Ubuntu Server 20 does not boot when exfat external drive is connected

You need to change the boot order of your drives in your BIOS/UEFI. Since the WD does not have a an OS your server won't start if it "thinks" it is the system drive.


E: Package 'maven2' has no installation candidate

maven2 package is in universe repository http://packages.ubuntu.com/search?keywords=maven2. So, you need to enable universe repo.

How do I enable the "Universe" repository?

Then use

sudo apt-get update

to update software index.

Then use

sudo apt-get install maven2

to install it


Is it possible to know which recognized flavor I am running using terminal?

This is the command that I use. It works for me all the time:

cat /var/log/installer/media-info

Output (my system) Correctly tells that I am running Kubuntu

Kubuntu 14.04 LTS "Trusty Tahr" - Beta amd64 (20140326.2)


How do I setup “name based” virtual hosts using Ubuntu 12.04?

This is more of an apache configuration question, than a Ubuntu one.

Yes, you may run multiple virtual servers on one host, each serving separate content, provided that they all map (e.g. via DNS) to the same server.

The official documentation on how to create virtual servers (version 2.2 but this feature hasn't fundamentally changed between versions) can be found here:

  httpd.apache.org/docs/2.2/vhosts/

The short answer is you need to:

define your virtual hosts
include some mapping between your host names and the content they serve

This is done by adding a virtual host clause to some apache config file, e.g. under /etc/apache2/sites-available/000-add-my-virtual-hosts (name designed specifically to precede the 000-default name in alphabetic order)

NameVirtualHost *:80

<VirtualHost *:80>
    ServerName hostname1.mydomain.com
    DocumentRoot /home/www/hostname1
</VirtualHost>

<VirtualHost *:80>
    ServerName hostname2.mydomain.com
    DocumentRoot /home/www/hostname2
</VirtualHost>

Note that you may also need to add links from /etc/apache2/sites-enabled/ to /etc/apache2/sites-available if the site you need is already in the latter but not the former.

EDIT 1:
 After reading the man page for a2dissite, it becomes clear that all it does is removing the symlink from /etc/apache2/sites-enabled/.
 The key is to understand that the order in which these configs are processed can affect the end result.  The default site is called 000-default in order to be loaded first.  If it matches all sites, i.e. acts as a 'anything else' wildcard, then you won't see the others.  Try renaming the link to have a higher number like 999-default so it is loaded last (after the other sites matched).

EDIT 2:
To your updated question: yes, it is necessary to rename or delete the default site because its config file name starts with '000' making it load first and 'take-over' due to the wildcard matching.  I suppose the documentation can be improved on this point.

EDIT 3:
The order in which server names appear, its importance and more is documented on this apache page in the section Name-based vhost One of the relevant sentences says:

The first vhost on this list (the first vhost in the config file with the
specified IP address) has the highest priority and catches any request to
an unknown server name or a request without a Host: header field.

and later under Observations:

... the ordering of name-based vhosts for a specific address set is significant.
The one name-based vhosts that comes first in the configuration file has the
highest priority for its corresponding address set.


Well, it looks like Netflix-Desktop and Wine actually naturally coexist. I don't think this used to be the case, but I believe the programmer made it so Netflix-Desktop is based off of a patched version of wine with a different name/folder system. Anyhow, they both run well, without conflicting with eachother.

For anyone interested in the Netflix-Desktop, here's the link:
http://www.compholio.com/netflix-desktop/


systemctl list-unit-files does not show my service

Use systemctl list-unit instead, it will show all loaded (active) units, including those generated.
The list-unit-files only works for the actual installed unit files. To debug the generated ones looking at the /run directory is I guess fine. Alternatively you can use systemctl show example.service to see the in-memory properties, which has some overlap with the unit files.
BTW, for a given unit name, you can use systemctl is-enabled <name> -l to see if it is „generated“, or where it is statically installed.


In general you create links when you want to have the same content reachable under different names.

Since some applications are looking for add and other for list-add, it is easier to provide both icons, then to change the software to only look for one of the names.

Another reason is that designers might want to keep the set of icons small, and thus provide related topics with the same icons.

Links in general are generated with the ln command.

Example: ln -s target.svg linkname.svg creates a symbolik link between the two files.

You can read the documentation of ln by running man ln or a shorter version ln --help.


Dualboot Ubuntu/Windows: "Error: file '/EFI/Microsoft/Boot/bootmgfw.efi' not found"

It is work for me.

Create a bootable windows 10 USB.
Select USB from boot menu.
"Repair your computer" > Troubleshoot > Startup Repair.
Done

It take few seconds. :)


You're missing a space after the command bash and the argument -c.

This should work:

0 15    * * *  root bash -c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

Some additional hints:

Don't run a crontab as user root if you don't need to.
You wrote that you put it in /etc/crontab file. Don't edit crontab files directly, rather use crontab -e command or sudo crontab -e for commands which need root rights. Note, that you don't put the user field in the "other" crontab files.
If you have more than one command you can use bash -c as you do, but I'd rather put the commands in a script and execute this from crontab.
To run a script on startup, you can use @reboot instead of 0 15 * * *.


E: Sub-process /usr/bin/dpkg returned an error code (1) as well as other errors

It is caused by default dpkg overwriting status. dpkg won't overwrite without your permission into shared folder. The workaround:

Press Ctrl+Alt+T
and do:

sudo apt-get -o Dpkg::Options::="--force-overwrite" -f install

Hope it helps...


"system policy prevents installing the bootloader"

Because the system policy for usb-creator-gtk is set up like that. See the /usr/share/polkit-1/actions/com.ubuntu.usbcreator.policy file and the /var/lib/polkit-1/localauthority/10-vendor.d/com.ubuntu.desktop.pkla file. Why? I don't know, maybe the usb-creator code is not safe enough, and the program can be used even to modify internal drives. Maybe it is safe, but the creators don't want to risk it, so they chose not to allow modifications without privileges.

If you don't like that, you can override it (of course that process will require root privileges).


Text editors need root access to work correctly

It sounds like the folder is not owned by your user, so you can't write to it - to sort this out either run this for a file:

sudo chown USERNAME:USERNAME /PATH/TO/FILE

or this for a folder/directory:

sudo chown -R USERNAME:USERNAME /PATH/TO/FOLDER

These commands will make the user USERNAME and group USERNAME the owner of the file or folder specified.

Alternately, you could just make 'Other' users have access to the file:

sudo chmod 766 /PATH/TO/FILE

or folder:

sudo chmod -R 766 /PATH/TO/FOLDER

Here are manual pages on chmod and chown

You can check the permissions of the contents of a folder by running:

ls -l /PATH/TO/FOLDER

You should get something like this:

drwxr-xr-x. 2 wilf wilf      4096 Jan 10 15:59 Desktop
drwxr-xr-x. 2 wilf wilf      4096 Jan 10 00:32 Documents
drwxr-xr-x. 3 wilf wilf      4096 Jan 10 18:25 Downloads
-rw-rw-r--. 1 wilf wilf     70582 Jan 11 22:22 gnomeRemove.txt

Where the drwxr-xr-x. is a directory with read and execute permissions to all users, with write permissions for the owner.

Your username should also be in place of wilf.


How to start graphical applications without lightdm running?

You can edit your .xinitrc. Instead of putting in the lightDM executable, just put:

cat

so that it does not try to run LightDM, nor terminate due to reaching end-of-file.

You can also tweak it to prompt whether you waht to run lightDM or not, but that is beyond the scope of this.

Save the file as .xinitrc in your home folder. Then, run startx, and switch back to a TTY. Run:

export DISPLAY=:0&&firefox

Now, it will both use X, but not lightDM, and will run.


ACPI wakeup script to keep LID0 enabled on Ubuntu 20.10

It looks like I've found the solution by removing the quotes from the line:
declare -a devices=("XHC1 LID0")
Then my script looks like this:
#!/bin/bash
declare -a devices=( LID0 XHC1 )
for device in "${devices[@]}"; do
    if grep -qw ^$device.*disabled /proc/acpi/wakeup; then
        sudo sh -c "echo $device > /proc/acpi/wakeup"
    fi
done

In this way it is working. Is it that easy?


The difference between lshw and lspci commands

lshw lists all computer hardware and lspci list devices connected to the computer.

From Ubuntu manpage:

lspci  is  a  utility for displaying information about PCI buses in the
       system and devices connected to them.

lshw  is  a  small tool to extract detailed information on the hardware
       configuration of the machine. It can report exact memory configuration,
       firmware version, mainboard configuration, CPU version and speed, cache
       configuration, bus speed, etc. on DMI-capable x86 or IA-64 systems  and
       on some PowerPC machines (PowerMac G4 is known to work).


How to install radeon-crimson-15.11-15.30.1025 in ubuntu 15.04?

First uninstall all previously attempted driver intallation by running

sudo sh /usr/share/ati/fglrx-uninstall.sh
sudo apt-get remove --purge fglrx*

If you driver wasn't manually installed then you can skip the first command.
Make sure universe and multiverse are enabled in your repository sources by going

  (System -> Administration -> Software Sources).

AMD driver needs some prerequisite packages to be installed.

For 32-bit system run

sudo apt-get install cdbs dh-make dkms execstack dh-modaliases linux-headers-generic libqtgui4 xserver-xorg-dev-lts-trusty

For 64-bit system run

sudo apt-get install lib32gcc1

Now downlod the Crimson Driver

mkdir catalyst15.11 && cd catalyst15.11
wget --referer='http://support.amd.com/en-us/download/desktop?os=Linux+x86' http://www2.ati.com/drivers/linux/radeon-crimson-15.11-15.30.1025.zip
unzip radeon-crimson-15.11-15.30.1025.zip
cd fglrx-15.30.1025/

Create and install .deb packages

chmod a+x amd-driver-installer-15.30.1025-x86.x86_64.run
sudo ./amd-driver-installer-15.30.1025-x86.x86_64.run --buildpkg Ubuntu/trusty
sudo dpkg -i fglrx*.deb


How to pick which graphic processor to use?

Here is the answer for it:

https://wiki.ubuntu.com/Bumblebee

Source: http://ubuntuforums.org/showthread.php?t=2117866


stop: unknown instance: networking stop/waiting ubuntu server 12.04.3

The problem you're seeing, as least as it relates to 12.04 Server, is that the networking service is not invoked and kept in a stopped state. I verified this on both my 12.04 servers with the following:

sysadmin@ubuntu-server:/$ service networking status
networking stop/waiting

However, NetworkManager is running:

sysadmin@ubuntu-server:/$ service network-manager status
network-manager start/running, process 1479

and both servers are connected to the network, reachable and functioning fine.

Therefore, if you wish to reload a changed configuration file, you should issue

service network-manager restart

Verify your changed settings through ifconfig. You may install any software you wish unless it requires a static IP address for some reason (very few do).


Trying to install a file (xf86-input-mtrack) downloaded from Github

If you'd like to save some effort and have the convenience of the APT package manager supporting you, xf86-input-mtrack is provided in Ubuntu's standard universe repository through the package xserver-xorg-input-mtrack.

Note that, except for Ubuntu 14.04, version 0.3.1 is provided, which is somewhat older than 0.5.0 at your Github link. Here's the Github readme for version 0.3.1, where you can see that TapDragEnable is still included, if you needed that in particular.

To install it:

Open a terminal (press Ctrl+Alt+T).
Run the following:

sudo apt-get update
sudo apt-get install xserver-xorg-input-mtrack

Reboot.


To disable your wireless card, blacklist its driver. From a terminal:

sudo -i
echo "blacklist rtl8188ee"  >>  /etc/modprobe.d/blacklist.conf
modprobe -r rtl8188ee
exit

We hope the tricky rtl8188ee will improve so that you can use your internal device. Please check back in a few months.


It's possible your scaling is set too large or your resolution is too low.
You can change these by navigating to the settings menu > Devices > Screen Display

The T480 I think, has a resolution of 2560 x 1440 so it should be set to that. If it isn't, then you may need to install additional graphics drivers. This resolution can considered a high DPI display, so the standard scaling of 100% might appear too small (and 200% may be too big).

The normal settings menu will only let you choose between 100% and 200%, however if install the Gnome Tweaks tool from the Ubuntu Software application, within it navigate to Fonts > Scaling Factor, then you can adjust that setting too, which might help.


run shell command when i save in sublime-text

Specify a build system for HTML:

{
    "cmd": ["google-chrome", "$file"],
    "selector": "text.html"
}

and install the SublimeOnSaveBuild package.


What's the button on the left corner of a XFCE4 window

I can't be 100% sure, because you are using a non-default theme, but chances are that this is the Stick button.
What this button does is that it makes the window "sticky" so it would appear on all workspaces.
You can make sure that this is the case by opening Settings Manager → Window Manager → Style tab and hover over this button in the Button layout section. You should get a tooltip as shown in the following screenshot:

Also have a look at this Unix & Linux question from which I got the above image: What is “stick” button on windows in xfce?
Sidenote: you can also hide and rearrange the position of the buttons in your windows title bar by dragging and dropping them in the respective frames of the Button layout section.


How do I disable the on-screen keyboard in the unlock screen?

GUI method

Search for Onboard settings from the gnome-shell overview.

Under General tab and Desktop integration heading, uncheck the option Show Onboard when unlocking the screen.

Command-line method

Thanks to fossfreedom's answer to a similar question

Run the following command in a terminal:

gsettings set apps.onboard xembed-onboard false

If the above is not working, try this one:

gsettings set org.gnome.desktop.screensaver embedded-keyboard-enabled false

worked for me (Ubuntu 12.04).


Is there any way to access USB drive from desktop

It should be available from the Unity launcher, if not try clicking on the desktop > go > computer. This will bring up all the drives connected to the computer.

If you would like a shortcut to access "computer" you can install "tweak tool" from the Software centre which gives you this option.

Hope this helps.


Your firmware is probably defective, as it seems to be forgetting the Ubuntu boot entry. I recommend trying the following, in this order:

Check the manufacturer's Web site for an updated firmware (probably called a "BIOS update" or something similar). Install it and run Boot Repair again. This may fix the problem, but I wouldn't hold out much hope.
If the computer is new enough, return it to the store for a refund and buy one that's not broken. The manufacturer is wasting your time, my time, and the time of everybody else who tries to help you. They've had years to fix this problem, yet some manufacturers continue to ignore it. If you return your computer, be sure to tell the manufacturer why you did so; if they don't know they're getting returns for this reason, they'll likely continue to release junk.
In Ubuntu, copy the /boot/efi/EFI/ubuntu directory to /boot/efi/EFI/BOOT and rename the shimx64.efi file in the /boot/efi/EFI/BOOT directory to bootx64.efi. (If there is no shimx64.efi file, you would instead rename grubx64.efi to bootx64.efi.) This workaround copies Ubuntu's boot loader to the fallback filename -- the filename that most EFIs try to launch if they can't find something else. Thus, this approach usually works. If you (or the package system) ever update GRUB, you'll need to repeat this step to use the newer GRUB. If you ever want to replace GRUB with something else, you'll need to do something equivalent with the new boot loader.
Activate the Compatibility Support Module (CSM) in your firmware and re-install Ubuntu in BIOS/CSM/legacy mode. (Alternatively, you could activate the CSM and install a BIOS-mode boot loader; but with a fresh installation, re-installing may be easier.)


I use liveusb-creator for Fedora. Worked fine with all versions of Ubuntu since 10.04 to 14.04 (not official, these are the versions I've created live USBs for myself).

You can grab it from here.

Supports creating persistent storage as well.

Just click on Browse and select your Ubuntu ISO, and select USB as Target Device.
Linux version offered only command-line interface the last time i used it, though years ago, things might have changed since then.


Your question looks a bit ambiguous as you say explicitly say you are trying to "create dvd from video file" in the title of your question but then you mention that you are "trying to make DVD image from .ts file" and you add that you wish an: "image with VIDEO_TS, AUDIO_TS folders and vobs inside."

Both tasks are related but seems to have different answers.

First of all, if you already have the .ts and the .vob files is that easy as burning them in a DVD inside of a folder called VIDEO_TS (AUDIO_TS is optional).

Now. If you have video files and you wish to create an iso image-file with the DVD files and folders inside of it, your best chance will be the usage of DVD Styler which can easily be installed in your system by dropping sudo apt-get install dvdstyler in a terminal or via the Software Center.

The process to create a video DVD from your collection of video files is a little bit complicated if this is your first time using DVD Styler, but you will get used to it soon.

Now let's cook a One Video DVD without Menu following the next Recipe.

The ingredients:

Ubuntu, your favorite flavour. I prefer 14.04 LTS
A fresh install of DVD Styler
One video file
Patience.

Directions:

1. Start New Project

Let's start with a Nautilus File Browser opened in the folder where we have the video to be used for this recipe. We'll also open DVD Styler, the scenery may look like this:

In the first window, DVD Styler will welcome us by asking for the new project specs, it is usually set to our region specs so we need not to change anything in this screen but if you wish you can adjust the video quality in the drop down list having in mind that a bigger bitrate will deliver high quality Videos but it will also reduce the capacity of the DVD.

When ready, hit the "OK" button after which you'll see the "Select template for DVD menus" dialog as shown in the next screenshot:

2. Select template

This recipe is for a Video with No Menu so we'll hit the "No template" button in order to continue.

Inside of DVD Styler we'll notice the left sidebar, the project preview to the right and the contents of the DVD at the very bottom with an item called "Menu 1", as shown in the next screenshot:

IMPORTANT! Please don't delete the "Menu 1" item. If you do so you may experience some errors when creating the iso or burning the project to a DVD. We'll simply override the menu in the next steps.

3. drag and drop our video

Now, let's drag and drop our video in the contents area, just aside the "Menu 1" item.

4. Override DVD-Menu

Now let's instruct the project to override the menu from appearing and let's place the "Title 1" item in first instance in order to make the DVD to start playing the video instead of a Menu. Let's hit the menu "DVD" then "Options" after which we'll see the "Properties" dialog. Let's change the "First Play Commands" and set "jump title 1;" as shown in the next screenshot:

5. Override Menu at the end of the DVD

Now, let's double click the "Title 1" item in order to see the "Properties - Title 1" dialog. In that window we'll set the "Post commands:" to "exit;" instead of "call last menu;" as shown in the next screenshot:

Then, hit the "OK" button and let's start the oven.

6. Burn

Go to the "File" menu and choose "Burn DVD", for the creation of a .iso image we'll use the "create iso image" option from the list. The "preview" is optional and will only open the video file after transcoded (so you can un-check this).

After choosing the right folder where the .iso image file will be saved, let's hit the "Start" button.

7.

A progress window will appear, and at the end of the transcoding, the media player will open the preview and once you close that player, you will be asked if you wish to create an iso image of the video. We should hit the "Yes" button, after which a "Generating was successful" message in green will appear. Illustration as follows:

Next simply hit the "Close" button and go to the folder where you requested the iso to be placed. You'll find it right there.

Serving

Remember to serve it cold with a good beverage for the commensal. Oh yeah! You can also burn the iso image with your favorite DVD burner, Brasero is a good choice. :)

If you wish to create a new recipe for more videos, just make sure that each item follows the proper "Post commands" and the DVD Properties (from DVD/Options menu) is set to "First Play Commands" to the menu item. You can also create custom menus with videos, graphics, images, text, etc. It's about to play a while with the options and you will create excellent artworks with ease.

Good luck!


Is there an editor for Octave with a "Run" button?

The newest version of octave has a full GUI similar to MATLAB. Assuming octave is already installed you can move onto the newest stable octave version by running:

sudo add-apt-repository ppa:octave/stable
sudo apt-get update
sudo apt-get upgrade

If you open octave now it should look like this:


Why doesn't Ubuntu make it's own File manager

Just use Nemo - it was created as part of the Cinnamon desktop, on Linux Mint, due to similar loathing to Nautilus - though it is based Nautilus 3.4, and still has the dual pane feature, and other things, that Nautilus had a while back.

[

There is an article here on WebUPD8 that may of help - It offers a patched version that does not require Cinnamon to be installed, and with Unity integration. It uses this PPA.

There is a helpful question here on making Nemo the default File Manager.

Wiki page on Nemo here - other file managers are listed at the bottom.

If this is not what you want, see @blade19899 's above comment.


How to host my commercial application in Ubuntu Software center?

No, there is no DRM support currently.

No, unfortunately if you can't load a set of pre-generated keys in the interface, then the myapps service can't (yet) sell your licenses [1].

Yes, you can add your demo/trial app - especially if you have another way for people to purchase license keys that will unlock it. [2]

[1] If you can create a bug with your needs at https://bugs.launchpad.net/developer-portal/+bugs the team will be able to start prioritising the various needs, but I'd assume storing other data within the key itself may be hard to support generally?

[2] Recently support was added for adding a demo/trial versions within the one application (ie. so software center won't show two separate applications, but one with options to install the trial or purchase), but it is not yet released - https://bugs.launchpad.net/developer-portal/+bug/830309


I just hit the same problem and think its a bug/feature.

I'm using 'terminator 0.97' and for me the following only works if you have not already set a title for your terminator terminal using '--title' or '-T':

echo -ne "\033]0;SOME TITLE HERE\007"


What does the cog wheel in Ubuntu's Settings > Search do?

The cogwheel lets you customise the search locations (for Files).

  But why doesn't this work on Ubuntu 18.04?

Because Ubuntu 18.04 doesn't have tracker pre-installed.

tracker is a metadata database, indexer and search tool for GNOME. It increases the speed of searching in the Files app and also supports full-text search. But this comes with a huge cost, it causes high CPU use and/or other performance issues.

That's why Ubuntu developers decided to ship Ubuntu 17.10 and 18.04 without tracker (see known issues).

If you manually install tracker and re-login, the cogwheel should be activated.


Trouble reinstalling MySQL 5.7 after uninstalling on Ubuntu 16.04

I had the same problem with the new Ubuntu 18.04. Here's what I did to solve this:

sudo mkdir /etc/mysql/conf.d

then I did what the error message suggested:

sudo apt autoremove

At this point MySQL server is probably working, but I prefer start again, just to be sure. So, I did:

sudo apt remove mysql-server
sudo apt install mysql-server

It should work by now! :)


apt-get update returns 404 errors for Debian repository on Ubuntu 14.04

That repository does no longer serve packages for Debian 7. But they have a repo for Ubuntu 14.04 specifically, so you should use that instead of any Debian version anyway.

Referring to the installation instructions here, to fix your issue, the simplest way is:

Find the list file where this "bareos" repository is configured. It might be something like /etc/apt/sources.list.d/bareos.list. If you have trouble, try this command to search for matching lines in all relevant files:

grep bareos /etc/apt/sources.list{,.d/*.list}

You will find a line like this in that file:

deb http://download.bareos.org/bareos/release/latest/Debian_7.0 /

For Ubuntu 14.04, replace this with the following instead:

deb http://download.bareos.org/bareos/release/latest/xUbuntu_14.04 /

It could be that you might need to install the new repository's key, but probably they use the same key for all of their current and past repos, so you should have it already. If you get an error that the repository key is missing, it can be downloaded from the same new URL as above and added with:

curl http://download.bareos.org/bareos/release/latest/xUbuntu_14.04/Release.key | sudo apt-key add -

Update your package lists and install any available upgrades, as usual.

sudo apt-get update
sudo apt-get upgrade

About the three questions you specifically asked in your post:

  What happens if I run apt-get upgrade without attempting to resolve that 404?

Nothing special. You just would not be able to install or upgrade any packages from that broken repository. All others continue to work.

However, you would be stuck with a potentially outdated, unsupported version of your application, which could imply all kinds of problems, including security threats.

  If I replace domains in /etc/apt/sources.list and get the previous release of Debian, will apt-get update continue to use the old-releases in the future?

Not sure what you mean. There is no repository for any "previous release of Debian" either. Only Debian 8 and newer, but even using those makes no real sense when there are specific Ubuntu repositories for your appropriate system release version. I also don't quite understand what you mean by old-releases.

  Are the possible solutions I mention above relevant here?

apt-get dist-upgrade is completely unrelated and won't have any effect on the issue here. This command just upgrades your installed packages (with the extra power to uninstall stuff if necessary, in contrast to just apt-get upgrade) to the latest versions it knows of, which are described in the package lists you update using the apt-get update command. A missing repository server can not be fixed with local package upgrades of any kind.
old-releases.ubuntu.com hosts the former official repositories of no longer supported Ubuntu versions. Your Ubuntu version has not yet reached end of life though, so you won't find anything for it on there. And the broken repository in question is not even an official Ubuntu repository but hosted by a completely unrelated third party. You will never find their packages on there.
Deleting /var/lib/apt/lists/* can be helpful if your downloaded package lists are corrupt somehow, as it forces apt-get to completely download everything again when you run apt-get update. However, as your problem is that your configured repository does no longer exist on the server, it can not be fixed by deleting your local cached copy of the package lists and trying to download them again. They're still no longer available on the server.


How to install numpy and scipy for python?

Ok, lets follow the installation guide:

It says you need python 2.7 (which you already have):

$ python --version
Python 2.7.4

Then it says that you need the numpy package too, version >= 1.4.1:

apt-cache policy python-numpy
python-numpy:
Installed: (none)
Candidate: 1:1.7.1-1ubuntu1
Version table:
 1:1.7.1-1ubuntu1 0
    500 http://archive.ubuntu.com/ubuntu/ raring/main amd64 Packages

As you can see, I have available numpy version 1.7.1, so lets proceed to install it:

sudo apt-get install python-numpy

Now it says that we need cython, lets check if that package is availabe:

apt-cache policy cython
cython:
Installed: (none)
Candidate: 0.17.4-0ubuntu1
Version table:
 0.17.4-0ubuntu1 0
    500 http://archive.ubuntu.com/ubuntu/ raring/main amd64 Packages

We have it, we install it:

sudo apt-get install cython

Please, do notice that there are other packages that are dependency that are being installed too.
Oddly enough, we also need the scipy module too:

sudo apt-get install python-scipy

Testing. Open python in a terminal and type the following:

$ python
Python 2.7.4 (default, Sep 26 2013, 03:20:26)
[GCC 4.7.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy
>>> import scipy
>>> import cython
>>> exit()

The above, has to be without errors. If something went wrong, go up and read the guide again, you forgot/skiped a step.
Downloading the CLASS sources from their page, go to the directory in the terminal, and untar it and make it:

cd where/the/tar/is
tar zxf class_v2.0.2.tar.gz
cd class_v2.0.2
make

Here we will wait until is complete. Once this is done, we go to the python directory and start the magic. Without moving from directories run this:

cd python
python setup.py build
python setup.py install --user

Now we have CLASS installed in our user directory. We should test it!

python
Python 2.7.4 (default, Sep 26 2013, 03:20:26)
[GCC 4.7.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from classy import Class
>>> exit()

Everything is nice a cozzy until here.
Now the truth time, download monthypython tarball in your code directory:

cd ~
mkdir code
cd code
wget https://www.dropbox.com/s/l7mnhwsktp1m8b5/montepython_v1.2.5.tar.bz2?dl=1 -O montepython_v1.2.5.tar.bz2
tar jxf montepython_v1.2.5.tar.bz2

In the installation instructions are some notes that aren't relevant in this peculiar case (a new install) but it may be important when you update montepython.
This change is important. You remember where you installed CLASS? Now you should tell Monte Python where is that. In my case it is /home/braiam/src/class_v2.0.2/class, yours may be different. You can use find to look for it:

find ~ -name class -print

Well, now I modify the default.conf file using whatever you like (I'll use nano) and modify the root path, so the complete file will looks like:

# Fill in the relevant path to your personal distribution.
# If you create a new file out of this one, please remember to call
# MontePython.py with the option '-conf my.conf'

# At minimum, this file should contain one line:
# ** path['cosmo'] =  path to the cosmological code you are using. Note, if you are
# using a modified version of class, be sure that the path contains the word
# class, otherwise the code might not recognise it.

# If you want to use a data folder different from the one present in the folder
# you are executing the code, please also add:
# ** path['data']  =  /path/to/the/other/data/

root = '/home/braiam/src/class_v2.0.2/'

path['cosmo']           = root+'/class/'

Save the file and exit.
Test montepython! If everything was ok, you should be able to run code/MontePython.py --help in your montepythong directory and everything should run:

~/src/montepython$ code/MontePython.py --help
usage: MontePython.py [-h] [-N number of steps] [-o output folder]
                  [-p input param file] [-c input cov matrix]
                  [-j jumping method] [-f jumping factor]
                  [-conf configuration file] [-chain_number chain number]
                  [-r restart from chain] [-bf restart from best fit file]
                  [-info [compute information of desired file [compute information of desired file ...]]]
                  [-bins desired number of bins, default is 20] [-no_mean]
                  [-comp comparison folder]
                  [-extra plot file for custom needs] [-noplot] [-all]
                  [-ext change extension for the output file]
                  [-fontsize desired fontsize, default is 15]
                  [-ticksize desired ticksize, default is 13]

Monte Python, a Monte Carlo code in Python

optional arguments:
-h, --help            show this help message and exit
-N number of steps
-o output folder
-p input param file
-c input cov matrix
-j jumping method
-f jumping factor
-conf configuration file
-chain_number chain number
-r restart from chain
-bf restart from best fit file
-info [compute information of desired file [compute information of desired file ...]]
-bins desired number of bins, default is 20
-no_mean
-comp comparison folder
-extra plot file for custom needs
-noplot
-all
-ext change extension for the output file
-fontsize desired fontsize, default is 15
-ticksize desired ticksize, default is 13

With this, you have montepython installed and ready to roll!


When exiting Byobu, close all non-exited vim sessions

Using set noswapfile in your vimrc file or files (or :set noswapfile otherwise) has some perhaps unwanted side effects, but does the trick from the vim side.

I don't know about byobu, but if you can customize it to send the quit signal 3 (kill -3 vimprocess) to all your vim processes, that would do the trick.

EDIT: The tmux plugin at https://github.com/jlipps/tmux-safekill will do what you want (and more: see the safekill.sh script for customization), without the drawbacks of set noswapfile.


I'd recommend a complete reinstallation.
The other possibility would be to reinstall the lost packages from your Live Ubuntu. With a complete new installation you also get a much cleaner system than before. If you want to upgrade to Saucy, you could also do this now.


"Disable Touchpad while typing option" gone in Ubuntu 16.04 LTS

I found a similar question AskUbuntu which provided a link to the details needed to solve this issue.
In short, edit your quirks file:
sudo vim /usr/share/X11/xorg.conf.d/51-synaptics-quirks.conf

And add the following to the end of the file:
# Disable generic Synaptics device, as we're using
# "DLL0704:01 06CB:76AE Touchpad"
# Having multiple touchpad devices running confuses syndaemon
Section "InputClass"
        Identifier "SynPS/2 Synaptics TouchPad"
        MatchProduct "SynPS/2 Synaptics TouchPad"
        MatchIsTouchpad "on"
        MatchOS "Linux"
        MatchDevicePath "/dev/input/event*"
        Option "Ignore" "on"
EndSection

Now restart Xorg:
sudo systemctl restart lightdm

Now, just start syndaemon as usual:
killall syndaemon
syndaemon -i 0.50 -m 0.10 -d -K

Note: For some reason, two-finger scrolling didn't work until I fully rebooted my laptop, but it eventually started working.
Edit
I eventually installed touchpad indicator like another answer suggests, when I had to switch to a different Dell laptop, and this fix no longer worked.


Why does a "GLib-WARNING" message briefly appear on-screen when entering or leaving suspension?

It's nothing to worry about and happens to all users, as far as I am aware.  It's actually there when you boot too, just covered over by Plymouth and then by your login screen.


Multiple VPN tunnels between two hosts to increase bandwidth

In the common case a bandwidth problem won't be solved by adding more tunnels.

If you have traffic that is compressible and option in openvpn is adding:

  comp-lzo

on each VPN endpoints server.conf
This can decrease bandwidth usage by compressing data before sending it through the tunnel.

you can read more about it in the manpage


"mountall main process executable changed" causing long boot times

The data you added is sufficient to say: your hard drive will probably fail soon. One reallocated (bad) sector is not bad per se, but given your bootchart issue I'd say: immediately back up your data (start with the more important stuff) and keep an eye on that sector count. If it raises in the near future, replace the hard drive.


Accidentally deleted EVERYTHING in /usr/local

Oops, did that just happen?

We all have made an rm mistake once in our glorious Linux lives.. well I've. Sadly, it can not be undone. Sucks that it has happened but maybe it is time to learn what whent wrong to prevent it from happing again.

sudo rm -rf newfolder

user ~/testrm$ ls
newfolder  test  test2  testdir
user ~/testrm$ sudo rm -rf newfolder
user ~/testrm$ ls
test  test2  testdir
user ~/testrm$ sudo rm -rf newfolder
user ~/testrm$ ls
test  test2  testdir

Welp, clearly that did not remove everything within the directory. The question is, what did?

Possibilty is often that people do sudo rm -rf newfolder *, the space after newfolder is what removes everything within the directory.

man rm
rm - remove files or directories, the -r is needed to remove directories and their contents recursively.

-f, --force, ignore nonexistent files and arguments, never prompt.

  I highly advice to not just use -f.

Check your history by the command history and you could discover what happened.

Good luck.


Cannot source .nanorc correctly: command "include" not found

I found a solution to the problem!

In order to perform syntax highlighting, nano uses a set of configuration files which located (in Ubuntu 16.04) in the directory /usr/share/nano. For example, you have a file related to syntax highlighting of shell scripts (sh.nanorc), Python scripts (python.nanorc), etc...

The syntax highlighting rules to be used is determined based on some pattern matching criteria specified in each file. Python files are matched based on the .py extension for instance.

When there is no match between the file characteristics (extension, interpreter line, etc...) nano uses the default file "default.nanorc".

This means that when you are opening a generic text file such as ~/.bashrc (for example) syntax highlighting is going to be performed using the regex rules contained in the file "default.nanorc". Just edit this file according to your required rules and then save it. Next time you open nano the changes are already stored and effective.

By the way, you can edit syntax highlighting for all other kind of files or the matching criteria between files and syntax highlighting rules by simply editing the corresponding *.nanorc file.


dpkg tells you it's doing something with the .desktop files, menu definitions, icons, ... from the package.


Download the printer driver for Linux from Canon
Extract it
change the directory to Debian 32bit
run sudo dpkg -i *.deb


Where is the wireless connection wizard in12.10?

If you click on the network icon  on the top right of your screen, you should have a list of wireless networks that are in range.

If there is no list, you may see something like "Wireless is disabled". If that's the case, then open a terminal with Ctrl + Alt + T and typr rfkill unblock all. This should re-enable your wifi and the lsit of wireless networks should appear after a few seconds.

See image below:


Fan - always on: Battery drain too high in Ubuntu 12.10 x64

Modify your governor to "quiet" or "Battery Performance"
If you don't know how to do that, go into your BIOS settings and look for a Fan setting
If it doesn’t have one, download "Speed Fan" and modify the value, so that the fan will only run when the CPU is active beyond a certain percent, Or when your machine reaches a threshold of temperature.
Hope this helped


Error ModuleNotFoundError with python3 reinstalling Ubuntu Server 20.04

apt cannot help you because it needs the broken Python 3.
dpkg does not need Python 3, so you can use it for the re-installation of Python 3.
However, it does not handle dependencies automatically, so you must install them in an order that functions.

Search for a suitable python3 for your distro in the https://packages.ubuntu.com/

For example, for focal (Ubuntu 20.04) in a few clicks you land on the package page: https://packages.ubuntu.com/focal/python3

That page lists with red bullets which other packages are dependencies of python3 and should be installed first. In this example

python3.8-minimal
python3-minimal
libpython3-stdlib

It looks like that:

Click on the names of those dependencies and download the deb files for your architecture on your computer. This is the area where you do that:

Install the deb files that you downloaded with
sudo dpkg -i [package name].deb
dpkg will throw an error if you should try a different order of installation or if other dependencies are missing in their turn.
Do not forget to finish with installing the main package of Python 3 after its dependencies (point 2).
Optionally you can do sudo dpkg -a --configure to check whether all packages are actually in order.

After Python 3 has been repaired, apt should work again.


Ubuntu SDK QML how to change the background color of TextField

The Ubuntu SDK comes with its own styled TextField element. On dark background you can use the default Qt version by importing QtQuick.Controls (14.04 only). It will always render a white background but can also be styled with TextFieldStyle:

import QtQuick 2.0
import Ubuntu.Components 0.1
import QtQuick.Controls 1.1
import QtQuick.Controls.Styles 1.1

MainView {
    width: 400
    height: 300
    backgroundColor: "black"

    Column {
        spacing: units.gu(2)
        anchors.centerIn: parent
        TextField {
            placeholderText: "ask"
        }
        TextField {
            placeholderText: "Enter text"
            text: "ubuntu"
            style: TextFieldStyle {
                textColor: "black"
                background: Rectangle {
                    radius: 5
                    color: "gold"
                    implicitWidth: 100
                    implicitHeight: 24
                    border.color: "#333"
                    border.width: 1
                }
            }
        }
    }
}

It will look like the screenshot below:

Source: http://qt-project.org/doc/qt-5/qml-qtquick-controls-styles-textfieldstyle.html


Application is not starting at boot time which should do

What kind of file is /etc/init.d/coc/coc.jar ?

It seems to be a java program, which should run via a command line :

java -jar /Path/to/coc.jar

Jar files are normally not executable directly ?


Can not enter sda_3 crpypt password when booting up!

It seems like defined your HDD to have full disk encryption

e.g. according to the document you can enable full disk encryption during install phase:

  During installation, check the checkbox “Encrypt the new Ubuntu
  installation for security”.

Since you just installed the computer, and you want to get rid from it completely:

The simple solution will be to reinstall Ubuntu on the same machine
This time without Encrypting the disk.

i.e. this time - do NOT check the checkbox “Encrypt the new Ubuntu
installation for security”


You may have to configure your laptop's BIOS to boot off the CD.  Restart your computer and watch closely for a brief message that tells you which key to press for 'startup options', 'system configuration', or something similar.  Once you have determined which key to press, enter the BIOS and set the boot priority to try the CD first.  Unfortunately BIOSs vary wildly so I cannot give you exact steps.


How to add and remove apps post-creation on LiveUSB?

Analysis of the problem

It seems that you did not run persistent live systems, but live-only systems, where you installed and removed items. This works while the systems are running, but the modifications do not persist, they are gone after reboot.

Maybe your USB drives have the capability to boot in persistent mode, but you have booted and/or rebooted them live-only. The boot option persistent makes the difference.
Maybe the tools that you used are not yet upgraded to work for persistence in Ubuntu 18.04.3 LTS.
Maybe you missed some minor detail in the instructions ...

Working alternative

I downloaded ubuntu-18.04.3-desktop-amd64.iso and used mkusb to create a persistent live drive in a 16 GB USB3 pendrive.

When booted persistent live I installed htop and removed usb-creator-gtk (like I did with Ubuntu 18.04.1 LTS as described in a previous comment), and then did [part of] what you describe in your edited question: removed Thunderbird, removed the button for Amazon, connected to Universe and installed stress and stress-ng.

It worked, the modifications persist after reboot. The following picture illustrates what it looks like.

Please notice that you can reboot a persistent live drive made with mkusb live-only, and then it will not see the modifications. The original system from the iso file is still there, but you can mount the casper-rw partition and see the files, where the modifications are stored.


Updated to Ubuntu 16.10 but it seems that I have 17.04 installed!

Really not much point in trying to fix something like that on a future realese (unless you just want to get in on the dev action and submit the fix to the daily build).

Gotta get a live cd + USB drive to backup your home folder then install something more stable. I ran into the same bug as you, using the prerelease iso from like a day or 2 before it went live. Everything been ok until today.

Was the 16.10 iso you downloaded the pre realese one?
Because a bug like that shouldn't happen on a full realese like that


I have a new file type that I would like to handle in gnome how to get file properties?

This is possible, but you will need to change the code for Nautilus to read that metadata from the file and display it in the file properties window.

This page describes how to get started developing code for Gnome and this page talks about development for Nautilus.


How do I set the panel whitelist back to the default?

Try installing the dconf-tools from software center.

Press ALT + F2 to run a command and search for dconf-editor

Highlight the whitelist entry as shown in the picture and click the Set To Default button.

Log-off and login for the change to take effect.


My problem seems to have fixed itself. Possibly due to the fact that I've changed video drivers from Nouveau to the NVIDIA binary driver.


Can't use external monitor with Ubuntu 12.04, Fn+F5 doesn't work

I would suggest you look at the System Tools, Preferences, and Sound and Video selections for a control panel useful for turning on the second monitor. The function key may have changed, or been eliminated, in Lubuntu from EEbuntu.


I never managed to get this feature running myself.

Development on launchpad seems to be stopped for this feature. Last activity dates back to 2012. I found the following bug for lightdm-remote-session-uccsconfigure (Ubuntu)

  Bug #1301897 UCCS configure should be dropped

Bug Description:

  The UCCS configure feature, part of the remote login mechanism should be phased out. It was a testbed for the whole feature.
  Right now we have disabled remote login by default, but kept it as an implementation reference for enterprises interested in such a solution.

I suppose the remote login feature has been silently deprecated. Please correct me if I’m wrong.


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

I want to share what I found here (running over port 80):

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 6494C6D6997C215E

And that was successful:

Executing: /tmp/tmp.BX24beQ8ze/gpg.1.sh --keyserver
hkp://keyserver.ubuntu.com:80
--recv-keys
6494C6D6997C215E
gpg: requesting key 997C215E from hkp server keyserver.ubuntu.com
gpg: key D38B4796: "Google Inc. (Linux Packages Signing Authority) <linux-packages-keymaster@google.com>" 3 new signatures
gpg: key D38B4796: "Google Inc. (Linux Packages Signing Authority) <linux-packages-keymaster@google.com>" 1 new subkey
gpg: Total number processed: 1
gpg:            new subkeys: 1
gpg:         new signatures: 3

I then run sudo apt-get update and everything went fine.


I don't think that there are 64bit WEP networks at all. And I think Wii does understand WPA after an update.
In ubuntu is the kernel used to deliver drivers for Hardware. If your computer is newer, you should use the newest version of ubuntu with the newer kernel.
As an user of XP I would use the lxde Version of ubuntu, lubuntu: https://help.ubuntu.com/community/Lubuntu/GetLubuntu.


Dependency not satisfiable - Offline deb package install

Synaptic has a useful feature that generates a script to download all required .deb files. Unfortunately, Synaptic is not installed by default in Ubuntu any more, so my answer will have two parts.

How to install Synaptic on an offline computer:

You will need to download these packages on a connected computer:

synaptic
libept1.4.12
libvte-common
libvte9

To do this, open a browser to http://packages.ubuntu.com. Search for the package name for your Ubuntu release, click on the relevant search result, click on your architecture (i386 for 32 bit and amd64 for 64-bit) and choose a mirror. Repeat for each required package.

Once you've saved all the .deb files, move the files over to the offline computer and install them one by one in reverse order by opening them in Ubuntu Software Centre.

If you look at synaptic dependencies, you'll notice that it has more dependencies than the ones I've listed. I've only listed the ones that will be missing from a typical Ubuntu 12.10 desktop install.

How to install a particular package on an offline computer:

At this point, you have Synaptic installed on both your online and offline machines.

In the offline computer:

Open Synaptic.
Find the package you want to install, and tick the box. If Synaptic asks you to confirm whether you want to install dependencies as well, accept the confirmation.
Click "File", "Generate package download script".
Save the script on a USB stick.

Take the USB stick to an online computer running Ubuntu. On the online computer:

Open a terminal, and navigate to the USB stick directory.
Run the script. It will download all the required .deb files to the USB stick.
Eject the USB stick safely.

On the offline computer, plug in the USB stick.

Open Synaptic.
Click "File", "Add downloaded packages".
Navigate to the USB stick.
Click "Apply".

(This presumes that you want to install a package that's in the "main" repo. If your package is in the "universe" repo, you will need to have run sudo apt-get update while connected to the Internet some point in the past. The installer will do this for you automatically.)


I found the solution hidden in a comment on unix.stackexchange. Use pactl list sink-inputs to find your application's sink input number. Then use pactl set-sink-input-volume [sink number] [volume percent] to set the volume of your application.


NVMe SSDs performing much poorer on ubuntu 20.04.2 comparing to Windows

If you truly want to test an NVMe drive you need a file 1/1000th of the drive size to flush the drive cache, otherwise you are just comparing cache speeds. So on a 1TB drive your test file size should be 1GB. Adjust as needed for your drive size. What program are you using to benchmark in Windows?
I have a pair of 500gb PCIe 4.0 Samsung 980 Pro drives in Linux raid 0, with a 1GB file (1/1000th of the partition size) I'm getting 13.0 GB/s, right where I expect it to be. I get around 1.3 GB/s write speed, much lower than you would get on a Windows benchmark like Crystal Disk Mark. I am not certain why that is. However I have done some real world tests reading from a PCIe 3.0 1TB drive and writing to my raid, large files over 35GB and my raid is writing at the full read speed of the PCIe 3.0 drive, indicating the Disk Bench in Ubuntu is off and the real world performance is just fine.
So here is what we know: Two completely different systems getting a similar read to write ratio using Gnome-Disk-Utility yet my independent testing indicates the Ubuntu test is somehow "flawed" or reporting some other sort of test for writes, like perhaps random writes.
One thing you can do for a real real world test, if you have a second NVMe to read and write from is:
fallocate -l 100G test.img

This creates a fake 100GB (107.4GiB) file full of zeros very quickly, then time moving it back and fourth with a stopwatch. I get between 1.8 GB/s and 2.3 GB/s depending which way I am going. I have another pair of 4.0 drives on the way with intentions of putting my OS on a Linux Raid 5 NVMe array and when I get them, and the add in 4.0 card I am also waiting on I plan to set them up initially as a pair in Raid 0 and run this back and forth test as well as time some real files, like disk images. For ME benchmarking is neat, but I want to know the real world performance.
I forgot to add to my comment. NVMe drives have fairly fast NAND flash but their real speed comes from fast cache on the drive, some tests give a false sense of speed by only filling the cache whereas a test like disk bench you've done in Ubuntu is writing 100 10MB files by default or 1GB total. On my Samsung drives the DDR4 SDRAM is 1 GB per 1TB drive size, so 512MB on my 500GB drives. Partitioned as a Raid 1 I have 1GB total cache. The first (1gb) file fills that, the next 99 are measuring the actual NAND speed. 100GB in less than a minute is impressive no matter how you slice it. On a read test it's just reading that 1GB file back directly from cache (in my opinion) while on a write test it has to actual put that file on the drive and therefore you are seeing the actual write speed of the drive. For this reason NVMe drives, while blazing fast, aren't truly what they are advertised as, again in my opinion, because rarely will you be reading files from cache, but small writes, less than the size of your cache will APPEAR to be super fast when in fact the drive will write that cache to NAND sooner or later.
Edit: See below for Sandbo's suggestion of using KDiskMark which is available as a snap package
sudo snap install kdiskmark

KDiskMark works very well, much better than the built in disk bench.


How to store the internal error message in a txt file?

Simply press the 'Details' button. this opens a text field with all information about the bug/error, then simply copy and paste to gedit for example, but every other text editor will do as fine as gedit.

Image is just an example message I found here on the site in an deleted post.

You may want to give it a bit time to collect all information tho.


PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php/20160303/zmq.so'

The zmq.so is from the PECL extension ZMQ. As you mentioned it is located there but it's not loading. If you have updated your PHP version recently this could have caused the issue (this could potentially have happened through a distro upgrade as well).

Either way I think your best bet is to try and rebuild the extension with these commands:

git clone git://github.com/mkoppanen/php-zmq.git
cd php-zmq
phpize && ./configure
make
sudo make install

# now we tell php to use this extension
echo "extension=zmq.so" >> /etc/php/{version_number}/mods-available/zmq.ini
sudo phpenmod zmq
sudo service apache2 restart #Since you also tagged this with apache2

I found this information from the following links:

https://github.com/mkoppanen/php-zmq/issues/147
https://eole-io.github.io/sandstone-doc/install-zmq-php-linux


Performance issues with Ubuntu 16.04 LTS

If you installed drivers from nvidia, I would try and uninstalling them.

If you did try to purge them from your install by booting to command-line(recovery-mode) and executing sudo apt-get purge nvidia*

Before rebooting do a sudo apt-get update && sudo apt-get dist-upgrade for good practice. If any packages are broken run sudo apt-get -f install

It should then fallback to legacy drivers.
I had more or less this problem on 16.04 and 16.10
Using those drivers immediately fixed it for me.


Uninstall Gnome 3.10 completly from Ubuntu 13.10

Install Unity and Unity desktop back-

sudo apt-get install unity unity-common unity-services unity-lens-* unity-scope-* unity-webapps-* gnome-control-center-unity hud libunity-core-6* libunity-misc4 libunity-webapps* appmenu-gtk appmenu-gtk3 appmenu-qt* overlay-scrollbar* activity-log-manager-control-center firefox-globalmenu thunderbird-globalmenu libufe-xidgetter0 xul-ext-unity xul-ext-webaccounts webaccounts-extension-common xul-ext-websites-integration nautilus nautilus-sendto nautilus-sendto-empathy nautilus-share activity-log-manager-common python-zeitgeist rhythmbox-plugin-zeitgeist zeitgeist zeitgeist-core zeitgeist-datahub

sudo apt-get install ubuntu-desktop

and reconfigurte lightDm by-

sudo dpkg-reconfigure lightdm

then  remove gnome it by using following commands -

sudo ppa-purge ppa:gnome3-team/gnome3-staging
sudo ppa-purge ppa:gnome3-team/gnome3-next
sudo apt-get purge gnome-shell

Hope it helped you.


How to change the current path to a directory that has an space on it's name?

You have to escape spaces in shell

So type cd Eclipse\ Indigo.

Also you can use quotes as well.

cd "Eclipse Indigo"


Why does this command keep popping up when I open my terminal

In all probability, there is a line in .bashrc that the shell attempts to execute before opening the terminal, and that shouldn't be there.


Argument list too long when copying files

cp *.prj ../prjshp/ is the right command, but you've hit a rare case where it runs into a size limitation. The second command you tried doesn't make any sense.

One method is to run cp on the files in chunks. The find command knows how to do this:

find -maxdepth 1 -name '*.prj' -exec mv -t ../prjshp {} +

find traverses the current directory and the directories below it recursively.
-maxdepth 1 means to stop at a depth of 1, i.e. don't recurse into subdirectories.
-name '*.prj' means to only act on the files whose name matches the specified pattern. Note the quotes around the pattern: it will be interpreted by the find command, not by the shell.
-exec … {} + means to execute the specified command for all the files. It invokes the command multiple times if necessary, taking care not to exceed the command line limit.
mv -t ../prjshp moves the specified files into ../prjshp. The -t option is used here because of a limitation of the find command: the found files (symbolized by {}) are passed as the last argument of the command, you can't add the destination after it.

Another method is to use rsync.

rsync -r --include='*.prj' --exclude='*' . ../prjshp

rsync -r … . ../prjshp copies the current directory into ../prjshp recursively.
--include='*.prj' --exclude='*' means to copy files matching *.prj and exclude everything else (including subdirectories, so .prj files in subdirectories won't be found).


14.04 -> 14.10 not shown in software updater

Ubuntu 14.04 is an LTS (Long-term supported) version so it will by default not ask you to upgrade to non-LTS versions like 14.10.

If you launch Software & Updates from Dash and then go to the Updates tab, at the bottom you can choose Ubuntu to notify you about new non-LTS versions as well ("For any new version"). Just choose this and run update-manager again and it should detect 14.10.


grub doesn't locate ubuntu after windows fresh install on a dual boot system

As far as update-grub is considered file libsudo_util.so.0 is not present in it's proper location.First type the command

  locate libsudo_util.so.0

If you get any output then link the location to correct location

  sudo ln -s current location /usr/lib/sudo/libsudo_util.so.0

If you did not get any output in locate you need to download the file and place it in /usr/lib/sudo folder.


If yours is Gimp>=2.8.2, which it most likely is in Ubuntu 12.10, You can simply select

Windows > Single Window mode

and you will get gimp in single window mode the next time.

As for keeping it maximised, install maximus from Ubuntu Software Centre.

sudo apt-get install maximus

Now run

maximus

and all the windows you open will be maximised. You can set maximus as an autostart app (the command is simply maximus).


Sorry, but seems that compact view was removed on nautilus :-(
https://mail.gnome.org/archives/nautilus-list/2012-July/msg00005.html

I can't believe that, but it's a fact.


I moved my /var/cache folder and broke the permissions. How can I restore them/find what they are supposed to be?

Rather than symlink, mounting a partition to /var/cache would likely accomplish your goals. As for file permissions, it's best not to guess with these things. This is what I have in my /var/cache directory (yours may differ):
drwxr-xr-x 19 root root  4096  5月 10  2020 ./
drwxr-xr-x 15 root root  4096  2月  4  2020 ../
drwxr-xr-x  3 root root  4096  4月 17  2019 PackageKit/
drwxr-xr-x  3 root root  4096  2月  4  2020 apache2/
drwxr-xr-x  5 root root  4096 10月 24  2019 app-info/
drwxr-xr-x  3 root root  4096  7月  2  2019 apparmor/
drwxr-xr-x  3 root root  4096  1月 27 09:46 apt/
drwxr-xr-x  2 root root  4096  4月 17  2019 cracklib/
drwxrwx---  3 root lp    4096  1月 27 00:00 cups/
drwxr-xr-x  2 root root  4096  1月 20 06:45 debconf/
drwxr-xr-x  2 root root  4096  4月 17  2019 dictionaries-common/
drwxr-xr-x  2 root root 24576  1月 26 17:01 fontconfig/
drwxr-xr-x  2 root root  4096  1月 27 06:12 fwupd/
lrwxrwxrwx  1 root root    16  5月 10  2020 fwupdmgr -> private/fwupdmgr
drwxr-xr-x  2 root root  4096  3月 16  2019 gdm/
drwx------  2 root root  4096  1月 13 21:59 ldconfig/
drwxr-xr-x 36 man  man   4096  1月 27 00:00 man/
-rw-r--r--  1 root root   160  9月  7 08:00 motd-news
drwxr-xr-x  3 root root  4096  2月  4  2020 postgresql/
drwx------  3 root root  4096  5月 10  2020 private/
drwxr-xr-x  3 root root  4096  1月 26 17:41 snapd/

However, even with this listing you cannot blindly set permissions. Case in point would be /var/cache/cups, which is used for printing, where different files have different permissions:
drwxrwx---  3 root lp      4096  1月 27 00:00 ./
drwxr-xr-x 19 root root    4096  5月 10  2020 ../
-rw-r--r--  1 root root    2534  1月 27 00:00 Canon_TS8230.data
-rw-r--r--  1 root root     280  1月 27 00:00 Canon_TS8230.strings
-rw-r--r--  1 root root     387  1月 15  2020 cups-browsed-options-canon_ts8230
-rw-r--r--  1 root root     406  1月 27 00:00 cups-browsed-options-Canon_TS8230
-rw-r-----  1 root lp        64  1月 27 00:00 job.cache
-rw-r-----  1 root lp        64  1月 26 00:00 job.cache.O
-rw-r--r--  1 root root       7  1月 27 00:00 org.cups.cupsd
-rw-------  1 lp   lp   6818188  5月  9  2020 ppds.dat
-rw-r--r--  1 root root     308  5月  9  2020 ppd-updates
drwxrwxr-x  2 root lp      4096  2月 16  2019 rss/

As you've recently re-installed the OS, you likely already have a lot of your important files backed up safely. Wipe the machine, re-install, carry on. If you really must put core tables on different partitions/storage devices in the future, use mount points to save the headache


Mounting drive in Ubuntu after reboot - error

Try

file -s /dev/sdb1

for see how (or if ...) the system detects the filesystem. Also, you should consider connecting it on a Windows machine and try running a checkdisk on the volume.


Are there any Application Lifecycle Managment tool like Mylyn or tasktop?

Tasktop will work very happily on Ubuntu.  Tasktop is built on top of Eclipse, which aims to be completely cross-platform.  (Eclipse probably won't run on Commodore 64s, but it will run on just about every major contemporary platform.)

I haven't tried in a while, but I ran Eclipse 3.3 and Mylyn on my home Hardy Heron laptop quite regularly two or three years ago.  (I ran it all day long on my work SUSE machine.)

Disclaimer: I recently started working for Tasktop.  I did not two or three years ago.


How to install Google-Earth 64bit in Ubuntu 13.10, ia32-libs Dependency error

This is only a workaround until Google Earth is repackaged.

Google Earth Build Package

Download Google Earth x64 .DEB
Open Terminal, Copy & Paste Following Command And Press Enter

sudo apt-get install libc6:i386 lsb-core

Open Downloads Folder
Right Click On Google Earth .deb package & Select Extract Here
Open the folder where files are extracted.
Open the DEBIAN Folder
Open the control file with gedit
Remove this whole Line: Depends: lsb-core (>= 3.2), ia32-libs
Now Click Save, & Exit Control File
Now Delete The Original Google Earth .DEB Package You Downloaded
Create A Folder called getfix, Now Move The Extracted Google Earth Folder Into The getfix Folder

Now we Are Going To Rebuild The Google Earth .deb Package:

Open Terminal, copy/paste the following command then press Enter:

dpkg -b ~/Downloads/getfix/google-earth-stable_current_amd64

Copy/paste the following command (this will install the repackaged .deb)

sudo dpkg -i ~/Downloads/getfix/google-earth-stable_current_amd64.deb


How can I install Uniscan on Ubuntu 13.04?

This can help

apt-get install libmoose-perl


How do I restore high-quality bluetooth audio after Teams call?

You can restore the high-fidelity audio by changing the configuration of the output device in the sound settings menu.

Open the dialog for the connected device.

Click the "Sound Settings" button.

Find the output section of the Sound Settings. Observe that the configuration in the output is "Headset Head Unit (HSP/HFP)".

Change the configuration option to "High Fidelity Playback (A2DP Sink)".

Observe that the sound quality immediately changes for all sound coming from the computer. No Teams restart required!


Gedit stating that its unable to retrieve file info even though it works

I suppose you started gedit from terminal using

gedit myfilename.blah

in this case gedit's standard output and standard error streams are connected to the terminal so any debug info is getting printed to the terminal.

To get rid of the messages, you can redirect stdout and stderr to /dev/null:

gedit myfilename.blah > /dev/null 2>&1


Error when trying to install steam with "sudo apt-get install steam"

First try:

sudo add-apt-repository multiverse
sudo apt update && sudo apt install steam

then should run steam.

If it´s not the problem try this thread posted by sejvenables. Maybe can help you.


How to delete files listed in a text file

Use xargs:

xargs rm < file  # or
xargs -a file rm

But that will not work if the file names/paths contain characters that should be escaped.

If your filenames don't have newlines, you can do:

tr '\n' '\0' < file | xargs -0 rm # or
xargs -a file -I{} rm {}

Alternatively, you can create the following script:

#!/bin/bash

if [ -z "$1" ]; then
    echo -e "Usage: $(basename $0) FILE\n"
    exit 1
fi

if [ ! -e "$1" ]; then
    echo -e "$1: File doesn't exist.\n"
    exit 1
fi

while read -r line; do
    [ -n "$line" ] && rm -- "$line"
done < "$1"

Save it as /usr/local/bin/delete-from, grant it execution permission:

sudo chmod +x /usr/local/bin/delete-from

Then run it with:

delete-from /path/to/file/with/list/of/files


Ubuntu 18.04 no longer adds second joystick device for Sony DualShock3's gyro/accelerometer, new sony_hid driver

Missing joystick device

I found your bug on launchpad, but as it turned out it's a 'regression' in the joydev driver introduced in

Input: joydev - blacklist ds3/ds4/udraw motion sensors

The author didn't explain the commit and I honestly can't see the reason behind it. I suggest you file a bug against it.

The evdev device doesn't work either

There's also a minor bug with the evdev device node created by hid_sony: it is not user accessible, so the Motion Sensors won't show up in applications that use evdev devices instead of joydev. If that is your problem, create the file /etc/udev/rules.d/51-ds3-accels-uaccess.rules with the following content:

SUBSYSTEM=="input", KERNEL=="event*", ATTRS{name}=="*Motion Sensors", TAG+="uaccess"

That rule will match every  device that ends in "Motion Sensors", so it also matches knockoff PS3-controllers like Gasia/Shanwan (the suffix is added by the hid_sony driver).

I need the js* device and can't wait for the bug fix!

Since the evdev device is present, we can work around the joydev blacklist by creating a new uinput device that will not be blacklisted and forward the events to it.

Install python-evdev and create the following 3 files:

~/.local/bin/evdev-forwarder.py:

import evdev, sys

device = evdev.InputDevice(sys.argv[1])
joystick = evdev.UInput.from_device(device, name=(device.name + ' forwarded'))

for event in device.read_loop():
    joystick.write_event(event)

~/.config/systemd/user/evdev-forwarder@.service:

[Unit]
Description=Forwarding evdev device: %I

[Service]
Type=simple
Environment="ARGS=%I"
ExecStart=/usr/bin/python %h/.local/bin/evdev-forwarder.py $ARGS

/etc/udev/rules.d/51-ds3-accels-workaround.rules

KERNEL=="uinput", SUBSYSTEM=="misc", TAG+="uaccess"
ACTION=="add", SUBSYSTEM=="input", KERNEL=="event*", ATTRS{name}=="*Motion Sensors", TAG+="uaccess", TAG+="systemd", ENV{SYSTEMD_USER_WANTS}="evdev-forwarder@$env{DEVNAME}.service"

Note: the aforementioned 51-ds3-accels-uaccess.rules is not necessary in this case.

Analog buttons

Using the hid_sony driver, we'll probably never get the analog buttons back. There are several comments in the source code that indicate this, e.g.:

  We use the same axis and button mapping as the DS3, which uses the Linux gamepad spec.

...and ...

  The DS3 provides analog values for most buttons and even
  for HAT axes through GD Pointer. L2 and R2 are reported among these
  as well instead of as GD Z / RZ. Remap L2 and R2 and ignore other
  analog 'button axes' as there is no good way for reporting them.

I highlighted those parts because they are probably the reason why. The Linux Gamepad Specification doesn't mention analog buttons except left/right triggers.

Unless you modify the driver yourself or use something really outdated like QtSixA/sixad, you won't be able to use the face buttons' analog events.


I think that if it starts checking the disk is because there are some problems.

You should use a live system and check the disks from there with

sudo fsck -fv /dev/sdXY

where XY are the letter and the number of the partitions you would check.

Check all the partitions, and if you've got some FAT/NTFS partitions boot with a Microsoft system and make sure you check them from there.


Ubuntu plays /usr/share/sounds/freedesktop/stereo/device-added.oga when a new device is inserted and this /usr/share/sounds/freedesktop/stereo/device-removed.oga when it is removed. So you may just replace these 2 files with any you want to use for this.

As one way to achieve this:

You can rename these 2 files with following commands in terminal :

$ sudo mv /usr/share/sounds/freedesktop/stereo/device-added.oga /usr/share/sounds/freedesktop/stereo/device-added_old.oga

$ sudo mv /usr/share/sounds/freedesktop/stereo/device-removed.oga /usr/share/sounds/freedesktop/stereo/device-removed_old.oga

And copy another sounds from the same folder in replace:

$ sudo cp /usr/share/sounds/freedesktop/stereo/service-login.oga /usr/share/sounds/freedesktop/stereo/device-added.oga

$ sudo cp /usr/share/sounds/freedesktop/stereo/service-logout.oga /usr/share/sounds/freedesktop/stereo/device-removed.oga

Then test by connecting your USB device.


How to upgrade gettext / autopoint on Ubuntu 15.04

Goto launchpad and choose the mirror which is close to you. Then just download autopoint and install it through dpkg.

Example:

wget http://de.archive.ubuntu.com/ubuntu/pool/main/g/gettext/autopoint_0.19.7-2ubuntu3_all.deb
sudo dpkg -i autopoint_0.19.7-2ubuntu3_all.deb
sudo apt-get install -f # resolve any missing dependencies


It can be done without deploying NTP like this:

sudo nano /etc/systemd/timesyncd.conf

Edit the NTP Server detail

[Time]
NTP=ur.ntp.srv
FallbackNTP=ur.fallbackntp.srv

Then

sudo systemctl daemon-reload
sudo timedatectl set-ntp off
sudo timedatectl set-ntp on

and you can check it with

timedatectl status


13.10 asus K56CB gets very hot and fan is very noisy

Nvidia's discrete graphics solution was built with Windows in mind. By default Linux will keep both your GPUs hot all the time. Bumblebee is the Linux answer to Optimus. In Ubuntu 13.10, sudo apt-get install bumblebee-nvidia and reboot. webupd8.org have a nice, up-to-date, high-level guide.


Does Ubuntu have any input tools for typing in Indian languages?

The tool that worked well for me is GXLiterate- A Google Transliteration Service based transliterator for OpenOffice.org for Indic Languages.

It's a libre office extension, but serves the purpose.

Cons: it does not provide an option to choose between transliteration suggestions, it directly translates to the language selected,  sometimes with wrong translation but, most of the time, accurate transliteration.

I am enjoying the same in LibreOffice writer. It solved my problem, however it would be better if there were some shortcut to disable and enable the same.

I also tried XlitHindi, which was developed by CADD, but unfortunately it didn't work on LibreOffice 5; it opened but LibreOffice froze, so I uninstalled the extension and started using Gxliterate, which is working pretty well for me.

Editor's Note: This answer is Kanhiya's.


I seriously did Not change much and suddenly it worked.
Thanks for The Reply!
-- Closed --

EDIT: Maybe adding "Nomodeset" to grub Made it work. I dont know for Sure.


btrfs partition won't mount after upgrading 64bit Ubuntu 11.10 laptop

I had this exact same problem and fixed it by running sudo btrfsctl -a (apparently running sudo btrfs device scan will work too, though I haven't tried it).

Unfortunately you need to run that after each boot. I found an automatic solution here, though from what I understand it's a bit of a hack.


External monitor not working with i915 graphics

Same problem here with Ubuntu 15.10 on a MacBook Pro 13 2011.
There is a workaround:

$ xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync

$ xrandr --addmode DP1 "1920x1080_60.00"

Then in Settings/Monitors I see the externar monitor. But this is no "plug & play". With Ubuntu 15.04 all works fine.


How can I enable bindings in Desktop Wall?

It looks like I found a way around to deal with the problem for binding the mouse corner over Unity. To do this I installed a program called xdotool to be able to execute commands to be sent till X. I found this answer over the OMG Ubuntu when they talk about binding the upper-left corner to auto open the Desktop Wall utility and for my surprise it worked like a charm. So here go the steps to do for making this way around.

Install xdotool:

sudo apt-get install xdotool

Open ccsm and go to your settings in Desktop Wall (Or whatever you want to bind, Ring Swichter for example)

Look at the commands that you have for binding the edge that you want. For me for example I have to command to switch till the left workspace is ctrl+alt+Left. This is the keystrokes that you have to know to create your binding edge. The others bindings, in my case are ctrl+alt+Rigt, ctrl+alt+Up and ctrl+alt+Down.

In ccsm go to the Commands option

Here we have to enter the xdotoll commands. At command line 1 I already entered the command to open the Unity Desktop Wall Utility so at command line 2 I put the command:

xdotool key ctrl+alt+Rigth

Now go to Edge Bindings tab to create the edge bind.

Now click over the Run command 2 to create the bind.

Choose the right corner and click OK

At this point the ccsm might pop-up that if you want to create this bind you have to disable the Flip Edge effect. I dont even knew that I had this on, it might be enable by default from the Unity. Thats no problem in disable it and enable this bind, so just disable the Flip Edge and enable this new bind (This one is for the Flip Edge effect is from rotate cube binding, and at this example we are using the Desktop Wall, so if you dont had the rotating cube enable it might dont pop up this message).

For creating the new binds for the other corners you just have to follow the same steps as you did for creating the right edge. But please read about the left-edge. The code for the other edges are:

xdotool key ctrl+alt+Up

xdotool key ctrl+alt+Down

The Left edge

xdotool key ctrl+alt+Left

For the left-edge dont use the left corner, instead use the lower-left corner or the upper-left corner. Because the left edge is used by the Unity to hide/access the Unity launcher (dock) and if you disable the default Unity effect IT WILL BROKE your Compiz/Unity. So be careful about disabling the unity effect if it pop it.

So once again, if pop up a compiz message asking for disable the Unity dont disable it, just change the corner to lower-left or upper-left corners.

I hope that it could help you out.


The photo lens only searches pictures imported in shotwell and some online apps.
If you got only the 2013/2013-06 folder imported there it won't search other folders.
If you import the other folders as well your problem should be gone.


How to access encrypted Ubuntu 16.04 files from Windows 10 in a dual boot system?

Since there are two methods that you could have used (independently or in combination) to perform encryption, I'll touch on both separately. And then I'll address access from Windows.

You could have encrypted your entire disk with LUKS like this during install

Or you could have encrypted your home directory with ecryptfs like this during install

Disk encryption with LUKS

If you encrypted your entire disk with LUKS, you may want to look into a program for Windows called LibreCrypt. I have used it with success in the past to access LUKS encrypted partitions from Windows 7.

Home directory encryption with ecryptfs

If you encrypted your home directory, there is currently no way to get at this from Windows. However, it is possible to remove the home directory encryption so long as you have enough disk space to make a duplicate of your home directory.

Accessing the Linux ext2/ext3/ext4 filesystems from Windows

Now, in theory, all you should need to do is mount your Linux file systems in Windows. I've not tried it, but supposedly, Ext2Read should enable you to mount ext2/ext3/ext4 filesystems in Windows. Furthermore, it is said to support LVM2 which will be important if you chose to use LVM when you installed.


You can't alter a mounted partition. Obviously your /dev/sda6 partition is mounted (since it contains root, /) since you're running Ubuntu with it. Also, the little key icon/symbol indicates that it is locked (a.k.a in use).

So yes you'll need to boot into a LiveCD or LiveUSB in order to do this.


The update command only updates the package meta data:

sudo apt-get update

If you want to make sure you have the latest software, you need to use dist-upgrade as well:

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

You may also just use upgrade. However, hat will not install/upgrade system packages such as the kernel.

If you really somehow uninstalled the Ubuntu Desktop (X11) then you can attempt to reinstall with:

apt-get install ubuntu-desktop

I have some details on my Linux blog (search on X11).

However, it could also be that you changed the startup scripts and it won't boot in the desktop. If that's the case, you'll need to tweak the boot parameters. I also have some info for 16.04 on my blog. For newer systems, you particularly want to look into the systemctl commands (also on that page) such as:

sudo systemctl start graphical.target

Also newer systems do not make use of Unity. (Well some people are still using Unity... but most of us are using Gnome now.)

Now, if your server doesn't connect, you probably have a network setup problem. There can be many reasons for that and it's a quite different question than "I lose the Ubuntu Desktop"...

I suppose you have a newer version of Ubuntu (18.04 or newer? You should specify in your question or use a tag.) The network setup is done in the netplan file:

sudo vim /etc/netplan/50-cloud-init.yaml

I also have a page about setting up netplan on 18.04+. I think here are two main things that can go wrong: you uninstalled a mandatory element (i.e. the DHCP handler/module) or your settings are wrong, somehow. In most cases, if you can ping an external IP address, but you can't determine a domain name IP address, then your name server info is wrong. I often try something such as:

ping example.com

where example.com is your favorite website (say askubuntu.com). The ping is not likely to work, but if it stays stuck on the first line that's because it can't resolve the name. You can try with an IP address too:

ping 1.2.3.4

If that works, then the network connection is good, but the name resolution is bad.

You can test with ping on another Linux or MS-Windows or MacOS machine. Under Windows you probably have to run a console as an administrator (ping sends a type of packet which require admin rights, even under Unix, but Unix automatically gives you the necessary authorization).

Look for netplan docs and network problems for that one.


could not copy the folder with .txt file in it to another folder

Try this:

cp -Ri ~/Desktop/linux ~/Desktop/ubuntu


Try editing your resolv.conf and put

nameserver 8.8.8.8

Save it and give it a try, it should resolve correctly, its not a fix but a workaround.


Unable to uninstall wine in Ubuntu 18.04

You can uninstall all dependencies related to wine

sudo apt-get remove --autoremove wine-*


Unfortunately unlike the x86 world the arm world doesn't have a common "platform".

PCs all boot in the same way, they have crucial system hardware like timers in the same place. They all have the registers used to enumerate the PCI bus(es) in the same place. They have a BIOS that passes further details of the hardware to the OS.

Arm boards don't, each SoC is very different and the boards they are installed on are often different too. At a minimum you tend to need a board-specific bootloader and "dtb". Sometimes you also need a board-specific kernel, especially if you want full functionality.

What tends to end up happening is that only a small selection of hardware is officially supported by the distro, then the community arround each given board puts together unofficial images for thier boards.


How would you install OpenSSL package for Ruby?

Use sudo apt-get install openssl, or use the software center to find it.

When I look for packages, I generally use apt-cache search whatever.
For openssl, here's what I see on my system:

$ apt-cache search ^openssl
openssl - Secure Socket Layer (SSL) binary and related cryptographic tools
openssl-blacklist - Blacklists for  OpenSSL RSA keys and tools
openssl-blacklist-extra - Non-default blacklists of OpenSSL RSA keys
libengine-pkcs11-openssl - OpenSSL engine for PKCS#11 modules
libxmlsec1-openssl - Openssl engine for the XML security library

For gem dependencies, you would normally use something like :

sudo apt-get install ruby-full build-essential ruby-rvm yorick rubygems

However, apparently ruby-rvm is broken, so the ex(?)-maintainer's advice is to remove it completely, and install via the provided URL and bash script:

sudo apt-get --purge remove ruby-rvm
sudo rm -rf /usr/share/ruby-rvm /etc/rvmrc /etc/profile.d/rvm.sh

  open new terminal and validate environment is clean from old rvm
  settings (should be no output):

env | grep rvm

  if there was output, try to open new terminal, if it does not help -
  restart computer

  install RVM:

curl -L get.rvm.io | bash -s stable

  do not forget to read rvm requirements before installing rubies


TV channel Identification using Linux C Programming

Call me old fashioned, but OCRing the text out of a live frame is probably the last thing I would try. The text won't always be there (will it?) and it's just a horrible way of dealing with things.

I think the only real option is to bring the capturing into the computer with a DVB card or USB stick. Then you control the channel rather than just receive it. Plus you get EPG access for free (in DVB-T/S/S2).

It's more hardware (and a slightly more convoluted setup) but much cleaner and easier to expand to handle other functions.


When I install packages, I keep getting fontconfig warning

As I analyse problem the solution is......

It is a bug in Khmer fonts, see https://bugs.launchpad.net/ubuntu/+source/fonts-khmeros/+bug/1254967.

If it bothers you and you do not need Khmer fonts, you can get rid of it removing (with configuration) the fonts:

 apt-get purge  fonts-khmeros-core

If you need the fonts, there are various workarounds in the aforementioned bug. The most correct way seems to edit the failing file and remove the  and  tags, as explained here: http://permalink.gmane.org/gmane.linux.debian.devel.bugs.general/1095401


Need 'Ubuntu 15.10 _Wily Werewolf_ - Release amd64 ' on USB

Looks like your CD is listed in Software Sources, you'd better remove it (e.g. this way). It isn't needed as a package source anymore once you've finished installation as you can get newer versions and more packages from the online repositories.

You can also mount the iso to this folder with sudo mount -o loop image.iso /media/cdrom but I believe it's the wrong way to solve this problem.


"No root file system is defined. Please correct this from the partitioning menu" during installation

Root filesystem defines topmost entry point on disk where operating system should be installed, and denoted by /. In the Windows world, that's C:\ and in Minix - >. In the picture from related post the disk is subdivided into several partitions, and root filesystem is on /dev/sda5.

Of course you can do a lot of fancy things with that: root filesystem can be on one disk or partition and /home can be placed on another partition or whole different disk entirely.

If you're not using anything fancy, selecting Erase Disk and Install Ubuntu in the menu should be enough. If it still doesn't let you install, select Something Else and in the next menu click + button to create new root partition. For more detailed steps follow the linked post.

Fun things for more advanced learning:

Note that "filesystem" in general denotes disk or memory space (for example tmpfs or ramfs) which are organized on the level of bits and bytes in particular way to store files (and also preserve their integrity as in case of ext4 journaling filesystem). Filesystems intended for user access(aka browsing files), however, need to be connected to a folder so that users can access the contents of filesystem. This is called mounting. In this case, root filesystem is mounted at / folder by convention, although there's other much more technical ways in which a root filesystem can be mounted on some other folder such as chroot.

However, there's difference between filesystems for users access ( aka userspace ), and kernel space. Such kernel filesystems as pipefs don't have any folder available to users to browse, and generally have FS_NOMOUNT flag set(source).


Best VPN package for a group of 8 people doing majority online gaming

If the machines on the VPN are all running Windows and the purpose of the VPN is to facilitate Windows gaming, and you have a powerful computer running Windows that you use for gaming, then you might just want to use that as your VPN server. Regardless of what VPN solution you choose, there's no fundamental reason why the server must be separate from the machines using the VPN.

Whether you host the VPN with Windows, Ubuntu, or some other OS, it seems from your question that you're most interested in knowing about the advantages of various VPN's from the perspective of Windows usability and performance. Therefore, you might get better answers if you were to ask a reformulated version of your question somewhere Windows is supported, such as Super User.

Since you're using Windows, presumably you're willing to use proprietary software. (Many games have proprietary engines, too.) So you might consider using Hamachi (see also this article). It's proprietary but not payware unless you use some of the more advanced features. It provides VPN without the need for a VPN server. Hamachi supports Windows and Mac OS X and has a beta client for GNU/Linux (including Ubuntu). This may work well even if the VPN must be accessed robustly by Ubuntu (for example, if you run dedicated game servers on an Ubuntu machine). If the VPN need only be accessed casually by Ubuntu, then this will almost certainly work well.


Wi-Fi not working with Ubuntu 14.04 in HP spectre

Looks to be an acer module loaded and you say it is a HP computer, so do this

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

Reboot and see if wireless is still hard blocked with rfkill list all


Dell laptop CPU temperature at 86°C while doing nothing ... and so fan at full speed

Just use Ubuntu 20.10 in place of Ubuntu 20.04
Details of the PC :
Inspiron 15 5000 Séries 5502
11th Generation Intel(R) Core(TM)i7-1165G7 Processor (12MB Cache, up to 4.7 GHz)


Did you try sudo rm -r.
What kind of files are there?
You could also delete all the files first then delete the folder. It's extra work, but sometimes it is worth it to get the job done.

sudo is for superuser actions.


There are two ways to do this,

Go to system>administration>Language Support in your menu, and choose your language settings.

looks like DoR got the same thing as me

Before you log in, you can change your language (bottom left, select your language).


wget --content-disposition 'http://spreadsheets.google.com/pub?key=pyj6tScZqmEfbZyl0qjbiRQ&output=xls'

will do the trick for you.

Its still not fully implemented and seems to bug out a bit sometimes so its not the default option in wget, use it at your own risk.


Try installing the grub customizer app, from ubuntu software. There you can set how many seconds to see the bootloader menu, and possibly turn it off. Tip, you better leave that menu you might need. As for the windows boot option we don't know if you have BIOS or UEFI?


How can i connect ubuntu 17.10 to my LG Smart TV

From your comments, it sounds like you're using Miracast under Windows, the successor being Miraclecast. I'd recommend downloading and installing the Miraclecast project. The quick procedure would be to:

Download the zip file from the release folder
In  the miraclecast-1.0 folder, run the autogen.sh script
Run ./configure
Run make
Finally, run sudo make install

This should install Miraclecast on your machine.

For a discussion and additional details, see the detailed AskUbuntu thread here.


Determine which version of a gem is installed?

gem list

should give you a list of all your gems with version number in brackets behind it


Tripplite KVM switch loosesUSB connection Ubuntu 19.10

I think I found a solution: Disable the autosuspend function (article I used https://www.makeuseof.com/tag/fix-usb-device-port-linux/)

Important part, in case article goes down:

Check if autosuspend is active:

cat /sys/module/usbcore/parameters/autosuspend

If this returns 2 autosuspend is active. After that you can follow the instructions of this answer: https://unix.stackexchange.com/questions/91027/how-to-disable-usb-autosuspend-on-kernel-3-7-10-or-above (which gives some further explanation)


Creating an icon for indicator applet in Vala

Solved by doing this:
- use install file to install icon to usr/share/icons
- in code, create indicator with icon name that matches the filename of the icon installed. I was doing something wrong the first couple tries, but figured it out and got it working. Feel free to ask for more details.


Can I resolve user issues by cleaning out my home folder?

Your issue was found to be limited to a corrupt configuration file in your home as the new user account did not have the issue you were facing. It doesn't happen all the time. Problems might be from the software level (in other words, a bug in the software) which can't be fixed by creating a new user account.

It clearly is a problem with just the home folder (or more exactly, the configuration files) because the newer accounts are not affected.

You could have possibly fixed your problem by resetting your gnome-session to the defaults but it didn't strike me when I was trying to fix your problem. Try resetting GNOME to the defaults and see if that fixes the problem with your old user account.


Can't install software from Ubuntu Software

There are many possible reasons why Ubuntu Software (a.k.a. gnome-software) is not working for you. I was having issues with it myself.

Firstly, since you started but were not able to complete installs, you probably have an install queue that you need to clear.

Make sure Ubuntu Software (gnome-software) is not running. Before making any changes, you want to backup the gnome-software folder that lives in your home directory, which holds the install queue. In Terminal or a CLI:

cp -r ~/.local/share/gnome-software ~/.local/share/gnome-software-BAK

Clear the install queue

rm ~/.local/share/gnome-software/install-queue

Reopen Ubuntu Software (either from launcher or by typing
gnome-software into the command line)
If the above doesn't work, you could also try removing your home folder's gnome-software directory altogether. Quit Ubuntu Software, then enter:

rm -r ~/.local/share/gnome-software

Restart Ubuntu Software. If that did not help, You can always undo the removal of the gnome-software folder and restore the backup:

rm -r ~/.local/share/gnome-software && mv ~/.local/share/gnome-software-BAK ~/.local/share/gnome-software

You could also be having problems because you need to run an upgrade.

In Terminal, enter:

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

Then restart your computer.

Your sources list might be causing issues for you. My problems with Ubuntu Software were resolved by fully removing PPA's that I thought I had gotten rid of using add-apt-repository --remove, which did not get rid of their .list files in /etc/apt/sources.list.d/, nor did it get rid of their keyrings in /etc/apt/trusted.gpg.d/. If the software you're trying to install is from a PPA, you could still try cleaning out other PPA's, as these may be slowing down Ubuntu Software. There are known issues with the PPA associated with google-chrome-stable, for example.

Edit the list (/etc/apt/sources.list) itself. It's much speedier to do it completely from command line: sudo nano /etc/apt/sources.list then sudo apt-get update. You can also do this in the Software and Updates GUI (run from launcher or open in command line with software-properties-gtk), but it seems to take so much longer to do the updating step when I use the GUI. I can add steps for doing it this way if you want, though.
If you already know the names of the PPA's you want to remove then you can get rid of them one by one using the command: sudo add-apt-repository --remove ppa:<repo>/<subdirectory>. Note: There's also ppa-purge, which I didn't want to use because it downgrades packages associated with the PPA to versions available in repositories, and I wasn't sure if this would affect the programs I had installed, as the programs themselves were not the problem.
After editing sources.list, you may find (like I did) that old PPA's are still showing up in /etc/apt/sources.list.d (a directory containing .list files of each PPA), and their keyrings were still in /etc/apt/trusted.gpg.d.

You can check this yourself by entering the command:

ls -lR /etc/apt/ | grep -v '~'

Then you can get a list of the .list files in sources.list.d and remove them one by one:

ls /etc/apt/sources.list.d
sudo rm -i /etc/apt/sources.list.d/<PPAName>.list
sudo apt-get update

To remove the keys:

sudo apt-key list
sudo apt-key del <KEY_ID>
sudo apt-get update

After this, Ubuntu Software was actually functioning, hope this helps you!

There's also the possibility you need to do a "deeper" version of sudo apt-get upgrade:

sudo apt-get dist-upgrade

and restart.


Cannot mount audio CDs (but DVDs are fine)

I've been troubleshooting this for a while and I just downgraded my package of udisks from 2.7.1-2 to 2.6.4-1 and rebooted gdm -- instant fix.

It seems there may have been a regression introduced in udisks. I don't see a bug yet, so one should likely need to be opened. If you're looking to play or rip the CDs a couple applications still can (those that don't use Udisks), so try VLC or CDparanoia which I've had good luck with, and then otherwise a fix will hopefully come as soon as possible.

Edit: The latest version of udisks 2.7.1-2 and libblockdev 2.10-1 seem to fix the issue as well. Hopefully the updates come down the pipe soon!


How can I stream music from a Mac to Ubuntu?

You should be able to switch on DAAP network sharing in Rythembox by going to the Edit > Plugins and checking the box next to DAAP. You can also use the configure button to share your Ubuntu music to itunes:


Use Nautilus (File explorer)

Right-click that folder, select Properties then Local network share. Change the Share name and then click Modify share button.


Check your /etc/ssh/sshd_config file:

Change from:

PermitRootLogin prohibit-password
StrictModes yes

Change to:

PermitRootLogin yes
# StrictModes yes

Then restart the sshd daemon.

$ sudo service sshd restart


How do I limit battery charging to 80% on Ubuntu?

You have to use Dell Command Configure.
After installing, run
$ sudo cctk --PrimaryBattChargeCfg=Custom:<low>-<high>

and adapt the low/high thresholds.