Is it possible to reinstall ubuntu to an older version?

You can install an older release keeping your /home. It is quite easy.
Boot from an Ubuntu installer, select "Install Ubuntu" and choose "something else" option.
You will be prompted to select partitions where you want to install it. If you don't have a separate /home partition, select the partition where Ubuntu is currently installed.
But don't check the format checkbox.
In this case the installer will re-write the system directories, but will keep /home intact.
It is preferable to enter the same user name and password as you had before.
As aways it is highly recommendable to do a backup first.
If you do have a separate /boot partition, you can tell the system to format / partition, and just use the existing /home.
Be careful if you don't understand the difference!!!


How to get the source code for a binary?

dpkg -S /sbin/ip to map from the binary to the package containing it (here, the package is "iproute2")
Enable source code repos in sources.list (easiest done via the "Software & Updates" config dialog)
sudo apt update to actually fetch the list of available sources
apt source iproute2 to dump the source in the current directory.

New-style source packages will have a .dsc file which contains helpful information like the maintainer and git (or other VCS) repo location.


Laptop keyboard defective after updating Ubuntu 14.04

I solved my problem through Ubuntu Forums, and it was simple.

The Num Lock was activated, though I don't know how or why. I switched it off by holding down the Fn key (the one with only blue writing) then pressing F11 (labelled NumLk in blue).


How to Set Up Nginx Permission In /root Directory?

For a start it is a huge risk to run a server as root, better you create another system-user for your project using useradd -r -U -s /usr/bin/nologin http. This creates a new system-user called http and creates a http group.

You can then use chown -R :http /root/myproject/ to change the owning group to http.

If your nginx.conf contains the statement user http; you should be able to access the socket now.

Additionally I'd recommend creating and using a normal user account. If you need root access you can use su or sudo to execute as such.


So, my question is, what is the best way for me to have both Ubuntu and windows 10?

I suggest you to have windows installed and then use Live USB stick to install Ubuntu. After that, you are able to use grub to choose which operating system you want to use. I am not sure if it is the best way, but it is the easiest way, and it is what people usually do.

  However, I can't find the UEFI editor in Windows 10 at all.

In my opinion, it has to be somewhere it cannot just dissapear. But the question is - do you really need UEFI?


How to postition within magnetic tape in rescue mode of the installer image

As the tape devices /dev/st0 (rewinding tape drive) and /dev/nst0 (non-rewinding tape drive) are discovered, the following workaround worked for me:

dd if=/dev/st0 of=/dev/zero count=0

rewinds the tape (equals "mt -f /dev/st0 rewind").

dd if=/dev/nst0 of=/dev/zero [bs=<block size>]

"fast forwards" to the next file space (equals "mt -f /dev/nst0 fsf 1"). But be aware: I saw some "out of memory"-messages from the dd command when the tape was created with large "block size" (i used 1MiB) and the  was not specified. So you should generally know the "block size" when restoring from tapes in the installer environment.

dd if=/dev/[n]st0 [bs=<block size>] | tar [<tar options>] -f - [<file spec>]

Finally retrieves the data (the "-f -" tells tar to read from STDIN). Also here it is a very good idea to know the "block size" the tape was created with.


BQ Aquaris E5 -> Device MSM8916 not found

i've recently bought the same phone and had the same problem.

you originally posted an answer elsewhere, about this:
https://askubuntu.com/a/843977/381059
but unfortunately it is now gone.

unfortunately, and quite irrationally, like various other companies, BQ have actually released various products with the same name but with substantially different components inside.

as you can see there are two BQ phones which include the name 'aquaris E5' that have the same hardware:
http://www.devicespecifications.com/en/model/05f034d3
http://www.devicespecifications.com/en/model/741b30e5

but there are another two which include the name 'aquaris E5' with different hardware, the newer one especially so !
http://www.devicespecifications.com/en/model/a75230e6
http://www.devicespecifications.com/en/model/ad803119

for a full comparison of all of them:
http://www.devicespecifications.com/en/comparison/d2aca7254


Easier route:

Boot into a Windows repair disk or Windows installer disk.
Once you're booted, you should see a window where you can configure keyboard and language. If not, proceed to step 3.
[Installer Disk Only] It should prompt you to install Windows (Install Now button). Instead of proceeding, you should see "Repair computer" or something on the lower left corner of the window.
Go to Troubleshoot -> Advanced options -> Startup Repair (Windows 10) Or just select Startup Repair from the menu (Windows 7)
Let it do its thing while you cross your fingers.


Two separate HDD's or Intel RAID for dual boot

Arranging disks and partitions is always a bit tricky to advise on since if you ask 2 different persons you will probably get 2 different answers but in your case you can think about 3 basic scenarios:

Speed setup:

Wont make you coffee and eggs in the morning but putting the 2 disks on a RAID0 setup will give you a significant speed boost, looks very attractive an you can just partition the disks as you like like you said on your question;

Safe setup:

Have in one of the disks the 2 operative systems installed and use the 2nd disk as a share between Ubuntu and Windows to keep your personal files and backups. Disks that have less access tend to break down less (this is not a universal rule but tends to be true);

EXTRA safe setup:

Create a RAID1 setup where all you data will be stored equally on the 2 disks, if one fails the other will contain all you hard working projects and personal files;

Easy split setup:

Use one disk to install Windows and the other to install Ubuntu. Keeps your systems apart, gives you some security over the stability of your systems (if you break down Ubuntu or windows it wont interfere with the other and can be easy fixed by repairing the MBR) and when you get tired of using Windows and you finally decide to use only Ubuntu you can just erase it and use the 2nd disk for your backups and files ;)

Just pick one and go with it, if you have 2nd thoughts later on (you probably will!) you can just choose another and test it up. Personally I always go for safety but I don't like wasted space so I would choose the safe setup: keeps my data on a 2nd disk, allows me to share date between systems very easily.


What's the difference between root account and simulated roots?

There is no difference.  sudo changes your user id to root, without regard for whether or not the root account has a password.

The difference between sudo -s and sudo -i is whether or not the environment variables ( things like $HOME ) are kept at your current values ( so ~ still points to your home directory ) or are reset to the values root would get if he logged in normally.


Dual Boot vs Virtual Machine for programming?

What I have at work which I find most comfortable is to have a Windows 10 VM under Ubuntu in dual boot with Windows 10 having an Ubuntu VM.

What you do is:

Create your dual boot
boot into ubuntu,
install virtualbox
use virtualbox to load up the physical windows. (yes this requires a second screen to really take advantage of)

As you already have W10 with Ubuntu in a VM, don't change that!

This works like a charm and is the best of both worlds because if you ever need to you can reboot to the physical version of the Windows and while in Ubuntu mode you can have a single mouse and keyboard for both active systems plus a shared clipboard (and if you go crazy on the configuration, even a shared drag and drop between the two systems)

That's what I find most handy. I don't have to halt work on either system. I can just keep doing what I'm doing on both at the same time. and it takes no getting used to.


How to prevent empathy from asking keyring password on every start?

There are 2 3 ways:

Don't use auto-login (it's not like having to type a password and then waiting 5 seconds for the desktop to load is going to harm your productivity).
If you really want to use auto-login, change the password of your keyring(s) to be empty (but remember that that might expose your passwords for IM/mail accounts, WiFi networks, etc. to other people).
In case you are loging in with your password but still get that prompt, then most likely you have different passwords for your keyring & login.  Make them the same and the prompt should go away.

You can change the password through System -> Preferences -> Passwords and Keys (or something like that, I don't have an English GUI currently).


18.04 - How to disable temporary/privacy IPv6 addresses?

I had the same problem.
I first tried to disable ipv6 autoconf and accept_ra in sysctl.conf

# sysctl -p
net.ipv6.conf.all.autoconf = 0
net.ipv6.conf.all.accept_ra = 0
net.ipv6.conf.lan.autoconf = 0
net.ipv6.conf.lan.accept_ra = 0
net.ipv6.conf.wan.autoconf = 0
net.ipv6.conf.wan.accept_ra = 0

But that did not change anything.
Since netplan has some timing problems I disabled accept_ra in netplan yaml file.

/etc/netplan/50-cloud-init.yaml

addresses:
- xxx.xxx.xxx.xxx/24
- xxxx:xxxx:xxxx::xx/64
dhcp4: false
dhcp6: false
accept-ra: false


You haven't provided the most interesting fact, what is the make and model of your SSD? I've installed a lot of different SSDs in various systems but only one does make this type of problem, a OCZ Agility 2 with Sandforce controller. Your problem is very likely to be hardware related. One solution could be to update your SSD firmware, but this comes with the not so unlikely risk to lose all your data, that's why i haven't done it. If it's the same problem like my ssd has, than the used disk space should be normal after a reboot?


You could use dd(1) to copy the sd card.

$ dd if=/dev/mmcblk0 of=sdcarddata.img bs=4M

After that, you could map the image with losetup(8)

# losetup /dev/loop0 sdcarddata.img

Once you have done recovering and get your files out, unmap the image (make sure you unmount it first)

# losetup -d /dev/loop0


I got the same problem and I found this solution from https://github.com/odoo/odoo/issues/9113 by daniel-adb-fa, that worked fine and easy for me (I needed sudo because I was not logged as root):

Install odoo 9.0 from the nightly repo according to documentation.
Install the current versions of less and less-plugin-css via npm. This will install the versions to /usr/local/bin:

sudo npm install -g less less-plugin-clean-css
Install the symlink /usr/bin/node. This can be done manually, but you can also use an official apt-package for it:

sudo apt install nodejs-legacy
Now the link to lessc has to be patched to point to the version installed by npm instead of the (broken) distribution version:

sudo rm /usr/bin/lessc
 sudo ln -s /usr/local/bin/lessc /usr/bin/lessc
This should work, but an update of the distribution package might still break the patched link later. To avoid this, its possible to do:

sudo apt-mark hold node-less

Then I restarted odoo service with:

sudo service odoo-server start

and don't forget to clear your browser cache after that.

Good luck!


Try looking up how to access the Boot Menu for your PC. (It varies by Manufacturer) There is usually a key sequence that interrupts the boot process and allows you to select an OS. Common keys for this are "Esc" or F2


How to set custom display resolution normally

The resolution is not only a factor of your TV (whose details you didn't specify) but also of your graphics card and your module (aka "driver").  So if your TV supports a 1776x1000, but your graphics card (which you didn't specify neither) doesn't, it'll just "scale" to the nearest solution which seems to be 1920*1080.

Otherwise, you'll have to go down to 1280*720, which is a well-known resolution...  :-(

Look up the exact model number of both your TV and graphics card and if both do support 1776*1000 and it still looks like crap bad, you'll have to raise a bug report for your "driver" and wait patiently until the developers do something about it.

Also: some TVs automatically "zoom" (aka "overscan") the images they receive.  You might test by turning this feature off by using the TV settings menu with your remote control (look this up in the manual of your TV)


Press Ctrl-Alt-t, in the terminal type

gksudo gedit /etc/default/grub

press Enter and enter your password.

find the line that says

GRUB_DEFAULT=0

change 0 to a number that corresponds to the boot menu entry you want as default. First entry is 0, second is 1 etc..

You can also change the timeout value in the following line.

GRUB_TIMEOUT=10

If set to 0 you will not see the boot menu anymore.

When you're done, save and close the file.

Back in the terminal type:

sudo update-grub

enter password (there's no feedback when you type it in), press enter, reboot.

enjoy


MacBook Pro 5.5 compatibility issues with 12.10

I have a MacBook Pro 5,2 model, one of the last 17 inch models. A few months ago, I did a clean install of 12.04 (no OS X). I upgraded to 12.10 yesterday, and everything is going well. I did have to take about three days to get my install working perfectly. This is a good weekend project.

BACKUP

Make sure to do a complete backup of all of your data on a separate drive. I recommend a complete byte-for-byte drive copy. I cannot stress enough how important this step is. After a clean install, you will need to copy all of your files over to your Ubuntu install.

Programs

There were a few problems that I had to get through first, however. Heat wasn't exactly an issue, since your fans will make sure that your CPU doesn't melt. However, without a special program installed, your fans will always run at max RPM, which is quite annoying and unnecessary. You want this program to control your fans:
macfanctld - Fan control daemon for MacBook

You will also want to add this repo for mac-related stuff in Ubuntu:

sudo add-apt-repository ppa:mpodroid/mactel

Drivers

You also might have some problems with WiFi drivers. If you do an install, make sure you have (1) power and (2) wired ethernet. On 12.04 I had to custom install some Broadcom drivers for WiFi to work properly. However, in 12.10, Ubuntu's Install Drivers thing works for me (Software Sources -> Additional Drivers (tab)). Make sure to install the Broadcom Corporation wireless drivers.

You will also want to install the current Nvidia proprietary drivers.

Additional Stuff

I did a good deal of web searching during / immediately after my install. These are a collection of websites that I used when doing my install. They might not be applicable for your situation, but I recommend that you do a read through to become aquainted with what others have done.

http://maketecheasier.com/install-dual-boot-ubuntu-in-macbook-air/2012/08/27

http://blog.projectz.me/2012/10/21/setting-up-ubuntu-12-10-on-a-macbook-pro/

Good luck with everything. I know that I am 100% glad that I made the jump to Ubuntu full-time.


I can't find aircrack1.1 common mak directory

Your going to break your system eventually if you don't start checking if same package is in the default Ubuntu repositories before you download and compile it. To install aircrack-ng in all currently supported versions of Ubuntu open the terminal and type:

sudo apt install aircrack-ng


Bitnami Lamp on Ubuntu mysql command not working in terminal

Go to your lampp/mysql/bin using terminal
after that use this

./mysql -u root -p

hope this will help you..


May I change the notification of low battery?

This is really easy to do with the help of dconf-editor. If you do not already have it on your system, you can install it like this:
$ sudo apt update
$ sudo apt install dconf-editor

Once installed, you can access it like any desktop application.

You can also open it from the terminal by typing: dconf-editor.
Once open, go to: org > gnome > settings-daemon > plugins > power. Scroll down a bit until you see "percentage-low" You will see something like this:

Click on that and you will see the current system settings for the low-battery message:

Toggle "Use Default Value" off and change 10 to 25 (or any other number you would like to see). Then click "Apply":

That's all there is to it. No need to restart any services or reboot the machine. If you would like to change this back to the default value later, just return to dconf-editor and make the change.
Hope this gives you what you need.


How to setup high contrast theme in Lubuntu?

Lubuntu does not include a high contrast theme by default. But you can install one yourself by running sudo apt-get install gnome-accessibility-themes from your terminal. Once the software is installed, you can open Customize Look and Feel to switch to that theme.

There are three aspects: widget, icon, and window border. Unfortunately, the window border aspect isn't covered by the gnome-accessibility-themes package. However, the default window manager in Lubuntu, Openbox, is highly customizable and most of the visual aspects can be altered by editing a plain text file, .themerc located here: /usr/share/themes/openbox_theme_name/openbox-3/. If you need specific help with that you could always ask :)

Alternatively, you could look at various sites that offer window border themes. Box-look.org is one such site. And High Contrast BlackandWhite maybe of interest to you.

This Lubuntu page has a bit about accessibility concerns.

Widget:

Icon:

Window border -- High Contrast BlackandWhite:


Why am I being asked for an unknown username & password during startup?

Thanks for all the help guys.

Finally found a way around it by going into an earlier version of Ubuntu from the startup options page. I'm embarrassed to say that I was entering the username incorrectly. After all, you have to enter your password every time you login but how often do you have to enter your username.

Thanks again, i've removed the driver that caused all the problems in the first place.


Inter paragraph space in libreoffice-writer

That can be affected by both the style and and "direct formatting."  For example, you can apply a set style to all of your paragraphs, and then decide that one or two paragraphs need more or less spacing. To do that, you select the paragraph (or part of it) and the Format>Paragraph (or get to the same point using the right-click menu.)

This brings up the paragraph formatting menu, where you can change the before and after spacing. If you do this, your selected paragraph will have different spacing to the others, even though it has the same style applied.

TO fix this, select all the affected paragraphs (at once, or a few at a time) then Format>"Clear direct formatting." That will leave only the style.

Note that the line spacing is also specified in the style, and can also be overridden on a per-paragraph basis.


I had same problem with Geforce 210 and Nvidia driver v304.

Try this in terminal:

sudo apt-get purge nvidia-*
sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt-get update
sudo apt-get install nvidia-340

then reboot.


how to sync files in linux - command prompt?

sync command flush file system buffers. for more info about sync see

man sync

When you use gedit as a editor then gedit create these file. These files are backup file of your original file with name ~. you can disable this in preference setting of gedit.
change

To

and reduce Autosave time. next time it will not create backup file.


libexpat1-dev and libgtk2.0-dev (No package 'gtk+-2.0' found)

I'm seeing that you are using LinuxBrew to install stuff on Ubuntu.
It may be good for other stuff, but in the current case it leads to unpredictable and non-reproducible results.
So I would recommend to remove OPAM and OCaML which where installed using LinuxBrew and then install all the stuff using deb-packages from official repositories.
brew uninstall ocaml-findlib
brew uninstall ocaml
brew uninstall opam
brew uninstall gcc
brew uninstall gcc@5

rm -rf ~/.opam
sudo rm -v /usr/local/bin/opam

Then to install ProVerif we can follow PKGBUILD from ArchLinux.
sudo apt install -y graphviz ocaml-nox liblablgtk2-ocaml-dev

cd ~/Downloads
wget http://prosecco.gforge.inria.fr/personal/bblanche/proverif/proverif2.02pl1.tar.gz
tar -xf proverif2.02pl1.tar.gz
cd proverif2.02pl1/
./build

# optionally run tests
#./test all
#./test-type all

# and install binaries
sudo install -Dm755 proverif /usr/local/bin/proverif
sudo install -Dm755 proveriftotex /usr/local/bin/proveriftotex
sudo install -Dm755 proverif_interact /usr/local/bin/proverif_interact

And then call the executables from anywhere as proverif, proveriftotex or proverif_interact.


Error while installing libqt4-core on Ubuntu 16.04

Do this from the command line

uname -i

If x86_64 is listed you have 64 bit system otherwise i386, i586, i686 you have 32 bit system.

sudo apt-get update
dpkg --get-selections | grep -i qt

This lists the following on my system

appmenu-qt:amd64                install
appmenu-qt5                 install
libaccounts-qt5-1:amd64             install
libdbusmenu-qt2:amd64               install
libdbusmenu-qt5:amd64               install
libgsettings-qt1:amd64              install
libqt4-dbus:amd64               install
libqt4-dbus:i386                install
libqt4-declarative:amd64            install
libqt4-declarative:i386             install
libqt4-network:amd64                install
libqt4-network:i386             install
libqt4-opengl:i386              install
libqt4-script:amd64             install
libqt4-script:i386              install
libqt4-sql:amd64                install
libqt4-sql:i386                 install
libqt4-sql-mysql:i386               install
libqt4-sql-sqlite:amd64             install
libqt4-xml:amd64                install
libqt4-xml:i386                 install
libqt4-xmlpatterns:amd64            install
libqt4-xmlpatterns:i386             install
libqt5core5a:amd64              install
libqt5dbus5:amd64               install
libqt5feedback5:amd64               install
libqt5gui5:amd64                install
libqt5multimedia5:amd64             install
libqt5network5:amd64                install
libqt5opengl5:amd64             install
libqt5organizer5:amd64              install
libqt5positioning5:amd64            install
libqt5printsupport5:amd64           install
libqt5qml5:amd64                install
libqt5quick5:amd64              install
libqt5quicktest5:amd64              install
libqt5sql5:amd64                install
libqt5sql5-sqlite:amd64             install
libqt5svg5:amd64                install
libqt5test5:amd64               install
libqt5webkit5:amd64             install
libqt5widgets5:amd64                install
libqt5x11extras5:amd64              install
libqt5xml5:amd64                install
libqtcore4:amd64                install
libqtcore4:i386                 install
libqtdbus4:amd64                install
libqtdbus4:i386                 install
libqtgui4:amd64                 install
libqtgui4:i386                  install
libqtwebkit4:i386               install
libsignon-qt5-1:amd64               install
libunity-action-qt1:amd64           install
oxideqt-codecs-extra:amd64          install
qml-module-qt-labs-folderlistmodel:amd64    install
qml-module-qt-labs-settings:amd64       install
qml-module-qtfeedback:amd64         install
qml-module-qtgraphicaleffects:amd64     install
qml-module-qtquick-layouts:amd64        install
qml-module-qtquick-window2:amd64        install
qml-module-qtquick2:amd64           install
qml-module-qttest:amd64             install
qml-module-qtwebkit:amd64           install
qt-at-spi:amd64                 install
qt-at-spi:i386                  install
qtchooser                   install
qtcore4-l10n                    install
qtdeclarative5-accounts-plugin:amd64        install
qtdeclarative5-dev-tools            install
qtdeclarative5-qtquick2-plugin:amd64        install
qtdeclarative5-test-plugin:amd64        install
qtdeclarative5-ubuntu-ui-toolkit-plugin     install
qtdeclarative5-unity-action-plugin:amd64    install
qttranslations5-l10n                install
sni-qt:amd64

From this list the package that you want is

sudo apt-get install libqtcore4


It is not in the Ubuntu manpage for touch but the exit status for touch are:

0  The touch utility executed successfully and all requested changes were made.
>0 An error occurred. The touch utility returned the number of files for
which the times could not be successfully modified.

So the 1 is the amount of times touch failed to execute. Most likely you are not using the correct user or group to issue this command with so check user and group permissions of the file you are trying to modify with

ls -l /home/mythbuntu/test

If it is user:group mythtv:mythtv you need to add your user to group mythtv for touch to work.


Why do I get an error when I try to postmap sasl password file with postfix?

"You need to make sure that postfix user is able to read that file. You can post the output of sudo ls -l /etc/postfix/sasl_passwd.db to get more help."

And from the comments: "Change the owner of the config directory of postfix to postfix and it works."

Source


Why can't I access the virtual terminal tty1 under VMware Workstation?

Enter full-screen mode first with Ctrl+Alt+Enter
Click inside the Ubuntu VM (to make sure input is grabbed)
Then try entering tty1 with Ctrl+Alt+F1

Works great for me here.


Try sudo apt-get install isc-dhcp-client, which will install the dhcp client, though it won't explain why it wasn't installed to begin with.  This also presumes that your problem is a lack of said client.

If that doesn't work, you should look into using the tcpdump command on one of the interfaces and post back here with the results.  For example, sudo tcpdump -i eth0 -n should show you if there is any traffic passing over the eth0 interface, though you may need to correct for the right interface.

Since tcpdump didn't see any traffic, start the tcpcommand again, unplug your LAN connection, wait a couple seconds for the computer to realize you've unplugged it, then plug it back in and look at the tcpdump output.  There should be several DHCP request sent out by you're computer, and under ideal circumstances, responses to those queries as well.  If you don't see anything at all, then perhaps DHCP is request an address on the wrong port, maybe check DHCP configuration.  If after checking your DHCP configuration you're sure that DHCP is requesting an address on the correct port but that you're not seeing any traffic with tcpdump, check the logs for any errors related to DHCP or errors transmitting network traffic.  If nothing is obvious, post the logs here.

Beyond that, I don't know what else to do to diagnose this, perhaps your suspicions of faulty hardware were correct, or more unlikely, driver trouble.


You can Install VLC player from the Software Center, it plays virtually anything.


There does not appear to be a direct method to do this with Gimp but there is an acceptable work-around that may be enough for you. Use the following 3 steps:

1. Export the Image. First use the 'Export Image' as usual:

2. Set your preferred location. Next navigate to your preferred location and then use the '+' key at the bottom left of the screen to set this location permanently in the Gimp preferences. In my example here I am using ~/test:

3. Export your next image. Next time you Export an image you will see your desired location in an easily accessible, single click location:

Not perhaps a perfect solution but this will hopefully fulfil your needs...


xrandr --addmode doesn't add to the wanted output (DVI-I-0), instead adding to HDMI-0

Okay, so do you recall that I own a Samsung SyncMaster S24B300? One of the reasons it had very bad capability is because Linux doesn't take kindly to "generic pnp monitors" apparently. My copy of that monitor did not come with driver software, and Samsung is still very finicky about giving drivers for anything other than Windows.

Install the drivers for any new monitors as soon as you get them. This will make them compatible with all resolutions as long as they are compatible with Linux. I had to wait until six months later when I bought myself a BenQ monitor that came with the drivers that I could use it with Linux. During installation, I realized that I used a DVI-to-VGA converter, so it was a DVI signal being confused as a VGA signal if that means anything.

Basically what I'm saying is that I've been wasting your time because I didn't have the driver software for my monitor.

tl;dr this problem could have been nonexistent were it not for Samsung not knowing how to make drivers compatible with other operating systems.


Obtain passphrase programatically before intial login with ecryptfs?

I can't say for sure if the current implementation of the encrypted home set up scripts allow you to do what you're trying. Someone else will have to help you with that.

However, I do want to point out that your use of eCryptfs is a bit misguided. eCryptfs isn't really designed to provide a form of enhanced access control and relying on it to do that has some problems.

If a malicious user is trying to access another user's data and that user's encrypted home directory is mounted (implying that the encryption key is in the kernel key ring), then eCryptfs doesn't really provide anything more than regular DAC permissions. If the attacker can bypass DAC, he likely has some type of a kernel exploit and eCryptfs provides no protection if the encryption keys are already loaded into the kernel key ring at that point.

Note that there is some useful protection for the users who do not have their home directory mounted at the time of the attack, but you'll have to determine if it is more or less likely for your users to have their home directory mounted at any given time.

Also note that if you're planning on making backups of the encrypted data, you'll get benefits from the backups being encrypted on a per-user basis. Admins won't have an easy time accessing the data and you'll lose less sleep over misplaced tape drives.

I don't mean to discourage you against using eCryptfs, but I do want you to understand what you're getting in return for the added complexity and slight decrease in performance when using file encryption.


You can boot with a live-cd and then mount the partition of your instalation with

  sudo mount /dev/sda1 /mnt/

(/dev/sda1 ist an example you have to figure out where your instalation is)

Then you have to chroot in the mounted system with

  chroot /mnt

And with

  passwd

you can set a new password for the root user.

Remember to unmount the filesystem when you are done

  sudo umount /mnt


if else condition with Remote server directory Size

First I wold suggest you to use the command df to get the free space. Also you should provide a system path (for example /) or device name (for example /dev/sda1) to make the things simple. The output of the command df / executed on my VPS looks like:

$ ssh -n user@host "df /"
Filesystem     1K-blocks    Used Available Use% Mounted on
/dev/vda1       25671932 8335064  16009768  35% /

We need only the available space so we can filter the output by the help of awk (for example):

$ ssh -n user@host "df /" | awk 'NR > 1 {print $4; exit}'
16009768

Second use the same units as the output of the above command (1K-blocks) for the value of the variable $LIMIT: 1.5 TB = 1500000000 KB.

Third put the main logic into a function that will call itself recursively again and again after the sleep command. In addition the places of sleep and continue should be inverted, I think :)

According to the above the script could be something as this:

#!/bin/bash -e

LIMIT='1500000000'

# define the function
main() {
    SIZE="$(ssh -n user@host "df /" | awk 'NR > 1 {print $4; exit}')"

    if [[ $SIZE -gt $LIMIT ]]
    then
        echo 'continue'
    else
        echo 'Not enough space.'; sleep 4h
        # call the function
        main
    fi
}

# initial call of the function
main

According to the @danzel's comment instead of recursion we can use infinite while loop:

#!/bin/bash -e

LIMIT='1500000000'

while true
do
    SIZE="$(ssh -n user@host "df /" | awk 'NR > 1 {print $4; exit}')"

    if [[ $SIZE -gt $LIMIT ]]
    then
        # remove the exit command if you do not want to interupt the loop
        echo 'continue'; exit
    else
        echo 'Not enough space.'; sleep 4h
    fi
done


I think this issue is raised due  to DNS-related problem. You need to check the config file /etc/resolv.conf. It should contains entries like:

nameserver your.dns1.server.ip
nameserver your.dns2.server.ip

check if there is any thing strange in that..


How do I open C libraries and functions implementations?

If you are referring to the sys/msg.h header file specifically, then it should be provided by the libc6-dev development package

First make sure that the package is installed, either via the Software Center application or from a terminal using

sudo apt-get install libc6-dev

after which you should be able to browse the header file at

/usr/include/i386-linux-gnu/sys/msg.h

(for 32-bit systems) or

/usr/include/x86_64-linux-gnu/sys/msg.h

(for 64-bit systems).

To see the actual implementation of a library function, you will need to download the corresponding source code package: first, you will need to enable the relevant source repository (see How do I enable the source code repositories? if you don't know how to do that) and then, for example, in a directory of your choice

apt-get source libc6-dev

will download, unpack, and patch the source tarball into that directory (in this case, it will pick 'eglibc' as source package instead of 'libc6-dev'). However msgget and msgsnd appear to be only stub functions - I don't know enough about Linux IPC to advise you beyond that.


How to ignore Eclipse workspace .metadata folder in Ubuntu One?

There is a hidden configuration option, which you can add a list of Python (not shell) expressions to, for ignoring specific file extensions for example. In the ~/.config/ubuntuone/syncdaemon.conf file you can add the following:

[__main__]
ignore = \A.*\.metadata\Z

This should keep the .metadata folder from being synchronized. If the file already exists, and has an existing [__ main __] (without spaces) section, don't add another one.

You should stop ubuntuone-syncdaemon by running u1sdtool -q in a terminal, first. Then make your changes, and run u1sdtool -c to restart and connect the syncdaemon.


Unfortunately, protobuf3 cannot be acquired through apt-get until Ubuntu 16.10 (Yakkety Yak). So you'll either need to update to that version of Ubuntu first, or get the library from its git repository.

Following the instructions at https://github.com/google/protobuf/blob/master/src/README.md, either install a prebuilt from here https://github.com/google/protobuf/releases or build it yourself from the sources (if you may want to join in the development effort for the library itself).


No Sound - sound cards are not visible on Ubuntu 18.04

To help your troubleshooting ... I have that error as well on a functioning:

Ubuntu 18.04 (3)
Kernel 5.0.0-34-generic
Nvidia 440.XX "Open Source"

and it is not affecting the Laptop seemingly adversely.

I was curious about this error as well!  It says it is "Important", but again, the system is working fine.


I have downloaded 12.04 but I cannot install it. How to do it?

You must create image on CD, for example run NERO or other tool to create CD, that will be readed by bootloader. Check Your booting options.

But first of all when I trying to download Ubuntu 12.04 (Desktop or Server) from http://www.ubuntu.com/ it will download ISO file. Try this again, because Your Zip can be a WUBI for example, or other instalation option.


With Samsung TLC memory, I'd stick to 512k bucket size. This will align with the page size for every 3 buckets (usually you would match the other way around but there's no sane way to align 1.5MB with any bucket size = 2^n). Use a sector size of 4k. BTW: This assumes, Samsung TLC uses 1.5MB page size but this is not officially documented somewhere. But 512k is still a safe value also for 2MB page size because it would align every 4 buckets.

Also, please align your data offset with your RAID5 setup. The bcache docs give some hints for that. It's very important to get that right. Personally, I didn't yet try such a setup but I guess [sysfs]/bdev*/partial_stripes_expensive may also be interesting in RAID-5.

I'm also guessing that the slowdowns show up when the cache has filled. You should disable discard for the cache, it's a synchronous operation for many drives due to firmware bugs. Instead, remove the bcache cdev, trim the whole partition, then resize the partition to 80-90% of its original size, align it to a 2MB boundary, and recreate bcache. Then, never touch this free partition space, it allows the drive to do background wear-leveling, discard is no longer needed then. You could create a protective partition to reserve this space, this makes it also easy to trim the reserved space.

To recreate the cache device, detach it from the backing device via sysfs, wait for completion, then unregister it, follow the steps for recreating it correctly, then attach the backing device back to the new cache. This can all be done online without reboot. But if you're not comfortable with it, make backups first.


Why does Ubuntu or Linux for that matter mount hard disk partitions when they are opened?

I am going to add the answer as it is in Official wiki

  Data on a computer, as you may know, is stored in binary as a series of 1s and 0s. The way these are stored on a device and their structure is called the "filesystem". In Linux devices are referenced in /dev. Data is not actually stored on a device so you cannot access this data by going into /dev, this is because it is stored inside the filesystem on the device so you need to access these filesystems somehow. Accessing such filesystems is called "mounting" them, and in Linux (like any UNIX system) you can mount filesystems into any directory, that is, make the files stored in that filesystem accessible when you go into a certain directory. These directories are called the "mount points" of a filesystem. In other systems this is done differently. For example in Windows there is no distinction made between a device and the filesystem on it, and the user is restricted to mounting a device's filesystem in a top-level volume which is automatically assigned a letter such as C:, D:, etc. and the files inside these filesystems are accessed inside each volume's root such as "C:\", "D:\", "E:\", etc. (remember, Windows uses back slashes instead of the more common forward slashes you find in Linux)


There are two issues here. First, when you run ps | grep ..., the grep process is also shown in the output of ps. The default ps output includes the arguments a process was launched with, not only the process's name. This means that if you run grep foo, and there is a running process called foo, there will be two ps results matching foo: the foo process and the grep itself since it is searching for foo. This is why you get two lines when running ps -f | grep thunderbird.

Now, the [ ] is a regular expression construct which defines a list of characters, a character class. For example, [abc] will match a or b or c. When you run ps -f | grep [t]hunderbird, that class only contains a single character so is equivalent to thunderbird without the brackets. However, the grep process was launched with [t]hunderbird as an argument this time, and not thunderbird. Therefore, its line in the output of ps will contain [t]hunderbird. It will look like this:

terdon   23101 10991  0 16:53 pts/3    00:00:00 grep --color [t]hunderbird

This means that it is not matched when you run ps -f | grep thunderbird since it contains [t]hunderbird and not thunderbird.

This is a common trick to avoid matching the grep process itself when running ps | grep. Another alternative is to run ps -f | grep foo | grep -v grep to exclude the grep. The best approach, however, is to use a program specifically designed for this, pgrep:

$ pgrep -l thunderbird
11330 thunderbird


I found the config in /etc/NetworkManager/system-connections/ edited it with GEdit and restored the broken line

[802-3-ethernet]
duplex=full
mac-address=F0:DE:F1:XX:XX:XX

[connection]
id=Wired connection 1
uuid=5872a1e2-fe69-4158-aa49-844d309f91a8
type=802-3-ethernet
timestamp=1424948640

[ipv6]
method=auto

[ipv4]
method=auto

I restored the MAC address line to my original MAC (masked in the above listing) and it's working now.


You should go to Region & Language and add the Anthy or Mozc input method to the active input sources. Once done, you can switch to Anthy (or Mozc) and start typing Japanese characters.


Reported/Confirmed as Bug #1639180. I had the same problem and ended up manually installing Nvidia-304.131 Note that you have to first install the MTRR patch to the Nvidia .run file (fairly easy to do ... instructions and the patch file can be found on-line).


The sec=ntlm solves it for me:

... -o sec=ntlm,username=...

Learned from:

http://www.linuxquestions.org/questions/linux-networking-3/cifs-mount-error-5-%3D-input-output-error-but-smbfs-works-456897/#post5042181


An easy way/manipulation would be to install the extension more-columns-in-applications-view and edit the extension.js file to replace the function setNbColumns(setting) content with below content.
//------------------------------------------------------------------------------

function setNbColumns(setting) {

    if (!injections['_init']) {
        injections['_init'] = injectToFunction(AppDisplay.BaseAppView.prototype, '_init', function(){
            this._grid._minColumns = setting;
        });
    }

    let appdisplayView = Main.overview.viewSelector.appDisplay._views;
    for (let i = 0; i < appdisplayView.length; i++) {
        appdisplayView[i].view._grid._minColumns = setting;
    }

    let folderIconsList = Main.overview.viewSelector.appDisplay._views[1].view.folderIcons;
    if (folderIconsList) {
        // Old GS versions only
        folderIconsList.forEach(function(i){
            i.view._grid._minColumns = setting;
        });
    }

}

//------------------------------------------------------------------------------

Please note that if you have ideas to use this extension for its original purpose, you may not achieve what you are looking for. This is just a workaround targeted for the Question only.


It was a font issue, I changed the interface font and the problem was gone.


I have been trying out a few password managers.

Revelation can import gpass databases and even looks and works the same as gpass.

It is in the repositories in oneiric.

It imports gpass (otherwise known as Gnome Password Manager), passwords just fine (the user below's problems notwithstanding).  I just did it.

To import from gpass click File->Import.  Browse to your .gpass directory, pick your passwords.gps file, and pick 'Gpass 0.5x or newer' as the filetype. (It does not seem to automatically detect the filetype).  Enjoy.


Built-in display shown as prime display which cannot be controlled by nvidia-settings

There is a command for switching between Intel and NVIDIA graphics called vgaswitcheroo. See this wiki page for instructions to enable it.


How to show only the active desktop's applications in the taskbar? (Lubuntu 18.10)

Right click the taskbar, click 'Configure "Task manager"', and enable "Show only windows from desktop 'Current'".

(courtesy of marneu in #lubuntu)


The top bar in Ubuntu (Unity) is called the panel. Sometimes the menus are called the global menu bar, but not often.

As an aside, menus actually are implemented in applications. They just appear in the panel.


Racing

Bump Race - bumprace package

Super Tux Racer - supertux-stable package

SuperTuxKart

Armagetron http://armagetronad.org

Worms-like

Hedge Wars - hedgewars package

Warmux - warmux package

Slingshot

RPG

Battle for Wesnoth http://www.wesnoth.org/

Lordsawar - lordsawar package

Wings 2 http://www.wings2.net

Tetris-like

Block Attack - blockattack package

Platform games

JVGS (http://jvgs.sourceforge.net/) - not in repository

Fish Fillets (http://fillets.sourceforge.net/) - in repository

Sport

Neverputt

Emulators

Super Nintendo - zsnes package
Nintendo DS - desmumepackage
Nintendo 64 - mupen64plus package
Nintendo Wii - xwiimote package
PlayStation - pcsxr package
Atari 2600 - stella package


`error: invalid signature.` when trying to boot Ubuntu Core

Had the same issue.  This ended up working for me:
virt-install --connect qemu:///session --name core20 --memory 2048 --vcpus 2 \
--boot uefi --os-variant ubuntu20.04 --video virtio --graphics spice \
--import --disk path=core20.img,format=raw


Use:

alias noAgtw="find $HOME -name '[gtw]*' | wc -l"

or:

alias noAgtw='find '"$HOME"' -name "[gtw]*" | wc -l'

Looking at this new definition, I think you can figure that you misused simple quotes...

Also, never use a variable (as in your case $HOME is) inside single quotes. See why here:

What’s the Difference Between Single and Double Quotes in the Bash Shell?.


Up-to-date method to stream to Ubuntu from Terminal

Try this:

ffmpeg -f x11grab -video_size 1280x720 -framerate 60 -i :0.0 -f pulse -i default \
  -c:v libx264 -preset fast -b:v 4500k -bufsize 9000k -maxrate 5000k -g 120 \
  -pix_fmt yuv420p -c:a aac -b:a 128k -f flv "rtmp://foo/your_stream_key"

View the console output during the encoding process. If the output fps is lower than -framerate then decrease -framerate and/or use a faster -preset. Use the slowest -preset that still provides the desired output frame rate.
-b:v is roughly determined by -video_size. See Figure 3 in Recommended Encoding Settings for HTTP Live Streaming Media for some suggested bitrates (but do experiment and see what works best for you). -bufsize is determined by -b:v. In this example a 2 second buffer is used so -bufsize is 2x -b:v.
-g should be 2x -framerate.
If you get "The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it" then your ffmpeg is ancient and you should update instead of using -strict -2. The FFmpeg AAC encoder has been improved and is no longer considered experimental, but your version lacks these improvements. The easiest method to update is to download a recent ffmpeg binary and move it to /usr/local/bin (or ~/bin but you'll need to re-login or run source ~/.profile for it to work).

Also see:

x11grab video input device documentation
pulse audio input device documentation
FFmpeg Wiki: H.264
FFmpeg Wiki: Encoding for Streaming Sites
Capturing desktop audio with ffmpeg


Open a terminal and type the following command to fix the problem:

mkdir ~/Music

problem fixed.

It is possible you may have dragged the original Music directory into another directory so if there were any music files in that folder, just do a search for them and move them to ~/Music.


How to resolve package conflict with apt-get

Read the error message carefully, looking for the actual dpkg error.

Here's yours, which is likely to be different from most others that find this thread.

  dpkg: error processing archive
  /var/cache/apt/archives/kde-config-telepathy-accounts_4%3a15.12.3-0ubuntu1_amd64.deb
  (--unpack):  trying to overwrite
  '/usr/share/accounts/services/google-im.service', which is also in
  package account-plugin-google 0.12+16.04.20160126-0ubuntu1

Let's take that apart and restate it a bit more clearly:

  dpkg: error processing PACKAGE_A
  (--unpack):  trying to overwrite
  FILE_NAME, which is also in
  PACKAGE_B

Now can you see what the error message is trying to say?

Most files on your system can be provided by only one package at a time. When two packages try to provide the same file, they conflict. You cannot have both installed at the same time.

You fix the problem by deciding which package you want to keep, and uninstalling the other.


Possible that 2,3 week old os is infected? rkhunter, chkrootkit

rkhunter is good software, but you have to know how to use it.
rkhunter looks for indicators of compromise (IOCs).
An IOC is not proof that you have been compromised but, as the name says, just an indicator that it may be so.
Consequently, if rkhunter emits a warning you should investigate that and, if it turns out that what it found is in in fact legitimate on your system, update your rkhunter policy so that it knows not to complain about that again.
As an example, rkhunter looks for certain types of shared memory segments that are known to be used by malware to hide itself. But there are also legitimate uses of that type of shared memory segments, for example in database software. So if you run rkhunter on a database server for the first time it will warn about those shared memory segments. You investigate and find that they are legitimately used by your database, you add a statement to that effect to your rkhunter policy, and rkhunter will not warn about them anymore.


How can I get a Canon CanoScan 4400F Scanner working in Ubuntu?

According to Ubuntu Wiki the CanoScan 4400F is not recognized by xsane. listed as unsupported in sane-device-database.

https://wiki.ubuntu.com/HardwareSupportComponentsScannersCanon

There is one try at creating a driver:
http://sane.10972.n7.nabble.com/Canoscan-4400F-driver-update-td5319.html


Live USB doesnt recognize any bootable file on usb. Booting from usb gives disc error

check USB is bootable or not. if not then follows this step to make USB bootable .

Afterwards you can boot from the USB as if you booted from a CD and proceed to install Ubuntu on your hard disk.

more information visit here


Did they forget about the 'Restart' button, or was it just not important?

The restart button no longer shows up in that list. You need to select Shut Down.

In the confirmation box, it asks you if you want Restart, Cancel or Shut Down

Screenshots for better understanding


This installation is failing because lack of permissions.

creating /usr/local/lib/python2.7/dist-packages/buster
error: could not create '/usr/local/lib/python2.7/dist-packages/buster': Permission denied

Did you install it with sudo?:

  sudo pip install buster


You can use Gimp with swf plugin.

Download the plugin to your folder ~/.gimp-2.6/plug-ins and mark it as executable.

The install libjpeg62-dev libfreetype6-dev zlib1g-dev from repositories and swtools from here.

Or if you're lazy, just paste this on terminal:

sudo apt-get install gimp libjpeg62-dev libfreetype6-dev zlib1g-dev && cd ~/.gimp-2.6/plug-ins && wget -c http://files.myopera.com/area42/files/flash-swf-export.py && chmod +x ~/.gimp-2.6/plug-ins/flash-swf-export.py && cd ~/Downloads && wget -c http://www.swftools.org/swftools-0.9.1.tar.gz && tar -xf swftools-0.9.1.tar.gz && cd ~/Downloads/swftools-0.9.1/ && ./configure && make && sudo make install

The go to "File" > "Flash SWF Export"


Is my graphics card being used and if so why doesn't it show as VGA compatible controller?

You're running in "Hybrid" mode: both the NVidia and Intel controller are working!

00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 0b)
02:00.0 3D controller: NVIDIA Corporation GM108M [GeForce 840M] (rev a2)

So if the PC isn't doing any anti-aliasing or 3D work, only the Intel card is being used.  Once you start watching videos or gaming (not talking about Tetris, but about an advanced 3D-game) you'll see the NVidia Utilisation shoot up!

So: you're fine; perfect job!  Don't break anything!  Take a system backup...  ;-)

Some background info:
Here's the output of my computer lshw -c video when my BIOS graphics setting is set to IGD: (Integrated Graphics adapter)

*-display
   description: VGA compatible controller
   product: Mobile 4 Series Chipset Integrated Graphics Controller
   vendor: Intel Corporation
   physical id: 2
   bus info: pci@0000:00:02.0
   version: 07
   width: 64 bits
   clock: 33MHz
   capabilities: vga_controller bus_master cap_list rom
   configuration: driver=i915 latency=0
   resources: irq:44 memory:f4000000-f43fffff memory:d0000000-dfffffff ioport:1800(size=8)

and here after setting it to NVidia:

*-display
   description: VGA compatible controller
   product: G96M [GeForce 9600M GT]
   vendor: NVIDIA Corporation
   physical id: 0
   bus info: pci@0000:01:00.0
   version: a1
   width: 64 bits
   clock: 33MHz
   capabilities: vga_controller bus_master cap_list rom
   configuration: driver=nouveau latency=0
   resources: irq:46 memory:f2000000-f2ffffff memory:d0000000-dfffffff memory:f0000000-f1ffffff ioport:2000(size=128)

and lspci now gives:

01:00.0 VGA compatible controller: NVIDIA Corporation G96M [GeForce 9600M GT] (rev a1)

So it's pretty clear from your settings that both cards are both doing what they do best individually, depending on your demands...


Can I install Linux kernel in Ubuntu appart of the default one?

To install Linux Kernel 3.4 on Ubuntu (or Kubuntu, etc.) 12.04, you want to use a Ubuntu version of the kernel, not the generic Linux kernel. This avoids the generic kernel problems mentioned by Thomas Ward in his answer.

A stable version of Linux 3.4 has just been released and this version has important changes for btrfs, so many users of 12.04 LTS may be interested in this kernel.

For new changes and improvements in Kernel 3.4, you can refer to this page.

You can find the Ubuntu specific kernels at this page.

There are three ways you can potentially upgrade to Ubuntu-specific kernel 3.4:

First, you can download the Ubuntu 3.4 kernel deb packages and install them manually. See details below.
Second, you can change the apt sources list as explained here: http://www.upubuntu.com/2012/05/how-to-install-kernel-340-stable-on.html. I haven't tested this approach and I'm not recommending it.
Third, you can wait on an official backport of this kernel in a PPA or in -backports for 12.04 LTS. I don't have any further info on this option.

Here are more details on how to do the first option:

To use a new kernel as-is you only need to download and install the image.deb package that corresponds to your architecture; however if you need to build any external modules you also need the correct header.deb and source.deb packages.

You can find the Ubuntu kernels here: http://kernel.ubuntu.com/~kernel-ppa/mainline/

Ubuntu apparently released kernel 3.4 for Precise on 21-May-2012 09:41. See this link:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.4-precise/

Make sure you download the correct matching files (32bit or 64bit or PAE).

Open a terminal and move to the directory where you have downloaded the Ubuntu 3.4 kernel packages. If the files are in /Downloads directory then run the following command.

$ cd ~/Downloads/

Then use dpkg command to install the packages, for example, here I assume the 32-bit versions of the packages. Run the following commands one by one and type the password for sudo access when prompted.

For linux-headers (of the 3 files, this one is not architecture specific):

$ sudo dpkg -i linux-headers-3.4.0-030400_3.4.0-030400.201205210521_all.deb

For linux-headers-generic (is architecture specific):

$ sudo dpkg -i linux-headers-3.4.0-030400-generic_3.4.0-030400.201205210521_i386.deb

For linux-image-generic (is architecture specific):

$ sudo dpkg -i linux-image-3.4.0-030400-generic_3.4.0-030400.201205210521_i386.deb

If you see any warnings or errors while installing then try installing module-init-tools (latest version) first, and try again now it should work. Restart your system now; by default it will boot kernel 3.4. To check the kernel version after booting, open a terminal and type "uname -a".


Installing multiple bootable distros in multiple partitions of single usb drive?

There are a variety of multiboot methods on this page: How to create a bootable USB with multiple ISO images in it

I think the method using MULTI FULL INSTALL most fits your description:

It is reasonable to fully install multiple OS's to a flash drive, (or make a hybrid drive with Live, Persistent and Full installs mixed).

Full installs are more stable and secure than persistent installs, but not as quick to make. They are better at utilizing disk space as no fixed size casper-rw file or partition is required. They are not much use at installing an OS, for this booting an ISO works fine.

Using GParted create GPT partition table on large flash drive.
Make as many ext4 partitions as you have OS. Size should be about 8GB each or larger.
Boot Live drive in UEFI mode and insert large target drive.
At partitioning selected "Something else".
Choose sdc1 for /.
Install bootloader to root of the USB drive.
Leave all other partition's format boxes unchecked.
Install choosing encryption of home directory if desired, Full disk encryption does not work for me on flash drive.
Repeat this with sdc2, sdc3, etc, and the OS's you choose to install.
After the last install boot the flash drive and do an update-grub. This will add all the OS to grub.cfg

You can leave a partition for any ISO's you wish to Live boot or persistent boot, loop mount these using grub.cfg.


No internet connection without VPN Ubuntu 17.10

Today I had the same problem using the Private Internet Access(PIA) VPN. After a long time searching in Google for this problem, I found the solution.
Disconnect from VPN and use the following commands:

sudo rm /etc/resolv.conf
sudo ln -s /run/resolvconf/resolv.conf /etc/resolv.conf

You might need to reconnect your network in NetworkManager (or reboot) for it to work and resolvconf to update the config.

P.S.: I'm using Ubuntu 16.04 LTS and version v76 of PIA

Source: https://www.privateinternetaccess.com/forum/discussion/22079/can-no-longer-connect-to-internet-when-i-exit-pia-app-ubuntu-16-04


How to reload .XCompose without a reboot?

Restart the input method program you are running (in my case fcitx) using the following command:

pidof fcitx | xargs kill -9; fcitx

All changes are instantly activated. However, some applications may be need to be restarted.

Example: if you're running ibus, then replace fctix with ibus to restart, and it should work:

pidof ibus | xargs kill -9; ibus


boot problems on ubuntu13.04 recursive fault, timeout killing /sbin/modprobe ... etc

I exactly get the same errors on my PC. What I have to do is press F6 and enable the nomodeset option before booting.


Admin Account Missing after 'shutdown now' Exit

Restart machine
In grub menu choose advanced option
Select "recovery" item
In window menu choose "root"
Type: passwd user_name
reboot

Your grub menu is probably hidden - so you need to use keyboard (ESC) to see it :-)

You can also use live-cd distro to do this task.
mount your "/" partition (let say: /media/sda1), and use chroot /media/sda1. Then type passwd user_name and done.


You have to create a seperate partition for EFI and boot at the beginning of your disk. Let's say Assign 210Mb to efi partition and 500MB to boot partition.
On the installation windows installation type > chose something else. if there is no other OS installed select all the partitions and click on - sign and delete all your partitions one by one. and then press + type of the new partion primary, Location for the new partition: begining of this space > use as: EFI System partition assign 210Mb.
2:- click again on free space Type of the new Partition PrimaryLocation, Beginning of this space > Mount Point: /boot assign 500MB and okay.
3:- click again on free space and Location for the new partition Primary, Location Beginning of this space, Use as: EXT4, Mount Point: /. Finally Chose location for Device for boot loader installation: in my case it's /dev/sda2/ the same partition we have created for /boot. chose and install now.


Emacs opened in terminal on an Ubuntu server does not show colors

(You may have found the answer already, but this question comes up pretty high in search results, so I want to come back around and make sure it has an answer.)

This StackOverflow question has a pretty good answer. If you just need to make a one-off edit, you can use

$ TERM=xterm-256color emacs $filename

That's a lot of characters to foul up. For my own workflow, I've just set up a permanent alias using this guide from nixCraft.

Putting the two together, you can append alias colormacs='TERM=xterm-256color emacs' to ~/.bash_aliases (creating it if it isn't there already).

(I called mine 'colormacs' because I don't like overloading existing commands with aliases. You can call yours 'emacs' instead if you don't want to work against muscle memory.)

To load your new alias, run

$source ~/.bash_aliases

Then you can just

colormacs $fileName


It looks like it is not possible to make a casper-rw file greater than 4GB because of a limitation of FAT32, however, it is not difficult to make a casper-rw partition.

Note: You may want to backup your data before you start doing this, data can always be lost while partitioning, copying, etc.

This is outlined in Method 0 of https://wiki.ubuntu.com/LiveUsbPendrivePersistent

You'll have to make use another live USB in order to resize the partition. After you've booted into the other live USB,

Open gparted
Resize the FAT32 partition of the original USB drive to almost as small as it can be
Make a new ext4 partition named "casper-rw" (without the quotes)
Click "apply"

Now you just have to copy the data over

sudo dd if=/path/to/casper-rw of=/dev/sdX

Where sdX is the new partition you created (also add "status=progress" if you're impatient and want to see the progress like me)

After it's done copying, delete the original casper-rw file and it should be good to go.


os-prober fails to identify a linux system so I need to write a custom grub2 menu entry as a workaround, how?

Let me know if this works:

menuentry 'Arch Linux' {
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='(hd6,msdos1)'
    search --no-floppy --fs-uuid --set=root 34a39f15-f1a8-46a3-88e7-00c370c3c6a2
    linux   /boot/vmlinuz-linux root=UUID=670b0cf-a644-48d6-903d-dc3e49395a04
    initrd  /boot/initramfs-linux.img
}


Using a windows based program on Ubuntu called Groupmail 5?

You could try to run it under Wine. Install Wine from the Softwarecenter. Afterwards right click on your setup.exe file and select "install with wine" or something like that.

For better performance, if it doesn't work well: In the Wine preferences menu you can select which Windows version you want to simulate. There is also a software called "winetricks", with it you can install missing .dll files, fonts etc.
For further help you should consult the Wiki.

http://wiki.winehq.org/FrontPage

There is also a page where you can browse programs and their functionality under wine. Groupware wasn't listed, which means, that nobody has tested it.

http://appdb.winehq.org/index.php

If it doesn't work try virtualbox. Install it from the Softwarecenter, than install your windows inside and install your program inside windows. You can use it as a program window in Ubuntu. Try it, it is surprising.

Well, and there are some Alternatives. Best one would be, as there isn't a native alternative, to work with Thunderbird Add-Ons. Open Thunderbird - Tools - Addons to search for thousands of addons. Mail merge Addon for example enables thunderbird to send the same mail to thousands of directions. Use it with caution! Other addons improve Address books.


Is there a way to automate a dist-upgrade at boot time?

Thanks so much for taking the time to find and report bugs in Ubuntu. It helps quite a bit. As you mention, during the development cycle things move very quickly and bugs are fixed on a daily basis. What we usually advise people to do is search for duplicates first; check if someone has already reported the bug you're observing before committing to filing a new one.

That said, you could create an upstart job to do apt-get update; apt-get -y dist-upgrade on boot (that is, if you don't mind upgrades potentially breaking your VM and/or leaving it in an unbootable state).

Here's a quick upstart primer:

http://upstart.ubuntu.com/getting-started.html


Can't run ELF 32-bit on x86_x64 server even after adding i386

You're missing the 32 bit loader, which causes ldd to falsely claim the "not a dynamic executable", instead of the correct "wrong architecture" error.  The 32 bit ld is in package libc6-i386.  I'll file the bug on the ldd report, never got around to file it.


I am not able to install this software 'zekr' from .tar.gz file

Zekr version 1.0.0 is available in the Ubuntu repository. But, it is in multiverse section, so you need to enable multiverse repository first. See the below question to get help on enable multiverse repository:

How do I enable the "multiverse" repository?

After enabling multiverse, You can download and install Zekr on your PC. There is two way to install it:
Graphical way:

or clicking this icon

Zekr

Terminal way:
Open a terminal with CTRL+ALT+T and type these commands
sudo apt-get update
sudo apt-get install zekr

Note, first command is not required if you have updated your repository information recently.
I don't know the exact amount of change in Zekr version 1.1 from 1.0, but I think, installing 1.0 will suffice.
Hope this answer will help.


Odd error message from ftp connecting on port 22

You are getting a response from the SSH server, which listens on port 22.  FTP servers usually listen on port 21.


How to make an environment variable available for a python program using os.environ module?

In Ubuntu, you usually put it in .bashrc, because users usually use bash. If you've verified that it exists in the terminal, probably you forgot to export it. Without exporting it, it exists only in your current terminal, not in your python script nor any program you calls from the terminal.
This is an example python code named envi.py:
import os
print(os.environ['MYVAR'])

First, let's test it directly in terminal:
export MYVAR="my value"
python3 envi.py
# the output should be: my value

If you're satisfied with the result, you can then put export MYVAR="my value" in .bashrc, open a new terminal, and then run your python script.


Way to set a file as a Nautilus Bookmark?

Unfortunately I don't think this is possible. You definitely cannot add a file as a bookmark from the GUI.

Nautilus bookmarks are stored in ~/.gtk-bookmarks.  I tried manually adding a path to a text file to that file.  The text file showed up in the side pane in Nautilus, but clicking on it opened the folder containing the text file.


I had roughly the same problem (back in May/Jun), when I tried to install Ubuntu Touch 13.04 (beta) over a previous install of 13.04 'Core' (AKA 'Desktop') on a Nexus 7 (16GB).

The first attempt (using phablet-tools) failed to complete, and I could not get any useful status from adb.

I recovered by getting the tablet into fastboot visible mode, then re-flashing to stock Android. I don't remember exact steps, but its probably pasted into one of my Nexus 7 posts from that time period.

Will research further ..

UPDATE:

(adapted from Problem restoring android after trying Ubuntu on Nexus 7)

The various builds/firmwares for the Nexus 7 all require different modes to recover and/or re-flash.

Try different power-up states, to try to get to: 'fastboot' mode, 'recovery mode', and 'Ubuntu running'.

Each time wait, until the device is that mode, before inserting the USB cable.

You will see different results for:

sudo fastboot devices
adb devices
lsusb

With the device usually only responding to one variant at a time ..

Report on what (if any) status you can get ..


How to install zotac gt 210 graphics card driver in Ubuntu 13.04?

I've found that manual installs work best for installing nvidia drivers, so go to here and download the latest drivers.  By default, it'll most likely go into /Downloads, but if not, just know where it is.  (I've heard that this method MIGHT not work well with older cards (such as yours) but it's worth a shot.  Also unless you're having issues with nouveau drivers, I'd stick with them if this proprietary install doesn't work.)  Then, you'll want to press

  ctrl + alt +F1-F6 (each is a different login)

And then sign in to your account.  Then, you'll want to use

  sudo stop lightdm (or sudo service lightdm stop)

This shuts down the things that are using the GUI, so they can be updated.

Then run

chmod +x ~/* Folder that said driver is located in * / * Driver *

For example,

  chmod +x ~/Downloads/NVIDIA-Linux-x86_64-343.13.run

Make SURE that you have the entire name of the driver, otherwise this will not work!  Caps do matter!

What you just did was make the file executable.  Next, you'll want to run the following command, changed of course like the example above to fit your directories/driver versions.

  sudo sh ~/Downloads/NVIDIA-Linux-x86_64-343.13.run

For me, tabbing the rest of the NVIDIA-Linux-x86_64-343.13.run file does not work for me, but it is CRUCIAL THAT YOU DO THIS.  If nothing happens after you run the second command, check your caps and spelling to make sure they are right.  You have to go through the program using the keyboard to correctly install it.  For me it will tell me that something went wrong right on the bat, just keep going and see if it still works.  If it asks you to install 32 bit libraries, do so.  Some programs (like steam games) will not run unless you have these installed.

After all of the above has been done, one final command must be completed, or of course you could reboot.

  sudo start lightdm (or sudo service lightdm start)

Then, you'll do

  ctrl + alt+ F7-F9ish (F7 is usually default, some people have different F keys though)

This should have worked for most people, if not keep looking, there's always a fix.  If anyone knows something about getting virtual 7.1 audio to work, please message me somehow.  Thanks.  Hope I helped someone.

Edit:I've also heard x-swat repositories work better at times.  Not sure about that, but worth a try.

(Pro tip, whenever Nvidia related stuff goes wrong, watch this.)


How to install ubuntu 12.10 on windows Virtual PC?

Windows Virtual PC exists solely to emulate other (usually earlier) versions of Windows.

To run Ubuntu 12.10 on a virtual machine you should download VMware Player:

http://www.vmware.com/products/player/overview.html

Or Virtual Box:

https://www.virtualbox.org/


How to find another end of ssh connection

If you just want to find the host you have connected from, use w:

$ who -m --ips
terdon   pts/4        2015-06-08 20:02 123.456.78.9

To get the IP only:

$ who -m --ips | awk '{print $NF}'
123.456.78.9

So, to scp from that host, you could do:

scp user@$(who -m --ips | awk '{print $NF}'):/remote/path /target/path


how to install flash player on ubuntu 16.04 LTS

1.Enable ubuntu canonical partners repo

$ sudo add-apt-repository "deb http://archive.canonical.com/ $(lsb_release -sc) partner"

2.Update the repos :

$ sudo apt update

3.Install flash plugin

$ sudo apt install flashplugin-installer

Exit the Terminal.

IF browser is open, restart it. and navigate to the adobe site ->>
Adobe flash player

Check whether plugin is installed.

Run the adobe flash link, a prompt will be shown, click on allow and flash content will work :)

Thanks!


How do I install mutt 1.7.0 on Xenial or Trusty?

As one may expect, Jonathon Fernyhough has a PPA for version 1.7.0 of mutt for Ubuntu 16.04 (and 14.04 too) at https://launchpad.net/~jonathonf/+archive/ubuntu/backports:

sudo add-apt-repository ppa:jonathonf/backports
sudo apt-get update
sudo apt-get install mutt


Installed Ubuntu on a thumb drive with full disk encryption. Doesn't accept the pass when mounted on another install

I'm not sure but if the Linux system you are moving the thumb drive too isn't running gnome the key may not work automatically.

Ensure your 'other' desktop has the following packages.

sudo apt-get install cryptsetup

See http://www.howtogeek.com/115955/how-to-quickly-encrypt-removable-storage-devices-with-ubuntu/  for further info.

The official Ubuntu page is https://help.ubuntu.com/community/EncryptedFilesystemsOnRemovableStorage

Where you also need to install the gnome disk utility, if you are connecting with gnome.

Looking at the 'expert' section you can use

dmesg | tail -20

To confirm that the disk is being correctly recognised.

I would recommend reading the official help page if you continue to have problems. Otherwise post your dmesg output into your question, and drop a comment to this answer if you need more help.

Reading to the end of the help page if the username on the 'other' system is not the same as on your 'main' one you may need to ensure that the username and group of /media/disk is correctly set. See the very bottom of the Ubuntu help page for more info.

If your other system isn't runny gnome by default head to the Debian help page http://www.hermann-uwe.de/blog/howto-disk-encryption-with-dm-crypt-luks-and-debian which from a quick scan should be desktop agnostic. Note however it is more command line oriented, so you may need to 'be brave' and not panic.

As I say post a comment if yo get problems.
Dave.


As I can't use Unity (2D or 3D), is there any reason to use 11.04 over 10.04?

There are many new packages, so, in normal case I would say it's worth the change, but!

Since I installed 11.04, I have tons of problems, preventing me from work, so I am moving back to 10.10 in some days. Sure, it has some nice new features (my WiFi connects much faster, general little improvements, and so on), but Natty seems unfinished for me. (Don't forget, the Ubuntu Classic desktop, which is the old Gnome one, is buggy in 11.04.)


How can i change the top right corner display Name?

/etc/hostname and /etc/hosts contains your hostname (the computer name). The name next to the shutdown button is your username.

Changing your username just to get a different name displayed is not recommended. To make your actual name to be displayed instead of your username, open a Terminal and run:

gconftool -s /system/indicator/me/display --type int 2

(taken from fluteflute's answer)

To change your actual username (which defaults to your username), go to System -> Administration -> Users and Groups. Select your user and click the "Change..." button after your current name. Enter whatever you like and press OK to save it. You'll need to re-login to make the name change take effect.


Lubuntu 14.04 Software Updater behaviour

Open a terminal (Ctrl+Alt+T) and do

sudo do-release-upgrade
Or by using Update Manager

sudo update-manager -d
sudo apt-get update and upgrade is the command for software updating, not distribution upgrading. After these commands you should run sudo apt-get dist-upgrade

It will upgrade to Lubuntu, not Ubuntu (or so it should).


Yes! I am in fact typing this from a MBP 7.1 (where everything except for bluetooth works) :-)

There are comprehensive instructions on the help wiki.


What is the difference between sudo X and running X as root?

That's somewhat too broad to explain it will end with conclusion like in a link that you linked to your question, but I'll try something more fullfilled maybe it will give you some answers.

sudo ("substitute user do") allows a system administrator to delegate authority to give certain users (or groups of users) the ability to run some (or all) commands as root or another user while providing an audit trail of the commands and their arguments.

Sudo is an alternative to su for running commands as root. Unlike su, which launches a root shell that allows all further commands root access, sudo instead grants temporary privilege escalation to a single command. By enabling root privileges only when needed, sudo usage reduces the likelihood that a typo or a bug in an invoked command will ruin the system. Sudo can also be used to run commands as other users; additionally, sudo logs all commands and failed access attempts for security auditing.

More detailed info about Root Sudo can be found on Official Ubuntu Documentation


Error parsing PCC subspaces from PCCT: ACPI PCC probe failed

I had the same problem after installing Ubuntu 16.04 on the Lenovo w540 with preinstalled Win 8.1. It appeared that I didn't install Ubuntu with correct bootloader. The Windows was booting in UEFI mode while the Ubuntu in BIOS mode.So I've reinstalled Ubuntu, but this time I read:

official Ubuntu installation guide
http://www.rodsbooks.com/linux-uefi/ (got most from it)
and the thread 'UEFI Installing - Tips' on ubuntuforums

.

When I created a bootable USB key from the ISO image I made sure it will boot in UEFI mode = I used Rufus and chose 'GPR partition for UEFI' as a partition type for the bootable USB key (they say that there is a version of YUMI that support UEFI as well - didn't try it though )
In my BIOS settings I've disallowed booting other than UEFI to make sure my USB key will boot with UEFI (I did the opposite of https://neosmart.net/wiki/enable-legacy-boot-mode/).
The Ubuntu knew that it was booted from UEFI bootloader and it installed with UEFI bootloader as well.

The problem with the PCC parsing... didn't appear since then.

I don't know if it's relevant but I've installed Ubuntu on a separate drive with separate efi partition.In my BIOS settings I have now another entry on the boot order list: 'ubuntu'. It was placed by the Ubuntu installer on the first place so I moved it below the USB stuff but above the Windows Boot Manager so I can boot from USB key or choose from the GRUB2 boot menu which system to boot on each restart.


Let's try to make setup

Topology

|--------------------|
| home.something.com |--------------------------|
|--------------------|                          |
                                                |   |----------|
|----------------------------|                  |   |          |
| server1.home.something.com |------------------|---|  server  |-- internet
|----------------------------|                  |   |          |
                                                |   |----------|
|--------------------------------|              |
| workstation1.home.something.me |--------------|
|--------------------------------|

All tree servers have installed apache.
All tree servers listen for connection on port 80
All traffic go from internet

IP setting

- server
-- internet --
ip: 192.168.1.100
nm: 255.255.255.0
gw: 192.168.1.1
-- lan to home.something.com--
ip: 192.168.2.100
nm: 255.255.255.0
-- lan to server1.home.something.com
ip: 192.168.3.100
nm: 255.255.255.0
-- lan to workstation1.home.something.me
ip: 192.168.4.100
nm: 255.255.255.0

- home.something.com --
ip: 192.168.2.1
nm: 255.255.255.0
gw: 192.168.2.100

- server1.home.something.com
ip: 192.168.3.1
nm: 255.255.255.0
gw: 192.168.3.100

- workstation1.home.something.me
ip: 192.168.4.1
nm: 255.255.255.0
gw: 192.168.4.100

iptables setup on server

clear existing chains

sudo iptables --flush
sudo iptables --delete-chain

allow loopback

sudo iptables -A INPUT -i lo -j ACCEPT
sudo iptables -A OUTPUT -o lo -j ACCEPT

allow all ICMP

sudo iptables -A INPUT -p icmp --icmp-type any -j ACCEPT
sudo iptables -A OUTPUT -p icmp -j ACCEPT

allow established connections

sudo iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

HTTP

RDR access to home.something.com

sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -m string --string "Host: home.something.com" --algo bm -j DNAT --to-destination 192.168.2.1:80

then rule to traffic from 192.168.2.1 to internet

sudo iptables -t nat -A POSTROUTING -s 192.168.2.1 -j SNAT --to-source 192.168.1.100

RDR access to server1.home.something.com

sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -m string --string "Host: server1.home.something.com" --algo bm -j DNAT --to-destination 192.168.3.1:80

then rule to traffic from 192.168.3.1 to internet

sudo iptables -t nat -A POSTROUTING -s 192.168.3.1 -j SNAT --to-source 192.168.1.100

RDR access to workstation1.home.something.me

sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -m string --string "Host: workstation1.home.something.me" --algo bm -j DNAT --to-destination 192.168.3.1:80

then rule to traffic from 192.168.4.1 to internet

sudo iptables -t nat -A POSTROUTING -s 192.168.4.1 -j SNAT --to-source 192.168.1.100

SSH

sudo iptables -A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

allow forward

sudo iptables -P FORWARD ACCEPT

deny all accept above rules

sudo iptables -A INPUT -j DROP

default policies

sudo iptables -P INPUT DROP
sudo iptables -P OUTPUT ACCEPT

save

sudo service iptables save

And add rule

sudo echo "1" > /proc/sys/net/ipv4/ip_forward

I'm not sure that this will work, but you can try :)


Turn old boot disk into secondary drive without losing data

Unfortunately, that cant be done without backing up your data. Assuming you have a tower instead of a laptop get a 2TB HDD and back up your data.


Command to move a file to a directory even if the directory is not present

The traditional method would be
mkdir -p

will create all elements of the path that do not exist.
You can change it with && mv
Example:
mkdir -p /tmp/1/2/3/ && mv /tmp/file /tmp/1/2/3/

The /tmp/1/2/3/ can be a variable that you can reuse.
It can also be done with tar but then you need to make it with the directory structure already there. Untarring it elsewhere will create the paths that do not exist.
You can also use rsync. If the destination does not exist it will create it for you. Example
rsync -a --relative /new/dir/1/2/3/ /old/dir/

That last one seems to the best method to me. rsync is an amazing tool for transferring files. Local and remote.


Should I backup Windows files as well, while upgrading Ubuntu in a dual boot PC?

Using Ubuntu's release-upgrade feature will not touch unmounted drives. It also won't touch your Windows install on mounted drives. It won't delete your data stored in your /home directory. It often won't touch data stored in other places.

A backup of Windows files is not necessary...when everything works as expected.

We don't know your setup, or what customizations you have made that might prevent a release-upgrade from working as expected. In that rare case, a reinstall might be necessary. A reinstall DOES risk overwriting your Windows system if you mistakenly select the wrong option. Humans make lots of mistakes. Note that this is not a single-failure, but a chain-of-failures that results in data loss and a very bad day.

This is why we generally recommend a full backup of all storage before upgrading any OS on the machine. Ask yourself: "If my data were lost by one of these unlikely errors or mistakes, how much time and/or money would I be willing to expend to restore it?" Whatever that amount is, a backup is likely much cheaper.


How can I open another window of an application in Unity 2D e.g. another Terminal?

Ctr+Alt+T will open you a Terminal ( as much as you want)

Also check this wallpaper out, for hotkeys in unity:
What are Unity's keyboard and mouse shortcuts?

Don't know if they work in Unity 2D also, but i think so.


How to automatically launch bash shell when opening terminal or in console mode?

You probably need to set bash as your new users's login shell. If you are logged in as that user:

chsh -s /bin/bash

To change it for another user

sudo chsh -s /bin/bash username

In future you might want to use adduser instead of the low-level useradd, since it defaults to setting bash as the new login shell.

You can check the login shell (among other details) by looking at the /etc/passwd file or using

getent passwd username


Ubuntu 20.04 + recent software update + terminal, software updates, software updater not working

I kept trying while waiting for an answer and came across this post and the answer suggested to try installing the python3-minimal again. However, the individual commands failed in my case.

So, I tried the alternative route of downloading the python3-minimal*.deb to install it manually. I tried the following commands initially from my home dir initially and it gave permission error that _APT does not access to write in this directory. However, I changed to /tmp and executed the following and it installed python3-minimal. Now, I can see the software updater and gnome-terminal working fine again.

apt-get download python3-minimal
sudo dpkg -i *python3*.deb
sudo apt install -f


How to skip the "Is ready" notification and directly open apps in Ubuntu 20.4?

There are some Gnome extensions that do exactly that:

Window Is Ready - Notification Remover
Focus my window


old version of npm is installed on running apt-get install npm on Ubuntu 18.04

Here is a guide to installing newer version of NPM on Ubuntu 18.XX using a PPA:
https://www.digitalocean.com/community/tutorials/how-to-install-node-js-on-ubuntu-18-04
You can also use NodeSource:
https://linuxize.com/post/how-to-install-node-js-on-ubuntu-18.04/


-bash: No such file or directory when trying to run a .cc file in Ubuntu

It's C++, not C. Both C++ and C are compiled programming languages. You need a compiler (typically gcc) to generate executable binary code from C source code.
This is completely unlike scripts that have an interpreter that executes source code line by line (which is several orders of magnitude slower; something in the order of 1000 or 10000 times).
To compile a simple C++ program consisting of only a single source file, use
g++ -o driver driver.cc

In your simple case, you can even invoke make without creating a Makefile:
make driver

Now you can execute the newly created driver executable.
Caveat: You need build tools installed:
sudo apt install build-essential


No sound in mac os x guest in virtual machine

I also have Ubuntu 12.04 LTS with VMware Workstation 10.0.0 and a guest OS X Mountain Lion 10.8.5.

I managed to have sound installing inside VM:

EnsoniqAudioPCI_v1.0.3_Common_Installer.pkg

VMsvga2_v1.2.5_OS_10.6-10.8.pkg

ATT: Before you do this installation please consult those links below:

http://www.insanelymac.com/forum/topic/291227-osx-ml-10834-in-vmware-89-with-a-linux-host-no-audio-anyone-able-to-help/

http://blog.bryansmart.com/2012/02/16/low-latency-sound-for-vmware/

best regards.


touchpad stops moving after some period of properly working

I had the same problem, no touchpad motion but left and right click work, with 20.04 after perfect performance for years on 16.04!

Running 'xinput list' showed a PS/2 Generic Mouse device, that upon disabling (xinput disable id), would reproduce my issue.

It turns out I had both xserver-org-input-synaptics and xserver-org-input-libinput installed! I got rid of synaptics, and havn't had the issue since.


Samba bug, need help running a command at boot to fix it

Create another startup script that runs before the samba startup (lower number) that executes that mount command.  Or you can edit your existing samba startup script to add that mount command at the top, and then verifying its existence before proceeding on with the samba startup.


/etc/environment takes a proper re-login to take effect, because it is processed by PAM at login. Further, as @przemo noted, it is not run or sourced as a script, so variables are not expanded. Put such variables in a .sh file in /etc/profile.d/:

sudo tee -a /etc/profile.d/my_vars.sh <<"EOF"
export M2_HOME=/usr/local/apache-maven/apache-maven-3.1.1
export M2=$M2_HOME/bin
export PATH=$M2:$PATH
export JAVA_HOME=/usr/local/jdk1.6.0_45
export PATH=$JAVA_HOME:$PATH
EOF

This will also take a re-login to take full effect, but you can test it out immediately by running a login shell:

$ bash -l
$ echo $PATH
/usr/local/jdk1.6.0_45:/usr/local/apache-maven/apache-maven-3.1.1/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games

As Gunnar has pointed out, the default assignment to PATH should remain in /etc/environment, and shouldn't be added to the above script. See this community wiki page for more information.


Can Ubuntu phones charge is the United States?

Short answer = You'll be fine.

The phone itself wont matter when it comes to charging. It's the adapter you use with it that will determine if it's compatible in your region. If you buy a Ubuntu phone or smart phone in Europe it will come with the plugs designed for the voltage in that region. If you buy a Ubuntu phone or smart phone from a vender from the United States it will come with the adapters required to charge the phone.

The phone doesn't care what country you charge it in. Just as long as it's getting power in was designed to receive.

Sometimes smart phones will come with multiple plug adapters for people that travel around the world.


The cx-oracle easy installer is obviously broken. The best thing to do is to go to the developers/packagers and get them to create a debian package for installation on Debian and Ubuntu distributions. This will allow the package to be installed with the known properties of the system instead of guessing where things should be.

If in doubt, report it: https://help.ubuntu.com/community/ReportingBugs


PC automatically power off while watching videos on chrome

See to it that your system is not overheated. Usually overheated system automatically turn off.


Enable network for guest session in Lubuntu 12.04

In your regular user-account (one with sudo privileges) check if the connection you want to use is aviable for all users in the networkmanager

(click on Network symbol, edit connections, connection you want to use, edit, on the bottom of the window: check: aviable for all users(or likewise).

You may have to enter (sudo enabled) password.


What does Banshee need to recognize an audio book?

As far as I know, the only way to currently add audiobooks to Banshee's audiobook library is to first import them into your Music library, then drag them to the Audiobook section.  Dragging them from other sources (such as playlists) doesn't work yet, and Banshee doesn't yet do anything special with a genre set to 'audiobook'.


BlueJ installed editor window not opened

Same problem here. It seems that openjfx is not compatible with bluej and others apps. bug openjfx
So I installed the "generic version" of bluej and the recommended openjfx lib:
Install bluej:

Download the openjfx from gluon Unpack its "lib" dir to
/usr/shares/openjfx11 (or another name)
Start the installation of    bluej with java -jar path/to/bluej.jar
In the opened dialog set the correct jfx path as mentioned above..


How can I give admin permissions to my account?

Follow any of the procedures for resetting a forgotten password (or this, this, or this), but do not run:

passwd username

Instead, run:

usermod -a -G sudo username

Of course, username should be replaced with your actual username.

Note: if you are on Ubuntu 11.10 or an older release, the command to run is:

usermod -a -G admin username


Try pinging the website:

ping www.edx.org

If that doesn't work, try resolving the domain:

nslookup www.edx.org

If that doesn't work either, test if you have internet connectivity at all:

ping 8.8.8.8 # public Google DNS server

If all commands failed, you're apparently not connected to the internet.
If the all but the last command fail try changing your DNS server to Google's public DNS.
If only the first command fails continue diagnosing your problem using traceroute:

traceroute www.edx.org

Some tips on diagnosing connection problems: http://www.cyberciti.biz/tips/linux-network-diagnose-tools.html


How to (re)configure my internet connection? (DNS resolving failed)

Your current /etc/resolv.conf expects a local (stub) resolver, so check that the resolver is actually running: sudo netstat -unlp | grep :53 should report at least one line of the form

udp        0      0  127.0.0.1:53    0.0.0.0:*       776/named

If not, you may need to restart the bind9 service (sudo service bind9 restart) or to change the nameserver line in /etc/resolv.conf to point at a known-good resolver: either your router (probably 10.0.0.1 or 10.1.1.1 or 192.168.0.1), or one supplied by your ISP, or a public one such as Google's 8.8.8.8.


Ubuntu Stopped working due to removed packages that have been gone for months

Looks as if the problem magically fixed itself, after using this for the last few days the errors went away with no changes made and my desktop is back to normal. i have no idea why.


With the help of the "Ubuntu phone" community on Launchpad (see here), I was able to set my system proxy settings via the 'gsettings set' command (identically to the working settings on my Ubuntu 14.04 desktop systems):

gsettings set org.gnome.system.proxy use-same-proxy false
gsettings set org.gnome.system.proxy mode "'manual'"
gsettings set org.gnome.system.proxy ignore-hosts "['localhost', '127.0.0.0/8', '192.168.0.0/16', '::1']"
gsettings set org.gnome.system.proxy.ftp host "'192.168.112.1'"
gsettings set org.gnome.system.proxy.ftp port 800
gsettings set org.gnome.system.proxy.socks host "'192.168.112.1'"
gsettings set org.gnome.system.proxy.socks port 800
gsettings set org.gnome.system.proxy.http host "'192.168.112.1'"
gsettings set org.gnome.system.proxy.http port 800
gsettings set org.gnome.system.proxy.http use-authentication false
gsettings set org.gnome.system.proxy.http enabled true
gsettings set org.gnome.system.proxy.https host "'192.168.112.1'"
gsettings set org.gnome.system.proxy.https port 800

Those proxy settings are currently not used by the browser app through and I have requested this feature accordingly (see here).

Addition from 2015-05-07 (also documented here - sorry, I am not allowed to include another link, my reputation is too low):
I think I made the bowser app work with the proxy. I was actually trying
to enable command line apps like wget to work via proxy and added to
/etc/environment

http_proxy=http://192.168.112.1:800/
https_proxy=http://192.168.112.1:800/
ftp_proxy=http://192.168.112.1:800/
no_proxy="localhost,127.0.0.1,192.168.0.0/16"
HTTP_PROXY=http://192.168.112.1:800/
HTTPS_PROXY=http://192.168.112.1:800/
FTP_PROXY=http://192.168.112.1:800/
NO_PROXY="localhost,127.0.0.1,192.168.0.0/16"

After that, I was able to run wget for the first time successfully:

phablet@ubuntu-phablet:~$ wget www.spiegel.de
--2015-05-07 10:09:33--  http://www.spiegel.de/
Connecting to 192.168.112.1:800... connected.
Proxy request sent, awaiting response... 200 OK
Length: 233514 (228K) [text/html]
Saving to: ‘index.html’

100%[======================================>] 233,514      400KB/s   in 0.6s

2015-05-07 10:09:34 (400 KB/s) - ‘index.html’ saved [233514/233514]

By coincidence, I found out that the browser app also seems to pick this
configuration up successfully and the browser started to work with the
proxy.

I have now three different types of proxy configurations on my phone:

via gsettings, see my earlier e-mails - not sure if this has
currently an effect on any application
via /etc/environment for certain command line applications and
seemingly the browser
via 95proxies in /etc/apt/apt.conf.d/ for apt

I am now testing if other apps actually up one of those configuration
types. "Shorts" (the RSS app) for example seems not to work still.

Addition from 2015-05-07:
Syncevolution is seemingly picking up the proxy information from type 2) as well. Quite important for me as I am using it to sync calendar and contact data with an owncloud server.


How do I launch a bash script using a keyboard shortcut?

I have a keyboard shortcut to launch a script to start conky for me.

Now it sounds like you have tried to 'all the right things'. In the command section of keyboard shortcuts I have: /home/karl/bin/start-conky.sh

If you have cd ~/Downloads && ./bash-script.sh in that field have you tried changing it to: /home/username/Downloads/bash-script.sh?


Does Opera work with the global application menu?

As Far as I know there is no way currently to integrate Opera with the application menu in the meantime. I searched but I didn't reach to a solution.

Even I've tried using latest opera; Opera-next , but It doesn't have support to it.


The cause is reported in the log message above "ICRC", you should check cables first. It is the most likely culprit to the issue you are having.

The reply from Kingston sounds very strange, there is nothing that can get out-of-sync in there, the CRC errors are caused on the physical transport between the two SATA interfaces (disk and motherboard) and if they are out-of-sync the entire disk is lost and becomes unreadable.

After a few failures Linux will downgrade the speed to 3Gbps or disable NCQ, both of which will severely impact the performance but will also reduce the change to see the CRC errors as the lower speeds and lower IO rate will increase the chance to withstand low error rate.


Lost option to use KDE after an update - how to bring it back without losing configuration

Maybe some KDE package got removed?

Try sudo apt-get install kubuntu-desktop.


Why does my speaker make a high noise if I remove my headphones and microphone?

The noise happens after removing both headphones and external microphone, right?

Does your laptop have a built-in microphone? If so, the noise can be audio feedback from the built-in speakers into the built-in microphone.

If this is the case, try lowering the built-in microphone volume.


Simple text editor with margin notes possibility

LibreOffice Writer actually already has the feature you want. The marginal notes function in Writer is simple to use and doesn't require any creation of frames, resizing text, or changing the actual body of the document, so I should experiment with that again as it is ideal for annotating all types of document.

You place your cursor where you want the comment bubble to emerge from (see screenshot below) and either use Insert > Comment or press Ctrl+Alt+C and the comment bubble appears in the margin.

As you can see in the screenshot below, you can have multiple comments and you can use the feature with any other kind of document such as .txt, but you would have to save it as .odt to retain the notes. If using the .doc format, the margin notes will be saved successfully, but use of .odt is always recommended if possible.

If you want to prevent the comments from displaying go to view > comments and make sure comments is unchecked. When the cursor is inside a comment box in the margin, enter Ctrl+Alt+PgUp to move to the previous comment, and Ctrl+Alt+PgDown to move to the next one.

More information on the comment feature is available at the official site. Full documentation on LibreOffice and its programs such as Writer are available in pdf format from this site.

I am reluctant to recommend another text editor, because when LibreOffice is used with the special comment feature it should actually be what you need for normal plain text documents as well as office documents.