Unable to change desktop environment with Lightdm in Ubuntu 20.10

I can confirm the discovered behavior on fresh Ubuntu MATE 20.10 VM.
I have reported bug 1910279 to LaunchPad.
As a workaround you have to remove Arctica Greeter by:
sudo apt autopurge arctica-greeter

then install Slick Greeter back with
sudo apt-get install slick-greeter

then apply green MATE theme from Ubuntu MATE 20.04 LTS to it by executing long single command
cat <<EOF | sudo tee /usr/share/glib-2.0/schemas/31_ubuntu-mate.gschema.override
[x.dm.slick-greeter]
background='/usr/share/backgrounds/ubuntu-mate-common/Green-Wall-Logo.png'
background-color='#3C3B37'
draw-grid=false
draw-user-backgrounds=false
enable-hidpi='auto'
font-name='Ubuntu 11'
icon-theme-name='Ambiant-MATE'
high-contrast=false
show-hostname=true
#logo=Logo file to use
onscreen-keyboard=false
#other-monitors-logo=Logo file to use for other monitors
# play-ready-sound=A sound file to play when the greeter is ready
screen-reader=false
show-power=true
show-a11y=true
show-keyboard=true
show-clock=true
show-quit=true
theme-name='Ambiant-MATE'
xft-antialias=true
xft-dpi=96
xft-hintstyle='hintslight'
xft-rgba='rgb'
EOF
sudo glib-compile-schemas /usr/share/glib-2.0/schemas

then reboot and login to i3 session.
Also I would recommend to revert all manual changes, which you have done.
All system files are controlled by APT and your method is incorrect.

Notes:

to revert the above customization use sudo rm /usr/share/glib-2.0/schemas/31_ubuntu-mate.gschema.override; sudo glib-compile-schemas /usr/share/glib-2.0/schemas ; sudo apt-get install arctica-greeter.
for longer support and to decrease number of surprises I would recommend to install Ubuntu MATE 20.04 LTS with 5-year support instead of 9-months-supported 20.10.


I don't know, but you can install firestarter, where you can disable firewall or see active connections. It's not best firewall manager, but it's easiest way to see active connections. After installing (most options are OK by default, you will see window look similar to this:

Click on Active connections, and you will see connection name, destination, description and port.


I recently went thru the same thing with a couple of programs (including Eclipse) that I had downloaded and ran locally from the user home directory via command line, but wanted a functional launcher icon to run from the desktop or dock.

This portion of the Ubuntu community docs pretty much covers everything you need.

Unity Launchers and Desktop Files


Fastest method to clone one drive to another

After enough tinkering I engineered a viable script solution.
The best way to optimize dd is increase/decrease bs.

This requires super user mode:
sudo su

Then execute:
pv -tpreb /dev/sda | dd of=/dev/sdb bs=64M

pv -tpreb displays a visual representation of the download rate along with download per second.

Changing the bs (blocksize) enabled a faster data rate for my cpu. Apparently it can handle a larger bs than I thought it could.


Installation stuck on creating ext4 file system # 1

I had the same issue but I was installing kali linux
I found a solution !

Its actually quite simple.

Boot into a live instance of any OS (can be the same one you are installing)
Go into the files and completely format the disk you wanted to install your linux on . If they give you an option for the file system just choose ext4
It should be done in a matter of a second , your drive wil dissapear but restart and install it this time
Give it at least 10 mins
It should be installing now !!


What do you suggest to use between Clamav and Sophos?

but if i transfer some files in Windows it should be good idea to scan the files

That is almost the only valid reason to use a virus scanner on Linux. If it is for Windows files you can stick with 1 up-to-date virus scanner. Those scanners do an amazing job on Windows files and will pick up all viruses when the definition of a virus is there.

  If i install both, can they to be in conflict?

You can install both. Thing is: both will claim as much resources to work with as they can so using both at the same time is not the smartest thing to do.

For scanning Linux files I would always install 2: update the definitions regularly, use one automatically and the other manually. When the 1st sets of an alarm, stop it and scan manually with the 2nd one, compare notices and dismiss all notices one and not the other reports. Those will be false positives (if they are both up-to-date). What remains should be investigated. You can do the same for Windows files.

  About the privacy, do Clamav or Sophos gather information about the files that they scan?

Not from what I have seen.


Will my all files be the same after updating from 10.04 to 12.04?

If you're doing an upgrade - your personal files, settings and applications you installed will be preserved, you won't have to reinstall them.

If you're doing a clean install then you will need to re-install applications.

In both cases it is advisable to make a full backup of your personal data.

Regarding Unity - Ubuntu 12.04 will include so-called "fallback mode" which is somewhat similar to Gnome 2, though it's not identical.

You can see a screenshot here: https://askubuntu.com/a/113991/14564


Skype indicator missing on 18.04 - Skype bug or related to my particular config?

Simple answer:

env XDG_CURRENT_DESKTOP=Unity skypeforlinux


I did the exact same thing and felt the wrath of my mistakes. The easiest solution is to first uninstall the new driver you have installed and then reinstall one from a ppa or the ubuntu repos.

To Uninstall (might not be necessary, but less chance of mistakes)

I can't quite remember which method I used because this was a few months ago, and I break my system a lot.

If you still have the .run file from NVIDIA's website you should be able to run the command:

/path/to/nvidia-XXXX.run --uninstall

Obviously replacing the "/path/to" path with the file system path. If you don't know how to enter that, just open a terminal and drag and drop the nvidia-XXXX.run file into the terminal and type --uninstall after it.

Alternatively (I'm not sure if this actually uninstalls the nvidia driver, but this is what I did I think, so I maybe I didn't even uninstall the old driver before updating :P)

sudo apt-get remove nvidia-current

To re-install the standard driver

Easy, just a couple commands.

sudo apt-get install nvidia-current

and then you can restart. If there is problems with your xorg.conf file, then this might not work immediately (but if you can log in and be on your way, great!)

If it doesn't immediately work, run the following

nvidia-xconfig

This should automatically generate a working xorg.conf for you.

To install the most up to date driver for your graphics card

Since you installed the driver from the website, I'm going to assume you wanted a more recent driver then in the standard repositories. This can be done very easily.

Simply add the X-Swat repo which contains up to date graphics drivers and all the other components they need to run smoothly.

sudo add-apt-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get update

and then install nvidia-current like normal, or update it if you didn't bother to uninstall it above. Just installing it by itself should prompt you to download the appropriate X versions as well.

sudo apt-get install nvidia-current

or

sudo apt-get upgrade

And again if it doesn't work after a reboot;

nvidia-xconfig

Hope that works out for you!


I have exactly the same laptop and the answer by izx from this thread did the job for me on Lubuntu 12.10:

Wireless card Realtek RTL8723AE-BT is not recognized

I also fallowed user239558 suggestions and downloaded newest driver from here:
www.liteon.com/UserFiles/driver/Module/Network/WLAN/RTL/rtl_92ce_92se_92de_8723ae_linux_mac80211_0007.0809.2012.tar.gz


Read about TestDisk here --> Tesdisk

It will rebuild the partition table so you can get to the data. I think it will work on your usb drive.

It's a command lines tool but you should be able to find a how-to for it.

TestDisk is in the repositories:

sudo apt-get install testdisk

Hope it`d work for you!


Note: I only recommended this method if you wish to disable a port for the long-term. If you want to fix undesired automatic port switching, and still be able to use all of your ports, I recommend a different solution.

To completely disable a port:

Navigate to /usr/share/pulseaudio/alsa-mixer/paths

Find the .conf file for the port you want to disable and add .backup to its name.

In your case, you might want to change analog-output-speaker.conf to analog-output-speaker.conf.backup

This makes the file invisible to pulseaudio while retaining it as a backup.

To make the change effective, log out and log in.


pyspark is available via pypi.

So all you need to install pyspark is pip and execute the following command.

pip install pyspark or sudo pip install pyspark


Grub doesn't recognize Windows after Ubuntu 12.10 installation

I am sorry you have the issue, this can be frustrating, try the following utility and let me know if it helps you.

Boot-Repair is a simple tool to repair frequent boot issues you may encounter in Ubuntu like when you can't boot Ubuntu after installing Windows or another Linux distribution, or when you can't boot Windows after installing Ubuntu, or when GRUB is not displayed anymore, some upgrade breaks GRUB, etc.

This can also be performed from a live-CD or live-USB.

Either add ‘ppa:yannubuntu/boot-repair’ to your Software Sources via the Software Centre or, for speeds-sake, add it using a new Terminal session:

sudo add-apt-repository ppa:yannubuntu/boot-repair

sudo apt-get update

sudo apt-get install -y boot-repair && boot-repair

Boot-Repair can be installed & used from any Ubuntu session (normal session, or live-CD, or live-USB). PPA packages are available for Ubuntu 10.04, 10.10, 11.04, 11.10, 12.04 and 12.10.


Boot ubuntu live usb and run install.Don't choose update from ubuntu 10.04 to 12.04,choose something else option.Select the ubuntu 10.04 partition and format it to ext4 filesystem.Then choose the same partition to install ubuntu 12.04.


I have Privacy: Record activity ON but how to view log and all the stuff?

You can browse the recorded data using the gnome-activity-journal tool.

sudo apt-get install gnome-activity-journal

From the command line, AFAIK there's no friendly tool to extract such data, but you can use the API, see this post on SO.


bash: .bashrc: line 148: syntax error: unexpected end of file

Your .bashrc should look something like this
# enable programmable completion features (you don't need to enable
# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
if ! shopt -oq posix; then
  if [ -f /usr/share/bash-completion/bash_completion ]; then
    . /usr/share/bash-completion/bash_completion
  elif [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
  fi
fi

PATH=$PATH:/home/rbh/PROGRAMS.330/bin export PATH

You deleted last fi which was closing the if block condition


Savvas Radevic (medigeek) wrote on 2010-06-13:
https://bugs.launchpad.net/ubuntu/+source/gnochm/+bug/538773


How to display wireless interface bitrate on the Unity panel?

Custom indicators to display bitrate

This answer provides two solutions to creating custom indicator to display wireless interface bitrate on the Unity panel.  Users are encouraged to choose which suits their needs more appropriately. The answer is made as detailed as possible, so please excuse the wall of text.

Reasoning for two solutions

It is my frequent practice to provide solutions to the user that require minimum dependencies and are as self-reliant as possible, while finding simplest solution. Solution #1 relies on use of an indicator-sysmonitor built by fossfreedom - one of our great community members and moderators, and requires use of two items - custom script and the mentioned indicator. The fact that I couldn't find a way to query bit rate from a statistics file somewhere in /proc or /sys filesystems also bothered me. Hence I created a second indicator, which however relies on Network Manager and dbus. Thus advantage and disadvantage of each method are apparent: one requires installing indicator-sysmonitor and custom script but will work if a user avoids Network Manager , while the other is more suitable for a standard Ubuntu system that uses Network Manager.

Ideally,the solution would be as self-reliant as possible, querying specific library and/or file within /proc or /sys filesystems. In my research so far, however, I didn't find such file, and iw command on which one of the solutions relies does so internally. What also complicates the things is that apparently 802.11 wireless standard has different modulation schemes to encode the signal and bitrate calculations are done considering the modulation scheme and frequency of the interface that is being used. While there are ways to obtain TX and RX bytes per second, the data differs from what iw output displays. On the other hand, going all the way to C and system level seems too much for this task. Thus, even though I'm not entirely satisfied with both solutions, they provide appropriate results for what this question asks.

Solution 1: indicator-sysmonitor with custom shell script

Indicator Sysmonitor is an indicator created by fossfreedom, and typically is used to display common statistical data like CPU and memory usage, but the best thing about it is that it allows use of custom scripts. Thus, the idea is to have a script that can query bitrate somehow, and display it via indicator-sysmonitor. For the sake of TL;DR here's abbreviated list of steps:

install indicator-sysmonitor by running in terminal

sudo add-apt-repository ppa:fossfreedom/indicator-sysmonitor
sudo apt-get update
sudo apt-get install indicator-sysmonitor

Create the ~/bin/bitrate_script.sh script , make it executable with chmod +x ~/bin/bitrate_script.sh with the following contents

#!/bin/bash
iw dev wlan7 link | awk -F '[ ]' '/tx bitrate:/{print $3,$4}'

Configure indicator-sysmonitor to display output of your script as custom sensor from Preferences->Advanced->New , using br for sensor and full path to script as command.

Obtaining indicator sysmonitor

As explained on the GitHub page of the project, you can install it from source or via PPA. The PPA method, in my opinion, is the simplest, hence given here:

sudo add-apt-repository ppa:fossfreedom/indicator-sysmonitor
sudo apt-get update
sudo apt-get install indicator-sysmonitor

Once installed, it can be called via command-line as indicator-sysmonitor or from Unity dash.

Setting up bitrate shell script

Such shell script can be done via parsing iw dev <IFACE> link command. The command takes wireless interface as argument, for example wlan1 or wlp6s5 ( note the difference due to predictive interface naming in systemd ) and displays various data, among which we have tx bitrate. For instance:

$ iw dev wlan7 link
Connected to XX:XX:XX:XX:XX:XX (on wlan7)
    SSID: my_wifi
    freq: 2447
    RX: 102456319 bytes (171120 packets)
    TX: 6992103 bytes (50371 packets)
    signal: -46 dBm
    tx bitrate: 150.0 MBit/s MCS 7 40MHz short GI

    bss flags:  short-preamble short-slot-time
    dtim period:    1
    beacon int: 100

As you can see, the output requires text processing to output one line of text (since that's what indicator-sysmonitor requires), and that can be done via awk command. Here's for example the way I've set up my script:

#!/bin/bash
iw dev wlan7 link | awk -F '[ ]' '/tx bitrate:/{print $3,$4}'

If you run the script on the command-line, the output will be simply the bitrate and the units string:

$ iw dev wlan7 link | awk -F '[ ]' '/tx bitrate:/{print $3,$4}'
135.0 MBit/s

Remember to make your script executable with chmod +x command, otherwise it won't run.

Displaying output of script in indicator-sysmonitor

To be precise, the indicator has several settings in the preferences which it calls "sensors". For instance, if you set to display CPU: {cpu} it would display CPU as text and substitute actual percent of CPU usage instead of the curly braces string. The great thing about it is that by clicking New button, you can add a custom script to be displayed as "sensor".

In the screenshot you can see that I've added my custom script as br sensor formatting string , and for Command I've given full path to the script which lives in my ~/WIP folder. There is nothing special about that folder, it just happened to be location for the stuff on which I currently work ( Work-In-Progress, basically ). Users however are usually encouraged to place scripts into ~/bin folder, thus I would recommend you do that.

If you have followed the instructions properly up to this point, you should have indicator-sysmonitor show the bitrate just like in the screenshot.

Solution 2: Custom indicator using Python and Network Manager's dbus properties

I wasn't quite satisfied with the above solution, which relies on indicator-sysmonitor and a custom script. I wanted to have a singular indicator which does the job all from within itself. Hence I've written an indicator of my own in Python 3 , which relies on information that Network Manager exposes via dbus interprocess communication system. In short, the big work is done by Network Manager - we just use the information it provides. Advantage of this indicator is that the user doesn't have to define the wireless interface to be used - it's done automatically.

Theory of operation

Indicator effectively repeats same action - the get_bitrates function every 1 second. That function queries dbus properties on several interfaces in sequence. First, it obtains all devices and filters out 802.11 wireless devices. Next, we iterate over each wifi device and query their name and bitrate. Everything is built up into one string of text which is then displayed on the indicator label.

In theory, the indicator should be able to determine bitrate for multiple wireless interfaces. For instance, users may have internal PCI-e wireless chipset, and USB chip. Unfortunately, I did not get to test this due to issues with my laptop , as well as due to time constrains. I may test this on another laptop once I have the chance and will edit the answer accordingly.

Source code

Also available on GitHub in my personal repository.

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import dbus
import gi
gi.require_version('AppIndicator3', '0.1')
import signal
from gi.repository import AppIndicator3,Gtk,GLib

class IndicatorBitrate(object):

    def __init__(self):
        self.app = AppIndicator3.Indicator.new(
            'indicator-bitrate', "gtk-network",
            AppIndicator3.IndicatorCategory.HARDWARE
        )
        self.app_menu = Gtk.Menu()
        self.quit_button = Gtk.MenuItem('quit')
        self.quit_button.connect('activate', lambda *args: Gtk.main_quit())
        self.app_menu.append(self.quit_button)
        self.app.set_menu(self.app_menu)
        self.app_menu.show_all()
        self.app.set_status(AppIndicator3.IndicatorStatus.ACTIVE)
        self.update_label()

    def call_dbus_method(self, bus_type, obj, path, interface, method, arg):
        """ utility: executes dbus method on specific interface"""
        if bus_type == "session":
            bus = dbus.SessionBus()
        if bus_type == "system":
            bus = dbus.SystemBus()
        proxy = bus.get_object(obj, path)
        method = proxy.get_dbus_method(method, interface)
        if arg:
            return method(arg)
        else:
            return method()

    def get_dbus_property(self, bus_type, obj, path, iface, prop):
        """ utility:reads properties defined on specific dbus interface"""
        if bus_type == "session":
            bus = dbus.SessionBus()
        if bus_type == "system":
            bus = dbus.SystemBus()
        proxy = bus.get_object(obj, path)
        aux = 'org.freedesktop.DBus.Properties'
        props_iface = dbus.Interface(proxy, aux)
        try:
            props = props_iface.Get(iface, prop)
            return props
        except:
            return None

    def update_label(self):
        self.app.set_label(self.get_bitrates(), '')
        GLib.timeout_add_seconds(1, self.set_app_label)

    def set_app_label(self):
        self.update_label()

    def get_bitrates(self):
        # https://people.freedesktop.org/~lkundrak/nm-docs/nm-dbus-types.html#NMDeviceType
        base = ['system', 'org.freedesktop.NetworkManager']
        call = base + [ '/org/freedesktop/NetworkManager', 'org.freedesktop.NetworkManager',
                        'GetAllDevices',None]
        devs = list(self.call_dbus_method(*call))

        wifi_devs = []
        for dev in devs:
            call = base + [dev,'org.freedesktop.NetworkManager.Device',
                           'DeviceType']

            if int(self.get_dbus_property(*call)) == 2:
                wifi_devs.append(dev)

        stats = []
        for dev in wifi_devs:
            # org.freedesktop.NetworkManager.Device.ActiveConnection
            call = base + [dev, 'org.freedesktop.NetworkManager.Device', 'IpInterface']
            iface = self.get_dbus_property(*call)
            call = base + [dev, 'org.freedesktop.NetworkManager.Device.Wireless',
                           'Bitrate']
            bitrate = int(self.get_dbus_property(*call))/1000
            # bitrate given by this property is in kilobits/second (Kb/s)
            # according to documentation
            stats.append((iface,bitrate))
        return " ".join([str(i[0])+": "+str(i[1])+'Mb/s' for i in stats]) if stats else "None"

ind = IndicatorBitrate()
signal.signal(signal.SIGINT, signal.SIG_DFL)
Gtk.main()

Setting up the indicator

All the standard rules of making files executable apply here as well.

Save the code as indicator-bitrate file in ~/bin folder
Make the file executable with chmod +x ~/bin/indicator-bitrate
Run from command-line via ~/bin/indicator-bitrate. If you want this to start automatically when you log-in , open Startup Applications from Unity Dash and add full path to script as command.

Conclusion

The two solutions given in this answer should satisfy multiple cases to provide desired results to the users. The first indicator is a little more flexible - it allows displaying other information and statistics in addition to bitrate, while second solution does the job for bitrate but only that; however, it does make use of Network Manager's dbus information, thus we can be sure the information is the same as what has been requested in the question.

The custom indicator may be further developed or become foundation for other indicators to display wireless information in more detail. Bug reports and feature requests are welcome on the linked github page.


Upgrade to 16.04 LTS from ubuntu server 14.04 LTS with ubuntu-zfs

I found the upgrade straightforward(ish) in my case of non-root ZFS, just needing to remove old tools before adding new ones and nothing was left in a weird state:

# Export ZFS Pool first - may need to switch to single user mode for this
zfs umount -a; zpool export <poolname>
# Remove old ZFS stuff
apt-get remove ubuntu-zfs zfs-doc spl-dkms
apt-get autoremove
add-apt-repository --remove ppa:zfs-native/stable

# upgrade time!
do-release-upgrade

apt install zfsutils-linux

#reboot

...and on reboot my zpools / zfs file systems all imported and mounted OK


You want to install kde-config-telepathy-accounts, but this packages contains the file /usr/share/accounts/services/google-im.service.

That file however is also part of the preinstalled package account-plugin-google and does therefore already exist. The package manager does refuse to overwrite already existing files by default, that's why you get the error.

You have three options:

Do not install kde-config-telepathy-accounts and purge the partially installed files as well as the packages depending on it again using these terminal commands:

sudo apt-get purge kde-config-telepathy-accounts kde-telepathy-minimal kde-telepathy
sudo apt-get autoremove

If you don't need that Google account integration (also needed for unity-scope-gdrive and maybe more), you could uninstall it.

That can be done using this terminal command:

sudo apt-get purge account-plugin-google

You will have to finish the installation of the other package though, like this:

sudo apt-get install kde-config-telepathy-accounts

You can also ignore the warning and let kde-config-telepathy-accounts overwrite that file with its own version.

sudo apt-get -o Dpkg::Options::="--force-overwrite" install kde-config-telepathy-accounts

There's no guarantee though that after overwriting this file with a different version, the original package accounts-plugin-google is still compatible with it and will not crash or work in an unintended way! Proceed with care!


Okay, I found the solution.
First I did

 uname -a; lspci -nnk | grep -iA2 net; lsusb; dmesg | grep -i bluetooth; dmesg | grep -i firmware; lsmod | grep bluetooth

output said

Bluetooth: hci0: BCM: Patch brcm/BCM43142A0-0a5c-216d.hcd not found
bluetooth hci0: Direct firmware load for brcm/BCM43142A0-0a5c-216d.hcd failed with error -2

So I did

cd /lib/firmware/brcm
sudo wget https://github.com/winterheart/broadcom-bt-firmware/raw/master/brcm/BCM43142A0-0a5c-216d.hcd

And rebooted the system and now Bluetooth is functional


How can I upgrade gnome-terminal on Ubuntu 14.04 LTS?

You have two ways to upgrade your terminal from 3.6.2 (stable) to the latest 3.12.3 and read step by step do not run apt-upgrade unless you done installing.

1st solution with Gnome3/staging PPA

sudo add-apt-repository ppa:gnome3-team/gnome3-staging

sudo apt-get update

sudo apt-get install --reinstall gnome-terminal

2nd solution with this PPA:

sudo add-apt-repository ppa:towolf/transparent-gnome-terminal

sudo apt-get update

sudo apt-get install --reinstall gnome-terminal

Though this PPA may require Gnome3/staging PPA to be installed also, this 2nd PPA contains different fixes and patches on RGB schema and transparency, opacity etc.

Notice!

After you add PPAs like Gnome3/staging beware of upgrading as you can even damage your system this is the latest bleeding edge updates and they don't guarantee the stability, so after you install gnome-terminal it's better to purge them e.g.:

sudo ppa-purge ppa:gnome3-team/gnome3-staging

sudo apt-get update

(PPA-purge has to be installed 1stly sudo apt-get install ppa-purge)


Why did the Ubuntu installer stopped after the Ubuntu logo screen? It didn't run afterwards

Subedi,

Before trying something else. Run it again, otherwise maybe you have a bad copy of the image on the USB.
Have you checked that the copy of your files on your linux bootable USB has all the files? You can find the md5sum of the image and compart it with the md5 list present in the iso.

Sometimes you can get a bad copy of one of the files so checking that would be a good starting point.


Do modifications to sysctl.conf take effect in openVZ container?

Already answered on superuser.com:

  there is only a single kernel running for both the host and all "VPS"es

For security reasons the openVZ container will not allow you to change any shared setting that may impact the host server, but the settings in the host server - at least many of them - will affect all containers.
If you receive access denied your settings are ignored for security reasons.
A good host server will have security measures that will prevent common kernel level vulnerabilities from affecting your container; in a shared enviroment, always notify the admin if you find bad or not safe settings (he will be happy, don't worry)!
You are still allowed to configure iptables firewall (official guide) in your container: it will block a good range of attacks!
If you have other questions feel free to answer by commenting under here and don't forget to press the UP arrow and set as favorite if I'm of any help.

Good afternoon.


Is there any precaution I need to take when booting from external hard drive?

The Lifewire page essentially describes using a bootable, external USB drive (produced by installing your ISO file onto the external drive using Rufus or a similar utility).  Most modern computers will allow booting directly from the external drive, usually by means of a function key to temporarily re-assign the boot order for available drives.  When you boot into Ubuntu from such a drive, the contents of your SSD will be unaffected, unless you specifically store or delete something on that drive.  The SSD will basically act as a second (data) drive, while the external drive is running the operating system.


compiz huge CPU usage while play Audacious

I have the same issues with cpu usage because of compiz. My workaround was to switch session from Ubuntu to Ubuntu 2D.


Unsupported GNU version! gcc versions later than 6 are not supported! - causes importing cpp_extension

There should be a copy of sources.list at  /usr/share/doc/apt/examples/sources.list   Copy your /etc/apt/sources.list to save the ppa changes you entered and start with the fresh copy.  Then run the

sudo apt-get update
sudo apt-get dist-upgrade

Then add in your ppas from your saved copy of sources list, and repeat the

sudo apt-get update
sudo apt-get dist-upgrade

Just in case, here's the contents of the fresh file:

# See sources.list(5) manpage for more information
# Remember that CD-ROMs, DVDs and such are managed through the apt-cdrom tool.
deb http://us.archive.ubuntu.com/ubuntu xenial main restricted
deb-src http://us.archive.ubuntu.com/ubuntu xenial main restricted

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

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


As steeldriver noted, #!/bin/sh refers to dash shell, and dash does not have source command. You can change your top line to #!/bin/bash to call bash instead of dash.

Alternatively, you can change source to .  , so line would be . /home/ubuntu/ros_package/devel/setup.bash . However, you're trying to source bash file. That means, there may be non-portable code lines there, and sourcing that file may fail

For roslaunch uvc_camera camera_node.launch & you need to change it to roslaunch uvc_camera camera_node.launch 2>&1 > /dev/null & so that the output of that command is not displayed.

Note also , that you should quote your variables ( like "$WID" ) to prevent word splitting  ( unless you do want contents of $WID to be treated as separate items , or if there is no separate words there).


How to install a GTK theme on Ubuntu 15.04?

The themes listed in System Settings... > Personal / Appearance / Theme are usually none other than Adwaita, Ambiance and Radiance that come with Ubuntu.

You can install other GTK themes (including Window themes) via some PPAs or manually.

PPAs usually install such themes under /usr/share/themes but you can also manually install themes by also copying files to ~/.themes (or ~/.local/share/themes) as well as copying them to /usr/share/themes using root privileges as PPAs do, and in either way you should be able to see and select them in Unity Tweak Tool or Ubuntu Tweak.

Note: It might also be a good idea to create a symlink for /root/.themes to have GTK2 apps use the same theme also when running as root if you put your theme at ~/.themes.

Lately Ubuntu has begun using the unity sub-folder under a theme for window control buttons (Close/Minimize/Maximize) but it still requires the   metacity-1 sub-folder containing at least a file named metacity-theme-{NUMBER}.xml - otherwise the theme will not be listed.


In Ubuntu 11.10 the Radiotray version is 0.6.4. The latest release is 0.7 so i decided to download latest .deb from sourceforge and installed the latest version on my PC. This solved the issue.


Enter the BIOS and change the boot sequence so that the pc boots from the CD/DVD drive first.

To access the BIOS, you'll need to restart your pc and press a specific key. This key is displayed at the start of the boot process. For example, you may see a message like "Press DEL to enter setup". Press the required key at that time and the BIOS will appear.

You could even simply try different keys, especially DEL and the function keys like F2, F11, F12.


How can I submit a NetBeans project to Ubuntu App Developer?

In short, you need to package your application in the Debian packaging format. If you know how to package, simply upload a tarball or a zip file with the source package.

If you don't know how to package, you've got two options:

If your application is a commercial app, you can upload the .jar files and Canonical will package it for you
If your application is an open source app, you can contact the Ubuntu App Review Board via e-mail or IRC and they will help you getting started. alternatively, you can learn more about packaging on the Ubuntu Packaging Guide

This is also explained in:

https://developer.ubuntu.com/publish/

And in more detail, in:

http://developer.ubuntu.com/publish/my-apps-packages/


Do you use the nvidia proprietary drivers or the nouveau open drivers? (If you don't know run lsmod | grep nouveau if it gives you any results, it's nouveau; if lsmod | grep nvidia gives you any results, it's the proprietary nvidia drivers). If you have the nvidia drivers you should be able to configure the monitors from the nvidia-settings utility that comes with the drivers.
Or you could try xrandr --output DVI-I-0 --auto --primary --left-of DVI-I-1
 as superuser, where DVI-I-0 is the name of the monitor (should work regardless of drivers)


AD (PAM) authentication stopped working after security update

Caught a very similar problem, with RedHat 7, but perhaps my solutions applies to your case. My machine was joined to the AD Domain with winbind client configured, therefore allowing everyone from the domain to logon to it (joining with sssd client doesn't cause this behavior).

These "PAM_AUTH_ERR (7), NTSTATUS: NT_STATUS_LOGON_FAILURE" error messages began to appear on the log files when we tried to restrict SSH logins with the "AllowGroups" option on the /etc/ssh/sshd_config file. There were an syntax error in the AD group that we configured, thus any logon attempt have failed, even members of this group.

After much head banging, we noticed the syntax error and then everything was fine (correct syntax is: AllowGroups "DOMAIN\group in lowercase", double quotes needed because the group name contains spaces).

Hope that it helps you!


Another website which works: http://www.audiotag.info

Would prefer an desktop application, too :)


gedit error : "Unexpected error: Invalid byte sequence in conversion input"

I am not sure what the cause of the problem is, but I was able to reproduce it on my system.

Experimentally, I ran dos2unix on the file and the output said it was a UTF-16LE file. For the curious, LE means little endian. After dos2unix had converted the file to UTF-8 format, I was able to open it with Gedit.

sudo apt install dos2unix
dos2unix -n oldfile newfile
gedit newfile

I used the -n flag to avoid overwriting the original file. Replace oldfile with the original filename and newfile with whatever you want the new file to be called. Use tab completion (type the start of the filename and press tab and the full name should appear) or ' quotes if your filename has spaces or other special characters.

As a sidenote, I was able to open the file without converting it using Pluma, a text editor based on Gedit, so I suspect that this may be a bug in Gedit. Passing --encoding UTF-16LE or --encoding UTF-16 to Gedit when opening the file did not help.


What is this 'X' command (with paramters) that uses 24% cpu?

/usr/bin/X is the program running

:0 is an argument to x telling it to run on display 0 (programmers count 0 first)

-auth /var/run/light/dm/root/:0 I am unsure but probably the lightdm authentication program

-novtswitch not sure if it disables ctrl+shift+F1 through F12 to switch to a vitrual terminal or if it does not switch at init to the vt (display :0 in this case) X runs on

-background none creates a root window with no background

more information can be found here
What is process "/usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch -background none"?


Juju installs some upstart files for local provider environments. Prior to removing juju it can be removed via juju destroy-environment for each local environment. Post removal that the upstart files can be removed from /etc/init by hand, their prefixed with the environment name and user name. update-rc.d doesn't work with upstart files afaik.


Netplan not creating route for interface

Your netplan config and your ip commands don't match: in the working command you are declaring the route on the device with no gateway, in the netplan you are declaring a gateway for the route but it is a gateway for which you do not already have a route.

You either need to declare your netmask such that 10.0.3.1 is in the route for the tunnel (i.e.: 10.3.0.2/30, not 10.3.0.2/32) or you need to declare the route as being on-link.

You should be able to check the output of ip link after setting up the tunnel both ways to compare whether they match.


Installation never finishes on an old Dell Latitude C400

The Dell Latitude C400 is a little bit old... Try to install from alternate cd download from here, this is a text based installer.

  The text-based installer is for computers that can’t run the graphical
  interface-based installer, either because they don’t meet the minimum
  requirements for the live CD or because they require extra
  configuration before the graphical desktop can be used.


I just installed after reading your post. I ran an apt-cache search

:~$ apt-cache search fvwm

and selected and installed fvwm-crystal

:~$ sudo apt-get install fvwm-crystal -y

Before installing fvwm-crystal I was using an openbox derivative and removed all of my /usr/share/xsessions/.desktop files, except openbox.desktop that way I would only be presented with the one DE option by the unity-greeter.

After downloading and installing FVWM DE, I clicked on the icon in the top left corner of the input dialogue box, and there was now three options to choose from: Openbox, FVWM, and FVWM-crystal. I chose FVWM-crystal it logged me right in.

Im using TrustyTahr 14.04 with the 3.13.53 kernel version. This is what the

/usr/share/xsessions/fvwm-crystal.desktop

file looks like which is what aloud me to login.

# /usr/share/xsessions/fvwm-crystal.desktop
[Desktop Entry]
Encoding=UTF-8
Name=FVWM-Crystal
Comment=Umm... Nice desktop. Transparent, and all...
Exec=fvwm-crystal
Terminal=False
#TryExec=fvwm-crystal
Type=Application

[Window Manager]
SessionManaged=true

Trying installing the Desktop Environment (fvwm-crystal) and not just the window manager, if you haven't already done so, and login to the fvwm-crystal option.


Apple Magic Trackpad aftrer upgrade from Ubuntu 11.10 to Ubuntu 12.04 (64 Bit) - Multitouch not working!

To get this working I had to install utouch:

apt-get install utouch

For details, read:

https://wiki.ubuntu.com/Multitouch
https://wiki.ubuntu.com/Multitouch/Architecture
https://wiki.ubuntu.com/Multitouch/AppleMagicTrackpad


Luckily Ctrl+Alt+F1 still gives you a console login.

With no network manager your systemd could be wasting time waiting for it to come up. After logging into the console use this command:

sudo systemctl disable NetworkManager-wait-online.service

Then reboot.

If you find out later you need the service at boot time use:

sudo systemctl enable NetworkManager-wait-online.service


Ubuntu 14.04 totem video player show big play/pause icon on screen

Something messed up with your icon set for totem.
Just reinstall it with:

sudo apt-get install --reinstall totem


Finding it impossible to boot Windows after deleting GRUB

If your Windows is installed in EFI mode, as is likely if the computer came with Windows 8 or later pre-installed, you should be able to recover as follows:

Starting with the computer powered off, turn it on.
Hit the keystroke to enter the computer's built-in boot manager. This is the tricky part of the procedure, since this key is not standardized. If you're lucky, it will be prompted on the screen (probably just for a second or two) or mentioned in the manual. If not, try some common possibilities: A function key (usually something in the range of F8 to F12), Esc, or Enter. You may have used this keystroke to tell the computer to boot the Linux installer. You may need to repeat steps 1 and 2 several times before you find the right key.
Once the built-in boot manager is open, select the option to boot Windows.
In Windows, download and install EasyUEFI.
Open EasyUEFI and use it to adjust the boot order, putting Windows first.


After I installed some DVD programs and cheese, audio input doesn't work in 12.04

I generated a custom installation of my Ubuntu using Remastersys, reinstalled the custom distribution and now all is working well. I will investigate the other applications I installed in order to determine which one broke my GNOME audio control.


After Installing Kivio I am not able to open it?

Kivio is the former name of this application. It's part of Calligra office suite and is called Calligra Flow, so you may want to search for that instead.


I would install ubuntu-desktop again. sp that you can log in and use your computer. Or you can install whatever desktop you want. I use Ubuntu fallback.

So what happens when you start the computer? Do you get a console only interface? If so, log in with your username and password.

Then type, sudo apt-get install ubuntu-desktop

Or whatever desktop you now want.


you can do that, but be avare that you actively remove the redundancy here so if just one of oyur drives is faulty it will fail to rebuild

so only do that if you got a complete backup

another option would be to just add another drive to the raid5, though this will increase likelyhood of failure a little bit since you simply have another drive that might fail and didn#t add more redundancy

there is a complete guide on https://raid.wiki.kernel.org/index.php/Growing


How do I install Unity global menu in a manual install of Firefox Developer Edition?

I... kind of have a solution, but it's at a compromise. Read the whole answer first.

(Note that if you manually installed Firefox developer edition to /usr/lib/firefox like I did, you need to back it up as it will be replaced. Also back up your ~/.mozilla folder in case the following fails and wipes your .mozilla folder.)

So first, add the Firefox beta ppa with sudo add-apt-repository ppa:mozillateam/firefox-next

Install Firefox beta with sudo apt-get update && sudo apt-get install --only-upgrade firefox

Now run firefox -P and your developer edition profile should still be there. Select it and open Firefox. You'll have the latest beta on the ppa, as you can see with "about Firefox," and you'll also have your developer tools and global menubar.

HOWEVER, I'm pretty sure none of the tools specific to developer edition will update. Only the base browser will.
Correction: there aren't tools specific to developer edition that beta doesn't already have. By upgrading to beta, you aren't losing anything; it's just more troublesome than keeping developer edition.

I immediately went back to my manual install with no global menu (and also a super annoying bug where the url bar doesn't autofocus on new tab) when I figured this out, so you may not want to follow these steps. But if you really want the global menu fixed now and also are fine with the current state of all the developer tools, this may be worth it. See above.

Otherwise, I guess you'll be waiting with me for Mozilla to patch this bug. Bug resolved as wontfix since it's a lot of trouble and Unity is dying anyway.

Sucks that the only answer to this is to scrap developer edition and install the beta ppa (which has the Unity integration, of course) but that's all I've got.


How to access files stored in one ubuntu account from another?

You can't copy files between two computers without using a network or storage device. This has no sense, you need a transfer media....

To use a network:

you have to use scp.

scp copies files between hosts on a network. It uses ssh for data transfer, and uses the same authentication and provides the same security as ssh.

Copy the file "textfile.txt" from a computer 2 to the local host

scp user2@computer2:textfile.txt /some/local/directory

To copy a folder "foo" from  the local host to cpmputer2

scp -r foo user2@computer2 /some/directory/computer2

More scp examples

PS: The command cp is used in the same computer for two different users and this is not the case in the question


Downloaded file is a .emerald file.

To install .emerald file you need to install the package emerald.

1). Install the package emerald. It can be installed with the ppa:nilarimogard/webupd8 PPA.

sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install emerald

2). Open the Emerald Theme Manager.

You can install the downloaded .emerald file with Emerald Theme Manager.

Go to preferences.
select Manage new Theme.
Select Import. Then select the downloaded file.

3). Start your theme.

You can start the emerald theme by the command :

emerald --replace


Any way to install drivers for VFS495 fingerprint reader?

Solution for Ubuntu 20.04
The driver I linked above works for this device. I was just using it incorrectly.
There are some things you should keep in mind when using this driver.

It only works in kernel below 5.2. I only tested it in 5.2, so I don't know if it works in versions like 5.3. From my other tests, kernel 5.4 and newer makes this driver really laggy and almost unusable.
Always check how you enroll your fingerprint. sudo fprint_demo isn't same as fprint_demo. The guide I followed suggests you to use sudo fprint_demo, which will enroll your fingerprint for the root user. This is actually why I was getting the Could not locate any suitable fingerprints matched with available hardware.. Yes, it was because I didn't have any fingerprints enrolled. I only had them enrolled for root.

So, here's a step-by-step guide for the installation:

Make sure your kernel version is 5.2 or older:
uname -r
If it's not, get an older release from Kernel mainline PPA. You can follow the instructions here.

Follow the next steps. They're for Ubuntu 18.04/18.10, but it works with 20.04 without much modification.

The first step is to install required dependencies:
sudo apt install libssl1.0.0 libusb-dev libssl-dev libglib2.0-dev libmagickcore-dev libgtk2.0-dev libpam-dev

Run these commands in this order:
mkdir vfs && cd vfs
wget https://github.com/PetreBoboc/vfs495_ubuntu/raw/master/Packages/libcrypto%2B%2B9_5.6.1-6%2Bdeb8u3_amd64.deb
sudo apt install ./libcrypto++9_5.6.1-6+deb8u3_amd64.deb
rm libcrypto++9_5.6.1-6+deb8u3_amd64.deb
wget https://github.com/PetreBoboc/vfs495_ubuntu/raw/master/Packages/1704/libMagickCore-6.Q16.so.2.0.0
sudo mv libMagickCore-6.Q16.so.2.0.0 /usr/lib/
sudo ln /usr/lib/libMagickCore-6.Q16.so.2.0.0 /usr/lib/libMagickCore-6.Q16.so.2
wget https://github.com/PetreBoboc/vfs495_ubuntu/blob/master/Packages/validity-sensor-setup_4.5-119_amd64.deb?raw=true
wget https://github.com/PetreBoboc/vfs495_ubuntu/blob/master/Packages/libfprint_0.0.6-1_amd64.deb?raw=true
wget https://github.com/PetreBoboc/vfs495_ubuntu/blob/master/Packages/fprint-demo_0.4-1_amd64.deb?raw=true
wget https://github.com/PetreBoboc/vfs495_ubuntu/blob/master/Packages/pam-fprint_0.2-1_amd64.deb?raw=true
sudo dpkg -i *.deb
sudo apt-mark hold fprint-demo
sudo ln -s /usr/lib/x86_64-linux-gnu/libssl.so /usr/lib/libssl.so.0.9.8
sudo ln -s /usr/lib/libcryptopp.so.9 /usr/lib/libcrypto.so.0.9.8
wget https://raw.githubusercontent.com/PetreBoboc/vfs495_ubuntu/master/vcsFPServiceDaemon
sudo mv vcsFPServiceDaemon /etc/init.d/
sudo chmod 0755 /etc/init.d/vcsFPServiceDaemon
sudo update-rc.d vcsFPServiceDaemon defaults
sudo /etc/init.d/vcsFPServiceDaemon start
wget https://raw.githubusercontent.com/PetreBoboc/vfs495_ubuntu/master/fingerprint_auth/modified/common-auth
sudo mv common-auth /etc/pam.d

Now, the original guide suggests to use sudo fprint_demo, but keep in mind this will enroll the fingerprints for the root user. If you want to enroll a fingerprint for your user, use one of the following methods:

fprint_demo
You should see a window similar to this:

Click Enroll next to Right index finger and enroll your finger.

An alternate method allows you to enroll your fingerprint from command line:
Run pam_fprint_enroll and press enter. Then, enroll your fingerprint.

Reboot.

In the login screen, when it asks for your password, press enter and scan your finger. (this applies to KDE Plasma and GNOME, other DEs may have a different way)

Troubleshooting
Here are some issues I experienced with this driver:

The scan hangs on login after resume from suspend/hibernation.
Solution:
Open /etc/pm/sleep.d/ValidityServiceSuspend.sh with your favorite text editor:
sudo nano /etc/pm/sleep.d/ValidityServiceSuspend.sh
Edit it so it looks like this:
#!/bin/bash

. /usr/lib/pm-utils/functions

suspend_FPS() {
    # Signal the vcsFPService about the suspend/hiberante
        echo " Sending Suspend Event"
        pkill -SIGUSR1 vcsFPService
}

case "$1" in
        hibernate|suspend)
                suspend_FPS
                ;;
        resume)
                /etc/init.d/vcsFPServiceDaemon restart
                ;;
        *)
                ;;
esac

exit $?

Save the file and try to suspend :)

Scan hangs and makes the lock screen unusable after upgrade.
This is because your kernel got upgraded. You'll need to downgrade (e. g. by booting the old one and removing the new one) to get the fingerprint reader working again.

These steps were tested on HP Probook 470 G4 with Ubuntu 20.04 - KDE Plasma (Kubuntu desktop) and GNOME (Ubuntu desktop)


How to make a folder in opt and paste something?

Basically, you require root permission.
In case you have the root password, in terminal do the following:

cd  /opt
sudo mkdir name-of-the-folder
cd name-of-the-folder
sudo cp path-of-file-to-be-copied/file-to-be-copied .

Don't forget the Dot (.) at the end of the last command.


What is the next step on the infected files and errors?

First of all, all these errors are happening because clamscan is scanning / and for scan / you need to execute it as root (i.e. sudo clamscan -r --bell -i /), otherwise it will fail because it hasn't permission to read many files.

When it finished, please update your question with the path and name of the infected files and I'll update my answer with what can you do with them.


How to exclude a folder by name recursively when making a tar archive?

To exclude the directory named node_modules wherever it is located under /srv/www/ even if there are multiple copies of it under different sub-directories, just do not specify a path in the --exclude part and use it like this:

tar -zcvf /backup/project.tar.gz --exclude "node_modules" /srv/www/

This will exclude all directories and files named exactly node_modules and all sub-directories and files under them anywhere in /srv/www/.


Installing full Kubuntu Desktop is the way of achieving full desktop installation  with its complete features, but the package itself comes bundled with tons of default programs: kubuntu-desktop will install its own file manager, document reader, terminal emulator, etcm which is annoying to some people.

Aside from that, there is kde-plasma-desktop that offer plasma desktop with minimal installation. Unfortunately, the package doesn't include the kde's network manager while kubuntu-desktop does.

But the good news is, you can always install it manually.

sudo apt-get install plasma-nm


Why doesn't Workspace Switcher Icon appear in Launcher?

By default, the workspace-switcher is not enabled in the Launcher. This setting is toggleable via the Appearance - Behaviour tab in System Settings

Untick the option to remove the workspace-switcher icon.


Weird folder permission behaviour - Some sub folders have full permissions other don't

Folder /var/www/html/Panel4/uploads/microsite has a SGID enabled. The microsite directory, its parent directory and all its sub-directories have SGID enabled and which can be identified with the s bit set in group part of the permission drwxr-sr-x.

As SGID is set any folder that is created within it will have group-id set to that of the parent directory. And if any binary file gets set with SGID then when you execute it the group-id of the user will be changed to the group-id of the binary.

But the SGID is not causing the issue, these folders don't have group write permission set for those directories. And so you cannot delete or create new files/folders inside them. To avoid this run chmod g=rwx <folder-name> to give write permission.

And also add your uername as the member of www-data group.

For more about linux file permission refer this.


how to run this everytime after a reboot

Cron/Cronjobs will allow you to automate the task above to after every restart HOWEVER, it won't leave a terminal window open.

For info on Cron you can look at the CronHowto:
https://help.ubuntu.com/community/CronHowto

Also please mention what operating system you are using.

Crons are really quite interesting so I highly recommend reading into them but TLDR.

Open a terminal window.

Install Cron

sudo apt-get install gnome-schedule

After that has completed type

crontab -e

If the script requires administrative privileges use:

sudo crontab -e

And then at the bottom of the file add the following with the path being to where that script is.

@reboot /home/username/start_application.sh


Chances are the FAT filesystem on your EFI System Partition (ESP) is damaged. This is common on Windows 8 and later dual-boot systems, since Windows now doesn't shut down by default -- instead, it hibernates. Thus, you need to disable Hibernation and the related Fast Startup options, as described here:

http://www.tenforums.com/tutorials/4189-fast-startup-turn-off-windows-10-a.html
http://www.tenforums.com/tutorials/2859-hibernate-enable-disable-windows-10-a.html

After you disable those features, you may need to fix the filesystem by using dosfsck in Ubuntu or equivalent tools in Windows. In extreme cases, you may need to back up the partition, create a fresh FAT filesystem on it (with mkdosfs or something similar), and restore it. If you do this, you may need to edit the "UUID" (really a serial number) for the ESP in /etc/fstab.

Note that problems like this sometimes crop up in one environment (Windows, Linux, UEFI) but not another because each environment has its own drivers that may respond differently to filesystem damage. In practice, many EFIs have pretty weak FAT drivers that seem to react badly to damage, or sometimes even to filesystems that Windows and Linux say are fine.


Almost every GPU will work. nVidia officially supports all GPU's from GT 630 to RTX 3090. AMD supports all GPU's since R9 285. (even Radeon VII). So I would say, buy something you can afford, and is availible for a decent price. Anti Linux support is rare. I cannot give you a complete list of supported GPU's, but I hope this helps. (btw, I have a gpu that isn't on any modern support list, but it works with lubuntu)


Everything opens dolphin file manager windows

Go to Tools->Options->Applications in Firefox to manage how files you download in Firefox are handled. What you're looking for may also be in Tools->Options->General.


when sudo apt-get install npm nodejs-legacy

I solved issue - had the same. Just run:

sudo apt-get install --reinstall nodejs npm nodejs-legacy


The OpenVPN command has --client-connect and --client-disconnect options that allow you to run scripts for those (and other) events.

You can then create a script that emails you with information about the connection.

OpenVPN will provide a number of environment variables when executing these scripts, allowing you to attach connection information to those e-mails.

In my configuration, I have the following lines in /etc/openvpn/server.conf:

script-security 2
client-connect /etc/openvpn/server/connect-disconnect.sh
client-disconnect /etc/openvpn/server/connect-disconnect.sh

My /etc/openvpn/server/connect-disconnect.sh is owned by nobody (as this is the user that my system executes OpenVPN as) and contains the following (warning! long and ugly shell script incoming!):

#!/bin/bash

# Connect/disconnect script for OpenVPN clients
# For all available variables, see the "Environmental Variables" section
# at https://openvpn.net/community-resources/reference-manual-for-openvpn-2-4/

from_address="openvpn@$HOSTNAME"
from_name="openvpn@$HOSTNAME"
to_address="my-email-address"

function unitify_bytes {
        bytes=$1
        if [ "$bytes" -gt "1073741824" ]; then
                echo $(( $bytes / 1073741824 )) GiB
        elif [ "$bytes" -gt "1048576" ]; then
                echo $(( $bytes / 1048576 )) MiB
        elif [ "$bytes" -gt "1024" ]; then
                echo $(( $bytes / 1024 )) KiB
        else
                echo $bytes B
        fi
}

function unitify_seconds {
        local SS=$1

        if [ "$SS" -ge "60" ]; then
                local MM=$(($SS / 60))
                local SS=$(($SS - 60 * $MM))

                if [ "$MM" -ge "60" ]; then
                        local HH=$(($MM / 60))
                        local MM=$(($MM - 60 * $HH))

                        if [ "$HH" -ge "24" ]; then
                                local DD=$(($HH / 24))
                                local HH=$(($HH - 24 * $DD))
                                local time_string="$DD days, $HH hours, $MM minutes and $SS seconds"
                        else
                                local time_string="$HH hours, $MM minutes and $SS seconds"
                        fi
                else
                        local time_string="$MM minutes and $SS seconds"
                fi

        else
                local time_string="$SS seconds"
        fi

        echo "$time_string"
}

if [ "$script_type" == "client-connect" ]; then
        action="connected to"
else
        action="disconnected from"
        action_specific_info=" \

Session Duration

$(unitify_seconds $time_duration)
 \

Received

$(unitify_bytes $bytes_received)
 \

Sent

$(unitify_bytes $bytes_sent)
 \
"

fi

now=$(echo $(date +"%c"))

cat <<EOF | /usr/sbin/sendmail -f "$from_address" $to_address
Subject: OpenVPN: $common_name $action $HOSTNAME
Content-Type: text/html
From: $from_name<$from_address>
Date: `date -R`

Client $common_name has $action OpenVPN

Connection Details

Client Common Name

$common_name

Connection Start

$time_ascii

Client WAN IP

$untrusted_ip

Client LAN IP

$ifconfig_pool_remote_ip

${action_specific_info}

OpenVPN at $HOSTNAME.

EOF

Note that you should update the variables at the top to match your environment. I have sendmail configured to forward all mail to my mail account, so you might need more configuration/script changes n that area...


How to auto-login in Xubuntu or Ubuntu Server with XFCE?

Type in a terminal (e.g. Xubuntu, Ubuntu Server with XCFE (e.g. Raspberry PI 3):
sudo -e /etc/lightdm/lightdm.conf
(Better than sudo nano /etc/lightdm/lightdm.conf or sudo mousepad /etc/lightdm/lightdm.conf, see below the reasoning* - Thank you red_trumpet for the hint)
Add these lines to the file:

[Seat:*]
autologin-session=xubuntu
autologin-user=YourDesiredAutoLoginUserName
autologin-user-timeout=0

You could use e.g. file /etc/lightdm/lightdm.conf.d/autologin-xubuntu.conf, instead, but then you should make sure settings in another file in that directory or in file /etc/lightdm/lightdm.conf do not override it.
For GDM-Users
The config file is located /etc/gdm3/custom.conf (according to the other answer, please vote Arbuntu's answer up if you found it helpful):
sudo -e /etc/gdm3/custom.conf

Uncomment the following lines (delete the #) and fill in your user name:
# Enabling automatic login
  AutomaticLoginEnable = true
  AutomaticLogin = YourDesiredAutoLoginUserName

Extra:
To remove password on resume, right-click the system tray power icon then Preferences. This brings up the XFCE power manager (Alternatively you can navigate to XFCE/Settings/Settings Manager/Power Manager). Click Extended in the left pane. Uncheck Lock screen when going for suspend/hibernate.
The last place is XFCE/System/Users and Groups. If it's set "Password: Asked on login" you can change it, and thereafter, if you logout or switch user, you can get back without entering password.
*Reason for using sudo -e instead of the editor directly:
sudo -e copies the file with user privileges, and opens it with your preferred editor. After saving, the file gets copied back to the original file. In this way, the editor does not obtain root privileges, which is a security improvement. (And if configured correctly, your preferred editor is chosen automatically, which is quite convenient).
Sources: lightdm/Read.me, Ubuntu Forum, SuperUser


Which Graphics driver works smoothly in ubuntu 14.10?

Ubuntu has built-in open source graphics drivers installed by default. If you install a proprietary graphics driver, you can have both the open source graphics driver and the proprietary graphics driver installed at the same time, and the operating system will use the proprietary driver instead of the open source graphics driver.

If you have an AMD Radeon graphics card, you should not be using an NVIDIA graphics driver. You should use one of the ATI binary X.Org drivers from the default Ubuntu repositories. These are the video drivers for the AMD Radeon and FireGL graphics accelerators.

There are several different ATI binary X.Org drivers to choose from in the Ubuntu Software Center. To identify the recommended proprietary graphics driver for your hardware open the terminal and type:

ubuntu-drivers devices

Wait for a minute or two for the command to scan your computer's hardware. The results should identify the recommended proprietary graphics driver for your computer. Install the recommended proprietary graphics driver using sudo apt install recommended-driver where instead of recommended-driver substitute the package name of the recommended proprietary graphics driver. Reboot to enable the newly installed graphics driver.

You may also want to install the Catalyst Control Center for the AMD Radeon and FireGL graphics accelerators, which can be installed from the default Ubuntu repositories.


You probably just need to adjust two bunch of settings - the project settings:

and the render settings:

(With both check the audio settings as well, and when rendering select the appropriate output format and codec, then you could try the advanced settings')

Bear in mind if you make it to high quality many devices may have difficulty playing/rendering it - though rendering a HD version and using ffmpeg to make lower quality versions could work well. Also if you do test renders with smaller chunks of video means you can tweak the settings until you get the result you want, and then you can save a preset so you can use those settings later.

Using Pitivi 0.94, with everything possible related to codecs, gstreamer (see here for why) and ffmpeg installed. The manual is available here.


vlc : how to specify playlist on command line

The playlist is a plain text file of filenames

It needs to be a .m3u list and it will look like this example:

# This is a comment
/music/opeth/white cluster.mp3
/music/moonlapse vertigo.mp3
http://ccmixter.org/a/song.mp3
/video/mononoke.avi

and you play them without any parameters like:

vlc playlist.m3u

The only issue I can see here is that the files are not correct in your file.


The linker cant find blas and atlas on ubunu 12.04

Use the find command to locate these libraries. Use gcc option -L to specify this library's location. You may also need to set environment variable LD_LIBRARY_PATH


No security updates will be provided, for any other app, it's up to the developers.


vsftpd installation not working on virtual server as of 14.04

Ubuntu 14.04 uses user sessions which was absent in 12.04, so service is looking at the user session, not the system session, and your user isn't running vstfpd(root is). So, you will need to specify --system when you use service to start, stop or check the status of a service.

vsftpd is a soft-link to upstart, so you won't be able to run it as an unprivileged user, you will need to be root to start or stop or check the status of such a process.

Doing an ls -l on /etc/init.d/vsftpd reveals:

lrwxrwxrwx 1 root root 21 May 16  2013 /etc/init.d/vsftpd -> /lib/init/upstart-job*

which is similar to cron, resolvconf and a few more, which are all upstart jobs and need to be root to be started or stopped.

  Upstart is an event-based replacement for the /sbin/init daemon which handles starting of tasks and services during boot, stopping them during shutdown and supervising them while the system is running.

These services are usually started on boot. See here for more on upstart:

What is upstart

Refer man page of upstart if you want even more!

So, long story short, to start, stop, check status, you need to be root. You can do that as follows:

sudo service vsftpd {start|stop|status|restart}

and enter your password or use:

service vsftpd {start|stop|status|restart} --system


Set Language Sources Key from Command Line

Changing to Hebrew (second item in the sources list):

gsettings set org.gnome.desktop.input-sources current 1

Changing to English (US) (first item in the sources list):

gsettings set org.gnome.desktop.input-sources current 0

Note: This does not apply as from Ubuntu 17.10, since it uses GNOME and the keys for the purpose are slightly different.

Edit:

Changing the shortcut for switching input source to "Shift+Alt L":

gsettings set org.gnome.desktop.wm.keybindings switch-input-source "['<Shift>Alt_L']"


I also had similar issue and resolved now.
i cannot comment to your question so trying to resolve issue via this answer.

Let me know few things

ubuntu version
kernel version (uname -a)
wifi devide is USB or PCI ?
brand, name and version details of wifi driver.

i will try to update answer with further details.


What happened to the App Menu in Ubuntu 17.10?

In the "Tweaks" tool, go to the "Top Bar" and turn "Applications Menu" to OFF.  That will remove the menu from the Top Bar and place it in the bar of applications.  (It'll be a small icon there, so look carefully).

If, for some reason, that doesn't work for you, you can easily enough turn the Applications Menu back on in the Tweaks tool.  ("Tweaks" is a poor name for that app: it is a very useful, fairly major tool.)


Changing numeric language from konsole in Kubuntu

Sounds like you want to change your locale settings.

Type locale in the console and observer what comes up (Note if LC_ALL= is set to something, this over rides all other settings).
If you want to change the numbers to english decimal (en_US.UTF-8), enter the following:

su - (switch to root)

export LC_NUMBERIC="en_US.UTF-8"

Try it out now and see.

Environment variables implement the locale codes. For example LANG=en_US.UTF-8 specifies that the computer uses US English with a UTF-8 encoding when displaying information.

Note: Type in locale -a to ensure you have the en_US.UTF-8 installed. If now use POSIX if you have that (I believe this is nessary but I am starting to doubt it now, most distro's will have that even if it isn't shown?)


Will Ubiquity recognize Windows 7 on different HDD for dualboot?

Yes, I've done nearly this exact setup and the installer recognized Windows 7 on the other drive and installed the GRUB bootloader appropriately.

Note that it might recognize Windows 7 as Windows Vista since they have the same (or similar) loaders.


ANACONDA - I have to type export PATH=~/anaconda3/bin:“$PATH” everytime I rerun the terminal

the file .bashrc (hidden file), located in the home directory, runs codes every time a new terminal is opened.

Then add a line on it:

export PATH=~/anaconda3/bin:$PATH


Get the download link of file downloaded in Software Center

Software Center should normally resume previous downloads automatically as should apt-get.

Alternatively you can tell apt-get to only show URIs of packages to download:

apt-get install --print-uris PACKAGE_NAMES...

shows the URIs and MD5 check sums of the named packages and all their missing dependencies.


How to create symbolic link to apache document root?

In sites-available/your-site what have you set for DocumentRoot?

Make it point to /var/www

          ServerAdmin webmaster@localhost

    DocumentRoot /var/www
    <Directory />
            Options FollowSymLinks
            AllowOverride None
    </Directory>
    <Directory /var/www/>
            Options Indexes FollowSymLinks MultiViews
            AllowOverride None
            Order allow,deny
            allow from all
    </Directory> . . .


Are there people know how to copy the all of data in root to normal user below /home

If your new user is a sudoer, just use

sudo cp -R /root ~

then change the owner of the newly copied files to your new user (change 'username' to your actual user accordingly)

sudo chown -R username:username ~/root


Likely a Hardware Problem

If the drive is not showing up at all on any system, likely something is wrong with the drive itself. It could have dirty contacts, been damaged or has reached the end of its life.

First thing to do is clean the contacts on the drive. Perhaps just a few plugs/unplugs will fix it.

Next, you can run a command to see if your computer even sees the drive when it's plugged in. In a terminal run:

dmesg -w

And watch for output as you plug/unplug the drive. Does the system see it? Does it output any errors?

If at this point your computer is completely non reactive to the plugging in of the drive, it's time to get a new drive.

If the drive is working intermittently, when it does actually mount, backup all of your data from the drive and COMPLETELY reformat it (new partition table and partition), and replace the data. If the reformatting doesn't make the drive reliable, it's time to replace it.


does Chrome in Ubuntu have "Recent Tabs"?

Basically, no.

The update your article refers to is about the Windows version of Chrome, and the Linux version didn't get this. We still have the 'Recently Closed' menu on the New Tab page. Personally, I prefer it, but you might want to hunt around chrome://flags and see if you can find a setting.

As Saurav Kumar noted, pressing Ctrl+Shift+T will bring back the recently closed tabs with the most recently closed tab first, which is very similar to the Recent Tabs menu item.


Keyboard capslock does not work as expected sometimes

Found a forum topic which might be usefull.

[SOLVED] Caps lock light reversed

It covers a selection of different solutions so hopefully one will work

Hope this helps.


Not enough space left while upgrading Ubuntu

In my case usual solution is to remove old kernels - instructions may be found here: https://askubuntu.com/a/153193/609098


Latest kernel installed, but not running

The variable GRUB_DEFAULT in /etc/default/grub defines the entry to boot by default (counting from 0). The default value is zero, which means that the first entry is going to boot.


Adobe Flash Player is not working in 12.04

Try Flash-Aid. It's a nice little script in the form of an extension to Firefox that will fix conflicts and install the correct version of Flash for your system, as well as the Firefox Flash extension.

I haven't used it 12.04 (since I haven't had any issues with Flash), but I have used it in previous versions and it worked great.

Just install, then run the extension (if it doesn't start when you start Firefox, it should show up in the tools menu), and follow the steps in the wizard. Once it's done, you can remove the extension if you want.


Installing Ubuntu Server 14.04.2 in a VMware

This partially depends on your use case.  the LTS versions are all Long Term Support and are meant for production installs.  Personally, I only use LTS versions so that I can ensure that there will be support for more than a few years.

If you are just looking to test stuff out, I would go with the linux-virtual-lts-utopic kernel, but if you are looking to mimic a realworld server, I would go with the linux-generic-lts-utopic.

Ultimately the choice is yours though.


In 13.04 using Unity Tweak Tool hot corners stops working after reboot

Install dconf-editor:

$ sudo apt-get install dconf-tools

Run dconf-editor (don't use sudo as the changes wont affect your account)
Navigate to org -> compiz -> profiles -> unity -> plugins -> core.
Copy the field active-plugins into Gedit, and edit it so unityshell is the last item. Paste it back into dconf.
Restart your computer.

(Tried on 14.04, it works.)


My friend, please use this:

sudo apt-get --purge airvpn

It is sufficient to remove all that you need to. This code dpkg -l | grep '^rc' | awk '{print $2}' | xargs dpkg --purge is going to get rid of a lot that isn't related to airvpn. I don't know where you got that code from but if you want to see what it removes run it this way:

dpkg -l | grep '^rc' | awk '{print $2}'

I don't think you want to run that command.


That is because at the moment you can not remove them. Developers are planning this feature for future releases.


Have you tried

sudo apt remove cqrlog

You can also remove it from within synaptic


How do I access Ubuntu filesystem from Windows on dualboot?


Apparently, there were some issues (that I don't know the details of and am not implying any comment on) when ffmpeg was forked into libav and the package was removed from Debian. Apparently, this caused issues for some applications that were built against libav but were developed using ffmpeg. Browsing around, I also see users of other distros talking about similar conflicts (though not necessarily about wmv).

These issues have apparently been resolved with the new FFmpeg 2.5 and the package is back in Debian Unstable and is slated for Ubuntu Vivid. It depends on the 56 branch of libavcodec, so you likely won't be able to install it until Vivid.

There are some PPA'a listed at the newest FFmpeg download page, at least one of which says it works with Trusty; so you might be able to get it working that way.

In the meantime, I think your current problem came from replacement of various codec related packages with problematic versions. (Ok, that's something of a guess since nothing at the instructions you used leapt out as a red flag, but that page appears to be older and not necessarily using the most recent source.)

The rollback instructions on that page really just point to the dev dependencies installed. You might need to dig into the package deeper to really find what it installed or replaced.

You might also just try purging vlc and ubuntu-restriced-extras. An apt-get -s autoremove might also be helpful; but it may not be needed, since a reinstall should replace the packages anyway. The -s option means it will just show what the command will do without actually removing anything. Check the results carefully. If it's ok, you can rerun it without the -s.

Then be sure to do a sudo apt-get update before reinstalling the packages. That should bring back the original versions of any files that were replaced.

If the problem comes from configuration issues such as symlinks or mimetype issues, the problem might ironically be easier to fix but much harder to pin down. That's where you might need to look at what the install program really did.


Ubuntu 15.10 does not recognize Gamdias Hermes keyboard

I was able to get my Gamdias Hermes Keyboard to work on my Linux desktop which is using Ubuntu Mate but I believe it will work will all forms of Linux distributions. I Want to make an application to run at startup to get it to work but I am personally unable to make it.
But the fix I was able to find is.

Sudo cat /dev/usb/hiddev#

You also need to press some keys on the keyboard to make sure it is the keyboard but if it is it will

This will require you to use a separate keyboard or mouse and a few tries to figure out the number of the keyboard but in all it has worked for me every time I find the right file.

You will need to do this command at every boot

Good Luck


There are plenty of results if you google for 'install adobe flash ubuntu'.
You downloaded the .deb file, then use Software Center to install it. Or use sudo dpkg -i path_to_the_flash_deb_file. Make sure you downloaded the correct version (32bit/64bit) for your OS architect.


A combination of setting the right USB Hardware ID/address AND plugging the device into a USB 3.0 port fixed this. I followed the tutorial of one of the links I posted above, however, I added the (correct) USB Hardware ID to /etc/modprobe.d/usbhid.conf and plugged the G933's receiver into a usb 3.0 port, and have had no issues for 2 days of pretty heavy usage.

I found correct hardware IDs by using lsusb.

cat > /etc/modprobe.d/usbhid.conf << EOF
options usbhid quirks=<Hardware ID>
EOF


How can I install dropbox in Ubuntu 18.04

Install Dropbox from the Ubuntu Software Center.

I have installed this on a number of 18.04 machines with absolutely no problems whatever. It also automatically adds an icon to the top bar which goes directly to your Dropbox folder or allow you to load the Dropbox website.

There is no further configuration required. It is designed for the job.


Is it possible to install Ubuntu on my Windows 8 computer without any CD or USB drive?

Do your repartitioning from Windows, it will not let you do any damage to the Windows OS this way. Leave the partitions where you'll install Linux unformatted, I assume you'll want to use ext4 and swap on them, and reserve a small partition, maybe 1GB, for the Linux installation media, that you can format to FAT32; copy the content from your installation ISO (not the ISO file itself) to this partition; add an entry to this partition to the Windows boot loader with EasyBCD, you can find how on the Internet, such as in this article. Note the order of your partitions so you'll remember which one you'll format and install on it, then restart and boot into the Linux live session from the install partition and perform normal installation. The installer will recognize the existing EFI system partition and will copy a boot entry there, but you can add another entry for your installed Linux to the Windows BCD the same way you added for the install partition.


go to sublime text website,click downloads

you have two options

sublime text 2  ,click linux 32 or 64bit link,unzip it , double click sublime_text

sublime text 3 beta ,you can get ubuntu debian package similar to windows installer, if you use this you can see sublime text in the menu.


How to make gnome-shell the default GUI in ubuntu-builder?

You should try Remastersys.

Install a fresh Ubuntu OS. 32bit or 64bit.
At the OS installation, instead of using your name, use something like "liveuser".
For the username, use "liveuser" too.
(You can use your name and username, of corse)
After the installation is complete, boot to your freshly installed Ubuntu.
sudo apt-get update
sudo apt-get upgrade
Install all the programs you want, including gnome-shell.
Log out and choose Gnome.
sudo wget -O - http://www.remastersys.com/ubuntu/remastersys.gpg.key | apt-key add -
sudo add-apt-repository deb http://www.remastersys.com/ubuntu precise main
sudo apt-get update
sudo apt-get install remastersys remastersys-gtk
sudo remastersys-gtk
Click the Backup button and wait for it to complete.
After it is done, the ISO should be in /home/remastersys.
Use Unetbootin to "burn" it to a USB pen.

With this, you should boot into live mode with all the configurations, that were present in your installed Ubuntu, live the choosed desktop manager.

!Warning! Do not have any music/video/wineprefixes/etc in your Home folder when using Backup or it will make your ISO huge.


Double Commander is a very good one. However, I do not know if it is available in Ubuntu repositories. If it is not available, then here is how to install it:

sudo add-apt-repository ppa:alexx2000/doublecmd
sudo apt-get update
sudo apt-get install doublecmd-gtk


Ubuntu 16.04 LTS in Intel Xeon E5-2630 v4 workstation?

Intel ARK's list of Broadwell processors includes the E5-2630 v4. Furthermore it doesn't contain a graphics co-processor.

This means that there should be no problem running it on Ubuntu 16.04. If you want to be sure try a Live DVD/USB.


Compiling GUI Java Client, Penguin Icon instead of Window

I made a really dumb mistake. The GUI wasn't set to visible >_<


why can't I install some packages after installing virtualbox

Ok, here is the short answer.

sudo apt-get remove ffmpeg
sudo apt-get install libav-tools


Misconfigured system: how to increase swapfile for LVM disks?

My solution:
Create a new swapfile
I've tried to increase the size of the swap_1 volume, but it failed. Probably because there was no space left in the volume group. I have used these instructions and got something like
# fsadm: Filesystem "swap" on device "/dev/mapper/vgubuntu-swap_1" is not supported by this tool.

for
$ lvresize -L +5G --resizefs vgubuntu/swap_1

Swapfile
I have used this answer.
Now I can see:
$ sudo swapon -s

# Filename              Type        Size    Used    Priority
# /swap_2               file        5119996 830464  -2
# /dev/dm-2             partition   999420  0       -3


Software Ubuntu Center is missing in Ubuntu 16

If you did a clean installation of 16.04, then you won't find Ubuntu Software center. It was replaced by GNOME’s Software.

http://www.omgubuntu.co.uk/2015/11/the-ubuntu-software-centre-is-being-replace-in-16-04-lts


Alternative Stand-alone Virtual Desktop Manager For Ubuntu 12.04 - Desktop X86-64

There do not yet seem to be any such applications made for the Linux world. However there are some dock/taskbar programs that have virtual desktop managers integrated into them.

lxpanel has a virtual desktop manager applet. If you remove the other applets it can be used for just virtual desktop management, and with an appearance similar to some Windows based virtual desktop managers like for AltDesk for example. Adjust the panel size to just enough pixels wide to fit the applet.

It doesn't work on Unity so I've hit a dead end, though perhaps a different panel/dock program can help me there, but if you install openbox and compiz you can use it though the menu for changing the applet's settings doesn't work. If you launch lxpanel from a terminal you won't be able to close that terminal, so it's better to make a desktop shortcut.

What I Used:

sudo apt-get install compiz

sudo apt-get install compizconfig-settings-manager

sudo apt-get install obconf

Then logged into OpenBox

Right clicked to get the OpenBox menu, and opened a terminal

lxpanel

Put in the settings I wanted

Result:

As you can you get a small floating panel displaying the available virtual desktops, that you can position in different areas of the screen, and open/close seperate from the desktop environment.


(note: all my references to menu entries and window titles may be broken. I don't have an english version of Ubuntu, so I'm just translating from my own UI. I hope it will help you find the propper items anyway.
Anyone with an English UI is welcome to edit my post with the propper names :-) ).

You seem to have a third party repository installed, that doesn't answer anymore.
Actually, given its name, it looks more like a "sample PPA address" than a real thing...
Do you remember adding an external software some times ago (say: 14 days ago) ?

Here are some ideas about what to do with it:

1) You can uncheck it from your sources list, to remove the error and upgrade everything else.

Go to System->Administration->Software Sources, then open the "Other software" tab. You should see a list of external repositories, and the one listed in your error (http://ppa.launchpad.net/user/ppa-name/ubuntu/) should be there.

Just uncheck the box next to it, or even remove it from the list, then close the window and launch the "Update Manager" again.

2) If the PPA should really be working and you installed things through it, removing it from the sources will break the link of this software to its original repository, which means it won't be updated anymore. Maybe you don't really care, and then it's ok, but if you want to know what software it is and see if you can re-install its repository, follow the guidelines below :

To locate it, you can go to Synaptics (System->Administration->Synaptic Package Manager). On the lower left corner, you can select the "state" button, which shows, on the upper left, the "local" installed components. All software that are not linked to a repository will be shown there (either installed by a .deb, or because the link is broken as said above).

If you have such "local" software, you can then try to understand where it was supposed to come from. Then you can try to re-install the propper repository for it (as you did in the first place).
This really depends on the software itself, so I can't be more precise...

Hope this helps...


My BenQ PD2700U does not work with Ubuntu 20.04

my BenQ PD2700U works with Ubuntu 20.04 without doing anything special.
While I upgraded to 20.04 with the monitor connected and it just worked.
On top right of the screen go to settings and than screens to select ho to
exploit the new added sceen (mirror or joint).
best
Fred


sed is a great tool but XML will eventually make any programmer who approaches it with a REGEX cry. I know. I've been there. If there is even the smallest chance that your data will change, you want a proper XML parser.

My choice would be to use BeautifulSoup but it makes handling it directly from Bash fairly hard. If you want to write an intermediary Python script, that's still an option... Otherwise xpath is a fairly classic option. It's a wrapper around Perl's libxml library and it does some fairly powerful things.

sudo apt-get install libxml-xpath-perl

And for your example, here's how I'd do this in the xpath query language:

xpath -e '*/serverName/*' big_xml_file.xml

Again, if you need to do anything useful with this XML, consider something even stronger like BeautifulSoup and Python.


using phpstorm and xampp and unable to create new project folder

unfortunately your target directory have no global permission so you can't create new directory or file in there!
open your terminal and type this:

cd /opt/lampp
sudo chmod 777 -R htdocs

first line navigate you to target directory and second line will change your permission with chmod command...


Incomplete update of tex-common during 20.04.2 upgrade

packages.ubuntu.com/search?keywords=jadetex suggests you need package texlive-formats-extra.
Same for pdfjadetex.
I wouldn't know why one system fails and not the others.


Here are a couple of links to get you started:
GTK Theming Tutorial
GTK Theming Guide


~ and ${USER} don't work in .desktop files

The command in a .desktop file is not run by a shell but using some system call. Because of that you can't use shell syntax like ~ or ${USER} there


HP ProBook 4720s UEFI boot only manually into 12.04

Well,

It seems the HP ProBook firmware is broken or i need to find a way to re-create the
HP_TOOLS partition and add some obscure HP-configuration tool

I now have a booting system.

I did copy

/boot/efi/EFI/ubuntu/grubx64.efi

to

/boot/efi/EFI/boot/bootx64.efi

and the system works.

I still don't get how I can physically change the NVRAM to accept ubuntu settings.


How to turn off Ubuntu 17.10's GUI (GDM)?

Instead of killing the gdm, you can change the systemd target.

Changing the systemd target

As mentioned here, starting from 16.04, Ubuntu uses systemd and the boot process relies on a set of targets. Each target defines the system software that Ubuntu must run.

This is a list of targets for Ubuntu:

   ┌───────────────────┐
   │ Target            │
   ├───────────────────┤
   │ poweroff.target   │ turn off the computer
   ├───────────────────┤
   │ rescue.target     │ minimal for admin/rescue tasks
   ├───────────────────┤
   │ multi-user.target │ multi-user, no GUI
   ├───────────────────┤
   │ graphical.target  │ multi-user, GUI
   ├───────────────────┤
   │ reboot.target     │ reboot the computer
   └───────────────────┘

To stop the GUI, you can change the target. The system checks all the running system software and kills those not included in the specified target. In consequence, if you change to the multi-user.target target, the GUI will be killed.

To change the "target" and kill the GUI:

sudo systemctl isolate multi-user.target

To make this the default "target" (and start booting your computer without GUI), you can use:

sudo systemctl enable multi-user.target
sudo systemctl set-default multi-user.target


I Secured my USB using bitlocker on a windows 7 pc but now i cant see it in ubuntu

Bitlocker is proprietary and only designed for Windows. You need to remove the encryption in Windows in order to use the USB stick in Linux.

There is an experimental tool to access bitlocker encrypted folders in Linux called dislocker. However, there is no guarantee it will work.


What happens when I run ln -s pear /tmp/pear-build-`whoami`

A command surrounded by back-ticks is replaced by its output. So `whoami` gets replaced by david on my computer. (To see more information on whoami, run man whoami.)

So this command:

ln -s pear /tmp/pear-build-`whoami`

gets turned into this (depending on your username):

ln -s pear /tmp/pear-build-david

ln is a command to create hard links or symbolic links. The -s flags indicates that it will create a symbolic link pointing to pear. Its own filename is /tmp/pear-build-david.

I'm not sure why this step is necessary for pear, as it depends on how pear works internally.


how to resize my main partition/ complete delete old one?

You can righ-click swap and choos "swap off". Swap is used by the system you're currently running. This is why you can't change it while your system is running.

It isn't recommended to change something on a disk your system is using and you can't remove the lock from /dev/sda1 since this is the partition your system is running on.

Boot into a live session and choose "swap off" to remove all locks.


When will Ubuntu Touch be available for Xperia Tipo release

I guess never. The device is even overclocked not that powerful, although it's not that spreaded.


why am i asked for a cdrom to perform upgrades?

Go to System Settings > Software Updates and uncheck the CD-ROM checkbox at the bottom of the leftmost tab.

This will remove your installation media from the repository list.

You could also do this by manually editing (with root privileges!) the file /etc/apt/sources.list and replacing every cdrom at the beginning of a line with #cdrom (the # marks the line as comment and lets apt-get ignore it).


XPS 9560 cannot install Ubuntu. ACPI Error / Empty Installation type / "unable to find a medium containing a live file system”

A combination of these things might work for you:

Change the boot mode to AHCI
hit X at the GRUB bootloader screen and change live splash to nomodeset
If it's a USB 3.0 USB make sure you use a USB 3.0 port
If the USB 3.0 USB isn't working - try a USB 2.0 port
If that still doesn't work - try a USB 2.0 key in a USB 2.0 port
If you have no USB 2.0 ports try going into the BIOS and disabling USB 3.0 at the BIOS level
If you can't disable USB 3.0 in BIOS then congratulations you're just as stuck as I am now


"errno 5 - input/output error" when trying to install Ubuntu

I had this problem too, during installation...

[Errno 5] Input/output error

Target machine was a brand new Asus K53e laptop. Installation image was ubuntu-11.10-desktop-amd64.iso (64-bit). I burned this image to CD... Errno 5. Burned it to bootable USB stick... Errno 5 again :( I tried 4 or 5 times.

fsck said the entire root partition was fine (after 10 hours). memtest86+ said all 6GB of RAM was fine too. I tried installing directly when the live image booted up (Install Ubuntu). I also tried the Try Ubuntu button, then ran install from the live desktop. Again, Errno 5.

In the end, it turns out the iso file I downloaded was somehow out of date or wrong. Can you believe it!?

$ md5sum ubuntu-11.10-desktop-amd64.iso

The output was different from Ubuntu's official hash (62fb5d750c30a27a26d01c5f3d8df459). Then I cast my mind back. I remember, when I downloaded this image, I think I was forwarded from ubuntu.com to a mirror site, and I chose a French one at random because my nearest UK mirror was down. It must've been slightly out of date or something. In fact, I now remember seeing entries like this

SQUASHFS error: zlib inflate error, data probably corrupt
squashfs_read_data failed to read block 0x1e457bbd

in the output of dmesg (I think) or somewhere in /var/log when checking after the installation crash dumped me back to the live (Try Ubuntu) desktop.

Basically, make sure you check the MD5 hash of your downloaded ISO file! (I know. I know. I rarely check either!)

Anyway,I downloaded 64-bit Ubuntu 11.10 again and, this time, I was prompted with a Save As dialog, instead of being asked to choose a mirror site. When downloaded, checksum matched :) Installation ok :)


Batch FFmpeg encoding - Variable CRF based on Bitrate

Here is - your ideas combined into a single script:
#!/bin/bash

# Script name: /usr/local/bin/ffscript.sh
# Usage:       go into the source directory and execute `ffscript.sh`

for file in *.mp4
do
        # Use command substitution `$()` in order to get the bit rate of the mp4 file as variable
        BIT_RATE=$(ffmpeg -i "$file" 2>&1 | sed -n -e 's/^.*bitrate: //p' | sed -r 's#([0-9]+)\skb/s#\1#')
        echo; echo "$BIT_RATE"

        SRC_FILE="$file"
        NEW_FILE="${file%.*}.mkv"

        if   (( BIT_RATE > 950 )); then CFR='26'
        elif (( BIT_RATE > 750 )); then CFR='24'
        elif (( BIT_RATE > 500 )); then CFR='22'
        else CFR='18'; fi

        echo "$CFR";

        # Remove the leading echo below in order to do the actions
        echo ffmpeg -i "$SRC_FILE" -c:v libx265 -crf "$CFR" -c:a libopus -b:a 48k -vbr on -compression_level 10 -frame_duration 60 -application audio "$NEW_FILE"
        echo mv "$NEW_FILE" ~/ffmpeg/hevc/
        echo rm -f -- "$SRC_FILE"
done


Listing packages installed outside of official repo

This is the code; To make the search faster first I saved the whole available package list in a text file and then did a grep on it.

# find_foreign_packages.sh
apt-cache search .| grep -o '^[^ - ]*' > pkg_lst.txt

for i in $(apt list --installed| grep -o '^[^/]*');
    do
    output=$(grep -Fx $i pkg_lst.txt)
    if [ -z "$output" ]; then
        echo "$i DOES NOT exists"
    fi
    done;


How to go back to the last screen after accidently click “Ctrl+A, c” when using Screen on Ubuntu

You can always use

screen -ls

to list all opened screens with their PID, and then you can just type

screen -r PID

to switch into that screen. For more information use

man screen


I'm having issues with finding the right nvidia drivers for Ubuntu 19.04

Try booting in advanced mode. Then on the login screen press Ctrl + Alt + F2 to switch to a tty. On there log in with your user and run sudo ubuntu-drivers install or select the Nvidia driver manually via sudo apt install nvidia-driver-430 (use 2x Tab to to autocomplete the package selection and choose the newest one).

If you're on wifi and have to connect first use the nmcli utity: nmcli device wifi connect "your ssid" password "your pw"


Had to reinstall Ubuntu, now it won't connect to my WiFi at home

Open a terminal and run:

gksu nano /etc/NetworkManager/NetworkManager.conf

At the bottom of this file, copy and paste the following:

[device]
wifi.scan-rand-mac-address=no

Restart nework manager :

sudo service network-manager restart

You find a reference of some fixes here :

Fix: Ubuntu 16.04 to 17.10 WiFi and Ethernet Problem


Why does the password for a zip-file not work?

Install 7zip via your package manager or type

sudo apt-get install p7zip

in your terminal. Then try it again.


Is there a method of linking your Ubuntu account to your Ubuntu One/Social Network?

Both of your sub-questions can be answered with a yes. Gnome 3.x (which is what Ubuntu 11.10 and up are based on) has online-accounts, which currently supports linking with Google, but will add other services, and Ubuntu One, Software Centre, and any other Ubuntu-specific apps will use your Ubuntu-Single Sign On.


You can filter files out of the stage directory, like this:

parts:
  part1:
    [...]
  part2:
    [...]
    stage:
      - -file_that_conflicts_1
      - -file_that_conflicts_2

Probably, you need to chose the files from one of the parts that will end up in the snap, and filter out the duplicates from the other part.

You can read more about limiting the number of installed files here:
https://docs.snapcraft.io/build-snaps/advanced-features#limiting-the-number-of-installed-files


Ubuntu installation issue side by side windows 8.1

You installed Ubuntu in Legacy mode.But you installed Windows in UEFI Mode.So you have to convert Ubuntu into EFI mode.

So this will help you.


The executable is named chrome. I'm not sure why they posted that the executable is named Chromium, since it hasn't been named that for a long time.


How to find full path of device I've connected?

From a Terminal prompt:

df -h

You should have a screen similiar to the one attached which should give you the mount point of the USB device.


Interesting question, I'm following it!

As for the answer, the OUYA runs a Quad-core 1.7 GHz ARM Cortex-A9 MPCore CPU inside a Nvidia Tegra 3 T33-P-A3 SOC. It uses the ARMv7 -A instruction set, so Ubuntu ARMEL should work, at least in theory.

Try looking at this question here: How to install Ubuntu on ARMv7 hardware? though it doesn't look like it got a marked answer.

There is a page for Ubuntu ARMEL on the Ubuntu Wiki (https://wiki.ubuntu.com/ARM) and you can download Ubuntu ARM images at http://www.ubuntu.com/download/arm.

There is a Reddit for Ubuntu on OUYA, though it doesn't have any real answers, just people expressing interest, so I didn't include the link (just google Ubuntu on OUYA and it should come up.)

Hopefully you can get it to run, this sounds like an interesting project.


Ubuntu Calendar does not give me notifications

It seems the actual part that shows the calendar notifications belongs to the evolution package, which is not installed by default in Ubuntu 18.04. If you install it, and then set up the calendar from there, it will show notifications for the events.


Problems with Software Sources -- I tried to add a Repository and it failed. How do I fix it?

Just open up terminal (ctrl+alt+T) and post the commands: [Replacing gedit with your favourite text editor]

gksu gedit /etc/apt/sources.list

and remove all references to the faulty repository.