Are PPAs safe to add to my system and what are some "red flags" to watch out for?

PPA (Personal Package Archive) are used to include a specific software to your Ubuntu, Kubuntu or any other PPA compatible distro. The "safeness" of a PPA depends mostly on 3 things:

Who made the PPA - An official PPA from WINE or LibreOffice like ppa:libreoffice/ppa and a PPA that I created myself are not the same. You do not know me as a PPA maintainer, so the trust issue and safety is VERY low for me (Since I could have made a corrupted package, incompatible package or anything else bad), but for LibreOffice and the PPA they offer in their website, THAT gives a certain safety net to it. So depending on who made the PPA, how long he or she has been making and maintaining the PPA will influence a little bit on how safe the PPA is for you. PPA's as mentioned above in the comments are not certified by Canonical.
How many users have used the PPA - For example, I have a PPA from http://winehq.org in my personal PPA. Would you trust ME with 10 users that confirm using my PPA having 6 of them saying it sucks than to the one Scott Ritchie offers as ppa:ubuntu-wine/ppa in the official winehq website. It has thousands of users (including me) that use his PPA and trust his work. This is work that has several years behind it.
How updated the PPA is - Let us say you are using Ubuntu 10.04 or 10.10, and you want to use THAT special PPA. You find out that the last update to that PPA was 20 years ago.. O.o. The chances you have on using THAT PPA are null. Why?. Because the package dependencies that PPA needs are very old and maybe the updated ones change so much code that they wont work with the PPA and possibly break your system if you install any of the packages of that PPA to your system.

How updated a PPA influences the decision to use it if he/she wants to use THAT PPA. If not they would rather go look for another one more up to date. You do not want Banshee 0.1 or Wine 0.0.0.1 or OpenOffice 0.1 Beta Alpha Omega Thundercat Edition with the latest Ubuntu. What you want is a PPA that is updated to your current Ubuntu. Remember that a PPA mentions for what Ubuntu version is made for or multiple Ubuntu versions was made for.

As an example of this here is an image of the versions that are supported in the Wine PPA:

Here you can see that this PPA is supported since Dinosaurs.

One BAD thing about how updated a PPA is, if the PPA maintainer tends to push into the PPA the latest, greatest and cutting edge version of a specific package. The down side of this is that if you are going to test the latest of something, you ARE going to find some bugs. Try to stick with PPAs that are updated to a stable version and not a unstable, testing or dev version since it might/will contain bugs. The idea of having the latest is also to TEST and say what problems were found and solve them. An example of this are the daily Xorg PPAs and Daily Mozilla PPAs. You will get about 3 daily updates for X.org or Firefox if you get the dailies. This is because of the work the put in there and if you are using their daily PPAs it means you want to help with bug hunting or development and NOT for a production environment.

Basically stick with this 3 and you will be safe. Always look for the maker/maintainer of the PPA. Always see if many users have used it and always see how updated the PPA is. Places like OMGUbuntu, Phoronix, Slashdot, The H, WebUp8 and even here in AskUbuntu are good sources to find many users and articles talking about and recommending some PPAs that they have tested.

Stable PPA Examples - LibreOffice, OpenOffice, Banshee, Wine, Kubuntu, Ubuntu, Xubuntu, PlayDeb, GetDeb, VLC are good and safe PPAs from MY experience.

Semi Stable PPA - X-Swat PPA is a in the middle PPA between bleeding edge and stable.

Bleeding Edge PPA - Xorg-Edgers is a bleeding edge PPA although I should mention that after 12.04, this PPA has become more and more stable. I would still mark it as bleeding edge but it is stable enough for end users.

Selectable PPA - Handbrake offers here a way for the user to choose, do you want a stable version or do you want the bleeding edge (Also referred to as Snapshot) version. In this case you can select what you want to use.

Note that in the case of using for example the X-Swat ppa with the Xorg-Edgers PPA, you will get a mixed between the two (With priority towards Xorg-Edgers). This is because both are trying to include almost the same packages, so they will overwrite each other and only the most updated one will show in your repositories (Except if you manually tell it to grab the package from X-Swat).

Some PPAs might update some of your packages when you add them to your repository because they will overwrite with their own version a certain package to make the PPA software work on your system correctly. This might be some code packages, python versions, etc.. Other like the LibreOffice PPA will remove all existence of the OpenOffice from your system to install the LibreOffice packages there. Basically read what other users have commented about a specific package and also read if the package is compatible with your Ubuntu version.

As the comment below suggest by Jeremy Bicha, some bleeding edge (PPAs that stay very up to date including adding Alpha, Beta or RC quality software in the PPA) could potentially damage your whole system (In the worst case). Jeremy mentions an example of many.


How does the Software Center keep track of packages?

dpkg (Software-Center is a graphical front-end of dpkg) keeps track of the installed packages in /var/lib/dpkg/status.


BCM4312/Dell 1397 wlan minicard drivers for Ubuntu 12.10 live usb?

For Dell 1397 wireless card, just search for 'bcmwl-kernel-source' in the Software Center and install it.


What's the best way to reinstall Ubuntu on a partition already used for Ubuntu, but seemingly empty?

Would a new installation install into the current Ubuntu partition?

Ubuntu will be installed onto that partition which you tell it to install. It can be either that old partition (and it will be erased if you install there) or new. For further information, read How do I install Ubuntu?

  Should I proceed as if it's a normal installation?

If you want to install Ubuntu, there is one straightforward way. Just install it. But you  might want to repair your existing installation. For the insight, read How can I repair grub? (How to get Ubuntu back after installing Windows?)

  Would it be possible to run a normal installation and leave XP there as before, or should I upgrade XP to 7 first?

If you want to upgrade Windows, it is better to upgrade it before you deal with Ubuntu. But if you want to leave it as is, you can do it. Probably you'll like Ubuntu so much that you decide not to return to Windows anymore.


Why do not the brightness of the screen?

Open terminal:  sudo nano /etc/default/grub
Look for the line that says

 GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Change it to: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Press ctrl + o to save and ctrl + x to exit.
Then update GRUB by:

 sudo update-grub

Reboot your PC and check your function keys. Post back if it doesn't work.

Look here more help


By default, most installed packages will be available to all users.  Some adminstrative tools and utilities may be restricted to the root user, but generally, all applications, packages, libraries, and binaries will be available system-wide.

To install a package, use apt install packagename.


How to change keyboard sleep button to hibernate?

If you have administrator privileges on your machine, you could try prepending gksudo to the front of your command, like so:

gksudo -S hibernate --force

Then when you press the key, you will be presented with a password entry popup, and hibernation should occur if you enter it correctly.

If you want this command to look nicer and be more self-descriptive when run, you can alternatively use the following:

gksudo -S -m "Enter your administrator password to hibernate." hibernate --force

(You can change the message between the quotation marks with anything you like.)


The only solution I know of at this time is to run the wipefs command manually and then format it again in gnome-disk-utility

[root]# wipefs -a /dev/sdc1


How to install Gimp and next remove it from terminal!

You DO NOT at all need to compile a package from source if you already have a .deb package for it. Why go through the hassle when someone else has already done all the hardwork for you?

It's like your dinner is already there in a restaurant that provides cheap, hygienic, tasty food with the desired menu for their customers minus the hardwork that goes into making the food and then washing the dishes later but still you want to make your own dinner.

So, to install the latest gimp package in Ubuntu, do:

sudo add-apt-repository ppa:otto-kesselgulasch/gimp -y; sudo apt-get update; sudo apt-get install gimp

EDIT:- Launchpad website proof of the above mentioned ppa.

You can also validate the above website, by doing a quick google search - gimp ppa.


The new version of gnome-shell is not compatible with some extensions. In particular those trying to show systray, such as "TopIcons Plus" are not working well.

Disable extensions (one-by-one?) to see if this reduces CPU usage.

To do this, install the gnome-tweaks package.

Open tweaks, check the extensions tab on the left, and disable extensions on the right (shown below, POP_OS, but should be similar/identical in other flavors of Ubuntu):

An alternative to TopIcons Plus which seems to catch most of the systray devices is "KStatusNotifierItem/AppIndicator Support"


Is there anything like online Ubuntu O/S

Use Amazon ec2 ubuntu image. You pay per hour of usage time
Check http://cloud.ubuntu.com


YouTube videos on Khan Academy do not play

You could try to enable HTML5 support for YouTube to avoid flash altogether.

Point your browser to

  http://www.youtube.com/html5

and enable HTML5 there. Reload the page from the Khan Academy and see if it works.


If it's an X11 issue you could try,

deleting your /etc/X11/xorg.conf

you may try it first, please give feedback on this:
http://www.freesoftwaremagazine.com/articles/how_to_fix_your_computers_graphics_with_dpkg-reconfigure

In either case, backup the file "/etc/X11/xorg.conf" before, if there is one.

If you feel it's related only to gnome config. you could try deleting your gnome config.

GNOME2

Run the following in the terminal or Alt+F2:

rm -rf .gnome .gnome2 .gconf .gconfd .metacity

That will do is remove all the GNOME2 configuration settings. Log out, and log back in. You'll be back to a stock desktop.

You can backup before playing around with your settings in the future:

mkdir ./.old-gnome-config && mv ./.gnome* ./.old-gnome-config && mv .gconf* ./.old-gnome-config && mv ./.metacity ./.old-gnome-config

GNOME3

If your config isn't worth saving run the following:

rm -rf .gnome .gnome2 .gconf .gconfd .metacity .cache .dbus .dmrc .mission-control .thumbnails ~/.config/dconf/user ~.compiz*


You didn't move your home directory...

We refer to ~ as tilde expansion, most of the times it will be  replaced with the value of the $HOME shell variable, before the command get executed.
\ is the strongest type of quoting in the shell.

So using \~ you are skipping the tilde expansion by quoting it. Means that you are actually saying: move the "sublime.desktop" to a new file named exactly "~...".

I can't reproduce your command's result, but somehow you ended up with a file/directory exactly named ~.

Check to see if it's a file or directory and get a list of its contents:

test -d ~/Desktop/~ && ls -l ~/Desktop/~ || echo 'it is a file'

Then move them to the correct path, if it was a file to move it back you have to escape its name again, otherwise it will be expanded to /home/liso:

mv \~ new-name
mv "~" new-name # works
mv '~' new-name # also works
mv ~/Desktop/~  new-name # works fine too

And remember by rmdir ~ you are trying to remove the actual home directory: /home/liso not the ~.


Or you can install Gnome Shell:

Download it here!

2.If you have a USB or DVD then plug that in!

Do the installation.
After the installation, Install CompizConfig Settings Again!

After that, you're done!


There are some missing libraries, it seems. On Debian Stretch, I had to:

sudo apt-get install libssl1.0-dev


Help installing Ubuntu 14 LTS on Pcduino3

The ISO comes with the Linux Kernel and some software. The ISO you need depends on the architecture i.e. i386 or am64.

14.04 uses kernel 3.13 but 4.0 (and newer) have been released somewhat recently.

Ubuntu ISO's


Some scripts (languages) are missing in my Character Map

Switch the view from By Script to By Unicode Block via the menu entry View.

After that is an entry Mathematical Operators in the left pane:

Or Tamil

sudo apt-get install ttf-tamil-fonts


How do I backport my favorite package 2-3 times each year?

One of the purposes of a backport request being a bug report on Launchpad that is filed by a specific person, is that this person can (and usually will) indicate that they are able to test backported packages. Thus, by filing the request and testing backported packages as maintainers on the backports team create them, you contribute significantly to the backporting process.

Since you are, in effect, doing part of the work of backporting by requesting the backport, indicating you can test it, and testing it, it's actually generally easier on the backporters if you file the request each time, because then you are making yourself available to help each time.

However, next time you file a backport request, you may want to indicate in it that you believe the package to be in perpetual need of backporting, and that you are perpetually available to test backports. That way, if there is a more efficient way to deal with this, it will likely be devised by the people who are actually doing the work of backporting (including you).

There is a new script in ubuntu-dev-tools starting in 12.04 called requestbackport that will show you what needs to be tested for each backport.  It provides a list with "checkboxes" that people can check off as the items are tested.

Using the backports repositories as opposed to PPAs for new releases of packages where possible allows users to get the latest version without having to modify their sources.  Starting in 11.10, backports is enabled by default, but given a lower priority than the release packages.  This means that someone has to explicitly choose the backport version if there is the same package in the main repository.


How to run software which requires the latest Intel modules

The easiest way to keep your video drivers updates is the xorg.edgers PPA.  These include Mesa, nVidia and Bumblebee.

However, as the xorg.edgers group ask not to give installation instructions directly without linking to their page, this is the best I can do for now...

If you don't know what a PPA is or need some guidance about rolling forward and backward of driver versions after reading their page, leave a comment below.
I like to honour the people that put all of their great work out there for us mere mortals, so this is a bit out of my control...

So feel free to comment below!


How to add a shortcut to a command to the Cinnamon menu?

or you could just use the

cinnamon-menu-editor

(Also available by right clicking the start button, selecting configure and Open the menu editor.)

Tip: When adding a custom icon, be careful to locate the icon image somewhere you won't be likely to change in the future.


Issues installing qt5 & sdk for phone app

Actually your problem seems to be that you haven't configured a network package repository and instead have still the line from installation time in there, referring to your installation media. The easiest thing would be to edit your /etc/apt/sources.list or grep -R 'deb cdrom' /etc/apt/ to see which of the files still refers to your installation media. Usually that would be /etc/apt/sources.list. Comment out the lines starting with deb cdrom: by prepending a # and then save.

After that make sure to also add some repositories. The normal method is to have contents such as these:

deb http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal main restricted
deb-src http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal-updates main restricted
deb-src http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal universe
deb-src http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal universe
deb http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal-updates universe
deb-src http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal multiverse
deb-src http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal multiverse
deb http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal-updates multiverse
deb-src http:/<country-code>.archive.ubuntu.com/ubuntu/ quantal-updates multiverse

deb http://security.ubuntu.com/ubuntu quantal-security main restricted
deb-src http://security.ubuntu.com/ubuntu quantal-security main restricted
deb http://security.ubuntu.com/ubuntu quantal-security universe
deb-src http://security.ubuntu.com/ubuntu quantal-security universe
deb http://security.ubuntu.com/ubuntu quantal-security multiverse
deb-src http://security.ubuntu.com/ubuntu quantal-security multiverse

where <country-code> would be a two-letter country code as used in ccTLDs, such as us for USA, de for Germany etc. Basically you "local" package repository mirror for added speed. Those lines should already exist and you probably don't need to add or adjust them at all. Simply commenting out the lines starting with deb cdrom should be enough.

After editing make sure to run:

sudo apt-get update

and watch out for further errors such as the ones from your question. Correct them until you see no errors and then install the packages you need or want.

Also make sure to consult man sources.list and this documentation. And here's an online tool to generate the entries for sources.list.

There is also a graphical method to this, but I have no experience in this, as I prefer to edit sources.list. Also the graphical method differs depending on the Ubuntu flavor you're using, such as vanilla Ubuntu, Kubuntu ... etc.


How do I change the order in which systemd services are started up

Systemd tries to start multiple services in parallel, unless you tell it not do.  If you have dependencies, you need to use directives like After in the services definition file.

In this case, if you need to start the nginx service after the dnsmasq service is running, you can add

After=dnsmasq.service

into the nginx.service file.

Hope this helps.


Restore root.disk files (or boot in low-graphics mode)

You can also use ext2read from Windows (read only).

If you are trying to repair it you can do the following:

Run chkdsk /f from Windows first. If it's the C: drive you'll need to reboot to complete the check.
If you have a live CD, I'd recommend trying to repair first by fscking the root.disk (see the Wubi Guide for help). This sounds like what is required based on your description, but I'd still run chkdsk first.
If both those fail, then you can fall back to the backup and reinstall. A normal dual boot is best.

One other thing you can look for is low space... that can cause weird issues.


After a lot of investigation I found out it was a Toshiba dynadock universal docking station. When I unplug it and reboot the mysterious CPU activity goes away. And when i replug it the CPU activity starts again.


Chromium and VAAPI problem (ubuntu 19.10)

The snap was vaapi was a short-lived experiment, it seems.

You didn't say what PPA you are using but you may have meant these.

beta: https://launchpad.net/~saiarcot895/+archive/ubuntu/chromium-beta

I use the dev ppa.

dev: https://launchpad.net/~saiarcot895/+archive/ubuntu/chromium-dev

then play https://www.youtube.com/watch?v=2MpUj-Aua48 in max resolution (2160p)

My user CPU is < 10% (Thinkpad t480) so that's definitely hardware decoded.
This integrated graphics has VP9 hardware support, so I don't have extensions forcing H264.
If I duplicate the tab so the video is running twice,  user CPU is still <10%.

in chrome://media-internals/ find the entry for the current player(s), click on the row and scroll down to see the  Player Properties -> Video Decoder
Example from my machine:

render_id: 248
player_id: 41
origin_url: https://www.youtube.com/
frame_url: https://www.youtube.com/watch?v=2MpUj-Aua48
frame_title: YouTube
surface_layer_mode: kAlways
url: blob:https://www.youtube.com/a7e04d98-3dd9-45f0-88b5-c0c32b4c1fcd
info: Selected video track: []
pipeline_state: kPlaying
found_audio_stream: true
audio_codec_name: opus
duration: 1536.001
found_video_stream: true
video_codec_name: vp9
event: PLAY
audio_dds: false
audio_decoder: FFmpegAudioDecoder
is_platform_audio_decoder: false
video_dds: false
video_decoder: MojoVideoDecoder
is_platform_video_decoder: true
audio_buffering_state: BUFFERING_HAVE_ENOUGH
height: 2160
width: 3840
video_buffering_state: BUFFERING_HAVE_ENOUGH
for_suspended_start: false
pipeline_buffering_state: BUFFERING_HAVE_ENOUGH

video_decoder: MojoVideoDecoder is a sign of hardware decoding.

In contrast, under Chrome: (User CPU as high as 40%, fans running)

render_id: 15
player_id: 44
origin_url: https://www.youtube.com/
frame_url: https://www.youtube.com/watch?v=2MpUj-Aua48
frame_title: 4K Video Relaxing Ultra HD TV Test 2160p 20 minutes - YouTube
surface_layer_mode: kAlways
url: blob:https://www.youtube.com/ebbda754-a09d-4d1f-a497-933d97ff34db
info: Effective playback rate changed from 0 to 1
pipeline_state: kPlaying
found_audio_stream: true
audio_codec_name: opus
found_video_stream: true
video_codec_name: vp9
audio_dds: false
audio_decoder: FFmpegAudioDecoder
is_platform_audio_decoder: false
video_dds: false
video_decoder: VpxVideoDecoder
is_platform_video_decoder: false
event: PLAY
seek_target: 40.91651
audio_buffering_state: BUFFERING_HAVE_ENOUGH
height: 2160
width: 3840
video_buffering_state: BUFFERING_HAVE_ENOUGH
for_suspended_start: false
pipeline_buffering_state: BUFFERING_HAVE_ENOUGH
duration: 1536.001


Unfortunately the guideline in nvidia website mentions .run while it is -run in the file you download. trying following would solve the problem:

sudo sh cuda_9.0.176_384.81_linux-run


I found this solution which works with my device: http://javier-rutas.blogspot.com.es/2011/02/gps-plugin-garmin-en-linux-ubuntu.html

Basically, you have to add the following repository:

sudo add-apt-repository ppa:andreas-diesner/garminplugin
sudo apt-get update
sudo apt-get install garminplugin

In the next step, you have to go to firefox and click in Preferences, Tools,  Defaul user agent --- GarminPluginFake -- Firefox

I hope it helps.


You can't install a 64-bit virtual machine into another virtual machine.

Maybe you can install a 32-bit OS  this way but it is a very bad idea  because it won't work well.


How to group variables based on time interval?

We can do this entirely using only awk:
awk -F, 'BEGIN{print"\"Time Interval\",\"Count of Sources\""}NR>1{gsub(/"/,"",$2);h=int($2/10000)*10000;m=int(($2-h)/3000)*3000;ctr[h+m]++}END{n=asorti(ctr,idx);for(i=1;i<=n;i++){print "\""idx[i]"\",\""ctr[idx[i]]"\""}}' fb.csv

For your given input file fb.csv this results in the output
"120000","4"
"123000","7"
"130000","8"
"133000","5"
"140000","7"

Important: This requires GNU AWK (gawk) to run, because it uses the asorti(...) function for sorting associative arrays by their indices. It does not work with mawk. You can find out your default awk version with using awk -Wv.

Explanation of the command:
We run awk like this here, setting the field separator that delimits columns to , and using the file fb.csv as input:
awk -F, '<COMMAND>' fb.csv

The awk command (placeholder <COMMAND> above) is this, after proper formatting:
BEGIN {
    print "\"Time Interval\",\"Count of Sources\""
}
NR>1 {
    gsub(/"/, "", $2)
    h = int($2 / 10000) * 10000
    m = int(($2-h) / 3000) * 3000
    ctr[h+m]++
}
END {
    n = asorti(ctr, idx)
    for(i=1; i<=n; i++) {
        print "\"" idx[i] "\",\"" ctr[idx[i]] "\""
    }
}

This looks horribly complicated (and I can't deny that it takes some thought to understand), so I'll try to break it up a bit:
The BEGIN { ... } code block will be executed once before the first line of input from the file is read. Then, for each but the first line ("line number greater than 1"), the NR>1 { ... } block is executed. Finally after all input is read, the END { ... } block will run.

Now the BEGIN block is pretty straight-forward, it only prints the new CSV header line.

Let's look at the NR>1 block. Remember that awk splits each line into fields, which were separated by the field delimiter (the one we set to , using the -F argument). The first column/field will be stored in the variable $1, the second in $2 and so on. We're only interested in the value of the second field, which contains the time.
Using the gsub(<PATTERN>, <REPLACEMENT>, <VARIABLE>) function, we replace all occurrences of <PATTERN> (a regular expression enclosed in slashes, here it simply matches only the quotation marks) with a <REPLACEMENT> (empty, as we want to remove them) string in <VARIABLE> ($2 i.e. the second filed containing the time here).
Next we decode the time stamp into whole full hours h (multiplied with 10000) and whole half hours m (without the full hours; multiplied with 3000). We use an associative array ctr as counter of how often the rounded time stamp h+m occurs in the input.

Finally in the END block, we print out the counter's values sorted by the rounded time stamp indices.


The simpliest way is probably to enable Drag'n'Drop between Guest & Host, but since you wrote neither about your Host OS nor about your Guest OS you might face some Problems. (Also the Virtual Box Version is unknown.)

Nevertheless you can enable Drag'n'Drop in the VM Settings:

You can choose between:

Disabled
Host to Guest
Guest to Host
Bidirectional

Version is 5.0.2. The feature was introduced in 4.2. Facing problems this topic might help. Regardless of your OS there are additional information as well: Bidirectional drag'n drop is not working with VirtualBox and ubuntu 14.04


ceph-osd remains in "blocked" state during juju openstack-base charm bundle installation

The issue for me was that the configuration file had "/dev/vdb" as the name of the drive to be used for ceph-osd

I've change the configuration using the following command from the machine running juju:

juju config ceph-osd osd-devices='/dev/sdb /dev/sdc /dev/sdd /dev/sde'

This added my drives to the configuration file, reloaded and it worked.

Thanks to Mr. Billy Olsen for this suggestion from the openstack bug section.


You can try different download Server and/or change your repository settings. See...

Update Manager failed to download repository, 401 error

How to resolve "Failed to download repository information"?

...for the basic idea. It might or might not help depending on what is wrong with your repository information. In the meantime try to investigate further by looking at the error logs and posting them here (edit your question to contain the logs).


Is it bad practice to git init in the $home directory to keep track of dot files?

Create a "bare" git repository:
cd $HOME
git init --bare .dotfiles

The --bare flag creates a repository that doesn’t have a working directory, making it impossible to edit files and commit changes in that repository.

Create an alias to manage the repository we just created:
alias dotfiles="/usr/bin/git --git-dir=$HOME/.dotfiles/ --work-tree=$HOME"

Ignore the files that are not being tracked from being shown up in git status:
dotfiles config --local status.showUntrackedFiles no

Add your desired files:
dotfiles add .bash_aliases

Commit.
dotfiles commit -m 'Add .bash_aliases'

Now with the use of a bare repository, there is no .git directory in your $HOME directory; so it does not introduce any surprises while working with git.
That's how I manage my dotfiles. I first read about it here years ago.


The binary assistant-qt4 is part of packages (oneiric) /1/ : http://packages.ubuntu.com/search?searchon=contents&keywords=assistant-qt4&mode=exactfilename&suite=oneiric&arch=any

qt4-dev-tools
qt4-bin-dbg

Both packages are build from the Qt sources (http://packages.ubuntu.com/source/oneiric/qt4-x11).

You could download the sources and add a new package: only-qt-assistant.

Links:
1. http://packages.ubuntu.com/


What's the ultimate way to install debug Flash Player in Firefox?

If you follow the links from the site you provided, download "For Other Linux (.tar.gz).  Once you download it, untar it, tar xvf install_flash_player_11_linux.i386.tar.gz (or whatever version you downloaded, then copy the .so into the right directory sudo cp libflashplayer.so /usr/lib/mozilla/plugins.  Then restart firefox and it should be fine


Problem installing update for Asus strix claw

Contacted Asus and got the answer that they don't support Ubuntu so I'm sending the mouse back and has bought an other one.


I found a solution for this annoying behaviour.

You have to install compizconfig-settings-manager

Open it and go to "Window decoration" and click the "Reset setting to the default value" in "Command".

The new command should be: /usr/bin/compiz-decorator

After this every new Window opens in it

http://i.imgur.com/7v0A4.png


How To Restrict Multiple Directories With Nginx But Still Access Files?

Problem is solved!

So, by default Nginx has an option called autoindex set to off!
This command line: autoindex on; will activate the ability to see your directories (to everyone).

In my case, I wanted to restricted people from wondering around my server just by typing the www.exemple.com/test1/test2 and be able to see what is inside it without specifying the direct link to it example: www.exemple.com/test1/test2/image1.png

There is a command also that is important that sets a priority of file searching;

location / {
    try_files $uri $uri/ =404;
}

This command means it will try to access the file 1st then the folder then give you an error 404 if nothing works.
More info: https://stackoverflow.com/questions/17798457/how-can-i-make-this-try-files-directive-work

Also, my configuration has index.html, index.php, index.htm set as default. So if you don't want people to access other folders without typing in the whole path change either you default settings or change the name of your files ex: index1.html ...


figured it out! there was an option in pcmanfm --desktop-pref that said "show menus provided by window managers when desktop is clicked


After update and reboot I see black squares everywhere

Upgrading all the apt packages that have been "held back" actually fixed the issue.

To be exact,

sudo apt-get upgrade libgl1-mesa-dri libgl1-mesa-dri:i386 libxatracker2


You've described a problem in Ubuntu where your graphical user interface is slow and not sufficiently responsive. Usually it is possible to solve this problem by changing interfaces from Unity to Unity 2D.

To do this, go to the login screen. (If you are currently logged in, log out.)

Click on the Ubuntu logo near your name. A drop-down menu comes up. One of the items--which is probably currently selected--is called Ubuntu. Another is called Ubuntu 2D. Select that. Then log in.

Once you've logged in once with Ubuntu 2D as your session type, it will be remembered, and you'll log in that way in the future (unless you manually set it back to Ubuntu or something else).

With the Ubuntu 2D session type, the GUI does not use 3D graphics acceleration. On computers without fast video cards, this improves performance.

I hope that solves your problem, and that Ubuntu works well for you from now on. However, if you do decide to remove Ubuntu, you can do that, and the hard disk space taken from your Windows system can be given back to it. This answer explains how.


Unable to run Sakis3g after downgrading to gnome 2?

Given the error message, I would suggestion you either need to install zenity or force a reinstall.

Try the following in a terminal:

sudo apt-get install zenity

or

sudo apt-get install --reinstall zenity


How do I use connect Office 365 via MS Exchange to a GNOME Online Account?

Am I right in assuming that you are using gnome online accounts? I had a similar problem in other distros, and I was able to replicate it on an Ubuntu 17.10 virtual machine.

After clicking the new exchange account button in gnome online accounts, I typed in my email and password and submitted. The following screen came up. (I switched out my normal email address.) See photo below.

Before

After changing the custom username field to be my entire email address and the server field to be "outlook.office365.com" (this server name may not apply to you; to find yours, look in the settings of your webmail page), the configuration succeeded, and ubuntu asked for my password again to add it to a keychain. See photo below.

After

Also, if you are using gnome evolution for your email, you may need to run the following command to install support for the exchange web server:

sudo apt install evolution-ews


How do you make printing use default settings every time you print?

Try clicking the 'gear' shaped icon in the top right of the Ubuntu screen to get to the 'Settings' window, and choose 'System Settings'.
Click on 'Printers', which will show you the printers you have installed.
Right-click on the printer you wish to set up, and click on 'Properties'.
There, in the left pane, are the default settings from which you can choose.
Fingers crossed!


Cursor disappear when I get close to the top of the screen

It turns out that the problem appears when we change the driver from X.Org driver to the proprietary driver. Going back to the originally installed VGA driver solves the problem.


Device for Bootloader installation Dual Boot

Your GRUB bootloader needs to be found by the BIOS/UEFI startup sequence on the primary startup device.  With the intended setup you describe, this will be the device Windows boots from -- likely a dedicated boot partition, if your computer was originally a Win10 machine.

The easiest way to be sure this is right is to verify with the partition manager during Ubuntu installation -- if you run this after installing the new SSD hardware, there'll be one device with two or three partitions on it, and one with none; GRUB needs to go on the first bootable partition on the drive that wasn't empty.


How to remove Gnome from Ubuntu Desktop 14.04

If it is already installed, you can remove the Ubuntu Desktop metapackage and install the server softwares you need:

sudo apt-get install openssh

Configure SSH according to your needs. Then:

sudo apt-get remove ubuntu-desktop
sudo apt-get autoremove


Cannot see the option to install Ubuntu 15.10 alongside Windows 10

I have laptop with UEFI technology, and for installing dual boot is pain.
Try to identify your laptop first, and if it have UEFI, you can learn a little about UEFI here.


Since official repo comes with 7.0 version, repo from ondrej/php has 7.1

Add the repository :

sudo add-apt-repository ppa:ondrej/php

Update :

sudo apt-get update

Install 7.1:

sudo apt-get install php7.1 php7.1-common

if needed you can remove old packages:

sudo apt-get purge php7.0 php7.0-common


Accidentally clicked "don't show this message again" - how to reactivate?

Not sure if there's a GUI way to do this, but this will work:

gconftool --toggle /apps/nm-applet/suppress-wireless-networks-available

This basically edits the Gnome "registry" to toggle the value that you set when clicking that button.


How can I run PHP scripts without prefixing my scripts with sudo?

Your script, php, python, bash, perl, or otherwise has to run as a user with privileges to access the files and services you are managing.

Since some of the tasks you mention require root access (start/stop apache), you will have to run it as root (with sudo). Schedule your scripts to be run as root (from root's anacron)

A more common user case is to run php in a web server (LAMP). In that event, normally one would have /var/www owned by the apache user (www-data), or at least any files php needs to modify. php scripts are then called by apache, and run as www-data and have access to files in /var/www. Just take care, unless you harden php the scripts have access outside of /var/www

The following links may be helpful

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

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


Upgrade from 12.10 to 13.04 failed, now neither Software Center nor Software Updater will open

Yes, you can upgrade with the ISO, you have both options upgrade (keeping your apps) or clean install. But you need to be connected to the web to be able to upgrade, use an ethernet cable instead of wifi if you can.


(noob) driver for GTX 970 install issues

Install the driver this way

sudo add-apt-repository ppa:xorg-edgers/ppa
sudo apt-get update
sudo apt-get install nvidia-352
sudo add-apt-repository -r ppa:xorg-edgers/ppa


I suggest you add the required line to /etc/rc.local:

gksudo gedit /etc/rc.local

Use nano or kate or leafpad if you don't have the text editor gedit. Add a single line right above exit 0:

ethtool -s eth0 autoneg off speed 100

Proofread carefully, save and close the text editor. You should be all set.


There are some Broadcom wireless cards for which there are two drivers. As you might expect, one usually works well and the other not well at all. The 'Additional Drivers' utility happily offers and installs the wrong driver in a few cases, as you've seen.

I suggest you also run:

sudo apt-get remove --purge bcmwl-kernel-source

You should also remove bcma from the blacklist.conf file. One of the dependencies of brcmsmac is bcma; you need both.


Sorry but those 2 commands are executed separately. The

*/10 * * * * export DISPLAY=:99

does not know about

*/10 * * * * python Crawler.py

You need to put the 1st command into the 2nd command if the "Crawler.py" needs a DISPLAY.

Besides that: it is also better to include the paths infront of both the "python" and the "Crawler.py".

I would assume it needs to be something like this ...

*/10 * * * * DISPLAY:99 && /usr/bin/python /usr/bin/local/Crawler.py

if python is in /usr/bin/ and you script in /usr/bin/local/.

There are better methods though:

Use xvfbwrapper. It is a independent wrapper you can use as a  context manager:

    from xvfbwrapper import Xvfb
    with Xvfb() as xvfb:
         # rest of your script goes here (start/stop etc)

This topic on stackoverflow has some more information about using "selenium".
Also interesting: Seleniumhq Plugin


How to install printer Brother HL-6180DW

download the brother Linux installer

Once download is finished then extract this compressed file.

now from you terminal give execution permission to the installed file

chmod +x /path-to-extracted-dir/linux-brprinter-installer*

Now run the script:

sudo ./linux-brprinter-installer*


No.

You can run it under wine or a Virtual Machine, but you will get better results if you use a supported OS like Windows or OS/X.


No video driver with Ubuntu 14.04 LTS with Asus Eee PC x101ch

The issue might be more than that. Ubuntu 14.04 brings a lot more eye candy to the table, but it's my educated guess that accelerated drivers are not enabled in any of the releases you have tried. It's just that the graphical problems are much more apparent when using the most graphically demanding one. But let me explain:

I have an Asus eee PC 1015cx, which uses the Intel Atom Processor D2xxx/N2xxx Integrated Graphics Controller Video. And yes, that's the same driver that the x101ch model uses as well.

After initially receiving it with a Windows7-Starter (ugh), I quickly decided I'd rather work with Ubuntu. But it wasn't that easy. After some digging, I quickly discovered that to enable my video drivers I needed to install the cedarview-graphics-driver (among a few related packages)

The problem with CedarView drivers is that they are close-source, but not only that - they are not actively developed or supported by intel anymore. And that brings a few limitations to the table, namely:

It doesn't support kernels newer than 3.2. There are attempts to patch this sort of thing, but I haven't tried them.
It does't work with newer versions of xserver.

In other words - your only option is to install Ubutnu 12.04.01. As of 12.04.02 and later releases of Ubuntu, they all use a newer xserver versions that will not work for you.

I will add one reservation I have - after installing Ubutnu 12.04.01 and the required drivers, updating the kernel didn't cause any trouble, nor did installing a pae kernel as the first link warns agains, so I'm guessing this is mostly an issue with xserver, though your mileage may vary.

One last thing - if you're afraid of installing an old version, keep in mind that 12.04 is a very solid LTS release, and it will remain supported until 2017.


You most likely have only 3,90625GB of RAM, producers mark 4000MB as 4GB, but ubuntu iterprets it as 4000/1024 GB, which equals to mentioned value.
If you have integrated GPU then some RAM is reserved for it, also system reserves a bit. Let's say that sums up to about 306MB, that's it, now you have 3.6GB left.

Keep in mind that in spite of comments, 32 bit Linux OS also support huge amount of RAM due to using PAE.


Run lsblk to see what disks/partitions you have. On the far right  you will see mountpoints, this info will help you with what partition/drive you are trying to make image of.

$ lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
vda    253:0    0   10G  0 disk
└─vda1 253:1    0   10G  0 part /
vdb    253:16   0  366K  0 disk


If you want to see the content of a file use

sudo cat /usr/bin/chromeos

If you want to edit the file

sudo nano /usr/bin/chromeos


Format hard drive with ntfs in order to switch back to Windows

This is probably because Windows uses a different filesystem than Ubuntu.

Boot into the Ubuntu Live CD
Open gParted (should be already installed)
Shrink the current Ubuntu partition and create an empty NTFS partition (30 gigabytes should be enough) that will receive windows
Using gParted, add a boot flag to the new partition
Apply your changes
Next boot into the Windows installer and you should be able to install Windows on the new NTFS partition that you just created.
After you have installed Windows, boot into Windows, delete the Ubuntu partition, and add the freed up space to your Windows partition.

Thats it!


Install many applications using one command

To build a list of installed packages use:

sudo dpkg --get-selections > package.list

To restore the packages use:

sudo dpkg --set-selections < package.list
sudo apt-get dselect-upgrade


How to adjust Screen brightness of Acer Aspire 573z?

Try these steps:

Add acpi_osi=Linux and acpi_backlight=vendor to GRUB_CMDLINE_LINUX_DEFAULT= in /etc/default/grub.
sudo update-grub2
Reboot.


Ubuntu Server is for exactly this kind of use. It operates in terminal mode all of the time, and takes up much less space as it doesn't contain all of the packages required for the GUI and other associated software.

If you wish to use your current Ubuntu Desktop installation in terminal mode, you can press:

Ctrl+Alt+F1

To switch to a virtual terminal. To get back to the GUI use:

Ctrl+Alt+F7

You can make your Ubuntu desktop boot to text mode by default you can edit the /etc/default/grub file. You'll probably want to make a backup of this file just in case something goes wrong.

Comment out the GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”, by
adding # at the beginning of the line, which will disable the Ubuntu purple screen.
Change GRUB_CMDLINE_LINUX="" to GRUB_CMDLINE_LINUX=”text”, this
makes Ubuntu boot directly into Text Mode.
Uncomment this line #GRUB_TERMINAL=console, by removing the # at the
beginning, this makes Grub Menu into real black & white Text Mode

So you'll end up with:

#GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”
GRUB_CMDLINE_LINUX=”text”
GRUB_TERMINAL=console

In your /etc/default/grub file. Now it's time to put these changes into effect with:

sudo update-grub

For Ubuntu 15.04 and later

There is one further step for Ubuntu versions which use systemd by default. It's necessary to change the default target from "graphical" target to "multi-user" target.

sudo systemctl set-default multi-user.target

You can always revert to desktop boot later by restoring GRUB config file and running:

sudo systemctl set-default graphical.target

Now, when rebooting, you should find yourself in a lovely console only environment.


I didn't need to reinstall, I just simply needed to apt-get -f install to install the client-common tools.


Screen Brightness not changing after installing Gnome Desktop

Apparently, it looks like gdm or GNOME Desktop itself didn't like the acpi_backlight=vendor line in my /etc/default/grub file. As a side effect, an error about fnfxd.service failing to start appears at boot. I guess that when I switch back to Unity, Fn+F2/F3 keys will not work. But as long as I am in GNOME, I guess this little bit of dirty workaround would do. If there will be someone who can give a better working answer, I'll mark you as the accepted answer. Thanks!


Printing indicator does not appear in Ubuntu 14.04.2

This bug has been fixed in the package 0.1.7+14.04.20140527-0ubuntu1.

The bug link


How to detect for a remote program that unity is running

Note that you may have more than one session manager available at your server.
See e.g. https://unix.stackexchange.com/questions/288545/handling-multiple-window-managers-multiple-xsessionrc-files .
I am not certain if any combination of session managers provides a stable ecosystem, though.
I have even seen mixed comments about having 2 different session managers running at the same time in different clients, although I never tried it myself.

So I am not certain if you want to check whether unity is available, it is currently running, or if the session you are connecting to is managed by unity.

You could start checking the values of a few environment variables. E.g., XDG_CURRENT_DESKTOP, GDMSESSION, DESKTOP_SESSION.

I guess you are not interested in the output of

ps -ef | grep -i unity


How can I use digital output instead of analog output for USB headset on 14.04?

As suggested in How can I enable digital output on a FiiO E7 without ending session?, to enable digital output you need to kill PulseAudio:

pulseaudio -k

Then you should be able to see a device like the FiiO USB Audio Class 2.0 DAC Digital Stereo (IEC958), with PulseAudio Mixer reporting something like a Digital Output (S/PDIF) port.


How do I reset all GSettings key to their default values?

Generally you can reset one key to its default value with

gsettings reset SCHEMA [:PATH]  KEY

So you might use a bash script to do for all available keys.
Something like (pseudocode):

for i in /dir/of/keys
do
    gsettings reset <key-path>
done

Look at its man-page for more information: man gsettings


SOLUTION IN THE EDIT SECTION

I know the reason, I'm still trying to find a solution for this.

Just to be sure if your situation is like mine, run:

dpkg -l | grep mysql

you should see most of the packages in version 5.6.x, except a couple, especially mysql-common which is 5.7.x.

As specified from the description of the package:

  MySQL database common files, e.g. /etc/mysql/my.cnf

Basically, any mysql-x-5.6 depends on mysql-common, which in this case comes from the main repository so it's for 5.7, and if you try to manually install mysql-common-5.6 it will either conflict or depend on mysql-common (because in the previous Ubuntu versions it was 5.6).

I still haven't found a solution for this, but maybe with this additional info someone can come up with one.

EDIT: I found a solution, it seems to be the easiest.
First off, remove all mysql packages and files (backup the important ones):

apt purge mysql*
apt autoremove
apt autoclean
rm -rf /etc/mysql/

You should now be clean.

Now go here and download the version you need, it contains all the dependencies except libaio1, so:

apt install libaio1
tar -xvf downloadedMysqlPackage.tar
dpkg -i mysql-common-xxx.deb
dpkg-preconfigure mysql-community-server-xxx.deb
dpkg -i mysql-community-server-xxx.deb
dpkg -i mysql-community-client-xxx.deb
dpkg -i libmysqlclient18-xxx.deb

And you're good to go!


configure a new renamed desktop file that does what you want. Change session manager to launch that one instead of other. Only difference b/t config file will be icon selection.

Here is a concrete example.

Open a terminal, run

$ charmap

Notice the character map pop into the Plank?

Right click on the icon, choose "keep in dock".
In terminal, cd to ~/.config/plank/dock1/launchers

You should see "gucharmap.dockitem". Edit that file, change the name of the desktop file it is using.

You better go create that desktop file you referred to in step 3, or else, well, this whole thing is no fun ;).  I had some fun, for example, by changing the icon for gucharmap in my dock to look exactly like firefox!  The top of my desktop file:

[Desktop Entry]
Name=Character Map
Comment=Insert special characters into documents
Keywords=font;unicode;
Exec=gucharmap
Icon=firefox

All I did was replace the icon with firefox, and now my plank looks twice as awesome.  I think I might  make all of the icons look like firefox.

Now, about your custom script, it is important to get the Exec line correct, or else Plank won't find your script and associate it correctly.  But I think you can get this done.


How solve "sudo: must be setuid root" on Joyent server

You don't have to use sudo - just log in as root with su, and then you should be able the change the permissions back. This should also work remotely.

There is manual page on chmod here - it has a rather useful table to work out what you need to run with chmod:


Only one device can connect to accesspoint created with wifi-ap

Turns out you have to change the operation mode (in my case from 13 to 14) so you can use Bluetooth & Wifi-Access-Point (up to 4 clients) at the same time. This is the Wifi AP Setup code were currently using to configure it properly:
sudo apt -y install haveged
sudo modprobe -r rsi_sdio
sudo chmod 777 /etc/modprobe.d/rs9113.conf
sudo echo "options rsi_sdio dev_oper_mode=14" >> /etc/modprobe.d/rs9113.conf
sudo modprobe rsi_sdio
sudo systemctl stop wpa_supplicant.service
sudo systemctl mask wpa_supplicant.service
sudo nmcli d set wlan0 managed no
snap install wifi-ap


Y'know what, my last comment was pretty snarky. Apologies.

You have node.js installed, except the binary is called nodejs and grunt is assuming it's node.

There's a built-in way to create aliases to programs: update-alternatives

sudo update-alternatives --install /usr/bin/node node /usr/bin/nodejs 10

After that, grunt should be able to find node that points to nodejs


How to download Ubuntu 10.04 (Lucid)'s repository?

There are some mirroring tools available, debmirror is one of them (apt-get install debmirror).

The following script (basically one command) hopefully works. The full release is quite many gigabytes, so I didn't test this thoroughly.

#!/bin/sh
debmirror -v --timeout=300 \
 --cleanup --host=old-releases.ubuntu.com \
 --root=ubuntu --method=http --diff=none \
 --getcontents --no-check-gpg \
 --no-source \
 --di-dist=lucid --di-arch=i386,amd64 \
 --section=main,restricted,universe,multiverse,main/debian-installer \
 --dist=lucid,lucid-updates,lucid-security \
 --arch=i386,amd64 /mirror/lucid


How do I change a specific file type Icon in Nautilus?

You can use Assogiate. See also Changing file type icons with Assogiate.


Broadcom 4313 on ubuntu 12.04 have some problem

I had the same problem with my netbook in 12.04.  You want the proprietary firmware so first you should install linux-firmware-nonfree.

But there is more than one adapter called broadcom 4313.  You'll need the pci id.  Enter in terminal:

lspci -vvnn | grep 14e4

Mine is 14e4:4727 (rev 01), and I don't feel qualified to guarantee this would work for others but it worked for me:

http://ubuntuforums.org/showthread.php?t=2132918&p=12594170#post12594170

I've run 12.04, 13.04 and now 13.10 on my netbook with the 4313/4727 adapter and used a backport every time, but it's been getting better with every new release.  I ran it for some time in 13.10 with just the firmware install and didn't realize I should use a backport for a while.

Eagerly awaiting the 14.04 lts ... 12.04 just doesn't work as well on this netbook, which also has the cedarview gpu.  Hopefully I won't need a backport next time ...


Easy way:

First, copy your 000-default.conf file to two new .conf files:

sudo cp /etc/apache2/sites-available/000-default.conf site1.conf
sudo cp /etc/apache2/sites-available/000-default.conf site2.conf

Edit each of these files, changing the ServerName, ServerAlias and DocumentRoot directives according to which URLs should redirect to which directory.

Now, just enable the sites and reload them:

sudo a2ensite site1 site2
sudo service apache2 restart

Want proof that it's working? This is exactly what I did for my crazy cluster of sites. You can confirm with:

dig +short www.techyteen.tk
dig +short www.brownvpn.tk
dig +short www.browntech.tk
dig +short www.comic-cult.tk
dig +short www.nelida.tk

All domains point to the same IP, as seen by the output of dig. However, visit those pages in your browser, and you will see very different things. (However, don't criticize that last one. The guy really wanted to impress his girlfriend with it :P)


There is a PPA available to get you the latest python:
IF you are in recovery mode
If you are in recovery mode you will need to do some things to make sure you can write to your drives, and any partitions are mounted. Per this question:

You can install software in the recovery mode, but there are a couple
of things to keep in mind:

Only / is mounted, so if you have a separate /var, /usr, /home, you need to mount then yourself

Filesystems are mounted read-only, so you need to remount them using
sudo mount -o remount,rw /

Drivers for your network card or wireless interface may not be loaded

Be sure to run:
sudo mount -o remount,rw /

Before proceeding.
Make sure your system is up to date
sudo apt-get update
sudo apt-get upgrade --fix-missing
sudo apt-get dist-upgrade

Add the PPA
MANUALLY, by adding the following lines to /etc/apt/sources.list
deb http://ppa.launchpad.net/deadsnakes/ppa/ubuntu trusty main
deb-src http://ppa.launchpad.net/deadsnakes/ppa/ubuntu trusty main

OR AUTOMATICALLY, if the following software is available, add it automatically:
sudo apt-get install software-properties-common
sudo add-apt-repository ppa:deadsnakes/ppa

Now reload your repos and upgrade:
sudo apt-get update
sudo apt-get upgrade --fix-missing

Reinstall Python
sudo apt-get remove --purge python
sudo ap-get autoremove autoclean
sudo apt-get install python

Install Updated Python(s)
sudo apt-get install python2.7

This will get you the latest python and should solve your problem!
You might also want to install python 3 and/or the dev packages:
sudo apt-get install python3
sudo apt-get install python-dev python2.7-dev python3-dev


Can't install libsfml-dev on 16.10; unmet dependencies

It's a good practice to always do update and upgrades before and after any installation, so run:

sudo apt update
sudo apt full-upgrade


Viruses detected in wubi.exe supplied with Ubuntu

Different virus scanners differ in what they classify as viruses and what they don't.  This tool scans files with 56 different virus scanners and reports back on whether any of them found any viruses.

In this case the vast majority (54) found nothing to be concerned about while two identified a virus.  It's up to you to decide how much you trust those two particular virus scanners to be accurate and not to display false positives, which can occasionally happen.

You also need to decide whether you want to trust that service (virustotal) itself.

If you look in the second tab it does say that this is a signed file with verified signature, so the tool itself is saying it is a legitimate file from Canonical UK Ltd and has not been tampered with.  So, if you can trust Canonical not to put viruses into files that lends additional weight to this being a false positive on the part of those 2 out of 56 virus scanners.


1st have a look at the answer by MaroCeppi here: Which logs should I pay attention to? It explains what some of the more common logs are used for. There is one more log named .xsession-errors in your home dir (and this records your login and has amongst others errors on loading indicators and laucher items), and often grows VERY large, especially if you never log out.

In general there is no need to check logs weekly. Security might be an exception but if that's the case your system probably is hosting a server (Apache for instance) and then it is more for seeing irregular access instead of errors.
I tend to not look at them unless something is really broken.

Specifically targeting your questions:

  use this tool to simplify your life

log file viewer is a good place to start:

  set up log notification this way and when somethings wired happened, start here

It is a bit hard to answer this but I always start with dmesg or with the log related to the problem (no need to look in .xsession-errors when you get an error during booting ;) )

  common command line usages and common uses of grep searching the logs

Commands that are rather useful:

cat will list the whole file.

grep will filter commands.

tail -f will keep a file active and you will see new notices show up in it when they happen. Rather helpful when tracking down what action you do results in a problem.
(tail -100 will show the last 100 lines)

wc -l to count how many times some search happend.

more and less show the file too.

One example of this:

How many times did someone try to login on 'our' apacher server using IP address 111.111.111.111: grep "GET /login.js" /var/log/httpd/access.log | grep  111.111.111.111 | wc -l


A quick fix for the current document (assuming English text) is Tools - Language - For All Text - English (USA).

I think the permanent fix is to make sure that the default language used for documents is supported by an installed dictionary.  This solution has been documented by "idiota" on LibreOffice's questions forum:

"The problem is fixed by clicking Tools/Options/Language Settings/Languages.  It allows dozens of flavours of English, BUT spelling is disabled for all the ones that don't have the little blue tick ABC icon beside them."

http://ask.libreoffice.org/question/1678/spell-checking-not-working-in-v342/


Install Ubuntu 20.04 desktop with RAID 1 and LVM on machine with UEFI BIOS

After some weeks of experimenting and with some help from this link, I have finally found a solution that works. The sequence below was performed with Ubuntu 20.04.2.0 LTS. I have also succeeded with the procedure with 21.04.0 inside a virtual machine. (However, please note that there is a reported problem with Ubuntu 21.04 and some older UEFI systems.
In short

Download and boot into Ubuntu Live for 20.04.
Set up mdadm and lvm.
Run the Ubuntu installer, but do not reboot.
Add mdadm to target system.
Clone EFI partition to second drive.
Install second EFI partition into UEFI boot chain.
Reboot

In detail
1. Download the installer and boot into Ubuntu Live
1.1 Download

Download the Ubuntu Desktop installer from https://ubuntu.com/download/desktop and put it onto a bootable media.

1.2 Boot Ubuntu Live

Boot onto the media from step 1.1.
Select Try Ubuntu.
Start a terminal by pressing Ctrl-Alt-T. The commands below should be entered in that terminal.

2. Set up mdadm and lvm
In the example below, the disk devices are called /dev/sdaand /dev/sdb. If your disks are called something else, e.g., /dev/nvme0n1 and /dev/sdb, you should replace the disk names accordingly. You may use sudo lsblk to find the names of your disks.
2.0 Install ssh server
If you do not want to type all the commands below, you may install want to log in via ssh and cut-and-paste the commands.

Install
sudo apt install openssh-server

Set a password to enable external login
passwd

If you are testing this inside a virtual machine, you will probably want to forward a suitable port. Select Settings, Network, Advanced, Port forwarding, and the plus sign. Enter, e.g., 3022 as the Host Port and 22 as the Guest Port and press OK. Or from the command line of your host system (replace VMNAME with the name of your virtual machine):
VBoxManage modifyvm VMNAME --natpf1 "ssh,tcp,,3022,,22"
VBoxManage showvminfo VMNAME | grep 'Rule'

Now, you should be able to log onto your Ubuntu Live session from an outside computer using
ssh <hostname> -l ubuntu

or
ssh localhost -l ubuntu -p 3022

and the password you set above.
2.1 Create partitions on the physical disks

Zero the partition tables with
sudo sgdisk -Z /dev/sda
sudo sgdisk -Z /dev/sdb

Create two partitions on each drive; one for EFI and one for the RAID device.
sudo sgdisk -n 1:0:+512M -t 1:ef00 -c 1:"EFI System" /dev/sda
sudo sgdisk -n 2:0:0 -t 2:fd00 -c 2:"Linux RAID" /dev/sda
sudo sgdisk -n 1:0:+512M -t 1:ef00 -c 1:"EFI System" /dev/sdb
sudo sgdisk -n 2:0:0 -t 2:fd00 -c 2:"Linux RAID" /dev/sdb

Create a FAT32 system for the EFI partition on the first drive. (Will be cloned to the second drive later.)
sudo mkfs.fat -F 32 /dev/sda1

2.2 Install mdadm and create md device
Install mdadm
  sudo apt-get update
  sudo apt-get install mdadm

Create the md device. Ignore the warning about the metadata since the array will not be used as a boot device.
  sudo mdadm --create /dev/md0 --bitmap=internal --level=1 --raid-disks=2 /dev/sda2 /dev/sdb2

Check the status of the md device.
$ cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb2[1] sda2[0]
      1047918528 blocks super 1.2 [2/2] [UU]
      [>....................]  resync =  0.0% (1001728/1047918528) finish=69.6min speed=250432K/sec
      bitmap: 8/8 pages [32KB], 65536KB chunk

unused devices: <none>

In this case, the device is syncing the disks, which is normal and may continue in the background during the process below.
2.4 Partition the md device
  sudo sgdisk -Z /dev/md0
  sudo sgdisk -n 1:0:0 -t 1:E6D6D379-F507-44C2-A23C-238F2A3DF928 -c 1:"Linux LVM" /dev/md0

This creates a single partition /dev/md0p1 on the /dev/md0 device. The UUID string identifies the partition of be an LVM partition.
2.3 Create LVM devices

Create a physical volume on the md device
sudo pvcreate /dev/md0p1

Create a volume group on the physical volume
sudo vgcreate vg0 /dev/md0p1

Create logical volumes (partitions) on the new volume group. The sizes and names below are my choices. You may decide differently.
sudo lvcreate -Z y -L 25GB --name root vg0
sudo lvcreate -Z y -L 10GB --name tmp vg0
sudo lvcreate -Z y -L 5GB --name var vg0
sudo lvcreate -Z y -L 10GB --name varlib vg0
sudo lvcreate -Z y -L 200GB --name home vg0

Now, the partitions are ready for the Ubuntu installer.
3. Run the installer

Double-click on the Install Ubuntu 20.04.2.0 LTS icon on the desktop of the new computer. (Do NOT start the installer via any ssh connection!)
Answer the language and keyboard questions.
On the Installation type page, select Something else. (This is the important part.) This will present you with a list of partitions called /dev/mapper/vg0-home, etc.
Double-click on each partition starting with /dev/mapper/vg0-. Select Use as: Ext4, check the Format the partition box, and choose the appropriate mount point (/ for vg0-root, /home for vg0-home, etc., /var/lib for vg0-varlib).
Select the first device /dev/sda for the boot loader.
Press Install Now and continue the installation.
When the installation is finished, select Continue Testing.

In a terminal, run lsblk. The output should be something like this:
$ lsblk
NAME               MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
...
sda                  8:0    0  1000G  0 disk
├─sda1               8:1    0   512M  0 part
└─sda2               8:2    0 999.5G  0 part
  └─md0              9:0    0 999.4G  0 raid1
    └─md0p1        259:0    0 999.4G  0 part
      ├─vg0-root   253:0    0    25G  0 lvm   /target
      ├─vg0-tmp    253:1    0    10G  0 lvm
      ├─vg0-var    253:2    0     5G  0 lvm
      ├─vg0-varlib 253:3    0    10G  0 lvm
      └─vg0-home   253:4    0   200G  0 lvm
sdb                  8:16   0  1000G  0 disk
├─sdb1               8:17   0   512M  0 part
└─sdb2               8:18   0 999.5G  0 part
  └─md0              9:0    0 999.4G  0 raid1
    └─md0p1        259:0    0 999.4G  0 part
      ├─vg0-root   253:0    0    25G  0 lvm   /target
      ├─vg0-tmp    253:1    0    10G  0 lvm
      ├─vg0-var    253:2    0     5G  0 lvm
      ├─vg0-varlib 253:3    0    10G  0 lvm
      └─vg0-home   253:4    0   200G  0 lvm
...

As you can see, the installer left the installed system root mounted to /target. However, the other partitions are not mounted. More importantly, mdadm is not yet part of the installed system.
4. Add mdadm to the target system
4.1 chroot into the target system
First, we must mount the unmounted partitions:
sudo mount /dev/mapper/vg0-home /target/home
sudo mount /dev/mapper/vg0-tmp /target/tmp
sudo mount /dev/mapper/vg0-var /target/var
sudo mount /dev/mapper/vg0-varlib /target/var/lib

Next, bind some devices to prepare for chroot...
cd /target
sudo mount --bind /dev dev
sudo mount --bind /proc proc
sudo mount --bind /sys sys

...and chroot into the target system.
sudo chroot .

4.2 Update the target system
Now we are inside the target system. Install mdadm
apt install mdadm

If you get a dns error, do
echo "nameserver 1.1.1.1" >> /etc/resolv.conf

and repeat
apt install mdadm

You may ignore any warnings about pipe leaks.
Inspect the configuration file /etc/mdadm/mdadm.conf. It should contain a line near the end similar to
ARRAY /dev/md/0 metadata=1.2 UUID=7341825d:4fe47c6e:bc81bccc:3ff016b6 name=ubuntu:0

Remove the name=... part to have the line read like
ARRAY /dev/md/0 metadata=1.2 UUID=7341825d:4fe47c6e:bc81bccc:3ff016b6

Update the module list the kernel should load at boot.
echo raid1 >> /etc/modules

Update the boot ramdisk
update-initramfs -u

Finally, exit from chroot
exit

5. Clone EFI partition
Now the installed target system is complete. Furthermore, the main partition is protected from a single disk failure via the RAID device. However, the EFI boot partition is not protected via RAID. Instead, we will clone it.
sudo dd if=/dev/sda1 of=/dev/sdb1 bs=4096

Run
$ sudo blkid /dev/sd[ab]1
/dev/sda1: UUID="108A-114D" TYPE="vfat" PARTLABEL="EFI System" PARTUUID="ccc71b88-a8f5-47a1-9fcb-bfc960a07c16"
/dev/sdb1: UUID="108A-114D" TYPE="vfat" PARTLABEL="EFI System" PARTUUID="fd070974-c089-40fb-8f83-ffafe551666b"

Note that the FAT UUIDs are identical but the GPT PARTUUIDs are different.
6. Insert EFI partition of second disk into the boot chain
Finally, we need to insert the EFI partition on the second disk into the boot chain. For this we will use the efibootmgr.
sudo apt install efibootmgr

Run
sudo efibootmgr -v

and study the output. There should be a line similar to
Boot0005* ubuntu HD(1,GPT,ccc71b88-a8f5-47a1-9fcb-bfc960a07c16,0x800,0x100000)/File(\EFI\ubuntu\shimx64.efi)

Note the path after File. Run
sudo efibootmgr -c -d /dev/sdb -p 1 -L "ubuntu2" -l '\EFI\ubuntu\shimx64.efi'

to create a new boot entry on partition 1 of /dev/sdb with the same path as the ubuntu entry. Re-run
sudo efibootmgr -v

and verify that there is a second entry called ubuntu2 with the same path as ubuntu:
Boot0005* ubuntu  HD(1,GPT,ccc71b88-a8f5-47a1-9fcb-bfc960a07c16,0x800,0x100000)/File(\EFI\ubuntu\shimx64.efi)
Boot0006* ubuntu2 HD(1,GPT,fd070974-c089-40fb-8f83-ffafe551666b,0x800,0x100000)/File(\EFI\ubuntu\shimx64.efi)

Furthermore, note that the UUID string of each entry is identical to the corresponding PARTUUID string above.
7. Reboot
Now we are ready to reboot. Check if the sync process has finished.
$ cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb2[1] sda2[0]
      1047918528 blocks super 1.2 [2/2] [UU]
      bitmap: 1/8 pages [4KB], 65536KB chunk

unused devices: <none>

If the syncing is still in progress, it should be ok to reboot. However, I suggest to wait until the syncing is complete before rebooting.
After rebooting, the system should be ready to use! Furthermore, should either of the disks fail, the system would use the UEFI partition from the healthy disk and boot ubuntu with the md0 device in degraded mode.
8. Update EFI partition after grub-efi-amd64 update
When the package grub-efi-amd64 is updated, the files on the EFI partition (mounted at /boot/efi) may change. In that case, the update must be cloned manually to the mirror partition. Luckily, you should get a warning from the update manager that grub-efi-amd64 is about to be updated, so you don't have to check after every update.
8.1 Find out clone source, quick way
If you haven't rebooted after the update, use
mount | grep boot

to find out what EFI partition is mounted. That partition, typically /dev/sdb1, should be used as the clone source.
8.2 Find out clone source, paranoid way
Create mount points and mount both partitions:
sudo mkdir /tmp/sda1 /tmp/sdb1
sudo mount /dev/sda1 /tmp/sda1
sudo mount /dev/sdb1 /tmp/sdb1

Find timestamp of newest file in each tree
sudo find /tmp/sda1 -type f -printf '%T+ %p\n' | sort | tail -n 1 > /tmp/newest.sda1
sudo find /tmp/sdb1 -type f -printf '%T+ %p\n' | sort | tail -n 1 > /tmp/newest.sdb1

Compare timestamps
cat /tmp/newest.sd* | sort | tail -n 1 | perl -ne 'm,/tmp/(sd[ab]1)/, && print "/dev/$1 is newest.\n"'

Should print /dev/sdb1 is newest (most likely) or /dev/sda1 is newest. That partition should be used as the clone source.
Unmount the partitions before the cloning to avoid cache/partition inconsistency.
sudo umount /tmp/sda1 /tmp/sdb1

8.3 Clone
If /dev/sdb1 was the clone source:
sudo dd if=/dev/sdb1 of=/dev/sda1

If /dev/sda1 was the clone source:
sudo dd if=/dev/sda1 of=/dev/sdb1

Done!
9. Virtual machine gotchas
If you want to try this out in a virtual machine first, there are some caveats: Apparently, the NVRAM that holds the UEFI information is remembered between reboots, but not between shutdown-restart cycles. In that case, you may end up at the UEFI Shell console. The following commands should boot you into your machine from /dev/sda1 (use FS1: for /dev/sdb1):
FS0:
\EFI\ubuntu\grubx64.efi

The first solution in the top answer of UEFI boot in virtualbox - Ubuntu 12.04 might also be helpful.


How can I get desktop notifications to display on both screens

The best what you can do for the moment is to make that the notification position to follow the mouse-focus. You can do this from dconf Editor: go to apps → notify-osd and change the value of multihead mode to focus-follow.

You can see also:

How to customize on screen notifications?
notify-osd and dual monitors


Well , minimum requirement is 15GB , and since you said you have lot of available space, you can go with 30-40 GB(20 GB for root and remaining for /home partition). Create multiple partitions so that you can give it to either windows/Linux depending on your requirement.


ubuntu 16.04 LTS Login Loop & Black screen TTY

Ctrl + Alt + F2 to get to a terminal. Login then shut down the graphic interface:

sudo service lightdm stop

Then update:

sudo apt-get update

then get rid of all nvidia stuff:

sudo apt-get purge nvidia-*

then try:

sudo apt-get install nvidia-340

Then

sudo reboot

Hope that helps! This is just a from-memory suggestion on similar issues I've had.


Set up Ubuntu Server 12.04 for my office

You are setting up a server in a "Small Medium Business" (< 100 employees), which may be very simple or very difficult, depending of what you will want to do with it.

Short answer

substitute a windows server by a linux server is not as easy as it seems, but possible (just it might be overwhelming for the amateur/enthusiast, leave that for the matured professional administrator)
add a linux server to an existing working network, is very easy and a good way to start with linux without any drawback, nor compromising the existing services. Benefit: linux services don't have licenses - they come  free and forever :)

Long answer

Window server does more than file sharing.

So to substitute it by linux, you will have to:

understand all that windows was doing
how to configure linux to do all that
and migrate the configuration settings from the windows -> linux

And do it all in the backstage without the clients (employees) noticing any change (or they will complaint: if they are your friends they will laugh and joke the first day, but not after 5 days of suffering :) antecipate it :) )

Before disconnecting the Windows Server, you should take into account some hidden things that the windows server might be doing besides being a File Server:

managing windows domains, primary controllers and active directory
share printers
email server (by gods sake, if this is the case, then be aware that preparing a linux email server is no small task... and neither is maintaining it)
login scripts used by windows clients, and delivered by the windows server (it can be done with linux server also, but you will have to do it (see samba))

This is not supposed to scare you, but instead to make you aware and avoid disaster :)

With that said, here comes the good news: linux runs in almost any machine, with much lower requirements than windows servers, meaning you can recycle old hardware to try and make a test linux server without buying anything, and use it to test&convince all other in the office.

The simplest way to start, is to add (not substitute) a Linux Server to the existing network, and create simple services in the Linux Server such as

File-Server (with samba, very easy, lots of info, can also share printers)
Chat service (see ejabberd, not so simple, but not that hard)
Internal Forum for employees (see phpBB, easy to install, up and running in a breeze)
HTTP proxy (well, better check before promissing anything)

Other services can also be implemented in Linux (and work better than in windows, that's the backbone of how internet works) but they require a more profound knowledge from the system administrator, such as email, firewall, vpn, active directory, primary domain controller, calendar/task sharing, Dns, system monitoring and alerts, ...

I would recommend you start by making a virtual machine (use VirtualBox) and try to make the server there as you intend to do in reality. Also use some linux distribution with which you feel comfortable and there is lots of info/people (big community to search for help), such as centOs or Ubuntu Server

Finally, if you only want to make a simple server-for-1-job, search for a linux distribution which gives you a service and comes ready-to-use, such as  FreeNas

Linux can provide a fantastic advantage, when well understood :)

Hope it helps - tell how it went


Press Alt+F2, type gksudo nautilus; enter your password. Now navigate to /lib/vlc and try pasting it.


If you're looking for a keyboard shortcut method, one way to do this would be to use pkexec in a shell script. This will prompt for a password before executing.
Here's a rough shell script to call pm-hibernate via pkexec:
#!/bin/bash
pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY pm-hibernate

This can be saved just about anywhere, so long as the file is accessible to every user account on the machine.
Once this is saved, set it to be executable with chmod +x and give it a test:
./nighty-night.sh

You should now be prompted for your password and, so long as the account is an authorised sudoer, the call to pm-hibernate will go forward.


It can be done by load balancing method. Nginx load balancing uses the upstream module. The simplest way is to add upstream block inside http field in nginx.conf file located at /etc/nginx/.

http {

   upstream backend {

      server 127.0.0.1:8081;
      server 127.0.0.1:8088;
    # server Backend_Server_IP;
   }
...

}

Here I have considered that varnish is running on localhost with port 8081 while apache is running on localhost with port 8088. Specifying IP address and Port number for Varnish wasn't necessary here but I have added it just in case.

After this, you just need to edit inside site setting which is located at the directory /etc/nginx/sites-available/. Just open your site file and add these lines in it.

location / {
     # First attempt to serve request as file, then
     # as directory, then fall back to displaying a 404.
     try_files $uri $uri/ =404;

     proxy_pass http://backend;
     proxy_set_header Host $host;
     proxy_set_header X-Real-IP $remote_addr;
     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
     proxy_set_header X-Forwarded-Proto $scheme;
}

Now Save it, Close it and then check nginx configuration file for any syntax error by typing:

   sudo nginx -t

Restart the nginx service if syntax is ok.

sudo service nginx restart

It will work like a charm. You can check it by stopping varnish service and then visit your site. nginx will bypass varnish if varnish service got failed and then it will forward its request to apache :-)


Video Playback is halting after updating ubuntu 14.04

Solved! In my case, in the Sound Settings -> output , a virtual "Simultaneously Output On All Local Cards" Output was selected, which was added by Pulse Audio. I disabled it from Pulse Audio Preferences and now its normal again.


.desktop file with date variable not working

As properly pointed out by steeldriver and muru, the freedesktop standard specifies that filetype arguments use % symbol, but can be escaped via double %  sign.

An additional issue in your program is that the default gnome-terminal will launch, but exit immediately once the child program exits. In your case, bash -c would exit once echo is complete. In order to hold terminal open, you need to add another shell call. In addition, you don't need to echo the variable, you can just use date directly. Thus your edited file would look like so:

[Desktop Entry]
Version=1.0
Type=Application
Name=test
Exec=bash -c 'echo "TEST";date +%%Y%%m%%d;bash'
Terminal=true
Icon=utilities-terminal

As you can see in the screenshot, the second call to shell properly holds window open and displays the timestamp:

See also:

https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html


Try with my mouse.lyt:

# QJoyPad 4.1 Layout File

Joystick 1 {
Axis 1: gradient, maxSpeed 2, mouse+h
Axis 2: gradient, maxSpeed 2, mouse+v
Axis 3: gradient, maxSpeed 2, mouse+h
Axis 4: gradient, maxSpeed 2, mouse+v
Button 1: key 111
Button 2: mouse 3
Button 3: key 116
Button 4: mouse 1
Button 5: key 115
Button 6: key 117
Button 7: key 110
Button 8: key 112
Button 9: key 36
Button 10: key 36
}


No WIFI or LAN on Ubuntu 12.04 or 12.10 Live CD/USB using Toshiba qosmio x870

The solution provided in this link Drivers for Realtek wireless module for Toshiba by @izx solved the wireless problem. Now I'm able to connect to my home wireless and can also see other wireless around from Ubuntu Live CD/USB.
All you need to do is open a terminal, and type/paste one line at a time the following:

sudo apt-get update
sudo apt-get install build-essential linux-headers-generic linux-headers-uname -r
wget -O- http://dl.dropbox.com/u/57056576/DRIVERS/REALTEK/rtl_92ce_92se_92de_8723ae_linux_mac80211_0006.0514.2012.tar.gz | tar -xz
cd rtl_92ce_92se_92de_8723ae_linux_mac80211_0006.0514.2012
make
sudo make install
sudo modprobe rtl8723e

Update: To get my Atheros AR8161 (LAN) working, I did the following:

apt-get update
apt-get install linux-generic-lts-quantal

After updating my kernel, my WIFI stopped working. Here is what I did to get it up and running.
For kernel 3.5 and above, use the newer driver version:

wget -O- http://www.liteon.com/UserFiles/driver/Module/Network/WLAN/RTL/rtl_92ce_92se_92de_8723ae_linux_mac80211_0007.0809.2012.tar.gz | tar -xz
cd rtl_92ce_92se_92de_8723ae_linux_mac80211_0007.0809.2012
make
sudo make install
sudo modprobe rtl8723e

If it doesn't work then you need to remove rtlwifi because the version that comes with the lower kernel is different from the one the newer rtl8723e is compiled against. That way, the new one will work!
Hence, do the following:

rmmod rtl8192se and any other rtl that was compiled with the previous kernel.
rmmod rtlwifi

Finally, execute

sudo modprobe rtl8723e

and your wireless should be up and finding all wireless around.


Dell XPS 13 7390 with Ubuntu 18.04: Touchpad stops working intermitently

A similar thing happened to me yesterday with the same computer. The main difference is that the touchpad stopped working full stop, and rebooting it does not change the situation. The touch screen still works instead. Any suggestion is welcomed!


You shouldn't need to edit the /etc/inetd.conf file if you're going to use the default /var/lib/tftpboot/ path. TFTP will default to this path already.

Typically the lines in your dhcpd.conf should be something like

next-server (ip address of tftp server); #this is if your tftp sever is separate from your DHCP server
filename "pxelinux.0";

pxelinux.0 will typically point to a boot image in pxelinux.conf for the machine you're trying to boot.

For a completely overblown example of how this is put into practice, you can check out something like Foreman, MAAS, or any other orchestration tool.


If you have root access then fire up your terminal and write

su
Password: (enter your root password here.)

Now mount your HDD (if not already mounted).
And type

chown -R "username_youwant" path_to_folder/folder_name

And now you're done!

It is generally a good practice to mount your HDDs in the /media or /mnt directory.


How to remotely lock out users from logging in temporarily

A quick-and-dirty solution would be:

ssh into the box
change the password of the user your kids log in with ("sudo passwd kiddies")
issue "sudo poweroff"
tell them to finish their homework before they can use the machine again.

There may be better ways to disable a user account without changing the password, such as

sudo usermod --expiredate 1 kiddies

or

sudo passwd -l kiddies

and to unlock:

sudo passwd -u kiddies


What sorted my trouble is running a script using ansible:
#!/bin/bash
#configure dock to be on the bottom
gsettings set org.gnome.shell.extensions.dash-to-dock dock-position BOTTOM
#configure buttons
gsettings set org.gnome.desktop.wm.preferences button-layout ":minimize,maximize,close"
#configure keymap swap
gsettings set org.gnome.desktop.wm.keybindings switch-input-source-backward "['<Alt>Shift_L']"
#configure keymap swap
gsettings set org.gnome.desktop.wm.keybindings switch-input-source "['<Shift>Alt_L']"
#remove autosuspend
gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-ac-type 'nothing'
#remove autosuspend
gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-battery-type 'nothing'
#remove current screenshot button
gsettings set org.gnome.settings-daemon.plugins.media-keys screenshot '[]'
#configure favourites
dconf write /org/gnome/shell/favorite-apps "['org.gnome.Nautilus.desktop', 'google-chrome.desktop', 'org.gnome.Terminal.desktop', 'linphone.desktop', 'flameshot.desktop']"
#configure bulgarian keymapping && us maps
gsettings set org.gnome.desktop.input-sources sources "[('xkb', 'us'), ('xkb', 'bg+phonetic')]"
#configure flameshot screenshot tool
gsettings set org.gnome.settings-daemon.plugins.media-keys custom-keybindings "['/org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/custom0/']"
gsettings set org.gnome.settings-daemon.plugins.media-keys.custom-keybinding:/org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/custom0/ name 'flameshot'
gsettings set org.gnome.settings-daemon.plugins.media-keys.custom-keybinding:/org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/custom0/ command '/usr/bin/flameshot gui'
gsettings set org.gnome.settings-daemon.plugins.media-keys.custom-keybinding:/org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/custom0/ binding 'Print'


The udp limiting rule used is non-specific, so you might well have issues with ntpd syncing if the packet comes immediately after other unrelated udp packets that caused the limiter to engage. One suggestion would be to allow source port 123 specifically:

iptables -A INPUT -i eth0 -p udp --sport 123 -m limit --limit 1/s --limit-burst 1000 -j ACCEPT
iptables -A INPUT -i eth0 -p udp -m limit --limit 1/s --limit-burst 1000 -j ACCEPT

Another, more secure suggestion would be only allow the packet if it is in response to a solicitation started by you (perhaps then followed by your original rule):

iptables -A INPUT -i eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT


Change the default Plymouth Spinner in 20.04

in Default installation of Ubuntu 20.04, bgrt Plymouth theme is used.
/usr/share/plymouth/themes/bgrt/bgrt.plymouth
this theme has below (some of the content only) content from the file /usr/share/plymouth/themes/bgrt/bgrt.plymouth
[Plymouth Theme]
Name=BGRT
Description=Jimmac's spinner theme using the ACPI BGRT graphics as background
ModuleName=two-step

The line ModuleName=two-step has something hard coded opposed to other plymouth themes which uses Script.
Some of the content from another plymouth theme
[Plymouth Theme]
Name=Script
Description=Script example plugin.
ModuleName=script

[script]
ImageDir=/usr/share/plymouth/themes/script
ScriptFile=/usr/share/plymouth/themes/script/script.script

Since your main goal is to stay with the default Plymouth theme shipped with Ubuntu 20.04, we need to concentrate on the MouduleName=two-step
I have tried to get the configurations/guides/specs of this Module named "two-step" but without success..
this Ask Ubuntu post https://askubuntu.com/a/85329/739431 might help something to understand Moudule named two-step.
from trial and errors with the default plymouth theme bgrt /usr/share/plymouth/themes/bgrt/ and with the help of above Ask Ubuntu post..
I did following steps to have custom Images to play as spinner..
1.
copy the spinner theme with below command
sudo cp -r /usr/share/plymouth/themes/spinner /usr/share/plymouth/themes/myplymouththeme

rename spinner.playmouth file to myplymouththeme.plymouth with below command
sudo mv /usr/share/plymouth/themes/myplymouththeme/spinner.plymouth /usr/share/plymouth/themes/myplymouththeme/myplymouththeme.plymouth

Open the file myplymouththeme.plymouth with below command and edit the contents as per your requirement.
sudo -H gedit /usr/share/plymouth/themes/myplymouththeme/myplymouththeme.plymouth

Some of the lines which needs to edit.. I have already edited.
ImageDir=/usr/share/plymouth/themes/myplymouththeme

HorizontalAlignment=.5
VerticalAlignment=.7
WatermarkHorizontalAlignment=.5
WatermarkVerticalAlignment=.96

Image directory is self explanative as we are going to keep our images in this.
HorAlignment .5 is center for the spinner.
VerAlignment .7 is from top of the screen towards bottom, you can reduce this to increase gap between watermark and spinner.
Watermarks are also similar to above explanation.

The image names seems to have throbber- prefix to its numbering like throbber-01.png throbber02.png etc.. Delete all the images with animation* and throbber* and then put your images in the said directory. seems it accepts only png files as Images.
Ok, configuration is done..
to use this theme, create a new file playmouthd.conf with below command
sudo install -D /dev/null /etc/plymouth/plymouthd.conf

and Open the file with below command and add the lines..
sudo -H gedit /etc/plymouth/plymouthd.conf

lines
[Daemon]
Theme=myplymouththeme
ShowDelay=0

You can change the watermark.png with your preferred Image (keep a eye on default watermark.png pic size)
Reboot and See the Changes..
While you are in Desktop you can test the plymouth theme by logging in to two tty's
In one tty, run the below command
sudo plymouthd --debug --tty=`tty` --no-daemon

In other tty, run the below command
sudo plymouth --show-splash

when you run --show-splash it automatically switches to other tty and shows the plymouth, to quit it.. open the other tty where you ran --show-splash command and run below command
sudo plymouth --quit

you can configure to not to show the Firmware Background, by editing the file myplymouththeme.plymouth with the line UseFirmwareBackground=
[boot-up]
UseEndAnimation=false
UseFirmwareBackground=false

Edit:
It seems tweaking an external script to your needs is easy.
Here is the zip file https://github.com/PRATAP-KUMAR/LinkOnly/blob/main/peppermint.zip tweaked from https://www.cinnamon-look.org/p/1471802/
to use peppermint theme, keep the extracted directory peppermint in /usr/share/plymouth/themes/ then edit plymouthd.conf file.
sudo -H gedit /etc/plymouth/plymouthd.conf

with below content..
[Daemon]
Theme=peppermint
ShowDelay=0

Reboot..
Tweaking few things in this peppermint.script may reach your requirements.
Example Lines from the .script file
#--------------------------------------Background functions --------------------------

fun centered_spinner(filename) {
    object.image = Image (filename);
    object.sprite = Sprite ();
    object.sprite.SetImage (object.image);
    object.width = object.image.GetWidth ();
    object.height = object.image.GetHeight ();
    object.x = Window.GetX () + Window.GetWidth () / 2 - object.width  / 2; # Edit to Align as per your requirment
    object.y = Window.GetY () + Window.GetHeight () - object.height / 2 - 100; # Edit to Align as per your requirment
    object.sprite.SetX (object.x);
    object.sprite.SetY (object.y);

    return object;
}

fun centered_logo(filename) {
    object.image = Image (filename);
    object.sprite = Sprite ();
    object.sprite.SetImage (object.image);
    object.width = object.image.GetWidth ();
    object.height = object.image.GetHeight ();
    object.x = Window.GetX () + Window.GetWidth () / 2 - object.width  / 2; # Edit to Align as per your requirment
    object.y = Window.GetY () + Window.GetHeight () - object.height / 2 - 40; # Edit to Align as per your requirment
    object.sprite.SetX (object.x);
    object.sprite.SetY (object.y);

    return object;
}

--
#Animation settings
spinner.rot.steps = 8; # steps for 1 full rotation
spinner.rot.delay = 0.05; # timing in secs

--
#    Window.SetBackgroundTopColor (rt, gt, bt);                  #gradient - darker at the top of screen
    Window.SetBackgroundTopColor (0, 0, 0);                      #no gradient
    Window.SetBackgroundBottomColor (0, 0, 0);


The shell doesn't expand variables inside single quotes. You need to use double quotes. Also, as Danatela says, you also need curly brackets in this case. Since the shell will then attempt to expand the $d too, you need to escape the $.

sed -f <(sed -e "1,${VAR1}d; 12,\$d; x; s/.*/10a\/;p; x" ../log/file2.txt ) ../log/file4.txt > ../log/file5.txt

I'm not sure if there are other parts in the quotes that will also need escaping since you use double quotes now (e.g. *?), so you can always switch between double and single quotes instead, using the former only when necessary.

sed -f <(sed -e '1,'"${VAR1}"'d; 12,$d; x; s/.*/10a\/;p; x' ../log/file2.txt ) ../log/file4.txt > ../log/file5.txt


I am trying to build a Realtek 8723e module for my wireless but I am getting errors

I have the exact quad core i7 Toshiba laptop Satellite S855-S5254 with Ethernet - Atheros AR8161/8165 PCI-E Gigabyte ethernet controller and Wireless - Realtek RTL8723AE Wireless LAN 802,11n PCI-E NIC.

I first installed Ubuntu 12.10 on March 1st. The basic install did not recognize either my Ethernet OR Wireless card. I was able to get the Ethernet going by following http://ubuntuforums.org/showthread.php?t=2114293 (praseodym's contribution). Once this got going, I was able to use apt-get to update. Following which I got the wireless going by following instructions on Wireless card Realtek RTL8723AE-BT is not recognized (user239558's contribution for the 3.5 linux kernel).

I think the issue is that you are using the driver build for the earlier kernel.


Oops, think I found it. There is a "Prefer inline sign/encrypt for plain text message" option in the "Security" tab of the account settings, not sure how I missed that.

Case closed.


Problems loging in after dealing with video drivers and black screen

If you can get to a Terminal prompt or Recovery Console,

sudo apt-get remove --purge nvidia-*

will remove the Nvidia drivers;

sudo rm /etc/X11/xorg.conf

will reset the X session settings; and

echo 'nouveau' | sudo tee -a /etc/modules

will load the default nouveau drivers to let you have a working GUI. A reboot may be required, or try service lightdm start to get to the login screen.


Check out quodlibet (disclaimer: I'm one of the current devs).

Recent versions come with a Automatic Library Update plugin (again, disclaimer...) which does exactly that, using the Python inotify wrappers. It will even update your current view / search results as you add or remove new songs...

You can get the latest stable version thus:

sudo apt-add-repository ppa:lazka/ppa
sudo apt-get install quodlibet quodlibet-plugins python-pyinotify

Hope that helps.


Steam doesn't start after upgrade to Ubuntu 16.04

I upgraded from 14.04 LTS to 16.04 LTS and also wasn't able to start Steam. It started (I mean, 'steam' continued to be running), but nothing happened after a few seconds.

For me, the workaround I finally found was to run Steam from commandline with:

LD_PRELOAD='/usr/$LIB/libstdc++.so.6' steam

Non-essential information below.

Steam provides essentially a "mini distribution" with it, called Steam Runtime, but it isn't currently doing a complete job so it somehow clashes with system C++ standard library and/or other libraries. During my experiments I had also a complaint of system libreadline6 <-> Steam runtime libtinfo5. After I manually unpacked the steam runtime tarball package under the Steam directory to overwrite what I previously had there, it changed to be as described in this problem (pcre_jit_stack_alloc).

An interesting tidbit is that before I found the solution above, I was able to start Steam so it downloaded an upgrade for itself by disabling the Steam Runtime temporarily with export STEAM_RUNTIME=0. Steam itself wouldn't run but that was my first step forward. I tried installing system equivalents of the 32-bit libraries required, but didn't finish / get it working.


After installing Ubuntu 16.04.02 LTS, restarted, doesn't boot to Ubuntu, but Dell Assistant runs check

Solution:

Before installlation, change BIOS boot mode to UEFI boot with
secureboot off.
Choose try UBUNTU via GRUB2.
Search and start gparted.
Via gparted, delete all partitions (thanks to WillemK).
Proceed with the install.
Restart, and go back to BIOS boot mode settings.
Change BIOS boot mode to Legacy with secureboot off.
Wait for UBUNTU installation (again).
Proceed with the install, and restart.
Done!

Lesson of the day: don't use live boot USB, not as reliable as dish. And don't use windows 10; It's a pain to switch to other OS.


In a terminal execute the following commands:

sudo chmod 775 home/myusername/Projects/myproject

sudo gedit /etc/apache2/sites-available/default

In the editor, change DocumentRoot /var/www to
DocumentRoot /home/myusername/Projects/myproject

Then you will see <Directory "/var/www">

Change your default /var/www/ directory to /home/myusername/Projects/myproject/

Save and exit the editor.

Now restart your apache service:

sudo service apache2 restart

Also chmod your second directory.

sudo gedit /etc/apache2/sites-available/default

Create alias  in gedit:

Alias /name /seconddirectory
<Directory /seconddirector>
    Options All
    AllowOverride All
    order allow,deny
    allow from all
</Directory>

Now you can point to the directory http://127.0.0.1/your-name

and by 127.0.0.1 to enter the root directory.


I got this working. It is very difficult if you don't know a lot about xorg.conf files. Here is my setup: 2 nvidia cards. The main one has 4 outputs, but only 2 may be used in Linux at any time (kernel limitation apparently). The second one has 3 outputs, but I only use one. To make the three screens that I am using work, I must define all 7 outputs in xorg.conf (Why? I don't know. If I remove just one definition of one output, it fails to work.) So, in the ServerLayout section, I have:

Identifier "default display"
Screen 0 "Screen0" 0 0
Screen 1 "Screen1" RightOf "Screen0"
Screen 2 "Screen2" RightOf "Screen1"
...repeated through Screen 6, which is RightOf Screen5
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"

The Files section, Module section, and InputDevice sections don't make a difference here. I have 7 Monitor sections, all with bare descriptions, just changing the monitor number.

Identifier "Monitor0"
VendorName "Vendor"
ModelName "model"

I have 7 Device sections, all with bare descriptions. It is important to get the BusID correct. I have four of them for Card0 on PCI:1:0:0 and three for Card1 on PCI:2:0:0. They look like:

Identifier "Card0"
Driver "modesetting"
BusID "PCI:1:0:0"

Notice, the driver is not nouveau or nvidia. Neither one of those will work (I even tried nv).

Of course, I have 7 Screen sections. I made these the minimal settings, but I did hard-code a request for depth 24. They all look the same, just changing the number for each one:

Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
SubSection "Display"
    Viewport 0 0
    Depth 24
EndSubSection

Now, when I run, I get all three screens up. The two on the primary card are joined with xrandr. The third monitor active, but not part of the main display. So, I cannot drag windows to it from the main two screens. But, I can open a window in that display if I want to. Now, I am going to experiment with using xinerama to make all three screens one desktop instead of two on a desktop and one off on its own.