Wired networking stops responding when wireless is connected. 12.04 Server

Given that they're on separate subnets, this is probably a routing issue.  It sounds like packets that should go out directly on eth0 to the 192.168.20.0/24 subnet are instead going to the default gateway on (presumably) 192.168.10.x, which then doesn't understand how to route them.

Also, I need clarification: are you saying that other machines on the LAN can no longer successfully ping the server, or are you saying that the server can no longer ping other machines on the LAN?


Permission denied to move files from a live session

To move files, you can use (1) sudo to execute a command as the root and ()2) mv to move them. You must open a Terminal, for instance, by pressing Ctrl+Alt+T on your keyboard to open Terminal and run the follwing command:

$ sudo mv -f -i <Source> <Destination>

The -f option will force the move. The -i will instruct mv to ask for permission before overwrite some file. Example: sudo mv -f -i /home/user/test /home/user/test1

To copy the files, you can use

sudo cp -i -v <Source> <Destination>

Example: sudo cp -i -v /home/user/test /home/user/test1


How do I increase the hard disk size of the virtual machine?

Open a terminal and navigate to the folder with the VirtualBox disk image, then use the following command:
VBoxManage modifyhd YOUR_HARD_DISK.vdi --resize SIZE_IN_MB

replacing YOUR_HARD_DISK and SIZE_IN_MB with your image name and desired size. sudo might be necessary in some machines or you might encounter an error. This answer and a fuller explanation are here, on webupd8. Credit to Andrew there for posting this answer.
After resizing, the extra virtual hard drive space needs to be partitioned and formatted for the guest to use it. This can be done with gparted by booting the guest from a live ISO. We can also resize the existing partition using gparted. For this we may need to disable /swap and create a new swap partition.
In case if VBoxManage is not found in your system, just set the path to:
set PATH=%PATH%;"C:\Program Files\Oracle\VirtualBox"

and it should resolve path issue. Do make sure "VBoxManage" is present at this path before setting it.


Error while installing VLC in Ubuntu 16.04

Same problem as here Trying to resolve PPA issues with libvlccore9 that rendered package management inoperable

IDK if it is kosher but this fixed it for me:

sudo dpkg -i --force-overwrite /var/cache/apt/archives/libvlccore9_3.0.0~rc1~~git20171215+r73271+108~ubuntu18.04.1_amd64.deb

Of course because you are using 16.04 you have to do this:

sudo dpkg -i --force-overwrite /var/cache/apt/archives/libvlccore9_3.0.0~rc1~~git20171214+r73255+108~ubuntu16.04.1_amd64.deb


Can I use the Gnome Shell built-in screencast tool in Unity?

The gnome-shell screencast tool you are referring to is built inside the shell and you cannot use it unless you are using GNOME session. It is part of the session and you can liken it to being something like Unity's top panel, which doesn't come outside of Unity.

And, there is no specific name given to this tool other than the generic built-in GNOME screencast tool.

If you are interested in creating screencasts, you can follow this question for alternative tools:

How to record my screen?


If there is no root password set, login as root is disabled. This is typically the default configuration of Ubuntu when you install it and set up a user password.

That said, it sounds like you are asking this from a security perspective so I'll mention a couple of things. Firstly, if a user has physical access to the machine they can get root access via a number of means such as replacing the boot drive, booting from something else. Full disk encryption can make it impossible for this person with physical access to see your data but not to wipe it.

Secondly, disabling the mechanism to log in as root doesn't really provide notable security over having a non-guessable passphrase, and just not giving that passphrase to others.

Thirdly, you mention giving sudo access to users. Done incorrectly this can inadvertently open up the ability for users to do much more than you intend for them to. If you have a locked down system it's not typical to let users do anything that requires superuser access.


Where is the username and password stored?

Passwords can be found (in hashed form) in /etc/shadow and the users in /etc/passwd.

The login program is used to establish a new session with the system.
       It is normally invoked automatically by responding to the login: prompt
       on the user´s terminal.  login may be special to the shell and may not
       be invoked as a sub-process. Typically, login is treated by the shell
       as exec login which causes the user to exit from the current shell.
       Attempting to execute login from any shell but the login shell will
       produce an error message.

   The user is then prompted for a password, where appropriate. Echoing is
   disabled to prevent revealing the password. Only a small number of
   password failures are permitted before login exits and the
   communications link is severed.

   If password aging has been enabled for your account, you may be
   prompted for a new password before proceeding. You will be forced to
   provide your old password and the new password before continuing.
   Please refer to passwd(1) for more information.

More info at: http://manpages.ubuntu.com/manpages/hardy/man1/login.1.html

http://manpages.ubuntu.com/manpages/hardy/man5/passwd.5.html


Remove a single file preview in the Unity desktop launcher menu

It will be difficult to remove a single thumbnail, because these are populated automatically according to certain algorithms. On the other hand, sharing your entire screen does exactly that: sharing your entire screen.
There are some workarounds:

Do not share your entire screen, but only the relevant Windows where your video conferencing software allows.
Launch your applications using the "Run" dialog that you get when pressing Alt+F2 or use a discrete launcher like rofi (sudo apt install rofi), dmenu (sudo apt install dmenu) or other launchers for the purpose.

rofi, when run like rofi -modi drun -show drun will show you a text only, very quickly searchable menu of all your applications. You can bind that command to a hotkey to quickly pull it up anytime. It only consumes resources after you actually called it, and fully quits when you made your selection. Although you may not prefer in this context, you can have it show icons by adding -show-icons to the command.


Permanent Alternative Monitor Resolution

From https://wiki.archlinux.org/index.php/Xrandr, you can add this section to /etc/X11/xorg.conf or create the file with

Section "Monitor"
    Identifier "VGA1"
    Modeline "1368x768_60.00"   85.25  1368 1440 1576 1784 768 771 781 798 -hsync +vsync
    Option "PreferredMode" "1368x768_60.00"
EndSection

Section "Screen"
    Identifier "Screen0"
    Monitor "VGA1"
    DefaultDepth 24
    SubSection "Display"
        Modes "1368x768_60.00"
    EndSubSection
EndSection

Section "Device"
    Identifier "Device0"
    Driver "intel"
EndSection

You have to change the line Driver to your correct graphic driver i.e. nvidia, fglrx, whatever.


Accidentally deleted english language. Can't log in

You can force the keyboard mapping using a boot parameter.

Just add this to your temporary boot parameters:

setkmap=de

Now you can make all the changes and reboot.


Try Use an on-screen keyboard, from Ubuntu's official documentation


How to disable (Not remove completely) global menu bar?

I found an easy fix.

It is juts F11 !!

Just press F11 after starting emacs and you will get it full screen.!


You don't need to write systemd script test.service to enable init.d script on boot. If your init.d script is already working fine, you just need to enable your init.d script to run on boot by following commands.

sudo update-rc.d test defaults
sudo update-rc.d test enable


My screen reader ended up still being on- it was extremely simple in the end.


I did "sudo apt install --reinstall gdm" and it was fixed.


x230 tablet , realtek 8192ce connects to router but no internet

For anyone interested, the relevant bug report is:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/902557

@Adam: I have the same setup as you (an X230 with the realtek adapter) and following these instructions fixed the issue:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/902557/comments/166

I am on Ubuntu 12.04 with 3.2.0-35-generic.


I have just found the answer to this, it thinks there is a middle button, to disable it follow the instructions in this post

Disabling middle button on Apple Magic Mouse


What is the difference between these two commands?

Apt is the new frontend. More specifically apt offers the same more-or-less functionalities as apt-get, apt-cache etc in a single command. You can read more about the differencies and similarities here: https://itsfoss.com/apt-vs-apt-get-difference/


How to mount Android external storage over WiFi instead of USB

Meet curlftpfs (package curlftpfs) - “mount a ftp host as a local directory”. First set up your Android device as an ftp server, e.g. using one of the apps explained in the question you linked, then on the host do:

curlftpfs server:port/directory /mountpoint

To unmount use:

fusermount -u /mountpoint

An example /etc/fstab line looks like this:

curlftpfs#server:port/directory /mountpoint fuse auto,user,uid=1000,allow_other,_netdev 0 0

Unfortunately since 2015 there’s a bug in libcurl3-gnutls which makes curlftpfs very slow on file operations, see these resources:

SO question: FTP with curlftpfs is extremely slow to the point it is impossible to work with
launchpad bug report
post on downgrading as an error-prone workaround

Sources/Further reading

man curlftpfs
How to mount FTP resources with fstab when connection is available?

https://wiki.archlinux.org/index.php/CurlFtpFS


Is it possible to use Unity8 on Ubuntu 17.10?

No, it is not possible to run the Unity 8 desktop on 17.10. You need 17.04 or 16.04 LTS.

EDIT:
Unity 8 is not in the 17.10 repository's, and Unity 7 is in Universe now and will be removed in 18.04 LTS.


How are repository details specified in apt?

unknown
The unknown part comes from the entry for Suite key in Release file for a debian repository. I think you've generated a local repository without properly setting the required keys for the Release (or InRelease )file and that's why apt shows unknown.
For example, a typical standard Release file may have these entries (taken from Ubuntu's official repository's InRelease file)
Origin: Ubuntu
Label: Ubuntu
Suite: zesty
Version: 17.04
Codename: zesty
Date: Wed, 12 Apr 2017  2:53:23 UTC
Architectures: amd64 arm64 armhf i386 ppc64el s390x

Check this section of debian wiki for more information about Release file format.
And check this slightly old but my favorite guide to create a proper Ubuntu local repository.
now
now refers to the version of the package currently installed (and thus considered available). The info is maintained in /var/lib/dpkg/status file. I have these entries in apt list --installed
zlib1g/zesty,now 1:1.2.11.dfsg-0ubuntu1 amd64 [installed]
zlib1g-dev/ubuntu-local,zesty,now 1:1.2.11.dfsg-0ubuntu1 amd64 [installed,automatic]
zsync/zesty,now 0.6.2-2ubuntu1 amd64 [installed]

As you can see zsync has a now entry which means it's installed and available as such. If you see no other entries except now it would mean you have a package installed which isn't available to reinstall from any known repository.
Here is the output of apt policy zsync again from the same system.
zsync:
  Installed: 0.6.2-2ubuntu1
  Candidate: 0.6.2-2ubuntu1
  Version table:
 *** 0.6.2-2ubuntu1 500
        500 http://bd.archive.ubuntu.com/ubuntu zesty/universe amd64 Packages
        100 /var/lib/dpkg/status
     0.6.2-1ubuntu1 500
        500 file:/mnt/Data/Software/Linux/Debian_Packages/xenial_debs2  Packages

As you can see /var/lib/dpkg/status was listed as a repo for zsync which means it's currently installed.


Changing column numbering system in Calc (spreadsheet), Not the formatting

Assuming your first number is in cell A1, enter the following formula into cell B1:

=CONCATENATE("1";MID(A1;1;3);MID(A1;5;4))

The "MID" function extracts a text sub-string from cell A1.  For example, the first instance starts at 1 and extracts 3 characters giving the "100" string.  Concatenate adds the substrings together so that your new value starts off as 1 + 100, and so on.


From the official /proc/sys/vm/* documentation:

  oom_kill_allocating_task

  This enables or disables killing the OOM-triggering task in
  out-of-memory situations.

  If this is set to zero, the OOM killer will scan through the entire
  tasklist and select a task based on heuristics to kill.  This normally
  selects a rogue memory-hogging task that frees up a large amount of
  memory when killed.

  If this is set to non-zero, the OOM killer simply kills the task that
  triggered the out-of-memory condition.  This avoids the expensive
  tasklist scan.

  If panic_on_oom is selected, it takes precedence over whatever value
  is used in oom_kill_allocating_task.

  The default value is 0.

In order to summarize, when setting oom_kill_allocating_task to 1, instead of scanning your system looking for processes to kill, which is an expensive and slow task, the kernel will just kill the process that caused the system to get out of memory.

From my own experiences, when a OOM is triggered, the kernel has no more "strength" enough left to do such scan, making the system totally unusable.

Also, it would be more obvious just killing the task that caused the problem, so I fail to understand why it is set to 0 by default.

For testing, you can just write to the proper pseudo-file in /proc/sys/vm/, which will be undone on the next reboot:

echo 1 | sudo tee /proc/sys/vm/oom_kill_allocating_task

For a permanent fix, write the following to /etc/sysctl.conf or to a new file under /etc/sysctl.d/, with a .conf extension (/etc/sysctl.d/local.conf for example):

vm.oom_kill_allocating_task = 1


You can use their bug reporting website click here


X forwarding Raspberry Pi to Ubuntu Gnome (Desktop)

In order to forward X, you need to have it installed. You also need installed Desktop Environment. XFCE seems to be working best for X-forwarding, from what I read online (I use 3rd party software for that)

so go ahead and install xfce on your raspberry Pi:

sudo apt-get install xfce

Aptitude should include xorg in the install as a dependency and install along and then you're ready to rock & roll.

Then you just need to login from your Gnome desktop machine into the Pi:

ssh -X user@host xfce-session


Thanks hiigaran for his answer. Btw I want to post here  what I did so anyone with this same issue can work his way out. First I opened terminal(ctr+alt+t by default) then I ran the command alsamixer which opened another window. You can move around by using left and right arrow keys and arrange levels by using up and down arrow keys. Also m key is used to mute or unmute.I had a bar with "Headphones" label and it was set to 0 and had "MM" written at the bottom. First I unmuted it with "m" key then set its level to 100. Then there was another bar called Auto-Mute which I disabled by pressing down arrow key. After this I pressed esc and ran "sudo alsactl store" command and everything worked.
p.s. this is a solution from this thread: Front panel audio jack is not working in Ubuntu 16.04


Is Live Video Chat with MSN/Windows possible?

telepathy-butterfly  which is a backend to the default Ubuntu IM client Empathy has just received support for the p2pv2 protocol, which will be the only voice/video protocol used by future version versions of the official Windows client. (see bug report and OMG! Ubuntu)

Whilst these fixes are in the source code, it will take time for a new version of telepathy-butterfly to be released, packaged and put in Ubuntu. We are also dependant on the uptake of future versions of the official Windows client (we will be compatible with all future versions, currently in Beta testing). I imagine this will be working in a mainstream way by Ubuntu release 11.04


For the internet connection, you'd have to create a script which ran on login which defines ufw rules to govern the conneciton.  You'd have to create one for yourself too in order to ensure that you don't inherit that profile when you login.

Dropbox is tricky since it uses Amazon ECS servers.  It's an extensive list of target addresses.  Something like :

ufw allow proto tcp from any to <target address 1> port 80
ufw allow proto tcp from any to <target address 2> port 80
...

Then to switch back to "your" profile, something like :

ufw reset
ufw enable

The full list of IP addresses is included at the bottom.

The allow/deny of programs can be achieved by configuring /etc/sudoers, but I'm not certain if you can restrict programs that don't require sudo.  Well, you can, by changing the persmissions of /usr/bin for example, but it's not amazingly elegant.  By which I mean, there's no nice GUI for doing so.

I'll try to add more detail once I'm sitting at my Ubuntu machine.

Dropbox IP addresses :

75.126.110.0/24
173.193.134.0/24
173.194.37.0/24
174.36.51.0/24
174.36.30.0/24
174.129.195.0/24
174.129.196.0/24
174.129.27.0/24
184.72.255.0/24
184.73.211.0/24
208.43.202.0/24
208.43.219.0/24
208.43.223.0/24
204.236.220.0/24


Try to download and install the driver from here
802.11 Linux STA driver | Broadcom


will my files still remain after OS replace install option?

It normally keep intact all your home folder but replace all the system. But, if there is a problem during install (Hardware problem), there is a possibility that you loose all your data. So make a backup of the most important things that you have.


How do I configure DHCP bridge with netplan for KVM on Ubuntu 18.04 LTS?

I modified the default yaml file in /etc/netplan as follows:

network:
  version: 2
  renderer: NetworkManager
  ethernets:
    enp0s25:
      dhcp4: no
  bridges:
    br0:
      dhcp4: yes
      interfaces:
        - enp0s25


go to settings -> Mouse & Touchpad -> choose the Edge Scrolling:after doing that Restart the computer


boot-repair fails with 'No known boot loader is installed in the MBR of /dev/sda.'

The solution was a combination of multiple things:

the boot-repair did work in that it successfully reinstalled grub.
however, it was also necessary to set the newly installed grub version as trusted in UEFI, as pointed out by oldfred above (thank you very much!); refer to Bootable device not found after clean install of Ubuntu 14.04 UEFI on Acer for more details
further, I needed to set the boot order such that the trusted grub was in front of windows in UEFI

Thank you again, oldfred!


If I Install Windows and Ubuntu in the same disc,Which one is better to instal first? Will I need anti virus in Ubuntu for Windows virus?

If I Install Windows and Ubuntu in the same disc...

I don't think you can have both in the same disc. They will most likely take up the whole DVD disc and some.

  Is it better to install Ubuntu or Windows first?

I believe installing Windows first is the way to go and then Ubuntu. Not sure about now but that was certainly the case back in 12.04.

  Will I need to install an anti virus in Ubuntu for Windows virus?

You don't need any antivirus in Linux (:

  If I install Windows first,Do I need to format Windows partition or Ubuntu takes part of the disc and formats in Ext4?

You don't format anything, Ubuntu at its installation will convert part of the disk space into ext4. If you have enough space left over, Ubuntu will just take as much space from Windows as it needs or you specify. So, when the partition finishes, Windows won't know about the partition Ubuntu resides in but interestingly from Ubuntu's side, you can access Windows files, which is an amazing experience if you are Windows centric person like I was.


x11vnc error: "The program "Xvfb" could not be found."

Install xvfb with sudo apt-get install xvfb -y in a terminal. Xvfb -- "X Virtual FrameBuffer" emulates/"fakes" an X disPlay when there is no physical display connected to the system. A common use for it is to run programs which require a display on headless systems.


How to install software to OS on other disk?

If you would like to configure software RAID 1 try with any SERVER edition, recently i tried to configure RAID 1 on 10.10 Desktop edition, failed many times, finally tried with server edition, easily can configure raid at the time of installation.


"Failed to download repository information" error

Try changing the server to main server, from the software resources menu option in the Ubuntu Software Center.


How to set DNS server address temporarily?

Write it into /etc/resolv.conf:

echo "nameserver 1.2.3.4" | sudo tee /etc/resolv.conf

Upon successful DHCP connection, it should be overwritten back to the "correct" DNS server.


I don't know if it'll help, this was on Debian Jessie, so YMMV
I was running a ./configure command and getting:
No package 'libglade-2.0' found

So, tried:

$ sudo apt-get install libglade2-0

and getting:
libglade2-0 is already the newest version.
(./configure still generating same error)

Finally tried:

  $ sudo apt-get install libglade2-dev

and it seemed to fix the problem
(configure worked, then make worked)


Ubuntu Server on HP ML10 v2: keyboard doesn't work in installation

Yes, I was able to get this to work, using Ubuntu 16.04 Server LTS.  I put the detailed instructions that worked for me here:  How can I install Ubuntu 16.04 LTS Server on an HP ProLiant ML10 v2 Server


Try from terminal:
   sudo usb-creator-gtk


Password for authenticating pkexec nautilus

Authenticate pkexec nautilus with your user password for that OS, the same password you use to run sudo commands on that OS.

pkexec PROGRAM allows an authorized user to execute PROGRAM as another user. If username is not specified, then the program will be executed as the administrative super user, root. pkexec will use the authentication agent registered for the calling process. However, if no authentication agent is available, then pkexec will register its own textual authentication agent.


How can I see what instruction my computer is executing?

To see what processes are currently most CPU or memory demanding, you can use htop
sudo apt-get install htop
sudo htop


DualBoot 32Win & 64Mac from Live USB +Persistance

Solution, but not really. I finally got my hands on some cd's and burned plop iso, then used that to boot usb.


The output shows that the CPU is Intel(R) Pentium(R) CPU B950 @ 2.10GHz.

It supports both 32-bit and 64-bit architectures.

You can install a 64-bit Ubuntu.


To uninstall lens, open terminal / Ctrl+Alt+t then type:

sudo apt-get remove unity-lens-xxx

The xxx is the type of lens. In general, Unity use this lenses:

Applications
Files
Gwibber
Photos
Shopping


Gedit inserts blank lines sporadically when using scroll wheel

So I think what's happening is it's registering as if you're clicking the scroll wheel (which is the same as 'middle click'.  This may fix it: https://wiki.ubuntu.com/X/Config/Input#Example:_Disabling_middle-mouse_button_paste_on_a_scrollwheel_mouse


Repair dual boot ubuntu 14.04 / Windows 10

1. Boot from a live disk/usb

2. Mount the ubuntu root partition to /mnt.
Find out ubuntu root partition by either

lsblk

or

sudo fdisk -l

(Assuming its sda5)

sudo mount /dev/sda5 /mnt

3. Bind mount other necessary partitions

for i in /sys /proc /run /dev; do sudo mount --bind "$i" "/mnt$i"; done

4. Chroot into /mnt

sudo chroot /mnt

5. Install grub

grub-install /dev/sda

6. Update Grub

sudo update-grub

7. Exit

ctrl + D

8. Reboot


Touchscreen don't click in google chrome

Edit /usr/share/applications/google-chrome.desktop and change the Exec=/usr/bin/google-chrome-stable lines to Exec=/usr/bin/google-chrome-stable --touch-devices=NNN where NNN is your touch screen device. My touch screen device is 12.


How to give root permission for permanent to an existing user?

The normal way to make a user an administrator on an Ubuntu system is to add them to the sudo group so they can use sudo to execute things as root when needed.
# usermod -a -G sudo normal

That adds the user normal to the sudo group. After that user logs in again they should be able to use sudo.


Do I have to set up mail for Ubuntu to be able to mail users?

If you haven't done it yet you will need to install postfix (sudo apt-get install postfix) or sSMTP (sudo apt-get install ssmtp) to replicate the sendmail commands.


The three standard MPMs (prefork, worker and event) are available in the apache2-bin package (and thus on all apache2 installations for Apache 2.4):

$ dpkg -L apache2-bin | grep mpm
/usr/lib/apache2/modules/mod_mpm_event.so
/usr/lib/apache2/modules/mod_mpm_prefork.so
/usr/lib/apache2/modules/mod_mpm_worker.so

From the changelog entry for 2.4.1-1:

* Refactor binary packages, now as things simplified. MPMs are simple
  modules now, they can be bundled into the same binary package which do not
  need to conflict with each other. Thus, Apache now primarily consists of the
  following packages:
  + apache2 - configuration files and init scripts, Debian specific helper
  scripts
  + apache2-bin - binaries and modules
  + apache2-data - error pages and images

By default, prefork is enabled.


Can't Install anything from Ubuntu Software Center in Ubuntu 15.10

Can you provide further details in the error window click on the arrow on Details please.

Try the commands below in sudo to see if refreshing your apt-get cache and removing any packages that are no longer needed.

apt-get autoremove
apt-get clean

Once your done try update and upgrading via sudo in terminal.

apt-get update
apt-get upgrade

If errors come up in terminal please post in here please.

Thanks


It only has packages for Ubuntu 11.04, but Rico Tzschichholz's Testing PPA has recent gnome-shell builds.


iPod shows more tracks than Library after sync with Banshee

Install gtkpod.

sudo apt-get install gtkpod

You can also copy the existing contents of your iPod in their original name unlike some system generated alphabets of iTunes.


ppa:w-shackleton/droidpad and ppa:w-shackleton/droidpad-daily do not support any Ubuntu release later than 14.04, so they should be removed from the software sources in Ubuntu 18.04. Open the terminal and type:

sudo add-apt-repository --remove ppa:w-shackleton/droidpad ppa:w-shackleton/droidpad-daily
sudo apt update

To install Blender in all currently supported versions of Ubuntu 18.04, open the terminal and type:

sudo apt install blender # recommended

To install the latest stable version of Blender in all currently supported versions of Ubuntu 18.04, open the terminal and type:

sudo snap install blender --classic


http://www.eastwoodzhao.com/thinkpad-middle-button-scroll-ubuntu-linux-10-04-lucid-lynx/

In short, run this: gksu gedit /usr/lib/X11/xorg.conf.d/20-thinkpad.conf and put this in the file:

Section "InputClass"
Identifier "Trackpoint Wheel Emulation"
MatchProduct "TPPS/2 IBM TrackPoint|DualPoint Stick|Synaptics Inc. Composite TouchPad / TrackPoint"
MatchDevicePath "/dev/input/event*"
Option "EmulateWheel" "true"
Option "EmulateWheelButton" "2"
Option "Emulate3Buttons" "false"
Option "XAxisMapping" "6 7"
Option "YAxisMapping" "4 5"
EndSection

Save and restart.


Apache web server and virtual host can not be accessed from other Ubuntu pc in LAN

First from clientPc check if the port 80 is open

nmap -p 80 -PN 192.168.0.21

If it's not open and you're using ufw firewall, allow connections from inside your lan with

sudo ufw allow from 192.168.0.0/24 to any port 80

Test again the port is open

nmap -p 80 -PN 192.168.0.21

Then edit the <Directory> part as follow (it works for me)

<Directory /var/www/50000SiteName>
    AllowOverride All
    Order allow,deny
    allow from all
    Require all granted
</Directory>


File Sync error. (auth failed (AUTH_FAILED))

Try setting your clock and timezone correctly and then reconnecting. It worked for me.

I think this is because Ubuntu One synchronizes your files based on the time it was last modified.


Creating a dedicated grub partition before installing ubuntu

Another option is to make a dedicated Grub2 partition (as opposed to dedicated /boot partition you mount at boot), see herman's tutorial.

Advantage: you can remove/install OSes at will.

Disadvantage: you need to edit the grub.cfg file manually. To avoid having to do that after every kernel update I recommend using the link to kernel images, not the kernel image itself, for example use something like

linux   /vmlinuz root=UUID=3e4xxxxx-027b-407c-ba1a-xxxxxxxx ro   quiet splash

not

linux   /boot/vmlinuz-2.6.35-28-generic root=UUID=3e4xxxxx-027b-407c-ba1a-xxxxxxxx ro   quiet splash

For more info on using symbolic links instead of full paths for kernel images look here.

Disadvantage2 (thanks psusi): when installing a new OS make sure you do not install its Grub image to MBR. Install it without Grub and then manually edit the grub.cfg file to include the new OS.


You need to use the installation media, DVD or USB stick, to do a fresh reinstall.


Ubuntu 16.04, how to get my GPU temp and fan speed?

Please use sensors-detect.

sudo sensors-detect

then launch it with:

sensors


For that you will have to disable the super+T shortcut in compiz settings in the unity section then change the terminal shortcut in keyboard shortcuts to super+T.


New Ubuntu user, wireless connection - firefox won't work

Welcome to askubuntu, and congratulations for diving into a decent computing environnment.

I suspect your wireless is connected, but you may have a DNS problem.

Try these 2 simple ping commands, in a console:

ping google.ca

Then:

ping 173.194.73.94

If the second ping does not resolve ( it should return 3 ping results by default), this would mean you HAVE an Internet connection, just no properly configured DNS resolver.

If that is the case, I suggest you configure your DNS by following this guide.

Oh, if you need a DNS server to setup against you can use google's public dns service.

If both pings do not resolve, it could be you are connected to your router but the router is not connected to Internet.
If you want to rule out that firefox is the culprit, try installing chrome or even lynx:

sudo apt-get install lynx

Or..

   sudo apt-get install chrome

Then, in a console:

lynx google.com

If this brings you the beautiful google page (in text mode), Firefox is the culprit. I would surprised if this was the case. I am betting you have a (quite common) DNS configuration problem.

Hope that helps. Cheers!


What is the difference between "00-installer-config.yaml" and "50-cloud-init.yaml"

I am in an Advanced Linux class, and found myself asking the same thing.
The 00-installer-config.yaml file is supposed to be for v20, the 50-cloud-init.yaml for v18, however my VM must think otherwise. I myself found the 00-installer-config.yaml file in my /etc/netplan folder instead. I then rebuilt the 50-cloud-ini.yaml file and removed the 00-installer-config.yaml file. After that, I went to /etc/cloud/cloud.cfg.d and looked through these few file and noticed a "subiquity....." file. This file had one line in it that appeared to act as the "network: {config: disabled}" from 99-disable-network-config.cfg file that disables netplan....so I hashed this out.
I then issued netplan generate then netplan apply and rebooted. All is well here now. However, I too need to know for my own development why this may happen.
I hope there is enough information I have provided to further your solution.


Bluetooth (Atheros AR5BBU22) not working

Support for Atheros AR5BBU22 is in the Kernel since 3.6.15 but additionally the proprietary firmware has to be installed on the system for bluetooth to work. It is available in the package linux-firmware (on ubuntu; resp. firmware-atheros on debian, non-free).


where is "startup applications" user config file for disabled and enabled applications?

If you edit the files inside ~/.config/autostart/ they are written in this way:

[Desktop Entry]
Name=Dropbox
GenericName=File Synchronizer
Comment=Sync your files across computers and to the web
Exec=dropbox start -i
Hidden=false
Terminal=false
Type=Application
Icon=dropbox
Categories=Network;FileTransfer;
StartupNotify=false
X-GNOME-Autostart-enabled=false

The last line is the one that specifies if the app is enabled or not (check it by yourself with the gnome-session-properties enabling and disabling an app and noticing the change of that option in the file).

Then, you only have to copy all the files inside the folder to make a backup of that configuration.


Open Terminal and type these commands:

sudo nano /etc/network/interfaces

Now edit the file:

auto lo eth0
iface lo inet loopback
inface eth0 inet dhcp

Now save that file.

After this step you have to open another file via terminal.

sudo nano /etc/NetworkManager/NetworkManager.conf

[main]
plugins=ifupdown,keyfile,ofono
dns=dnsmasq

[ifupdown]
managed=false

After doing this editing job. Run this final command :

sudo service network-manager restart

And then restart your Ubuntu.


LXC Container not pining from host or network

Maybe, the problem is that there is no route information to LXC container.

I think the information you give here is not sufficient.
You should show:

1. the ip and  route table of the windows host .

2. the ip and route talbe of the Ubuntu VM.

Then, I will give you the solution.


12.04 Dashboard's search opens program as text file rather than running as app

it sounds like the file isn't marked as executable. You can pop into the command line and use

chmod +x (file name)

or find the file in nautilus, right click, go to the permissions tab and check the "allow executing file as program" button.

EDIT: also ensure the correct shebang is present; try adding

#!/bin/bash

to the top of the file


Where are the .desktop icon files stored?

The .desktop link files are stored in /usr/share/applications for software installed for all users, and $HOME/.local/share/applications for things you have installed only for yourself.

The actual icon (image) files are a bit more scattered (since a .desktop file can specify their absolute path), but /usr/share/pixmaps and /usr/share/icons contain a good fraction of them. (icons at  $prefix/share/icons/ with required fall-back version in hicolor theme can be loaded without the full path, thus such as Icon=video-display where $prefix can be /usr, /usr/local or ~/.local; See specification at freedesktop.org: Icon Theme Specification )


How can I mount a subvolume on BTRFS from Arch in Ubuntu?

Have you tried
    sudo apt install btrfs-progs -y

https://linuxhint.com/install-and-use-btrfs-on-ubuntu-lts/
Then retry your mount command.  Please be sure to specify the type of filesystem you want to mount.   In this case, -t  btrfs  is going to be the type.
    sudo mount -t btrfs -o subvol=markus /dev/nvme0n1p3 /mnt/backup/


Installed Ruby 1.9.2 but new gems won't create scripts into /usr/bin

As far as I'm aware, Rubygems on Ubuntu and Debian use /var/lib/gems/$ruby_version as their installation root (to keep gems installed via apt, and manually-installed gems cleanly separated).

In your case, since you're using Ruby 1.9, the executables should be installed in /var/lib/gems/1.9/bin. Try adding something like this into your ~/.bashrc file:

export PATH="/var/lib/gems/1.9/bin:$PATH"


Endless swap operation slows computer to a halt. How to fix?

Simply by exceeding RAM space you get everything else put in swap partition, which is way slower than RAM. Thus, resulting is slower system response.

So the solution would be having less programs open.
On the other hand, there's swappiness

  Swappiness is a property for the Linux kernel that changes the balance between swapping out runtime memory, as opposed to dropping pages from the system page cache

from wiki

and this thread explains how to use it.


Is it safe to switch from GRUB2 to BURG?

BURG is old and no longer maintained. Instead, I recommend that you use rEFInd: http://www.rodsbooks.com/refind/

It is a graphical multi-boot bootloader which is very stable and easy to customize. You can find many themes to choose from, some of which are listed in the official website linked above.


skype crashing when other contact logs on

If you downloaded from with Software Manager or Synaptic or apt-get, you may have issues.  I've always have, so I go to the site and have better success.

Go here:
http://beta.skype.com/en/download-skype/skype-for-computer/
From the site drop down menu, and choose dynamic.
Extract to your home directory.
Open terminal and navigate to the Skype directory.
type ./skype
Enjoy, I think you will have better results.


How to free the ROM memory allocated to Ubuntu on Virtual Box?

To free the ROM memory(fixed or Flexible) you need to delete the Ubuntu.vdi file from your system. This will free the disc space.

After lot of search I found folder where "Ubuntu.vdi" is located.

Ubuntu.vdi file location

I hope on all windows system Ubuntu.vdi file will be located in same location. Just delete the VirtualBox VMs folder before you re install it. It will free up the disc place earlier allocated.


Grub rescue: how can I find where my Ubuntu installed?

I've been using Linux for more than 15 years and I dread having to type commands in grub.  The grub CLI is a difficult challenge. Documentation does not keep up, changes in types of hard disk partitions and the types of boot systems (UEFI, BIOS) and partition table types (MBR, GPT) make this confusing.  You can learn a lot by fighting through grub2 in the CLI, but it is a chore.

I think the most dependable fix is to run the Ubuntu installer again and let the system get it right for you.  I had this problem after installing Ubuntu 16.04 because I tried to get an encrypted partition and it just did not work the first time.  Running the re-install fixed it like magic.  When you start the install, be careful to choose the custom partition option and tell it to use the same disk partitions that you have now, it is much more likely come out with a working system. Don't reformat your "/home" partition, but anything else can be reformatted.

The only problem, then, is to be sure what is in your current partitions so that you know how to name them in the installer setup.

You can save yourself some heartache if you use the bootable USB Ubuntu image to start a live session and take a look at your hard disk.  You can make sure what the partitions are, and you can mount them and see that the files are actually there.  Of course, the vital ones you are looking to re-use are "/" (the root partition), "/boot" (if you have a separate boot partition,  need to name it) and "/home". If your previous install did not have a separate "/boot", it is not fatal these days, but I still like to set up that way.  You may also see separate partitions for "/tmp", "/var", "/usr/local" and whatnot, depending on what mood you were in when you installed that.

If you do keep trying to interact with grub, good luck. You will learn doing that.  If you need to ask for more help, we need more information about your partition table. Get that info in the live session. I was going to say that the output of "/sbin/fdisk /dev/sda" followed by "p" would help, but that won't help if you have a new SSD and a GPT disk partition. It appears to me the program "parted" is most likely to run and will show the broadest set of partition types. If you run

sudo parted

then run

print all

Then show the whole thing.


If this adapter worked on Ubuntu 16.04, then it is supported by Ubuntu 4.4 kernel.

You need to upgrade kernel in Ubuntu 14.04 to get it working, You can do it by running

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

Reboot after you install the kernel.


How to set Passwordless login on ubuntu 18.04?

This works, but I don't know if it's safe.

  If you want to bypass the password prompt in GDM then simply add the following line on the first line of /etc/pam.d/gdm-password:

auth sufficient pam_succeed_if.so user ingroup nopasswdlogin

  Then, add the group nopasswdlogin to your system.

  Now, add your user to the nopasswdlogin group and you will only have to click on your username to login.

I don't know if it's safe, because the sufficient control bypasses the other rules that follow, including SELinux session rules, and I don't understand what any of that stuff does.


Unity elements sometimes appear while full screen in Virtualbox - how to stop it?

The best way to run virtualbox without any interference with the host operating system (Unity in your case) is create a special session for Virtualbox from your login manager (Lightdm).

The best is following this process
http://www.ashokgelal.com/2008/10/run-your-virtual-os-directly-from-gdm-in-ubuntu/

It's applied to GDM but should working also with Lightdm.


How do I turn bluetooth on/off in ubuntu 15.10?

Check if you've got the following packets installed:

bluez-utils
libopenobex1
gnome-bluetooth
blueman

If you are using an USB-device check if it is recognised correctly:

lsusb | grep Bluetooth

Also try runnig the following command to restart the bluetooth service:

sudo service bluetooth restart


Lenovo T480 with Thunderbolt Docking Pro - USB 2.0 devices not recognized

Reset the usb system for the usb port on the dock:

echo -n "0000:3c:00.0" | sudo tee /sys/bus/pci/drivers/xhci_hcd/unbind; sleep 2 && \
echo -n "0000:3c:00.0" | sudo tee /sys/bus/pci/drivers/xhci_hcd/bind

Somehow the issue solved itself in my case after months of irritation -- probably a kernel fix.


Limitation of having 9 workspaces with 3 monitors solution - Ubuntu 18.04

By updating "multi monitors add-on" and "Gnome workspace grid" it is now possible in "workspace grid" to set up to 36 workspaces.


Problem in upgrading from 12.04 to 12.10

Try to use the main repositories while upgrading. To do that open a terminal, type:

software-properties-gtk

and on the first tab choose Main repository, enter your password when promted, than close and run:

do-release-upgrade

If does not work, you can first remove libxatracker1, and try like that. If you use vmware, you can reinstall it after the upgrade.


Perhaps you are looking for different workflow.

You can first cut out the parts that you want with oggz-chop. Simply type in the terminal:

oggz-chop -o output.ogv -s start -e end input.ogv

This should give you good files that you want to keep. Make sure you name them in some sequential order, to be able to deal with them later.

After that:

There is an oggCat command, which is able to concatenate two or more ogg files together producing one ogg file of the length equal to the sum of all provided.

The command line that will help you is:

oggCat output.ogv infile1.ogv infile2.ogv infile3.ogv ...

Do not confuse it with another command from the same package titled oggJoin, which does something quite different, creating a single file with several streams that will run in parallel.

Now, for cropping, i know that there is a way to do that losslessly, by editing the header of Theora stream, but i was unable to figure out how to do that as of yet. I will update the answer if i'll find the way.


I do not have experience with this particular issue but from the grub2 manual (assuming that is your boot-loader):

5.3.4 DOS/Windows 5.3 Some caveats on OS-specific issues

GRUB cannot boot DOS or Windows directly, so you must chain-load them (see Chain-loading). However, their boot loaders have some critical deficiencies, so it may not work to just chain-load them. To overcome the problems, GRUB provides you with two helper functions.

If you have installed DOS (or Windows) on a non-first hard disk, you have to use the disk swapping technique, because that OS cannot boot from any disks but the first one. The workaround used in GRUB is the command drivemap (see drivemap), like this:

drivemap -s (hd0) (hd1)

This performs a virtual swap between your first and second hard drive.

I do not know if the following will work out of the box but hopefully it may point you in the right direction. Best of luck.

menuentry "Windows" {
    insmod chain
    insmod ntfs
    drivemap -s (hd0) (hd1) # swap hd1 for hdo
    set root=(hd0,1)
    chainloader +1
}


Used iptables to disable internet and now I need to undo it

Try this:

sudo iptables -F

And open:

sudo gedit /etc/network/interfaces

then remove the lines that you put there.


Can I make a *.desktop item always be maximized?

gnome-terminal has an undocumented --maximize option (and also --full-screen).  You can add that to the launcher's EXEC line to have it start maximized.


Yes, sync to vblank can only work for one monitor with NVIDIA and TwinView.

I found that this answer helped me fix the syncing to the monitor I wanted:

https://askubuntu.com/a/140036


How do I show what command runs my Eclipse project?

Look in the 'Run > Run Configurations' dialog and find your Java Application in the list. There should be a 'Show Command Line' button near the bottom right of the dialog.

This button was added in Eclipse 2018-09 (4.9) (sudo snap install eclipse --classic). The eclipse snap package has Java IDE pre-installed. Older versions of Eclipse don't have a way to see the command line.


bash file comparison line by line with selected string

This reads all the lines in a.txt and keeps track of all of its column 2 values.  It then reads b.txt and prints out any repeated values of column 2:

$ awk 'NR==FNR {seen[$2]=1; next} seen[$2]==1 {seen[$2]++; print $2}' a.txt b.txt
abcd
2dfg

The awk command can be divided into the two parts.  The first part is:

NR==FNR {seen[$2]=1; next}

awk first tests whether the total number of records (lines) processed, NR, is the same as the number of records processed in this file, FNR.  This is true only for the first file processed which is a.txt in this case.  Thus, for every line in a.txt, the associative array seen with a key set to the value of the second column, $2, is set to a value of 1.  This will be used to indicate that this value of column-2 was "seen" in a.txt.  The following command is next which tells awk to skip the rest of the commands and go get the next record.

The second part is:

seen[$2]==1 {seen[$2]++; print $2}

Because of the next command in the first part above, this part is only executed by file b.txt.  This part begins with a test: it checks to see if the column-2 value, $2, for this record has been seen before.  If is has been seen before once, then the commands in braces are executed.  The first command in braces, seen[$2]++ increments the value of seen so that we will never process this value of column-2 again.  (Consequently, repeat values of column-2 are ignored.)  The second command simply prints the value of column-2 that had been seen before in a.txt.

If we can trust that there are no repeated values for column 2, a simpler script is possible:

$ awk '{print $2}' a.txt b.txt | sort | uniq -d
2dfg
abcd


No.
Your computer will boot without any problems (provided you installed the right kind of RAM, etc.).
Afterwards, take a minute to double the swap size as well. You may even wait until you experience memory problems. If you have a little more time, get rid of the swap partition altogether, and create a swap file.


Disable Ethernet permanently to speed up boot time

Blacklist the NIC driver

Create a blacklist file in /etc/modprobe.d/

Note that files in /etc/modprobe.d/ must have .conf suffix. Also naming modules in /etc/modprobe.d/blacklist.conf does not affect autoloading of modules by the kernel so you have to make your own file.

Example of a blacklist file: blacklist-ethernet.conf

blacklist driver_0     # eth0 by default

Note: here driver_0 is the name of your NIC driver. you can find the name of kernel driver for your LAN card by using the command lspci -v command in a terminal.
For Example my output was :

........
........
6:00.0 Ethernet controller: Broadcom Corporation NetLink BCM5906M Fast Ethernet PCI Express (rev 02)
    Subsystem: Lenovo Device 3861
    Flags: bus master, fast devsel, latency 0, IRQ 46
    Memory at b8000000 (64-bit, non-prefetchable) [size=64K]
    Expansion ROM at  [disabled]
    Capabilities:
    Kernel driver in use: tg3
    Kernel modules: tg3
........
........

Here, I see the driver is tg3. so you need to write tg3(or your driver) in the place of driver_0.

Generate modules.dep and map files by running: depmod -ae
Recreate your initrd: update-initramfs -u

Plenty of info can be found here.


last command to the rescue

The last command shows by a given user name or all user names:

$ last rick
rick     tty7         :0               Wed Apr 24 16:25    gone - no logout
rick     tty8         :1               Wed Apr 24 16:24 - down   (00:00)
rick     tty7         :0               Tue Apr 23 20:12 - down   (20:06)
rick     tty7         :0               Tue Apr 23 18:30 - crash  (01:42)
  (...SNIP...)
rick     tty7         :0               Tue Apr  2 16:52 - down   (00:31)
rick     tty7         :0               Tue Apr  2 03:14 - crash  (13:37)

By default it only shows history for the current month. If you need to go further back in history than one month, you can read the /var/log/wtmp.1 file with the last command.

last -f wtmp.1 rick will show the previous month's history of logins for user rick:

$ last -f /var/log/wtmp.1 rick
rick     tty7         :0               Sun Mar 31 16:53    gone - no logout
rick     tty7         :0               Sat Mar 30 19:18 - down   (13:20)
  (...SNIP...)
rick     tty7         :0               Fri Mar  1 20:55 - down   (11:55)

wtmp.1 begins Fri Mar  1 18:23:28 2019

Security is hardened such that normal users can't write or delete the file:

$ ll /var/log/wtmp.1
-rw-rw-r-- 1 root utmp 107520 Mar 31 16:53 /var/log/wtmp.1

Console only logins

The console uses the login command which records data to /var/log/lastlog:

$ ll /var/log/lastlog
-rw-rw-r-- 1 root utmp 292292 Apr 24 16:22 /var/log/lastlog

The lastlog file though cannot be tampered with so easily when you look at the File Owner and File Group above. "Normal" users just have read access. It's a binary file though so you can't just cat it and get meaningful information. Use this command instead:

$ lastlog
Username         Port     From             Latest
root                                       **Never logged in**
daemon                                     **Never logged in**
bin                                        **Never logged in**
sys                                        **Never logged in**
  (...SNIP...)
usbmux                                     **Never logged in**
rick             tty1                      Wed Nov 28 04:19:53 -0700 2018
vnstat                                     **Never logged in**

It's interesting to see all the different user IDs that could log in but never have and never should. I was surprised I haven't logged into the console / terminal since November last year.


That's normal. The internet connection must stay open throughout the whole download.

There are some programs that enable you to pause the download if you use them but that's not recommended

It is best to download using torrents to deal with such cases.


Which file to add to /usr/local/bin from a program installed from source?

Whatever you try to do or to archive, please try as much as possible to not add your executable files in a system directory like /usr/local/bin. This can be unpleasant for other users who use the same system.

You can put your executable files in your ~/bin directory. If you don't have already one, create it:

mkdir -p ~/bin

This directory is already added to your PATH as you can see in the last lines from your ~/.profile file. So, any executable that you put there can be run only by typing it's name.

And which file to add? - Any file you want, nobody (other than you) and nothing will be disturbed because of this.

In case of a program installed from sources you better create a symbolic link to the executable file which starts the program, instead to copy the executable file:

ln -s /path/to/program/executable_file ~/bin


How to install DE from Ubuntu 17.10 on Ubuntu 16.04

You probably will not be able to install the gnome session of 17.10 as such on Ubuntu 16.04, especially as you indicate valuing stability. However, you can rather quickly mimic the 17.10 desktop on your 16.04 by installing gnome and two gnome extensions, dash to dock and KStatusNotifierItem/AppIndicator. Then configure dash to dock to have it appear as a panel on the left. The dock in Ubuntu 17.10 is actually a fork of Dash to dock, where the customization options have been limited or concealed.

A less "stable" solution would be to add PPA for a more recent gnome shell version. However, it may not be worth it. With a three-week wait, you will be able to install the 18.04 release candidate, which will update itself to the release version within a week.


FLareget wont show any file on the list after reboot

There doesn't seem to be any issue with resuming. I hope you are using the latest version. You can try exiting the flareget before restarting your PC.

Please note: This website is not meant for particular software related issues. Most of the applications provide their own support. The better place to ask this question will be Report FlareGet Issues


How to recover Ubuntu installed with Wubi with corrupted GRUB

One way would be to use EasyBCD, a free tool which is like Grub editor for the Windows Boot Manager.

The steps involved would be :

Install EasyBCD
Add an entry for Ubuntu (Wubi) using EasyBCD
Open a command prompt Win+R -> cmd and then type bcdedit
Note the entry (device-id) for Ubuntu that you just made
Run bcdedit /set {device_id} partition=X: (This is if your Ubuntu wubi was installed somewhere other than C:\)
Run bcedit /set {device_id} path \your_ubuntu_path\winboot\wubildr.mbr and substitute the correct path to wubuildr.mbr on your system

Source: How To Restore the Wubi Ubuntu Bootloader via How To Geek


Owncloud Appliance SSH key fail to import

To make this work step 4 in the installation proceedure has to use the cat command to get the proper listing from the id_rsa.pub file.
Surprising what a god night's sleep can do.


Can see all computers on the networks but can't see each other

After editing the smb.conf, the interfaces, the host and hostname files, and still not having any luck I restarted both machines several times and still no luck.

Finally I restarted them at the same time and they are able to see each other and the other computers on the corp.local network.


How can I backup my apps, ppas, firefox bookmarks, fonts, icon sets, webcam drivers before a clean install?

Well if you have a different partition for /home things are a lot easier.

1-)fonts, themes, icons, firefox bookmarks are all in your home folder
2-)ppas, apps and drivers are in / partition so you need to save them in some other way

Start the installation and choose advanced partition or something like thta. In your existing /home set up a mount point for /home and DON'T select to format it, then choose another partition for / and format it.

When the installation finish you can restart and you will have your theme, fonts, settings, account and documents like before.

For apps you can use OneConf which is avalaible in the software center and preinstalled in oneiric

For driver and ppas i don't know


Sharing folders VMWare 12 and Windows 10. Shared folders are not found

Using that source:
https://communities.vmware.com/message/2510025#2510025

I composed joined command:

sudo apt-get remove open-vm-tools; sudo apt-get update; sudo apt-get install git; sudo git clone https://github.com/rasa/vmware-tools-patches.git; cd vmware-tools-patches; sudo ./download-tools.sh; sudo ./untar-and-patch.sh; sudo ./compile.sh

After that you will see shared folder.
Keep in mind, at the time of command executing, dozen of vmware tools different versions are download and installed and it takes around 1 hour.


This was a fairly annoying problem, however I managed to resolve by by simply switching over to SFTP- at least, for now. However, if anyone knows if this is an issue that persists, answers are welcome!


Installed Ubuntu 14.04.1 on DELL Vostro 3445 but display is jerky

I have resolved this problem.
Step 1. I opened the system settings > software updates
Step 2. Clicked additional drivers tab ... it took some time to fetch the list
Step 3. My computer was using X.org Xserver -AMD/ATI display driver wrapper from xserver-xorg (open source code). I changed it to Video driver for AMD graphic accelators from fglx (proprietary)

Now my problem is gone. Even HD videos are running smoothly.


CYMK Support

GIMP is an open source program and so is built and maintained by the community.  The GIMP FAQ states:

  It is clear from the product vision that GIMP eventually needs to support CMYK, but it is impossible to say when someone finds the free time and motivation to add it. In the meantime it is possible to work with CMYK to some extent using plug-ins, such as the Separate+ plug-in.

Alternative Software

Alternative software to GIMP can be found by using the popular Alternative.To website.


File Symbolic link broken as shown in Desktop icon

I managed to solve the broken link problem by manually mounting the mount point and make it persistent in /etc/fstab

/dev/sdb5    /media/WESTERN       ntfs     auto

Upon reboot, the mount point /media/WESTERN will appear under devices.


X11 Server Won't Start - Write-Protected Filesystem

My problem has been resolved, & apparently had been resolved somewhere in the steps I took mentioned in my question. The reason I was getting the results that I did appears to have been related to a manual entry that I had in the GRUB2 bootloader.

After I initially installed Ubuntu MATE on my MacBook, I was having trouble booting into the system. It would freeze even before the Plymouth splash screen was loaded. The original kernel line in the GRUB2 menu entry was as follows:

linux    /boot/vmlinuz-5.0.0-29-generic root=UUID=<UUID> ro  quiet splash $vt_handoff

I came to the conclusion that the $vt_handoff value was causing the problem. Removing it from the line allowed the system to boot. So, I manually created an entry in GRUB2 that omitted $vt_handoff, & I also added the nomodeset option. When my system crashed, I continued to try to boot using this manual entry & I kept getting stuck in the tty terminal. Not long after posting my question, I went into the original GRUB2 menu entry & added the nomodeset option so the line read as follows:

linux    /boot/vmlinuz-5.0.0-29-generic root=UUID=<UUID> ro  quiet splash nomodeset $vt_handoff

Now the system boots fine. In the end, the answer was to have both nomodeset and $vt_handoff present in the GRUB2 menu entry line. I can't say I understand why this was happening & why adding nomodeset fixed the problem, but it did. I'm sure this won't be the answer for everyone, but hopefully it helps somebody else.

Note: My first problem when I couldn't get the system to boot after the initial installation appears to be the same or similar to this question. Not sure if my system has an nVidia graphics chipset.

Edit: After I was able to boot up with the X server running, the filesystem was still corrupted & marked write-protected. I simply did another restart & it resolved the issue. Root filesystem is now clean & mounted as read-write.


Light DM is is the process that handles the display. You could try and use Alt + PrtScr/SysReq + K for resetting the display in Ubuntu. I hope this works in Xubuntu too.

The instructions on how to restart the Xserver may help you.


Ubuntu 18.04.1 kernel upgrade stuck at setting up linux-headers-4.15.0-36-generic

I had the exact same problem with my laptop, which has a discrete Nvidia graphics card. I did some research and found that this is problem if fairly common if your machine has an Nvidia graphics card.

I was able to get past this problem by running killing all apt and dpkg processes:
sudo killall apt && sudo killall dpkg

Then this to finish configuring the packages:

sudo dpkg --configure -a

After that, the setup finished like it normally does.


Ubuntu 18.04 , XRDP, session will not log off or disconnect

Can you provide exact version of Ubuntu you are running (i.e. 18.04 or 18.04.3,...)
How did you perform the installation of the xrdp package ?  manual installation or scripted installatioin ?

When you perform a remote connection, which desktop interface is actually used ? (Default Gnome Ubuntu with the Dock or default Gnome Desktop interface ?)

the first I would try is to execute this command

**

> sudo sed -i.bak "4 a #Improved Look n Feel Method\ncat <<EOF >
> ~/.xsessionrc\nexport GNOME_SHELL_SESSION_MODE=ubuntu\nexport
> XDG_CURRENT_DESKTOP=ubuntu:GNOME\nexport
> XDG_CONFIG_DIRS=/etc/xdg/xdg-ubuntu:/etc/xdg\nEOF\n"
> /etc/xrdp/startwm.sh

**

This command will update the /etc/xrdp/startwm.sh file. The script will create the  ~/.xsessionrc file for each user performing a remote desktop connection.   The ~/.xsessionrc file will basically ensure that the Default Ubuntu Desktop interface (when logged locally) is also available when remotely connect.  The Desktop interface between local login and remote login (on this specific Ubuntu machine) should be the same.....

Logout functionality should then be working for the users.....

If this is still not working, we then might need to have a look at polkit configuration and ensure that standard users are indeed allowed to logout from remote session

Hope this help

till next time

See ya


How to resolve dpkg error while installing Firefox?

In most cases, such errors occur when some file was moved from one package to another in a newer version.

This should fix it:

sudo dpkg -i --force-overwrite /var/cache/apt/archives/firefox_20.0~b1+build2-0ubuntu0.12.04.1~mfn3_i386.deb
sudo apt-get install -f

More about this: Fix DPKG Error "Trying to Overwrite X Which Is Also In Package Y" In Ubuntu


Slow boot in fresh install of Ubuntu 18.04

I finally solved my problem by following the steps in this tutorial: https://www.hiroom2.com/2018/05/01/ubuntu-1804-lvm-swap-wait-for-root-en/

Apparently, the issue was with my swap partition waiting for root and eventually timing out. I am not hundred percent sure if this is a valid solution but it definitely speeded up boot time for me:

Startup finished in 6.204s (kernel) + 6.059s (userspace) = 12.264s
graphical.target reached after 5.618s in userspace


When completing the form at myapps.developer.ubuntu.com, should I change the Suggested package name?

If you wish. The reviewers may not be able to use the suggested name, but will try if you suggest one. The existing name in there is a known bug, but low priority since that field is only a suggestion.


Advisable: yes.  The sunset date for Vista is on 11 April 2017 so you'd better start now. I did the same thing a year ago and deleted Vista about 6 months ago.

Some advice on strategy:

Install all the open source software you can find that can replace your current software on the Vista machine and make them the default! (One per week, so you get the hang of them)

VLC for video playing
LibreOffice for Office automation
FileZilla for FTP stuff
Firefox as a web browser
Evolution / Thunderbird for mail
qBittorrent
GIMP
gedit

Download the end-user manual.
Backup your entire system using the CloneZilla Live CD (use disk-to-image) before you start on an external HDD!
Delete/off-load unimportant files on the same external HDD.
Shrink the Windows partition using gparted from the Ubuntu Live CD so there is at least 24GB for the Ubuntu partition available
Create 3 partitions for Ubuntu: swap (look here how to calculate your RAM size) / (24GB at least) and then move your /home directory on the same "drive" as you currently store the windows "users" directory (probably c:\users)

How to install Ubuntu: click here


yes there can only be one EFi system partition.

However, you may have to do some tweaking on some systems to get grub to boot instead of windows.


You can use the tools setfacl and getfacl. And with a bash script go running it from the cron. And simply and adding or removing permissions from the script.


I think that there is an issue with using "ubuntu on xorg" option in ubuntu 17.10. I have strange behavior, my screen was starting to rotate itself vertically and horizontally and
I fixed this issue by selecting unity from gear icon in the login screen. I think these issues are related to the current graphics drivers is not somehow supporting these new gnomes


WICD WPA2-PEAP connection without domain

A little late, but as promised, here's the edited encryption template.

name = TUSecure
author = atiketemola
version = 1
require identity *Username password *Password
protected password *Password
-----
ctrl_interface=/var/run/wpa_supplicant
network={
    ssid="$_ESSID"
    proto=RSN
    key_mgmt=WPA-EAP
    pairwise=CCMP
    eap=PEAP
    identity="$_IDENTITY"
    password="$_PASSWORD"
    phase2="auth=MSCHAPv2"
}


Stuck in an infinite login loop on Ubuntu 18.04 on both the GUI and Shell login options

I cannot comment so adding it as an answer.

I had a login issue on Ubuntu 16.04 LTS because of the conflict between display manager and nvidia graphic drivers. Please note that the default display manager for Ubuntu 18.04 is gdm3 and for Ubuntu 16.04 is LightDM.

Did you try the resources Q&A here?

Can you share more details? What's the make and model of your machine? Did the issue start immediately after a fresh install or just after you ran the software updater?

Edit:

Press Esc as soon as you see the manufacturer's logo (not Ubuntu logo). This is the first thing that shows up on the screen after you press the power button. This should work in all likelihood. I tried it on a Ubuntu 18.04 machine for testing. The official method here says the same. Once you are able to select advanced options for Ubuntu -> select a line ending with (recovery mode). You should be then able to boot into ubuntu. Fire a terminal and purge the nvidia drivers :-)


I am not sure about your particular problem, but may have a similar situation. From what I gather, there is a slow syncing ongoing issue:
https://wiki.ubuntu.com/UbuntuOne/FAQ/WhyIsItTakingSoLongForMyFilesToSync

This might have kicked in when you restarted using your laptop... I did restart and "reinstall" it all several times if it didn't work, but letting it do it's thing over night always somehow proved to be working. I read somewhere as well that it could take a long while before syncing actually started as it was checking structure/syncing new folder structures first.

It is supposed to get better with Natty, let's keep fingers crossed, I will apparently have to wait 40 days for my music library to sync! ;)

Until then, what I added as programs are ubuntuone-indicator and magicicada. Both give more information than just the Disconnected/Connected/Synchronizing... messages ;)
(I am a rather beginner user of Ubuntu, there will probably be much better answers coming your way!)
Good luck!


How to insert linuxefi module during boot

It's conceivable that the Boot Repair tool would fix this problem; however, I've never heard of your specific problem before, so I can't promise that this will do the trick.

Another thing you can try (and with essentially no risk) is to prepare a USB flash drive or CD-R of my rEFInd boot manager. (There are download links for both types of images on that page.) If rEFInd can boot Linux (and any other OS, if you're multi-booting), then you can install the Debian-package version of the program to have it take over from GRUB. Note that rEFInd will probably give you options to boot via GRUB (which likely won't help) or to boot the Linux kernel (vmlinuz option(s)) directly; the latter option is what you should try.


You're best bet is to install gparted. It's available in the ubuntu software center.

In simple terms, yes - you can resize while in ubuntu, BUT sometimes ubuntu handles it's harddrive in a funny way which makes it harder (LVM). If you are using LVM (unlikely), then I would try resizing until you understand a bit more about ubuntu and partitions.

The other situation where you can't resize, is if you're moving the operating system files by resizing. In this case just create a live usb and use gparted while booting from there


Here are your best options

Upgrade your RAM!

The more RAM you have the more Ubuntu can cache and the smoother your system will feel. Also, the offical requirements state that you should have at least 1 GB of RAM.
Use the classic desktop

You can switch to the classic desktop very easily. Just go to the shut-down menu in the top–right corner, and click "System settings". There you can change your default desktop environment.

If you can't upgrade your RAM or use the classic desktop you can always tweak your system. If you open the System Monitor you can see what programs use a lot of RAM, try to use others or try not to open all the programs you need at the same time.

If you have classic desktop

If you have some heavy themes or other effects you can turn those down.
just go to System → Preferences → Appearance (If you have a classic desktop.)

If you have unity

Just click on the power button in your right corner and select system settings in there you can select Appearance.


How does run option in geany text editor work?

Geany documentation explains how this operations work and how to customize them.

http://www.geany.org/manual/current/#build-menu


Ubuntu 18.04 fails after boot on Ryzen 7 3700x

To bypass the hard regression described here and here, download Ubuntu 16.04 LTS and install it. There's also a solution to test at Ubuntu & Ryzen 3000 CPU


How to install a specific version of openssl

In Ubuntu, at least in LTS releases, the upstream version numbers of many packages never change for a given release. There are very few exceptions, such as Firefox, and the kernel.

You have three options:

Upgrade a release. Not really an option.
Find a PPA you can trust.
Compile from source. This is definitely a viable option, but the exact steps depend on the software in question (so you'd best consult the OpenSSL site for instructions).

Compiling from source can be helped along by using apt. To install the libraries needed to build OpenSSL, you can do:

sudo apt-get build-dep openssl

You can also get the source package from the Ubuntu repositories and modify it to use a different upstream source tarball.

To get the source package used by Ubuntu:

apt-get source openssl


How do I get a Canon MG5550 printer to work under Ubuntu 12.04?

Download the latest debian packages for your printer from here.

There's a package that supports the scanner, and an "IJ" package that supports the printer.

You can open and extract them with Archive manager.

The content of the scangear package looks like this:

Run the highlighted install.sh script to install the scanner requirements.

The content of the IJ package looks very similar, and again, run the install.sh script to install the printer requirements.

If you have difficulty with the install scripts you can try installing the deb packages directly which will be found in the packages folder. To do this choose the packages that correspond to your version (i386 for 32-bit or amd64 for 64 bit and double click them to install with the software center. If you have difficulty installing the deb packages with this approach and get errors regarding dependencies, take a look at this.

Note: I do not have one of these printers to test this solution with but if something is unclear or you get stuck feel free to drop a comment and we will do our best to help.


This  is the newest i could find:

The Zotac GeForce GT 520 has one feature you don’t see on 99% of the graphics cards released today: a PCI connector. Your typical motherboard still has a PCI slot or two, but for graphics cards the PCIe slot is the connection of choice offering much better performance.

The Zotac card uses the Nvidia GT 520 GPU and is clocked at 850MHz. The shader clock is running at 1620MHz with 48 shaders available to take advantage of. There’s 512MB of DDR3 memory running at 1333MHz, and your get VGA, DVI, and HMDI connections. The card also drags your system compatibility bang up to date with DirectX 11 and OpenGL 4.1 support.

I'm pretty sure the newest nvidia drivers or the nouveau drivers support the card.

Source.


How to get AMD graphics card working well 12.04?

I had EXACTLY similar problems. Here's what i did : I purged FGLRX install by using these commands :

sudo sh /usr/share/ati/fglrx-uninstall.sh

sudo apt-get remove --purge fglrx fglrx_* fglrx-amdcccle* fglrx-dev*

(if the first one does not work, it's normal, just use the second one)

Then i rebooted, went on AMD's driver download section, downloaded the drivers i needed, ran the .run drivers into a terminal and installed them. Rebooted, went into Catalyst Control Center>Display Settings>Tear free and checked activate tear free.

Then i went on compiz settings via CompizConfig (you may need to install it via Ubuntu's Software Center) clicked on OPENGL and unchecked Sync to VBlank and everything went fine.


Update 12.04.4 LTS without uninstall CUDA 6

It seems like something in the nvidia and mesa upgrades is conflicting with cuda.

You can do a simple apt-get upgrade, which should not ask to remove anything, only do what upgrades can be done without removing anything.

To investigate why cuda is being removed, you can try upgrading the remaining packages (after apt-get upgrade) one at a time and see which one is removing cuda. You can use synaptic to graphically do this, or simply do apt-get install <package> to upgrade a single package (install will upgrade packages if possible).

It's possible that you can just proceed with removing it and then reinstall it after the upgrade, but it's better to know ahead of time what packages are conflicting.

You can get CUDA here if needed.

https://developer.nvidia.com/cuda-downloads


If you suspect its a software issue and that it never occurred in previous versions of ubuntu, I would boot your computer with a LiveCD of 10.04/10.10/11.04 and leave your power-pack plugged in.

If the problem persists this would indicate a hardware issue.


unmet dependency problem while upgrading Ubuntu

From your output:
E: Invalid archive member header
E: Prior errors apply to /var/cache/apt/archives/samba-libs_2%3a4.11.6+dfsg-0ubuntu1.8_amd64.deb

This means that your samba-libs package is corrupt. Delete it from your local cache, and let apt download a fresh copy.
sudo rm /var/cache/apt/archives/samba-libs_2%3a4.11.6+dfsg-0ubuntu1.8_amd64.deb
    # The file path/name is provided by the error message.

sudo apt update
sudo apt upgrade
    # Apt will automatically detect that the package is missing and download it.


How to launch another app from my Ubuntu Touch app?

This can be achieved using the Url dispatcher:https://developer.ubuntu.com/en/phone/platform/guides/url-dispatcher-guide/

You can put these urls in the code just like you were going to open other urls/external websites.

For example, I can use this to call the terminal like:

appid://com.ubuntu.terminal/terminal/current-user-version

But, if since you say the camera I assume you may want to use the picture it takes in some way instead of just launching the app, In this case you should look into the content hub: https://developer.ubuntu.com/en/phone/platform/guides/content-hub-guide/


Ext4 partition converted to swap. How to recover?

When formatting a partition as swap only the first few couples of bytes get overwritten, so the data should be recoverable to some extent.

I'd try testdisk and in its options mark the partition as ext4 and try to list files.

If that doesn't work, I'd try to recover by using the backup superblock (still in testdisk).

If still no luck, then try photorec to recover the files at least.

For more info see

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


grep command to find 'words' that begin and end with * (e.g., *way*, *then*)

You need to make the match non-greedy: in a basic (BRE) or extended (ERE) regular expression you can enforce that by using an exclusive character set [^*] in place of the inclusive .* i.e.

grep '\*[^*]*\*'

or

grep '[*][^*]*[*]'

If you a prefer perl-compatible regex, that has an explicit non-greedy modifier ?

grep -P '\*.*?\*'


Converting a LibreOffice Impress slideshow so that it will run on my wife's blog

.swf is flash and can be used to embed video's.

To export the presentation as a Flash file:

File > Export.
Under File Format, choose Macromedia Flash (SWF) (.swf) and click Save.


The T1 needs to be activated by the WINDOWS installer on the initial 128M partition. Once this has been done the full 500GB partition (not GiB partition) will be available for use as exFAT.

I have tested the T1 on Ubuntu 15.04. Sadly it performs closer to a standard platter based HDDs with speeds of 52MB/s when doing a dd between my internal SDD and the T1 in Kubuntu live. I've tried tweaking the bs for dd but no luck :(

While testing with rsync using the exFAT driver in Linux I got speeds closer to 250MB/s still it sucks because I bought the drive for disk cloning using dd and 52MB/s doesn't come close to the 450MB/s advertised.

It appears the drive is optimised for a "tweaked" exFAT format. Possibly proprietory to Samsung? If so I hope the code gets leaked/reverse-engineered for a Linux port soon.

To top it off the cable doesn't fit well in my Lenovo's USB ports for some reason and I am sad to have made this purchase because it does not cater for my needs.


Ubuntu 18.04 on VirtualBox Version 5.2.12 r122591:

There's absolutely no need to install Perl or any other prerequisites from source to install guest additions. All of them are either installed by default in Ubuntu because other default system components rely on them (e. g. Perl) or are available in the official package repositories (see the last step below).

If so far all you did with this virtual machine was to install Ubuntu, Perl and maybe guest additions the most economic solution is to

shut down the machine,
reinstall Ubuntu from scratch and
refer to How do I install Guest Additions in a VirtualBox VM? for the installation of guest additions.

To track down and resolve the specific issue caused by the installation of Perl would likely be a waste of everybody's time in comparison.


From Apt-Cacher-Server:

  Server side configuration.

Install apt-cacher and apache2 webserver on the system that you want it to host: sudo apt-get install apt-cacher apache2. Remove apache is you already have that running.
Enable apt-cacher: sudo gedit /etc/default/apt-cacher.Change autostart to 1
If apache is already installed before installing apt-cacher: sudo invoke-rc.d apache2 restart. You should be able to access http://server:3142 now.
/etc/apt-cacher/apt-cacher.conf contains all the settings. Adjust them to your needs.
Import local cache: sudo /usr/share/apt-cacher/apt-cacher-import.pl /var/cache/apt/archives
Mount the installer CD:
sudo mount -o loop /home/username_or_other_path/ubuntu-9.10-rc-alternate-i386.iso /media/cdrom0 and import the CD cache: sudo /usr/share/apt-cacher/apt-cacher-import.pl -R -r /media/cdrom0.

  Client side configuration:

Sources.list: change all the URLs to point to your servers URL.
(ie. deb http://apt-cacher-server:3142/archive.ubuntu.com/ubuntu/)
(change 1 client and if it works copy it over to all other systems)

2a. Use as a proxy to APT: Static configuration. In a terminal, type:
sudo nano /etc/apt/apt.conf.d/01proxy Add:
Acquire::http::Proxy "http://<IP address or hostname of the apt-cacher server>:3142";

2b. Use as a proxy to APT: Roaming configuration: see the link at the top for setup and script.

untested by myself but someone at work used this page to set it up for ourself.

edit: About the error: apparently Perl’s rename function can’t move files across devices, and that’s how the imports and cache laid on the disk.

Options:
1. use the -s parameter (only creates symlinks).
2. Manually move the files onto the same device before importing.


How do you multihome with netplan - bind multiple IPs to one network adapter?

Independent of netplan, it is best practice today to assign multiple addresses to a single interface rather than using interface aliases.  The lack of clean support for this in /etc/network/interfaces is actually a matter of ifupdown showing its age.

Configuring multiple addresses on an interface is simple with netplan: https://netplan.io/examples#multiple-addresses-on-an-interface

To handle these addresses in iptables, you can use -s and -d options to specify the source and destination addresses to match, instead of using -i and -o options to distinguish by input or output interface.  In the vast majority of cases this is equivalent.  The one exception is if you have multiple aliases on the same interface configured with dynamic addresses, and want to apply different rules to traffic sent to each address; you can't configure the firewall rules before you know the destination address.  But you also can't configure netplan to ask for dhcp multiple times on the same interface, so if you need this, you probably do have to use vlans.

You can minimize repetition of addresses in your iptables rules by using something like the following:

iptables -N eth0
iptables -N eth0_0
iptables -N eth0_1
iptables -A INPUT -i enp3s0 -d 192.168.1.5 -j eth0
iptables -A INPUT -i enp3s0 -d 192.168.1.6 -j eth0_0
iptables -A INPUT -i enp3s0 -d 192.168.1.7 -j eth0_1
iptables -A INPUT -i enp3s0 -j DROP
iptables -A eth0 [... eth0 rules here]
iptables -A eth0_0 [... eth0:0 rules here]
iptables -A eth0_1 [... eth0:1 rules here]


Correct /etc/networking/interfaces script for 4 ethernets with 1 bridge, two subnets and a wan interface

The quickest and easiest route to bridging an interface that is being used by many services (like dhcp, dns or iptables etc.) is to rename the interface (Changing Network Interfaces name Ubuntu 16.04). Then proceed to name the bridge with the original interface name. This worked for me with everything that I am running on linux. Its not elegant but hey, beats setting everything up again. Here is my current script where I renamed eth1 to phys1 from the script in the question and the bridge is now named eth1:

#Loopback lo
auto lo
iface lo inet loopback

#WAN on eth0
auto eth0
iface eth0 inet dhcp

#phys1
auto phys1
iface phys1 inet manual

#Subnet 1 bridge interface on eth1
auto eth1
iface eth1 inet static
    address 192.168.1.1
    netmask 255.255.255.0
    broadcast 192.168.1.255
    network 192.168.1.0
    bridge_ports phys1 eth3

#subnet 2 on eth2
auto eth2
iface eth2 inet static
    address 10.13.0.1
    netmask 255.255.255.240
    broadcast 10.13.0.15
    network 10.13.0.0

#eth3
auto eth3
iface eth3 inet manual

#alias on eth1:0
auto eth1:0
iface eth1:0 inet static
    address 192.168.1.2
    netmask 255.255.255.0
    broadcast 192.168.1.255
    network 192.168.1.0

I personally don't like netplan, so I hope this helps anyone with similar tastes.


Cannot boot 16.04 in normal and recovery mode. Only can with upstart mode

SOLVED: I have solved the problem!!. It is a bug: Bug 1253523 SOLVED BY Iván Jiménez 2015-11-02 23:28:31 EST . He wrote: This bug is caused by the file /var/lib/systemd/backlight/platform-dell-laptop:leds:dell::kbd_backlight created by (I guess) systemd-backlight@.service, because I can boot with kernel-4.2.3-200.fc22.x86_64 after I remove that file. As that file is re-created at shutdown, I have to mask the service systemd-backlight@leds:dell::kbd_backlight.service with: sudo systemctl mask systemd-backlight@leds:dell::kbd_backlight.service .     I followed his intructions and  now  it boots normally. THANKS VERY MUCH


I have to say that really there is no definite way of knowing.  From experience, and trying different hardware with Ubuntu, I can tell that it will probably work.  Check the Ubuntu Certified hardware website to have a better idea.


How to alter the keyboard layout key-by-key?

You need to install these applications:

sudo apt-get install xbindkeys xautomation xev

Use "xev" to find the button number that you need. You will see a little white windows appear, put your mouse in it and press the button.
You should get output like this for each button:

KeyRelease event, serial 41, synthetic NO, window 0x4e00001,
root 0xc6, subw 0x4e00002, time 430656, (39,24), root:(765,76),
state 0x10, keycode 38 (keysym 0x61, a), same_screen YES,
XLookupString gives 1 bytes: (61) "a"
XFilterEvent returns: False

KeyPress event, serial 41, synthetic NO, window 0x4e00001,
root 0xc6, subw 0x4e00002, time 432854, (39,24), root:(765,76),
state 0x10, keycode 56 (keysym 0x62, b), same_screen YES,
XLookupString gives 1 bytes: (62) "b"
XmbLookupString gives 1 bytes: (62) "b"
XFilterEvent returns: False

The important lines are the thirds.

Now create the xbindkeys config file using:

xbindkeys --defaults > $HOME/.xbindkeysrc

Inside this file you can change behavior of all keys or combination of them.

gedit $HOME/.xbindkeysrc

Now you need to restart the pc.


Go to System Settings, and choose Keyboard Layout

Just add the desired layouts, and a new icon will appear on the right top corner of the screen, along with the other notification icons, and you can switch the layout from there at any time.

In addition, please make sure the option Use the same distribution for all the windows is the one selected. It's much easier that way.


Ubuntu 18.04 Installer Crashing on XPS 15 9570/9575

If you have this problem, then you are experiencing Bug #1751252. I know the issue is meant to happen on XPS 9560 and the errors aren't the same but I fixed it using the same patch.

Before you begin, make sure you do all the partitioning BEFORE opening the installer.

Then I used the patch from the answer below, copied from this question.

====

...there is a patch you can use as a workaround...

Boot your 18.04 Live ISO
Select Try Ubuntu
Before you start the Ubiquity installer, open a Terminal window (CTRL-ALT-T)
Execute the following commands in the Terminal to download and apply the patch

cd ~/Downloads

wget https://code.launchpad.net/~azzar1/ubiquity/+git/ubiquity/+merge/345056/+preview-diff/831305/+files/preview.diff --output-document ubiquity.patch

sudo cp /usr/lib/ubiquity/ubiquity/misc.py /usr/lib/ubiquity/ubiquity/misc.py.original

sudo patch /usr/lib/ubiquity/ubiquity/misc.py ubiquity.patch

Start the installer by clicking on the Ubiquity icon, and it should now allow you to proceed through the installation


Run:

sudo dpkg -r rsyslog

if it is successful or not, run:

gksudo gedit /var/lib/dpkg/status

In the resulting gedit, delete the whole section starts with

Package : rsyslog

close and run an update.


Is there a way to get Broadcom 802.11ac WiFi (43b1) working on Ubuntu 12.10?

According to Linux wireless LAN support there is no support yet.


I'll be honest, and I have no idea why this worked. I booted into recovery mode. Ran fsck. Then fixed broken packages (which downloaded 3 new packages). Resumed boot into the new image. It threw one error, uploaded the details and it's all good now.


Fonts can become corrupted.

Try re-installing ttf-ubuntu-font-family and then rebooting.

To re-install use Synaptic  or run in a terminal:

sudo apt-get --reinstall install ttf-ubuntu-font-family


Just simple answer is :
apt can be consider as front-end for dpkg

But more than that apt is complete package manager for update,install,upgrade,dist-upgrade and a lot of other things check this  https://help.ubuntu.com/community/AptGet/Howto

sudo apt update checks all the configured source for latest package available there and it downloads all the details for package available for installation.you can know a lot by man apt

update (apt-get(8))
           update is used to download package information from all configured
           sources. Other commands operate on this data to e.g. perform
           package upgrades or search in and display details about all
           packages available for installation.

Now on performing sudo apt install <package> if there is package available for installation it start downloading the package (.deb file) and perform dpkg to install the package. Otherwise if there is no package availabe it throw error message.


Rootkit Hunter is not a virus scanner. It is an integrity checker. That is, it does not report a file as "infected", but as "modified".
This is an important difference because it explains why Rootkit Hunter may start or stop reporting a file.

If Rootkit Hunter stops reporting a file this may be simply because Rootkit Hunter's file properties database has been updated with the new properties of that file via rkhunter --propupd. Equally, if Rootkit Hunter starts reporting a file this may be simply because someone ran apt-get upgrade and there was a new version for it. Neither indicates directly that the file is or isn't infected.


How to make pdfsam work in Xubuntu 16.04?

If you have multiple Java versions installed, you can set the version used by default.

Use the following command:

sudo update-alternatives --config java


Fixing conditional in an interactive backup script

I think a better script would read command line input - something like:

#/bin/bash
echo "Shall back up $1 as $2 - press Ctrl-C to exit if this is not what you want"
sleep 3
echo "Backing Up..."
tar -cvpzf $2.tar.gz $1
echo "Backing up of $1 Complete"
notify-send -t 8000 "Backing up of $1 complete"
exit

You could then enter the command like this:

COMMAND "/path/to/input" "/path/to/output"

The notify-send will also send graphical notification, so it will notify you when it is done.

This is just my suggestion - I will take a look at yours in a second...

The problem with your script is this. It will say successful, as $CONT1 = y, so it will execute the backup tar...command, and then echo Success. It will only echo unsuccessful if you enter the continue parameter not as y. So for this particular script, a better end to it would be (this only changes what is echoed in the terminal output):

if [ "$CONT1" == "y" ]; then
        tar -cvpzf "$after.tar.gz" "$back"
        echo "Backing up File finished!" ;
else
        echo "Did not backup" ;
fi
exit

This seems to work:

#!/bin/bash
echo ""
echo "Which File you want to backup?";
read input
echo "Where do you you want it to be backed up? (include .tar.gz extension)";
read output
read -p "Continue (y/n)? " CONT
if [ "$CONT" == "y" ]; then
        tar -cpf "$input" "$output" || 'echo "Backing Up Failed" && exit;'
    echo "Backing Up Successful!"
else
        echo "Did not backup" ;
fi
exit

The || after the command means that it will only execute 'echo "Backing Up Failed" && exit;' if the command produces errors, which will cause it to echo that it has failed and then exit. If the command does not produce errors, it will ignore that, echo Successful, and exit.

This may have problems with path's to some files, so you may want to use the other script I suggested...

Hope this helps.


Ubuntu 12. 04 Android Studio will not load

Do what it mentions! Change your Java installation to Oracle, here are some instructions.


What type of path in shebang is more preferable?

If you want to use the system-installed version of a given interpreter that's installed in a standard location, use the direct path.  If you want to use whatever version of the interpreter appears first in the user's $PATH, use #!/usr/bin/env ....

The env command invokes a specified command, letting you set or unset environment variables:

env FOO=BAR do-something
env DISPLAY=:0.0 xterm -ls &

If you don't specify any environment variables or other options, it will just invoke the named command.  (Using it this way is arguably a bit of a hack.)

The purpose of writing the shebang as

#!/usr/bin/env interp

is to invoke whatever interp appears first in $PATH.

This means you don't have to know, when writing the script, exactly where interp is (say, if it could be in either /bin, /usr/bin, or /usr/local/bin).  Of course you do have to know that env is /usr/bin/env, but that seems to be reasonably universal.

The advantage is that it invokes whichever version of the interpreter appears first in the user's $PATH.  The disadvantage is that it invokes whichever version of the interpreter appears first in the user's $PATH.

For example, suppose I've installed a personal build of perl under my home directory, as $HOME/bin/perl, and I have $HOME/bin at the front of my $PATH.  If I run a script whose shebang is

#!/usr/bin/env perl

then it's going to be run with my own installed perl executable -- which might not be a good thing.  The author of the script probably hasn't tested it with the bleading-edge Perl that I built from source a month ago.

For something like Perl or Bash that's likely to be installed in a consistent location on most systems (/usr/bin/perl and /bin/bash, respectively), I'd use the direct path to the command.  For something more obscure that could be installed differently on different systems, I'd either use the /usr/bin/env trick, or I'd write an installer that adjusts the shebang line as the script is being installed.  (I used to have to do that for my Perl scripts.)

UPDATE : I've gone into a bit more detail in this answer to this question on the Unix & Linux site.


What should I consider when purchasing a (flatbed) scanner?

I have jet to find a scanner, that Ubuntu has no drivers for. Most scanners use a  standardised USB interface similar to other hid devices such as keyboards, mice etc. If you want to be on the safe side choose a scanner mentioned in the SANE project's supported devices list.

As for applications: SANE handles scanners in Ubuntu. They all revert to SANE. You'll be fine.


Error when trying to mount using live CD

If your drive already has partitions with data on them you absolutely do not want to mount the drive.  You want to mount the partition:

sudo mount /dev/sdb2 /mnt


Ubuntu 12.04 boots into low-graphics mode

I found the commands for when I disabled the guest account and suspecting that this could be possibly be the reason for the boot problem.

I deleted the changes I made and everything now works fine. I ended up adding the new line of code in the wrong place, at the top of the page.

I fixed it and now everything is OK.


How to replace current directory with a backup directory?

Non-destructive

#Make a backup in "current.old"
mv current current.old

#copy from backup
cp -R backup current

Destructive - you will loose files in current and changes since backup will be overwritten

rsync -avh backup/ current/ --delete


cmake fails with "CMake Error: your CXX compiler: "CMAKE_CXX_COMPILER-NOTFOUND" was not found."

Install build-essential  if you haven't done so already. You can install it in the Software Center or with:

sudo apt-get update && sudo apt-get install build-essential


raspberry pi samba share not visible in ubuntu 18.04

And what happens when you access the raspberry directley with it's mDNS qualified host name ( its host name with a .local attached at the end )? Like this from a terminal:

nautilus smb://raspberry.local

Make sure you have avahi installed on the pi:

sudo apt install avahi-daemon

You can then bookmark it in nautilus or we can make a avahi service registration file for samba so that it shows up in nautilus under "Other Locations":

Create a file on the pi at /etc/avahi/services/samba.service.
Add this to file:

<?xml version="1.0" standalone='no'?>
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
   <name replace-wildcards="yes">%h SMB</name> ## Display Name
   <service>
       <type>_smb._tcp</type>
       <port>445</port>
   </service>
</service-group>

Then under "Other Locations" in nautilus it will show up as raspberry SMB

Either way the two systems will talk to each other using smb3


You can provide more information to solve the problem, like:

What program are you using for burn the DVD ?
Did you check if you really burn from ISO file or just burn the .iso into Dvd ?
As @levlaz said, try to make a LiveUSB (in Windows, Universal USB Installer )

When burning Dvds to try distros, i always do with the lowest speed, always close the disco (prevent futher record) and use "smart decision" (make the program choose the type of burning method). Always work for me.

If you have another computer with Linux, try LiveUsb from UnetBooting app (Software Center on Ubuntu) or Brasero (pre-installed app)
When booting with LiveUSB make sure to select "USB HDD" to boot first.

PS: switching HD to SSD will not cause any problem or trouble in both windows or linux distros. SSD is really like a HD to the motherboard, just with much more read/write speeds.


Answering my own question.

One of the solution would be

Editing (as root) the file

/etc/sudoers

And commenting out the line that says:

Defaults requiretty


Bash alias -=... (alias name should be a simple dash) not working

With most commands, you can pass -- as an argument, and all subsequent arguments are treated as operands and not options, even if they begin with a dash. The alias builtin in bash recognizes --.

alias -- -='cd -'


How to record audio along with video in deepin screen recorder?

Deepin Screen Recorder is a simple tool designed to record the screen. It does not support recording audio.

Is there any way? You can record sound using another application such as Audacity, and afterwards combine sound and video using a video editor.
Should I switch to another application? That is your preference. There are screencasting applications that support the recording of both screen and audio, some more simple (Simple Screen Recorder) and others very powerfull (OBS Studio).


GIMP 2.7.5 crashed theme and applications

sudo apt-get install ppa-purge

sudo add-apt-repository ppa:gnome3-team/gnome3
sudo add-apt-repository ppa:ricotz/testing

*without previous two commands I had problems with "ppa-purge"

sudo apt-get update && sudo apt-get upgrade
sudo ppa-purge ppa:ricotz/testing
sudo ppa-purge ppa:gnome3-team/gnome3

reboot


How to change/disable password complexity test when changing password?

Ok, I will answer my question :)

I've found that pam_unix module performs password complexity check and it can be configured.

man pam_unix:

   minlen=n
       Set a minimum password length of n characters. The default value is
       6. The maximum for DES crypt-based passwords is 8 characters.

   obscure
       Enable some extra checks on password strength. These checks are
       based on the "obscure" checks in the original shadow package. The
       behavior is similar to the pam_cracklib module, but for
       non-dictionary-based checks.

Solution:
Alter the line in the pam_unix module in the /etc/pam.d/common-password file to:

password    [success=1 default=ignore]  pam_unix.so minlen=1 sha512

It allows you to set any password with minimal length of 1.