I use VirtualBox to run Win7 and other OS's.

My client only allows Windows and I just go to full screen mode in their office and they don't know any better.

At home I use the seamless mode to get back and fourth quickly


According to this related question, it appears that the overlay is only compatible with GTK applications, which unfortunately excludes Firefox, Chrome, LibreOffice and others.

In fact, the overlay-scrollbar testcase page specifically lists which applications are compatible.


By default, a virtual machine will be set up to NAT networking. This means that VirtualBox acts as a "virtual router" that allows the VM to access the internet, but will not allow external users to access the VM properly.

To do what you want, you need to set your VM up to use "bridged" networking. This way, on the host computer, an interface will be created that will be "bridged" to the VM's network interface. Thus, the VM will act, for all intents and purposes, as if it were hooked up to the same network as the host system (down to you needing to configure its IP address as you did for the host system).

Read here for the different VirtualBox networking modes and what each of them does. http://www.virtualbox.org/manual/ch06.html. Pay special attention to the section on "bridged networking".


6 month passed, and as there is no answer, I will try and explain what I've found out.
First off: It is working. It is perfectly fine to resolve DNS over one interface, and then send the actual request over another.
I cannot tell exactly what the problem was, but it was solved when I added a line with DNS = .... to the wireguard configuration, instead of setting the DNS on the wlan-device. Intuitively, that makes less sense to me, however it is working now and I am happy that it is! ;)


APT-GET behind a proxy with DIGEST Authentication

I am facing the same problem, my university use a proxy with digest authentication.
The only way around I have found so far is to use a tool like redsocks which can authenticate with your digest proxy, then you redirect your traffic (ex. with iptables) to the redsocks proxy which don't need authentication.

Step 1: Install redsocks

sudo apt install redsocks

but since you can't use apt in your company you will need to download the .deb file and install it using sudo apt deb xxxxx.deb

Step 2: Configure redsocks to use your proxy

Edit /etc/redsocks.conf and replace the following parameters in the redsocks section:

redsocks {
...
ip = <YOUR-PROXY-IP>;   // example: 10.12.1.77
port = <YOUR-PROXY-PORT>;  // example: 3128
...
type = <YOUR-PROXY-TYPE>; // example: http-connect
...
login = <YOUR-USERNAME>;   // the username for your proxy
password = <YOUR-PASWORD>;  // the password for your proxy
}

Step 3: Restart redsocks service to update configuration

sudo service redsocks restart

Step 4: Configure iptables

Save the following to a shell script so you don't have to type it every time:

#!/bin/bash
if [ -z $SUDO_COMMAND ]; then
    sudo $0 $*
    exit 0
fi

## Create new chain
iptables -t nat -N REDSOCKS

## Ignore LANs and some other reserved addresses.
## See http://en.wikipedia.org/wiki/Reserved_IP_addresses#Reserved_IPv4_addresses
## and http://tools.ietf.org/html/rfc5735 for full list of reserved networks.
iptables -t nat -A REDSOCKS -d 0.0.0.0/8 -j RETURN
iptables -t nat -A REDSOCKS -d 10.0.0.0/8 -j RETURN
iptables -t nat -A REDSOCKS -d 127.0.0.0/8 -j RETURN
iptables -t nat -A REDSOCKS -d 169.254.0.0/16 -j RETURN
iptables -t nat -A REDSOCKS -d 172.16.0.0/12 -j RETURN
iptables -t nat -A REDSOCKS -d 192.168.0.0/16 -j RETURN
iptables -t nat -A REDSOCKS -d 224.0.0.0/4 -j RETURN
iptables -t nat -A REDSOCKS -d 240.0.0.0/4 -j RETURN

## Anything else should be redirected to port 12345
iptables -t nat -A REDSOCKS -p tcp -j REDIRECT --to-ports 12345

iptables -t nat -A OUTPUT -p tcp -j REDSOCKS

execute the above script so the iptable rules are created.

Step 5: Have fun

Just start using apt-get

  See http://www.darkk.net.ru/redsocks/ or the redsock manual for more information.


Distro matters mainly for these reasons:

1) It will define the default (or lack of) GUI (e.g. Gnome, Xfce, KDE, Unity, Cinnamon etc)

2) It will define the default set of app software installed

3) It will define its package manager - the app that un/installs software

One option is to try some of the distros out in a virtual machine (VM) on your main machine, e.g. using VirtualBox which is free and which supports Linux in a VM on Windows (and vice versa).  Personally speaking, this would involve too much time and effort :-)

Have a look at distrowatch.com .  I would say the main contenders would be Mint, Ubuntu, Kubuntu or if you are of a techy disposition, Scientific Linux or CAE Linux.

In my opinion, having to choose a distro is one of the biggest barriers to using Linux :-) .  Once you have installed it once though, it's easy to trash it and do it again, so it's no biggy really.

Edit:  MadMike raised an important point about Long Term Support releases (LTS) - I too favour these as they give stability but provide bug fixes e.g. over several years.


Deleted old kernels, now can't boot from hard drive or live-usb

Usually there is a button to press when booting to show boot order and select where you want to boot from. Usually f8, f11 or f12. Have you tried that? Press it right when the motherboard logo is shown.

If you are able to boot into the live session then it's probably easy to fix with boot repair. There is a guide for installing it here.
It also explains the option of installing boot repair on a disk. Maybe you could try that?


How to copy settings from a live usb ubuntu

Since Ubuntu Live USB works fine on your computer, probably something went wrong behind the scenes during installation.

If what you mean by "big display problem", "no other desktop option", etc. is that you cannot have a usable desktop session, I think formatting the partition you've installed Ubuntu, and trying to install it again might be a better option than trying to overcome this system (display?) configuration problem in some way.


gnome-terminal use bright colors for bold

Short version: Please try TERM=xterm nethack, it'll most likely do the trick.

Long version:

Please try out and examine the output of the script from my answer at Print a 256-color test pattern in the terminal.

The attribute you're talking about (\e[1m) has a legacy confusion whether it means bold, bright, or both. With extended 256-color palette appearing in pretty much all terminal emulators, and subsequently true color support appearing in some (including gnome-terminal), the tendency is shifted towards  this attribute meaning bold. Obviously it's not intended to tamper with direct RGB colors, and it'd be problematic with the 256-color palette too (would there be a mapping among these indices, or would it result in out-of-palette colors?).

There are multiple ways to access the first 16 entries of the palette. The legacy escape sequences with the numbers 30–37 (foreground) and 40–47 (background) stand for the first 8. The foreground ones, if combined with the 1 (bold/bright) mode, still enable their bright counterparts for legacy compatibility reasons (e.g. for nethack to still look as it looked before... sigh).

The codes 90–97 (fg) and 100–107 (bg) stand for the next 8 palette entries which are the bright ones anyway.

The new 256-color palette escape sequences (38;5;0 – 38;5;255 for fg, 48;5;0 – 48;5;255 for bg) behave differently, though (following xterm's behavior): Here the 1 (bold/bright) attribute enables boldness only and does not change the color.

So, in your case, the difference is probably that your app used to emit the old-fashioned escape sequences, but now emits the new (256-color palette) ones which refer to the colors of the very same palette, the only difference is that mode 1 works differently: means bold only here rather than bold and bright.

This, in turn (walking backwards in the reasoning chain) is probably caused by the TERM environment variable defaulting to xterm-256color, rather than xterm as previously. Try reverting this variable and see how it effects your app.

Something that I don't understand without investigating (and will not investigate due to lack of time and interest): nethack seems to be using ncurses. ncurses does not allow the app to decide which kind of escape sequences to use, it only offers access to 256 colors, and it's ncurses's private business which escape sequence it uses for the first 16. In fact, as seen from the output of tput setaf and tput setab, in some weird syntax it encodes an if-else branch for the intervals 0–7, 8–15 and 16–255, that is, as far as I know, it is supposed to emit the legacy escape sequences for the first 16 colors, which in your case should mean that even with TERM=xterm-256color the behavior should not change compared to TERM=xterm. I'd let you further investigate from here given the input you received so far, e.g. use script to record nethack's output and examine with a text viewer to see which kinds of escape sequences it emits.


To add the new user, go into System -> Administration -> Users and Groups.
You can add a new account from here which you should definitely give limited permissions. I would set the account type to 'Desktop User'.

You can then click on 'Advanced Settings', click the 'User Privileges' tab and untick the following:

'Connect to the internet using a modem'
'Connect to wireless and ethernet networks'

This should disable the internet.

I don't think there is an easy way to not show the whole 'System' menu but you can disable menu items using alacarte by right clicking on the menu bar and clicking edit menus. As long as the new user account doesn't have administration privileges, they can't do any harm to the system through these menus anyway. She won't be able to do anything with the System -> Administration programs for instance. The worst thing she can do is completely mess up her theme and delete all her personal files but this will not affect the system as a whole.

Alternatively, if there is only a small number of programs you want her able to access, you could delete the menu applet from the top panel and add shortcuts to the desktop of the programs you want her to access.

See this question for other parental control options.

You may be interested in a program called GNOME Nanny although it is still under development and there are no stable releases.


Run sudo -H gedit /usr/share/X11/xorg.conf.d/90-libinput.conf

and add

Option "Tapping" "true"

to the end of the touchpad section of that file. Tapping is disabled in libinput in Ubuntu 16.04.

Save the file and reboot.


How to install pgAdmin 4 in desktop mode on Ubuntu

For pgAdmin 4 v4.21 on Ubuntu, according to the download page:

Install dependencies, create a virtual environment, download, install & configure

Using Python2.x

sudo apt-get install virtualenv python-pip libpq-dev python-dev

cd
virtualenv pgadmin4
cd pgadmin4
source bin/activate

pip install https://ftp.postgresql.org/pub/pgadmin/pgadmin4/v4.21/pip/pgadmin4-4.21-py2.py3-none-any.whl

Using Python3.6 (Preferred to avoid encoding related issues)

sudo apt-get install virtualenv python3-pip libpq-dev python3-dev

cd
virtualenv -p python3 pgadmin4
cd pgadmin4
source bin/activate

pip3 install https://ftp.postgresql.org/pub/pgadmin/pgadmin4/v4.21/pip/pgadmin4-4.21-py2.py3-none-any.whl

Configure

Override default paths and set it to single-user mode in the local configuration file:

nano lib/python2.7/site-packages/pgadmin4/config_local.py

For Python3.x:

nano lib/python3.6/site-packages/pgadmin4/config_local.py

Write:

import os
DATA_DIR = os.path.realpath(os.path.expanduser(u'~/.pgadmin/'))
LOG_FILE = os.path.join(DATA_DIR, 'pgadmin4.log')
SQLITE_PATH = os.path.join(DATA_DIR, 'pgadmin4.db')
SESSION_DB_PATH = os.path.join(DATA_DIR, 'sessions')
STORAGE_DIR = os.path.join(DATA_DIR, 'storage')
SERVER_MODE = False

Run

python lib/python2.7/site-packages/pgadmin4/pgAdmin4.py

For Python3.x:

python3 lib/python3.6/site-packages/pgadmin4/pgAdmin4.py

Access

Access at http://localhost:5050

Exit

Exit with Ctrl-C

Run again

cd ~/pgadmin4
source bin/activate
python lib/python2.7/site-packages/pgadmin4/pgAdmin4.py

For Python3.6

#!/bin/bash
cd ~/pgadmin4
source bin/activate
python3 lib/python3.6/site-packages/pgadmin4/pgAdmin4.py

Make a shortcut

touch ~/pgadmin4/pgadmin4
chmod +x ~/pgadmin4/pgadmin4
nano ~/pgadmin4/pgadmin4

Write:

#!/bin/bash
cd ~/pgadmin4
source bin/activate
python lib/python2.7/site-packages/pgadmin4/pgAdmin4.py

For Python3.6

#!/bin/bash
cd ~/pgadmin4
source bin/activate
python3 lib/python3.6/site-packages/pgadmin4/pgAdmin4.py

Now you can just run it with a simpler command:

~/pgadmin4/pgadmin4

Python3 users

Replace [x] in Python3.6 with your respective version.

Conflict with pgAdmin 3 configuration

pgAdmin 4 will not start in the environment where pgAdmin 3 was previously installed and used because of incompatible configuration in the .pgadmin directory. The simplest solution is to either clear that directory or tweak config_local.py to point to a clean new .pgadmin4 directory.


Kubuntu 14.04, K3B, burning group is missing / there's no burning group

Fixing the 'burning group' error:

I can confirm this issue with Ubuntu 14.04 and k3b run as either ordinary user or running with sudo k3b. The solution on my system was to manually create the group from the commandline before opening k3b, demonstrated on my system as follows:

andrew@corinth:~$ sudo addgroup burning
[sudo] password for andrew:
Adding group `burning' (GID 1001) ...
Done.
andrew@corinth:~$

After this add yourself to the new 'burning' group:

sudo usermod -a -G burning $USER

And then going to the k3b configuration screen:

k3b -->  Settings --> Setup System Permissions

and checking all of the following boxes:

Use burning group: burning (this should work now)
Devices: (Select the device you wish to use)
External Programs: Found Programs (select the applications you wish to use)

Press 'Apply' and all should now be well :).

Further Error Messages?

If however you managed to create the required group but continue to get odd burning problems and errors consider adding Brandon Snider's CDRTools PPA:

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

And then installing Jörg Schilling's cdrtools and friends (this will safely replace the Debian fork burning tools):

sudo apt-get install cdda2wav cdrecord mkisofs

And finally returning to:

k3b -->  Settings --> Setup System Permissions

to setup the new applications with the appropriate permissions.

Another few things to try if problems persist:

Try a different brand of disk and if using DVD -R try DVD +R and the reverse.
Experiment with turning Nautilus 'auto-mount' off and on. The k3b FAQs implicate auto-mount in a variety of errors when burning.

Finally here is a screenshot showing the final settings on my own system:


Auto-click the mouse while specific keyboard button is held down

Here's my first and fifth attempts. The first is decent if you don't need to change the delay. It seems to have some problems with certain key combinations, not sure what was causing it however.

Method 1, in ~/.xbindkeysrc:

keystate_scrolllock = enable

"xdotool click 1"
    Scroll_Lock

Method 5:

keystate_scrolllock = enable

"/home/USER/infinite_clicks.sh event16 KEY_SCROLLLOCK 0.1 &"
    Scroll_Lock

With infinite_clicks.sh being:

#!/bin/bash
kbd=$1 #"event16"
key=$2 #"KEY_SCROLLLOCK"
delay=$3 #"0.1"
fn=`basename "$0"`

if [  $# -le 1 ]; then
    echo "Usage: $fn input_device key_name delay"
    echo "Example: $fn event16 KEY_SCROLLLOCK 0.1"
    echo "Must run as superuser."
    exit 1
fi

# do not start if already started
if [[ $(pidof -o %PPID -x $fn) ]]; then
    exit 0
fi

while true; do
    # this is why you need to use sudo/superuser
    evtest --query  /dev/input/$kbd EV_KEY $key

    # get evtest return code, if it's 0 the key is up
    if [[ "$?" -eq "0" ]]; then
      break
    fi

    xdotool click 1 &
    sleep "$delay"
done

exit 0

With this code you also need to run xbindkeys as sudo xbindkeys -f ~/.xbindkeysrc

You can find your keyboard event number using sudo evtest then find the key names using sudo evtest /dev/input/eventXXX using the event number.


How can gnome based applications such as rhythmbox use a proxy

Some of the newer GTK3 based gnome-applications ignore/don't use environment variables when dealing with proxies.
Instead, they use values stored in gsettings / dconf
If you use dconf-editor installed as part of the dconf-tools package you can define the proxy in a GUI manner.
First - set the proxy mode to manual as shown

Second - set the proxy host & port.  If you dont have an anonymous proxy you need to set the authentication-password and authentication-user values

If your corporate network uses https then set the equivalent system - proxy - https tree values instead of system - proxy - http that is shown above.
Via the terminal you can use the following:
gsettings set org.gnome.system.proxy mode 'manual'
gsettings set org.gnome.system.proxy.http host 'proxy.askubuntu.com'
gsettings set org.gnome.system.proxy.http port 8080
gsettings set org.gnome.system.proxy.http authentication-user '[host]\[username]'
gsettings set org.gnome.system.proxy.http authentication-password 'mypassword'

Where [host]\[username] corresponds to your corporate network credentials e.g. mywindowsdomain\fossfreedom
If your corporate network uses https then substitute http with https in the above terminal commands.


How do I remove the 'Write the Changes to the Disks?' question during preseed?

It may be a bug of Ubuntu, see:

https://serverfault.com/questions/415174/debian-6-preseeding-keeps-asking-write-the-changes-to-disks-and-configure-lvm

The one required for Ubuntu that appears to be forgotten sometimes is:

d-i partman-lvm/confirm_nooverwrite boolean true


Easy quick way to Migrate LAMP settings and Ubuntu Users from old Ubuntu 19.04 to new fresh copy of Ubuntu 20.4?

Home directories - copy /home folders, but remember to keep ownership & permissions (tar/untar should do the job)
Users - copy lines with uids >= 1000 in /etc/passwd and /etc/shadow files. Also copy user groups in /etc/group and /etc/gshadow.
Mysql databases - the canonical method is to make mysqldump of the old databases and import the dumps into the new instance. You may also need to copy MySQL settings, if there's something non-default there (/etc/mysql directory)
PHP and Apache settings - copy /etc/apache2 and /etc/php directories to the new server
What else? Depends on what other services you run on the server, you need to copy settings for these  too.


Installing Ubuntu 11.10 x64 alongside Windows 7 x64 doesn't boot into Ubuntu

This question has come up in past threads on this site.  Below is a link to help resolve your problem.  It requires booting from an Ubuntu live cd to be able to re-install GRUB in the master boot record.  Process is explained in detail

Recovering GRUB after installing Windows 7?


Ubuntu 14.04 upgrade - Stopped halfway though

How do you know the upgrade didn't complete? If the upgrade didn't complete then you would be getting many errors from apt-get about unresolved dependencies. The fact that you can boot and it says there are no updates suggests that you upgrade actually completed...

Try apt-get update && apt-get dist-upgrade from a terminal. It will show you which packages still need updating.


launchpad build fails, but pbuilder works

This is probably not the proper solution but it works, sort of. Adding explicit depends on the install target in binary makes the trick. However, the install target is part of the sequence, so this is some kind of abomination. And, it's not required in pbuilder.

-override_dh_auto_install:
+override_dh_auto_install: debian/tmp/etc/lirc/lircd.conf
+debian/tmp/etc/lirc/lircd.conf:
     dh_testdir
     dh_testroot
@@ -46,5 +47,5 @@

# Build architecture-independent files here.
-binary-indep:
+binary-indep: debian/tmp/etc/lirc/lircd.conf
# Use system library instead of bundled jquery.js (symlinked below).
echo INSTALL TREE
@@ -67,6 +68,8 @@

 # Build architecture-dependent files here.
-binary-arch:
+binary-arch: debian/tmp/etc/lirc/lircd.conf
    echo PWD: $$PWD
+   echo INSTALL TREE
+   tree -L 4 debian


During installation of Ubuntu there are few options:

You can choose "Something else":

and here choose disks of your Mint to format and set as / and /home or whatever partition you want for Ubuntu. Grub will be edited automatically, and Windows should stay in.


Are all "Important security updates", updates to already installed packages?

Yes, Ubuntu only installs updates for stuff installed on your system. But if you don't trust what Ubuntu is telling you, why trust me? If you want evidence, install ubuntu once with only the default packages, then again with every single package installed. You should be able to do a number of comparisons that will quench your thirst for empirical data.

Ubuntu by default includes tons of drivers for things that aren't currently attached to your system. The extremely common case is that right now I don't have device X plugged into my computer, but I might later, and I'll be pissed if Ubuntu doesn't just work even though it could, especially at the cost of a few kilobytes or megs. (and for more people than you might think, downloading drivers on demand is impossible. we need a working system all the time, not just when connected to the internet)

Ubuntu is not a good distro if you want extremely fine grained control over everything. You might be better off with LFS, slackware, or arch linux


If you are root, a permission error can happen when another process opened that file. You can check it with fuser, e.g.

sudo fuser -a /var/lib/dpkg/lock


Remove it from the case and use normal connectors to try to access the drive: it might be just a data channel cable that was broken during the fall.

If you remove the drive from the case you will find yourself 99.9% of the cases with a perfectly normal hard disk that can be plugged in to a computer and accessed as a normal drive. If plugging it in to the computer as a normal drive gives you the same results (disk is visible but seems that there is no access to it) then I would start to be worried about your data.

If plugging it in to the computer works then I would say its just a matter of buying a extra hard disk USB case and installing the drive back.


Will upgrading Windows 7 to 8 affect Ubuntu installation (dual-boot)?

You can upgrade Windows from 7 to 8. I did it and it did not effect my Ubuntu Installation in any way.

If in-case you loose the Ubuntu boot option ( Grub is replaced with windows boot loader ), Then to fix this issue you will only need to Boot your computer with a live Ubuntu USB stick And run this command in the terminal

update-grub

I would recommend you to update From 12.04 to 12.10 Cos of cool new features and much improved look, feel, speed and Performance. :)


web browsing vs. torrent traffic, and bandwidth priority?

As the comment above suggested, you will need Traffic Shaping. One of the most known program is Wonder Shaper. However I would recommend Trickle, because this software is more userfriendly.

Trickle runs in userspace and uses LD_PRELOAD to inject some own networking libraries. You can install it using apt-get install trickle (or any other tool you like). Normally you would use Trickle like:

trickle -d 1234 -u 567 my_software

Where -d is the download rate (1234 KB/s in the above example), -u upload rate (567 KB/s) and my_software is any software like Firefox, BitTorrent or else.

In your case it makes more sense to use trickled with an own trickled.conf. This configuration file should look like the following example:

[bittorrent]
Priority = 8
[www]
Priority = 1

So WWW has the highest priority, while BitTorrent gets the lowest. So Trickle will make sure, that browsing is always possible. Further details in setting up Trickle are in trickled.conf(5) and trickled(8).


Trying to install amd radeon hd 7450 driver on Ubuntu 12.04?

This is more a suggestion than an answer;

There is a known bug in Ubuntu 12.04 release (LTS) where your graphical driver is listed as "unknown" ( Visit system settings / Details / Graphics ).

I had the problem with my AMD Radeon graphic card on 12.04 and I couldn't get any proprietary drivers to work. Switching to Ubuntu 13.10 solved the problem.

I suggest you try clean installation with new Ubuntu (burn 13.10 ISO image on a DVD and reinstall).


Trying to remove Windows XP OS without DVD drive nor USB booting ability

What have you been smoking? ;-) You are making your life way too difficult: Just install gParted in Ubuntu and you can remove any partition that is not mounted. That, ofcourse, includes your XP partition. From gParted you can also merge the removed partition into your current one or create a separate partition for Ubuntu.

Only if you want to delete the primairy operating system do you need your dvd/usb installer.

gParted

After installation it will be included in the launcher. Click it and you'll get an overview of all your discs, partitions on those discs (and labels identifying those partitions). Mark the XP partition for deleting or for formating to ext4 if you want to include it into Ubuntu.

You can identify Windows partitions due to them having NTFS (or older: FAT) as a filesystem but do take care not deleting any directory that holds personal data if there is a 2nd Windows partition (Ubuntu will mount such partitions so you can extract the data from it to your Ubuntu)


Compiled wireshark 1.10.0 presents an uncomplete interface in ubuntu 12.04

Fixed the problem by unselect the 'save window size' option in Preferences->User Interface.
Still have no idea why this happen and I'm considering to report a bug to the Wireshark team.


Cannot find "/usr/bin/deluge" but can open Deluge Ubuntu 16.04

Use the following command to help you find the right executable:

sudo find / -iname \*deluge\*

Then you should be able to find the correct executable from the "Choose" box.


Add a call to the wait command after you halt vagrant. Something like this,

# Shutdown vagrant
vagrant halt
# wait for the halt
wait


How to minimize open windows by a click?

Open the System Settings program, go to Appearance, go to the Behavior tab, and click on Add show desktop icon to the launcher.

Show Desktop will then be added to the dash. Clicking on it will hide all windows. Clicking on it again will unhide them.


How to retrive data on a internal harddisk that is partially broken

To check the file system on your Ubuntu partition...

boot to the GRUB menu
choose Advanced Options
choose Recovery mode
choose Root access
at the # prompt, type sudo fsck -f /
repeat the fsck command if there were errors
type reboot

If for some reason you can't do the above...

boot to a Ubuntu Live DVD/USB
open a terminal window
type sudo fdisk -l
identify the /dev/XXXX device name for your "Linux Filesystem"
type sudo fsck -f /dev/XXXX # replacing XXXX with the number you found earlier
repeat the fsck command if there were errors
type reboot

Update #1:

To retrieve any data you'll need:

Ubuntu Live DVD/USB
some external destination to store your data

Then...

boot to the Ubuntu Live DVD/USB
open a Files window
open a second new Files window showing your external storage
single-click on your hard disk in the left window pane to mount it
find your Home folder in the right window pane
drag any important files from your Home folder to the second Files window


Create a quickly app with build dependencies

The good thing is that Quickly will handle this for you, so you don't have to worry about it at all :)

Once you've added the import statement to add Twisted in your code, the next time you run the quickly package (or share or release or submitubuntu), Quickly will automatically detect that you're using it and will add it to the dependencies in the debian/control file in your source tree.

This will take care of your package pulling in python-twisted as a dependency whenever it is installed.

In addition to that, if you really need additional dependencies that you don't use directly in the code, you can use the quickly configure dependencies command and add a comma-separated list of extra dependencies to the text editor that's then fired up. Quickly will then always add those dependencies to the package. Be sure to know what you're doing if you're using that command.


Help setting up reverse lookup with BIND9

rev.1.168.192.in-addr.arpa:

$TTL 86400
@           IN    SOA    group2.lab.  root (
              2009031001 ; serial
          28800 ; refresh
          14400 ; retry
          3600000 ; expire
          86400 ; ttl
          )
        IN    NS    192.168.1.3.
1           IN    PTR   ns1.group2.lab.

should be:

$TTL 86400
@           IN    SOA    group2.lab.  root (
              2009031001 ; serial
          28800 ; refresh
          14400 ; retry
          3600000 ; expire
          86400 ; ttl
          )
        IN    NS    192.168.1.3.
3           IN    PTR   ns1.group2.lab.

Thanks for at least taking a look guys, after spending countless hours/days on this, I figured it out...the 1 should've been a 3 :).


Ubuntu 12.10 is increasingly slower until compiz is restarted through change in ccsm

I reinstalled my computer with 12.4 instead hoping that the LTS would solve my problems. And it did, it's been working for over two five eight hours and still feels quick and snappy.


Its really easy to do that !
Just right click on the desktop and select change background image from the menu.
Then a window will open up.There you will see a simple option to change themes. The name of your current theme is Radiance, Change it to Ambience to get a whitish bright new theme for your title bars.
If you want to customize it more than this, Then you might need Unity Tweak
You can understand everything on how to customize ubuntu anyway you want in this link : Click here
To install Unity Tweak software, Then just follow these simple steps:
Type/paste this code in Terminal(Ctrl+Alt+T)

sudo apt-get update && sudo apt-get install unity-tweak-tool

That's all !
Its easy  !


If I follow instructions from a blog or Ask Ubuntu, etc, is it always safe?

TL;DR No, you are not 100% safe. Or with other words, think twice. ;)

Don't execute code snippets without understanding the basics. Use man to learn more about a command or a program. Use Google or an other search portal if you don't understand. And if you still doubt, simply do not execute the code.

Do you trust me? Then run:

man man

Ok, not dangerous, you see the man-page of man

But what about the code below, do you trust me?

$(perl -MMIME::Base64 -0777ne 'print decode_base64($_)' <<< "ZWNobyAnQk9PSCEnCg==")

Not? Good idea. Let's breakdown the code:

perl

The Perl language interpreter
-MMIME::Base64

Encoding and decoding of base64 strings
-0777ne

-0777 - Changes the line separator to undef, letting us to slurp the file, feeding all the lines to Perl in one go.

-e - (execute) flag is what allows us to specify the Perl code we want to run right on the command line.

-n - Feed the input to Perl line by line.
'print decode_base64($_)' - Decodes a string, the string is saved in $_.
"ZWNobyAnQk9PSCEnCg==" - And this? What is this?

Let's start a test.

We know, it's something like base64 and it looks encoded. Therefore decode the string with:

base64 --decode <<< "ZWNobyAnQk9PSCEnCg=="

And the output is … ok, not really dangerous:

echo 'BOOH!'

Now, we can do the same with perl

perl -MMIME::Base64 -0777ne 'print decode_base64($_)' <<< "ZWNobyAnQk9PSCEnCg=="

And the output is, what a surprise:

echo 'BOOH!'

But was it dangerous? This is dangerous:

$(…)

This construct executes the output of the commands in the round brackets.

Let's try it, do you trust me?

$(perl -MMIME::Base64 -0777ne 'print decode_base64($_)' <<< "ZWNobyAnQk9PSCEnCg==")

'BOOH!'

And what's about

c3VkbyBraWxsYWxsIG5hdXRpbHVzCg==

Try it out … Do you trust me?


Import Error: No module named Quirks while trying to install nvidia-390

sudo apt-get install --reinstall ubuntu-drivers-common

This fixed missing Quirks.quirkapplier when installing nvidia-410.


Why is the Apache httpd stop command not graceful by default?

Update: Debian bug #974665 has been resolved, so as of version 2.4.46-2 in Debian unstable, httpd now uses graceful-stop by default. I expect Ubuntu to inherit this change starting with 21.04.

Well, I've found my way around the Ubuntu and Debian dev platforms.
Ubuntu inherits this systemd configuration from Debian, and I've traced the initial work to configure systemd for apache2 to Debian bug #798430. In the discussion for that, the initial proposed patches actually specified graceful-stop/SIGWINCH; however, the final change committed is what we have now, and there was no specific mention of why the non-graceful command was used in the end. I found another, earlier bug report, #641206, requesting a similar change but for init.d, and the Debian maintainer replied, explaining why it was not feasible then. I'm not sure if it applies to systemd too; in any case I have filed #974665.
As for the follow-up concern, it appears that it can be done with the help of Debian ‘diversions’ and the dpkg-divert tool. Update: while 'diversions' may work, the easier and more conventional way to override systemd configurations is to use systemctl edit; see this answer about overriding systemd services.


xbmc / kodi what ports to open on firewall so I can see files via upnp

This is what I had to do.

1) Do a netstat to find the PID of kodi.bin on the Local Kodi server

sudo netstat -lp --inet

2) Then get the pid and do a grep on it, this will tell you the udp and tcp ports it uses.

sudo netstat -lp --inet | grep "$7609/"

Link to example of it


Update on Ubuntu - coloured lines around everything

This is a bug with unofficial Nvidia drivers that you installed from a PPA.

The 375-378 drivers my be recommended by Nvidia at their site, but they are not tested for Ubuntu and not recommended by Canonical.

Run in a terminal

sudo apt install ppa-purge
sudo ppa-purge ppa:graphics-drivers/ppa
sudo apt update
sudo apt install nvidia-367

and reboot.


Two computers can't connect to the same VPN simultaneously

Any of us can connect without trouble

So both of your side works.

  but when we try together, the second computer fails to connect.

That is a common thing when using VPN. At our office regardless of who it is and what operating system we have the following happen:

1 client wants us to use Cisco VPN and only ONE person can log in. The 2nd one kills the connection of the 1st one. Very annoying since we needed to talk to all at our office to see if the VPN was free. This later got changed by our client to the 2nd one (and others) not being able to log in at all until the 1st one exits.
1 client wants us to use Cisco VPN and we can all log in at the same times.
1 client wants us to use Citrix VPN with security key and we can all log in at the same time with 1 key each (the same key can not be used 2 times at the same time).

  office headquarter

They probably need to fix this for you. It is probably a configuration in the VPN that prevents the 2nd one from logging in.

A more specific answer probably relies on the type/brand of VPN used.


Adding the PPA will let you install the latest wine updated before it is released in the official repository.

According to the official website wine1.5 is still in beta. So I wouldn't suggest installing it if you need something stable, so I would install wine1.4 instead. Unless you are certain the Windows application you need to run, only works on wine1.5.

So in short I would recommend the following:

sudo add-apt-repository ppa:ubuntu-wine/ppa #This is optional since 1.4 is already available in the official repositories
sudo apt-get update
sudo apt-get install wine1.4

But in case you are willing to install a beta package, and accept a few crashes every now and then (not saying that crashes WILL happen, but they are possible), then installing wine1.5 and reporting bugs and crashes is the way to go:

sudo add-apt-repository ppa:ubuntu-wine/ppa #This is required since 1.5 is not available in the official repositories
sudo apt-get update
sudo apt-get install wine1.4


`TERM` environment variable not exported from `.profile`?

~/.profile is typically run by login shells, so sh,bash, and zsh do not process it when called normally. Invoking them by using the -l option makes them login shells, and results in sourcing of ~/.profile. zsh does not use ~/.profile, but ~/.zprofile, because of incompatibilities with other sh syntax.

Most terminals have an option to run shells as login shells (at least GNOME Terminal, XFCE4 Terminal and Terminator do). You can enable that (if you make frequent changes to the profiles, or simply log out and log back in.

Further reading:

What's the difference between .bashrc, .bash_profile, and .environment?
Difference between .bashrc and .bash_profile


No dash? No items on the launcher? No browser? .... That is going to be hard...

I would suggest to try and find a KIOSK version of Ubuntu and alter that (the answers in How to customize live Ubuntu CD? will help). Kiosk means it is suited for 1 task and 1 task only but this most times is a browser, music or video oriented system. Or  an information booth. Plus point here is that it is already restricted and stripped down.

Customize Ubuntu for a library Internet kiosk
http://www.instructables.com/id/Setting-Up-Ubuntu-as-a-Kiosk-Web-Appliance/?ALLSTEPS

Here is an ISO for 12.04:

http://jacob.steelsmith.org/category/section/ubuntu-kiosk-edition


E: Problem executing scripts APT::Update::Post-Invoke-Success

Remove libappstream3 with the CLI command

sudo apt-get remove libappstream3

or

sudo apt remove libappstream3

Afterwards, apt update should work fine again.

Source: https://forum.siduction.org/index.php?topic=6174.0


Unchecking all desktop effects in Kubuntu 14.10 Plasma 4

No, there is not.

The list is not big
People who want it are rather rare.

You can totally disable compostion manager with (by default) the Ctrl+Alt+F12 key combo. But it is not the same as disabling all effects.
If you wanted it for some sort of script, you could do it with manual config editing. Ask separate question for it.


Sync files between folders and keep the latest version

If it helps you, symbolic link will keep the path of the file, and hard link will keep the content of the file (a reference to the inode). So in case you delete it the hard link will keep the file, but the modification on the file will be done on the same file.
So, if there are on the same partition, you can do a hard link with

ln /path/to/your/target/banned_user.cfg /path/to/your/linkname/on/server/2
 ln /path/to/your/target/banned_user.cfg /path/to/your/linkname/on/server/3
...
if you are on a different partition you'll have to deal with symbolic links with the same principle but with the -s option

ln -s /path/to/your/target/banned_user.cfg /path/to/your/second/server/banned_user.cfg

here is more documentation about symlinks and hardlinks


Permission denied on ~ even though owner listed as me

chmod -R 666 /home/nroach44

or

chmod -R 644 /home/nroach44

This will make all the files on your home dir non executable. It was not a good idea ;)

I don't know how to clean this mess, as a quick workaround you can try to do as root:

chmod -R 755 /home/nroach44

This command will give execute permissions to all files on your home folder. It should solve your immediate problems, but it could be a security nightmare.

The best solution is to open another user account and transfer to it files and settings one by one.


How can I speed up Ubuntu 16.04 as much as I can? Should I switch to GNOME from builtin Unity?

Just keep calm and run Ubuntu MATE with

sudo apt-get install ubuntu-mate-desktop^

Then select MATE session on login screen.


If KDE Kubuntu gets stuck sometimes, you can install a different, more lightweight desktop environment without reinstalling the entire operating system. You can have multiple desktop environments installed and you choose your desktop environment on your login screen.

To install a new desktop environment to your existing Ubuntu installation, run the following commands:

sudo apt update
sudo apt install tasksel
sudo tasksel

Now, you can select a desktop from the list. Do not choose any of the "LIVE CD" or "CD" options.

ONLY choose from the desktop or minimal. If any of the other options are already chosen, leave them alone and do not un-select these.

Some good lightweight options are Xubuntu, Lubuntu, and possibly Ubuntu Mate. Lubuntu has a QT (LXQT) and a GTK (LXDE) version available. Both Xubuntu and Lubuntu have "minimal" versions that are even more lightweight.

The GTK version of Lubuntu may not be available on Ubuntu 19.10+

Since you are already running KDE, you may want to go with the Lubuntu QT option or Lubuntu minimal QT as KDE runs on QT so those dependencies will already be installed. The Lubuntu QT version is lightweight, runs fast, and is designed to run on desktops with limited resources so you can allocate more resources to gaming. However, Xubuntu and Lubuntu GTK are also lightweight and designed to run on limited resources. Ubuntu Mate is lightweight and runs on GTK as well.

UbuntuStudio (which is based on the same XFCE desktop as Xubuntu) is also designed to use less resources and is centered around music production and graphic design. However, UbuntuStudio contains a lot of added music and graphics production software which may not fit your needs.

Use your arrow keys to navigate and SPACE BAR to select. When you are done, use the TAB key to highlight "OK" and then press ENTER.

After installing the new software, you will have to logout or reboot and then you can select which desktop environment to use from your login screen settings.

Keep in mind, that the login or "display-manager" screen may change when you do this. If you don't like your new login screen, you can always change back by selecting a different display manager (usually by running sudo dpkg-reconfigure sddm and then select the desired display-manager from that screen following the instructions). GTK based desktops like Xubuntu usually use Lightdm whereas QT desktops like Kubuntu and Lubuntu QT use SDDM.

However, if you choose Lubuntu QT, you can select the SDDM theme through your KDE desktop settings: System Settings > Startup and Shutdown > Login Screen (SDDM). The default Kubuntu SDDM theme is called "Breeze" and the Lubuntu SDDM theme is called: "Lubuntu chooser".


I found this WebRTC implementation that allows you to share a browser screen through the browser via  a url. It is free software.

https://www.webrtc-experiment.com/Pluginfree-Screen-Sharing/

It should work in both Chromium and Firefox, but may require you to configure some additional settings in about:config. The observing user should not have to.

If one implementation does not work, there are other options available under the demos page. These are all demos, but  the source can be used to create your own solution as well if desired.


Why is the Amazon and Ubuntu One Music webapp part of common? Can it be removed without removing all others?

As discussed in the comments to the previous answer (by Paul Hänsch), the Amazon webapp is part of 'unity-webapps-common', and all the other 'unity-webapps-*' depend on 'unity-webapps-common', so at this time there is no way to remove the Amazon webapp without removing the rest.

However, I just discovered a way to disable the Amazon webapp, without uninstalling it, so you can leave other webapps installed and not be bothered by the Amazon webapp.

open 'dconf-editor'
go to 'com>canonical>unity>webapps'
edit the "preauthorized" field to say just '[]' (or remove 'amazon.com', and any other desired domains from the list)
visit www.amazon.com
when prompted to "install Amazon", tell it "Don't ask again".

I found these instructions here:

https://twitter.com/ghalfacree/statuses/269760421437775872


Do I have to connect my laptop to a switch/router before a virtual OS(Ubuntu) installed on VirtualBox could communicate with the hosting OS(Win7)?

When using Bridged mode, Yes you need to be connected. Since all traffic is bridged over the Physical Adapter.

To make it work when not connected use a NAT connection or HostOnly. Disadavantages of both are that other computers on the physical network cannot access the machine. However when using NAT you can add Port Forwards from your local machine to the virtual machine.

I hope this helps

Kind regards,
Jochen.


How to prevent an "always on top" application from usurping focus every time the workspace is switched

This is preliminary:

Make application always on visible workspace by default? uses CCSM and the Window Rules plugin, which comes with an option of "no-focus". So I guess that could pass as an acceptable, though sub-ideal work-around.

Why sub-ideal? Because a) it requires CCSM ('nuf said) and b) would require setting up a rule, rather than having c) this "bug" fixed...


How to use the `od` command to check HDD zeroization?

No. head will cut off output after 10 lines by default. Since there were only three lines total in the output, you'll get only three lines with or without head.
As for lines, why should only files have lines? Do you want all command output to be stuffed into one line?
It's an octal number showing how many bytes have been read since the start of the input. It can be more digits if needed.
From man od:

-v, --output-duplicates
      do not use * to mark line suppression

So od tries to avoid printing duplicate lines. * marks those.
From the original od documentation (which is clearer):

  Each line of output consists of the offset in the input, followed by
  groups of data from the file. By default, od prints the offset in
  octal, and each group of file data is a C short int’s worth of input
  printed as a single octal number.

So each block as a whole is an octal number. A C short int is usually 2 bytes. od takes two bytes worth of data, treats it as a number, and prints it in base 8 as a single number, and repeats. Each line has 8 such blocks, so we have 16 bytes per line. The offset is also printed in base 8, and 20 in base 8 is 16 in base 10.
Since the offset is in base 8, converting to base 10:

$ echo $((8#7216060060000))
500107862016
$ echo $((8#7216060060000 / 1000 / 1000 / 1000))
500

$((N#X)) tells bash to read X as a base-N number. Since bash outputs in base 10 by default, doing $((8#...)) converts from octal to decimal.
Yes.


Unable to stat /etc/sudoers: no such file or directory

Shortcut:
dpkg-reconfigure:
If only something is wrong with the permission of /etc/sudoers file, with root access run: dpkg-reconfigure sudo. something like pkexec dpkg-reconfigure sudo should do the work.
visudo: If dpkg-reconfigure does not works for you, then just run pkexec visudo, the sudoers file will be opened in an editor, then just save and close the file, visudo will fix the permission for you.
After all, if you changed sudoers.d directory permissions too, then run:
pkexec chmod 755 /etc/sudoers.d

If files are there, and their permissions are as it should be but you still get this error message, the only possibility that come into my mind is that you have broken other permissions and sudo does not have access to /etc/sudoers. the most possible guess is permissions of /etc/.
So run:
pkexec chmod 755 /etc

We are done, however if you want a detailed instruction to restore broken or removed sudoers file with messed up permissions follow along, we are going to use another way to fix things.

Introduction
I messed around my /etc/sudoers file to get a similar error as you. I get really close, so I completely delete mine and it's became exactly as yours.
What I've did to fix the issue:
My root account was locked, and It didn't have any password, so it was impossible for me to do what I wanted to do. however if your root account is active and has a password, switch to root user with su - and skip this part. if not, follow the instructions.
Before going further I have to mention that You can always use a live disk to do a chroot into your system, there are a lot of instruction about chroot using a live disk, so I'm not going to bother  with giving all those instruction again, instead I'm going to assume we don't have any live disk and we are going to use what we already have, to fix this issue. If you are happy with cheroot go that way, that would do the work too.

Getting root access

Reboot your system
When grub appears press e to edit it
At the end of the line which starts with linux, add init=/bin/bash
Press CTRL+X

Now you will be dropped into a bash shell with root access. first remount the file system with write access:
mount -o remount,rw /

Then unlock the root user and set a password on it:
passwd -u root
passwd root

Now If your /etc/sudoers still exists on /etc, move it somewhere else:
mv /etc/sudoers /etc/sudoers.broken

Because we are going to tell our package manager that this file is missing, and it's going to replace it for us with a correct one, so it shouldn't be there.
We are almost done, reboot your system. login as your normal user, open a terminal then try su - to switch into root user. I wasn't able to do this, so what I've done was using CTRL+ALT+F1, to go into tty1, then I logged in as root with the new password we just set.

Bring sudoers back
We simply should reinstall the sudo package, however reinstalling does not bring this file back, we should tell the dpkg to fix the missing config files too, like this:
apt-get -o Dpkg::Options::="--force-confmiss" install --reinstall sudo

Remember that it will asks you about installing the /etc/sudoers file, by inserting y say yes.
If it did not work for you, do as following as root:
mkdir /root/tmp
cd /root/tmp
apt-get download sudo
dpkg-deb -x sudo*.deb .
cp etc/sudoers /etc/sudoers
cd /root
rm -r tmp

Now there may be some different between permissions, run dpkg-reconfigure sudo to fix it. if it did not work, run visudo as root user, the sudoers file will be opened in an editor, then just save and close the file, visudo will fix the permission for you.
If everything goes right, your sudoers file will be back and you will be able to use sudo as you were before.


Remote Desktop hang OS or block all the connections

Looks like a known issue with Ubuntu 18.04.2 and xrdp.  xorgxrdp package does not get installed when using xrdp packages from official Ubuntu repositories.  This is because a new package (xserver-xorg-core-hwe-18.04) has been introduced and which is not supported by xorgxrdp package

To fix your issue, the easiest would be to use the "unofficial xrdp packages" compilied against this new xserver-xorg-core-hwe-18.04 package...  To use these "unofficial packages", you can issue the following commands

  sudo add-apt-repository ppa:martinx/xrdp-hwe-18.04 -y

  sudo apt-get update

  sudo apt-get install xrdp

More information about the issue can be found at  http://c-nergy.be/blog/?p=13390

Hope this help
Till next time
See ya


The iso images are too large for a standard 700 mb CD. Many if not most people have started using flash (usb) drives as it is cheaper, faster, and just as easy to use a flash drive. I would personally use a 2 gb flash drive.

See: https://help.ubuntu.com/community/Installation/FromUSBStick


UbuntuShowdown apps installation unable to locate package error

You made a mistake with the command:

 sudo add-apt-repository ppa:brianrobles204/xkcd-browser
 sudo apt-get update
 sudo apt-get install xkcd-browser

It should be:

sudo apt-add-repository ppa:brianrobles204/xkcd-browser
sudo apt-get update && sudo apt-get install xkcd-browser

Hope this solves it!


badblocks taking really long time. or is it frozen?

You can watch per-process I/O activity with iotop. Install:

sudo apt-get install iotop

Then launch:

sudo iotop

Watch it for 30 sec. Does it show badblocks doing any I/O? If yes, then it is working, if not, it is likely frozen.

Next time you may launch badblocks with the -s parameter:

sudo badblocks -nsv /dev/sda6

this will show progress.


Failure to boot in Ubuntu for only-Ubuntu + Nvidia laptop

An Ubuntu image is a "live" iso, so "burned" on a stick you can first check if it starts, without installing anything. So that's what I would do:

Take the correctly "burned" usb stick and put it into an usb slot. Power up the machine and "tell" the bios from where to boot (..the usb stick)
if you can't see the initial Ubuntu screen you may see an error message.Then your Iso hasn't been saved correctly
if you can see that screen, start Ubuntu - but thats a sure sign that linux can cope with your graphics card.
If installed Ubuntu usually uses the non proprietary nouveau driver. It might lag and looks grizzly. Now you would have to install the correct nvida driver for your card.

Maybe you did all these things, but didn't tell ;-). Then you probably installed an nvidia driver that is not working for your laptop

.


How to tell if Ubuntu is using WiFi or Ethernet

Ubuntu will use both your Wireless and your Ethernet at the same time. I use a program called vnstat for Internet traffic monitoring:

$ vnstat

                      rx      /      tx      /     total    /   estimated
 wlp60s0:
       Apr '18     20.83 GiB  /    1.55 GiB  /   22.38 GiB
       May '18      4.33 GiB  /    5.34 MiB  /    4.34 GiB  /   11.36 GiB
     yesterday    404.97 MiB  /     509 KiB  /  405.47 MiB
         today    593.05 MiB  /     773 KiB  /  593.80 MiB  /      --

 enp59s0:
       Apr '18    206.79 GiB  /   56.90 GiB  /  263.69 GiB
       May '18     63.19 GiB  /   13.34 GiB  /   76.53 GiB  /  200.60 GiB
     yesterday      6.73 GiB  /  817.44 MiB  /    7.53 GiB
         today      4.03 GiB  /  376.32 MiB  /    4.39 GiB  /    5.31 GiB

Today the WiFi (wlp60s0) has sent/received 593 MB and Ethernet (enp59s0) has sent/received 4.39 GB.

To setup vnstat see this Q&A: How to track the total network data in a month

You don't have to tell Ubuntu to use Ethernet over Wifi because it automatically uses the fastest connection. The exception being if your Ethernet is 100 Mbps and your WiFi is faster than 300 Mbps. In this case the WiFi would take precedence.

If your WiFi is faster than your Ethernet click the Up/Down arrow representing network connection in the Systray. From the drop down menu disable the WiFi link by clicking disconnect button. You can also disable the Ethernet link from the same drop down menu.


How to install wps office via flatpak in ubuntu 19.04?

It seems that you have not follow setup guide for FlatPak.

You need to add flathub "repository" first with:

flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

and then install WPS or any other FlatPak from flathub.


Unable to use TL-WN821N wireless adapter

Dude, you shall take a look at the following pages:

http://wiki.debian.org/ar9170usb
http://wireless.kernel.org/en/users/Drivers/ath9k_htc
http://wireless.kernel.org/en/users/Devices/USB

and perhaps also http://partner.atheros.com/Drivers.aspx

One of those must work for you.


Google Chrome cannot determine or set the default browser

To change the default browser:

via command line:

 sudo update-alternatives --config x-www-browser

and choose the number correspond to google chrome. Now exit and check the problem will be solved from chrome settings(I noticed that a wired thing happen just when Opera become the dfeault).

via GUI:

Click on the dash button in the launcher and search for 'System info'. Then, open 'System info' and move to 'Default applications' section.


Whenever I use ALT-TAB, Firefox display freezes

I would have liked to really solve the problem, but meanwhile here is how to avoid the problematic consequence: Select the Compiz "Static application switcher".


From the Live DVD, issue a swapoff -a and then retry sudo fsck -f /dev/sda5. If that doesn't work (because sda5 is the physical volume), you will have to give fsck the lvm name like /dev/ubuntu-vg/root. Use lvmdiskscan to see the names.

update: sudo fsck -f /dev/ubuntu-vg worked.


Use play command to play the file. So something like ssh user@hostname play /location/of/file.mp3 on each of the PCs. If up to 5 seconds delay is alright then you can simply use a for loop to run that command from any PC. Something like for PC in list of hostnames; do ssh user@$PC "play /location/of/file.mp3" & done.

Setting up public key authentication will eliminate the need for password inputting for each of the hosts. How can I set up password-less SSH login?


open markdown files in vim: only a few lines shown

It seems that the file is folded; in that case moving on the line 2 and pressing za (or zA for recursively opening folds) should work.

If this is the case, there are tips here to set-up vim in order to decide how to fold files.


man  doesn't display anything after package installation with conda on Ubuntu 17.10

Turns out, after the anaconda installation or some package installation through conda, the default pager is re-written. The exact cause of this is unknown.
Just some more information

~$ anaconda --version
anaconda Command line client (version 1.6.9)
~$ conda --version
conda 4.4.10
~$ history | grep conda
  108  bash Anaconda3-5.1.0-Linux-x86_64.sh
  110  anaconda-navigator
  181  anaconda-navigator
  187  anaconda-navigator
  311  conda info --envs
  312  conda install rpy2
  313  conda search PySide
  314  conda search Python
  366  conda install findspark
  367  conda info --envs
  370  conda install findspark
  373  conda search findspark
  374  conda install -c conda-forge findspark
  495  anaconda --version
  496  conda --version
  497  conda list
  499  history | grep conda

My strongest guess is that rpy2 installation had this effect of changing the pager information given the time of events.

But these are the steps I took to solve the issue.

~$ update-alternatives --display pager
pager - auto mode
  link best version is /bin/less
  link currently points to /bin/less
  link pager is /usr/bin/pager
  slave pager.1.gz is /usr/share/man/man1/pager.1.gz
/bin/less - priority 77
  slave pager.1.gz: /usr/share/man/man1/less.1.gz
/bin/more - priority 50
  slave pager.1.gz: /usr/share/man/man1/more.1.gz

~$ rm /home/abhilash/anaconda3/bin/pager

Ensure that the pager defaults to the one that came with man-db by typing the following to confirm

~$ ls -l "$(type -p pager)"
lrwxrwxrwx 1 root root 23 Apr  9 13:57 /usr/bin/pager -> /etc/alternatives/pager

This solution was arrived at after going through this link in an attempt to set the pager to default.

Thanks to glenn and terdon for their inputs in solving this issue.


Corebird twitter client for Ubuntu 14.04

There's now a PPA that contains Corebird packages, available for Ubuntu 14.10 and Ubuntu 14.04.

sudo add-apt-repository ppa:ubuntuhandbook1/corebird

sudo apt-get update

sudo apt-get install corebird

Ubuntu 14.04 user also need Gnome3 and Gnome 3 Staging PPA for the dependencies:

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

sudo add-apt-repository ppa:gnome3-team/gnome3-staging

via: http://ubuntuhandbook.org/index.php/2014/07/install-corebird-ubuntu-ppa/
PPA: https://launchpad.net/~ubuntuhandbook1/+archive/ubuntu/corebird


If I have a portable ubuntu webserver which I run ad hoc on my laptop and I want devices to connect to the server how do I do it?, how?

You can buy a USB wireless card(for hotspots) for your computer or use a router.

Most routers have DHCP servers which assign IP addresses to all the machines connected to them.
You can set a hostname to your computer and have it accessible via the hostname for other devices. This wouldn't require you to setup a static ip on your computer . For example if it's user@hostname, you should be able to access your webserver at http://hostname:port . If the port is 80, your server should be accessible at http://hostname to those connecting to your router.

Otherwise you can setup a static ip to your system. You can go to the network manager, go to the properties of the network, change ipv4 settings and set a valid ip address.
The valid ip address should be in the range of the router DHCP assignment.
If the router assigns an ip say, 192.168.0.104, then the ip addressess are in the range 192.168.0.0 to 192.168.0.255
You can check this using the command ifconfig in the terminal.
Now to get the ip address of your router use the command ip r | grep default.
Set your desired ip address in the ip address, the appropriate subnet mask and the router address for the gateway.

Once you do this the other devices would be able to connect to your machine using your preferred ip address.

Hope I've answered your question.


Use NVIDIA Hybrid gpu only for CUDA and not for KDE Plasma

I think have figured it out. First I have re-moved the 10-nvidia.conf file. Instead I have added a 10-intel.conf. Then I have commented out every line the 11-nvidia-prime.conf, it is basically an empty file. Since this file gets created/overwritten at every start/stop of xserver one needs to protect it with chattr +i
$ pwd
/usr/share/X11

$ ls -l xorg.conf.d/
total 36K
drwxr-xr-x 2 root root 4.0K Okt 20 20:15 .
drwxr-xr-x 6 root root 4.0K Okt 20 18:12 ..
-rw-r--r-- 1 root root   92 Okt 22  2019 10-amdgpu.conf
-rw-r--r-- 1 root root  327 Okt 20 18:10 10-intel-only.conf
-rw-r--r-- 1 root root 1.4K Sep  4 15:34 10-quirks.conf
-rw-r--r-- 1 root root   92 Okt 22  2019 10-radeon.conf
-rw-r--r-- 1 root root  341 Okt 20 20:15 11-nvidia-prime.conf
-rw-r--r-- 1 root root 1.5K Mai 30 15:34 40-libinput.conf
-rw-r--r-- 1 root root 3.4K Mär 11  2020 70-wacom.conf

ls -l bak.xorg/
drwxr-xr-x 2 root root 4.0K Okt 20 20:08 .
drwxr-xr-x 6 root root 4.0K Okt 20 18:12 ..
-rw-r--r-- 1 root root  206 Okt  5 11:19 10-nvidia.conf
-rw-r--r-- 1 root root  333 Okt 20 20:08 11-nvidia-prime.conf

$ cat xorg.conf.d/10-intel-only.conf
Section "ServerLayout"
    Identifier "Layout0"
    Option "AutoAddGPU" "false"
    Screen 0 "IntelScreen"
EndSection

Section "Device"
    Identifier "IntelDevice"
    BusID "PCI:0:2:0"
    Driver "intel" # or maybe "modesetting"?
EndSection

Section "Screen"
    Identifier "IntelScreen"
    Device "IntelDevice"
EndSection


Try pressing Ctrl+Alt+F1. That should allow you to enter tty1. If that doesn't work, try Ctrl+Alt+F2, Ctrl+Alt+F3, etc. etc.

It will say something like:

Ubuntu 14.10 ComputerName tty1

ComputerName Login:

Type your username here and hit enter, and then your password.

You should be able to access tty and go from there.


How do I make Ubuntu 14.04 recognize my Galaxy S4 as a Microphone via 3.5mm jack/USB?

Select correct  input jack in "input device" tab from "Pulseaudio volume control"
Type this command in terminal (vlc and vlc-plugin-pulse must be installed ):
vlc pulse://

Vlc will capture pulseaudio recorded signal  and play it to the default pulse output (speaker or headphone).


Just installed Ubuntu 16.04 but no software center

You don't have any software sources configured, which means something went wrong with your installation. As there may be more problems I'd install the system again. Make sure you use an official up-to-date Xubuntu image.

If you want to try to repair your system you can use for example https://repogen.simplylinux.ch/ to create a new sources.list

After saving the new /etc/apt/sources.list run

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

apt-get should offer you to upgrade some packages. Do that, and then run

sudo apt-get install xubuntu-desktop

to get all the software installed for Xubuntu by default.


Unable to start the web application from localhost:3000(ruby on rails)

Command to start it is ruby script/server and not rails script/server
that is the solution :P


There are several ways to achieve this, but here is the most clean and proper one ...

Copy all data from the D partition to an external location (hard disk/USB disk).
Boot from Ubuntu installation media and select Try Ubuntu without installing.
When the Ubuntu desktop appears, press the Windows key and type GParted.
Open GParted and delete all partitions - create 3 new partitions (Note below).
Close GParted - click on Install Ubuntu - when asked - choose Something else.
Select the ext4 partition you created before - choose / (root) as mount point.
Start installing Ubuntu and when finished boot the Ubuntu operating system.
Copy back the data you transferred to the external drive to the ntfs partition.

Note :

Create a new partition and format it with ext4 - choose a size that fits your needs.
Create a new partition and format it with linux-swap - the size should match RAM.
Create a new partitiion and format it with ntfs - choose a size that fits your needs.

These are my recommendations ... the advantages are a complete clean new setup
and in case you want to install Windows later, you can access your data from there.


Looking for way to transcribe audio files into text

Try Mozilla DeepSpeech. It's opensource tool for automatic transcription. But you will need to train the tool. You can download Mozilla's pre-trained model, or use Mozilla's Voice DataSets to create your own model, and you can use it for recordings in English. For very clear recordings, the accuracy rate is relatively good. but for my transcription projects, it was still not sufficient, as the recordings had lots of background noises, they were not of good quality, I used Transcribear instead, it's web based editor that allows for automatic transcription, but you will need to be connected online to upload recordings to the Transcribear server.


Ubuntu 12.04 - Bumblebee 3.1 - Error - Unable to locate package Bumblebee

After hours of googling to no avail, I managed to solve it:

Go to Update Manager > Settings... > Other Software (tab) > (tick both) Bumblebee PPAs

Apparently, using the purge commands somehow unticked them.  Hope this will help someone.


I had the same problem and also tested it in a VM with Ubuntu 20.04 and 19.10. Both worked right away.
Then i tried it on my laptop again with a wired network connection because there was only a wired connection available in the VM and that worked also!
After a lot of trying and searching to get it to work via the WIFI Adapter (i mostly work wireless), i ended up with setting the WIFI adapter name to default wlan0.
To change the adapter name do this:

Open /etc/default/grub
Add "net.ifnames=0" to the line GRUB_CMDLINE_LINUX_DEFAULT. On my system, it now looks like this: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash net.ifnames=0"
Save the file
Run update-grub and reboot your machine
You might have to reconnect to your network and enter your passphrase


Why system hangs up while using multiple tabs on firefox or chrome?

Because chrome consumes a lot of memory. You can use mozilla and stop the unnecessary services running at the back end.

To check the status of running services at background:

sudo service --status-all

If you want to stop a service from autostart:

sudo update-rc.d -f [ServiceName] remove

In case, if you want to stop service temporarily:

sudo service stop [ServiceName]

Hope your system will work better enough.


Can't detect external monitor on Thinkpad W530 running Ubuntu 14.04

Well, here's what I did to fix it (and I'm not 100% sure that it's fixed, but it seems like it! Hopefully there's no regressions!) Everything is run as sudo; I probably rebooted at some points during this, but I don't remember exactly when :/ I'm guessing you should reboot after step 5, and maybe after step 3.

Disable Optimus in BIOS; only use the discrete NVIDIA video card.
apt-get remove --purge bumblebee nvidia*
apt-get install --reinstall libgl1-mesa-dri libgl1-mesa-glx libegl1-mesa-drivers
apt-get install nvidia-common nvidia-settings nvidia-331
Run nvidia-xconfig (not sure if this is necessary, but it seems like you have to do it at some point)
Add nvidia_331 to /etc/modules
At this point, my libGL was pointing to mesa's version of openGL for whatever reason, so I followed the advice here: I added /usr/lib/nvidia-331 and /usr/lib32/nvidia-331 to /usr/lib/nvidia-331/alt_ld.so.conf, and ran ldconfig.

And now I have multiple external monitors connected, openGL working, and no weird pixelly artifacts on my screen. Nvidia persistenced daemon doesn't crash on boot, and the nvidia kernel module is loaded on boot.


You do not need install packages any more!

In directory tools, there are many types of emulator, while my computer works with emulator64-arm! My system is Linux Mint 16 amd64! Good luck!

./emulator64-arm @yxphone -sdcard yxsd -scale 0.8


In LibreOffice, this is called Quickstart, and is enabled on this tab: Tools/Options/LibreOffice/General. It may tell you that the Quickstart module needs to be installed for this, but as far as I'm aware, that is installed automatically.


Keep external monitor on when laptop is closed

This is often a setting in the BIOS for the laptop. Reboot the computer and press the appropriate key to get into the BIOS. It will usually say "press del for settings", "press F10 to edit BIOS" or something like that while it boots. Usually there will be an option in the power settings on what to do when the lid is closed.

Even after enabling it, some laptops won't boot at all with the lid closed (when they have power buttons accessible on the side) and you will have to open it, power it on, wait a few seconds, then close it. Some laptops just don't allow you operate the laptop with the lid closed at all too.


Ubuntu 14.10 can't connect to "Wireless N" signals

Thanks SO MUCH for your help Jeremy31.  The exact suggestion didn't work.  But  I googled "11n_disable=8" because I thought it should be "11n_disable=0," but didn't want to respond with a stupid comment if I was wrong (which I was).  Anyway, that led me to this similar solution for a different problem:

echo options iwlwifi 11n_disable=8 | sudo tee /etc/modprobe.d/iwlwifi-11n.conf
echo options iwlwifi bt_coex_active=0 | sudo tee -a /etc/modprobe.d/iwlwifi-11n.conf

I did this, rebooted, and it worked.  I am now connected to my wireless router, which is in 2.4GHz N only mode.

Thanks again!


/etc/ssh/ssh_config: line 58: Bad configuration option: subsystem

Just remove the last lines  beginning with 'Subsystem' from ssh_config.
#Subsystem      sftp    /usr/lib/openssh/sftp-server
Subsystem       sftp    internal-sftp

Match Group sftp_users
  X11Forwarding no
  AllowTcpForwarding no
  ChrootDirectory %h
  ForceCommand internal-sftp

Then you may open sshd_config and uncomment or change settings there.


The easy way is to point your Firestick's web browser at the Plex web page. Plex will allow library selection and play media in the browser window (with fullscreen option).

A slightly more complex way is to enable UPnP in Plex settings, then any VLC player (or any other UPnP-aware player) on your home network can detect and browse your library.


Had the same problem and found a quick, simple and very effective performance.

Have a look at cat /proc/cpuinfo and see if your CPU is not being underclocked. I downloaded the simple scale.sh script and ran it with the performance switch and got an amazing improvement. An alternative would be to use something like indicator-cpufreq app.


“Alloc magic is broken”/No bootable devices found on non-dual boot computer

Secure Boot
Secure Boot should be disabled in your BIOS.
Corrupt Ubuntu
If Secure Boot doesn't fix your problem, then you may have some file corruption. Try booting to an older kernel from the GRUB menu, and see if it boots.
Note: Edit your question with screenshots of the Disks app SMART Data scrollable window.
Note: If the remainder of my answer doesn't fix the problem, you may just have to reinstall Ubuntu.
fsck
Let's check for a file system problem...

boot to a Ubuntu Live DVD/USB in “Try Ubuntu” mode
open a terminal window by pressing Ctrl+Alt+T
type sudo fdisk -l
identify the /dev/sdXX device name for your "Linux Filesystem"
type sudo fsck -f /dev/sdXX, replacing sdXX with the number you found earlier
repeat the fsck command if there were errors
type reboot

BIOS
Dell XPS 9370
You have BIOS version 1.3.3.
There's a newer BIOS available, version 1.13.1, dated 8/19/2020, and it can be downloaded here.
Note: Confirm that I have the correct web page for your model #.
Note: Have good backups before updating the BIOS.


Set persistent notification for certain app

I use Grown-up notifications
combined with Permanent notifications extensions to solve your same problem. (:


Milter-greylist socket always owned by root?

I tried to find a nice solution, but in the end, I resorted to setting the group sticky bit on the directory. That did the trick.


Can global application menu be made to behave better with GIMP?

If you want one particular application to not use the global menu you can set a little known (but very useful) environment variable: UBUNTU_MENUPROXY=0

Thus, the following entered in a terminal will start gimp with the global-menu disabled:

UBUNTU_MENUPROXY=0 gimp-2.6

You'll note the global menu is disabled for Gimp - it's now with the main Gimp window.

As a suggestion, if you launch Gimp via a launcher icon, copy the /usr/share/applications/gimp.desktop file to your home folder ~/.local/share/applications (create if necessary).

Change the exec= value to a script file - for example /home/dad/launchgimp.sh

Copy and paste UBUNTU_MENUPROXY=0 gimp-2.6 into this new file and give it execute rights (chmod +x ~/launchgimp.sh)

Logout and login.


I backed up my files from ubuntu to windows, the in windows I deleted both ubuntu partitions. Then I created a partition for my files. Then reinstalled windows.
Now I have 2 partitions for windows, 1 partition for my files, and 1 partition for ubuntu. I am now waiting for ubuntu 16.04 and then I am going to install it. When installing I will create an extended partition for ubuntu and ubuntu swap partitions.


C++ code compilation fatal error: xdo.h: No such file or directory

This compilation needs xdo.h to be installed:
sudo apt-get install libxdo-dev

Hope this helps.


How to fix Ubuntu touch calendar and a Google calendar out of sync?

The only way I found to fix a bad synchronisation between Google calendar and the calendar app is following this steps:

In Settings > Account, remove the Google account.
Close the Calendar application on the phone (explained here how to do this).
In Settings > Account, create again the Google account.
In Settings > Account > Google, check at least the Calendar box.
Launch the Calendar app on the Phone. In the upper right menu (button with three horizontal bars), go to Calendars and select your Calendar again.
Synchronisation will start.
After a surprisingly short time, your local calendar is reinitialised and identical, as far as I can see, to the Google Calendar.

Voilà. Let us hope that the developpers of the app will soon fix all the bugs that cause the app to be out of sync.


With the package iat, available from the standard repositories, it is possible to convert a .mdx file, to an easy mountable .iso file.


I think Seahorse takes care of remembering the keys.


Problem after interrupted installation of Adobe Flash

You will need to completely remove Adobe Flash Player Plugin and re-install using the commands below:

Ctrl+Alt+T
$ sudo apt-get remove --purge adobe-flashplugin flashplugin* nspluginwrapper
$ sudo apt-get install --reinstall adobe-flashplugin


Where are the database files queried by dpkg-query?

It depends upon exactly what kind of query you do, but all of dpkg's database files are under /var/lib/dpkg. They are often plain text files.
For example, a simple dpkg-query -l will find what it needs in /var/lib/dpkg/status:
$ strace -e trace=open,openat dpkg-query -l base-files
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/var/lib/dpkg/arch", O_RDONLY) = 3
openat(AT_FDCWD, "/var/lib/dpkg/status", O_RDONLY) = 3
openat(AT_FDCWD, "/usr/share/locale/locale.alias", O_RDONLY|O_CLOEXEC) = 4
openat(AT_FDCWD, "/usr/share/locale/en_GB/LC_MESSAGES/dpkg.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale/en/LC_MESSAGES/dpkg.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/usr/share/locale-langpack/en_GB/LC_MESSAGES/dpkg.mo", O_RDONLY) = 4
openat(AT_FDCWD, "/usr/share/locale-langpack/en/LC_MESSAGES/dpkg.mo", O_RDONLY) = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/var/lib/dpkg/updates/", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 3
openat(AT_FDCWD, "/var/lib/dpkg/triggers/File", O_RDONLY) = 3
openat(AT_FDCWD, "/var/lib/dpkg/triggers/Unincorp", O_RDONLY) = 3
openat(AT_FDCWD, "/dev/tty", O_RDONLY)  = 4
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache", O_RDONLY) = 4
||/ Name              Version       Architecture  Description
+++-=================-=============-=============-=======================================
ii  base-files        10.1ubuntu2.1 amd64         Debian base system miscellaneous files
+++ exited with 0 +++

Update: Question has been changed from simple dpkg-query to specify dpkg-query -S. So to answer that:
As mentioned, exactly where dpkg-query looks depends upon what type of query you do, but all of its information exists below /var/lib/dpkg/. For dpkg-query -S queries for example, it examines every *.list file in /var/lib/dpkg/info/:
$ strace -e trace=open,openat dpkg-query -S /bin/ls
[…]
openat(AT_FDCWD, "/var/lib/dpkg/info/fonts-sil-abyssinica.list", O_RDONLY) = 4
openat(AT_FDCWD, "/var/lib/dpkg/info/libatk-adaptor:amd64.list", O_RDONLY) = 4
openat(AT_FDCWD, "/var/lib/dpkg/info/libvorbisfile3:amd64.list", O_RDONLY) = 4
openat(AT_FDCWD, "/var/lib/dpkg/info/libquadmath0:amd64.list", O_RDONLY) = 4
[…]
openat(AT_FDCWD, "/var/lib/dpkg/info/tzdata.list", O_RDONLY) = 4
openat(AT_FDCWD, "/var/lib/dpkg/diversions", O_RDONLY) = 4
coreutils: /bin/ls
+++ exited with 0 +++


Which Ubuntu Flavor is best for old PC WITH Nvidia GeForce 6150SE nForce 430 and AMD 64Bit and 4 GB Ram?

It is probably best if you use Lubuntu or Xubuntu, which both use lightweight desktop environments. Make sure you use the proprietary nvidia drivers, as there are known issues with running nouveau drivers on this device. Other good options include Peppermint, Puppy, Crunchbang (now deceased but there are forks). You may even wish to run Unity2D.

(I recommended these other distributions mainly because you asked for an Ubuntu based distribution, which probably means you're most familiar with the apt package management)


Is it possible to run a program installed on an SD card?

It should definitely be possible. I have a similar setup (HP Chromebook 14) with a tiny 16 GB hard drive. I run Unity3D on it, which is installed on my 32 GB microSD card. You may run into permission problems though. I had to format mine to ext4 format as well as mount it with the "exec" mount flag to get programs running. Personally, I haven't used MatLab, but if there is a Linux build available, it should be a straightforward process.


I think somehow grub got corrupted. There have been reported cases where Windows update messed up grub. You should reinstall grub from an Ubuntu live disc or USB drive. Be sure to use the same Ubuntu version that is installed in your machine.

I have already answered a similar question in detail. The same solution will work for you as well. Follow the steps and proceed carefully. Let me know in the comments if you have difficulty in understanding something.


Aver. Quieres poner el ubuntu de 32 bits, en un ordenador que tiene preinstalado el windows de 64 bits....... eso es raro. Ti sistema tiene que ser de 64 bits   Intenta con el ubuntu de 64 bits

English: From what I understood, you want to put 32 bits ubuntu in an orderer that has 64 bits Windows pre-installed? This is rare, Your system has to have 64 bits, try with the 64 bits ubuntu.


It depends on the getty-type program employed on the system:

man issue

  The  file /etc/issue is a text file which contains a message or system
  identification to be printed before the login prompt.  It may contain
  various @char and \char sequences, if supported by the getty-type
  program employed on the system.

man agetty

  ISSUE ESCAPES
         The issue-file (/etc/issue, or the file set with the -f option) may contain certain escape codes to display the system name,  date,
  time  etcetera.   All
         escape codes consist of a backslash () immediately followed by one of the characters listed below.

...

  n      Insert the nodename of the machine, also known as the hostname.
  Same as uname -n.
  O      Insert the DNS domainname of the machine.
  s      Insert the system name (the name of the operating system).  Same as uname -s.  See also the \S escape code.
  m      Insert the architecture identifier of the machine.  Same as uname -m.
  r      Insert the release number of the OS.  Same as uname -r.
  t      Insert the current time.


I a recent blog post I read an article about booting Linux on an Acer Aspire One indirectly from the SD card via a boot loader on a Pen Drive. Maybe this could provide a solution for you.

http://www.barryhubbard.com/linux/booting-acer-aspire-one-from-sd-card/

Having heard about the issue with booting an Acer Aspire One from the SD card and having read myself a note on Acers website that it's not supported and not possible I was surprised to read a comment to a blog post mentioned above where someone claimed that it was possible on his Acer aspire E11 ES1-111M-C7DE.

It seems that some newer BIOS's support direct boot from an SD card.


To expand on your discovery and meuh's comment above, the tablet has two VID:PIDs. One for Android Mode, one for regular Linux mode. It is not ideal, but in order to switch in to the correct mode you need to hold down the buttons on both ends for a few seconds. More info here:

https://github.com/linuxwacom/xf86-input-wacom/wiki/Known-Issues#android-misdetect


Keyboard shortcuts in terminal in Ubuntu 16, 18 and 20

See my answer on this duplicate question as to that such hotkeys indeed are not implemented in Gnome, and what you can do instead (apart from switching to another desktop as suggested in the answer.
These window menu hotkeys are quite universal, and a lot of people are used to them for a long time. They are not implemented in Gnome Shell, and nobody has bothered implementing them. Even more, menu mnemonics apparently are not supported in Gnome Shell.
Ubuntu: Bug report at launchpad
Gnome: Upstream bug report at former bugzilla site
Gnome: Currrent issue on gitlab


How can I change the format of the panel clock in Ubuntu Mate 20.04?

Clock indicator in Ubuntu MATE 20.04 LTS is controlled by indicator-datetime service, so to customize it, you have to use commands below:
gsettings set com.canonical.indicator.datetime time-format custom

gsettings set com.canonical.indicator.datetime custom-time-format '%l:%M %p %A %B %d'

it probably was doable in dconf-editor, you would have had to set the time-format to "custom" in order for your changes to show...


What's the name of the feature in Unity that allows windows to be tiled on the left and right sides of the screen?

This is part of the Compiz Grid plugin.  On Ubuntu 10.10, I believe you need to install compiz-fusion-plugins-extra ; it can then be configured using
CompizConfig Settings Manager → Grid → Edges → Resize Actions
The defaults in Ubuntu 11.04 involve Upper Left Corner, Left Edge, and Lower Left Corner being set to Left Half, and Upper Right Corner, Right Edge, and Lower Right Corner being set to Right Half.


Ubuntu hangs after grub while installation

Boot-Repair should allow you to solve this problem, there are several ways to run it, but I suggest you to install it on Try mode of your Ubuntu Live .iso


Some older machines can't boot from USB, which might be your problem there. How far did you get with the DVD install? Does it work with e.g. just playing a DVD?

If it's just a CD drive (not DVD), you might need to use https://help.ubuntu.com/community/Installation/MinimalCD as the normal installer doesn't fit on a CD. While a bit less user-friendly than the more modern installers*, if you were on XP before, you shouldn't find it too old-fashioned, as XP's installer lacked the same modern UI advantages too.

*Though slightly easier for one or two specialist tasks.


How can I run the 16.04 installer without using `nouveau`?

I encountered a similar problem when setting up my computer with Ubuntu, which also uses the GTX970M.
The solution I ended up using was to edit the boot parameters to include the nouveau.modeset=0 option.

When booting into Ubuntu, press "e" while with Ubuntu selected as the boot option to edit the boot parameters.

After quiet splash, you should add nouveau.modeset=0.

You might also try nomodeset instead of nouveau.modeset=0

This thread might also help: ubuntu 14.04 black screen when installing


Fixing right-click context menu (Sublime Text 2)

You can try fixing the application's individual settings (in Ubuntu 12.04 onwards w/ Unity). In your terminal, enter:

sudo gedit /usr/share/applications/sublime.desktop

Now paste the following and save the file:

[Desktop Entry]
Version=1.0
Name=Sublime Text 2
# Only KDE 4 seems to use GenericName, so we reuse the KDE strings.
# From Ubuntu's language-pack-kde-XX-base packages, version 9.04-20090413.
GenericName=Text Editor
Exec=sublime %f
Terminal=false
Icon=/opt/Sublime Text 2/Icon/48x48/sublime_text.png
Type=Application
Categories=TextEditor;IDE;Development
X-Ayatana-Desktop-Shortcuts=NewWindow
[NewWindow Shortcut Group]
Name=New Window
Exec=sublime -n
TargetEnvironment=Unity

Hopefully now Sublime Text 2 will work fine from your right click context menu.


I summarize two different problems from your description

You cannot establish an SSH connection from any external IP address to your server
Once logged on to the server (from internal network) you still cannot ping an external IP address from the server.

Since you mention port-forwarding and show a private IP on your server it appears that there is NAT/NAPT in action.

The reasons for out-going ping failure and inbound SSH connect failures could be different

ping may be blocked (even at the NAT configuration)
Inbound connections need to be forwarded through NAT

your inbound SSH problems may be of this kind
lack of this configuration will not stop outbound translation and connectivity

have you tried telnet www.google.com 80 ? or to some other simple HTTP site?
This Serverfault question on ping over TCP my be of interest.


Windows 10 bootloader is not showing up in grub menu

This issue was due to Ubuntu was not installed in UEFI mode. Ubuntu should be installed in the same mode as the primary OS (in my case it is Windows).

This link solved my problem.


The answer is to put absolutely nothing for the wifi adapter into your /etc/network/interfaces file, regardless of what other sites or such state to do for configuring a static IP address for an interface.  Adding anything to /etc/network/interfaces for the wifi interface will have Network Manager not manage the wifi device, which is what you saw when it shows no networks.

When working with wireless networks and Network Manager, (or Ethernet connections and Network Manager, it's the same basic process) you have to configure network manager for how to handle the connections.  That is, you need to set the static IP in the network settings specifically for a given wifi network, like so for a given network:

That is, I connected to the wifi network (in this case an Xfinity gateway), then afterwards I went into the Network Manager settings via left-clicking the icon and selecting "Edit Connections...", selecting the wifi network, opening it in "edit", and setting the address (in this case, 192.168.215.2), netmask (it's a last-octet-variable network, so all IPs are within the 192.168.215.0 and 192.168.215.255 range, which is 255.255.255.0 for the netmask - or '24' for CIDR range designation), and gateway (192.168.215.1, the router) accordingly for my network.  You'll probably want to put 8.8.8.8 and 8.8.4.4 into the DNS servers field, though, so you can actually resolve domains.

Hit "Save", close the "Edit Connections" window, disconnect from the wifi network, and reconnect by clicking the wifi network in the networks list.  Static IP addressing is now enabled for the network and in effect, so you won't need to rely on DHCP.

You'll need to do this for every wifi network you want to set up with a static IP though.  It's not a 'global' setting.


Huawei UML397 U.S. Cellular 4G LTE Broadband USB Modem?

Better to contact the service provider

Try with selecting a similar service (providing same Modems and service Packages) in your county.


Can't Connect to MySQL via CLI or phpMyAdmin, but WordPress still connects fine

I ran across something similar to this, while setting up mysql.  MySQL doesn't consider localhost and 127.0.0.1 to be the same accessible address (despite documents often using them interchangeably).  The trick is, in your case getting connected to make changes to who can connect and how.  I'd try conncting to the loopback IP explicitly:

mysql -h 127.0.0.1 -u root -p

If that doesn't work you'll have to dig through your wordpress settings to find the host, port, username and password settings.  The good news is if wordpress is working there is a way to get in.

Once you're connected your problem is in the mysql database (use mysql) in the users table.  It's either that access control only allows one of 127.0.0.1/localhost/external IP, or anonymous users that are messing up your connections.

To see if you have any anonymous users:

SELECT User,host from mysql.user;

If you see anything with blank @ localhost etc, that's them.  To remove:

DELETE From mysql.user where User='' and host='localhost';
FLUSH PRIVILEGES;


cairo-dock starts up at the bottom-right

I had the same problem in Ubuntu 14.04 Cairo-Dock. On start up the dock would align to the right of the screen and half the apps could not be seen. To bring it back into alignment I have to right click on the dock, go to Cairo-Dock, configure and before the configuration window popped up the dock would realign itself. Then had to close the configuration window. Had to do that every time I rebooted. I tried to uninstall and re install the Cairo-Dock through the command line, but that did not work.

I right clicked on the Cairo-Dock, up to Cairo-Dock, configure, then wait for the configuration window opens. Go to themes tab to your right. Click on the theme you have chosen and have been using. Go to apply down the bottom right. Now you will have a choice, green tick, continue and loose any changes you have made or red cross to cancel. I was just able to press the cancel button and my dock repaired itself and has opened correctly ever since. You may need to apply the changes if that doesn't work. You will have to adjust all your apps, but it worked for me.

I am a new user myself, so let me know how you went.


How do I access Linux commands from Wine?

Sometimes it's better to say "no" and this is one of these cases... What you're trying to do is to put a secure front-end over an insecure back-end.

Windows comes from a heritage of a single-user, single-tasking OS. (DOS)
Linux comes from a heritage of a multi-user, multi-tasking OS (Unix)

For the former, security was an afterthought, (though it has come a long way) and the latter, security was by design.

What you're trying to do is to secure an insecure system by opening up the things on the secure system it's running on, therefore propagating errors instead of containing them.

To put this in human terms: you're putting in a firewall and then opening up too many ports.

Don't do it!

Instead, secure Ubuntu more instead of less...


How to add workspace indicator in Unity/Metacity?

I know exactly what you are going for. I saw this in an article some time ago the link to which can be found at the bottom.

In 12.04, you can install that by running these codes in terminal:

sudo add-apt-repository ppa:geod/ppa-geod
sudo apt-get update
sudo apt-get install indicator-workspaces

Once installed search for it in the Unity dash and done. You may also need to add it to the list of start-up applications.

In 12.10 Quantal, you have to install the .deb file built for 12.04 Oneiric manually (as of January 2013, the PPA doesn't have a package for 12.10). The .deb file you can obtain from the aforementioned Launchpad PPA page. Run these in terminal:

wget https://launchpad.net/~geod/+archive/ppa-geod/+files/indicator-workspaces_0.6.4_all.deb
sudo dpkg -i indicator-workspaces_0.6.4_all.deb

Source: http://www.techdrivein.com/2011/05/10-useful-application-indicators-for.html


In alsa-utils 1.0.26, arecord has the option --dump-hw-params for this.


AR9485 - Kubuntu (Ubuntu 14.04.1 LTS) wireless not connecting anymore

Do:

sudo ifconfig wlan0 down
sudo modprobe -rv ath9k
sudo modprobe -v ath9k nohwcrypt=1
sudo ifconfig wlan0 up

the settings will be lost after you reboot, so if it helps we will need to make it permanent.


Kernel Panic while Installing Ubuntu 12.10 from USB Drive

That seems to be an hardware failure using Ubuntu software architecture... That fault is hard to discover, my guess is CPU overload or some bridge overload due to high speed disk communication... I have a similar situation when I boot from USB3 port, but, if I boot in the USB2 port everything works, which proves that software and configuration is OK, the solution is just to make things work slower!


How can I disable scrolling between windows if my mouse is in the xfce panel?

This can be changed, but the toggle is really well hidden.

Right click on the panel, select "Panel" then "Panel Preferences".

Switch to the "Items" tab, select the "Window Buttons" item in the list and click the wrench icon.

Then uncheck "Switch windows using the mouse wheel"

You're done!


Connecting to two different wifi networks from 2 different devices(internal and external)

From: https://www.garron.me/en/bits/ubuntu-configure-wired-or-wireless-network-only-for-internal-use-internet.html

  Say you have two network interfaces configured on your Ubuntu Desktop,
  and you want one of them to be used for Internet and the other only
  for its own internal resources.

  We will do this using the graphical interface and this how-to works
  for both Unity and Gnome Shell.

  Go to System Settings and then to Network Settings.

  Then select the interface you want limited for internal use, which can
  be a wired interface or a wireless one:

  Select routes, and in the next screen, toggle on "use this connection
  only for resources of its network"

  Click OK and enter your password where prompted.