Remove all files within directory older than the most recently added ten files

A simple way that works fine with your file names is to use:

ls -t1 | tail -n +11 | xargs gvfs-rm

ls -t1 gives us a list of files based on their modification time, and newest files are first.
using tail -n +11 we are skipping first 10 line and getting everything else
then we pipe the list to xargs gvfs-rm for removal.

Note that gvfs-rm moves the file to the trash, use rm to permanently remove them.

If you want to work with the file names instead of their modification time then use ls -1r | tail -n +11 | xargs gvfs-rm instead.

A similar find solution that decides based on file names:

find -type f | sort -r | tail -n +11 | xargs gvfs-rm

or

find -type f | sort | head -n -10 | xargs gvfs-rm


I would use GParted:

for data security back up the original hdd (e.g. using dd)
make the new and the old hdd available to the same system (e.g. your server)
start GParted (as sudo)
shrink the biggest partition of the original hdd to a lower value (to fit to the smaller hdd)
copy and paste all partitions to the new hdd
start processing

To correct booting if necessary you can use this: http://gparted.org/faq.php (GRUB fails to boot. How can I fix this?)

Another way could be to use Clonezilla ...


You may want to halt the system after shutdown. Try the following command.

sudo shutdown -H now


I had the same issue today (2016-08-29).  It is unclear what caused it since I didn't upgrade anything in the past 4 days.

Rebooting didn't help.

Key observation: xev wasn't showing any event coming from the mouse when clicking the middle mouse button (scrollwheel) inside the xev little square. This indicated some low-level driver issue as opposed to an application config issue.

Mouse selection was working fine: clicking Shift+Insert or running xsel from a terminal were both pasting the current selection.

Only the pasting via the middle mouse button didn't work.  The problem affected all applications, including firefox and terminals.

Eventually, this fixed it for me.

sudo dpkg-reconfigure xorg


How do I do a minimal install so I can customize Ubuntu?

The 'Alternate ISO' installation method will give you a bare-bones Ubuntu you can build upon. It's explained at Ubuntu's Help site under Low Memory Systems and MinimalCD, and here are current versions you can download and install to start.


Is there a proper procedure to include $PREFIX (and other variables) in debian/package.install?

So it looks like the files in debian/ should be as architecture agnostic and standard as possible.  This means taking care of architecture-specific steps at build time and making 'standard' files (binaries, libraries) available for the extra files in /debian.


suddenly don't have acces to Mounted Drives, chown/chmod don't help

If you used:

sudo chmod 666 /mnt/nameofdrive

It will give you read and write privileges, but you need execute permission to look inside any directories. You may want to try 777 instead, though this is entirely insecure, it can definitely let you know if permissions are causing the problems.


Is there any easy way to get the direct download link of all updates in ubuntu?

On the command line:

apt-get update
apt-get --print-uris upgrade

To extract the URLs from the output:

apt-get --print-uris --yes upgrade | awk '/^'\''/ {sub(/^./,"",$1); sub(/.$/,"",$1); print $1, $2}'

This snippet prints the URL for each package followed by the local file name. The local file name is usually the same as in the URL, but occasionally differs (I think only for packages whose version has an epoch).

If you can run wget on the computer with the network connection, use apt-zip  which automates this task: it provides a tool that generates a shell script to perform the download, and a tool to import the downloaded packages. You can use that script even on a Windows machine, with a port of Unix tools such as Cygwin.


What's the lastest version of Openstack that I can deploy with Juju? Where can find this information?

You openstack-origin configuration is not quite correct - try:

openstack-origin: cloud:precise-havana

other valid options include:

cloud:precise-havana/updates
cloud:precise-havana/proposed (for testing)

You can find out about the latest OpenStack releases for Ubuntu 12.04 on the Ubuntu wiki


Overheat problem with Ubuntu 15.04 on Asus K55VD

It isn't specific of NVIDIA. What is been overheated are the CPU cores, and also started happening to me with Ubuntu 15.04 running Intel graphics.

My brother also has an Intel graphics laptop, and suffers from this problem from a long time ago. Even when we changed the thermal paste for a high quality one (Artic Silver), the laptop is still shutting.


You might have to explicitly specify the IP address, e.g.:

sudo mount -t cifs //my-disk/j -o "username=me,password=s)mePasss,ip=10.10.10.43" /mnt/sync


Installing multiple version of chrome & firefox on one ubuntu machine

If you download firefox from Mozilla's page you don't get a deb package, you get a folder with an executable in it. You can have as many as you want of those.

If you don't want you configuration files to clash, simply use different home folders for different versions. For example, if you downloaded firefox, extracted it and renamed the folder to "firefox2" in your home folder, do the following:

cd firefox2
export HOME=$(pwd)      #sets current folder as your home for all programs invoked from this terminal or script
./firefox --no-remote   #without "no-remote" firefox creates a new window for active firefox session

Notice that linux created a ".mozilla" folder in your firefox2 folder. You can have as many versions as you like and even run them at the same time.


How to push files to Android SD card in TWRP recovery

Download thee ROM file and GAPPs for your phone
copy the files to an sd card
insert the card into your phone
boot the phone into recovery
go to install
select the rom file
and flash it(swipe to flash)
same with the GAPPs


Untrusted Package Errors, After installing Security Tools

I have solved this problem following steps up from here.

First I removed all extra software source and then I ran these commands one by one.

sudo fuser -vvv /var/lib/dpkg/lock
cat /etc/lsb-release
uname -a
sudo rm /var/lib/apt/lists/lock
sudo cp -arf /var/lib/dpkg /var/lib/dpkg.backup
sudo cp /var/lib/dpkg/status-old /var/lib/dpkg/status
sudo cp /var/lib/dpkg/available-old /var/lib/dpkg/available
sudo rm -rf /var/lib/dpkg/updates/*
sudo rm -rf /var/lib/apt/lists
sudo rm /var/cache/apt/*.bin
sudo mkdir /var/lib/apt/lists
sudo mkdir /var/lib/apt/lists/partial
LANG=C;sudo apt-get clean
LANG=C;sudo apt-get autoclean
LANG=C;sudo apt-get --purge autoremove
LANG=C;sudo apt-get update -o APT::Cache-Limit=25165824
sudo dpkg --configure -a
sudo dpkg --clear-avail
LANG=C;sudo apt-get -f install
LANG=C;sudo apt-get --fix-missing install
LANG=C;sudo apt-get update -o APT::Cache-Limit=25165824 && sudo apt-get dist-upgrade


How can I solve display glitches and poor performance with ATI fglrx driver on my ThinkPad X100e?

To revert back to the open source drivers it should be a simple matter of disabling the Proprietary Drivers in the Additional Drivers application. After that you will need to restart (or at least logout and log back in).

Also take a look here for a bunch of xorg.conf options to tweak the FGLRX drivers. If I were you I'd setup a xorg.conf which would a) allow you to easily swap between the closed source and open source drivers and b) allow you to tweak the drivers more. To do so take a look at the Ubuntu wiki


Keybinding to launch another terminal rather than gnome-shell

Run sudo update-alternatives --config x-terminal-emulator and choose the number that corresponds with your favorite terminal-emulator.

Example:

parrot@i7-4770U:~$ sudo update-alternatives --config x-terminal-emulator
[sudo] password for parrot:
There are 2 choices for the alternative x-terminal-emulator (providing /usr/bin/x-terminal-emulator).

  Selection    Path                             Priority   Status
------------------------------------------------------------
* 0            /usr/bin/gnome-terminal.wrapper   40        auto mode
  1            /usr/bin/alacritty                20        manual mode
  2            /usr/bin/gnome-terminal.wrapper   40        manual mode

Press <enter> to keep the current choice[*], or type selection number: 1
update-alternatives: using /usr/bin/alacritty to provide /usr/bin/x-terminal-emulator (x-terminal-emulator) in manual mode
parrot@i7-4770U:~$

This is automatically bound to Ctrl+Alt+T.


Upstart is an event-based replacement for the /sbin/init daemon which handles starting of tasks and services during boot, stopping them during shutdown and supervising them while the system is running.

rc is the command line interpreter for Unix.

rc file: Script file containing startup instructions for an application program (or an entire operating system), usually a text file containing commands of the sort that might have been invoked manually once the system was running but are to be executed automatically each time the system starts up.

Source:Linux Guide/Linux Dictionary V 0.16


How to use NetBeans in Dark Mode with the Darcula Theme?

Darcula LaF is only downloadable from the pre-Apache NetBeans catalog (http://plugins.netbeans.org/PluginPortal/) and not the Apache one (https://netbeans.apache.org/plugins/index.html).

To install it on Apache NetBeans, you will need to add this catalog as a plugin source.

To do this :

open NetBeans ;
go to Tools > Plugins ;
the Plugins window opens. Click on the "Settings" tab ;
click "Add" to add a new update center ;
name it as you wish and provide the following URL: http://plugins.netbeans.org/nbpluginportal/updates/8.2/catalog.xml.gz then click "Ok". I think it's here that you did not provide the correct URL :) The number of available plugins should suddenly raise ;
You should now be able to find Darcula LaF !

Alternatively, and as you seems to know already, you can download the Darcula archive from plugins.netbeans.org and  install it manually from the Tools > Plugins > Downloaded tab.

Enjoy and save your eyes ;)


Wireless extremely slow on Ubuntu 14.04 LTS

I would check the results of iwlist scan for your access point to look for TKIP as it will reduce download speed and try echo "options iwlwifi 11n_disable=8" | sudo tee -a /etc/modprobe.d/iwlwifi.conf and reboot

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1319630 is a bug report that says that performance dropped 85% without using the 11n_disable=8 parameter

EDIT: You may also see improvement by setting your country code with

sudo iw reg set CA

And by editing the crda file gksudo gedit /etc/default/crda and change the line that is usually REGDOMAIN=00 to REGDOMAIN=CA then save and exit program, reboot


Configuring Wireless Static IP through Terminal

Your interface wlan0 is not going to properly connect 192.168.0.108 given a gateway of 192.168.1.1. One or the other is incorrect. I suggest you check other devices on the same network to verify these details.

Also, any wireless interface requires the name of the network and the WPA key in order to associate. I suggest your /etc/network/interfaces file be amended to:

auto lo
iface lo inet loopback

auto wlan0
iface wlan0 inet static
address 192.168.1.108
netmask 255.255.255.0
gateway 192.168.1.1
dns-nameservers 192.168.1.1 8.8.8.8
wpa-ssid <your_network>
wpa-psk <your_key>

Restart the interface:

sudo ifdown wlan0 && sudo ifup -v wlan0

Check:

ping -c3 www.ubuntu.com

Of course, substitute your verified details above.


Try this in terminal:
sudo modprobe -r psmouse && sudo modprobe psmouse proto=imps

Hope this works.


Alternatives to Photoshop and Illustrator

In Open Source realm, you can find many alternatives to what you want. I just want to point for something, don't ever treat applications as if they are the same, You can't find SAME alternative for Photoshop, instead you can find mostly all properties and maybe sometimes more but you have to learn how to use.

Photoshop alternatives:

gimp

sudo apt-get install gimp

krita

sudo add-apt-repository ppa:kubuntu-ppa/backports
sudo apt-get update
sudo apt-get install krita

For more options take a look: http://www.ubuntufree.com/top-5-photoshop-alternatives-on-ubuntu-14-04-and-14-10/

Illustrator Alternatives:

The best to use would be inkscape:

sudo apt-get install inkscape


How can I replace all the characters from a string?

What's the problem?

$ echo signaldate signaltime period UwThiSon3dH140__mean UwThiSon3dH140__sigma \
  | sed 's/ /,/g'
signaldate,signaltime,period,UwThiSon3dH140__mean,UwThiSon3dH140__sigma

Perhaps what you're seeing isn't whitespace or it's mixed whitespace. Try the \s character instead:

$ echo signaldate signaltime period UwThiSon3dH140__mean UwThiSon3dH140__sigma \
  | sed 's/\s/,/g'
signaldate,signaltime,period,UwThiSon3dH140__mean,UwThiSon3dH140__sigma

Failing that, do as your question's comments suggest and pass the output through hexdump so you can see what's really going on because it's not a space.

Note that you could also use tr to replace the character but I doubt that's going to fix your issue if you can't get sed working:

$ echo signaldate signaltime period UwThiSon3dH140__mean UwThiSon3dH140__sigma \
  | tr ' ' ','
signaldate,signaltime,period,UwThiSon3dH140__mean,UwThiSon3dH140__sigma


in this particular case, it seems that the problem was occurring because of the time system difference between windows and ubuntu.

I noticed whenever I shutdown or restart from windows the next start the problem was happening. the fast start on windows was off. also noticed whenever I use Ubuntu the next booting to windows cause windows to have not a correct time.

therefore I made Ubuntu to use local time

timedatectl set-local-rtc 1 --adjust-system-clock (which was an easier solution than making windows use UTC) and since then I have not faced the issue


Why does GtkCalendar counts months from 0?

Doc for GtkCalendar: http://developer.gnome.org/gtk/2.24/GtkCalendar.html

General explaination for zero based:

The use of zero to start counting is actually an optimization trick from Assembly programmers. Instead of assigning 1 to the count register, they XOR'ed the register with itself, which was slightly faster in CPU cycles. This meant that counting would start with 0 and would always be up to the length of elements, excluding the last one.

Also, the use of zero is also popular with pointer arithmetics where you would use one base pointer pointing at some allocated memory, plus a second pointer which would be at an offset from this base pointer. Here, using the value zero makes a lot of sense to point the offset to the base of the memory block. (General array logic tends to be the base address plus the offset x record size.)

And zero-based month numbers? Often, many programming environments calculate the data as a number of days since some default data. December 31, 1899 is a popular date, although there have been plenty of other dates used as base date. All other dates are offset from this base, and will just be stored as one single number. Fractions would be used to indicate hours, minutes and seconds, where 0.25 would be 24/4 = 6 hours. Thus, to transform a date into a real date, all the environment has to do is transform this number into a real date.

However, the combination of zero-based arrays and 1-based month values does bring a problem. To get the month name of month 9, you would have to get item 8 from the month array. Some developers would be happy with decreasing the month number before getting it's name. Others preferred to change the month into something zero-based since people just want to know the name, not the number. It's a personal view.

Moreover, there is more than a reason why one could think there is wrong with Date/Calendar:

Surprising bases (1900 as the year base in Date, admittedly for deprecated constructors; 0 as the month base in both)
Mutability - using immutable types makes it much simpler to work with what are really effectively values
An insufficient set of types: it's nice to have Date and Calendar as different things, but the separation of "local" vs "zoned" values is missing, as is date/time vs date vs time
An API which leads to ugly code with magic constants, instead of clearly named methods
An API which is very hard to reason about - all the business about when things are recomputed etc
The use of parameterless constructors to default to "now", which leads to hard-to-test code


hcitool scan does not find my bluetooth device

man hcitool lists the following option:

-i <hciX>
       The command is applied to device hciX , which must be the name of an
       installed Bluetooth device. If not specified, the command will be sent
       to the first available Bluetooth device.

I suspect your “small device” bluetooth chip is not the default hci0, so hcitool doesn't send commands to it unless you say so. To display available local devices, run:

hcitool dev

This will show a list of devices with their device names. Pick the one you want and execute e.g.

hcitool -i hci1 scan


As per this announcement, Google Compute Engine now have Ubuntu images curated by Canonical available.

You can find more information on how to spin up instances using these image in the GCE documentation.


So I figured it out.

Open: CompizConfig Settings Manager
Select: Window management from the left pane
Compiz
Make sure Place windows is selected
Window Management options


Failed to start Windows after Ubuntu 11.10 install

Try running Ubuntu from the live CD. Download the Boot-Repair app by choosing try Ubuntu and following the instructions of the linked page above. First try the recommended settings and see if it fixes your loading issues. IF not try the advanced options, or view the log that is generated by the boot-repair application.


Where are applications installed via Applications Manager stored

Applications in Linux are actually stored in a range of locations. An executable, the file you run to start the program, is stored in a folder in your path, typically in `/user/bin' for graphical applications that come with software center. The main program files may then reside under /usr/lib. Some configuration data may have been written under /etc/, etc.

In summary, it is quite complex to answer where applications installed via package manager are stored.

To find out what files have been installed by an application installed through software center, you can use Synaptic package manager. Synaptic is not installed by default. Install it using software center or with the command sudo apt install synaptic.

Fire up synaptic (you need to provide your user password because the application runs with root permissions).
Search the program (package) you installed.
Right-click the package and select "Properties".

The "Installed files" tab lists all individual files that the package installed onto your system. The "Dependencies" tab lists all packages that the package you are looking at, depends on.

When you installed your program, any of these dependencies that were not yet on your system, will have been installed as well. Looking up these dependencies in Synaptic will allow you to view the files these dependent packages installed.


Keyboard not working with full disk encryption after installing Nvidia drivers on Ubuntu 16.04

I think you're having the same issue I am. You get to the disk decrypt stage but you can't type in the password to decrypt the drive. It seems to be related to the fact that the nvidia drivers need access to something on the encrypted disk. I don't have a solution yet but I can tell you if you boot into rescue mode you can enter the password to decrypt the disk and then resume the boot and you'll be able to get into the system. As for what you can do to fix the issue without going through that process, I don't have that answer yet.


Can I make a read only image read write?

You can make you BQ Ubuntu Phone read/write.

For that you will need to install the following on your Ubuntu desktop :

sudo apt-get install android-tools-adb

Then make it possible for adb to detect your BQ Aquaris 4.5 (Ubuntu Edition) Phone as following (required only once) :

echo "0x2a47" > ~/.android/adb_usb.ini

Your phone should be setup for developer mode:

Go to Settings > About this phone > developer mode

setup a lock security code

then enable developer mode

Connect your phone :

on your desktop's terminal execute:

adb devices

adb shell

You should be connected to your phone now and your sudo password is the same as your lock security code :

sudo mount -o remount,rw /

If you need to enable ssh access you will have to do the following :
enable ssh service

add your public key to the authorized key list on the phone (phablet user)

ifconfig for the phone ip

ssh into it (ssh phablet@ip)

I remember that it was possible to access some software on the the phone repositories on Nexus 4, I'm still working on this to be sure all the software is accessible on BQ too.


What software could I use to do video surveillance?

I found an easy way with a webcam and thanks to this french documentation.
The idea is:

define a service to synchronize a folder on your PC and your Smart Phone
or to let you consult it from an other computer on Internet:

install the synchronization service on your PC
install the synchronization service on your smart phone
  or do nothing and just use internet to consult the captured video from an other PC.

install a video software to record videos when movement is detected

Let's do it with DropBox and Motion:

Install the service to synchronize: Dropbox

On your PC, install DropBox
follow the instruction and install with the default options
It will create a folder /home/boris/Dropbox  (with boris your user logon)
Install DropBox on your smart phone, depending on your Smart Phone, find here the way to install it.
I personally installed it from the GooglePlay on my Android phone. (without giving my phone number on the web site)

Install Motion  on your PC, and configure it:

copy the configuration file in your user environment:

sudo cp /etc/motion/motion.conf ~/.config/motion.conf
sudo chown boris:boris ~/.config/motion.conf

(replace boris by your user logon)
edit the configuration file:

gedit ~/.config/motion.conf

modify the target directory to be your dropbox directory
(replace boris by your user logon)

you may also want to define the resolution of the capture

then launch your video surveillance:

$ motion -c ~/.config/motion.conf


Display/theme problems after reinstalling Ubuntu 16.04.02

Okay so in case anyone is interested I figured out what the problem is: It seems that when I reinstalled Ubuntu the package gtk2-engines-pixbuf, which controls all of the pixmap parts of themes, wasn't installed. I don't remember installing it manually the 1st time around, but if it doesn't come with Ubuntu then I must have. I just ran the following command to install it:

sudo apt-get install gtk2-engines-pixbuf


need russian keyboard option I DO NOT have a GNOME desktop have ubuntu

Ubuntu desktop has mostly the same settings for Gnome Desktop - search for 'keyboard' settings and open them

Click 'Layout Settings'

Then click the +, add the Russian layout and move it to the top of the list

Like this:


What does it mean when a symbolic link (symlink) is red in Ubuntu?

~/temp$ mkdir dir1/ln2dir21/dir3 you can't create a directory in a directory that is inexistent use mkdir -p

ln -s dir2/dir21 dir1/ln2dir21 is not working, because you're a) linking to a file not a dirrectory and b) it should be a full path. https://stackoverflow.com/a/9104390

so it should be: ln -s ~/temp/dir2/dir21/ ./dir1/ln2dir21

and it should workl...


I gather from the comments that you want the output to look like name1=adeo name2=student.  If that is the case, try:

$ awk -v today="$(date +'%Y-%m-%d')"  '$1 == today && /Completed executing command/ { cnr = NR } cnr && NR == cnr+3 {sub(/\//, " name2=", $NF); print "name1="$NF }' filename
name1=adeo name2=student


You appear to be using very outdated libraries, for example "libavcodec-extra-53 (>= 4:0.7-1) but 4:0.7.2.1ubuntu2 is to be installed". That version was released in 12.04 dev on 2011-12-26 and has been Superseded numerous times.

The current 12.04 version is 4:0.8.3ubuntu0.12.04.1) precise-security

So open software sources,  software-properties-gtk & make sure that under Ubuntu Software the 1st 4 are checked & under Updates the 1st. 2 are checked

Then update your sources  & see


Find images higher than a specific resolution in a Linux directory

How about that:

find /path/to/dir_with_major_dirs -path "*/*/*/*.jpg" -type f -exec bash -c '
  for i; do
    [[ "$p" = "${i%/*}" ]] || identify -format "%d, %w, %h\n" "$i"
    p="${i%/*}"
  done' _ {} + |
awk -F ',' '$2 > 800 && $3 > 600'

This test for every jpg file found whether its path matches the previous file’s path and only if not runs identify. The output is piped to awk as you already figured out, I just removed /%f from the identify command to get rid of the unnecessary file name.


What are these "_embedded.jpg" files that Shotwell created?

If you're using the "Camera" developer, Shotwell extracts the embedded JPEG from the RAW file and places it beside the file.  This JPEG is then used to display the RAW photo.

There has been some traction on changing this behavior to display the embedded JPEG without extracting it.  See this ticket for more info: Camera RAW developer wastes disk space by extracting embedded JPEGs

Edit: It appears this bug has been resolved; bugs related to shotwell are now here: https://launchpad.net/ubuntu/+source/shotwell/+bugs?field.searchtext=jpeg


Connect SFTP in Dolphin with keyfile and passphrase and nonstandard port

You should be able to add a custom host entry in your ~/.ssh/config file, specifying the port, key file, and domain to use. Something like this, modified to have the values you need:

Host specialport
  HostName real.domain.com
  Port 50000
  IdentityFile ~/.ssh/special-key_rsa.1

You can make the specialport value in there be whatever you want. Once you place that in the ssh config file, you can use that value as the hostname to connect to in Dolphin, like sftp://specialport/home/ (if that is the URL scheme that Dolphin uses these days).


How to solve the flickering of splash screen in 16.04?

The messages that show in between your splash screen are messages that the kernel thinks are important for you to see. It is advised to take note and see if the cause of these messages can be tackled. That might be difficult though, and if your system is otherwise fine when booted, you can just choose to ignore these messages, and not have them appear by changing the log level.

To eliminate display of any kernel messages during boot, proceed as follows:

Open the file /etc/default/grub as root user with your text editor.
If you use nano, you can open the file as root with the command sudo nano /etc/default/grub
Change the line starting with GRUB_CMDLINE_LINUX_DEFAULT= to include the option loglevel=0. For example, in a default Ubuntu install, the line might look like:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Change it to read:

GRUB_CMDLINE_LINUX_DEFAULT="quiet loglevel=0 splash"

Save the file and exit the editor (in case of nano, Ctrl+s Ctrl+x will do.)

Update your grub to reflect the changes with the command sudo update-grub


Stuck on orange screen during/after installing 12.04.1

I have just installed the 32bit version but happened exactly like you. Start Ubuntu in Recovery mode from Grub, from there, start session in low graphics mode (I don't remember the name exactly) and installed the graphic drivers, that solved my problem for now. You can do this from a terminal, or from Recovery mode too, it may work to you.


This is tested on Ubuntu 11.10, I don't seem to need it for 12.04.
Note, this involved adding a third-party PPA - proceed with caution.
More on the dangers of PPAs here.
First, make sure we're both experiencing the same problem. Run the following in a terminal:
cat /usr/share/X11/xorg.conf.d/50-synaptics.conf
You should see something like the following:

Section "InputClass"
   Identifier "touchpad catchall"

   Driver "synaptics"

   MatchIsTouchpad "on"

Now, you need to add the PPA - for precise instructions on how to do that, take a look here.
The PPA you need to add is ppa:sergio91pt/synaptics+clickpads
Now, update your system - run the following in the terminal:
sudo apt-get update && sudo apt-get dist-upgrade
What that command does:
First part updates your system software list - this tells the computer where the software is that it needs to download.
The second part does the actual update of your system software.
Once that's done, reboot your computer - your trackpad should be working now.
After the reboot, you'll want to update/tweak your touchpad settings.
Head to System Settings > Mouse and Touchpad, and then switch to the touchpad tab, and you'll see something like this:

You can play around with those settings as much as you want, just so you can figure out what works best for you.


If file contains foo.pdf, you can strip the .pdf using ${file%%.pdf}.

With szSavePath, you can test if it contains .txt and add it if it doesn't:

szSavePath=$(zenity --file-selection --save --confirm-overwrite)
[[ $szSavePath != *.txt ]] && szSavePath="$szSavePath.txt"

You can provide the PDF's filename with .txt instead of .pdf as the default filename, using the --filename option:

szSavePath=$(zenity --file-selection --save --confirm-overwrite --filename="${file%%.pdf}.txt")

Also, remember to quote your variables, so that filenames with spaces and other special characters don't cause problems:

pdftotext "$file" "$szSavePath"


How do you automatically set infiniband mode to connected?

Since netplan does not support the pre-up scripts, you do have two options here:

Get rid of netplan

Modify /etc/default/grub and add netcfg/do_not_use_netplan=true to GRUB_CMDLINE_LINUX. Then run update-grub.

GRUB_CMDLINE_LINUX="netcfg/do_not_use_netplan=true"

After a reboot /etc/network/interfaces is used again.
Use networkd as netplan's renderer

Basically, it is networkd-dispatcher which will provide the functionality to call scripts. A detailed description can be found here.


How can I copy files from damaged external HDD?

If you're unable to copy file by file, use ddrescue to copy the entire partition block by block. ddrescue will just copy the good blocks, leaving the space in the image file where the bad blocks were.

General usage is like this:

sudo ddrescue -n /dev/sda1 sda1.img sda1.log
sudo ddrescue -r3 /dev/sda1 sda1.img sda1.log

This will copy the entire partition /dev/sda1 to an image file sda1.img. This should be done from a different partition which has enough room for the entire partition image.

The second command will attempt to read from the bad blocks again and fill in the blanks.

Then you can mount the img file and do what you want with the files on them:

sudo mount sda1.img -o loop /mnt; nautilus /mnt

More info:

http://wiki.lunarsoft.net/wiki/Data_Recovery#ddrescue

http://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html


Package integration process from Debian case in point: portaudio

You are correct. The patch is in Groovy.
Let's review how to confirm:

You already did the hard part: You found the patch in Debian.

Information: One line in the patch header includes the Debian bug number (944509), which is very handy:
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=944509

You found the lowest version of Portaudio19 that includes the patch from either the URL, the web page, or the changelog: 19.6.0-1.1

You checked Ubuntu for the releases that include that version or higher...
$ rmadison portaudio19
  portaudio19 | 19+svn20111121-1       | precise         | source
  portaudio19 | 19+svn20140130-1       | trusty          | source
  portaudio19 | 19+svn20140130-1build1 | xenial          | source
  portaudio19 | 19.6.0-1               | bionic/universe | source
  portaudio19 | 19.6.0-1build1         | focal/universe  | source
  portaudio19 | 19.6.0-1.1             | groovy/universe | source

...so Bionic definitely does NOT have the patch, Focal might (or might not), and Groovy definitely does have the patch.

Let's look more deeply into Focal. Here's the changelog on launchpad.net for the Focal package. The lack of a patch mention or a bug number in the changelog is a flare-lit tip-off that Focal does NOT have the patch:

portaudio19 (19.6.0-1build1) focal; urgency=medium

No-change rebuild for libgcc-s1 package name change.

Finally, let's double-check that the patch is in Groovy. Here's the changelog. The mention of the patch, with the corresponding correct Debian bug number is conclusive proof that the patch in question was applied in this build.

portaudio19 (19.6.0-1.1) unstable; urgency=medium

Non-maintainer upload.
Apply crash fix patch (Closes: #944509)

BONUS: See how the Groovy version was a "Non-maintainer upload?" That often means that the volunteer Debian package maintainer welcomes help keeping the package up to date. It's not difficult or time-consuming, and it's a great way to contribute to Ubuntu. Debian (and Ubuntu) welcome new volunteers to learn the skills and contribute a bit of effort to keep everybody's favorite distro going strong.


why is 'Brackets' sidebar not working in Ubuntu 18.10?

gdebi Brackets.Release.1.13.64-bit.deb

Probably a version that is too old or too new since Dependency is not satisfiable: libcurl3 means it can not install a mandatory piece of software for this to work.

I would have issued a ...

sudo apt install libcurl3

and see if that installs and then act upon the error or install brackets again if it does not throw an error. gdebi likely does not install dependencies so you will need to do that yourself.

  After problem 1 i tried to install Brackets from "Ubuntu's software center" and i installed successful .

That would be my 1st choice (over gdebi installation).

  then i saw that the 'sidebar' doesn't display any files .

That we probably can not help you with. That seems related to the software itself. It could be a bug in Brackets.


Autorun Exterminator type alternatives for Ubuntu 14.04

Ubuntu comes with autorun blocking straight from the get-go.

Navigate to System Settings > Details (near the bottom) > Removable Media.

From there, select the dropdown next to Software. To disable autoruns, just set that value to Do Nothing:

Your system will no longer autorun anything that it sees on a USB stick. It's also worth noting, however, that even leaving this option on Run Software isn't exactly dangerous. The system will prompt you before running anything first:

Sourced partially from this answer on AskUbuntu


Samba doesn't work upon boot until restart of service

You can check Samba binding to your network interfaces with

root@server:~# lsof -ni:139
COMMAND  PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
smbd    2265 root   29u  IPv4  13788      0t0  TCP 127.0.0.1:netbios-ssn (LISTEN)
smbd    2265 root   31u  IPv6  13790      0t0  TCP [::1]:netbios-ssn (LISTEN)

Here it's binding only to the loopback interface and doing a smbclient -L 127.0.0.1 will work.

Depending on your smb.conf (interfaces, and bind interfaces only) Samba will bind only to the loopback interface if you use DHCP and will bind OK after you restart it.

This is happening because upstart doesn't wait for all network interfaces to be up, see https://askubuntu.com/a/349142/332223


Which Version of Netbeans is more appropriate with JDK 10.0.1

JDK 8 is required for installing and running both NetBeans IDE 8.2 and Apache NetBeans 9.0.
The Eclipse snap package from the default Ubuntu repositories is perfect for Java programming because it is bundled with a Java development environment. To install it open the terminal and type:
sudo snap install eclipse --classic

This command will install the latest Photon Release 4.8 version of Eclipse IDE for Java Developers. Eclipse Photon JDT supports Java 10. Eclipse changed its codename policy so that Eclipse releases from September 2018 and onward are named after the year and month of the release date, for example Eclipse 2020-06. This naming scheme also applies to the eclipse snap package.

Select Java version from Installed JREs in Eclipse -> Window -> Preferences
To go through the built-in tutorials in Eclipse Photon select Help -> Welcome -> Tutorials.


Dual boot problem: different disks and boot mode

Try to open your BIOS, and then change the Boot Mode from UEFI to Legacy First.


You need to use chmod command to change the permission, How to use Chmod command, or You can lunch the app as Root, How to launch application as root


Unable to write to disk but disk isn't full

Answered in edit by OP:

  Edit: It turned out that I was out of inodes even though I wasn't out of disk space. Problem was solved here:

You are out of inodes. It's likely that you have a directory somewhere with
many very small files.

What are inodes?

  Ext4 has a theoretical limit of 4 billion files, which is restricted by the size of inode number it uses to identify each file (ext4 uses 32-bit inode numbers). However, as John says, Ext4 allocates inode tables statically, so the actual limit is set when the file system is created.

Source


I've searched and found this it does have some workarounds like enabling the setting "Override software rendering list" in chrome://flags/ some say it works but it's not guaranteed may be worth a try.


One click shutdown Ubuntu and load into alternative bootup

In case you know the entry number for your Windows installation (start counting with 0 for first position) in the grub menu you can reboot into Windows (assuming to be 3rd on the list) by this command:

grub-reboot 2

Alternatively you can also use the textual entry used:

grub-reboot '<type entry here>'

This command can also be put in a launcher for "single-click" usage.

To make this procedure work we need the entry GRUB_DEFAULT=saved in /etc/default/grub.


This is a known bug. Sorry. The good news is that it will be fixed in 11.10 in 6 months but unfortunately it's unlikely to be fixed in 11.04. You could try using Ubuntu Classic instead if you need to use an onscreen keyboard.


Nonbonded interactions on the GPU were required, but not supported for these simulation settings

here there are some idea:
You can't use multiple energygrps in any .tpr file that will be run on a
GPU. Previous versions ran but the energy group output was garbage.
Separate groups should only be specified as analysis and done with mdrun
-rerun on CPU.

https://mailman-1.sys.kth.se/pipermail/gromacs.org_gmx-users/2018-August/121644.html

In other words you need to remove energy groups from .mdb file. Than you may add them in rerun step to calculate the free energy for example.


Touchpad double tap and two finger scroll not working on Ubuntu 17.04

After the upgrade the user space xorg-synaptics was replaced by libinput. In most cases it works better and is now default in new Ubuntu releases.

"Tap to click" is disabled in libinput by default for a reason I can't understand. You can fix it by editing the /usr/share/X11/xorg.conf.d/40-libinput.conf file.

Add

Option "Tapping" "True"

to the touchpad section of the file after Driver "libinput", and restart the session.

Regarding two-finger scrolling. Not all touchpads support this feature. All new do, but old ones don't. According to your output only edge scrolling is available.

libinput Scroll Methods Available (296):    0, 1, 0

The first number should be 1 if the touchpad supports two-finger scrolling.

The touchpad capabilities are reported to user space by the kernel. I don't think that xorg-synaptics and libinput read it differently.

If that is a bug and your touchpad is really capable of multitouch, that is more likely a kernel bug. Also you can always switch back to xorg-synaptics by

sudo apt install xserver-xorg-input-synaptics
sudo apt remove xserver-xorg-input-libinput


graceful shutdown of libvirt virtual machines on host shutdown

Update upon suggestion:
According to the blog/wiki author:

However, there is the problem that each VM will only receive one shutdown request. For Linux VMs this is usually fine, but Windows VMs sometimes do not react to the first request, resulting in the VM being killed forcibly after the timeout. The only way to fix this problem is modifying the shutdown script so that it sends shutdown requests again and again until a VM has shutdown or the timeout has been reached.

So the solution is to patch /usr/lib/libvirt/libvirt-guests.sh in Ubuntu 16.04 LTS (Xenial Xerus) (credit to the wiki author: Sebastian Marsching):
--- /usr/lib/libvirt/libvirt-guests.sh  2016-10-10 09:33:38.000000000 +0200
+++ /usr/local/lib/libvirt/libvirt-guests.sh    2016-11-08 11:58:33.000000000 +0100
@@ -339,6 +339,19 @@
     retval run_virsh "$uri" shutdown "$guest" > /dev/null
 }

+# shutdown_guest_retry URI GUEST
+# Start a ACPI shutdown of GUEST on URI. This function returns after the command
+# was issued to libvirt to allow parallel shutdown.
+# This command does the same as shutdown_guest_async, but does not print a
+# message.
+shutdown_guest_retry()
+{
+    uri=$1
+    guest=$2
+
+    retval run_virsh "$uri" shutdown "$guest" > /dev/null
+}
+
 # guest_count GUEST_LIST
 # Returns number of guests in GUEST_LIST
 guest_count()
@@ -407,6 +420,14 @@
         format=$(eval_gettext "Waiting for %d guests to shut down\n")
     fi
     while [ -n "$on_shutdown" ] || [ -n "$guests" ]; do
+        guests_retry=$on_shutdown
+        while [ -n "$guests_retry" ]; do
+            set -- $guests_retry
+            guest=$1
+            shift
+            guests_retry=$*
+            shutdown_guest_retry "$uri" "$guest"
+        done
         while [ -n "$guests" ] &&
               [ $(guest_count "$on_shutdown") -lt "$PARALLEL_SHUTDOWN" ]; do
             set -- $guests

However, when I checked the same code for Ubuntu 20.04, the similar logic is already there. So this is no longer a problem.
It is late as an answer, but it is useful for documenting:
This post gives a solution for Ubuntu.


SDK Installation Issue On Ubuntu 14.04 LTS

sudo is required if you want to use the apt packaging system, there is no way round that. You only need to be in the sudoers group to have root privileges via sudo on the default settings.

A partial workaround would be to configure sudo to allow you to sudo for just the apt-get command but this is insecure and may not completely work.

You could ask for an account to be used just for installing, this would then not be used for running services or scripts, this is marginally less risky for the admin but could be secured more heavily because of its particular focus.

This simplest workaround here is to use docker or a virtual machine (assuming its subsystem is already installed, as that will require sudo) to create a slice that you can administer without root.
There is a guide here for docker - https://www.microsoft.com/net/core#docker

Ultimately you will be struggling to make this work without root so just go get root or get another box.

A fundamental rule in the unix world is that you must be running as root to serve data on a port numbered less than 1024, this will prevent you from serving on most of the standard ports.


What is the best practice for saving data in Ubuntu one db from mobile?

There will be; we're working on it. I plan to have the QML U1DB declarative API published soon.

In the meantime, until that arrives, you may find this code interesting; it is a simple notes app, but written with QML and using U1DB. This U1DB QML addition follows the declarative QML U1DB API I mentioned above, but it's a Python-based prototype of that API. So, it's very very hacky indeed, and will be replaced with a proper U1DB QML setup as part of the Ubuntu SDK, but you may find it useful to experiment with. In particular, you'll see from this code how to declaratively declare a U1DB database, indexes, documents, and queries, and from this code that a U1DBQuery is a ListModel. That code should give you some idea of how you will be able to use U1DB from QML in Ubuntu Phone, although I must repeat that the implementation of that API from Python is a hacky prototype.


uTorrent 3.1.2 via Wine -> Black background of main panel

Goto wine configuration and try diffrent msstyle

now mine is look like this

install win7 msstyle theme

if it wont work goto preferances - ui settings -alternate wall paper


16.04 - DNS problem when waking laptop up from suspend-mode

Same issue here on XPS13 9350 running Ubuntu GNOME 16.10.

I've found a solution/workaround, but I have to admit that I don't fully understand why it works.

I noticed that I kept seeing references to 127.0.1.1 as a nameserver, particularly in /etc/resolv.conf. Once I found that, it led me to the solution here:

nameserver 127.0.1.1 in resolv.conf won't go away!

The issue is with NetworkManager.  It seems that it had the bogus notion that I was running a DNS server on my local machine, despite the fact that I don't. (This seems really silly as a default behavior, though, so I'm willing to concede I may have accidentally poked something or installed something that made it think so)

Regardless, it can be fixed by simply commenting out the following line in /etc/NetworkManager/NetworkManager.conf:

dns=dnsmasq

I've tried several reboots and sleep/wake cycles since making the change, all with positive results.  I'll try to update this if I run into any future issues. Good Luck!


ksoftirqds are kernel threads that run when the machine is under heavy soft-interrupt load. You should have one ksoftirq for each CPU.

The soft interrupts are normally serviced on return from a hard interrupt.  It is possible that the soft interrupts can be triggered faster than they can be serviced.  If a soft interrupt is triggered again while the soft interrupt is being handled then the ksoftirq daemon handles the soft interrupts in a kernel thread.  If this happens a lot you will see a heavy soft interrupt load on the ksoftirqd threads.

100% CPU utilisation in a ksoftirqds and the need to reboot sounds like some hardware is saturating the machine with an interrupt storm. Does the kernel produce any errors or warnings? (Use dmesg to see what it is reporting).


How do I screenshare over the internet using Remmina Desktop client?

The IP address to connect you to a remote desktop is the adress given to this remote computer by their Internet Servie Provider. You will have to find out this address from the remote computer (e.g. by opening an Internet browser there an go to WhatIsMyIP):

How can I find my public IP using the terminal?

In case you need a frequent access to this computer you may also want to consider setting up a dynamic DNS service:

see Ubuntu help wiki: Dynamic DNS


Firefox
You can use some firefox options to both disable the default action which is to paste on clicking the middle-mouse button and also to turn on auto-scrolling.
First - in the Firefox - Preferences - Advance settings ensure you have the following options checked:

Use Autoscrolling
Use Smooth scrolling

Then in the Awesome bar type about:config
Search for *autoscroll and double click *general.AutoScroll to change from "false" to "true"
Now search for middlemouse

middlemouse.contentLoadURL = false
middlemouse.openNewWindow = false
middlemouse.paste = false

Then restart firefox
When you middle click you should now see this symbol to scroll:


What would happen if I deleted the Ubuntu partition from OSX?

You would no longer be able to access those partitions. Meaning, no booting Ubuntu, and no accessing any data that was on those partitions and depending how you installed GRUB, you could not boot OS X.


Why does "pgrep -a" output differ depending on how a file is opened?

This is because pgrep -a shows both a program's name and its command-line arguments, and when you right-click on /home/dkb/.bash_aliases and open it with gedit, this actually runs gedit with /home/dkb/.bash_aliases as a command-line argument. This is to say that it is as though you had run the command gedit /home/dkb/.bash_aliases. Passing filenames as command-line arguments isn't just for programs you would normally run in a terminal. It is also essential to how opening files in a desktop environment works.

When you run a program to open a file, whether by right-clicking on the file and selecting the program, double-clicking on the file when it is of a MIME type that is configured to open with that particular program, or dragging the file onto a launcher for the program, this causes the program to be run with the filename passed to it as a command-line argument. This works the same way as if you ran gedit filename in a terminal window, which also works.

In contrast, opening gedit without an initial file to edit doesn't pass it any command-line arguments. This works the same way as if you ran just gedit. When you then open the file in the program, that doesn't change what command-line arguments were passed to it.

It's possible for a program to attempt to change what command-line arguments will appear to have been passed to it, when programs like pgrep check. But this is rarely done, most often as a half-measure to redact sensitive information like passwords. (A better approach is to not convey passwords in command-line arguments.)

The command-line arguments don't represent the state of the program. Instead, they specify how the program was run, or, to put it another way, what it was told to do initially. (They're not the only information a program receives when it's started--programs also have environment variables, a current working directory, and a umask, for example.) Both command-line and graphical editors accept filenames as command-line arguments.

For a more complete picture, I should say that the specific way command-line arguments are passed to a graphical program run in a desktop environment varies across programs. It is specified in the launcher--that is, the .desktop file--that is used to run the program.

To work, a .desktop file must specify an Exec key1 that gives the command and also--for commands that support being launched to open a file or other resource--a placeholder for arguments. Multiple placeholders are available, but %U is common. It is replaced with zero, one, or more URLs or filenames. The Exec line in gedit.desktop is:

Exec=gedit %U

1 That link goes to GNOME documentation, but this also applies to KDE and other desktop environments. It is a freedesktop.org specification.


How do you change the current keyboard layout from the terminal?

You can use setxkbmap:

setexkbmap [langauge code] (Langauge code could be en, etc)


You can find the wireless card details from the command line. Please open a terminal Ctrl+Alt+t and run:

lspci -nnk | grep 0280 -A2

That funny pipe symbol | is on the right side of my US keyboard on the same key with backslash.


How to tell apt-get to install another version of Eclipse?

You can tell apt to install a specific version as follows:

apt-get install package=version

example:

apt-get install eclipse-platform=3.5.2-6ubuntu1.1

But AFAIK the version 3.6 is not available in the repo. It is better to install manually . Check a similar thread here How to install Eclipse?


Desktop freezes regularly. Ctrl+Alt+F keys doesn't work

The first thing I recommend people do when their computer starts to freeze up randomly is check harddrive health. Probably the easiest way to do this within Ubuntu (or another Linux environment), is via GSmartControl, which I personally use as a technician to check hard drive health through Parted Magic. If it's not your hard drive it might still be some form of hardware issue (I've had systems act this way due to dieing graphics cards), or it might be something your recently configured/installed that's interfering with a system process.


How can I disable continuous scrolling in ubuntu touchpad?

Your question is similar to this one (and was answered): Turn off trackpad scroll "momentum"

Running this command helps:

synclient CoastingSpeed=0


Installing Ubuntu on a new HDD, no previous operating system

Have you set up your BIOS to boot from CD or flash disk yet? when the system says that insert proper boot media means that it can not find the boot media, open your BIOS setting, and choose to boot from CD/DVD or usb first.. if it fails again tell us.


Mount(Windows Drive) gets unmount whenever I reboot my system

If you want Ubuntu to automount a partition at startup, you must configure it to do that either by manually editing the /etc/fstab file (advanced method) or by using gnome-disks' GUI settings dialog (easy method). I'll describe the easy method here:

Open your Dash's Application lens (Super+A) and search for the application gnome-disks (or simply "Disks"). Launch it.
Select the disk where the partition you want to mount is located in the left side panel. In the right panel, select the partition you want to automount.
Click the gear button below ("Additional partition options") and select "Edit mount options..." from the appearing menu.
In the new dialog window, switch "Automatic mount options" off. Now the manual settings unlock.
You should make sure that "Mount at startup" and "Show in user interface" are checked. You can edit the "Display name" and "Icon name" if you want, but you should leave the mount options line (no caption) as it is. "Mount point" specifies the directory through which you want to access the partition. You should edit this field as well. The other options should remain as they are unless you know what to do.
Close the dialog by clicking "OK" and exit gnome-disks.

To be able to mount the Windows partition writeable, make sure that Windows Fast Boot is turned OFF though, otherwise Ubuntu can just mount the partition in read-only mode.


Unable to install Ubuntu on Toshiba M50D-A-103, AMD A6-5200

It seems that there is a problem reading from the filesystem on the USB stick. I don't know what exactly is be the cause. I had a laptop from a friend where I encountered the same problem. I then tried with a CD and that worked.

Sorry for not providinig a real explanation. But give the CD a try.

kind regards


Pam_mount won't automount encrypted partiton

Now it is working again. The reason it did not work is indeed because they changed the format of the config file

/etc/security/pam_mount.conf.xml

in Ubuntu 11.10. So, I backed up my old *pam_mount.conf.xml* and uninstalled the pam-mount module via

apt-get remove --purge libpam-mount

and reinstalled it using

apt-get install libpam-mount

Now I opened the new

/etc/security/pam_mount.conf.xml

and inserted this line,

<volume user="user" fstype="crypt" path="/dev/sda5" mountpoint="/media/personal" options="fsck,relatime" />

from my old config file into the volume section of the new config file.

This is how it look now

<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE pam_mount SYSTEM "pam_mount.conf.xml.dtd">
<!--
        See pam_mount.conf(5) for a description.
-->

<pam_mount>

                <!-- debug should come before everything else,
                since this file is still processed in a single pass
                from top-to-bottom -->

<debug enable="0" />

                <!-- Volume definitions -->

<volume user="user" fstype="crypt" path="/dev/sda5" mountpoint="/media/personal" $

                <!-- pam_mount parameters: General tunables -->

<!--
<luserconf name=".pam_mount.conf.xml" />
-->

<!-- Note that commenting out mntoptions will give you the defaults.
     You will need to explicitly initialize it with the empty string
     to reset the defaults to nothing. -->
<mntoptions allow="nosuid,nodev,loop,encryption,fsck,nonempty,allow_root,allow_ot$
<!--
<mntoptions deny="suid,dev" />
<mntoptions allow="*" />
<mntoptions deny="*" />
-->
<mntoptions require="nosuid,nodev" />

<logout wait="0" hup="0" term="0" kill="0" />

                <!-- pam_mount parameters: Volume-related -->

<mkmountpoint enable="1" remove="true" />

</pam_mount>


Changing decimal separator in existing columns in LibreOffice Calc

Go to the Edit, and select Find & Replace.

Under Search for, put ,- and under Replace with, put .. Then press Replace All


How to choose default output port (boot screen) in a nvidia card?

Launch nvidia-settings either from a Terminal or from the Dash,
then find and click X Server Display Configuration (the second line in the left side panel for me)...

Click on the VGA monitor in the right side panel that appears,
then look below for [ ] Make this be the primary display for the X screen
- make that box contain a tick -> [v],
then click Save to X Configuration File and Quit

Does that make any difference?

FWIW: I have the X login prompt come up on the upper of the right side displays, despite of the above. I'd like to have that prompt in front of me instead. <- Yes, that is a "mee too!". I don't see the grub menu elsewhere than on the left side display though  :-I
And yes, that is a total of four displays.


How can I open two half-screen windows in a row without overlapping?

Since I don't use Unity, I don't know for sure, but if you set the Unity launcher be always hidden, then maybe your windows won't shift to the right to accommodate it.


Are there any command to see how processes are working?

strace will show system calls made by a process. It won't give you an instruction-by-instruction view of what happens, but it will give the calls into the kernel performed.


As so often happens, I found the answer after posting a question.

Right-click the panel, select "Panel Settings", click the "Panel Applets" tab, click "Task Bar (Windows List)", click "Edit", and tick the box that says "Icons Only".


ReadOnly Access from windows 7 to a shared folder in ubuntu

Windows cannot read ext4 partitions straightaway.

Using 3rd party software to access your Linux partitions is not recommended by me as it has the potential to corrupt your ext4 partition.

The best bet is to make a NTFS partition in Ubuntu and keep the files you want to share with windows over there. It is because Linux has no problem with NTFS partitions.


I think your USB MBR (Master Boot Record) has corrupted. Open Terminal and type these commands:

sudo apt-get install mbr
sudo fdisk -l (to find out which device is your flash drive)
sudo install-mbr /dev/sdx (replacing x with your flash device)

If you see: install-mbr:/dev/sdc: No boot signature found.  Use --force to override. Then try:

sudo install-mbr /dev/sdx --force

and then create the live USB again.


How to install dual boot Kubuntu and Remix OS

As per these instructions: https://forum.xda-developers.com/remix/remix-os/how-to-install-remix-os-alongside-t3352890 you will need to create a new partition large enough to house Remix OS, install Remix OS onto that partition, and then update grub to be able to see Remix


Getting following error while installing `cowsay`

If another apt-get instance is running in another terminal, you should close it or let it complete the task before running apt-get in another terminal. If that's not the case, remove the lock file in /var/lib/dpkg/ directory with

sudo rm /var/lib/dpkg/lock


How to connect to Samba share on an ASUS router

The Samba world would be in a much better place if we would all use updated software. These NAS devices all seem to be a generation behind.

Run a test. Open your terminal and run the following command - replacing XXX with the name of your router or its ip address:

smbclient -L XXX

Do you get the following error:

  Server does not support EXTENDED_SECURITY but 'client use spnego = yes
  and 'client ntlmv2 auth = yes'

Note: You may have to install a package first because Ubuntu 18.04 does not have an smb.conf file by default:

sudo apt install smbclient

If you do then edit smb.conf:

gedit admin:///etc/samba/smb.conf

And right under the workgroup = WORKGROUP line add the following two lines:

client use spnego = no
client ntlmv2 auth = no

THe reason why a CIFS mount as suggested by Gin Gon is a better solution is that you can "dumb down" the CIFS mount specific to your one device without altering smb.conf to dumb it down for all connections in your file manager.


In short.  Persistence is the space on your USB key the will be used to store information, so that that information is still there after a reboot.

Confirm that your syslinux.cfg, has the word persistence in it.
If not you can add it after the first --.
Code:

-- persistence

For more information click Here


How we can define more than 2 DNS server (IP) in MAAS?

As you see you can not define more than one DNS in MAAS web interface

you must leave the  Upstream DNS blank in MAAS web interface

and define forwarders ins /etc/bind/named.conf.options as this:

forwarders {

ip 1;

ip 2;

};

I hope this save a lot of time for you.


Monitor Flickers after resolution detection

You display adapter (nvidia) seems not receiving the DDC/CI data from the new screen.

As:

I can see from it LG 25UM65-P Specification Sheet it should support that. (Anyway any modern monitor should have this)
You have tried two digital cables DVI-D and HDMI without success.

So for solution:

It could be that DDC/CI sending feature is disabled in the monitor (I have one Dell monitor that offer possibility to disable it)

Look for DDC/CI or EDID and enable it. (I looked at manual but does not seem there)
If you are using an adapter, look for a direct & relatively short cable.
A workaround when no EDID data available from monitor

Create a /etc/X11/xorg.conf file that contains

Section "Monitor"
    Identifier  "Configured Monitor"
    HorizSync       30.0 - 90.0
    VertRefresh     56.0 - 75.0
EndSection

Values got from the user manual.


Where do I direct download for 11.10/11.04?

For downloading 11.04 version , 11.10 version simply browse through this page , select the 11.10 directory for 11.10 version , you will find wubi at the end of that listing, you can similarly download for 11.04 version.

As per this page

  Why is the AMD64 version of Ubuntu being downloaded and installed?

  The machine you are trying to install Ubuntu on is 64 bit. The AMD64
  installation is appropriate for all 64 bit architectures, no matter if
  they are AMD or Intel.


I know this is an old post, but I might have an idea.

You could try installing Fusuma, there is an explanation on how to install it on this thread.

It allows you to do custom commands for things like swipe and pinch. You might be able to configure it someway to do it with clicks? Or check the GitHub for a how to do it.

Hope it helps.


how to change the place of the local server files to avoid permissions problems?

First of all, go through this about changing your apache root directory to another drive.

Now you have to give permission to all users to upload files on your server in the present root directory.

Run the following command to give permission.

sudo chmod 777 /path/to/upload/folder.

After that you will be able to uplad files on the desired directory.


Save stdout and stderr of programs running under GNU Screen when you forgot to redirect it

If it's still in the GNU screen's buffer, you can:

press Ctrl + a
press : to enter the command mode
type hardcopy -h file.log

The default size of scrollback buffer in GNU screen is 1024 lines and you can check it with Ctrl + a
 i. It will be the first number after coordinates.

You can increase it (for future) in .screenrc file with defscrollback setting.


Your problems probably mitigates from using the default Ubuntu with Unity. I'd advise to move away from that distro since you have such low specs and move toward Lubuntu or Xubuntu. The problem occurs because you have such low RAM and Unity is a RAM hog. I don't think your problem will be solved if you move to a 32-bit version. You can change this from your current image by using instructions provided on this older post or you can re-install Ubuntu if don't have anything worth saving on that partition.

Here is a page which shows the memory usage of the different Linux Desktop environments.

  Just tell me what the "lightest" desktop environment is!
  OK, for those of you who just want the final answer, with none of the explaination, here it is:

  | Desktop Environment  | Memory Used |

  | Enlightenment 0.18.8 |    83.8 MiB |

  | LXDE 0.5.5           |    87.0 MiB |

  | XFCE 4.10.2          |   110.0 MiB |

  | LXQt 0.7.0           |   113.0 MiB |

  | MATE 1.8.1           |   123.0 MiB |

  | Cinnamon 2.2.13      |   176.3 MiB |

  | GNOME3 3.12.2        |   245.3 MiB |

  | KDE 4.13.1           |   302.6 MiB |

  | Unity 7.2.0.14       |   312.5 MiB |


Every program, when runs, is a process. Processes are an important
part of any OS. Each process has its own, unique ID, which is a number.
You can send signals to a process to kill it. This is explained below.

Managing processes, beginner's manual

First open a Terminal (press Ctrl+Alt+T).
A terminal allows you to run commands on your computer,
and see what they output.

Once the terminal is open, type:

pidof firefox

Press ENTER to issue the command, and if you had Firefox open,
it will output something like that:

14497

Which means “a process named ‘firefox’ is running and his ID is 14497”.
Now, to kill that process:

kill <PID>

Replace PID with the process ID (in this case 14497) of the process
you want to kill. Press ENTER and Firefox will close.

Now, if you run pidof firefox again, it shouldn't output anything,
because there's no longer a Firefox process running.

All at once

Since running pidof and then killing is tedious, you can simply run:

killall firefox pidgin

And it'll kill all the processes that are named firefox or pidgin.
If no processes are found, it'll tell you:

firefox: no process found
pidgin: no process found


MacBook Pro screen brightness adjust not working (15" mid 2014 model w/ GeForce 750M, Ubuntu 20.04.1 LTS)

I put
sudo setpci -v -H1 -s 00:01.00 BRIDGE_CONTROL=0
manually into the terminal and it worked!
The problem was, that starting with Ubuntu 18.04 LTS there is no /etc/rc.local by default and creating one manually is not recommended. Instead, I used @reboot in /etc/crontab to execute the command on startup:
orkhans@matrix:~$ cat /etc/crontab
# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.
SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
# m h dom mon dow user  command
17 *  * * *  root    cd / && run-parts --report /etc/cron.hourly
25 6  * * *  root  test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
47 6  * * 7  root  test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
52 6  1 * *  root  test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )
#
@reboot root setpci -v -H1 -s 00:01.00 BRIDGE_CONTROL=0

Now it works fully and I can control my screen brightness as usual using F1 and F2!


df -h - Used space + Avail Free space is less than the Total size of /home

By default, ext2/3/4 filesystems reserve 5% of the space to be useable only by root. This is to avoid a normal user completely filling the disk which would then cause system components to fail whenever they next needed to write to the disk.

You can see the number of reserved blocks (and lots of other information about the filesystem) by doing:

sudo tune2fs -l /dev/sda8

For a /home partition, it is probably safe to set the reserved fraction to zero:

sudo tune2fs -m 0 /dev/sda8

Which should make an additional ~5GB available.


Pre-requisites

You will need these two extra packages if you don't have them:

sudo apt-get install build-essential libxml2-dev

Install PHP

In terminal:

wget http://in1.php.net/distributions/php-5.3.29.tar.bz2
tar -xvf php-5.3.29.tar.bz2
cd php-5.3.29
./configure
make
make test # Neither mandatory nor a bad idea.
sudo make install

The instructions will untar the source build and they will install php in your system.


Ethernet Cable not detected in Ubuntu 14.04 LTS

I had a problem like this before, and the issue was related to Realtek ethernet cards.

Here's how I fixed my issue:

ran this command that enabled my Internet access: sudo ethtool -s eth0 speed 100 duplex full
followed this guide for a permanent fix

Not sure if it'll help you, but it's worth a try.


I found an alternative way to get the resolution I wanted, what I did was use xrandr to create the new resolution I wanted, so even though it still says unknown display I have the option to select the correct resolution, and the screen looks perfect now.

In my case I needed the 1360x768 resolution (it only gave me the option for chosing 1024x768 or 800x600)

so here is how I got the right resolution:

alex@Minx:~$ xrandr
Screen 0: minimum 8 x 8, current 1024 x 768, maximum 32767 x 32767
HDMI1 disconnected (normal left inverted right x axis y axis)
VGA1 connected primary 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768      60.00*
   800x600       60.32    56.25
   848x480       60.00
   640x480       59.94

VGA1 is my device, then I created the resolution I wanted

alex@Minx:~$ sudo cvt 1360 768 60
# 1360x768 59.80 Hz (CVT) hsync: 47.72 kHz; pclk: 84.75 MHz
Modeline "1360x768_60.00"   84.75  1360 1432 1568 1776  768 771 781 798 -hsync +vsync

Created a new mode for my resolution:

alex@Minx:~$ xrandr --newmode "1360x768_60.00"   84.75  1360 1432 1568 1776  768 771 781 798 -hsync +vsync

Finally added the new mode to my VGA1 device:

alex@Minx:~$ sudo xrandr --addmode VGA1 1360x768_60.00

Then I went to Displays and was able to select the 1360x768 resolution.


ssh, by default, does not allow X11 forwarding (a method of forwarding X11 windows to your computer). To enable it, pass the -X option to ssh. The SSH server also needs to allow it; make sure the line:

X11Forwarding yes

is in your server's /etc/ssh/sshd_config file. If it isn't, add it and restart the SSH daemon:

sudo service ssh restart

However, some programs, due to the way they draw graphics, don't work at all with X11 forwarding. I haven't tried it with Visual Studio Code before, but I wouldn't be surprised if it didn't work.


Ubuntu 16.04 with Linux 4.4.0-83, is it outdated?

The latest kernel version for Ubuntu 16.04 is currently 4.4.0-89-generic. You can update the kernel to the latest version using the Software Updater. Ubuntu 16.04 is a long term support release which is supported by updates until April, 2021. Ubuntu is designed to be a secure operating system which is updated regularly. If you continue to update your operating system regularly using the Software Updater, your OS will be fine until April, 2021.


Install and run Python 3 at the same time than Python 2

Yes, you just need to install python3 package.

$ sudo apt-get install python3

Python 2.X will still be the default Python used, so if you want to run a script with Python 3.X you need to run

$ python3 /path/to/script.py

or add in the first line of your executable script:

#!/usr/bin/env python3


Why's this PCManFM command line not working?

From https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#exec-variables:

  The Exec key must contain a command line. A command line consists of an executable program optionally followed by one or more arguments. The executable program can either be specified with its full path or with the name of the executable only. If no full path is provided the executable is looked up in the $PATH environment variable used by the desktop environment. The name or path of the executable program may not contain the equal sign ("="). Arguments are separated by a space.

So, because of that equal sign from --profile=album, I think you have a problem. What you can do is to use a simple script like this:

#!/bin/bash

/usr/bin/pcmanfm --profile=album "/home/user/Downloads/videos"

Don't forget to make the script executable:

chmod +x /path/to/script

And finally add in your videos.desktop file this line:

Exec=/path/to/script

This method worked for me all the time.


Unable to start apache2 as it throws an error

The answer is right there in the message: (98)Address already in use: AH00072: make_sock: could not bind to address 0.0.0.0:80. When apache2 tried to use the bind system call to start listening to port 80, it failed, because some other process had already succeeded with its bind call.

Which other process? man lsof leads one to:

sudo lsof -i TCP:80

Since I don't serve port 80, let's look at port 22 (sshd) on my system:

$ sudo lsof -i  TCP:22
COMMAND  PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
sshd    1686 root    3u  IPv4  13939      0t0  TCP *:ssh (LISTEN)
sshd    1686 root    4u  IPv6  13941      0t0  TCP *:ssh (LISTEN)


How do I Access Files from one Ubuntu Partition on Another

Did you used separate partitions for your home folder? if you didn't:

Mount the filesystem then Navigate through the filesystem to /home/your-user/ and search for the files copy them to a safe place.

If you did:

Locate the correct partition and then Navigate through the partition and select your files and copy them to a safe place.


You can open a terminal and enter:

sudo aptitude reinstall apache2

This should bring  back removed files and if files have changed you'll be asked what to do with them.


Banshee is uninstallable due to broken depends. This is because the PPA for Banshee Team has NOT allowed or created a repository for 12.10 yet check this https://launchpad.net/~banshee-team/+archive/ppa and you will see what I mean.

you can try adding it using sudo apt-get install banshee

For those who wish to compile from trunk, add the deb-src line and then run "sudo apt-get build-dep" to install all required dependencies before starting to compile.

see https://launchpad.net/~banshee-team/+archive/ppa for reference


Use a date in the name of your archive

tar -cpzf /home/john/stuff_`/bin/date +%F`.tar.gz /mnt/test


Secondary Dell Display with Ubuntu on Acer Predator Helios 300

Please, try to lower the resolution from your monitor to Full HD and 60Hz and use Mirror Displays first. Does it work?. Is the external screen detected?.
If this works try to have the laptop's screen working at 60Hz and then extend the image.
I suspect that what happens is that the GPU is trying to use the same frequency for the external monitor than for laptops monitor. Then the external monitor does not support that frequency.
In other words, try to make it work at 1920x1080 FHD at 60Hz, the common for most mortals, and if that works lets start going for the higher specs.
Should not be a problem to use the max resolution of the display, but I think the problem may reside on operating on different frequencies.
Cheers.


What does last dot in the file permission attribute mean?

. means an SELinux ACL. (+ means a general ACL.)

Source, more info: What does the dot mean at the end of -rw-r--r--? How do you set it with chmod? on Super User


13.10 and 12.04 discs say I have no Windows 7 on my hard drive

If you check your hard drive with Gparted, you will notice that it will have a Yellow warning mark in any of your NTFS partitions. The way to fix it is shutting down totally Windows (no hibernation, no suspend, but correct shutdown of the system). If that doesn't get rid of the warning, you should run chkdsk /f in cmd (just type cmd in the start menu) with Administrative Privileges and restart Windows twice.

In case of Windows 8, apart of the actions above, you should disable Fast Boot and shutdown the system.


fatal error: 'openssl/bn.h' file not found on Ubuntu 18.04

I think you are probably missing libssl-dev.
  sudo apt-get install libssl-dev


Ubuntu 11.10, kernel 3.0.0-17 Booting problem "Hangs"

It happen to me too. I solve mine by editing the GRUB loader and setting to boot on VT=3 the once booted on terminal. I re-install the Nvidia driver downloaded from Nvidia website.


Why did Canonical choose Mir over Wayland as the display server?

Why Not Wayland / Weston?

  An obvious clarification first: Wayland is a protocol definition that defines how a client application should talk to a compositor component. It touches areas like surface creation/destruction, graphics buffer allocation/management, input event handling and a rough prototype for the integration of shell components. However, our evaluation of the protocol definition revealed that the Wayland protocol does not meet our requirements. First, we are aiming for a more extensible input event handling that takes future developments like 3D input devices (e.g. Leap Motion) into account. Please note though that Wayland's input event handling does not suffer from the security issues introduced by X's input event handling semantics (thanks to Daniel Stone and Kristian Høgsberg for pointing this out). With respect to mobile use-cases, we think that the handling of input methods should be reflected in the display server protocol, too. As another example, we consider the shell integration parts of the protocol as privileged and we'd rather avoid having any sort of shell behavior defined in the client facing protocol.

  However, we still think that Wayland's attempt at standardizing the communication between clients and the display server component is very sensible and useful, but due to our different requirements we decided to go for the following architecture w.r.t. to protocol-integration:

  A protocol-agnostic inner core that is extremely well-defined, well-tested and portable.
     An outer-shell together with a frontend-firewall that allow us to port our display server to arbitrary graphics stacks and bind it to multiple protocols.

  In summary, we have not chosen Wayland/Weston as our basis for delivering a next-generation user experience as it does not fulfill our requirements completely. More to this, with our protocol- and platform-agnostic approach, we can make sure that we reach our goal of a consistent and beautiful user experience across platforms and device form factors. However, Wayland support could be added either by providing a Wayland-specific frontend implementation for our display server or by providing a client-side implementation of libwayland that ultimately talks to Mir.

There is a more detailed discussion here : https://wiki.ubuntu.com/Mir/Spec?action=show&redirect=MirSpec

And from the Mir technical architect:

http://samohtv.wordpress.com/2013/03/04/mir-an-outpost-envisioned-as-a-new-home/

More information:

http://blog.cooperteam.net/2013/03/artistic-differences.html
http://blog.cooperteam.net/2013/03/mir-and-you.html
http://blog.cooperteam.net/2013/03/for-posterity.html


a wifi connection that used to work is no longer recognized

As I have two of these asus repeaters I noticed the other not having the problem. It seems to be DHCP related as when I switch the location after more then an hour the problematic one is now recognized whereas the other instantaneously. After my laptop 'found' it it reappears quickly after reboot. So now it is solved for me.


the certificate below OVPN_ACCESS_SERVER_WEB_CA_BUNDLE_START, is your CA certificate
the -----BEGIN RSA PRIVATE KEY--- , is your private key

copy the content of these certificates into separate files.
including everything from the  ---BEGIN----   , to ----END----  part
and add the in the corresponding entry in the vpn tab of network manager

I cant really tell from your configuration file which cert is the user certificate. But it's not the openvpn static key. copy and save the ones left to separate files, and try them one by one by one until you manage to connect


WUBI Ubuntu 12.04 boot, No kernel, GNU Grub, nothing works

Did you update your kernel?
If so you might have a problem because the grub.cfg generated by wubi
is different from the one generated by update-grub after you update.

In the original grub.cfg generated by wubi, the root.disk will be mounted through
the loopback device and used as the root, and then the location of the kernel is specified according to this root directory.

After you update your kernel, the grub.cfg file won't do the same because update-grub won't know that you are using wubi and needs to mount root.disk.

The solution to this is to take a look at the grub.cfg file before your update (if you still have it or find it somewhere else) and update the grub.cfg manually using a liveCD.

Wubi is just for experiencing ubuntu on windows, but not for long-term usage.


get into the console using ... ctrl-alt-F1 ... login ... then issue

sudo apt-get update
sudo apt-get install --reinstall ubuntu-desktop
sudo apt-get install unity

sudo reboot now

P.S. above trick to reach the console prompt also works for ctrl-alt-F1 through F6 whereas ctrl-alt-F7 will return you back to your normal desktop session


14.04 gets black screen unless radeon.modeset=0

this Question ist older, but I found a some how working solution I could not find for this context in any other answers to this problem.

I expirienced an similar behavior when booting up Kubuntu 16.10 on an iMac (late 2009) since a few weeks:
The system is running but the backlight is switched off some how at that moment when the framebuffer driver is activated.

It started after using the external displayport or an kubuntu-update I can not tell which. The nomodeset/...modeset=0 thing somehow works but then the radeon driver isn't loaded anymore and things that benifit a lot from hardware accelleration like googelmaps are not usable or only usable with pain.

At the moment I only have a solution for X:

SSH ssh username@yourImacIP -XC (-XC means: compressed with X-forwarding) to the iMac and run:

xrandr -d :0 --output eDP --crtc 1 --brightness 0.8

This how ever only works if I start the normal X-Displaymanager/Desktop-environment (in my case KDE) on the iMac.  So i have to assume that the correct useraccount is allready selected and I only have to type in the password blindly. Of course xrandr must be installed.

If I run the same command again - the screen turns black and if again the screens turns on again. So the logic of the command as I understand it (changing the brightness to a value between 0 and 1) is not working correct.

If anyone has a solution for the framebuffer-bootup not turning off the monitor-backlight I would appreciate it.

Update:

After the upgrade to kubuntu 17.10 the radeon driver didn't work at all in this setup.

But (current) happy end: with the latest updates (around middle of November) of the current Version of Kubuntu (17.10) the described procedures above seems not necessary anymore!
The Display comes up without any hassle and I can use the console again. Thank the almighty kubuntu or radeon-driver developers!

Still not working is my external display port :( The hardware seems to be gone...

If you still need the procedure above - attaching the line

xrandr -d :0 --output eDP --crtc 1 --brightness 0.7

to your local (in your user directory) *.xinit, .xinitrc or .xsessionrc* (whatever works) eases your live. You only have to authenticate blindly. A remote ssh is not necessary anymore.


How can I know how many archived logs are saved?

That is all handled by logrotate. Read man lograte, and look at your /etc/logrotate.conf.


WiFi stopped working after sometime 14.04 LTS on HP laptop

Press Ctrl+Alt+T

On terminal type this command

rfkill unblock all

This will help you if you have soft blocks on your network interface

If it doesn't work try these

ifup  This command will bring your network interface up.Run this as your root by specifying your network interface

If you don't know your name of your network interface try this command  ifconfig -a


Google Earth and $BROWSER environment variable

From the Ubuntu Community Documentation on environment variables:

  System-wide environment variables

  Environment variable settings that affect the system as a whole (rather then just a particular user) should not be placed in any of the many system-level scripts that get executed when the system or the desktop session are loaded, but into

  /etc/environment - This file is specifically meant for system-wide environment variable settings. It is not a script file, but rather consists of assignment expressions, one per line. Specifically, this file stores the system-wide locale and path settings.

  Not recommended:

  /etc/profile - This file gets executed whenever a bash login shell is entered (e.g. when logging in from the console or over ssh), as well as by the DisplayManager when the desktop session loads. This is probably the file you will get referred to when asking veteran UNIX system administrators about environment variables. In Ubuntu, however, this file does little more then invoke the /etc/bash.bashrc file.
  /etc/bash.bashrc - This is the system-wide version of the ~/.bashrc file. Ubuntu is configured by default to execute this file whenever a user enters a shell or the desktop environment.

The two files under Not recommended will work, but /etc/environment is there just for this purpose so we'll edit that file:

gksu gedit /etc/environment

And add the following line:

BROWSER=/usr/bin/firefox

You can replace /usr/bin/firefox with the path to whatever browser you prefer.
NOTE: You will have to restart your computer for the changes to take effect.


How to add iBus to start up applications?

You need to add ibus-daemon to your startup applications:

Open startup applications from the power cog

Add ibus-daemon


Apparently it's down to the 'adaptive technology', making brightness settings in many newer monitors redundant.
Many monitor and TV models no longer have a brightness setting because for HDR or eyecare to work properly peak brightness must be maintained, meaning the brightness slider serves no useful purpose. If you lower the brightness while in HDR, you’ll just ruin the image quality and defeat the whole logic of having an HDR-capable display.
In this particular BenQ the Brightness Intelligence sensor monitors ambient light in your environment and actively adjusts screen brightness for the most comfortable viewing experience. So there is no way to overide this, other than to choose one of the 'settings in the monitor's menu.
I've actually found I don't need the old brightness adjust button, it does indeed seem to adapt intelligently to the ambient light.


you need to enable packet forwarding in the kernel

edit /etc/sysctl.conf and activate the line

net.ipv4.ip_forward=1

by removing the # at the beginning.
reboot or enable the setting immediately  with

echo 1 | sudo tee /proc/sys/net/ipv4/ip_forward

Don't use SNAT (in fact don't use any kind of NAT at all). You have two networks, the router is attached to both (it has a leg in both). So remove the 3rd line of your iptables-rules.

remove the NAT rule from the router
configure all systems to reach the "other" network via the router

on the servers replace your route with
192.168.103.0/24 via 192.168.102.30 dev eth2
(this tells them how to reach the whole network, not just one client)
on the client add the following route
192.168.102.0/24 via 192.168.103.30 dev eth0

Now you will see that every packet from both servers will reach the client with the original source address. The client knows how to reach that source address and can send a reply to exactly the server that pinged it.


My Unity Desktop Broken because of MyUnity

can you open your terminal ?

OK either in terminal or press ctrl+alt+F1 and login there & then do as

unity --reset

restart your PC and try again .


Is it possible to change display settings and apply without logging out like Windows?

Anything that modifies xorg.conf requires the X server to be restarted before the changes can be applied. This is a limitation of the X server.

However, depending on your video card, you may be able to work around this issue by using one of your video card manufacturer's utilities. Nvidia, for example, ships a GUI configuration tool with its driver that allows you to add, remove, and modify the geometry of displays without restarting the X server (the tool also provides the option of permanently saving the changes to xorg.conf but that's not what you're asking). These tools cannot, however, add or remove X displays since that capability is reserved for the X server itself.

Something to consider down the road: X is eventually being replaced by Wayland which will (hopefully) be much easier to configure than X and offer the ability to add or remove displays while running.


Install Ubuntu to a discrete drive without touching the main bootloader

At the end of the installation process, you are asked to install a bootloader aka grub.

At the bottom of the screen choose the device on which to install it with the drop-down menu.

That's it.

Although, the installer will certainly auto-detect other OSes and populate the grub menu with it. But that' not a problem. Just ignore those entries.


Can't log into ubuntu 13.10, tried unity, cinnamon and gnome session

Log in to the guest account. Push Ctrl + Alt + F2

Login with username and password

sudo apt-get install ubuntu-desktop && sudo apt-get install --reinstall lightdm

This happened to me and it fixed when reinstalling Unity and LightDM


java file will not launch from .desktop file - Ubuntu 12.04 LTS

Answer taken from comments

Chaos

  I would write KeeperDesktop.jar in an absolute path:
  /path/to/KeeperDesktop.jar

DaveyT

  SOLVED - chaos- your suggestion was correct, I changed the path to an
  absolute one and it works …


Problem with ubuntu 18 dual boot windows 10

Later edit:

After trying a lot of different solutions, here's how I finally solved it, in case anyone else has the same problem. Follow along and you should be able to boot into Windows again without losing any of your data.

I created a bootable Windows DVD (I've tried with a stick also, but
for some reason it wouldn't boot; for you, a USB stick might work)
When setup starts, click next and follow the instructions until you
reach the point where it asks you where you want to install Windows.
Format the partition on which Ubuntu is installed.
Continue installing Windows to the formatted partition (the one in
step 3)
Wait for the setup to finish. When the setup is done it should boot
into the newly installed Windows version
Once you are logged in, go to Computer and make sure that the old
Windows partition is there. If it is, everything's all right, you
can continue. Make sure to remember the letter associated with it
(for example D:)
Install EasyBCD (you can find it here:
https://www.techspot.com/downloads/3112-easybcd.html)
Launch EasyBCD, press 'Add New Entry' and name it however you like.
For 'Drive' choose the letter at step 6)
Once it's done, go to 'View Settings' to make sure that the settings
have been saved.
Reboot. Now, you should see the newly created option. If everything
 is all right you should boot into the old Windows wihout any
 problems. The following steps are optional.
IF you want to remove the newly installed Windows, install EasyBCD and
 remove the boot option from the boot menu (from 'Edit Boot Menu')
Run 'diskmgmt.msc', format the partition you've just installed and
 extend the current partition. You're done


How to make terminal transparent while still having its own background image?

Assuming you are asking about Gnome Terminal, select your background image and adjust below transparency slider - it's in same tab in same preferences dialog


Type the following command in a terminal:

xrandr -r 85

But before that you have to make sure that the CRT monitor supports the new refresh rate.

Please type into a terminal the following command and paste the output: xrandr


Does Visual Studio Express work well with Wine?

It looks unlikely that it will work in Wine.

You have several other options:

Dual boot - install Ubuntu alongside Windows and use Windows to run Visual Studio Express when you need to do school work.
Install Windows in a virtual machine using Virtual Box or other virtualisation software. You can then install Visual Studio Express in the virtual machine and use that when needed.
Use IDEs available on Ubuntu from the Software Centre in the Developer Tools > IDEs department:

You may want to ask your teachers about using other IDEs. The code you write should work for any IDE unless it is platform specific or uses a particular GUI designer.


Is it safe have more than one version of java?

Yes, it is safe to have more than one version of Java installed. Ubuntu uses the Debian alternatives system to make this work safely and smoothly.


Purpose of '~/.cache' directory and when is it safe to delete?

This is by no means a definite answer.

According to the XDG Base Directory Specification, $XDG_CACHE_HOME which defaults to $HOME/.cache holds

  [...]user-specific non-essential (cached) data[...]

It is however not specified what constitutes 'non-essential data'. Furthermore an application might not play by freedesktop rules and put whatever it wants in .cache.

Browsing through my cache folder, I find things like

Browser caches. Safe enough to delete.
Thumbnails. Will be recreated if deleted.
software-center. Wasn't sure about that. Contains a file apthistory.p with your - well - history of apt. Moved it out of the way and it was recreated on the next start of the Ubuntu Software Center.
I guess the Software Updater stores package lists apt-file. Will be downloaded anew if deleted.
icon-cache. Like thumbs, will also be recreated.
compizconfig-1. Contains binary files; compiz seems to cache its configuration in optimized form from ~/.config/compizconfig-1.
dconf. This directory actually doesn't belong to $USER but root. Mine contains a single non plaintext file user. Since you can't delete it anyway without sudoing... No problem.
And some more directories which I don't deem critical.

In summary, I believe it perfectly safe to empty the cache folder. In fact I do this from time to time and never experienced faulty behaviour afterwards.

This is not a guarantee though, just my two cents and a (somewhat) educated guess.


Tata Docomo 3g Dongle in Linux [Mint or Ubuntu ]

I also have tatadocomo3g. I tried to install setup but it was not working properly because some packages were missing and I was not able to connect internet to dowload those also.

After so much frustration I finally found alternate way using sakis3g to connect internet.

I am using dual boot with Win7 and ubuntu 13.10 so I downloaded sakis3g script in win7 and ran it on ubuntu and it worked.

Installation procedure is explained here

Then setup connection by following steps given below

run sakis3g then an interactive window will come
select > connect to 3G
select > USB device
select > ZTE WCDMA Technologies MSM
select >  interface #3
give apn: tatadocomo3g
username:  TIM  |  password:  TIM

actually nothing is required in username and password field, but sakis3g interactive won't allow you to leave username and password blank so just give it as TIM.

It will connect... if not connect modem on different usb port and try again.


Try changing ATTRS to ATTR for vendor and product


If you prefer to install from a ppa you can use this one for Ubuntu 12.04:

sudo add-apt-repository ppa:michael-astrapi/ppa
sudo apt-get update && sudo apt-get install truecrypt

And to remove it:

sudo apt-get install ppa-purge
sudo ppa-purge ppa:michael-astrapi/ppa

In the past others have used different PPA: link here


Firefox profiles with different icons in Ubuntu dock

Edit profile's .desktop file:

add --class SomeClass to the end of Exec key to change program's WM_CLASS value (see this article)
add new key StartupWMClass=SomeClass to the end of file (see this article and desktop entry specification)

The string SomeClass must be the same in both changes.

Example .desktop file:

[Desktop Entry]
Name=Firefox Test
Exec=firefox -p test -no-remote --class FxTest
Terminal=false
Type=Application
StartupNotify=true
Icon=/path/to/custom/icon.png
StartupWMClass=FxTest


You can install imagemagick on terminal using this command:

sudo apt install -y imagemagick

This will prompt you for your password to use root level access. (required for installing packages)

apt will automatically resolve and install any necessary dependencies automatically.

You can confirm it is installed with (version may be different):

$ convert --version
Version: ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org
Copyright: © 1999-2017 ImageMagick Studio LLC
License: http://www.imagemagick.org/script/license.php
Features: Cipher DPC Modules OpenMP
Delegates (built-in): bzlib djvu fftw fontconfig freetype jbig jng jpeg lcms lqr ltdl lzma openexr pangocairo png tiff wmf x xml zlib


Create files in folders created by other users

You want to change the users' umask

There is an answer describing it here.

TL;DR

$ umask 007

for each user.


Ubuntu 14.10 Install Fails to Boot on Gigabyte PC

Did the IMAGE ISO download and write perfect?

I've had many times the ISO download was corrupted / forged.

Also I have 2 gigabyte PCs here both identical, one installs runs UBU perfectly the other not at all - its a mystery to me


When running the arping command in the terminal, I get the following output:

$ arping -U 192.168.13.1 -w -1
arping: device (option -I) is required.
Usage: arping [-fqbDUAV] [-c count] [-w timeout] [-I device] [-s source] destination
  -f : quit on first reply
  -q : be quiet
  -b : keep broadcasting, don't go unicast
  -D : duplicate address detection mode
  -U : Unsolicited ARP mode, update your neighbours
  -A : ARP answer mode, update your neighbours
  -V : print version and exit
  -c count : how many packets to send
  -w timeout : how long to wait for a reply
  -I device : which ethernet device to use
  -s source : source ip address
  destination : ask for what ip address

The solution is in the first line after running the command. Use -I and -s to fix your problem. -I specifies the interface to do the arping on and -s is to specify the source your are doing the arping from. It's crappy, I know, but update your command to look like the below:

arping_cmd = 'arping -U $_IP_$ -w 1 -I ethX -s SOURCE_IP'

where ethx is your ethernet and SOURCE_IP is the IP you are going to do the arping from.

Hope this helps,
Cheers


How to configure micromax 352g modem in  12.04

Try Betavine Connection Manager
It's from vodafone, and works for a wide range of mobile broadbands
https://forge.betavine.net/frs/?group_id=76&release_id=285