How to set permissions so that files cannot be deleted?

You can set the append-only attribute. From man chattr:

A  file  with the `a' attribute set can only be open in append mode for
writing.   Only   the   superuser   or   a   process   possessing   the
CAP_LINUX_IMMUTABLE capability can set or clear this attribute.

For directories, this means that new entries can be created, but no entry can be renamed or deleted:

$ mkdir foo
$ sudo chattr +a foo
$ touch foo/bar
$ echo a > foo/bar
$ rm foo/bar
rm: cannot remove 'foo/bar': Operation not permitted
$ mv foo/bar foo/baz
mv: cannot move 'foo/bar' to 'foo/baz': Operation not permitted

This attribute does not inherit, so you will have to apply this to all subdirectories recursively:

sudo find . -type d -exec chattr +a {} +


Ubuntu 18.04: libcrypto.so.1.0.0: cannot open shared object file: No such file or directory

First locate where is your library:

sudo locate libcrypto.so.1.0.0

Then copy that into your /usr/lib/ folder:

sudo cp /snap/gnome-3-26-1604/82/lib/x86_64-linux-gnu/libcrypto.so.1.0.0 /usr/lib/


LILO is an alternative for GRUB. It is a Linux boot Loader. Because GRUB is has more features it is commonly used with most distributions. LILO is smaller, brilliant for booting from floppy disk, but otherwise can be considered a legacy application.

Having said that LILO is still used as the default boot loader by the Slackware distro which uses the most recent release: version 24.2 which came out on November 22nd 2015.


HiDPI Screen + Monitor application scaling issues (Wayland and X windows)

I have a similar issue with Matebook X Pro (3000x2000) and external 1440p display. Weyland scaling factor not apply to all programs as above.

I also checked other distros and desktop environments, it works somehow on KDE Plasma - I mean scaling was proper on second display - but there was a lot of other issues, for example, some programs not scale in general.

On Ubuntu I also notice touchscreen issue, it works, but it is not the best user experience for me.

I type it with pain, but... for now - it is really hard to write - for now only Windows 10 works fine with this setup. It looks like we have to wait for better Linux support of HiDPI.

Update

After about one week i gave up... Windows 10 is so useless. I am very impressed that OS provided with hardware works so bad (minimum 1 crash/hang per day, about 10Gig RAM used by OS, Candy Crash in menu, preinstalled, in profesional OS!! and many many more bad experiences).

Then I switch back to only right OS - Linux. I'm really sorry that I doubted him.

In some way I workaround this issue. I disabled scaling on both screen (1x scale factor was seted).  Then on my HiDPI screen I changed resolution to 1920x1280. I know that is strange resolution but it is because my screen aspect ratio is 3:2. This resolution is apropriate to properly see UI elements and do not casue strange graphical glitches. Everything looks perfect. All programs works like charm. I was afraid when I changed resolution to smaller one then everything will be looking odd. I am impressed how everything works so great and there is no need for scaling.

I setted this weird resolution using xrandr (google is your friend).

For every day use my setup is 3000x2000, 1920x1080, 1920x1080 screens and finaly I can use this potential with power of only right OS.

Currently I am using Ubuntu but this should work on any Linux based OS.


how to tell pip to uninstall python modules from previous python version?

Every Python has own pip and check if you can do
pip3.8 uninstall ...

You can also try
python3.8 -m pip uninstall ...

If you don't have pip3.8 and there is no python3.8 then system doesn't use this version and you can simply delete folder
sudo rm -R /usr/local/lib/python3.8

Using pip -V you can see for what version it works. The same python -V show python version.
If you have many versions installed (ie. 2.7, 3.8, 3.9) then you should have programs python2,python2.7, python3, python3.8, python3.9 and pip2, pip2.7, pip3, pip3.8, pip3.9


black screen after nvidia driver installation after upgrade to 18.04

disable Secure Boot in BIOS, as Secure Boot blocks the nvidia modules from being loaded in this case.


From the README.Debian file:

  USAGE

  The application will be available at http://localhost/phpmyadmin/
   after install if you use one of supported web servers (Apache and Lighttpd
   at time of writing this). Please note that you need to have enabled PHP
   support in your webserver (for Apache you can do this by a2enmod php5, for
   Lighttpd by lighty-enable-mod fastcgi).

You can access this file if you install the phpmyadmin package here: /usr/share/doc/phpmyadmin/README.Debian.gz


Deja-dup failing to restore from 14.04 to 18.04 LTS

I don't use Deja Dup, but I use duplicity. (Pretty much the backend for DD).

Did you encrypt the files with a private key? If so, you need that secret key to decrypt the files. Try:

gpg --import /path/to/key/key.key


terminal message on opening "conda: command not found"

You need to erase the appended line by Anaconda in your .bashrc. Looks like:

. /home/muddy/anaconda3/etc/profile.d/conda.sh


How to install google chrome for ubuntu- touch?

According to the Google Chrome website, Google has not made Chrome available for Ubuntu.  Please contact them for further details.

https://www.google.com/chrome/browser/mobile/index.html


Problems installing scrypt-0.7.1 on Ubuntu into a virtual environment

Two error messages, two answers:

Simply run the command below to install the ssl development libraries

sudo apt-get install libssl-dev

Why?

From the error message:

scrypt-1.1.6/lib/crypto/crypto_aesctr.c:38:25: fatal error: openssl/aes.h: Datei oder Verzeichnis nicht gefunden
#include <openssl/aes.h>

Where is openssl/aes.h?

% apt-file search openssl/aes.h
libssl-dev: /usr/include/openssl/aes.h

And the other error message

/home/nuc/Dropbox/Julie/julie/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning

Use this commands

conda install cryptography
pip install 'requests[security]'

or use Python > 2.7.9


Why isn't Firefox 8.0 available as an update in the Update Manager?

Firefox 8 had some issues with language packs and has finally been pushed out via an update:

https://bugs.launchpad.net/ubuntu/natty/+source/firefox/+bug/887339

Micah Gersten, one of the maintainers of Firefox in the distro adds:

  In this case, there was an issue found upstream in 8.0 almost immediately after release. Since this was discovered before I could complete my acceptance testing for 8.0, I decided to wait for 8.0.1. Mozilla should be releasing 8.0.1 fairly soon and we will release shortly after them.

Normally Firefox is kept up to date via the update manager (a delay like this is unusual):

How do I install the latest stable version of Firefox?


I would recommend installing the gimp flatpak.

https://www.gimp.org/downloads/

For the gimp flatpak...

flatpak run org.gimp.GIMP --help


Where are MCE (machine check events) logged in ubuntu 18.04?

mcelog was removed in Debian 10+ (Buster) and Ubuntu 18.04+

The functionality has been replaced by rasdaemon.


How to Dual-boot Ubuntu 15.10 with Windows 10 (OLD HARDWARE! NO UEFI)

The problem in your case is that, in the image shown above your 289.09GB HDD is of MBR (Master Boot record)partition style which only supports up to 4 primary partitions (i.e blue partitions) .

If you want more than 4 partitions then you have to create an extended partition such that the total HDD has 3 primary and 1 extended partition. Then from that extended partition you can create any number of logical extended drives in which Ubuntu can be installed.

The one thing on your system I don't understand is that why you have 2 Recovery partitions each of same size.

And also the one thing I recommend is to delete one of the primary partitions, so that you have only 3 primary partition and keep the 4th one unallocated. Now boot from the UUI (Ubuntu Live USB) and click on "Try Ubuntu".

Now open Gparted Partition Editor and create an extended partition of that unallocated as a logical volume and apply the changes.

Now click on Install Ubuntu and you'll see that it has the option of installing Ubuntu alongside Windows 10 or you may use the "something Else" option to create your own partitions.

NOTE: I don't recommend you to delete the Recovery Partition as it may result in the unusual booting of Windows 10, but see in the Microsoft Community for why your PC has 2 recovery partitions.

If you need more help regarding this I will post pictures as I've also gone through this problem recently.


To be sure that all the dependencies of a software will be met, you should install it using the Ubuntu Software Centre or apt-get. However, I understand that sometimes you need to download software from other sources. In that case sometimes dependencies are not met. To fix this, download a graphical .deb installer called GDebi. It will download all the necessary dependencies, if any, at the time of installtion.


How can I create a Windows bootable USB stick using Ubuntu?

WinUSB is old, obsolete, and outdated.  It can cause problems on newer systems.  You should be using WineUSB or other software in place of WinUSB.
This answer is, however, left here as-is for historical purposes.

Create a bootable Windows USB (Vista and above) from Ubuntu through WinUSB software.
Ubuntu 12.04 through 15.04
Run the below commands on terminal to install WinUSB from a PPA,
sudo add-apt-repository ppa:colingille/freshlight
sudo apt-get update
sudo apt-get install winusb

Warning for Ubuntu EFI:
installing WinUSB on EFI loaded Ubuntu will uninstall the grub-efi packages in order to install the grub-pc packages. It will make your system unbootable if you don't manually reinstall grub-efi package before rebooting.
To do the manual re-install do:
sudo update-grub
sudo grub-install /dev/sda
sudo update-grub
sudo reboot


That battery appears to be in fairly good shape for a 3 year old laptop with 87% of original capacity remaining, not "broken" at all.

Looking a bit more closely at your output:

state:               fully-charged
energy:              55,5333 Wh
energy-full:         57,1428 Wh
energy-rate:         0,0111 W

Looking at "energy rate", the battery is actually still charging, just at a very slow rate, something not uncommon when the battery is nearly full.

It appears that the battery controller just signals "fully charged" due to the very slow charge rate (also not uncommon, just a convenience for the user), e.g. it tries to tell you this:

  Just go ahead and unplug the device now, because topping the battery off will take a long time.

Leave the laptop plugged in, and you will see the battery charge creep up to 100% very slowly.

My laptop does the same thing, it will show "fully charged" (and even a green LED on the charger will light up) as soon as it reaches 95%.

This makes perfect sense, since charging it from 10% to 90% takes 2 hours, from 90% to 95% takes 30 minutes, and from 95% to a full 100% can take another 1-1.5 hours.

Edit:

To answer your question in comment "it is plugged in for 24 hours already", and given the very low rate at which it charges currently, this can be a sign that the part of the battery that is still charging is about to fail, again very normal for an aged battery.

In this case, the battery controller will soon update the "energy-full" value (likely after plugging it out and restarting the device from being turned off) to the new capacity.

With your output above, you'll probably then be looking at a remaining total capacity of about 85% instead of 87% like you have now, which is still excellent for a 3 year old battery.


How do I get Skype 4.0 to open multiple chat windows?

From the Skype Support Center:

  It’s possible to show instant message conversations in separate windows. To do so:

  Sign in to Skype.
  In the menu bar, click View.
  Select Compact View.

For older versions read below this line.

Alright after extensive trying I found out.

Click the Skype Icon on the bottom left of the main Window
In the Menu select "Options"
In the resulting Window select "Chat" on the left
Then uncheck the checkbox to the left of "User Default View"


There are two packages in the repositories:

Screen ruler
sudo apt-get install screenruler

kruler

I haven't tried either of them, but they might be what you're looking for.


error on running the comand "sudo add-apt-repository ppa:hanipouspilot/rtlwifi"

That PPA is obsolete and should not be added to your system. (as said so in question comments by Pilot6 themselves)
Do not use the PPA.  The lack of OpenPGP data is an issue only fixable on Launchpad, but since the PPA is obsolete, there's no need to fix this issue.


How to execute query to a DB from a terminal and store output to a file?

Try man sqlite
You'll find that sqlite expects a syntax such as sqlite [options] filename [SQL]
Then do this sqlite [options] filename [SQL] > file_with_results.txt and the result would be in file_with_results.txt

From what you write, I believe you need:

sqlite .mozilla/firefox/profile_name/places.sqlite "SELECT moz_places.url FROM moz_places;" > file_with_results.txt


Open a terminal and type

echo $DESKTOP_SESSION

If the output is ubuntu then you're running Unity; ubuntu-2d otherwise.


Use zenity and xdotool to emulate the behaviour via Thunar Custom Action. With the help of command line tools, no need to look at source code for such capability.

How it works

First, use zenity to display GTK+ dialog box with custom text "Confirm to quit Thunar?" using the question format. When either button (OK or Cancel) is pressed, zenity will return an exit value (0 or 1).

A zero indicates success and a nonzero value indicates failure. Therefore, when the OK button is pressed, that will return exit value 0 and parsing to logical AND && will continue to run the following command.

The following command will use xdotool to emulate key press to quit Thunar, which is Ctrl+Q, via command line. The final result is same as the user pressing Ctrl+Q directly from the keyboard.

How to setup

Follow the steps to create the custom action in Thunar.

Open Terminal and install the required programs via APT, or install from the package manager of choice.

sudo apt-get install zenity xdotool

Open Thunar file manager, and go to Edit > Configure custom actions... to open the Custom Actions window.
In the Custom Actions window, click on "plus" in the list of buttons (the one labeled with a "+"), and a dialog with two tabs will appear.
Under Basic tab, fill in the details in corresponding fields.

  Name: Quit after confirm

  Description: (optional)

  Command: zenity --question --title="Thunar Custom Actions" --text="Confirm to quit Thunar?" && xdotool key ctrl+q

  Icon: (optional)

To select the same icon used for "Close Window" menu in Thunar, click on No icon button and search for "system-shutdown", select the icon and click OK. The icon will be selected.
Under Appearance Conditions tab, look for "Appears if selection contains:" and fill in the checkbox for "Directories".
Click OK to close the dialog.
Finally, click Close to finish.

How to use

Open Thunar file manager, and browse any directory. Right-click on mouse and select "Quit after confirm" (or whatever name given in step 4) in the context menu. That will display a dialog with the specified details.

Click No will do nothing.

Click Yes will run emulated combination key press that will close the current window of Thunar.

If the user wish to close all window and not just current window of Thunar, change the key combination in step 4 from ctrl+q to ctrl+shift+w instead. That is all.


After installing Dart commands like pub, dart2js are not found

I know nothing about Dart, yet I downloaded the deb and looked inside it. The files you're looking for are located at /usr/lib/dart/bin/. You're getting "command not found" because that directory is not in $PATH.

You should be able to run them by providing the full path:

/usr/lib/dart/bin/dart2js

Or you may want to add /usr/lib/dart/bin to $PATH.


Has anyone tried putting Ubuntu on the new macbook pro retina?

I'm running Ubuntu 12.04 in Virtualbox 4.2.1 on the Macbook Pro Retina. For the most part it works fairly well after installing guest additions.

It freezes up at times for a minute or so then catches up with itself. (Sometimes I get a black screen for 30 seconds or so until I see Ubuntu again.)

The only other issue might be the fact that since OS X is scaling the resolution, everything in Ubuntu looks slightly blurry. It's not too problematic for general tasks, however it can definitely be an issue if you are a designer who wants pixel perfect accuracy.


Install/Enable Adobe Flash Player debug version in Ubuntu 14.04 for Firefox (if possible for Chrome too)

Yes sir, debug is possible, but more effectively, you can get adobe flash for Mozilla Firefox in the Ubuntu Software Center. Just go in and search "Adobe Flash," then install and restart Mozilla. And that's it! If this works for you, make sure to vote up and check it so that other people can see this if they want to know the same question!


Your USB installation media seems to not be properly configured.

Create a working USB drive by using the disks tool from within Ubuntu.

Open it and select Restore Disk Image from the menu on the top right.

Choose the ISO file and the USB drive to write it to and start restoring.

If you have or want to do it from within Windows use the diskpart tool.

Open command prompt as administator and execute:

diskpart

list disk
select disk * (* = number of USB drive)
clean
create partition primary
active
format fs=fat32 (quick)
assign letter=** (** = select a free drive letter)

Mount the ISO file and copy the content to the USB drive.


how to map a folder in my VM to my local machine

By default, Vagrant will share your project directory (the directory with the Vagrantfile) to /vagrant.

In your Vagrantfile, you should have the following

Vagrant.configure("2") do |config|
  # other config here

  config.vm.synced_folder "src/", "/srv/website"
end

  NOTE: The first parameter is a path to a directory on the host machine. If the path is relative, it is relative to the project root. The second parameter must be an absolute path of where to share the folder within the guest machine. This folder will be created (recursively, if it must) if it doesn't exist.

Other options

Option 1

Recommended sshfs
Install sshfs package, mount a path on the host via ssh, for example, mount the $HOME/project to /srv/www on the guest

sshfs user@host:~/project /srv/www

To unmount sshfs

fusermount -u /mnt/sshfs

/srv/www on the guest appears as if it is local.

Option 2

NFS See => Vagrant - NFS


19.10 installer not recognising hard drives

I had help with this. The solution ended up involving the BIOS. I had to find SATA Mode and change it to AHCI. It was hidden under the main tab but was revealed by pressing Ctrl+s.


I am guessing you may not have properly installed your desktop environment or somehow your system crashed during installation. I would suggest reinstall gnome desktop environment (first install classic gnome desktop environment)

sudo apt-get install gnome-session-fallback


Ubuntu Server 18.04 cannot switch to external display

Seems as if the adapter was an HDMI to VGA cable, not VGA to HDMI...


Why does "echo $DISPLAY" output ":0.0" on my secondary monitor

The two physical displays are joined into a single logical display. Notice how a window can be dragged so it's half on one monitor and half on another.

Follow-up to OP comment

Almost everyone sees ":0.0". the exception are people with two video cards who will see ":0.0" for the first video card and ":0.1" for the second video card.

Although I only have two monitors of 1920x1080 pixels built-in and 1920x1080 pixels HDMI TV my Intel Graphics card supports a region of 32 KB x 32KB pixels (there abouts) so there is lots of "virtual space" for not only these two monitors but many more.

I don't feel I'm answering your question properly because I don't fully understand the significance of your question and comments. Are you curious how an application knows which pixels in virtual space to draw a window on when there are two or more monitors? You will notice when a given monitor window has focus and you press Ctrl+Alt+T to open the Terminal it opens on the top left of that monitor and not the other. Is something like this the basis of your query?


How can I kill a screen session running a Minecraft server and save the world?

Seems to make sense to backup the world before shutting down the screen session.

I would think this would help:
http://www.scaine.net/site/2013/08/backing-up-your-minecraft-server-in-ubuntu%EF%BB%BF%EF%BB%BF/

or this:
https://forum.feed-the-beast.com/threads/minecraft-custom-linux-backups-using-crontab-and-screen.45575/


Make sure that there's a character at the end of each line

The simplest approach is to use sed with in-place editing:

sed -i 's/,*$/,/' file

The -i makes the changes to the same file. You can use i.bak to create a file.bak backup file of the original. You can also run it without the -i to see the changes before they're applied. The s/foo/bar/ is the substitution operator. It will replace the first instance of foo with bar. The $ marks the end of the line, and * means "0 or more". So, s/,*$/,/ means "replace 0 or more commas at the end of the line with one comma". If no commas are there, one will be added and if there are more than one, they will be replaced with a single one.

Some other options, for the sake of completion:

Perl

perl -i -pe  's/,*$/,/' file

Same idea as the sed above. This is where sed got the -i idea from.

If speed is an issue, this one will be the fastest of all the solutions here:

perl -i -lne 'printf join ",", (grep {$_ ne ""}split(/,/) ); print ","' file

awk

awk '{sub(/,*$/,",")}1;' file >newfile

Or, with newer versions of (g)awk:

awk -iinplace '{sub(/,*$/,",")}1;' file

Pure shell (slower and less efficient, only included as an example):

while read line; do echo "${line/%,*/},"; done < file > newfile

The ${var/%foo/bar} will replace any foo from the end of the variable var with bar. Here, we're replacing everything after the last comma, so this won't work if you have multiple commas per line, it only works on your example. The other solutions don't have any of these limitations.


I recently built a system around an ASRock Z370M-ITX/ac and was able to get HDMI audio working after some debugging. I am not using multi-monitor so I don't know if I can help you there, but it is worth a shot and may at least get audio working.

In my case, HDMI audio was not working because the i915 graphics driver failed to properly load and register its capabilities (including its audio component) with the Linux kernel. There are a number of different reasons why the i915 driver might fail to load, and the driver was not giving any error messages. However, later in the boot process, the sound driver (snd_hda_intel in my case) was giving the following error:

snd_hda_intel 0000:00:1f.3: failed to add i915 component master (-19)

If you are getting this error, take a look at my other answer here and see if that helps. Or tl;dr and add the following line to /etc/modprobe.d/modesetting.conf:

options i915 modeset=1


windows likes to put itself at the top of the boot order. a work arond is this:

boot from a live CD. install efibootmgr.

find the file /efi/ubuntu/grubx64.efi. copy it to /efi/boot/bootx64.efi. if the file is there already overwrite it. this makes grub the default loader.

next use efibootmgr to delete all entries in the boot list. restart you computer, be sure ubuntu is the fiirst OS you boot into so it is placed in the first slot.


Set umask, set permissions, and set ACL, but SAMBA isn't using those?

SAMBA/UMASK

Running Ubuntu 14.04, samba Version 4.1.6-Ubuntu. I was previously running Fedora 16/samba3 and everything was OK. With Ubuntu/samba4, I could not get Samba to set group write bit on directories.

smb.conf parameters (for testing) included:

create mask = 700             # The file AND mask
force create mode = 775       # The file OR mask
directory mask = 700          # Directory AND mask
force directory mode = 777    # Directory OR mask

From Windows 7 client, I could create files with mode=775, but created directories always had mode 755.

The problem is with default "UMASK 022" on my personal login which I use to access the shared directories. Edited /etc/login.defs and changed "UMASK 022" to "UMASK 002". Rebooted, and now directories created from Windows 7 client have mode=775. I do not believe this was the same behavior as my previous setup (Fedora/Samba3).

Interestingly, smb.conf parameter "inherit permissions = yes" kind of worked. This parameter supersedes the previous parameters. With parent directory having mode=2777, created subdirectories had mode=766 (the execute bits weren't set), and files had mode=755 (the group/guest write bits weren't set).

The Samba/UMASK interaction and interdependency should be documented.


Force "Save As File" Option When Sharing File From Ubuntu One

As of next Wednesday (or Tuesday afternoon, depending on where you are in the world) when the change gets deployed you can add ?attachment=true to any public URL to have it delivered with content-type: attachment. So for example if your public URL as given by the system is http://ubuntuone.com/2tmgfbyPMAURzYDraoMo7e, if you need to force it to be delivered as an attachment you specify http://ubuntuone.com/2tmgfbyPMAURzYDraoMo7e?attachment=true.

Hope this helps.

  Update: this is now live.


How to disable pulseaudio automatic device switch?

Let me know if this doesn't work for you and I'll delete my answer. I don't have your speaker system but this should work.
Disable automatic device switching
When signal is lost to during sleep, Pulse Audio is automatically configured to activate the default source (your HDMI). Upon resume the sound device is still on HDMI. To override this setting, tell Pulse Audio to never switch sound devices automatically:

edit the file /etc/pulse/default.pa
find the line load-module module-switch-on-port-available
insert a # at the beginning of the line to disable automatic port switching
save file and exit editor
type pulseaudio -k to reload configuration


When I ran the Landscape Server for Personal Use (the Landscape Dedicated Server), I had quite some difficulty getting the QuickStart to work.

I had much more luck with the Manual Installation than I did quick-start.  I think that the Manual Installation gets everything working the way it should, while QuickStart isn't a guarantee to make it 100% work.

The instructions change from version to version, slightly, so copying the key instructions into here would be useless - please refer to the link for Manual Installation.


WiFi is disabled and not able to turn it on in Ubuntu 18.04

I had a different wifi driver but I think this is the same problem. I solved it by following the direction in the following link How to install Wi-Fi driver for Realtek RTL8821CE on Ubuntu 18.04?
You can also check if there is the source code for your driver so you install it by yourself.
Cheers!


You cannot install Ubuntu (and any other Linux system I know) from already booted system. What you need is write the disk image (file with .iso extension) you installed to DVD or USB with pendrivelinux to create a bootable media.

I highly recommend getting somebody who knows computers to assist you.

Then you need to boot from that media (DVD or USB). Restart your computer and look at screen for info. You are looking for something like Press X key to enter boot(BIOS) setup. Hold that X key. It's usually F8, F12 or Esc in my case. There you look for change boot order or something similar. Navigate with keyboard to that option. Select the media, holding your Ubuntu installation.

You may try Ubuntu before installing it. Because your machine had WindowsXP, I guess it's quite old. If so, Ubuntu may be too much for it and you would see it before doing any changes to your main disk. Just check Try Ubuntu option.

If Ubuntu is too heavy for your machine, you may try Lubuntu - a derivative of Ubuntu which strips down on eye candy and some functionality to use much less computer resources. As a side bonus, it resembles WindowsXP.

Steffen offered a great link to extended and detailed explanation.


First of all, you can see the permission of /var/www has,  by this command ls -l /var/www.  You will see like this (this only for example):

drwxr--r--  7 www-data www-data  4096 Jun 21 10:53 CodeIgniter
drwxr--r-- 11 www-data www-data  4096 Oct  2 19:49 eAdministration

drwxr-sr-x is permission status and www-data www-data is ownership status.  By default, when you installed for first time, ownership status is www-data www-data. The thing that you should do, add your username belongs to www-data group by this command:

sudo adduser yourusername www-data

After that, you should change the ownership to your username:

sudo chown yourusername:www-data -R /var/www

It will result in:

drwxr--r--  7 yourusername www-data  4096 Jun 21 10:53 CodeIgniter
drwxr--r-- 11 yourusername www-data  4096 Oct  2 19:49 eAdministration

Then, you should change permission to 755 (rwxr-xr-x) for directories, 644 (rw-r--r--) for files, and I do not recommend to change permission to 777 (rwxrwxrwx). As suggestion from temoto to make easier to be understand, you can do this:

sudo find /var/www -type d -print0 | sudo xargs -0 chmod u=rwX,go=rX
sudo find /var/www -type d -print0 | sudo xargs -0 chmod u=rw,go=r

OR

sudo find /var/www -type d -print0 | sudo xargs -0 chmod 0755
sudo find /var/www -type f -print0 | sudo xargs -0 chmod 0644

To ensure that setting has been running well, you can try php code in /var/www.


Asus laptop suddenly stuck at UBUNTU loading screen

What you can try to do is to use Recovery Mode.

Choose it on GRUB screen by selecting Advanced options for Ubuntu.

Then choose your kernel with (recovery mode) (should be second option)

On next screen choose Drop to root shell prompt

Log into root account. Then you can try to uninstall binary driver you've installed before or use dpkg-reconfigure to refresh its configuration.


Dependancies not met while instaling digikam 2.9

open your terminal and type this

sudo add-apt-repository ppa:mikevaughn/omnilinux
sudo apt-get update

Now try again .


Headset mic and speakers not working at same time

I don't know if you ever figured this out, but I just ran into the same problem using Pop!_OS 20.10 - basically Ubuntu.
I just killed pulseaudio and restarted it to get stereo sound and mic back. I did it with:
$ pulseaudio -k
$ pulseaudio -D

My system had another symptom in that my headphones were only playing mono sound. I don't know if that was your experience as well.
I don't know how long this will fix it, but it seems to have worked this time. I found my solution here: https://appuals.com/how-to-fix-pulseaudio-issues-in-linux/


Browse Android's external SD card from Ubuntu PC

Finally I make it with "gMTP".

(The program gMTP it’s intended for managing MP3 players, but it works great for managing devices.)

To install it:

sudo apt-get install gmtp

To connect:

just plug the android via the USB cable into your computer, start gMTP and click “Connect”.

When you press "Connect" you will asked if you want to browse internal memory or sd card.


Install apache2 and tomcat7 without apt-get (Ubuntu Server)

Ok, so it looks from our comments like the issue is that you're behind a proxy.  Reference this question for an answer:

Configure proxy for APT?


How can I load Ubuntu when all I have is Grub?

Using Grub

If you get to a grub prompt and the system and kernel are still installed on the partition, you can "manually" boot the system - i.e. without the help of a working grub.cfg. This also works with a grub run from live media. To this end grub includes a rudimentary command ine, which you can use to find the partition and boot the system.

find /vmlinuz

This should give you the partition like (hd0,0). You can also use the ls command to poke around the partition and see which kernels are available. The search command works similarly. You can also use tab completion.

set root=(hd0,1)

Of course, replace the parition identifier with whatever find showed you.

linux /vmlinuz root=/dev/sda1
initrd /initrd.img

Select the kernel image and initrd image, a pair which always needs to be used together. Luckily Ubuntu creates a pair of symlinks in the root directory which point to a working image and initrd. Note that you need to replace /dev/sda1 with a representation of the partition in the scheme used by the Linux kernel. Roughly, (hd0,1) corresponds to /dev/sda1; (hd0,2) corresponds to/dev/sda2;(hd1,1) corresponds to /dev/sdb1.

boot

This boots the selected kernel from the selected partition. Once you've managed to boot your system, you can use that to restore grub, as is detailed e.g. here.

Grub with Wubi

The above was premised on the assumption that Ubuntu was installed regularly, i.e. in its own separate partition. As you write, you used Wubi, which means you installed it to a large file on a Windows (NTFS) partition using a technique called "Lupin". I see no reason why this couldn't work in principle, though the process is more complicated. Here's the content of a grub.cfg based on a Wubi install:

insmod part_msdos
insmod ntfs
set root='(hd0,msdos5)'
search --no-floppy --fs-uuid --set be300f9c300f5ab3
loopback loop0 /ubuntu/disks/root.disk
set root=(loop0)
linux /boot/vmlinuz root=/dev/sda1 loop=/ubuntu/disks/root.disk
initrd /boot/initrd.img

You'll need to adapt this to your particular case. In this snippet, taken from a 10.10 install, the search command finds the root partition using a filesystem UUID or identifier, which you presumably don't know; you can use --file --set /ubuntu/disks/root.disk instead (here's the official documentation). This grub configuration creates a virtual disk - a "loopback device" - called loop0 which represents the contents of the "partition file", /ubuntu/disks/root.disk on your NTFS partition. With a bit of trial and error, you should be able to make this work.


Guide to installing Hardy Heron via USB drive on a laptop running Windows XP?

As the commenters have noted, Hardy Heron 8.04 LTS is no longer supported for desktop use and will soon not be supported, period. Your problem sounds like its a newer hardware incompatibility with the very old Hardy.

Please consider using the latest Precise 12.04 LTS, or if you need a legacy release for some reason, try 10.04 LTS.


Environment Modules can't find installed modules

Environment Modules works with modulefiles, which are scripts written in Tcl that describe environment changes (like the addition of a directory to an environment variable).
You could look at /usr/share/modules/modulefiles/dot on your setup to see an example of modulefile.
In your situation, you install Perl modules, but once installed there is no modulefile to bridge them in the Environment Modules context.
Their may be a confusion here between Environment Modules and Perl modules. Environment Modules may help to define an environment variable to reach the perl modules you have installed (for instance by adding the /usr/local/share/perl/5.26.1 directory to the PERL5LIB environment variable, see perllocal modulefile example below) but Environment Modules will not give you the visibility of the Perl modules you have installed.
/usr/share/modules/modulefiles/perllocal:
#%Module
append-path PERL5LIB /usr/local/share/perl/5.26.1


How to turn off update for Wireless card

I'm not sure if 12.10 has synaptic, if it doesn't, you can sudo apt-get install synaptic. Here are some alternatives I can think of:

Go to the synaptic package manager. Settings > Repositories > Updates, check Only notify me about updates. Then, when you see the Updates available icon, click it and only check the updates you want to install -- don't check the drivers update. This works in Debian, it should work on Ubuntu too, although I'm not sure what process manages updates.
On synaptic, find the driver's packages, check them, Edit > Lock Version. Apparently this won't prevent aptitude and apt-get of installing new versions, so check this answer.

I only noticed after I answered it, but I think your question is a duplicate of this one.


Ubuntu 14.04LTS running Kodi random freezes

It was a problem with the HDMI sound.

If everything is set to defaults it doesn't freeze. It has been running 3 days now without a hiccup.

If I set the sound to HDMI instead of the default pulseaudio it freezes.
I am running with the defaults now and everything seems to work just as it should.


How to use use period (.) as decimal separator in Qalculate / qalc?

Solution
Set decimal_comma=0 in the following two configuration files:

~/.config/qalculate/qalc.cfg for the command-line calculator tool
~/.config/qalculate/qalculate-gtk.cfg for the GUI calculator tool

Alternative Solutions

A command line option. As a non-permanent way to provide the same configuration as above, you can call qalc like this:
qalc -set "decimal comma off" "binomial(5, 3)"

A command in interactive mode. When you start the command-line tool as just qalc you are in interactive mode. There, you can apply the same configuration as above by entering this command and pressing Return:
set decimal comma off

Changing the locale. Qalculate! evaluates LC_NUMERIC from your system's locale settings to determine what character to use as decimal separator (source). The remaining character of period and comma then becomes the parameter separator. So execute echo $LC_NUMERIC to see if it's right. If not, you might want to change or fix your locale settings.

"Ignore locale" option. Starting with version 3.0, there is an option to ignore the system locale and instead use English. Usage: qalc -set "ignore locale" "binomial(5, 3)". Or in the qalcinteractive mode, useset ignore locale`. (source)


Unable to boot Ubuntu on a laptop with two hard drives

You should enter BIOS/UEFI Setup and choose 1 TB HDD as first booting device in boot priority menu. Then in Ubuntu just run sudo update-grub to be able to boot to windows from grub2.


Thanks to RevExNET comment I solved this with the following command:

 sudo apt-get install libgl1-mesa-dri libgl1-mesa-dri:i386

For me, only the :i386 was missing, but I'm guessing you need both.

I believe this is an issue faced by those using intel graphic cards.


blackberry desktop will not prompt for install

Use LinBerry to manage your blackberry phone

Here are some of the functions currently available in LinBerry:

Manage Your Contacts
Install/Uninstall Applications
Backup/Restore Your Data (files, music, video, etc.)
Turn Your Device Into A Modem To Connect To The Internet

The developer is intending to include the follwing functions in next LinBerry' updates:

Software Updates (OS Upgrade)
Wipe Out Your BlackBerry
Sync Your BlackBerry With Thunderbird Lightning/Evolution
More Language Support

LinBerry Installation

To install LinBerry on Ubuntu 11.10/12.04 via PPA, open the terminal and run the following commands:

sudo add-apt-repository ppa:upubuntu-com/mobile

sudo apt-get update && sudo apt-get install linberry -y

You can start LinBerry from the Unity Dash or from Application Menu

Enjoy!


First, check the settings in the router. WPA2-AES is preferred; not any WPA and WPA2 mixed mode and certainly, absolutely not TKIP. Second, if your router is capable of N speeds, you may have better connectivity with a channel width of 20 MHz in the 2.4 GHz band instead of automatic 20/40 MHz, although it is likely to affect N speeds. I also have better luck with a fixed channel, either 1, 6 or 11, rather than automatic channel selection. Also, be certain the router is not set to use N speeds only; auto B, G and N is preferred. After making these changes, reboot the router.

Next, I recommend that your regulatory domain be set explicitly. Check yours:

sudo iw reg get

If you get 00, that is a one-size-maybe-fits-all setting. Find yours here: http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2 Then set it temporarily:

sudo iw reg set IS

Of course, substitute your country code if not Iceland. Set it permanently:

gksudo gedit /etc/default/crda

Use nano or kate or leafpad if you don't have the text editor gedit.

Change the last line to read:

REGDOMAIN=IS

Proofread carefully, save and close the text editor.

Next, I'd set IPv6 to Ignore in Network Manager: http://docs.fedoraproject.org/en-US/Fedora/18/html/Installation_Guide/images/netconfig/network-connections-ipv6-ignore.png  This example is for ethernet, but you want wireless.

After these things are done, reboot and test. Give us your report. If the issue is not improved, please let us have an updated wireless_script.


SanDisk SSD Plus: Half the performance on Linux than on Windows?

This may not be a good enough answer, but I am new and can't "comment", and wanted to share with you in case it helps:

I used to work with eMMC flash memories, similar hardware underpinnings as SSD.  discard_zeroes_data sounds like it could matter.  There were very slow features called Erase and especially Trim (like Erase, but on a 4kB read-block basis instead of the much larger Erase Group Block needed for performance.  Later a "Discard" feature was introduced which didn't erase the data to all zeros (really all-ones under the hood, but inverted for your convenience), but just changed the state of the data to "don't care".

So if you did a discard on 4kB of data, it was faster because didn't do an erase, but let the firmware know that you didn't need the data anymore, and it kept track of that physical area in a table.  This allowed the garbage collection type of mechanism to reclaim that data location (likely re-map it to a different address) later when enough of its neighbours could be erased, copying any needed data to another area as needed and then doing the expensive "Erase" operation in the background.

TBH we ended up disabling discard at first, because it didn't work so well in and caused us performance issues when too much data was left in discard state, and the physical erases never happened.

So I can't tell what "discard_zeros_data" exactly means, but if I were you I'd definitely try changing it to the opposite state and see what happens.  If it reads like "subject verb object", then it could be a security feature where it takes the time to forcibly erase even small bits of data (expensive) so that there's no chance that someone can reclaim your old files after you think you've deleted them.  I would think that setting this to "Zero" would actually increase performance, if that's how you read it, but you're seeing the opposite.

Also try doing the biggest forcible "erase" that you are able to, whether using special SSD tools, or a full format, or something, and see if the performance is better right after this erase.  That will at least give you some information about the problem.

The filesystem type should definitely matter also, but I think this is a constant in your two experiments.


Recursively copy the contents of subfolders

You can use for

for d in /path/to/source/*; do echo mkdir /path/to/dest/"$(basename $d)" && echo cp -rvb -- /path/to/source/"$d"/src/* /path/to/dest/"$(basename $d)"; done

If you are doing this from the parent directory of source and dest, you can use relative paths:

for d in source/*; do echo mkdir dest/"$(basename $d)" && echo cp -rvb -- "$d"/src/* dest/"$(basename $d)"; done

After testing, remove echo to actually copy the files

for d in source/*; do mkdir dest/"$(basename $d)" && cp -rvb -- "$d"/src/* dest/"$(basename $d)"; done

More readable...

for d in /path/to/source/*; do
  echo mkdir /path/to/dest/"$(basename $d)" &&
  echo cp -rvb -- /path/to/source/"$d"/src/* /path/to/dest/"$(basename $d)"
done


I just tried booting another time and I got fixed :)


unattended-upgrades do not work properly

Contrary to the answer above my: "/etc/apt/apt.conf.d/50unattended-upgrades" did have:

  Unattended-Upgrade::InstallOnShutdown "false";

Yet I still was seeing:

Welcome to Ubuntu 18.04.3 LTS (GNU/Linux [...] x86_64)
[...]
29 packages can be updated.
0 updates are security updates.

So why were these 29 packages not updated?

As it turns out, "/etc/apt/apt.conf.d/50unattended-upgrades" also contained this declaration:

Unattended-Upgrade::Allowed-Origins {
        "${distro_id}:${distro_codename}";
        "${distro_id}:${distro_codename}-security";
        // Extended Security Maintenance; doesn't necessarily exist for
        // every release and this system may not have it installed, but if
        // available, the policy for updates is such that unattended-upgrades
        // should also install from here by default.
        "${distro_id}ESM:${distro_codename}";
//      "${distro_id}:${distro_codename}-updates";
//      "${distro_id}:${distro_codename}-proposed";
//      "${distro_id}:${distro_codename}-backports";
};

The key to a fix for me was simply to uncomment this line:

//      "${distro_id}:${distro_codename}-updates";


Upgrade Ubuntu without getting a ton of new software installed

The Ubuntu installer will try to reinstall all the recommendations of ubuntu-desktop. This will draw in a lot of dependencies.

If you are feeling adventurous, you could:

Bypass the Ubuntu installer and manually rename all occurences of natty to oneiric in /etc/apt/sources.list, comment all ppas, do a apt-get update && apt-get dist-upgrade on the command line. (This used to work on older debian, YMMV)
Dump your current packages as outlined in How to backup settings and list of installed packages and Backup Software Sources, do a basic command line install with debootstrap and play the packages back in.


installation problem in VLC Media player

just type the following in terminal:

To open terminal press the keys Ctrl +Alt+T

sudo apt-get install vlc

and you are done.


How to add second email account to Geary?

It seems like already one year ago - but I could have the solution, because I had the same problem: Type in both the passwords, else the "Hinzufügen"-Button (Add) will not be activated.

Hope that helps at least other guys who googles this.


GIMP returns Segmentation fault in fresh 17.10 installation

In a fresh and up to date installed system of Ubuntu 17.10 running with Wayland, gimp version 2.8.20-1 is installed from Ubuntu's repositories and it works for me, at least the basic functions. (There are bugs, for example the general screeenshot via the PrintScreen button works, but not gimp's screenshot option.)

Maybe your gimp will work after update & upgrade,

sudo apt update
sudo apt full-upgrade

Otherwise I suggest that you start gimp from a terminal window and check if there is some specific error output.

Edit: The original poster, @GiorgosKapetanakis, found this to be an issue with nvidia (one of many issues with nvidia proprietary drivers in Wayland).


tshark can't open /sys/kernel/debug/usbmon ubuntu 18.04

Found good solution at: https://www.kernel.org/doc/html/latest/usb/usbmon.html,
where use of usbmon gets logs via cat to log file.  Rough, but have track of usb traffic desired.


How to change lock screen background Ubuntu Mate

for Ubuntu MATE 16.04 try the following:

Open a terminal ( [Ctrl] + [Alt] + [T] )
Change to the following directory: cd /usr/share/backgrounds/ubuntu-mate-common/
Rename the old background picture: sudo mv Ubuntu-Mate-Cold.jpg Ubuntu-Mate-Cold.old
Copy your image here: sudo cp [path/to/your/image] Ubuntu-Mate-Cold.jpg

Note: Do not change the file extension for the background image, even if it is not a jpg but for example a PNG. The background image should be displayed normally anyway.


WiFi disabled on Dell Vostro 5459 (Ubuntu 16.04)

To bring up a disabled adapter you can use the command:

sudo ifconfig wlp2s0 up

If it tells you, that it is blocked by rfkill you can see if something is blocked with the command

rfkill list

and unblock it with

rfkill unblock all


Need to add "Boot from USB" to UEFI Boot Priority order

First, be sure that you've actually plugged an EFI-bootable USB flash drive into the computer. The option may not be present if there's no USB flash drive inserted or if it's not bootable in EFI mode.

If you've done that, I recommend you try another image for diagnostic purposes. Another distribution should work fine if you've got it handy. If you want something quick to download, there's a USB flash drive image of my rEFInd boot manager that you can download and prepare quickly for testing purposes.

Another thing to try is another physical medium. I've seen a few reports of USB flash drives that work fine in an OS but that firmware doesn't seem to like. I'm not sure of the cause of the problem, but if this is what you're running into, a new USB flash drive might fix it.

You could try using rEFInd to work around the problem. Install it on your hard disk from Windows (see the rEFInd documentation for instructions), or use it on another USB flash drive. When you boot to rEFInd with a bootable USB flash drive plugged in, it should give you an option to boot it. This might work around EFI bugs, but probably not hardware incompatibility.

Speaking of EFI bugs, you might try upgrading your firmware.

Finally, you could try setting up a partition with the Ubuntu installation files on it and use rEFInd to boot the installer from there. In theory this should work, but there may well be some "gotchas," and I don't have detailed step-by-step instructions.

Try these in whatever order you like; I don't mean to imply anything by their ordering (except for the first item, which is the most basic one).


What will Happen If I dont Upgrade 11.10 to 12.04 ? Can I still be able to use Ubuntu?

Sure.  This chart: https://wiki.ubuntu.com/Releases shows that 11.10 will be supported until April 2013

Eventually it will not be supported and then will not get bug fixes and the like.  If you never do any installs or upgrades again you'll be ok, but with most software updating pretty frequently these days, it's not a good choice long-term.

Also if someone discovered a security bug it may not be fixed or fixed quickly in an old version, potentially compromising your data.

Security, fixes and bug patches aside there's no reason it will stop working,

i.e. there is no expiry date to actually using it.


GeForce GT740M

Download and install the 418.1130 driver from https://www.geforce.com/drivers or https://www.geforce.com/drivers/results/153717 for the direct download.

Update #1:

The install error is probably due to the Nvidia software you tried to install before. Do dpkg -l *nvidia* | grep ii and uninstall all of the old Nvidia stuff, then reboot. Retry install.


Is it possible to uninstall the 'programs' rm, cp and mv from the system?

All the Ubuntu meta-packages, all the way down to ubuntu-minimal indirectly depend on coreutils (which these are part of)... There isn't really to properly uninstall them because everything else needs them.

And what's to stop somebody bringing their own tools? I could, for example, write a version of cp in Python in a few minutes. If you're trying to lock things down, it might make most sense to ask yourself "What damage could this user do?" then fixing that rather than papering over the holes with obscurity.

If you need certain files to not be damaged, fix their permissions. You've got a few options:

Mount them as readonly from another location
Make them owned by a different account and give global read access (chmod 744 for example)
Use acl (access control list - like the chmod permission on steroids) for granular permissions over lots of users)
Imaging and reimaging on reboot and netbooting to restore to a known-working system on boot.

You can use a lot of this stuff together but chances are if you remove something (aside from the technical arguments) you're just inconveniencing the people that really need the tools. Those with nefarious intentions are more than well equipped enough to work around simple blocks.


Graphic tearing is a widespread complaint about nvidia. I have not solved it in a Dell precision 5510, despite trying about 20 fixes. On the laptop itself, tearing is not horrible. On external monitor, it is awful. I get weird pie shaped tares.

If you google this, you will see this is not a Kubuntu problem. It is an Nvidia problem.

Things to try

Run nvidia-settings, find power setting and change to high performance.

Many posts will say set "Vblank", but that option disappeared in new version.

Kubuntu settings, under devices, has settings. Make sure compositor is on. It has buttons to turn.


firefox-wget-window doesnt close after download

It's not a wget issue, it's FlashGot. From their changelog:

[Unix] Turned the "Press any key to exit..." prompt
  (which was a lie) into "Press [ENTER] to quit..."
  The flashgot.term.autoClose about:config preference
  can be set to either to -1 (default) to prompt, 0
  to close the terminal immediately, or an integer
  number of seconds to wait before closing

https://flashgot.net/changelog


USB camera /dev/video0 and TV card /dev/video1 are mixing

You need to create a persistent udev rule, in /etc/udev/

See /lib/udev/rules.d for help on how to configure the specific rule.

I am not sure how the rule should exactly look like, however it should be similar to these network rules:

# PCI device 0x8086:0x1242 (iwlagn)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:12:ab:52:44:36",
  ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="wlan*", NAME="wlan0"

which says that if the hardware address of the device is 00:12:ab:52:44:36, then it should use the name wlan0.

UPDATE: See http://reactivated.net/writing_udev_rules.html and http://hackaday.com/2009/09/18/how-to-write-udev-rules/ for instructions.


Black Screen With A buzz after installing ubuntu 18.04

I Finally found the solution, the problem was related to NVIDIA driver,

What I did is:

started Ubuntu in the test mode (live boot from the USB)
opened terminal and removed Nouveau:
sudo apt-get --purge remove xserver-xorg-video-nouveau
Then I installed the NVIDIA Driver using:
sudo apt-get install nvidia-331.

after the installation complete, I reboot the system and it worked!.

PS: I Still have the Buzz sound when I start my computer again

`


This is a problem between Ubuntu and Chrome, in this page, you can see which theme the system is using.
https://codepen.io/alisterlf/full/LYbvwER
This page works on ubuntu with firefox, but not in chrome.
In windows, this page also works with chrome, so that's why I think it's a problem between Ubuntu and Chrome.


My Ubuntu is 13.10, how to do a clean install of 16.04.2 LTS

If you want to do a clean install then boot from the USB and install the new version of Ubuntu, when you get the partition/ drive screen I believe it should format them or you can tell it to format them (depends on what options you select).

Since you want a clean install it would be just like installing it over again.


Evolution Calender event not showing in panel date menu

What version of Evolution are you using? For me in 14.04 LTS the Software Center shows 3.10.4-0ubuntu2. (Although there is a newer one available). I needed from optional add-ons:

Standard plugins for evolution (evolution-plugins)
GNOME panel indicator applet for Evolution (evolution-indicator)

sudo apt-get install evolution-indicator

sudo apt-get install evolution-plugins

And in Evolution>Edit>Plugins>Enable Both.

If you use Google Calenders, then there is a as well a workaround without need of Evolution:
http://helpdeskgeek.com/linux-tips/view-your-google-calendar-events-in-the-ubuntu-unity-panel/

http://www.webupd8.org/2012/02/calendar-indicator-displays-google.html

sudo add-apt-repository ppa:atareao/atareao
sudo apt-get update
sudo apt-get install calendar-indicator


Installing Ubuntu 18.04 while planning to install another OS alongside in the future

The installation of Ubuntu 18.04 LTS does not need anywhere near 256 GB. The files created by a full Ubuntu install (before you add any more packages) is 5 GB, and the swap file (for swap partitions are passé) should be no more than your RAM size to start.

If you started with less (like, oh, say, 30 GB or 100 GB), you can always resize the default ext4 partitions of what you listed as your first option up or down if you need more space, with a LiveUSB, such as you will use to install Ubuntu.


Log in and enter "history | less".

Scroll up and down using the arrow keys. You should be able to find those earlier commands that caused the problem.

If you were also root, you can do the same there.

Mike G.


Ubuntu Server 18.04 - ExpressVPN at boot

Dont know if this is what your looking for, i just created a text file, right clicked -properties - permissions tab and selected allow executing file as a program, saved then pointed start up programs to the file.

#!/bin/bash
expressvpn connect smart

you can leave the smart off or replace with preferred server, worked for me


Maybe the network isn't ready yet, when rc.local is executed.

The following code will wait for the network before connecting:

(
until ping -nq -c3 W.X.Y.Z; do
   # Waiting for network
   sleep 5
done
ssh -R 32400:192.168.0.100:32400 root@marcin.com -N
)&

W.X.Y.Z is an IP address that is reachable and replies to pings. It maybe be the default gateway of your network, the Google DNS (8.8.8.8), etc.

Code between parenthesis runs in a new shell, and the & makes it run in background. It won't block the execution of rc.local.

The commands between until and done will be repeated until the ping is successful, i.e., it gets a reply (i.e., the network is up).


How do you add Debian experimental repo to Ubuntu, for those understanding the risks associated?

Sorry for this long answer, but the previous answers are all erroneous in one way or another, so I hope this attempt to be a bit of help to everyone.

Besides "experimental", Debian has several streams of packages that it calls "distribution". And every such distribution has its very own name. The current stable distribution was just released and is called "buster". Before that, now referred to as "oldstable" was "stretch", before that was oldoldstable "jessie". The 5/2013 released "wheezy" still sees another year of long-term support (https://wiki.debian.org/LTS). The one that is under current development is always called "testing", and it also always has a name that testing will be known to at the time it is released, this is "bullseye" now. There is also a distribution to which developers upload new packages, which is "unstable" and runs under the permanent name "sid". Packages uploaded to sid are auto-transferred to testing if there was no critical bug assigned to it during the first days (the uploader says how many days) of presence in unstable. For non-critical machines it is perfectly fine to run testing or unstable. The "unstable" refers to packages changing a lot, not to "software that crashes".

Experimental is kind of special in that

it only has the name "experimental", no assignment to a toy story
character
it has a dual use as an ever lasting repository for
packages that are not considered ready for the general public to use and
as a temporary store for packages while the release is finalised and new uploads are put on hold ("freeze").
packages are auto-removed from experimental when newer versions of a software appear on unstable

Debian developers typically expect users of testing or unstable to be the ones that install packages from experimental. Users of stable are likely to need updates to libraries. A recent version of Ubuntu should be fine with installing Debian packages from experimental directly, you would indeed just add

 deb http://httpredir.debian.org/debian/ experimental main contrib non-free

to your /etc/apt/sources.list but this is not what I tend to recommend. It depends a bit on the number of packages that are dragged in by the update and the dependencies on specific versions of libraries. If it is too many that apt-get suggests to install, then stop the installation if you fear a negative effect on your other binaries.

Instead, I suggest that you compile the software yourself. You may add

 deb-src http://httpredir.debian.org/debian/ experimental main contrib non-free

to sources.list (instead or in addition to the prior mentioned line describing a source for binary packages) and after apt-get update do

 apt-get build-dep wantedpackagename # installs build dependencies
 apt-get source --compile wantedpackagename # fetches source and builds

If the right version is downloaded you see at the time of the download. For binaries, have not tried with apt-get source, to retrieve from the experimental section you may also from Ubuntu need to specify "-t experimental" as additional flags to apt-get install. With apt-cache show wantedpackagename you see all versions of the package available to the system.

When building from source, there is absolutely no risk at all to damange your system since you leave all libraries at the version that your regular distribution already offers. There should hence be no side-effects. If the build fails, then it may already fail because the build dependencies could not be matched upfront. With build dependencies matched, a failed build you may decide to report to the package maintainer to improve his build instructions and possibly continue working on the package together. It is common for a package maintainer to be very happy about constructive feedback, so do not be shy.


"error: the plugin does not support import capability" when attempting to import openvpn config file

My setup

I also had the same issue, trying to import on an Ubuntu 16.04 client a .ovpn file produced by a home pritunl server.

The .ovpn file contained comment lines (#) as well as inline certificates (<ca>, <tls-auth>, <cert>, <key>). And there was no apparent reason to remove comments or keys. This same .ovpn had already been successfully imported into the Kubuntu 16.04 network manager, with only a warning about reneg-sec being too high; A clue to import issues on Ubuntu 16.04.

Solving the OP's errors

The reneg-sec value is too high and encounters known import bug:

reneg-sec 2592000

Comment it out or use default value 3600.

#reneg-sec 2592000

This value can be re-set from Advanced settings in VPN config tab under:

The config had two remote definitions:

remote hostname.org 14195 udp6
remote hostname.org 14195 udp
remote-random

Try with only one:

#remote hostname.org 14195 udp6
remote hostname.org 14195 udp
#remote-random

After these two modifications, there were no import errors.

Further issue with remote configuration

Although there was no import error any more, the remote was not imported properly, i.e. the port and protocol were not properly parsed, so I had to further break the remote directive down in the .ovpn file as follows

    remote hostname.org
    port 14195
    proto udp

Summary

My .ovpn file contained comments as well as inline certificates, etc.. After reading some other posts, I thought the problem lied in the inline files or the comments, so I split the inline certificates and keys into separate files and removed all comments.

So in the end, after applying the above fixes, the .ovpn file with the inline keys and comments was imported.


ubuntu 16.04 no boot device found using external usb hard drive

OK no replies or assistance here so I tried to re-install from a Clonezilla image. Clonezilla told me system was set to boot in EFI mode but no EFI partitions, my hard drive is ext4.  I checked the BIOS and for some reason factory defaults had been reset I enabled the option to boot in Legacy mode and ensured first boot option was usb hard drive - all works well now. I answer my own question in the hope it may help others.


How I can set program autostart to my second desktop?

You Want to look into a program called devilspie. Ubuntu-Link

It is in the repos so a simple sudo apt-get install devilspie will do it.


Yes, from this google search I found this OMG Ubuntu page, and that has Amiga OS theme to download.


Download the file definitions from the ClamAV site:
wget http://db.local.clamav.net/main.cvd
wget http://db.local.clamav.net/daily.cvd

The two files are required
Copy these files into the ClamAV directory:
cd ~/Downloads
sudo mv daily.cvd main.cvd /var/lib/clamav

This will overwrite the old definition files


How to access pyspark in anaconda installed in another user?

Make sure user2 has SPARK_HOME environment variable configured if not, set it. If you have set SPARK_HOME for all users should, accessing SPARK_HOME should not be issue for user2.
Once SPARK_HOME is variable is configured, add following script in the first cell of the Jupyter notebook and after this cell is executed you should be able to use sparkContext(sc).

# Configure the necessary Spark environment
import os
import sys

spark_home = os.environ.get('SPARK_HOME', None)
sys.path.insert(0, spark_home + "/python")

# Add the py4j to the path.
# You may need to change the version number to match your install
sys.path.insert(0, os.path.join(spark_home, 'python/lib/py4j-0.8.2.1-src.zip'))

# Initialize PySpark to predefine the SparkContext variable 'sc'
execfile(os.path.join(spark_home, 'python/pyspark/shell.py'))


Intel wifi AX200 does not work on ubuntu 16.04

If you do decide on 5.1 kernel, I would skip to 5.3 kernel instead. Latest is version 5.3.6 released October 11, 2019:

How to update kernel to the latest mainline version without any Distro-upgrade?

Updating the kernel is less risky than updating the entire desktop and all your applications. After installing a new kernel you can still boot your previous kernel in grub. OTOH, after installing a new desktop your old desktop is gone and the only way of going back is to restore backups or reinstall.


After upgrade to 11.10, display for main account is messed up

What desktop theme was set on your original user account in 11.04?

I suspect some leftover theme files are effecting your desktop display in 11.10 from your original user account.

Try and change the theme to Ambiance or Radiance in your original desktop and let me know what happens.

11.10 does not support installed theme files as yet other than those provided with the installation. You can however change icon sets using dconf editor.


Please only ask one question at a time. A helpful person might know one answer, but hesitate to reply due to not knowing the other.  I wanted this to be item 0, to match the question
Read man man, which says, in part:

A manual page consists of several sections.

Conventional  section names include NAME, SYNOPSIS, CONFIGURATION, DESCRIPTION, OPTIONS, EXIT STATUS, RETURN VALUE, ERRORS, ENVIRONMENT, FILES, VERSIONS, CONFORMING TO, NOTES, BUGS, EXAMPLE, AUTHORS, and SEE ALSO.

The following conventions apply to the SYNOPSIS section and can be used as a guide in other sections.

bold text          type exactly as shown.
italic text        replace with appropriate argument.
[-abc]             any or all arguments within [ ] are optional.
-a|-b              options delimited by | cannot be used together.
argument ...       argument is repeatable.
[expression] ...   entire expression within [ ] is repeatable.

Exact rendering may vary depending on the output device.  For instance, man will usually not be able to render italics when running in a terminal, and will  typically  use  underlined  or coloured text instead.

To see if your system thinks that it has working network interfaces: ifconfig -a, check for UP, inet addr: and inet6 addr: reasonable values; to see a few more values, sudo ifconfig -a

To see if your system knows where to send packets, ip route and ensure that the default via route exists and mentions the IP address of the "right" interface from ifconfig -a;

To see all of the systems on the same Ethernet link as your system: arp -an. You should see at least the IP address of the default route, and may see other IPs.;

For other networking information (stats, counts, etc), see man 5 proc (the /proc/net part, and man netstat.


You can use the PhotoRec application from the testdisk package to do this. It's in Ubuntu archives, so it's easy to install. It'll most likely be able to recover everything for you. However, data recovery is serious business, so please do read the documentation and take your time before you begin. PhotoRec won't cause any damage, but testdisk (another application in the package) can. If possible, you'll probably want to create a backup of your "C:" partition before you begin. It will require that you have some storage with at least as much free space as the size of C: though.


When my ibus crashes I open a shell and input:

ibus-daemon -rd

which replaces the current ibus and run the new one in background.


1 - Back Up Your Data.
2 - Make a space. 'by delete a partition or something you can do that from the Ubuntu installation '
3 - Boot from live CD/DVD/USB. 'if it doesn't boot auto make it boot from the cd 1st'
4 - Proceed with installation until you gets in Installation Type.
5 - chose something elese then make a partition as click on the freespace'under the windows parts''
a type : Primary.
b size : your size - 1000 MB .'you need 1000 Mb for the swap partition 1k Mb is just an example'
c use as :ext4.
d mount point chose : / . click ok
now click again on the free space '1000 MB you should know how much you need for swap part from this link https://askubuntu.com/a/49130/299605'
a type : logical
b use as : swap area  click ok click install now


How to edit /etc/fstab if it in ro mode?

ubuntu@ubuntu:~$ sudo mount -o remount,rw /dev/sda1 /
ubuntu@ubuntu:~$ cd /media/ubuntu/
ubuntu@ubuntu:/media/ubuntu$ ls
5aab4fef-bdbd-4f6f-bf59-7c164354a8fa
ubuntu@ubuntu:/media/ubuntu$ cd 5aab4fef-bdbd-4f6f-bf59-7c164354a8fa/
ubuntu@ubuntu:/media/ubuntu/5aab4fef-bdbd-4f6f-bf59-7c164354a8fa$ ls
bin    etc             lib         mnt   run   swapfile  var
boot   home            lib64       opt   sbin  sys       vmlinuz
cdrom  initrd.img      lost+found  proc  snap  tmp       vmlinuz.old
dev    initrd.img.old  media       root  srv   usr
ubuntu@ubuntu:/media/ubuntu/5aab4fef-bdbd-4f6f-bf59-7c164354a8fa$ cd etc/
ubuntu@ubuntu:/media/ubuntu/5aab4fef-bdbd-4f6f-bf59-7c164354a8fa/etc$ sudo nano fstab

It's solution!


How to completely remove Night Light 18.04 in Gnome 3.28.4

Settings → Devices → Screen Display → Night Light → click and set the slider as required in the second window to turn it off (or set the conditions).
As guiverc says in his comment under the OP it is easier (and safer) just to disable it as upgrades increase the chance of it re-appearing and release-upgrades causing future problems with your system. So, in short, whilst it might be possible to remove it altogether it would be best just to disable it and maintain system integrity.


Read here: How to install Ubuntu to know how to install Ubuntu. If you downloaded an ISO file, you could burn it into a DVD disk, or a USB drive. I recommend the second one because is faster, and easy to setup. On windows you can use rufus or unetbooting to burn the ISO file into your USB drive. Then enable the USB boot option in your BIOS to be able to boot into the live Ubuntu system. However, please check the link provided in the comment to obtain more information.


Ubuntu (GNOME) default video player name

This isn’t obvious, but the GNOME Videos applications is also known as Totem, and the corresponding package is totem:

ubuntu-bug totem

To find this out, the most reliable way, based on an application’s name in the launcher, is to find the corresponding launcher configuration file. Open a terminal, and run

grep -r Videos /usr/share/applications

This will list /usr/share/applications/org.gnome.Totem.desktop; to find out which package supplies this file, run

dpkg -S /usr/share/applications/org.gnome.Totem.desktop


I think it's similar to my problem.

I can't login in Unity 3D and GNOME 3 if my local network is turned on but cable isn't connected. Try to turn off the network in network-manager and then restart your laptop, login in Unity 3D. I hope it works for you.


External sound card UR22 Steinberg works in one installation but doesn't in other

I have found that there wasn't installed snd_usb_audio kernel module.

sudo apt install linux-modules-extra-4.15.0-43-generic

decided the problem


battery backup issues on acer timeline 3830tg

I am also using acer aspire 5742 laptop.

I made changes in GRUB_CMDLINE_LINUX_DEFAULT and GRUB_CMDLINE_LINUX to /etc/default/grub
- GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=force"
- GRUB_CMDLINE_LINUX="acpi_osi=Linux"
and after adding these lines update grub from terminal by executing

sudo update-grub

By default the above lines will be different please check it and modify it.

If you are using sandbridge processor then after making change refer

Laptop minimal power consumption tweaks

And then check hows the performance and the operation of fn key


How can I encrypt all my internal drives on install and mount them at start?

I suggest VeraCrypt.  VeraCrypt is a port of TrueCrypt but is still maintained.  It uses substantially stronger encryption than TrueCrypt ever did.  You can download VeraCrypt here.

For your stated purpose, you're going to want the command-line version, so install that.  Then you'll want to encrypt with a long and impossible-to-remember randomized passphrase.  Let's say that's "Olei1ahFNooyae1Goot."  Now write a startup script that invokes

  veracrypt --password=Olei1ahFNooyae1Goot /dev/sdx /mnt/point1

replacing /dev/sdx with the actual device names and of course /mnt/point1 with your desired mount points.

Of course the passphrase you pick (Olei1ahFNooyae1Goot) will only exist on the encrypted system volume, so it cannot be exposed.

That's how I'd do this, anyway.


Ubuntu 13.04. fail to start after installing nvidia drivers (Vostro laptop)

I have a dell Latitude E6500, and got the same problems
the only solution I found was the following :

Switch to console mode: Alt+Ctrl+F1
Kill x server: sudo service lightdm stop
Remove nvidia drivers: sudo apt-get remove --purge nvidia*
Generate new xorg.conf file: sudo X -configure -- this will create
xorg.conf. A new file in your current dir
Rename and move: sudo mv xorg.conf.new /etc/X11/xorg.conf
Return to GUI: sudo start lightdm

Of course  I would prefer a better solution


Why am I might be able to login with ssh to another server without password?

Turned out that I was able to login because authorized_keys file was not empty.
It looked empty because first I run

nano authorized_keys

I mean without sudo command.


Trying to update, but it's forcing me to install 15.04 alpha

It looks like I had some 14.10 and 15.04 repos in my repo list. I removed them and the update process is working properly now. Thanks!


Clearing Firefox History via Command Line

This short command cleans Firefox backups, cache, cookies, crash reports, DOM storage, download history, form history, passwords, session restore, site preferences, and URL history (as of BleachBit 1.8):

bleachbit --clean firefox.*

(See also BleachBit documentation: command-line)


dhclient does not send DHCPv6 Solicit message on disconnect/connect, keeps old lease

my solution for it is to remove the lease file which you can see in ps command. The solicit will be send after dhcpc is restarted.


add-apt-repository returns "Error: need a repository as argument" when adding a repo

Assuming that you copy-pasted the command from your terminal, you're using the wrong quotes. Your code has asymmetric codes intended for typography: “opening and closing”. You need to use the symmetric double quote character from the ASCII character set, the one that you insert by typing Shift+' on a US keyboard.

sudo add-apt-repository "deb http://archive.canonical.com/ $(lsb_release -sc) partner"

If you copy-pasted the command from a tutorial, you're entitled to complain about the typesetting of that tutorial: it should ensure that characters in code snippets are not modified.


Yes, it's quite possible.  Boot from a live USB and do a Something Else install.  Mark the partitions you already have used for Lubuntu to be used for Ubuntu : if you did a default install, you probably just have a system partition and a swap partition.  Mark the system partition to be used, mounted at /, and formatted.


Should I increase my partition size when the volume “Filesystem Root” has only few disk space remaining?

Yes, you should definitely increase the size of root from 39GB. Suggest you

A) Make two backups of each partition with data

B) Do

sudo apt-get autoclean && sudo apt-get autoremove && sudo apt-get clean

C) Use gparted after booting from a Live USB and adjust partition sizes to increase the space available to root.


File Dialog box does not see symbolic links

I am pretty sure permissions is the problem now. Clearly I did not know anything about snaps, and after a couple of hours of reading about them I am not even sure I like the idea of them. But I learned some kindergarten manipulation of the snap interfaces/plugs/slots and realized I was not going to have any success. (at least, that is what I gather). It doesn't look like the one permission that I desire, can be allowed without basically opening all of the permissions.

Then I found this:

Snap application doesn't see files from another partition

It provided an explanation I could understand.

I will just use freeplane instead.

Thanks for the direction @mook765.


From the comments...

When booting from -45 kernel, symptoms are "weird resolution (smaller screen), no internet connection, almost no options in settings menu, and hibernation problems".

Booting to the prior -44 kernel and all of these symptoms were cured. For the short term, continue to boot to this kernel to maintain full system operation. (note: -44 kernel may have an issue with console ttys).

Monitor Software Updater for -46 or newer kernel updates, then boot to them and see if symptoms are also gone.


Missing libSM.so.6 library - QT creator installation error

libSM.so.6 (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libSM.so.6

The program requires 32-bit libraries. You need libsm6:i386

sudo apt-get install libsm6:i386

And now, ldconfig -p | grep libSM.so.6 should look like this:

libSM.so.6 (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libSM.so.6
libSM.so.6 (libc6) => /usr/lib/i386-linux-gnu/libSM.so.6

And for all other missing libraries use the same strategy:

e.g. libXrender.so.1

$ apt-file search libXrender.so.1
libxrender1: /usr/lib/x86_64-linux-gnu/libXrender.so.1
libxrender1: /usr/lib/x86_64-linux-gnu/libXrender.so.1.3.0
libxrender1-dbg: /usr/lib/debug/usr/lib/x86_64-linux-gnu/libXrender.so.1.3.0

$ sudo apt-get install libxrender1:i386


No, there is no automated way to do this. There are mdadm monitors out there which parse the various events to enable you to create a custom application to manage the array according to your wishes. There are plenty of NAS appliances that use MD and developed a closed source daemon to manage md, to my knowledge, no open source equivalents exist.


how to change the keyboard layout for all programs from the command line?

This is a variant on the US layout keyboard, so the following succeeds:

$ setxkbmap -model pc105 -layout us -variant intl
$ echo $?
0

In fact, the -model pc105 part wasn't even necessary in my case.


A really long boot time in Ubuntu 16.04 LTS because of "cfg80211: World regulatory domain updated"! Need a fix!

I was seeing this issue and it turned out that it seemed to be down to an old modprobe config file (in /etc/modprobe.d) I had installed a few years ago. Specifically it specified an option for the cfg80211 (WiFi stack module) options cfg80211 ieee80211_regdom="EU"

I commented/removed the option then rebooted and it was fixed. So check to see if any of your modprobe.d files contain config options for cfg80211.

Also I noticed that the REGDOMAIN was not set in /etc/default/crda so I set that. For more details see Linux Wireless Regulatory info.


How do I package a Python script for Ubuntu?

The Ubuntu developer portal has a very complete Packaging Guide.

There is also a tool, Quickly, designed to help new developers hack and package their applications easily and... quickly. This tool will also help you creating the setup.py script.

Finally, take a look at how to get started at Ubuntu application development.


How can I disable update checking on boot?

For any future duckduckgo-ers (yeah, I'm calling it that, sue me), here's a solution:

Enter this in the terminal. It will allow displaying of 'hidden' startup services.

  sudo sed -i 's/NoDisplay=true/NoDisplay=false/g' /etc/xdg/autostart/*.desktop

Afterwards, search 'startup applications' in the dash and launch it. It will show a host of options previously hidden. Uncheck the update notifier.

To hide everything back again, run the following:

  sudo sed -i 's/NoDisplay=false/NoDisplay=true/g' /etc/xdg/autostart/*.desktop


If you modified your grub.cfg, you can boot from a live usb, chroot into your installation and run update-grub to reset it


How to restart python script after one second of going down using UPSTART?

I don't really understand why you are using the root directory for this "test", and I don't really think that's what you want to do (you can end up breaking your system badly). Also, notice that if you are root (the # prompt) you don't need to "sudo".
Please consider editing the question to reflect what you are trying to achieve.

I will repeat, for the sake of completeness:

  Consider putting the conf file in ~/.config/upstart/ so that you don't need to sudo: you would use initctl start testing to start the script for example. (I am assuming that your conf file doesn't need root privileges.)

On reading the cookbook, it says that the pre-start, post-start, and post-stop stanzas are rerun on a respawned job. This means you can do something like this:

start on runlevel [2345]
stop on runlevel [016]

chdir /path/to/a/folder
respawn

exec python testing.py

post-stop script
  sleep 1
end script

This way there will be a 1 second delay before the script is respawned. (You can do the same with the pre-start stanza, this way the first invocation would have a 1 second delay, though.)


D-Link DWA172 (ID 2001:3318) not working

Please try:
git clone https://github.com/aircrack-ng/rtl8812au.git
cd rtl8812au
sudo ./dkms-install.sh
sudo modprobe 88XXau

Reboot. Your wireless should now be working.


How do I install an Asus USB-N53 WiFi adapter?

The driver won't install automatically as of right now, but it's not too bad to get it to work. You'll have to compile the drivers from Ralink, so make sure you have build-essential, linux-headers, and all that good stuff.

Download RT3572USB from http://www.ralinktech.com/en/04_support/license.php?sn=5017
Change to the directory you downloaded to and run

tar -C . -xf 2011_0427_RT3572_Linux_STA_v2.5.0.0.DPO.bz2

Change to the new directory (2011_0427_RT3572_Linux_STA_v2.5.0.0.DPO).
Change HAS_WPA_SUPPLICANT and HAS_NATIVE_WPA_SUPPLICANT_SUPPORT to 'y' in the config.mk file:

sed -ir -e 's/^HAS_WPA_SUPPLICANT=n/HAS_WPA_SUPPLICANT=y/' -e 's/^HAS_NATIVE_WPA_SUPPLICANT_SUPPORT=n/HAS_NATIVE_WPA_SUPPLICANT_SUPPORT=y/' ./os/linux/config.mk

Add you Vendor and Product ID to the RT2870 supported list:

sed -ir -e 's!^#endif /* RT2870 */!        {USB_DEVICE(0x0B05,0x179D)}, /* Asus USB-N53 */\n#endif /* RT2870 */!' ./common/rtusb_dev_id.c

Update some function names:

sed -ir -e 's/\tusb_buffer_alloc/\tusb_alloc_coherent/' -e 's/\tusb_buffer_free/\tusb_free_coherent/' include/os/rt_linux.h

Install the module:

make && sudo make install

Create a modprobe.d config file to make sure the modules load:

sudo su -c "echo -e 'alias ra0 rt3572sta\nblacklist rt2800usb' > /etc/modprobe.d/rt3572sta.conf"

Now load the module and it should work (did for me):

sudo modprobe ra0

Almost forgot, shamelessly stole (then modified) this info from http://forums.fedoraforum.org/showthread.php?p=1353558


Determining if I have wifi (Ubuntu 14.04)

Not necessarily. Check the output of the following command to view hardware info:

lspci -v


Ubuntu 16.04 LUKS passcode does not appear

I found a similar problem for older versions of ubuntu. https://bugs.launchpad.net/ubuntu/+source/cryptsetup/+bug/1375435

The solution being used there also worked for me at Ubuntu 16.04.

Add this to /etc/default/grub : GRUB_GFXPAYLOAD_LINUX=wxh
and update the configuration with update-grub .


How do I access the exploding task switcher in Plasma?

I think you are looking for "Present Windows"

Ctrl+F10    Present Windows
Ctrl+F9 Present Windows on current desktop

One of these should produce the desired result.

Source:

https://docs.kde.org/trunk5/en/applications/fundamentals/kbd.html


How to update gtk-3.4 themes to the new gtk-3.6

For this (with custom WARNINGs !) you need add Gnome Testing PPA and update your system:

sudo add-apt-repository ppa:ricotz/testing
sudo apt-get update
sudo apt-get upgrade


Lubuntu 14.04 on Dell Latitude D600 WiFi

Looks like I got it working by purging linux-firmware-nonfree for some reason.


Chromium + Firefox - flash doesn't function w/Pepper.

I decided to try an install 14.04 again.
I tried upgrade, then fresh install via crouton.
Read a few snippets, found that 14.04 was not recommended for my chromebook.

Wiped and fresh install of 12.04  with chromium...sound works.
Even after adding JRE & Eclipse. (which may have been the problem with prior versions)

Thanks for the pointers for this n00b. Much appreciated.


Packages in the official archives have debug packages build for them automatically. They are stored in a different archive though. They will have the names foo-dbgsym  You can access them by putting the following in your /etc/apt/sources.list:

deb http://ddebs.ubuntu.com natty main restricted universe multiverse
deb http://ddebs.ubuntu.com natty-updates main restricted universe multiverse
deb http://ddebs.ubuntu.com natty-security main restricted universe multiverse
deb http://ddebs.ubuntu.com natty-proposed main restricted universe multiverse

(Replace natty with the release you are running.)

Information on how these are generated can be found here:

https://wiki.ubuntu.com/AptElfDebugSymbols

If you'd like to provide debug packages for a package which you maintain outside of the official archives, that is possible as well. This Debian wiki article is the best place to start.

Briefly, you must first create the new package in debian/control by adding:

Package: foo-dbg
Architecture: any
Section: debug
Priority: extra
Depends:
    foo (= ${binary:Version}),
    ${misc:Depends}
Description: debugging symbols for foo
 foo is a library that lets you do stuff.
 .
 This package contains the debugging symbols for foo.

Then in debian/rules, use dh_strip to strip debugging symbols from binaries, but retain them for use in the debug packages.

override_dh_strip:
        dh_strip --dbg-package=foo-dbg


upgraded from 16.04 to Ubuntu 18.04 but kernel didn't change how to fix

I ran the command below to unhold the kernel but it didn't work.

sudo apt-mark unhold linux-generic linux-headers-generic linux-image-generic

But when I ran the command below it download and upgraded my kernel.

sudo apt-get dist-upgrade
sudo apt install linux-image-generic

And to check it I used

uname -sr

Linux 4.15.0-20-generic

Success.

On a side note everything was really slow I also had some old KDE files that were causing problems and had to run

balooctl disable

For more information about it here's a link

permanently disable the baloo file indexer


What is the minimum requirement to compile Kernel modules

You need build-essential and kernel headers.

sudo apt-get install linux-headers-$(uname -r) build-essential


why do people use virtual machine to use ubuntu?

It depends on what you want to do. Your teacher needs a Virtual device for teaching purposes s it makes no sense to have to install Ubuntu just to teach and that's another great use for Virtual devices.

So it depends on what your intentions are, you either install it alone or alongside Windows or use a Virtual device or machine to run it and learn stuff that would be dangerous or risky as a learner to do on your own computer. I for one usually use it to learn and make all sorts of mistakes and because its a virtual device I will simple remake another and retry my learning aims till I have perfected. For dual booting see this link for more help.


I don't fully follow your quest but I have this little script that can return the filename without that long part but retains the " quotes and I suspect that some of those files have spaces in their names so they might have to stay.

for i in /path/to/files/*; do mv "$(realpath $i)" "$(realpath "${i%%\?*}"); done

Result:

"file_name".jpeg

Note: I couldn't create a sample with that name so I used a varaible in a script.


Are gcc versions tied to kernel versions?

You might have trouble compiling new kernels with very old versions of GCC.

Besides that, no, GCC versions are not tied to the Linux kernel's version:

You can run an ancient GCC version on a system with a new kernel.
You can run a new GCC version on a system with a very old kernel. The only thing that would stop you from doing this would be if your new GCC version requires a version of libc that will not run on that kernel. But this is not a particularly likely scenario.

With that said, you should be careful about installing an older GCC over a newer GCC, since the newer GCC may be needed. If you're building GCC yourself from source, you can configure the build to install in its own prefix (rather than /usr). If this still breaks builds, make sure the newer GCC (which was there before) is in a directory earlier in the PATH environment variable than the older GCC (which you more recently installed).


I guess I would like to also know which driver I should be running anyway.

The one that works best for you... And that includes license concerns.

If you do not game on Ubuntu the generic one is more than enough to have a working system and there is not really a need for the 3rd party version.
If you do not want to have drivers open source community has no control over don't use the 3rd party driver.

  I am unable to have auto login work.

As stated during install: using encryption will disable auto login.

  However, under software & updates> additional drivers. I have the option of choosing either "X.Org X Server" driver or NVIDIA binary" driver. When I choose the 'X.Org X" option there is no issue but there is an issue with the NVIDIA driver.

That could be a bug. Problem: the nvidia driver the community has no control over so there probably is no fix if it is a bug.

install the 3rd party driver. Set auto login to on. Close the user window and check if the setting sticks before you reboot.
Check .xsession-errors in /home/$USER/ for error notices about auto login.
Check /var/log/  with ls -ltr and see if the log that was last changed has a notice about auto login.

If there is anything edit your question to add the information.


The size of the file set as a limit in limits.conf

The ulimit value appears to be in kibibytes (2001 x 1024 = 2049024 bytes) whereas bs=1KB is kilobytes (2049 x 1000 = 2049000 bytes). The dd suffix for kibibytes is just K (or k) not KB.
So
:~$ ulimit -f
2001

:~$ dd if=/dev/zero of=file1 bs=1k count=2001
2001+0 records in
2001+0 records out
2049024 bytes (2.0 MB, 2.0 MiB) copied, 0.0210431 s, 97.4 MB/s

:~$ dd if=/dev/zero of=file2 bs=1k count=2002
File size limit exceeded (core dumped)

:~$ ls -l file1 file2
-rw-rw-r-- 1 username username 2049024 Dec  4 13:15 file1
-rw-r--r-- 1 username username 2049024 Dec  4 13:15 file2


You can define a file called  70-synaptics.conf in /etc/X11/xorg.conf.d and put the following content in it:

Section "InputClass"
    Identifier "touchpad"
    Driver "synaptics"
    MatchIsTouchpad "on"
        # Enable clickpad/multitouch support
        Option "ClickPad" "true"
        # Middle-button emulation is not supported
        Option "EmulateMidButtonTime" "0"
        # Define right soft button at the bottom
        Option "SoftButtonAreas"  "50% 0 82% 0 0 0 0 0"
EndSection

Hope this helps.


I managed to fix this by editing /etc/default/grub.
Remove the nomodeset option from GRUB_CMDLINE_LINUX_DEFAULT and then sudo grub-update.
After reboot your second monitor should work.


How to change the color of a cell or row of a table in libre impress

There are some serious usability issues with this aspect of Impress tables indeed. It is not quite obvious how a row can be selected using the mouse or the keyboard.
Marvelously hidden in the Table Toolbar, you can reveal buttons to select a row or a column. Right click on an empty space on the toolbar, and in the menu, enable these buttons one by one from the "Visible buttons" menu.
I am not aware of other options to select individual rows or cells. If they are there, they are equally undiscovered as the option I have shown.


Simply move your mouse to the top of your screen and the menu of your window appears.
In fact your window border is merged with the screen border and top menu bar.


Keyboard shortcuts work ONLY in qwerty layout

I just encountered this exact problem, and I was able to resolve it by disabling (using Backspace) and then entering the keybinding again in

  System Settings -> Keyboard -> Shortcuts.

It appears to be tied to the keyboard layout I have enabled when I set the keybinding, and I have to go through this process every time I change keyboard configurations. Obviously, this becomes tedious if I switch keyboard configurations often. I have not found a workaround for automating this yet.


"a Plugin is Required" but I have already installed it from Software Center

You must restart Firefox to load installed plugins. The same for Chrome/ium. Plugins are loaded at startup time.


Curl -K - works fine, but with -Z it outputs some zero length files

There's a bug that is fixed in version curl 7.70.0 which causes this problem. The current version shipped with Ubuntu 20.04.2 LTS is 7.68.0, so it needs to be updated either by building it yourself, or waiting for ubuntu to do so.


Windows 8 install turned my ext4 partition into unallocated space. How do I recover it?

Boot a live system, install testdisk, launch it, choose "Intel", choose "recover partition".


Linux can do this using the /etc/motd system, or any system that extends that (namely, update-motd).

Given this information, it's possible to add a simple shell script to /etc/update-motd.d/40-holiday:

#!/bin/bash
echo Happy holidays from your local sysadmin!

Upon marking this as runnable (sudo chmod a+x /etc/update-motd.d/40-holiday), the MOTD can be forcefully updated using the command update-motd (as root).

Any subsequent logins will use the new (expanded) MOTD, finally bringing some holiday cheer to anybody who has to log on to a server on Christmas day.

Note that this method depends on the update-motd package, which should be pre-installed. But if it's not, sudo apt install update-motd.


Will my 3g usb modem support any linux distro?

Get a USB stick, put Ubuntu (or another Live OS) on it, and boot into trial mode. Then, connect your 3g modem to see if it works. You don't have to blow away your current installation to find out if it's supported out of the box when there is a live OS available.


I assume that you want to be able to access the Internet from machines on 192.168.1.0/24 and you want 192.168.1.21 to serve as a gateway for those machines which I also assume are connected to a switch which has an uplink to your gateway's eth1 interface.

I don't see you mention a couple of things:
1. NAT functionality being configured
2. IP forwarding enabled
3. Other appropriate firewall rules added
4. DHCP server running on eth1 assigning IP configuration to your internal machines.

If you confirm my assumptions and let me know what the state of those 4 components is, I'll update my answer and help you set it up.

PS. Let's say that you have a machine with the IP address 192.168.1.50 connected directly to your server's eth1. Are you able to ping 192.168.1.21 from it?


No.

However Matthew Garrett recently wrote about problems getting some machines to reboot cleanly.  It's possible that your machine might be one of them, and that a newer kernel might fix the problem.  I don't know how likely that is, and even if it is, I don't know if you can expect a backport of the fix in Natty, or if you'll have to wait until 11.10 is released.

Sorry!


Go into your phone's settings and make sure the "Connect to PC" is set to "Disk Drive."


Create a keyboard shortcut to move windows to a specific screen edge

Check out the Grid Plugin in CCSM - you can change the different shortcuts which are usually on the keypad!


How to update Sublime Text 3 icon in Ubuntu?

I had the same issue. It was caused by a local (custom) desktop icon config. I must have had a need for this in the past.

It was stored in ~/.local/share/applications/sublime_text.desktop (filename might be different for you). Renaming it to sublime_text.old-desktop made the new icon appear.


Here are the contents of the accepted answer for the same question on SO:

You should be able to deal with the root window (which the wallpaper is, in fact) by studying the source of xsetroot.c, the most interesting part of which I copypaste here:

static void
SetBackgroundToBitmap(Pixmap bitmap, unsigned int width, unsigned int height)
{
    Pixmap pix;
    GC gc;
    XGCValues gc_init;

    gc_init.foreground = NameToPixel(fore_color, BlackPixel(dpy, screen));
    gc_init.background = NameToPixel(back_color, WhitePixel(dpy, screen));
    if (reverse) {
        unsigned long temp=gc_init.foreground;
        gc_init.foreground=gc_init.background;
        gc_init.background=temp;
    }
    gc = XCreateGC(dpy, root, GCForeground|GCBackground, &gc_init);
    pix = XCreatePixmap(dpy, root, width, height,
                        (unsigned int)DefaultDepth(dpy, screen));
    XCopyPlane(dpy, bitmap, pix, gc, 0, 0, width, height, 0, 0, (unsigned long)1);
    XSetWindowBackgroundPixmap(dpy, root, pix);
    XFreeGC(dpy, gc);
    XFreePixmap(dpy, bitmap);
    if (save_colors)
        save_pixmap = pix;
    else
        XFreePixmap(dpy, pix);
    XClearWindow(dpy, root);
    unsave_past = 1;
}