How do I prevent suggestions in the location bar in Firefox with history empty?

Even though the suggestion settings in Firefox 18 allow you to disable all, it won't do it!

Make sure the above setting in "Privacy" is set to "Nothing" (if you want to disable them).

Either way, search suggestions are still enabled. To disable this:

Go to about:config in the address bar
Click the "I'll be careful, I promise!" button.
In the search at the bottom of the "page", enter: suggest
You'll find this result: browser.search.suggest.enabled
Double-click this item to toggle its value to false.

Enjoy!

Below is a screenshot in case you find my steps described a bit hard to follow.


How to backup a folder with cloud like storage but offline?

You can use the famous rsync. Read rsync - Community Help Wiki.
Example:
rsync --stats --delete -avzh /source/dir /dest/dir

Be aware of the --delete option matching mirroring needs (not archiving).
For syncing to/from a cloud storage, see https://rclone.org/


Tried switching between python verions. Ended up messing the whole thing. How to fix it?

py2 and py3 are usually found side by side and like I discovered better left for the system to pick which version it needs. If you want to use any version then you have to point whatever app you are using to the version you want.
Running "python" will always run the 2.X version, but running "python3" or "python2" will give you the respective versions.
Run following commands in terminal:

sudo apt-get update

sudo apt-get install --reinstall python
Another solution will be to use the dpkg since this doesn't depend on
python, but requires more effort go here for this option. This will mean you will download all required packages. Hope it Helps.


Ubuntu Touch - Issues logging into Trello

Since installing the latest system update, I have been able to open Trello on my tablet all OK.


One WiFi network not working, others are fine

This docker support forum has various answers to check out:

Wifi Adapter Disabled When Hyper-V Network Adapter Enabled - Native

The easiest answer (not guaranteed to work for you) says:

  I changed the subnet address on docker settings to match my wifi ipv4
  address and it worked for me.

Even if this doesn't solve the problem you should read the whole thread and search the rest of the docker forum for similar questions.


Perhaps its an issue over the type of Network? Are you connecting to a 5gHz or a 2.4gHz network? I know that I sometimes have issues with the 5gHz networks being picked up.  I had to you Wine to set up my drivers.  It sounds like you are technically more adept than I am so I won't bother giving you instructions on how I did that...unless you arent sure how to use wine. Then I would be happy to help/   Also check to see that windows is disconection from your network so the router knows to allow you to connect. You wouldnt be using static IP would you? if so that could be the case...


What's the reason for Ubuntu officially supporting versions such as Kubuntu, Lubuntu, Xubuntu?

I see three reasons:

Community ownership of the projects - with a distinct vision
Having a unified "look" of desktop Ubuntu (that matches phone and tablet and TV Ubuntu) for marketing purposes
Canonical can focus its efforts on QA for one desktop environment versus multiple

The flavours are not simply Ubuntu with a different desktop environment. For instance, if you take an Ubuntu desktop installation and apt-get install lxde, you will have a very different computing environment than installing Lubuntu itself.

From Lubuntu.me:

  Lubuntu is designed to be fast and easy to use. It has lots of applications for every daily need, while keeping your system light and responsive, being it ideal not only for old computers and netbooks, but for newer computers too making them lightening [sic] fast.

To that end, Lubuntu includes a set of packages and applications to perform typical PC tasks (office applications, media players, photo viewing and editing, etc) that are typically lighter-weight in terms of RAM and CPU usage than comparable applications in Ubuntu. (Abiword vs LibreOffice Writer, for example.) The focus is on low overhead.

In that way, the vision of a flavour like Lubuntu is fundamentally different from the vision of the Ubuntu Desktop project. For instance, two of their marketing points are, as stated on Ubuntu.com's desktop page:

  Complete

  Ubuntu comes with everything you need to run your organisation, school, home or enterprise.

  [...snip...]

  Looks great on the latest devices

  Ubuntu is designed to work beautifully on the latest laptops, desktops and touch screen devices, it looks incredible on high resolution screens — and with touch screen enhancements and interface refinements including individual menu bars in each application window, it’s now even easier to use.

If Canonical wished, I suppose it would be possible to offer an LXDE spin, but if it contained the same packages and same amount of software, it would be far less usable on older hardware than Lubuntu is (which is part of the Lubuntu team's vision), and arguably take away from the unified, beautiful, modern experience that is important to Canonical's desktop marketing efforts.

I don't work for Canonical, but I have been involved with the Lubuntu community, and that to me is the fundamental difference I see between the projects.

Finally, as to quality: when I triage bug reports against LXDE packages, there are a number of unique and interesting bugs that happen when running LXDE on Ubuntu (apt-get install lxde on Ubuntu) vs. running Lubuntu. A lot of bugs that occur on Ubuntu with LXDE do not occur on Lubuntu. I'm not a developer, so I can't really help explain why, but for some reason the Lubuntu desktop is packaged and arranged in a way that makes LXDE work much better with Ubuntu than just installing the LXDE package.


How can I configure Okular to save annotations in the pdf file by default?

Update to Okular >= 1.3 (shipped with KDE Applications >= 17.12)


How do I install 64-bit Ubuntu Server on MacBook?

(My) Steps to success

To be clear, my goal was to actually dual-boot Mac OSX and Ubuntu Server on my old busted macbook. The following steps my be helpful for anyone trying to install a disagreeable OS on mac hardware.

Install OS X at the beginning of the hdd (50Gbs). I have OS X 10.6 Snow Leopard (w install disk)

50Gbs was my personal choice. This is really up to you

Install rEFIt and test that it works. You should see it after a restart with some boot options.
Install Ubuntu desktop using the amd64+mac iso. rEFIt should let you boot from the disk.

I put this at the end of the drive (20Gbs) with the intent of removing it. You may be able to get by using a LiveCD but I had already installed it to explore other options.

Within Ubuntu (select it via rEFIt), create a partition (1Gb) using gparted and then copy the Ubuntu 64-bit Server iso to it. For simplicity, let's say we now have /dev/sda6/ubuntu.iso
Restart and select Ubuntu again, this time before Ubuntu loads access the GRUB2 command line by pressing c when the GRUB menu appears. Type the following:

loopback loop (hd0,6)/ubuntu.iso
linux (loop)/install/vmlinuz boot=install iso-scan/filename=/ubuntu.iso quiet splash --
initrd (loop)/install/initrd.gz
boot

You should now be entered into the Ubuntu Server install process. Success!

At one point, it asked for the CD-ROM which I happily provided by inserting it into the disk drive and then continued the installation process flawlessly.
I was also able to delete all the unwanted partitions I had created, even the one containing the iso I booted from, without any issue.

I now can boot into either OS (Snow Leopard or Ubunutu Server 12.04.1) via rEFIt.

Also, big thanks / reference to this post about installing ubuntu from iso file using grub2. It was key to my success.


How to make Eclipse CDT's Linux GCC toolchain resolve C++ standard library headers?

If you had the same issue I did, I suspect that your project builds but code-completion / code highlighting fails? I've just found some notes that may be useful. Here's what I did:

Project->Properties
C/C++ General
Paths and Symbols
select the appropriate language
Click "Add" and add the compiler-version specific directories

For language 'GNU C++' I added:

  /usr/include
  /usr/include/c++/4.6
  /usr/include/c++/4.6/bits
  /usr/include/i386-linux-gnu
  /usr/include/i386-linux-gnu/bits
  /usr/include/c++/4.6/debug
  /usr/include/c++/4.6/i686-linux-gnu
  /usr/include/c++/4.6/i686-linux-gnu/bits

For "GNU C" I added:

  /usr/include
  /usr/include/i386-linux-gnu
  /usr/include/i386-linux-gnu/bits

TBH, I don't think all the directories above are actually required (you could probably remove the 'bits' directories) but the list above worked for me at the time.

I am now using Eclipse Indigo (version 3.7.2) from eclipse.org and it automatically finds and adds the correct include directories. The list is different for me:

/usr/include/c++/4.6
/usr/include/c++/4.6/i686-linux-gnu
/usr/include/c++/4.6/backward
/usr/lib/gcc/i686-linux-gnu/4.6/include
/usr/local/include
/usr/lib/gcc/i686-linux-gnu/4.6/include-fixed
/usr/include/i386-linux-gnu
/usr/include

Clearly, only add the include directories that actually exist on your system ;-)


For fstab in Ubuntu 12.10, what does it show for the Ubuntu UUID?

It is UUID for your partition. Each UUID can be found with ls -l /dev/disk/by-uuid/


You can only upgrade from one version to the next (ex. 17.04 to 17.10) or from LTS to LTS (ex. 16.04 to 18.04). 17.04 is not a LTS version.


Looking for an ultra portable laptop for Ubuntu


Opening program in Unity Dash opens about:blank tab in browser?

Found solution to the bug.  The issue resides in online accounts needing authorization.  Another user posted online that once they logged in and authorized their Google Accounts, the problem stopped.

I have decided to turn off google integration because despite authorizing access, google periodically makes you re-authorize access.  I hope this prevents the issue from comming back.

Now I know how to fix.


Postfix Using Gmail Relay: Must issue a STARTTLS command first


Disabling IOMMU in the bios allowed Ubuntu to boot. (It was previously set to auto.)


Ubuntu sudo su and server su clarification

You could try to get to root by typing in the terminal:

sudo -i

or you can also type.

gksudo thunar

there you can also change privileged, and su normal can only go to root whit enter in the terminal:

 sudo -i | su

could might work fine this way.


How do I embed a terminal on the desktop?

Well, here you go

http://www.screenlets.org/index.php/Terminal

( if there wont be better answer, mark this as answered )


how would i allow non-root users to install, but only from a repo

You can blacklist all the packages ending in ".deb".
To do so you need to modify your "Never-MarkAuto-Sections" block in /etc/apt/apt.conf.d/01autoremove file.

sudo nano /etc/apt/apt.conf.d/01autoremove

The content of "Never-MarkAuto-Sections" should look like this:

  Never-MarkAuto-Sections
  {
    "metapackages";
    "contrib/metapackages";
    "non-free/metapackages";
    "restricted/metapackages";
    "universe/metapackages";
    "multiverse/metapackages";
  };

Add another entry at the end:

  Never-MarkAuto-Sections
  {
    "metapackages";
    "contrib/metapackages";
    "non-free/metapackages";
    "restricted/metapackages";
    "universe/metapackages";
    "multiverse/metapackages";
    "*.deb";
  };


No Boot Device Detected after Clear install of Ubuntu 15.10 dell latitude 6420

Reinstall the GRUB boot loader - select the fitting version below.

GRUB boot loader installation when the PC has a legacy BIOS

Boot from Ubuntu installation media.
Select Try Ubuntu without installing.
On the Live desktop open a terminal.
Execute the following commands :

sudo mount /dev/sd** /mnt
sudo grub-install --boot-directory=/mnt/boot /dev/sd*

Note : sd* = disk | sd** = system partition

GRUB boot loader installation when the PC has an UEFI BIOS

Boot from Ubuntu installation media.
Select Try Ubuntu without installing.
On the Live desktop open a terminal.
Execute the following commands :

sudo mount /dev/sd*** /mnt
sudo mount /dev/sd** /mnt/boot/efi
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done
sudo chroot /mnt
grub-install /dev/sd*
update-grub

Note : sd* = disk | sd** = efi partition | sd*** = system partition

To identify the partition numbers use GParted ... it is included in the Ubuntu installation media.


Can't shutdown xubuntu after updating to 16.04

The accepted answer sudo init 0 doesn't work for me in Xubuntu based in Ubuntu 16.04.

While waiting for a patch this is how I can shutdown my laptop:

Using poweroff

sudo poweroff -f

-f to force the computer to shutdown without contacting the init system.

Detecting the process that prevents the computer to shutdown

In my case there is always the tty process that blocks the poweroff process. So detecting it, killing the process and starting the systemctl target.

ps aux | grep tty

root       983  0.0  0.0  15408  1128 ?        Ss   11:49   0:00 /bin/systemd-tty-ask-password-agent --wall
Kill the process: sudo kill 983
Shutdown the computer: First sudo systemctl start poweroff.target and if it fails execute the command again: sudo systemctl start poweroff.target.

Related questions

Debian won't shut down (Failed to start poweroff.target: Transaction is destructive)
Ubuntu 16.04 won't power off: poweroff.target is disabled


get the list of all root dependent devices

df -h will list all devices/mounts.
lsof / will list all open files under root.
lvs, lvscan, and lvdisplay are used for LVM information.


It sounds like you have a Wubi system--that is, that you installed Ubuntu while booted into Windows.

If that is the case, you should be able to remove Ubuntu, including the selection for Ubuntu in the Windows boot menu (that comes up when you start your computer), by going to Add/Remove Programs (in the Control Panel, in Windows), and removing Ubuntu.

If you've already uninstalled Ubuntu and it worked, except that you still get to "choose" between Windows and Ubuntu when you start up, then this question, which @user68186 found, should help you:

How do I remove the extra Ubuntu option on the Windows Boot Manager menu?

If you find you're unable to uninstall Ubuntu in Add/Remove Programs, you got errors when you tried to do so, or it never appeared in Add/Remove Programs, then you can manually uninstall it as explained in this section of the Wubi Guide.


Configure UFW to allow only established and related conections (on IPv4)

Looks like you don't need to do anything to allow RELATED/ESTABLISHED Connections.

In ver. 0.36 of UFW I'm looking at on Ubuntu Core 16.04, the rules to allow RELATED/ESTABLISHED connections are there by default.

Crack-open the before.rules rules, you'll see the job has been done for you:

# quickly process packets for which we already have a connection
-A ufw-before-input -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A ufw-before-output -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A ufw-before-forward -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT


Getting error when running apt-get -f install

Run :

sudo dpkg -r tzdata

If it is successful or not, then run:

gksudo gedit /var/lib/dpkg/status

In the resulting Gedit remove the whole section starts with:

Package : tzdata

save the file and close.

Then run your command.


GL_EXT_texture_compression_s3tc error when opening a Steam game

This is just saying that it needs a driver that supports than GL extension. If you had an Nvidia card then installing the latest proprietary ones (The ones that come in the Xorg Edgers PPA) will solve this issue as seen in the following image:

But since you have an Ati then you are doomed... just kidding ^^. Simply do the following steps in order to have full support (This is my quick way of solving video support issues like this):

Open Dash by pressing the SUPER key (Which is called the Windows key in Windows, in my case it still has the Windows logo on it and I think I got the flu by pressing on it yesterday). Now type terminal. It should look something like this:

Now press ENTER and a terminal window should appear similar to the following:

Now type the following line to install the Xorg Edgers PPA:

sudo add-apt-repository ppa:xorg-edgers/ppa -y
Update and Upgrade system so the system knows you have included Xorg-Edgers:

sudo apt-get update && sudo apt-get upgrade
Install the latest Ati Radeon Drivers which you can do in any of the following ways. I will include them in the order I would do them first (Only do one of the following options):

Installing the fglrx-installer package (Which is the one that shows in Xorg-Edgers:

sudo apt-get install fglrx-installer

After this, reboot the computer and you should be finished installing with the Ati Driver. I put this one here first since it is the one that is more compatible with Ubuntu, is updated, less bugs and easy to install. Go to step 4 if you did this.

If you had an Nvidia card, it would also be easier to do just by reading How do I install the Nvidia drivers?

Type Software Sources in Dash. Open the Software Sources Window and go to the last TAB that says Additional Drivers. Look for the proprietary drivers for your Ati there. For Nvidia it looks like the following image but it will be the same for Ati (Just imagine all Nvidia drivers mentioned there to be Ati ^^):

Download the latest drivers from the Ati/Amd site and follow this guide: What is the correct way to install proprietary ATI Catalyst Video Drivers (fglrx) directly from AMD?
For other "older" type of Ati cards go here: How do I install Gallium3d Drivers in Ubuntu 12.10?

After making sure you have the latest driver that supports your video card and have only installed one of the ones mentioned above, reboot the system and test again. The latest driver makes sure your video card supports the S3TC texture compression. To test this you can do one of the following options:

Run sudo amdcccle in the terminal. If the Catalyst Control Center appears you are good to go.
Type Catalyst in Dash and see if it appears there.
Type fglrxinfo and see if it shows information about your video card. If you get "Command not found" or something similar, the drivers are not installed yet.

Lastly if you get a message similar to Required OpenGL extension GL_EXT_texture_compression_s3tc it just means that, either your video card does not support this compression or you are missing installing the correct libraries. If it is the libraries do the following:

sudo apt-get install libtxc-dxtn-s2tc0

I want to also add that there are a couple or articles in PHORONIX about the S3TC issues regarding patents and open source work. It is a good reading: http://www.phoronix.com/scan.php?page=search&q=S3TC

VIRTUALBOX - All of the above is for cases where you were running Steam in Ubuntu on the host, not on the Guest. Since you have just limited Ubuntu to what Virtualbox can offer, I will point you to this link Sharing between Host and Guest in Virtualbox which should cover the installation of the Guest Addition for Ubuntu. After you have done both, installing the driver and installing the Guest Addition, if the problem is still there, this basically means that Virtualbox is not letting the driver (Inside Virtualbox) read directly the mentioned GLX extension. So the problem would go from an Ubuntu problem to a Virtualbox one where you should go to the Virtualbox site and explain to them the problem.

Let me know if you solve the problem with this little tips. If not I can go deeper with more information. Just trying to make it as simple as possible.


How to change index.html file in apache from normal user when apache is installed in root?

Do

ls -l in the directory where index.html

is residing

Find out the file permissions for that.

You could very well done this

sudo gedit index.html

make the change and it will work

You need to make use of the command

chown ashish:ashish or
chown ashish:root

to change the onwership of the files in that directory


Intel AC7260 does not sniff LDPC packets

The reason why Intel AC 7260 does not sniff LDPC packets is because it has H/W issues with LDPC. Intel claims it is fixed in next H/W AC7265.

In station Mode, though it connects by advertising LDPC support, there is a lot of packet loss, so disable LDPC to get it working.


Could not connect to cran.stat.ucla.edu:80

The repository server at http://cran.stat.ucla.edu seems to be down, You can try the repositories given at
https://cran.ma.imperial.ac.uk/bin/linux/ubuntu/README.html
Edit: You can use them by appending
deb https://cloud.r-project.org/bin/linux/ubuntu xenial-cran40/

in
sudo gedit /etc/apt/sources.list

After appending and saving, issue this command
sudo apt-get update
sudo apt-get install r-base

If you get some key error in above commands, issue
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E298A3A825C0D65DFD57CBB651716619E084DAB9

and repeat update and install commands.


During a release-upgrade is about the worst possible time to lose power. If you are new to Ubuntu, you may lack the skills to recover your system...if it's recoverable at all.
Here's a method of recovery that does not require much skill. But this method does require patience and diligence in each step.

Use a different machine to create a new Ubuntu 20.04 Desktop Installer (liveUSB).

Boot the LiveUSB. Select the "Try Ubuntu" environment. Mount your hard drive.

Back up all of your data to some other media.

When your backup is complete, clean-install Ubuntu 20.04.


What does 'pwd' mean? In context of this install script

pwd is a simple command that outputs your Present Working Directory (apparently the command stands for Print Working Directory), or whatever folder you've cded into. This is used in backticks, which instructs bash to execute pwd and then pass it as an argument to ./install_***.sh. All it's doing is simply telling the installation script where you are on your hard drive. If you were in the folder, for example, /home/billy/Documents when you executed the script, this would be the exact same as executing
./install_***.sh /home/billy/Documents
It's not a placeholder put in by the documentation or anything, it's an actual command.
Update
As mentions in comments by @ThomasWard, backticks are, at least sort of, deprecated, and you should use "$(pwd)" instead


using mosh your connection is always alive.
Mosh takes all the security benefits of SSH and builds upon it a greater tolerance to poor network conditions and roaming connections. It also increases responsiveness and lowers bandwidth usage by only communicating state changes to the currently visible screen region, rather than transmitting complete buffers.


If you don't find the Singleton* files discussed in other answers, another source of this error is exhaustion of disk space.

Try df -h to see how much space you have left on your partitions; if any are full, free up some space and try again.


Various applications crashing with SIGSEGV, diagnosed memory issues

It is a RAM issue I have seen this a lot. You do say windows tests also fail so it is not a Ubuntu only issue. If you want it fixed replace the RAM.


There is an option that allows you to overwrite everything on one machine. When you add a new device, there should be an option on it that will overwrite all local content with the stuff that's stored on the server.

I don't think your tabs will sync. Also, it won't be an instant process. Don't expect new bookmarks to show up on another PC the instant you add them to the first one. You will get them after a while however.


Check if bluetooth is soft-blocked by the system. rfkill can help you figure it out and probably fix it too.

Open command prompt by pressing Ctrl+Alt+T.

Type rfkill and press enter, you will get output as below.

 ID TYPE      DEVICE      SOFT      HARD
 0 wlan      phy0   unblocked unblocked
 4 bluetooth hci0   unblocked unblocked

Now, if you see locked in the SOFT coloumn, you need to run the command to unblock it.
Type rfkill unblock all in the commant prompt.
If the bluetooth device is hard blocked, you either need to switch it on from the BIOS or need to check your device for damage.


By default, the left ALT key drags and moves windows. How can I get rid of that?

You can change it from Alt to Super and vice-versa. Go to System ➜ Preferences ➜ Windows and in the Windows Preferences Choose which "Movement Key" you wish to use.

A screenshot to illustrate is placed here:

Additionally, if you are using compiz, you can change which key bindings you wish to use in order to "Initiate Window Move" when the "Enable Move Window" plugin is in use.

Here is a screenshot to illustrate what I say in the above words:


Upgrade/change flavor for my old laptop?

I agree. Your laptop is not that old. Mine is older. You can easily upgrade it to the newest version and it will support everything mentioned.

I described the upgrade process from 17.04 here:
Can't update anything nor download updates from server [17.04]

Personally, I prefer to upgrade in steps. Not 4 years at once. If you do too, given currently available releases, you will have to upgrade to 16.04 next. From there you could either go 17.10 or directly to 18.04. Again, you'll find the step by step in the mentioned link.

Once upgraded you can take additional steps to get the apps you want and get everything running. I suggest looking into that at this later point. One step at a time.

But for example, you should be able to easily install wine, gimp and inkscape using

sudo apt-get install wine gimp inkscape

I'm not a gamer, but I did install Steam on 3 Ubuntu devices. It has been a while back though. So, I don't remember the process. But shouldn't be too hard.

One step at a time. Start with the upgrades first, then go from there.

One more thing: if you choose to install a new version instead of upgrading, I too would suggest some alternative option, not the mainstream Unity version. Personally I favor Mate. It might not be the lightest, but it is lightweight. But the reason I like it is, it is quite stable and reliable. For example, with Unity I missed my mouse cursor on some device. While Mate worked without trouble out of the box. XFCE for example too is very light on load. However, although it seems to offer more configuration options, my experience is, it's less stable than Mate. I'm sure I tried LXDE, but I don't remember why I went with Mate instead. This is my personal opinion, but it seems, the Mate version is less troublesome these days? I see a lot of questions by Lubuntu users.


Do I need to umount USB drive before unplugging it when using udev?

Seeing as no-one has said I don't need to manually unmount the USB external drive before unplugging it, I'm going to assume I should.

I've got the udev rules working now so it automatically mounts & unmounts the file system when plugged or unplugged. There are no error msgs given or shown anywhere in /var/log that I can find, when I manually unmount the file system and the udev rules also try to unmount it when it is unplugged.


Ubuntu 14.04 login loop after apt-get upgrade

Lets you edit /home/username/.Xauthority ?

or install Lightdm for now:

sudo apt-get install lightdm

After installing lightdm enter the following commands to set lightdm as the default display manager:

sudo dpkg-reconfigure lightdm

Accept and follow instructions.

Reboot


(wired) network down after a while with 16.04

You can write simple shell script to round this problem (bug,etc ) that it will be like this :

/bin/bash
ping google.com
if [ $?=0 ]
then
else
systemctl restart NetworkManager #or ifup eth0
fi
And put this script on crontab.


How much hard drive space should I allocate to Ubuntu for a 1tb hard drive?

If you are a fan of linux/ubuntu and you plan to stay on it for life - that means that you will not need to install other OS (operating system), you will play games only in ubuntu / wine - then use whole space for it.

You can always add another (smaller) HDD if you would need to install another OS, or you can install another OS into VirtualBox.

On the other hand if you will need some other OS for example Windows because of gaming, or use some specific graphic programs that do not run on Ubuntu then I would leave some space free (windows installation = at least 30gb, games = additional 50-70gb just to be sure). You can always mount this NTFS space into linux to have it visible in Ubuntu too.


Chrome or Firefox render pdf's much better than Evince's

The image from Chrome appears to have subpixel rendering enabled, while the one from Evince does not.

Some people do not like subpixel rendering because it addes red and blue edges to either side of glyphs.

Subpixel rendering is less beneficial on higher resolution displays.

While you can "enable" subpixel rendering system-wide, it's really only a suggestion. It's ultimately up to each application or library to implement subpixel rendering or not. In this case, it appears the Poppler library does not currently support subpixel rendering.
There are a couple related issues in Poppler's git repository that have been open for years. I wouldn't expect any progress anytime soon.

[patch] add support for subpixel rendering support for cairo backend (4 years)
subpixel-hinted rendering of text with poppler (15 years)


Windows 8 will not overwrite your boot partition (/media/sdb8) if you you specifically tell Windows not to do so during the installation process (hard disk setup where you select which partition to install C: drive on...). But Windows 8 will overwrite your MBR, as far as I know. So, once Windows 8 is installed, you will not be able to boot into Ubuntu; even though you will still be able to boot into Windows 7.

To fix this problem, you will need the same version of the Ubuntu LiveCD from which you had installed Ubuntu. Using the LiveCD, you can fix the MBR to show a boot screen to select Windows 8, 7 and Ubuntu. The detailed instructions can be found here: https://help.ubuntu.com/community/Grub2#Copy_LiveCD_Files.

I am listing them here for convenience.

Boot the LiveCD Desktop.
Open a terminal by selecting Applications, Accessories, Terminal from the menu bar.
Determine the partition with the Ubuntu installation. The fdisk option "-l" is a lowercase "L". sudo fdisk -l or sudo blkid. The device/drive is designated by sdX, with X being the device designation. sda is the first device, sdb is the second, etc. For most users the MBR will be installed to sda, the first drive on their system. The partition is designated by the Y. The first partition is 1, the second is 2. Note the devices and partitions are counted differently. Example: the MBR may be installed on /dev/sdb and the Ubuntu partition may be on /dev/sdb3.
Mount the partition containing the Ubuntu installation: sudo mount /dev/sdXY /mnt. Example: sudo mount /dev/sdb3 /mnt. Note: If the user has a separate /boot partition, this must be mounted to /mnt/boot. Since you have a separate boot partition (which contains grub - /media/sdb8 - you will need to run the following command as well: sudo mount /dev/sdb8 /mnt/boot. Note: If the user has a separate /home partition, this must be mounted to /mnt/home. Encrypted home partitions should work.
Run the grub-install command as described below. This will reinstall the GRUB 2 files on the mounted partition to the proper location and to the MBR of the designated device. If you are using 10.04 or 10.10, then run sudo grub-install --root-directory=/mnt /dev/sdX. Example: sudo grub-install --root-directory=/mnt /dev/sdb. If you are using 11.04 or 11.10, then run sudo grub-install --boot-directory=/mnt/boot /dev/sdX. Example: sudo grub-install --boot-directory=/mnt/boot/ /dev/sdb.
Reboot into the Ubuntu installation on your hard disk.
Refresh the GRUB 2 menu by typing the following command in your terminal: sudo update-grub.

NOTE: As answered by Steve, "Windows 8 uses the new Protogon file system". Grub does not have support for this file system (yet!). Once this support comes, you can use Grub to boot into the Windows 8 bootloader. Until that time, as suggested by jart, use a separate hard disk to hold the Windows 8 partition and it's bootloader. This way, even the Ubuntu hard disk MBR will not get over-written. Unplug the Ubuntu hard disk when you are installing to the Windows 8 hard disk. Once the installation is complete, plug the Ubuntu hard disk back in, boot into the Ubuntu hard disk (by setting it in the BIOS boot sequence) and follow the steps which I have outlined above.


how to convert 1280x720 jpg files to 640x240 ppm files using ImageMagick convert command?

The command you need is:
convert -resize 640x360\! -crop 640x240+0+60 filename.jpg filename_crop.ppm

The \! in -resize is used to resize to the specified size without keeping the aspect ratio of the image. If we don't add that, the image will resized to best fit the given size.

In the crop command, 640x240 (width*height) specify the cropped image's dimensions, while +0+60 (+left_offset+top_offset) specify the offset from the top left of the initial image. In this case, it crops the image with an offset of 60 pixels from the top.


After suspend, steam client freezes on startup but works again after a reboot

I could solve it by installing the 32-bit version of libnss3:

sudo apt-get install libnss3:i386

That addresses the following error in ~/.steam/error.log:

[0102/162746:ERROR:nss_util.cc(1018)] Failed to load NSS libraries.

(I'm still not sure why the problem does not occur after a reboot.)


Flash in browsers does not play sound accurately using Pulse network audio

Preface

I was able to replicate Dave's issue in experiments, and they lead me to believe that Flash is somehow sending the sound to PulseAudio in such a way that it creates a lot of network traffic (think lots of tiny packets, not bandwidth); this overwhelms the network "tunnel" PulseAudio has created, i.e. you have

Youtube => [PA-client => network => PA-server] => speakers

I could solve the issue by putting both the client and server on their own virtual network, giving them effectively infinitely fast connectivity (10 Gbits/sec) between them; obviously, that doesn't work for real-world networks :)

So, a bit of googling and this post and this one gave me the idea of dropping the tunnel (middleman, as Dave aptly put it), and having the client talk directly to the server, i.e.

Youtube => network => PA-server => speakers

And that worked for me; Flash videos/sound play flawlessly.

Let's try it!

This assumes your client-server are on a local network (router, etc.)

Preliminary: On the client machine, if you have an existing setup, open paprefs and uncheck everything; then kill PulseAudio to be sure.
On the server machine (i.e., the one with the speakers), start PA Preferences (paprefs) and set it up as follows:

Then close it, and kill PulseAudio in a terminal as shown, wait, and check that it is now listening on port 4713:

If you don't see it, open paprefs again and check the remaining boxes in the Network Access and Network Server tabs (they don't hurt)
Make sure you know the server's IP address - use ifconfig, etc. We'll use 192.168.0.4 in our example.

On the client machine, open a terminal, and test our direct connection first, with a speech sample WAV (replace 192.168... with your server IP!)

wget http://www.signalogic.com/melp/EngSamples/Orig/female.wav
paplay --server=192.168.0.4:4713 female.wav

Abort with Ctrl-C if it works, it can get boring ;)

Now, close all running browser instances, and then start it (assuming Firefox here with the following syntax):

PULSE_SERVER=192.168.0.4:4713 firefox &

Replace 192... with the appropriate IP for your server!
In that Firefox instance, open up Youtube (or whichever Flash video site), and try playing videos back --- fingers crossed, it should work without stuttering/pausing!

Make it stick

If you want to make this fix apply to all programs instead of having to put PULSE_SERVER=192.168.0.4:4713 in front of every command, edit /etc/environment on the client and add PULSE_SERVER=192.168.0.4:4713 on a new line at the end of the file. Also add a line break at the end.

This will make all sound on the client go to the Pulseaudio server, so be sure that's what you want before making this edit to your /etc/environment file.

Reboot, and enjoy a smooooooth audio experience. ;)


Right-click on any pdf and choose to open with Foxit. Foxit should open with the pdf displayed. Then in Foxit's menu bar choose Edit/Preferences/General. Uncheck the box that says "Show Start Page". Foxit should now open without the error.


Accidentally created additional folder while trying to extend swap memory in Ubuntu 18.04 LTS

You can try to put the name of the file in single quotes:

rm 'swa[fo'

or escape the square bracket

rm swa\[fo

P.S. And IMHO this is a file, not a directory. You can check with above command using ls -l instead of rm. If it is really directory use rm -r instead of rm


Ubuntu doesn't boot after upgrading to 14.04

If it's a grub problem, use boot-repair.  It works almost every time, and is a one click fix: http://www.howtogeek.com/114884/how-to-repair-grub2-when-ubuntu-wont-boot/


The problem is in your while loop conditions. This line:

while [[ $menu_choice -ne 3 && $quit_program != "y" ]]

is saying "while menu_choice isn't 3 and quit_program isn't y, keep looping." The problem is that, if either of those conditions is no longer true, the while loop will end.

What you want is this:

while [[ $menu_choice -ne 3 || $quit_program != "y" ]]

using || instead of &&. This way, the while loop will continue to loop as long as either condition is true, instead of both.


Ubuntu 15.04: eth0 is no longer working after last software upgrade

After some research, I've found the root cause.

As reported here: https://bugs.archlinux.org/task/44315, the issue is due to the combination of the new linux kernel version with the Qualcomm ethernet driver

The following combination IS NOT WORKING

Linux kernel 3.19.0-18 (Ubuntu 15.04)
Ethernet driver alx 0000:04:00.0 eth0: Qualcomm Atheros AR816x/AR817x Ethernet

In the above post it has been suggested to either

Downgrade the Linux kernel to 3.18.6 or
Configure the eth0 interface with the MTU = 900

Before downgrading the Linux kernel, I've tried to enforce the MTU configuration on the eth0 interface but unfortunately it worked only for a little while and then it stopped working again.
According to other users comments, this work-around should have fixed the issue but unfortunately not for me.

Finally I decided to downgrade the Linux kernel to 3.18.6-031806-generic and my wired interface is working fine again.


Which is the best version of Ubuntu for Aspire 4736z?

You can try to switch to Unity 2D, which is less dependent on the graphics card. You switch to it by clicking on the button next to the password field when logging in. It's called Ubuntu 2D.


How can I remove desktop environments on 18.04

Try this, it worked for me:

apt remove --purge ubuntu-desktop

To remove the old desktop that are interfering with
each other:

When you're in the folder /usr/share/session
do:

rm -rf ubuntu-c* ubuntu.d* xfce*

Only mate.desktop will be left alone

ls -al /usr/share/session

Now you just have to reboot and it will be fine.
Tested a few minutes ago on Ubuntu 18.04.3


Nvidia Drivers, Ubuntu 12.10, GeForce GT 540m

Since I found the answer, this is me posting it. The fix here is bumblebee. Nvidia cards that use Optimus, such as the 540m, need to be able to utilize Optimus in order to function properly. Well, not really; but without Optimus the computer can't differentiate between the two cards. Bumblebee allows support for Optimus on Linux systems. Install it, and the problem will cease to exist.


stop your server and delete file /var/lib/dhcpd/dhcpd.leases


Developing for Ubuntu comprises a number of sections which it's important to think about as separate but associated elements:

Project Creation

When starting off a brand new project there will always be a set of best practices to follow and easiest routes to take. These are codified in the quickly project which provides a set of instant use templates for various languages and coding problems. Right now I believe templates exist for python, vala and pygame.

Project Management

Ubuntu platform uses the launchpad service in order to provide a place online where code can be shared, bugs can be tracked and other project management tasks can easily be performed. This service is where translations are done, teams are set up and even support questions are asked.

You can integrate project management into your desktop work flow using a range of tools. From the fancy GUI GroundControl to command line tools for tracking bugs and running reports.

Code Management

The source contents of a project in Ubuntu are normally stored in a bazaar branch. These branches are generally files with your project in launchpad, but they don't have to be. There are some pretty extensive tools on the Ubuntu platform for dealing with code branches, everything from the bzr command itself to bzr-gtk and the aforementioned GroundControl.

Publishing

This is the last step in the process and it allows you to get your app to more users, for testing and for true distribution. First it's a matter of creating viable deb packages, there are various guides on how to make Debian packages; but the aforementioned quickly creates the standard templates for you to work from.

The launchpad ppa system was developed to allow quick distribution channels without too much checking or verification. Your Debian packages can be submitted to launchpad under any person or group that you have ownership or membership in.

However the best route to take is to take your packages to the Debian project where they will be submitted for review and if they pass can be uploaded directly into the Debian repository and available in the next version of Ubuntu. There are a host of tools for helping with this process, but it's not yet as easy as the other steps mentioned above.


How can I get the specific colors that are being used in my vim ruby plugin / theme?

If you have a GUI, you could use gpick:

 sudo apt-get install gpick

The colors themselves are reliant on what terminal you use. They are all the named colors, i.e. orange, blue, etc. The specific hex codes for these are very reliant on how your terminal interprets them (at least from my experience). The different color themes are stored here:

 /usr/share/vim/vim73/colors


How to enlarge encrypted swap partition?

Because the partitions are encrypted, it's not possible to resize them using the normal tools such as parted/gparted.  This is because the actual partition on disk is not a valid file system, but just an encrypted block, which appears like a string of seemingly random data.

You can delete them and totally recreate them.  If you only need to resize your swap, and to do this you don't need to resize any other (encrypted) partition, then trashing and re-installing it is going to be easy.  But I assume that's not the case, as not many people will just leave unallocated space on the drive should they want to increase the swap partition (unless you're able to expand it into your un-encrypted root partition?).  Otherwise you may be able to recreate your swap and home partitions, and copy across your files from an external drive.  You will probably need to be familiar with cryptsetup and the way luks works.  Otherwise a clean install is in order.

A common configuration with LUKS is to use LVM on top of it, which gives you a much easier way of resizing partitions inside your encrypted block - because LUKS means you have multiple partitions inside the same block, you don't need to resize the container to resize the partitions inside.  If you are going to resort to a clean install, the alternate installer CD makes setting up a LUKS partition with LVM on top of it easy.

Most online tutorials you'll find about resizing a LUKS partition are actually about resizing LVM volumnes inside of one instead.


Is there a default folder for sharing files with other users?

Generally, the folder that is predefined for that use would be your public folder. It is sometimes, on some distros, even set up to be available via network request and is usually pretty unprotected permission wise unless you have encrypted your home folder if you want my personal advice, I would either create a new folder in / (root) or a new partition with gparted or another partition editor for that kind of use.


How do I run xkbcom on Ubuntu GNOME startup?

Open your text editor of choice and paste this into it

[Desktop Entry]
Name=Keyboard
GenericName=A descriptive name here
Comment=Some description about your script
Exec=xkbcomp ~/.keyboard-map $DISPLAY
Terminal=false
Type=Application
X-GNOME-Autostart-enabled=true

Save this as keyboard.desktop into  ~/.config/autostart and make it executable

sudo chmod +X ~/.config/autostart/keyboard.desktop

Reboot and it will start at boot.


Changed all bios boot settings to legacy only.
Finally the lsi boot info showed up.
Cntl+H for webbios.
Spammed del to get to setup.
Override boot for raid cd.
Repaired.
Changed all the boot settings back to good config that will boot 20.04 again.
Hopefully remember what I did when the new drives shows up to replace the failing one.


Do USBs with hybrid images content require boot flag?

The hybrid ISO images are intended to be written directly to the storage device, rather than a partition on the storage device (i.e. so you'd write it to /dev/sdb instead of /dev/sdb1, for example).  The image itself contains a partition table, so you shouldn't need to adjust things after writing.


How to install PPAs and Proprietary Drivers on a persistent LiveUSB

The easiest way is to mount the filesystem.squashfs, copy everything out into a temp directory, chroot into that directory, add all of your new entries/download all new packages, and recreate the squashfs. The commands to do so would be as follows:

mkdir /mnt/temp; mount -o loop /path/to/ISO /mnt/temp
mkdir /mnt/temp2; mount -o loop /mnt/temp/casper/filesystem.squashfs /mnt/temp2
mkdir /tmp/toEdit; rsync -avhP /mnt/temp2/* /tmp/toEdit
mount --bind /dev /tmp/toEdit/dev
mount --bind /dev/pts /tmp/toEdit/dev/pts
mount --bind /sys /tmp/toEdit/sys
mount --bind /proc /tmp/toEdit/proc
cp /etc/resolv.conf /tmp/toEdit/etc/
chroot /tmp/toEdit

From here just edit like you would a normal system, then when you exit make a new squashfs and proceed like normal.

I WOULD NOT RECOMMEND a full install on the usb, if you plan on using the usb for longer than a year or two. That will eat your read/write cycles up in no time and bring the lifetime of the usb to about 1/10 of what it should be. Aside from that, don't forget to make your secondary casper-rw partition and put persistent as a kernel argument. Good Luck!


Ensure that any files/folders in your user's home directory have correct permissions...

sudo chown -R user:user /home/user

That fixed it for me...

OR

Remove the ~/.Xauthority -> https://askubuntu.com/a/289735/168033


Icons for source code files are not proper in Ubuntu file manager

Go to Nautilus (the File manager), Edit > Preferences > Preview tab and set Show thumbnails to never. But it will disable preview for images and videos too.

Since Ubuntu 14.04, the Nautilus version does not allow to disable preview for text files only.


Why does my name show as [Invalid UTF-8]?

try to update the UID_MIN in /etc/login.defs

UID_MIN                  500

See also here: https://bugs.launchpad.net/ubuntu/+source/indicator-session/+bug/834137/comments/20


Any app/GUI to manage a Huawei USB dongle?

An excellent tool I was directed to helps in managing the Modem Manager GUI Modem Manager GUI is frontend for ModemManager daemon able to control specific modem functions. The main features listed on the project website are:

GTK3 interface
Send and receive SMS messages with messages concatenation
Send USSD request and receive answer in system encoding
Get modem and SIM information (Device info, Operator name, Mode, IMEI, IMSI/ESN, Signal level)
Scan available mobile networks
Control data transmission process and set session traffic and time limits

USSD requests works perfectly. Can send and receive SMS but it seems the messages don't get saved on the sim but only displays via Notify-OSD

Finally as noted already in this question, the call function doesn't work with this tool. To get this function working again, wammu and gammu packages from this PPA should be added by running the following commands:

sudo add-apt-repository ppa:nijel/ppa
sudo apt-get update
sudo apt-get install wammu gammu

NOTE: Not all dongles are supported. Here is a list of all the Huawei dongles supported along with the supported feature


Wine nor winetricks show up on applications menu

Wine is used to launch EXEs, so it has no point being in the menu.  When running EXEs, Wine will open them.  As far as Winetricks, just run 'winetricks' in the terminal.


Use Remmina to RDP into home Remote Desktop Gateway Server

I run the following script to log in to a remote server through RD-gateway, current freerdp git-master works rather well.

#!/bin/bash
# Get the password once since the same password are used for RD-gateway and remote server
PW=$(zenity --password)

# RDP to remote server remote1.server.com through RD-gateway rdg.server.com
xfreerdp /g:rdg.server.com /gu:mysuername /gd:MYDOMAIN /gp:$PW /v:remote1.server.com +compression /u:myusername /p:$PW /d:MYDOMAIN +clipboard /size:1548x846 /network:broadband /bpp:32 /cert-ignore

Information on compiling FreeRDP can be found here:
https://github.com/FreeRDP/FreeRDP/wiki/Compilation


Can't run PHP script accessing my Mysql databse

Syntax problems on line 8:

die("Couldn't connect to the database: <br />", mysql_error());

. is used as concatenation, not ,

Same problem on line 15 and 30.

Also, turn on error reporting. To do so:

ini_set('display_errors',1);
ini_set('display_startup_errors',1);
error_reporting(-1);

This will turn on all errors.


Remmina connection issue to Windows Server 2012R2 after Windows Update

The issue is the certificate was changed on the server as a result of the update, but Remmina did not prompt to update the certificate. Navigate to the .freerdp folder and edit known_hosts file. The entry for the target machine needs to be removed. Upon the next connection attempt you will be prompted to accept the new certificate and will be able to connect to the server after accepting the certificate.


It seems that "traditional apps" do not work with the virtual keyboard. That is stated at the very end of  the aquarius m10 user manual. The same goes for libreoffice, firefox, ....


How to produce a MSWord like document on Ubuntu 11.10?

Unless some other person needs to edit the document, create a PDF version and print that. In LibreOffice Writer: File / Export as PDF ... / Export.


Open with "Wine Internet Explorer" option left in Shutter after removing Wine

Manually edit .local/share/applications/mimeapps.list and remove any lines with wine.  I noticed that installing a package may add lines to the file, but uninstalling it will not update this file. It would be too risky, I guess.

Also, cd to ~/.local/share/mime, and remove all occurrences of wine: find and delete lots of files called x-wine..., and remove lines from types that contain wine.
Then, run update-mime-database ~/.local/share/mime.


No wired connection from router when waking up from suspend/reboot/reconnect

I checked my /etc/network/interfaces and it was like this (I never changed anything before):

auto lo
iface lo inet loopback

So I modified it:

auto lo eth0
iface lo inet loopback
iface eth0 inet dhcp

And now it automatically connects when I reboot or plug the ethernet cable. Not sure why was this the solution because I never touched interfaces file.


Unable to use ubuntu in dual boot with windows 7

If you have installed windows as well as ubuntu on your system and only ubuntu is booting at start up, than follow below steps.
1. Create a live USB/bootable UBS of Ubuntu and run it on live mode.
2. Now, install Boot-Repair.
3. after successful operation of boot-repair, restart your system. It will shows option to boot windows as well as ubuntu operating system.


What do I do after backing up my data (with Deja Dup)?

Can I store the files on an USB or optical disk and then simply reinstall my system..?

Yes. Things to consider: Duplicity will not overwrite an existing file. Encryption.

Command line restore according to the man page:

duplicity [restore] [options] [--file-to-restore <relpath>]
[--time time] source_url target_directory

Example (adding encryption; skip that if you did not use it):

export PASSPHRASE=SomeLongGeneratedHardToCrackKey
duplicity restore {--no-encryption} --file-to-restore single.txt "file:///media/{mountpoint}/" "/home/{username}/"
unset PASSPHRASE

where {no-encryption} if no encryption, single.txt can be wildcards, {mountpoint} points to your external disk, and {username} your user name.

Mind that you will need the passphrase if you used encryption and can not retrieve it if you forget it. Besides that: always test if you can restore it BEFORE deleting you current OS. It might even be worth it extracting the last backup onto the external media and use that to restore your personal files (that way you know you have the files that you want).


How do I add minimize / maximize buttons to GNOME shell windows?

You need gnome tweak tool.

Click the Download button to install with Ubuntu Software Center:

Or you can install in Terminal:

sudo apt-get update; sudo apt-get install gnome-tweak-tool

Then open Advanced Settings to change the minimize and maximize buttons.


Kernel driver for your touchpad supports these kind of gestures. You do not need to install any drivers.

You can disable 2-finger tap by

synclient TapButton2=0

in terminal.

To make this setting permanent you can add this command as automatically started application.

As far as I know, unity (Ubuntu desktop Environment) does not support other gestures. Correct me, if I am wrong.


Just create opt folder and install in it

 sudo mkdir /opt

and then

 sudo tar xvfz xampp-linux-1.8.0.tar.gz -C /opt

opt

It holds optional software and packages that you install that are not required for the system to run.

Opt is reserved for additional software you install; although, most providers don’t use it. This is kind of like ‘Program Files‘ for linux.

Sources

https://stackoverflow.com/questions/12649355/what-does-opt-mean-as-in-the-opt-directory-is-it-an-abbreviation

http://www.linuxtopia.org/online_books/linux_beginner_books/linux_filesystem/opt.html

http://www.nixtutor.com/linux/understanding-the-linux-directory-layout/


First install on a laptop without internet access

I'm assuming you have the Asus X205TA or F205TA. It's essential to install with internet access and use 16.04 or later, 64-bit. GRUB will most likely install correctly if you do that - you do not need to follow that old guide. Please be aware there are still no audio drivers for this device.

To answer your question directly:

To get online, you can tether to a phone (for example Android) or tablet that has that feature and is connected to wifi. This works reliably.  Or, you can use a USB wifi adapter, but there is no guarantee that a particular model will work...

You must have an internet connection for any of the following to work.

Try the installation again. ("Erase the disk and install Ubuntu") For me GRUB installed perfectly both times I tried it with 16.04 with no special intervention.

For thorough installation guides for this device, see How to install (L)Ubuntu 16.04 on the ASUS X205TA (F205TA)


How do I copy to DVD my VirtualBox Windows data?

Seems that your virtual guest not detecting your host CD drive.  So, first make sure you have installed guest addition. Then choose your host drive going to Settings --> Storage and then choose your host cd driver:

Or You can mount ubuntu on windows and move all windows file to Ubuntu and then burn or something. check this answer Auto-mount shared folders using Virtualbox Manager


Can't format hard drive back to Windows 7 after fully installing Ubuntu

I'm pretty sure Windows installer has an option to delete partitions/use entire disk/something similar, though the last time I used it it was WinXP, not Win7.

At any rate, it's not a problem for Ubuntu to be concerned with, it's a problem/defect of the Windows installer :)

However, if you boot from Ubuntu live CD, you should be able to delete the Ubuntu partition and you also may be able to create a new partition and assign it NTFS partition ID.

Just to clarify: partitions have an "ID" attribute, so if you created a partition for Ubuntu, it's ID will be 83, which is "Linux". You can not just format this partition to NTFS - you need to delete it and create a new one with different ID.

Obviously, all data will be lost, so make a backup.


In my case this was related to clang-10. I would recommend to uninstall it and remove it's ppa as it is now provided by default then run something similar to the following:
sudo apt install clang-10/focal libstdc++-9-dev/focal libgcc-9-dev/focal libobjc-9-dev/focal libclang-common-10-dev/focal libclang1-10/focal llvm-10-dev/focal libomp-10-dev/focal gcc-9-base/focal libasan5/focal gcc-9-base/focal chrome-gnome-shell/focal cpp/focal  cpp-9/focal debhelper/focal dh-autoreconf/focal gdm3/focal gnome-control-center/focal gnome-initial-setup/focal gnome-settings-daemon/focal gnome-shell/focal gnome-shell-extension-appindicator/focal gnome-shell-extension-desktop-icons/focal gnome-shell-extension-prefs/focal gnome-shell-extension-ubuntu-dock/focal gnome-tweak-tool/focal gnome-tweaks/focal libtool/focal ubuntu-desktop/focal ubuntu-desktop-minimal/focal ubuntu-session/focal x11-xserver-utils/focal xorg/focal

Basically telling the package manager that yes, you really do want all the focal versions for all these things. I think someone has borked the versioning on these as I get a few downgrade warnings.
If you don't want clang-10 you could try:
sudo apt install libstdc++-9-dev/focal libgcc-9-dev/focal libobjc-9-dev/focal libclang-common-10-dev/focal libomp-10-dev/focal gcc-9-base/focal libasan5/focal gcc-9-base/focal chrome-gnome-shell/focal cpp/focal  cpp-9/focal debhelper/focal dh-autoreconf/focal gdm3/focal gnome-control-center/focal gnome-initial-setup/focal gnome-settings-daemon/focal gnome-shell/focal gnome-shell-extension-appindicator/focal gnome-shell-extension-desktop-icons/focal gnome-shell-extension-prefs/focal gnome-shell-extension-ubuntu-dock/focal gnome-tweak-tool/focal gnome-tweaks/focal libtool/focal ubuntu-desktop/focal ubuntu-desktop-minimal/focal ubuntu-session/focal x11-xserver-utils/focal xorg/focal

But I have not tested the above.
You may need to add additional packages to this line to get it to work, in any case just add the package it's complaining about and /focal to the above line.
Make sure to read the output to make sure apt hasn't decided it needs to remove a bunch of system files. That is why there are so many packages in my example.


The apache2 processes are probably threads of the main process, and the 7MB is shared across all those processes. Multiple dbus processes in the list are common, yes. They're not using as much memory as you think they are.


How to keep last login shell as current shell in next login?

You can have a command in your .bash_logout and .zlogout files to change the current login shell to the one you're using.

The command could be

chsh -s "$(which "$(ps -p $$ -ocomm=)")" $USER

Since, .bash_logout and .zlogout is supposed to be sourced before exiting shell, this should change the login shell to the currently running shell. However, you'll need to give password to change the shell before exiting.

I used the information from this question from SO and tested with zsh and bash.


How to differentiate between identical printer drivers in settings list?

There are just two actual files in /usr/share/ppd/HP

hp-laserjet_pro_m501dn-ps.ppd.gz
hp-laserjet_pro_m501n-ps.ppd.gz

So this is a bug of the driver selection dialog.


How do I switch between Ubuntu and Vista and how do I delete Ubuntu?

Once you install Ubuntu alongside Windows, when you restart you'll see a screen that offers you a choice to boot into Ubuntu or Windows.  That screen is the interface for the Linux bootloader known as Grub, which will be installed by default when you install Ubuntu.

Removal of Ubuntu, as czifro mentioned above, would be a simple matter of deleting or formatting the partition which contains it.


Ubuntu 14.04 wants to update same package every day

Try with the below to disbale the automatic update by adding the below in /etc/apt/apt.conf.d/10periodic,

sudo -e /etc/apt/apt.conf.d/10periodic

APT::Periodic::Unattended-Upgrade "0";

Hope this helps.


Seeking a Hand-Written Note-Taking App that Snycs Between PC and Ptablet

Evernote is the only thing that I found that works for this.  Even though it lacks some features of Xournal, it's the only one that works.


I have been able to answer this question by using ssh.

As I can see the transfer rate of one transfer with pv source > /dev/null, I set up multiple ssh sessions and executed one transfer per session


Using sed to edit any one of the occurrence of a matching pattern

Although you've mentioned sed, these are sort of awk-y tasks:

awk -v pat="Fred Flintstone" '$0 ~ pat {count++;\
               if (count == 2) { $0 = $0" someString" ;} ;}; 1' file.txt

-v pat="Fred Flintstone" saves the Regex pattern to match as variable pat to be used inside awk expressions
$0 ~ pat checks the record against pat for a match; if matched, the count variable is increased by 1 and if count is 2 the record is reset as having the current content plus someString ({count++; if (count == 2) { $0 = $0" someString" ;} ;})
1 is an idiom; as it is truthy, all the records would be printed

Example:

% cat file.txt
Fred Flintstone
Johnson Stone
Fred Flintstone
Fred Flintstone
Michael Clark

% awk -v pat="Fred Flintstone" '$0 ~ pat {count++; if (count == 2) { $0 = $0" someString" ;} ;}; 1' file.txt
Fred Flintstone
Johnson Stone
Fred Flintstone someString
Fred Flintstone
Michael Clark


PPA and direct installs won't work...bad file

To solve the error messages, in the terminal, type:

sudo mv /etc/apt/apt.conf.d/20auto-upgrades.ucf-dist ~/Documents

this will move the offending file to your Documents folder. The file was originally created during a "unattended-upgrades" Software Update. If needed in the future, it will be recreated as "20auto-upgrades", without user action.


Trying to run a Program called worldforge but it comes up with an error

It's not trivial to get the librtmp0 package in Xenial, so my first idea is to use librtmp.so.1 from the librtmp1 package instead since there's a good chance that the library is backwards-compatible.

To achieve that we need to create a symbolic link to it in a location where the program executable can find it. Since this is kind of a hack, it would be preferable if other applications don't find the same link automatically. Helpfully, this application adds ~/.ember/lib to its library search path by default.

I suggest that you

assure that the librtmp1 package is installed,

sudo apt install librtmp1

create the directory ~/.ember/lib,

mkdir -p ~/.ember/lib

put the symbolic link there.

ln -sT /usr/lib/$(uname -m)-linux-gnu/librtmp.so.1 ~/.ember/lib/librtmp.so.0

If the application now fails with a "missing symbol" error message (or something like that) please update your question with the error message and notify me with a comment so I can address it.

If there are more missing shared libraries you can search for their packages and

install them if they're available in Xenial or
search for newer version of the same shared library (without the version number at the end of the package name) repeat the above process for it.


Unable to use USB port to program radio in Chirp

You need to add your user to the "dialout" group. Open a terminal an do:

sudo usermod -aG dialout username

Replace "username" with your Ubuntu user.

Source: Running CHIRP under Linux


Ubuntu Mate 19.10 - check compatibility before install

Is there any option to check before install if this OS will solve my problems?

You do not even explain what those issues are so how can we answer that? Please create a question with a problem so someone can try to explain a fix for it if there is an intention to find a fix.

You can install drivers and software during the live USB session and have a look how that operates. But the live USB sessions are slow so the answer is probably no. Not with results you'd expect from a normal installation.

  Can LiveUSB operate this GPU and allows to do some fps test?

Yes, but Ubuntu is not a gaming platform so if that is your target forget about it. We use OpenGL and most games do not. You can install any software during the live session and run it. During a live session install one of the drivers and then do ...

$ sudo apt install mesa-utils
$ glxgears

Or use the Phoronix test set:

$ sudo apt install gdebi-core
$ sudo gdebi phoronix-test-suite_*.deb
$ phoronix-test-suite run unigine-heaven

It will require an internet connection during the live session. And again ... the USB live session is slow so will also show low numbers.

It is better to do this with a normal installation.


How can I tell if I am using the gstreamer codecs?

VLC and MPlayer both use FFmpeg (+ some other) codecs to play media, but not the gstreamer ones (like fluendo-mp3). It is my understanding that this can't be changed by arguments or configuration, as it has not been implemented.

To be sure that you're using, say, fluendo mp3 decoder (flump3dec), use a command line similar to this:

gst-launch-0.10 filesrc location=file.mp3 ! flump3dec ! audioconvert ! pulsesink

Other software may provide a way to inspect which gstreamer elements it is using for media operations.

(To add to the confusion, it is also possible to use FFmpeg through gstreamer, but it is not what you want.)


What time will Ubuntu 16.04 LTS be available for upgrade in Ireland from Ubuntu 14.04 LTS?

It's probably just a matter of time....if you can't wait try this:

In Software & Updates choose Download from: "Main server"

Then open the terminal and run

sudo apt update
sudo update-manager -d

EDIT: also check this tab (in Software & Update)


Trouble installing Ubuntu 15.04 on a virtual machine

The warning you see on booting Ubuntu in a Virtual Machine is just to tell you, that in this virtualized environment there is no System Management Bus. This of course is expected, as we do not install on bare metal. We can safely ignore this warning.

After installing Ubuntu from the .ISO file we have to remove this virtual CD-ROM from the virtual machine to be able to boot from the virtual hard drive (.VDI) we had created. Otherwise it will just boot again from the CD image which will offer you to re-install (see e.g. my answer here).


Wild card expansion that works on command line but not in a bash script

If you are using the default Ubuntu ~/.bashrc file, then extended globbing is enabled by default1 for interactive shells - which is why it works on the command line.

Inside a script however, you will need to enable it with

shopt -s extglob

shopt is documented in man bash under the SHELL BUILTIN COMMANDS section, or via the shell's online help

help shopt

1 albeit rather opaquely, via bash completions. See for example Where is bash's “shopt extglob” turned on for my interactive shell?


Firstly when you're at the login screen open console Ctrl+Alt+F1 and run:

sudo /etc/init.d/lightdm stop
sudo dpkg-reconfigure xserver-xorg
sudo /etc/init.d/lightdm start

if it doesn't work try this:

From your tty remove the .Xauthority file and also need to remove the .xsession-errors files.

sudo rm .Xauthority
sudo rm .xsession-errors*

Check the home directory:

ls -l /home

you may have to give ownership back to your account using chown

sudo chown -R username:group /home/username


Why can I not ping outside my network with this configuration?

You are trying to send ip packages from one network to another without a router doing the routing for you:

Members of network A (10.0.10.100/24) are limited to their IP range (10.0.10.0 - 10.0.10.255) whereas your Router is located on network B (10.0.0.1/??) and therefore not in the list of peers your machine can reach.

Now you have various options:

set the network for all machines including router to 10.0.0.0/20
change the ipadress of the router to something in 10.0.10.0/24 (i.e. 10.0.10.1)
change the network configuration of all machines that are not in the same network as the router to match those settings of "router"

help on those steps is most probably enough text for a new question ;)


how can I set num lock on as the boot default in Ubuntu 20.04

Thanks to this video,
I installed numlockx
sudo apt install numlockx

then setup a startrup application with "numlockx on" as the command.


Certain Netbeans Libraries seem to be missing in Ubuntu so program don't work

None of that can be installed directly by the package manager and the absence of libraries has nothing to do with Netbeans. The error messages are from the Java compiler.

Simply add the libraries to your Java project via project properties. AWT and Swing are part of the Java JDK/JRE.

Additionally libraries, normally JAR files, you need to download at the project pages and add into your Java project, eg. org.imgscalr and JMyron.


You need to install the tablet drivers first, try searching in the Wacom site for your model and then download the linux version.

After the installation, you can open the main configuration interface and set the buttons there.


Change time format for a specific application

Theoretical part

You can change the locale or only parts of it for a specific process before you create it by changing its environment.

Check it out by launching gnome-calculator via

env LC_NUMERIC=de_DE.UTF-8 gnome-calculator

if you currently use a period as your decimal point and via

env LC_NUMERIC=en_IE.UTF-8 gnome-calculator

if you currently use a comma as you decimal point.

The gnome-calculator process will use the locale stated before its call.

Note that this doesn't persist if you close the application and open it via the Dash or just call gnome-calculator in a terminal. In fact, it is process-specific and you can use several instances of gnome-calculator, some of them using periods and some of them using commas as their decimal points. Check it out by running gnome-calculator in a different terminal. It will use your normal settings.

Finding the right locale

You don't need to find a single locale which matches your needs for everything. Instead, it's sufficient to find one that matches what you want in a specific localization category. Here, we only care about the time format which can be changed by manipulating the environment variable LC_TIME.

You're probably interested in the international time format (ISO 8601) or the time format of some country of which you know the time format. For the former, use en_DK.UTF-8. For the latter, use the 2-letters abbreviation of the language in lowercase letters, an underscore, the 2-letters abbreviation for the county in capital letters, and then .UTF-8. For example, en_IE.UTF-8 is Irish English, de_DE.UTF-8 is German German, de_CH.UTF-8 is Swiss German, and fr_CH.UTF-8 is Swiss French.

Practical part

Now that you learned a bit about how cool Linux is, let's get to the practical part.

You probably launch your application via the Dash. If you do so, you use a desktop file. Find your desktop file. It's either in /usr/share/applications or in ~/.local/share/applications. The former is system-wide, the latter is user-specific.

I'll use Firefox as the example application. It's desktop file is /usr/share/applications/firefox.desktop.

After you found the desktop file you want to manipulate, copy it to your user's desktop file folder:

cp /usr/share/applications/firefox.desktop ~/.local/share/applications

You can now manipulate the copy such that your changes only affect the user-local version.

Open it in a text editor. It doesn't matter whether you use a command line one or a graphical one. Normal Ubuntu comes with GEdit as its default graphical text editor:

gedit ~/.local/share/applications/firefox.desktop

If it doesn't work because you use a flavor of Ubuntu which doesn't come with GEdit, just use nano:

nano ~/.local/share/applications/firefox.desktop

Find the line which begins with Exec=. For Firefox, it's Exec=firefox %u. Then take whatever comes after Exec= and get it into this format with the locale you want instead of en_DK.UTF-8:

Exec=env LC_TIME=en_DK.UTF-8 firefox %u

Of course, you need to substitute en_DK.UTF-8 by whatever locale you want to use.

Save the file.

After you made your changes, you need to make the desktop file executable. The file you copied was executable but that property isn't copied, so you need to set it again for the new file. Do do so, run this command:

chmod +x ~/.local/share/applications/firefox.desktop

Now, restart your application.

Dash usually updates the desktop files automatically but on slow systems, it might take a while. Or at least it did in some version. If it doesn't work instantly, log out and back in again.


How can I decrease the mouse sensitivity in zsnes?

Go to zinput.cfg in the folder with zsnes. Find Mouse Sensitivity [1..255] and charge MouseSensitivity=1 to 2 or 3.


Failing to Start gunicorn.service using systemd

I am able to resolve this issue now. I have changed configurations in the gunicorn.service file in the below properties.

WorkingDirectory=~/Python-Projects  to /root/Python-Projects


Gallium is the default and generic driver for this video card. I had a similar issue so I had to install the privative video driver (fglrx-updates) and it solved all.


X11 forwarding MATLAB under Ubuntu 15.04 leads to issues with text visualization

Solved. It was a particular case of the following issue:
https://xpressubuntu.wordpress.com/2015/08/08/random-disappearing-letters/
which in my case only affected MATLAB over ssh. Reverting from SNA to UXA fixed the problem.


bluetooth stops working - "Failed to set power on: org.bluez.Error.Failed"

Trying to use my Logitech K380 bluetooth keyboard, I had the same issues as Soraphis. Uninstalling TLP from my system ultimately solved it for me.

Try disabling or uninstalling TLP if you have it installed.


how to install gstreamer0.10-plugins-bad? WONT INSTALL

I found a package installer for this issue:

http://www.linuxfromscratch.org/blfs/view/svn/multimedia/gst10-plugins-base.html


Error found when loading /home/[user]/.profile at boot

Your ~/.profile (or ~/.bashrc) contains a ifconfig line that appears to not work. You can find that line and comment it out like this:

# ifconfig ...


Please open a Terminal from Applications>Accessories>Terminal then copy and paste this following line

sudo dpkg --configure -a

Enter your password,wait some time and done.


How can I change the keyboard shortcuts for single line scrolling in the terminal?

According to https://help.gnome.org/users/gnome-terminal/3.8/adv-keyboard-shortcuts.html.en, there are some shortcuts that cannot be edited in gnome-terminal. These are exactly: Ctrl+Shift+↑ and Ctrl+Shift+↓:

In Xubuntu you can use Ctrl+↑ and Ctrl+↓ because Xubuntu uses xfce4-terminal which is different by gnome-terminal. The same happens with other distros.


How to install older version of GhostScript?

As an alternative solution - you could compile the older version of ghostscript.

download and extract the tar file

Download the tar file from launchpad.

setup the build environment

sudo apt-get build-dep ghostscript-x

compile and install ghostscript

cd [ghostscript folder location]
sh autogen.sh
make
sudo make install

binaries

All the binaries are installed in /usr/local/bin

Thus if you run gs -v:

  GPL Ghostscript 8.71 (2010-02-10) Copyright (C) 2010 Artifex
  Software, Inc.  All rights reserved.

If you want to run ghostscript you can reassign the current symbolic link:

sudo rm /usr/bin/ghostscript
sudo ln -s /usr/local/bin/gs /usr/bin/ghostscript


How to resolve "Failed to download repository information"?

Try cleaning up your apt-cache and running any updates
sudo apt-get clean
sudo apt-get update
sudo apt-get upgrade

If you still have issues, then change your repo mirror:
Open Update Manager or Software Updater, then click Settings > Ubuntu Software tab, then select Other from the Download From menu and click the Select Best Server button. Once finished, the best server will show up selected (highlighted), so just click the  Choose Server button. Now try updating/upgrading again.


It is. Totem does that when you're watching a video, for instance. I don't know how though.


So I added a MySql apt from the link Steps to fresh install MySql

When those are really the steps that you followed, then this is your solution.

Open a terminal and run this command if you want to remove all configurations:

sudo apt-get purge mysql-apt-config

Otherwise, this command is sufficient:

sudo apt-get remove mysql-apt-config


32 bit vs. 64 bit Ubuntu on a Samsung Netbook NC-210

You said that the system could only ever run 32bit Windows.

That likely means your processor in the system is a 32-bit processor.  The same limitations apply here.

You are limited by the architecture of the CPU in the system, which is 32-bit only.


Why are utopic packages installed by default on 14.04.2?

There are no "utopic" packages installed by default in 14.04.2. However, 14.04.2 is the hardware enablement release, which includes the kernel version which was included in Utopic (14.10), by default. This is packaged as linux-generic-lts-utopic as you see in the package name.

The packages are held back, not because the system doesn't know how to upgrade them, but because they require installing new packages (a new kernel image). You will need to use apt-get dist-upgrade to install them from the CLI.


You can create a partition table on your HDD with Gparted and restore it, however you will lose all your data on it. This can be done in the Try Ubuntu without installing option of Live Ubuntu (the ISO you wrote onto the USB or CDROM you installed from).

Find the Gparted application and launch it.
Change the dropdown to the name of your HDD (e.g: /dev/sdb). If unsure, look at the size of the disk.
Select the "Device" tab at the top, and then select "Create Partition Table". The type can be whatever you want, but msdos is recommended.
You should now see unallocated space on the device in Gparted. Now make a new partition with the filesystem NTFS (NOT EXT4!!!).
Confirm your operations, and once complete, your HDD will be in full working state!


Enabling and disabling network card through commandline

Since ifconfig has been deprecated for many years now, you should probably use the ip command :

To list the interfaces:

ip link

or with the ip addresses:

ip a

To take one down:

if=eth0
sudo ip link set $if down


Accidently deleted /usr/lib, how do I restore it?

There are tools that might help you undelete the files, but usually it's a slow and mostly manual process. Search engines are your friends.

It may be easier to boot up a live CD or USB, mount your system's root partition, then copy /usr/lib to /mnt/{root.drive}usr/lib, but you will only get the default lib files and not what you may have added.

I think the best option is to reinstall the OS. Of course, you will want your data on a separate partition that is not formatted during install, good practice IMHO.


A workaround I found is using OBS Studio. To get it working:

Open the window you want to project on the main screen and resize it so it is roughly the same aspect ratio of the second screen.
Open OBS Studio on main screen, create a new scene, add a window capture source and configure it to show the desired window.
From the OBS system tray icon on top, choose "Fullscreen projector (preview)" and select the second monitor.

It's a bit of an overkill of use a powerful program like OBS to mirror a window, but this is the only solution I found so far. However, using OBS gives you the possibility of, not only to mirror one window, but to configure what you project on the second screen (like having more than one window for example) by setting up your scene as you wish.


Help with creating Systemd Timers to Automate Window Theme Changes

(Late edit of WantedBy=default.service to WantedBy=default.target)

This may be a long journey, but here are some pointers. All of the WantedBy entries are wrong. They cannot depend on a shell script. A timer unit x.timer is always associated with a service unit x.service. If you were to start the timers, they will start their service at the given time. But you would need to do this at each login. So instead you need to enable the timers, and have systemd start them automatically. To do this you need to have the timers WantedBy= a target that is fulfilled at login for users. Typically, this is default.target. Though there are many system targets, there are very few user targets.

Since your scripts are very short, you might like to include them in the service units, to keep things smaller. The service and timer files have to be in ~/config/systemd/user/. You need to create this directory if it does not exist. Eg: dark.service:

[Unit]
Description=Automatically change the "Window Theme" to "dark" in the evening.
[Service]
Environment=DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
ExecStart=/usr/bin/gsettings set org.gnome.desktop.interface gtk-theme Yaru-dark

dark.timer:

[Unit]
Description=Automatically change the "Window Theme" to "dark" in the evening.
[Timer]
OnCalendar=*-*-* 18:00:00
Persistent=true
[Install]
WantedBy=default.target

light.service:

[Unit]
Description=Automatically change the "Window Theme" to "light" in the morning.
[Service]
Environment=DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
ExecStart=/usr/bin/gsettings set org.gnome.desktop.interface gtk-theme Yaru-light

light.timer:

[Unit]
Description=Automatically change the "Window Theme" to "light" in the morning.
[Timer]
OnCalendar=*-*-* 06:00:00
Persistent=true
[Install]
WantedBy=default.target

Whenever you change the content of these files, or add or remove files from this directory, you need to notify systemd by giving the command:

systemctl --user daemon-reload

I'm not sure what gnome "Startup Application Preferences" does. The systemd method to start using these units is to do, once only, not as root:

systemctl --user enable dark.timer light.timer

Now, whenever you login, these units will be started, and stopped when you logout.

While developing the units you may want to test them immediately, without needing to login/logout. You can start them explicitly with:

systemctl --user start dark.timer light.timer

and you can stop them with

systemctl --user stop dark.timer light.timer

You need to stop them before you can start them again. You can combine stop and start with

systemctl --user restart dark.timer light.timer

You can check their status with

systemctl --user list-timers

which should say when they will next trigger, and what service they will run.

It would be nice to have a tutorial on systemd user units, but I haven't found anything suitable. They mostly talk about system units. You can glean some basics from this large redhat document, but it is for administrators, so a little too detailed, but it would help to understand that some of it is in common for user units.


Dual booting Windows 10 Insider (Upgrading frequently) and Ubuntu

If you have an EFI based installation setup you don't even have to restore GRUB
because GRUB is installed to a separate folder (Ubuntu) within the EFI partition.

You can use bcdedit ( Windows command line tool ) to update the Windows BCDstore.
Then boot into BIOS setup and switch the default OS to boot from Windows to Ubuntu.

When booting your machine, you now can select which OS you want to boot from GRUB menu.
Anyway, to answer your main question : No, it will not hurt Windows Insider Preview installation.

Note: Only in case your installation setup is mbr based (legacy BIOS) you  have to reinstall GRUB.


In XFCE you can change the default browser (and other default applications like the File manager or the e-mail client) using the main menu: Settings -> Settings Manager -> Preferred Applications


ddrescue error: ddrescue: Can't open output file: No such file or directory

This will work

sudo ddrescue /dev/sda2 /media/it/84CEABF4CEABDD24/ImageFileName.img /media/it/84CEABF4CEABDD24/TextFileName.txt

When you are referring to a file/directory absolutely, you need to put a / in front of it. Without it, you are looking in the current directory


AMD proprietary drivers do not support this old adapter.

You need to remove them. The right way to remove the drivers depends on the way you installed them.

If you installed AMD drivers from a deb package, Ubuntu repositories or a PPA, you can un-install the drivers by running:

sudo apt-get purge 'fglrx.*'

in terminal.


sudo dkms remove -m virtualbox -v 6.1.10  k --all

This is an attempt to remove virtualbox from all kernel versions.
sudo apt purge virtualbox

If apt ist not working
sudo dpkg -P virtualbox virtualbox-dkms virtualbox-qt

I hope I remember my solution right.


How do I find a public key ID in terminal?

Open your terminal and type as

apt-key list

It will list all the keys you have added with its public key ID's. I have tried your way I have seen the Google pub ID

abcdefgg@abcdefgg-virtual-machine:~$ wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
[sudo] password for abcdefgg:
OK
abcdefgg@abcdefgg-virtual-machine:~$ sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'
abcdefgg@abcdefgg-virtual-machine:~$ apt-key list | grep google*
uid                  Google, Inc. Linux Package Signing Key <linux-packages-keymaster@google.com>
abcdefgg@abcdefgg-virtual-machine:~$ apt-key list
/etc/apt/trusted.gpg
--------------------
pub   1024D/437D05B5 2004-09-12
uid                  Ubuntu Archive Automatic Signing Key <ftpmaster@ubuntu.com>
sub   2048g/79164387 2004-09-12

pub   1024D/FBB75451 2004-12-30
uid                  Ubuntu CD Image Automatic Signing Key <cdimage@ubuntu.com>

pub   4096R/C0B21F32 2012-05-11
uid                  Ubuntu Archive Automatic Signing Key (2012) <ftpmaster@ubuntu.com>

pub   4096R/EFE21092 2012-05-11
uid                  Ubuntu CD Image Automatic Signing Key (2012) <cdimage@ubuntu.com>

pub   1024D/3E5C1192 2010-09-20
uid                  Ubuntu Extras Archive Automatic Signing Key <ftpmaster@ubuntu.com>

pub   1024D/7FAC5991 2007-03-08
uid                  Google, Inc. Linux Package Signing Key <linux-packages-keymaster@google.com>
sub   2048g/C07CB649 2007-03-08

abcdefgg@abcdefgg-virtual-machine:~$


Grab Handles appearing randomly, causes erratic mouse behavior

It would seem to me, despite the response in the comments, that disabling the Unity MT Grab Handles option in ccsm should be able to turn these off, erratic mouse behavior notwithstanding.

Steps to disable the grab handles:

Install the CompizConfig Settings Manager (ccsm). You can do this either by clicking the provided link, or by opening a terminal and entering sudo apt-get install compizconfig-settings-manager, providing your password as needed.

  WARNING: ccsm has been known to break Compiz if you are not careful! Try not to mess around in it too much.

Start CompizConfig Settings Manager. Look for a plugin called Unity MT Grab Handles. It should be at the very bottom when you scroll all the way down, under Uncategorized. Click its entry to enter its settings.
Once in, find the checkbox labeled Enable Unity MT Grab Handles on the left side of the window under Use This Plugin. Uncheck it. This should be all you need to do; close ccsm.

If there is still an issue, then perhaps you should file a bug if then restarting Compiz does not work (compiz --replace).


How to restore the Unity login screen after installing Xubuntu desktop in Ubuntu 14.04

re install lightdm
in the login form type alt+ctrl+f1

$ sudo service lightdm stop
$ sudo apt-get remove lightdm
$ sudo apt-get update && sudo apt-get install lightdm
$ sudo service lightdm start
$ sudo service lightdm restart

the alt+ctrl+f7


Execute this command to remove Xscreensaver

sudo apt-get autoremove xscreensaver
sudo apt-get --purge remove xscreensaver

To disable, you've to go to:

in gnome

system->preferences->Sessions->Startup Programs

and delete the entry of xscreensaver.

Also give a look at System -> Preferences -> Screensaver

in Unity

Search Brightness and Lock in dash, and just click Off under Lock, you can set configurations according to your need.

More help

man xscreensaver


sed 's_.*/_& _'

substitutes everything until the last slash (.*/, regexes are greedy) with itself followed by a space (&␣) in every line.

Example run

Provided your text file is called file and resides in the current working directory:

$ <file sed 's_.*/_& _'
../pool/main/a/aalib/ libaa1_1.4p5-44build2_amd64.deb
../pool/main/a/accountsservice/ accountsservice_0.6.45-1ubuntu1_amd64.deb
../pool/main/a/accountsservice/ gir1.2-accountsservice-1.0_0.6.45-1ubuntu1_amd64.deb
../pool/main/a/accountsservice/ libaccountsservice0_0.6.45-1ubuntu1_amd64.deb
../pool/main/a/acl/ acl_2.2.52-3build1_amd64.deb
../pool/main/a/acl/ libacl1_2.2.52-3build1_amd64.deb
../pool/main/a/acl/ libacl1-dev_2.2.52-3build1_amd64.deb
../pool/main/a/acpid/ acpid_2.0.28-1ubuntu1_amd64.deb
../pool/main/a/acpi-support/ acpi-support_0.142_amd64.deb
../pool/main/a/adduser/ adduser_3.116ubuntu1_all.deb
../pool/main/a/adium-theme-ubuntu/ adium-theme-ubuntu_0.3.4-0ubuntu4_all.deb
../pool/main/a/advancecomp/ advancecomp_2.1-1_amd64.deb
../pool/main/a/adwaita-icon-theme/ adwaita-icon-theme_3.28.0-1ubuntu1_all.deb
../pool/main/a/aisleriot/ aisleriot_3.22.5-1_amd64.deb
../pool/main/a/alabaster/ python3-alabaster_0.7.8-1_all.deb
../pool/main/a/alembic/ alembic_0.9.3-2ubuntu1_all.deb
../pool/main/a/alembic/ python3-alembic_0.9.3-2ubuntu1_all.deb
../pool/main/a/alembic/ python-alembic_0.9.3-2ubuntu1_all.deb
../pool/main/a/alsa-driver/ alsa-base_1.0.25+dfsg-0ubuntu5_all.deb
../pool/main/a/alsa-driver/ linux-sound-base_1.0.25+dfsg-0ubuntu5_all.deb

To alter the file in-place, use:

sed -i 's_.*/_& _' file


How to prevent apt-get/aptitude keeping a cache

According to the documentation you can add a config file to /etc/apt/apt.conf.d/ named no-cache containing Dir::Cache ""; and Dir::Cache::archives ""; according to manual of apt.conf. There is a bug report raising issues with this method, and I don't recommend it.

There is one remaining method according to this tutorial:

echo 'DPkg::Post-Invoke {"/bin/rm -f /var/cache/apt/archives/*.deb || true";};' | sudo tee /etc/apt/apt.conf.d/clean

This will carry out an rm command just before apt quits.


There seems to be quite a lot of versions of the Lenovo S10 (I don't own one, so it's hard to comment,) however the Ubuntu Hardware List states that it is supported and works fine, and a search on the forums seem to support this.

I noticed that you picked LUbuntu, I wonder if you could try the vanilla Ubuntu installation- you should be able to get an indication from the liveCD as to whether any of the bugs you mention persist.

Apparently MeeGo uses the rpm package management system, so it would be difficult to simply 'install' any ubuntu interface (which uses apt) on top of it.


Ubuntu download and install on VirtualBox

amd64 is all 64-bit XX86 class processors regerdless of manufacturer.

vitrualbox is 32 bit. get the 32bit version. i386 will be at then end of the image name


Use Ctrl+Alt+T and there use sudo apt install PACKAGE_NAME to install anything you like .

Alternatively use synaptics package manager

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install synaptic


adb not found even if path set in /etc/environment

In /etc/environment variable expansion is not performed. You cannot define a variable here and then reference it with $. Your path literally includes "$ANDROID_SDK" which is not expanded into /opt/android-sdk

If you want to define your path in /etc/environment then use the full paths

    PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/opt/android-sdk/platform-tools:/opt/android-sdk/tools

(and your full JAVA_HOME path which I don't see in your question.)

Rather than defining your path system-wide, you may want to define it locally (generally preferred).

The local version of /etc/environment is ~/.pam_environment. This has a slightly different syntax. To set the path here, reference the current path and append your additions like this:

PATH DEFAULT=${PATH}:/opt/android-sdk/platform-tools:/opt/android-sdk/tools

(and your JAVA_HOME path too after another colon)

You also can use ~/.profile or in ~/.bashrc - in these files you can use the normal shell syntax with $ expansion like you did before.

After you define it, you then need to source the file by doing source .profile or whichever file you used, or by logging out and back in. (The exception is .bashrc which is sourced every time you start an interactive shell, so opening a new terminal would be enough)


After additional information in the comments, You need to add your user to the kvm group.


Ubuntu: Are there negative implications for making dot files like .profile and .bashrc read-only?

... a bad actor would need my sudo user password in order to change, add or remove anything in these dot files.

False. If your home directory is writable by you (which it likely is, and which you likely want to keep that way), anybody who can run commands as your user  can delete or rename them, and create a files in their place.

That could be worked around by making it immutable, though.

That said, packages from the official repositories are not allowed to directly mess with user home directories. You're safe on that count. If you download random debs from elsewhere, they may or may not make assumptions about your home directories - there's no telling.


How to create a log file of all the commands I executed

Bash keeps a log of commands you've run.  You can access the log from the current session with the command:

history

After your session finishes it is written out to the file:

~/.bash_history


Ubuntu 17.10 GNOME Shell Theme Color Sometimes Blue

It seems you're (inadvertently) switching between the (vanilla) "GNOME" session and the modified GNOME session titled "Ubuntu" ("Ubuntu" is orange, "GNOME" is blue).

You may load the "bluish" GNOME shell theme from your home directory. To do that follow the steps below.

Create a directory, say MyTheme either in ~/.themes or in ~/.local/share/themes. (You may create ~/.themes or ~/.local/share/themes if they don't exist.)
Create another directory inside MyTheme called gnome-shell.
Create an empty document in this gnome-shell directory and name it gnome-shell.css.
Open this gnome-shell.css in a text editor and add the following line

@import url("/usr/share/gnome-shell/theme/gnome-shell.css");

Install and activate the User themes extension from here.
Launch Tweaks, go to Appearance section and click on the drop-down box next to "Shell theme". MyTheme should appear in the drop-down list. Select it.


Which is a better laptop for 11.10: Dell Precision M6600 or MacBook Pro 17-inch?

Both laptops ships with high end specs. The Dell M6600 is an Ubuntu certified laptop, So chances of glitches are very low while running Ubuntu.

Macbook Pro

Things like special function keys won't work out-of-the-box.
Battery life will be significantly lower [citation needed].
A generally less integrated experience (Thunderbolt and WLAN aren't working yet with Natty or later and the
latest offering of MacBook Pros). Hibernate and suspend tend to be a
bit iffy.
The clickpad is atrocious under ubuntu. It's completely impossible to do things like right-click-drag, and there's no middle click at all like there is with the dell.

Final Thoughts

Installing and working of ubuntu in Macbook will require little bit more effort than installing it in a Dell machine (Check this).  The Dell runs ubuntu 11.10 very well.


Add Short Date Format for Nemo File Manager

If you don't mind using the terminal a bit, first run locale -a. That'll tell you which locales are available to you according to man locale.

Now, I don't use the nemo file manager but let's assume the program can be invoked by running nemo in a terminal (as opposed to taking a GUI route for now).

Keeping the output of locale -a in mind, try various LANG options to see which one gives you the format most close to what you like:

LANG=en_GB.utf8 pcmanfm works for me with the PCManFM file manager. The date modified column with this command has the output like this: dd/mm/yy hh:mm.

Just default PCManFM gives me Monday 15 August 2016 20:39.

If you find a LANG option that you like, you could modify your Exec line accordingly in nemo's desktop file (after backing up the original .desktop file for safety). Alternatively, copy "nemo.desktop" or whatever it's called from /usr/share/applications to ~/.local/share/applications and modify the copied version.