How to move windows to a certain screen when using more than two monitors in gnome-shell?

The good news is that the y- resolution of all screens is the same, and the screens are vertically alligned, so we do not need to take care of possible y- position clashes, like here.

Moving windows across multiple screens, using the screen as an argument

Below a script to make available under three (for three screens) shortcut keys.
By pressing the keys, you can move the windows to either screen 1, 2 or 3. The script calculates on what screen the window is on, and the distance the window has to be moved.

The script

#!/usr/bin/env python3
import subprocess
import sys

target = int(sys.argv[1])

# --- for Unity, there is a deviation in the y coordinate of the wmctrl -command
# --- for Unity, set: deviation = -28
deviation = 0
# ---

# get the (sorted) x resolution of the screens as a list
screens = [int(s.split("+")[-2]) for s in subprocess.check_output(
    ["xrandr"]).decode("utf-8").split() if (s).count("+") == 2]
screens.sort()
# get the frontmost window and its coordinates
frontmost = [l.split("#")[-1].strip() for l in subprocess.check_output([
    "xprop", "-root"]).decode("utf-8").splitlines() if "_NET_ACTIVE_WINDOW(WINDOW)" in l][0]
active = frontmost[:2]+(10-len(frontmost))*"0"+frontmost[2:]
windata = [l.split() for l in subprocess.check_output(
    ["wmctrl", "-lG"]).decode("utf-8").splitlines() if active in l][0]
# get the current screen the window is on, and (thus) the x-position (of the screen)
currscreen = len([cr for cr in screens if cr <= int(windata[2])])
currpos = sum([item for item in screens[:currscreen]])
# calculate the target position/the distance to move the window
target_pos = screens[target-1]
move = target_pos-currpos
command = ["wmctrl", "-ir", active, "-e", "0,"+(",").join(
    [str(int(windata[2])+move), str(int(windata[3])-28), windata[4], windata[5]])]
# move the window to the targeted screen
subprocess.Popen(command)

How to use

The script needs wmctrl:

sudo apt-get install wmctrl

Copy the script into an empty file, save it as move_window.py
Test- run the script by running it in a terminal window, with the commands:

python3 /path/to/move_window.py 1

To move the active window to screen 1,

python3 /path/to/move_window.py 2

To move the active window to screen 2,

python3 /path/to/move_window.py 3

To move the active window to screen 3

Since the terminal is your active window, it should move across your screens on the commands.
Add it to three different shortcut keys, e.g. Ctrl+Alt+1, 2 and 3: choose: System Settings > "Keyboard" > "Shortcuts" > "Custom Shortcuts". Click the "+" and add the command(s)

Notes

The question was on Gnome, but the script should work on (at least) Unity as well. There is however a deviation when used on Unity, as explained in the head section of the script and here.
Since the script gets the screen information from xrandr, it should work as well with 2, 3, 4 or any number of screens.


dpkg Errors were encountered while processing

The file appears to be corrupted, it's not an installation issue.

Delete the file, redownload it, and try to dpkg it again.


How to make 'python' program command execute Python 3?

A simple safe way would be to use an alias. Place this into ~/.bashrc or ~/.bash_aliases file:

alias python=python3

After adding the above in the file, run source ~/.bashrc or source ~/.bash_aliases.

For example:

$ python --version
Python 2.7.6
$ python3 --version
Python 3.4.3
$ alias python=python3
$ python --version
Python 3.4.3

To circumvent the alias use the command built-in command:

$ command python --version
Python 2.7.6

Another way to circumvent the alias is to use \ before the command.

$ \python --version
Python 2.7.6

To disable the alias in the current shell use the unalias built-in command:

$ unalias python
$ python --version
Python 2.7.6


Increase space for Ubuntu Server on VirtualBox

You made the wrong decision. You have to resize the partition instead of creating a new partition.

Now boot from Gparted and delete the newly created 30Gb partition
Resize the old partition and get the space you need

To resize it, click ‘Resize/Move’ button

Next, use the slider to drag the line to the left to repartition the free space. The available free space is the area with the white background. Ubuntu is installed in the area with the yellow background.  When you’re done, click ‘Resize/Move’ button to apply the changes.

Finally, review the changes and click ‘Apply’ to save.


Assiging a static IP - write permission denied

First, you cannot simply rename your interfaces to eth0 if your system is using enp4s0. I suggest that you do:

 sudo nano /etc/network/interfaces

Set up the file something like this:

auto enp4s0
iface enp4s0 inet static
address 192.168.1.107
netmask 255.255.255.0
gateway 198.168.1.1
dns-nameservers 192.168.1.1 8.8.8.8

I suggest a static address of x.107 as it is unlikely to conflict with the range of addresses used by the DHCP server in your router. The network address may safely be omitted, and therefor not subject to guesswork. Lastly, it is dns-nameservers and not dns.

Restart the interface:

sudo ifdown enp4s0 && sudo ifup enp4s0

Check:

ping -c3 192.168.1.1
ping -c3 www.ubuntu.com

If you get ping returns, you are all set.


14.04.3 LTS + xenial kernel upgrade + nvme SSD - won't boot

This just happened to me, and it turns out the nvme kernel module wasn't loaded into the initramfs.

When you get dropped into the busybox prompt, try modprobe nvme. If it doesn't show up in /proc/modules afterwards, the initramfs is missing it.

Simply add nvme to your /etc/initramfs-tools/modules file, and then run:

sudo update-initramfs -u -k all

and it should fix your problem.

(Someone with an launchpad account should report this bug to Ubuntu)


Compositing is provided by Compiz, which is a compositing window manager. What it means is explained below:

A compositing window manager is a
component of a computer's graphical
user interface that draws windows and
their borders. It also controls how
they display and interact with each
other, and with the rest of the
desktop environment. The main
difference between a compositing
window manager and other window
managers is that instead of outputting
to a common screen, programs each
output first to a separate and
independent buffer, or temporary
location inside the computer, where
they can be manipulated before they
are shown.[1][2]
The window manager then processes and
combines, or composites, output from
these separate buffers onto a common
desktop. The result is that the
programs now behave as independent 2D
or 3D objects.[1] Compositing allows
for advanced visual effects, such as
transparency, fading, scaling,
duplicating, bending and contorting,
shuffling, and redirecting
applications. The addition of a
virtual third dimension allows for
features such as realistic shadows
beneath windows, the appearance of
distance and depth, live thumbnail
versions of windows, and complex
animations, to name just a few.[3][4]
Because the programs draw to the
off-screen buffer, all graphics are
naturally double buffered and thus do
not flicker as they are updated.
The most commonly-used compositing
window managers include the Desktop
Window Manager in Microsoft Windows,
the Quartz Compositor in Mac OS X, and
Compiz, Metacity and KWin for Linux,
FreeBSD and OpenSolaris systems.
http://en.wikipedia.org/wiki/Compositing_window_manager

If you see a black border around docky, then compositing is not properly enabled. The warning you are getting is most likely a result of Docky starting before compositing kicks in.
See https://bugs.launchpad.net/docky/+bug/552273


alias updt='sudo apt update -y && sudo apt full-upgrade -y && sudo apt autoremove -y' ... What could go wrong?

Lots of terrible things are possible. It's a big world. You can make those terrible things less likely several ways:

Read output instead of suppressing it. The output is there to tell you what is happening. It's there to tell you what went wrong. On a bad day, you NEED it.
Avoid using the -y flag: Confirmation dialogs are the brightly-painted guardrails that keep your car from flying off the cliff into the sea. Use it for the intended purpose.
Learn how to use Unattended Upgrades (built into apt) instead of hacking together your own script. UU will happily update/upgrade your system in the background daily, has many configuration options, can pull from only certain repos if you so choose, and can be triggered either by you (sudo unattended-upgrade) or by a cron job/systemd timer. It's smart enough to only run once daily regardless of triggering method, and you already have it as part of apt.

YES, it's possible for an apt-update/upgrade to cause problems with your system. However, the human admin is almost always the real cause of the disaster - they ignored months of warning messages, they added an unofficial or wrong-release repo, they unwittingly removed a critical lib or application, they installed some conflicting software they found on some random github site, etc.


I have to toggle ethernet off/on to get online every restart

There is a file in your home directory called .profile.

The above post recommends you add a line to it (ifup eth1) which enables your network card.
You could also add a line before that (ifdown eth0) which would shut down your network card.
This would in theory simulate what you are doing in the guitar.
Essentially it's a script or batch file that will run that command at boot which in theory is the same as disabling and enabling your network card that you are doing to make your network work.

It's a workaround not a solution for why it's happening but it will make your virtual machine function on boot up.


Sharing playlist between any music player in Windows and Ubuntu

I assume your music resides in somehting like a library of mp3 files, shared between the operative systems (either on a common partition in a dual boot system, or via e.g. dropbox) .

In that case, the .m3u format works with most media players (both iTunes and Rythmbox) on any OS, and you should be able to both create and edit your playlists on either side.


How do I achieve a PPPoE connection over wifi?

Obviously, it is at least funny question if I right understand where this intended :)
It can be missed LAN cord for example ... ok.
I suggest to clear your DSL(PPPoE) settings which you created through Edit Connections dialogue. Then reset your DSL router, and connect to him through your Ubuntu Wireless like to the default Wireless Network, by default IP. Next, just you will need configure your router through router's interface.
Defaults, like the default wireless network SSID for your router you can find at official website. However, I do not know how much possible that wireless is enabled by default.

If yes, obviously YES, it possible.


Finding all used IP addresses within a LAN without assigning an IP address to your NIC?

No, that's not possible.  You cannot use the TCP/IP tools without an IP address.  That would be like connecting to a network without a network card.

What would be possible is test MAC address to MAC address communication, but both NICs would have to have similar firmware loaded and knowledge of each other's MAC address to be able to do this (Intel cards used to be able to do this 20 years ago).

Sorry to be the harbinger of bad news...


I cannot mount a partition as the home directory

If you did not create a home partition, there is nothing to mount.  If you want to create a home partition, you will need to resize your root partition, create the home partition, and edit /etc/fstab.

To resize and create partitions, it would be easiest to use GParted Live.
To add the newly created home partition to /etc/fstab, add a line that looks like this:

UUID=XXXXXXXXXXXXX /home       ext4    defaults        0       2

Check the output of blkid to replace XXXXXX with the uuid of your home partition.  Change ext4 to correspond to the filesystem of your partition.

See the fstab manual for more information.


Can I copy large files faster without using the file cache?

There is the nocache utility, which can prepended to a command like ionice and nice. It works by preloading a library which adds posix_fadvise with the POSIX_FADV_DONTNEED flag to any open calls.

In simple terms, it advises the kernel that caching is not needed for that particular file; the kernel will then normally not cache the file. See here for the technical details.

It does wonders for any huge copy jobs, e. g. if you want to backup a multi terabyte disk in the background with the least possible impact on you running system, you can do something along nice -n19 ionice -c3 nocache cp -a /vol /vol2.

A package will be available in Ubuntu 13.10 and up. If you are on a previous release you can either install the 13.10 package or opt for this 12.04  backport by François Marier.


I have an error when install ros-melodic-slam-gmapping

This worked for me. The package maintainer status is unmaintained, so you should migrate to other solution.
sudo apt-get install libsdl1.2-dev
sudo apt install libsdl-image1.2-dev

cd ~/catkin_ws/src/
git clone https://github.com/ros-perception/openslam_gmapping
git clone https://github.com/ros-perception/slam_gmapping.git
git clone https://github.com/ros-planning/navigation.git
git clone https://github.com/ros/geometry2.git
git clone https://github.com/ros-planning/navigation_msgs.git
cd ~/catkin_ws
catkin_make  (or catkin build) -- Compiling will take a while but with ros melodic on a jetson agx and ubuntu 18.04 I didn't have issues.

(reference: https://www.programmersought.com/article/52912958276/)
Juan.


Disk Usage Analyzer and other programs reporting incorrect partition capacities

http://ubuntuforums.org/showthread.php?t=1122670
This is a very large topic, so go to section #5, where it says:

While DUA provides valuable information, it often brings up questions
about its use. Here are some things to keep in mind:
Once a scan is
complete, the top entry, whether it is the system or a single folder,
will always show 100%. The sub-folder percentages add up to 100%. 100%
does not necessarily mean there is no space left on the partition.

A similar thing happened to me on Debian 7/Gnome 3.  I tried to install google-chrome, but it installs to /opt so my root partition filled and it aborted.  Gnome opens Disk Usage Analyzer and it says 100%, but df only says 52% in use.  So in my case, DUA misled me and wasted my time only.  I'm sorry I can't say why your program fails through, I would only say make sure that it is not generating large files somewhere on that partition.


Since it's 100°C, that's high enough that it's certainly not accurate.

The likely explanation is that it's a software bug, due in part to the drive being so new that it's unlikely this software utility had been tested with it.

You could try installing the package hddtemp and using the hddtemp tool to check the drive temperature.  There's a chance it'll say the same thing, but maybe not.

An SSD is usually not something you'd normally need to worry about getting too hot - they don't usually require active cooling and don't have moving parts.  As long as you have working ventilation/fans in your case it should be fine.  Unless you have some other reason to be concerned, you probably don't need a working temperature indicator on your SSD.


if ps ax | grep -v grep | grep apache2 > /dev/null
    then
        exit 0
    else
        echo "apache2 is not running!" | mail -s "Apache2 is down"
        sudo service apache2 start

    fi

and about the running the bash script, it depands on you how often you wanna check it,
I think , every 15 minutes will be enough to check or every hour.

that will be the crontab command if you want to check every 15 minutes:

*/15 * * * * /tmp/checkservice.sh >/dev/null 2>&1

this will check the service every 15 minutes and if the service is not running then it will send you an email,
you can also add auto start code in else part if you want this task also to be automatized.


Gzip has error-detecting code, like if there's an error (ex. one changed byte) gzip will complain & tell you about it. Some archive formats like zip and 7z say if there's an error, I just tested gzip (changed one byte in a 3k .gz) and it complained: gzip: test.gz: invalid compressed data--crc error

Does gzip (gunzip) complain about any corruption while uncompressing, or are the files just silently messed up? If gzip doesn't complain then maybe they were messed up to start with when they were stored, and were successfully stored with the corruption.

Maybe storage medium/disk errors, or transmission/network/copying errors, or I've even seen bad ram that would give occasional random errors in the middle of files before. I'd try memtest, then some testing on the storage drive like fsck or badblocks, or did you make hashes to test for file errors, like crc32/md5/sha checksum files?


gpg key generation sync to keyserver not a key ID: skipping

The question is old and you undoubtedly have found an answer by now - but to put it here, you need to put an 0x in front of the key ID: 0x8749B0B57526888D32FF6AEEB7BA37
That tells the system it is a hexadecimal number.


How to Install Ubuntu on separate hard drive in a dual boot?

You can install Ubuntu on a separate drive by booting from a CD/DVD or bootable USB, and when you get to the installation type screen choose something else.

The images are instructional.  Your case might be different.

Be careful to make sure that you're installing on the right hard drive. If by mistake you install on the C Drive it can cause a problem with Windows.

Just make sure that you read the instructions, especially which hard drive to install to, since Linux lists drives different than Windows.  Check the capacity of the drive that you want to assign to Ubuntu, and make sure that you have select the correct hard drive.


How do I control the fan on a Apple Mac Mini?

Try to use fancontrol. It might help.
You could then edit your config file /etc/fancontrol or run pwmconfig (sudo su - -c /usr/sbin/pwmconfig). You can also edit the config file like this one, but bear in mind that you have different hardware:
Taken from https://wiki.archlinux.org/index.php/Fan_speed_control

INTERVAL=10
DEVPATH=hwmon0=devices/platform/coretemp.0 hwmon2=devices/platform/w83627ehf.656
DEVNAME=hwmon0=coretemp hwmon2=w83627dhg
FCTEMPS=hwmon0/device/pwm1=hwmon0/device/temp1_input
FCFANS= hwmon0/device/pwm1=hwmon0/device/fan1_input
MINTEMP=hwmon0/device/pwm1=20
MAXTEMP=hwmon0/device/pwm1=55
MINSTART=hwmon0/device/pwm1=150
MINSTOP=hwmon0/device/pwm1=105

INTERVAL: how often the daemon should poll CPU temps and adjust fan speeds. INTERVAL is in seconds.

The rest of the configuration file is split into (at least) two values per configuration option. Each configuration option first points to a PWM device which is written to which sets the fan speed. The second "field" is the actual value to set. This allows monitoring and controlling multiple fans and temperatures.

FCTEMPS: The temperature input device to read for CPU temperature. The above example corresponds to /sys/class/hwmon/hwmon0/device/temp1_input.
FCFANS: The current fan speed, which can be read (like the temperature) in /sys/class/hwmon/hwmon0/device/fan1_input
MINTEMP: The temperature (°C) at which to SHUT OFF the CPU fan. Efficient CPUs often will not need a fan while idling. Be sure to set this to a temperature that you know is safe. Setting this to 0 is not recommended and may ruin your hardware!
MAXTEMP: The temperature (°C) at which to spin the fan at its MAXIMUM speed. This should be probably be set to perhaps 10 or 20 degrees (°C) below your CPU's critical/shutdown temperature. Setting it closer to MINTEMP will result in higher fan speeds overall.
MINSTOP: The PWM value at which your fan stops spinning. Each fan is a little different. Power tweakers can echo different values (between 0 and 255) to /sys/class/hwmon/hwmon0/device/pwm1 and then watch the CPU fan. When the CPU fan stops, use this value.
MINSTART: The PWM value at which your fan starts to spin again. This is often a higher value than MINSTOP as more voltage is required to overcome inertia.

There are also two settings fancontrol needs to verify the configuration file is still up to date. The lines start with the setting name and a equality sign, followed by groups of hwmon-class-device=setting, seperated by spaces. You need to specify each setting for each hwmon class device you use anywhere in the config, or fancontrol will not work.

DEVPATH: Sets the physical device. You can determine this by executing the command

You should have these values set accordingly to the values of the the command sensors.


You'll get this error if there are no *.ttf files there. By default, if no files match a glob pattern, then the pattern itself remains in the command. Turn this off with the bash nullglob shell option
To be a bit safer, verify there are actually some files to move:
#!/usr/bin/env bash
...
shopt -s nullglob
# store files in an array
files=( /home/vaishnavi/Downloads/*.{ttc,ttf} )
# and if the array is not empty, move the files.
if (( ${#files[@]} > 0 )); then
    sudo mv -t /usr/local/share/fonts/ms_fonts/ "${files[@]}"
fi


Missing access rights to other partitions

run sudo nautilus in terminal

input password

and your should be able to edit all the files and folders on that partition. You can even give permissions to the current user by right clicking >>properties>>permissions


when will gnucash 3.8 turn up in the ubuntu repos?

From https://packages.ubuntu.com/search?keywords=gnucash:

  focal (gnome): personal and small-business financial-accounting software [universe]
  1:3.8b-1build3: amd64 arm64 armhf ppc64el s390x

So you'll get it when Ubuntu 20.04 LTS is released in late April 2020, tentatively on April 23.

Alternatively, if you don't mind using a ppa in 19.10, search Launchpad for gnucash ppa. One example is https://launchpad.net/~sicklylife/+archive/ubuntu/gnucash?field.series_filter=eoan.


How to run a MS-DOS application in Wine?

DOSBox is a good solution, but Dosemu is a more powerful option; for example, in DOSBox you can't use a printer.

$ sudo apt-get install dosemu

you can edit the configuration if it doesn't suit you:

$ vi /etc/dosemu/dosemu.conf

see http://manpages.ubuntu.com/manpages/oneiric/man1/dosemu.bin.1.html


Will Ubuntu 12.04 LTS run on my GIGABYTE GA-Z87M-D3H motherboard?

The Scott Deagan and FangQ posts at https://communities.intel.com/thread/19133 indicate it will install automatically, but you may need to reconfigure for best performance. However, the CPU you select, since that generation of Intel CPUs also include the GPU, will determine the exact driver to select at http://www.intel.com/support/graphics/sb/cs-010512.htm

To enable SNA, you have to modify or create /etc/X11/xorg.conf to add the following:

Section "Device"
Identifier "Card0"
Driver "intel"
Option "AccelMethod" "sna"
EndSection

After doing this, reboot. You can check SNA is running by opening up a terminal and entering:

grep -i sna /var/log/Xorg.0.log

If there is output from the above command, then SNA is running.


After forcing shutdown during early startup, POST takes super long, and other problems

Thanks to @Zacharee1 for helping me with this one.

Four simple steps to solve this (make sure the power is OFF before doing this!):

Pull out the power cord. On a phone, remove the battery.
Press the power button. The power led will likely turn on and briefly after that turn back off.
Put the cord or battery back in.
Turn the power back on, and everything should work again.

What you just did is reset your PC/phone. It means that all volatile memories (such as the RAM or BIOS cache) that may possibly have retained some bad data will be reset, although any non-volatile memories such as your hard drive will be unaffected, so don't worry.

You may have to boot into the system once more for it to fully fix the problem. After that, the next boot will succeed normally.

Also, don't forget to go back into the BIOS setup after doing this, as many settings will reset to factory defaults when you power cycle a device. Usually, the time will remain in order, unless you took so long that the battery that powers the clock will have died. But that takes several months.


Easy Method to Encrypt a 500GB portable USB drive with True Crypt?

USB connected drives are slower, and the encryption selected does also slow things down.

If there's a scheduled defrag or antivirus, those processes will also delay the process; you may wish to disable those pro tem, especially if your laptop CPU is single core.

http://www.truecrypt.org/docs/troubleshooting  has more specific information.


Wrong ideas and errors

  I have leared that I cannot use backticks or environment variable substitution in the ExecStart line.

You have learned a falsehood.  The doco does not in fact say this.  You can use environment variable substitution (with a syntax that is subtly different to most Unix shells').  It is simply the case that there is no HOSTNAME environment variable to substitute.  Service processes are not spawned with such an environment variable set up.

Unit files are parameterizable, and the %H parameter expands to the (dynamic) host name as it was at the point in the past that the unit was loaded from file.

  ExecStart=/bin/sh -c "/usr/bin/autogetty.sh"[…] I have yet to try modifying the service type yet.

Good.  Do not.  That's the wrong thing to do.  Only change the readiness notification protocol to forking if your service actually implements that protocol.  Don't do it as a kludge because you have erroneously made a program that forks for no good reason.

Because that's exactly what you have done.  The unnecessary /bin/sh is forking a child to run autogetty.sh, which ends up being a second shell process running that shell script.  The second shell process is then forking to run mingetty as a grandchild.  This does not match the forking readiness protocol anyway, as that relies upon fork followed by exit in the parent.

Take a lesson from the world of daemontools:  Services are run, not spawned.  The program that you run as ExecStart should be the service process, not something that spawns the service process.

The right way

The right way to set things up is this:

Override a specific instance of the template, for the specific terminal device, not the whole template.
Use %H to obtain the host name in ExecStart.  Or use %m and the machine ID as your user account names.
Invoke things properly:

Just run agetty directly, for best results.  You don't actually need any scripting for the task as described at all.
If you do nonetheless choose to insert a superfluous wrapper script:

Don't use /bin/sh -c scriptfile.  Just make scriptfile executable, with a properly specified script interpreter, and run it directly.
Make sure that your script uses exec to become the dæmon getty process.

Further reading

Werner Fink and Karel Zak. agetty.  Ubuntu 15.04 manual pages.
https://askubuntu.com/a/659268/43344
https://unix.stackexchange.com/a/233855/5132
https://unix.stackexchange.com/a/194218/5132
Jonathan de Boyne Pollard (2015). Readiness protocol problems with Unix dæmons. Frequently Given Answers.
https://unix.stackexchange.com/a/200365/5132
https://unix.stackexchange.com/a/194653/5132


This means that your GPU is powerful enough to provide you with the option of using a resolution up to 4096 x 2160.

Given your the result you get on your display when selecting the mode, I'd say:

Unfortunately, your display is not up to par with your GPU :'(


Package missing when I run `sudo apt install ...`

Your sources.list doesn't contain any binary sources.

Go to System Settings -> Software & Updates and enable all sources at the first tab.

Then the system will suggest to update and you'll be able to install everything from the repos.


The post in question uses tmpfs, which means it uses a combination of ram and swap. You may want to look into ramfs instead as it only uses ram space. I would imagine the command is similar. You could also use ramdisk which creates a virtual device that you can apply a filesystem to and everything.

Sources:

  "tmpfs will use swap space when neccessary"

source = https://stackoverflow.com/questions/7242484/can-i-over-run-the-tmpfs-size

  "If you compare it to ramfs (which was the template to create tmpfs)
  you gain swapping and limit checking."

source = www.kernel.org/doc/Documentation/filesystems/tmpfs.txt

  "The memory used by tmpfs grows and shrinks to accommodate the files it contains and can be swapped out to swap space"

source = http://en.wikipedia.org/wiki/Tmpfs

  "Tmpfs uses swap, where as Ramfs doesn't."

source = What is the difference between tmpfs and ramfs


The Transmission GTK has a web interface.

In menu: Edit > Preferences, the Web tab, allows to enable web, and configure port, authentication and accepted incoming IP addresses.  That web interface controls the same torrents that are governed by the GTK.

I am not sure if the Web tab is available without having installed transmission-deamon, though.


Where can I find what filesystem lvm2 uses/

LVM is a way to manage your data volumes in a flexible way : Your can picture it like a pool of virtual HD : Like any HD, it support every file system, and won't create it for you.

The basics steps are:

Create some PV
Create at least one volume group,
create logical volumes in a group, allocate space for them from your physical volumes

These LVs appears as regular disks on your file system hierarchy (in /dev/groupe-name/logical-vol-name)

Finally create a filesystem on your LV


How do I install memorex 6142u scanner into virtualbox?

You can access that scanner from within the Virtual Machine. Look at the menu at the top you will see devices select that and go to usb and there you will see your connected scanner.

Click on the scanner entry and you should be fine.


Error while updating and installing a package in ubuntu server 14.04 LTS

Please, run the following command in a terminal.
nslookup. Then, see if your server DNS could be resolved running

  server

If the server DNS resolution is correct then you have another problem.
Exit nslookup

Or, maybe another problem.

Clean your cache:

sudo apt-cache gencache
man apt-cache

gencaches creates APT's package cache. This is done implicitly by all commands needing this cache if it is missing or outdated.


How do I get a Broadcom BCM4313 wireless card working?

I have a vostro myself. But a BCM43224. Maybe the solution does not fit for you. However this helped me out.
Somehow the "sta" driver stopped working correctly. You need to install another driver. Before installing remove the following packages

sudo apt-get purge bcmwl-kernel-source broadcom-sta-common broadcom-sta-source

(removing these was essential for me. Without I had massive connection problems with the b43 driver)

Afterwards install the following packages

sudo apt-get install b43-fwcutter firmware-b43-installer
sudo echo b43 >> /etc/modules

then reboot and check if your card is found.
(You can try by hand without rebooting. If you currently use the wl driver execute

sudo modprobe -r wl
sudo modprobe b43

)

More info, what helped me can be found here:

http://www.linuxwireless.org/en/users/Drivers/b43

http://wiki.ubuntuusers.de/WLAN/Broadcom_bcm43xx

Alternatively try the driver described here:
http://www.linuxwireless.org/en/users/Drivers/brcm80211
this one should support your chip.


Ubuntu 19.10 is End Of Life - https://fridge.ubuntu.com/2020/07/17/ubuntu-19-10-eoan-ermine-end-of-life-reached-on-july-17-2020/
It's recommended to upgrade to 20.04 https://help.ubuntu.com/community/FocalUpgrades
For ubuntu desktops the process is as follows
You can easily upgrade over the network with the following procedure.

    Run the update-manager application;

    In Update Manager, click the Settings... button, and enter your password to start the Software Sources application.

    Select the sub menu Updates from the Software Sources application.
    Confirm the "Notify me of a new Ubuntu version:" option is set to "For any new version" if you are using 19.10 or to "For long-term support versions" if you are using 18.04 LTS. If it is not set properly modify it the appropriate option.
    Close the Software Sources application and return to Update Manager.

    In Update Manager, click the Check button to check for new updates.

    If there are any updates to install, use the Install Updates button to install them, then exit.

    In a terminal run update-manager -c -d.

    Follow the on-screen instructions.

This site shows two possible processes : via software apps or via terminal commands in more detail : https://www.linuxbabe.com/ubuntu/upgrade-ubuntu-19-10-to-ubuntu-20-04


Option 1: Reconfigure Package Database

Probably the database got corrupted while installing a package. Reconfiguring can fix the problem.

sudo dpkg --configure -a

Option 2: Remove post info files of the troublesome package

Try removing the files associated with the package in question from /var/lib/dpkg/info.

From your terminal output, it looks like debconf is causing problems

ls -l /var/lib/dpkg/info | grep -i debconf

Now, just remove these files(or just move them to another location):

sudo mv /var/lib/dpkg/info/debconf.* /tmp


If i upgrade my ubuntu to non-beta version, will my installed software lost?

If you upgrade from the CD/ISO all of your software will be removed as the Upgrade feature on the CD is actually just a reinstall without formatting. Your files will be kept intact.

If you upgrade using update manager, to a beta, alpha, pre-alpha or even a normal release, locally installed software will sometimes be determined by the system to no longer be needed and removed. Software(s) with unmet dependencies in the new distribution might also be removed during the upgrade to a beta version where the repository is still constantly changing.


Unable to build Spark 1.5.2 on Ubuntu 14.04

I am a newbie myself and ran into same issue. Try running chown command and get ownership of the spark-1.5.2 folder

cd /home/peter
sudo chown peter -R spark-1.5.2


Open the terminal and try these commands:

sudo apt-get install iw
iw reg get
sudo iw reg set NZ
iw reg get
sudo rmmod lib80211_crypt_tkip


Make Gnome shortcuts available to other users

All of your users's menu settings are stored in ~/.config/menus/.  All you have to do is copy yours to the desired users.


"juju status" error on machines which are already in "allocated" state

Juju asks MAAS for a new machine, but both machines are already allocated as you indicate, so MAAS doesn't have any machine available to hand off to juju. Juju doesn't keep an inventory of what's available in MAAS, it just asks MAAS to get a new machine with a set of constraints.

You have commission your machines and then deploy wordpress.

I hope this solves your problem :)


How to access my virtual machine server via hostname?

I think you need Apple's 'Bonjour' for this, and it needs to be installed on the Host OS. as well as the Guest OS. It should be installed by default in Ubuntu. If it is already installed, accessing:

http://hostname.local/

should work, where the hostname is the name you get at a CLI on the Guest OS, e.g.:

username@hostname:~$

If you don't have 'Bonjour' installed on either then just install the packages avahi-daemon and libnss-mdns with:

sudo apt-get install avahi-daemon libnss-mdns


Why does my custom launcher file create two icons on the launcher bar?

Launcher does not recognize the window as "his"

Specifically Tkinter windows do not recognize their "own" window (class). This makes the icon blink in vain, waiting for its window. Once the window  appears, the launcher doesn't recognize its own window and pops out of the launcher when timeout has passed.
Since a "normal" window is always represented by an icon in the launcher, you are left with a generic icon (usually, if there is no duplicate launcher) or a different one (see further below).

You can simply fix that by adding:

StartupWMClass=Tk

to your launcher (since it is a Tkinter window)

Look at the difference (I gave the launcher the firefox icon for testing):

without the line, when opening multiple windows. Watch the three generic icons + a blinking firefox icon, disappearing after 10 seconds or so.

Now I add the line StartupWMClass=Tk, all windows are grouped in the same icon:

Why no generic icon in your case?

Adding the WM_CLASS to your .desktop file will fix your issue. I am pretty sure however, you accidentally created an extra launcher (or have Unity created one automatically). Look in /.local/share/applications/ and make your launchers executable. The icon will show. Most likely, your dupe will have "unity" in its name.

In general, how to find the WM_CLASS of a window?

Open a terminal, type

 xprop WM_CLASS

Subsequently click on the window. two strings appear, separated by a comma. The one in Title case is the one yoiu need to add.

Notes

Not your issue, but:

You don't need to set the lines below:

Version=1.0 (no harm, but not needed)
Since your script is executable, you don't need python3 (you can have the script call the interpreter directly)
Path=/home/user/app/timer/ (unnecessary)
Terminal=false (this is the default)


Install Apache, Php, Mysql latest versions not available via apt

Before to install the new versions, you should uninstall any other versions that you have installed before.

Install Apache 2.4.4

Before installing Apache 2.4.4, you should install PCRE, otherwise it will not succeed. The process of installing PCRE is simple. After you downloaded it, run in terminal next commands:

sudo ./configure
sudo make
sudo make install

Download APR and APR-Util from http://apr.apache.org, unpack them to Apache directory, /srclib/apr and /srclib/apr-util (no version numbers in the directory names) and type following commands to install Apache:

sudo ./configure --with-included-apr
sudo make
sudo make install

Type following command to start Apache:

sudo /usr/local/apache2/bin/apachectl start

There may be something wrongs like:

/usr/local/apache2/bin/httpd: error while loading shared libraries: libpcre.so.1: cannot open shared object file: No such file or directory

Type following command to see httpd’s shared library dependencies:

ldd httpd

Found "libpcre.so.1 => not found", then type the following command to update links:

sudo ldconfig

Restart Apache and should work.

Source: http://zhuojun.info/?p=1121

Install PHP 5.4.16

Download PHP 5.4.16 from http://php.net/downloads.php
Check this post to see how to install a .tar.bz2 file: How to install a .tar.gz (or .tar.bz2) file?

Install MySQL 5.5.31

Download MySQL 5.5.31 from http://dev.mysql.com/downloads/mysql/5.5.html. In fact, MySQL 5.5.32 is the latest version.
Check this post see how to install a .rpm file: How do I install and manage RPMs?


How do Ubuntu updates appear on Amazon EC2?

How does updates notices appear on Amazon EC2?

Your EC2 instance is just a machine like any others in this respect. Your package management updates the package lists from the repositories regularly by default on Ubuntu. When you log in to the system a script queries the package management for the amount of updates in the regular and security channels and displays it.

  If these updates are new how are they shipped from Canonical to Amazon Server?

Canonical publishes the packages in the main repositories and also sets up mirrors to which your machine connects to in the default install. See the file /etc/apt/sources.list and files in /etc/apt/sources.list.d/ (if any).

Around the globe, many mirrors exist and Amazon is just one of them.


I managed to solve this myself. Here are the steps:

eth0 configured like this

ipv4=85.185.254.69,255.255.255.0,85.185.254.66,dns=4.2.2.4.

eth1 configured like this:

ipv4=185.185.185.1,255.255.255.0,85.185.254.69.

Restart ubuntu.
Open terminal and run:

sudo bash -c 'echo 1 > /proc/sys/net/ipv4/ip_forward'
sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
sudo iptables -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT

sudo bash -c 'iptables-save > /etc/iptables/rules.v4'
sudo bash -c 'iptables-restore < /etc/iptables/rules.v4'


How can I adjust internet settings such as TTL, Rwin, and Max Connections?

The IPV4 settings are accessible through proc filesystem at /proc/sys/net/ipv4

Example: to read the current TTL value:

cat /proc/sys/net/ipv4/ip_default_ttl

To set a new TTL:

sudo su
echo 255 > /proc/sys/net/ipv4/ip_default_ttl

After you decide which settings you want you may wrap the commands in a simple bash script and add it to /etc/rc.local

There may be some GUI programs to do that, but real men don't need them, huh?


How to solve "Extra junk at end of file" syntax error in "01autoremove-kernels" file? // invalid characters

Found a solution which also worked for me:

sudo /etc/kernel/postinst.d/apt-auto-removal

which will first return the above error yet again and secondly and crucially cleanly re-write the problematic file, to be finished off by something along the lines of

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

Contents of problematic /etc/apt/apt.conf.d/01autoremove-kernels

before applying the above mentioned "recovery":

../../../linux-headers-3.2.0-65/scripts/kconfig/streamline_config.pl\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\.............

after applying the above mentioned "recovery":

// File autogenerated by /etc/kernel/postinst.d/apt-auto-removal, do not edit
    APT
    {
      NeverAutoRemove
      {
        "^linux-image-3.2.0-65-generic$";
        "^linux-image-extra-3.2.0-65-generic$";
        "^linux-signed-image-3.2.0-65-generic$";
        "^linux-backports-modules-.*-3.2.0-65-generic$";
        "^linux-headers-3.2.0-65-generic$";
        "^linux-tools-3.2.0-65-generic$";
      };
    };


what is the command line to install xenial?

Upgrading Ubuntu Desktops to 16.04 (Recommended)
You can easily upgrade over the network with the following procedure.

Run the update-manager application from the Unity Dash or a command line
In Update Manager, click the Settings... button, and enter your password to start the Software Sources application.
Select the sub menu Updates from the Software Sources application.
Confirm the "Notify me of a new Ubuntu version:" option is set to "For any new version", and change it if otherwise.
Close the Software Sources application and return to Update Manager.
In Update Manager, click the Check button to check for new updates.
If there are any updates to install, use the Install Updates button to install them, and press Check again after that is complete.
A message will appear informing you of the availability of the new release.
Click Upgrade.
Follow the on-screen instructions.

For servers:

Install update-manager-core if it is not already installed:

sudo apt-get install update-manager-core

Launch the upgrade tool:

do-release-upgrade

Follow the on-screen instructions.

Source:

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


Try These car racing games.

3D rally racing .

TORCS .

Vdrift

Speed Dreams


wireless woes Ubuntu won't hook up to my built in hardware gateway laptop

If you described your hardware, Ubuntu version, showed us the output of sudo lshw -short | grep -i network, it would help us help you. On my laptop (Dell Latitude D630) I get:

sudo lshw -short|grep -i network
[sudo] password for walt:
/0/100/1c.1/0                    network     BCM4311 802.11b/g WLAN
/0/100/1c.5/0        eth0        network     NetXtreme BCM5755M Gigabit Ethernet PCI Express

and I can easily find out that for the BCM4311 chip I need the b43 driver, and how to access it. (sudo modprobe b43 in my case, for testing, echo "b43" | sudo tee -a /etc/modules to make it permanent). This works for me, YMMV.


ipython shows invalid syntax when running from terminal

async has become a reserved keyword starting from Python 3.7, so you have to upgrade your pexpect package.
You can run sudo python3.7 -m pip install --upgrade pexpect. If you still encounter the same error, try removing possibly conflicting versions using sudo apt-get remove python-pexpect python3-pexpect.


Output of your script on ShellCheck. Correct the problems:

Line 4:
echo `java -jar /opt/portmapper/portmapper.jar -list | grep $mylanip > /opt/portmapper/0prelims`
     ^-- SC2046: Quote this to prevent word splitting.
     ^-- SC2005: Useless echo? Instead of 'echo $(cmd)', just use 'cmd'.
     ^-- SC2006: Use $(..) instead of legacy `..`.
                                                            ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 6:
portprelim=$(cat /opt/portmapper/0prelims | grep ${mylanip}:443 | awk '{print $4}')
                 ^-- SC2002: Useless cat. Consider 'cmd < file | ..' or 'cmd file | ..' instead.
                                                 ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 7:
if [ "$portprelim" = $mylanip:443 ]; then
                     ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 10:
if [ "$portprelim" != $mylanip:443 ]; then
                      ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 12:
    java -jar /opt/portmapper/portmapper.jar -lib org.chris.portmapper.router.sbbi.SBBIRouterFactory -add -protocol TCP -internalPort 443 -externalPort 443 -ip $mylanip -description HTTPS >/dev/null ; sleep 2 ;
                                                                                ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 16:
portprelim=$(cat /opt/portmapper/0prelims | grep ${mylanip}:57 | awk '{print $4}')
                 ^-- SC2002: Useless cat. Consider 'cmd < file | ..' or 'cmd file | ..' instead.
                                                 ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 17:
if [ "$portprelim" = $mylanip:57 ]; then
                     ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 20:
if [ "$portprelim" != $mylanip:57 ]; then
                      ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 22:
    java -jar /opt/portmapper/portmapper.jar -lib org.chris.portmapper.router.sbbi.SBBIRouterFactory -add -protocol TCP -internalPort 57 -externalPort 57 -ip $mylanip -description PrivateTTY  >/dev/null ; sleep 2 ;
                                                                                ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 26:
 portprelim=$(cat /opt/portmapper/0prelims | grep ${mylanip}:80 | awk '{print $4}')
                  ^-- SC2002: Useless cat. Consider 'cmd < file | ..' or 'cmd file | ..' instead.
                                                  ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 28:
if [ "$portprelim" = $mylanip:80 ]; then
                     ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 31:
if [ "$portprelim" != $mylanip:80 ]; then
                      ^-- SC2086: Double quote to prevent globbing and word splitting.

Line 33:
    java -jar /opt/portmapper/portmapper.jar -lib org.chris.portmapper.router.sbbi.SBBIRouterFactory -add -protocol TCP -internalPort 80 -externalPort 80 -ip $mylanip -description HTTP  >/dev/null ; sleep 2 ;
                                                                                ^-- SC2086: Double quote to prevent globbing and word splitting.


Capturing contents of loop into a variable

The answer is going to be a bit long, but I've to address quite a few parts, so stick with me here.

Well, let's start off with the fact that your approach for iterating over grep output isn't quite right. The for i in $(); do ...done approach breaks with lines that contain leading spaces (due to word splitting), and generally isn't recommended(see this).

However, what typically is done is command | while IFS=<word separator> read -r variable; do...done (which as additional bonus is portable between Bourne-like shells). Also, I see that you're making use of cut -d : -f 1 to get first item out of colon-separated list in each line. We can make use of IFS=":" then to get rid of cut part. Your original command is thus transformed as so:

grep 'dook' /etc/trueuserowners | while IFS=":" read -r first_word everything_else
do
    du -sh /home/$i
done | sort -nr

The first_word variable obviously  will contain only the first field, and the unused everything_else will contain...everything else.

Note that I also quoted 'dook' part; although grep understands first item. Although grep understands first non-option item  as PATTERN, it really is a good practice to protect pattern with single quotes, because if you use * or some other regex patterns that are used by the shell, that will unintentionally perform filename expansion by bash, and will attempt to read files in your current working directory. See this one for a detailed example.

Next, let's address arrays. We surely can add new item to arrays  with the while loop I showed above, and += operator:

$ declare -a my_array
$ while IFS=":" read -r name null; do my_array+=("$name"); done < /etc/passwd
$ echo "${my_array[0]}"
root

This can be convenient if you want to process the items you're extracting later. However, considering the fact that you have pipe there, variables disappear once subshell in which while runs exits. See my old question about that.

What I'd recommend is processing everything in the while loop and use du -sb for precision in calculations. Thus, you could do:

# read what grep finds line by line and print total once there's no more lines from grep
grep 'dook' /etc/trueuserowners | while IFS=":" read -r first_word everything_else || { echo "$total"; break;}
do
    user_usage=$( du -sb /home/"$first_word" | awk '{print $1}' )
    # output the usage for current user
    printf "%s\t/home/%s\n" "$user_usage"  "$first_word"
    total=$(($total+$user_usage))
done

Notice how I used || { echo "$total"; break;}. Once there's nothing to read from stdin ( which in this case comes from pipe ), read command returns exit status of 1, so when read returns 1 we know it's done reading and processing, and we can output the total usage we calculated.

As for outputting human-readable data, we could make use of numfmt or some other utilities. Something like numfmt --to=iec-i --suffix=B  $user_usage would suffice.

Overall, this can be used as one-liner if we trim variable names to something short, but there's no particular advantage in having a one-liner. Just do things as correctly as possible and don't worry about code length.

Putting it all together, the complete solution should be:

grep 'dook' /etc/trueuserowners | while IFS=":" read -r username trash || { printf "%s\ttotal\n" $( numfmt --to=iec-i --suffix=B "$total"); break;}
do
    # get usage in bytes
    user_usage=$( du -sb /home/"$username" | awk '{print $1}' )
    # get human-readable
    usage_human_readable=$( numfmt --to=iec-i --suffix=B "$user_usage" )
    # output the usage for current user
    printf "%s\t/home/%s\n" "$usage_human_readable"  "$username"
    total=$(($total+$user_usage))
done


How to make python module run in dist-packages folders in the desired order?

Open a python shell and type:

import sys
sys.path

/usr/local should normally be first, so it will be searched first.


whenever i try to install chrome this gives dependency problem?

first of all, make sure you are in your .deb folder, then, try to reconfigure all dpkg config files and programs running this:

dpkg-reconfigure --all

Then, run this to install dependencies

apt install -f

Next, you should be able to install chrome .deb file

dpkg -i /root/Downloads/google-chrome-stable_current_amd64.deb

If you get another error, just install chrome via apt, following this steps:
First of all, add google repo:

wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -

Then,

sudo sh -c 'echo "deb https://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list'

and finally:

apt update && apt install google-chrome-stable -y

That should be enough.


IBus methods do not show up in text entry settings

The comments in Writing Japanese with Ubuntu 14.04 Trusty Tahr suggest the following workaround:

  I was not able to add the Anthy text entry in Ubuntu 14.04 using Gnome Fallback. Then I switch to Gnome Shell and I add it. Finally I switch back to Gnome Fallback and I can use it now.

I encountered the same problem after upgrading from 13.10 to 14.04: The Text Entry dialog in gnome-control-center does not list Japanese (Anthy), only plain Japanese and several others. Using the former, Super + Space (which previously was Ctrl + Space in 13.10), only toggles between the default keyboard layout (German for me) and English, but Anthy doesn't enable, even though it can be selected in the language selector applet (and then works and can be disabled once via keyboard, too).

For another user of that system, the toggling was still working, so I compared the configuration using dconf-editor. Under org.gnome.desktop.input-sources, I changed [('xkb', 'de'), ('xkb', 'ja')] to , [('xkb', 'de'), ('ibus', 'anthy')], logged out and in, and it worked!


How to disable Raise-on-Click in Trusty?

First check current state of raise-om-click option using gsettings by the command below:

gsettings get org.gnome.desktop.wm.preferences raise-on-click

The result would be true if you didn't disable it before.

Then if it was "true" then you can disable it by the command below:

gsettings set org.gnome.desktop.wm.preferences raise-on-click false

or If it returned "false" and still you don't get your desired effect then it sounds something is wrong or missing on your system.

From all apps that is from below setting:

org.gnome.desktop.wm.preferences raise-on-click

Also you can type dconf watch / in Terminal and check the any changes from your settings.


Cannot find ethernet in new Xenial install

There may be many causes for this and your information is not enough for a full troubleshoot.

But if you run 'ifconfig -a' it will show you all the available network interfaces in the system.

The most probable result is that 'ifconfig -a' will show you the card with a different name. It may be 'emX' instead of 'ethX' for example. You should configure and start using the new interface.

If no ethernet card appears, most probably it will be a driver problem, but you should check the 'ifconfig -a' output before investigating this route.


You should give it an executable bit. To do so, run from the directory contains it:

chmod +x ProxyChainsGUI

and then just execute it.


Kubuntu and Windows 7 dual boot, clock time changes automatically

By default Ubuntu assumes that the BIOS clock is set to UTC and adds or subtracts the appropriate amount of hours from it to get your localised system time. By contrast, Windows sets its system time directly to the time shown by the BIOS clock on boot. Thus, Windows assumes BIOS clock to be in your local time.

If Ubuntu keeps showing the correct time automatically and Windows keeps reverting to UTC, your Ubuntu installation is probably set to automatically get the correct time from a time server on boot.

The easiest way to fix the problem is to edit /etc/default/rcS and change the line that says UTC=yes to UTC=no. You can open the file for editing by opening a terminal and entering:

sudo nano /etc/default/rcS

Then simply find the appropriate line, replace yes with no, and save. If you prefer a graphical text editor try using gedit (Ubuntu) or kate (Kubuntu) instead of nano in the above command.


How to configure SFTP to login in the "/" directory?

Warning: This method might be unsafe for server users.
Ubuntu doesn't allow root user and also login in ssh as root by default.
So the first thing you have to do is to enable your root user account:
$ sudo passwd root

Now you have got your root account enabled now.
I am not sure whether you have installed your OpenSSH server or not.
So I will teach you how to install OpenSSH server.
$ sudo apt-get install openssh-server

Now you are able to edit the ssh config:
$ sudo vi /etc/ssh/sshd_config

Find the line contains "PermitRootLogin no", modify it to "PermitRootLogin yes".
Oh yeah, now restart the ssh server:
$ sudo service ssh restart

Now give it a try


When installing from the bootable USB, I get an error on my monitor (Monitor Out of Range)

1.) When running the installer, just before the error occurs, you will see this cryptic screen:
2)That cryptic little keyboard next to that cryptic little man apparently means “press any key.” If you do that, a menu will pop up. First, select a language, then press F6 (“Other Options”). A new menu will pop up; use the arrow keys to move to “nomodeset”, and press Enter to select it. Press Esc to dismiss the menu. Then you can proceed with the installation as normal.

3.)Of course, this only works for the installer. When you first try to boot your newly installed system, you will get the same error as before. To boot, you will need to add nomodeset to the kernel command line. When you boot the machine, wait for the GRUB menu to appear. (If the menu does not appear, you may need to hold down the Shift key when booting.)

Press e to edit the kernel command line:

Add nomodeset right after quiet splash:

Press Ctrl+x to boot

3.) Of course, editing the kernel command line only affects the current boot process; the next time you boot the machine, you will have to manually add nomodeset again. To fix the problem permanently:

If you have an NVIDIA video card, installing the proprietary NVIDIA driver may make the problem go away.
Alternatively, you can edit the file /etc/default/grub and change the line

GRUB_CMDLINE_LINUX=""

to

GRUB_CMDLINE_LINUX="nomodeset"

Then run

sudo update-grub


Why do I have to access software through a folder rather than in the dash?

You have to create a new file in ~/.local/share/applications called blender.desktop with the following content inside:

[Desktop Entry]
Name=Blender
GenericName=3D modeller
Comment=3D modeling, animation, rendering and post-production
Exec=/path/to/bleder-version-2.68a
Icon=blender
Terminal=false
Type=Application
Categories=Graphics;3DGraphics;
MimeType=application/x-blender;

Change /path/to/bleder-version-2.68a with the absolute path of Blender, version 2.68a.


The problem is not in the gnome-control-center because after intallation that one nothing changed. Perhaps, topicstarter uninstalled "Zeitgeist" ("Activities and Privacy Manager Tool" in "Ubuntu Applications Center"), - that's why it disappeared from "System Settings". When you reinstall it, it wiil appear in "System Settings" again.


You can give bitcoin-qt a try.

Add the repository

sudo add-apt-repository ppa:bitcoin/bitcoin

Update Software List

sudo apt-get update

Install the application

sudo apt-get install bitcoin-qt


Uninstalled Ubuntu but still get Grub menu

I presume you want to get rid of Grub and just go back into booting direct to Windows?

You can use bootrec /fixmbr from Windows to overwrite it.


How to edit the Table of Contents in a PDF?

Sorry, but it is not possible. If you want to edit the toc you can ether use command line tools like pdftk and many others, or if you like to have a gui based solution simple install the 3rd party program like MasterPdf.


Search applications to install from whisker menu

The terminal way is to set the whisker search action like this:

    Name: Enter package name(s) to searh for
    Pattern: !s
    Command: xfce4-terminal --execute /bin/bash -c "/usr/bin/apt-cache search %s ; /bin/bash"

%s - passes the string tiped in whisker to the command

/bin/bash - at the end will keep the terminal window open after apt-cache command finishes.
Another option is to make a script for this.

Opening a GUI and inserting text at the right search box would be very tricky. But probably possible with the right tools.

One option (without the terminal):
- Install dctrl-tools and zenity (for UI)

apt install dctrl-tools zenity

save next script and make it executable (chmod +x)

#!/bin/bash

PKG="$@"

PKGNAME="$(grep-available -sPackage -sVersion -sDescription . /var/lib/apt/lists/*_Packages |
grep -A 2 -E "^Package\: .*${PKG}" |
awk '{$1="";print $0}' |
zenity --list --width=900 --height=700 --column="Package" --column="Version avail" --print-column=1 \
       --column="Description" --column="" --hide-column=4 --title "package info" --text "pkg info")"

[[ ! -z ${PKGNAME} ]] && apt-cache show $PKGNAME | zenity --text-info --title="apt-cache show $PKGNAME" --width=800 --height=500

Set the whisker search action like this (replace /path/to/script e.g. /home/dsstorm/Desktop/pkginfo):

Name: Enter package name(s) to searh for
Pattern: !s
Command: /bin/bash -c "/path/to/script %s"


Lenovo G50-80 Ubuntu 14.04 low sound input

Try out pulseaudio, it might help playing with the settings.
Type in to install:

sudo apt-get install pulseaudio


Check Disk Defects: Can not mount /dev/loop0

If the checksum is correct and the check for defects come out fine, try another USB stick first!  If that still fails, try a CD.

If all that fails as well, you should  file a bug here, following these instructions and attach the /casper.log from your USB stick to it.


Can I receive Twitter updates without granting write permissions for my Twitter account?

Currently there is no Read Only (via the API) for Gwibber and Twitter. Gwibber uses the OAuth method to associate your twitter account and push/pull data to and from Twitter.

If you page isn't protected you can use your RSS feed and a Desktop rss Aggregator for Read Only mode.


ubuntu 13.04 - Some radeon firmware files missing - low resolution problem

I had the same problem after upgradeing to 13.10 on a AMD HD4650 and the OS radeon drivers. (amds drivers didn't work after upgrade to kernel 3.11 and I wanted to get rid of them anyway)

After reading your post, I just reinstalled linux-firmware:

apt-get install --reinstall linux-firmware

It installed 1.116

This resolved it for me.


Conversion of disk image from Encase (E01) to Raw format

The problem should be clear from the message

export_handle_open_output: unable to open file: /user/manu/Downloads nps.

i.e. the path and/or filename that you have specified is not valid. First, are you sure your home directory is under /user? The standard Linux location would be /home (although that may be different if you are in a corporate environment), so that if you are trying to save the raw file as nps in your own Downloads directory the full path and filename with extension will probably be something like /home/manu/Downloads/nps.

[The wording of the prompt is unclear, but it appears to actually require a single contiguous target/path/to/filename.ext, not a whitespace separated list like target/path/to file ext]

Or since you are running the ewfexport file from that directory, you can just use . to indicate the current directory i.e.

Target path and filename with extension or - for stdout: ./nps

although personally I would probably use something like ./nps-2010-emails.raw to make the image's origin more obvious, i.e.

Target path and filename with extension or - for stdout: ./nps-2010-emails.raw


How to add/edit PATH when using X2Go client logging into ubuntu terminal

I had to check the Wikipedia page for X2Go to find It provides secure remote sessions via ssh. Therefore, by reading man ssh ( Online ssh man page ) one finds:

 Additionally, ssh reads ~/.ssh/environment, and adds lines of the format “VARNAME=value” to the environment if the file exists and users are allowed to
 change their environment.  For more information, see the PermitUserEnvironment option in sshd_config(5).

...

~/.ssh/environment
         Contains additional definitions for environment variables; see ENVIRONMENT, above.


These distributions offer the Haskell Platform in their package repositories. You can easily install the Haskell Platform through your distribution's native package manager.

Ubuntu
...

Source: http://www.haskell.org/platform/linux.html
Enable universe repository, then
sudo apt-get update
sudo apt-get install haskell-platform


How do I execute a sudo command without a password?

replace localhost by your hostname or use ALL if your sudoers file is not dispatched on other hosts

anthony ALL= (root) NOPASSWD: /usr/sbin/myscript

edit:
Scripts can be tricked by environment parameters. It is more secure (and easier to use) to sudo the killall command into your script than to sudo the script itself. Full killall command with its parameters can be put into the sudoers file, limiting the sudo killall usage.


Can't reset or recover password in Ubuntu 15.10

From the grub menu, select advanced options and then select recovery mode.

Then, select **"root    Drop to root shell prompt. **

Now, run the following command:

mount -rw -o remount /

Next, create a new user using the following command:

adduser newusername

Finally, add the newuser to the sudoers group:

adduser newusername sudo

Now you should be able to log in as newusername and you will have sudo permission and everything.

If you want to, transfer all your personal files from your old user account to the new one and then delete the old user account using the sudo deluser command.


Add a feature like one in Windows task manager?

Task Manager

Available in Software Center
It does Monitor and Control the Running Processes.
For Command Line Installation:
sudo apt-get install lxtask


http://dev.wifidog.org/wiki/doc/install/ubuntu/auth-server

Here is one captive portal installation howto.

Hope that is what you are looking for.


Is someone porting ubuntu one and software center for derivatives?

There's a Lubuntu Software center available:

Kubuntu uses the Muon Suite as it's software center

Xubuntu does have the Software Center aswell.

(This is probably not the latest Xubuntu, but as you can see it runs the Software center too).


How can I connect to the internet in Ubuntu server?

Option1:

if you are working with dhcp

First of all, make sure that your interface is down

sudo ifdown eth0

Now edit the interfaces

sudo nano /etc/network/interfaces

and then add the following lines

auto eth0
iface eth0 inet dhcp

Replace eth0 with the correct number if it's not true.

Now head back , and make interface goes up

sudo ifup eth0

Option2:

For giving static IP.

First of all, make sure that your interface is down

sudo ifdown eth0

Now edit the interfaces file

sudo nano /etc/network/interfaces

and then add the following lines

auto eth0
iface eth0 inet static
    address <IP Address>
    netmask <Network Mask>
    gateway <Default Gateway>

I suppose you know what is Ip,netmask and gateway.

Now for your DNS

sudo nano /etc/resolv.conf

This file should be edited to contain the following lines only

nameserver 208.67.222.222
nameserver 208.67.220.220

Replace the values with yours

Now head back , and make interface goes up

sudo ifup eth0

check this : https://help.ubuntu.com/community/NetworkConfigurationCommandLine/Automatic


Reconfigure root and postmaster mail recipient in Exim

Changing Exim aliases (postmaster,root)

Check and modify /etc/aliases (text) file.

Pretty standard procedure is to redirect:
* postmaster to root
* root to non privileged (non root) account of preson acting as root


Install lame 3.100 under Xenial Xerus 16.04LTS?

The safest method that I have found that for the most part will not interfere with any system installation is to take a page from the FFmpeg trac site and install a local copy of lame.

The following single command gave me a working executable of the latest lame, safely installed in $HOME/bin:

mkdir -v $HOME/{lame_build,bin} && cd $HOME/lame_build && \
sudo apt-get install nasm build-essential && \
wget https://downloads.sourceforge.net/lame/lame-3.100.tar.gz && \
tar xvf lame-3.100.tar.gz && cd lame-3.100 && \
PATH="$HOME/bin:$PATH" \
./configure \
       --prefix="$HOME/lame_build" \
       --bindir=$HOME/bin \
       --enable-static \
       --disable-shared \
       --enable-nasm  && \
PATH="$HOME/bin:$PATH" make && \
make install

The detritus can then be removed with the following command:

rm -rfv $HOME/lame_build

The following now shows on my system:

andrew@corinth:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.3 LTS
Release:    16.04
Codename:   xenial
andrew@corinth:~$ lame --version | head -n 1
LAME 64bits version 3.100 (http://lame.sf.net)
andrew@corinth:~$

And all is well :)


How to install VMware Workstation 9 on Ubuntu 12.04?

Download your installer.
Open the Terminal (Dash Home > Search for Terminal)
Change the file permission to make it executable

chmod 755 VMware-Workstation-Full-9.x.x.x86_64.bundle

Install workstation

sudo ./VMware-Workstation-Full-9.x.x.x86_64.bundle

Then follow the simple installation steps.

(Source)


Kubuntu 18.04: How do I control SD Card auto-mount directory and permissions?

After a lot of searching, this stackexchange question pointed me to this piece of udisks source code, which shows the mount point is hard coded!


Tensorflow reader slowdown on Ubuntu 16.04

How much memory on your GPU (better yet, its model no.) and do you have an estimate of the problem memory size?

I'm wondering if it's doing some GPU equivalent of thrashing.  Still that it could recover from slow back to fast indicates something in the algorithm.  Is this a publicly available program (say an example program) or one of your own?  Is this the first "large" program that you've tried or run or have you run others, that presumably ran fine.


Touchpad while holding on touchpad it doesn't work

You can install libinput that in most cases solves the problem. Run in a terminal

sudo apt install xserver-xorg-input-libinput

and reboot.


How do I remove the LAMP stack so I can start over?

sudo apt-get purge mysql-server apache2 php5
That will remove the "big-boy" packages, which should take care of most cases.
You can find this information in the documentation, specifically this section on how to start over:

To remove the LAMP stack remove the following packages:
Note: This assumes you have no other programs that require any of these packages. You might wish to simulate this removal first, and only remove the packages that don't cause removal of something desired.
sudo apt-get remove apache2 apache2-mpm-prefork apache2-utils apache2.2-common libapache2-mod-php5 libapr1 libaprutil1 libdbd-mysql-perl libdbi-perl libmysqlclient15off libnet-daemon-perl libplrpc-perl libpq5 mysql-client-5.0 mysql-common mysql-server mysql-server-5.0 php5-common php5-mysql
To also remove the debconf data, use the purge option when removing. To get rid of any configurations you may have made to apache, manually remove the /etc/apache2 directory once the packages have been removed.

Don't use tasksel to remove packages, bad things can happen, this is covered in this bug report.
The rest of the documentation covers how you would reinstall  apache and all the stuff you'll need to get going again.


Can I connect to my Ubuntu session from my Windows 7 session, both installed in the same computer?

Nope.

The nearest you can do to this is to virtualise one of the operating systems inside the other using software like VirtualBox, VMWare, etc. This usually has somewhere between a slight and severe performance effect on the virtualised OS depending on what you're doing.

For example, I use XP in VMWare to handle my Adobe tools that I need for work... But I wouldn't use it for gaming.


Download only apt-get without installing

You could execute
sudo apt install --download-only gnome-tweak-tool

This will download gnome-tweak-tool with any dependencies you need and place them in /var/cache/apt/archives. Later a subsequent apt-get install gnome-tweak-tool will be able to complete without any extra downloads.


Upgrading Mono on lucid? getting "version 2.4 (tarball Fri Oct 2 12:47:18 CEST 2009)"

If you're wondering why it's not upgrading to 2.8 the answer to this question has your answer.


When I had a similar problem, I just blindly commented out the offending assert and it worked like magic!

So modify /usr/bin/duplicity and comment out line 1370 and run again and it should be fine.


Black screen with mouse cursor after 18.04 upgrade

I found this answer, and I tried

sudo apt-get install xorg

And I got:

E: dpkg was interrupted, you must manually run
 'sudo dpkg --configure -a' to correct the problem.

Running that, I got a whole bunch of Setting up (such and so package), and then, after a LONG while, it all finished.

I rebooted and now it's working!  (WiFi still isn't, but that's a separate issue I think/hope.)


unstable wifi conection Ubuntu 14.04 Acer Aspire V 13

I used to get this on my computer, I dont know why this happens but the solution that worked for me was to disconnect from your internet and reconnect and re-enter that code to access your internet.


Can't install Lollypop music player in Ubuntu 16.04

There isn't a package named lollypop for Ubuntu 16.04 in ppa:gnumdk/lollypop. The name of the package for 16.04 is lollypop-xenial. To install it in Ubuntu 16.04 open the terminal and type:

sudo add-apt-repository ppa:gnumdk/lollypop
sudo apt update
sudo apt install lollypop-xenial
sudo reboot


Dell XPS 15z Graphics Freezes, Black Screen, Overheating

I got it to work be uninstalling Compiz Config Settings Manager, deleting the Ubuntu partitions and installing Ubuntu 13.10, and installing Cpufreq Indicator and setting it to Powersave.


What is the text box on the desktop for?

That is the GNOME3 desktop Nautilus search integration.

You can test that by giving the desktop focus and start typing something that exists in your Desktop, it will jump to that item.


Why is Firefox Prism not in the repositories anymore?

Easy solution

Close all Firefox windows (also this one!). Run firefox -ProfileManager and add a new profile for your web application. You can then remove the tab bar in the preferences and all other disturbing GUI elements. Close everything and run the profile manager again to select your default profile this time. Now Firefox should start your default profile if you untick "ask everytime".

Then create a file my_webapplication.desktop and create a launcher. This is an example for the Google calendar:

[Desktop Entry]
Name=Google Calendar
Exec=firefox -P gcalendar -no-remote
Terminal=false
Type=Application
Icon=firefox

The icon should be better not firefox, but a path to a icon of your choice.
gcalendar is the profile name I chose before.

Improvement

If your application is already open, opening this launcher again will result in an error. You can install wmctrl and use this small script to run your web application:

# Is there any window with Google Calendar in the title?
if [ -z "`wmctrl -l|grep 'Google Calendar'`" ]; then
  # No --> run it
  firefox -P gcalendar -no-remote;
else
  # Yes --> change focus to this window
  wmctrl -a 'Google Calendar';
fi

Use Chromium

Well... I ḱind of gave up. Chromium is the easiest solution. Just click "Create application shortcut..." (in "Tools") and you're done. You'll find a *.desktop file in ~/.local/share/applications which can be customized.

You might want to customize the *.desktop file. E.g. docky does not recognize a Chromium web application as a different application, so the Chromium icon is displayed instead. You can change this behaviour using the WMClass as described here. But you will have to add also a parameter --class=MyArbitraryChromiumAppname as discussed in this bug report. If you want to run Google Calendar your *.desktop file in .local/share/applications/ should look like this:

[Desktop Entry]
Version=1.0
Name=Google Calendar
Exec=/usr/bin/chromium-browser "--app=https://www.google.com/calendar/render?gsessionid=HERE_GOES_THE_SESSION_ID_CREATED_AUTOMATICALLY" --class=gcal
Terminal=false
X-MultipleArgs=false
Type=Application
Icon=/home/peter/.icons/google_calendar.png
Categories=Network;WebBrowser;
StartupNotify=true
StartupWMClass=gcal

Note: you have to add --class=gcal and set the property StartupWMClass=gcal (you can choose any name instead of gcal).


How to keep zoomlevel in Evince constant after clicking a link?

this should work.

open up a terminal and type:

gsettings set org.gnome.Evince allow-links-change-zoom false


How can I synchronize Windows links (.lnk) to 12.10 using Ubuntu One?

We do not currently have any proposals to convert lnk files to text files, but you're looking in the right direction. What you could probably do is write a script that watches your U1 directory and calls FindFirstFileNameW on each file (or configured files) to find out what files have links and what the links are called. Then write that to a file which is synchronized by U1, then on your other clients (your linux machine(s)), open that file when it's changed and maintain your file->link setup.


I don't think there's really a way to do that. Of course, having options is always nice, but in my experience such an option isn't really desirable, anyway.

The trouble is that these days, most laptops have wide screens--with varying aspect ratios--while projectors still prefer 1024x768 (4:3). If you clone the screen, you're going to get a stretched and/or low quality picture on one or both screens unless the projector knows how to compensate.

Using Ubuntu's default makes it possible for everything to look good, even if you have to manually set the resolution if you're using certain hardware. (The two projectors I regularly use don't adequately report their preferred resolution, leaving me with a stretched display until I manually correct it, while the TV I've been using recently in lieu of one of the projectors manages to get everything automatically configured correctly.)

Finally, I don't think there's any real advantage to having a cloned screen. OpenOffice automatically shows presentations on the correct screen, assuming that the screen is connected and enabled when the program starts. Other windows can easily be dragged to the proper screen. Then, they'll behave correctly. And, you don't have to worry about things like your panels and icons showing up on the big screen.


Operating System that boots depends on boot mode

It sounds like you installed Ubuntu in BIOS (legacy) and Windows in UEFI mode. Those aren't compatible. I'd advise you back up your data and reinstall Ubuntu making sure that you boot the Ubuntu flash drive in UEFI mode.


Why don't my lightdm.conf edits affect my desktop screen resolution?

I tried a similar thing and after some debugging I think I figured out what's going on. Your script probably is run and probably does set the resolution correctly. However, since it is run by the login manager, it runs before Unity has finished setting up your desktop environment and Unity reads its own settings and resets the resolution to what you had. So, I think that what happens is:

lightdm correctly runs your script
This sets your desired resolution
Unity launches, reads its settings and reverts to the default resolution you have there
Your resolution goes back to what it was before

Now, this happens because the VESA driver does not detect your desired resolution automatically. This means that when you change the resolution from the Displays section of Unity's settings, you are giving it a resolution that is not available unless you run the xrandr commands. Therefore, this is ignored next time you restart and Unity reverts to the default resolution.

So, what you need to do is make the resolution available to Unity, then set it as default and let it handle it. To do so, you must first add this line to /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf:

session-setup-script=/usr/bin/lightdmxrandr.sh

Then, make sure that /usr/bin/lightdmxrandr.sh looks like this:

xrandr --newmode "1368x768_60.00"   85.25  1368 1440 1576 1784  768 771 781 798 -hsync +vsync
xrandr --addmode DVI-0 1368x768_60.00

Note that I am not actually setting the resolution, only making it available. Once you have done this restart, then log in. The new resolution should now be available in Settings => Displays. If so, choose it there, log out and log back in again and the resolution should be set correctly.It should now persist across reboots.

Alternative approaches:

Create an /etc/X11/xorg.conf file that lists your desired resolution. Something like this:

Section "Monitor"
    Identifier    "Monitor0"
    Modeline "1368x768_60.00"  109.00  1280 1368 1496 1712  1024 1027 1034 1063 -hsync +vsync
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Card0"
    Monitor        "Monitor0"
    SubSection "Display"
        Modes       "1368x768_60.00"
    EndSubSection
EndSection

Section "Device"
    Identifier    "Card0"
    Driver        "vesa"
EndSection

Add the script that runs the xrandr commands to your session's startup applications.


How to copy complete content on terminal to a text file using commands ?(Not for one output but everything on terminal)

You can use screendump.

As in the man page:

 screendump - dump the contents of a virtual console to stdout

You'll need root privileges to run screendump, so use sudo.


Attach gcc or gcc-8 in C++ compiler in toolchain. gcc-8 is the latest installed version which is a good choice.


When you are in the live USB/CD you need to create a new the partition table.
To do this open up a terminal by pressing Ctrl+Alt+T type in

  sudo gparted-pkexec

Now make sure you have selected the drive that is encrypted, Then click on Device menu and then click on create a partition table then create a msdos partition table. You shoud be fine with installing Ubuntu.


So you don't have lapack and blas libraries. You should be able to install them like

sudo apt-get install libblas-dev
sudo apt-get install liblapack-dev

When I tried the compilation it ended the same as for you, after installing the two libraries it finished successfully.


I get some pretty brutal debugging about chrome browser, it goes on indefinitely and I'm thinking of giving up using chrome altogether.
Look in the log journalctl -b-0 -g error, maybe you have a similar situation with it.
In addition, I still don't fully understand why I need debug.exception-trace=1, because I'm not a developer and it consumes too much energy.
On a device as weak as mine, this is very noticeable (and causes the algorithms to fail).
Try disabling it. I delivered it a value of 0, and my machine is now as cold as a sheet of paper.


Total RAM Usage:

This command will return your RAM total usage as GB:

free -h |grep Mem| cut -c 20-32 | sed -e 's/^[ \t]*//'

This will return your RAM total usage as Bytes (just remove the -h):

free |grep Mem| cut -c 20-32 | sed -e 's/^[ \t]*//'

This will report the percentage of memory in use

free | grep Mem | awk '{print $3/$2 * 100.0}'

This will report the percentage of memory that's free

free | grep Mem | awk '{print $4/$2 * 100.0}'

MAC Address:

If you want to output ONLY the mac address of a specific device, you can do this (replace "wlp2s0" with the name of your network interface):

nmcli -t -f GENERAL.HWADDR device show wlp2s0 | sed 's/GENERAL.HWADDR://'


After upgrading to 20.04.1LTS Text Editor is typing in gibberish

This is usually a post-upgrade, font-related issue. If you change the text editor to use something else, such as “Ubuntu Regular” or “Ubuntu Mono”, you should see correct characters.


From Ubuntu's GPG Howto:

  Backing up your public key

  List your public keys:

gpg --list-keys

  Look for the line that starts something like "pub 1024D/". The part after the 1024D is the key-id. To export the key:

gpg -ao _something_-public.key --export key-id

  Backing up your private key

  List your private keys:

gpg --list-secret-keys

  Look for the line that starts something like "sec 1024D/". The part after the 1024D is the key-id. To export the private key:

gpg -ao _something_-private.key --export-secret-keys key-id

How to restore is also listed there.


Very Strange - Ubuntu messing up Windows LAN

Sounds like the Windows driver doesn't agree with the state Linux leaves the LAN hardware. Realtek is known for issues like this.

Try a echo "options rtl8723be swenc=1 fwlps=0 ips=0" | sudo tee /etc/modprobe.d/rtl8723be.conf to make the module work in a more reliable state where Windows might be able to take over again from usage after Linux.

Explanation:

swenc:using hardware crypto (default 0 [hardware])
ips:using no link power save (default 1 is open)
fwlps:using linked fw control power save (default 1 is open)

To make the values known to the driver, do

sudo service network-manager stop
sudo modprobe -rfv rtl8723be
sudo modprobe -v rtl8723be
sudo service network-manager start

before you use the LAN.


Send Unicde "Clear Key" to GUI program on keypress

The unicode can be used directly in the xmodmap keycode directive:

xmodmap -e "keycode 77 = U2327 Num_Lock"


Display unknown after nvidia driver update, resolution stuck at 800x600

Looks like you need a custom modeline for your display (Basically a custom "output"). Either that or your drivers aren't working properly... I had this issue with an old monitor and a custom modeline sorted it right away :P

You can add the native resolution modeline (1920x1080_60.00?) and then you should be able to switch to it, any other resolutions will probably need one too... EDID can be buggy with some monitors. :(

How to set a custom resolution?

^Someone posted a guide here :D


liveUSB doesn't detect my intel wifi device. Can't enable wifi

Please refer to this link. As per that Intel certifies Linux kernel 4.2 onwards for that wifi card.

I had Intel 3165 and struggled a lot with Ubuntu Desktop 14.04 LTS. Finally i decided to fresh install Ubuntu 15.10 and that fixed the problem. Same i will suggest for you - it will save time and efforts.

You can refer to my thread here

I could only fix it by installing Ubuntu 15.10 which comes with Kernel 4.1/4.2. With the upgraded kernel in Ubuntu Desktop 14.04 LTS i used to get some what intermittent connection issues with the work around suggested in that thread.

When you are installing Ubuntu 15.10 - i will suggest connect your laptop via Ethernet cable. Once everything is installed then you can test your wifi card also. It should work.


Launching Chrome (Incognito Mode) From Terminal

For Chromium

chromium-browser --incognito

For Google-chrome

 google-chrome --incognito

Note:  get used to see man for cli options, in this case man chromium-browser or man google-chrome


If Unity will be touch friendly, will window buttons become easier to touch?

Gestures will be the easiest method for closing windows in touch environment. There have been several ideas discussing how to improve the window button in a touch environment, however no firm decisions have been made. Ideas range from making the buttons grow bigger on tap (so you have a bigger hit area) to having just plain ol huge buttons.


Checking files differences before an update

Here's an example of one way to find the diffs on Launchpad:

First, locate the project page on Launchpad.

Example: Unattended Upgrades is at
https://launchpad.net/ubuntu/+source/unattended-upgrades

Next, at the bottom of the page are the various releases. Look for the release that you are interested in, and expand it. The diffs used are in the release details.

Example: The diffs used in Unattended Upgrades 1.5 are at
https://launchpad.net/ubuntu/+source/unattended-upgrades/1.5ubuntu2


It seems that the ppa you added that is available longer or added outdated PPA.
you have to type following command in terminal to install skype.

sudo sh -c "echo 'deb http://archive.canonical.com/ubuntu/ quantal partner' >> /etc/apt/sources.list.d/canonical_partner.list"


UPDATE: Heres solution How do I solve this super 11.10 heating problem

Old post: That's cause its using processes for showing that unity and effects.

I tried on netbook 11.10 and 10.04.3 but found best results with Ubuntu Netbook Remix witch last version is made in 10.04 LTS and LTS on every Ubuntu version coming out witch means that its sub-version made just a month ago.

Take Ubuntu Netbook Remix 10.04.03 from here.

You can learn about LTS here .

Believe me it will be faster. Also I recommend my "clean installation 1st time one liner" command witch sets better performance and less useless programs and it will later be more longer with more speed up settings.


Trying to upgrade from 12.10 to 14.04 and not having any luck...404 error occurs

One of the easiest solutions is to boot a liveUSB/DVD, choose install Ubuntu, then "Something else" and choose the actual Ubuntu partition as the root (/) partition and select it for formatting.

Backup your important files and your home folder first.

Ubuntu 14.04 will replace 12.10. You will have to reinstall any extra software you had installed.


Is the BFS Scheduler better than Completely Fair Scheduler for desktop computing?

There is an excellent PDF document here,  which explains in detail the differences. It also does several tests that show in graphs how both behave under certain conditions.

Here is a small document from the creator of BFS: http://ck.kolivas.org/patches/bfs/bfs-faq.txt about why he created this scheduler.

But the main differences are:

BFS is better for interactive tasks that block on I/O or user input
BFS is generally a bit faster but a bit more inconsistent
BFS in low latency apps will show a big improvement over CFS (Like video apps)
BFS has much less "spikes" in cpu usage

CFS is generally more consistent for a consistent performance
CFS is better for batch processing that is CPU bound
CFS in multi cpu intensive tasks + multiple tasks will have better performance than BFS
CFS has more spikes than BFS but it works to be more fair between tasks

For the normal user, BFS might give a "better" performance but it will give less performance if you do a lot of batch process.


Wifi stops working after suspend, 14.04.2

Try to restart network-manager

sudo service network-manager restart


Restoring clonezilla image to newly created LVM partition

As no one seems to be answering anything, I'll chuck in: No experience with LVM under Ubuntu, but experience on other OSes...

I would use Clonezilla to clone and I would clone partitions, not the entire system, using partition-to-image.

Why? Full system clone will clone the GPT or MBR as well and restoring that on top of the LVM system will surely break it
Before cloning: edit your fstab and get off UID and back to device paths

Why? when moving disks around on one system or between systems, UID is the clear winner as nothing needs to be adapted.  In your case, you're going to rebuild the entire system, so using UID will only complicate matters, thus has no benefits.
Install a minimal OS as similar to the existing one as possible once LVMs have been defined.

Why?
You can clone that too to go back to (I would take an entire system-to-image now!)

You will see the relative paths and UIDs of your LVM system and restoring the images will become easier.
Keep the Ubuntu Boot CD handy, because you will have to edit the fstab of the system after restoring the partition clone.


Nvidia driver issues: Blank screen on boot

It appears something is playing better in 18.04 than in 16.04 and derivatives, at least on the M4800 QHD+ system that I've been pulling my hair out with a similar issue. With 16.04.4 and older we had been running along fine in Legacy boot mode but some recent stable 4.4.x backport caused a bad reaction with the Nvidia drivers and we haven't been able to find a stable combination that didn't require booting via recovery mode every time.

With 18.04 we were able to install the nvidia-390 package from the ppa:graphics-drivers and reboot and the system actually started up and was functional without any more fuss and we got the full resolution of 3200x1800 instead of 1600x1200 which looks crappy on a 16:9/16:10 screen since it is a 4:3 ratio.


Is your wifi driver is enabled?.. check it in

software sources -> additional drivers

if it is not enabled. try by enabling it.Comment if problem is not solved.


14.04 Multiarch dependencies conflict when trying to install steam

You have a mix of graphics drivers from Ubuntu 14.04.1 and the “LTS Hardware Enablement Stack” of Ubuntu 14.04.5 (the *-lts-xenial packages) and the two cannot coexist on the same system. Please decide for one graphics driver set (I recommend the LTS variants if you care about gaming).

You can list all those packages with apt-cache search '.*-lts-xenial$' and you can perform a full multi-arch LTS upgrade with:

sudo apt-get install -f --install-recommends linux-generic-lts-xenial xserver-xorg-core-lts-xenial xserver-xorg-lts-xenial xserver-xorg-video-all-lts-xenial xserver-xorg-input-all-lts-xenial libwayland-egl1-mesa-lts-xenial libgl1-mesa-glx-lts-xenial libgl1-mesa-glx-lts-xenial:i386 libglapi-mesa-lts-xenial:i386

(source and further info: Kernel/LTSEnablementStack)

If that doesn't work out cleanly (which may happen, especially with many PPAs or with existing package management issues), please open a new question asking how to perform the LTS HWE upgrade and include the full, verbatim output of the above command.


Wired internet is connected to internet, but no internet access!

There are many ways that he could be setting parental controls.  Either by things like OpenDNS or via your router, including others.  Router would probably be the easiest and make the most sense. So we can start there.

I'm not sure how old your router is but many new ones come automatically equipped with parental controls, and if you go to do a hard reset of the router it will actually turn the parental controls ON.

If you're not worried about getting in trouble with your father, my suggestion would be to go to the router and do a hard reset on the device.  You can find a reset button that can be accessed with a paperclip or pointed pen/pencil at the back of the device.  Hold the button down for 10/15 secs and it will hard reset the configuration settings.

There will also be a home configuration URL on the back of the device.  For example most(if not all) of Linksys routers are 192.168.1.1.  Input the URL on the back of the router into your web browser.  It will take you to a login page, USUALLY the username and password is "admin" and "password" respectively.  This is based on device model though, and can sometimes differentiate.

From here, you can access all the of the router settings and particularly, parental control settings.  Make sure all of these are set to OFF.

Now, if this is an actual application like a Time Keeping app or a parental control software application and your family uses the same computer...you could just search the computer for the application via root and disable/modify it.


How to execute one command over the files where the paths of all the files are listed in the file?

You don't need a shell loop, because even with -i, the sed command accepts multiple filename arguments and operates on each named file separately. Unless all the files are already fully backed up, though, I encourage you to use -i.bak--with whatever suffix you prefer, it doesn't have to be .bak. Using sed -i without making a backup file often results in accidental data loss. (This recommendation would apply equally if you were running sed once for each file in a loop.)

Since sed accepts multiple filename arguments, and since you can use xargs instead of a loop to build up the list of filenames and pass them to sed, you can do everything in one short command. Depending on your needs, you could just run that command instead of writing a script. Or your script might consist just of that one command, aside from the #!/bin/sh hashbang at the top. You do not need to use any shell variables, nor any loops or other control structures in the shell. (Processing text, such as a list of filenames, using a loop in a shell script, is often not the best approach.)

I assume the input file contains one filename per line, even though separating filenames with null characters rather than newlines would be better (in that it would work correctly even if some filenames contained newline characters). Assuming that's the case, here's a command you can use:

xargs -d'\n' -a files sed -i.bak '1i\10004'

-d'\n' tells xargs that the filenames it reads are separated by newlines, that is, that they appear one per line in the input file.
-a files tells xargs to read its input from a file named files. (You could use redirection and write <files instead of -a files, as is often done.) Replace files with the actual filename of the file you wish to read the filenames from.
-i.bak performs in-place modifications (-i), as you know. The inclusion of .bak, with no space, in that same command-line argument, tells sed to save backup files with a .bak suffix. If you want a different suffix, use that instead of .bak. If you really want to do this without creating backup files, then you can simply omit the suffix and write just -i.
As you know, '1i\10004' passes 1i\10004 to sed to use as its command for processing lines of the file. (Other readers will wish to replace this with whatever sed command they are using.)


How can I create a 4TB partition on my software RAID5 device?

My fault. I didn't realize I couldn't create a partition while the array was rebuilding.

I thought I had done this in the past, but I guess I waited first.

Once I waited for the rebuild to finish, I was able to successfully create a partition.


Ubuntu web server can't connect to internet

I had this yesterday and it was all due to a mis-configuration in my "/etc/network/interfaces" file.  Make sure you are using the actual NIC/Wireless names (type "ip link" in a terminal to find them) to make the bridge and not eth0 / eth1 unless you've made the necessary changes to call them that make and make sure you have the necessary gateway/broadcast etc. in the same file if using static rather than DHCP.

Also, comment out any line in reference to your current NIC/Wireless (add a # to the beginning of the line(s)) as you should only set the IP on the bridge and not the NIC/Wireless directly.

I'm still new to the Ubuntu and Networking but this was what I learned yesterday whilst trying to add a router function to my (dedicated) server.

Good luck and please let me know if this works or not - I don't like to give unreliable feedback / help.


LibreOffice needs no other "loading" than the system itself provides. Make sure you run sudo fc-cache -f -v from the terminal to update fonts for the system. That should be all LibO needs to find them. See further help on the Ubuntu wiki.

If the fonts are stored locally (i.e., ~/.local/share/fonts), you might have run into the TTF problem, but that was specific to the LibO 5.4.4x version(s), and is no longer an issue for 6.0+.