How to switch windows manager on-the-fly?

Pretty much any window manager can replace the one currently running. Normally, you use the --replace option. Read the window manager's man page for details. You just need to determine the command name for a particular wm. Google or apropos can help you there.
Examples:
xfwm --replace   # xfce, I think
metacity --replace   # default wm in Gnome 2
icewm --replace    # old-school wm, my favorite back in the 1990s before modern wms

Switching wms won't have any effect on which windows are open, though it'll likely affect their placement.
By the way, even though desktop environments such as Gnome, KDE, or Xfce have a default wm that works well with the environment, window managers are actually separate and can normally be mixed and matched. Note, however, that some window managers also provide some other features, such as panels, which you won't have if you switch wms.
Edit
Determing the proper command to use: These kinds of things are really easy to determine for yourself. Just take a guess at the beginning of the name. For example, "open". Then start typing the first few letters and hit Tab. If the name isn't completed,  hit Tab a second time to see a list of possible matches. Once you've found the command name, type man <command_name> to access documentation.
If you can't find the command name that way, look at the process list through some system monitor such as htop while the program in question is running. You'll see it there, though you might not be able to use the command in exactly the same form as it's listed, particularly if it's running through an interpreter such as Python.


Getting latest version of evolution on Ubuntu 14.04

The instructions here:

sudo apt-get remove evolution
sudo apt-get update
sudo apt-get install evolution

are for 15.04 (vivid) (and 14.10 (utopic)) - no packages are available in the PPA for 14.04 etc, so the package manager falls back on the version provided in the ubuntu repos:

The problem is that Gnome programs generally is they depend on other parts of Gnome to work properly - since 14.04 uses Gnome 3.10 as a base version it becomes difficult to install some Gnome programs for 3.8, 3.12, 3.16 etc as they may break as they don't have the right libraries etc available (unless patched) - and trying to install those libraries which in turn probably will break Unity and other Gnome apps.... see dependency hell.

You can get Evolution 3.16 in 15.10 Wily, and if you wait two weeks you can get 3.18 in 16.04 (also a LTS like 14.04, but still in beta currently).

If you really want to, you can try installing the packages for 14.10 (may break stuff, I recommend backing up Evolution's data before doing it) by adding the a different entry for the PPA:

sudo apt-get remove evolution
sudo add-apt-repository 'deb http://ppa.launchpad.net/fta/gnome3/ubuntu utopic main'
sudo apt-get update
sudo apt-get install evolution

This will try and install the packages for 14.10 , which might work...


To close this thread: I've booted 16.04 from DVD and directed the install process to an USB key of 15.9 GByte which was visible for the installer as sdb. The installation went fine on the 3rd try. After rebooting the installed system from the USB key, I fetched and installed
http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.7-rc6-yakkety/linux-image-4.7.0-040700rc6-generic_4.7.0-040700rc6.201607040332_amd64.deb by just running

sudo dpkg -i linux*.deb.

After a reboot it says now:

$ uname -a
Linux tiny-ubuntu 4.7.0-040700rc6-generic #201607040332 SMP Mon Jul 4 07:34:26 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux


In CompizConfig Setting manager you can set overlay icons to the Scale windows plugin.

You can even set a keyboard shortcut to display windows from just one workspace or for a group of windows of the same applications in the Bindings tab of Scale plugin.

Plus there are a lot of alternatives in the Window Management section, just discover them and choose to one suites you more.


WiFi authentication not accepted on samsung nc10

I have a Samsung N110 and had a similar problem.  I found that I clicked on the edit connection tab, told it to ignore IP6, and chose manual for IP4 (and inserted an IP address, subnet mask, gateway address, and DNS server) clicked save and it connected right away and I have had no problems since.


Try this:

sudo dpkg --configure -a
sudo apt-get clean
sudo apt-get update
sudo apt-get install --fix-missing
sudo apt-get install openssh-server


`at` command: what is the meaning of the option `-w`?

The message is from your job, not from at (and at also does not have a -w option BTW). By default, at sends STDOUT and STDERR from any job via mail, unless specified otherwise.

Presumably, your job was a iptables task -- based on the message regarding xtables. And the -w (--wait) option of iptables waits for the xtables lock to be released, as suggested in the message.


How to delete gnome 3.4 themes in Ubuntu 12.04

Themes are normally located at:

If installed via PPA:

/usr/share/themes/

If installed locally:

~/.themes/

Removing themes:

PPA ones:

sudo apt-get remove <theme_package_name>

Local ones:

rm -rf ~/.themes/*

Don't forget to set your GTK theme to the default first, otherwise your current session might go nuts :)


How to get rid of "The authenticity of host 'bazaar.launchpad.net (91.189.95.84)' can't be established."

No. The first time you connect to any SSH host, you will be presented with a similar message for that host. That is just how SSH functions.


If you don't want to execute them in parallel you can do this :

dotnet /srv/DiagAC2/WebApi/MDP.Api.dll && dotnet /srv/DiagAC2/Hub/CL.Hub.dll

If the first one returns successfully ( return code of 0 ) then the second one gets executed.( you can replace the double ampersand && with semicolon ; to eliminate the successful return condition)

And if it doesn't take much time to get executed , you can add that line to your ~/.profile file in order to execute them every time you log in as your user.(but it may slow down the logging-in process.)

But if it takes so much time , you should consider creating a systemd service for it and you have to add the above command to the ExecStart option of your .service file (full path not just dotnet)

If there's any better solution , I'm glad to hear.


How to install sublime text on ubuntu chromebook?

You can't run sublime as it's not build for ARM processors.

ARM builds are wanted, but not available.


After Installing Ubuntu 16.04 Two days ago I have no sound at all (youtube,loadspeaker or headphones)

Try launching pavucontrol and check which devices are available and being used for output.  It may be that you've accidentally muted your primary output, or that the applications are outputting sound to the wrong channels.


When to use single or double quotes in Ubuntu command-line?

Normally, double quotes (" ") are used for print the value of any variable and single quotes are used to print the exact string.

For example, you have a variable foo which contains pwd as value.

foo=pwd

now, when you do:-

echo "$foo" - it will print the value of variable foo i.e. pwd
echo '$foo' - it will print $foo (exact string passed in single quotes
Also, Back quotes are used in command line/shell scripting, which is normally used to run the command stored in variable.
echo `$foo ` will print your current directory, i.e. output of pwd command.


Such a tool happens to already exists: the Bookmarks Lens.
You can install it by following these directions:

Run the following command in a terminal:

sudo apt-get install libunity-dev libsqlite3-dev intltool

Download this file.

Extracting the contents of the archive somewhere (say ~/bm-lens).

Open a terminal and navigating to the directory you extracted the files to.

Run the following command:

./configure ; make

Once that completes, run:

sudo make install

Restart Unity.


Which driver do I need to Install for my gt540M if i want to use bumblebee?

The current nvidia driver (nvidia-current) in Natty is version 270.41.06 which does not support your GT 540M. 280.13 does support it though. You can get it by installing the ubuntu-x-swat/x-updates PPA:

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

As for Bumblebee, see Is a NVIDIA GeForce with Optimus Technology supported by Ubuntu? for the latest installation instructions. After installing that version, you can get nvidia-settings to run with:

nvidia-settings -c :8


How to link to executable file in ubuntu 11.10 with cairo dock?

Just drag the executable onto Cairo Dock. But don't drag it onto an already placed icon. Put it in between two icons. That's it.


Error Writing /etc/networking/interfaces/ : No SUch file or directory

My plan is :
1. Setup a wifi on windows 10
2. change NAT with Static IP Ubuntu 18.04 on Win10 host => It didn't worked
3  Configure the asterisk server (sip.conf and extension.conf)


Internet goes on and off after updating to 12.04

It looks like your connection is trying to get IPv6 DHCP from the router, but failing. Unless you want to configure your router for IPv6, you can edit the connection to not look for an IPv6 address:

Click on the network-manager icon in the system tray.
Click "Edit Connections".
Click the "Wireless" tab.
Select the network, and click "edit".
Click the "IPv6 Settings" tab.
Change the "Method" to "Ignore".


Items cannot be installed or removed until the package is repaired. Do you want to repair it now?

Open a terminal and type the following command to fix the broken packages:

sudo apt-get install -f


Xfce4-mixer is the front-end for mixer settings delivered together with the Xfce4 desktop environment. It does the same jobs other mixer front-ends do, but is integrated into the Xfce4 desktop as a plugin for the Xfce4 main panel. To install xfce4-mixer from the terminal in Ubuntu 12.04-14.04 run:

sudo apt-get install xfce4-mixer

Right-click on the panel and choose Panel -> Add New Items. From the Add New Items window, add the Audio Mixer applet, or drag the Audio Mixer applet icon from the Add New Items window to the panel.

There isn't a Sound icon in Xubuntu 13.10 Settings Manager, so if you want to change the sound settings, you have to right-click the Audio Mixer applet icon in the panel, and change the sound settings from there.


Unmet dependencies preventing installing anything else

That package must be conflicting with some other already installed package so try this:

sudo dpkg -i --force-depends  /var/cache/apt/archives/libart-2.0-2_4%3a14.0.0-r5-0ubuntu12.04.1_i386.deb

or

sudo dpkg -i --force-all  /var/cache/apt/archives/libart-2.0-2_4%3a14.0.0-r5-0ubuntu12.04.1_i386.deb

this is not a perfect solution but a work around since you should find which package is conflicting with  /var/cache/apt/archives/libart-2.0-2_4%3a14.0.0-r5-0ubuntu12.04.1_i386.deb


Windows is excruciatingly slow after wubi installation

This turned out to be a hard drive failure in the making; complete reinstallation of windows caused a subsequent hardware failure.  Turns out that SSDs aren't the magic bullet against hardware failure after all.


Booting Windows VM in server asks for OS CD

Check if the CD device is still "attached" to that VM.  If you had the CD "attached" to the vm when you installed it... make sure you "detach" the cd from the VM.


bash: =/opt/jdk-9.0.1/: No such file or directory - Error after adding Java Path in bashrc. Even though file is there

To set a variable you need to omit the $, so in your case the line has to be:

JAVA_HOME=/opt/jdk-9.0.1


This may sound stupid but I had an issue like this and found that if your airport/air travel connection is turned on you will have issues getting connected even if running straight wire hookup. No idea why this happens. Hope this is your issue also.

   Artook


Why do the docs switch from sbd to sbd1 here?

/dev/sdb (or, just sdb) is the device.

/dev/sdb1 (or, just sdb1) is the partition within the device to use.


How do you get a *.desktop file to work for a non-repository app?

If running

/home/myname/kindle-web-linux-x64/kindle-web

in Terminal indeed launches the application whereas the .desktop launcher doesn't, then change the Exec line from

Exec=/home/myname/kindle-web-linux-x64/kindle-web

to

Exec=bash -c '/home/myname/kindle-web-linux-x64/kindle-web'


I followed this and it's autologging into root.


How do I use the exec command inside a for loop after a find command?

Two issues:

for f in some_file does not iterate over the content of some_file, just iterate over or take the literal string some_file. To get over this forget about for looping for iterating over file content, use a properly implemented while construct.
Variables won't be expanded when put inside single quotes, '$f' in this case. To get your original idea working, use double quotes.

Putting these together, assuming the filenames are newline separated inside file_list file:

while IFS= read -r f; do
    find /path1 -name "$f" -exec cp '{}' /path2 \;
done <file_list

Or if you know the files would be in the /path1 directory, not under any subdirectory of it, you can just use an array to get the filenames, and use (GNU) cp directly, again assuming newline separated filenames inside file_list:

(
 IFS=$'\n'
 files=( $(<file_list) )
 cp -t /path2 "${files[@]}"
)

In case of huge number of files, you would be better off iterating over and cp individually rather than dumping into an array:

while IFS= read -r f; do cp -- "$f" /path2; done <file_list

If you have file list like e.g. file1 file2 file3 ... directly in the for construct, then just using double quotes would do:

for f in file1 file2 file3; do
    find /path1 -name "$f" -exec cp '{}' /path2 \;
done

Now, you can use cp directly here too if all files would not be in any subdirectory:

cp -t /path2 file1 file2 file3

Or you can give static absolute or relative paths in case you want to use cp only to deal with any files under any subdirectory.


Clipboard history: Need to get something far back

If you don't have a clipboard manager then it's gone forever.


My sound and ALSA has gone when I installed Realtek drivers

This is from a post by lidex on Ubuntu forums

Using a Terminal="Applications->Accessories->Terminal"
sudo aptitude --purge reinstall linux-sound-base alsa-base alsa-utils linux-image-`uname -r` linux-ubuntu-modules-`uname -r` libasound2

Reboot.
For a 'command not found' error simply install aptitude:
sudo apt-get install aptitude


What's the easiest way to get started with LaTeX?

Just install the texlive package, this will pull in all the essentials. Additionally you can install documentation in your language, eg. texlive-doc-en. If you're writing in a language different from English, you should also add the respective language package, e.g. texlive-lang-french. There are also nice topic oriented packages like texlive-science or texlive-humanities -- but if you want to learn the basics of LaTeX you certainly don't need them.
If you just need basic editing support like syntax highlighting, any text editor will do, including the standard GNOME text editor gedit. More advanced options include:

texworks : A LaTeX editor with a quite clean and simple interface, featuring an integrated PDF viewer and synchronisation between the editor and the viewer (i.e. you can jump to the same position in both)
kile : a powerful editor for KDE (can be installed under GNOME and works fine apart from changing some configuration details to use the GNOME pdf viewer for example)
texmaker : Similar in scope to KILE, but more "GNOME-like" (e.g. less buttons in the toolbar ;-) ), a bit fewer features than KILE probably
latexila : Like KILE, but targeted to GNOME.
lyx : not really a LaTeX editor but more a word processor that uses LaTeX internally -- opinions differ whether this is the best way to learn "real" LaTeX.

Most of these editors don't really have a preview pane but this is not really necessary: Just keep evince open with the document you are working on, evince will automatically refresh its content as soon as you "compile" your latex document


Will Plugging A Windows Fomatted Storage Drive Into A Computer Running Ubuntu Automatically Format It?

If it is connected as an external (say, USB) drive, then Ubuntu will try to automatically mount it so that you can access the files. If it is connected as an internal drive, Ubuntu will not try to mount it by default.

In neither will case will it try to format the disk.


How to disable Okular from following links?

Okular 1.10.3 on Manjaro does not open any links automatically, not even by clicking on the linking strings. Text selection has to be enabled, the string has to be selected and open via context menu.
Maybe try selecting Browse instead of Text Selection.


I had the same issue with a low res boot screen. Try this:

Run in Terminal

1.sudo apt-get install v86d

2.gksu gedit /etc/default/grub

3.Replace Line: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

New Line: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset video=uvesafb:mode_option=1280x1024-24,mtrr=3,scroll=ywrap"

5.Replace Line:#GRUB_GFXMODE=640x480

New Line:#GRUB_GFXMODE=1280x1024
6.Save & Close

7.gksu gedit /etc/initramfs-tools/modules

8.Add Line: uvesafb mode_option=1280x1024-24 mtrr=3 scroll=ywrap
Save & Close

9.sudo update-grub2

10.sudo update-initramfs -u


You just need to restart Network Manager:

sudo service network-manager restart


you could run it from the terminal, and enter this in the terminal:

wine /path/to/file/exe

and it might work fine this way.


Virtual Machine Ubuntu 20.04 LTS : connect: Network is unreachable

I had the same problem after moving my ubuntu vm to a different host. The following steps worked for me, the reloading of the kernel modules might not be required, cannot reproduce as it is working now. I guess the network-manager is broken.

unload /reload the kernel modules
list the network adapters to get the name of the device (in my case it was „ens33“)
get an ip for the device
do an apt-get update / upgrade
reinstall network-manager

sudo rmmod e1000
sudo rmmod e1000e
sudo rmmod igb

sudo modprobe e1000
sudo modprobe e1000e
sudo modprobe igb

sudo dhclient ens33

sudo apt-get update && sudo apt-get upgrade
sudo apt-get purge network-manager
sudo apt-get install network-manager


This is expected behavior when no WiFi driver has been installed. For whatever reason, the Ubuntu installer won't automatically install some drivers -- these must be installed by hand.

The first step is to identify the WiFi card. Open a terminal window and type

lspci -vvnn | grep Network

Then google for Ubuntu driver installation instructions for that card. This particular computer has a Broadcom card that's pretty common on older Dell computers. Refer to the Ubuntu Documentation for driver installation instructions.


How to solve cursor couldn't move and keyboard not working?

I solved the same kind of problem on my HP dm1-4136sf with Ubuntu 12.04 64bits.

Solution was to blacklit the USB-attached Bluetooth device (Broadcom).

$ sudo vim /etc/modprobe.d/blacklist.conf
blacklist btusb

You can try first by unload the module :

$ sudo rmmod btusb

I hope this solve your problem.


How do I get the scanner to work on a Samsung SCX 4521F Multi function printer?

NOTE: The instructions here are for Ubuntu 9.10 onwards. For setting up this printer with older Ubuntu, go to this page.
1. Installation

A few important points with the approach here:

Some Xerox printers are Samsung OEM. This printer looks like a clone of Samsung SCX-4521F [www.samsung.com]. Treat this printer like the latter whenever possible.
Use CUPS for the printer.
Use the Samsung Unified Linux Driver for the scanner.

Step 1: Setup the Repository for Samsung Unified Linux Driver

No free or open-source alternatives are available to make full use of this multifunction printer yet. You will see later that we need the Samsung Unified Linux Driver mainly for supporting the scanner.

Add the following repository:

deb http://www.bchemnet.com/suldr/ debian extra

You can do this with Synaptic Package Manager, Software Sources, etc.
Install the GPG key, from http://www.bchemnet.com/suldr/suldr.gpg, for the repository. You can do this with Synaptic Package Manager or Software Sources, or paste this line to your terminal:

wget -O – http://www.bchemnet.com/suldr/suldr.gpg | sudo apt-key add

Reload / update the repository information.

Step 2: Install the Printer Driver

Here, you can choose to use either one of the following drivers:

{Recommended. The driver is very stable.} The open-source driver provided by the Splix project. (Check this too: http://www.linuxprinting.org/show_driver.cgi?driver=splix)
The Samsung unified printer driver. In this case, install the samsungmfp-driver package first.

Either of the drivers seems to work fine. I personally do not have any particular recommendation yet until further testing. (For the moment I use the Splix driver.)

From the start menu, invoke System -> Administration -> Printing.
Choose ‘Samsung’, and then ‘SCX-4521F’.
For the driver, choose either the Splix or the Samsung driver according to your preference.
Check the ‘Printer Options’ in the ‘Printer Properties’. Change the options where appropriate (especially the ‘Media Size’).
Try to print a test page. It should work!

Step 3: Install the Scanner Driver

Install the samsungmfp-scanner package.
{ONLY FOR Ubuntu 11.10.} Use your favorite editor to modify [i]/etc/modprobe.d/blacklist-cups-usblp.conf to comment the following line by prefixing with a ‘#’: #blacklist usblp. Restart your computer.
{ONLY FOR Ubuntu before (not including) 10.04.} Add users you allow to access the scanner into the lp group. You can use System -> Users and Groups from the start menu to do this, or use the adduser command. Logout and re-login.}
Now Graphics -> Simple Scan or xsane should be able to detect and use the scanner! You can use sane-find-scanner or scanimage -L to detect the scanner too. (If it does not work, refer to this troubleshooting guide.)

Some Technical Details

Splix is included in Ubuntu since 9.10. So it is now possible to use the printing feature of the printer out-of-box (without using the Samsung unified printer driver.)

For very complete and detailed instructions including various approaches for setting up Samsung printers, please refer to http://ubuntuforums.org/showthread.php?t=341621 and http://www.bchemnet.com/suldr/.


resolv.conf keeps getting reset by something

You can make static additions to /etc/resolv.conf. Those additions could override the things that are being automatically added.

First, install the resolvconf package.

Then, press Alt+F2 and run gksudo nautilus. Open /etc/resolvconf/resolv.conf.d/head if you want to add to the start of the file; open /etc/resolvconf/resolv.conf.d/tail if you want to add to the end. Make your changes, save/close the files, and then run sudo resolvconf -u to apply the changes.

(Sorry that I don't remember if the settings at the start or end of the file have the highest priority.)


What is "packagekitd" and how do I make the Software Updater stop waiting for it?

PackageKit is a system made to use the distribution's software installation and update tools easier. You can read more about it here: https://www.freedesktop.org/software/PackageKit/pk-intro.html

You can stop packagekitd with the command:

systemctl stop packagekit

If, for some reason, you wish to disable it, you can use:

systemctl disable packagekit


The below answer is based on a similar Q&A in SO with some relevant modifications:

$ awk 'FNR==NR {dict[$1]=$2; next} {$2=($2 in dict) ? dict[$2] : $2}1' file2.txt file1.txt
item1 platA
item2 platB
item3 platC
item4 platD
item5 platE

The idea is to create a hash-map with index, and use it as dictionary.

For the 2nd question you asked in your comment (what should be changed if the second column of file1.txt will be the sixth column):

If the input file will be like file1b.txt :

item1 A5 B C D carA
item2 A4 1 2 3 carB
item3 A3 2 3 4 carC
item4 A2 4 5 6 platD
item5 A1 7 8 9 carE

The following command will do it:

$ awk 'FNR==NR {dict[$1]=$2; next} {$2=($6 in dict) ? dict[$6] : $6;$3="";$4="";$5="";$6=""}1' file2.txt file1b.txt
item1 platA
item2 platB
item3 platC
item4 platD
item5 platE


Ubuntu 18.04 Vulkan Problems (AMD HD7950 Graphics Card Tahiti)

I used the following instructions which got the game working just fine on a clean install of Ubuntu 18.04...you still get the "CPU Governor" message but it can be set to "ignore".
Click through the warning messages, and go to the "Advanced tab" of FERAL games menu (not the in game menu).
After following the instructions below you'll see the Driver selected is the Vulkan TONGA driver.
Start the game and do the Benchmark first....It takes a while for the game to load but it does, and I get an average of 50fps on the benchmark.

Here is what I did pressing enter after each line:

$ sudo add-apt-repository ppa:oibaf/graphics-drivers
$ sudo apt update
$ sudo apt upgrade
$ sudo apt install libvulkan1 mesa-vulkan-drivers vulkan-utils


Add GRUB boot entry for Windows 10 installer iso

You can't add a USB install media or DVD install media to Grub.  When you install grub or run Grub update it will automatically add the detected Installed OSes to the grub menu.  Windows isn't installed on the USB Windows Install ISO.

You would have to install Windows 10 to your computer.  If you'll having problems setting the BIOS to run the Windows 10 disk installer, you'll have to consult with your computer's manufacturer for how to Boot to the Windows I install Disk.
When you install Windows 10, it will likely cause the Grub not to function correctly, and the computer will boot directly into Windows 10, without recognizing that Ubuntu is installed.

Your next step would be to Update Grub.

Repair Grub after Installing Windows

You can update grub by booting into the Ubuntu live session.  Bring up a terminal screen with Alt+Ctrl+T.  Then run these steps.

Mount the partition with the Ubuntu installation:

$ sudo mount /dev/sdaX

Link the system needed directorys for the grup install/update (the $ symbol represents the command prompt where you will type the command):

$ for i in /sys /proc /run /dev; do sudo mount --bind "$i" "/mnt/$i"; done

Change make the Installed Ubuntu your effective root

$ sudo chroot /mnt

Install and update grub (Replace 'X' with the drive letter of your boot drive... most likely /dev/sda).  The # represent the command prompt you see in the terminal commandline.

# grub-install /dev/sdX
# update-grub
# exit
$ sudo for i in /sys /proc /run /dev; do sudo umount "/mnt/$i"; done
$ sudo umount /mnt

Reboot the computer

Now check and ensure your BIOS is set to Ubuntu and you'll have both Ubuntu and Windows 10 as your boot options.


What happen when Ubuntu is repeatedly shutdown and restarted?

If it's a clean shutdown, thats is not correct.
If you just cut the system of any power source, that might corrupt it depending on which filesystem you use.


How do you get http:// to load automatically in a web browser?

Assuming the address entry is called address_entry, try it like this:

url = address_entry.get_text()
if not "://" in url:
    # Is http a sane prefix?
    url = "http://" + url


Cannot execute /sbin/false while installing Solr 5.3.1

You may try creating a symbolic link:

ln -s /bin/false /sbin/false

At least it solve my similar issue.


Real time Sonic Visualizer, to analize current played audios internly in the computer

If you're running Ubuntu Studio 18.04, you need to add the Ubuntu Studio Backports PPA to get some updated software.

This will include the updated Calf Studio Gear plugins which include an analyzer. However, they require Jack in order to run. Once you have the PPA enabled and your system upgraded, also install Carla (sudo apt install carla) as this will let you put the analyzer in your audio chain the way you need it.

Next, run Ubuntu Studio Controls and configure your audio, and start Jack. Open Carla, and add the Calf Analyzer plugin. From the Patchbay tab, this can then be patched to your microphones or other applications. If it's not a Jack-aware application, such as a web browser, patch the audio output of PulseOut to the input of the analyzer. If you wish to listen to the audio, either patch the output of the analyzer to your system output or patch PulseOut directly to your system output.

Double-clicking the analyzer in the patchbay or clicking the GUI button on the plugin in the rack tab will open the analyzer's window.


Dell Ubuntu Super Key maximize a window vertically not working

I found it. In ccsm under window management / grid it is possible to configure the short cut.


What is kerneloops applet in the Startup Application Preferences?

The kerneloops applet allows the kerneloops crash reporting utility to ask a desktop user for permission before submitting an oops report to the oops.kernel.org website.

Source


Increasing partition size with unallocated space to the left

Move the partition to the right, then extend it into the free space, in two steps (move -> apply changes -> extend -> apply changes)

Yes, there can be data loss or problems if you more or resize partitions, so back up any data first.

if you can not boot, fix it with boot repair - https://help.ubuntu.com/community/Boot-Repair

You can run boot repair from a live CD.


An error saying segmentation fault (or segfault, or SIGSEGV) in Ubuntu and other Unix-like operating systems, or saying general protection fault in Windows, is when a program attempts to access a part of memory that cannot be accessed, or which the program is prohibited from accessing. A segmentation fault is a kind of program crash, that is, an abnormal termination of a program. See the Wikipedia articles on crashes, memory protection, segmentation fault, general protection fault, and SIGSEGV for more information (and a more textured understanding of the topic than is presented here).

A segmentation fault is almost always due to a bug in the program where it occurs. I am guessing most or all of your segmentation faults are happening from the same application. Please provide more details about the circumstances under which segmentation faults are happening on your machine, and what program is crashing. Please also provide the full and exact text of the error message you're receiving and any other messages that appear before it. This should make it possible for us to provide detailed advice specific to your problem (rather than just general information about what a segmentation fault is).

The best way for you to provide this information is for you to edit your question to include it. Alternatively, if you want this question to be just about segmentation faults in general, you could post a new question to ask about what specifically is causing your segmentation faults (if you do this, make sure to provide all these details in your new question).


Can I disable the splash screen and output verbose information when I shutdown?

Have you tried just hitting escape when you shutdown? Perhaps even hitting it twice in some cases. Some distros use F2 or alt+F2 as well.

If that does nothing, either the key binding is different or that method will not work. Temporarily you can change the plymouths splash to off by restarting and hitting e to edit the grub command line, and then e again on the correct line, most likely the second line.
Here you would scroll all the way to the end with your right arrow key and remove all of these if they exist: silent splash quiet splash=silent and any variation of them. Editing from the grub command line this way is safest because it will reset itself after each reboot. To continue booting from here you would hit enter and then b, or enter or ctrl enter.

Another option is to shutdown manually fron terminal using one of the following:

a) to restart:

sudo shutdown -v -r now

b) to shutdown:

sudo shutdown -v -h now

c) to shutdown but stop the shutdown process allowing you to read the verbose output:

sudo shutdown -v now


Is there a Dell Longevity option in Ubuntu?

As previous answers have mentioned, this is not a hardware switch, but instead a software function. There is a kernel module available (tp-smapi-dkms), but it only works for Lenovo ThinkPads.

Enabling this function on your Dell laptop would require you or the vendor to write and implement a kernel module for your laptop model, the same way as they wrote the software for Windows.

Right now, your best bet is to unplug the battery manually when it's reached 80%. If you have some coding skills, you can use acpitool and notify-send to write an script to let you know when the battery has reached its 80%. acpitool -B will display information about your battery, from where you can grep some information.

tl;dr: No, you cannot do it at this point, your vendor would need to write the software as it's not a hardware switch.


How to restore Regolith i3xrocks status bar

I completely uninstalled Regolith using apt purge regolith-*
Delete ~/.config/regolith
Delete /etc/regolith

Reinstalled apt install regolith-desktop-complete now the status bar is back.


Problems with games on-line in Ubuntu 14.04 LTS

Try playing the games in Chromium browser. Since both League of Angels and Legend Online are Flash Player games, maybe you'll have better results using the more up-to-date Pepper flash player in Chromium browser. Install Pepper flash player by following the instructions from Get latest Flash player on Ubuntu.


To solve this issue, Blueman needs to be uninstalled:

pkill blueman
sudo apt-get purge blueman

The icons are now gone. To access the bluetooth settings now, you need to go to your system settings.


How to boot to command prompt with network

Depends on what you want to do. For example, the fastest way I know is to boot using "recovery mode" and choosing "netroot": http://imageshack.us/photo/my-images/401/recoverymode.png/

The bad side is that you login as root... with all the security consequences that follow. :)


I had the same problem that I was able to fix with the following steps:

Click on the Networking Interface icon;
Click "Manage Connections";
Selected the "Wired" tab;
Selected "My Connection";
Click "Edit""
Change Ipv6 to "automatic";
Deselected the "ipv4 is required for this connection" (Which I think was the culprit)

(If this doesn't help you, you might be using Firefox.. If so try using Chromium. That worked for me.)


How to convert Ubuntu Desktop into Ubuntu Server?

There is not much difference between Desktop & Server. Check this link. You dont need to replace your desktop rather install servers like apache,etc

Execute this command in terminal to make your desktop Ubuntu server :

sudo apt-get install apache2 phpmyadmin lamp-server^ mail-server^ openssh-server^


Hi and welcome to AskUbuntu!

You seem to have way more drivers than you need. Try to remove them and then reinstall with:

sudo apt-get purge nvidia*

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt update
sudo ubuntu-drivers autoinstall


How to make zsh in byobu to be a login shell?

I was searching for the the same answer and finally I succeed by define ZSH as my default SH :
not sure those command was useful but just in case

# set -g default-shell /usr/bin/zsh
# set -g default-command /usr/bin/zsh

and after I installed byobu :

# sudo apt-get install byobu -y

and enable it into a ZSH session with the command :

# byobu-enable

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


trying to get mythmote to work on mythbuntu

Run nm-connection-editor in the frontend machine. Edit the connection you use. In IPv4 or IPv6 tab choose manual method. Add address: Choose IP that is outside of range used by DHCP of your router, use 255.255.255.0 as netmask and your router's IP as Gateway. Save and reboot.

Don't forget to enable "Enable Network Remote Control interface" setting in Setup->General of the frontend.


After you successfully installed Google Chrome, click on the Dash and search for "Chrome". When you find it, open it:

Another way is to open the terminal and run inside of it the following command:

google-chrome

Next, if you want to have it all the time on the Launcher, just right click on the Google Chrome icon from the Launcher when it is opened and select "Lock on Launcher":


Why is Ubuntu One slow to sync in 11.10, either backup or any sub-folder contents?

I contacted Ubuntu One, and they were very helpful.

They suggested I tried the following:

Press Alt-F2, type "gnome-terminal", press "Enter" and run:

u1sdtool -q

sudo rm -rf ~/.local/share/ubuntuone

u1sdtool -c

Let that go for at least 30 minutes.

Files have started to transfer, seems to be going ok.... will monitor

....still slow to sync sub folders and files


How to fake a package version installed?

Despite an answer being already accepted, inlining the accepted better conveys the process:

There is a Debian package called equivs that is able to create dummy packages.  Install it by running sudo apt-get install -y equivs
Once installed, you generate a template "control" file using the following command: equivs-control postfix (replace postfix with your package name). In my case, I might use an alternate package name, e.g. postfix-custom or whatever but have my custom package fulfill or Provides the installation dependency of postfix (again replacing postfix for whatever package you want.
Once the template control file is generated, I will typically remove a lot of the commented out statements (statements that begin with #). One that I like to keep specifically is the Provides: statement where I can say that my package provides the capability offered by the other package that I'm trying to fake, e.g. Provides: postfix tells the Debian/Ubuntu dependency resolution mechanism that my package—of whatever name—provides the same capabilities of the target package, again postfix or whatever. This allows me to name my package independently of the target package to avoid confusion. Erlang Factory does this with their stuff, e.g. esl-erlang provides erlang.
Finally, once the template control file is created, you use equivs-build to generate the fake package, e.g. equivs-build /path/to/generated/control/file.
It takes a few seconds to build the package and then you can run sudo dpkg -i my_package_name*.deb

For advanced users, if your template control file has a Requires: dependency line, you may want to use a tool like gdebi to install your package as well as the various the packages it declares as dependencies.


You could try the Classic Menu Indicator to get an category-sorted application menu in Unity. Another way is to install gnome-session-fallback and to select the GNOME Fallback Mode at login, which makes GNOME 3 to imitate the look and feel of GNOME 2. You could also consider to switch to XFCE, which is quite similiar to GNOME 2.


How to integrate Google tasks in evolution 3.12

You do have to use a GNOME Online Account for your Evolution to integrate with Google Tasks. According to Milan Crha, who completed the Evolution integration with Google Tasks:

On Tue, 2014-11-18 at 06:40 +0100, Milan Crha wrote:

  Evolution cannot authenticate using OAuth on its own,
  it handles only user+password authentication requests (it can ask for a
  password only), but the Google tasks require OAuth, thus the only way
  is to use GNOME Online Accounts (GOA) and enable the Calendar part. If
  any user had already created a GOA account, then it might also need to
  re-authenticate it, because the OAuth key has a bit flag which
  services are enabled and the Google tasks had been added in time of
  the feature being added into evolution-data-server. There is also
  needed certain libgdata version (0.15.1 or later).

  Feel free to use this answer in the Ubuntu forum

On Tue, 2014-11-18 at 07:07 +0100, Milan Crha wrote:

  On Tue, 2014-11-18 at 01:00 -0500, Matthew wrote:

    It seems strange that Google Tasks require OAuth, but

    Evolution can access Google Calendar without OAuth.

  there are used different protocols. Calendar uses CalDAV, while Google
  Tasks uses libgdata, because the tasks cannot be accessed using CalDAV.
          Bye,
          Milan


How to log in to an internet provider with with a password and user name through terminal?

Found the answer online here

Open the terminal.

Type ifconfig wlan0 and press [Enter]. You will not see any output in the terminal, as this command just turns your wireless card on. Most wireless cards are designated wlan0. If yours has a different designation, use that instead.

Type iwconfig wlan0 essid name key password and press [Enter]. Replace name with the actual network name, and replace password with the actual security key for the network. If your wireless network does not require a security key, do not enter key password.

Type dhclient wlan0 and press [Enter] to obtain an IP address and connect to the WiFi network.

What I see on the terminal are given below.


Remapping Caps Lock to Control and Escape (not the usual way)

I have this setup on my Mac and I had tried to find a way for Ubuntu without luck.
Well, it's now working. Thanks tungd for ponting me to xcape. What I have done is really simple and straightforward.

Under System Preferences → Keyboard Layout → Options... → Ctrl key position, I checked Caps Lock as Ctrl.

In a terminal run:
xcape -e 'Control_L=Escape'

Done, Caps Lock works as Ctrl when used like a modifier, and as Esc when pressed alone (there's a slight delay of a few hundred milliseconds, as noted on the xcape README file, so it's still not as optimal as the Mac solution which uses KeyRemap4MacBook.)


Extended monitor shuts off internal monitor

similar issue with debian 8 and HP probook laptop. turns out the internal monitor is just dimmed down. fn+F10 (keyboard combination for luminosity printed on the internal keyboard) resurrects it.


Basically pin tools are designed as "Just In Time (JIT)" compilers, so the two components behind the architecture are Instrumentation and Analysis Code. As you may know, PIN tools has the ability to instrument the architecture independently. Therefore, as instrumentation occurs immediately before the code sequence execute the first time, you have to treat the program directly with the target benchmark.

Here are some tips:

First of all go to the parent directory of the Pin tool, the general usage of pin is defined as :

pin [OPTION] [-t <tool> [<toolargs>]] -- <command line>

Secondly, export the path of pin to the env to be able to use it everywhere else (in my case is):

export PATH=$PATH:/home/amir/pin-2.12-58423-gcc.4.4.7-linux/

Now you can use it everywhere to pin the instrument (compilation counts, branch takens, etc).

i.e. :
There are some sample sources in order to start working around in

$ cd source/tools/ManualExamples

like inscount, linux_buffer, etc. use the make command to g++ compile the source codes:

make inscount0.test

and then :

$ pin -t inscount0.so -- /bin/ls

to get the output of the /bin/ls.

Hope that helps you.


Seriously, dconf, gconf, gsettings... How do I save my terminal settings?

This is an old question but clearly still relevant.

Based on this useful post, here is how to backup/restore your GNOME Terminal settings; this can be used for instance when migrating from one computer to another.

* Please be advised * : this will overwrite the default Terminal profile on the new machine!

Make sure you're using the same profile name on both machines by renaming it under "Profiles" in the Preferences dialog and activate it if necessary (click on drop-down menu and select "Set as default")
On the source machine run this little script:

gprofile=$(gsettings get org.gnome.Terminal.ProfilesList default)
gprofile=${gprofile:1:-1}
gschema=org.gnome.Terminal.Legacy.Profile
gpath=/org/gnome/terminal/legacy/profiles:/:${gprofile}/
gsettings list-recursively ${gschema}:${gpath} > /tmp/term_profile.gsettings

Examine the profile backup file (/tmp/term_profile.gsettings) to make sure it looks sensible.  It might be useful to delete any unwanted settings that you don't want to carry across.
Copy the backup file across to the new computer, eg:

scp /tmp/term_profile.gsettings new-host:/tmp

Now run the following little script on the new computer; we'll start with a dry-run to have a chance to spot any unexpected stuff:

gprofile=$(gsettings get org.gnome.Terminal.ProfilesList default)
gprofile=${gprofile:1:-1}
gschema=org.gnome.Terminal.Legacy.Profile
gpath=/org/gnome/terminal/legacy/profiles:/:${gprofile}/
cut -f2- -d' ' /tmp/term_profile.gsettings | while read line; do
   key=$(echo $line | cut -f1 -d' ')
   value=$(echo $line | cut -f2- -d' ')
   echo "$key => $value"
   # commented out for dry-run:
   # gsettings set ${gschema}:${gpath} $key "$value"
done

Assuming the output looks good, repeat the above script but un-comment the gsettings set line.  Your changes (eg: palette change) should apply immediately to your running Terminal.

Tested on 19.10 but should work on some older (and possibly newer) versions too.

Note that this only takes care of the preferences found under "Profile"; assuming the relevant gsettings keys can be discovered, the technique should work to backup/restore them too.


I have a launch command that works but only in the terminal - how can I get this command to work in Startup Applications?

I figured it out. Not sure if I should delete the question now or leave it with an answer for anyone else to use. I'll just answer and let the mods decide.

Open gedit and enter:
'XDG_CURRENT_DESKTOP= keepassx'
Save as a ".sh" file-type. Just remember where.
Right click on your .sh and select Properties, go to the Permissions tab - check the box next to "Execute".
In Startup Applications select Edit for KeepassX. In the Edit window next to "Command:" use the Browse button and select your .sh.
Once KeepassX opens in startup for the first time after these changes you'll need to go to settings and enable the system tray functions by checking the according boxes.

Note: The KeepassX setting "Minimize to tray instead of task bar" may be problematic since the panel/systray icon offers no option to show the KeepassX GUI. The icon offers the same two functions when right or left-clicking - Quit and lock. But as long as you have KeepassX set up and auto complete enabled everything works fine.


linker cannot find a package that is already installed

Ubuntu 18.04 : No issues with the Git version of Fast-DDS. (My cmake version is 3.16.3 : memory requires cmake => 3.11)
sudo apt install libasio-dev libtinyxml2-dev

git clone https://github.com/foonathan/memory.git
cd memory/ && mkdir build && cd build/
cmake .. && make && sudo make install

git clone https://github.com/eProsima/Fast-DDS.git
cd Fast-DDS/
git submodule update --init --recursive

cd thirdparty/fastcdr/ && mkdir build && cd build/
cmake .. && make && sudo make install && exit

cd Fast-DDS/ && mkdir build && cd build/
cmake ..
make                    ## No errors
[ 99%] Built target fastrtps
Scanning dependencies of target fast-discovery-server
[ 99%] Building CXX object tools/fds/CMakeFiles/fast-discovery-server.dir/server.cpp.o
[100%] Linking CXX executable fast-discovery-server-1.0.0
[100%] Built target fast-discovery-server
sudo make install        ## No errors


special character in smb field in Printer dialog

It is a known bug and the workaround is explained here:

https://bugs.launchpad.net/ubuntu/+source/kdeadmin/+bug/909769


How to get pngcrush to overwrite original files?

Since version 1.7.22, pngcrush has an overwrite option.

Try

pngcrush -ow file.png

See Changelog for more information:

Version 1.7.22  (built with libpng-1.5.6 and zlib-1.2.5)
  Added "-ow" (overwrite) option.  The input file is overwritten and the
    output file is just used temporarily and removed after it is copied
    over the input file..  If you do not specify an output file, "pngout.png"
    is used as the temporary file. Caution: the temporary file must be on
    the same filesystem as the input file.  Contributed by a group of students
    of the University of Paris who were taking the "Understanding of Programs"
    course and wished to gain familiarity with an open-source program.


Standard accounts are able to get root access using sudo without password request

If you look at the very bottom of your sudoers file, it says "ALL ALL=(ALL) NOPASSWD:ALL". This is the syntax for passwordless execution of sudo. Make a backup of the file and then delete that line.

Andrew


cannot change file content owned by me (system file)

First, do not change ownership or permissions of system files, doing so can break ubuntu. Most are owned by root and keep them that way.

Second, if you have not already, read up on permissions and sudo

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

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

These are important for security issues.

Third, rather than editing these files you can usually edit a configuration file somewhere.

Fourth run from a root shell:

sudo -i
echo 5>/sys/class/drm/card0/device/pp_sclk_od

And fifth, if you want to redirect with sudo use tee or similar

echo 5 | sudo tee >/sys/class/drm/card0/device/pp_sclk_od

See When using sudo with redirection, I get 'permission denied' for details


By default, Ubuntu doesn’t use a separate /home partition by default and all the Linux directory are stored on the same partition. But there is one benefit of using a separate home partition: It allows you to reinstall Ubuntu without losing your personal files.

While Installing Ubuntu, choose the “Something Else” installation option to use a custom partition layout and create multiple partitions. Set the mount point for one of your partitions as /  which will contain the root file system – and another mount point of another partition as /home


Firewire audio interface not working on a Mac Pro

last time i tried to wire my presonus firepod on linux was when freebob project still existed, but it seems it reincarnated in this form: http://www.ffado.org/ i'm not sure if those drivers are shipped by default with ubuntu

check this thread (warning: specific to setting up in Ubuntu Studio):

http://www.ffado.org/?q=node/35


No graphical interface after editing /etc/default/grub

To fix your /etc/default/grub, do:

sudo nano /etc/default/grub

Remove everything and add these (default Ubuntu grub file instructions excluding comments):

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

Save using Ctrl+X.

Then do:

sudo update-grub


View audio files by length - command line?

If you have ffmpeg installed, try

#!/bin/bash
for file in *.mp3
do
 duration=$(ffprobe "$file" 2>&1 | awk '/Duration/ { print $2 }')
 echo -e $duration"\t"$file
done | sort -n

If you need only the filename, pipe the sort through cut -f 2.
Obviously replace *.mp3 with whatever fits your needs.

ffmpeg understands pretty much any common (and not so common) formats.


Maximum time for which a Linux PC can be UP?

Working as a system administrator, I see Linux servers up for over 700-800 days without reboot, so there are no uptime limitations; the errors you got are not related to Linux (the kernel) itself.

A lot of services can be restarted and most errors can be solved on production systems.


How do I stop Screenlet widgets from showing up in Installed Programs?

It must be a bug - or a feature - of Screenlets, but it's not one I like.  For another problem I had to reinstall Ubuntu, and when I put Screenlets back on it still did the same thing.  I'll live without Screenlets now until they get that fixed.


Synaptic - How can I search in only my installed programs?

You need to install one extra package -
sudo apt-get install apt-xapian-index

to get Quick filter field between Properties and Search buttons

and then restart Synaptic.


Why is Unity 2D running so much faster on system with ATI 6770?

If you have installed the Graphics drivers through the software center or the 'Additional driver' button in system settings I would suggest to reinstall them using the newest driver package from the amd website.
It's a pretty straight forward process and done very quickly through the terminal, just copy and paste every command I put here.

sudo apt-get remove --purge xorg-driver-fglrx fglrx*

sudo apt-get remove --purge fglrx*

sudo apt-get install build-essential cdbs fakeroot dh-make debhelper debconf libstdc++6 dkms libqtgui4 wget execstack libelfg0 dh-modaliases

sudo apt-get install --reinstall xserver-xorg-core libgl1-mesa-glx libgl1-mesa-dri

sudo dpkg-reconfigure xserver-xorg

These commands remove the previously installed drivers and make sure all the dependencies for the new drivers are included.
These next ones download and activate the driver installer script from amd

cd $HOME/Downloads

wget http://www2.ati.com/drivers/linux/amd-driver-installer-12-3-x86.x86_64.run

sudo chmod +x amd-driver-installer-12-3-x86.x86_64.run

sudo sh amd-driver-installer-12-3-x86.x86_64.run --buildpkg Ubuntu/oneiric
sudo dpkg -i *.deb

The graphical amd installer will now guide you through the driver installation (just as it would in windows for example)
After it's done just type

sudo aticonfig --initial

Now reboot your system and see if the issue is resolved.


Ralink RT3290 wifi driver is not working in 14.04

I followed these instructions and they fixed my issue with the WiFi card on my HP 650.

The WiFi card is now working again, as it was on 12.04, but the Bluetooth don't.

I hope it helps.


No graphics after installing Nvidia driver

Can you provide the version which comes up as installed when you run this command:

# dpkg -l | grep nvidia

From the console you can use the following command to install (and I guess replace or remove) the binary driver installed:

# jockey-text

Keep in mind that you may just need to (re)move your xorg.conf (video server config file):

# mv /etc/X11/xorg.conf /etc/X11/xorg.conf.old-darkness

Hope this helps.


How to "see" the actual files used as the bootloaders?

The bootloader that is run by your UEFI bios is not loaded from /dev/sda7, but from your EFI partition, /dev/sda2. Your current system has this partition mounted at /boot/efi/. Search this partition as root to find the grub binary and grub cfg file.

This cfg file points grub to your boot partition, and then to another autogenerated cfg file you can see at /boot/grub/grub.cfg. This cfg file contains all the data used to build the grub boot menu and is written when you type "sudo grub-install" from within linux.


Second monitor turns to black after loading OS

I solved this by installing a different nvidia driver.
Apparently there is an issue with 384.111, because after reinstalling that one the problem appears again. Specifically, I went to 387.34, although 384 is the long-term branch.


Hey I have the exact same problem with my Acer, with the Suyin camera. It is detected but show black. It has been working the first three weeks I change to Linux and now it show black. I don't know what to do... Sorry I am not helpful but you are not alone.


Cant run FoxitReader after installing it

I had the same problem and found a solution that worked for me.

The issue with Foxit reader is that it only does a 'partial' install and misses the main executable file that allows it to run.

There is a fix for this - after running the install via USC you need to extract the executable that is located in the /usr/bin/ folder from the .deb file you have downloaded using the Archive Manager.

Extract the Foxit executable to your home folder then run sudo cp FoxitReader /usr/bin in a terminal and Foxit reader should now work as expected.

Steps to follow with screenshots can be found here


Can't install Oracle Java 8 in Ubuntu 18.10

Azul manages and provides for free very functional packages of OpenJDK, from 7 to 12.
As per their instructions, to install one or more java version you just need to do:

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 0xB1998361219BD9C9
sudo apt-add-repository 'deb http://repos.azulsystems.com/ubuntu stable main'
sudo apt-install zulu-8

to have a fully functional java 8 environment. If you want to have more than one java versions installed you can choose the default one as usually done in debian/ubuntu:

update-java-alternatives -l                # to list available ones
update-java-alternatives -s zulu-8-amd64   # to set java8 as default


Ubuntu 16.04 hangs on shutdown, suspend, when left idle for sometime

You appear to be affected by this bug. I suggest that you subscribe to the bug so that you can be notified about any progress.

A confirmed workaround is to boot the 4.4 series kernel which boots just fine.


How do I update the firmware on my Sony eBook Reader?

To update the firmware, you can:

Get an access to a windows machine, and do the update that way.
Install Windows in a Virtual Machine under Ubuntu.
Follow the steps mentioned Here

    The page above give step-by-step instructions for installing firmware
    to the Sony PRS-T1 eReader.

    Fully charge your PRS-T1
    Connect your PRS-T1 to your PC. Start the Reader software if it doesn't auto-start.
    Check for Updates, and follow the GUI prompts.

Then

  Fully charge your PRS-T1
  Download the stand-alone firmware updater file from Sony's support site.
  Extract the file by right click, and choose "Extract here"
  Connect your PRS-T1 to your PC with the USB cable (causing it to mount its 'SETTING' and 'READER' partitions).
  Go to the location where you extracted the file.
  Copy the PRS-T1 Updater.package files to the 'READER' file system.( /media/READER/ )
  Disconnect the PRS-T1 from the USB cable.
  Power down the PRS-T1 (a full power off to the blank screen).
  Hold down both the home button and the menu button, and, while keeping them held, press the power button to turn on the PRS-T1.
  Release the home and menu buttons once the boot screen is shown.

  The PRS-T1 should now install the update and automatically reboot once
  done.

For other info you can check this out

Source: http://wiki.mobileread.com


How can one share internet between two computers? (18.04.5 LTS)

Sometimes a simpler solution is better. While I can appreciate the wonder of IP routing or proxying through your laptop, I would buy a cheap wifi adapter for your PC, or get a really long Ethernet cable instead. Would save a lot of headache.


How to run nosy (IEEE 1394 packet sniffer)

Following up on @mikewhatever's comment, and this thread, I ran make in the tools/firewire subdirectory of the kernel source tree. If there are no errors (see below) that will result in a nosy-dump executable that you can run. Your nosy device might not be /dev/nosy as written in the code so you can change that before compiling or use the -d flag. In my case the devices are fw0 and fw1, since I'm using a laptop PCI card with 2 FW interfaces. Check out the code for the rest of the flags. I don't get any output upon running nosy-dump, but that's another problem.

If you could compile then don't read any further.

I got an error saying that uapi/linux/types.h could not be found. I had to add an extra include path in the MakeFile, on line 9, so that it looks like nosy-dump : CFLAGS = -Wall -O2 -g -I /usr/src/linux-headers-4.15.0-55-generic/include/uapi. Of course, this path depends on the kernel and distro.


How to upload an image to deviantArt directly from Inkscape and GIMP?

You have to install the Inkscape extension and GIMP plugin by Martin Owens for this .

Add the PPA ppa:doctormo/deviantart-plugins and install inkscape-extension-dastash and gimp-plugin-dastash from the software center.

To share an image in Inkscape go to Extensions → Publish to → deviantArt Stash.

In GIMP go to Image → Publish to → deviantArt Stash.

Fill in the necessary information in the windows that appears.

That's it, enjoy.

Source: doctormo.org


30 seconds isn't slow at all, especially for a 7-year-old computer. I don't know why you wouldn't be satisfied with it, since 20 seconds is the normal boot time for Ubuntu.


No this is not an error. The script runs and give the output which is "1".  It is added to the same line the Terminal sees, and not making a new line after output through, so it seems like it isn't running.

All you have to do is to add a new line character which is mostly the \n at the end of the output so that you print a new line to the end of the output, so you don't have this behavior.


Enabling Ubuntu dock on GNOME adds unremovable trash icon

It seems, somehow you have enabled the below key to true, either by installing dash-to-dock extension or changing the values in dconf-editor.
to know the key value, run below command.
gsettings get org.gnome.shell.extensions.dash-to-dock show-trash

Probably it gives true because your trash icon is visible when you turn on this extension (ubuntu-dock).
set the value to false with below command.
gsettings set org.gnome.shell.extensions.dash-to-dock show-trash false


with the command "su" to get administrator privileges

There is where you went wrong.

"su" is old skool Linux where you use a root account. We are no longer using this as using "sudo" is considered slightly more secure (*)
In Ubuntu we use "sudo -i" to get to a root prompt where the password you provide is the admin password (by default this is the password of the user you created the system with).

(*) someone trying to gain access to your machine needs to find out your username instead of knowing it is "root". "sudo -i" also logs every action done as your admin user. So if you have more than 1 admin you can see which of the 2 users it was. And there are a few more benefits (all slight improvements over using "root").


Turns out a restart and an upgrade

sudo apt-get upgrade

was all I needed.

I actually ended up not being able to restart. Something weird with the running services not responding(?!). I ended up rage quitting with the power button and it seems that's all I needed to do. Hope this helps someone.


How do I copy MySQL databases to another Ubuntu machine?

To backup/save databases as SQL files, run

mysqldump -uroot -p database_name > dumpfilename.sql

Replace database_name with the name of the database you want to copy over and enter the root password when asked.
Copy the dumpfilename.sql file over to the other system like any other regular file and import the database using this command:

mysql -uroot -p database_name < dumpfilename.sql

Again, replace database_name with the (new) name of the database and enter the root password when asked.

Note that this is totally not OS-specific, but a general way of dumping/importing MySQL databases.


Long startup time in ubuntu 20.04.with SSD

You can disable the NetworkManager-wait-online if you don't have a bunch of resources on the network that need to be connected before signing in. If you do not run your notebook on a corporate LAN, chances are you can go without it.
Do these things after Ubuntu eventually finishes booting:

Open a terminal
Disable the Network Manager wait:sudo systemctl disable NetworkManager-wait-online.service
Reboot

Problem solved. If you do need to restore this function later, you can do so like this:
sudo systemctl enable NetworkManager-wait-online.service

Hope this helps


How to change the partition that grub loads from?

I had to install grub-efi-amd64 in order for grub-install to work, and i had to mount /dev/nvme1n1p1 to /boot/efi (which I mkdir'd), and then grub-install --target=x86_64-efi /dev/nvme1n1 worked and the grub that was set up now gets loaded.
Now I can decide which OS's grub menu and config to load by choosing which drive to boot from the motherboard UEFI boot menu.


What's the difference between flashplugin-installer and adobe-flashplugin?

I've just downloaded both packages to inspect them, the process for comparing the packages can be found on the bottom.

adobe-flashplugin

It contains the Flash player library and configures itself as default for Internet browsers. It was only available for 32-bit systems, but since October 2011 a 64-bit version is available too for Ubuntu Lucid and later. This can be installed from the partner repository, see also How do I enable the "partner" repository?

flashplugin-installer

It extracts the 32-bit Flash player library from the adobe-flashplugin package (which is retrieved from http://archive.canonical.com/) and configures itself as default for Internet browsers. Additionally, it installs a 32-bit compatibility layer for 64-bit systems.

Conclusion

There is no change in the installed Flash player for 32-bit systems. For 64-bit systems, flashplugin-installer installs the 32-bit version of Flash and a related compatibility library which may be slower and less stable. I would recommend using the native 64-bit library instead (adobe-flashplugin).

Analysis

adobe-flashplugin was found in http://archive.canonical.com/pool/partner/a/adobe-flashplugin/?C=M;O=D (I haven't enabled the partner repository):

wget http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_10.3.181.26-0natty1_i386.deb

flashplugin-installer can be downloaded using apt-get download flashplugin-installer. For comparison, I downloaded the 32-bit package from http://packages.ubuntu.com/natty/i386/flashplugin-installer/download.

Programs used:

dpkg-deb --control package_version.deb target-dir - extracts the control files (e.g. post-installation scripts) to directory target-dir
dpkg -x package_version.deb target-dir - extracts the contents of the package to target-dir
dpkg --contents package_version.deb - shows the contents of the package
diff -Nur one two - compare directories one and two
The postinst scripts were the most interesting as it makes the only difference between the packages.


How to execute PHP code in Linux every 500 milliseconds?

You could use a simple shell-script for that:

#!/bin/bash
while true; do
    php /path/to/your/script.php & sleep 0.5s;
done

The '&' will fork the process in the background, so the timing should be somehow accurate. I guess after some time it will become out of sync with a real clock, so you might either want to add timestamps to whatever your script does or use an approach with an daemon which uses the system time.

(Thanks for the input in the comments)

I recommend adding that script with systemctl. This tutorial looks fine for that:
Creating my own systemd service files


Using Axis2/Java to generate code from WSDL

You seem to be lacking the commons-logging jar in your classpath:

Install Ubuntu package libcommons-logging-java:

sudo apt-get install libcommons-logging-java
Append /usr/share/java/commons-logging.jar and its relatives to your classpath:

java -cp /usr/share/java/axis.jar:/usr/share/java/commons-logging.jar:/usr/share/java/commons-logging-api.jar:/usr/share/java/commons-logging-adapters.jar org.apache.axis.wsdl.WSDL2Java foo.wsdl

It's quite likely that there will be other dependencies missing; you might want to use the JarAnalyizer tool to find them and add to the classpath.


Ubuntu is unable to start Wifi (hardblocked)

HP laptops use a module hp-wmi to translate key presses into action; in your case, turn off the hard block and turn on the wireless.

Let’s troubleshoot your problem.

First, check to see if the module hp-wmi is loaded.

lsmod | grep hp

If so, remove it:

sudo modprobe -r hp-wmi
sudo rfkill unblock all
rfkill list all

Any improvement?


Can't install ubuntu 14.04 with usb & md5 check sums are different

If you have calculated md5sum for your downloaded ubuntu.iso file and it differs to the original one, then you are not recommended to do anything with this .iso fle, but throw it away.

Download again and be sure that md5sum matches. Only after this make your USB device bootable with this image.


ushare doesn't like the fact that eth0 is down even though I am using wlan0

Simple answer this one (i hope):

ushare needs to run as root (maybe not, see commments)

Rather than starting it with the
command you've mentioned, try doing
this:

sudo service ushare start

after you've set all of the options
in the configuration file.

The configuration the error message
is mentioning is located at
/etc/ushare.conf (or perhaps
/etc/ushare/ushare.conf I'm not
sure). In it, you'll be able to set
the network interface permanently.

These are the relevant bits:

# Interface to listen to (default is eth0).
# Ex : USHARE_IFACE=eth1
USHARE_IFACE=wlan0

# Directories to be shared (space or CSV list).
# Ex: USHARE_DIR=/dir1,/dir2
USHARE_DIR=/home/rich/Music

Two things additionally: I don't
know what -x and -c do, i hope
there's an option for it in the
configuration. Secondly, the
directories in USHARE_DIR might have
to be absolute path (i.e. not ~ but
/home/rich or whatever your user
name is).
If all of this doesn't work
properly, or if you just don't want to try it out, you can also just run your
command prepending sudo.

Note: my sources for ushare needing to be ran as root are all either concerning different Linux distribution or they are rather old. If this is no longer the case, please let me know - I don't want to send anybody down the wrong path.


Setting correct (16:9) screen resolution for a Philips 166V3LSB/00 LCD monitor

you could try forcing a modeline in your xorg.conf file

be careful, if your card doesnt support, you can have some serious issues,
make sure you make a back up of that file before you begin to edit it.

check this out for more information: https://wiki.ubuntu.com/X/Config/Resolution

its possible, that your video driver does not support the resolution and aspect ratio that you desire.


Brightness not working on an HP Pavilion Dv6 with a ATI Radeon HD6770M

To get working brightness key. try following

press Alt+f2 , execute gksudo gedit /etc/default/grub

Change this line

GRUB_CMLINE_LINUX_DEFAULT="quiet splash"

to something like below

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Open a terminal by Alt+ctrl +T, Execute sudo update-grub and reboot . See if brightness keys are working.

If the above is not working set a fixed value for brightness. To do so,

Open a terminal by pressing Alt+ctrl+T.

Type ls /sys/class/backlight/*/brightness, copy the outputs to a separate text file

The possibility is there will be two paths,try the following for each path and replace accordingly

example paths will be like

/sys/class/backlight/acpi_video0/brightness

Run following commands in terminal,

For the above path Get the maximum brightness:

cat  /sys/class/backlight/acpi_video0/max_brightness`

Try a lower value to set the brightness, say output is 16 so I will try with half of it

echo 8 | sudo tee  /sys/class/backlight/acpi_video0/brightness

If this works,  make this happen in each login automatically by doing the following

sudo gedit /etc/rc.local

Enter this line just before exit 0. It should look like

echo YOUR_VALUE_HERE > /sys/class/backlight/acpi_video0/brightness
exit 0

Also you can try with xdotool


What happened to Last.FM radio service in Rhythmbox?

Last.FM has brought some changes to their radio services. Here's a relevant quote from their blog post.

  In the United States, United Kingdom and Germany, radio in the desktop client is now a subscription feature, as it is elsewhere.
  In Canada, Australia, New Zealand, Ireland and Brazil, there will be no significant changes to our service.
  Unfortunately, in all other countries, we are no longer offering a radio service after this date.

Going forward from 15 January 2013 onwards, the radio service will be a subscription feature available to the countries United States, United Kingdom, Germany, Canada, Australia, New Zealand, Ireland and Brazil.

For all the other countries, there won't be any radio streaming available since the above mentioned date.


Kwallet system disabled in Kubuntu 15.10 but Kopete still uses it

The solution that worked  (after disabling the service as seen in the image) was to remove

~/.config/kwalletrc
~/.kde4/share/apps/kwallet/*
~/.kde4/share/config/kwalletrc

(as indicated in this answer)


Installing Wordpress on 14.04 - Apache2 Ubuntu Default Page appearing

You are most likely installing WordPress under the wrong path. You have the following options:

Move the files: Copy all the WordPress files from where ever you installed it to /var/www/html.

Change the path used by apache: change the DocumentRoot in the file /etc/apache2/sites-available/000-default.conf to the path where you installed WordPress.

Create a new vHost: Create a new vHost, by adding another site. Copy the /etc/apache2/sites-available/000-default.conf to something like /etc/apache2/sites-available/wordpress.conf and edit it to make your changes. You can than either use a ServerName, to access the server through an URL (for example by adding it to your /etc/hosts file), or disable the default host with a2dissite 000-default. Than you need to enable your new site with a2ensite wordpress (Change wordpress to whatever you named the conf file).

When you change the path or create a new vHost you need to restart apache: /etc/init.d/apache2 restart.

Maybe you also left the index.html in the directory /var/www/html when installing WordPress. Apache searches for the index.html before it searches for the index.php. So you should simply delete it


Unable to set "never" to "show battery status in menubar"?

Install dconf-tools, open dconf Editor in System Tools then click on com/canonical/indicator/power. In the right panel choose icon-policy "never"


Why would 'groups' and 'groups [myname]' give different results?

This is the case if you have modified your account (adding yourself to a group) and not logged out and back in.

To fix your situation, relogin to your session.  You can, but do not need to reboot.


How to fix "/etc/apt/sources.list" could not be read error?

You have appended the second command to the sources.list with tee. Edit your sources.list with sudo nano /etc/apt/sources.list. Remove the sudo ... line (you should find it at the end) save and exit Ctrl+O, Ctrl+X.

Then update your sources with sudo apt-get update and you should be fine again.

If you delete the sources.list while editing ths sources.list.Open the terminal ctrl+alt+T and become root by typing sudo -s and cd /etc/apt and then check the file sources.list.distUpgrade then type cp sources.list.distUpgrade sources.list that's all.

Then update your sources with sudo apt-get update and it should be fixed.


How to install gcc 6.3.0 on ubuntu 18.04

For getting gcc version 6.3.0, first you've to download the source:

wget https://github.com/gcc-mirror/gcc/archive/gcc-6_3_0-release.tar.gz

Then extract it:

tar xvzf gcc-6_3_0-release.tar.gz

Then install it according to their official documentation.


Smart playlist changes to normal playlist in banshee while syncing to ipod nano.

Banshee is limited in its ability to work with Ipods.

Try GTKPod, it is a dedicated Ipod manager and should meet you needs

sudo apt-get install gtkpod


How to combine separate partitions created by initial install of kubuntu

Open the other partition in the file browser and press ctrl+L. You will be shown a path. Copy it. Then open a terminal and enter

cd "[whatever path]"

Where [whatever path] is the path you copied. Keep the quotes. They don't do any harm and make things easier if there are spaces or some other characters in the path. This will set your location in the current terminal to the mount point of your second partition.

Then enter these commands:

sudo chown -R [your user name] .
sudo chmod -R 777 .
sudo chown -R root "lost+found"
sudo chmod -R 700 "lost+found"

This will set the rights the way you want them to be. The first command makes you the owner of everything on the partition. The second command gives you all rights to it, but also every other user of the computer, in case you want to have several accounts and share files this way. If you don't want to do so, change 777 to 700 (others can't do anything) or to 722 (others can only read). The last 2 commands set everything back to the previous state for the (hidden) folder "lost+found" which is a special folder which you probably never will not have to use.


Changing the DNS servers Ubuntu Server 20.04 - Arm64 (Raspi)

Use netplan instead of resolv.conf
cd /etc/netplan
ls
sudo nano 50-cloud-init.yaml

Add nameservers entry.
network:
    ethernets:
        [network-device]:
            ...
            nameservers:
                addresses: [8.8.8.8,8.8.4.4]

Then to apply and test:
sudo netplan apply
systemd-resolve --status


You are running a program from /opt folder.
You need  to run it with sudo

or you could move your sdk to your home folder where you have read/write access.

Third way is to set chmod -R 775 /opt/android-sdk-linux .
I suggest the second method.


Enable both NAT and Host Only on Ubuntu 18.04

I am also hitting the same issue. I am able to get it work by removing this line:

      gateway4: 192.168.56.1

There are other alternatives discussed in netplan configuration on Ubuntu 17.04 virtual machine, however what I need is just to set up a lab environment for testing, so I didn't try those out.


Empathy, Google account, 2 step verification needs authorization every time I login

This has been reported on Launchpad as a problem report.

The only suggestion in the report is to switch to Pidgin since that supports 2-step verification.


Unconfirmed 371801.crdownload is a temporary file that
represents an unfinished download.

In general is not a virus. (unless what were you downloading is a virus)

To delete it you can try to close your browser (if is google-chrome check also that background processes are closed) and try to delete it.

If it doesn't work you can open a terminal pressing ctrl+alt+t.

Now you have to change the directory where the terminal is working with the following command:

cd Desktop

(I'm assuming that your file is placed in your desktop directory and you installed Ubuntu in English international / US).

To delete the file run this command:

rm -f Unconfirmed\ 371801.crdownload

This command will remove the file ignoring any errors. (add \ character because terminal doesn't take into account space in names).
If you want more info about the command you can run from terminal this command:

man rm

If the file is still there you can try to run the rm command as superuser:

sudo rm -f Unconfirmed\ 371801.crdownload

This command will ask you superuser password and after will do the work.

In the end, if the file doesn't disappear, you try to click on your desktop and then press Ctrl+R. This will refresh your desktop.


Print multiple lines starting with "D" after multiple greps

Here's an awk script that does what you want:

awk '
  NR==FNR { C[$2]=1; next }
  $1 == "C" { if (C[$2] == 1) { print; D[$3]=1 } }
  $1 == "D" { if (D[$2] == 1) print }
' f1 f2

Example

Here's some sample data.

$ cat f1
C 010
C 020
C 024

$ cat f2
C 005 Carbon
D Carbon 1
D Carbon 2
D Carbon 3
D Carbon 4
C 010 Hydrogen
D Hydrogen 1
D Hydrogen 2
C 017 Oxygen
D Oxygen 1
C 020 Nitrogen
D Nitrogen 1
D Nitrogen 2
D Nitrogen 3
C 024 Sulphur
D Sulphur 1
D Sulphur 2

Results

$ awk '
>   NR==FNR { C[$2]=1; next }
>   $1 == "C" { if (C[$2] == 1) { print; D[$3]=1 } }
>   $1 == "D" { if (D[$2] == 1) print }
> ' f1 f2
C 010 Hydrogen
D Hydrogen 1
D Hydrogen 2
C 020 Nitrogen
D Nitrogen 1
D Nitrogen 2
D Nitrogen 3
C 024 Sulphur
D Sulphur 1
D Sulphur 2

You can put the awk script into it's own file like so, cmd.awk:

NR==FNR { C[$2]=1; next }
$1 == "C" { if (C[$2] == 1) { print; D[$3]=1 } }
$1 == "D" { if (D[$2] == 1) print }

Then run it like so:

$ awk -f cmd.awk f1 f2
C 010 Hydrogen
D Hydrogen 1
D Hydrogen 2
C 020 Nitrogen
D Nitrogen 1
D Nitrogen 2
D Nitrogen 3
C 024 Sulphur
D Sulphur 1
D Sulphur 2


Changed bottom bar in gnome to left, now both bars are gone. Can I use terminal to fix this?

Did you use an extension to change this in gnome-shell?  If so you can use the terminal to remove the offending extension from ~/.local/share/extensions/


How can I update XZ-utils system-wide after building from source?

OP's own solution in the comments:

  I removed the anaconda binary, ran sudo ldconfig (since I got some
  errors about the new library not being found), and now xz --version
  shows the new version, and works. SUCCESS!


you don't have to re-installing it, did you try to reset Firefox? just open Firefox and click Help --> Troubleshooting Information and click refresh Firefox then it should load as a freshly installed Firefox browser

Other thing, after upgrades or whatsoever some add-ons can cause the issues then try Step 2 and load Firefox with disabled add-ons once it worked you have to disable your add-ons one by one to figure it out which one is causing a lag.


wide-dhcpv6 is failing to start because its using an interface that does not exist

there was a file in /etc/defauls setting the address to ask for a prefix on

ciaran@router:/etc/default$ cat wide-dhcpv6-client
# Defaults for dhcpv6 client initscript
# Used by /etc/init.d/wide-dhcpv6-client

# Interfaces on which the client should send DHCPv6 requests and listen to
# answers. If empty, the client is deactivated.
INTERFACES="enp0s31f6"

# Verbose level for syslog. Default is 0 (0: minimal; 1: info; 2: debug)
#VERBOSE=0

after I changed that to wan0 it worked


Can't get repository information in order to upgrade 10.10 to 11.04

It sounds like you are trying to upgrade from lucid (10.04) to natty (11.04). Which is not allowed.

You have to first upgrade to maverick (10.10) and then to natty (11.04).

Take a look at these questions and answers:

Is it possible to skip releases during an upgrade?
How do I upgrade straight from a very old release to the latest one?
How to update from 10.04 to 10.10?


The current client is at the bottom of this page at the Feathercoin site.

The official forum will likely have discussion of wallet apps.

And, although your graphics card is OpenCL compatible, it was optimized for gaming, not number crunching, so it may not be as fast as you like.


Total noob here. Just installed 13.04 and it doesn't recognize my second monitor

I also was unable to get output on my second monitor (HDMI). The system saw that a monitor was connected, but no output. I had to go to the System Settings, Software & Updates application, and on the tab farthest to the right, "Additional Drivers", it listed about seven different drivers for the NVidia card. I tried a couple before I found one that would run the second monitor. The one I am using now, which seems to work well, is the "NVIDIA binary Xorg driver,  kernel module and VDPAU library from nvidia-313-updates (propietary). Perhaps one of those will work for you too.


When I select and deselect some file on my desktop, an orange line appears near the file name

As part of the way that an entry is highlighted, the name is surrounded by an orange bar as an additional visual indication of which item has been selected, and to draw attention to the name of the selected item, which may help differentiate from other similar items.

You may notice this same behaviour for files shown anywhere in nautilus: the name is surrounded by a rounded rectangle (this is more clearly defined as the shape for items with very long names, preferably containing spaces, which wrap).

This behaviour may be changed by selecting an alternate theme in the Appearance control panel.  Note that alternate themes may well also highlight the name of the icon, but perhaps in a different way, or in a different colour.

On the other hand, if I've misinterpreted your question, and you have a thin orange line appearing near anything you select, and staying there for a while when you select something else, you've probably found a display update bug of some sort: please report it as a bug against nautilus (nautilus may not ultimately be at fault, but it is essential to replication, and will help to find the actual bug).


What are all the parameters for iso-scan?

iso-scan is wired to not ask anything by default, so it will mount all known drives one by one and look for the iso in them.

But if you run it with very low debconf priority it will ask whether it should look into all devices or let you select which ones (shared/ask_device=manual) and in the latter case, which ones (shared/enter_device=/dev/<SOMEDEV>)

Both values can be preseeded from the kernel command line.


is there any performance issue if we install ubuntu on windows based laptops?

It's good to check first if your machine is certified for Ubuntu. Here you have the list of certified Acer Desktop machines:https://certification.ubuntu.com/desktop/models?vendors=Acer

If your machine is not in this list, it does not mean it is impossible but you will need to check the main hardware components' specs to make sure there is support for those. Sometimes, a quick web research to see of someone else succeeded is faster:
This page suggest several people managed to install Ubuntu on this model

Last, if you are trying to create a dual boot. Some PC manufacturers are now freezing their system to avoid that. You need to check first Acer's technical specs to see if their setup is compatible with a UEFI.

Finally if you already have the machine you can also run Ubuntu with a USB Live boot before installing to validate you don't have any error.


Your keyboard USB port isn't turned on, most of the times it happens because at the startup of the system the only USB ports that works properly are the ones directly connected to the motherboard, so try changing the USB port that your keyboard is attached to.

If the problem persits even trying all the possible USB ports you will need to skip Grub (purple screen where you select the OS), if you have a dual-boot system (Windows and Ubuntu on the same machine) you will have some problems because you won't be able to switch between then, but if you have just Ubuntu installed in your pc just do these steps to reinstall Ubuntu and get rid of the problem:

Create a Live CD/USB
Startup the Live CD/USB and select to "try Ubuntu without installing it"
Wait the desktop to load and select to install Ubuntu
Doing a fresh install you should start Ubuntu without passing through Grub

So now your problem should be solved.


apt-get -f install removed software center and several other files

From command line, run:
sudo apt-get update && sudo apt-get dist-upgrade

Should resolve your dependency issues.

Amended
If it doesn't, you could try:
sudo apt-get update && sudo apt-get -f dist-upgrade

OR

sudo apt-get update && sudo apt-get -f upgrade

Similar to above listed, but with -f option added, obviously.

If the above options do not help you, you could run:

sudo apt-get update && sudo apt-get -f install ubuntu-desktop
(Or replace ubuntu-desktop with whatever version you're using, your question doesn't specify)


iso file size for 13.04 is larger than cd's available space

The ISO is intended for DVDs and USB sticks. If you don't have a DVD or USB stick consider using the mini.iso:

https://help.ubuntu.com/community/Installation/MinimalCD


Gnome Terminal transparency broken in 13.04 in Parallels VM

I don't know the root cause or a true fix, but I had the same problem after upgrading to 13.04 (not in Parallels, though), and on a hunch I ran xcompmgr, which fixed it. If that works for you, maybe that'll be a clue for someone better able to tackle this.

Previously I only needed xcompmgr if I wanted special effects or window manager-driven transparency, but maybe recent versions of gnome-terminal switched to compositing-based transparency rather than whatever method it was using before?


How to completely delete a file, so that data recovery softwares can't recover it?

in short: yes, but no...

You cannot make the physical media to appear "as new",
but you can hide the original content of the file.

ubuntu has the program shred pre installed. This overwrites the file with merily ramdom data.

Unfortunatel there may have been written some temporary files with the same content while editing it. The location, the names and the number of this copies depend on the editing program. Its almost impossible to find them all, especially if the editing program deleted them itself. In that case you would have to use a recovering mechanizm to find the temorarry copy(-ies).

So if you want to be sure to remove a file in an unrecoverable way the only option is to make a freash (file based) backup of all disks after deleting the file, fill the discs with random data (using dd if=/dev/random of=/dev/sd?/ baybe more than once) and recover from the backup.

I think this is less of a problem with SSDs, but I'm not sure about it.


How to change GRUB 2.04 to a GRUB version with recovery mode?

The cause was as in comments but I'm sure I used these commands in the recovered(via recovery mode) PC before doing some advanced boot-repair things from the PC itself and rebooting to find this issue.
sudo chroot dpkg --configure -a
sudo chroot apt-get install -fy
sudo chroot apt-get purge -y grub*-common shim-signed

Using a LiveUSB with Ubuntu, I resolved it with a basic boot-repair after I restored the MBR(advanced boot-repair option) and rebooted.
Boot-repair advises you use such commands as part of the process so the mistake could be using them in terminal separately but I'm unsure since one of the last commands it suggested is also used to purge unnecessary files. Messing with the old laptop proved its hard to not recover your own machine provided the OS is in order.


How do I change the default keyring password?

I've found the best solution to use the seahorse package, which can handle changing the password of the keyring, deleting the keyring, creating new keyring an so on ...

So, if you have some derivative of Ubuntu (like Lubuntu), you should first install seahorse:

apt install seahorse

Launch the seahorse, right click your Default keyring and choose Change password.

You will be prompted for your old password first. Then you have to enter your new password twice & submit.

Done.


You need to have LAMP stack installed to set up Wordpress.

1) Install Apache HTTP Server

sudo apt-get install apache2

2) Check if its working by going to http://localhost/

3) Install PHP

sudo apt-get install php5 libapache2-mod-php5

4) In order for PHP to work with Apache you need to restart

sudo /etc/init.d/apache2 restart

5) Install MySQL

sudo apt-get install mysql-server

6) Optional Install phpMyAdmin (Recommended : Make's Life Easier)

sudo apt-get install libapache2-mod-auth-mysql php5-mysql phpmyadmin

7) To add phpMyAdmin to Apache web server you need to edit apache2.conf file

gksudo gedit /etc/apache2/apache2.conf

8) Add this to the last line of apache2.conf file

Include /etc/phpmyadmin/apache.conf

9) Then you need to reconfigure your phpMyAdmin package

sudo dpkg-reconfigure -plow phpmyadmin

10) Restart Apache and everything should work

sudo /etc/init.d/apache2 reload

Note: When you reconfigure phpMyAdmin it might ask about which socket you're going to use select Unix Socket.

The htdocs directory in Ubuntu is /var/www


This is standard behaviour. You're probably used to see asterisks (*) that represent the characters that you type. This is against any security logic because anyone can already see the length of your password, which shouldn't be visible to anyone looking over your shoulder ;)
Unix terminals don't show anything, but they do accept input. If it doesn't accept your password, that's a whole different issue then. If that's the case, open a new thread with as much detail as you can provide.


How do I get a Radeon RX 550 working with OpenCL on Ubuntu 16.04?

I just spent the whole day on this too - I couldn't find any working instructions so here's what I came up with for AMD Radeon RX 580 on Ubuntu 16.04 system with no graphical desktop, installed over SSH:

Assume a fresh Ubuntu install system

Get the AMD APP SDK from here - Download, Unpack and then use sudo to run the install script.
Download the most recent linux driver (17.50 at time of writing this answer) from here, extract the .xz file using tar Jxvf <filename> and cd into the directory created after extracting the .xz file.
Now run the installer with sudo:

sudo ./amdgpu-pro-install --opencl=legacy -y

Reboot
Run clinfo again and you should see that you now have OpenCL 1.2 support:

$ clinfo|grep OpenCL

Platform Version:               OpenCL 2.1 AMD-APP (2527.3)
Execute OpenCL kernels:         Yes
Device OpenCL C version:        OpenCL C 1.2
Version:                        OpenCL 1.2 AMD-APP (2527.3)

The reason for this is that specifying --legacy pulls in opencl-amdgpu-pro-icd which is not normally installed.

I think this is because the latest drivers want to do things with ROCm:
https://rocm.github.io/ROCmInstall.html

On my own rig, ROCm is unusable because I've got PCI-e 1x slots with risers and a basic Pentium CPU instead of an i7. You check that ROCm was disabled like this:

$ dmesg |grep atomic
[4.885958] kfd kfd: skipped device 1002:67df, PCI rejects atomics

So I guess this is why I had to do legacy to get OpenCL working at all.

I'm not sure what the pros/cons are of OpenCL 1.2 vs OpenCL 2.0 vs ROCm, or even if the ROCm driver presents as OpenCL 2.0 externally - would be great if someone with more insight could comment.


Installing tarball when you already have a package (different versions)

Installing from source in that way does not involve the use of Ubuntu's package manager. Also, default behavior of all most all applications' source distributions (tarballs) is to install in /usr/local rather than /usr (where software is installed by the package manager). Therefore, you don't have to remove the version already installed through the package manager, though it may be helpful to do so (it will make sure the version you want is always the version that gets run and will decrease the likelihood that different versions will use each other's libraries and throw subtle and bizarre errors), and is unlikely to hurt.

Software installed from source in the way you've described certainly will not be updated by apt-get.

To uninstall the version installed from a source tarball in the way you've described, you can usually run sudo make uninstall. You must be in the same directory you were in when you ran sudo make install.


Unity Applications Lens: a daemon that exposes you applications with their usage statistics and status to Unity.
Unity Files Lens: a daemon exposing your files and file history to Unity.
Unity Music Lens: slams your music face first into the dash so you can get your grubby little paws around your collection faster than you can say bon-jovi's-greatest-lovesongs-volume-four.
Unity Videos Lens: a lens for Unity to search local and remote videos.

For more available lens for Unity, check: What lenses for Unity are available?


Raring has the package in "universe": Ubuntu – Details of package libglui2c2 in raring

But releases after that do not have it any more.

So I would advice to install it from the 13.04 repository.

You can find it here:

i386
amd64

Download the file and click it for Ubuntu Software Center to try to install it.


Set the sound settings the way you would like to have them when you boot. Then, run the following command.

sudo alsactl store

Next time you boot, the sound settings will be restored.


Systemd interaction with Minecraft server

You can monitor by reading logs/latest.log, located in the minecraft directory. That log includes all console output.

Example: My Minecraft Server runs under separate system user (not me, not root), so my minecraft directory is /home/minecraft, and my log is at /home/minecraft/logs/latest.log
I monitor the file using the 'less' application: less -F /home/minecraft/logs/latest.log


create link to a serve a website in nginx

Just add them to your config as follows for each directory you want to serve

location /test {
    root /var/www/test;
}


No graphical interface after hard shutdown

You can reinstall. Or the geeky method would be this:

Boot from the live CD into Ubuntu.
Mount your hard drive by opening it in Nautilus/Dolphin
Open a terminal window
type cd /media to go where the harddrives are
type ls to see the names of all of them. One is your root drive.
become root by doing sudo su, the password is empty, just press enter
chroot HARD_DRIVE_NAME
passwd YOUR_SHORT_USER_NAME and enter a new password
reboot and use your new password


multiple preinstalled programs with similar jobs

I would be careful with removing seemingly superfluous programs. Other packages, even unrelated ones coming with the DE might depend on them. On LXDE for instance you can't remove lxterminal (≙ gnome-terminal) or leafpad (≙ gedit) without deleting essential packages such as lxrandr, lxinput and other ones.

Save for these dependency issues there is no reason why you shouldn't be able to remove  duplicate applications. Just make sure that you can configure the DE to use a replacement of your choice, e.g. gnome-calculator instead of galculator.

If it's not the wasted disk space that bothers you, but clutter in the respective DEs menus, you can always add the OnlyShowIn= parameter to the application launchers in question. See here for a tutorial on Kubuntu entries.


IDLE 2.7.5+ doesn't work in Ubuntu 13.10

This is a known bug. It's fixed in idle 2.7.6, but you can easily(*) fix it yourself.

Open the file /usr/lib/python/idelib/IOBinding.py as root with your favorite editor:

sudo gedit /usr/lib/python2.7/idlelib/IOBinding.py

Go to line 128 and change:

str = str.split("\n", 2)[:2]

to:

lst = str.split("\n", 2)[:2]

and save the file.

(*) Easily if you are a python programmer.


How to connect to a L2TP VPN given some info from a sysadmin

Try:

conn tab-vpn
    ...
    rightid=192.168.122.2

in /etc/ipsec.conf

The rightid parameter can be used to specify the IP address that the server identifies itself as (ie. it's LAN IP address rather than the public IP address of the router).

If the expected IP address and the IP address that the server identifies as don't match then ipsec abandons the connection attempt.


Unable to Install HP Printer (Moving this to my regular account)

You need to install HPLIP driver.

This driver can be download from Sourceforge via HP website.

To download and install follow this commands.

cd ~/Downloads

sudo wget -c "http://kaz.dl.sourceforge.net/project/hplip/hplip/3.13.11/hplip-3.13.11.run"

sudo sh hplip-3.13.11.run

** There is a nice GUI application called hplip-gui . It is a versatile tool. Even you can Fax using All-In-One printers with this application.

sudo apt-get install hplip-gui