cc1plus: error: unrecognized command line option ‘-std=c++11’. I am getting this error whileinstalling HElib-master

GCC 4.6.x pre-dates support for the C++11 standard so does not provide
-std=c++11. It anticpates C++11 experimentally and provides -std=c++0x
to enable that experimental support. -std=c++11 is first available in
GCC 4.7.x. If you cannot upgrade to a more recent compiler then change
-std=c++11 to -std=c++0x.

Contd. for OP's comments

Perhaps you have not read the INSTALL.TXT file of the HELib package?
Specfically:

  Before building HElib, you may want to look at the Makefile, and
  consider adjusting some of the defaults for CC and CFLAGS. The
  defaults should be OK on most systems, but you can see the suggested
  options, which are documented in the Makefile.

Following this advice, edit src/Makefile, find:

CFLAGS = -g -O2 -std=c++11 -pthread -DFHE_THREADS -DFHE_DCRT_THREADS -DFHE_BOOT_THREADS

and change -std=c++11 to -std=c++0x.

Be aware that the project is not guaranteed to build successfully with gcc 4.6.3
- a very old compiler version - after this change; but without making this change gcc 4.6.3 cannot be used with any degree of C++11 support at all.

You have not given any reason for using such an old compiler.


Can I have a single login for multiple machines?

If your Windows server is a Domain Controller, you can use Likewise-open to join to the Windows domain. See e.g. this: http://galigio.org/2011/06/13/including-a-ubuntu-machine-into-a-windows-domain/


can awk simultaneously read multiple input files?

Yes, you can read from multiple files at the same time using awk.

In order to do that, you should use the getline command to explicitly control input.

In particular, you want to use getline with a file so that you're not reading from the file(s) passed in as main arguments to awk.

One possibility, in your case:

$ awk '{
      getline line < "tab2"
      print $0, FS, line
  }' tab1

This is not doing much error handling or anything, and as you can notice, the filename is now hardcoded in the awk script. You can fix those issues somehow, at the cost of making the script really uglier.

So, while yes, you can do this from awk.

(Side note: Whether it's a good idea to do this from awk, that's another story... In my opinion, this starts getting messy really quickly from here, so you're probably better off switching now to a higher level language, such as Python, Perl, Ruby, Lua, etc., as that kind of language will give you much better support for file handles and objects than what you'll get in awk. While bash / shell scripting would do somewhat better in dealing with multiple files, I wouldn't recommend that either, since it doesn't do as good as the aforementioned ones in writing modular maintainable testable code. Just my 2c.)


If you used btrfs while installing, then a btrfs subvolume is created for /home (usually named @home). See Btrfs subvolumes vs folders? for more about subvolumes. It shouldn't be a problem, subvolumes are a nice feature of btrfs.


How to setup Java-Home and Path in Ubuntu 12.04

Installation of Oracle Java:

Donwload the tarball from Oracle website
unzip it using this command:

sudo tar -xvpzf fileName -C /installation_folder_name`

change the files permission and ownership
add the following two lines in /etc/profile

export JAVA_HOME=/home/abu/Java/jdk1.8.0_45/
export PATH=$JAVA_HOME/bin:$PATH

restart the machine and check by java -version and javac -version


Bash doesn't expand variables when pressing Tab key

You have the following two options for expanding a variable in Bash:

Use the Ctrl+Alt+E keyboard shortcut whenever you want to expand a variable.
For example, if I write in my terminal:
$LANG $BASH

and then press the shortcut, the above will expand both variables to:
en_US.UTF-8 /usr/bin/bash

Enable the shopt builtin's direxpand option by running in your terminal:
shopt -s direxpand

Now, if you type:
ls $MY_DIRECTORY/<Tab key>

it will be expanded to:
ls /path/to/a/folder/

To have the direxpand option enabled for all terminal sessions, append shopt -s direxpand in your .bashrc file either manually or by running:
echo "shopt -s direxpand" >> ~/.bashrc


Most likely you have installed both versions of PHP,

the PHP version provided by default by the AWS Ubuntu 18,
the PHP version provided by the third-party repository deb.sury.org.

However, whichever version is used by your Web server, is the version that is configured in there.
For example, if you are using nginx, then check the configuration file of the server block, where it says the following. You need to find the correct Unix socket for the third-party PHP package, and replace /var/run/php/php7.0-fpm.sock with the proper Unix socket. Finally, restart the Web server.

    # pass PHP scripts to FastCGI server
    #
    location ~ \.php$ {
        include snippets/fastcgi-php.conf;
    #
    #   # With php-fpm (or other unix sockets):
        fastcgi_pass unix:/var/run/php/php7.1-fpm.sock;
    #   # With php-cgi (or other tcp sockets):
    #   fastcgi_pass 127.0.0.1:9000;
    }


Install Ubuntu 12.10 on UEFI along Windows 8

In theory, no, you don't need to disable Secure Boot; Ubuntu 12.10 includes Secure Boot support. In practice, this feature is still new enough that it may not work reliably on all systems.
No, you don't need a second ESP; Ubuntu should be able to share a single ESP with Windows (or any other OS). In fact, sharing an ESP is the way it's supposed to work (although multiple ESPs are also legal).
The "boot flag" is simply libparted's (and therefore GParted's and parted's) way of identifying an ESP.
In principle, you can mount your ESP anywhere you like, or not at all. In practice, some tools may require the ESP to be mounted at /boot/efi. This would be most important for GRUB package updates, but some other tools might need this, too.
In an EFI system, GRUB doesn't install any code directly to the hard disk's MBR, although of course code does go on the hard disk -- just in the ESP. Thus, installing GRUB on /dev/sda doesn't really make sense. That said, some user interfaces may refer to doing so because they haven't been properly updated for the EFI case. (I'm not sure what Ubuntu 12.10's state is on this score, offhand.)


In Grub (boot manager) select the Ubuntu entry and press e now look for the words quiet splash navigate with your arrow keys to the place and replace quiet splash with nomodeset now press F10 (or ctrl+c) to boot. See also this the answer at this question for a illustrated walktrough


Migrating from Mac to Ubuntu, What will I miss?

I've been an *nix user for years and have used Ubuntu for simplicities sake on all my notebooks from the last 3 years or so (everything.. just works!).  My current job provided me with a shiny new MacbookPro when I started just over a year ago, great hardware (almost no complaints), but OSX lasted about a month on it.

To get to the point (sorry about the lenghty diatribe), I've found very FEW issues with the switch, however:

the setup is a little more
complicated than a similar spec
Dell/Thinkpad/etc, it's not too hard
though
the Mac's greatest asset, by
far, is the Trackpad, the new
multitouch driver (check
www.ubuntuforums.org) are almost
there, but its not quite as silky
smooth as in OSX

On the good side:

Compiz is a beautiful, beautiful
thing (I turn most of the 3D effects
off), it combines a great way of
applying keyboard/mouse/gesture
shortcuts to enhance window
management and common, often
laborious tasks with some great
eyecandy (if you're that way
inclined).
4GB RAM goes a whole lot further in Ubuntu/Gnome than it ever went in MacOSX, I can code, browse, listen, watch, game all without issue.
Ubuntu's package management, APT, and
the new Ubuntu Software Centre is
great for keeping software up to
date, and allows the installation of
new apps easily, ironically enough
its becoming more and more like the
Apple App Store by the day.

The pitfalls would be the lack of some software like Photoshop (and the Adobe Suite), Microsoft Office (though 2008 was terrible in my experience compared to the Windows version) and many games, but coming from Mac, you probably wouldn't many anyway.

Finally, I'd say, give it a go, at least in a dual boot situation, what have you got to lose?


How can I set the system clock to GPS time?

BTW, why do I have to use sudo to run gpsmon every time?

Most likely, your normal user account doesn't have privileges to /dev/ttyUSB0.

From the command line, type:

ls -l /dev/ttyUSB0

And it will return something like:

crw-rw---- 1 root dialout 188, 0 Jan  2 20:46 ttyUSB0

The "root" part is the user that owns the file, the "dialout" is a group associated with the device. You need to add your user account to the group "dialout" then you wont need to start gpsmon with sudo.

This should get you going:

usermod -a -G dialout yourusername

Hope this helps...


Delete all files except files with the extension pdf in a directory

cd <the directory you want>
find . -type f ! -iname "*.pdf" -delete

The first command will take you to the directory in which you want to delete your files
The second command will delete all files except with those ending with .pdf in filename

For example, if there is a directory called temp in your home folder:
cd ~/temp

then delete files:
find . -type f ! -iname "*.pdf" -delete

This will delete all files except xyz.pdf.
You can combine these two commands to:
find ~/temp -type f ! -iname "*.pdf" -delete

. is the current directory. ! means to take all files except the ones with .pdf at the end. -type f selects only files, not directories. -delete means to delete it.
NOTE: this command will delete all files (except pdf files but including hidden files) in current directory as well as in all sub-directories. ! must come before -name. simply -name will include only .pdf, while -iname will include both .pdf and .PDF
To delete only in current directory and not in sub-directories add -maxdepth 1:
find . -maxdepth 1 -type f ! -iname "*.pdf" -delete


LibreOffice causing conflicts with OpenOffice when installing with apt

OpenOffice and LibreOffice should not be installed with each other.
They are both forks of the same software and will conflict with each other if you try to install them both on the same system.


Ubuntu server ports refuse connection occasionally

I was experiencing the same problem with a server a couple of months ago, turns out it was a routing problem in my case I got two ether nics, both with a default route, so I deleted one and problem solved, check if it's the same problem in your case.


admin pack can be found in /usr/share/postgresql/9.1/extension

To install

sudo -u postgres psql

CREATE EXTENSION adminpack;

Also to see a list of installed extensions select * from pg_extension;


Can I increase Xubuntu 16.4 partition size after deleting dual boot partition? Do I need to use live CD?

In order for this to work, you need to boot a LiveCD of Ubuntu. In that case, all your drives will be unmounted, which makes it safer. After you have booted it, open up gparted.

Once that has loaded, you will need to right-click on the /dev/sda2 and click on Resize/Move. We need to do this since we have a partition within another partition. The outer partition, which is /dev/sda2 is the one we'll need to increase first. Increase it to the left. Then click Apply.

This should increase the outer partition. Once that's done(after refreshing), click on the /dev/sda6 and increase it to the left again.That will increase the inner partition which is in turn, your Xubuntu partition. Click Apply and you should have the space returned to you.

If you want to be extra careful, you can run boot repair, to make sure that you boot into Xubuntu, but generally, it should work.


Will gcc be upgraded to 4.5.* in one of the 10.04.* releases?

gcc is one of the core base components, part of what we call the toolchain,  of an Ubuntu release. Everything else on the system depends on it, changing it for everyone could easily introduce new bugs.

  Once an Ubuntu release has been completed and published, updates for it are only released under certain circumstances, and must follow a special procedure called a "stable release update" or SRU.

You might like to take a look at the wiki page for Stable Release Updates that explains the few situations in which updates are published for Ubuntu packages..

So yes you will have to wait until 10.10 for gcc 4.5 to appear in the main repositories. However there is a PPA with gcc 4.5 in it for Ubuntu 10.04. If it breaks your system, you get to keep the pieces - this isn't officially supported by any means. To upgrade:

sudo add-apt ppa:ubuntu-toolchain/test
sudo apt-get update
sudo apt-get upgrade


Why Windows 10 Splash screen not working with Ubuntu 16.04

I had the same problem (I am using SSD) and here is what I did in BIOS:

Under Boot Sequence, I have Legacy option selected
Under Advanced Boot Options, I have checked Enable Legacy Option ROMs
Secure Boot is disabled
Fastboot is set to Minimal
I have my SATA operation set to RAID mode (this was already checked)

If the above points don't work, just try changing to UEFI mode and boot. If that doesn't work, try changing it back which worked for me!


Gedit preference only available to superuser

You can find the files and directories under $HOME that don't belong to you (to your $USER) with (note sudo - this needs to run as root):

sudo find $HOME \! -user $USER -print

If you want to change the owner back to you, you can (this will handle funny filenames, too):

sudo find $HOME \! -user $USER -print0 | xargs -0 sudo chown --verbose $(id -u):$(id -g)


Ubuntu 18.04 and Windows 10 only boot in recovery/safe mode

I found a quick solution for my system with dual booted Ubuntu 20.04  and Windows 10. I could start the ubuntu (system hangs) only in safe mode but could start windows normally.
I am not sure how it was connected, but when I uninstalled the just installed a graphic software in windows, I could start the ubuntu in the normal mode.


16.04 Restrict the ability to change the desktop wallpaper and greeter wallpaper

Since you say "even as root", the answer is no. All of the methods of restriction built in to Ubuntu rely on the user you're trying to restrict not being able to become root. If you want to set any serious restrictions on your users, you need to block their root access.


What version of Google Chrome do I have?

It does have the option listed:

OPTIONS
       Google  Chrome has hundreds of undocumented command-line flags that are
       added and removed at the whim of the  developers.   Here,  we  document
       relatively stable flags.

       ...

       --version
              Show version information.

So you can use the command google-chrome with the --version option:

google-chrome --version

gives:

    Google Chrome 36.0.1985.125

For the following commands, I am using grep and regex, because it is much more adaptable to changes in Google Chrome version format changes

To get just the version number run the following command:

google-chrome --version | grep -iE "[0-9.]{10,20}"

It gives:

    36.0.1985.125

And this one:

google-chrome --version | grep -iE " [0-9]{1,3}.[0-9]{1,3}

gives you just the main version numbers.

    36.0

If you have beta installed:

Running this command:

google-chrome-beta --version

gives:

Google Chrome 37.0.2062.58 beta

And then there are the gui methods:

You can go to the following sites:

chrome://chrome

gives you this:

And

chrome://version

or

about:

Thanks Jeff Inventor Chrome OS.

gives this:

Google Chrome   36.0.1985.125 (Official Build 283153)
OS  Linux
Blink   537.36 (@177902)
JavaScript  V8 3.26.31.8
Flash   14.0.0.145
User Agent  Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36
Command Line    /opt/google/chrome/google-chrome --no-startup-window --flag-switches-begin --flag-switches-end
Executable Path /opt/google/chrome/google-chrome
Profile Path    /home/tim/.config/google-chrome/Default
Variations  e950616e-37fb3cc2
            c70841c8-4866ef6e
            3664a344-be9e69ba
            9e5c75f1-ad69ceb0
            24dca50e-837c4893
            ca65a9fe-91ac3782
            8d790604-9cb2a91c
            4ea303a6-3d47f4f4
            d8f57532-f23d1dea
            b2612322-f8cf70e2
            5a3c10b5-e1cc0f14
            244ca1ac-4ad60575
            5e29d81-f23d1dea
            3ac60855-486e2a9c
            246fb659-bca011b3
            f296190c-cdc3d902
            4442aae2-4ad60575
            ed1d377-e1cc0f14
            75f0f0a0-4ad60575
            e2b18481-a5822863
            e7e71889-e1cc0f14
            cbf0c14e-bf3e6cfd

My pronouns are He / Him


Chainload from windows boot manager to Grub with Secure Boot enabled

Boot both Linux and Windows from UEFI. Its that simple, as you can see chainloading either Windows from GRUB or Linux/GRUB from Windows Boot Manager has drawbacks for Secure Boot and Bitlocker.

Many Motherboards give the UEFI boot menu with F11. If that doesn't work try Escape or Delete to either get a functions menu or this might drop right into configuration which might give you a boot order configuration or an option to "instant boot" which is the same thing the boot menu does.

The key is you're selecting the OS you want from UEFI not from a boot loader.


I want to see if a file is opened with gedit. Is it possible?

gedit doesn't keep the file open while you are editing it, so I'm not sure you can.
You could probably write a gedit plugin that could tell you, but let's ignore that option for now.

Going on the comments above, you are really just wanting a way to edit a file, and know when it's been closed. @TimoKluck suggests --standalone, but I think you probably want --wait instead.

You can also achieve the same thing through gedit's D-Bus API. When you open a file, it gives you a cookie, which you can then wait on.


File permissions change after copying to portable hard disk

Your external drive is using either FAT32 or NTFS, which do not support permissions.  You either need to switch to a unix compatible format on the external drive, or you can use tar ( or the gui archive utility ) to preserve the correct permissions in the archive while it is stored on such a disk.


Installed Ubuntu to run along side of Windows 7, no option to boot Windows

If you can boot into Ubuntu, you might give Boot Repair a try.  I've used it several times and it works well.  Of course, it requires that you Windows stuff is still there, and it probably is.  The following text I copied from the Ubuntu Community Documentation:

Either add ppa:yannubuntu/boot-repair to your Software Sources via the Software Center or, for speeds-sake, add it using a new Terminal session:

sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get
update sudo apt-get install -y boot-repair && boot-repair

Boot-Repair can be installed and used from any Ubuntu session (normal session, or live-CD, or live-USB). PPA packages are available for Ubuntu 10.04, 10.10, 11.04, 11.10 and 12.04.

Then:

Launch Boot-Repair from either :

the Dash (Unity)
System->Administration->Boot-Repair menu (Gnome)
by typing 'boot-repair' in a terminal

Then try "Recommended repair" button. When repair is finished, reboot and check if you recovered access to your OS.


Short answer.

Go to System Settings -> Software & Updates.

Make sure that main, universe, multiverse and restricted repositories are checked.

Then remove DVD disks as software sources, then

run in terminal

sudo apt-get update
sudo apt-get install firmware-b43-installer

and reboot.

It looks like you used some daily build to install the system, not the final release. But that does not matter much if you do all the previous actions.


In a terminal window, run:

sudo /usr/lib/prey/current/bin/prey config gui


On ubuntu, keyboard shortcuts can be managed through 'Settings Editor' and 'Keyboard'. These programs can be respectively installed by

sudo apt install xfce4-settings-editor

sudo apt install xfce4-keyboard-settings

In xfce4-keyboard-settings (the simpler program), go to the 'Application Shortcuts' tab and double-click on the shortcut that you want to edit, presumably Ctrl+J, then edit the shortcut.


There seems to be an issue with the mcrypt package in that it isn't included in the available mods after being installed.

https://stackoverflow.com/questions/19446679/mcrypt-not-present-after-ubuntu-upgrade-to-13-10
https://bugs.launchpad.net/ubuntu/+source/php-mcrypt/+bug/1241286

To fix, simply:

sudo ln -s /etc/php5/conf.d/mcrypt.ini /etc/php5/mods-available/mcrypt.ini
sudo php5enmod mcrypt
sudo restart apache2

If the last command doesn't work, do sudo service apache2 restart instead.


How to share wired internet connection to wifi (non Adhoc)?

You need some packages and have to configure it:
1. HostAPD
2. DHCP
3. ip masquerading

To know how to configure these packages please read this article: http://techmites.com/laptop-wired-establish-wifi-in-ubuntu/


Can't disable nouveau drivers in Ubuntu 18.04

I found the solution. I'll write it here for who may have the same problem.

My gdm3 session was running in wayland. To check it:

 $ loginctl
 SESSION     UID  USER     SEAT     TTY
       2    1000  velix    seat0    tty2
      c2    1000  velix
      c1     120  gdm      seat0    tty1

The command loginctl show-session <session-n> -p Type show the session type:

$ loginctl show-session c1 -p Type
Type=Wayland

To change it, edit the file /etc/gdm3/custom.conf and uncomment the line WaylandEnable=false.

After rebooting:

$ loginctl show-session c1 -p Type
Type=x11

Now blacklisting nouveau drivers in /etc/modprobe.d/blacklist.conf (as in the question) works and doesn't give the above error.

The key point is to run xorg instead of wayland

(That's why it was working in my 17.10 ubuntu, forced to run xorg)


can I get the document viewer Evince in Windows

I think you are referring to the Document Viewer Evince.
Yes, it is available for Windows:
https://wiki.gnome.org/Apps/Evince/Downloads


How to recovery files from formatted HDD by UBUNTU?

If you have formatted those disks (used the Ubuntu installer to repartition, format and install onto those disks) then you are loosing your data all the time; every time those disks are written to, your old blocks of data are being overwritten. Given that the filesystem that you installed with Ubuntu (likely EXT3/EXT4) is completely different to the exFAT or NTFS filesystem that Windows would have used, you will be writing all over that data. As CelticWarrior has said in your posts comments, the more you use those drives - the less are the chances of recovery.

Formating drives tends to take place when you don't want the data on that drive anymore.

Use something like Ultimate Boot CD (http://www.ultimatebootcd.com/download.html) to boot to a live environment, not touching your hard drive and attempt to recover data. UBCD has file recovery tools which may be able to retrieve the blocks of data that have not yet been overwritten. There are two videos here which may be of use in doing this.


You may be interested in the following terminals:

tilda
guake
yakuake
stjerm

Second two are drop-down terminals so they don't take out much of screen real-estate.

Tilda isn't actually drop-down, but a very minimalistic terminal, without any window embellishments  at all. It can be moved around the screen by holding Alt, double clicking on it, and dragging around

Exiting can be done with exit command


Ubuntu loads and then monitor loses signal?

Most likely it's either a wrong display mode which the monitor cannot handle, or Ubuntu, for some reason, switches from the graphics adapter you use to another one.

Since you have an i5 CPU with integrated graphics and a motherboard with DVI/HDMI, etc connectors, the easiest thing to try first is swapping your display cable from your graphics card and plug it into the motherboard connector (I would try this before boot). If you're already using the motherboard connector, try this reversed - naturally.

Now if this doesn't help, you'll have to get to a terminal prompt and reconfigure the GUI display settings.

Most likely you can get to a terminal by pressing CTRL-ALT-F1. Then login and follow one of the several answers here about re-configuring or resetting the GUI, for example:

How to reset monitor settings to default through terminal?

Now... if this really is a old "testing machine" with a old Ubuntu installation - the easiest way to solve all your problems is probably going to be a full installation of a newer version of Ubuntu. Just a thought.

At least do a full upgrade before attempting a fix; there might be never drivers in the new kernel, more up to date settings in X configs, etc.


How can I uninstall specific NVIDIA drivers?

This is meant to be general information for you and all the other users reading your question. There are several different graphics drivers available in the Ubuntu repositories - BUT ... there is only one single graphics driver installed and in use when the Ubuntu operating system boots !

So when you install the NVIDIA drivers 375.26 and had, let's say the drivers 367 installed before, the old drivers automatically are getting uninstalled and the new drivers - in your case 375 - are getting installed and are active after rebooting the operating system. To check which drivers are installed, execute the following command : dpkg --get-selections | grep nvidia. Example :

dpkg --get-selections | grep nvidia
nvidia-375                  install
nvidia-opencl-icd-375       install
nvidia-prime                install
nvidia-settings             install

Of course you can alternatively remove the old drivers manually before installing new drivers.
The command to remove the currently installed drivers would be : sudo apt purge nvidia*


Follow the instructions on Ubuntu Download page, to create an install CD/USB on your Windows platform.  This DOES require the 'bootloader', which is downloaded separately.

Even better, have a friend with Ubuntu create a USB for you.  All needed tools, elements are now included in standard install (once installed).


Options error: Unrecognized option or missing parameter(s) in [PUSH-OPTIONS]:1

As far as I understand you don’t need this command in Linux. The command block-outside-dns is for windows only.
To achieve the proper DNS configuration you need at least the three following lines in your client.conf:

script-security 2
up /etc/openvpn/update-resolv-conf
down /etc/openvpn/update-resolv-conf

/etc/openvpn/update-resolv-conf is the standard path if you didn't change it after openvpn installation via apt-get.

Post 4 in https://github.com/ValdikSS/openvpn-fix-dns-leak-plugin/issues/12

https://github.com/Nyr/openvpn-install/commit/acca10ba1a87b86da3f402ef08e07ad42126913e


What does/will the directory /srv contain?

More information on the Filesystem Hierarchy Standard is available from Wikipedia at https://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard or from the Linux Foundation at https://wiki.linuxfoundation.org/lsb/fhs

From https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s17.html :

  This main purpose of specifying this is so that users may find the
  location of the data files for a particular service, and so that
  services which require a single tree for readonly data, writable data
  and scripts (such as cgi scripts) can be reasonably placed. Data that
  is only of interest to a specific user should go in that users' home
  directory. If the directory and file structure of the data is not
  exposed to consumers, it should go in /var/lib.

  The methodology used to name subdirectories of /srv is unspecified as
  there is currently no consensus on how this should be done. One method
  for structuring data under /srv is by protocol, eg. ftp, rsync, www,
  and cvs. On large systems it can be useful to structure /srv by
  administrative context, such as /srv/physics/www, /srv/compsci/cvs,
  etc. This setup will differ from host to host.

  Therefore, no program
  should rely on a specific subdirectory structure of /srv existing or
  data necessarily being stored in /srv. However /srv should always
  exist on FHS compliant systems and should be used as the default
  location for such data.

  Distributions must take care not to remove locally placed files in these directories without administrator permission.

This is where you put the (static?) data for your servers, http, ftp, etc ....


Made slight change to /etc/network/interfaces and system won't boot GUI correctly

Found a solution.  Instead of messing with the Graphics detection, I learned how to use the recovery features.  Basically reboot and immediately started pressing ESC until my BIOS interface came up.  One of the options is to Continue Startup.  Selected Continue Startup and immediately started pressing ESC again.  This brought me into the boot manager menu where I could select

Ubuntu
Advanced Options for Ubuntu
Access System Setup (basically taking me back to the BIOS setup)

I selected Advanced Options.  On the next menu, I selected recovery mode.  It will run for a few minutes spitting a bunch of messages to the screen.  Eventually I  got a recovery menu with a host of options.  Many of these looked useful.  One option was to boot in graphics safe mode but I did not use it.   Since I knew that reverting my last /etc/network/interfaces change would fix the problem, I selected the recovery menu “Drop to root shell prompt”.  At that point the file system was mounted readonly which prevented the changing of any config files.  So I used the "mount all" command.  This mounted the hard drive with rw permissions for root.  I then opened the config file in vim editor, made the changes and rebooted the system.


How to dual boot ubuntu from an external hdd, with the ability to boot to windows without the exernal plugged in

Indeed it seems that your boot records and managers are only on the external drive. Normally they are on the internal drive.

You should create a Boot Repair Disk and boot into it. It is a handy disk to have anyway.

While in the BRD system, first use gparted to make sure that your internal drive has an active partition with a boot flag set to it. Then running the Recommended repair option should fix the booting problems on your internal hard drive. Reboot.

You should also read this forum post about How to create an external USB bootable Linux hard drive (without dual-boot)


How to install Popcorn Time using installer from their official site?

Updated answer: June 2019

Download PopCorn Time for Linux.
Open a Terminal (Ctrl+Alt+T ) :

cd ~/Downloads
sudo mkdir /opt/popcorntime
sudo tar -xf Popcorn-Time-*.tar.xz -C /opt/popcorntime

(You can now run Popcorntime with :)

/opt/popcorntime/Popcorn-Time

Create the application launcher

sudo ln -sf /opt/popcorntime/Popcorn-Time /usr/bin/Popcorn-Time
sudo gedit /usr/share/applications/popcorntime.desktop

And enter the following content :

[Desktop Entry]
Version=1.0
Type=Application
Terminal=false
Name=PopCorn Time
Exec=/opt/popcorntime/Popcorn-Time
Icon=/opt/popcorntime/src/app/images/icon.png
Categories=Application;


Unable to forward X11 graphics from Centos on Vagrant

Make sure you have installed all the required packages on the CentOS machine. You can do that simply by installing whole group for X system:

yum groupinstall "X Window System"


Is there a command to see who owns an Internet domain?

whois is definitely the command to use.

In some cases however the owner of the internet address chooses to withhold this information. For some TLDs this is not allowed.

whois example.com is an unusual special case. However try something like whois ubuntu.com - this clearly gives you a name, physical address, email address and phone number.


It happened exactly the same thing. In my case I had PulseAudio Equalizer installed and I just launched the equalizer and the sound was back.


Next step to loading Ubuntu on the USB drive after downloading

When you burn the ISO into the USB flash disk,maybe you should use bootice to do like this:

 Choose the `Destination Disk`
`Process MBR` >> Choose one of `UltraISO USB-HDD+/USB-ZIP+` >> install
`Parts Manage` >> Active you device

when you start your computer,set your BIOS,select your usb flash disk as the first boot option.save it,restart your PC, you'll see the System installation interface.

download bootice


MATLAB interface configuration window pops up while trying to install packages

If you do not need the MATLAB integration to your system, then simply remove this package by
sudo apt-get purge matlab-support

or forcefully by
sudo dpkg -P matlab-support


How do I reinstall the software packages that came with Ubuntu 18.04?

Installing the ubuntu-desktop package ought to pull the default packages.

sudo apt install ubuntu-desktop


If your hard disk has errors, you need to buy a new hard disk, or get the one you have replaced under warranty, if it is under warranty. No software can fix mechanical problems with the disk.


Not able to boot to already installed Windows and Ubuntu in Hard drive

Here's my advice.  Please boot your computer to boot repair.  Please do not try to install boot repair onto your ubuntu installation or you may make matters worse.  I hear it works for others but never for me, so I must advise you not to try doing it that way.

When prompted to copy down a code, please to that so that you can recover and post the results here for further analysis should you be unsuccessful.  I'm no expert at determining those results, but I learn a little more each time, and several times, I've spotted the problem.


install ubuntu mate over xubuntu 18.04 - not showing up

I can't reproduce your issue on clean Ubuntu 18.04.1 LTS (on both 32-bit and 64-bit).

Try to purge /etc/lightdm-related packages with:

sudo apt-get purge lightdm ubuntu-mate-lightdm-theme

and then install them again

sudo apt-get install xubuntu-desktop lightdm ubuntu-mate-lightdm-theme

and then continue with apt-get:

sudo apt-get update
sudo apt-get install -y --reinstall mate-desktop mate-common ubuntu-mate-desktop^ \
ubuntu-mate* mate-core mate-desktop-environment mate-desktop-environment-extra \
plymouth-theme-ubuntu-mate-logo plymouth-theme-ubuntu-mate-text
sudo apt-get dist-upgrade # get all new dependencies

Try to switch login screen to LightDM:

sudo apt-get install lightdm
sudo dpkg-reconfigure lightdm # select lightdm

Also consider installing the following packages:

sudo apt-get install ubuntu-mate-default-settings mate-session-manager

Finally reboot and select MATE session in LightDM:

Note: usually steps above are not needed. I install MATE with
sudo apt-get install ubuntu-mate-desktop^.


How to find RBG or HEX code of a picture area?

There a several color pickers that allow selecting colors from the screen:

gcolor2

Gcolor2 is a GTK2 color selector to provide a quick and easy way to find colors for whatever task is at hand.Project home

gpick

Select colors to create and export palettes in various formats.Project home

grabc  (Command line)

When this program is run, the mouse pointer is grabbed and changed to a cross  hair  and  when  the  mouse is clicked, the color of the clicked pixel is written to stdout in hex prefixed with #. It will the R, G,  B component also in the stderr.Manpage


VirtualBox Ubuntu 12.04 LTS guest cannot shutdown

Did you install the Guest additions? If not, log into the VM to install the following packages:

sudo apt-get install virtualbox-guest-dkms virtualbox-guest-utils virtualbox-guest-x11

Finally restart the VM to complete the installation.

ACPI shutdown should halt the VM now.


How can I to set a custom configuration for a snap app?

You cannot do that. The developer who made the snap must expose a configuration system.


You can consider different options:

  Installing Ubuntu 16.04 will do faster both booting and working.
  Install SSD drive and run the OS from it - will extremely increase speed of both booting and working.
  Remove Startup Apps if any.
  Change the desktop manager to the smaller and faster - LXDE, Xfce and etc


From my experience, I was able to add the PPA, install and use GNOME 3, and then remove it effortlessly, without breaking my Unity setup.

I added the GNOME 3 PPA, installed all the required packages and libs, logged out and tried GNOME 3. Then I used this little neat utility called ppapurge (in the repos) to remove and revert all packages from the GNOME 3 PPA. It worked wonderfully. Just to reallly check it, I did a quick scan through Synaptic of all packages in the PPA, and none was installed.

It worked not only for me, but for others too. However, if you really praise your Unity setup, it's probably better not to touch anything. And anyway, the current GNOME3 experience in Ubuntu Natty is way below of what it should be, and I recommend you to try it using one of the live images made available on gnome3.org.


Intel Graphics Installer vs stock driver

The intel-linux-graphics-installer v 1.0.4 does not support Ubuntu 14.04 LTS. You will receive an error that this distribution is not supported when trying to run the installer.
I would guess vs 1.0.5 will include 14.04 LST support as 14.04 is mentioned in the documentation.


On my machine, i915 gmbus dpb refers to my DVI-connected monitor. i915 is the Intel graphics module.

The Display Data Channel (DDC) runs on the I²C bus and is mainly used to transmit Extended Display Identification Data (EDID) information from the display to the computer. EDID information describes the display's capabilities such as what resolutions it supports.

Running ddcutil detect will let you know if any DDC-enabled displays are connected.

And in monitors that support it, DDC/CI (Command Interface) can be used to control settings such as brightness/contrast/color/volume/input/etc. without having to use the OSD menu. ddcutil capabilities will let you know what DDC/CI capabilities your monitor supports, if any.


What do I do about a file that was literally split into two while moving it?

cat can do that for you.

$ cat partA partB > allParts

This will take a while with such large files. Also you need to check, if the  Caja file manager didn't lose any data while crashing.


ShipIt service has now closed.

The old link was: http://www.ubuntu.com/shipit

Accessing the link will redirect you to the URL (link) provided below

For more details regarding ShipIt's closing, please read the link:
http://blog.canonical.com/2011/04/05/shipit-comes-to-an-end/


Simply hold the packages again, this will remove them from the removal-list:
sudo apt-mark hold php*

Here an example that shows that it works, I just picked the package kmines for this example:
~$ sudo apt-mark hold kmines
kmines set on hold.
~$ apt-mark showhold kmines
kmines
~$ sudo apt-mark remove kmines
Selected kmines for removal.
~$ apt-mark showremove kmines
kmines
~$ sudo apt-mark hold kmines
kmines set on hold.
~$ apt-mark showhold kmines
kmines
~$ apt-mark showremove kmines
~$

As you can see, the package is not listed for removal anymore.


Screen dim buttons not working on Toshiba Satellite

This script will automatically applies toshiba-acpi patch to your kernel.

sudo apt-add-repository ppa:keks9n/main

Update it.

sudo apt-get update

then install,

sudo apt-get install toshiba-acpi-fix

Check Settings

sudo toshset -q

for list of Toshiba settings

sudo toshset

I guess this will help you, I got the controls back using Fn key.


You killed off a critical service that all these others need. The quickest way to fix it and the most reliable is a fresh install.


Where is the login screen wallpaper for GDM stored?

Are you using Unity or Gnome?

You seem to refer to the "noise"  background of gnome-shell gdm login - if it is this one it's build somehow by adding the file /usr/share/gnome-shell/theme/noise-texture.png with a grey background ... I think it's in /usr/share/gnome-shell/theme/gnome-shell.css:

background: #2e3436 url(noise-texture.png);


The Iceland mirror has often been out of date and is now offline. Blame the maintainer/operator Siminn hf.

Unfortunately that is the only Ubuntu mirror in Iceland. Please try one of these up-to-date mirrors that should be close to you, network-wise:

Norway: https://launchpad.net/ubuntu/+mirror/ftp.blix.eu-archive
Netherlands: https://launchpad.net/ubuntu/+mirror/nl3.archive.ubuntu.com-archive
UK: https://launchpad.net/ubuntu/+mirror/ftp.ticklers.org-archive

You can change them from Software Sources in the Software Center, or press Alt+F2 and run gksudo software-properties-gtk, and see the below answer:

  How can I get apt to use a mirror close to me, or choose a faster mirror?


Wired network connection fails after installing Ubuntu 12.04

After the next reboot (to be able to answer the above comment) the networking magically started working. Absolutely nothing changed between reboots. So... solved by pixies, I guess.


This sounds like it is faulty:

From the SanDisk Forum:

  Re: SanDisk Cruzer Blade 16GB write protected error
  > 05-17-2012 10:55 AM

  Dear All who are suffering from write protection error,

  The customer service answered to me and they know about the issue, so here it is to clarify the situation to everyone:

  "I understand that you are getting write protection error while accessing your Cruzer flash drive. The flash drive has detected a potential fault and has become write protected to prevent data loss. There is no method to fix this. You will need to backup your data and replace the flash drive.
  Our team of developers is in combination with the OS developers looking into a solution to resolve this issue.
  Please note that only a minor percentage of users are experiencing the write protection issue and these are the customers posting on the internet to find a solution."
  So wait, or change back your drive if it's under warranty...


ubuntu 12.04 booting from a thumb drive - how to reasonably safely eject the drive after boot?

After the machine comes up, you should be able to use something like

# Remount as read-only
mount -o remount,ro /

Alternatively, you can set it to read-only in the fstab and use something like

# Remount as read-write
mount -o remount,rw /


To upgrade to the latest version, please do the following:

Add the Ubuntu repository that contains the latest version 0.9.3-2, run the following command in terminal:

echo "deb http://cz.archive.ubuntu.com/ubuntu eoan main universe" | sudo tee -a  /etc/apt/sources.list
Update the repositories, run the following command in terminal:

sudo apt update
Upgrade to the latest version, run the following command in terminal:

sudo apt install liburiparser-dev

After this you should have the latest liburiparser-dev installed.

CAUTION:

At the moment 19.10 (Eoan) is pre-release -- it's still in testing. If you run into problems, we don't provide support for pre-release here. Also, one of the most common problems we help untangle is folks who have mixed sources from different releases of Ubuntu and broke their system, so we usually don't recommend it. Folks who want newer software should use a newer release of Ubuntu instead. It is strongly advised to just upgrade the needed package and remove the repository added above, once you have successfully upgraded the needed package. This can be done by editing the /etc/apt/sources.list file and commenting out or removing that line and running sudo apt update afterwards.

NOTE:

To know which official Ubuntu repository contains the latest version of a certain package, you can search for it at Ubuntu packages.


Can I completely remove snappy packages from Ubuntu 20.04 without affecting the system?

I'm currently running Ubuntu 20.04 LTS in a real enviroment and in a VM and I removed snap snapd following this steps:
# stop snapd services
sudo systemctl stop snapd && sudo systemctl disable snapd
# purge snapd
sudo apt purge snapd
# remove no longer needed folders
rm -rf ~/snap
sudo rm -rf /snap /var/snap /var/lib/snapd /var/cache/snapd /usr/lib/snapd

Then, in order to avoid that other applications may reinstall it (chromium-browser is an example of application that restores snapd even if installed via apt) you can create a file no-snap.pref by issuing:
sudo -H gedit /etc/apt/preferences.d/no-snap.pref
and then copying the following content in it:
# To install snapd, specify its version with 'apt install snapd=VERSION'
# where VERSION is the version of the snapd package you want to install.
Package: snapd
Pin: release a=*
Pin-Priority: -10

The file above prevents you from installing snapd if you type sudo apt install snapd, but allows you to install it if you run sudo apt install snapd=2.45.1+20.04.2 (the version in the command is just an example).

Original answer (2020/06/19):
I'm currently running Ubuntu 20.04 in a real enviroment and in a VM and I removed snap following this article: https://www.kevin-custer.com/blog/disabling-snaps-in-ubuntu-20-04/
I've never had any kind of issue following these steps.
Note that if you receive some errors while removing some snap package, try to remove another one and then come back to the one that gave you troubles: snap packages may have some dependencies, and you cannot remove one before before another one.
Moreover, before the command sudo umount /snap/core/xxxx run sudo systemctl stop snapd


Lubuntu 12.04, what is the best method to upload pics from my Canon Powershot A520-A510

Lubu!

First, I would install the lightweight photo manager called gThumb. You can install it by pasting the following code into your terminal.

sudo apt-get install gthumb

Second, you will need to connect your camera to the computer. There are a few ways to do this, depending on your camera.

The easiest is to insert the SD card into your computer SD port (if it has one).
The alternate way is to connect your entire camera to the computer via a USB cable.

You should see a pop-up that appears after you complete the connection above. Chose the gThumb option.

Finally, follow the import steps/options given by gThumb. Be sure your folder destination is your home/USERNAME/Pictures directory. That keeps your directories clean and simple.

If you did not see a popup when you connected your camera, the alternative way is to open gThumb and chose the import option (File -> Import From -> Removable Device)

You will again have upload options.

Finally, there are other options instead of gThumb that you may like. Here are four more standard options. I like gThumb because it fits Lubuntu's philosophy: (1) Lightweight and (2) Minimalist.

Enjoy your photos!


Do I have to dual-boot or can I do a fresh install?

You do not have to dual boot.  Ubuntu will be just fine by itself even with UEFI, you just have to keep/create a UEFI boot partition when you install it by itself.


Can't find printer driver files in terminal after downloading

You will probably find them in your ~/Downloads directory. When you open a terminal you usually start in your user's home directory, so typing

ls

Will show you what's in there. If you see Downloads (or, if your locale is not English, some equivalent in your language) type

cd Downloads

Or if you don't see it

cd ~/Downloads

Then run ls again and hopefully there are your drivers. For Ubuntu you want .deb not .rpm packages. To install a .deb file (replace name-of-file with the name of the file!)

sudo dpkg -i name-of-file.deb


How to adjust sensitivity of my touchpad?

Problem solved. I needed to install the Synaptics driver and restart. The output of xinput list then showed all kinds of Synaptics stuff. Using the info on this page:
https://help.ubuntu.com/community/SynapticsTouchpad
I was able to at least change the sensitivity. Now to tweak it a bit more...


it seems ssh does not use the same init scripts when starting a session. Have you already tried editing .bash_profile?

Here is a similar question, that might give you some extra information:
https://stackoverflow.com/questions/820517/bashrc-at-ssh-login


Note your computer-on-a-board has a: Fast UART 16550 serial port

From: Serial HOWTO

5.6 Standard PC Serial Cards

In olden days, PCs came with a serial card installed. Later on, the serial function was put on the hard-drive
interface card. In the 1990s and early 2000s one or two serial ports were usually built into the motherboard
(on-board). Most of them (as of 2002) use a 16550 but some use 16650 (32-byte FIFOs). But one may still
buy the individual PC serial cards if they need more serial ports. They can be used to connect external serial
devices (modems, serial mice, etc...). Only a tiny percentage of retail computer stores carry such cards. But
one can purchase them on the Internet. Before getting one for the PCI bus, make sure Linux supports it.
Here's a list of a few popular brands:

Byte Runner (may order directly, shows prices) http://www.byterunner.com
•
SIIG http://www.siig.com/products/io/
•
Dolphin http://www.dolphinfast.com/sersol.html
•

Note: due to address conflicts, you may not be able to use /dev/ttyS3 with a IBM8514 video card (and some
others) simultaneously. See Avoiding IO Address Conflicts with Certain Video Boards


script to concatenate multiple text files found in zip archives nested in multiple folders

find is a good tool when you need to do something recursively in directories. zcat can

My approach would be  something like this :

find /home/username/zipFiles -type f -name "*.zip" -exec zcat {} \; > outputfile.txt

Example:

$ df > testfile.txt
$ zip testArchive testfile.txt
  adding: testfile.txt (deflated 54%)
$ find . -maxdepth 1 -name "*.zip" -exec zcat {} \;
Filesystem     1K-blocks     Used Available Use% Mounted on
udev             1954212        4   1954208   1% /dev
tmpfs             393160     3392    389768   1% /run
/dev/sda1      115247656 82424300  26946008  76% /
none                   4        0         4   0% /sys/fs/cgroup
none                5120        0      5120   0% /run/lock
none             1965792       80   1965712   1% /run/shm
none              102400       32    102368   1% /run/user
cgmfs                100        0       100   0% /run/cgmanager/fs
/dev/sdb1       30343056       48  30343008   1% /media/xieerqi/SDCZ43-032G


Nothing seems to be blocking your PORT#. Your output clearly shows that it's not a firewall issue.

A default install of Ubuntu has no exploitable listening services, so the default firewall settings are to [ACCEPT] all connections.

The likeliest answer is that you simply don't have any service listening on PORT# to receive the connection. Applications listen on specific ports - that's how the systems know which packet is meant for which application.

If a packet arrives addressed to a port that nothing is listening on, then system doesn't know what to do with the packet, and sends a 'reject' back to the sender. You seem to be looking at such a 'reject' message.

Nomenclature:

You OPEN ports in the firewall by changing the firewall rules.
Applications BIND TO and LISTEN ON ports, receiving packets that have already passed through the firewall.

History: Firewalls became a big deal on systems that had built-in exploitable listening services that admins could not control or disable any other way. A stock install of Ubuntu does not have any of those (if you discover one, please file a bug report. We don't like those).


SSH is not supposed to use passwords provided via pipe for several security reasons. But there are some alternatives:

SSH_ASKPASS http://manpages.ubuntu.com/manpages/trusty/man1/ssh.1.html
sshpass http://manpages.ubuntu.com/manpages/trusty/man1/sshpass.1.html

See also https://stackoverflow.com/questions/1340366/how-to-make-ssh-receive-the-password-from-stdin


I need to execute my python code on raspberry pi 4 automatically, in Every per minute

As I understand it, this message informs you that your cron job has been executed, but output produced by it cannot be mailed to you because there is no Mail Transfer Agent installed on this machine.
I only wonder what output could it produce if you redirected everything to file. As one of the comments suggests, it may be an error message related to the fact that you probably don't have a file python/home/pi/Desktop/sensor.py on your system, so it cannot be executed. If you want to have the file /home/pi/Desktop/sensor.py executed by python interpreter (which is probably what you meant), you should write it as python /home/pi/Desktop/sensor.py (note the space).
Or do it "the proper Linux way" ;) - insert #!/usr/bin/python as the first line of your script, make the file executable and call it just as /home/pi/Desktop/sensor.py


I would use
du -hs /var/lib/flatpak/*

or even
du -hs /var/lib/flatpak

instead. Where

-h, --human-readable

print sizes in human readable format (e.g., 1K 234M 2G)

-s, --summarize

display only a total for each argument

See man du locally or online for details.

Also please note that flatpak list --show-details will show sizes of applications in more user-friendly form.


Can I make backup for the dpkg on linux mint and restore it on ubuntu?

You can use the following command to see packages installed by the user and output it to a file:

comm -23 <(apt-mark showmanual | sort -u) <(gzip -dc /var/log/installer/initial-status.gz | sed -n 's/^Package: //p' | sort -u) > ~/packages

Source

Then on your new install after bringing over that generated file, you can install them like so:

sudo apt-get install $(cat packages)

Why this approach is better

It allows apt to manage the dependencies for your platform like it is supposed to, and doesn't bring over system-installed libraries from Mint that Ubuntu will want to handle.


hdparm spin down time not persisting between reboots

Ubuntu 16.04's hdparm version is "9.48" and if you have a look at its configuration file man page: man hdparm.conf you will find out that:

  Blocks beginning with the keyword 'command_line' instead of a device identifier are no longer supported for backwards compatibility by this version of hdparm.

So the correct configuration file should looks like:

/dev/sda {
    spindown_time = 120
}

/dev/sdb {
    spindown_time = 120
}


I wrote a converter myself, for a specific use case, but it can be used for general purposes as well. See : here . It can download to either mp3 or flac and adds metadata. Again : check if what you are doing is legal before using it.

Download it as:

hg clone https://bitbucket.org/geertvandeweyer/spotify_recorder

It depends on the QT libraries and pulse-audio, recording the spotify signal in realtime. After the playlist finishes, songs are splitted and metadata is provided in ID3 tags.

Simply copy the URI from spotify of an album or playlist, and run the following command:

perl stream_recorder.pl --uri 'spotify:album:3BS9MUmVKghsOa7Y3otqpE' --silent --format flac --outdir /home/user/Music/

Options are :

uri : the album/playlist identififier. Copy it from the three dots & share in the spotify client
silent : a boolean to mute spotify while recording
format : flac or mp3 (vbr high quality)
outdir : target location of the recorded songs


agent-state-info: 'hook failed: "config-changed" deploy wordpress using juju

What you see is an error that occurred during the hook execution for MySQL's configuration changed hook. This typically occurs due to one a few things

A charm bug
Missing configuration options
a "hiccup" during hook execution

To start you will need to collect some information about your currently executing operation in the debug logs. Under production environments (like aws, hpcloud, etc) you run juju debug-log -n 500 however, since you're running the local provider this will be located in

$HOME/.juju/local/logs/unit-wordpress-0.log
$HOME/.juju/local/logs/unit-mysql-0.log

The format of the log files is fairly straight forward, and should you require additional help parsing them, upload it to paste.ubuntu.com and we can go through the logs either in #Juju on IRC or update the question.

Usually when an error is encountered due to corner cases, or race conditions, you can resolve the error and retry hook execution by running juju resolved -r <service>/<unit>

so in the example of your mysql hook failure, juju resolved -r mysql/0 will re-run the failed hook and if it completes successfully, the service will continue deployment.


Wireless drivers not working on Dell Ispiron 3543

Install synaptic package manager and search bcm43 drivers.
I agreee with AndroidDev, you could find the solution on the link provided by his/her answer.


ubuntu phone textfield displayed different

Background of a text field is invisible if this text field is readOnly. For me they are invisible both on the phone and desktop (15.04).

Theme styling file
/usr/lib/x86_64-linux-gnu/qt5/qml/Ubuntu/Components/Themes/Ambiance/TextAreaStyle.qml (qtdeclarative5-ubuntu-ui-toolkit-plugin:amd64 1.2.1458+15.04.20150422-0ub) shows that it's intentional:

property Component background: UbuntuShape {
    property bool error: (styledItem.hasOwnProperty("errorHighlight") && styledItem.errorHighlight && !styledItem.acceptableInput)
    onErrorChanged: (error) ? visuals.errorColor : visuals.backgroundColor;
    color: visuals.backgroundColor;
    anchors.fill: parent
    visible: !styledItem.readOnly
}

Ideal workaround (that doesn't work yet because there are no Ubuntu.Components.Styles in this version) is to override the style:

import QtQuick 2.4
import Ubuntu.Components 1.2
import Ubuntu.Components.Styles 1.2

TextField {
    readOnly: true

    style: TextFieldStyle {
        background: UbuntuShape {
            color: Theme.palette.normal.field
            anchors.fill: parent
        }
    }
}

For now, I can only think of a hardcoded background like that:

TextField {
    readOnly: true

    UbuntuShape {
        z: -1
        color: Theme.palette.normal.field
        anchors.fill: parent
    }
}


Why is the font spacing on some websites broken?

it was "Helvetica" for me. Had to install for some Scribus compatibility and since started noticing fonts overlapping everywhere - documents, web pages, web-based editors. Removing the font fixed the issue.

Yet to figure out why the incompatibility but as far as this issue is concerned, look for that font or any other recently installed fonts.


Will the latest versions of Firefox be brought into old Ubuntu releases?

Yes, while a release of Ubuntu continues to be supported, it will receive the updated versions of Firefox.

Note that most Ubuntu releases are supported for 18 months after release. For example 10.10 is over 18 months old, and will not receive security updates, such as new versions of Firefox. There are some Ubuntu releases that are LTS (Long Term Support) releases which will continue to be supported for three or five years.

The graph below (from Wikipedia) shows the support for various releases. Yellow is the standard 18 months. Orange is the extended support on the Desktop. (Red is extended support on the Server only, this does not include Firefox.)


How can I merge numbered pdf files with pdftk?

If I understand correctly, in your example you want to merge the first 20 pdf files, i.e. the files with names from 1.pdf to 20.pdf. You can do that using brace expansion, so the command you need to run is:
pdftk {1..20}.pdf cat output out.pdf

In essence, {1..20}.pdf is expanded by the shell to 1.pdf, 2.pdf, 3.pdf, ...,  20.pdf, so it's the same as running (the ellipses signify the intermediate files):
pdftk 1.pdf 2.pdf 3.pdf ... 20.pdf cat output out.pdf


Install Windows7 on drive with Ubuntu 12.04 already on. Is my plan good?

Should work just fine. If you want to see what the 776MB are, take a look into the folder /ext4a using nautilus or a terminal. Because it is mounted it will have an entry in the file /etc/fstab. Edit it and delete the entry for /dev/sda1 respectively /ext4a.

You are also right about sda5 and sda6. sda5 is the root mount point /. That means everything that has no different mountpoint is saved on that partition. In this case your system and your installed programs. sda6 contains the home folders. Your home folder is used for saving your personal files including the Pictures, Music, Documents, etc folders and even the Desktop. Most programs you use also save their settings in your homefolder. So if you want to reinstall your Ubuntu at some time, you should be able to format sda5 and use sda6 as /home mountpoint again without formating and all your files and program settings will be kept.


How can I set up different startup profiles?

I think the easiest way would be to create multiple accounts with activity as real name and then you link them together with symlinks and you can put a script in "Startup Application" to have the services started you want.


My folders have been synced but I don't see any files

Depending on what version of Ubuntu you're on, what you're seeing is normal. Folders get created first, and then files. Very slowly, if we're talking thousands of files.

We've worked on fixing this slowness and it should be much better by the time we release Natty, on Natty; older versions will get the speedups soon after that.

Meanwhile, to make sure you are progressing, you can follow the instructions on How can I tell whether Ubuntu One file sync is working, and what progress it is making?


not able to get php7 after add ppa:ondrej/php

It seems ppa:ondrej/php is not support the Ubuntu 14.04 LTS according to https://wiki.ubuntu.com/Releases
which indicates the standard support is ended April 2019.

After I upgrade my ubuntu to 16.04 LTS, I can install the php 7.3 from the repository.


GNOME sushi not working on desktop in Ubuntu 19.10

No, you do not miss anything.

In Ubuntu 19.10, icons on the desktop are not anymore provided by the file manager Files (a.k.a. nautilus), but by a separate Gnome Shell extension, "Desktop Icons". Sushi works with Files, but not with the extension.

To preview files that live on the desktop, you can go to the Desktop folder in Files.


How to know whether an nvidia graphic card is installed or not?

You can see what graphic card is installed by going in System Settings... → Software & Updates and select Additional Drivers tab:


How can I enable palm detection for Synaptics touchpad in my laptop?

My solution might not work for you, but I fixed this issue by switching to Wayland.

I use the Lenovo ThinkPad X1 Yoga 3rd Gen, and the palm detection features when using X.org didn't seem to do anything. I knew that the hardware was capable of doing true Apple trackpad style palm detection, because, on Windows, I could rub my palm vigorously across the touchpad and the mouse pointer wouldn't budge.

To switch to Wayland, log out of your user account, and there should be an option on the login page that shows a dropdown with "Wayland" as an option. If not, see this answer for more details.

Voila! I can now smear my whole palm on the touchpad again and not worry about accidental taps and mouse movement.


Why deja-dup fails with dependencies in 16.04?

To fix the original issue, try the following commands:

To make sure your computer is fully up-to-date:

  sudo apt update ; sudo apt upgrade

To resolve any dependency issues which may exist:

  sudo apt install -f

To see if  reinstalling the program helps:

  sudo apt remove deja-dup ;  sudo apt install deja-dup

As for the issue with permissions, I'm not sure deja-dup does full backups very well because, as you have found, you have to run it as root and then you have problems with your mounted drive. Either just backup your home folder, or use a different tool (see this question, though having done some other Googling people seem to recommend Clonezilla a fair bit). This Launchpad Question back from 2010 seems to suggest that deja-dup doesn't do full backups very well, maybe that issue hasn't been worked on much since then.


automated Ubuntu Desktop 15.10 installation from local DVD with preseed

A bit late response (I use 16.04 but must be the same) ...

Create a copy of the CD in a local folder:

# mkdir /mnt/cdrom
# sudo mount -o loop ubuntu-16.04.1-desktop-amd64.iso /mnt/iso
# mkdir /opt/iso
# cp -rT /mnt/iso /opt/iso

Change the timeout to a non zero value in the file /opt/iso/isolinux/isolinux.cfg  (10 == 1 second):

path
include menu.cfg
default vesamenu.c32
prompt 0
timeout 10
ui gfxboot bootlogo

Modify the 'live-install' option in the file /opt/iso/isolinux/txt.cfg to (192.168.1.1 is the location of the web server) and make it default:

default live-install
label live-install
  menu label ^Install Xubuntu
  kernel /casper/vmlinuz.efi
  append auto url=http://192.168.1.1/xubuntu.cfg keyboard-configuration/layoutcode=us and console-setup/ask_detect=false boot=casper automatic-ubiquity noprompt initrd=/casper/initrd.lz ---

Create the new iso:

mkisofs -D -r -V "ATTENDLESS_UBUNTU" -cache-inodes -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -o /opt/autoinstall.iso /opt/ubuntuiso

Booting with autoinstall.iso the instal·lation will be totally automated.


WHY is there conflict between python versions?

Hello I am not 100% sure what conflict you encounter. Why did you need to change those files in /usr/bin to use 3.6? What errors did you get and what is python3 pointing to right now?

The 'python3' is usually just a link, a pointer, to a particular python version on the system. If you need to work with different python versions there are a few different ways to do so. I will mention three that I commonly use:

Use a virtual environment like conda. When you install conda you basically create a manager for virtual environments where you can install python modules or even python/pip versions without any impact to the outside system. I suggest you go check conda, especially if you are worried that you will break your system by changing python stuff.
Run your scripts with a particular python version like

python3.7 my_script.py

If you really want to use python3, you can just make an alias in your ~/.bashrc (or ~/.zshrc etc)

alias python3="/usr/bin/python3.7"

To check what binaries respond to the python command run

whereis python

This will give you the paths to all binaries, you can use these to make an alias like above. You can also use these to get more precise info:

whereis python3
which python3
which python3.7

Add shebangs to your scripts and make them executable, this is maybe less portable and you seem to know about it already.


Canon has Ubuntu drivers for both the printer and the scanner on their website.  You need to download the driver, and extract it to install.


rtw_pci indicates a realtek wifi adapter, which has a lot of compatibility issues with linux. I assume you have used a bootable USB stick for installation, and if so, open it and repair the disk using GParted or Disks. Then, Please check out this github repository for the appropriate drivers needed, as I guess these might be causing the problem.


Prevent Ubuntu from freezing, even if system memory is low

I still don't have a solution for the problem, but I can offer two workarounds which might be of interest to others:

1) earlyoom

That's a service that watches memory usage and kills the process that consumes the most memory when a certain threshold is reached (see also this and this question regarding the OOM killer in the linux kernel)

I've tested it with a demo process that indefinetly requests memory in small chunks. Here's my first impression: When I start the rogue process, it quickly eats up all of my RAM. Then swapping begins, the system becomes inresponsive. A few seconds later the system is back online. The log of earlyoom shows that it killed the memory eating process after both memory and swap usage reached 90%.

There is still the annoying lag when swapping begins and after the process was killed, some portions of other processes usually remain in swap until they are requested, but it's a start.

2) just disable swap

I know this is a controversial topic, but for the purpose of desktop systems and especially development machines where it can happen from time to time that a process tries to eat up all your memory, it makes sense: Without swap, the OOM killer just works as intended. When you run out of memory, it finds the best process to kill and gets rid of it. No lag, no delay.

You can disable swap for the current session with sudo swapoff -a or make the change permanent.

The proper solution for the problem would of course be that the system stays responsive when the main memory is depleted and it starts to swap memory like there's no tomorrow, but that doesn't seem to be happening any time soon.


Building a .Deb package after locally modifying the files

I've not tried myself the following commands, but they should work with none or minimal modification.

How can I build a package from the development branch to install locally on my system ?

Download branch

  $ bzr branch lp:~pmarchwiak/synapse-project/recoll-plugin

Install dependencies

  $ sudo apt-get install devscripts equivs dh-autoreconf bzr-builddeb
  libcrypt-ssleay-perl

  $ cd recoll-plugin && sudo mk-build-deps -i

Build package

  $ bzr bd --native -- -b -uc -us

Install package

  $ sudo dpkg -i ../build-area/*.deb

How can I modify source files that I receive from running apt-get source synapse and repackage them into a deb file? (not sure about license violations in this case though).

Get source

  $ apt-get source synapse

Edit it

  $ cd synapse && $EDITOR files

Install dependencies

  $ sudo apt-get install devscripts equivs dh-autoreconf libcrypt-ssleay-perl

  $ cd synapse && sudo mk-build-deps -i

Build package

  $ debuild -b -us -uc

Install package

  $ sudo dpkg -i ../*.deb


apt-get install nfs-common does not create an idmapd

I had the same problem and this work for me :

$ unset UPSTART_SESSION

here explain the problem.


You cannot use a "simple" bash script to interact with a telnet session.

As per @Melebius comment, the answers to this question on StackOverflow propose some solutions, like using expect. As a simpler alternative you can pipe your commands to telnet:

{ sleep 3 ; echo "root" ; sleep 1 ; echo "labrat" ; sleep 1; } | telnet board

Please keep in mind that this way the telnet session terminates soon after the input is processed. If you want to create an automated script, it might be enough (but then expect is still a better way).

EDIT as per comments

If instead you want to open an interactive telnet session, but save yourself the "hassle" of entering username and password every time, I'm afraid there's not a simple solution. You can pass the username via the -l flag (i.e. telnet -l root board) so
you need to enter only the password.

Looks like expect can be used successfully to automate telnet logins while leaving an interactive prompt via the interact directive.

A simple example based would be:

#!/usr/bin/expect

spawn telnet board
sleep .3;
expect "login:"
send "root\r"
expect "password:"
send "labrat\r";
interact

Just edit to your needs.


To try and check where your wifi issues may be, troubleshooting using these commands in a terminal (Ctrl + Alt + T) can be handy:

Check status of connectivity: nmcli networking connectivity
Check that wifi is properly activated: nmcli radio wifi off ; nmcli radio wifi on
See wifi access-points: nmcli device wifi rescan ; nmcli device wifi list
Try to connect to wifi: nmcli device wifi connect "$WIFI_AP" password "$WIFI_PW"

Each of these should give you a hint as to why they fail , if they do.

Further information can be found in man nmcli


How to totally remove ubuntu from boot menu after Windows dual boot

I've  gotten the solution https://askubuntu.com/a/63613/410771

You should be able to do this via a Live Ubuntu CD.

Install efibootmgr:

sudo apt-get install efibootmgr

Then add to the kernel efi support

sudo modprobe efivars

Then run sudo efibootmgr to check your boot entries. It will return something like this:

BootCurrent: 0004
Timeout: 2 seconds
BootOrder: 2001,0003,0005,0006,0000
Boot0000* Lenovo Recovery System
Boot0001* EFI Network 0 for IPv6 (B8-88-E3-84-F3-EF)
Boot0002* EFI Network 0 for IPv4 (B8-88-E3-84-F3-EF)
Boot0003* Windows Boot Manager
Boot0004* EFI USB Device (SanDisk)
Boot0005* ubuntu
Boot2001* EFI USB Device

Then delete the option you dont want. In this example, Ubuntu is entry 5. the following could be called to delete entry 5 and remove it from the BootOrder.

(CAUTION: Before executing the following command make sure you enter the correct Boot entry number)

sudo efibootmgr -b 5 -B

Further details described here: http://linux.die.net/man/8/efibootmgr

Note: as for anything that changes your bootloader, please ensure you have a good disk image that you can boot with.

Now you should also delete the ubuntu subdirectory in the EFI partition to prevent the UEFI firmware from restoring the entry into the BootOrder.

To do that, first find your EFI partition. Run sudo fdisk -l to see the partitions on all attached drives. The EFI partition has EFI Partition under the Type column.

Suppose your EFI partition was /dev/sda2, then mount it on an empty folder anywhere.

    sudo mkdir /mnt/efipart
    sudo mount /dev/sda2 /mnt/efipart

Now we have to find the directory Ubuntu or any other distro's name in this partition. It is mostly under EFI/distro_name.

Remove that directory and its contents by (PLEASE MAKE SURE YOU ARE DELETING THE CORRECT DIRECTORY) sudo rm -r ubuntu.


How to burn torrent movies to a dvd-rw that work!

From https://wiki.gnome.org/Apps/Brasero:

What is Brasero?
Brasero is an application to burn CD/DVD for the Gnome Desktop. It is
designed to be as simple as possible and has some unique features to
enable users to create their discs easily and quickly.
Features

Supports multiple backends: cdrtools, growisofs and libburn(optional).

Note: compiling against libburn is not enough. You need to activate
the backend through GSettings
Data CD/DVD

supports edition of discs contents (remove/move/rename files inside directories)
can burn data CD/DVD on the fly
automatic filtering for unwanted files (hidden files, broken/recursive symlinks, files not conforming to joliet standard,
...)
supports multisession
supports joliet extension
can write the image to the hard drive
can check disc file integrity

Audio CD

write CD-TEXT information (automatically found thanks to gstreamer)
supports the edition of CD-TEXT information
can burn audio CD on the fly
can use all audio files handled by Gstreamer local installation (ogg, flac, mp3, ...)
can search for audio files inside dropped folders
full edition of silences between tracks

CD/DVD copy

can copy a CD/DVD to the hard drive
can copy CD and DVD on the fly
supports single-session data DVD
supports any kind of CD

Others

erase CD/DVD
can save/load projects
can burn CD/DVD images and cue files
song, image and video previewer
device detection thanks to HAL
file change notification (requires kernel > 2.6.13)
a customisable GUI (when used with GDL)
supports Drag and Drop / Cut'n'Paste from nautilus (and others apps)
can use files on a network as long as the protocol is handled by gnome-vfs
can search for files thanks to beagle (search is based on keywords or on file type)
can display a playlist and its contents (note that playlists are automatically searched through beagle)
all disc IO is done asynchronously to prevent the application from blocking


I just created a folder on Ubuntu one, and was able to delete it.  Take a look at the images below for clarification.


How to make a show desktop icon in a corner of the screen?

disclaimer: I am author of this indicator and it is written for this specific question

Introduction

Ubuntu by default doesn't have option to move "Show Desktop" icon - it has to live on the launcher. You can also have it show up in the Alt+Tab menu. However, it is possible to create a small indicator applet, that will live in your top panel, which comes pretty close to your requirement of placing the icon into the corner of the screen. This answer provides exactly that

Usage

Usage is very simple. Save the code in your ~/bin folder, for example for me it would be /home/serg/bin/show_desktop_indicator. In order to make it open every time you log into your Ubuntu, search in Dash for "Startup Applications", open that app, and add the full path to the indicator as new command.

You can also download the zip folder with the indicator from the project's Github page

Essentially, it minimizes all the open windows. There's two ways to go about it. One, you can click on indicator icon, and click the "Show desktop" menu entry, or use middle-mouse click on the icon itself.

Code

Also available on Github

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

#
# Author: Serg Kolo , contact: 1047481448@qq.com
# Date: November 5th, 2016
# Purpose: appindicator for minimizing all windows
# Written for: http://askubuntu.com/q/846067/295286
# Tested on: Ubuntu 16.04 LTS
#
#
# Licensed under The MIT License (MIT).
# See included LICENSE file or the notice below.
#
# Copyright © 2016 Sergiy Kolodyazhnyy
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import gi
gi.require_version('AppIndicator3', '0.1')
gi.require_version('Notify', '0.7')
from gi.repository import GLib as glib
from gi.repository import AppIndicator3 as appindicator
from gi.repository import Gtk as gtk
from gi.repository import Gdk

class ShowDesktop(object):

    def __init__(self):
        self.app = appindicator.Indicator.new(
            'files-indicator', "user-desktop",
            appindicator.IndicatorCategory.OTHER
        )
        self.app.set_status(appindicator.IndicatorStatus.ACTIVE)
        self.make_menu()

    def add_menu_item(self, menu_obj, item_type, image, label, action, args):
        """ dynamic function that can add menu items depending on
            the item type and other arguments"""
        menu_item, icon = None, None
        if item_type is gtk.ImageMenuItem and label:
            menu_item = gtk.ImageMenuItem.new_with_label(label)
            menu_item.set_always_show_image(True)
            if '/' in image:
                icon = gtk.Image.new_from_file(image)
            else:
                icon = gtk.Image.new_from_icon_name(image, 48)
            menu_item.set_image(icon)
        elif item_type is gtk.ImageMenuItem and not label:
            menu_item = gtk.ImageMenuItem()
            menu_item.set_always_show_image(True)
            if '/' in image:
                icon = gtk.Image.new_from_file(image)
            else:
                icon = gtk.Image.new_from_icon_name(image, 16)
            menu_item.set_image(icon)
        elif item_type is gtk.MenuItem:
            menu_item = gtk.MenuItem(label)
        elif item_type is gtk.SeparatorMenuItem:
            menu_item = gtk.SeparatorMenuItem()
        if action:
            menu_item.connect('activate', action, *args)

        menu_obj.append(menu_item)
        menu_item.show()

    def make_menu(self):
        self.app_menu = gtk.Menu()
        content = [self.app_menu,gtk.MenuItem,
                   None,'Show Desktop',
                   self.show_desktop,[None]
        ]
        self.add_menu_item(*content)
        last = None
        for i in self.app_menu.get_children():
             last = i
        self.app.set_secondary_activate_target(last)

        content = [self.app_menu,gtk.ImageMenuItem,
                   'exit','Quit',
                   self.quit,[None]
        ]
        self.add_menu_item(*content)
        self.app.set_menu(self.app_menu)

    def show_desktop(self,*args):
        screen = Gdk.Screen.get_default()
        for w in screen.get_window_stack():
            w.iconify()
            w.process_all_updates()

    def run(self):
        """ Launches the indicator """
        try:
            gtk.main()
        except KeyboardInterrupt:
            pass

    def quit(self, *args):
        """ closes indicator """
        gtk.main_quit()

def main():
    """ defines program entry point """
    indicator = ShowDesktop()
    indicator.run()

if __name__ == '__main__':
  try:
    main()
  except  KeyboardInterrupt:
    gtk.main_quit()

Indicator in action:

Ubuntu with Kylin icon theme:


See if ntfs-3g is installed.

  ntfs-3g --version

If not, install it

  sudo apt-get install ntfs-3g

With this utility you can mount and read/write NTFS files.


If you have the Ubuntu ISO image, Wubi is already part of it.
You can either burn a disc and load it inside Windows or mount the ISO image in Windows using programs like Daemon Tools.


How to align Conky text to centre of desktop?

To put your conky on top center, find alignment tl line 37 in you conky script and put this

alignment top_middle

gap_x 0
gap_y 0

Allignment code

top_left

top_middle

top_right

To center your text put

${alignc} on :

${alignc}${font ETIAW v3:size=75}${time %A}${font}
${alignc}${font ETIAW v3:size=75}${time %B} ${time %e}${font}
${alignc}${font ETIAW v3:size=75}${time %I:%M %p}${font}

Conky script basic

My output as im not using your font :


How can I start webfsd every time I boot up/log in?

My first idea was a simple upstart script. /etc/init/webfs.conf:
description "WebFS server"
start on (local-filesystems and net-device-up)
respawn
exec webfsd -F -p 80 -u d3vid -g d3vid /home/d3vid/Documents/www/ -f index.html

The -u and -g arguments are really important. These drop root privileges after binding the port... Which means there's not a net-accessible process running as root that can be exploited.
The other idea is running it on a high port (>1024) as you, auto-starting that however you like... And then either using a real server to reverse proxy (nginx is a common and lightweight tool here) from port 80... Or just use an iptables redirect.
iptables -A INPUT -i eth0 -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 10010 -j ACCEPT
iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 10010

The advantage there is webfs is never running as root... But then you're just left with needing to run the iptable commands as root every boot. Swings and roundabouts.
I think on balance, if you're not exposing the server to the internet directly, the first route is probably safe enough.
But if you're going any further, dump WebFS and just use nginx...

It does everything WebFS does (and a whole lot more)
It's simple to use
It's efficient beyond reason
Its SSL has decent documentation
Most importantly, lots of people have a vested interest in nginx remaining secure, including Canonical, so you'll get updates for it fast (critical when dealing with web-facing things)

To give you some sort of idea what efficient means, I have a webserver hosting around 20 domains, a few of them do some pretty serious traffic. nginx's four worker processes account for 15MB of RAM combined and no observable CPU time. It's insane.


Why does gnome-terminal freeze when an SSH session gets disconnected?

The session will eventually time out and disconnect; this will happen faster if you configure ServerAliveInterval and ServerAliveCountMax in ~/.ssh/config.  To force an immediate disconnect, Return~..


Well, it seems that it works, so any one who wants to buy it can use it on Ubuntu


Are you running the program as root? Most of the time when accessing cds or disk drives, ubuntu has permission issues when trying to access as the current user.


After CTRL+ALT+F3 during login, CTRL+ALT+F7 only blackscreens

CTRL+ALT+F1 did the trick, returned to Plasma login screen correctly.


New versions of Ubuntu have ureadahead enabled by default, which improves boot speed using the same broad method, but is more adaptable: it works for both HDD and SSD rather than just HDD, and it pretty much just works without any manual intervention, detecting when you make a change to the boot process, re-monitoring the boot process and re-compiling its cache.

They won't work properly together (probably what would happen is that e4rat would be ineffective when using ureadahead) so I'd recommend sticking with ureadahead.


How to sign a Deb package with dpkg-sig and GPG2 in Ubuntu 16.04?

You say that the pass phrase in ${signPass} comes from some secure storage. If you can store a pass phrase securely you could also store a key chain with a password-less secret key securely.

Change the password of the key to empty. You can use your favourite key chain manager or the following command:

GNUPGHOME=... gpg2 --passwd user_id

Store the key chain in secure storage.
Run dpkg-sig with GPG options that use the securely stored key chain:

dpkg-sig --gpg-options "--secret-keyring /path/to/secret-keyring.gpg"

Alternatively you can use a pass phrase file directly with dpkg-sig (see the edit below):

dpkg-sig -f /path/to/pass-phrase ...

You could even use standard input:

printf '%s' "${signPass}" | dpkg-sig -f - ...

Edit: It appears that a long standing bug breaks the -f option but you can work around it via --gpg-options '--passphrase-file /path/to/pass-phrase' (except that you can't use passphrase file names with white-space).


tmux in terminal forcing 16 color approximation

Nevermind, turns out that I just needed for force tmux to believe I have 256 colors (this became clear once I realized what it really meant that I was only seeing 16 colors inside tmux; I had previously mistakenly thought I was getting 256) using the -2 option.


Switch the login display manager from gdm3 to lightdm. LightDM is a more lightweight login display manager than gdm3.

sudo apt install lightdm
sudo dpkg-reconfigure lightdm
sudo reboot

sudo dpkg-reconfigure lightdm will open up a new window allowing you to select lightdm as the default login display manager. Use the arrow keys to select lightdm, press the Tab key to put the focus on <OK> and press Enter. Then reboot by running this command: sudo reboot


You could try wavemon. This tool should give you at least a basic overview.


Accessing Another User's data on same computer(GUI)

Disclaimer

Yes, you can log in graphically, if you use xhost. If in your own computer at home, fine, but in a network with several people, for example at work, it is a security risk. So the general recommendation is to do such things via command lines in text mode.

Log in graphically from one user to another one

Log in as user2 according to your question
Open a terminal window
Allow the other user (in your question user1) to open windows in your desktop environment

$ xhost +si:localuser:user1
localuser:sudodus being added to access control list

Log in as the other user

$ su - user1
Password:

If you wish, you can run some text mode commands to check where you are, pwd, and who you are, whoami.
Next you can start your file browser or some other graphical program. I'm running Lubuntu, so I start pcmanfm. In standard Ubuntu you would run

nautilus --no-desktop

The following screenshot illustrates how it works.

LANG=C pcmanfm makes pcmanfm use the default language, US English, instead of my local language.

Copy files

You want to copy files from user1 to user2.

If 'personal data'

When logged in as user1, check that user2 has read access to the directories and files, that you want to copy and modify the permissions if necessary. This is possible with the file browser, but I think it is easier to check with the command ls -l and modify with the command chmod.
When logged in as user2, open two windows of the file browser and copy/paste from the window, that is 'looking at' user1 files, to the window
that is 'looking at' the user1 directory, where you want the copies.

If system data (configuration data). Risky!

The permissions and ownership of system data files is often very important. This means that you must preserve these properies, if you want them to work.
It is a good idea to back up your previous system data before you start using some system data from the other user, particularly when there are problems logging into that user (so some system data are bad).
This is relatively easy to do with command lines with

sudo rsync -Havn source target

or

sudo rsync -Havn source/ target

See man rsync for more details, for example the effect of the trailing slash.

An alternative is to run the file browser with elevated permissions (preparing with xhost for root and running with sudo -H or pkexec or using some other method, that is considered relatively safe, for example nautilus-admin. See the following link,

Why don't gksu/gksudo or launching a graphical application with sudo work with Wayland?


Which is the "correct"/"official" kernel version? (server vs cloud-img installs)

I hope this link will help you: https://wiki.ubuntu.com/Kernel/LTSEnablementStack


If you're not averse to using the terminal, there's a package called qpdf that you can install. It's in the software center. To remove protections from your file you can use something like this:

qpdf --password=your_password --decrypt yourfile.pdf output.pdf

That should do the job.  As a side note, another useful (also command line) tool to have for working with pdf files is pdftk.
Example from man pdftk:

pdftk secured.pdf input_pw foopass output unsecured.pdf

Hope that helps!


Do I need to restore iptable rules everytime on boot?

apt-get install iptables-persistent

On install, it should save your current iptables config. Otherwise you can save them to these files (depending on v4 or v6) and iptables-persistent will load them on boot :)

iptables-save > /etc/iptables/rules.v4
ip6tables-save > /etc/iptables/rules.v6


How can I find the URL for a flash video in Firefox?

More detail is needed. What do you mean by "viewing a link"? Normally you can find the link to video files in the page source, or via the Firebug network tab (if you don't have Firebug, you should get it). It should be something that ends in ".flv", or sometimes ".mp4", and once you have it it's easy to download: just open a terminal and type:

wget "http://www.nasul.tv/wp-content/uploads/2013/05/nasul1305.m4v" -O filename.m4v

(with the quotes).


Couldn't update and Software Center isn't working

open your terminal and remove those pkg's.

I mean in the terminal paste these two lines one by one

sudo rm -rf /var/cache/apt/archives/ubuntu-sso-client-gtk_3.0.2-0ubuntu3_all-deb
sudo rm -rf /var/cache/apt/archives/python-ubuntu-sso-client_3.0.2-0ubuntu3_all.deb

Then try again .


How to see if there are any qbittorent torrents from shell script?

What about checking the directory you've configured qbittorent to store .torrent files in?

Under Options > Downloads, take a look at the Copy Keep incomplete torrents in setting and select a location.

Simply modifying your start up script to check this directory for .torrent files that haven't completed yet might be good enough.

If not, and you need a little more functionality, then, enable the Run an external program on torrent completion setting and write a simple script that does whatever additional things you want.

Anyways, the point is, a combination of these various settings and scripts can be used to do a number of things with qbittorrent depending on what you want.


I finally solved the problem!
The reason why I could not see png, pdf thumbnails was that my ~\.cache\thumbnails folder had only root privileges (I do not know why). After a sudo chown -R user:user ~\.cache\thumbnails, my thumbanails started rebuild.

Before changing the ownership:

After changing the ownership:

(look at total dimension)


http://www.howtoforge.com/setting-up-unison-file-synchronization-between-two-servers-on-ubuntu-11.10

This tutorial shows how to set up file synchronization between two Ubuntu 11.10 servers with Unison. Unison is a file-synchronization tool similar to rsync, but the big difference is that it tracks/synchronizes changes in both directions, i.e., files changed on server1 will be replicated to server2 and vice versa.


Is there a way to type accented characters in a similar fashion than the one in macOS?

Yes. Add the English (US, intl., with dead keys) keyboard layout and switch to it to type accented characters easy.

https://help.ubuntu.com/stable/ubuntu-help/keyboard-layouts.html


Install grub2 to usb-drive in order to boot to hdd-installed Ubuntu 13.04 x64 in UEFI mode

You cannot set two /boot partitions with boot-flag ! There is only one boot-flag necessary for grub2 in /boot partition - so simply deactivate boot-flag in your partition /dev/sda1

After this activate boot-flag in /boot partition of /dev/sdi - sure ? this is correct ? You have a /boot partition in /dev/sdi ? So there you need to activate boot-flag ( simply with gparted ).

As you say ... grub2 is already installed in /dev/sdi ? If not now follows (necessary because you modified boot-flags) :

  sudo grub-install /dev/sdi

  sudo update-grub2

Before this all your machine was booting into Windows 7 of /dev/sda3 via /dev/sda1 - but now boot-flag is deactivated and set to /boot partition of /dev/sdi - and your machine should now boot to installation of your usb-drive.

Only in case that in UEFI-mode your machine is not able to boot into usb-drive - then you should disable UEFI-mode in BIOS-settings and enable there EFI-mode instead.


Problem installing Photoshop on 16.04 LTS

Manually install the latest version of Winetricks:

cd /usr/bin
sudo rm -f ./winetricks
sudo apt install wget
sudo wget https://raw.githubusercontent.com/Winetricks/winetricks/master/src/winetricks

Then run the winetricks command again.


Can you only install and not try ubuntu from a live usb in ubuntu 20.04?

The comment of @https://askubuntu.com/users/43926/c-s-cameron is right. In fact you can't "try Ubuntu" with a server version. I downloaded the desktop version of the ISO and achieved what I wanted to do.


How can I partition a physical SSD into one part for Ubuntu and one NTFS data drive?

Most of the comments were either aiming at too complicated solutions or at dual-boot systems. Eventually, I found a much simpler solution: After installing Ubuntu without further manipulations and the standard partitioning / formatting options, I started my system from USB and then used the disk manager to resize the partitions to 250 GB Ext4 holding the Ubuntu installation (including home an all that) and to 750 GB NTFS holding my data. No need for any extra mounting, playing around with the bios or else.


Where Can I Find "mkisofs" and "cdrecord" for Ubuntu 12.04 (e.g., iso9660 ufs)

The good news is that if you are after the authentic cdrecord and mkisofs (rather than the Debian fork of these applications) Brandon Snider's PPA holds version of these great applications as far back as Ubuntu 12.04 and forward in time to the most recent Ubuntu release.

Add the PPA as follows:

sudo add-apt-repository ppa:brandonsnider/cdrtools
sudo apt-get update

Then install the following from  Terminal window:

sudo apt-get install cdda2wav cdrecord mkisofs

And now you should be good to go for any version of Ubuntu...


Invalid YAML in Netplan/Bridging/VLAN tags for qemu/libvertd

br50, br90 and br100 are all indented one space too many.  They need to line up with br20 like:

  bridges:
    br20:
      dhcp4: no
      dhcp6: no
      interfaces: [ vlan20 ]
    br50:
      dhcp4: no
      dhcp6: no
      interfaces: [ vlan50 ]
    br90:
      dhcp4: no
      dhcp6: no
      interfaces: [ vlan90 ]
    br100:
      dhcp4: no
      dhcp6: no
      interfaces: [ vlan100 ]


Yes it will. Linux kernel supports almost every hardware (95% of all hardware) . Install ubuntu without any fear.


Portable virtual machine with preinstalled Ubuntu for Windows?

Well, you can create a Live-USB using LinuxLiveUSB-Creator which includes a ready-to-run portable Virtualbox for Windows to immediate use the Live Ubuntu.

No installation is required (well, except for the USB creator program :)
Virtualbox is better supported, easier to use and has more features than qemu on Windows
You can always copy the contents of the LiveUSB to your hard-disk for a more permanent/faster Virtual Live-Ubuntu


Is there any way to make sure that any file created in a specific folder has a certain group as owner?

Add the setgid bit.

chmod g+s /path/to/directory

See http://mywiki.wooledge.org/Permissions


Sharing another folder over LAN using NFS Mount between two ubuntu machines so that one can be source (client) and other can destination (server)

As covered in comments; you have multiple options which are not mutually exclusive.

SaMBa - small|server message block; an old IBM protocol dictated to be used for IBM PC Lan Manager coded by microsoft (thus its still used today by windoze, with a new name CIFS (common internet file system)).

NFS - network file system. It's a unix/*nix file system, is faster & has many advantages over SaMBa but isn't available by default for windoze workstations without additional software.

You needn't restrict yourself to one (or in fact just these two!); ie. I use NFS for all real work (read/writes), but also allow read-only access to some folders via SAMBA so simple media players can access mp3's etc.

For clients (machines using the data) the package nfs-common is required, for the servers you'll need the package nfs-kernel-server; or both if boxes want to act in serving & client modes.

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


How to copy Folder as root to another hard drive?

In order to copy directories you'll need the flag '-r':

From man cp:

   -R, -r, --recursive
          copy directories recursively

So  run something like:

 sudo cp -r recoverd/ /media/samerlol/7E7D1D0C55C0ABDF


Is it possible to exclude folders in Clonezilla?

No, that would defeat the idea of "cloning". Cloning is intended to have you end up with an exact copy.

  CLONING » The process of duplicating either an individual partition or the contents of an entire hard drive onto a new hard drive. After cloning, the destination drive/partition will look identical to the source.