Sometimes writing down the question helps

1 -> https://bugs.debian.org/cgi-bin/pkgreport.cgi?pkg=librsvg2-dev;dist=unstable

3 -> https://wiki.debian.org/BuildingTutorial and http :// ccm. net/faq/809-debian-apt-get-no-pubkey-gpg-error


Hidden sidebar: how can I disable popping up icons?

The described behavior is done by design and so, the default and expected behavior. There is a possibility to avoid the popping up of those icons using the unity-tweak-tool. You can install the tool by executing sudo apt install unity-tweak-tool. Open Unity Tweak Tool from the dash  and switch the Icons settings of Urgent animation and Launch animation to No animation.

Now the little caveat : I have tested it and mostly it works as expected, but sometimes it didn't ... (because as mentioned before, it is not the default behavior being intended by the design team). But that might be due to the fact that I switched the settings too often during the testing phase. When you just keep the changed settings and restart the session, it also might work persistently.


The package that needs to be installed for the MySQL server is named mysql-server. If /etc/init.d/mysql does not exist, the MySQL server is not installed. After installing it using sudo apt-get install mysql-server, it will be started automatically (after the installation and on startup).

Ubuntu has migrated from traditional initscripts to Upstart. If you run /etc/init.d/mysql [action] you'll get a notice.

To stop MySQL, run:

sudo stop mysql

To start it:

sudo start mysql


My computer boots to a black screen unless I run memtest

Add nomodeset to your grub commandline.

Edit your /etc/default/grub file.

Look for this line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Append nomodeset to the line so it looks like this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset"

Now update your grub with:

$ sudo update-grub

Then reboot.


Problematic Installation of MOLDEN on Ubuntu

Follow this pointers to satisfy the requirements to install molden from source: Pointers for installing Molden from source

sudo apt-get install gfortran libX11-6 libX11-dev libgl1-mesa-glx libgl1-mesa-dev build-essential mesa-common-dev libglu1-mesa-dev libxmu-dev makedepend xutils-dev wget


Ubuntu 14.04.3 Intel HD 4000 stuck at 1050-1100Mhz => Heat

I had this kind of a problem on a Samsung notebook too.
After looking into the logs I found that a CPU microcode update was needed.

You can do it by running:

sudo apt-get install intel-microcode

Samsung does not release bioses with new microcode. That is a problem.

It may solve your problem. I had the same generation Core i3.

You can also try to toggle CPU powersafe in BIOS, if the first solution does not help.


How to recover files deleted in encrypted home before a failed upgrade?

Problem solved.

I used a live USB of 12.04 and ran sudo ecryptfs-recover-private after mounting the target drive with the previous install.
I followed the prompts and entered my login and it was decrypted to a temp folder. Using gksudo nautilus I copied the entire home directory to another HDD.
I made a fresh install of 12.04 and then copied the same folder to desktop, I could not unmount the drive after and noticed that the trash was full, it contained the same files I had deleted from windows, I copied those files back to the windows HDD rebooted and everything is back to normal.

BACKUP before you do anything, i was very lucky on this occasion.


Installing Ubuntu I get: please use a kernel appropriate for your CPU

Sounds like your computer is set up to run a 32 bit operating system. You need to download the 32-bit (i386) version of Ubuntu in order for it to work with your hardware. 32-bit is more common on older machines.


Questions viz. UEFI enabled post Ubuntu Mate installation while the Partitioning is still MBR

Without adding an EFI partition and then installing the EFI bootloader(s), you cannot boot in UEFI mode.  UEFI mode does not depend upon the disk partitioning type, but usually, UEFI is put on a gpt partitioned disk because Windows requires gpt for UEFI (Ubuntu does not care).  If your amchine allows a preference selection for mode (legacy before UEFI, or vice versa), then your machine should still boot (in legacy). If you machine settings only allow UEFI or legacy(CMS), then setting it to UEFI will not boot (no UEFI bootloaders).


sed to var which save special characters

It's the ampersand in the replacement part that is like causing your concern. An Ampersand in the replacement part is replaced with the text that matched the pattern. An example:

$ before="time&again"
$ after="to&fro"
$ sed "s/$before/$after/" <<END
> hello
> world time&again !
> END
hello
world totime&againfro !

So, the matched text time&again is replaced by to&fro, except the & between "to" and "fro" is itself replaced by the matched text.

The solution is to escape the ampersand in the replacement side. Using bash parameter substitution will give the desired results:

sed "s/$before/${after//&/\\&}/"


Is there a windows installer (wubi) for Ubuntu 15.04?

Quoted  from https://gameplayjdk.wordpress.com/2014/04/19/ubuntu-the-big-mystery-about-wubi-explained-19-04-2014/

  Canonical has stopped the official support and promotion of wubi for
  all Ubuntu versions past 12.10. But wubi got shipped until 13.10 on
  releases.ubuntu.com and is still shipped as part of the .iso images
  for the future ubuntu releases (verified for 14.04 &<), where it’s
  functionality is limited to a prompt which tells you to burn the image
  onto a DVD and restart and boot your PC from CD-Drive.


Results of apt-cache rdepends mono-devel:

$ apt-cache rdepends mono-devel
mono-devel
Reverse Depends:
  mono-mcs
  monodevelop
  nant
  mono-xsp4-base
  fsharp
  mono-complete
  libmono-cil-dev
 |cli-common-dev

As you can see, although mono-runtime is a dependency of pinta mono-devel is not, so you can safely uninstall mono-devel without it affecting pinta. There isn't any reason to leave mono-devel on your HDD unless you have any of the programs in the block quoted list in the answer installed.


Windows are disappearing and I don't know how, why and how to reverse it

It looks like you are accidentality switching to a different workspace (desktop). It's easily done in Xfce by simply scrolling the mouse wheel while the mouse is over the workspace switcher. You can find the workspace switcher on the top bar near to the right.
The mouse wheel shortcut can also be disabled by right-clicking the workspace switcher then Properties > uncheck Switch workspaces using the mouse wheel.


How do I prompt users with a GUI dialog box to choose file/directory path, via the command-line?

You can use this for files:

zenity --file-selection

and this for folders:

zenity --file-selection --directory

for usage, run:

zenity --help-general
zenity --help-file-selection

Generally it matches the current theme (for GTK window managers anyway), on my machine with a modded version of Zukitwo 3.8 it looks like this:

One way of using it is like this:

echo "you selected $(zenity --file-selection)"

Which would result in you selected /path/to/file.

You can also use options to set an appropriate title, and the directory it starts in - With your rsync use case, for example:

zenity --file-selection --directory --title="Choose rsync source directory" --filename=$HOME/Desktop/

For files, you can also specify a filetype to select - e.g:

zenity --file-selection --file-filter='PDF files (pdf) | *.pdf' --title="Select a PDF file"

NOTE: You can also use YAD, a fork of Zenity that has loads more features.

sudo add-apt-repository ppa:webupd8team/y-ppa-manager
sudo apt-get update
sudo apt-get install yad

Source

For the most part you can use it the same way - for the file browser:

yad --file-selection

and for the help page:

yad --help-all

Though at the time (around version 26?), it had not been updated to match the new GTK 3.14+ interface (zenity had) - it has more features, but check compatibility (based on documentation it should work on GTK+ >= 2.16.0


My linux has got stuck in grub rescue mode

Switch on the laptop, wait till you get the Grub Rescue Screen
Type the following commands
ls
It will show you a list of partions you have made
You will get something like this (hd0),(hd0,msdos1)(hd0,msdos2)(hd0,msdos4)
 You need to find which drive is your Ubuntu root for which type the following:
set prefix= (hd0,msdos1)/boot/grub
If it’s not the root drive you will get an error message "unknown filesystem". In that case try the same command with the next partion, ex:   - set prefix=(hd0,msdos2)/boot/grub
If you are not getting an error: Congrats, you have found your root drive. You can proceed to the next command after that:

set prefix=(hd0,msdos1)/boot/grub
insmod normal
normal
Your PC will now boot successfully. Now select Ubuntu & login.
Open Terminal( Ctr+Alt+T or use the search)
sudo update-grub
sudo grub-install /dev/sda

 Now the bootloader error is fixed you should be able to boot your laptop normally & even your data is intact.
Note: If sudo update-grub didn't work, type sudo grub-update
 Once In my case, grub-update didn't happen same day but few days alter alongwith sudo apt dist-upgrade


How do I get the Tascam US122L USB audio interface to work?

"This sound device does not have any controls"

Sounds like you face a problem similar to what I had getting the FCA610 to work. The device has probably been detected and brought up by ALSA just fine (you can check this be suspending pulseaudio and use the card with aplay and arecord), but doesn't get picked up by PulseAudio because it cannot find a matching profile for your interface (look at the output of pulseaudio -vvvv to find messages of PulseAudio giving up to configure the device after trying for 5 times).

I was pointed to a discussion from January 2014 for a workaround on the PulseAudio mailing list and was able to get my device working.

Note that the topic was about firewire devices. For USB devices you would have to use a matching udev rule with vendor and product id for your device, mine looks like this:

ATTRS{idVendor}=="1397", ATTRS{idProduct}=="0003", ENV{PULSE_PROFILE_SET}="multichannel.conf"

you can find the vendor end product id of USB devices by using lsusb, here is the example for the Behringer FCA610:

Bus 003 Device 051: ID 1397:0003 BEHRINGER International GmbH

To create and edit files on the commandline you can use nano. Ctrl+o saves changes and Ctrl+x quits.

There is also a patch from David Henningson that adds functionality to properly detect such devices, but you would have to compile PulseAudio yourself to test this (which I didn't find enough time for).


Well after looking pretty closely into other replies, turns out the color problem was a delink from the bashrc, it was solved using source ~/.bashrc, but my airflow server is still unrecognized
And after a lot of efforts I found the problem with the command not found, it was a problem of PATH that was never going into anaconda, where all the stuff I wanted to launch was.
A simple export PATH=$PATH:/home/florentin/anaconda3/bin/ closed the deal !


Ubuntu 18.04 unable to reach DNS after upgrade

After upgrade from 16.04 (xenial) to 18.04 (bionic) Network Manager had no DNS.

Although I wrote DNS in GUI.

Really, removing dns=dnsmasq helped me.

Thank you very much!


After installing nginx with Passenger support in '/opt', why won't it start from 'init.d'?

The usual way of installing a Rails + NGINX + Passenger + RVM setup usually involves nginx being placed in /opt/nginx, but it in fact doesn't create the init.d startup file. This blog post shows how you can easily grab one from Linode:

wget -O init-deb.sh https://www.linode.com/docs/assets/660-init-deb.sh
sudo mv init-deb.sh /etc/init.d/nginx
sudo chown root:root /etc/init.d/nginx
sudo chmod +x /etc/init.d/nginx
sudo /usr/sbin/update-rc.d -f nginx defaults

For posterity, here is the script from Linode:

#! /bin/sh

### BEGIN INIT INFO
# Provides:          nginx
# Required-Start:    $all
# Required-Stop:     $all
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: starts the nginx web server
# Description:       starts nginx using start-stop-daemon
### END INIT INFO

PATH=/opt/nginx/sbin:/sbin:/bin:/usr/sbin:/usr/bin
DAEMON=/opt/nginx/sbin/nginx
NAME=nginx
DESC=nginx

test -x $DAEMON || exit 0

# Include nginx defaults if available
if [ -f /etc/default/nginx ] ; then
        . /etc/default/nginx
fi

set -e

case "$1" in
  start)
        echo -n "Starting $DESC: "
        start-stop-daemon --start --quiet --pidfile /opt/nginx/logs/$NAME.pid \
                --exec $DAEMON -- $DAEMON_OPTS
        echo "$NAME."
        ;;
  stop)
        echo -n "Stopping $DESC: "
        start-stop-daemon --stop --quiet --pidfile /opt/nginx/logs/$NAME.pid \
                --exec $DAEMON
        echo "$NAME."
        ;;
  restart|force-reload)
        echo -n "Restarting $DESC: "
        start-stop-daemon --stop --quiet --pidfile \
                /opt/nginx/logs/$NAME.pid --exec $DAEMON
        sleep 1
        start-stop-daemon --start --quiet --pidfile \
                /opt/nginx/logs/$NAME.pid --exec $DAEMON -- $DAEMON_OPTS
        echo "$NAME."
        ;;
  reload)
          echo -n "Reloading $DESC configuration: "
          start-stop-daemon --stop --signal HUP --quiet --pidfile     /opt/nginx/logs/$NAME.pid \
              --exec $DAEMON
          echo "$NAME."
          ;;
      *)
            N=/etc/init.d/$NAME
            echo "Usage: $N {start|stop|restart|reload|force-reload}" >&2
            exit 1
            ;;
    esac

    exit 0

One thing to look out for: if you've changed your nginx.pid location (defaults to /opt/nginx/log, I changed mine to /var/run), you'll need to change it in this file. Near the top, just declare it as a variable:

PIDPATH=/var/run/$NAME.pid

And replace anywhere that has the path to the pid with $PIDPATH. (Even if you're keeping the original path, this makes the script more readable).


How can I combine application launchers into one launcher icon?

GUI quicklist editor

Combining (commands to start-) applications is one of the options of QLE Unity Quicklist Editor. Although you can create a new icon and add your applications, I'd suggest adding your application shortcuts to an existing launcher icon, like below:

Adding applications to an existing icon

In the QLE main window, In the left column, you'll find the current Launcher items, click on the launcher you'd like to edit (Gimp in our example):

In the right column, you'll see possible quicklist (right-click) items of the launcher (currently none).
Click on the  icon, a drop-down list will appear, choose, "Add an application shortcut":

In the (alphabetical) list that appears, pick your application and click "Add". Repeat untill all the applications you want to add to the iconb are added.

That's it. This way you can save a lot of space in your Unity Launcher.

Note

The quicklist editor is currently being rewritten in Gtk, mainly for "cosmetical" (appearance) reasons. The current version still works fine in 16.04 though.

To install

sudo add-apt-repository ppa:vlijm/qle
sudo apt-get update
sudo apt-get install qle


debian for truecrypt-7.1a for ubuntu 14.04

Im pretty sure TrueCrypt is a dead project. I don’t think you’ll see new packages coming out, and I dont think the mainline debian devs will be touching it either. Here is an article on why:
http://krebsonsecurity.com/2014/05/true-goodbye-using-truecrypt-is-not-secure/


No sound in ubuntu 17.10 with Intel Corporation Sunrise Point-H HD Audio

found the answer:
open terminal and type "sudo apt install pavucontrol"

open the pavucontrol and click the ">" sign until you found configurations tab

select "Analog stereo duplex (unplugged)"

now close the app and you are done.

(if you only have headphones; go to the "output devices" tab and select headphones from the drop down)


Binding the meta key (a.k.a. super key / Windows key) to left click

You can use xdotool + xbindkeys

insall xdotool and xbindkeys

sudo apt-get install xdotool xbindkeys

generate the default configuration file for xbindkeys

xbindkeys --defaults > ~/.xbindkeysrc

open ~/.xbindkeysrc with some text editor

kate ~/.xbindkeysrc

add these lines in the end of the file

"xdotool mousedown 1"
    Super_L
"xdotool mouseup 1"
    Super_L + Release

this will make the left 'windows/super/meta' button act like the left mouse button .
for me the releasing thing didn't work specifically with the super button , but it worked with other buttons (I actually used KP_Delete which is the del/. button in the numpad, instead of using Super_L ), but I think this may be a hardware related issue.
save the file and close the editor.
start (or restart) xbindkeys

sudo killall xbindkeys && xbindkeys


Installation using WUBI stops after reboot

WUBI is very unstable. You can test ubuntu with livecd/liveusb. When you use in install option "Install alongside Windows" you do not have a chance to lose data.


how I can download and install C++ in Ubuntu?

Just install G++, the C++ compiler of GCC:

$ sudo apt install g++

You can then compile your source code like this:

$ g++ code.cpp -o file

This will compile "code.cpp" to "file"


My guess is that since the data you are transferring are written in memory through DMA from your network card, and then stored to disk again using DMA (i.e. memory regions that cannot get swapped), the kernel just swaps pages from other applications, which is normal and, imho, shouldn't alarm you.

When system cannot allocate any memory theoretically it terminates processes to free memory (I don't know the algorithm that it uses to choose which ones). Practically system freezes and/or panics in my experience.
When transfer is complete, swap data will be read back to memory when needed.
You can turn off the swap and then turn it on again using swapon and swapoff commands.


Some indicators are missing when unlocking the screen

You can first try to update to the new gnome-screensaver with apt. the new Version is 3.6.0. and fixes some broken links with the lock screen!

Here is the Changelog - i think this might help! It has been released  four days ago!

  gnome-screensaver (3.6.0-0ubuntu2.1) quantal-security; urgency=low

  SECURITY UPDATE: broken screen locking with Unity desktop (LP: #1120126)

  debian/patches/19_autostart_in_unity.patch: change AutostartCondition
  so gnome-screensaver gets started properly in the Unity session also.
  CVE-2013-1050  -- Marc Deslauriers    Sat, 09 Feb 2013 09:44:56
  -0500

  ** Changed in: gnome-screensaver (Ubuntu Quantal)
         Status: Confirmed => Fix Released


Ubuntu 14.04 Running Low Graphics Mode After Upgrading Software

There is bug at ubuntu 14.04. It not working as the same as older version. When you install Ubuntu, press left shift. Choose your language, press f6, choose pci off. Then esc, than try Ubuntu. You have to try it before install it. In the live image choose to install than it will work.


How can I install Ubuntu Studio on Alienware 17

i don't know if this will answer your question , but i had the same issue installing Ubuntu 16.04 LTS on my alienware m17x , couldn't find a fit solution for it, ive fixed it by removing dell raid and made my hd with non-raid standard.

doing so after bios menu , ctrl+i , and i deleted dell raid partition then installed Ubuntu on it.

notice : what i did is deleting all the hd. before doing so backup your alienware drivers and applications in a flash drive, because all alienware drives and applications are based on java/jar, so there is a way to combine them into Ubuntu.

cross-complied alienware alienfx-lite

read first:
(http://forum.notebookreview.com/threads/alienfx-lite-linux-windows-alienfx-tool.458528/)
getting alienware fx:

install git:

sudo apt-get install git

clone alienware fx:

sudo git clone https://github.com/r0ttten/AlienFxLite


Share external hard drive between two Ubuntu computers

It is likely not a samba issue but a Linux permissions issue.

When you attach an external USB storage device to your system it automounts to a mount point at /media/your-user-name/XXX. The problem is Linux sets  /media/your-user-name with special permissions ( acl ) that prevents anyone other than "your-user-name" from traversing the folder to get to XXX.

If you set your share allowing guest access the client will never gain access.

THere are a number of ways around this but if this is a home network just edit /etc/samba/smb.conf and right under the workgroup = WORKGROUP line add this one using your local login user name:

force user = your-user-name

Then restart smbd:

sudo service smbd restart


If Apt can't resolve this conflict itself you should be able to solve this if you force the installation of the higher of the two package versions:

sudo apt-get install -f libc6:i386=2.23-0ubuntu7

If Apt still refuses you can resort to a manual installation:

cd /tmp
apt-get download libc6:i386=2.23-0ubuntu7
sudo dpkg -i libc6_2.23-0ubuntu7_i386.deb
sudo apt-get install -f


As far as I know, it doesn't support anything other than Ubuntu (it is the Ubuntu Linux SDK after all). You can install it by downloading the .deb for it here: http://packages.ubuntu.com/raring/devel/ubuntu-sdk and then using this command in Terminal:

alien -r <FILE>.deb

This isn't recommended by the users I got the command from


Do sudo update-alternatives --remove-all gccc.


sounds like a graphics driver issue. make sure to install the appropriate drivers for your graphics card.


Check this related post... Here

I would try and re-build the MBR and boot to windows OS first. Then try re-install of Ubuntu.


Unable to re-install VLC after a partial upgrade (12.04) due to broken packages

If you're using ppa:videolan/stable-daily to install vlc, please consider that 64bit builds were still pending until 9 minutes before since the instant I'm writing.

To add repo, if you didn't add it before:

sudo add-apt-repository ppa:videolan/stable-daily

Then:

sudo apt-get update
sudo apt-get upgrade


sources.list broken -- missing universe, multiverse etc.. in 18.04.1 server?

There is no way to know what happened but here is what the file looks like from a vanilla desktop install.  I removed the comments.

You can remove the "us." if you don't want to use the US server.

deb http://us.archive.ubuntu.com/ubuntu/ bionic main restricted
deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates main restricted
deb http://us.archive.ubuntu.com/ubuntu/ bionic universe
deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates universe
deb http://us.archive.ubuntu.com/ubuntu/ bionic multiverse
deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates multiverse
deb http://us.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu bionic-security main restricted
deb http://security.ubuntu.com/ubuntu bionic-security universe
deb http://security.ubuntu.com/ubuntu bionic-security multiverse


Basically : it's a complete pain.

Drivers are copies from macOS-cups, so you have to modify the ppd.gz,
(cups says filter missing and the the problem is that the ppd refers to some files in the wrong location under /Library/...)

Status can only be monitored with the Windows "Print Center" ( until somebody deciphers their protocol )

Duplex key has to be activated in Windows "Print Center", and you have to send 2 pages (1 Front , 2 Back)

Labels:
For the labels you might try glabels.
I personally use GIMP with the "digital print template" from here on youcard.de, because you have to send the proper "paper size" (card).
(For double side printing you could just

"merge visible layers" in GIMP
then duplicate the 1 remaining layer
export the file as MNG (e.g. test.mng)
then convert file.mng file.pdf

to yield a multi page pdf.)

Printing Modes:
Example for MonochromeMultiplex :
lpadmin -pEVOLIS-Primacy -o GDuplexMode=DUPLEX_MM -o GRibbonType=RM_KBLACK ;lpr  -o landscape -o fit-to-page -o media=Card -PEVOLIS-Primacy Vorlage-Digital-Plastikkartendruck.pdf

possible printing modes: 'SIMPLEX','DUPLEX_CC','DUPLEX_CM','DUPLEX_MM','DUPLEX_MC'

Ribbon Selection:
it is important to select the according ribbon mode
this is one of

'RC_YMCKO'
'RC_YMCKOS'
'RC_YMCKOK'
'RC_YMCKOKOS'
'RM_KO'
'RM_KBLACK'
'RM_KWHITE'
'RM_KRED'
'RM_KGREEN'
'RM_KBLUE'
'RM_KSCRATCH'
'RM_KMETALSILVER'
'RM_KMETALGOLD'
'RM_KSIGNATURE'
'RM_KWAX'
'RM_KPREMIUM'
'RM_HOLO'`


I installed the 7.1.2 version and it seems to work a lot better than the 7.2.In fact,it is working perfectly.I do not know if this happened only in my system or happened in other systems as well.After a small google research it seems that many people are blaming the Auto Updater of Netbeans for those kind of errors.


How to fix a broken gsettings setting without gnome-session?

1. Get back to a working desktop

Ctrl+Alt+F1 and log in.

mv .config/dconf/user{,-old}
exit

Alt+F7 back to the gdm login screen and log in. All your settings are gone, but at least you're back to your desktop.

2. Dump your old settings

Start a Terminal.

echo "user-db:user-old" >db_profile
DCONF_PROFILE=~/db_profile dconf dump / >old_settings

Now edit old_settings with your favourite editor and remove/correct the bit you broke.

3. Import your corrected old settings.

rm db_profile
mv .config/dconf/user-old ~/user-settings-delete-later
dconf load / <old_settings

Things should be Ok now and you can delete your ~/user-settings-delete-later file if happy.

Credit due here: https://unix.stackexchange.com/a/199864/23542


How to change Video Settings in Ubuntu 12.04

I can't tell if you have one monitor working or not from the question. Assuming one monitor is working, I had a similar issue with Ubuntu 12.04.

When I go to "Displays..." my second monitor isn't detected so I could not enable it. However, when I searched for Nvidia in my application directory (Dash Home) I found the "Nvidia X Server Settings" utility. That utility detects my second monitor, and once I enable it there it works just fine.

So, assuming you have one monitor working and have already installed the correct video drivers, search Dash Home to see if there is a config utility.


Restoring the Ubuntu desktop and access to files

Given your situation i would consider a fresh install because
8.04, 8.10, 9.04, and 9.10 have reached there EOL end-of-life, which means they no longer receive support or updates. However, they have been archived and are available:

old releases

http://old-releases.ubuntu.com/releases/8.10/

http://old-releases.ubuntu.com/releases/8.04.0/

http://old-releases.ubuntu.com/releases/9.04/

http://old-releases.ubuntu.com/releases/9.10/

Given those options you may also want to consider Lubuntu because it is a lighter-less bloated distribution.

It can be found here:  https://help.ubuntu.com/community/Lubuntu/GetLubuntu


Using a Mercusys AC650 usb wifi on in Ubuntu 20.04

You can use dkms to install the driver for a new kernel version, in terminal do
cd rtl8821CU
make clean
sudo ./dkms-install.sh


Keyboard shortcut to focus on (idle) terminal

First set the world "Terminal" to appear in the window title of your gnome-terminal. To do this, when you are in gnome-terminal go to Edit → Profile Preferences, select Title and Command tab and be sure that the field Initial title contain the word "Terminal":

Second, add a new custom keyboard shortcut for the following command:

bash -c "[[ \"$(cat /proc/$(xdotool getwindowpid $(xdotool getwindowfocus))/comm)\" != \"gnome-terminal\" ]] && wmctrl -a Terminal || xdotool key Alt+grave"

To do this, go to System Settings → Keyboard, Shortcuts tab, select Custom Shortcut and add a new custom shortcut:

As you can see, I chose as shortcut F8 key which is working great in this case for me.

Note: wmctrl and xdotool must to be installed in order to use them. If you don't have them installed, you can install them from terminal using:

sudo apt-get install wmctrl xdotool


Random system halt/crash with Ubuntu 20.04 on Raspberry Pi 4

I have put some more time into this problem. After running stable for 24h hours now I am quite certain the issue is related to the suspend feature offered by the hardware and several desktop environments. The Raspberry Pi either fails to wake from suspend or fails to suspend.

What solved the issue for me was turning off Auto-suspend. For example, Gnome allows you to set suspend under System Settings -> Power. The Auto-suspend setting there is enabled by default. If you change that setting to Never, the Raspberry will run stable.

On a somewhat related note, it would be very nice to have kdump/kexec work on the Pi. Did someone ever figure out an initramfs/cmdline that works?


ubuntu server crashes on startup while loading/saving backlight brightness

I had the exact same problem on LXLE which is an Ubuntu flavor of the LTS desktop version 16.04.4 which I was trying to run on an Inspiron 1018 which has no keyboard backlighting.

Did you get this problem figured out?  Did some research & found the answer at the Linux Lite forum.

Go directly into recovery mode only stopping long enough to hit the e & change the file system to rw from ro.
At the recovery menu select root & then enter to get to the prompt.
Being a novice I went to the /var/lib/systemd/backlight folder to look at the platform-dell-laptop:leds:dell::kbd_backlight file when actually I think all I would have had to do was systemctl mask systemd-backlight@leds\:dell\:\:kbd_backlight.service.

That fixed the problem & I hope this helps someone else.


This is not secure as hint, but this could help, but only when gnome is your
windows-manager :

sudo apt-get install --reinstall bash gnome-terminal

In case of windows-manager xfce4 you type :

sudo apt-get install --reinstall bash xfce4-terminal

In case of unity a rebound of packages could help as follows :

sudo apt-get install --reinstall python3-all
sudo apt-get install --reinstall gnome-terminal
sudo apt-get install --reinstall ubuntu-desktop
sudo apt-get install --reinstall unity

Then in the end :

sudo reboot

This hint could help too :
You should clean you ubuntu installation with software-package bleachbit, perhaps some caches are untidy. And keep it clean too with clamav.


First, run locale and check output (in my case):

LANG="it_IT.UTF-8"
LC_COLLATE="it_IT.UTF-8"
...

then, generate locale and finally reconfigure (replace it_IT.UTF-8 with your lang):

sudo locale-gen it_IT.UTF-8

sudo dpkg-reconfigure locales

this should solve the problem


Install your display driver. http://support.amd.com/us/gpudownload/linux/Pages/radeon_linux.aspx


Are you using Chromium? Because Google Chrome does include Flash Player by default, Chromium does not. If you don't want to do that much with commands and terminals, I'd recommend to download Google Chrome from Google their official download page, and then double-clicking it to open it up with the Software Center. Or you could use the dpkg command in order to install the package.


I think it should be

alias myconf='sudo nano /opt/nginx/conf/sites-available/efiling'

with single-quotes instead of double-quotes.

You can also use

$ source ~/.bashrc

to load bash.rc without closing the terminal/logging out.


Will Google Chrome update itself considering that it has been downloaded as a standalone .deb file?

Google Chrome

The .deb file of Google Chrome adds a repository automatically to your software sources - you will get automatic updates once a new version appears in the stable channel.

With it in your software sources, you can also easily swap between the stable, beta and unstable versions of Google Chrome: google-chrome-beta and google-chrome-unstable can be installed simply from Synaptic or the terminal way (installing either one will first ask to remove google-chrome-stable).

Go to Software Sources > Other Software, in the list you will see:

http://dl.google.com/linux/chrome/deb/


config Squid for allow user working between monday to saturday 08.00 AM to 08.00 PM

The days of the week are defined with letters, to be used as follows:
S - Sunday
M - Monday
T - Tuesday
W - Wednesday
H - Thursday
F - Friday
A - Saturday

When the first letter is ambiguous, the second letter is used.
Source: Access Control and Access Control Operators - Squid User Guide


Download the 3.4.2 source files from here
Extract it to a temporary directory within your Downloads folder
Open a terminal session.
Navigate to the folder with cd ~/Downloads/Python-3.4.2
As per the Python documentation, run the following commands from the terminal:

./configure
make
make test
sudo make install

This will upgrade your existing Python-3.4 installation to Python-3.4.2 (accessible as python3)


sudo apt-get update gives the following errors and hence cannot update my system

Try to remove "in." from http://in.archive.ubuntu.com in

/etc/apt/sources.list

Now what you might do to automatize this is:

sudo sed -i 's/in.archive/archive/g' /etc/apt/sources.list
sudo apt-get update -y
sudo sed -i 's/archive/in.archive/g' /etc/apt/sources.list


I was able to expand it using lvextend -L +XG /dev/HOSTNAME-vg/root

As seen here


AFAIK, the non Proprietary Drivers dont work well with games

And on how to report a bug, Take a look at this answer


Had the same on 12.04 with cinnamon 1.6.7. All 4 cores (i5) were at ~50% constant with strace revealing intense polling activity (futex, poll, recvfrom). Mem usage was excessive too, nearing 2GB virt and ~250MB res.
Searching for cpu at Cinnamon issues suggested it may be related to "Cinnamon 2D", which is what i was using.
Solved it by switching to "Cinnamon" (you have to logout for that), CPU now is below 4%.


Downloading the whole content of my storage into another computer

Ubuntu One is a file synchronization service. If you simply install the client, log in, and subscribe to all your folders in the client, all your files will be downloaded by the client.

There is no way on the web site to download all your files at once though, no.


If you take a quick look at Server Block Examples, you may notice the first example shows how NGINX can server two different domain names.
http {
  index index.html;

  server {
    server_name www.domain1.com;
    access_log logs/domain1.access.log main;

    root /var/www/domain1.com/htdocs;
  }

  server {
    server_name www.domain2.com;
    access_log  logs/domain2.access.log main;

    root /var/www/domain2.com/htdocs;
  }
}

Typically, these server blocks are separated out into their own files in a directory NGINX is configured to scan for (ie /etc/nginx/conf.d/ or /etc/nginx/sites-enabled/).
By loading up two valid server blocks which each have a different server_name will result in NGINX serving both (or more) domains.
I always check Pitfalls and Common Mistakes when creating configurations as well.


Ubuntu 20.04 file browser showing all zfs mounts explicitly in side-panel

I have reported a bug. No action here :-)
https://bugs.launchpad.net/bugs/1899089


Is there any way to use Auto Hot Keys on ubuntu?

I have already used AutoHotKeys on Windows, I doubt it can work fully on Linux (because It tries to control the desktop environment), however several Wine users reported good results, read this: https://appdb.winehq.org/objectManager.php?sClass=application&iId=5173


Why is there a one-second timestamp difference on copy?

If you don't fear the terminal you could write a small shell script which copies your files periodically. Use cron to run the script for example every 15 minutes.

#!/bin/sh

source=/path/to/your/source/folder
target=/media/your/usb/drive

sudo rsync --verbose --recursive --update --human --progress $source $target

Then create an cron entry with crontab -e

Check these links for detailed information:

https://wiki.ubuntu.com/ManXamples/rsync

http://linux.die.net/man/1/rsync


Remove Gnome Shell completely after installing it?

software center
Gnome-Shell and Gnome-Classic (also known as gnome-fallback/gnome-session-fallback) can be simply removed from the Software Center:
search for gnome shell

search for gnome-session-fallback

remove all packages
However, removing from the software center does not remove every package originally installed.
To do this, copy and paste the following into gnome-terminal:
to remove gnome-shell
sudo apt-get purge alacarte cups-pk-helper gir1.2-accountsservice-1.0 gir1.2-caribou-1.0 gir1.2-clutter-1.0 gir1.2-cogl-1.0 gir1.2-coglpango-1.0 gir1.2-folks-0.6 gir1.2-gconf-2.0 gir1.2-gdesktopenums-3.0 gir1.2-gee-1.0 gir1.2-gjsdbus-1.0 gir1.2-gkbd-3.0 gir1.2-json-1.0 gir1.2-mutter-3.0 gir1.2-networkmanager-1.0 gir1.2-panelapplet-4.0 gir1.2-polkit-1.0 gir1.2-telepathyglib-0.12 gir1.2-telepathylogger-0.2 gir1.2-upowerglib-1.0 gir1.2-xkl-1.0 gjs gnome-applets gnome-applets-data gnome-contacts gnome-icon-theme-full gnome-panel gnome-panel-data gnome-session-fallback gnome-shell gnome-shell-common gnome-themes-standard indicator-applet-complete libcaribou-common libcaribou0 libclutter-1.0-0 libclutter-1.0-common libcogl-common libcogl-pango0 libcogl9 libgjs0c libmozjs185-1.0 libmutter0 libpanel-applet-4-0 mutter-common python-gmenu

to remove gnome-classic
sudo apt-get purge alacarte cups-pk-helper gir1.2-gconf-2.0 gir1.2-panelapplet-4.0 gnome-applets gnome-applets-data gnome-panel gnome-panel-data gnome-session-fallback indicator-applet-complete libpanel-applet-4-0 python-gmenu


The module included in GitHub is only kernel module. It creates /dev/fl2000-0 (or -1) and allows you to talk to the device. It does not handle extending your display to that device.


Weird looking screen after Ubuntu Server 11.04 boot

Temporarily edit your grub boot settting: remove vga=something and replace it with nomodeset. If you can boot normally to the desktop, do your troubleshooting and perhaps install/uninstall proprietary graphics driver or maybe remove any unsuitable graphics option.


Multiple possible interpreters in a shebang?

In the ~/.profile file, there is a piece of code that adds $HOME/bin to your PATH. You can use this feature to make "node" link to "nodejs":

mkdir ~/bin
ln -s /usr/bin/nodejs ~/bin/node

You may have to re-login if your $HOME/bin directory did not exist before. You could also skip the shebang line and specify the interpreter directly:

nodejs learnyounode.js


I'm using Gnome in 13.10. I just did an apt-get upgrade to ensure it was the latest version. The version check produced:

~$ gnome-shell --version
GNOME Shell 3.8.4


try this:

ssh-keygen -lv -f .ssh/id_rsa

This can be found in ssh-keygen's manpage.
As for randomart's purpose:

"The randomart is meant to be an easier way for humans to validate keys.

Validation is normally done by a comparison of meaningless strings (i.e. the hexadecimal representation of the key fingerprint), which humans are pretty slow and inaccurate at comparing. Randomart replaces this with structured images that are faster and easier to compare."

This text was taken from here: https://superuser.com/questions/22535/what-is-randomart-produced-by-ssh-keygen


What is 'linux-libc-dev'? "Linux kernel headers for development" for another kernel series in software updater

The linux-libc-dev package contains headers of user-space libraries.

In Ubuntu LTS releases they are not upgraded with the HWE kernels.

It is normal, and you don't need to change it.

The Linux headers are in another package called linux-headers... that does match the kernel version.

See apt-cache show linux-libc-dev

Linux Kernel Headers for development
 This package provides headers from the Linux kernel.  These headers
 are used by the installed headers for GNU glibc and other system
 libraries. They are NOT meant to be used to build third-party modules for
 your kernel. Use linux-headers-* packages for that.

Almost exactly what I wrote before ;-)


Set up a  GUI managed firewall for other machines?

You might be interested in checking out:

zentyal

From their webpage:

  Manage all your computer network services through one single platform. Zentyal is a Network Gateway, Unified Threat Manager, Office Server, Infrastructure Manager, Unified Communications Server or a combination of them. All services based on the same technology and fully integrated. For the first time you can make your network act as one single unit.

Any of the ones listed here should work as well:
Wikipedia list of router or firewall distributions


Unable to start service on VMware Workstation 11

Enter these commands:
sudo apt-get install curl
curl http://pastie.org/pastes/9934018/download -o /tmp/vmnet-3.19.patch
cd /usr/lib/vmware/modules/source
sudo tar -xf vmnet.tar
patch -p0 -i /tmp/vmnet-3.19.patch
sudo mv vmnet.tar vmnet.tar.SAVED
sudo tar -cf vmnet.tar vmnet-only
sudo rm -r vmnet-only
sudo vmware-modconfig --console --install-all


Last upgrade crashes network manager (no internet connection, no applet)

Cause

This is caused by a regression introduced with a fix for libnl3 bug #1511735.
Resulting network-manager crash has been reported in network-manager bug #1539513 or network-manager bug #1539634

Solution

Downgrade libnl packages and wait for an upgrade of network-manager package

Step 1

Try to downgrade libnl with apt-get as in @Max answer:

sudo apt-get install libnl-3-200=3.2.21-1 libnl-route-3-200=3.2.21-1 libnl-genl-3-200=3.2.21-1

Step 2

If Step 1 fails,
because the packages aren't anymore in your cache and obviously cannot be downloaded by package manager, you need to downgrade libnl packages manually (download + install):

Download and copy them to your system
[ from booting a live distrib/rescue cd or from another computer + usb stick ]
Download links for amd64:
libnl
libnl-genl
libnl-route
Download links for i386:
libnl
libnl-genl
libnl-route
Back to your system, where you saved these .deb files, install them with dpkg:

sudo dpkg -i libnl-*.deb

Step 3

Now you should be able to (re)start NetworkManager and bring back networking:

sudo service network-manager restart

Notice

These bugs hits ubuntu trusty 14.04 with Pre-released updates : trusty-proposed

Where last update of libnl packages from version 3.2.21-1 to 3.2.21-1ubuntu1 introduced a regression causing network-manager to crash

There isn't yet any upgrade on network-manager in trusty-proposed
Current version: 0.9.8.8-0ubuntu7.2
An update of network-manager is now available in trusty-proposed
Updated version: 0.9.8.8-0ubuntu7.3
please test proposed package (#1539634 comment n°11)

Thus until an upgrade for it triggers on your package manager you should apply a "hold" - as mentioned in libnl3 bug #1511735 comment n°29:

sudo apt-mark hold libnl-3-200 libnl-genl-3-200 libnl-route-3-200

Once the future upgrade from trusty-proposed is installed you can remove that hold with:

sudo apt-mark unhold libnl-3-200 libnl-genl-3-200 libnl-route-3-200

Which then will allow you to upgrade again libnl


Ubuntu 16.04: Steam - "libGL error: failed to load driver: swrast"

Just give it a try, run it with docker container, based on my dockerfile
https://github.com/allenyllee/server_setup/blob/master/nvidia_docker/Dockerfile_cuda80

This dockerfile is based on official cuda image, modified to run all cuda samples with OpenGL, you should use nvidia-docker to build & run it.

This solves my similar problem while running windows program via WINE.


Command substitution does not work in Ubuntu shortcuts

Create a file somewhere you like, e.g ~/script.sh and add your command into that file, then add your shortcut with a command like this:

/bin/bash /home/username/script.sh

It should work now.


Error "Service Unavailable" while using conjure-up openstack

You'll want to make sure you've run sudo lxd init and go through the steps to setup storage and an IPv4 network for LXD to use.

Additionally, you'll want to make sure that  you can talk to LXD as the user you plan on running conjure-up as. To test that simply run lxc finger as your user.

We have a package update coming out in the next week or so that improves this new user experience and pre-configuring LXD to be ready out of the box for conjure-up use.


Direct Short(er) Answer
Is this a bug?
Probably, the DBUS error is nothing, the hanging pxgsettings is either bad config or poorly written interface in some program that runs (and reads settings) frequently. If you can try down the cause you should submit a bug report.
Has my computer been compromised?
Almost certainly not. Again the DBUS error is not ever really an error. It is technically a bug but not one that would effect anything. The hanging processes is likely a bug.
More Info
If someone did compromise your system the information they could get from pxgsettings would be rather pointless. I suppose there could be sensitive data there, but mostly it would be window positions, label names, color choices, etc. Nothing like passwords should be stored there. To rule out "compromise" you can always run users and see if there's more then just you running the system. If there is someone else on your system it will show there. You can also check top for ssh sessions or high running CPU/MEM programs that you didn't launch. Finally /var/log/auth.log will show all login attempts and successes (with some other data) if you still want to dawn your tin foil hat.  But truthfully all that is a bit overboard.
Links
This may help. Basically pxgsettings is "A helper binary to query gsettings".
It would appear that you have something quarring gsettings and crashing. GSettings is a High-level API for application settings. In short it looks like there is a process running every one in a while that hangs reading some settings from something. Unfortunately you don't have enough info to track down the process. It could be related to the program your trying to kill.
I do not think it's related to Bluetooth. That Bluetooth message is normal. The Rejected message is from DBUS and not Bluetooth. In fact that error has almost nothing to do with Bluetooth.


Wireless network not connecting in Kubuntu 11.04

It's probably not related to network manager but wireless drivers:

http://ubuntuforums.org/showthread.php?t=1752851

Solution is in the last post in the link, although it's not easy.

Just to avoid link rot: solution is to install from source compat-wireless using laptop's wifi firmware.


MAAS does not support integration with IPAM technologies, and unfortunately, it is not something that's within the MAAS Roadmap. Although, it does sound interesting and would probably be something for future discussion.


LXDE is the default desktop for Lubuntu 18.04. The project plans to switch to Lxqt but this has not yet happened.


In case we connect to a remote X-Server via VNC we have the advantage that the graphical application will stay running even when the SSH connection to the remote is down. We can then reconnect to resume the graphical application. See also:

Differences between VNC and ssh -X

To speed up reconnection we may combine the connection to the remote with an SSH session by using vncviewer from tightvncviewer  with the option -via. By this we can run on the remote server:

vncserver:0  ## or any other display number e.g. :1

to establish a connection on the viewer via an SSH tunnel:

vncviewer -via user@remote localhost:0

Doing so will need considerably more bandwith because the whole desktop will have to be transmitted from the VNC server. Therefore it may not really be a good idea for low bandwith connections but it may give you a somewhat better experience on high bandwith but unstable connections as compared with X-forwarding.


To find out if any hardware is certified for running under Ubuntu head to the Official Ubuntu Certification catalog and choose your hardware from there...

Furthermore, specific hardware recommendations are off-topic on this site...  :-(


You should be able to adjust your brightness using control settings on your monitor, when using a desktop. There are a couple of ways to control brighness from the CLI, but I just use my hardware controls.


Can you mount it manually? Run

dmesg | tail

Find out which drive it's using. Then:

sudo mount /dev/sdXY /mnt

Replacing the /dev/sdXY with what ever port it is.

EDIT:

Run:

sudo mount /dev/sdc1 /mnt

Then:

cd ls /mnt


Install a single specific package from future distribution

If you want to mix repositories like that you should use pinning.

See https://help.ubuntu.com/community/PinningHowto for details.

When pinning, you install a single package and as few dependencies as possible.

Without pinning, sudo apt-get upgrade will update (upgrade) many or all your packages and very likely will cause breakage.

In general, unless you have a lot of experience with apt, mixing repositories, even with pinning is inadvisable.

Better to find a ppa or use backports.

My advice is that you use Craven's ppa.

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

IMO, if a package is not available, I agree with the advice to build from source as, IMO, it is less likely to cause irreparable harm to the system.


Looking for a consistent way to configure cgroups on Ubuntu 14.04 Desktop

# vi /etc/cgrules.conf
tomcat7:wkhtmltopdf cpu,cpuset  group1

# cgrulesengd -d -v -f /var/log/cgrulesengd.log &
# cat /var/log/cgrulesengd.log
CGroup Rules Engine Daemon log started
Current time: Thu Jan 15 16:04:20 2015

Opened log file: /var/log/cgrulesengd.log, log facility: 0, log level: 7
Proceeding with PID 28569
Rule: tomcat7:wkhtmltopdf
UID: 500
GID: N/A
DEST: group1
CONTROLLERS:
cpu
cpuset

Started the CGroup Rules Engine Daemon.


The following packages have unmet dependencies: python-samba : Depends: samba-libs

Please read the error logs.. It says try

apt-get -f install

Add sudo to run it as admin. It'll solve the problem.


Go to the Desktop folder and right click on the Software Install icon. Choose properties and under Command just enter gnome-software with no tags.


From man apport-bug:

You can provide a package name or  program
name to apport-bug, e. g.:

   apport-bug firefox
   apport-bug /usr/bin/unzip

So try:

apport-bug apport

I got this when I tried:

(I didn't submit.)
See the guide on reporting bugs.


Sandboxing applications will help you.

In computer security, a sandbox is a security mechanism for separating running programs. It is often used to execute untested code, or untrusted programs from unverified third parties, suppliers, untrusted users and untrusted websites. A sandbox typically provides a tightly controlled set of resources for guest programs to run in, such as scratch space on disk and memory. Network access, the ability to inspect the host system or read from input devices are usually disallowed or heavily restricted.

Apparmor is a default sandboxing application.
I recommend it to use.

Guide: Apparmor Documentation

See also:

Run an untrusted C program in a sandbox in Linux that prevents it from opening files, forking, etc.?

How to sandbox applications?


Chromium, Tweetdeck, and Geany don't work when set to run at login

The only suggestion I can make is you just add start up entries for each of them (in system, prefs, start up applications) and file a bug.

This means they will always load up on login but that sounds desirable.


Having problems getting Samba4 and Bind9 working together because of apparmor

This is what I've done (after some trial and error):

$ cat /etc/apparmor.d/local/usr.sbin.named
# Site-specific additions and overrides for usr.sbin.named.
# For more details, please see /etc/apparmor.d/local/README.
  /var/lib/samba/private/named.conf r,
  /var/lib/samba/private/dns.keytab kwr,
  /usr/lib/samba/** m,
  /var/lib/samba/private/dns/** krw,
  /var/tmp/** krw,
  /dev/urandom rw,

$ service apparmor reload

$ service bind9 start

It should work fine then.


Having spent an entire day probing various possible solutions from the old thread with no success, here is the solution(s) that worked for me:

I did the following two things, then reboot($ sudo reboot):

1/@julianromera's solution referred to an Ubuntu open bug. More info:bugs.launchpad.net/ubuntu/+bug/1285444
His command line was:$ mv ~/.config/dconf/user ~/.config/dconf/user.old

2/@Fullbuffer's solution on another forum was moving the ~/.cache directory out of the way and restart.
His command line was:$ mv ~/.cache ~/.cache-NOGOOD

I did these two things then rebooted with ($ sudo reboot) and now I'm up and running.

Hope this will help someone! One advise: do not despair! If I managed to solve it then anybody can :)


After update 15.04 to 15.10 just black screen on boot

I believe your laptop has switchable graphics as described here http://www.notebookcheck.net/Review-Acer-Aspire-3820TG-Timeline-X-Notebook.30294.0.html

This is comparable to nvidia optimus which i have to same problem with Bumblebee Intel+Nvidia on 15.10 blackscreen issue

Someone told me it is a bug with i915 + 4.2 kernel see comments in http://rajat-osgyan.blogspot.fr/2015/10/how-to-install-bumblebee-and-latest.html

But yet i don't have a clue. But nvidia driver is working fine so looking at your thread this looks the is really problem with the i915 driver, what is strange is that i tried to use different kerneles and still got the same issue see https://www.kubuntuforums.net/showthread.php?69190-Bumblebee-Nvidia355&p=381043

I also posted a thread here for interested people http://ubuntuforums.org/showthread.php?t=2300628


Why do I see different versions of node and nodejs

node and nodejs have identical functionality but they are different versions because they are two different packages in Ubuntu Software. nodejs is the older version apt package and node is the more up-to-date snap package. Most Node.js users will be happier using the up-to-date node snap package, because it is updated automatically and it can be configured to either be updated automatically to the latest stable version or to not be updated except within a specific Node.js release. The latter feature is designed for Node.js users who need to work with a specific Node.js release. The node snap package also supports the installation of multiple Node.js releases, which allows the user to choose which Node.js release to use for each project.

One important difference between node and nodejs is that node has npm built-in in the snap package, whereas in nodejs npm must be installed separately. Since the npm in the node package is much more up-to-date than the apt version of npm, it is recommended to use the more up-to-date version of npm for both node and nodejs. After installing the node snap package, run the following command to enable npm update checking:

sudo chown -R $USER:$(id -gn $USER) /home/your-username/.config

Replace  your-username in the above command with your own username.

For more information about node snap package installation and usage read this answer.


faile to resolved " /usr/include/linux/errno.h:1:23: fatal error: asm/errno.h: No such file or directory"

On my Ubuntu 14.05.5 system (YMMV), /usr/include/asm/errno.h is provided by the following packages:

linux-headers-*
linux-libc-dev:amd64
linux-libc-dev:i386


Stop cups with sudo service cups stop and edit  /etc/cups/printers.conf with your preferred editor.At the top of the file there should be a

AuthInfoRequired username,password

Now I had some mixed results with this and with one printer I has to it out and with another I could put in a username, password. After editing start cups with sudo service cups start and retry printing it.

Also make sure the printer is using ipp.

By the way: from the "view print queue" you can also enter username and password to unlock a job by right clicking a job and pick "authentication"


Wifi problems Acer Aspire M3 Ubuntu 12.04

i had loads of trouble with all sorts of methods not working.

Get to a wired connection,

Terminal,

sudo apt-get install linux-firmware-nonfree

after installing i removed the wired connection and rebooted the system.

worked like a charm


Install the Disable Gestures  extension using either Chrome or Firefox.


What are the drm-intel kernels in the repo?

No, if you have to use the Ubuntu mainline kernel, do not use one from the drm-intel-next directory, unless you are a developer or have a specific need for something that has not yet been merged into the main upstream tree.

It is an unstable working branch specific to DRM/i915, but ultimately gets merged into master linux kernel source tree. See also here.


Do I have to move swap partition to the right side?

You don't have to, but...

Although having the Swap partition at the end might not affect performance, it might let you modify the other partitions (enlarge/reduce etc.) more easily later without touching your Swap again.

And to do this in GParted:

Select sda6, Right-click > Swapoff (to unmount the swap partition so that you can perform operations on it)
Delete Swap (sda6) partition, which will create a larger unallocated space at the end of sda4
Create one or more partitions as you need and then re-create the Swap partition at the end.


By executing this command

sudo vim filename

you create new file, whose owner is the root user. You can confirm that by executing ls -al. From the output you can see that the owner and the group to which the file belongs are set to root.

If you try to edit it with your normal user, you wont be able, because the file does not belongs to your user. Again you are able to read the file but not write to it, because of the permissions. You can check them to from the command line with ls -al command. It should be something like:

-rw-r--r-- 1 root   root       4 Apr  9 07:40 filename

the first part -rw-r--r-- means that only owner can read and write to file, users from the same group and other user can only read the file.

Here is a good diagram that describes the meaning of permissions:

If you wish to be able to edit the file, you must do so as the root user - this is almost always the best way:

sudo vim filename

If you wish to edit it as normal user you can assign additional permissions to it, (but you should not do this to system files outside your home directory - use sudo to edit them instead):

sudo chmod 777 filename

This way the file will be readable, writable and executable from every user. This is rarely a good idea.

To give ONLY write permissions to all other users:

sudo chmod o+w filename

Otherwise if you want the file to be writable only by you, you can change the owner to you:

sudo chown yourusername:root filename


Zenity from command line Linux installation

zenity need a graphical environment (X server) to run.

Have a look at whiptail (package whiptail) or dialog (package dialog) if you want to display dialog boxes in text mode.


Lo interface not coming up on boot (upgrade fom 12LTS to 14LTS, work in container mode)

I can't give you an answer, but I can give you a workaround.  Changing /etc/network/interfaces to treat the interface as static seems to do the trick:

auto lo
# iface lo inet loopback
iface lo inet static
address 127.0.0.1
netmask 255.0.0.0

Yes, I know.  This is ugly.  It's wrong.  However it got me over the hump.  YMMV.

I got bitten by this after I removed NetworkManager from a clean install of 14.04.  Don't ask about nuking NM. :-(


your chmod changed the permissions on the copy in ~/Downloads.  You need to set the executable bit on the copy in /usr/bin.

Also the ./lein is trying to run the file in ~/Downloads.

Try it in this order:

sudo cp ~/Downloads/lein /usr/bin # note cp, not scp, there's no need to use scp
sudo chmod +x /usr/bin/lein
lein

Assuming lein is a valid runnable file, this should work.


gm3u app needs libgnomeui.so.32 - how do I install it?

That looks like a very old package -- libgnomeui.so.32 refers to the old GNOME 1 libraries. It's no longer available in Ubuntu.

Unfortunately, I tried compiling the gm3u source code but even that wants the GNOME1 development libraries and fails...


Search specific text from file and output the line (Shell script)

Use this:

grep "$str" filename.txt

to prevent misinterpretation of special characters.

To know more, refer this:

Quoting variables


Ubuntu Mate 16.04 LTS Power Mac G5 Booting loop

I would try installing off of USB drive.  It works well for me.  First, download the last PPC Ubuntu-MATE here.  Make sure the .iso is on your desktop.

In Mac OS X, run:

diskutil list

After this, find the number of your flash drive, e.g., disk, disk2, disk3, or disk7, you never know so run this and look for the flashdrive's brand next to the BSD identifier.  (If you cannot access, Mac OS X, then insert the OS X CD/DVD with command-C and open a Terminal from within the install OS.)

Then, still within the Terminal, execute this command to format your flash drive and lose all the information (where disk# = disk3 or disk7 or whatever the above shows you):

sudo diskutil eraseDisk JHFS+ Test disk#

sudo dd if=/Users/<usernamenobraces>/Downloads/<nameofisofile> of=/dev/disk# bs=16m && sync

Here is an example with user name tom and disk3

sudo dd if=/Users/tom/Downloads/ubuntu-mate-16.10-desktop-powerpc.iso of=/dev/disk3 bs=16m && sync

You might find this fails, so if your disk identifier is 3 like the example, run this command first:

sudo diskutil unmountDisk disk3

Use -f if you have trouble, then run this command again (make sure to wait until the drive is fully written to):

sudo dd if=/Users/tom/Downloads/ubuntu-mate-16.10-desktop-powerpc.iso of=/dev/disk3 bs=16m && sync

Once, this is done, restart the G5 with the flash drive inserted and press commadn-option-f to enter open firmware.  Upon entering Open Firmware, enter the following:

boot usb0/disk@1:2,\\yaboot

If that does not work, enter the following:

boot usb1/disk@1:2,\\yaboot

(If neither of those work, try again after taking the USB out and putting back in (no matter what do this once - trust me). Or, adjust the command in open firmware by increasing the usb# to usb3, usb4, etc.  There is one for every USB port and they do not increase by USB port #, but by device number, so there can be a skip.  Usually, it is usb1 or usb2.)

Once you get to the yaboot prompt, enter install or simply press enter at the Yaboot bootloader screen that follows.  If you have an old graphics card the enter videoof=only or cli or cli-expert and then press enter. Whether you chose graphical or text, follow the steps for a normal / default install after tat (which can be found elsewhere).  I wrote this from my G5 which is running 16.04.2, but I have used 16.10 on this machine as well prior to this.  Screenshot below:

@oemb1905

These instructions are drawn from Ubuntu, miscellaneous sites, and my own experience.  Consolidated for ppc architecture.  Various Lubuntu and Ubuntu distributions worked in the past but have lost support or elegance, and Ubuntu MATE 16.04.2 LTS / Ubuntu MATE both work now in both elegance and function (with updates).


udev run scripts as root. So change the permissions of the created folder /media/usbdisk before mounting the block device.


How to combine multiple text files into one text file ordered by date created?

It can be done with a python script, with one sidenote: I took the modification date instead of the creation date, since the creation date will almost certainly not match the real creation date: it is the date the file was copied to the computer, while the modification date seems unchanged during copying  (see discussion at @cOrps answer). You will have to see if it works in your situation.

If that is acceptable for you, you can use the script below to create a combined file with your notes. It reads the notes, sorts them and appends them to a text file (creates it if it doesn't exist).

The good news is that you can append your new notes to the same file without overwriting the old ones.

Example output:

Mon Sep 29 08:48:31 2014
This is my first note.
As you can read, I am not really awake yet.

----------
Mon Sep 29 09:04:06 2014
It is really time I am going to eat something.
I am a bit hungry.
Making it a bit longer.

----------

How to use:

Copy the script below into an empty file, save it as add_notes.py
change the directories for files_dir (where your notes are) and the file in which you want to save the notes: combined_file (the script creates the file if it doesn't exist)
run the script in a terminal window by typing the command:

python3 /path/to/add_notes.py

The script:

#!/usr/bin/env python3

import os
import time
import subprocess

# --------------------------------------------------------
files_dir = "/path/to/your/textfiles"
combined_file = "/path/to/your/combined/file.txt"
# ---------------------------------------------------------
notes = []

if not os.path.exists(combined_file):
    subprocess.Popen(["touch", combined_file])

def read_file(file):
    with open(file) as note:
        return note.read()

def append_file(combined_file, text):
    with open(combined_file, "a") as notes:
        notes.write(text)

for root, dirs, files in os.walk(files_dir):
    for name in files:
        subject = root+"/"+name
        cr_date_text = time.ctime(os.path.getmtime(subject))
        cr_date_n = os.stat(subject).st_mtime
        notes.append((cr_date_n, cr_date_text, subject))

notes.sort(key=lambda x: x[0])

for note in notes:
    text = note[1]+"\n"+read_file(note[2])+"\n"+"-"*10+"\n"
    append_file(combined_file, text)


While this could theoretically be done, it would involve some hacking around with manual grub installation and set up. As an alternative, you could move your existing FAT32 partition towards the end of the drive to allow for installation of live USB images to the beginning of the flash drive.

First, shrink your existing FAT32 partition down far enough to ensure that there is enough free space for the live OS image, then use a partition manager to move this partition towards the end of the partition table until there is enough free space at the beginning to do your live OS installation.

You could use a program like Gparted to accomplish this quite easily.

sudo apt-get -y install gparted
sudo gparted

Alternatively, you can backup your files from the USB flash drive, format the entire flash drive as FAT32, install the live USB image onto the flash drive via unetbootin, then create a folder at the root of your USB drive called "my files" or whatever you'd like, then store your files in there.

Note: I know this to work for Ubuntu Live USBs, but I cannot guarantee that it will work for non-debian distributions. For instance, Fedora Live USB does not work correctly when created from unetbootin.

Installing unetbootin:

sudo apt-get -y install unetbootin


How to install Ubuntu in USB to boot in a Mac system?

On windows I would use a program called "iso to usb". I would burn the iso to the usb key using that. Then I would setup the bios to boot from that. On Macs though, you cannot do this. The efi on macs wont let you boot from a USB key nor is there a similar program to "iso to usb" for macs. So, the only option you got is to get an external dvd rewritable or whatever ... drive, and burn ubuntu linux to a disc using that. What I am saying is based on the suggestion given on the wiki.ubuntu site. SEE, https://wiki.ubuntu.com/UbuntuOnMac


youtube-dl delete files that are no longer in a playlist

Rather than writing it yourself, you can use this script to keep a folder in sync with a playlist:

https://github.com/chewett/youtube-playlist-sync/blob/master/README.md

To set it up you run:

yps.py --init <playlist url> --dir <folder>

To sync you run:

yps.py --sync <folder>


is there an installer for xubuntu that works on 32bit and 64bit systems?

As such, there is no "dual installer" for Xubuntu (see the official site) that can detect CPU architecture and decide whether to install a 32 bit or 64 bit system as appropriate. However, as explained in answer by @sudodus the 32 bit version of the OS may be installed on 32 bit or 64 bit architecture (the reverse is not the case, of course), so if in doubt, the 32 bit iso may be used.

What you should do is run:

uname -i

This will give you the architecture of your friend's system so that then you can download the appropriate iso.


BSNL EVDO Ubuntu 14.04 connected but no internet

Try installing gnome-ppp package by :

sudo apt-get install gnome-ppp

It's a graphical interface which does same work as wvdial.
Open it from the applications panel and in settings try "detect serial port". And manually change the modem type to "USB" and save. On main screen enter the credentials and try connecting. Let us know what you get.


Running OpenResty as a service on Ubuntu 14.04

And now, the Ubuntu answer.

You are using Ubuntu Linux. You already have either upstart or systemd (the former in this particular case). Do not begin by writing System 5 rc scripts.

So write an upstart job file.  Take one of the ones already written for nginx, in fact, and modify it for OpenResty.

The Ubuntu version 15.10 nginx-common package comes with an upstart job file supplied, straight out of the box, as /etc/init/nginx.conf; although the Ubuntu version 14.04 nginx-common package is several versions behind and does not.  It's fairly easy to pull the file directly out of the Debian source repository (nginx.upstart).  There's also an /etc/init/nginx.conf job file on the nginx wiki.

Applying your OpenResty modifications yields this:

# /etc/init/openresty.conf

description "OpenResty nginx"

start on filesystem and static-network-up
stop on runlevel [016]

env DAEMON='/usr/local/openresty/nginx/sbin/nginx -c /usr/local/openresty/nginx/conf/nginx.conf'

expect fork
respawn

pre-start script
    [ -x $DAEMON ] || { stop; exit 0; }
    $DAEMON -t || { stop; exit 0; }
end script

exec $DAEMON

pre-stop exec $DAEMON -s quit

Use as an upstart job, in the usual manner, with initctl start, initctl stop, and so forth.

Of course, people have already done these modifications, long since.

Further reading

Oliver Frommel (2014). /etc/init/openresty.conf. The OpenResty distribution for Nginx.  ADMIN Magazine  19.
Edward Stone (2013-02-18).  nginx-upstart.conf.  openresty-pypi.  GitHub.
George Shammas (2015-08-11). /etc/init/nginx.conf.  nginx wiki.


How to disconnect and connect the wired connection from the command line?

You can try using nmcli to disconnect and re-connect a particular network device ex.

nmcli dev disconnect enp0s25 && nmcli dev connect enp0s25

where the wired ifname (interface name) enp0s25 may be obtained if you don't already know it using nmcli dev status

$ nmcli dev status
DEVICE   TYPE      STATE        CONNECTION
wls1     wifi      connected    NETGEAR68-5G
enp0s25  ethernet  unavailable  --
lo       loopback  unmanaged    --


Install Python 3 alongside python 2.7 on Ubuntu 18.04

As Hugo stated in the comment above, python3 should already be installed and you can run it by using python3 in the terminal as he mentioned.

Setting up virtual Environments:
You can also setup virtual python environments using pip. Install pip with the following command.

sudo apt install python-pip

(to install pip3 for python3, use this command sudo apt install python3-pip)
Now that you have pip installed you can refer to the instructions at this link to learn how to setup these virtual environments for testing various python versions and packages

Switching between python versions using update-alternatives:
If setting up virtual environments is not what you want to do, then you can also use update-alternatives to switch between python version. Run these two commands first, but make sure the python versions match what you have on your computer

sudo update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1
sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.5 2

You may then run update-alternatives with the --config option so that you may select which version you want to choose to be the default

$ sudo update-alternatives --config python

Use the interactive menu to select which version you would like to use as the default. In order to check if your changes have worked you can use python --version


How to open a new tab in the server command line?

For doing command line work in general I would recommend using screen, tmux or other of these sort, but to get started, try out byobu:

Default key bindings:

F2 create a tab
F3 & F4 you can move around back and forth
F6 detach session. Resume later - very powerful!
F7 copy mode - allows you to scroll using arrow keys and search for keywords
F8 rename window
F9 Menu & help (more key bindings and features here!)
type exit, Ctrl+D to exit regularly one shell/window.

Byobu works regardless the type of connection to your server. This works in regular terminals (also desktops), Virtual Terminals, serial TTYs, SSH sessions, etc.


How do I uninstall Windows XP from my NTFS if I have Ubuntu installed there as well

First of all , your XP and Ubuntu are not on the same NTFS drive!!! They can't be!
Ubuntu is using ext4.

An easy and secure way of doing this is :-
Make sure all drives are unmounted(easiest by going in live ubuntu CD)

Then open up Gparted , locate your NTFS drive , delete it and create a new ext4 partition or merge it with your existing one.

If you can't use Gparted , then I recommend cfdisk its a terminal based utility with nice GUI like interface but very powerful.


Ubuntu partitioning and installation error, due to bad HDD sector(s)

When I time ago decided to install Ubuntu,

I had an error on the beginning of the installation

I then discovered that the download of the ISO file wasn't properly made.The second time I did a verification of the download and was fine , I was able to install it.

Also , make sure to choose the proper one for your pc ,32bit or 64bit.

**And btw , Ubuntu will automatically guide you on partitioning during the installation if you need it


Update packet fontconfig to newer version in ubuntu 18 LTS

Backup all critical data on your LTS system and upgrade to 20.04 which should be available here when it's released on April 23rd, 2020. On that date you should be able to utilize the standard upgrade method. If you can't wait you can obtain a daily build here. Be aware that Ubuntu 20.04 daily builds will contain bugs and broken packages, and you may encounter many usability and/or stability issues as features are added (and in some cases removed). 20.04 has fontconfig 2.13.1-2ubuntu2 currently available in the repositories. This approach should avoid many of the pitfalls that can occur when blending packages approved for different releases.


Is there a maximum swap partition size for 12.04, 64 bit

I don't think it really matters.  However, if you're using multiple memory intensive applications, you can allocate as big a partition as you want for swap.  How much will be used is another question entirely. Depends on the system.

Personally I don't see any need for a swap partition size larger than twice the amount of ram, not to exceed 8GB.  Having such a huge swap, the swapping process will be probably much less effective.


What is the equivalent for switching drives in terminal on Linux?

Linux doesn't really have a way to work with "drives", per se, except with system utilities that access partitions; they often need to specify the drive that contains the partition.  But if your drives each only have one partition, it doesn't really matter.

Anyway, to access a drive, you actually need to specify the partition in some way, usually by a definition like /dev/sda1 (1st partition on 1st drive) or /dev/sda2 (2nd partition on first drive).  Using the Disk Utility or gparted, you can see all the partitions graphically.  If you're only using the terminal, I've found that the command "blkid" is handy to list the drives with their UUIDs.  I use the form:

sudo blkid -c /dev/null

Using the terminal, you need to mount a partition to actually use it.  This is actually pretty easy to do.  In most cases, you would want to use an empty directory as the "mount point"; if the directory is not empty, its contents will be masked and unavailable during the mount.  This may be useful in certain circumstances, such as testing or temporarily changing a configuration for some other reason, as it will alleviate the need to rename or delete the current contents.

If you have a directory named /mnt/drive2 (/mnt is commonly used, but it can be in your home directory if you want), and your drive is /dev/sdb, with a single partition, then the simplest command is:

sudo mount -t type /dev/sdb1 /mnt/drive2

where "type" is the type shown in the blkid command, such as ntfs, ext4, etc.

EDIT:  to experiment, don't be afraid to try the mount command.  It is only temporary until you reboot (or unmount using the "umount" command).  To make it permanent, you need to enter it into /etc/fstab.  If you want to do that, you can experiment by creating an entry, then using the command "mount -a" to mount everything in /etc/fstab.  If there are errors, it will tell you, and you can correct and repeat until it works.


Problems while doing 'sudo apt-get upgrade'

here are the steps that should fix your problem.

This will clean out downloaded archives

sudo apt-get clean

This will check for the latest packages and updates available

sudo apt-get update

This will push apt to update all available packages

sudo apt-get dist-upgrade

Hope this helps!


The xboard was installed without default values for some of the options.
The xboard file .xboardrc, in home directory, defines values for various options. Set the following options:

-whitePieceColor                #FFFF20
-blackPieceColor                #202020
-lightSquareColor               #C8C3C5
-darkSquareColor                #77A26D
-highlightSquareColor           #FFFF00
-premoveHighlightColor          #FF0000

This solved the problem.


Problems reinstalling Windoxs XP instead Ubuntu

What OS did your netbook had originally?

XP needs some drivers to recognize some more modern hard drives, depending on what mode they're operating on.

My advice would be re-install whatever came with your netbook.

BTW, some more info on the netbook itself might produce better/more useful answers than this one (I hope i don't get downvoted...)


In Ubuntu an URL shortcut is stored in a .desktop file as follow (for example):

[Desktop Entry]
Encoding=UTF-8
Name=Link to Ask Ubuntu
Type=Link
URL=http://www.askubuntu.com/
Icon=text-html

You can drag links from Firefox or Chrome and drop them on the Desktop or any other folder where you have permissions to save files.

Note: Link will appear on your Desktop or your file explorer (i.e. caja) under the name in the line Name=…, not by its actual filename. And without any ….desktop extension.


You can still install this using the deb file. It just takes a second command.

Open Terminal
Type:

sudo dpkg -i /path/to/deb/file

For example:

sudo dpkg -i /Downloads/openjdk-7-jdk_7u131-2.6.9-0ubuntu0.14.04.2_amd64.deb

Then type:

sudo apt-get install -f

This will install any dependencies you need.

Openjdk 7 should now be installed. In order to have your system use Openjdk 7 as default, you will need to run the following command in the terminal:

sudo update-java-alternatives -s java-1.7.0-openjdk-amd64

I hope this helps!


How can I configure multiple MaaS environments for juju?

OP posted:

  I've resolved that in this way: after to add the new environment i run these commands:

juju sync-tools -e maassvr02
juju bootstrap -e maassvr02 --to node4.maas --debug


For IntelliJ 13/14,

Click File-> Settings. Keyboard shortcut is Ctrl+Alt+S.
Search for "Version Control"
Choose "Git" under "version Control"
In the SSH executable dropdown, choose Native


Why Ctrl+Shift+Alt+Down won't move a window one workspace down in 13.10

That's not a bug, it's because in 13.10 the default shortcuts for moving a window one workspace down or up changed to Shift+Super+Page Down and Shift+Super+Page Up respectively:


How to add website (URL) shortcut to Ubuntu dock on Ubuntu 18.04

Try the following to create a launcher to open a website with Firefox and add it to Ubuntu dock.

Create a new file, say MyWebsite.desktop in your ~/.local/share/applications/ directory. You can do that by running the following in Terminal

touch ~/.local/share/applications/MyWebsite.desktop

Open this file with a text-editor, for example by running

gedit ~/.local/share/applications/MyWebsite.desktop

Add the following lines to this file and save the file

[Desktop Entry]
Comment=Open XYZ website
Terminal=false
Name=XYZ website
Exec=firefox website-URL
Type=Application
Icon=applications-internet
NoDisplay=false

In place of website-URL put the address you want to visit, for example https://askubuntu.com for Ask Ubuntu. Also edit the the Comment= and Name= fields accordingly.
Click on "Activities" at the top bar or "Show Applications" in the dock and search for "XYZ website". It should appear.
Right click on it and select "Add to favourites".


Can't install any applications on Raspberry Pi 4

Raspberry Pi 4 has an arm CPU. It can't run amd64 or i386 binary code.
So you can't install or run amd64 or i386 software.
You need to search for arm64 packages, or build software from source.


how to play flash videos in a browser using mplayer or vlc

If you just want to abandon flash you might be interested in

yt-download

which you can use to download videos from youtube (and some other sites) and watch them using any player you choose.

There was an add-on for Firefox some while ago wich automaticly replaced the flash-video by a native player and add some controlls but it was abandoned. It might still work but that is not for sure

The original thread by the author:
http://ubuntuforums.org/showthread.php?t=1487327

Or you could use this script:
https://userscripts.org/scripts/show/87011


Crosshair as standard mouse pointer. But how?

http://gursormaker.sourceforge.net/ allows for importing and creating of X11 cursors. Probably .curs too.


Sound not working with some applications; it does work with others... What's going on?

Have you tried this...

Start playing some audio in the affected programs (music, movie, whatever)
While it's playing click on the sound icon on the top right
Click on Sound Settings
Then go to Applications and see if the audio got turned off for those certain soundless programs


How do I get Broadcom drivers to be recognized Ubuntu during setup from Windows installer?

In the article referenced in http://wireless.kernel.org/en/users/Drivers/b43 you can see the instructions to install your firmware

From a Terminal window run the following command

sudo apt-get install firmware-b43-installer

This should be enough to solve your problem

Edit: I am assuming you can install this firmware from the cd / iso


Ubuntu with KDE and kernel 3.6.2 - performance issues

when you login u can choose old kernel on GRUB menu with advance menu and open konsole

You can check your current used kernel with this command:

uname -r

To find a list of all installed kernels on your system, run this command:

dpkg --list | grep linux-image

To remove all unused kernels, run now this command:

sudo aptitude purge ~ilinux-image-\[0-9\]\(\!`uname -r`\)

In case aptitude is not installed, then install it with this command:

sudo apt-get install aptitude

Update now your Grub2 boot loader with this command:

sudo update-grub


How can I remove orphaned start menu entries?

You can use the following command to list application icons that link to nonexistent programs:

for i in {/usr,~/.local}/share/applications/*.desktop; do which $(grep -Poh '(?<=Exec=).*?( |$)' $i) > /dev/null || echo $i; done

I suspect you'll find that most of yours are customized icons in your home folder, since these are not automatically cleaned up by the package manager. If this is the case and you'd like to trash  them all at once, you can use a modification of the previous command:

for i in ~/.local/share/applications/*.desktop; do which $(grep -Poh '(?<=Exec=).*?( |$)' $i) > /dev/null || trash $i; done

Or, of course, browse to ~/.local/share/applications/ in Nautilus and trash them via the graphical interface.


What is the file size of the ubuntu iso image?

These are numbers are taken directly from the iso files I've downloaded. Also if you download your iso from http://releases.ubuntu.com/13.10/ or http://releases.ubuntu.com/12.04/ it lists the file sizes beside the names, in the directory browser at the page bottom.

13.10:

Ubuntu 13.10 - Desktop X86-64 = 883 MB

Ubuntu 13.10 - Desktop X86-32 = 895 MB

Ubuntu 13.10 - Server X86-64 = 672 MB

Ubuntu 13.10 - Server X86-32 = 658 MB

Lubuntu 13.10 - Desktop X86-64 = 702 MB

12.04:

Ubuntu 12.04 - Desktop X86-64 = 698 MB

Ubuntu 12.04 - Desktop X86-32 = 701 MB

Ubuntu 12.04.3 - Server X86-64 = 665 MB

Ubuntu 12.04.3 - Server X86-32 = 648 MB

Lubuntu 12.04 - Desktop X86-64 = 697 MB

Kubuntu 12.04.3 - Desktop X86-64 = 707 MB

Xubuntu 12.04.3 - Desktop X86-64 = 712 MB

14.04:

Ubuntu 14.04 - Desktop DAILYBUILD-JAN-21-2014 X86-64 = 912 MB


What is the 'canonical-census' package?

It's for counting the number of installs of Ubuntu in the wild, put there by OEMs. OEMs (in this case) are companies selling computers with Ubuntu pre-installed. Like Dell, System76, etc.

It connects to a Canonical server on a daily basis and tells it the following:

How many times it has connected in the past (/var/lib/send-install-count/counter)
The OEM's ID (stored in /var/lib/ubuntu_dist_channel)
The hardware product (/sys/class/dmi/id/product_name)
Which release of Ubuntu it's using (/etc/lsb-release's $DISTRIB_RELEASE)

Implicitly it also tells Canonical which IP the computer is using and from that they could work out the country, sometimes company it's being used from. If they're doing this is another question.

  Why is (was) there so much fuss about it?

Some people see this as an attempt to track users. In a way it does. But how much of that information is helpful to actually work out who a user is?

Well I'm a cynic. With the IP, Canonical could look at the other services they provide  (Ubuntu One, Launchpad, etc). If the users uses another service, they could perhaps work out who has done business with Dell (et al)...

But even cynical as I am, what does that really give them? Not much. Its only real value is working out how many OEM computers are get used with their default install of Ubuntu.

I'm not going to get bogged down in the paranoia of some people but it's fair to say, all but the most cut-off hermits give out more personal, traceable and potentially harmful data to much bigger and uglier companies on a daily basis.

  Why is it under the 'Canonical Partners' section in the Software Center?

I don't know.

It doesn't really matter where it sits but the partner repo is as good as any other place, I guess. It's open source but it's not really something for all users.

  Should I install it?

No. You could but it won't do anything meaningful unless you bought the machine with that copy of Ubuntu pre-installed by a Canonical-registered OEM.

This is because it checks for the existence of /var/lib/ubuntu_dist_channel before submitting any data. Normal installs won't have this file.


i have found the error in my setup......in the /etc/dconf/db/local.d/01-lockdown i have set the key ....but i have made it with a string and not a boolean......if i change the key to disable-log-out=true insted of disable-log-out='true' ..it works


Not able to install Ubuntu 'Can not mount /dev/loop0'

Maybe CD is damaged? Try to boot ISO image on VirtualBox. If it works, CD media is probably damaged. Possible reason might be that your CD/DVD drive is dirty or broken.
If you cannot boot ISO image in VirtualBox, downloaded ISO image might be corrupted. In this case, try to calculate checksum of ISO image, and compare to md5 checksum on ubuntu page where you downloaded your ISO image.


Can Compiz work in an Ubuntu guest in VMware workstation 9?

Yes, Compiz can run on a guest in VMWare Workstation 9. Compiz has worked on the standard X.Org server since May 22, 2006 by using Accelerated Indirect GLX (AIGLX)

Edit: Compiz depends on OpenGL rendering which is what previously prevented it from being compatible with VMWare Workstation.  The current version of VMWare WS supports proper OpenGL rendering and because of this it should be able to run Compiz once you have the proper drivers installed on the guest machine.


Since nobody answered, I gave it time to research about how to get around this. The root cause is Chrome/Chromium does not respect OS font scaling. To address this, I added --force-device-scale-factor=n to Exec=* line in /usr/share/applications/google-chrome.desktop. n is the value that's suitable for you, for me it's .92. I did this to all electron apps and now everything is all good. I'm sticking to Ubuntu after all!

Be sure to save a backup for each .desktop file you edit. Ciao!


Make sure you're using the correct graphics driver, that is, more importantly, make sure your hardware is accurately detected. The easiest way to do this is to go to "Settings" and under "System" click on the "Details" icon.

You should see your CPU and GPU chipsets referenced here listed over on the right hand side of the window.

If you see something like "Gallium 0.4 on llvmpipe" listed here and you are not using this chipset . . . you have found the problem and you need to install the proper drivers for your hardware.

Ubuntu and other like distros usually end up with the Gallium driver as a fallback when either the hardware is not properly detected or the proper drivers are not available, loaded, or installed. This usually causes all kinds of visual shuddering and display issues.


Difficulties installing Gephi on Ubuntu 14.04

Your package needs the package libgoogle-collections-java as a dependency, but you do not have a repository which provides this package. It seems that it was available in 10.04 and 12.04, but not in 14.04 for reasons that are unclear... You need to find this package in order to install Gephi.


You can get all you want from this command:

sudo dmidecode --type memory

1st part of the information you get:

SMBIOS 2.7 present.

Handle 0x001B, DMI type 16, 23 bytes
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: None
    Maximum Capacity: 16 GB
    Error Information Handle: No Error
    Number Of Devices: 2

Handle 0x001C, DMI type 17, 34 bytes
Memory Device
    Array Handle: 0x001B
    Error Information Handle: 0x001E
    Total Width: 64 bits
    Data Width: 64 bits
    Size: 4096 MB
    Form Factor: SODIMM
    Set: None
    Locator: ChannelA-DIMM0
    Bank Locator: BANK 0
    Type: DDR3
    Type Detail: Synchronous
    Speed: 1333 MHz
    Manufacturer: ELPIDA
    Serial Number: 5A0C95A6
    Asset Tag: 0123456789
    Part Number: EBJ41UF8BAS0-DJ-F
    Rank: Unknown
    Configured Clock Speed: 1333 MHz


Youtube and other online videos will not play

I uninstalled the google chrome remotedesktop.  Somehow now youtube and other video streaming works.


How should I respond to 404 errors in winetricks?

Here's how you install it manually when you get a 404 error:

Google for the package name, here WindowsXP-KB975337-x86-ENU.exe
Download it.
From the terminal, simply run wine ~/Downloads/WindowsXP-KB975337-x86-ENU.exe (or similar) to install in your default Wine prefix.

You may have to click on EULAs, press one or two Next buttons, etc.; winetricks usually performs the quiet install.

  Note: you can also try updating winetricks to the latest bleeding-edge version from their github (winetricks is a script)


There is quite a bit of literature out there:

https://serverfault.com/questions/256896/advantages-and-disadvantages-of-logical-volume-manager-lvm-and-lvm-vs-encrypt

https://unix.stackexchange.com/questions/7122/does-lvm-impact-performance

The upshot is this:
In almost all scenarios LVM will offer you more flexibility and easy of maintenance. Even in the case of recovery the oft-cited problem of oh-my-god-when-one-disk-goes-all-is-lost problem is mostly easier to deal with than many RAID setups. Provided you leave some slack in your disk space you can swap a broken disk for a new one with the system running. Quite nice.

The second worry cited: performance hits due to an additional virtual layer is also not a problem for most scenarios: The throughput is as good as good-old direct partitions.

However, all of these are rather vague statements given the unclear specifics of your setup. So to find out you need to provide a  lot more information on usage scenarios etc. And even then, your best bet is some benchmarking (e.g. bonnie++). Btw, doing those with your virtual machine will not be helpful. It is however a good way to practice the setup which initially seems a little cumbersome.

Edit: How to deal with backups:
If you are used to backing up your system hard disks using dd, you can continue this with logical volumes (LV). Keep in mind that LVs are also block devices to which dd can be applied. The underlaying organization for a block device is hidden from the recipient of a dd (one reason you can dump a partition into a file: dd if=/dev/hda1 of=/tmp/part_a1

However, using dd on a running system is dicey due to the potential changes in your disk while you are doing the backup (one protection would be to mount read-only). With LVM, however, none of that is necessary since you now have access to the fantastic new feature: snapshots!

Previously, you would have backed up the 'partition' directly and that is still valid:

dd if=/dev/mapper/VolGroup00-LogVol00 of=...

Now you can make a snapshot of a running system (provided there is some space, you might have to add disks and extend volume groups. All very easy ...)

lvcreate -s -L 64M -n mysnapshot /dev/VolGroup00/LogVol00

You can dd this to image it safe in the knowledge that it won't change.

So in summary, with a bit more work (in needing to understand the tools) you have more flexibility to get done what you are trying to achieve under many scenarios (including the backup issue)


upstart-supervised init script for Apache?

Woooo!

I've written my own version that is pretty much working - with some conf file hacking, and using -D NO_DETACH.

First up, I had to set User, Group and PidFile in /etc/apache2/apache2.conf manually, rather than have them coming in from /etc/apache2/envvars. I couldn't work out a way to get those vars to be exported properly (I tried both env and export as per http://manpages.ubuntu.com/manpages/lucid/man5/init.5.html, but no good).

root@lucid:/etc/apache2# diff -u apache2.conf.orig apache2.conf
--- apache2.conf.orig   2010-09-20 13:46:33.857868534 +0930
+++ apache2.conf        2010-09-20 13:47:22.377842204 +0930
@@ -63,7 +63,7 @@
 # identification number when it starts.
 # This needs to be set in /etc/apache2/envvars
 #
-PidFile ${APACHE_PID_FILE}
+PidFile /var/run/apache2.pid

 #
 # Timeout: The number of seconds before receives and sends time out.
@@ -142,8 +142,8 @@
 </IfModule>

 # These need to be set in /etc/apache2/envvars
-User ${APACHE_RUN_USER}
-Group ${APACHE_RUN_GROUP}
+User www-data
+Group www-data

 #
 # AccessFileName: The name of the file to look for in each directory

Then, this is my working /etc/init/apache2.conf:

# apache2 - http server
#
# Apache is a web server that responds to HTTP and HTTPS requests.
# Required-Start:    $local_fs $remote_fs $network $syslog
# Required-Stop:     $local_fs $remote_fs $network $syslog

description "apache2 http server"

start on runlevel [2345]
stop on runlevel [!2345]

pre-start script
    mkdir -p /var/run/apache2 || true
    install -d -o www-data /var/lock/apache2 || true
    # ssl_scache shouldn't be here if we're just starting up.
    # (this is bad if there are several apache2 instances running)
    rm -f /var/run/apache2/*ssl_scache* || true
end script

# Give up if restart occurs 10 times in 30 seconds.
respawn limit 10 30

exec /usr/sbin/apache2 -D NO_DETACH
respawn

I can do start|stop|status|reload apache2 and get meaningful results; if I kill -9 the master apache process, it gets respawned pretty much immediately, and it starts and stops on boot as expected. So it's working reasonably well I reckon.

There were things I tried that I could not get working.

Tried to remove -D NO_DETACH, in conjunction with:

expect fork
expect daemon

That failed to start the service.

Tried to use a similar method to /etc/apache2/envvars to populate the ${APACHE_*} variables:

export APACHE_RUN_USER=www-data
export APACHE_RUN_GROUP=www-data
export APACHE_PID_FILE=/var/run/apache2.pid

That failed to start, and produced an error about apache2: bad user name ${APACHE_RUN_USER}.

Tried console output and console default options; at this point I was really just flailing about trying to get meaningful error messages. Seemed to make no difference.

console output
This was useful for debugging apache messages:

exec /usr/sbin/apache2 -X -e debug -E /var/log/apache2/foo.log
This was another attempt to not modify /etc/apache2/apache2.conf that failed:

exec APACHE_RUN_USER=www-data APACHE_RUN_GROUP=www-data APACHE_PID_FILE=/var/run/apache2.pid /usr/sbin/apache2 -D NO_DETACH -e debug -E /var/log/apache2/foo.log


Need to change $EUID value to non-zero in the bash shell

Read man sudo https://manpages.ubuntu.com/manpages/xenial/man8/sudo.8.html and use -u user, e.g.
sudo -u nobody /path/to/the/script


How to download ubuntu sdk documentations for offline reading?

scrapbook firefox addon is amasing, try it.


Can't get Mac to detect installation media

I figured it out by taking the img file I created, transferring it to my PC, and burning that img to a blank DVD-R. For some reason, Mac then was able to read the DVD.


Why is installing the latest Linux kernel for Ubuntu taking so long?

Aha, I found the solution myself! What I did was I rebooted from a live USB and repaired grub (according to this guide), as I noticed that line in the message generated by sudo dpkg --configure -a namely Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported. and it made me wonder what would happen if I repaired grub. After booting back into Ubuntu on my HDD I re-ran sudo dpkg --configure -a and it installed the new kernel in what seemed like less than a minute.


How to synchronize files with Ubuntu One automatically as soon as they are sent to the provided directory

It should just work automatically in all supported platforms. If it doesn't, please contact support.


You can run dpkg -L $package | grep "usr/bin" to see all the binaries or scripts that should appear in your $PATH to be executed by a normal user.

Some packages may install binaries in other locations which are not meant to be executed by normal users, though.


Good question. It's actually quite flattering to the developers of Unity 2D that it's of so high quality that you really do have difficulties noticing the difference between them.

If you're running Unity 2D, then you'll see processes like "unity-2d-launcher" in your system monitor. But a faster test is to click and drag a launcher entry. If you're using Unity, then you can pull it outside the launcher. If you're using Unity 2D, then you can only drag it up and down within the launcher.

The dash also do look a little different.