Upgrading to latest version of OpenGL on Ubuntu 15.10

You dont have OpenGL 3.0... you have OpenGL 3.3 with some OpenGL 4.x extensions, because your card is OpenGL 4.x compliant.

I have Ubuntu 14.04.3 with Intel HD 4000 and Mesa 10.5.9 and i get:

glxinfo | grep OpenGL

OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Ivybridge Mobile
OpenGL core profile version string: 3.3 (Core Profile) Mesa 10.5.9
OpenGL core profile shading language version string: 3.30
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 3.0 Mesa 10.5.9
OpenGL shading language version string: 1.30
OpenGL context flags: (none)
OpenGL extensions:

Obviously it is not possible that i have a higher OpenGL version with an older card..!

That OpenGL 3.0 you see is the compatibility profile!
Your actual Core Profile is 3.3 and in a few months maybe 4.x

So then you would need ppa:oibaf/graphics-drivers for the absolute latest drivers, but it is not recommended unless the intel driver reaches OpenGL 4.x compliance!


How can I stop wine from modifying my display layout?

Open winecfg

On the Applications tab, add the desired app to the list via the Add button.
Once added, select or highlight the added application and change to the Graphic tab.
Check the box that says "Emulate a virtual desktop" and select the window size.  If you want to run the wine app at full screen on one of your monitors, specify the resolution of the desired screen.


Can not connect to internet after upgrade to UBUNTU 14.04

Edit /etc/network/interfaces and see if your config is OK. (you can edit with "vi")
1) Good IP
2) Good SubnetMask
3) Good Gateway
4) Good dsn-nameservers.

If you're not sure, copy and paste your config.


Odd include errors building using Ubuntu SDK

In case you're using cmake instead of qmake, try this:

find_package(Qt5DBus 5.2 REQUIRED)


Installing MS Office 2010 updates in PlayOnLinux/Wine

This ended up being a very manual process with quite a bit of trial and error. Even though there was a message during the installation process saying updates were being installed, I am still unsure if the process below worked and the updates were actually installed.
The general process was:

Use a Windows machine (eg on VirtualBox) to Slipstream Office 2010 setup with SP2.

Use a Windows machine (eg on VirtualBox) to download any post-SP2 security updates using wsusoffline.

Once the individual security updates are downloaded, you will need to extract each one individually and then copy the updates into the ./DVD/Updates folder from the previous step. This needs to be done in the order of update so that any earlier update files are overwritten by subsequent files with the same name.

I used a .bat file in windows to automate this process based on this script:
wsusoffline/client/o2k10 seems to contain static downloads, mostly service packs.
wsusoffline/client/ofcseems to contain dynamic updates for all office versions. I could not figure out how to extract these.

Install MS Office 2010 into POL using the Slipstreamed ./DVD/setup.exe.

If you have any issues with activation, try Andrew Conley's answer.

Once installed, check your office version number from the MS Word Help menu

14.0.4760.1000 = Office 2010 RTM installed
114.0.6023.1000 = Office 2010 with SP1
14.0.7015.1000 = Office 2010 with SP2
14.0.7258.5000 = Office 2020 updated to September 2020

Good luck!


Changing effects in compiz causes problems with the top panel

I'm sorry you are encountering this problem (even if you didn't state exactly what the problem is ("get's screwed" does say much :)). (I assume you are running unity and 11.04 from what you describe).

In the future, all you need to do after changing you compiz settings, is:

Press alt+f2

If you are running unity:

Type in unity --replace or simply unity

If you are running Ubuntu Classic Desktop:

Type in compiz --replace

Press enter

This will reload compiz and unity and should fix your problem as well. Hopefully the problem will be fixed in some soon_to_come bug fix updates.

P.S.:

stuff means keyboard_key_to_press


Ubuntu 15.04: Installation not possible because there is no screen

It seems as if Pilot6 doesn't post his comment as an answer. So I will:

  Boot with nomodeset parameter. After installation you will need to install a proprietary Nvidia driver.


The best way I know to troubleshoot problems with fstab is to use sudo mount -a from a terminal to see where the problems are, and interactively make changes until the errors are fixed.

mount -a simply mounts everything in your fstab.  If certain entries mount without error, but give access problems, you might want to unmount, make edits to fstab, then run mount -a.

Using UUIDs makes the file easier to maintain, but don't get too distracted by all the people talking like it's an immediate requirement.  For right now, it may be simpler to use the devices if you're willing to maintain the file whenever you make changes.  Even though UUIDs make it easier to maintain, it's not an immediate requirement to fix problems, in my opinion.  One problem at a time!

More on UUIDs

Once you get everything working, here's how to switch to UUIDs, and maintain them in the future.

The original fstab has a comment at the top, but here are some more details and tips:  in the terminal, enter the command sudo blkid -c /dev/null.  I add this as a comment at the top of fstab so it's easy to remember.  The '-c' switch just makes it reread the information instead of using a cached copy, to make sure it's up-to-date.  Unless you have a lot of partitions, it won't make any difference in time.

The result of this command is a list of all partitions, by device, with label, UUID, and type of filesystem.  You can cut and paste the UUID into your fstab file, replacing the /dev/sdx notation with UUID=xxxxxxxx-xxx-xxx-xxx-xxxxxxxx /mountpoint ...  Once you get used to it, it really isn't much trouble to maintain the UUIDs.  I'd suggest leaving a comment above the line with the old notation, although remember to update it if it changes.


You can set the default via the update-alternatives mechanism, using the command

sudo update-alternatives --config awk

e.g.

$ sudo update-alternatives --config awk
There are 2 choices for the alternative awk (providing /usr/bin/awk).

  Selection    Path            Priority   Status
------------------------------------------------------------
* 0            /usr/bin/gawk    10        auto mode
  1            /usr/bin/gawk    10        manual mode
  2            /usr/bin/mawk    5         manual mode

Press enter to keep the current choice[*], or type selection number: 2
update-alternatives: using /usr/bin/mawk to provide /usr/bin/awk (awk) in manual mode.

When you want gawk instead, simply invoke it as gawk instead of awk


Pausing a long running program in the terminal?

Press Control+Z.

This will suspend the process and return you to a shell. You can do other things now if you want or you can return to the background process by entering % followed by Return.

Note that if you're doing this to something that needs to be responsive, you're going to tank the system, but if it's just something like a nano instance, everything should be okay.


What is the unit of the "signal" when running nmcli?

It looks like the SIGNAL value is a percentage. Maximum signal is 100.
The more is the better.

iwlist gives output in dBm. It is always negative. The more is the better too. "-20" is better that "-50".

I tested it with a powerful router close to the client machine. It shows 100.


security - is this my public key? my private key? or the keys of the program I'm using?

76F1A20FF987672F

No! This is the keyID of the key-pair from Winehq.org!!

This is not your public (or private) key. You probably don't have one yet. If you ever need a private-public key pair, you will have to create them.

The keyID is like the number on a physical key. the same number is also on a lock the key belongs to. There is no harm in posting this information in a public forum. The private key of winehq is safely with the... (guess who?)

WineHQ

WineHQ changed their private-public key combination. Why? The same reason people change their locks. Physical keys (and digital keys) get lost (or deleted) or stolen.

See signature verification error for wine - index files failed to download - changing mirror doesn't help for how to download the new public key from WineHQ. Once you have the new public key, the update will go through. The new public key will verify that the wine update is coming from the WineHQ and noone else. That is because only WineHQ has the matching private key.

Hope this helps


What is the write-mode policy that is used in Ubuntu?

In a write-back cache, when changes are made to cached data, they are not simultaneously made to the original data as well. Instead, the changed data is marked, and the original data is updated when the chached data is deallocated.

In a write-through cache, by contrast changes made to cached data are simultaneously made in the original copy. A write-back cache can perform more quickly than a write-through cache. But in some contexts, differences between cached and original data could lead to problems, and write-through caches must be used

source

Now, Its doesn't matter what OS are you working on the really thing that affects is the file system you are using.

Ubuntu by default use ext4 as it filesystem and to know ext4 uses the both modes write-back and write-through.

To enable write back mode

Run:

 tune2fs -o journal_data_writeback /dev/sd*

Edit fstab

vi -w /mnt/sdXY/etc/fstab

Find the line that references sd* It will look something like:

# /dev/sda2
UUID=be2f0ac2-4683-4550-bcd1-704a1a840b3e / ext4 relatime,errors=remount-ro 0 1

  The first entry is the UUID .

  The second entry is the path.

  Third is the fstype .

  Fourth are the options.

  Fifth is for dump

  Sixth is pass.

Change the options(4th) to:

noatime,data=writeback,barrier=0,nobh,errors=remount-ro

Reboot your system to complete changes.

source

Also check this for more information.


Ubuntu 16.04 broken packages after fresh install

16.04 is new and all packages are not ready to use in all servers. Using Main Server to download packages solve my problem.

System Settings
Software & Updates
Select "Main Server" from "Download from" section


How to connect my Bose Headphones to Ubuntu through Bluetooth?

If you are running kernel version 5.9 or newer, the kernel may be the problem.
https://bugzilla.kernel.org/show_bug.cgi?id=209745
It seems that Link Layer Privacy being enabled in 5.9 breaks bluetooth for some mice.  There are some workarounds for disabling Link Layer Privacy but they are not for the technically faint of heart.  A simpler solution would be to revert your kernel back to 5.8.


How do I install kernel v3.6 on Ubuntu 12.04 x86_64?

Download kernel files from http://kernel.ubuntu.com/~kernel-ppa/mainline/. Like for kernel v3.7.1-raring download your required files. For x86_64 download the "amd64" files, for x86 download the "i386" files, for ARM download the "armhf" files. And for all architectures download the "all" file. Then put them in a folder, like in Downloads/kernel. Then from terminal go to that folder, like "cd ~/Downloads/kernel". Then run "sudo dpkg -i linux-*.deb", enter password when prompted. When installation completes, restart. That's all. You can check your kernel version by entering "uname -a".
Thanks.


How to use touch-gesture-recognition-stack on multitouch-enabled touchpads?

From what I can find, it seems like support currently exists in the gesture-recognition framework, but there is a kernel bug that is blocking it from working with Synaptics devices. I found a bug report for it that has a status of "Fix Committed." It seems to indicate that it supports devices that are not explicitly multi-touch.

However, this bug report for an issue with the kernel has been triaged. There is discussion up to today, and it seems like fixes have been committed to the natty git kernel repo that may provide the support you require.

You could try compiling the kernel from this (presumably very unstable) natty kernel snapshot: git://kernel.ubuntu.com/cndougla/ubuntu-natty.git

Or just watch the kernel bug report over the next few weeks and try to upgrade to that kernel version ASAP.

Also, for what it's worth, the kernel issue prevents the framework from working with a Synaptics touchpad, but you might be able to enable multitouch gestures using X11 by following this guide.


MenuBar in the right corner doesn't work

Not sure if you still need this but you can restart or quit the multiload indicator by running the following command in a terminal:

indicator-multiload &


Function keys not working on Toshiba C-50-B

I've just got a Toshiba C50-B-14D model. I was able to make most of the function keys working with the following procedure:

Make the /etc/udev/hwdb.d/70-keyboard.hwdb file with the following content (you will need root privileges to make the file):

#Satellite C50-B
keyboard:name:Toshiba input device:dmi:bvn*:bvr*:bd*:svnTOSHIBA*:pnSATELLITE*C50-B:pvr*
 KEYBOARD_KEY_13c=brightnessdown
 KEYBOARD_KEY_13d=brightnessup
 KEYBOARD_KEY_13e=switchvideomode
 KEYBOARD_KEY_13f=f21                                   # Touchpad toggle
 KEYBOARD_KEY_158=wlan

Note that it is important to have exactly one whitespace before the lines starting with KEYBOARD.
Run sudo udevadm hwdb --update
Run sudo udevadm trigger (This command would save you from restarting the machine, but if it doesn't work, try restarting the machine.)

After this the only key which do not work for me is the Wifi On/Off key.

To find more information on this process you can look e.g. here or here.


Accessing the debugfs requires root privileges. To open a root shell, open a normal shell and run

$ sudo -i

You will be asked for your password, then be given a root shell. In that shell, you can cd to /sys/kernel/debug.


Ubuntu 16.04 LTS kernel 4.4 does have Meltdown & Spectre mitigation, as changes are backported to supported kernels.

Unless you've done something with updates, or moved to say an EOL 16.10 (kernel 4.8) or 17.04 (kernel 4.10) or other EOL kernel, you'll be protected.

please refer to
https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/SpectreAndMeltdown


Ubuntu Server does not install the Desktop environment, and I believe is what you are looking for.  You are not required (or forced to) run any server services after installing Ubuntu Server.


~ is a special shell replacement. It's replaced with your home directory (typically /home/$USER but not neccessarily). It's a shortcut we use because it's nice and short and it's impossible to know everybody's $HOME.

Files and directories prepended with a dot are hidden. In Windows it's a boolean setting on files, in Unix it's based on the filename. You can still access them though:

In Ubuntu's default file browser you can:

Toggle the display of hidden files
Use the address bar to manually go to the path (Control + L to toggle raw address mode).
Use a run dialogue (Alt+F2) to run nautilus <full path>

In a terminal you can cd directly to the path.


How to access Samba shares in Lubuntu 12.10

This should work:

smb://<machine_name/ip>/filepath/filename

in the PCmanFM address bar.
e.g:

smb://192.168.1.111/some_folder/sub_folder/file.pdf

Courtesy: https://help.ubuntu.com/community/Lubuntu/PCManFM#Browse_Windows_PCs_with_Samba

Update:

If you want to connect as a particular user, use

smb://username@smb_server/some_folder

Under Lubuntu 14.10, this brought up a password dialog and then connected with the expected ownership and privileges.

Courtesy: Comment by Randall Cook

FYI, PCmanFM mounts samba shared devices in /run/user/userid/gvfs (id -u can help to find user id)
so after mounting Samba shares using PCmanFM, we can also access files/directories using console


How to install Ubuntu 13.10 alongside Ubuntu 12.10

First install Ubuntu 12.04 LTS.

Then attempt to install 13.10 (latest). It will prompt you to install alongside OR replacing 12.04.

If you have a more detailed question, please add to your earlier question ..


... Not.
That window was taken out in Ubuntu... I think it was 8.10? So it wouldn't be included in Ubuntu 11.04 either.
It was replaced by a simple login screen configuration tool with only a few options.


Is there an alternative task switcher to KRunner which is focused exclusively on window switching?

If I understand your question correctly, there are several routes that don't require the Alt+F2 route.
Alt+Tab
This basic method has a few possibilities itself which you can explore via System Settings > Window Management > Task Switcher. My preference is the very simple one shown below. On pressing Alt+Tab, I have a plain text display of open windows.

I keep the Alt key depressed and cycle through the choices with the Tab key. You can try various other options available on the Task Switcher page.
As shown in the image below, I've chosen "Text Only" from the dropdown and I have "Show selected window" unchecked. You may like something else.

Flip windows
Open System Settings > Desktop Behavior > Desktop Effects and type flip in the search bar at the top of the page. Activate Flip Switch.

If you click on the circled icon, you'll see a preview of what this can do. (It may take a while to load.)
If you decide you want to try it, open System Settings > Shortcuts > Global Shortcuts > System Settings and enter flip in the search bar (as before). Here, decide on a keyboard shortcut of choice to activate the Flip Switch or leave the existing choice in effect if there is one there. I've gone with Ctrl+MetaF10. Use Alt+Tab to cycle through the choices and press Enter when you've found the one you want. (Meta is the Super or Windows key.)

Present Windows
I won't go into detail here because the procedure to find it is the same as for Flip Switch. In this case, I went with Ctrl+F10 because that was already set up. Here, as you hover over individual windows, they're highlighted and clicking on the hovered one brings it into focus.

Using Screen Edges
Another thing for you to explore is System Settings > Desktop Behavior >  Screen Edges. Again, I'll not go into detail but just leave you with an image which I took after right-clicking on the top-right corner white square:

Edit:
To use many of the desktop effects, you must have compositing enabled and compositing is enabled by default if your system provides it.
To check, run qdbus org.kde.KWin /KWin supportInformation | grep -i composit
My system shows:
$ qdbus org.kde.KWin /KWin supportInformation | grep -i composit
Composite: yes; Version: 0x4
compositingMode: 1
useCompositing: true
compositingInitialized: true
windowsBlockCompositing: true
Compositing
Compositing is active
Compositing Type: OpenGL
$

By the way, you can toggle compositing on or off using Alt+Shift+F12.


Try running startx. This is the command to start the GUI. It will give you a log in Xorg's log file if it fails. Post that content for troubleshooting.


How can I update only the flash player for chromium when I have set the 'Automatically check for updates' as 'Never' ?

Which version of flash are you using ?

dpkg -l|grep flashplugin

It could be (1) flashplugin-installer or (2) pepperflashplugin-nonfree

For (1) run:

sudo apt-get update && sudo apt-get install --reinstall flashplugin-installer

For (2) run:

sudo /usr/sbin/update-pepperflashplugin-nonfree --install

Note:
If you're using (1), I suggest you switch to (2) because it is the latest flash version; run:

sudo apt-get purge flashplugin-installer && sudo apt-get install pepperflashplugin-nonfree && sudo /usr/sbin/update-pepperflashplugin-nonfree --install


I want to use my secondary HDD for everything

All of your files will be save in your /home directory. One great thing about linux is that any folder in in the directory tree can be on an separate drive rather than on the same drives as the root directory. So to have your files on your HDD and your documents on your SDD you need to mount your HDD at \home when you boot.

The easiest way to do this is to set up custom partitioning when you first install Ubuntu and select your HDD and give it the mount point /home.

If you already have ubuntu installed then you will have to copy the contents of home to the HDD, rename \home to something else and then edit your fstab file to mount the HDD at \home. Once you restart and everything works you will need to delete the renamed home directory.

This is a rather in depth process but there is a great ubuntu community wiki article detailing the whole process: https://help.ubuntu.com/community/Partitioning/Home/Moving


How can I increase window title font size?

Simply run following command on terminal:

gsettings set org.gnome.desktop.wm.preferences titlebar-font 'Ubuntu Bold 11'

Number 11 is default font size for title bar font, I believe you want to adjust their size to your preferred size.


Resize2fs: The filesystem is already blocks long. Nothing to do!

You don't need to run anything from the command line as gparted takes care of this all for you.  Simply resize the partition in gparted.  You will first need to move sda11 over so that the free space follows sda10 before you can grow it.


Severe screen tearing on Chrome without any proprietary graphics drivers

I have three suggestions for you:

Install updated open source video drivers

sudo add-apt-repository -y ppa:oibaf/graphics-drivers
sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install amd64-microcode

This will update open source video AMD driver to more recent version and install CPU microcode

Disable DRI3 acceleration for Chromium based browsers

echo 'export LIBGL_DRI3_DISABLE=1' >> ~/.profile
# restart after doing this

Try the most recent optimized kernel from XanMod

echo 'deb http://deb.xanmod.org releases main' | sudo tee /etc/apt/sources.list.d/xanmod-kernel.list
wget -qO - http://deb.xanmod.org/gpg.key | sudo apt-key add -
sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install linux-xanmod-4.11


why does /proc/cpuinfo show a single processor on the BQ Aquaris phone?

The kernel will offline cpus when they are not required to keep the power consumption low.  When the load increases it will automatically put more CPUs online.

One can see how many CPUs are available and how many are online using:

getconf -a | grep NPROCESSORS
_NPROCESSORS_CONF                  4
_NPROCESSORS_ONLN                  1

Above, 4 are available, and 1 is online.


add this option in kernel drivers settings

  $ sudo echo 'options iwlwifi 11n_disable=1' >>
  /etc/modprobe.d/iwlwifi.conf

Then restart the system this must fix wifi problem.


After installing Ubuntu alongside Windows, Windows boots fine and I can log in but Windows can't find data

Open Windows File Explorer.
On the View ribbon, put a check in the checkbox marked Hidden items.
Right-click and copy the Desktop folder contained in the Default folder - C:\users\Default\
Browse to: C:\Windows\system32\config\systemprofile
Right-click and paste the Desktop folder into the systemprofile folder.
Reboot (not shutdown) the computer.


What are some good developer resources for QML/Qt Quick?

http://doc.qt.digia.com/4.7/qtquick.html - Specific to Qt 4.7, but has a wide variety of topics to do with QML, and Qt Quick
http://qt-project.org/wiki/Category:Developing_with_Qt::Qt_Quick - Variety of demo's, tutorials and best practices
http://doc.qt.digia.com/qt/qml-tutorial.html - Hello World tutorial, which leads onto an animation effect
http://qt-project.org/wiki/Qt_Quick_Tutorial - Currently only has 2 sections done - for the topics basics and components


How to extend my "locked" root partition ? - Ubuntu 17

Okay I've solved this by resizing the root partition from booting from Ubuntu usb stick, but make sure first that the unallocated memory are collected and placed just after the root partition.


Mount FAT32: Can't find a valid FAT filesystem

After creating the partition with fdisk you must create the FAT file system:

sudo mkfs.vfat -F 32 /dev/sdc1

Then you should be able to mount /dev/sdc1 with -t vfat.


Here are precisions added to bert's answer, about the fix that worked for me :

sudo add-apt-repository ppa:jfi/test
sudo apt-get update
sudo apt-get dist-upgrade

It should then work.


What is the "default" font for xubuntu terminals?

So, with some help, I am able to answer my own question:

The default font is "DejaVu Sans Mono Book 9"
"factory defaults" can be restored by removing the corresponding config file: rm ~/.config/xfce4/terminal/terminalrc


Ubuntu 12.04 Cannot adjust brightness on Dell Inspiron 15: the suggested solution to change the grub fails

You can use this app if anything else does not work.


I had the same problem, by me it helps to remove the latest kernel. I did it like this:

check that there is a second older kernel:

  dpkg --list | grep linux-image

if there is an older one, remove the newest:

  apt remove --purge 4.4.0-75-*

update grub:

  update-grub

Now it needs a reboot and after it should be working.

When you want later a new kernel, you have to install them with: apt install linux-generic

Another solution is to add vers=3.0 to the fstab mount statement.


Install Ubuntu on an external hard drive

Definitely not. As being compatible with USB 3.0 as well as if it is SSD supported, performance of the hard drive will be much greater than internal hard drive.


Apt-get take long time to update\upgrade

My ubuntu servers were always very fast at apt-get updates and upgrades. Typically the lines on the screen went too fast to be seen. Then all of a sudden they slowed down to a crawl overnight.

It was IPv6 doing it.

I found the following solution:

sudo nano /etc/gai.conf

Uncomment the following line:

precedence ::ffff:0:0/96 100

For me it was line 54 (make sure you don't uncomment the one that ends in 10).

Save and exit.

sudo nano /etc/apt/apt.conf.d/99force-ipv4 # (this is to make a new file)

Add the following line to the new file:

Aquire::ForceIPv4 false;

Save and exit.


D'Link Wireless DWA-140 speeds are crippled on 12.04

I followed the same steps. However, the rt5370sta module does not support all DWA-140 B1 devices, believe it or not.

My devices product id is 3c09. Thus when I install the module rt5370 is not loaded.

I have modified the files:

/os/linux/rt5370sta.mod.c
/common/rtusb_dev_id.c

In (1) I searched for 07D1 and after the following:

MODULE_ALIAS("usb:v07D1p3C0F ....

I added the exact same line but with 3C09 instead of 3C0F.

In (2) I also searched for 07D1 (you can see where this is going) and copied one of the lines which contained 0x07D1,0x3C0 and changed it to 0x3C09.

The same steps were then followed (sudo make & sudo make install).

Now whenever I plug it in rt5370 is loaded and after a reboot it works wonderfully.


Assuming you are using Ubuntu, you should usually not attempt to install packages with yum. It is provided for very special circumstances only. Usually you should install software with Ubuntu's package manager, APT (using apt-get, or the alternative, aptitude), or with one of its graphical frontends (like the Ubuntu Software Center or the Synaptic Package Manager).

yum is primarily used on Red Hat based systems (including Fedora, Red Hat Enterprise Linux, and derivatives of those). The above commands are what you'd use instead. The lower-level tool on Red Hat based systems, for installing a package from a specific package file, is rpm. dpkg (or its graphical frontend, gdebi) should be used to for this purpose on Ubuntu. dpkg installs .deb packages--if you find you actually need to install an .rpm package, you should use alien to make a .deb package from it and install that.
See Installing Software for more information.

In this particular situation, you may be able to install flex by clicking here:

Or you can install it by running these commands:

sudo apt-get update
sudo apt-get install flex

The first command updates information about what packages are available in what versions and from what software sources. It's advisable to run that before installing or upgrading packages from the command line. Whereas yum will always fetch this information before attempting an installation (which is handy, but which also makes it take a lot longer than necessary if you run a number of yum commands in a short time), sudo apt-get install ... does not fetch this information.

If you don't run sudo apt-get update first, and you haven't run it in a while, you may be getting an old version of the package, attempting to fetch a version so old it's no longer available, or getting a version that doesn't work right with the other packages you have installed.


Ubuntu 18.04.5 LTS stuck on 800x600 resolution

Ubuntu Server does not use the X windowing system, so xrandr and glxinfo will not work for you. That said, you should be able to accomplish this with a little help from fbcon (frame buffer control) and some edits to your Grub file.
First, let's rotate the screen. This can be done at any time while the system is running, so let's get the rotation index that you'll need:
echo 1 | sudo tee /sys/class/graphics/fbcon/rotate

Using 1 in the command above will rotate your screen clockwise. There are four options available:

Value
Action

0
Normal rotation

1
Rotate clockwise

2
Rotate upside-down

3
Rotate counter-clockwise

You'll probably want 1 or 3 depending on how your screen is rotated.
Once you know which option you want, you can edit your Grub configuration file to include this orientation at startup:

Edit the Grub file as root:
sudo vi /etc/default/grub

Note: Feel free to use the editor of your choice. It does not need to be vi.
Add the rotation to GRUB_CMDLINE_LINUX:
GRUB_CMDLINE_LINUX="fbcon=rotate:1"

Note: Be sure to change 1 to the proper rotation index.
Save the file
Update Grub:
sudo update-grub

Your orientation will now default to the rotation index you have chosen.
Next, let's look at the resolution. You will need to reboot and do a bit of work with Grub, so hopefully you're not doing this with a production server during operation hours.

Reboot your machine
Hold down the Shift key after the BIOS/UEFI has finished to bring up Grub
Press C to for the Grub command line
Type videoinfo and hit Enter*Note: If you get a "Command not found" error, use vbeinfo instead.
Identify the supported video mode that you want to use. For example, you might see something like:
Mode 0x0366: 1920x1080 (+1920), 8 bits
Mode 0x0367: 1920x1080 (+3840), 16 bits
Mode 0x0368: 1920x1080 (+7680), 24 bits

It's the 0x0368-type value that you need.
Reboot back into Ubuntu

Now let's add some more values to the Grub file:

Edit the Grub file as root:
sudo vi /etc/default/grub

Note: Feel free to use the editor of your choice. It does not need to be vi.
Add the video and gfxpayload flags to GRUB_CMDLINE_LINUX_DEFAULT and GRUB_CMDLINE_LINUX. ⇠ DO NOT REMOVE ANY VALUES THAT MIGHT ALREADY EXIST IN THE LINE. SIMPLY APPEND THESE.
GRUB_CMDLINE_LINUX_DEFAULT="video=0x0368 gfxpayload=true"
GRUB_CMDLINE_LINUX="video=0x0368 gfxpayload=true"

Uncomment the GRUB_GFXMODE line if required, and set the resolution to the value that matches your desired setting:
GRUB_GFXMODE=1920x1080x24

Add two more GRUB_GFX items:
GRUB_GFXPAYLOAD=1920x1080x24
GRUB_GFXPAYLOAD_LINUX=1920x1080x24

Save the file
Update Grub:
sudo update-grub

Reboot

This should give you exactly what you're looking for.


Black screen after upgrading from 14.04 to 14.10

I solved the problem by getting another computer and downloading the same version of Ubuntu to a USB stick. When I booted from the USB stick it gave me the option to reinstall it (which would keep all my files). I did it and everything worked out great. The installation was fine and all my files were intact.


Wireless not working on Dell Latiude 3330 ubuntu preinstalled

You should install the wifi driver from the additional drivers tab from the settings menu,where you can find your required driver for your wireless card.


Is it safe/ normal to install apps using snap? I have never done it in the past. I have always used sudo apt-get install method.

Yes. Some might argue safer as many snaps are strictly confined, so cannot reach beyond what they're permitted to access.

  To which folder do applications installed with snap get installed?

They don't get "installed" in the traditional sense. The snap file is a compressed file which sits on disk as a read-only image. It's mounted when the snap is installed, and the files inside are uncompressed at runtime. They're not upacked onto directories on disk.

The snap file can usually be found in /var/lib/snap/snapd/snaps and when mounted the files inside can be viewed in /snap/<snapname>/current.

  Can other users on the same computer access these applications?

Yes. They're installed for all users. The user data will be separate for each user though. Typically in /home/<user>/snap/<appname>/current.

  There is a snapd process with root as owner always running. Is it normal?

Yes. Snaps automatically update, and it's the snapd process which takes care of this.

  snap list shows core installed. Is this normal?

Yes. The core snap contains a minimal, stable, common Ubuntu runtime environment which the snapped application runs against. This ensures the same snap can be run on Ubuntu 17.10, 17.04, 16.04, 14.04 and other distributions like Debian, Fedora, OpenSUSE and others.


fail to auto install ubuntu 16.04 with preseed.cfg,http not work

Preseeding does support the http protocol. In fact, it should support any question asked by the installer and all of them may be answered with a seed file (some minor rare bugs here and there do exist depending on version and your initrd, but irrelevant here).
When questions are answered with a wrong / unsupported answer, the installer usually ignores your d-i stanza and lets the installer decide what to do (depending on your selected priority kernel parameter or manual choice within the installer).
Empty strings usually answer with an empty string or skip a question.
Looking at your mirror stanzas there seems to be a problem:
d-i mirror/protocol string http
#d-i mirror/country string manual
d-i mirror/http/hostname string 192.168.18.81
d-i mirror/http/directory string /ubuntu/
d-i mirror/http/proxy string

When using http, there is no need for a d-i mirror/protocol stanza - http is the default. Debian's preseed documentation in section B.4.4. Mirror settings comments this stanza.
Regarding your repository location issue: you have commented the critical d-i mirror/country stanza - it is only allowed when using the ftp protocol:

If you select ftp, the mirror/country string does not need to be set.

So your installer ignores the mirror selection when using http, and chooses one of its defaults. When doing so, it ignores the hostname and directory stanzas as the relevant questions were never asked by the installer.
If you would like to use your own repo, do not comment this line - leave it as string manual.
Overall your mirror section should look something like this:
d-i mirror/country string manual
d-i mirror/http/hostname string 192.168.18.81
d-i mirror/http/directory string /ubuntu/

Some resources to help you understand and use preseeding better:
Official Debian documentation for preseeding
An official preseed example file with almost every parameter available documented by Debian: Debian 10 (buster). Debian 10 is the latest release.


How do I install gcc 4.8.1 on Ubuntu 13.04?

Use the mirrors listed Here and download the 4.8.1. The process is pretty straightforward. I would recommend to use this Procedure to complete your installation.

As you may know GCC doesn't support "make uninstall" and it has been suggested that you install GCC into a directory of its own and simply remove that directory when you do not need that specific version of GCC any longer. Hope this helped. Cheers

Edited: The Option 2:

I assume that you already have a former version of gcc, the easiest way could be adding PPA to your repositories and Update and upgrade you can have the latest version with no worries:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update

this will add the new PPA to the other sources.

Then unistall the alternative:

sudo update-alternatives --remove-all gcc
sudo update-alternatives --remove-all g++

then:

sudo apt-get install gcc-4.8
sudo apt-get install g++-4.8

and as the alternative packages install :

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 20
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.8 20
sudo update-alternatives --config gcc
sudo update-alternatives --config g++

at the end:

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

Hope this changes the --version ;)


You can rename your exfat drive by this command, if your drive is /dev/sdb1

sudo exfatlabel /dev/sdb1 new_name


Is it possible to obtain an e-mail address like myname.surname@ubuntu.com

If you became an Ubuntu member you get the benefit of an @ubuntu.com email.

Here is how you can become an Ubuntu member: https://wiki.ubuntu.com/Membership

Ubuntu members are people who are helping the development and growth of Ubuntu. It does not require coding or packaging. You can be an Ubuntu member by just contributing to translations or marketing.

By just using Ubuntu it is not that easy to get an email address.


~ no longer takes me to my home directory

~ takes you to whatever the variable $HOME points to.

Therefore, run

echo $HOME

to see the value of $HOME.
Then find where $HOME is set to that inappropriate directory and fix it.


restarted the machine and typed sudo-apt upgrade and went from there


Passenger (mod-rails) can't find libopenssl-ruby

You need to change to your ruby ext/openssl/ directory, then run

ruby extconf.rb
make
make install

then try passenger-install-nginx-module again


Which sqlite database uses new Skype for Linux?

From the Skype for Linux forum site: Skype for Linux - main.db is not updated

Quoting Van_M, Skype Community Moderator:

  Moving forward the messages that you will send / receive through this new Skype version will be stored in the cloud for two years.
  However, the older conversation will not carry over on the new Skype application.

  Hope this information helps.

  Thanks.

  Van_M
  Skype Community Moderator

So it seems that the new Skype application (versions 5.5 & 8.10) does NOT store anymore a local sqlite database having messages, contacts, conversation, etc...


You have 2 options.

1) Leave things as they are and provide your original 14.04 disk when prompted.

2) Remove the CD from your software sources (recommended)


There is problem with pacpate "Locale"

Reconfigure it and try again

Try running dat 4 reconfiguration languages

sudo dpkg-reconfigure locales

Source

It Worked for me soo i hope it will work for you too


You may have clicked the screen reader 'ON' accidently. You can turn it off by going into Settings-->Universal Access-->Screen Reader-->Off. Hope it helps, if not, i can attach an screenshot.


The Magic Mouse works out of the box in 12.04, with right-click, middle-click, left-click, vertical scroll and horizontal scroll. As far as I can tell, more advanced functions (two-finger swipe, three-finger swipe, pinch, and zoom) don't work yet.


You can install Diodon clipboard manage using the below commands :

sudo add-apt-repository ppa:diodon-team/stable

sudo apt-get update

sudo apt-get install diodon unity-scope-diodon

Starting from 16.04 and up yoy only need to run the last command.

Plugins package is to show an indicator icon in Ubuntu. Start Diodon from the menu/launcher or logout to start at next log-in.


How to find an ubuntu password which i removed?

This is a bug described here and here, where setting the no password login also removes the password therefore using sudo etc. is impossible. The link given by @Rohit is essential to re-create your lost password. If you can still login however, you can open up the terminal; usually CTRL+ALT+T and type passwd to change your password.


Similar problem with 16.04 overview here, maybe it help you
https://www.google.com/amp/s/codeyarns.com/2017/02/04/how-to-make-intel-wireless-ac-3165-work-in-ubuntu/amp/


can i install Ubuntu14.04 in my ideapad?

These are the official system requirements:
700 MHz processor (about Intel Celeron or better)
512 MiB RAM (system memory)
5 GB of hard-drive space (or USB stick, memory card or external drive but see LiveCD for an alternative approach)
VGA capable of 1024x768 screen resolution
Either a CD/DVD drive or a USB port for the installer media
Internet access is helpful

I'd say you are good to go, but really try xubuntu, it's also supported by Canonical but it's more light, or Lubuntu (but it's not Canonical supported) that is even more light.They are both Ubuntu compatible.


Any lightweight video editors for Ubuntu?

Try LosslessCut. It will allow, "Lossless merge/concatenation of arbitrary files (with identical codecs parameters, e.g. from the same camera)".


Fixed IP address reset everyday on Ubuntu Server 12.04

Speculative answer: You probably have a DHCP server on your network, that periodically hands out "leases" on the addresses in its pool. Your static address ending in 110 is in that pool, but it hasn't been handed out by the DHCP so it takes it back, and gives you 134 in return.

Try a different IP address as far away from the DHCP pool as possible, which would be as low as 2 or as high as 252 (some conventions dictate that gateways have high numbers, although yours is 1).


Testing an application in new Wine without losing access to current Wine

What I would do is make a backup of the Wine prefix (cp -r ~/.wine ~/.winebak), try the upgrade, and if the new version causes issues, uninstall the new packages, reinstall wine1.6, remove ~/.wine, and rename ~/.winebak to ~/.wine.

Rarely does Wine have regressions, especially if using the stable version (2.0.x).


How to add more space for Postgresql Ubuntu?

You can use PostgreSQL tablespaces when data must grow across several disks or disk partitions. From the documentation:

  By using tablespaces, an administrator can control the disk layout of
  a PostgreSQL installation. This is useful in at least two ways. First,
  if the partition or volume on which the cluster was initialized runs
  out of space and cannot be extended, a tablespace can be created on a
  different partition and used until the system can be reconfigured.

  Second, tablespaces allow an administrator to use knowledge of the usage pattern of database objects to optimize performance.


You can use

xdg-screensaver lock

To lock your screen. Adding this to your start-up applications would lock on log in.


The version 0.2 of oblogout in the PPA appears to be the latest version. Therefore, I would say that would be the one to try. It is over 3 years old but I don't believe that Openbox has seen any major developments that would break it. Additionally, I have seen articles and forum posts from this year that indicate that it is still being used on current distros.


Kerberos and google-authenticator (2-factor auth)

Ok problem solved (in theory). There actually 2 options: Rolling out your own 2-factor authentication using GSS-API [1] or using the AuthHub and AuthHub-TOTP magnificent plugins [2].

[1] http://www.ibm.com/developerworks/aix/library/au-twofactors/

[2] https://fedorahosted.org/AuthHub/wiki/GettingStarted


I've run into this before, and this fixed it for me.  However, I've just changed this back to the original state, and it doesn't seem to be re-appearing.  Perhaps it has been made moot by an upgrade -- but here's the process I used to fix it.

If you are running into the problem now, and just want to test real quick if this fix works, you can do the temporary:

sudo sh -c 'echo N > /sys/module/drm_kms_helper/parameters/poll'

To keep this change, do:

sudo sh -c 'echo "options drm_kms_helper poll=0" >> /etc/modprobe.d/local.conf'
sudo update-initramfs -u


Impossible from what I gather. Unless you install it yourself. There seems to be a way to install it in mozilla as an extension. But yes, you will need to install that extension yourself. Not much of a "trojan"...

And from what I found out you have some more problems getting it to run.  A lot of the Ubuntu users probably do not even get it to build due to an old used libc. Besides you needing to use an end of life Ubuntu you also need to kill pulseaudio yourself for the trojan to be able to use it. You also need to disable compositing yourself or the only screenshot it takes is a desktop image.

And now for the kicker: the group/person that detected this trojan does not disclose where they found it, do no even provide the source code but they are willing to sell you an anti-virus software for you to use!

B O G U S.


How to remove duplicated Ubuntu image from boot menu?

This is normal. Ubuntu installation keeps two kernels: the current and the previous. It is done for a case when you can't boot the latest kernel for some reason.

If you remove the corresponding linux-generic-... package, the vmlinuz will be removed.

I don't recommend doing it.


How to rename and move thousands of files at once?

You could try a file renaming tool such as those listed in the link provided by tachyons in the comments.

If that fails you may need to script something.

As you say in the question, you know PHP, why not write a solution yourself in PHP. What you suggest seems a reasonable approach.


404 error for CodeBlocks repository when I update my system

As was mentioned - the ppa:damien-moore/codeblocks-stable do not have packages for 18.04.

But search on Launchpad for Code::Blocks related PPAs results in other PPA named ppa:pasgui/ppa.

You can add it with

sudo add-apt-repository ppa:pasgui/ppa
sudo apt-get install codeblocks

and you will get CodeBlocks 17.12.

Optionally you can install contrib plugins with

sudo apt-get install codeblocks-contrib

and enjoy the plugins.


sqlite make test fails because of "tcl.h not found" or "undefined reference to Tcl_Free"

The sqlite configure script appears to look for a Tcl installation as follows:

checking for Tcl configuration... found /usr/lib/tclConfig.sh
checking for existence of /usr/lib/tclConfig.sh... loading

This shell script sources a suitable environment such as INCLUDE and LIB directives, but it is provided by the tcl-dev meta package, rather than the specific tcl8.6-dev package that you installed.

If you install the tcl-dev meta package and do a clean build then the Tcl components should be located without any need to set other variables in the make command.

The tclConfig.sh script seems to be Tcl's own equivalent of the more generic pkg-config mechanism.


How to clone a Windows 7 hdd into a smaller hdd?

Since your're running Windows, try Macrium Reflect (no-cost version), which worked for my similar case.  It claims to get the alignment for SSDs correct.


Replace text in one file and match in second file

How about

awk '
  BEGIN{n=0}
  NR==FNR && a[$2]=="" {
    a[$2]=n++
  }
  {
    $2=a[$2]; print $0 > "new"FILENAME
  }' file1.txt file2.txt


Is it possible to use the 'screen' command to work with files on an encrypted home directory?

There is a file named /home/.ecryptfs/$USER/.ecryptfs/auto-umount which is used as a flag for umounting the encrypted partition whenever you don't have a login shell anymore.

You might want to remove this, or (untested!) try to create another session within screen (eg run sudo login and login with the same user, within screen, this should keep the number of login-shells above zero).

EDIT: ecryptfs use who to count the number of logins. If you feel like troubleshooting...


Following the recent 18.04 updates, my Laptop now hangs after resume

Seems that my reply to the comment is too long, so I've pasted it here as a reply.

On Saturday 22nd Feb, I downloaded Ubuntu, Lubuntu & Mint from the official websites, all 3 worked fine until the package manager made some updates which presumably also come from an official source, after the updates my Laptop either has a blank screen  on resume or the screen that was showing when I suspended the Laptop. In both cases the system is frozen. If it's not possible to work out what's on the official websites & what's in the official updates, then there's more to worry about than my Laptop. Do the updates only contain kernel changes, or are there perhaps also video driver updates. As I need my laptop for day to day use and as suspend / resume form an integral part of the daily use, I've had to move on to a Debian based distro that works just fine at the moment so I can't dig out the kernel versions. Up til now, Lubuntu has served my needs very well so it's a shame that I've had to move on. Maybe I'll come back when the next LTS version is released.

Hopefully someone else will be able to pick up on this issue and work out what changes have been released in Feb.


Nvidia GeForce GT540M Ubuntu 18.04 overheating

Which OS were you running prior to Ubuntu? Were there any temp problems with that OS? Here is a link to install Psensor which will allow you view the temps in an applet at the top of the screen.

Install Psensor

Usually these problems are caused by blockages in the ducting of the machines air passages. Do you have a dog or cat that sheds? Is the machine fairly dusty. 9 times out of 10 cleaning the fan and air intake ports with compressed air will solve these problems as will disassembling the bottom of the laptop and then manually cleaning the debris out. Could you please try that and report back with the results.


Is postfix 3.0.x available for ubuntu 14.04 LTS

No there is not in the repository atleast. There is version 2.11.0-1.

You can search for packages from here: http://packages.ubuntu.com/.


You have NetBeans 10 version in Ubuntu 18.04 but your JDK is either version 11 (openjdk-11-jdk) or version 8 (openjdk-8-jdk), so install latest NetBeans version and openjdk-11-jdk instead. Apache NetBeans can be installed from the terminal in Ubuntu 18.04 with the following command.
sudo snap install netbeans --classic

The netbeans snap package includes the Base IDE, Java Development Tools and Plug-in Development Tools.


Install OpenCL on ubuntu 16.04, Intel i5 7th gen Dell Inspiron Laptop

Ok so I figured it out. Also, it was NOT rocket-science :/

The link (OpenCL On ubuntu 16.04, Intel Sandy Bridge CPU) I followed earlier was perfect since I was working on a Xeon machine. It would not have worked (big surprise!) on my Laptop since it obviously isn't a Xeon machine.

I needed to use the sdk for linux which is available after filling out the form. Once the form is filled out you get redirected to a page where you can choose the product and the version and download either a .gz file or a .tgz file. The .tgz is for the Yocto OS but during installation you can run it without any loss of generalization for Ubuntu 16.04.

The installation is fairly simple since there is an extremely handy executable install.sh shell script to use.

The general steps to follow are:

extract the folder

tar -xzvf intel_sdk_for_opencl_2017_yocto_7.0.0.2567_x64.tgz

run the shell script

./install.sh

follow the instructions

The output of the python script then shows:

============================================================
OpenCL Platforms and Devices
============================================================
Platform - Name:  Intel Gen OCL Driver
Platform - Vendor:  Intel
Platform - Version:  OpenCL 1.2 beignet 1.1.1
Platform - Profile:  FULL_PROFILE
beignet-opencl-icd: no supported GPU found, this is probably the wrong opencl-icd package for this hardware
(If you have multiple ICDs installed and OpenCL works, you can ignore this message)
============================================================
Platform - Name:  Experimental OpenCL 2.1 CPU Only Platform
Platform - Vendor:  Intel(R) Corporation
Platform - Version:  OpenCL 2.1 LINUX
Platform - Profile:  FULL_PROFILE
    --------------------------------------------------------
    Device - Name:  Intel(R) Core(TM) i5-7200U CPU @ 2.50GHz
    Device - Type:  CPU
    Device - Max Clock Speed:  2500 Mhz
    Device - Compute Units:  4
    Device - Local Memory:  32 KB
    Device - Constant Memory:  128 KB
    Device - Global Memory: 8 GB
    Device - Max Buffer/Image Size: 1962 MB
    Device - Max Work Group Size: 8192
============================================================
Platform - Name:  Intel(R) OpenCL
Platform - Vendor:  Intel(R) Corporation
Platform - Version:  OpenCL 2.0
Platform - Profile:  FULL_PROFILE
    --------------------------------------------------------
    Device - Name:  Intel(R) HD Graphics
    Device - Type:  GPU
    Device - Max Clock Speed:  1000 Mhz
    Device - Compute Units:  23
    Device - Local Memory:  64 KB
    Device - Constant Memory:  3209904 KB
    Device - Global Memory: 6 GB
    Device - Max Buffer/Image Size: 3135 MB
    Device - Max Work Group Size: 256
    --------------------------------------------------------
    Device - Name:  Intel(R) Core(TM) i5-7200U CPU @ 2.50GHz
    Device - Type:  CPU
    Device - Max Clock Speed:  2500 Mhz
    Device - Compute Units:  4
    Device - Local Memory:  32 KB
    Device - Constant Memory:  128 KB
    Device - Global Memory: 8 GB
    Device - Max Buffer/Image Size: 1962 MB
    Device - Max Work Group Size: 8192


Can I use the 2.6 kernel provided with my embedded system to run 12.04?

The minimal kernel required for Ubuntu 12.04 is 2.6.24
Ubuntu 12.04 should install and run successfully on any kernel that is newer than 2.6.24. The root cause of this requirement is the libc libraries shipped with 12.04 -- libc is the basis on which every single Ubuntu binary/library depends. This requirement can be bypassed too.
For 10.04 (or newer), your manufacturer requires you to use a special 2.6.34 kernel
You must use the special 2.6.34 kernel DMP supplies here, which is required to install Ubuntu 10.04 (or newer, if possible).
This fact is made perfectly clear on their support page:

Can you use the 2.6.34 kernel with Ubuntu 12.04?
I see no reason why you can't. DMP's FTP directory provides the kernel source as well as all patches. Of course, no one without a Vortex86DX/SX can confirm if it will work out of the box, or what you will need to make sure it works.
I very much doubt the manufacturer is going to hand you official 12.04 support on a platter since they seem to be having problems even with 10.10 and are stuck on 10.04. Unfortunately, that's how proprietary embedded hardware often is.


How to rename many files, using a prefix ID?

You can use a loop variable, and reference it using ${loop_variable_name} in your command.
Use...
for directory_name in PJA_*; do
    echo "Processing ${directory_name}."
    mv "${directory_name}/results/variants/variants.vcf" "${directory_name}/results/variants/${directory_name}_variants.vcf"
done

...to modify the file structure like...
PJA_001
└── results
    └── variants
        └── variants.vcf
PJA_002
└── results
    └── variants
        └── variants.vcf
PJA_003
└── results
    └── variants
        └── variants.vcf
PJA_004
└── results
    └── variants
        └── variants.vcf
PJA_005
└── results
    └── variants
        └── variants.vcf

...into the file structure like this...
PJA_001
└── results
    └── variants
        └── PJA_001_variants.vcf
PJA_002
└── results
    └── variants
        └── PJA_002_variants.vcf
PJA_003
└── results
    └── variants
        └── PJA_003_variants.vcf
PJA_004
└── results
    └── variants
        └── PJA_004_variants.vcf
PJA_005
└── results
    └── variants
        └── PJA_005_variants.vcf


Downloading files in place similar to github

Assuming you are on Ubuntu, use wget:

wget -r -nH -np http://www.intoxitones.com/mtg_render/

-r - Download recursively
-nH - Do not create a directory for the hostname (www.intoxitones.com)
-np - Do not ascend to a parent
directory

This will create a few files named index.html with some garbage affixed to it, which you can manually delete.


The command for forwarding port 80 from your local machine (localhost) to the remote host on port 8000 is:

ssh -R 8000:localhost:80 oli@remote-machine

This requires an additional tweak on the SSH server, add the lines to /etc/ssh/sshd_config:

Match User oli
   GatewayPorts yes

Next, reload the configuration by server executing sudo reload ssh.

The setting GatewayPorts yes causes SSH to bind port 8000 on the wildcard address, so it becomes available to the public address of remote-machine (remote-machine:8000).

If you need to have the option for not binding everything on the wildcard address, change GatewayPorts yes to GatewayPorts clientspecified. Because ssh binds to the loopback address by default, you need to specify an empty bind_address for binding the wildcard address:

ssh -R :8000:localhost:80 oli@remote-machine

The : before 8000 is mandatory if GatewayPorts is set to clientspecified and you want to allow public access to remote-machine:8000.

Relevant manual excerpts:

ssh(1)

  -R [bind_address:]port:host:hostport
  Specifies that the given port on the remote (server) host is to be forwarded to the given host and port on the local side.  This works by allocating a socket to listen to port on the remote side, and whenever a connection is made to this port, the connection is forwarded over the secure channel, and a connection is made to host port hostport from the local machine. By default, the listening socket on the server will be bound to the loopback interface only. This may be overridden by specifying a bind_address. An empty bind_address, or the address ‘*’, indicates that the remote socket should listen on all interfaces. Specifying a remote bind_address will only succeed if the server's GatewayPorts option is enabled (see sshd_config(5)).

sshd_config(5)

  GatewayPorts
  Specifies whether remote hosts are allowed to connect to ports forwarded for the client. GatewayPorts can be used to specify that sshd should allow remote port forwardings to bind to non-loopback addresses, thus allowing other hosts to connect. The argument may be 'no' to force remote port forwardings to be available to the local host only, 'yes' to force remote port forwardings to bind to the wildcard address, or 'clientspecified' to allow the client to select the address to which the forwarding is bound. The default is 'no'.

See also:

How to create a restricted SSH user for port forwarding?


Try explicitly requesting the installation of all those packages, like so:

sudo apt-get install libsdl1.2-dev libx11-dev libglu1-mesa-dev libpulse-dev libxt-dev libxext-dev

That will either work or give you another error. In the latter case, please update your post with the details on that error using the edit function.


dpkg: error: parsing file '/var/lib/dpkg/updates/0006' near line 0: newline in field name `#padding'

Easily just delete that file error

sudo rm -rf /var/lib/dpkg/updates/0006

then run again

sudo dpkg --configure -a


Adding hard disc to existing Samba Share folder

You might create a new folder inside your samba share and mount the new 5TB disk in this new folder. Maybe not the most elegant solution, but is quick and easy one.

First you need to partition your disk as you see fit. You may find a lot of tutorials on Google (https://www.google.com/search?q=how+to+partition+disk+in+linux).
I'll assume that you made only one partition on your new disk and that system sees your new disk as 'sdb' device (for more on identifying disks, please see https://www.google.com/search?q=how+to+identify+hard+disk+in+%2Fdev+linux).

Create a folder called 'new_disk" in your samba share directory:

mkdir /path/to/samba_share/new_disk

Then edit your 'fstab' file (found in /etc/fstab):

sudo nano /etc/fstab

and it might look similar to this:

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>

proc  /proc  proc  defaults  0  0
# /dev/sda5
UUID=be35a709-c787-4198-a903-d5fdc80ab2f8  /  ext4  relatime,errors=remount-ro  0  1
# /dev/sda6
UUID=cee15eca-5b2e-48ad-9735-eae5ac14bc90  none  swap  sw  0  0

/dev/scd0  /media/cdrom0  udf,iso9660  user,noauto,exec,utf8  0  0

And you need to add a mount point for your new hard disk. Add the following line to your /etc/fstab file:

/dev/sdb1  /path/to/samba_share/new_disk  ext4  defaults 0  0

Save the changes and mount the new disk manually (or reboot for automatic mount):

sudo mount /dev/sdb1 /path/to/samba_share/new_disk

Make sure there is a new line at the end of the fstab file.

Adjust access rights to your new disk/folder as you see fit, and you should be ready to go.


Unity: Shortcut to open new Terminal doesn't work after enabling workspaces

There is a bug here https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/975416

But you can solve the problem by assigning a new keyboard shortcut to terminal

From Dash open Keyboard then go Shortcuts tab and navigate to Custom Shortcuts then Click on +

Use the following command

gnome-terminal --profile=Default

Now assign the key combination (Ctrl+Alt+T) on clicking on it.


Login loop, can only login as Guest. Ubuntu 12.04

I had the same problem. It seems there was some kind of problem in my ~/.profile file. Rename it to something else (so you don't loose it) and try logging in again.

This solved my problem.


Unable to use IntelliJ IDEA keyboard shortcuts on Ubuntu

As a bit of reading taught me that Intellij IDEA is a keyboard-centric IDE. What it means, is that a use can work with it without having to touch the mouse. Also I manage find keymap setting.

For Ubuntu

See how to change keyboard shortcuts?

Here’s a list of tweaks you need to make with default system key bindings so that they won’t interfere with IntelliJ IDEA actions (listed in brackets).

  Disable the Shade window action, assigned to Ctrl + Alt + S (Settings dialog)
  Change or disable the Lock Screen action, assigned to Ctrl + Alt + L (Reformat code)
  Change or disable the Launch terminal action, assigned to Ctrl + Alt + T (Surround with)
  Change or disable the Switch to workspace action, assigned to Ctrl + Alt + Arrow Keys (Navigation)
  Disable the Move window action, assigned to Alt + F7 (Find usages)
  Change or disable the Resize window action, assigned to Alt + F8 (Evaluate expression)

Hope this helps!

Note: You can always revert Ubuntu shortcuts back to its default state. Just refer to How can I restore default keyboard shortcuts?, in case if you're lost.

Source: --  Intellij IDEA Keymap


How do you use Qutecom to connect to other services?

Clients of libpurple don't have to use all the protocols, or have them as options. Looking at the QuteCom wiki and various documents I could find, it looks like they're using libpurple for specific backend/frontend handling and their client doesn't support other protocols.

Have you tried connecting to QuteCom's backend using Empathy?


Is there a way to alias the command cd so that it protects the arguments?

You can do it, but only if your directory names don't contain several consecutive spaces, and only if they contain no shell special character other than spaces.

cd () { builtin cd "$*"; }

In practice, use completion: type cd My then press Tab. Bash will insert backslashes before special characters.


Can not install nautilus-gksu in Ubuntu 14.04 LTS

gksu is now deprecated.

I believe the proper way to open nautilus as root would be to use sudo -i instead.

Here's an example:

sudo -i nautilus &


You could try to disconnect the external hard drive, then see if it boots. My guess is that at its worst you would have to rewrite the master boot record or something, for wandows but i don't know if your windows is on the solid state drive or the terabyte drive, anyways there are a number of ways to approach this you can drop in the old windows 7 disk and fire up a dos command prompt and type fixboot, or fixmbr you could us a generic freedos, and do the same i have not worked much with solid state drives so much so i cant tell you from experience but i think if you know how to run the command prompt you should be fine


First of all :

In security terms, in the absolute : Wifi or any wireless data system cannot be secured. This is due to the fact that anyone can "ear" you and then "decypher" you.

It means that, if the hacker want to and have the knowledge : he will always win in a short time.

The only thing that you can get is getting the work of hacking you harder.

That being said, Here is the recommendations without being too specific :

You are actually connected via WEP and I assume that you use TKIP. Those settings have to be changed directly with the device that provides you Wifi. This must be done first to be able to use something else.

Most of those devices are the Wifi of the DSL box of your provider and mostly only have those settings available. If it's the case : you must purchase a modern Wifi Access Point that you will wire connect to this box in order to shutdown the wifi of the box and use the wifi of the access point you set.

If you can change your wifi settings or purchased a new wifi access point :

WARNING : Any modification in the wifi device will cause disconnection. If it's badly set then it'll not be able to reconnect. If this happens : connect your computer with an ethernet wire and put again the old setting.

In Wifi security, you have three settings to care about :

The Wifi password must be more or equal to 14 caracters that must not contain words and must contain letters in upper case and lower case with numbers (no date) and special caracters such as space, @ or #. Think to change your password in a regular basis (at least each semester).
The key cipher must be WPA2 personal (the other one needs a server that you wouldn't be able to use)
The cipher must be AES with is more secure than TKIP

Any hardware filtering is quite useless because any hacker will begin by using the hardware ID of any connected existing device. Plus it does not avoid to be listened (and so to be deciphered or hacked). Those protections only block any unknown hardware to speak with them : not to be eard.

But watch out : some wireless devices cannot use those settings (or need update to be able to).

Hopes that will help you.

BTW : WEP+TKIP now takes less than 5 minutes to decipher.


udev held back by apt-get while using ondrej systemd PPA

The problem is the ondrej/systemd ppa.

If you expand the package files for precise, you'll see the ppa is providing sysv-rc.

Moreover, the main page says the [ppa] follows latest systemd packages as maintained by Debian systemd team.

Look at the package details in Debian and you'll see the apt is looking for a Debian-style name; but it's odd that apt is proposing the standard, non-ppa package.

Maybe the ppa needs to re-configured or re-installed; or perhaps you should file a bug against the ppa.


How can I enter and also rename folders like ''Human (2012)''?

You could double quote your path:

cd ~/"folder1/Human (2012)"

or you should provide escape sequence for (,) and  (space) (as these are special characters):

cd ~/folder1/Human\ \(2012\)

and

mv ~/"folder1/Human (2012)"

With escape sequence:

mv ~/folder1/Human\ \(2012\)


Running native ubuntu installation from fusion or parallels

I am doing this to my macbook now,  fresh Macbook Pro i7 - Mountain Lion.

I will post the steps I take.


Oddly, redirecting does work normally (I've just tested this with my mouse)... It seems to be a problem specific to the virtual device.

Well this was a much bigger, stranger problem than I initially thought. The short answer is: it's buffered and when you Control+C, that buffer is lost. Now, I have no idea why it's being buffered for the virtual device and not physical ones.... That's above my pay grade.

How to work around it is pretty simple though (again from Stephane Chazelas at Unix & Linux):

stdbuf -oL xinput test 5 > test

And the reason you were seeing some output before is because they virtual keyboard writes to the active window (like a physical keyboard would).


Ubuntu 16.04 and Chrome address bar highlight color

The reason why you're seeing this low contrast is because of a change to Google Chrome's user interface (UI) that took place in version 69. Certain aspects of the UI no longer obey the user's gtk theme. A bug has been filed in this regard and one can star GTK+ theme ignored in omnibar in the new interface.

There is a workaround, for now, described in How to get back my previous omnibox in Google Chrome 69 or Chromium 69?.

You can solve the contrast issue described in your question by applying the workaround described in the Ask Ubuntu link above.

The image below uses the "default" mode which is the new mode present in version 69. Note the somewhat rounded tab corners and the low contrast for entries in the dropdown:

The next image uses the "normal" mode which retains the tab design of version 68 (and earlier) and also provides better visual contrast for the selected item in the dropdown just as you would expect from your current gtk theme:

Both images were taken with the Adwaita theme and Google Chrome Version 69.0.3497.92 (Official Build) (64-bit).


Linux platform only

You can use the disk utility that comes installed with Ubuntu by default.

Install the cryptsetup package: sudo apt-get install cryptsetup

If the gnome-disk-utility package is not installed: sudo apt-get install gnome-disk-utility

Some things to have in mind prior:

Any data that is on the partition will get erased
This is NOT suitable for a partition that is running your current OS
Again, back up everything and be sure to format the correct drive!

Creating a new encrypted partition:

Start the Disk Utility:

Make sure you identify the proper drive in the left hand panel.
If needed, create empty space on the disk by resizing/deleting partitions.
In the Volumes graphic overview, click the appropriate empty block.
Click Create partition to create the partition to be encrypted.
Check Encrypt underlying device.

They will then prompt you for a password. Chose a decent password - your encryption will only be as strong as your password. It is probably also safer not to store the password, choose the option Forget password immediately.

Encrypting an existing partition

Select the partition that you want to get encrypted
Make sure that it is not mounted by pressing on the "stop" button
Click the "gear" icon under the partition and choose Format...
Select the type Encrypted, compatible with Linux systems (LUKS + Ext4)
Enter a name to distinguish the partition
Enter your passphrase to encrypt it and confirm it

For higher security, if you have have any existing data in this partition, select the erase option. You can overwrite existing data with zeroes, but this could take several hours depending on the disk.
Format it and wait until it finish in a couple of minutes!

Using your encrypted partition

Once your partition is formatted, it will be encrypted.
In fact, you have two partitions, a container partition and the encrypted partition.
Disk Utility will show them above each other when the volume is unlocked.
From the Disk Utility, you can lock and unlock the volume by selecting the partition with the little lock and clicking Lock Volume or Unlock Volume.

Make sure that you leave it closed/locked before unmounting the system, otherwise you will get an error. Also, with two partitions, you will have to unmount both before being able to safely remove the drive.

In the Disk Utility, there also is a button Change passphrase, which works much faster than the initial formatting.

From Nautilus, you can mount and unmount the encrypted volume almost like a normal external USB drive or memory stick, except that you will be prompted for the password.

Source: https://help.ubuntu.com/community/EncryptedFilesystemsOnRemovableStorage


It is no longer necessary...has not been needed for a while.  Xorg uses some built in intelligence so that it is not needed...
Now the extra keys in mice are recognised by the kernel but nor mapped to anything.  This may be sorted by using  xbindkeys... e.g. http://nxfifteen.me.uk/en/20130320/getting-logitech-custom-mouse-buttons-working-within-linux


Alternative To DD For Back/Restore Of MBR

I haven't tried it yet, but Partimage says it has the ability to restore the mbr from a disk image you've made. However my understanding is that you must backup the disk not just the mbr which isn't what I had in mind.

For more about partimage: http://www.partimage.org/Main_Page


Is it possible to connect to already running session on Xubuntu 12.04 machine?

vncviewer allows to specify the display number in the connection string:

  If you run the viewer with no arguments it will prompt you for a VNC
  server to connect to. Alternatively, specify the VNC server as an
  argument, e.g.:  vncviewer snoopy:2

  where 'snoopy' is the name of the machine, and '2' is the display
  number of the VNC server on that machine. Either the machine name or
  display number can be omitted. So for example ":1" means display
  number 1 on the same machine, and "snoopy" means "snoopy:0" i.e.
  display 0 on machine "snoopy".

Source: manpage for vncviewer

I could not find an explicit option in Remmina to specify display number, however:

  By default, a VNC server will listen for connections from a VNC viewer
  on TCP port "5900+N", where N is the "Display Number" (usually just
  zero). So a VNC server setup for Display-0 will listen on TCP-5900,
  Display-1 is TCP-5901, etc.

  Additionally, the VNC server will listen for connections from a
  web-browser on TCP port "5800+N", where N is as above. If you point a
  web-browser to this port, the VNC server will automatically provide a
  Java VNC viewer that runs right in your web-browser. This Java Viewer
  will then exchange data with the VNC Server on the same ports a normal
  VNC Viewer would use: "5900+N".

(source)

So I guess you may try to connect to a specific display by specifying port number in connection settings.


Cannot start Ubuntu 18.04 on a Dell Precision Tower after a fresh install - login screen turns blank

The key to this is the following:

1- Create a bootable stick

2- Boot the stick, and in the menu with the options "Try Ubuntu", "Install Ubuntu", etc, press e and add nomodeset right before quiet splash. Then press F10

3- The stick will boot properly this time. Install Ubuntu, the installation should go through without a problem

4- After installing Ubuntu, when you restart, the screen might flicker and die before you can log in, that is what happened to me.

This answer, in particular the Black/purple screen after you boot Ubuntu for the first time section, provides some solutions, but none worked for me... I tried pressing Right Shift but nothing happened. If that is the case, do the following:

5- If you press Esc while booting, you will go to the grub> command line. Here, and thanks to this link, you can type the following, adding nomodeset like before (type what's after grub>):

grub> ls
(hd0) (hd0,gpt2) (hd0,gpt1) (hd1) (hd2)

grub> cat (hd0,gpt2)/etc/issue
Ubuntu 18.04 LTS \n \l

grub> linux /boot/vmlinuz-4.15.0-23-generic root=/dev/sda2 nomodeset

grub> initrd /boot/initrd.img-4.15.0-23-generic

grub> boot

This will allow you to boot to Ubuntu with no problem!

HOWEVER, with the nomodeset option you will not be able to adjust the screen brightness (as specified here).

I have tried the solutions involving making changes to the /etc/default/grub file, and they all cause that you cannot boot anymore. If anyone has a proper solution for this problem, please let me know, otherwise I will open a new question.


Realtek Wifi connection drops after couple of minutes or hours on Ubuntu 20.04

This will be less of an answer and more of an experiment. Please try:
sudo -i
echo "options rtw88 lps_deep_mode=0"  >  /etc/modprobe.d/rtw88.conf
exit

Reboot.
I suspect that the cause of the drops and failure to properly recover is caused by imperfect implementation of power saving deep sleep.
Reference: https://patchwork.kernel.org/patch/11146427/
https://patchwork.kernel.org/patch/11146433/


you may use cp -a to preserve owner/permissions when copying files,
so it wouldn't change


All you need to do is install Ubuntu over it. Follow the instructions at https://askubuntu.com/a/145652/54298 and when you get to step 8, you can choose to use all space for Ubuntu.


Bug in firefox address bar autocomplete running on KDE

Marcus, you will need to file a bug for this issue. The easiest route would be from within Firefox. On the the application menu, click Help, then Report Bug. Once you fill out the form, it will be sent to the developers. If you are not able to report a bug this way, there are a few other methods described in the link below:

https://wiki.kubuntu.org/Kubuntu/Bugs/Reporting/

Unfortunately, as with many bugs, the quick and easy fix is to have the developers make an update for this! If you submit your bug in LaunchPad, you may find that other users are also seeing the same glitch, or the developers may point you to a temporary solution until a patch rolls out.


atheros AR9285 compatibility with wpa2 enterprise

I have this problem all the time with Linux-based OS's.

sudo gedit /etc/NetworkManager/system-connections/'name of SSID'

The problem is that it's looking for a certificate on the PC to validate the connection.

Go in and find:

system-ca-certs=true

and change it to:

system-ca-certs=false

And then try reconnecting. Hope that helps.


How can i lock a device id to a particular port address

Compare your /dev directory before and after you plug in your GSM modem. It is very likely that a softlink /dev/gsmmodem appears, pointing to the appropriate ttyUSB device.


How to add entry to /etc/hosts with a built-in command line

After seeking for CLI for /etc/hosts , we find : https://github.com/macmade/host-manager

Amazing :

host-manager -add www.example.org 127.0.0.1
host-manager -remove www.example.org


WiFi connects, but no internet. How to.problemsolve?

Try going to a random unused domain that you have never browsed before making sure to use http:// and not https:// - if you're in a captive portal it will likely redirect you to a login page.


help, no gui or desktop after upgrage from 16.04 to 20.04

Well, I can't post my output because it reads the links in the output as links in my post and I can't do that until I have 10 points on the forum or something. Puting in in CODE doesn't seem to work..
Errors show it could not resolve any of the ' us.archive - bionic- release' of anything, output lines like this:
Err:1 http://us.archive.ubuntu.com/ubuntu bionic InRelease Could not resolve 'us.archive.ubuntu.com'
Other errors were like this:
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/bionic/InRelease Could not resolve 'us.archive.ubuntu.com'
The following packages have been kept back:
gnome-sessions-bin gnome-session-common qtchooser ubuntu-session
0 upgraged, 1 newly installed, 0 to remove and 4 not upgraded.
Neet tro get 17.3kb of archives.
After this operation, 100 kb of additional disk space will be used.
Err:1 http://us.archive.ubuntu.com/ubuntu/bionic-updates/main amd64 libgles2 amd64 1.0.0-2ubuntu2.3
Could not resolve 'us.archive.ubuntu.com
E: Failed to fetch http:us.archive.ubuntu.com/ubuntu/pool/main/libg/libglvnd/libgles2_1.0.0-2ubuntu2.3_amd64.deb
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
Sorry this is a botched description of the output until I can post in in this editor.
boot screen img 1
boot screen img 2
boot screen img 3


Switch languages ubuntu 20.04 lxqt desktop

Solution posted here: https://discourse.lubuntu.me/t/lubuntu-19-10-lxqt-cannot-change-keyboard-layout-shortcuts-not-working/507/1
To tell a long story short

Add or remove keyboard layout
Set new shortcut for switching languages and/or set keyboard model
Press apply


Why can't I build Python code from Sublime Text 3 when I launch it from Ubuntu Dash vs Ubuntu Terminal

Your python path is not configured correctly. To fix:

Create a .bash_profile in your home directory. Then, add the line

PYTHONPATH=$PYTHONPATH:new_dir
EXPORT $PYTHONPATH\

Or even better:

if [ -d "new_dir" ] ; then
    PYTHONPATH="$PYTHONPATH:new_dir"
fi
EXPORT $PYTHONPATH

The .bash_profile properties are loaded every time you log in.

The source command is useful if you don't want to log in again.


Can't change brightness in Kubuntu 18.04

As just a simply workaround you can use the following command-line to set your brightness:

echo 255 | sudo tee /sys/class/backlight/*/brightness >/dev/null

Change the 255 value with one from 0 to 255 to move from min to max value.


How do I install Falkon browser in Ubuntu GNOME?

Falkon is a new and very fast QtWebKit browser. It aims to be a lightweight   web browser available through all major platforms. This project has been  originally started only for educational purposes, but from its start Falkon has grown into a feature-rich browser. Falkon has AdBlock built-in and enabled by default. Falkon also can import bookmarks from Firefox, Chrome, Opera and .html file(s).

To install the native Falkon browser snap package in all currently supported versions of Ubuntu open the terminal and type:

sudo snap install falkon --channel candidate

The candidate version of the Falkon browser snap package is currently 3.0.1, the same as the current version at https://www.falkon.org/.

To launch Falkon from the terminal:

snap run falkon

The falkon snap package will be updated automatically when updates are available.

Support for playing Flash videos in Falkon can be added with the following commands:

sudo apt install adobe-flashplugin
sudo apt install browser-plugin-freshplayer-pepperflash # 16.04 and later


Does Ubuntu offer tactile sign language accessibility options for persons both blind and deaf?

Sadly, Ubuntu does not offer this accessibiliiy option, the technology I don't think is publicly available for such robotic hands, but definitely no features on Ubuntu support this. Maybe in the future. Hopefully, this would very helpful, but not now.


Nextcloud client complains about missing keychain at startup

After digging around on the internet, I've found this topic, with a possible solution. Please read the topic for the security implication of the approach.

The solution is running in a terminal:

snap connect nextcloud-client:password-manager-service

or you can use the software center as well:


The problem is that the default gateway gets changed by OpenVPN, and that breaks any connection coming in on the non-VPN interface. Linux will send responses to packets that came in on the real interface out the VPN interface! You need to set up appropriate routes before you start OpenVPN.

What follows works for me. It uses iptables and ip (iproute2). Below, it is assumed that the default gateway interface before OpenVPN is started is "eth0". The idea is to ensure that when a connection to eth0 is made, even if eth0 is not the default gateway interface anymore, response packets for the connection go back on eth0 again.

You could use the same number for the connection mark, firewall mark and routing table. I used distinct numbers to make the diffences between them more apparent.

# set "connection" mark of connection from eth0 when first packet of connection arrives
sudo iptables -t mangle -A PREROUTING -i eth0 -m conntrack --ctstate NEW -j CONNMARK --set-mark 1234

# set "firewall" mark for response packets in connection with our connection mark
sudo iptables -t mangle -A OUTPUT -m connmark --mark 1234 -j MARK --set-mark 4321

# our routing table with eth0 as gateway interface
sudo ip route add default dev eth0 table 3412

# route packets with our firewall mark using our routing table
sudo ip rule add fwmark 4321 table 3412

===

UPDATE:

The above works fine for me on Debian Jessie. But on an older Wheezy system I have just found that I need to add "via" to the routing table entry:

# our routing table with eth0 as gateway interface
sudo ip route add default dev eth0 via 12.345.67.89 table 3412

There "12.345.67.89" must be the original non-VPN gateway.


Does running top and/or gnome-system monitor slow down your computer?

Every process consumes resources from your system but top is not going to be in the top 5. Gnome system monitor can be as it is more than just showing information, it also creates graphics and other ways to show you data that all will need resources.

You can use this to view the top 10 memory consuming processes:

ps -eo pmem,pcpu,vsize,pid,cmd | sort -k 1 -nr | head -10

Also have a look at htop, it is a little bit quicker when starting.

  I like knowing if some software I'm running is starting to mess up the system, so I like to keep it up all the time. I

I do not think that will work. When there is a spike, you might get to the screen that has top before the spike ends. You really should set up some sort of log to be able to see what spiked the system.

You are better of with ...

 sar -u 1 0 -f /var/log/sar

This will show once per second (1) forever (0) cpu usage (-u) and it is all saved in /var/log/sar for future reference.

Some remarks:

that log on 1 second interval will grow. Quick.
sar also eats resources. More when it has to work a lot.

... so choose a more sane interval.

sar might actually already log to /var/log/sa/.


Find keyboard commands by name in Ubuntu

A list of Hotkeys is provided from the Official Ubuntu Documentation. For reference, the default Desktop Environment of Ubuntu, 18.04 and newer, is GNOME, so these will also work on any current GNOME system.


Why isn't lxd init working on new install of Ubuntu 18.04?

Have you tried using LXD from snaps? As per https://discuss.linuxcontainers.org/t/migrate-from-ppa-to-snap/816

Run snap install lxd and then lxd.migrate

It will move all your data and then remove the old packages (deb) from your system.

I did that recently on my latest server install (from my history):
   10  sudo snap install lxd
   11  sudo /snap/bin/lxd.migrate
   12  /snap/bin/lxd init
   13  lxc list


bash script : is it possible to recognize video format from files (to batch extract audio from them)?

You are looking for file

e.g.

 $ file -b 01--Frank_Sinatra--Close_to_You_And_More--Close_to_You.m4a
 Audio file with ID3 version 2.4.0, contains: ISO Media, MPEG v4 system, iTunes AAC-LC

It should cover all well-known media types.
If something is missing, you can add it yourself (see man magic).


Unable to install Latte-Dock on Ubuntu 18.04 with KDE Plasma

I fixed this by adding the KUbuntu Backports PPA and doing an update. This updated the packages which were outdated.

sudo add-apt-repository ppa:kubuntu-ppa/backports

This updated all the packages (many) and the installed Latte through the KDE Store.


Getting Started

Homepage
Hardware Requirements
What's New (Official)
Online Tour (Official)
Rick Spencer’s Getting Started(This is a great beginner guide, start here)
OMG!Ubuntu's Guide to Unity
Rick Spencer’s Video Guide
Jorge’s Video Guide to the Dash
Jorge’s Video Guide to Multitasking

Frequently Asked Questions

Common Questions

What’s the right terminology for Unity’s UI elements?
How can I configure Unity?
Unity Mouse/Keyboard Shortcuts
Does Unity support disabling the global application menu?
How do I reset my Unity configuration?
How do I turn on Unity drag handles?

Launcher and Quick Lists

What are the custom launchers created for Unity?
How can I edit/create new launcher items in Unity
How do I make a custom launcher for terminal applications?
How to add my favorite places as a quicklist in my home’s icon in Unity?
How can I keep recent files from appearing in Unity?
How do I add a static quicklist that opens a web page?
How do I put a web application on the Launcher?
Launcher icon to share files with Dropbox - drag and drop
Drag and drop imageshack uploader
Show desktop icon for the launcher

Indicators and notification area

How do I access the system tray?
What happened to the weather-app in the panel?
List of application indicators

Lenses

What exactly is a “lens”?
What Lenses are available?
5 neat Unity lenses in development
Unity Lens Documentation
How do I install the Reddit Unity Lens?
How do I install the Ask Ubuntu Unity Lens, and how do I use it?
How do I install the Books Lens, and how do I use it?

Task Switcher

How to show windows only from the current workspace in switcher?
Video on how to use the task switcher.

Developers

For application developers

Launcher API
All API Documentation
What is nux and what’s it used for?

Contributing to Unity

Get Involved
How do I build Unity from source?
Unity Architecture
Bitesize Bugs (getting started bits of code)
Coding Style
Unity’s development visualized
I’m a Unity developer ask me anything
We're the Unity Development team, as us anything.


I was able to solve this using something similar to the second example posted on the Arch Wiki for NVidia cards - TwinView.

Each monitor is plugged into a separate graphics card and I've enabled SLI Mosaic mode. I've also forced the refresh rates to 60 Hz for the moment, but may uncomment this and use a range to see if that works.

I created a new file in /usr/share/X11/xorg.conf.d named 99-custom.conf and it looks like:

Section "Device"
    Identifier     "Card A"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX TITAN X"
    BusID          "PCI:1:00:0"
EndSection

Section "Device"
    Identifier     "Card B"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce GTX TITAN X"
    BusID          "PCI:2:00:0"
EndSection

Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Left Monitor"
    VendorName     "Unknown"
    ModelName      "DELL P2715Q"
    HorizSync       31.0 - 140.0
    VertRefresh     60.0 - 60.0
    ## Original Vertical Refresh rate
    #VertRefresh     29.0 - 75.0
    Option         "DPMS"
EndSection

Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier     "Right Monitor"
    VendorName     "Unknown"
    ModelName      "DELL P2715Q"
    HorizSync       31.0 - 140.0
    VertRefresh     60.0 - 60.0
    ## Original Vertical Refresh rate
    #VertRefresh     29.0 - 75.0
    Option         "DPMS"
EndSection

Section "Screen"
    Identifier     "Left Screen"
    Device         "Card A"
    Monitor        "Left Monitor"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "SLI" "Mosaic"
    Option         "BaseMosaic" "True"
    Option         "metamodes" "GPU-0.DP-0: 3840x2160_60 +0+0, GPU-1.DP-0: 3840x2160_60 +3840+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"
    Identifier     "Right Screen"
    Device         "Card A"
    Monitor        "Right Monitor"
    DefaultDepth    24
    Option         "Stereo" "0"
    Option         "SLI" "Mosaic"
    Option         "BaseMosaic" "True"
    Option         "metamodes" "GPU-0.DP-0: 3840x2160_60 +0+0, GPU-1.DP-0: 3840x2160_60 +3840+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Section "ServerLayout"
    Identifier     "Default"
    Screen 0       "Left Screen" 0 0
    Option         "Xinerama" "0"
EndSection


One project/piece of software you might want to look into is NitroShare.

This project is actually developed by a couple of guys from this site (NathanOsman & Mateo) and it's nice and simple, is cross-platform, and works between platforms without much hassle at all.

Basically, you install the program, launch it, and it sits in the background until you need it.

Taskbar Menu:

Device Menu:

This isn't quite like Dropbox where it automatically syncs, but it is a very useful tool and you can send whole directories at a time.


I would check battery state because that's where boot up sequence stops. If it is laptop then connect it to power source.


virtualbox dkms package issue (ubunty 18.04)

I had a similar issue and I'm guessing it is the same root cause for you since we are both on 18.04 Bionic; however I'm using mainline kernel 5.4.21, I don't believe you mentioned what kernel you're using.

My root cause was that 18.04 Bionic defaults gcc to gcc-7 and the latest VBox 6.1 when run with kernels 5.4.x and 5.5.x requires gcc-8 or higher.
So when /sbin/vboxconfig is run (whether in a script or manually) it is using the default gcc-7 which fails to include a header in building some of the binaries.

I already had gcc-8 and actually thought I was already using it.  However when I ran gcc --version it showed 7.4.0.

I forced gcc-8 as the default using sudo update-alternatives --config gccthen chose gcc-8.
Then I ran sudo /sbin/vboxconfig.  No errors
Then ran VBox and voila!  All working again!

So Steps [I don't know what you have so listing here assuming you haven't got most of it, but keeping it high level so you can have fun figuring out the syntax :) ]

Shutdown vbox
install update-alternatives
install gcc-8
setup gcc with update-alternatives and force gcc-8 as default
run /sbin/vboxconfig
run VBox 6.1


GitKraken and Kubuntu - installs but doesn't run

You may be missing libgnome-keyring try installing it with:

sudo apt install libgnome-keyring-common libgnome-keyring-dev


Did not enable "Download updates" and "Install-third party software" during installation. How do I turn then on?

From Ubuntu Software go to: Software Updates and in the Ubuntu Software and Updates tabs enable the ones you want enabled. This works for 16.04 but the behavior should be pretty similar unless you have a really old version.


dd: Operation not supported (on unmounted, but not ejected drive)

Solution

There is (normally) no device called /dev/discY.

You will have to find your device using ls /dev|grep sd

this will return you someting like

$ ls /dev|grep sd
sda
sda1
sda2
sdb
sdb1
sdc
sdc1

then you mount the partition, of wich you think it could be your usb-stick

and see if it is the right device.

mount /dev/sdc1 /mnt && ls /mnt

if it is it, unmount it

umount /mnt

and use

dd if=whatever.img of=/dev/sdc

to write the image to the device.

Explanation

Ubuntu seperates four kind of device types:

scsi drives

these are today the most common. They are under the name sdX

(sd = scsi drive) the the partitions are called sdXY.

X is always a small letter starting from a and Y always an  integer starting from 1 .

usb works with a kind of scsi protocoll, too.
parallel drives

these are called hdX for hard drive.
removable devices (without usbs)

these are called srY for optical drives, Y is here an integer starting from 0.

fdY are floppys and so on..
Tapes

are called nstY (guess what Y is) but you will most likely never face a tape.

The are all listed in the directory /dev/ dev for device.


Try changing/updating the default graphics driver. From my experience, installing linux in a mac is better than keeping the default apple software, but as far as gaming is concerned, apple's software is simply better. That is because graphics drivers are better developed in windows and mac osx.


Get variable from Zenity list generated from .csv file

Your original code didn't work because you have to capture the whole while loop in the ans variable.

Try the following snippet:

#!/bin/bash
INPUT=data.csv
OLDIFS=$IFS
IFS=";"
ans=$(while read IP hostname subnetmask gateway
do
echo -e "$IP"

done <$INPUT|zenity --list  --text "Choose witch IP-address you want to connect to " --column "Choose")
echo "You chose: $ans"


Problem adding NetBeans IDE to Docky Ubuntu Gnome

You need a .desktop file, eg:

[Desktop Entry]
Encoding=UTF-8
Name=NetBeans IDE 8.0.2
Comment=The Smarter Way to Code
Exec=/opt/netbeans-8.0.2/bin/netbeans
Icon=netbeans
Categories=Application;Development;Java;IDE
Version=1.0
Type=Application
Terminal=false
StartupWMClass=NetBeans

In /usr/share/applications/ or in ~/.local/share/applications/.

After that, open the Activities menu and type Netbeans. Move the icon with the left mouse button in the panel on the left hand site. That's all.

But there seems to be a problem. After the start of NetBeans, I have two icons if NetBeans is started. To solve this problem, you have to write your own start script instead of using /opt/netbeans-8.0.2/bin/netbeans


MegaSync freezes on firefox and doesn't recognise on chromium

For now, we can offer these temporary solutions:

OPTION A

This installer (no need to uninstall the previous one):

https://mega.nz/#!NVQ0hS5A!a9bDFny67f7C7A8XQ1sQEw0tdl1COX_PkEICBGZXwUI

This one prevents megasync from freezing (download will fail tough)

OPTION B

Manually add CA-certificates.

Steps:
    1) Save certificates
https://knowledge.rapidssl.com/support/ssl-certificate-support/index?page=content&actp=CROSSLINK&id=SO26457
    and
    https://www.geotrust.com/resources/root_certificates/certificates/GeoTrust_Global_CA.pem

into /usr/local/share/ca-certificates/ with .crt extension

2) update system certificates with:
        sudo update-ca-certificates

We are working on a permanent solution.


configure: error: X Window system libraries and header files are required

You do not need to install all dependencies of Thunar manually.
You should use the power of APT to get the dependencies:

sudo apt-get build-dep thunar

along with new dependencies of the 1.8.4-1 source code package for upcoming disco:

sudo apt-get install libexo-2-dev libgtk-3-dev libxfce4panel-2.0-dev libxfce4ui-2-dev

and then compile and install it with checkinstall make install.


Close all Java applications(browsers etc..) and try clearing your cache from terminal:

  javaws -Xclearcache

Worked for me.

If it doesn't work then wait until someone aswers this question:
Unable to start topcoder arena in Ubuntu 14.04


Can I configure Unity search result behavior?

Both of these are currently unconfigurable in Unity in 11.10 and 11.04, sorry.


Solved by manual installation of MariaDB as follows:

sudo apt-get install software-properties-common
sudo apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xF1656F24C74CD1D8
sudo add-apt-repository 'deb [arch=amd64,i386] http://nyc2.mirrors.digitalocean.com/mariadb/repo/10.1/ubuntu xenial main'

sudo apt-get update
sudo apt-get install mysql-common mariadb-common libmysqlclient18 libmariadbclient18
mariadb-client-core-10.0 mariadb-client-10.0 mariadb-server-core-10.0
mariadb-server-10.0 libmariadbclient-dev mariadb-server

After that set the same  root password you had before.


What X keysym to use for rfkill / flight mode?

I found the easiest way to set keys is to use "key touch"

Open a terminal and enter these commands:

sudo apt-get install keytouch keytouch-editor

You should now be able to find KeyTouch under System > Administration.

KeyTouch-Editor - The tool to setup your keyboard by teaching it. You select your multimedia keyboards input, then press keys and identify them from a drop down list. Save the configuration file when your done and simply import into Keytouch itself.

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