Full output: http://pastebin.com/wHF82M9P

Well - Maybe not...

Akonadi

Akonadi: http://userbase.kde.org/Akonadi

  The Akonadi framework is responsible for providing applications with a
  centralized database to store, index and retrieve the user's personal
  information. This includes the user's emails, contacts, calendars,
  events, journals, alarms, notes, etc...

Nepomuk & Baloo

The Nepomuk was replaced with the Baloo - http://community.kde.org/Baloo


You have an Aspire R7. If my assumptions are correct, it is either an Intel Broadwell-based computer or Skylake-based. (core i5/i7-5xxx/6xxx)

There are many ways to conserve power in Ubuntu. In 16.10, TLP is by default now included. Configure TLP from:

gedit admin:///etc/default/tlp

or

sudo nano /etc/default/tlp

I recommend setting your CPU governor to powersave when on battery, and performance when plugged in. There are also several other power saving settings there.

Install powertop:

sudo apt-get install powertop

And open it up with sudo powertop in terminal. You can view "Tunables" in the rightmost tab.
You can either auto-adjust with:

sudo powertop --auto-tune

Or create a an HTML power report:

sudo powertop --html=powertop.html

Which you can view in the terminal directory. In that HTML file is a list of Tunable commands. Put that in your rc.local script.

If you have the Broadwell/Skylake version of the R7, you will most likely have the known C-state bug with current Intel CPUs. C-states are the sleep states that can be utilized by the CPU, and higher sleep states can save considerable power. You may need to play around with disabling certain devices (SD card reader, Ethernet, etc.) to get working C-states. Unfortunately, this is a known issue and may not be fixed for quite a while.

The current C-state bug does not allow the CU to achieve C-states lower than C3. You can view current C-states in "Idle Stats" in powertop, on the left hand side.

Finally, if you're fairly desperate, I would use a lightweight DE, or even a WM. After fixing C-state issues in my laptop, and switching to i3 window manager, I get at least 7 hours of battery life (heavy browsing, videos, even casual gaming).


How to run perform different actions from one script

You can use this script :

#!/bin/bash
if [[ $1 == 'new' ]]; then
  touch "$2" && echo "File $2 is created"
elif [[ $1 == 'del' ]]; then
  rm "$2" && echo "File $2 is removed"
else
   echo "THe first srgument can be 'new' or 'del'"
fi

If the first argument to the script $1 is new then the filename given in second argument $2 will be created and the user will be notified
Accordingly if $1 is del then the file given in $2 will be removed and user will be notified
In other cases user will be given a notification os correct usage patten

Example :

$ ls -1
scr.sh

$ ./scr.sh new foo
File foo is created

$ ls -1
foo
scr.sh

$ ./scr.sh new bar
File bar is created

$ ls -1
bar
foo
scr.sh

$ ./scr.sh del foo
File foo is removed

$ ls -1
bar
scr.sh

$ ./scr.sh foobar
THe first srgument can be 'new' or 'del'


Here's a quick & dirty way: go to the ppa with your web browser, browse into http://ppa.launchpad.net/rob-caelers/workrave/ubuntu/pool/main/w/workrave/ and download the specific wanted files, then dpkg -i (or dpkg -i -R [dir with all .deb's] ) and see if it will work, or needs some other packages?

FYI, got to that link by following your link to the PPA in the Q, then the link in the sources.list entires.

I just tried adding the PPA (ppa:rob-caelers/workrave) to linux mint 17 (based on Ubuntu trusty, uses ubuntu repos) and Synaptic tells me there's 2 versions avaialble, 1.10.1-4 (trusty) and 1.10.5.0-ppa1~trusty1 (trusty) and it installs 1.10.5 (so does apt-get). Maybe your apt_preferences, or something else (Synaptic's Lock Version?) is deciding to not update to 1.10.5? Does Synaptic or apt-cache show workrave show either/both versions (Synaptic package, Properties -> Versions)? If it says 1.10.5 is available you could force the version, with apt-get install workrave=1.10.5.0-ppa1~trusty1 or synaptic Package menu -> Force version?

ps. the "Time for a micro-break" mouse-eluding window is a little annoying if not prepared for it ;-)


Install a list of packages only if they aren't already installed

apt-get will fairly silently skip over any package that is installed already so I'm not sure why it needs to get special treatment? ie:

root@bun:~# apt-get -y install  vlc
Reading package lists... Done
Building dependency tree
Reading state information... Done
vlc is already the newest version.

Is there a particular reason this won't work for you as-is?


It meets the minimal requirements for both Xubuntu and Lubuntu. Xubuntu has slightly more eye candy, Lubuntu is slightly lighter. Still, they're pretty close, so unless you have a particular preference for lxde over xfce, I would try Xubuntu and go straight for a super-lightweight distro like Puppy Linux if Xubuntu turns out to be too heavy.


One thing you didn't  mention was the module in /etc/apache2/mods-available/rewrite.load, which enables the rewrite engine.  If you haven't done this, you need to add a link in the directory /etc/apache2/mods-enabled; from the directory /etc/apache2/mods-enabled, enter ln -s ../mods-available/rewrite.load to create a symbolic link to this.

You can also use 'sudo a2enmod rewrite'


I found three possibilities:
1. Date and Time Indicator in the Indicator Plugin of the panel
1. Install indicator-datetime from the Software Center or in the terminal sudo apt-get install indicator-datetime (it will install several other packages)
2. Add the Indicator Plugin to the Panel (right-click on the panel and choose add new items) if not done before
3. Right-click in the Indicator Plugin and choose Properties and hide “Keyboard” if necessary and wished
4. I could not open the "Date & Time Settings" from the drop-down menu of the indicator. But you can set the timezones with the dconf-editor: Install the dconf-editor (Software Center or sudo apt-get install dconf-editor)
Dconf-editor: Select com > canonical > indicator > datetime
Look at the locations field as shown in the first answer of this question and add your new location(s) - each entry is in the format ,'timezone city' i.e. separate entries with commas
Look at the locations value.
['UTC UTC', 'Asia/Nicosia Nicosia']
You can find the list of time zones here

2. Orage
It's possible to display multiple timezones by using multiple applets of the Orage Clock Panel.
Right click on the clock -> properties and in the clock dialog there is a button ('Time and Date Settings...') under the Timezone text-box. Clicking that button will bring up a dialog that allows you to select which timezone you want that applet to use. (You'll have to unlock this dialog by providing you password to edit it).
Each applet will use the timezone you set it for.

3. Orage and Global Time Window
You can sort of use Orage.
Middle click on orage in the panel and you'll get a new window Global Time - you can there set as many new timezones as you want.

Middle click to lose the global time window.

So far I like the Date and Time Indicator the best as it also shows the calendar entries from Evolution and several time zones can be added without multiple time zones showing up in the panel what might be confusing.


display UNCLAIMED on Ryzen CPU series with Radeon graphics

The problem is that most recent hardware doesn't get timely support with Linux kernels even with latest versions of Ubuntu. Here is the step-by-step workaround that made a trick for me at Lenovo X13 which has Ryzen 7 Pro 4750U with Radeon graphics codename 'Renoir' on Ubuntu 18.04. Should be the same for any other codemane correspondingly:

Check the folder /lib/firmware/amdgpu of your installation. Most expectedly it hasn't any files with *.bin extension and 'Renoir' tag in the name.
If folder 'amdgpu' is missing in your /lib/firmware path, create this folder by yourself using sudo. You gonna need one for the next steps.
Go to bash and install Ubuntu Kernel Mainline Utility (UKMU) with following:

$ sudo add-apt-repository ppa:cappelikan/ppa
$ sudo apt update
$ sudo apt install mainline

UKMU is needed to get most recent kernels. DO NOT install any new kernels at this step!

Install one of two ppa for mesa (in 2020 oibaf is lagging behind due to delayed updates, so kisak is more up to date):

option 1:
$ sudo add-apt-repository ppa:oibaf/graphics-drivers

or
option 2:
$ sudo add-apt-repository ppa:kisak/kisak-mesa

complete installation of mesa drivers by:

$ sudo apt update
$ sudo apt dist-upgrade
$ sudo apt install mesa

Go to https://packages.debian.org/sid/all/firmware-amd-graphics/download and find ftp server which is closest to you, i.e. http://ftp.de.debian.org/debian/pool/non-free/f/firmware-nonfree/firmware-amd-graphics_20210208-3_all.deb

It has direct link for the debian installation package of AMD drivers, which is of Feb 08th, 2021 to the date of this post

Click selected link and download the file

DO NOT install the deb by itself! Instead open it with archive viewer and find a folder 'amdgpu' inside the archived file data.tar.gz

Once located extract 'amdgpu' to your drive. With Renoir in particular you don't need other folders like 'r128' or 'radeon' for Renoir (owners of older graphics may find their hardware exactly in those two folders).

Copy or move the contents of extracted 'amdgpu' to /lib/firmware/amdgpu (or to r128 or to radeon correspondingly).

Check the contents of of /lib/firmware/amdgpu. Now it should have several *.bin files with 'Renoir' tag in the name i.e. 'renoir_me.bin' on so on.

now tell the kernel it has some new drivers for installed hardware:

$ sudo update-initramfs -u

If at step 11 you made sure files for renoir are in /lib/firmware/amdgpu folder, do not worry if you will see something like:
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8125b-2.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8125a-3.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168fp-3.fw for module r8169
W: Possible missing firmware /lib/firmware/amdgpu/navi12_gpu_info.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/arcturus_gpu_info.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/raven_ta.bin for module amdgpu
...

Now go to UKMU and install one of most recent kernels. IMPORTANT: install the kernel 5.4.x or above as lower kernels may lack support for WiFi on most recent machines. You don't want to lose your connection to the internet while solving the issue with AMD graphics.

Once installation of selected kernel is completed, reboot the PC.

Upon the reboot your new kernel should find proper driver for your hardware so it must work normally already. If not repeat step 12 and reboot to newly installed kernel once more.

Use below to make sure your graphics card now 'CLAIMED' by the system:

$ sudo lshw -C display

In case the output shows:

     *-display
.......

and has no UNCLAIMED than everything is fine now.

if earlier you have tried various options in grub, prior you send the PC to reboot/shut down make sure you made below changes to the file

/etc/default/grub

as below

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

or you may find unexpected difficulties while shut down.


how to manage mirror legs and stripes in graphical way now w/o KVPM on 20.04?

Just as a test, I installed these packages from 18.04:
liblvm2app2.2_2.02.176-4.1ubuntu3.18.04.3_amd64.deb, the deb link from downloadable files at https://launchpad.net/ubuntu/bionic/amd64/liblvm2app2.2/2.02.176-4.1ubuntu3.18.04.3
kvpm_0.9.10-1.1_amd64.deb, the deb link from downloadable files at https://launchpad.net/ubuntu/bionic/amd64/kvpm/0.9.10-1.1
initially I didnt think they would even install, now KVPM is running in ubuntu 20.04!
It is working very fine, just created a mirror leg to my root filesystem!
TIP: if you need to modify the filesystem label (that is mounted at /media/$USER/TheLabel) you can use the Disks application and then click on the gears and choose "edit partition" as the only thing you can do there is change the label :)


There is space missing in your command.
Use this command (also mention by Thomas in comment).

sudo ln -s /opt/sqldeveloper/sqldeveloper.sh /usr/local/bin/sqldeveloper


What "permissions problem"?  I'll have to guess.

Is your userid a member of the cdrom group?

These commands helped me:

walt@bat:~(16)$ ls -l /dev/cdrom
lrwxrwxrwx 1 root root 3 Sep 11 01:30 /dev/cdrom -> sr0
# /dev/cdrom is /dev/sr0 on my system               ^^^

walt@bat:~(0)$ ls -l /dev/sr0
brw-rw----+ 1 root cdrom 11, 0 Sep 11 01:30 /dev/sr0
# /dev/sr0 is a Block device Read-Writeable by user `root` and members of group `cdrom`

walt@bat:~(0)$ id
uid=1000(walt) gid=1000(walt) groups=1000(walt),4(adm),7(lp),20(dialout),27(sudo),101(systemd-journal),106(input),113(lpadmin),142(motion)
# I'm not in the `cdrom` group

walt@bat:~(0)$ sudo adduser $USER cdrom
[sudo] password for walt:
Adding user `walt' to group `cdrom' ...
Adding user walt to group cdrom
Done.
# And now I AM a member of group `cdrom`, when I logout/login, or...

walt@bat:~(0)$ newgrp cdrom
# (starts a subshell with GID set)

+walt@bat:~(0)$ id
uid=1000(walt) gid=24(cdrom) groups=24(cdrom),4(adm),7(lp),20(dialout),27(sudo),101(systemd-journal),106(input),113(lpadmin),142(motion),1000(walt)
# I AM a member of the `cdrom` group

+walt@bat:~(0)$ exit
exit
# And now I'm not
walt@bat:~(0)$ id
uid=1000(walt) gid=1000(walt) groups=1000(walt),4(adm),7(lp),20(dialout),27(sudo),101(systemd-journal),106(input),113(lpadmin),142(motion)


What screen recorder records my desktop audio?

You can use SimpleScreenRecorder, install it using

sudo add-apt-repository ppa:maarten-baert/simplescreenrecorder
sudo apt-get update
sudo apt-get install simplescreenrecorder

if you want to record 32-bit OpenGL applications on a 64-bit system:

sudo apt-get install simplescreenrecorder-lib:i386

For more info : http://www.maartenbaert.be/simplescreenrecorder/


Have you tried to look at /etc/resolv.conf ?
Check or change "nameserver"


Unable to install Ubuntu 12.10 on the integrated SSD of an Asus UX32A

Try examining your firmware boot options. Look for options to enable CSM, BIOS, or legacy boot features; or to disable EFI or UEFI boot features.
Launch Linux's fdisk (not gdisk, parted, or GParted) and use the a option to set the "bootable flag" on the one partition that you should see. Use the w option to save changes.
If neither of the above works, consult this page of mine, which goes into more detail about this problem and provides more obscure possible workarounds.


lenovo t460s + 16.04.2: Freeze if suspend after undock

I had this problem too and did some investigation.
The problem is caused by the i915 driver. It occurs if an external display was enabled whilst using the dock. The i915 driver is backported to the 4.4.0 kernel in Ubuntu 16.04, which may not help.
The actual crash is:
[440183.307053] kernel BUG at /build/linux-0uniEn/linux-4.4.0/ubuntu/i915/intel_ddi.c:730!

If you look at the code the issue is that the driver is surprised/confused that one output has gone away and deals with this by bringing the whole kernel crashing down, rather than just reporting a failure. This is pretty shoddy code.

I tried kernel 4.12.3 from the ubuntu kernel upgrade PPA, and that works better but still crashes sometimes. It quite often hangs for several minutes on unsleep, before the screen finally appears, which is better than crashing and losing stuff, but tiresome.

A completely reliable way to work around this is to explicitly turn off the external display before undocking. This script 'undock' does that:

#!/bin/sh
xrandr | awk '$2 == "connected" && !/^eDP/ {system("xrandr --output " $1 " --off")}'

(A corresponding one with s/--off/--auto/ will turn it back on.)


ubuntu upstart script execute a script.py program

Okie, a bit old question but lets answer it from completeness sake :-)

Lets say you saved this job in /etc/init/myapp.conf, then the job name would be myapp. Asking for the job status (and process id) would simply be: status myapp (as root) or sudo status myapp in typical Ubuntu user case.

Init errors go to dmesg by default, so doing dmesg | grep "init:" gives you the log. More verbose logging can be enabled by sudo initctl log-priority info. Debug levels more verbose than that will spam and confuse you :-)

Doing sudo stop myapp, sudo start myapp gives you feedback instantly on success, plus the process id. In case you get init: unknown job or such, Upstart has failed parsing the configuration file and exact line and reason can be found from dmesg.


Making my first bash script, can't get the cd command to 'stick.'

In your example, go /etc will do cd; ls /etc. That means, first, cd will change the current directory to your home directory. Then, ls /etc will display the contents of /etc.

You could achieve what you want by defining a function, like so:

function go() {
    cd "$1" && ls
}

Or just type it in the command line on a single line:

function go() { cd "$1" && ls; }

Then go /etc will do what you want.

$1 refers to the first parameter passed to the command in this example /etc. You can refer to subsequent parameters with $2, $3 and so on.


How to get Nvidia 555M working on Ubuntu 12.10 (drivers, optimus, cuda)?

To fix the Toolkit problem, make sure you are using gcc version 4.6. You can sudo apt-get install gcc-4.6 and then

    sudo mv /usr/bin/gcc-4.6 /usr/bin/gcc

(To un-do this afterwards, you can move the other one back). There may be some way to do this with options to the CUDA installer, but I can't figure it out.

To fix the Samples problem, you can put a link to where it is expected:

    sudo ln -s /usr/lib/x86_64-linux-gnu/libglut.so /usr/lib/libglut.so


Go back to my servers IP instead of domain

You need create separate VirtualHost for IP like a domain and target it to page you want. It can be 404 page or blank page or something else.

With Apache 2.4, the first vhost will be main host which located by IP, no need "ServerName"

<VirtualHost *:80>
    ServerAdmin YourEmail
    DocumentRoot /home/apache/www
    <Directory /home/apache/www/>
        Require all denied
    </Directory>
    ErrorLog /var/log/apache/error.log
    CustomLog /var/log/apache/access.log combined
    ServerSignature Off
</VirtualHost>
Include /path/to/vhosts/*.conf


You don't need to install gd from source, it's in the repositories:

sudo apt-get install python-gd

If, for some reason, you still want to install from source, it's easy to install all build dependencies as well:

sudo apt-get build-dep python-gd


I could finally find the answer. You should change +100G part with your missing space. This was a problem about my logical volume size.

I didn't hit enter again on last line as I did it already but you should. You will see a message about resizing was succesful. Nothing else to do afterwards. Just that.


Can the Android files app sync local file changes to U1

No, the Android files app does not currently do two-way sync of any files. The only files that are automatically uploaded right now are photos.


Replacing one operating system with another

YES, there is no reason why you can't install over your Ubuntu with OS X and visa versa as many times as you like.

Using more than one operating system on the same computer

Installing 2 operating systems on the same computer is called "dual-booting" (or "multi-booting"). It depends on how you do the installation (it's a slightly different process with OSX and Ubuntu than it is with Windows and Ubuntu), but here again, the answer is YES.


Plug in an ethernet cable.

If you want to use tcpdump on a different interface, like wlan0, then you need to use the -i option, such as tcpdump -i wlan0. If you read the tcpdump documentation, this is clearly documented.


How to configue a DNS server statically?

I've just found the answer - it is to add dns-nameservers line to /etc/network/interfaces as described here.


Raspberry pi 3 B with Ubuntu 18.04 server arm64: what pi version

At least on Ubuntu 18.04 server for arm64 and with a Raspberry Pi 3 B, the following command gives the board, including revision:

lshw

A less verbose output that's easier to read is given by:

lshw -short

That gave me my board as a "Raspberry Pi 3 B Rev 1.2", which is exactly what was needed in this case.


How to change the default gnome text highlight color?

Fixed the issue by settings themes from gnome-look.org. The blue Yaru theme is just thr thing I needed.


This is more of a workaround than an answer to your question. You can use xkbset to adjust the speed of the cursor when using the mouse keys feature. The idea came from this post:

http://www.exuro.co.uk/2012/07/114/

The setting I found most comfortable was:

xkbset ma 60 10 10 5 2

Hope that helps!


Cannot download build-dep for indicator-sound

To edit your sources.list first you might want to make a backup copy

sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup

then:

sudo nano /etc/apt/sources.list

all the deb-src... lines are commented out by default. You actually only need to uncomment the first one. Change this:

# deb-src http://gb.archive.ubuntu.com/ubuntu/ xenial main restricted

to this:

deb-src http://gb.archive.ubuntu.com/ubuntu/ xenial main restricted

save and exit and you will be able to run

sudo apt update && sudo apt build-dep indicator-sound

and in your home (it's a good idea to make a directory to unpack sources because they unpack to multiple files so this keeps them together)

mkdir indicator-sound; cd indicator-sound
apt source indicator-sound


Juju deploy OpenStack bundle just on 3 nodes

3 nodes are expected if you did invoke commands like juju deploy cs:bundle/openstack-base.
I need more information to answer your question. For example, which section of the guide you followed? Is it "Single-node OpenStack deployment", "Multi-node OpenStack deployment" or "Data centre cluster deployment".
I assume you were talking about the installation guide of "Data centre cluster deployment" section. If yes and you did invoke this command "juju deploy cs:bundle/openstack-base" then it is totally expected to have 3 node deployed. You may refer to the charm bundle description https://jaas.ai/openstack-base , or refer to the bundle file directly https://api.jujucharms.com/charmstore/v5/bundle/openstack-base-70/archive/bundle.yaml only 3 nodes are needed:
machines:
  '0':
    series: focal
  '1':
    series: focal
  '2':
    series: focal


Keyboard shortcut for input language doesn't work on Gnome shell

I've had the same problem as you had except I installed the whole Gnome desktop package. To solve this problem I log of the Gnome Shell then log in the Unity and set (re set) hotkey to change keyboard layout in Unity. Check if it work there and then go back to the Gnome Shell. It works for me.
My answer is probably irrelevant for you now but I hope it'll help someone else.
Sorry for my poor English.


How to find out which NTP (Network Time Protocol) is configured on Linux-ubuntu

This will list all running deamons:
systemctl | grep daemon

Look for "time" in the results as we nowadays use timesyncd:

systemd-timesyncd is a system service that may be used to synchronize the local system clock with a remote Network Time Protocol server. It also saves the local time to disk every time the clock has been synchronized and uses this to possibly advance the system realtime clock on subsequent reboots to ensure it monotonically advances even if the system lacks a battery-buffered RTC chip.
The systemd-timesyncd service specifically implements only SNTP. This minimalistic service will set the system clock for large offsets or slowly adjust it for smaller deltas. More complex use cases are not covered by systemd-timesyncd.
The NTP servers contacted are determined from the global settings in timesyncd.conf(5), the per-link static settings in .network files, and the per-link dynamic settings received over DHCP. See systemd.network(5) for more details.
timedatectl(1)'s set-ntp command may be used to enable and start, or disable and stop this service.


bash - wrong answer by word count command

Assuming you mean character count not word count (which would be 1), the issue is that echo adds a newline character. You can either use

len=`echo -n $str | wc -c`

(the -n switch suppresses the newline) or - better - just use the bash # variable length operator

len=${#str}


Using ubuntu 20.20.4, want ubuntudde. Downloaded the rufus.exe to usb but get an error message from archive manager when trying to open?

Just use Ubuntu's Built in "Startup Disk Creator" software. It is GUI and easy to use.


Jigdo only works with non-live images. Since Ubuntu dropped the Ubuntu Alternate image, the only image that will work with Jigdo is the Ubuntu Server image.  Even then that image is now using some kind of live image to make installation faster so Jigdo won't be nearly as efficient as before.  If you're just looking for ways to minimize the amount of data needed to update a 13.10 64-bit image, you're probably best to use zsync as it seems to be the most efficient way to do delta based updates of the live images.


Gparted check and repair failed "/dev/sda has unsupported feature(s): metadata_csum e2fsck: Get a newer version of e2fsck!"

As indicated by the error message:

e2fsck 1.42.13 (17-May-2015)
/dev/sdb2 has unsupported feature(s): metadata_csum
e2fsck: Get a newer version of e2fsck!

the version of e2fsprogs package is too old to support the feature mentioned.

One way to use a more recent version of e2fsprogs is to boot from more recent live media such as the latest GParted Live.  The latest GParted Live 0.30.0-1 includes e2fsprogs 1.43.6-1.


Can't set up public key ssh authentication

OP answered:

In case anyone encounters this in future. For me the problem was solved by realising that lshd rather the opensshd was answering port 22. Removing lshd (apt-get remove lsh-server) fixed everything.
Thanks to @Gilles for pointing me in the right direction.


After uninstalling Postgresql 9.4 postgresql 9.4 service is still there

Presuming you'd already backed up any 9.4 databases, a "purge" instead of the "remove" would have gotten rid of the /etc/postgresql/9.4/main/postgresql.conf file with the "port=5432" line.  Since it still existed when you did the 9.5 install, the install used the next port, 5433.  Generally, this is done to allow a later version of postgresql to be installed, and checked out, before deleting the old version.

You can edit the /etc/postgresql/9.5/main/postgresql.conf file port to be 5432 and redo the apt-get purge postgresql-9.4 to clean up the old config files.

You can track down any leftover 9.4 files with locate

locate postgresql/9.4

and remove them manually to keep systemd fromt trying to start the no-longer present service.


Bluetooth but not WiFi works on Broadcom 43142A0

There's two driver setups for Broadcom Wifi, bcmwl-kernel-source and firmware-b43-installer. Some chips work with the former, some work with the latter. Don't have them both installed at the same time.

You need to install bcmwl-kernel-source for your chip according to this page. You can install it with Terminal command sudo apt install bcmwl-kernel-source. Some chips also work better if IPv6 is set to "Ignore" in Wireless properties.

You can download the .debs for 17.10 from here: https://packages.ubuntu.com/artful/bcmwl-kernel-source

Install it by running sudo dpkg -i bcmwl-kernel-source_6.30.223.271+bdcom-0ubuntu3_amd64.deb. You may also have to download and install its dependencies.


Try this.  jJust press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo apt-get install libjson0 libjson0-dev


start / run / cmd  (as administrator)

diskpart

list volume

select volume 1  (Considering this is 100 MB system partition)

online volume

exit

http://ubuntuforums.org/showthread.php?t=1871823


I'll use this answer to record what I've worked out and will update as I progress.
The kernel modules for Thunderbolt are not included in the kernel package (linux-image-5.4.0-26-generic) - there is another package that needs to be installed:
$ sudo apt install linux-modules-extra-($uname -r)

After a reboot Thunderbolt works and displays connected via a dock become usable; it may be enough to modprobe the required modules (I think these are thunderbolt and intel-wmi-thunderbolt) but I rebooted to be sure.
Current status: After a "power event" (e.g. suspend, disconnecting/reconnecting the dock) my external displays are black. The mouse pointer correctly and visibly tracks across them but nothing else is visible. I've tried reconfiguring via settings panel but it made no difference. I'll update if-and-when I get to the bottom of this.


Permanent Fix
I'm placing the permanent fix discovered a week later at the top of this answer because that is what people are likely most interested in.
Digging through old bug reports I found this related problem: Logitech M515 does not work after upgrade to 12.04. Using solutions here I edited /etc/rc.local and inserted the following lines:
# Jan 05 2018 - Reload Logitech Unifying Receiver to get Mouse in Power Stats
modprobe -r hid_logitech_dj
modprobe    hid_logitech_dj

Then I rebooted twice. On the first reboot the external display didn't appear and the login prompt was delayed. On the second reboot everything was normal and the Power Statistics appeared as they should:

Temporary work-around
I found this bug report which suggests unplugging and replugging the Unifying Receiver. Sure enough it worked:

This bug report suggests running kernel >= 4.12 and upower >= 0.99.5. Although the current upower version is 0.99.7 it is unstable and the current version in Ubuntu is 0.99.4 released February 2016. It's not feasible to get a version >= 0.99.5
Login screen battery status
At the boot-up login screen the system tray displays the battery icon. Clicking on it reveals only the UPS and Laptop battery statistics.
udev rules not running during boot only on replugging
This bug report details how udev rules aren't running on boot but only when replugging cables. This "sounds" similar to the unifying receiver here. The bug report does provide clues on additional information to look for. ie udev (or something else) has enumerated devices in the system paths:
$ udevadm info /sys/class/power_supply/hidpp_battery_0
P: /devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.2/0003:046D:C52B.0005/0003:046D:2010.0007/power_supply/hidpp_battery_0
E: DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.2/0003:046D:C52B.0005/0003:046D:2010.0007/power_supply/hidpp_battery_0
E: POWER_SUPPLY_CAPACITY_LEVEL=High
E: POWER_SUPPLY_MANUFACTURER=Logitech
E: POWER_SUPPLY_MODEL_NAME=K800
E: POWER_SUPPLY_NAME=hidpp_battery_0
E: POWER_SUPPLY_ONLINE=1
E: POWER_SUPPLY_SCOPE=Device
E: POWER_SUPPLY_SERIAL_NUMBER=2010-6d-b5-4b-fe
E: POWER_SUPPLY_STATUS=Discharging
E: SUBSYSTEM=power_supply

$ udevadm info /sys/class/power_supply/hidpp_battery_1
P: /devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.2/0003:046D:C52B.0005/0003:046D:101A.0006/power_supply/hidpp_battery_1
E: DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.2/0003:046D:C52B.0005/0003:046D:101A.0006/power_supply/hidpp_battery_1
E: POWER_SUPPLY_CAPACITY_LEVEL=Normal
E: POWER_SUPPLY_MANUFACTURER=Logitech
E: POWER_SUPPLY_MODEL_NAME=Performance MX
E: POWER_SUPPLY_NAME=hidpp_battery_1
E: POWER_SUPPLY_ONLINE=1
E: POWER_SUPPLY_SCOPE=Device
E: POWER_SUPPLY_SERIAL_NUMBER=101a-e6-ce-45-71
E: POWER_SUPPLY_STATUS=Discharging
E: SUBSYSTEM=power_supply

IMPORTANT NOTE: Even though /sys/class/power... contains information on Keyboard and Mouse batteries the Power Statistics display currently shows NOTHING, not even the keyboard anymore. After writing this paragraph I replugged the unifying receiver and the battery levels were displayed.

June 13, 2020 update
Today neither keyboard nor mouse appear in Power Statistics. Also:

hidpp_battery_0 has changed to hidpp_battery_1
hidpp_battery_1 has changed to hidpp_battery_4

Googling for new information on the Power Statistics problem I discovered someone made a scrolling video of this Ask Ubuntu Q&A without credits or source:

Ubuntu: Logitech Performance MX mouse shows as "unknown" in Power Statistics

It wasn't helpful watching a video slowing scrolling through what I already posted...
I did find this new link suggesting kernel > 4.7 and upower >= 0.99.5 fixes the problem:

Logitech MX Master (Unifying adapter) no power info


VirtualBox 4.3 Guest Additions on OSX guest

You're right, VirtualBox doesn't have guest additions for OSX. https://www.virtualbox.org/wiki/Guest_OSes

They only list Mac OSX Server (Leopard, Snow Leopard) under Mac and even that doesn't have guest additions.

It has something to do with licensing restrictions:
https://forums.virtualbox.org/viewtopic.php?f=22&t=31104


20.04 headless on Raspberry pi 4 re-install will not allow password authentication on ssh

And the answer is:
do not edit the user-config file as suggested because, no doubt, you will follow the examples and/or the cloud-init 'readthedocumentation' and then it will not work.
Why?
Because the YAML parser will not deal with the space in ': ' required by cloud-init for the ssh_pwauth: yes thereby causing the server to default to non-password authentication.
It only took me 2 days. I just hope I save someone else the time.


I am new so cannot comment, hence leaving this as an answer.

You appear to have done the correct things so I would have to ask: did you burn the ISO as a complete image, or did you just copy the files to the CD? If you did the latter, it will not boot. Secondly, I would double check the md5 sum of the CD image, just to make sure it downloaded correctly.


Keyboard shortcut to move windows between monitors?

As @jrg mentioned, this is still possible as Unity (Unity 3D, not the low-power 2D version) is largely built using Compiz.

You'll need to install the Compiz Config Settings Manager Yourself though. Precise steps are:-

Install CompizConfig Settings Manager using apt-get install compizconfig-settings-manager compiz-plugins-extra.
Run it (just type Compiz in the dash and you'll see it).
Click Window Management.
Enable the Put plug-in (select the check-box).
Click on Put.
Configure the shortcut for Put to next Output (click the pencil icon next to the keyboard shortcut for Put to next Output.
Logout and login again for the changes to take effect (from the comments!)


Trouble connecting to a Wi-Fi with given user and password

Try copying the URL from your android device browser into the browser on your Ubuntu machine, and you should be able to get to the wifi registration page for your hotel.


How can I invoke "scsi start stop" from command-line since gnome-disks seems to support this call?

You can use sg_start, which can be found in the sg3utils package:

sudo apt-get update && sudo apt-get install sg3utils


NS_ERROR_FAILURE Virtual Machine Doesn't Run

If this is a recent change in VirtualBox behavior, look for updates/upgrades.  Frequently, when Ubuntu or other distributions update it will cause VB to fail with that message.
Solution for me has always been to remove VB and install the latest version together with the VB Extension Pack which, (on Sept. 17, 2020) is version 6.1.14 for both.
Make sure you install both! I download mine directly from the Oracle Virtualbox website.


Lyric player just like Miniyrics in ubuntu 12.10 with highlighted scrolling lyrics

OSDLyrics is lyric player similar to Minilyrics ,displays lyrics with many mediaplayers including Banshee and Rhythmbox.

to install with ppa from Ubuntu try:

sudo add-apt-repository ppa:osd-lyrics/ppa
sudo apt-get update
sudo apt-get install osdlyrics


If I buy an Ubuntu tablet, will I be able to use it in the same way as an ubuntu PC?

Yes, There are plenty out there. You can check out Dell Latitude XT3 laptop or Inspiron 13 7000 Series. You can also buy one with Windows and later install Ubuntu on it.


Has anyone out there been able to get Thunderbolt 3 to work on an X570?

There is an issue with PCIe bus number allocation on this chipset and motherboard, described here. The recommendation (adding pci=realloc,assign-busses,hpbussize=0x33 to the kernel command line) has worked for me and I was able to connect a Lenovo Thunderbolt 3 dock. However, certain other Thunderbolt devices (e.g. an eGPU) don't work for me on the system, which suggests that something else needs fixing.
EDIT: My current PCIe-related command line is: pcie_ports=native pci=assign-busses,hpbussize=0x33,realloc,hpmmiosize=256M,hpmmioprefsize=16G
This makes it possible to connect an NVidia Quadro P5000 inside a Razer Core X Chroma as an eGPU. My forum posts with details and context can be found on egpu.io, on ArchLinux forums, on NVidia forums and on Razer forums.
Thunderbolt docks still work and so do Thunderbolt 5k monitors (e.g. LG 27MD5KL, including the built-in USB-C hub, camera and audio device). (One just needs to plug the GPU's DisplayPort outputs into the motherboard's DisplayPort inputs meant for Thunderbolt.)


What's the name of the package to record YouTube audio to mp3?

You can do the following using the terminal:

To see all packages and look for the one you installed - dpkg --get-selections | grep -v deinstall
To see a broader list - dpkg -l
Use grep tool to search for the two keywords you mentioned above - dpkg --get-selections | grep [youtube-to-mp3]

If using Ubuntu version greater than 14.04, use apt list --installed.

Then after identifying the package (note: options 1 & 2 will give you large outputs as I saw when I ran it) you can simple do:

For Ubuntu 14.04 and older:

sudo apt-get purge <the-package-name>

For Ubuntu 16.04 and newer:

sudo apt purge <the-package-name>


Rate 144.0 Hz not available for this size

I solved this by typing in the full input. For some reason, this worked. I added the following line to my startup applications:

xrandr --output DVI-I-2 --mode 1920x1080 --rate 144.00

Where you can see the output by just running xrandr and choosing your resolution plus desired hz. Remember 144.00, just 144 will not work.


Keyboard layout stuck into CZ_german no english layout after update, restore into original EN_us and EL_Gr ones

Boot from a live usb and mount the disk that has the GNU/Linux Installed, keep in mind to mount the partition having the INSTALLED system's root filesystem (and not the root folder from the liveusb distro).

In my case has been the /dev/sda2 and I mounted as:

sudo mount /dev/sda2 /mnt

Using the command sudo fdisk -l and judging from the size and the type (correct one Linux Filesystem) you can mount the appropriate partition. In case of a wrongly mounted partition you can unmount it via the command (we are using the cd command as well in order to make not busy the mounted partition):

cd && sudo umount /mnt

Also In the mounted partition should containe the etc folder as well.

Having said that now you can nou type the following command:

sudo nano /mnt/etc/default/keyboard

And from:

# KEYBOARD CONFIGURATION FILE

# Consult the keyboard(5) manual page.

XKBMODEL="a4techKB21"
XKBLAYOUT="cz"
XKBVARIANT=""
XKBOPTIONS=""

BACKSPACE="guess"

Change it into:

# KEYBOARD CONFIGURATION FILE

# Consult the keyboard(5) manual page.

XKBMODEL="a4techKB21"
XKBLAYOUT="us"
XKBVARIANT=""
XKBOPTIONS=""

BACKSPACE="guess"

In case that the change has been into a desktop session that you are already logeedin then edit the /etc/default/keyboard directly (as long as you are able to locate the correct layout on the CZ_german layout.)

Save the file and then reboot. Once you login configure the keyboard layout via these steps:

First of all go to "System Settings" as the following Images show (System Language In Greek):

On the opened window then select "Input Devices" (in Greek "Συσκευές Εισόδου") as seen In the following Image:

Afterwards select Keyboard and click on the icons as seen in the following image (with the particular order):

Afterwards select to Change the layout using Alt+Shift following the instructions shown in this image:

So now you have restored the input languages back to Greek and English. Similar steps can be followed to restore into any desired layout.

The whole idea behind it is to first setup into basic us layout via any GNU/Linux live usb/cd, then install any localized layout.


you can use xfontsel to get the correct name of some fonts installed on your system. Then call it using for example xterm -fa "-*-nimbus mono l-*"

(you can also control+right click on the xterm window to get a menu)

But I advice you to use gnome-terminal or other alternative such as sakura or lxterminal which are easier to configure.


Is there a way to page through text one occurance of a string at the time?

Read man more.

It describes the command line option:

+/string
     The string to be searched in each file before starting to display it.

And it also describes the '/' and 'n' interactive commands:

/pattern  Search for kth occurrence of regular expression.  Defaults to 1.

n         Search for kth occurrence of last regular expression.  Defaults to 1.


Can I integrate the gmail ubuntu webapp with a google apps domain?

This was a bug, just fixed last week, it will not prompt you to integrate with either google apps or gmail accounts.


Anne Pro 2 Bluetooth keyboard sometimes disconnects with Ubuntu 20.04

I am using ANNE PRO2 as the latest firmware in the same environment. It works fine.
App Processor 2.19
Light Processor 2.16
BT Processor 2.03

Why not try making a Bluetooth connection again?
Ubuntu 20 asks for a PIN when connecting Bluetooth. However, the Bluetooth connection method of ANNE PRO2 does not provide a PIN, so the connection fails. So, you need to try pairing without a PIN number to connect successfully.
$ bluetoothctl
[bluetooth]# power on
...
[bluetooth]# discoverable on
...
[bluetooth]# pairable on
...
[bluetooth]# agent NoInputNoOutput
...
[bluetooth]# default-agent
...
[bluetooth]# pair XX:XX:XX:XX:XX:XX

Where XX:XX:XX:XX:XX:XX is to be replaced with the correct hardware address of the keyboard. To find this address, you can use:
[bluetooth]# scan on

The output will show addresses for available devices.


VirtualBox is a "virtual computer"; it looks like a full computer to the programs, and includes audio, video, disk drives, etc.  When it starts out, it is like a brand new computer without anything installed.

If you have a Windows CD, you can install windows within VirtualBox just like installing it to a new computer; same with other Windows versions or Linux.  You put the Cd in, or mount an ISO image of a CD, and reboot the virtual machine (called the "guest" OS).  The host OS continues to run normally while this is happening.

But you can't run the existing windows 7 OS in virtual box, or simultaneously with Ubuntu.


How can I fix the iptables error message "unable to initialize table 'filter'"?

You need to load a kernel module for enabling the filter table. Run the next command as root:

modprobe /lib/modules/$(uname -r)/kernel/net/ipv4/netfilter/iptable_filter.ko

(uname -r gives the current kernel version)

For a list of available modules for iptables, list the directory containing iptables modules:

ls /lib/modules/$(uname -r)/kernel/net/ipv4/netfilter/

To get information on all modules:

modinfo /lib/modules/$(uname -r)/kernel/net/ipv4/netfilter/*.ko


I think you have experienced a hard disk crash.  It was not severe enough to prevent rebooting, but when it mounted the drive / partition, it found the error and mounted it read-only (a fallback for most mounts).  Thus the padlocks.

If you do not have a good backup, my advice would be to shut down the computer and carefully remove the hard drive.  You may be able to mount the drive on another machine (using a USB->SATA cable) and backup your important data.  I expect that the drive is no longer trustworthy.


KDE connect unable to detect devices on same wifi network

Eventually, I found out the solution to my problem.
The true culprit was my wifi network which not allowing the communication between two connected devices. So here is the solution
go to your router settings and turn off the option access point(AP) isolation which dont allow the communication between the devices on the same network.
for me settings were at the following place but it may varry router to router

router>admin page>settings>wlan>wlan advanced settings>ap isolation>turn off

then your devices would be able to communicate with each other being on the same wifi network
admin for most of the routers can be accessed at

192.168.1


Can windows and its applications have any access to ubuntu data? (dualboot)

If you do not install ubuntu on a fs than natively supported by Windows (ntfs, vfat, ...) there is no way for Windows to directly access the data on the partition linux.

So if you install on ext4 and xfs there are no problems.

This however does not guarantee that in case of infection of other parts of the disk, such as the malware affecting the MBR


Wifi does not work well on Lenovo Thinkstation P320

I tried many things that did not work. The following simple fix did:

sudo apt-get install --reinstall network-manager


I don't know what that code means, but if you try installing the 64 bit version of 13.04 on a processor that has 32 bit architecture it won't work. Your VIA C7-M 1.6 GHz Ultra Low Voltage processor is single core and I can't seem to locate any specs that say it has a 64 bit instruction set, so it might be only a 32 bit processor, every reference I found said it was manufactured around April of 2005, I have older computers than that which support 64 bit, but they're not low voltage technology and yours seems to have come standard with XP or Vista with a non-specific Linux option. I don't recall if xp and vista were available in both 32 and 64 bit version as the last version of windows I used was xp.

I would suggest trying to install with the 32 bit 13.04 if you're not already... I hope it helps

Philip


Map caps-lock to control on Ubuntu 17.10

You probably want to install the gnome-tweak-tool package

sudo apt install gnome-tweak-tool

and start Tweaks.

Then: Keyboard & Mouse -> Additional Layout Options -> Caps Lock behavior


As grub does not natively support DOS based boot, you will either need to set up a truly complicated install setup, with a lot of chain loading, or you can just install burg, which supports as many OSs as I have ever tried with it. Use this to install it:

sudo add-apt-repository ppa:n-muench/burg && sudo apt-get update

sudo apt-get install burg burg-themes

Plus it supports themes, some really awesome ones out of the box too!


LibreOffice Writer inconsistent units: lines & inches

Go to Tools>Options (Then LibreOffice Writer - General).
Here is Screen-shot for selecting Measurement unit:


Slow folder opening due to folder scan in XFCE

I do following steps and it works for me:

Open /usr/share/gvfs/mounts/network.mount this file using an editor: sudo nano /usr/share/gvfs/mounts/network.mount
change AutoMount=true to AutoMount=false.
Save file and login again.

This will stop Thunar stating the Network every time you run it.

Have a nice time.


Ubuntu Phone BQ Aquaris E4.5 USB Problem

Ubuntu touch does not allow USB interaction as long as the phone screen is locked. Even if it is only locked by slide, this can block the interaction. I also made sure my screen doesn't lock after idleness, so this locking doesn't happen halfway through a transfer.

Also, ~/.android/adb_usb.ini on your computer is a list of valid vendorIDs that are allowed to connect. I found that list empty (or non existent, don't remember, doesn't matter). Just add a new line with the vendorID for your phone:
If you have MX4, add 0x2a45, if Aquaris E4.5, the ID is 0x2a47. Otherwise look it up by using lsusb. You can of course also add both to be sure ;)

~/.android/adb_usb.ini :

0x2a45
0x2a47


The 19.10 version works slow on VirtualBox

I miss 6.1.x release, under it it work as fast as I expected, without any additional changes. Thanks heynnema for hint.


Run a php or py script once at a unique dynamic wanted time

To schedule a command to run one time in the future, you can use at command. See the manual page (man at) for how to specify time and date.

From php you can use the system () range of commands to call any system command, inclusive at. Python also have a system but also a subprocess.run command.

PHP
PYTHON
man at


How to delete Google Drive files with GNOME online account?

I found the problem. I was trying to delete documents shared with me. I have discovered that shared files appear when I select to show hidden files in the file manager (Nautilus). In order to avoid confusions I think it is better no show hidden files.


New UbuntuGnome install doesn't pick up /home partition as 'home'

So I went back and re-installed UbuntuGnome and found that selecting partitions brings up other options that I wasn't aware of the first time (or was too scared to try!).

My old desktop and browser bookmarks are right where I left them.

Thanks for looking.


How to Create Virtual USBs on Ubuntu host connected to machines in virtualbox

Finally me and a friend came across a solution for this problem .
we add a virtual hard disk to the machine and yes !
it's working now :D


Testing Fgrep Gives Same Results As Grep

You may find it helpful to add the -o switch to make it easier to see what's happening:

$ grep -o 'subscribe|unsubscribe' testfile
subscribe|unsubscribe

Here we are using grep in Basic Regular Expression mode, where | is not special (it would need to be escaped \| to mean OR), so the pattern is matched as a single string

$ grep -oE 'subscribe|unsubscribe' testfile
subscribe
unsubscribe

Here we have switched to Extended Regular Expression (ERE) mode, where | is a regex special character, so we are matching two patterns, subscribe and unsubscribe

$ grep -oF 'subscribe|unsubscribe' testfile
subscribe|unsubscribe

Now we are matching in fixed string mode (like fgrep) and as expected | is not special - just like BRE.

fgrep is an (officially, deprecated) equivalent of grep -F so it behaves exactly the same:

$ fgrep -o 'subscribe|unsubscribe' testfile
subscribe|unsubscribe

As far as I know, @ isn't special in either BRE or ERE, so will always give the same result as fgrep or grep -F.


Intel Backport driver crashes the system completely

I fixed it by switching to a tty (Ctrl - Alt - F2) and then doing a

sudo apt purge backport-iwlwifi-dkms


How to get rid of double dash before the signature?

Open the Config Editor: Either
Tools -> Options or Edit -> Preferences

Go to Advanced -> General -> Config Editor

Then search for mail.identity.default.suppress_signature_separator
and set it to TRUE by double-clicking it.

Now all new emails are created without the -- before the signature.


From what you mention I that your laptop is running in UEFI mode and your other computers in BIOS mode , so your usb is booting fine in your other BIOS computers but not in your new UEFI Laptop.

Thats why you get normal boot screen in your BIOS computer.

UEFI is a new boot mechanism and replacement for BIOS.

You need to tell how you made the USB drive, and it should be made in such a way that it runs on UEFI systems.


Can't open viewport for graphics in NG Spice

This has been an irksome problem for me for some time.I found that if libXaw-devel is installed, (not just libXaw) and ngspice is reconfigured and compiled, then the "can't open viewport for graphics" goes away and ngnutmeg actually works.


It seems I can patch it with paramater -p0 instead of -p1 as suggested here

teddy@teddy-K43SJ:~/mapserver-6.4.1$ patch -p0 < oerdnj.patch
patching file debian/rules
patching file debian/control

I'm not sure but I dont get any error anyway


Take a file from Windows to Linux via tftp

TFTP predates Windows, so it does not use Windows naming conventions.  No C:\ drive for you! ;-)

Depending on the TFTP server you installed (Microsoft's?) and the version (which?) and what the configuration is of your server (config file?  Registry keys?)  you are "sharing" some subdirectory somewhere on one of your hard disks.

The tftp commands (type ?Enter or helpEnter depending on the server) actually look a lot like bash and the following are the most useful:

ls Lists files
cd changes directory
get gets (=downloads) a file
put puts (=uploads) a file
bye closes the session

Examples:
get test.txt or get test/test.txt gets the file text.txt if and only if you put your C:\ as the "shared directory" in the settings of your TFTP server.


Can apps developed in the Ubuntu SDK be ported to Android?

No, this isn't possible since apps for Android are written in Java and a special version of Java with a lot more classes that are just for Android. Ubuntu apps are written mostly in Python and C, not Java. There's your problem, you need to find apps written in Java and then they might go to port, but I wouldn't do it. It will be a lot of work for a thin chance of success.
And even if you get the Java app to start on your phone how will you interact with it? There will be no touch support or any other of the functions of your phone.


Spiking CPU frequency on Thinkpad X220 with i5-2540M Processor, Ubuntu 20.04

And when it begins, the CPU frequency is driving mad, going up and
done quickly, without stabilizing.

Yes, this is normal.

I suppose it could be related to the linux drivers and the power and
frequency management tools. Do you think it could be related ?

Don't know yet.

Currently, my computer uses the intel_pstat driver in active mode but
without the "Harware Managed P-states (HWP)" function available.
Should I run it in passive mode (intel_cpufreq) ? Or even use the
acpi-cpufreq driver instead ?

Your processor does not have HWP.
Yes, you should try both intel_cpufreq and acpi-cpufreq.
You should also try limiting your maximum CPU frequency with the current intel_pstate driver, as a test. Do:
$ echo 75 | sudo tee /sys/devices/system/cpu/intel_pstate/max_perf_pct

adjust the 75 up or down as required.

Would you know some tools that would allow me to precisely look at my
CPU frequency ?

I prefer turbostat, (I forget which package, maybe linux-tools-common and/or linux-tools-5.4.0-26 (or whatever kernel version)) and it is the only tool that upstream escalations will accept as authoritative. Myself, I run this command almost always:
~$ sudo turbostat --Summary --quiet --show Busy%,Bzy_MHz,PkgTmp,PkgWatt,GFXWatt,IRQ --interval 6
Busy%   Bzy_MHz IRQ     PkgTmp  PkgWatt GFXWatt
0.01    3568    194     30      1.81    0.00
0.01    3700    112     30      1.76    0.00

And never use a short interval. Often users do not seem to realize that idle CPUs can go into deep idle states for multiple seconds at a time, and they wake them just to sample stuff.

Do you know where I could my processor Model Specific Registers (MSR)
to help me to configure my driver settings ?

If you want to start messing with the MSRs yourself, then you need to use the several thousand pages Intel 64 and IA-32 Architectures Software Developer’s Manual. It is very difficult to follow and to find the appropriate pages for your specific model of CPU. I wouldn't go there just yet.


3G D-Link DWM-157 Modem Install on Ubuntu 12.04

I am running the 157 on Mint 16 now, working fine, but the install not smooth: installed the .deb no problem, nothing happened though- no detection by network manager. Had to unplug eth0 and reboot- then Network manager detected it.

The documentaion for this device is close to non-existant, playing around I discovered a more elegant solution (but still not perfect):

The software installs a script: 3g_connect.sh

Run 3g_connect.sh form the terminal:

3g_connect.sh 003:010

ie the arguement to 3g_connect.sh is the BUS:DEVICE pair from you post:

  my USB-device is found ("Bus 003 Device 010: ID 2001:a707 D-Link Corp.")

Note: The 3g_connect.sh script should be run as root for it to work, but running it as a normal user did force Network manager to detect the dongle- and I could then use Network manager to manage it- which I prefer).

Hope this helps.


Copy ubuntu.iso to Usb Stick with two partitions

I'll answer you question in an effort to clear your confusion.

You can make a bootable USB.  Just install Ubuntu the USB stick.  Once you have this bootable disk, you can repartition, resize, and make the same changes to the USB drive the same way you do on your regular system's hard drive.

This bootable drive that you have created can be cloned to an ISO, just as your regular internal hard drive can be cloned to an ISO.  You use the dd command in your question to make copies of this ISO into other drives.  After you make copies you can also edit and modify the partitions as you indicated for your criterion.

The thing you can't do is make an ISO of a CDROM installer, or use a LiveUSB ISO installer (which is built using the same basic algorithm of a DVD, but on an USB stick instead) as your cloned drive.  As you see from the details your experience included in your question, the drive would be corrupted (as far as being able to boot) if you make partition changes.

While this isn't what you are looking for, a deliberate and specific design has gone into making an installer version (called a persistent usb) to overcome the limited design and intent of the OS installer.

An ubuntu installer with the ability to modify the partitions of the media doesn't exist at this time.  If it did exist, someone would post the source as an answer, or point you to the solution.

You could, alternatively, while it may take a lot of work, make your own installer and add it to your own Ubuntu pendrive.  It's discussed here:
 Install from existing Linux

This is an alternate method of making your own LiveUSB for your Pendrive:
Installation/FromLinux

I haven't attempted to create this environment.  So I can't comment on whether the task would be easy.  I'm just trying to provide you with what would be involved if you are trying to have a Pendrive that can be used as an installer and also have partitions that are editable.


Have you installed a PPA for gwibber recently?

If so, I would guess it is a problem with the repository.
Check in

System Settings > Software Sources > Other sources

and look for a line ppa.launchpad.net/gwibber

Remove it or disable it and it should solve your issue (but you won't have the latest version of gwibber anymore).


How to detect html5 video playing in Chrome?

I had the same question on Ubuntu & Unix Stack Exchange site and I understood that:

  The HTML 5 "player" doesn't have any corresponding plugin and the code
  for it  is embedded directly into the browser. So you won't see a
  process getting forked from Chrome when it's dealing with this type of
  content.

Thanks to slm for this answer.

Related: How can I determine if HTML5 player is running in browser?


The semicolon must be removed

Exec=xfce4-terminal --geometry 94x51+0+0 --title asd -H -x sh left_terminal.sh;

should instead be:

Exec=xfce4-terminal --geometry 94x51+0+0 --title asd -H -x sh left_terminal.sh


After upgrade from 12.04 to 14.04 log in loop

Perform the following:

Ctrl + Alt + F3.
Login as your user.
sudo service lightdm stop
startx

Please post the results in your original question.  I'll update this answer depending on your output.

Update

As per your comments, now that we've verified your terminal is working we need to install some tools, you may already have these:

sudo apt-get install lshw pciutils nano

Now that we have the tools, post the output of lshw -class display and nano -w /var/log/XOrg.0.log

Update 2

Knowing your Laptop model is a Compaq 615 AMD Athlon X2 Dual Core QL-66 leads me to the official tech spec document, and the following Linux Mint Post:

ATI Mobility Radeon HD 3200 Proprietary Driver for Linux Mint 12

The big red note on that link is what you're experiencing.

Explanation

During the distribution upgrade process your kernel was updated to a newer kernel.  Doing so, the upgrade process was unable to use the default radeon driver for your cards, because you had the frglx driver installed.  Since your old driver is not compatible with the newer kernel, we have 2 options:

Downgrade to the kernel your frglx driver works with, or
Replace the frglx driver with the default driver and then manually install the older frglx driver.

I personally prefer option 2. So without further ado, I present the

Resolution

From the Command Prompt, issue a:
sudo apt-get remove --purge xorg-driver-fglrx fglrx*
sudo apt-get install --reinstall libgl1-mesa-glx:amd64 libgl1-mesa-dri:amd64 libgl1-mesa-glx:i386 libgl1-mesa-dri:i386 xserver-xorg-core
sudo dpkg-reconfigure xserver-xorg
sudo reboot

This should get lightdm started so you have a GUI, because we need a browser to go to the Legacy AMD Driver Download Page and Download  Legacy Version 13.1 for ATI Radeon Series 3xxx.  If something failed, and you have no GUI, issue:
    sudo apt-get install wget && wget http://www2.ati.com/drivers/legacy/amd-driver-installer-catalyst-13.1-legacy-linux-x86.x86_64.zip

Save this for later, as this driver only works for kernels where the version is <= 3.4.0.  Since the Ubuntu Kernel is now >= 3.13.0, we will run into the same issue again.  This leaves us 2 options:

Manually Download the last available release of the 3.4 Kernel for Ubuntu Manually.  If you choose this option Download and install every .deb file in that directory, along with the patches.  Note: Using this option prevents you from upgrading to any kernel above Debian 3.4.105 during system updates!
In exchange for a permanently downgraded kernel, you may now install the legacy frglxdriverby unzipping the file above.  Be sure to use chmod +x on the extracted file.
Install the in-kernel Radeon Driver.  This was done in step 1 of the Resolution Section.  You can now delete /etc/X11/xorg.conf if you still have one.  In exchange for the in-kernel driver, you can continue upgrading to newer kernels as they come out.

References

X Troubleshooting -  Ubuntu Wiki - Purging frglx
The definitive guide to proprietary AMD graphics drivers
Ubuntu Wiki - Radeon Driver


Ubuntu 20.04 not booting with /dev/nvme0n1p7:clean

Boot with a live Linux USB, in Terminal on it.
sudo fsck -p /dev/nvme0n1p7

You have file system corruption that needs to be fixed on the install partition, that is what that error is telling you.


It is always a good practice to use last version of softwares and operation systems unless it's somehow is not possible for you or your situation.

It's been a while that Ubuntu adopted systemd and all further versions will came out with systemd unless something magically happens. so it's better to use 16.04 now and learn to work with systemd from beginning.

The other thing you should consider is the support.
Ubuntu 14.04 end of life is April 2019 while 16.04 is April 2021. From: Releases.

If you want to don't touch your OS for a long time, enjoy stability and more up to dated softwares, I suggest updating to 16.04.

If you don't have any important installed package, config, etc. I even suggest a fresh install of 16.04.


Which package should I install to solve this problem?

Use apt-file to search through the contents of packages.

To install and build the file index:

sudo apt-get install apt-file
sudo apt-file update

To search:

apt-file search predefs.h

That will give you a package name and an absolute path to where the file would be installed.

If that doesn't return anything, then search through the Ubuntu package directory using the package contents search (make sure you have your version selected in the "Distribution" field).

If that didn't turn up anything, my last piece of advice would be to Google it (I.e. "Ubuntu trusty predefs.h package) - although, I should warn you, what you find may not be as secure as the other two methods.


Set appropriate ownership to .Xauthority and .ICEauthority.

chown username:username .Xauthority
chown username:username .ICEauthority

Set permission for /tmp

sudo chmod a+wt /tmp

Restart lightdm

dpkg-reconfigure lightdm
sudo service lightdm restart

Reboot and login, this should fix your problem, if not then remove incompatible graphics driver:

For Nvidia:

sudo nvidia-settings --uninstall
sudo apt-get remove --purge nvidia*

For amd:

sudo apt-get purge fglrx*


How well will the Toshbia Chromebook 2 (celeron 3215U processor) running Ubuntu be suited for local android and web development (not cloud)?

Frm my experience using the acer chromebook c720, the celeron processor, although works great with ubuntu in terms of hardware support (I suggest HugeGreenBug's custom build), chokes a bit at processor-intensive tasks like compiling. If your development involves such tasks, I suggest you go with the acer c720 with core i3.


How to ssh into a server running on a home network, behind a router?

There are multiple things you need to do:

1) Like fkraiem mentioned in his comment, make sure your VM is accessible on the local network. Using a 'bridge' network connection in the VM settings should accomplish that. Then using one of your other computers (even your host), check to see if you can log into the SSH server. If you can, congrats, let's move to the next step.

2) Next you need to know how to port forward on your router. Since you didn't mention what router you have, you will have to figure that out yourself. Port 22 is the one used by SSH. Of course you can listen on a higher port on the router to avoid having your logs filled up by a bunch of script kiddies trying to hack into your server, and then forward the port to 22 on your server. For example, lets imagine your local IP for your server is 192.168.0.10. Your WAN (Internet) IP is 99.99.99.99.

99.99.99.99:60022 -> Router -> 192.168.0.10:22

What you want to do is tell your router to listen on port 60022, and forward that to IP 192.168.0.10, and port 22.

To figure out what your WAN IP is, simply google 'what is my IP address'. There are other ways, but it is the easiest.

Now, after you setup the router, try to connect with an outside computer to your WAN IP with the higher port. You could tether with your cellphone to a laptop to accomplish that.

If you could connect with that, congrats again.

3) Now you have to make sure your IP addresses stay static on your local network, and you would need to get a dynamic DNS entry for your WAN IP address. This way you would use a domain name instead of your WAN IP. Google 'dynamic dns' to find some free service.

Hope that helped.


Your video card drivers version should be 340.46. I am sure you can open nviida-settings and check out version, and also adjust all related power-management fields in nvidia-settings.

In Kubuntu default power management, make sure you check your settings for all of the 3 sections present in there, namely AC POWER, ON BATTERY, ON LOW BATTERY. Disable Dim Display feature for AC POWER, ON BATTERY and ON LOW BATTERY, and disable Suspend feature for ON LOW BATTERY.

You can always reinstall your drivers from nvidia official page, and this is the link for G105M 32bit, and this one is for G105M 64bit. These are complete drivers, and not stripped drivers, and to install these drivers after downloading them you need to press Ctrl+Alt+F1 key combination, login with username and password, and run the usual command for installing drivers. Nvidia installer will give you a prompt about uninstalling old drivers in order to install the new ones.

If you find errors when trying to install official drivers for nvidia cards, you need to install previously to that the following packages --> dkms fakeroot build-essential:

  sudo apt-get install dkms fakeroot build-essential

Aftyer that you reboot, and finally you can enter the text-mode console (press Ctrl+Alt+F1 key combination, login with username and password) and install new drivers.

This one is for 32bit Ubuntu:

  sudo sh NVIDIA-Linux-x86-340.46.run

This one for 64bit Ubuntu:

  sudo sh NVIDIA-Linux-x86_64-340.46.run

After reboot, run this command in a terminal window:

  sudo nvidia-xconfig

And reboot again, and you're done, you can open nvidia settings with sudo nvidia-settings command, adjust settings to your preference, apply new settings and Save to x configuration file (uncheck "Merge with.." when saving your new X config)

Do the same steps in Kubuntu power management as shown above, and also make sure you adjust video drivers with nvidia-settings to match your power-manager configuration.


In bash, to call (refer) a function just use the function's name, () is not to be used.

So change call() to just call to refer to the defined function named call.

Note that, you still need () in function declaration time.

So, for example, while declaring:

foobar () { .... ;}

While referring:

foobar

In sh (dash), the reference call() will be silently ignored without raising an error and the shell will just move on to the next line of script.

Also unless you are sure, it is better to use bash to run these sort of scripts to avoid surprises.

Also there are many things that could be improved in your code, which is out of the scope of this question.


Issue with booting from USB with GNU Grub2

There could be a few reasons why this is the case:

a) For some reason the BIOS is not detecting your applied boot order. Try pressing F12 or the appropriate key for your laptop/PC to get into the "One Time Boot Menu". This should allow you to boot from the USB.

b) The ISO you downloaded could be corrupt. Try re-downloading the ISO and putting it on the USB again.

c) The USB could have bad sectors/some other critical problem. Try using a different USB.

d) You have not put the ISO on the USB correctly. You might like to see one of create a Ubuntu USB stick on Windows, create a Ubuntu USB stick on Ubuntu or create a Ubuntu USB stick on Mac OS X.


Telephone Call Answering Machine Software

Sounds like a job for mgetty:

 Mgetty is a versatile program to handle all aspects of a modem under Unix.
 .
 The program 'mgetty' allows you to use a modem for handling external
 logins, receiving faxes and using the modem as a answering machine without
 interfering with outgoing calls.
 .
 This package includes basic modem data capabilities. Install mgetty-fax to
 get the additional functionality for fax. Install mgetty-voice to get the
 functionality to operate voice modems.
 .
 Mgetty is also configurable to select programs other than login for
 special connections (eg: uucico, fido or other programs) depending on the
 login userid. It also supports caller-id if the modem and phone line
 supply it, and can deny connections based on originating telephone number.

Note that mgetty will require you to be comfortable with command-line utilities and modifying configuration files, as it has no graphical, friendly front-end. Feel free to google for "vgetty frontend" to get pointers to options for this need (sorry, I can't help there as I don't use either mgetty or any frontend for it).


How can I set up Evolution to access a local mail box?

This answer follows the premise that you're using a mail spool, if its mbox format your mileage may vary:

Start Evolution, then go to Tools -> Settings.
Click Mail Accounts -> Add -> Forward.
Type in a name in the Full Name field.
For the Email Address field, type in your login ID followed by @localhost. For example: lazypower@localhost Click Forward.
Click on the drop down list box and select Local delivery. If the Path field in the Configuration section isn't already filled in, you'll need to type in the location of your local mailbox. Using the login ID from above as an example, here's what would be entered: /var/spool/mail/lazypower Click Forward.
If you like, you can setup Evolution to automatically check this
mail account. Click Forward.
You're not going to be sending mail with this account, so you could just leave everything alone in the Sending Email window. However, I change the Server Type to Sendmail. Click Forward.
Finally, enter a name for the mail account. The name "Local Messages" is a good choice. Click Forward and Apply.

Thanks go to this post I've verified the instructions locally. Works without a hitch.


Firefox Automatically Starts Video Audio In New Web Pages

It's easy to disable autoplay. Type 'about:config' in the address bar, search for media.autoplay.enabled, and set it to false.


Problems with Netplan's config for Ubuntu Server 18.04.5 for Raspberry Pi

Your .yaml file lacks proper formatting...
It should look like this... same indentation, spacing, and no tabs:
network:
  version: 2
  renderer: networkd
  ethernets:
    eth0:
      dhcp4: true
      optional: true
  wifis:
    wlan0:
      dhcp4: true
      access-points:
        "YOUR-SSID-NAME":
          password: "YOUR-PASSWORD"

sudo netplan generate
sudo netplan apply
reboot
You must also install wpasupplicant...
sudo apt-get update
sudo apt-get install wpasupplicant
reboot
If your .yaml keeps getting overwritten...
You may also need to create /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
network: {config: disabled}


If you are using Deja-Dup you click on Storage location in the left column, then click on the down arrow in the top box.  Scroll down and select "Local Folder".  Then, back on the main screen, click on Choose Folder and find where your network share is mounted.

I found it a little confusing at first to look for my network share in Local Folders too....


Ubuntu not Booting ,GRUB screen not disappearing

Can you boot your computer to the live CD/DVD?  If so, and if the computer appears to work correctly booted to the CD/DVD then open Disk Utility from that CD/DVD and check to see if the hard disk is healthy.

It has been my experience that when people install Ubuntu on old computers and have problems, the cause very often is that the hard drive is sick.

On the other hand, if you cannot make your computer work correctly even running Ubuntu from the live CD/DVD, it could just mean that your computer simply isn't particularly compatible with Ubuntu.  I run into that occasionally.


SABnzbdplus will not start on boot but running the init.d script runs fine

The guide forgot

sudo update-rc.d sabnzbdplus defaults

This command will add the links at the correct runlevels so that sabnzbdplus starts and stops when booting, rebooting, shutting down, etc.

edit: if you get the message that those links are already in place have a look at this question

edit2: or this one


Mute key mutes Master and Headphone/Speaker (alsa channels), but unmutes only Master

Thanks so much! This helped me with my Arch/LXDE setup - the mute button xml that is recommended on the LXDE wiki mutes all of the channels in alsamixer and doesn't unmute them (at least not for my sound card).
How I got it fixed:
I changed the XF86AudioMute command value to:
amixer -q -D pulse sset Master toggle


Wired Connection not detected on Ubuntu 12.04 LTS, which was working fine few days ago. Solution for "wifi disabled by hardware switch on Dell xps"

Ok..I realized what the problem is... it is because of a loose connection in my lan port (a little loose lan wire), Ubuntu 12.04 couldn't recognize my lan wire, but surprisingly Windoes 7 recognizes without any problem... I dont understand this , though. When I replaced my lan wire, with a nice tight one, Ubuntu recognized it instantly...

Somebody can please throw a light on this.

Also , I want to answer about a kind of solution for 'wifi disabled by hardware switch on Dell xps' but i couldnt as i my reputation is low.
So, I am asnwering it here.

There are many opinions in the forums, like:
you can get your wifi enabled on Dell xps (where one doesnt have a separate hardware switch)
1) Fn + F2
2) Alt + Fn + F2
3) changing ssomething in the /etc/network/interfaces file

I have tried these all, but these wont work all the time...

but for me, what works all the time on my Dell xps L502x is:
CLICK ON THE STAR BUTTON ON THE RIGHT TOP CORNER ON UR DESKTOP AND CLICK on 'SUSPEND'
then, IMMEDIATELY, WAKE UP FROM THE 'SUSPEND' MODE
and , then DO 'Fn + F2' one or two times...
Then wifi gets enabled on my laptop without any fuss whatsoever
I accidentally figured this out. had I figured it years ago, I would have saved myself of lot of torture about wifi connectivity problems

Hope this helps many other people like me, who was frustrated for about 1 and half years with this problem, but beleive me, I absolutely don't have a problem now


Different nmap results from different machines?

To configure Postfix for for Gmail, please use host-names instead of IPs.

For example to connect to Gmail's SMTP server, you need to use smtp.gmail.com and for IMAP you need to use imap.gmail.com

Yes, IP's will change based on your location and results may vary but host-names will work fine.

Please, refer to this link for ports and additional configuration help.

Please note:

Insecure connections are not supported by and may not be used with Gmail servers