I had a similar issue, though, only my set-up column width in Detailed View didn't get used permanently.

For me, changing the permissions (was 700) for the folder ~/.config/xfce4/xfconf/xfce-perchannel-xml wasn't the solution. Thunar's settings got saved correctly with every switching of View mode or changing of column width. Still, every new Thunar window opened with a default column layout. Even setting permissions of ~/.config/xfce4/xfconf/xfce-perchannel-xml/thunar.xml to read-only after verifying the correctly saved settings in the XML's entry last-details-view-column-widths did not fix the issue; the file permissions were even reset once Thunar was restarted.

For me, the solution was to uncheck the setting Automatically expand columns as needed in Thunar's menu View" > Configure Columns.... This setting seems to work in a faulty manner, as even when opening a folder that has only one-letter items, the "Name" column was opened with a width of about 600 pixels, pushing columns such as "Type" and "Date Modified" out of view in a window 1100 Pixels wide, so I still had to scroll horizontally to see those columns.

After unchecking above setting, Thunar opens all windows and folders with the column layout I set up.


I think your control file is corrupted.

Try this:

sudo rm -rf /var/lib/apt/lists
sudo mkdir -p /var/lib/apt/lists/partial
sudo apt-get update && sudo apt-get upgrade


Make a bootable internal drive to install Ubuntu on current drive?

You can try either making a bootable flash drive or unetbootin.

Unetbootin will run on Windows. When installing the Ubuntu Desktop ISO, choose the free drive  as the location to install into, then boot from your drive.

Unetbootin home page


Skype [4.2.0.11] - black Video on KDE - 13.04 32bit

What worked for me is adding:

<VideoRenderer>
  <DisableXv>1</DisableXv>
  <ForceOpenGL>1</ForceOpenGL>
</VideoRenderer>

to the UI section of the file ~/.Skype/[username]/config.xml.


Radio Tray Unity panel icon color change

Radio tray icons are placed in different folders, but the one you are interested on is named radiotray_on.png, whose location may be found by dropping locate radiotray | grep .png in a terminal in order to know all the locations of the Radio Tray ICons.

The one which manages the notification area status icon for the Radio Tray application is set inside of the folder: /usr/share/radiotray/images specifically called radiotray_on.png.

I suggest you to run nautilus with administrative rights (gksudo nautilus) over that folder in order to open the icon in gimp or any other software of your choice on which you can change the hue, saturation and curves of the icon, then save it (remember to backup) and restart Radio Tray in order to the changes to take effect (you need just to re-play your current radio station if already playing).

Illustration here: (check the radiotray notification's area icon and the edited radiotray_on.png highlighted with inverse colors in nautilus)

Here is a copy of the image that you can use if you don't feel like editing the icon manually (right click, save as, etc.):

Good luck!


Why cant i find site_perl directory in Ubuntu?

Try this command:

$ oldperl -S pmpath CGI CGI::Imagemap

This should output the location of the Imagemap module, which should be in pm_perl/CGI/ if it exists.


wget unable to locally verify the issuer's authority but curl works

it should be finding google's root certs. So something is asmiss
try:
sudo apt install ca-certificates
or
sudo apt reinstall ca-certificates
Some other are root certs are however not present by default (at least on my 20.04)
wget --ca-certificate=<ca-root.crt>   https://....
The root cert you can get from the cert vendors site


Ubuntu 13.04 touchscreen and touchpad support on Dell XPS 12

I had the same issue on my brand-new XPS12. It might be the newer model that prevents installation from 12.x or 13.04. I had success with 13.10 beta 1, though. Pretty much everything works out of the box, except multi-touch. No idea where to look as sputnik is already supposed to be integrated...


Installing a Graphic User Interface in Ubuntu 14.04

The first error regarding package enlightenment has not installation candidate means either there is no package in the already installed repositories or you haven't updated them. So you need to either add the relevant PPA or updating your local database using apt update.

The second error clearly shows there is no Xorg on your system. So, simply install it using:

sudo apt install xorg


Is itoa() available in stdlib.h in Gcc >=4.1?

It doesn't appear to be defined in 4.4.4, but if you don't care about radixes other than 10

char *itoa(long i, char* s, int dummy_radix) {
    sprintf(s, "%ld", i);
    return s;
}

Is a quick and dirty (and tested) replacement.


Can't unzip compressed files - Ubuntu 15.04

The problem was that file-roller somehow became corrupted. I just had to reinstall it and everything is working.


How to add dockbarx (gnome) panel applet to unity panel?

The latest version of DocBarX supports both gnome-panel and AWN (see this article).

Thus if you install AWN together with the latest DocBarX from the PPA then this should work very nicely with the Unity Interface.

An alternative would be to add the Gnome Panel to the Unity Interface and add DocBarX as usual to the Gnome Panel.


Perhaps some of the needed packages were not installed. I would advise re-installing gnome, without removing it first. This way you will only download the pieces you are missing.

sudo apt-get install gnome (Entire Gnome Desktop + Pre-Installed Programs, if you are unsure, pick this one)

or

sudo apt-get install gnome-shell (Just Gnome Desktop)

sincerely, tapthoseshoesandwish

sources: http://candlelight.any.djun.net/x/1/index.php?topic=576.0


Wi-Fi only loads websites and nothing elese

Well, this was very strange but I am answering my own question. (Feel free to reply and give your theory as to why this happened if you would like just in case this happens to me again)
So I was very frustrated because I was using my Phone's hotspot to connect to my school and so I kept looking for answers on this website. I also had this issue which was frustrating Why is the Edit button greyed out in Network Manager?
but the internet issue was more important (i could still edit connections in the settings menu at the time)
So the top voted answer in that link was "Run in terminal sudo /etc/init.d/networking restart"
On xUbuntu this is called network-manager not networking but anyways. What I did instead of sudo /etc/init.d/network-manager restart is sudo /etc/init.d/network-manager status
This told me every thing it was doing when connecting to a network. It said it was still connected to my phone so I switched to my home wifi. I ran the command again and the last thing it said was manager: NetworkManager state is now CONNECTED_GLOBAL and I tried pinging google.com and my personal website and it replied. I opened a game as well just to make sure and it booted up just fine with online connectivity. I have no idea why checking the status fixed it but it did. I didn't do anything else other than connect to my phone and then back to the home wifi and type in that command. I had done the connecting back and forth between the phone and my home network for a few days now so idk what the heck the command did but it fixed it.
EDIT:
It is broken again and this answer DOESNT fix it so this proboly didnt fix it the first time


You apparently originally installed Sublime Text from a third-party source or PPD. On the command line, run

sudo apt-get remove sublime-text-installer

to remove the old package, then switch to the directory where you downloaded the new .deb file and run

sudo dpkg -i sublime-text_build-3103_amd64.deb

to reinstall from the official source. This method will not remove your custom settings or packages. However, depending on how you set up your previous installation, you'll need to use the command-line shortcut subl instead of sublime.

Finally, I recommend reading through my answer here for information on making Sublime your default text editor, if you haven't already.


Celestia was available somehow for Ubuntu 14.04 LTS and still available for Debian Jessie.

In the whole FOSS world it is spread well.

Official site have a link to bintray repository. So you can install Celestia from it with commands below:

wget -O- https://bintray.com/user/downloadSubjectPublicKey?username=bintray | sudo apt-key add -
sudo add-apt-repository "deb https://dl.bintray.com/celestia/releases-deb bionic universe"
sudo apt-get install celestia

so there is no need to compile it from source.

Details about compilation:

The libgnomeui-2.0 is a part of libgnomeui-dev package, which is not available for 19.10. So you can't install this package on the Eoan system in easy way.
The gtk+-2.0 is contained in libgtk2.0-dev which is still available for 19.10.
The gtkglext-1.0 is contained in libgtkglext1-dev which is still available for 19.10


Cannot extend a partition located AFTER the unallocated space

You can't resize because of the following problems:

The ext4 partition on sda5, within the sda4 Extended Partition, is mounted and in use.
The swap partition on sda6, within the sda4 Extended Partition, is mounted and in use.

You also said that Ubuntu is installed via Wubi.  This complicates things.  We can't easily resize a Wubi installation.  A Wubi installation is not a true dual-boot.  It's a single container file installed in Windows that takes up Windows filesystem space.  You then have it 'booting' into that container, and it is not a true dualboot.

Resizing in the way you look to be trying to achieve may not work correctly, if at all.

I advise you take the data inside your Wubi installation and copy it to an external drive, then do an actual dual boot installation, while removing the Wubi installation.


Set up an Ubuntu 15.04 based mini-pc as WiFi router

Yes, this can be done with hostapd. The Ubuntu documentation might be of help for you:

https://help.ubuntu.com/community/WifiDocs/WirelessAccessPoint


Which video card for a 1680x1050 resolution?

Unfortunately AGP is a dated technology and its a bit difficult to find good agp cards in the markets now. AtI needs to be commended because they have R600/R700 Cards which still support the agp specification. Depending on your budget, you can go with either the Radeon 3650, 3850 or 4650. Even 3650 will not have a problem handling your resolution. Plus using the proprietary fglrx driver, cards would run very fine.


I don't think you could connect to grub, afaik it doesn't have any networking capability. In the future you might be able to set your computer's BIOS to always boot from another networked computer? Or you could set up grub to have a timeout and a default action if no keys are pressed, might just need to add this to grub.cfg (apparently the top/first entry is 0):

set timeout=30
set default=0

But as for making your computer press enter now, right now, when you're nowhere near it, all I can think of is a telephone to call someone nearby to do that.


create a AP-hotspot from a wireless connection

I just tried this out to verify that it works. No hostapd and no script. (I tried wp5.sh but it wouldn't work.) Sharing wifi from a wireless router to my laptop internal card (wlan0) to an acer chromebook from the laptop usb (wlan1). For some reason I couldn't get my internal card (wlan0) to broadcast.

Click on the network-manager indicator and select "create new wifi
network" from the dropdown menu.
I first selected the wlan1 card and named the network "pineapples".
I have it set to ad-hoc and under ipv4 it's set to "share connection
with other computers", no security.

Also, I clicked to connect from the chromebook while "pineapples" was still resolving as soon as the network appeared; then, the two computers connected to each other.

If the laptop drops or doesn't connect to "pineapples", it should
still be listed as an available network from the network-manager
dropdown list. Click on "pineapples" and while it is resolving,
connect to "pineapples" from the other device.

At first, nothing would resolve but I clicked on my wlan0 network to reset the connection to the router and now both computers have internet.


Boot Ubuntu from Fully Encrypted USB Stick

back up your data before start !
check this link luks encryptation usb
*this was tested with Ubuntu 12.04.


Steps needed to troubleshoot a failed X-Window startup

Look in /var/log/Xorg.0.log and look for lines with (EE) in it. This will give you not only the error but also the cause. From there it is only a simple step to enter it into a search engine of your choice:

grep 'EE' /var/log/Xorg.0.log

Other sources that might help you on Ubuntu wiki:

Troubleshooting
Freeze
VideoDriverDetection.


Files or folders starting with a dot are, by Unix/Linux convention, hidden files or folders.

As such, they are being served like any other files or folders but not seen by the clients.

This guide describes the settings needed for some FTP clients so they can "see" hidden files/folders. Depending on the client being used by those accessing your server the instructions vary a lot.

For the ubiquitous FileZilla (free, open-source and multi-platform) it's as easy as:

Click the Server tab at the top.
Select Force showing hidden files.


Macbook 8.2 wifi drivers- No internet connection

First, I would really really try to get a wired connection with your Macbook pro. It will be easier. It's always a good idea to have wired as a backup, in case say an update knocks out your wireless drivers or you accidently uninstall the drivers.

Okay, since you said you can't get a wired connection, this should help you install the drivers without a wired connection. You will need an install CD of Ubuntu (or perhaps a USB drive with the CD image mounted on it).

https://help.ubuntu.com/community/WifiDocs/Driver/bcm43xx

From the webpage:

"No Internet access

If you do not have any other means of Internet access on your computer, you will have to install the bcmwl-kernel-source package from the restricted folder under ../pool/restricted/b/bcmwl on the Ubuntu install media.

Note: Systems installed from CDROM can simply add the install CD as a package source and install bcmwl-kernel-source, automatically installing the required dependencies."

Good luck!


How to install Elementary's Pantheon Mail client on Ubuntu (15.10)

Right now I was able to successfully install the package pantheon-mail after adding ppa:elementary-os/stable to the list on Ubuntu 16.04.


Boot into the live CD and try repairing it with the following command:

sudo fsck /dev/sda1

The sda1 might be vary for you sometimes.If you are not sure on the name of your drive then run gparted.It should list the name of the drive.Just replace the sda1 with the name of your drive. Let me know if this helps you. :)

You can boot into a rescue console by starting your computer from a live cd and selecting "Rescue a broken system" from the menu.


In my case the cause was that ~/.Xauthority was owned by root.

EDIT:

$ ls -l ~/.Xauthority
-rw------- 1 root root 61 Sep 16 15:43 .Xauthority
$ chown group:user ~/.Xauthority

where 'group' and 'user' are the group and the user that you use to login. in my case:
$ chown akonsu:akonsu ~/.Xauthority


tar.xz extracting error "xz: (stdin): File format not recognized"

file.tar.xz: HTML document, UTF-8 Unicode text, with very long lines

indicates that I downloaded a website. That's why it won't extract.


How to install gnome-open in ubuntu 20.04 desktop

Another solution found is:
xdg-open /mnt/star/note

Seems xdg-open is available on ubuntu 20.04, by default.


how do I configure ubuntu to download to a usb drive

Mount the disk to /mnt/Download (You can edit /etc/fstab to let it mount every time you boot, see How to make partitions mount at startup? , make sure to add x-systemd.automount,nofail into mount options.)
sudo chmod ugo+rw /mnt/Download
ln -s /mnt/Download /home/yous-username/Downloads
You can also config the browser to directly download to /mnt/Download
If you use a  command-line downloader (wget, etc.), you must first cd into /mnt/Download


What is the easiest way to do multi party video conferencing

Faceflow offers a four way video conferencing.
http://www.faceflow.com/video-conference


How to set the SSH key of the root user during an automated 20.04 server install?

I just had the same problem. It would certainly be better to solve this with the users block from could-init or user-data as mentioned here, but I couldn't get either of them to work.
So I went with your solution and added a mkdir /target/root/.ssh to the late-commands. Not pretty but works.


Ctrl + Spacebar Causes Issues Between Linux and Minecraft

You should figure out what action is bound to Ctrl+Space.

You need to list all key bindings. This line should show you all bindings:

gsettings list-recursively  org.gnome.desktop.wm.keybindings | sort | more

There are some exceptions e.g. Alt+F1 this is hard-coded in Unity so you can't change it and it's not shown by this command.


You don't need to do anything.

The kernel always runs /sbin/init to start the system, and in 14.04 that's Upstart (and in later versions of Ubuntu a symlink to systemd).

Running

/sbin/init --version

should tell you which version of Upstart you are running.


How to configure Adminer to be reachable on the local network

I found on Ubuntu 16.04 that after installing Adminer via

sudo apt-get install adminer

it didn't correctly set up the Adminer Apache configuration file. I did the following to get it working:

cd /etc/apache2/conf-available
sudo ln -s ../../adminer/apache.conf adminer.conf
sudo a2enconf adminer
sudo service apache2 reload

After that the it worked locally and remotely for me


How to set noapic and pnpbios=off parameters for boot

Edit your GRUB configuration file e.g. using the command

sudo nano /etc/default/grub

Add those two parameters to GRUB_CMDLINE_LINUX_DEFAULT, so that it looks like this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pnpbios=off noapic"

Then update GRUB's configuration using the command

sudo update-grub


Why do the Sound Settings ignore the Output Device?

Ok, I still have no idea what exactly went wrong but the fix for me was simple. It might have to do with Skype, though.

For some reason, pulseaudio's user configuration files can become corrupt(unsynced?) in some way, and deleting them (and forcing fresh ones to be generated) fixes a no sound condition. After using the command below, log out/in.

rm -r ~/.config/pulse; pulseaudio -k

Source: https://wiki.ubuntu.com/PulseAudio#Resetting_User_Configuration
For me this fixed everything without even having to log out and in. Just had to reconnect the headphones and things work again.


Microphone recording approximately 12x slower than normal in certain applications (new install Ubuntu 16.04.3)

According to this reply to the corresponding bug report, you should find your audio device (I used audacity and tried both devices listed, see screenshot.)

In my case the command required was
pacmd load-module module-alsa-source device=hw:2,2

After that, recording works when you choose pulse in Audacity.

After restarting Audacity the device you used will no longer be visible

and there will be a duplicate device in Settings > Sounds

Also this fix does not persist a restart. Run this command on login (e.g. using Startup Application if you need, or see the bug reply for another solution.


I was trying to remove Thunderbird but I saw ubuntu-mate-dektop package was also being removed

The safer way to remove/ uninstall a package is by using the command :

sudo apt-get purge thunderbird

The autoremove feature removes all the packages in the system that are not needed.

Hope it helps.


An application named "DNG converter just popped onto my screen and I don't remember installing it

The application dngconverter is part of the KDE kipi-plugins package. This a package of several applications that aim to extend the capabilities of image manipulation under KDE.

The role of the DNG Converter is to convert RAW image files to the DNG or 'Digital Negative Format' of Adobe.

Actually you have picked up several applications along with the DNG Converter; the kipi (KDE Image Plugin Interface) plugins package comes with the following applications:

/usr/bin/dngconverter
/usr/bin/expoblending
/usr/bin/panoramagui
/usr/bin/photolayoutseditor
/usr/bin/scangui

The fact that you have inadvertently installed the DNG Converter is undoubtedly a result of a tangle of interrelated packages that came with a KDE application that you have installed. By themselves they could simply be left as is or you could see how many packages Ubuntu wants to remove when you run:

sudo apt-get remove kipi-plugins

If the package management system wants to remove too much simply allow this package and its associated applications to lie dormant on your computer...

References:

Ubuntu Packages: kipi plugins filelist
Wikipedia: KDE Image Plugin Interface
KDE Wiki: Convert RAW Files to DNG with DNGConverter


How can I determine the page count of odt, doc, docx and other office documents from the CLI?

Thanks for all the answers, everyone. With your help I was able to compile a list of commands that can extract the page count from almost all relevant office documents:

DOCX/PPTX

unzip -p 'sample.docx' docProps/app.xml | grep -oP '(?<=\<Pages\>).*(?=\</Pages\>)'

unzip -p 'sample.pptx' docProps/app.xml | grep -oP '(?<=\<Slides\>).*(?=\</Slides\>)'

Note: unzip can be installed with sudo apt-get install unzip.

DOC/PPT

wvSummary sample.doc | grep -oP '(?<=of Pages = )[ A-Za-z0-9]*'

wvSummary sample.ppt | grep -oP '(?<=of Slides = )[ A-Za-z0-9]*'

Note: wvSummary (case-sensitive!) is part of the wv package. Install it with sudo apt-get install wv.

ODT

unzip -p sample.odt meta.xml | grep -oP '(?<=page-count=")[ A-Za-z0-9]*'

PDF

pdfinfo sample.pdf | grep -oP '(?<=Pages:          )[ A-Za-z0-9]*'

Note: pdfinfo is part of poppler-utils and should come preinstalled on Ubuntu.

DJVU

djvused -e "n" sample.djvu

Note: djvused is part of the djvulibre-bin package and may be installed with sudo apt-get install djvulibre-bin.


How to share files from Host to Guest in VirtualBox? Host-Ubuntu, Guest-Ubuntu

I do not believe its possible to share files between the host and the guest without installing the extension pack first though I could be wrong on this.

You can find that here: https://www.virtualbox.org/wiki/Downloads

Check that the version of Virtualbox you have. Mine is 4.2.18 and double click the link

You should see something like this

Click OK and let it install.

Next step create a folder on your host machine as as share area

I've created one called VboxShare in my home directory.

First, make sure that your virtual machine is powered off.

Then, go into settings for your virtual machine, select shared folders then the plus icon to create a shared folder and fill in the details set it to auto mount.

Click OK then start your guest.

Job Done the shared folder appears on you guest machine as

/media/sf_Vboxshare

There is only one more step add any user in your guest system that needs access to the folder to the group vboxsf:

sudo adduser $USER vboxsf

Log out and back in, everything should work fine now.


First, Remove your previous installed version.

Now follow this

Step by step guide

Download Netbeans from here, in my example, I'm using the "All" bundle.
Go into your download folder, E.G.

cd ~/Downloads

Make the installer executable

chmod +x netbeans-8.0.2-linux.sh

Start the installation

sudo ./netbeans-8.0.2-linux.sh

Change the installation target

/opt/netbeans-8.0.2

Finish the installation and start Netbeans via your Launcher

Create a sample app, E.G. PHP TodoList and start the application on the build in server


How to protect a computer name from being disclosed to network peers?

That's probably the most excentric question I've read on AskUbuntu so far. You can connect to a computer on your network by using hostname.local instead of using the IP address. I don't understand why anyone would want to hide that. You can easily change it, though, if you don't like the default of using the username in the hostname. That is understandable.

Just edit /etc/hostname to the hostname you like and then edit /etc/hosts to reflect that change. You need to reboot afterwards.


Unable To Make Working Bootable USB of 32 GB but It is possible in 16 GB

Have you tried this method? You also may need to format the usb drive as bootable first, use format fs=fat32 To answer your secondary question above, 'Linux box' is a computer with Linux already running


After reboot i've lost all my programs and files

Based on the output of mount, i can tell you're running the system from a LiveUSB. This will not save any programs or files you store, and they will disappear when you shut down.

You need to install ubuntu to your hard drive, or to another external drive in order to keep any files or programs. (Ubuntu will also run faster when installed to a hard drive)

You can also set up a persistent thumb drive. See https://wiki.ubuntu.com/LiveUsbPendrivePersistent/ for more information on that.

If you've already installed Ubuntu to your thumb drive, then it seems you've accidentally booted to a thumb drive. Shut down, remove the thumb drive, and turn your computer back on everything should be back to where it was.


Why doesn't Libre Office Writer 5 correctly check spelling?

First, select an installed language for Default Languages for Documents. Installed languages have an little icon in front of the name as you can see in my screenshot.

Second, install your missing language English (UK) via

sudo apt-get install libreoffice-l10n-en-gb

or via the Language Support

Install via

sudo apt-get install language-selector-gnome

Open Language Support and all missing libraries will be installed automatically


Foolproof way to Install Ubuntu on an external hdd, independent of other hdds & OSes, w/o unplugging the other hdds

Well, hello.

I have a dual boot (from 2 different drives) Debian/Windows desktop. I suppose the installation process is quite similar in Ubuntu if not identical.

Follow these steps:

Burn your .iso in a thumb drive or a CD/DVD
Boot from it (you should read on MBR/GPT on that)
Fire up the OS installer (click install)
When prompted to select an installation option choose "Something Else" (other options are "Erase disk and install Linux", "Install Linux alongside X", etc.)
In "Something Else" you are required to partition the hard drive you're going to use and set a swap partition as well. (Take extra time & care in this step as formating the wrong drive means data loss)
IMPORTANT: In the end of the OS installation process, you'll be promted to install/setup Grub (bootloader). Once Grub is installed you'll be asked on which drive you want boot info saved (this defaults to /dev/sda but you most likely don't want it there, you want Grub to install and save it's config ONLY on your external hard drive which means when the drive is connected Grub fires up, and when it's not Windows Bootloader does).

If all of the above is done properly you'll be able boot in both Linux & Windows without losing any of your data.


Can't install any packages on Ubuntu 16.04

Just completely remove the the broken apache2 and reinstall.

sudo apt-get purge apach2* && sudo apt-get update && sudo apt-get install apache2


How do I tunnel and browse the server webpage on my laptop?

There are two ways you can do this with SSH.

Tunnel Everything with a SOCKS proxy

Log in to the remote machine using the following command:

ssh -D 8080 remote-host

Now go to your browser's proxy settings, and configure it to use a SOCKS proxy with host name 127.0.0.1 and port 8080 (or whatever port you passed to the -D option).  Now all pages you load in your web browser will be tunnelled through the SSH connection.  You should now be able to access the private web page in the same way you would from the remote host.

Once you are done, set your browser's proxy settings back to normal.

One down side of this method is that all other traffic in the web browser will also be going through the SSH connection.  On the upside, you can access the remote servers with their real host names, and can easily access multiple private sites.

Tunnel a single port.

The alternative method is to use SSH to forward a single port:

ssh -L 8080:server-hostname:80 remote-host

Now if you point your web browser at http://localhost:8080/, you should see the contents of http://server-hostname/ as it would appear from the remote host.

The benefit of this method is that it leaves the rest of the browser traffic alone.  The downside is that some links might not work if the remote site uses absolute URL references.  If the site mostly uses relative URL references, then this method should be sufficient.

For both of these solutions, there is nothing special about the port 8080.  You can use any free local port number you want, as long as you remember to use the same one in the ssh invocation and in the web browser.


Is there an audio mixer able to map any audio source to any output in the system?

jackmix will probably do what you need
There is also jack_mixer but may be harder to find as some distros dropped it due to age

Try Patchage for better display of JACK connections
(prob want 'sprung layout' option turned off in settings to stop things moving around!)

Best if you can have as much as possible running in JACK
Hardware devices can be added to JACK with alsa_in and alsa_out commands
but some software packages are better left in Pulseaudio

Pulseaudio JACK Sink and source connections in and out of JACK are not limited to just one connection
Extra connections can be added by running commands:

pactl load-module module-jack-sink channels=2

Will create 2 channel 'Pulseaudio JACK Sink 01'

pactl load-module module-jack-sink channels=1 connect=0

will make mono 'Pulseaudio JACK Sink 01' with no connection
(no feedback from connecting to JACK mic input)

repeat commands for more numbered connections


Network between host OS (18.04) and guest (*nix) in VirtualBox

Figured out that I hadn't set up VirtualBox properly, thus why it wouldn't work at all. I hadn't set the Paravirtualization interfacein VirtualBox to KVM, and thus the virtio driver wasn't enabled. Now that this is taken care of it all works like a charm - I probably got fooled by the fact that I didn't have to do this in VMware player.


usb device descriptor read errors after upgrade to 20.04

In the interest of being quick, the kernel is telling you there's an issue with your usb hardware: specifically 1-3. Use lsusb for figure out which piece of hardware it corresponds to, and make sure that piece of hardware works. Unless you want to fix the issue in question, the number probably isn't that important.

If you're booting is slow, you might consider looking on the web for a workaround, but that may prove iffy. I've had issues in my own usb system since kernel 4.4 and they still haven't been fixed. They are a nuissance but don't keep the computer from not working.


How to recover from a botched attempt to clean /boot, incomplete kernel/drivers

Here was the solution.  Thanks to Rmano for pointing me in the right direction.

I ran sudo apt-get install --reinstall linux-generic and it generated an error, so I then ran
sudo apt-get -f install
and then re-ran
sudo apt-get install --reinstall linux-generic

and restored the system.  Everything is back!


Using Patchage, can I connect Musescore to a soft synthesizer

So I ended up installing Yoshimi and ended up using JACK MIDI in MuseScore's preferences.


IP Messenger showing Error on Ubuntu 12.04

Install from PPA
sudo add-apt-repository ppa:fossfreedom/g2ipmsg
sudo apt-get update
sudo apt-get install g2ipmsg

to run g2ipmsg

If you are using the Gnome-Classic interface, then G2ipmsg will be found in the Accessories menu option
If you are using Gnome-Shell then search in Activities for g2ipmsg and the application will start minimized in the system-tray notification area (bottom right) of the screen.  You will need to move you mouse to that area to make the application icon visible.  My recommendation would be to use the system-tray extension to make the application icon visible at all times in the top-right of the screen.  See my link answer below for more information about these areas and how to install the extension
If you are using Unity/Unity 2D you will need to manually enable the system-tray area for the application to start in the top-right area of the screen next to the indicator area.

how to compile

Get the sources:

cd ~/Downloads
wget https://launchpad.net/ubuntu/+archive/primary/+files/g2ipmsg_0.9.6%2Bdfsg.orig.tar.gz
wget https://launchpad.net/ubuntu/+archive/primary/+files/g2ipmsg_0.9.6%2Bdfsg-1.1.diff.gz

Now install some prerequisites and libraries

sudo apt-get install build-essential devscripts cdbs debhelper autotools-dev libgnomeui-dev libgstreamer0.10-dev libxml-parser-perl libssl-dev

Then uncompress and patch the sources

 tar zxvf g2ipmsg_0.9.6+dfsg.orig.tar.gz
 gunzip g2ipmsg_0.9.6+dfsg-1.1.diff.gz
 patch -p0 < g2ipmsg_0.9.6+dfsg-1.1.diff

Compile to create deb packages

cd g2ipmsg-0.9.6+dfsg/
debuild -us -uc

Install the deb package

cd ..
sudo dpkg -i g2ipmsg_0.9.6+dfsg-1.1_i386.deb

Note - if you are compiling 64bit - then the package name will end in amd64.deb


Cannot change screen resolution for 14.04.3 in Virtual box

Try to modify the resolution using xrandr.

WARNING! Make sure you enter into a tty console (outside of lightdm),
or else it will mostly cause errors in the x server. (Use
Ctrl+Alt+F1/F2/F3/etc.)

Now, use these commands:

xrandr --fb [enter width here]x[enter height here] --display [display number, default: 0]
sudo service lightdm restart

These lines of commands will make the X server to reboot and they will change the display resolution to your desired resolution.

Hope this helps! Peace,
matemate01


Upgraded to 11.04 and now most of the UI is gray and boxy

Using the answer to the question @Uri Herrera linked in his comment, I couldn't fix the issue.

However, one of the answers did point to a bug that tracks this issue, and I found a comment on the bug that solved it for me.

Here are the key bits:

First, create a bash script (I named it /etc/xdg/autostart/gnomesettingsdaemonfix.sh)

#!/bin/bash

pid=$(pgrep gnome-settings-)

while [ -n "$pid" ];
do
  pid=$(pgrep gnome-settings-)
  sleep 0
done

exit 0

Make sure it is executable (run chmod +x).

Then edit /etc/xdg/autostart/gnome-settings-daemon.desktop

Change the Exec line to:

Exec=bash -c 'bash /etc/xdg/autostart/gnomesettingsdaemonfix.sh; /usr/lib/gnome-settings-daemon/gnome-settings-daemon

That seems to have fixed it so far for me.


How do I stop wireless from reactivating after waking from suspend?

You should unset in the wireless connection the checkbox "Connect automatically" as you see in the following screenshot:


mongod: unrecognized service , mongod.service is present already

I had the same problem after pulling the ubuntu:17:04 docker image and installing mongodb-org

It looks like Mongodb created a systemd startup file which was already replaced by upstart.

As a workaround:

Create a new file /etc/init/mongod.conf (requires sudo rights). You can use: sudo gedit /etc/init/mongod.conf
Paste the following contents into the newly created upstart file:

# Ubuntu upstart file at /etc/init/mongod.conf

# Recommended ulimit values for mongod or mongos
# See http://docs.mongodb.org/manual/reference/ulimit/#recommended-settings
#
limit fsize unlimited unlimited
limit cpu unlimited unlimited
limit as unlimited unlimited
limit nofile 64000 64000
limit rss unlimited unlimited
limit nproc 64000 64000

kill timeout 300 # wait 300s between SIGTERM and SIGKILL.

pre-start script
  DAEMONUSER=${DAEMONUSER:-mongodb}
  if [ ! -d /var/lib/mongodb ]; then
    mkdir -p /var/lib/mongodb && chown mongodb:mongodb /var/lib/mongodb
  fi
  if [ ! -d /var/log/mongodb ]; then
    mkdir -p /var/log/mongodb && chown mongodb:mongodb /var/log/mongodb
  fi
  touch /var/run/mongodb.pid
  chown $DAEMONUSER /var/run/mongodb.pid
end script

start on runlevel [2345]
stop on runlevel [06]

script
  ENABLE_MONGOD="yes"
  CONF=/etc/mongod.conf
  DAEMON=/usr/bin/mongod
  DAEMONUSER=${DAEMONUSER:-mongodb}
  DAEMONGROUP=${DAEMONGROUP:-mongodb}

  if [ -f /etc/default/mongod ]; then . /etc/default/mongod; fi

  # Handle NUMA access to CPUs (SERVER-3574)
  # This verifies the existence of numactl as well as testing that the command works
  NUMACTL_ARGS="--interleave=all"
  if which numactl >/dev/null 2>/dev/null && numactl $NUMACTL_ARGS ls / >/dev/null 2>/dev/null
  then
    NUMACTL="$(which numactl) -- $NUMACTL_ARGS"
    DAEMON_OPTS=${DAEMON_OPTS:-"--config $CONF"}
  else
    NUMACTL=""
    DAEMON_OPTS="-- "${DAEMON_OPTS:-"--config $CONF"}
  fi

  if [ "x$ENABLE_MONGOD" = "xyes" ]
  then
    exec start-stop-daemon --start \
        --chuid $DAEMONUSER:$DAEMONGROUP \
        --pidfile /var/run/mongodb.pid \
        --make-pidfile \
        --exec $NUMACTL $DAEMON $DAEMON_OPTS
  fi
end script

Now, you can use the following commands:

sudo service mongod start

sudo service mongod stop

sudo service mongod status

reference:
https://github.com/mongodb/mongo/blob/master/debian/mongod.upstart


Remove ATI video card and install Asus/Nvidia 210 silent

If installed, remove the proprietary AMD driver.
Shut down, and swap the cards.
Boot up.

Hope that works.


You either haven't installed qemu-kvm or you don't have virtualization enabled from BIOS.

Run this to make sure that you have KVM modules installed:

sudo apt-get install kvm qemu

And run this to make sure you have virtualization enabled from BIOS (If you don't then enable that):

grep vmx /proc/cpuinfo


I had the exact same problem. Stuck on the GRUB screen. No Windows, no Ubuntu! How I reached there? I wanted to remove Ubuntu, so I logged into Windows, deleted the Ubuntu partitions using Disk Management, then restarted my PC and got stuck at the GRUB screen.

All solutions that involve a Windows Recovery Disk (bootrec.exe and bootsect.exe) and those involving an Ubuntu live CD (boot-repair and grub-install) did not work. Should I have run bootrec or bootsect before I had deleted the partitions and restarted? I don't know. But it was too late now! Not until I found this hidden comment that saved my day.

I simply typed exit at the GRUB command prompt and was finally booted into Windows 10. As simple as that! If you want a "clean" boot into Windows, directly without having to type exit each time, then this is the procedure to follow. Once logged into Windows (after the exit from the grub loader), run cmd.exe with administrator privileges and use the DISKPART utility. No recovery disk needed. The procedure is detailed here, which is copied from here. I also copy it briefly down here in case any links are lost in the future.

Run cmd.exe with administrator privileges.
Run diskpart utility.
At the DISKPART> prompt, type: list disk then sel disk X where X is the drive your boot files reside on. To make sure which drive to choose, you can open the Disk Management GUI tool in Windows (since we are running full Windows version) not a rescue disk. In Disk Management, you will find Disk 0 is usually the boot C drive, and hence the one to choose. You can also recognize it from within the command line DISKPART> from its size. In modern systems, it is usually the smaller (or the only) drive, the SSD one.
Type list vol to see all partitions (volumes) on the disk.
Type sel vol Y where Y is the System volume (you find System written in the Info column in the previous listing). There is very good chance it is the only FAT32 partition. In Disk Management, it is clearly marked as EFI System Partition. You can match the size with the one that appears in DISKPART>.
Assign a drive letter by typing: assign letter=Z: where Z is a free (unused) drive letter. This is all what we need DISKPART> for.
Type exit to leave DISKPART>. Now we're back to the Windows (DOS) prompt.
At the cmd prompt, type: Z: and hit enter, where Z was the drive letter you just created.
Type dir to list the directories on this mounted EFI partition.
If you are in the right place, you should see a directory called EFI.
Type cd EFI and then dir to list the child directories inside EFI.
Type rmdir /S ubuntu to delete the Ubuntu boot directory.
Done! Restart and see for yourself a clean Windows boot.


Install Ubuntu alongside Windows (legacy mode)

Disable UEFI boot support .  Now try to install again.  If not working follow these steps...

  Shrink your Windows partition
   Windows takes up the whole of the drive when it is first installed. In order to install Ubuntu you will need to make space for it.
  Press the "super key" (Windows key) on your keyboard and click the magnifying glass in the top right corner. In the search box start typing "Partitions".
  Click on the option called "Create and format partitions". This will bring up the "Disk Management" screen.

To shrink the drive, right click on the "OS (C:)" volume and select "Shrink volume".

A screen will appear showing how much you can shrink the drive by. You can of course choose to shrink the drive by less than offered but never go for any more than offered as you will break your Windows 8.1 operating system if you do.

Click "Shrink" to continue.

When you are finished you will see that there is a lot of unpartitioned space. This is where Ubuntu will be installed.

  Turn off fast boot
  Turn off secure boot
   Install Ubuntu

for  installation guide here

If not working refer here to install manually.


Help! Monitor not giving proper edid information

Do the following:

sudo apt-get install read-edid

sudo get-edid | parse-edid

It should fix the problem. I had it once with my TV.
EDID is the Extended Display Identification Data
and describes what features your display has.


Ubuntu 13.04 with old (radeon HD 4850) graphic card

As I said here: Overheating on VAIO SB36

  Usually, the overheating problem in Ubuntu is related to the graphic
  card, and in your case, you have an Hybrid graphic card with the open
  source drivers. In this case, by default, you have both graphic cards
  connected but you are only using the integrated (Intel). If you want
  to use only one and when you want, you need to install the privative
  drivers following this answer:

  What is the correct way to install proprietary ATI Catalyst Video Drivers (fglrx) directly from AMD?

  And using the latest driver:

  (6 jun)
  http://www2.ati.com/drivers/linux/amd-driver-installer-catalyst-13-4-linux-x86.x86_64.zip

The problem is that the latest stable driver from AMD is not compatible with the last version of Ubuntu with the latest version of the Xorg Server. Download the latest beta driver which is compatible with Ubuntu 13.04:

http://www2.ati.com/drivers/beta/amd-driver-installer-catalyst-13-6-beta-x86.x86_64.zip

You can try to install it, but as you can see, the privative driver is not compatible with 4XXX series: http://support.amd.com/us/kbarticles/Pages/AMDCatalyst13-6LINBetaDriver.aspx

Also I found this: Radeon HD 2000, 3000, 4000 on Ubuntu 12.04.2 and higher: fglrx (legacy) unsupported, what to do?

  As I have found out (4850 here), you can't via any method install
  fglrx-legacy on stock ubuntu 12.10, even if you use catalyst 12.6
  which supports our cards, because the x server that 12.10 uses (1.13)
  is not supported by catalyst 12.6 or older.

  However, this is somewhat of a solution, that I can confirm works on
  my machine:
  http://www.ubuntuvibes.com/2012/10/how-to-install-amd-catalyst-legacy.html

sudo add-apt-repository ppa:makson96/fglrx
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install fglrx-legacy

  Just follow that (well, uninstall any fglrx you have installed now
  first), and you should have a better experience.

  I should note, you will be downgrading your x server to version 1.12,
  and these packages are not supported by ubuntu, but this is the
  closest to a "solution" as can possibly exist at this time.

  I hope this helps some!


Fortunately there are tools available for this.

fwts

This is the firmware test suite, designed to interrogate and look at BIOS + ACPI firmware bugs. Several tests are available in the latest development version.

Installation:

A quick check of Ubuntu Packages indicates that we must first enable the universe repository if it isn't already enabled.

Then we install either via the Software Center or with the command:

sudo apt-get install fwts

fwts can run several useful tests.

Perhaps the one used most often is the interactive test which tests backlight, brightness and battery. This one is launched with the command:

sudo fwts --interactive

And results in the following.

Running 6 tests, results appended to results.log
==== Please press the laptop power button. ====
==== Setting backlight to a low level ====
==== Is the Backlight now set to a dim level? [Y/N]:
==== Setting backlight to highest level ====
==== Is the Backlight now set to a bright level? [Y/N]:
==== Backlight will now slowly transition from dim to bright ====
==== Did the backlight go from dim to bright? [Y/N]:
==== Press the brightness UP hotkey for acpi_video0 ====
==== Press the brightness DOWN hotkey for acpi_video0 ====
==== Make sure laptop is connected to the mains power. ====
Press <Enter> to continue
==== Please unplug the laptop power. ====
==== Please re-connect the laptop power. ====

The results of your tests can be found in the directory that you launched fwts from in the file results.log

The results from an Acer Aspire D270-1865 are as follows:

Results generated by fwts: Version V16.03.00 (2016-03-14 09:10:20).

Some of this work - Copyright (c) 1999 - 2016, Intel Corp. All rights reserved.
Some of this work - Copyright (c) 2010 - 2016, Canonical.

This test run on 25/07/17 at 18:44:34 on host Linux me-AOD270 4.4.0-78-generic
#99-Ubuntu SMP Thu Apr 27 15:29:09 UTC 2017 x86_64.

Command: "fwts --interactive".
Running tests: hotkey power_button lid brightness battery ac_adapter.

hotkey: Hotkey scan code tests.
--------------------------------------------------------------------------------
Cannot determine keymap for this machine.
Aborted test, initialisation failed.
================================================================================
0 passed, 0 failed, 0 warning, 1 aborted, 0 skipped, 0 info only.
================================================================================

power_button: Interactive power_button button test.
--------------------------------------------------------------------------------
Test 1 of 1: Test press of power button and ACPI event.
PASSED: Test 1, Detected PBTN power button event.

================================================================================
1 passed, 0 failed, 0 warning, 0 aborted, 0 skipped, 0 info only.
================================================================================

lid: Interactive lid button test.
--------------------------------------------------------------------------------
Test 1 of 3: Test LID buttons report open correctly.
PASSED: Test 1, Detected open LID state.

Test 2 of 3: Test LID buttons on a single open/close.
Got 2 SCI interrupt(s).
Got 2 interrupt(s) on GPE gpe11.
Got 2 interrupt(s) on GPE gpe_all.
PASSED: Test 2, Detected ACPI LID events while waiting for LID to closed.
PASSED: Test 2, Detected lid closed state.
Got 6 SCI interrupt(s).
Got 1 interrupt(s) on GPE gpe01.
Got 1 interrupt(s) on GPE gpe02.
Got 5 interrupt(s) on GPE gpe11.
Got 7 interrupt(s) on GPE gpe_all.
PASSED: Test 2, Detected ACPI LID events while waiting for LID to open.
PASSED: Test 2, Detected lid open state.

Test 3 of 3: Test LID buttons on multiple open/close events.
Some machines may have EC or ACPI faults that cause detection of multiple open
/close events to fail.
Got 2 SCI interrupt(s).
Got 2 interrupt(s) on GPE gpe11.
Got 2 interrupt(s) on GPE gpe_all.
PASSED: Test 3, Detected ACPI LID events while waiting for LID to closed.
PASSED: Test 3, Detected lid closed state.
Got 2 SCI interrupt(s).
Got 2 interrupt(s) on GPE gpe11.
Got 2 interrupt(s) on GPE gpe_all.
PASSED: Test 3, Detected ACPI LID events while waiting for LID to open.
PASSED: Test 3, Detected lid open state.
Got 2 SCI interrupt(s).
Got 2 interrupt(s) on GPE gpe11.
Got 2 interrupt(s) on GPE gpe_all.
PASSED: Test 3, Detected ACPI LID events while waiting for LID to closed.
PASSED: Test 3, Detected lid closed state.
Got 7 SCI interrupt(s).
Got 1 interrupt(s) on GPE gpe01.
Got 6 interrupt(s) on GPE gpe11.
Got 7 interrupt(s) on GPE gpe_all.
PASSED: Test 3, Detected ACPI LID events while waiting for LID to open.
PASSED: Test 3, Detected lid open state.
Got 2 SCI interrupt(s).
Got 2 interrupt(s) on GPE gpe11.
Got 2 interrupt(s) on GPE gpe_all.
PASSED: Test 3, Detected ACPI LID events while waiting for LID to closed.
PASSED: Test 3, Detected lid closed state.
Got 2 SCI interrupt(s).
Got 2 interrupt(s) on GPE gpe11.
Got 2 interrupt(s) on GPE gpe_all.
PASSED: Test 3, Detected ACPI LID events while waiting for LID to open.
PASSED: Test 3, Detected lid open state.

================================================================================
17 passed, 0 failed, 0 warning, 0 aborted, 0 skipped, 0 info only.
================================================================================

brightness: Interactive LCD brightness test.
--------------------------------------------------------------------------------
Test 1 of 3: Observe all brightness changes.
PASSED: Test 1, Backlight psb-bl set to dim level.
PASSED: Test 1, Backlight psb-bl set to bright level.
PASSED: Test 1, Backlight acpi_video0 set to dim level.
PASSED: Test 1, Backlight acpi_video0 set to bright level.

Test 2 of 3: Observe min, max brightness changes.
PASSED: Test 2, Backlight psb-bl was observed going from dim to bright.
PASSED: Test 2, Backlight acpi_video0 was observed going from dim to bright.

Test 3 of 3: Test brightness hotkeys.
FAILED [HIGH] BrightnessNoIncrease: Test 3, Did not see brightness increased for
psb-bl.
FAILED [HIGH] BrightnessNoDecrease: Test 3, Did not see brightness decrease for
psb-bl.
FAILED [HIGH] BrightnessNoIncrease: Test 3, Did not see brightness increased for
acpi_video0.
FAILED [HIGH] BrightnessNoDecrease: Test 3, Did not see brightness decrease for
acpi_video0.

================================================================================
6 passed, 4 failed, 0 warning, 0 aborted, 0 skipped, 0 info only.
================================================================================

battery: Battery tests.
--------------------------------------------------------------------------------
Test 1 of 1: Battery test.
This test reports which (if any) batteries there are in the system. In addition,
for charging or discharging batteries, the test validates that the reported
'current capacity' properly increments/decrements in line with the charge
/discharge state. This test also stresses the battery state reporting codepath
in the ACPI BIOS, and any warnings given by the ACPI interpreter will be
reported.
Found 1 batteries.
Test battery 'BAT1'.
Got 12 SCI interrupt(s).
Got 12 interrupt(s) on GPE gpe11.
Got 12 interrupt(s) on GPE gpe_all.
PASSED: Test 1, Detected ACPI battery events.
FAILED [HIGH] BatteryNoEvents: Test 1, Could not detect ACPI events for battery
BAT1.
PASSED: Test 1, Battery BAT1 charge is decrementing as expected.
Got 6 SCI interrupt(s).
Got 6 interrupt(s) on GPE gpe11.
Got 6 interrupt(s) on GPE gpe_all.
PASSED: Test 1, Detected ACPI battery events.
FAILED [HIGH] BatteryNoEvents: Test 1, Could not detect ACPI events for battery
BAT1.
PASSED: Test 1, Battery BAT1 charge is incrementing as expected.
Please ignore this error with a new battery
FAILED [LOW] BatteryZeroCycleCount: Test 1, System firmware may not support
cycle count interface or it reports it incorrectly for battery BAT1.
Test battery 'BAT1' downward trip point.
Got 4 SCI interrupt(s).
Got 4 interrupt(s) on GPE gpe11.
Got 4 interrupt(s) on GPE gpe_all.
PASSED: Test 1, Detected ACPI battery events.
FAILED [HIGH] BatteryNoEvents: Test 1, Could not detect ACPI events for battery
BAT1.
Test battery 'BAT1' upwards trip point.
FAILED [HIGH] NoSCIInterrupts: Test 1, Did not detect any SCI interrupts.
FAILED [HIGH] NoGPEInterrupts: Test 1, Did not detect any GPE interrupts.
FAILED [HIGH] BatteryNoEvents: Test 1, Did not detect any ACPI battery events.

================================================================================
5 passed, 7 failed, 0 warning, 0 aborted, 0 skipped, 0 info only.
================================================================================

ac_adapter: Interactive ac_adapter power test.
--------------------------------------------------------------------------------
Test 1 of 3: Test ACPI ac_adapter state.
PASSED: Test 1, Detected a state in the ac_adapter state info.

Test 2 of 3: Test ac_adapter initial on-line state.
PASSED: Test 2, Detected ac_adapter on-line state.

Test 3 of 3: Test ac_adapter state changes.
PASSED: Test 3, Detected ac_adapter off-line state.
PASSED: Test 3, Detected ac_adapter on-line state.

================================================================================
4 passed, 0 failed, 0 warning, 0 aborted, 0 skipped, 0 info only.
================================================================================

33 passed, 11 failed, 0 warning, 1 aborted, 0 skipped, 0 info only.

Test Failure Summary
================================================================================

Critical failures: NONE

High failures: 8
 brightness: Did not see brightness increased for psb-bl.
 brightness: Did not see brightness decrease for psb-bl.
 brightness: Did not see brightness increased for acpi_video0.
 brightness: Did not see brightness decrease for acpi_video0.
 battery: Could not detect ACPI events for battery BAT1.
 battery: Did not detect any SCI interrupts.
 battery: Did not detect any GPE interrupts.
 battery: Did not detect any ACPI battery events.

Medium failures: NONE

Low failures: 1
 battery: System firmware may not support cycle count interface or it reports it incorrectly for battery BAT1.

Other failures: NONE

Test           |Pass |Fail |Abort|Warn |Skip |Info |
---------------+-----+-----+-----+-----+-----+-----+
ac_adapter     |    4|     |     |     |     |     |
battery        |    5|    7|     |     |     |     |
brightness     |    6|    4|     |     |     |     |
hotkey         |     |     |    1|     |     |     |
lid            |   17|     |     |     |     |     |
power_button   |    1|     |     |     |     |     |
---------------+-----+-----+-----+-----+-----+-----+
Total:         |   33|   11|    1|    0|    0|    0|
---------------+-----+-----+-----+-----+-----+-----+

An alternative is acpiexec from the acpica-tools package. This package also requires that we  enable the universe repository in order to install it either via the Software Center or with the command:

sudo apt-get install acpica-tools

For more information on this alternative see the sources below:

Sources:

https://wiki.ubuntu.com/Kernel/Reference/ACPITricksAndTips

https://acpica.org/documentation/

https://www.systutorials.com/docs/linux/man/1-acpiexec/


Converting Pdf in Taml language to epub using calibre

I had a similar problem and I solved it by including the fonts I needed in the epub version of the file. You can do this with Sigil, which is an epub editor. To see how to include custom fonts in your epub with Sigil see http://web.sigil.googlecode.com/git/files/OEBPS/Text/tutorial_embed_fonts.html. See also karel's very useful comment below.


You could also add the following to your xorg configuration to achieve a greyscale output:

Section "Screen"
    Identifier "greyscale configuration"
    Defaultdepth 8
    SubSection "Display"
        Depth 8
        Visual "GrayScale"
    EndSubSection
EndSection

This might work depending on your video driver.


Here a solution based on LaTeX. It uses the pdfpages package to include the scanned PDF (here called scan.pdf). The PDF page labels you want can be set using the hyperref package with the pdfpagelabels option enabled. It uses the normal \thepage macro as a label which can be defined to lower case roman numbers. The page counter is then reset and changed back to normal numbers.

\documentclass[a4paper]{article}% or use 'letterpaper'
\usepackage{pdfpages}
\usepackage[pdfpagelabels]{hyperref}
\begin{document}
% Set lower case roman numbers (\Roman would be upper case):
\renewcommand{\thepage}{\roman{page}}
\includepdf[pages=1-3]{scan.pdf}
% Back to normal (arabic) numbers:
\renewcommand{\thepage}{\arabic{page}}
% Reset page counter to 1:
\setcounter{page}{1}
\includepdf[pages=4-]{scan.pdf}
\end{document}

Place the above code into a file (e.g. scan_mod.tex) and compile it with pdflatex:

# pdflatex scan_mod

This will produce scan_mod.pdf. However any special annotations incl. hyperlinks will disappear. This shouldn't be any problem with scanned PDFs.

If you need this more often you could write a script which accepts the number of roman numbered pages and the file name(s) as arguments and creates a tempfile with the above code where the name and numbers are variables, which is then compiled.


Problem with 5.1 AC-3 through Alsa, Pulseaudio on SPDIF, Ubuntu 14.04

Finally managed to set this permanently, I had to add the following command in the startup applications.

pacmd set-card-profile 0 output:iec958-ac3-surround-51

To verify the name of you sound profile, run following command, u'll get all available profiled for ur sound card.

pacmd info

For some reason adding this default device in default.pa didn't work, but adding it as a startup command is working, now I don't need to open pavucontrol every time I reboot my machine.


You can run gdb under emacs and it will track the source code in the other window.  You can also open watch windows and such.  It also has a bunch of other features that can make reviewing the code easier, such as tags tables which allow you to quickly jump directly to the definition of a given function, and the mark ring, which allows you to jump to one place, review the code a bit, then tap C-x C-x to jump back to where you came from.


How to remove `t=canonical` from Firefox browser searches made on DuckDuckGo?

&t=
Through partnerships with developers and companies, DuckDuckGo has
been integrated into many applications. In these partnerships, a
portion of DuckDuckGo's advertising revenue is sometimes shared back.
To assign advertising revenue and collect anonymous aggregate usage
information, developers add a unique "&t=" parameter to searches made
through their applications.
If you want to remove it, edit the file:
/usr/lib/firefox/distribution/searchplugins/locale/*language-here*

Edit all the languages just to be sure.

Edit for 20.04

Open Firefox, navigate to Preferences --> Search, and remove the
per-installed DuckDuckGo search engine
Download the search engine new from the Firefox Add-ons directory. Select
this as the default search engine in the preferences The string,
&t=canonícal, ceased to insert itself into the searches via the address
bar thereafter.  With help from Komalleana Byzantis

Below are before and after pictures:

Source:DuckDuckGo Forums


how to allot any ip(in case of multiple ip's ) to any process?

Depending on how you do it, you can have 32768 or 4294967296 IPs.

The Linux kernel supports 32768 interfaces according to this random discussion on the internet, supported by net/core/dev.c.

 *    duplicates.
 *    Limited to bits_per_byte * page size devices (ie 32K on most platforms).
 *    Returns the number of the unit assigned or a negative errno code.
 */

static int __dev_alloc_name(struct net *net, const char *name, char *buf)

So if you have one address per interface, that's the limit. You can assign alias IPs to interfaces, so maybe you can assign all the available IPv4 addresses to it. (Or maybe 3.4×10^38 with IPv6).

(Of course, with physical interfaces, and one IP per interface, the answer depends on your motherboard.)


Juju - Can't deploy mysql/wordpress ; Invalid hardware information error

Does this work after bootstrap?

juju deploy --repository=/opt/charms local:trusty/mysql
juju deploy --repository=/opt/charms local:trusty/wordpress

There is no need to add-machine and then deploy.

You can also specify --constraints in the deploy command line if needed, but let's start simple.


From the log it seems like it is unable to find the libcurl shared library:

1) Try to install curl.

sudo apt-get install curl

OR

sudo apt-get install libcurl3 php5-curl

2) If that doesn't work, try the command ldconfig (actualising libs)

3) If that too doesn't work :

go to /usr/lib
run find . | grep curl, locate the .so file (eg like curl_path.so or latest libcurl.so.xx)
run ln -s {curl_path.so} /usr/lib/libcurl.so
run ldconfig


Open terminal and type:

  sudo nano /etc/apt/sources.list

and look for a malformed line that with the word "maindeb". Delete "deb" and keep only "main"

eg: if the line reads:

  deb http://extras.ubuntu.com/ubuntu/ trusty maindeb

change it to:

  deb http://extras.ubuntu.com/ubuntu/ trusty main

Save and close.


No network device after installing Ubuntu 16.04

Since you have the 4.8 kernel, try
sudo apt-get install git build-essential
git clone https://github.com/rtlwifi-linux/rtlwifi-next.git
cd rtlwifi-next
make
sudo make install

Reboot

It should compile with a few warnings with the 4.8 kernel

Lets disable the power save in the module

echo "options rtl8822be ips=N" | sudo tee /etc/modprobe.d/rtl8822be.conf

And we will use the next command to keep Network Manager from attempting to enable power management

sudo sed -i 's/wifi.powersave = 3/wifi.powersave = 2/' /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf

Reboot


If your machine is not one of the fastest, I would assume that the system-monitor CPU-graph window itself is eating the CPU time.
I have Intel Duo 2x2.0GHz and I can't get the displayed load below maybe 50% if that graph window is open.

Go to the settings and adjust the refresh delay to 1sec or so. That should make a huge difference, but at least for me, it does not save this setting.

Or check the CPU usage with other tools like top from the terminal or indicator-multiload (usually has to be installed first), which displays a small graph in your panel.


How to route static routing tables and error"RTNETLINK answers: No such file or directory"

How about ip route add 10.2.0.0/24 via 7.0.0.1 dev sim0 or ip route add 10.2.0.1/32 via 7.0.0.1 dev sim0 for Host0?

EDIT: It seems that if the routing target is host/network form, no extra bit should be set. For example, when '/24' is supplied 4th octet should be zero, when '10.2.0.1' is supplied '/32' should be supplied regardless of target host's netmask.


Can I switch to Gnome 3 without problems without having to wait for 17.10? If so, how can I switch to gnome 3?

The only command you need:

sudo apt install ubuntu-gnome-desktop && gnome-shell

During the installation you will be asked to choose between gdm and lightdm so you don't need another command to switch.


Unable to set my screen resolution higher

Ubuntu or the other versions of it like (k,l,x,edu,etc.,) are required to add the resolution we want to set on some monitors.
So follow my steps:-

Open a Terminal by CTRL+ALT+T

Type xrandr and ENTER

Note the display name usually VGA-1 or HDMI-1 or DP-1

Type cvt 1920 1080 (to get the --newmode args for the next step) and ENTER

Type sudo xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync and ENTER

Type sudo xrandr --addmode VGA-1 "1920x1080_60.00" and ENTER (replace VGA-1 with your display type (step 3) like HDMI-1 or DP-1)

Now close the terminal and go to Settings >> Display settings and change it to 1920x1080

Enjoy FHD.

To make the above settings stick when you restart your computer, do the following.
For integrated displays

goto your terminal and type vim ~/.profile ENTER
Paste in the shell command from step 5 and 6, then save.

For external displays

create a script called external_monitor_resolution.sh in the directory /etc/profile.d/. using sudo vim /etc/profile.d/external_monitor_resol.sh.

Paste in the shell command from step 5 and 6, then save.

(Note: if using sudo would require you typing a password, your system might freeze on startup while waiting for you to input a password. So when pasting do away with the sudo)
Something like this:
xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync
xrandr --addmode VGA-1 "1920x1080_60.00"` and <kbd>ENTER</kbd> *(replace **VGA-1** with your display type (step 3) like **HDMI-1** or **DP-1**)*


Overheating in an dual-boot system (windows 8+Ubuntu 14.04)

DO NOT LEAVE GRUB OPEN! IT MIGHT CERTAINLY CAUSE MAJOR COMPONENT DAMAGE! IF YOU ARE ALTERING A GRUB BOOT COMMAND, BE PREPARED TO COMPLETELY FINISH THE ALTERATION AND BOOT BEFORE STOPPING; IF YOU ARE INTERRUPTED, TURN OFF THE COMPUTER IMMEDIATELY BY PRESSING AND HOLDING THE POWER BUTTON!

Figure out what you want to do in grub before you use it, just to be safe. This danger is caused by a poll loop.

An advanced understanding would be required to fix this: it is not editing TIMEOUT because that only works prior to user input: according to GRUB support, there is no current working method to fix this.


It turns out that removing carefully the not-quite-installed 1.8.0 packages and installing 1.7.6 work as expected as per the tests already done. The metadataserver app 0015 "migration" gets applied and that leaves the migrations at 0120 for the maassserver app and 0015 for metadataserver which happen to be the right migration level for 1.7.6.

Important note: to remove the not-quite-installed 1.8.0 packages takes some hand-editing of /var/lib/dpkg/info/status and sometimes a related file to fake them being installed when they aren't.


PlayonLinux cannot install MS office 2010 spanish in Lubuntu 14.04.1 32 bit, winbind missing

I solved the problem myself:

Perform a clean installation of Lubuntu.
Update the system through the System Updater (in System Tools). If you do this in a Live USB with persistence created on Windows with a FAT32 file system, as I did, The maximum space allowed for new software/files/folders is 4GB, so, after the system update you'll find that there is no space enough to install MS Office. In this case you must perform a partial system update: check mark only samba/winbind/phyton related items, leave the others unmarked and perform the update.
Install PlayonLinux from Lubuntu Software Center
Install MS Office 2010. It will also download some missing packages from the internet. If there are any error messages/warnings, don't worry, continue the install.
Reboot and enjoy.

I cannot yet activate all the complements in Excel (only Analysis Tools, but Analysis Tools - VBA, Euro Tools and Solver cannot be activated) but otherwise it's working.


Edges of Xubuntu desktop are cut off on my Sony TV?

Most TV's have overscan enabled by default; see if you can disable it in the TV's onboard menu.

  Overscan is a behavior in certain television sets, in which part of
  the input picture is shown outside of the visible bounds of the
  screen. It exists because cathode-ray tube (CRT) television sets from
  the 1930s through to the early 2000s were highly variable in how the
  video image was positioned within the borders of the screen.

  Source: Wikipedia

If overscan is enabled, this will happen, which is exactly what you've described:


As I said in my comment, perhaps your only issue a full /boot partition. Since you're using LVM, the output you posted in fstab, mount, etc look fine.

And the best way to free space in /boot is to remove old kernel versions. If you're new to this, I suggest using Software Center:

Search for "linux-image". Take a note on the most recent one (your current kernel), and delete all the previous ones. Only remove the ones with version numbers like linux-image-3.2.0-xx-server, do not delete the "main" linux-image-server or linux-image. Be sure to keep your current version number.
Do the same with "linux-headers"

You're good to go!

Also, as a side-note... you may reconsider administering an Ubuntu Server if you still need tutorials for managing disk space and kernel versions. Have you tried Ubuntu Desktop?


How to install packages to external drive (and run them)?

The easiest solution would be to install Ubuntu on the external SSD.

The "problem" is that Linux does not install programs into a single directory, so, when you install an application it installs pieces in various locations on the hard drive.

See http://brajeshwar.com/2008/filesystem-file-organization-in-linux/

So, generally what you "normally" would do is, as a part of the installation, partition the ssd and mount the various partitions at various locations such as /home or /usr or /var

So you could reinstall or move part of the file system, such as /usr to your ssd. Moving will take longer and be more involved then simply re-installing, making a partition or partitions such as /var and /usr on the ssd. The installer will do this for you.

To move see How can I store /var on a separate partition?

Other options : How to use second HDD as program installation drive path

Your last option would be to compile from source. When compiling you specify the location, again you would make a partition on the ssd and mount it at /usr/local. When compiling you use the --prefix option

./configure --prefix=/usr/local

See https://stackoverflow.com/questions/8902698/linux-configure-make-prefix

So, if you did not understand what any of that means, you are best off installing Ubuntu onto the ssd.


Pepper flash plugin for Chrome:

sudo add-apt-repository ppa:skunk/pepper-flash
sudo apt-get update
sudo apt-get install pepflashplugin-installer


If you are using Ubuntu 18.04 with a 5.3 kernel, you will need to do in terminal
wget http://mirrors.kernel.org/ubuntu/pool/multiverse/b/broadcom-sta/broadcom-sta-dkms_6.30.223.271-11_all.deb
sudo dpkg -i broadcom-sta-dkms_6.30.223.271-11_all.deb
Then reboot


Upgraded HP Pavilion G7 1317cl with Bios vers F45 to 8GB only 3.3GB recognised in Ubuntu 12.04 X64

Upgraded Bios to ver F.52 - no help. Re-installed Windows 7 with same symptoms. Returned laptop as bad system memory slot 2. As an aside, HP was incredibly not helpful and the 90 day return policy from the retailer was my best option for resolving the issue with an entirely new laptop.


Why Extented Regular expression works on command line input but not when reading from a file

The issue, I was validating the csv file through Excel, by drag-drop csv file. Excel must format the date, based on its default configuration. Substitution using sed works fine. Data shows correctly when I view the file on the command prompt.


how to safely update php 7.2.24 to 7.2.33 on ubuntu 18.04

This PPA - sudo add-apt-repository ppa:ondrej/php - seems to be well maintained, includes updates for php versions 7.0 through 7.4.


Xubuntu - manually restart network after reboot?

Im guessing you want network-manager to manage your connection as this is the norm on most laptops if so you shouldn’t be using /etc/network/interfaces I'd remove all references to wlan[?] from their and reboot.


Custom command - one less than current brightness level

Why not make one command  that will increase by one or decrease by one based on the options you pass to it ? That's the basic idea behind the script you will see bellow. We store current value in CURRENT variable, then use bash's arithmetic expansion $(( numberA + numberB )) to increase or decrease by one. As for decision making, we call the script with single command line argument + to increase , or - for decrease.

Per muru's suggestion in the comments , I also made a small edit to the code, which now allows you to call brightness.sh with an integer parameter less than or equals to the max brightness

#!/bin/bash

###########
# Variables
###########
FILE="/sys/class/backlight/acpi_video0/brightness"
MAX="$(cat /sys/class/backlight/acpi_video0/max_brightness)"
MIN=0
CURRENT="$( cat  $FILE )"

###########
# functions
###########

function printUsage
{
  echo "Usage:"
  echo "sudo brightness.sh [ + | - | INTEGER ]"
}

######
# Main
######

if [ $# -eq 0  ];
then
   printUsage
   exit 0
fi

if [ "$1" == "+" ];
then
   NEW=$(( $CURRENT+1  ))
   # are we trying to go past maximum value ? If yes, quit
   if [ $NEW -ge $MAX  ]
   then
       echo ">>> ERROR: Current value already the maximum; "
       echo ">>> Exiting"
       exit 1
   fi
   # if not, then proceed
   echo "$NEW" > "$FILE"

elif [ "$1" == "-"  ];
then
   NEW=$(( $CURRENT-1  ))
   # Is NEW value going past 0 ? If yes, quit
   if [ $NEW -le $MIN ];
   then
       echo ">>> Error: already at minimum. "
       echo ">>> Exiting."
       exit 1
    fi
    # If not, then continue
    echo "$NEW" >  "$FILE"

# Note: new test w/ regex; for portability
# probably better idea to use awk
elif [[ "$1" =~ ^[0-9]+$ ]] && [ $1 -le $MAX   ];
then
    echo "$1" > "$FILE"

else
    echo "<<< ERROR: wrong parameter "
    printUsage
    exit 1
fi


Is there a way to get 2x3 workspaces in gnome 3.6

Check this extension (works with GS 3.6 and 3.8 as well): https://extensions.gnome.org/extension/484/workspace-grid/


RunTime error when installing package on raspberry pi

I just had this same issue. I was unable to install a version of urllib3 later than 1.9 through apt-get, and any instance trying to use pip resulted in the urllib3 error.

I fixed it through installing it manually from the github repository.

$ git clone git://github.com/shazow/urllib3.git
$ python setup.py install

Another option, although unsafe, is to manually edit /usr/local/lib/python2.7/dist-packages/requests/__init__.py and replace line 53 with

major, minor, patch = (1,22,0)


How can I move the top panel to the bottom in Gnome 3?

An easy way to move the panel to the bottom of the screen is MMOD Panel by rik.

Open the link in Firefox and activate the extension with the switch in the left area.

The extension also works in GNOME 3.18 (tested on my system).

Screenshot taken from here


Can I have rectangular grid workspace in Ubuntu 18.04?

The option to install GNOME extensions using GNOME Tweaks is removed from last few versions of the application. But you can simply install and manage extensions from their official websites. To do that first install the chrome-gnome-shell package by running the following command in Terminal

sudo apt install chrome-gnome-shell

Then visit https://extensions.gnome.org/ using Firefox or Google Chrome, the website should ask you to install one browser add-on/extension. Install it.

Then go to the extension's homepage, you'll be able to install the extension just by toggling on the button at the top-right:

Alternatively, you can manually install extensions following this answer.


Persistent USB with more than 4Gig guides not working?

Persistent partitions have not been working with Ubuntu, syslinux type installs since 14.04.

These include Rufus, UNetbootin, Universal, Startup Disk Creator, etc.

Persistent partitions do work with grub2 type installs and can automatically be created with mkusb and dus, both created by Sudodus.

Latest info on these installers can be found at:

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


How to remove Kylin GUI completely and install Kubuntu GUI?

You can use sudo apt-get remove 'ubuntukylin*' to remove kylin desktop and all dependencies.
I suggest you to reset all the keyboard shortcuts too. For me some shortcuts was disabled, e.g: Win+D to minimize all the windows.
If you just use apt-get remove ubuntukylin-desktop it will not remove all the data.
For file manager ukuy removal:
sudo apt-get remove 'peony*'

More ukuy data:
sudo apt-get remove 'ukuy*'


Not sure if Matlab can be installed in Ubuntu in a easy way.So if use of Matlab is not strictly compulsory you can use other softwares just like it which are of open source.

One of that is Octave.You can install it using the command

  sudo apt-get install octave


Probably a parent directory in the path does not exist.

You can try with

mkdir -p /path-to-directory/directory-name

See man mkdir

   -p, --parents
          no error if existing, make parent directories as needed

If you get a permission denied error, you have not permissions to create a directory in the specified path.

Check if you can get around the problem by modifying the group membership or ownership, so that you get the permission needed for the whole directory path involved.

Otherwise you need elevated permissions, so try with sudo

sudo mkdir -p /path-to-directory/directory-name


How to install Browser source plugin in obs(Open Broadcaster Software) studio

The Browser source for OBS Studio webpage says:

  There is not currently a Linux build of this browser plugin, but in the meantime bazukas has built obs-qtwebkit, another browser source based on qtwebkit.

Using the latest version of OBS Studio from ppa:obsproject/obs-studio (currently version 0.16.2) will simplify the installation of obs-qtwebkit.

Installation

  Make sure you have necessary dependencies installed, which are obs-studio and qt5 and qt5-webkit development packages. You may need to set OBS_INCLUDE and OBS_LIB env variables (see Makefile).

  On Ubuntu 16.04 you may need to install the developer libraries to compile.

sudo apt-get install qtbase5-dev
sudo apt-get install libqt5webkit5-dev

  Run make in the obs-qtwebkit directory to build the plugin. If your OBS version is < 0.11.2, run OBS_PLUGIN_BUILD_OLD=1 make

  Run make install to copy plugin binaries into $HOME/.config/obs-studio/plugins. If your OBS version is < 0.11.1, run OBS_PLUGIN_INSTALL_OLD=1 make install


Bad credentials Magento extension manager

Make sure that you are not copying an extra space character either at the beginning or the end of the key. You can verify this by first copying the key to a text editor like GEdit.

Notice the extra space in the example below which normally won't be visible in normal text.

Hello World
 Hello World


Touchpad not working at all on Toshiba Satellite with 18.04

I had the exact same problem except perhaps for the fact that my touchpad worked in windows 10. Other solutions, like modifying grub or disabling and enabling the touchpad did not work for me. I could see it listed in devices menu but my cursor was stuck.
This is how I got mine working again;

I booted into windows 10
Located and ran the synaptics installer that came with the laptop
Shutdown
Booted into Ubuntu
touchpad started working


Unpack a war file to a destination folder without verbose output

You can unzip quietly, just use the -qq option (see man unzip)

   -q     perform  operations  quietly  (-qq  = even quieter).  Ordinarily
          unzip prints the names of the files it's extracting or  testing,
          the extraction methods, any file or zipfile comments that may be
          stored in the archive, and possibly a summary when finished with
          each  archive.   The -q[q] options suppress the printing of some
          or all of these messages.

Your command becomes:

unzip -qq myFile.war -d /home/app/


Open the flash-all.sh script in an editor,
scroll down to the last line which looks something like:
fastboot -w update image.zip

Remove the -w flag,
save the script,
run it again and it should work.


Where to find Docker container filesystem

The Python script is execute inside the docker container and this is also where the output of your script is located.

Docker images creation

The Dockerfile is correct, concerning the installation of the required environment (numpy, sklearn). Place the script in a separate directory e.g. qc to avoid collisions with the container filesystem.

FROM python:3

ADD qc.py /qc/

RUN pip install numpy
RUN pip install sklearn

CMD [ "python", "./qc/qc.py" ]

docker build -t qc .

Add volumes to running container

Run the container and mount a output folder inside the container:

docker run -it -v "$(pwd)":/qc/output qc

The run command mount the current directory to the /qc/output folder inside the container. The qc.py needs to be modified to place its output inside the output folder.

Then the output of script is placed inside the local folder.


If you know what disk they are:
dd if=/dev/input partition of=/dev/output partition

Find the disk names in Disk Utility.


Install all the scanner driver packages and use the scanner with the application simple-scan

sudo apt-get install sane xsane xsane-common sane-utils libsane libsane-common libsane-dbg libsane-dev libsane-extras libsane-extras-common libsane-extras-dbg libsane-extras-dev


Bug reports can be submitted using the apport-bug application from a terminal.

Open a terminal and use the command apport-bug package_name and press enter.

In your case, for cups you would use :

apport-bug cups

For more options and instructions you can read the apport-bug man page using :

man apport-bug


How to install for the person that can't make sense of the how to page

You have tried to make a bootable DVD/CD? On Windows you just download the .iso file and click 'burn'. You should check the 'verify disk' option if it asks for it. I have installed Ubuntu on 7 different computers, and in my experience I have found disks to me infinitely  more reliable then USB sticks/drives.


You could convert the floating point to an integer number and print it.  There would be no trailing zeros and you could print with format code %d or %ld.

I think that changing %f to %d might do the trick however w/o having to do the conversion explicitly (i.e. let printf do the conversion).


E: The package ubuntu-mono needs to be reinstalled, but I can't find an archive for it

I Found The Solution
FINALLY....
first, open the terminal and write this command:

sudo dpkg --remove --force-all ubuntu-mono

after that, write this command

sudo apt-get update

then restart your PC.
^_^


I've solved it with a bit different way but not as in How can I fix a 404 Error when using a PPA or updating my package lists?.
I don't know how to solve it in command line but I did it in UI.

Open update-manager.
After checking go to Settings... > Other Software.
Uncheck all matched with link http://ppa.launchpad.net/clicompanion-devs/clicompanion-nightlies/ubuntu

For now apt-get update works fine.


Can't install lib32ncurses5-dev or ia32-libs

ia32-libs is in the universe component. It sounds like you don't have this repository enabled.

You need to enable it, either in Software Center -> Software Sources, or by editing /etc/apt/sources.list and uncommenting lines with universe at the end.

Don't forget to do an apt-get update (or press Update in Update Manager)


Which version of Ubuntu for Toshiba NB500?

I would go with Xubuntu or Lubuntu, both will run just fine on your hardware. You could give Ubuntu a whirl, but don't expect lightning speed.

As for versions, I would definitely stick with the latest (or the latest LTS), which is 14.04.


Websites in Firefox using only half of the screen

I had a similar problem. I checked the screen resolution and found it to be less then maximum. After maximizing it, in settings -> display, it again took up the whole screen.
I did not think that it would be that easy!


Command to display virtualbox vm network information

Hi i found Command to display Virtualbox network info

vboxmanage showvminfo <VM Name> |grep "NIC"


As the comment at the start of /boot/grub/grub.cfg says:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

In other words, any time you run update-grub or it is run for you ( for instance, when install a new kernel, or certain other packages ), grub.cfg is thrown out and recreated, so edit /etc/default/grub.


Installing Ubuntu Onto a Computer That Doesn't Have An Operating System

If you know how to install ubuntu beside windows or another OS you should be fine to install ubuntu as the only OS. The only challenge I can imagine could be, that the HD is not formatted at all. To solve this challenge, boot into the live session, either from usb stick or cd, and use gparted to format the drive, either fat 32 or ext 4, after this install ubuntu and hopefully if the hardware is supported everything should work fine


"Folders" are pretty pictures displayed in a GUI; the structures in a filesystem are called "directories". (The difference is that directories exist independent of any program, whereas folders may or may not be ephemeral names created by some graphical shell.)
You've got is exactly backwards: you don't mount directories on partitions, you mount filesystems on directories.
To place /home under /var, assuming we are speaking of a freshly installed server with no GUI:

Create a directory /var/home, then
Move everything from /home to /var/home with

cd /home && for d in *; do sudo mv "$d" "/var/home/$d"; done

Mount bind temporarily /var/home on /home:

sudo mount --bind /var/home /home

Add

/var/home /home none bind 0 0

at the end of /etc/fstab; this will mount --bind the directory /var/home on /home at boot.
Reboot and enjoy.


Adjust your concept, also regarding safety / reliability aspects.

If it is really justified that your website needs to adjust system configuration, you'll want to contact e.g. a´self-written daemon process which provides a suitable amount of protaction and is specialised only in applying limited changes.

You do definitely not want to grant super user rights to your web server.

[Edit]

To be clear, your web server should also not write files in /etc/network/ because that alone requires that you change permissions there, which is not such a good idea. Your daemon process must coordinate this, also wrt potential race conditions.


Sort Nautilus data by text after a delimiter

Short answer: that is not possible.

You can use "Select items matching" to select all the files that match your criteria. Press Ctrl+s. In the resulting dialog, provide a wildcard match, e.g. *- Author name.epub, which would select all matching file names.
Alternatively, the search function allows to quickly retrieve all files that contain a certain string, e.g. "Author". The search function by default is recursive: it searches the current folder and all folders below. In "Preferences", "Search & Preview" tab, you can disable the search in subfolders.


Control point for DLNA renderer and Minimserver library?

Bit late for you probably, but if anyone else stumbles upon this question - the answer is upplay. I use it on a 20.04 laptop to drive a couple ("group") of Jam renderer-speakers from a pi running minidlna.
http://www.lesbonscomptes.com/upplay


I suggest you amend your /etc/network/interfaces file to:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 192.168.100.42
netmask 255.255.255.0
gateway 192.168.100.1
dns-nameservers 8.8.8.8 192.168.100.1

Restart the interface:

sudo ifdown eth0 && sudo ifup -v eth0

Check:

ping -c3 www.ubuntu.com


Oh, yes:

$ sudo apt-get install -y postgresql-client
$ psql --version
psql (PostgreSQL) 9.5.12


Use ubuntu laptop as external screen for windows PC

I had a requirement of using windows laptop as second screen for my windows desktop. But the solution I used isn't really specific to an OS, hence I'll share.

Idea:

Use synergy software to share mouse and keyboard between desktop
and laptop. This requires both devices to be connected over a
network, so that they can access each other's ip address. Here,
desktop becomes server as it is sharing mouse and keyboard attached
to it. Laptop becomes client, so that its screen can be accessed.
You need to configure screen position, like laptop is to the left or
right of desktop monitor. Accordingly, moving mouse past the edge of
desktop screen will make it go to laptop screen.
synergy (atleast the free version i use) doesn't solve requirement of sharing sound. For this I use NoMachine. I make laptop the server and my desktop
the client. Nomachine allows forwarding sound from server to client
(and even mutes it on server if desired, so that sound doesn't come
from laptop's speakers as well!). Once you connect to nomachine
server on laptop, from desktop, you can control laptop screen from
desktop. However, we don't care about this so we will just minimize
the screen. This screen however will allow listening to all sounds
produced on laptop, on desktop.

End result:

Synergy allows moving mouse connected to desktop, on laptop screen.
It also allows using keyboard attached to desktop, to type on laptop
screen.
Nomachine allows listening to any audio playing on laptop,
from desktop speakers.

Thus, even though laptop screen is running a video session on laptop's own operating system, but the input can be given using desktop peripherals and audio output can be listened through desktop speakers.

Software links (you will have to install appropriate version for your desktop and laptop OS). Google has lot of resources to help with installation:

https://www.nomachine.com/
https://blog.symless.com/2014/12/16/download-synergy-free/

NOTE
It is still not a complete external screen because drag and drop doesn't work across screens. In my case I needed to only access resources from cloud, so  I could access them through any system. For locally saved files, you'll have to transfer them to laptop. NoMachine, fortunately, supports that as well!
https://www.nomachine.com/sharing-files-between-computers


Ubiquity install wizard crashes; cannot install ubuntu-MATE 18.04.4

SOLVED: My live USB drive itself had permissions enabled for user only.  I created read and execute permissions for group and other:

chmod go+rx /media/name-of-live-USB-stick


Follow the instructions detailed in this post: Convert ext2/3 to ext4


Is it possible to blacklist subfolders in Banshee?

You could create a smart playlist (Media → New Smart Playlist...) matching all songs which filepaths (File Location from the dropdown menu) contain --All-- and then remove all those songs from the library. Definitely not the best solution.


S3fs can't access bucket permission denied

Since I found a fix for this I feel obligated to share it sense I asked for help.

What worked for me was fixing my permission immediately via the mount command like so:

s3fs babylon ~/MyMount -o passwd_file=~/.passwd-s3fs -o umask=0000

Umask works like a subtractor so with all 0s it sets things to 777. When I open my bucket via a script I made I now see the following:

-rwxrwxrwx 1 kaz  kaz       0 Mar 26 03:11 drfg.txt
-rwxrwxrwx 1 kaz  root   2272 Mar 26 19:48 lab8.cpp
-rwxrwxrwx 1 kaz  kaz      16 Mar 24 22:44 nextday.txt
-rwxrwxrwx 1 kaz  root 814493 Mar 26 19:48 Refactoring - A good example.pdf
-rwxrwxrwx 1 root root 522010 Mar 26 20:06 revy_3.jpg
-rwxrwxrwx 1 kaz  root    586 Mar 26 19:49 sample.c
-rwxrwxrwx 1 kaz  kaz       6 Mar 26 01:29 temp.txt

I hope that this helps anyone struggling with s3fs.


I had issues with openGL. Matlab support team suggested I start matlab with the following command:

matlab -desktop -softwareopengl

By the way, I use Nvidia driver, not Xorg


If you want to start it manual have a look at screen. First install it with sudo apt-get install screen. Then you can start a screen session with one screen -S NAME and you can deteach the session with ´Ctrl+A D´, so it remains after you closed your ssh session. With screen -r NAME you can reteach it, if you need to.

For an autostart, you can place your script in the file /etc/rc.local for a execution on every boot. But watch out, exit 0 must remain as last line. The commands in this file will be executed with root. If you don't want this, you can add a su USERNAME -c "COMMAND"  If you want to acces it later, I prefer screen -dmS NAME COMMAND, so you can reteach it with screen -r COMMAND. In completion: su USERNAME -c "screen -dmS SESSIONNAME COMMAND"


How do I mass install apt packages conditionally from a file?

There's already a format for controlling apt using a file. It's an ordinary shell script.

#!/bin/sh

# Instructions: Run me using sudo: $ sudo install_script.sh
# WARNING: All errors have been muted or thrown out. Guess I don't want to know...

# PPA
add-apt-repository -y ppa:deadsnakes/ppa &> /dev/null
add-apt-repository -y ppa:font-manager/staging &> /dev/null
add-apt-repository -y ppa:fish-shell/release-2 &> /dev/null
add-apt-repository -y ppa:zanchey/asciinema &> /dev/null

# packages
apt install --allow-unauthenticated -qqy tree symlinks

# deb
wget https://github.com/jhawthorn/fzy/releases/download/0.9/fzy_0.9-1_amd64.deb -O /tmp/fzy_0.9-1_amd64.deb
apt --install /tmp/fzy_0.9-1_amd64.deb -qqy
rm /tmp/fzy_0.9-1_amd64.deb

There are lots of ways to make a script more complex and fun to play with.

There are also lots of ways to clean up a script and make it more readable and maintainable for you.


how to keep the app indicator menu visible after clicks?

Unfortunately at this time you can only use standard menu items in the application indicators.  All of the standard menu items cause the menu to close, where the one in the sound menu is a custom item that avoids that.  We plan in the future to provide the ability to use custom menu items to application indicators, but that work is not yet complete.


Ubuntu 18.04 LTS freezes on shutting down (mouse disappears and everything hangs)

Try to remove all the Nvidia drivers instead. Lots of people reporting similar problems with recent updates.

I've tried new kernels(4.17.17) and latest Nvidia drivers and couldn't make it work either.


How to connect computer to tv with hdmi?

IN display settings, choose mirrored display.


You need to have nodejs and npm installed:

sudo apt install nodejs npm

Note that this will install nodejs 4 and npm 3, but for plain angularjs this should be enough.

Then, in a node package (you can create one by running npm init in a directory, if you don't have any yet), install the angularjs module using

npm install --save angular


How to hear my voice in speakers with a mic?

Here is a solution that I've tested with Pulse Audio on Ubuntu 12.04.

Install PulseAudio Volume Control (pavucontrol):

sudo apt install pavucontrol

Now we will route your microphone to your speakers. Do this by running the following command:

pactl load-module module-loopback latency_msec=1

On the Recording tab of pavucontrol, you can show all streams (combobox at the bottom) and then configure which microphone (if you have more than one) should loopback into the built-in analog stereo

To stop it running, run:

pactl unload-module module-loopback


After doing much Googling I have come up with this solution. This solution will enable Wayland even if you have proprietary NVIDIA drivers on Ubuntu 20.04.

Execute sudo apt install gnome-session-wayland.
Open /etc/gdm3/custom.conf and ensure WaylandEnable=false is commented.
Open /usr/lib/udev/rules.d/61-gdm.rules and comment all lines.
Execute sudo systemctl restart gdm3.
Click on the cogwheel and select GNOME or Ubuntu on Wayland.
Execute echo $XDG_SESSION_TYPE in order to confirm you are running Wayland (output should be "wayland").

This solution can be a bit buggy, for example the Ubuntu environment took a long time to fully load in my case. In my case I am running a GTX 1050 Ti on proprietary drivers.
EDIT: Performance in games is terrible if running this solution. Would not recommend for gaming.


Almost everything in Linux can be considered a file, but the main difference between a regular file and a named pipe is that a named pipe is a special instance of a file that has no contents on the filesystem.
Here is quote from man fifo:

A FIFO special file (a named pipe) is similar to a pipe, except that it is accessed as part of the filesystem. It can be opened by multiple processes for reading or writing. When processes are exchanging data via the FIFO, the kernel passes all data internally without writing it to the filesystem. Thus, the FIFO special file has no contents on the filesystem; the filesystem entry merely serves as a reference point so that processes can access the pipe using a name in the filesystem.
The kernel maintains exactly one pipe object for each FIFO special file that is opened by at least one process. The FIFO must be opened on both ends (reading and writing) before data can be passed. Normally, opening the FIFO blocks until the other end is opened also.

So actually a named pipe does nothing until some process reads and writes to it. It does not take any space on the hard disk (except a little bit of meta information), it does not use the CPU.
You can check it by doing this:
Create a named pipe
$ mkfifo /tmp/testpipe

Go to some directory, for example /home/user/Documents, and gzip everything inside it, using named pipe.
$ cd /home/user/Documents
$ tar cvf - . | gzip > /tmp/testpipe &
[1] 28584

Here you should see the PID of the gzip process. In our example it was 28584.
Now check what this PID is doing
$ ps u -P 28584
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
c0rp     28584  0.0  0.0  29276  7800 pts/8    S    00:08   0:00 bash

You will see that it is using no resources. 0% CPU usage, 0% memory usage.
Verify hunch regarding file space usage
$ du -h /tmp/testpipe
0   testpipe

And again 0, nothing. The testpipe could be used again if needed.
Don't forget to kill gzip, using kill -15 28584. And remove our named pipe using rm /tmp/testpipe
Example Usages
You can redirect almost everything using named pipe. As example you can see this one line proxy.
Also here is one more nice explanation of named pipe usage. You can configure two processes on one server to communicate using a named pipe instead of TCP/IP stack. It is much faster, and does not load network resources. For example your Web Server can communicate with the database directly using a named pipe, instead of using localhost address or listening to some port.


Why isn't ubuntu checking the correct directory in the $PATH variable?

Chances are there used to be a redis-cli in /usr/bin/redis-cli which has now been deleted.

Bash maintains an internal hash of executables on your path which hasn't been updated. If you encounter this problem again, rehash it and it will work.

hash redis-cli


Desktop launch icon "there was an error launching the application"

The .desktop file for MySQL Workbench already exists in /usr/share/applications. Here it is...

$ more mysql-workbench.desktop [Desktop Entry]
Name=MySQL Workbench
Comment=MySQL Database Design, Administration and Development Tool
Exec=mysql-workbench
Terminal=false
Type=Application
Icon=mysql-workbench
MimeType=application/vnd.mysql-workbench-model;
Categories=GTK;Database;Development;
StartupWMClass=mysql-workbench-bin


What happens if you choose pci=off at the LiveCD prompt?

From the Linux BootPrompt Howto:

pci=off:

  Using this option disables all PCI bus probing. Any device drivers
  that make use of PCI functions to find and initialize hardware will
  most likely fail to work.