This can be a useful tool for debugging certain applications but in some cases (and most of KDE is a prime example) you end up with way too much stuff just sitting in there.

Deleting (or otherwise abusing) the file will not be a permanent solution because the sessions are set to recreate this file on login. However you have a few options to deal with it.

For the sadist: break all the things!

You can break that behaviour simply by running sudoedit /etc/X11/Xsession and looking for the section that squawks on about ERRFILE. Obviously make a backup first, but I would say you can comment (prepend each line with a #) or remove all the following code:

ERRFILE=$HOME/.xsession-errors

# attempt to create an error file; abort if we cannot
if (umask 077 && touch "$ERRFILE") 2> /dev/null && [ -w "$ERRFILE" ] &&
  [ ! -L "$ERRFILE" ]; then
  chmod 600 "$ERRFILE"
elif ERRFILE=$(tempfile 2> /dev/null); then
  if ! ln -sf "$ERRFILE" "${TMPDIR:=/tmp}/xsession-$USER"; then
    message "warning: unable to symlink \"$TMPDIR/xsession-$USER\" to" \
             "\"$ERRFILE\"; look for session log/errors in" \
             "\"$TMPDIR/xsession-$USER\"."
  fi
else
  errormsg "unable to create X session log/error file; aborting."
fi

# truncate ERRFILE if it is too big to avoid disk usage DoS
if [ "`stat -c%s \"$ERRFILE\"`" -gt 500000 ]; then
  T=`mktemp -p "$HOME"`
  tail -c 500000 "$ERRFILE" > "$T" && mv -f "$T" "$ERRFILE" || rm -f "$T"
fi

exec >>"$ERRFILE" 2>&1

echo "$PROGNAME: X session started for $LOGNAME at $(date)"

For the long-login user: cron

I stay logged into my desktop for weeks at a time and if something blows up, chances are I'll only need the debug for a couple of hours, if at all. So I ran crontab -e and created a line like this:

0 * * * * bash -c ">/.xsession-errors"

That just gives the file an hourly colonic.

For the masochist: fix all the bugs!

You have to remember that .xsession-error output is there to indicate a bug or something behaving in a way that it should not. This is not always true (glares at KDE) but in your case with your VNC client, this may indicate that something is going wrong.

If you have a look at the errors you might be able to change your application settings to avoid the error, or failing that, report the error (along with some of the sample messages) to the author of the software.

If it is just spam (Eg: "connecting to server") report that as a bug to the author too. They're misusing the infrastructure.


If you run locate *.cpp in the shell the shell will first try to expand *.cpp to all file names matching that pattern and then call locate with this file names as argument.

So if there are any .cpp files in your current directory locate will never see the *.cpp but only the file names it expands to.

Use

locate '*.cpp'

if you don't want the shell to try to expand the pattern.


How to install hplip 3.17.11 under Ubuntu 17.10 for HP OfficeJet Pro 8720

The fact that hplip 3.17.11 added support for Ubuntu 17.10 is not relevant to your problem here. You don't want to look at which distribution is supported natively by HP, you want to see from which version on your printer is supported. hplip is supplied by Ubuntu for quite some time, you don't need to have it supplied by HP.

hplip is part of Ubuntu 17.10 in version 3.17.7. You can install it without problems with just apt install hplip.

Now what version do you need? From the release notes you quoted, it is apparent that your printer HP Officejet Pro 8720 is supported since hplip 3.16.5, so you would be fine with the distribution-supplied version.

To rescue your installation, roll back and uninstall what you have installed for the shell installer. Afterwards, do a apt install hplip as mentioned above.

That should do the job.


Application integration with Unity launcher

There is some simple  drag-and-drop support built into Unity. If an application can take a filename as a commandline argument, you simply need to use a variable in the Exec field of the desktop file.

Take for example Gedit's desktop file (with some content removed for readability):

[Desktop Entry]
Name=gedit
GenericName=Text Editor
Comment=Edit text files
Exec=gedit %U
Terminal=false
Type=Application
StartupNotify=true
MimeType=text/plain;
Icon=accessories-text-editor
Categories=GNOME;GTK;Utility;TextEditor;

If you drop a file on a Gedit launcher in Unity, the %U will be replaced by the file's uri.

The variable is part of the Desktop Entry Specification:

%u - A single URL. Local files may either be passed as file: URLs or as file path.
%U - A list of URLs. Each URL is passed as a separate argument to the executable program. Local files may either be passed as file: URLs or as file path.


WiFi is not working and doesn't show up in Network Manager and System settings

You have blacklist rt2800pci in /etc/modprobe.d/blacklist.conf and rt2800pci should be the kernel module to support your wifi.

To fix this, open a terminal window and enter
sudo sed -i 's/blacklist rt2800pci/#blacklist rt2800pci/' /etc/modprobe.d/blacklist.conf

Reboot and wifi should work.  The code simply replaces blacklist rt2800pci with #blacklist rt2800pci  The additional # at the beginning of the line makes it a comment


Install Ubuntu 18.04 LTS on small SSD and HDD

According to the space requirements on this page, 15 GB is the absolute requirement for Ubuntu:

  The required disk space for an out-of-the-box Ubuntu installation is said to be 15 GB. However, that does not take into account the space needed for a file-system or a swap partition.

If you want to install Ubuntu to another drive that is larger, you can always use the smaller SSD to install software you use on a frequent basis, that would benefit from the faster read and write speeds SSDs have.


This problem appears in kernel versions < 3.19
Try to install latest stable kernel with this:

sudo apt-get install linux-generic-lts-vivid


How do I find the password to a hard drive partition?

I don't think your issue is about a forgotten or wrong password. It seems that your installation does not have cryptsetup installed. Install it: cryptsetup  and try again.

  How can I find the password to a drive partition if I forgot it?

Well, the whole purpose of the hard drive encryption is to keep the data safe for ones not having the password. Storing the password on the system would basically undermine the whole purpose of running encryption in the first place. Passwords are for you to remember, not to store anywhere!


grub cannot load my newly installed kernel

Change the name of bzImage to vmlinuz-kernel-version (vmlinuz-3.2.6 or what have you).

Also, kernel (vmlinuz) versions must start with a number vmlinux-[0-9] , update-grub will otherwise throw an error dpkg: error: version 'version-rt19' has bad syntax: version number does not start with digit (error message used with vmilinuz-version-rt19)

You probably also need to install the modules

sudo make modules_install

And you probably need to make an initrd (depending on your hardware), again change "3.2.6" to your kernel version

sudo update-initramfs -c -k 3.2.6

Then re-run update-grub

sudo update-grub


My external USB sound card is not working

On my other laptop, internal sound card died, so I also use USB sound card ( Daffodil US01 ).

On the laptop I use right now, it's Ubuntu. In System Settings -> Sound you should see your usb sound card listed as headphones. Look at screen shot bellow:

If you highlight the Headphones option, you should receive sound through the usb card.

Now, you can do this every time, or you can select your USB card as default. Now there is small problem. On that laptop where I must use USB card I have Fedora, not Ubuntu, so I don't remember what steps I used, and if those steps can be used. But this post here  explains it exactly for Ubuntu.

Good Luck ! Let me now if this helps


I can't change the keybinding theme from emacs to default in gnome tweak tool

gsettings reset org.gnome.desktop.interface gtk-key-theme


Mount is throwing an error because you aren't specifying a mount point, and it can't find one in fstab. I would just create a mount directory in /mnt (short for mount) or /media with

sudo mkdir /mnt/sdcard

Then mount it with

sudo mount --options remount,rw /dev/sdb1 /mnt/sdcard

This will mount your sdcard at /mnt/sdcard but note that the files will be owned by root, if you want to mount them as your user add uid=user,gid=user to the options (where user is your username). For example.

sudo mount --options remount,rw,uid=myuser,gid=myuser /dev/sdb1 /mnt/sdcard

When you're done, unmount the SD card

sudo umount /mnt/sdcard

And then after you've removed the card, delete your mount point with (WARNING rm will delete whatever you tell it to! TRIPLE CHECK your typing for errors before you run it, especially as sudo!)

sudo rm -ir /mnt/sdcard

Thats about it! Nothing more to do.


Uninstall a package & getting a long list

Autoremove & Purge

apt-get autoremove

will remove all old packages that are no longer needed.

apt-get purge

Will removes a specific package install. When running

apt-get autoremove --purge package

you are telling the system to remove old pakages then uninstall package. It is completely safe to execute the command as written.


Need help on my Ubuntu server installation

If you installed Ubuntu Server, the command prompt you show in the photo is perfectly normal. A graphical desktop environment is not installed by default.
Either you can reinstall Ubuntu (the normal desktop version) and setup your server applications from there, or you can install a graphical desktop on top of your existing installation as follows (I'll just give you an example for Gnome, if you want anything else the internet is full of help :) ).
Run the following commands from the command line:
sudo apt update
sudo apt upgrade
sudo apt install tasksel
sudo tasksel install ubuntu-desktop
sudo reboot

You should now be shown a graphical login screen!


You need to edit your files to point to http:// instead of http//.

First, run the following command to fix your sources.list:

sudo sed -i 's|http/|http:/|g' /etc/apt/sources.list

Then, run the following command to fix your google-chrome.list:

sudo sed -i s|http/|http:/|g' /etc/apt/sources.list.d/google-chrome.list

Finally, run the following command to update apt-get:

sudo apt-get update


How to put suspend, turn off, reboot buttons on Kubuntu's lock screen?

Edit:
In light of the querist's clarification that it's the lock screen and not the login screen that is the issue the following links maybe of interest:

Bug 392798 - Power button actions should be handled from lock screen
Suspend linux from KDE Plasma 5 lockscreen

What follows was a response to the original question which mentioned login screen.

This is what I see:

If that's not what you see, I'm afraid there's something "non-standard" about your system or I could have misunderstood your question.


Just add the header line before printing the data to the file:

#!/bin/bash

Header="Filename1,ProcessType1,TotalDuration1,Initialization1,MPEProcessDuration1,TotalPartitionDuration1,WaitPartitionDuration1,MainPartionDuration1"
echo $Header >>OutputFile_Validate.csv

cd /path/to/manoj/version_2019_logs/
for file in log_Job_*/manoj.log; do
set of commands

Var1="$Filename1","$ProcessType1","$TotalDuration1","$Initialization1","$MPEProcessDuration1","$TotalPartitionDuration1","$WaitPartitionDuration1","$MainPartionDuration1"
echo $Var1 >>OutputFile_Validate.csv
done

For the sake of completion, bash also has a variable name expansion feature, thus

${!Filename1@}

expands to the variable name

"Filename1"

and if $Filename1 and $Filename2 are set

${!Filename@}

expands to this space-separated variable name list:

"Filename1" "Filename2"

Unfortunately that’s not really helpful here.


You may need to go into your PC's BIOS setup and find the

USB Flash Drive Emulation Type

setting and change if from "auto" to "hard drive". Worked for me on an 2012 model HP Microserver.
Also answered in Ubuntu 12.10 won't boot from usb - isolinux.bin missing or corrupt and "isolinux.bin is missing or corrupt", when attempting to boot using disk in USB CD DRIVE


You end up in read-only mode because of one or more inconsistencies in your (root) file system. If they keeps appearing you either have a bad habit of not shutting down your system correctly, or you have a bad disk that needs replacing.


In this case a format seems like an aggressive solution to me.

I would try to fix the sudoers file (I guess you edited it by hand? You probably wanted to give a user "admin rights"?) and then add /sbin in to the PATH.

You may also want to add your user to the adim group and uncomment the line in the sudoers file that gives the members of the admin group root privileges.


How do I Factory Reset a BQ Aquaris M10 tablet?

There's a timing play to successfully factory reset the BQ Aquaris M10 tablet

Start with the tablet powered off.
Press the power and volume up keys simultaneously
Release both keys immediately when the BQ logo appears.
Use the volume buttons to cursor down to wipe data/factory reset then press the power button to select it
Select Yes--delete all user data and press the Power button once
You'll now have the screen shown here, simply cursor to  reboot system now with the volume buttons and select it with the power button. This should bring you back to factory condition.

If for some reason this doesn't work for you you should likely reflash the firmware.

Sources:

https://www.hardreset.info/devices/bq/bq-aquaris-m10-hd/hardreset/first-method/

Problem flashing Ubuntu Touch Firmware on Aquaris M10 (frieza)


Problems with Lubuntu 16.xx installation - LVM with encryption

Did you check that the download was good with md5sum?

I would recommend that you try Lubuntu 16.04.1 LTS, and not only 16.10, because 16.04.1 has long time support for 3 years (until April 2019) while 16.10 has only 9 months support. 16.04.1 LTS, the first point release, is debugged and polished, much better than the original 16.04 LTS version.

Try Lubuntu's alternate iso file with the text mode installer! It does not use zram and does not suffer from the problem with swap. Installing with LVM  and encrypted disk was tested during the development cycle (by me; the testcase with both encrypted disk and encrypted home inside the encrypted disk), and works also in very old computers.

You can use the following link with instructions to perform an installation with encrypted disk. The name of the testcase is slightly confusing, but it helps you do what you want:

Alternate Install (Unencrypted home) in Lubuntu Alternate i386 in Xenial Daily (archived)


Boot into Windows and install EasyBCD on it.

Open it.

In the Deployment section, you'll have an option to write the Windows XP bootloader in the MBR. Click on it and reboot.

If everything goes well, and Windows boots up without encountering GRUB, delete the Linux partition.


According to http://packages.ubuntu.com/precise/php5-gd You should have libgd 2.0.36 in Ubuntu 12.04. I believe the "2.0" there is just a major/minor version and isn't sharing with you the patch level. Perhaps something else is going wrong.


Accidentally deleted Ubuntu installation, how can I reinstall it cleanly on a dual boot system?

boot through a Live CD or USB. ask to install Ubuntu. the installer will detect the broken partition and ask to repair it. if there are no files to recognize, you will need to delete those partitions (careful, do not delete the windows partition) or re-install in them. the installer will handle the grub.


How can I pan single application's audio?

It can very easily be done with PulseAudio Volume Control (pavucontrol )

Make sure the paddlock () is unlocked when changing the balance


No sound in system at all after installing puredata

This answer helped fixed the issue
Installed Lubuntu 16.04 version no audio now
I removed all alsa packages and killed all pulsaudio processes, then rebooted the system


Access Files on a Computer with Ubuntu when Windows Fails to Boot

It should work with any version of Ubuntu or Linux as long as you can properly mount the filesystem. I've retrieved files from my windows 7 partition (NTFS) from Ubuntu 12.04.

These instructions would work from the terminal on a Linux machine:
http://www.pendrivelinux.com/mounting-a-windows-xp-ntfs-partition-in-linux/

Edit: To specifically answer your question, yes it will work with other versions of linux and all recent versions of Ubuntu.


I had the same experience myself, but resolved it with a fix to an ostensibly unrelated problem. From what I understand, this is an issue with gnome-settings-daemon and mate-settings-daemon conflicting.

Follow these steps:

cd /etc/xdg/autostart/

Always backup your files, just in case:

sudo cp gnome-settings-daemon.desktop gnome-settings-daemon.desktop.bak
sudo cp mate-settings-daemon.desktop mate-settings-daemon.desktop.bak

Now start the editing:

sudo nano gnome-settings-daemon.desktop

Then replace the text with the following:

[Desktop Entry]
Type=Application
Name=MATE Settings Daemon
Exec=/usr/bin/mate-settings-daemon
OnlyShowIn=MATE;
NoDisplay=true
X-GNOME-Autostart-Phase=Initialization
X-GNOME-Autostart-Notify=true
X-GNOME-AutoRestart=true
X-Ubuntu-Gettext-Domain=gnome-settings-daemon

Then edit the mate daemon

sudo nano mate-settings-daemon.desktop

Replace the line beginning with Exec= with this:

Exec=/usr/bin/mate-settings-daemon --no-daemon &

You should be set after a reboot.


Show information on selected apps when browsing installed apps

I don't think there is a way to get information about installed apps without using synaptic or the software center, if I need information about an app, I just google it, and usually, the company/person/team/business that made the app, their website usually is on the first page of google, that's what I do, but if you don't have internet, then i don't know what else to tell you, is it a specific app? or is it that synaptic and the software center don't supply enough information?


You can't use slashes in an alias name. Bash allows them in function names, however, so you can make that a function:

cd../.. () { cd ../..; }

You can't use backslashes in an alias or function name. The backslash character quotes the next character, so cd..\.. is parsed as cd...., well before that string is looked up as a command name. If you want to call a command named cd..\.., you need to type cd..\\.., 'cd..\..', or something equivalent. Furthermore, a command name which was quoted in any way isn't considered for alias lookup, so you can't ever use an alias name containing a backslash. Bash doesn't allow backslashes in function names, either. Since cd..\.. is parsed as cd...., you can define a function called cd.... (as above).

If you use the cd command, you'll have to type the space after it, just like any other command. But you can save typing by not typing cd at all. Set the autocd option with the following line in ~/.bashrc:

shopt -s autocd

Then you can type a directory name on the command line, and “executing” that directory will change to it.

~/some/sub/directory$ ../..
~/some$


How do I install Ubuntu onto my USB drive?

I'm adding this answer because it does explain one of the OP's original questions, which was "can I do this?" I'm explaining why he can't.

The reason you can't select it is because the USB is mounted, and you can't partition mounted devices. So to install Ubuntu on it like you're trying to do, you'd need another USB to boot from, so the original USB can be left unmounted.

If you would like to install onto a USB drive, check out How do I install Ubuntu to a USB key?


Lower than max resolutions not scaling to full screen

This should be solving your problem.

http://dfourtheye.blogspot.in/2013/04/ubuntu-screen-custom-resolution.html


Since the md5sum of the .iso image turned out wrong when you tested it, you have a bad .iso file. It's highly likely (though not certain) that this is the cause of the problem.

You should make sure you're comparing against the correct hash, though. The hashes here are missing for some of the newer iso files. In particular, it doesn't currently have the md5 hashes for the 14.04.1 images, which is what you likely downloaded if you downloaded 14.04 recently.
http://releases.ubuntu.com/14.04.1/MD5SUMS includes the MD5 hashes of the 14.04.1 images.

You should download the iso again, md5 test the new one, and assuming that one is good, burn a new DVD from it. If the .iso file has a different md5sum from what it's supposed to have, that means it got corrupted, most likely during download. (Or it's possible the download didn't finish all the way.)

Corruption in file downloads is the exception rather than the rule, so most likely this second download will work. You should md5 test it too, though.

But if the md5sum of the new iso is wrong too, then provided you're comparing it to the correct official md5sum, that suggests a problem with the quality of the Internet connection used to download it. You could then use bittorrent or zsync to download it more reliably.


Remote Desktop Settings aren't allowing setup in Ubuntu 18.04.1 LTS?

On one of my machines, I had to install vino and dconf-editor:

sudo apt install vino dconf-editor

then edit the values under /org/gnome/desktop/remote-access/ (see Ubuntu MATE: Where is Vino in dconf?).

on another, I had an entry from old times in /etc/network/interfaces which I had to remove so that only the following remains:

auto lo
iface lo inet loopback

then follow the description on Linux Config - however, I made one change, namely I made NetworkManager manage all connections. So I created a file /etc/netplan/01-network-manager-all.yaml that looks like:

# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager

Then reboot and everything worked. Totally crazy, I would really like to know what went wrong at Canonical when they switched from 16.04 to 18.04


Containers loses its volumes which are autofs sshfs mounted from a remote server to the host. How can I autorecover when the mount is down

After some further investigation on Askubuntu, I found some additional options for sshfs which keeps the connection alive. This seemed to do the trick, combined with a script which checks the mount directly and via a container shell and then restarts them if there is a failure.
autofs / sshfs additional options to include:
-o reconnect,ServerAliveInterval=15,ServerAliveCountMax=3
I hope this helps.


When I rarely have a linux or Windows computer that won't boot I pull out my Boot Repair CD. It is downloadable in ISO format to be burned to CD. Then you boot from it. It fixes the boot software automatically. (I use Linux Mint. I used Boot Repair a couple of weeks ago. I don't remember what caused the boot error. It fixed the boot process.)


1) change your password passwd
2) you can turn off sshd if you do not need it


How can I share media from ubuntu 13.04 to windows XP

I got the same problem and solved it by adding the user to the samba share, with this command:

sudo smbpasswd -a <USERNAME>

just change < USERNAME > by the username (an ubuntu prevously added user) you want to access to the shared resource.

Also I didn't change any file, I just right click the folder from nautilus and use "Sharing options" menu.

Hope this help you


Not able to install ubuntu 14.04 using wubi

ubuntu14.04amd64 is 64-bit version of ubuntu that is applicable for both AMD and Intel Processor. As your system has a 64-bit processor Wubi is downloading+installing 64-bit Ubuntu by default.

Check "Why is the AMD64 version of Ubuntu being downloaded and installed?" in Official Documentation


Changing email application in Preferred Applications to GMail?

To set GMail as the default for mailto links in Ubuntu 11.10 :

Install gnome-gmail
Edit ~/.local/share/applications/mimeapps.list and add the line below:

x-scheme-handler/mailto=gnome-gmail.desktop;
Open System Info (use the Dash) and under Default Applications change Mail to Gnome Gmail


How to update Sublime Text-3 in Ubuntu 16.04?

Follow the steps given below:

Download the latest version of Sublime Text 3 (at this time, it is Build-3126) as a .deb package
Install GDebi Package Installer (if not installed).
Then remove Sublime Text 3 (Build-3114) by opening its .deb package(which you downloaded earlier) using GDebi Package Installer and then click on Remove Package.
Then open the .deb package of the latest Sublime Text 3 version (probably, Build-3126) using GDebi Package Installer and click Install Package and install Sublime Text 3 Build-3126.

All your configurations (packages installed and other customisations) in Sublime Text 3 which you did earlier will be restored automatically even after following the above procedure. So you need not worry about installing the packages again. You will find those customisations and packages automatically in the latest version you have installed, because updating through this procedure doesn't remove/purge Sublime Text 3 configuration files.

This procedure works also for other code editors like Visual Studio Code and Atom. I have myself tested and verified it.

But you have to install Package Control again.

EDIT: Sublime Text 3.0 has been released. To install it in Ubuntu, use apt package manager and run the commands given below one-by-one in terminal:

Install the GPG key:

wget -qO - https://download.sublimetext.com/sublimehq-pub.gpg | sudo apt-key add -

Select the channel to use:

Stable

echo "deb https://download.sublimetext.com/ apt/stable/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

Dev

echo "deb https://download.sublimetext.com/ apt/dev/" | sudo tee /etc/apt/sources.list.d/sublime-text.list

Update apt sources and install Sublime Text

sudo apt-get update
sudo apt-get install sublime-text

Now whenever a Sublime Text update(after Sublime Text 3.0) will be available (depending on the channel you chose while installing Sublime Text), you can update it using Software Updater or by running the commands given below (one-by-one) in terminal:

sudo apt-get update
sudo apt-get upgrade


The problem is that you chose to encrypt your Ubuntu installation. When it asks for a passphrase it is asking for your encryption pass.

If this is a new installation and you didn't have a prior version on the HD then just try re-installing  (and make sure not to choose encryption).


You can't.

But there is a workaround:

If you haven't already done so, go to System Settings -> Language Support and click the "Apply System-Wide" button.
Get root privileges using sudo su

Reference: https://help.ubuntu.com/community/EnvironmentVariables#sudo_caveat


No sound in Ubuntu 14.04 after HDMI detatch

That was not the whole problem as I see now. You see, after the re-installation of the alsa drivers, there was no 'sound indicator' in the system tray. I tried to access system options but... there were only some of them, like here. I needed to re-install the unity-control-center and that did the trick. Finally,

  Welcome to Ask Ubuntu! ;-) Could you please try to connect the TV again, System settings - sound, set it to internal speakers, disconnect TV. Please let us know if this helps... –  Fabby

Yeah, that was the final part, which did the trick. My sound is up and running again - Thanks for help :) I hope this will be a good solution for others, who encounter such obstacles.


If you install the official packages from Ubuntu there not much wrong you can do. I would install the following packages using the terminal:

sudo apt-get install octave-io octave-java openjdk-7-jdk openjdk-7-jre  openjdk-7-jre-headless

and then set the java path in .octaverc. Create the file using the  terminal

gedit $HOME/.octaverc

and paste inside

setenv ("JAVA_HOME", "/usr/lib/jvm/java-7-openjdk-amd64");


I looked around and found that I need to add two lines to the bottom of the conf file so that every time I use openVPN it modifies the  DNS configuration in the  /etc/resolv.conf file because it gets overwritten every time

up /etc/openvpn/update-resolv-conf
down /etc/openvpn/update-resolv-conf

then invoke the command

sudo openvpn --script-security 2 --config your-openvpn-config.ovpn

Found the answer in this article on running OpenVPN with Ubuntu 14.04


I used the window decoration plugin to restore window borders and minimize/maximize/close buttons.


This looks like another revision of RTL8111/8168/8411 controller. It may be not supported very well by the kernel r8169 module.

If you did not upgrade the kernel to 4.2 yet, do it now. That will get a newer version of this module. It can be done by running

sudo apt-get install linux-generic-lts-wily

Reboot after that.

If the new kernel does not fix it, you can install another driver, that is more specific for this adapter. Run

sudo apt-get install r8168-dkms

and reboot again.

The r8168-dkms may not build for kernel 4.2, because maintainers did not update it for Ubuntu 14.04.4. In this case download and install this package:

http://mirrors.kernel.org/ubuntu/pool/universe/r/r8168/r8168-dkms_8.040.00-1_all.deb


Software Installation Not Working (apt-get)

That usually means there is another package installation in progress.


Citing https://help.ubuntu.com/community/EnablingPAE:

  To check if your processor supports PAE, try

grep --color=always -i PAE /proc/cpuinfo

If it outputs something, you have PAE support. Otherwise, the output will be empty.


There are a few steps that you could try. First try resetting your configs to the default:

vlc --reset-config --reset-plugins-cache

If this does not work try altering the Video Out device used by vlc by going to:

Tools --> Preferences --> Video --> Output

and experimenting a little until you find a successful setting. If this does not work try altering the Audio Out device used by vlc by going to:

Tools --> Preferences --> Audio --> Output module

and experimenting until you find a successful setting.


Recovering disk with corrupted superblock

Try to fix, using backup superblock. Probably you'll need livecd to get around automount / fsck on boot. See instruction shere:

http://linuxexpresso.wordpress.com/2010/03/31/repair-a-broken-ext4-superblock-in-ubuntu/


The problem appears to be that yEd opens on a different workspace, while I have multiple workspaces disabled in the settings under appearance. Therefore, it was not possible to find what was wrong with yEd. Currently, I do not have a fix so it would always open on the current workspace other than manually moving the window.

The other interesting point is that I do not see a similar behaviour when I run the application on my laptop, but my desktop computer with two monitors. This could not be the reason though.


Terminal can't find img file of Ubuntu 12.10

If you are trying to create a boot-able Live Ubuntu USB installer then i suggest you try this software : UNetBootIn software :


how to install akonadi 5.2 on ubuntu 16.04

Normally to install a newer version in an older environment we would use backporting.  It looks like backporting of a newer version of akonadi is not available for Ubuntu 16.04.  Reference this post:

Backport of kdepim / kmail

I recommend upgrading to Ubuntu 17.04 and installing PIM 16.12.3

KDEPIM Update

I did that on Kubuntu and Kmail is running a lot better.  You'll end up with Akonadai 5.4.3 and Kmail 5.4.3


How to effectively navigate the Terminal and installed packages/commands?

Is there a "list" of everything I can call at the terminal that is dynamic and adapts to the current set of packages/binaries/functions currently installed?

Yes! If you're using bash as your shell (which I assume as it is the standard shell) you can press TAB twice which will give you a complete list of commands you can run (beware that it can be quite long).

Edit: I've learned that pressing tab twice without any characters only works when bash uses its default configuration - not Ubuntu's one. So you may want to run bash --norc. Pressing TAB twice should work then.

Another alternative would be installing and configuring zsh or fish which are nice replacements for bash and offer more functionality. (I prefer fish because it provides a nice autocompletion when you type.)

  Where exactly are the various installed packages stored? I've looked in /bin/, but that seems to only be a fraction of what is available to me. /bin/ seems to have a lot of core binaries, but other seemingly core binaries like info and whatis seem to be absent. Likewise, none of my installed packages obtained through apt, nor apt itself, are present.

You can see where your shell is looking for installed programs:

$ echo $PATH
/home/niklas/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/home/niklas/.gopath/bin:/home/niklas/.gopath/bin

(Note that this may look a bit different for you.)

Today, most executables are located in /usr/bin as per FHS.

If you want to know where one particular program is located, use which:

$ which apt
/usr/bin/apt

As I don't have great experience of Windows, I don't think I can answer the last part of the question, but:

$PATH is the "path environment variable specifying where the system will look for binaries".
Most programs are installed to /usr. (This is split into executables (/usr/bin), libraries (/usr/lib), and shared files (/usr/share). The documentation is in /usr/share/doc.)


Tint2 not showing all windows since 17.10

I had this problem too, and I went along with it since I couldn't find any solution. I know it has nothing to do but I downloaded TeamViewer and I was having some issues, and it said something about some sessions, and I had to change these settings: in /etc/gdm/custom.conf set WaylandEnable=False

I don't know what does this have to do with it, but it fixed it. Now I can see every window.

Hope it helps.


As changing another user's password is an administrative task it should be done from a user with administrator permissions. Any such administrator has access to sudo and will then be able to change another user's password with the following command:

sudo passwd USERNAME

You will be asked for your sudo password first, then you will have to enter the new password for the given user USERNAME twice.

From the security point of view it does not make much sense to let non admintrator users change the passwords of all users. This would be a perfect way to gain administrator access (or to accidentally lock the administrator out).

Therefore all users you need to be able to change the password of other users should have an administrator account (and be taught about the responsibility that comes with this).


If LC_ALL is set it overrides the values of all the other LC_ variables. Hence setting it by default would have the same effect for your locale settings as setting all the LC variables but would make it more difficult to change only some of the values.


What hardware does Ubuntu Touch support?

Supported Devices

Nexus 4
Nexus 7 2013 WiFi
BQ Aquaris E4.5 (announcement)
BQ Aquaris E5 (announcement)
BQ Aquaris M10 (announcement)
Meizu MX4 (announcement)
Meizu PRO 5 (announcement)

Previously Supported Devices

Galaxy Nexus
Nexus 7 (2012)
Nexus 10

These devices have been deprecated and further development & updates may longer be available.

Porting to Other Devices

Directly quoting from the Ubuntu Wiki (obsolete URL removed!):

  We want to port Ubuntu Touch to all kinds of devices. If you have experience in porting code to Android devices or are generally knowledgeable in terms of porting, working with the Kernel and other core bits and pieces of a distribution, this might be interesting to you.

Moreover, there's really no way to tell which future devices people will choose to work on, however there is a working list of devices that the community is working to enable here:

https://devices.ubuntu-touch.io/

Release Notes in the blog

Be sure to check for Known Issues before you proceed.
And Device Specific Issues as well.

Applications Available

  The Developer Preview comes with the following functioning applications:

  Gallery
  Phone (Dialler, SMS, Address Book)
  Camera
  Browser
  Media Player
  Notepad
  Music app
  Calculator
  Weather app

Installing Applications

Download application from store. Supported Application can be found in App-Store!
Or you can use The SDK to create an application of your own.

Only for Evaluation

Quoting from Ubuntu Wiki (obsolete URL removed!):

  The Touch Developer Preview project provides the open source code for enthusiasts and developers, to familiarise themselves with Ubuntu's phone and tablet experience and develop applications on spare devices.

  It is currently work in progress and intended for enthusiasts who want to contribute testing and building the platform.

Further quoting from their Install page (obsolete URL removed!):

  It does not provide all the features and services of a retail phone and cannot replace your current handset.

  This process will delete all data from the device. Restoring Android will not restore this data.

So be sure to do a complete backup before venturing out.

Flashing the device

Head here for instructions on flashing your device.

What to expect after flashing

  Shell and core applications
  Connection to the GSM network (on Galaxy Nexus and Nexus 4)
  Phone calls and SMS (on Galaxy Nexus and Nexus 4)
  Networking via Wi-Fi
  Functional camera (front and back)
  Device accessible through the Android Developer Bridge tool (adb)
  Daily use of the phone
  Advanced usage

More Ubuntu Touch Documentation

NOTE: This answer was quite old, with many obsolete URLs! Many of them are migrated and that data not available on newer portal, I have tried to keep original answer as it is with this edit. Help this answer to serve better!


Owncloud provides comprehensive settings for 'strict' permissions in its administration manual. Check here: OC Manual
Other settings might be possible. Please keep in mind that with strict settings, auto update does not work.


Advanced searching in Tracker Search Tool? Filter by folders?

The best app I found for doing advanced full text searches is regexxer it was a god send for editing website files. Regexxer is available in the Software center.

Hope this helps.


Highlight open apps on dash in Ubuntu GNOME

In the Dash to Dock settings, try these settings...

Update #1:
The user's problem only occurs with snap applications. Suggested to contact the author of Dash to Dock and report a bug.


Solved.
I used:

sudo find / -xdev -type f -size +500M

To find files larger than 500M.

The output included some very strange file name in the root
directory.
This would make sense, as I ran the Bleachbit also for the root directory.
I opened my filemanager as root and saw 4 files (exactly how much Bleachbit had written), all with similar names (very long, starting with tmp and the rest being random characters and numbers).
So I deleted them all.


Mark the packages as manually installed:

sudo apt-mark manual <package_name>

From man apt-mark

manual
    manual is used to mark a package as being manually installed, which
    will prevent the package from being automatically removed if no
    other packages depend on it.

After the start of your restore all the packages have been set to the status "manually", which were installed by restore.


'Insufficient permissions' error on `adb push` command on 12.04

I ran into this same problem. Adding a udev rule as indicated here did the trick:

Log in as root, create a file /etc/udev/rules.d/51-android.rules and add a line like this to give permissions to anyone in the plugdev group:

SUBSYSTEM=="usb", ATTR{idVendor}=="0bb4", MODE="0666", GROUP="plugdev"

In this example, the vendor ID is HTC. You need to use the vendor ID for your device, which can be obtained by running lsusb and searching for a line like

Bus 002 Device 009: ID 2a47:9e18

In this example your vendor ID would be 2a47, so you would have to replace 0bb4 with 2a47. The correct line would thus read:

SUBSYSTEM=="usb", ATTR{idVendor}=="2a47", MODE="0666", GROUP="plugdev"

Now assign read permissions on the files, reload udev and reload the adb daemon:

sudo chmod a+r /etc/udev/rules.d/51-android.rules
sudo udevadm control --reload-rules
adb kill-server
adb start-server

You may have to disconnect and connect again your device to the USB port.


How do I stop server mounted USB drives showing a dialogue on thin clients

Try this

Open gconf-editor from terminal.

Then untick /apps/nautilus/preferences/media_automount_open key.

This disables automatic opening of a folder for automounted media

This seems to be a per user setting.


How to display usage of the Intel HD 3000?

There is a tool called intel-gpu-tools from the http://intellinuxgraphics.org/ project, which provides the command intel_gpu_top.

found via: https://unix.stackexchange.com/a/38568/26851


gnome-panel broken with xmonad session in 14.04

Here's how I got xmonad+gnome-panel to work. Tested on Ubuntu 14.04 desktop 64-bit.

Install xmonad:

sudo apt-get install xmonad gnome-panel

Create ~/.xmonad/xmonad.hs with the following [1]:

import XMonad
import XMonad.Config.Gnome

main = do
    xmonad $ gnomeConfig

Select session "GNOME with Xmonad" at lightdm

Hope this helps.


Why doesn't system() work when called in a loop with cd and rm commands?

system() runs a command in a shell. That shell is a new process. It is a child process of your C program. The cd command changes the current directory for the shell process in which it is run. This is inherited by child processes of that shell. But it does not affect the current directory for parent processes.

You're calling system() three times. Each time, a shell process is started, it runs a command, and it ends. cd in one call to system() does not affect the current directory in separate calls to system().

If you must use system(), then the best solution for you problem might be to avoid cd and just get everything done in one command. But this will only work if you can change provaMake.txt. In particular, this should work as the contents of provaMake.txt:

rm -f /home/giorgio/Desktop/a/pippo.txt

If you must use system() but can't or don't want to change provaMake.txt, or if you are specifically interested in how to use system() to run all the commands in a file in the same shell process, then you can pass system() a hard-coded command that starts a new shell and runs all the commands in that file in the same shell. For example, your C program could use the code:

system(". /home/giorgio/Desktop/provaMake.txt");

You would replace just about your entire program with that command. No buffer is needed, because your C program is not itself reading from the file. Similarly, no fopen() call is needed. The shell is what opens, reads from, and executes commands from the file--this is the action of its . builtin, which is present when any Bourne-style shell is used. (system() uses sh, which is a Bourne-style shell, as is bash.)

Note that, if your C program subsequently relies on or otherwise observes its current working directory, that will still be unaffected by the cd commands run (just as in your original code) because they only ran in the shell.

It's sometimes reasonable to do things in a contrived manner, for learning purposes, so I don't want to tell you not to write a C program that uses system() to run all the shell commands from a file one by one. However, in the case where your actual goal is simply to run all the commands in a file, you don't need a C program. You can just use your shell:

If you want to run the commands in your current shell process, so that its environment is affected--for example, so that the effects of cd commands persist afterwards--then you can just run:

. /home/giorgio/Desktop/provaMake.txt

If you want to run the commands in a new shell, so that the current shell's environment is not affected, then pass the name of the file as a command-line to the shell:

bash /home/giorgio/Desktop/provaMake.txt

You can adjust that command if the shell you are using, or want to use, is not bash. For example:

sh /home/giorgio/Desktop/provaMake.txt

You may want to make the list of commands itself be executable. To do that, add something like this to the beginning (adjust according to what shell should be used to interpret it):

#!/bin/bash

And change its permissions so that it is executable, by running the command:

chmod +x filename

Replace filename with the actual filename, such as /home/giorgio/Desktop/provaMake.txt.

Then you can run the file like any program:

./provaMake.txt  # when you're in the directory that contains it

/home/giorgio/Desktop/provaMake.txt  # from anywhere

In that last case especially, it is unusual to name the file with a .txt suffix. In general, it is common that files whose contents will be run with the . builtin are named with a .sh suffix, and that files that will be marked executable and run as scripts are named with no suffix. (The filename doesn't matter as far as the shell and operating system are concerned, though.)


Open nvidia-settings and configure it there.

The proprietary driver does not integrate very well with Ubuntu's system settings.


Get error(115) trying to mount a Windows filesystem from Ubuntu

try telnet 1.2.3.4 445
the expected result is:

$ telnet 1.2.3.4 445
Trying 1.2.3.4...
Connected to 1.2.3.4.
Escape character is '^]'.

if not - you have a problem with the firewall.


After a quick review of your output as well as the rkhunter howto the only thing that would give me any concern in your output is "File '/tmp/.org.chromium.Chromium.mEHtjR' (score: 274) contains some suspicious content and should be checked." As this is in your /tmp folder it's likely it would be gone after a reboot but it wouldn't hurt to check again. It's my understanding that you should do a sudo rkhunter --propupd first to update the database of file properties (this has to be done every time new software is installed) See the howto for details.

sudo rkhunter --versioncheck will tell you if there's a newer version available than the one you are using.

The suspicious file types in /dev/shm appear to be normal pulseaudio files but appearances can be deceiving so I make no guarantees.

You might wish to subscribe to Rootkit Hunters mailing list which is a good source of info on false positives.

Sources:

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

man rkhunter


Seems you don't have write access to the ~/.config path.

run:

mv ~/.pki{,.bk}
chown -R $USER:$USER ~/.config

if you still got problem:

chown -R 775 ~/.config

If you get any permission error while running these commands, run them as root with sudo.


I can suggest to disable BT Coexistence Technology that traditionally works poorly with Intel chips.
Run in a terminal:
sudo tee /etc/modprobe.d/iwlwifi-opt.conf <<< "options iwlwifi bt_coex_active=N"

and reboot.
That may help to solve the problem.
You can revert this setting by
sudo rm /etc/modprobe.d/iwlwifi-opt.conf


Add a udev rule, e.g. to /etc/udev/rules.d/60-md-stripe-cache.rules:

SUBSYSTEM=="block", KERNEL=="md*", ACTION=="change", TEST=="md/stripe_cache_size", ATTR{md/stripe_cache_size}="8192"

I haven't actually tried this so it might not be 100% right (may be some typos), but it should be close.  Check man udev to understand more.

You may also want to run the following commands afterwards to immediately apply the new rule:

udevadm trigger
udevadm control --reload-rules


Ubuntu 17.10 keeps locking up and freezing. Mouse and Keyboard input doesn't work as image on screen is frozen. Help!

I've had a similar issue to this where random freezing would occur with my mouse, this was after and upgrade from 16.04.

A lot of probing and research later, I found out it was linked to a problem with my display manager (gdm3) not being able to start Wayland. Using lightDM has fixed this issue for me.

Hope this helps

sudo dpkg-reconfigure lightdm


Most likely the issue is not in the OS but on hardware level. I recommend making a thorough check with memtest. Check this out for more info regarding memtest: How do I run memtest86+?


After considerable research it was because it was placing them into the /home tree. I didn't believe they to be the case because it was working fine previously, but i still don't know why that was. I have since used the /media tree and made my chosen path point to it, allowing all my software that utilizes those drives work properly. So now I'm a happy camper, per se.


How can I disable the window manager's alt+drag action?

Install the Compiz settings manager if you don't have it already. In terminal:

sudo apt-get install compizconfig-settings-manager

Now find and open the settings manager.  Find the Move Window plug-in.  (You don't want to disable the plug-in; if you do that you won't be able to move windows at all.)

Just change the first setting, Initiate Window Move. It can be change it from Alt+Button 1 to Super+Button 1, but you stated that is not what you want, so just click on Alt+Button 1 and uncheck Enabled.


icons not appearing properly after installing plasma 5

Solved the issue by changing the values in Settings -> Application Style -> Gtk Style

Select a Gtk2 Theme -> Oxygen-GTK
Select a GTK3 Theme -> Oxygent- GTK
Font -> Ubuntu 10
Set Icon Theme -> Breeze
Set Fallback Theme -> Oxygen


Have installed chrome on Ubuntu. However cannot find where to run it

type the command below to locate chrome

whereis google-chrome

and execute /usr/bin/google-chrome command to run chrome


Which algorithm does "encrypt home directory" use?

The default ecryptfs algorithm is aes.

It can be shown during the creation of a new encrypted mount point of folder that only aes is presently loaded but ecryptfs supports other logarithms.

bruno@ubuvbox:~$ sudo mount -t ecryptfs secret/ ~/secret/
Passphrase:
Select cipher:
 1) aes: blocksize = 16; min keysize = 16; max keysize = 32 (loaded)
 2) blowfish: blocksize = 16; min keysize = 16; max keysize = 56 (not loaded)
 3) des3_ede: blocksize = 8; min keysize = 24; max keysize = 24 (not loaded)
 4) cast6: blocksize = 16; min keysize = 16; max keysize = 32 (not loaded)
 5) cast5: blocksize = 8; min keysize = 5; max keysize = 16 (not loaded)
Selection [aes]:

Default selected cipher is between [].


Does order of mount operations matter when mounting into an existing mountpoint?

Yes, it matters! Your first example:

mount /dev/sdb1 /home
mount /dev/sdb2 /home/mythtv

is the only right way, when mounting you must respect the tree order.

In your second example,

mount /dev/sdb2 /home/mythtv
mount /dev/sdb1 /home

If we are assuming /home/mythtv exists on the filesystem, it is gonna mount it with no problem, but after you mount the second volume you won't be able to access the first one anymore.

This is because you let the system mount sdb2 on an existing path at /home/mythtv. When you mount on /home/, you are telling your system to mount it on the /home path which also exists but is going to "cover" existing mount point. They are both mounted, but when you type cd /home/mythtv, Bash takes you to sdb1:/home/mythtv instead sdb2:/home/mythtv because they are different paths.

I hope the explanation is clear. If not, please ask in the comments, I'll try to get it to you more clearly.

Update

as per @mook765's comment, the order is important also in the fstab files:

The fstab file is read up to down while mounting, and down to up when umounting. In another case, if you try to umount /home before /home/mythtv mount will tell you the /home resource is busy because you have the /home/mythtv mounted and it cannot handle it.


Update md5 checksum when files are modified

This is a very rough script trying to do what you want to. Feel free to copy, modify, optimize - would be nice to have some response if it works for you. If have tested in my "Downloads" folder and found only one error left (a filename containing [, which grepdid not like).

Edit: Modified the source again, as the creation of timestamps (in the first version) is no longer needed as new/modified files are found with find -newer. Also added parameters to setthe name of the hash file and possibly the top folder to start with; so the script does not have to be called from the top directory.

#!/bin/bash
#
# Script to create md5 hashes for files in and below the current directory
# or the directory passed at the commandline
# In the first run, create the sums for all files.
# In the second run,
#  - if the files have not changed, keep the entries
#  - if the files have been deleted, forget the entry
#  - if the files have changed, create new md5 hash.
#
# Rough version - should be optimized
#

if [ $# -lt 1 ] ; then
  echo "Usage:"
  echo "$0 <hashfile> [<topdir>]"
  echo
  exit
fi

export HASHFILE=$1
export TOPDIR='.'
if [ $# -eq 2 ] ; then TOPDIR=$2; fi

export BACKFILE=$HASHFILE.bck
export TMPFILE=$HASHFILE.tmp

# In the first run, we create the file $HASHFILE if it does not exist
# You have to make sure that $HASHFILE does not contain any garbage for the first run!!

if [ ! \( -f $HASHFILE -a -s $HASHFILE \) ]; then
  echo -n "Creating $HASHFILE for the first time..."
  find $TOPDIR -type f -print0 | xargs -0 md5sum > $HASHFILE
  echo "done."
  exit
fi

# In the second run, we proceed to find the differences.
# First, find the newer files

find $TOPDIR -type f -newer $HASHFILE -print > $TMPFILE

# Now save the old file and create a new one, starting with new files

mv $HASHFILE $BACKFILE
echo -n "Processing new or modified files ..."
cat $TMPFILE | while read filename ; do
  md5sum "$filename" >> $HASHFILE
done
echo "done."

# Now walk through the old file and process to new file

cat $BACKFILE | while read md5 filename ; do
  # Does the file still exist?
  if [ -f "$filename" ] ; then
    # Has the file been modified?
    if grep -q -e "^$filename$" $TMPFILE ; then
      echo "$filename has changed!"
    else
      echo "$md5  $filename" >> $HASHFILE
      #echo "$filename has not changed."
    fi
  else
    echo "$filename has been removed!"
  fi
done

# We now may delete temporary files
# rm $BACKFILE
# rm $TMPFILE

exit


Chromium display is remanent since 14.04 upgrade with gpu acceleration enabled

If you're running this on Oracle VirtualBox, uncheck the Enable 3D Acceleration box under the Display settings. Your VM has to be turned off before you can do that.

If not on VirtualBox, it would be interesting if there's another way to disable 3D acceleration.

Something changed between 13.10 and 14.04. I had Enable 3D Acceleration checked previously with my Xubuntu 13.10 VM, but Chromium broke on that, too.

EDIT: This appears to slow down everything. I didn't realize 3D acceleration had such a big effect.

EDIT 2: It appears that chromium-browser --disable-gpu may be a better solution as it doesn't require me to disable 3D acceleration, and it is workable for people who don't use Ubuntu as a VM guest.


The first things to analyze the problem is to look into the logfiles of the system. If you go to a terminal and enter dmesg, you will get the messages of the running session.

In the terminal look at the log files in the folder

ls /var/log

where probably syslog will be most interesting for you. Try to figure out if there are messages just before the freeze - easily identified by the fact that any new session begins counting by 0 again. When you find some hint, post the corresponding lines and maybe someone can help.

The commands you want to use for reading the files are e.g.

tail -n 250 /var/log/syslog

which returns the last 250 lines of syslog. Ore you can go through the files line by line with

less /var/log/syslog


Where is the configuration for laptop-mode-tools max CPU frequency?

If I understand you correctly, you are trying to configure LMT so that it can run at max speed or ondemand even on battery, right?

If so, please look for power.d folder within laptop-mode directory for individual modules.  When you open cpufreq.conf, look for CONTROL_CPU_FREQUENCY="auto" and set it to 1 to activate that module.  Then scroll down for further configuration.

I'm on 12.04 LTS so let's hope it is not too different.  I'm pretty new to Linux myself so don't be offended if my answer didn't help.

UPDATE:  I don't have any "pointer to documentation", sorry.  I found out a quick and painless technique to achieve your objective.

Turn off by editing the file /etc/laptop-mode/conf.d/cpufreq.conf (I removed mine).
Look for and set CONTROL_CPU_FREQUENCY="0".
Use Ubuntu Software Center, type in search box "indicatorfrequency". There you will see indicator-cpufreq. Go ahead and install it.
Now, open a Terminal and type indicator-cpufreq to run it for the first time.
Restart the PC.
Voila! You should be able to selectively pick a desired speed or a governor - conservative, ondemand, powersave or performance.


Save As/Upload or any such new window not Opening

I will answer this myself. Sorry for all the hassle created. The problem disappeared when I made my display single instead of joining two displays. Thank you for all the assistance.


What is a working VNC client for latest Xubuntu

As mentioned by Jean-Marie's comment. Going into the settings for the VNC server and changing it from the default Unix username and password to VNC password makes it work with more VNC clients.


HP 15 ab035ax with rtl8723be WiFi not working properly

The following might be useful:

sudo apt-get install git build-essential
git clone [https://github.com/neurobin/MT7630E.git][1]
cd MT7630E/
chmod +x install test uninstall
./install


Identifying an application using network

Find the PID of prx and its location on system using proc-fs. Then u can analyse what it is


Note that for upgrade or dist-upgrade you must first run an update to get the list of packages to determine what actually needs updated.

This is a breakdown of the apt-get commands:

update - Only updates the software list.
upgrade - Only upgrades to newer versions of the same files.
dist-upgrade - upgrades to newer software versions (same as upgrade) and installs new software.

So to make get a completely upgraded system allyou have to do is:

apt-get update && apt-get dist-upgrade

The most common new files are new kernel versions, since new ones are installed instead of the old one just getting replaced, so that you can run an older one if it breaks the install in some way.


Kubuntu 14.04 as guest in VirtualBox on Win 7 host

Disable 3D and set the video output to "X11 Video output (XCB)"

If I didn't enable 3D acceleration, video playback freezed in vnc when I chose full screen playback. So I enabled 3D which solved the full screen problem, but gave me the problem you describe.


How to install Gnome 3 without breaking Unity?

There is currently no easy way to do this, GNOME 3 requires a major transition to the GTK+ stack (from 2 to 3) that has not been done in Ubuntu yet.

This is a goal for 11.10, but currently I'm afraid trying GNOME3 on Ubuntu is more of a one-way upgrade.


Try to open as root the file /etc/default/grub and find the following variables:

GRUB_HIDDEN_TIMEOUT
GRUB_TIMEOUT_STYLE

if GRUB_HIDDEN_TIMEOUT exists, comment it with a #

Also, set GRUB_TIMEOUT_STYLE=menu (maybe it is currently set in your machine as "hidden")

After saving the file, run sudo upgrade-grub


Shell script won't run some command when run from GUI

If you have checked the option Ask each time for the Executable Text File in the Nautilus Preferences, then you will have two options Run in Terminal and Run, when you (double) cluck on an executable by the mouse:

You need to choice Run to achieve what you want. This is also the default behavior if you have set Run executable text files when they are opened in Nautilus Preferences.

These two options Run in Terminal and Run have different behavior, but unfortunately I didn't found any additional documentation. Probably the first one creates a temporal environment that is annihilated when the terminal is closed. We can prove that by adding exec sh at the bottom of your script:

#!/bin/sh --
oathtool -b --totp XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX | xclip -sel clip
echo "OTP Copied!"
sleep 2
exec sh

The command exec sh will replace the current shell (of your script) by a new sh shell, thus the terminal window will be kept open and your clipboard will be active until you are close the terminal window. Another option is to extend the sleep time, then your clipboard will be active while the terminal window sleeps.

If you are using the Run option or custom shortcut I would suggest you to modify your script in this way:

#!/bin/sh --
oathtool -b --totp XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX | xclip -sel clip \
&& notify-send "OTP Copied!"

Thus notify-send will send you a notification within the GUI environment only when the previous command returns true, which is the meaning of &&.

I've tested the described above in Ubuntu 16.04 and 19.04, there is no difference - the same behavior and the proposed solutions are working in both OS.


I am not testing these suggestions because I do not want to set a default. Nor do I know how to recover if something were to go awry, so, standard disclaimer...
"Back everything up and use at your own risk"
That being said, the below suggestions seem harmless to the system. Just a thought, you MAY be able to recover using the 'edit' feature in the GRUB menu.
Good luck!
References are listed below the suggestions.

I would try changing: GRUB_DEFAULT="saved"
to: GRUB_DEFAULT=0

This is assuming that the default you want to use is the first GRUB menu item (0=first, 1=second, etc). [And for font's sake: 0=zero]

Otherwise, you can quote the actual menu item title that you choose in the GRUB menu:
GRUB_DEFAULT="Ubuntu (lowlatency)"

Or go deeper by finding the title. I found mine in "/boot/grub/grub.cfg" on the first "menuentry" line. It is after "$menuentry_id_option".... it is: 'gnulinux-simple-ea05c38e-393e-41ee-8cfe-f17f93b818af'
GRUB_DEFAULT='gnulinux-simple-ea05c38e-393e-41ee-8cfe-f17f93b818af'

You probably only want to stick to the "menuentry" lines and NOT the "submenu" or 'submenu + menuentry' lines.

And maybe you can also try in a terminal: "grub-set-default 0"

And that's all I have for now. Peace........
_____Below is the terminal output from "grub-set-default --help"
Usage: grub-set-default [OPTION] MENU_ENTRY
Set the default boot menu entry for GRUB.
This requires setting GRUB_DEFAULT=saved in /etc/default/grub.
-h, --help              print this message and exit
-V, --version           print the version information and exit
--boot-directory=DIR    expect GRUB images under the directory DIR/grub
instead of the /boot/grub directory
MENU_ENTRY is a number, a menu item title or a menu item identifier.
Report bugs to bug-grub@gnu.org.
__ output end_________________________________________
_____Excerpt from "info grub"
Next: fallback,  Prev: debug,  Up: Special environment variables
15.1.10 default
If this variable is set, it identifies a menu entry that should be
selected by default, possibly after a timeout (*note timeout::).  The
entry may be identified by number (starting from 0 at each level of the
hierarchy), by title, or by id.
For example, if you have:
menuentry 'Example GNU/Linux distribution' --class gnu-linux --id example-gnu-linux {
...
}
then you can make this the default using:
 default=example-gnu-linux

If the entry is in a submenu, then it must be identified using the
number, title, or id of each of the submenus starting from the top
level, followed by the number, title, or id of the menu entry itself,
with each element separated by '>'.  For example, take the following
menu structure:
 GNU/Hurd --id gnu-hurd
   Standard Boot --id=gnu-hurd-std
   Rescue shell --id=gnu-hurd-rescue
 Other platforms --id=other
   Minix --id=minix
     Version 3.4.0 --id=minix-3.4.0
     Version 3.3.0 --id=minix-3.3.0
   GRUB Invaders --id=grub-invaders

The more recent release of Minix would then be identified as 'Other
platforms>Minix>Version 3.4.0', or as '1>0>0', or as
'other>minix>minix-3.4.0'.
This variable is often set by 'GRUB_DEFAULT' (*note Simple
configuration::), 'grub-set-default', or 'grub-reboot'.
_____ output end________________________________


127.0.0.1 is a loopback adress. Every machine has it (windows, linux, mac, android, litterly every device). It is called localhost and it is used quite often.
Example 1 (let's assume server ip adress is 192.168.2.15):
You have a web server on a computer running and you want to view the website it's hosting. From a different computer, you go to 192.168.2.15:80 in google and you'll see the webpage your server is hosting.
Now you want to access the webpage from the server (aka access the webpage the server is hosting, from that server). Instead of typing the ip adress of the server (which will make the server connect to itself ofcourse), you can just type 127.0.0.1:80 and that will give you access. Because 127.0.0.1 (aka localhost) is... the server itself. You can also type localhost:80.
Example 2:
You have Prometheus (gathers info about your computer) and Grafana (makes nice graphs out of the info of Prometheus) installed. While setting up Grafana, you need to make a connection to Prometheus so that Grafana can use the info Prometheus is gathering to show it in a nice graph. When you have Prometheus and Grafana installed on the same computer, you can type localhost:9100/metrics in grafana to make a connection to Prometheus.
Example 3:
You have a Minecraft server running on a computer. Now you want to play on your new cool minecraft server ofcourse. If you want to play on the computer that the server is being run on, when adding a server, you can just type localhost and it will connect to the minecraft server running on itself.

If you understand it correctly, you should be able to understand this:
"ping localhost will always work."
Just remember:
localhost = 127.0.0.1 = itself


Open the Software Center and click on Installed it will show a menu tree of installed applications.

Open each menu tree and you can see the program installed, when you click on them they will highlight and tow radio buttons will be visible: More Info and Remove

Click Remove and enter your password and it will remove the app.

Click on More Info to get a description of the app. You can then use the back arrow at the upper left to get back to the Installed tab and the previous menu will will still be open and the last selected app still highlighted.


Pull up your network connections UI.
Select the WiFi connection.
In the WiFi tab, there is the option band which defaults to Automatic.
Change this to 5Ghz.

Alternatively, on your router, change the SSID of each to distinguish them at the name level.  This can be beneficial for a few reasons.  It will allow you to choose a specific band on routers with more than two bands (I have two 5Ghz bands, there is no way to distinguish them in Ubuntu).  Some people can have issues with one of the bands and it prevents them from connecting to any of them when the names are same (My 2.4Ghz will sometimes start dropping devices for no reason and it would not switch to 5Ghz, changing the names allowed it to fail over at the connection level instead of the band level.  A hard reboot fixes it but that requires getting up).


Wifi not working on Ubuntu 20.04 and taking long to boot up in Legion

Intel Wireless-AC 9560/9462 is not correctly enabled on IceLake
platforms.
https://bugs.launchpad.net/ubuntu/+source/linux-oem-osp1/+bug/1835879
A release has been released..
sudo apt update
sudo apt install linux-oem-osp1


rmdir on my machine doesn't have the -r argument

rmdir has no -r option. The purpose of rmdir is to delete only empty directories.

If you want to delete non-empty directories, that's when you'll use the -r option of the command rm.

Delete empty directory called emptydir:

$ rmdir emptydir

If directory nonemptydir is non-empty, you'll have an error:

$ rmdir nonemptydir
rmdir: failed to remove `nonemptydir': Directory not empty

To delete non-empty directory nonemptydir:

$ rm -r nonemptydir

Hope this helps!


Triple monitor display that used to work now shows "Could not switch the monitor configuration" error

Finally found a solution on http://www.dell.com/support/article/us/en/19/sln298529/how-to-configure-multiple-displays-on-a-dell-pc-using-the-ubuntu-operating-system

Run: sudo apt-get install compizconfig-settings-manager
Run: ccsm
Click 'General Options' in General.
Click the Display Settings tab.
Uncheck Detect Outputs as seen here.


How to change battery mode on my laptop?

I don't know any program that can make modes for the battery.

But you can always change the settings by clicking on the battery icon (in the upper right corner), then click "Power Settings", change what ever you want to.

To access and modify the brightness settings, open the dash, go to System Settings, and click on Brightness and Lock.


xrandr looked promising but you have to run it as user connected to a display.

This is, strictly speaking, not true. It must be able to connect to the X server, but all that requires is 1) the display number, and 2) permission to talk to the X server via the magic cookie or via xauth.

The easiest way to get the cookie is to run as the user that is currently logged onto the display. Giving the display number is as easy as passing $DISPLAY to the program.

sudo -u displayuser env DISPLAY=:0.0 xrandr | grep -q '^xxxx disconnected'


GNOME Display Manager says "OK" but does not launch

I am also experiencing this problem, and so far no fixes can be found. Unlike yours, I cannot access terminal.

Since you can use terminal, try this command:

sudo gdm

Good luck.


Will Ubuntu work smoothly with these computer specifications?

500 RAM is the issue here. Ubuntu by itself is not the problem, but the desktop environment Unity; so it is most advisable to use Lubuntu (which is the same Ubuntu, but with LXDE desktop).

At 1GB, I would use Xubuntu/Xfce, but, from my experience, Unity and KDE are fully comfortable only above that.

More on this here.


You are probably encountering a type of "copy protection" whereby the DVD is filled with up to 98 "fake" titles that contain the movie scenes in the wrong order, with only a single title that is actually the one you want to play. This has nothing to do with encryption or CSS so installing updated libraries or switching distributions probably won't help.

It is also my experience that Disney are notorious for doing this with their recent DVD releases (including almost anything from Pixar).

There are a couple of techniques that usually work for me.

Try playing dvdnav:// rather than dvd:// in mplayer. This will show the DVD menus, which you can often navigate to the correct title. If you pass the -quiet option to mplayer it sometimes prints out which titles it it is switching to, which will reveal the correct title once the main feature starts playing.
Use xine to play the DVD, and navigate the menus to the main feature as above. Once the movie is playing, dragging the playbar backwards and forwards causes the title number to be briefly shown in the status display. You can then use this title number as the argument to mplayer dvd://<titlenum>, or in VLC or your application of choice.
If all else fails, I reboot into Windows and use Media Player Classic to play the DVD. This has not failed so far, and shows the correct title number in its status display. Much as I hate having to use Windows software to work around a problem in Linux, I have had to resort to this with a couple of particularly stubborn disks.

It may be possible to use other software that I haven't tried; the important point is that you must navigate through the DVD menus because only the menus "know" which of the DVD titles contains the actual movie.


Install older version of gfortran in ubuntu 16.04

The E: Unable to locate package gfortran-4.8.4 error message means exactly what it says. There is no package named gfortran-4.8.4 in Ubuntu 16.04. The closest match in 16.04 is gfortran-4.8 which installs gfortran version 4.8.5, not 4.8.4.

In Ubuntu 14.04 the command sudo apt install gfortran-4.8 installs gfortran version 4.8.4. You could install an Ubuntu 14.04 guest OS in VirtualBox and run gfortran 4.8.4 that way. Before you do it try installing gfortran 4.8.5 in Ubuntu 16.04 with the command sudo apt install gfortran-4.8 and test if it can do what you need it to do.


Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command below.

xgamma -gamma 0.5

Or

xgamma -gamma 0.6

similarly

xgamma -gamma 0.4


Repeat keys doesn't work after upgrade from 17.04 to 17.10

You said: ^@ was constantly being printed withou pressing any key, this suggests driver problem.

lsmod | grep wmi

If peaq_wmi is present do with sudo:

modprobe -rv peaq_wmi

If it works properly become permanent by adding to blacklist:

nano /etc/modprobe.d/blacklist.conf

blacklist peaq_wmi


The -49 and -50 kernels are flawed, and have been withdrawn. There are graphics issues (possibly only with internal Intel video subsystems).
Boot your computer. At the GRUB menu, select the 2nd choice, Advanced Options (or some such), and select your -48 kernel, or earlier if you don't have -48, and run off of that for now.
Keep up to date with Software Updater and once you see the -51 kernel, or later, then choose it at next boot.


Execute sudo command (openvt) with global shortcut

Actually now I found the solution myself - the problem and the solution are the same as in this question. I just had to add this line into my script:

export TERM=xterm


How do I suppress GtkDialog warnings in zenity and yad using Bash redirection in a script?

I don't think syntax alone can help you here - because of the order in which the shell sets up redirections and expands variables. To give a very simple illustration:

$ arr=( ">" "/dev/null" )
$ set -x
$ echo foo "${arr[@]}"
+ echo foo '>' /dev/null
foo > /dev/null

i.e. everything has been expanded "correctly", but > /dev/null has simply become a list of string arguments passed to echo.

You could force evaluation using eval:

$ eval echo foo "${arr[@]}"
+ eval echo foo '>' /dev/null
++ echo foo

but really it would be better to redirect the stream for the duration of your script using exec:

exec 2> >(grep -v GtkDialog >&2)

or, if you want to be able to turn the filter off before the end of the script, then based on After using exec 1>file, how can I stop this redirection of the STDOUT to file and restore the normal operation of STDOUT? it should be possible to do

exec 3>&2 2> >(grep -v GtkDialog >&2)

and then later

exec 2>&3 3>&-

to recover the duplicated stream.


How can I remove icons like "home" or "boot" from desktop

The files on the Desktop are mainly links to the actual locations of these files so removing them won't delete them from those locations. In your case some of these files were created when you switched language by a root process, so their ownership would be those of root.

To get rid of them:

Change ownership of these files with:

sudo chown -R $USERNAME.$USERNAME  file

Then remove them as usual:

rm -rf file


Download Ubuntu, create a bootable CD/DVD or a bootable USB flash drive.  Boot form whichever one you create, and once you get to the installation type screen, choose replace Windows with Ubuntu.

If you're comfortable with dealing with partitions, then you can choose something else, delete any existing partitions, and then create a Ext4 partition mounted at / and a swap partition.

For more information on how to install Ubuntu see Install Ubuntu


Why does Zeitgeist use ~/.local/share/ instead of ~/.cache?

Use it for what exactly? Persistent user data is stored in ~/.local/share, or more aptly $XDG_DATA_HOME, while more transient data such as logs would be stored in $XDG_CACHE_HOME. Ubuntu One uses both of these directories, to store different types of data.


Error with NPM (cannot find module 'semver')

I had the same error. npm uninstall npm -g, rm -rf node_modules didn't help me, because when I tried I was getting Error: Cannot find module 'semver'. And Can solved my problem with these steps (this will delete other global modules you may be using):

LPB_Tandn_IT:~ tannetto$ rm -rf /usr/local/lib/node_modules
LPB_Tandn_IT:~ tannetto$ rm -rf ~/.npm
LPB_Tandn_IT:~ tannetto$ brew uninstall --force node
LPB_Tandn_IT:~ tannetto$ brew install node

Hope this will help those who are getting a similar problem.


how to get a launcher desktop icon for matlab R2019a

You need to create .desktop file and put it in special folder = homedir/.local/share/applications/matlab.desktop.
Desktop file example follows, just change to correct path to your matlab binary.
After that matlab will appear in applications list, you can copy desktop shortcut to desktop or anywhere else.

[Desktop Entry]
Version=1
Name=Matlab
Comment=Your comment
Keywords=matlab
Exec=/media/srikar/Code/Matlab/bin/yourbinary
Terminal=false
X-MultipleArgs=true
Type=Application
Icon=preferences-system
Categories=GTK;Development;
StartupNotify=false


Rebuilding grub.cfg did not help and trying to fix the UUID for my EFI partition also did not work. However, the fix here, which rebuilds more of the boot information or the boot partition, resulted in a successful repair.


Can't use Ethernet or Wifi in Ubuntu server

Ubuntu 16.04 is the 2016-April release, so is largely limited to kernel modules (drivers) of that era. Ubuntu's use of HWE allows you to use an updated software stack (ie. ISOs are available with 16.04 using 16.10, 17.04, 17.10 and 18.04 kernel & stack) but it's still only parts of the stack updated.
Ubuntu 18.04 provides the full 2018-April release, and likewise it's ISOs are available with different stacks, including 18.10's, 19.04, 19.10 & 20.04 stack. The latter is the most modern being released as the 18.04.5 media.

http://fridge.ubuntu.com/2020/08/14/ubuntu-18-04-5-lts-released/

Canonical/Ubuntu is moving away from i386/32-bit, however it was still supported in some releases post 18.04, however they're now EOL. The last media was 18.04.5 and can be found for example at

http://cdimage.ubuntu.com/netboot/bionic/

Flavored desktops have ISOs too, however Ubuntu Server now uses the subiquity or live installer, which is 64-bit only so no live i386 ISOs exist for later server installs, however netboot installs are still available.

https://wiki.ubuntu.com/Kernel/LTSEnablementStack
https://wiki.ubuntu.com/Kernel/RollingLTSEnablementStack


Ubuntu 19.04 display hanging - is it hardware?

SO it seems that the NVIDIA drivers need to be set to 'Prefer Maximum Performance' in the Powermizer settings to avoid this problem. No crashes since setting that.

However it needs to be set every boot which is a pain.

Thanks guiverc for the lesson in Magic keys!


How to make rsync show system time after each file transfer?

The manual page of rsync tells that you can customize the log format. The %t tag means the current system date-time. For instance you can add the following switch to rsync:

  --log-file-format="%t [%p] %o %h [%a] %m (%u) %f %l"

More information in the manual pages
http://manpages.ubuntu.com/manpages/trusty/en/man1/rsync.1.html (log-file-format) and
http://manpages.ubuntu.com/manpages/trusty/man5/rsyncd.conf.5.html (log formatting tags).


Why can't I execute Wubi in Windows 8 Consumer Preview?

The latest Windows release WUBI is compatible with is Windows 7. It may work on Windows 8 previews/betas, then again, it may not. It's unsupported, so you're not likely to get much help trying to make it work, sorry.


Well, this is being done your shell itself. Apparently it is monitoring the file (or directory) pointed by the MAIL (or MAILPATH) environment variable.

This is documented in man bash :

MAIL
       If  this  parameter  is  set  to  a file or directory name and
the MAILPATH variable is not set, bash informs the user of the arrival
of mail in the specified file or Maildir-format directory

On a different note the contents of motd is actually governed by the PAM module pam_motd (the shell might have something to add though as per user configuration files).

By default pam_motd shows the static content of the /etc/motd file along with the dynamic outputs generated from running scripts in the /etc/update-motd.d directory (using run-parts).


Transfer music from ubuntu 18.04 to Android device

On Android, pull down your top bar after connecting the phone. You will see a notification "USB charging this device". Tap that and you will see that it defaults to only charging your device. Thus, you can, by default, not mount the drive. Tap "transfer files" on your Android phone to have it mounted in your file manager. To unmount it, you can use the same screen on your Android phone, or use Files.

After this, you can transfer music files, or eventually access it with your music playing software.


You only use sudo or elevated permissions when you want to install stuff for the global, systemwide Python installation with pip or pip3. Otherwise install python packages locally with pip3 install --user <package> (e.g. pip3 install --user mysqlclient).

Malicious packages are occasionally found on PyPI, the official third-party repository for software for the Python programming language. It is best to use a Python virtual environment to isolate packages that you install with pip/pip3.  The virtualenv utility creates virtual Python instances, each invokable with its own Python executable. Each instance can have different sets of modules. Virtual Python instances can also be created without root access.


How can I make the launcher disappear after notification

Unfortunately the whole launcher pops out even though the design is to only pop out the relevant icon (as it is implemented in Unity 3d). It is technically feasible but nobody has had time to do it.

Otherwise I guess we could as a temporary measure shorten the time: 5 seconds is a bit high.


All of my icons appear blank. How can I change them back?

All you have to do is to install the drivers for your graphic card. I had the same problem and now it is fixed.


How to add licensing to Ubuntu Application?

For starters, licensing/drm do not prevent piracy. If someone does not respect your IP, they will find a way around your drm. Unfortunately, that is the world we live in today.

That being said the license key infrastructure in MyApps is meant to be simple. The reason is that there are many, many ways to manage drm and no standard mechanism to implement it. Because there are so many ways, we do not have a tutorial or suggestions for best practice.

We have developers that use it to email a key which the user must install and we have developers using it to download a key to a specific location at install/purchase of the application. Some require the key for any use of the app (app does not function w/o a key) and some allow for limited use of the app w/o a key and full use with a key.


RTL8812AE cannot connect to 5ghz networks

I had similar problems with my D-link DWA-582 (same Realtek chip), only I could not connect to any network.

I uninstalled the Ubuntu network-manager and installed wicd (see https://help.ubuntu.com/community/WICD) as I read somewhere some problems could be caused by the network manager.
This fixed the connectivity problems to both 2.4 and 5GHz, but speeds were limited to about 2Mbps, this was on Ubuntu 16.10 .

Then I installed the latest driver from https://github.com/lwfinger/rtlwifi_new (build with make && sudo make install and insert in kernel with modprobe -v rtl8821ae, notice: rtl8821ae not rtl8812ae). This raised speeds to 40Mbps (on 5GHz), which is consistent with the speeds from the Windows driver.

Note: I also installed the new kernel 4.9 somewhere during this, so I'm not sure whether installing the drivers from the github repo is really necessary.


How do I enable visual effects when running Ubuntu as a Guest machine in VirtualBox?

Inside the guest, install the package virtualbox-ose-guest-x11 and restart the VM; that may resolve the issue. X on the guest needs to be aware of the VirtualBox drivers, and as far as I know this is the way to go about that. Versions 2.2 and up should make this functionality seamless, but it's possible there are some bugs in there.

Also, be sure you've allocated plenty of video memory in the VM settings. I gave it a go just now with 128 MB VRAM (which might be excessive) and it worked fine after installing the -x11 package I mentioned. Start high if you can and lower it if you need to until it stops working.


How to downgrade Thunderbird 12.04 to Thunderbird 11.01.1 on Ubuntu 10.04.4 LTS

To downgrade a package in ubuntu will follow this way

sudo apt-get install <pkg_name=Version>

in the version name place the version you want .

i mean like sudo apt-get install thunderbird=11.01.1


No audio over HDMI on Intel Broadwell-U Integrated Graphics

My solution was: click on loudspeaker symbol, click on Sound Settings, click on the right arrow until I reached Configuration and then set Profile off.


You need to use sudo to execute the mount command.  Sudo will execute the command with root permissions.


How to set passwordless session with x2go

It appears that the documentation wiki is outdated.
It states (bold emphasis is mine):

After the transfer you can add the path to the private part of the key
to the session preferences inside x2goclient. x2goclient should now
establish the connection without asking for a password by simply
clicking on the session card view.

Instead, only setting the option Try auto login is actually required.
the field Use RSA/DSA key for ssh connection must be left empty.


How can I recover my old windows 7 after Ubuntu installation?

Try use your CD/DVD installation/FD Drive where you install Ubuntu, then choose Try Ubuntu. Find your data, then copy to another drive. edit: If you can't, recheck using GParted Partition Editor.


Dropbox is not up when I login remotely via ssh

First, make sure you have installed the dropbox cli.

mkdir -p ~/bin
wget -O ~/bin/dropbox.py "https://www.dropbox.com/download?dl=packages/dropbox.py"
chmod +x ~/bin/dropbox.py

Now you can at least start the dropbox daemon from an ssh login using:
dropbox start -i &

This line can be added to your .bash_profile to always start the daemon when logging in via ssh.  The command will confirm that Dropbox is already running if it is in fact already running.

Dropbox CLI documentation can be found here:
https://www.dropbox.com/en/help/9192

Headless install instructions here are also helpful
https://www.dropbox.com/install-linux


Unable to install Skype in Ubunutu 12.04

The error is caused by dependency problems (absence of some packages which skype requires for it to be installed). The following lines that were displayed confirm this:

skype depends on libqtwebkit4 (>= 2.2~2011week36); however:
  Package libqtwebkit4 is not installed.
skype depends on libxss1; however:
  Package libxss1 is not installed.
dpkg: error processing skype (--install):
  dependency problems - leaving unconfigured

Therefore, it is obvious that the error can be overcome by installing the missing packages (libqtwebkit4 & libxss1). To install these packages,

Open the Terminal.
Type sudo apt-get install libqtwebkit4 to install the libqtwebkit4 package.
Type sudo apt-get install libxss1 to install the libxss1 package.
After installing the required packages, continue with the process of installing skype with the command sudo dpkg -i skype-ubuntu-precise_4.2.0.11-1_i386.deb


You can use cut to get desired fields from your path:

SPTH=$(cut -d / -f-5 <<< $PWD)


Ubuntu 14.04 LTS freezes during installation in the same spot - dual/triple boot process

Most likely you have burned a bad image. Your download may have gone wrong, or it may have been while transferring to your DVD/USB.

I'd recommend that you download the ISO file from Ubuntu again, and give it another try.

Also, 32Gbits (4GB) is a good amount of SWAP space, but I'm assuming you meant 32Gbytes, and that would be much bigger than required.


oneconf is designed for that.

Read more about oneconf here: https://wiki.ubuntu.com/OneConf


It was simple.
Firstly just add bridge:

ovs-vsctl add-br br0

Then add port with your default internet interface (in my case it's eth0):

ovs-vsctl add-port eth0

Your internet connection will be lost.
Then remove IP from default interface (remember previous IP!):

ifconfig eth0 0.0.0.0

Then put IP that you remembered on br0:

ifconfig br0 192.168.0.100

if you use static IP-addressing or use

dhclient br0

if you use DHCP.

That's all!


What does %h mean in SSHD configuration?

According to man 5 sshd_config:

  %h is replaced by the home directory of the user being authenticated

This means the file will be /home/user/.ssh/authorized_keys. If the .ssh directory is missing (which seems normal if not previously configured) you can create it and also the authorized_keys file within and then populate the file's contents with your public key.


Not a big fan of IDEs, and FORTRAN is kind of a niche (especially 77, you'll be in a world of pain, let me guess: engineering student?). I honestly believe in the "one tool for one job" mantra, and I think a decent text-editor + command line tools is the better choice.

That being said, IDEs are really helpful and I think Photran is the best bet. You will have to install Eclipse 4.2 first.

TIP: Never install Eclipse from Ubuntu's software center, it's really old and won't work for your case. Install Eclipse from their website.

good luck


No Android item under: Eclipse>Window> Preferences

Running Eclipse as root then installing Android SDK fixed this problem.


Automatic address only for all connections

Edit connections and select your network and it should be an option under a drop down menu, I have mine set up on Google DNS so it over rides torrent site blocks. Hope this helps!


You can do this with default system keyboard shortcuts.

Press Alt+F8 (Resize) to start resizing a window. Use the Arrow keys to adjust the size and press Enter when done.
Press Alt+F7 (Move) to start moving a window. Use the Arrow keys to move the window and press Enter when done. Try also Shift+Arrow for quickly aligning with the screen edge or the border of another window.
Press Alt+F10 (Toggle Maximization State) to maximize/unmaximize the window. This is equivalent to the Super+Up shortcut.

These shortcut keys optionally can be changed in Settings - Keyboard


No keyboard response in applications due to permissions of /.config/ibus/bus

Press Ctrl+Alt+F1, log in then run:

sudo chown -R $USER: $HOME


sharing a PC's internet connection to connect HTC One M8 device to the internet

I was looking for a solution for reverse tethering on my unrooted Android device as well, but could not find any.

Eventually, I developed my own app: ReverseTethering NoRoot. It works on all Android versions 4.0+ and on Windows, Linux and Mac.

It is available on Google Play.


In theory, almost anything that both the Linux kernel and GRUB (or whatever boot loader you use) can read is suitable for /boot. Most distributions default to ext4fs, but I've used ext2fs, ext3fs, and XFS with no problems under Ubuntu. I don't recall offhand if JFS is supported at installation. If so it should work fine, too. ReiserFS, HFS+, and FAT are not supported for /boot by Ubuntu's installer, but they all work fine if you set them up after the fact. Chances are a few more (NTFS, exFAT, and some others) would work, too, but I've never tried them -- at least, not with GRUB. FAT deserves special mention because, if you're using EFI, the EFI System Partition (ESP) is FAT, and mounting the ESP at /boot can simplify use of certain boot loaders and boot managers, such as ELILO and gummiboot, which require the kernel to reside on the same partition as the boot loader. Ubuntu uses GRUB 2 by default, so this isn't an issue with Ubuntu if you use the default boot loader, but if you want to experiment it might be worth considering. OTOH, using FAT for /boot will slightly complicate OS version updates and re-installations.

One complication to changing the filesystem on /boot (on an already-installed system) is that you may need to completely re-install GRUB. The reason is that its filesystem driver gets built into its binary (stored in the sectors following the MBR, in the BIOS Boot Partition, or in the grubx64.efi file, depending on the boot mode and partition table type). Thus, if you change the filesystem, that binary must be reconstructed, which is done by grub-install. This isn't an issue for fresh Ubuntu installations, since the installer will run grub-install as part of the installation process, so it should work fine as long as the Ubuntu installer itself accepts your choice of filesystem -- which, as I've said, will actually narrow your choices from what GRUB permits.


I faced a similar challenge - wanting to run Ubuntu from external USB storage and came here looking for answers. Eventually I figured it out, however: Here is a solution that worked for me.

How to boot Ubuntu on a mac from external USB storage?


ubuntu core - kiosk mode with web browser

Here is a snap-based solution using 2 snaps:

First, install mir-kiosk:
sudo snap install mir-kiosk

Then, install chromium-mir-kiosk. Please note to add the devmode flag, otherwise, the screen will remain black:
sudo snap install chromium-mir-kiosk --beta --devmode

Finally, daemonize mir-kiosk to start after boot:
sudo snap set mir-kiosk daemon=true

To customize the startup URL for chromium use:
 sudo snap set chromium-mir-kiosk url="https://yoururl.com"

This answer was adapted from the topic "Install mir-kiosk and chromium-mir-kiosk under Ubuntu 18.04 Server on Ubuntu Community Discourse.  The source pertains to Ubuntu server, but should also work on Ubuntu Core since it is snap-based.


Open source alternatives to PD- Proxy Premium

You can use the TOR network if anonymity is what you're looking for. Basically, "Tor is a network of virtual tunnels that allows people and groups to improve their privacy and security on the Internet. It also enables software developers to create new communication tools with built-in privacy features" (quoted from the official website).
TOR provides a client for Ubuntu, you can download it here.


First of all, uninstall any Flash version on your system. Download the suitable (32bit or 64bit) installer here:
http://labs.adobe.com/downloads/flashplayer11-2.html

Extract the archive and put libflashplayer.so file in /usr/lib/mozilla/plugins for system wide:

sudo cp libflashplayer.so /usr/lib/mozilla/plugins

For user only:

mkdir ~/.mozilla/plugins # If there is not
cp libflashplayer.so ~/.mozilla/plugins


Why did I lose my wifi connections after upgrading to 17.10?

In my case I had to reset the bios to factory defaults to regain wifi.
You can use a camera to record what you have before resetting.
My best guess was it had something to do with power rather than networking itself.
Same hardware, same wifi same everything just an updated Ubuntu.
If you figure out what fixes your problem please report back.


How can I print-screen just one window and not my entire desktop?

I'm not sure if Ubuntu 12 has a similar settings tools. Pull up System Settings and look at your Keyboard settings. Shortcuts contain many keys that your system may be expect you to use. Make sure you don't have a conflict with another keyboard shortcut and check that your screenshot shortcut is what you are expecting to use. I've disabled the general ALT key for dashboard that might interfere.

This is what it looks like in Ubuntu 13:


What cell phones (feature phones, not smart phones) work well with Ubuntu?

gnome-phone-manager and Gnocky rely on http://www.gnokii.org/ (Wammu and Gammu are forks of that) all Nokia are fully supported, others have basic support (phonebook).


Linux Kernel compile: File format not recognized

Perhaps this tmp file is left over from a failed build. I suggest removing the object file and re-trying the build.

You can use the file command to find out more about the file, e.g.:

file mm/.tmp_oom_kill.o

maybe that will explain why you are getting that error.


Why isnt there an Ubuntu release name starting with C (and A)

The first two release was named randomly and came from a joke. And from the third release they decided to use alphabetical order in release names. This is documented very well in the Ubuntu Wiki page

From Mark Shuttleworth's writing, I'm quoting this from the wiki page:

  Many sensible people have wondered why we chose this naming scheme. It came about as a joke on a ferry between Circular Quay and somewhere else, in Sydney, Australia:

  lifeless: how long before we make a first release?
     sabdfl: it would need to be punchy. six months max.
     lifeless: six months! thats not a lot of time for polish.
     sabdfl: so we'll have to nickname it the warty warthog release

  lifeless is Robert Collins. sabdfl is Mark Shuttleworth.

So, the naming convention or policy wasn't fixed before the first release as you might have been assuming. That convention is later introduced and of course it is one of the greatest feature of Ubuntu OS.

Read the history in Wiki page
Also read all the dashing naming suggestion given for upcoming releases

Though they decided to use alphabetical name after Breezy, they also decided that they might avoid some letters. I think that is why there isn't a C name after Breezy. The relevant part form the Wiki page is

  We might skip a few letters, and we'll have to wrap eventually

And from 17.10 the release names will be wrapped up and will be restarted with A. So, don't forget to suggest your awesome names.