How to use Evince to loop over ps files in current folder?

You can use a small nautilus script to use evince to loop over ps files in current folder. Here is the script,

#!/bin/bash
var="$(dirname "$NAUTILUS_SCRIPT_SELECTED_FILE_PATHS")"
evince "$1" &
for i in "$var"/*.ps
do
    if [[ "$i" != "$1" ]]; then
        zenity --question --title="Choose an option" --text="No: To exit any time\nYes: Move to next file" --width="300"
        if [ $? = 0 ]; then
            #killall evince  #Remove the hash if you want to open next ps file after closing the previous file.
            sleep 1
            evince "$i" &
        else
            notify-send "$(basename "$0")" "Slide-show is aborted prematurely"
            exit 0
        fi
    fi
done
notify-send "$(basename "$0")" "No file left to show"

Steps to install the script

Say the above script name is evince slide show. If you are using Ubuntu 12.04 save the script in ~/.gnome2/nautilus-scripts/, For Ubuntu 13.04 or later save it in ~/.local/share/nautilus/scripts/.
Make the script executable. It will not work otherwise. Right click on the script, then go to Properties >> Permissions and check the box corresponds to Execute

How to use the script

Go to a folder containing ps files. Right click on any ps file. Choose the option evince slide show under Scripts.

Selected ps file will be open in evince. At the same time you will get an option in a zenity pop-up dialogue box,

If you choose "yes" next ps file will be opened in evince. You will get similar option for all ps files in your current directory. If you choose "No" the script will be terminated immediately.

Note:

Similar script can be used for .pdf file also. One need to replace the line for i in "$var"/*.ps with for i in "$var"/*.pdf.


sudo ufw allow 443/tcp

And have a read through the docs on Ubuntu UFW interface on iptables. This should open it for your web application.

Also make sure that your application is serving off the external IP as well as the internal. The app.js file there is usually a setting to specify a interface for it to run on. 0.0.0.0 should run it on both internal and external.

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


Alt+Tab is not switching between windows on Ubuntu 12.04 (Precise Pangolin)

Well, just to finalize the answer, a reboot has done the trick for me after doing the following:

I went to system-settings -> keyboard -> shortcuts and almost all of them were disabled. I assigned "Alt+Tab" to "Switch applications". Then even though the problem specified in one of the comments above persisted, a reboot has solved the problem and I'm able to switch between windows without any problem.

Edit: Sometimes you have to reboot multiple times.


apt-get install is not working because of dpkg, how to solve

Remove broken locks

Be sure any process is still running associated with these locks:

sudo lsof /var/lib/dpkg/lock

sudo lsof /var/lib/apt/lists/lock

sudo lsof /var/cache/apt/archives/lock

If all of these commands output is empty, you can proceed.

Remove any locks you find in these locations:

sudo rm /var/lib/apt/lists/lock

sudo rm /var/cache/apt/archives/lock
sudo dpkg --configure -a
Try with sudo apt-get install again.

You should have superuser privileges to run those commands.


How to turn off the boot up beep of Ubuntu Live USB?

The boot should only happen when you're not booting in UEFI mode (which would be pretty much always on old systems). It's due to this line in the Syslinux configuration (isolinux/menu.cfg):

menu title Installer boot menu^G

If you're using an USB, it should be enough to edit that file and remove the beep, which is caused by the ^G (or ASCII bell - \a - character).

Source:

Debian forums: SOLVED! disable "BEEP" from syslinux by wheezy hdd live


Syncing Data and Coordinate Scripts Across Machines

Yes, it is possible. But first, you may want to define which data you want to sync. You can write a simple bash script that copies all the desired files from one computer to another (you should consider using SSH-keys to avoid entering the user's password every time that you want to coy files).
My approach would be to have a menu with the option "copy data from". You can list the laptops/PC's and select the one that is going to update the rest.

Please note that you can also use any cloud solution like dropbox/drive, etc. to sync both personal and config files.


Is it possible to use a mic and speaker connected to a phone or computer to do noise cancelling?

Delays in the digital processing of the audio inputs and in generating the inverse waveform will result in imperfect cancellation as noted in https://superuser.com/a/72557/264083. Suggest you instead get noise cancelling headphones or earbuds, where the noise cancellation runs in the headphone's hardware, and is not delayed by what else is going on in your PC.


How to run installed oh my fish plugins?

This is not a permanent (neither a "clean" one, I think).

It is indeed possible to make the plugins work by putting the function.fish script into the ~/.config/fish/functions folder. This is a raw fix which I don't necessarily like but it works.


Why was heirloom-mailx deleted from Ubuntu 18.04?

heirloom-mailx is a transitional (meaning "dummy" package that could go away at any time) package that was included in the s-nail source package.

Starting with s-nail version 14.9.4-1 in Debian, they removed the heirloom-mailx package as it was a transitional package.  All it did was pull in s-nail and then set up a symlink of heirloom-mailx to s-nail's binaries.

The changelog for this is here (from http://metadata.ftp-master.debian.org/changelogs/main/s/s-nail/unstable_changelog):

s-nail (14.9.4-1) unstable; urgency=medium

  * New upstream version 14.9.4
  * Modernize package: DH compat level, Vcs-* URL, Standards-Version
  * Remove heirloom-mailx transitional package (Closes: #876871)
  * Drop patch
  * Simplify debian/rules: Fix parameter setting, use tmp $HOME for tests

 -- Hilko Bengen <bengen@debian.org>  Sun, 01 Oct 2017 11:17:41 +0200

The Debian bug for this was Debian Bug #876871 about a non-empty transitional package - transitional packages are supposed to be 'dummy' packages which contain nothing but dependencies on other packages, but in this case it just contained a symlink for compatibility (and was not a valid 'transitional package' per Debian policy).

It looks like the Debian maintainer removed the package since it's not a transitional package.  You should adapt your mail agent (if possible) to use the proper executable rather than the heirloom-mailx which only was a symlink to an actual executable.  Failing that, you should consider looking for a new replacement MTA.


I ended up switching from libinput to synaptics for the touchpad driver. Synaptics has many functions that libinput lacks, and disabling a section of the touchpad is one of them. Fine-tuning the "disable touchpad while typing" time interval is also a useful Synaptics feature.
#disabling right part of touchpad

#install synaptics drivers
sudo apt install xserver-xorg-input-synaptics
reboot
xinput list-props "PNP0C50:00 06CB:CDAA Touchpad"
xinput list-props "PNP0C50:00 06CB:CDAA Touchpad"|grep Edges
#check the right edge dimension for the touchpad
synclient -l | grep RightEdge
#change the right edge boundary (and add this to startup programs)
synclient AreaRightEdge=900
#adjust cursor speed (and add this to startup programs)
xinput --set-prop "PNP0C50:00 06CB:CDAA Touchpad" "Device Accel Constant Deceleration" 1.05
#disable touchpad while typing (disable touchpad for 1 second after each keypress - add this to startup programs)
syndaemon -i 1 -t -K -R -d


Ubuntu 16.04 - VirtualBox 5.0 - Host crashes

Figured it out after following:

https://ubuntuforums.org/showthread.php?t=2382314

(Had to upgrade VBox to 5.2 and all worked ok)

In case you need it, had also to follow : VirtualBox - RTR3InitEx failed with rc=-1912 (rc=-1912) in order to completely uninstall all the previous installations

There was a silent security update that caused old VirtualBox installations (older than 5.2) to hang the entire host.


Ubuntu 14.04.1 install on Areca ARC-1883i - kernel detects partitions, installer sees no disks

FIXED!!!!!

Turns out the controller created the array volumes with write-protection on, so the installer detected the disks, but marked them as unusable.

I found this out by running fdisk from the installer debug console, and it told me that the filesystems were read-only. I then found the setting on the controller and disabled it.

I have a running install now! :-)


How to upgrade from Ubuntu GNOME 14.04 beta 2 to 14.04 LTS final release?

You don't need to do anything apart from apt-get update and apt-get upgrade or simply wait until the new updates appear on the Update Manager. This will simply move your Beta 2 version to the final release. No need to download the ISO, reinstall everything or need to format.

So hold on a bit until Update Manager shows the new packages or do an:

apt-get update

apt-get upgrade

And reboot. Enjoy 14.04 Final.


How does ubuntu 18.04 (gnome) autodetect monitor changes?

EDIT:
this is actually done by gnome, there's more to it than just this but this is what determines default monitor setup.
org/gnome/settings-daemon/plugins/xrandr/default-monitors-setup (recently moved to mutter).
If this doesn't' work for you, you can try finding where what you're looking for is by setting up alerts when you plugin monitors
link
and check and see what gnome settings were altered or accessed when you plugin a monitor.
ORIGINAL:
gnome tweaks has a tool for this
https://extensions.gnome.org/extension/1066/fix-multi-monitors/
to install gnome tweaks (which comes with all sorts of nifty extensions and lots of settings) Open up terminal and type
sudo apt install gnome-tweaks

you can then go to applications and open tweaks, turn on extensions. Then go to https://extensions.gnome.org/extension/1066/fix-multi-monitors/
there should be a switch at the top that you can switch that will turn it on and you're all set!
This works for me even when I disconnect from a dock or monitor then add it back it automatically remembers their location relative to each other!


Sorry, Ubuntu 12.04 has suffered an internal program error

Random crashes like this are often the symptom of hardware failure, particularly RAM. I suggest you run the memory test option available to you from the initial bootloader (or from the LiveCD you installed from).

While my current install of Precise has had it's crashes, they've been consistently the same programs. A random distribution of processes, and the crash reporter itself crashing, would not be consistent with a programming error.

On the matter of your external drives, they are probably formatted with the NTFS file system ; Linux doesn't really have a satisfactory NTFS filesystem check / fix (fsck) utility, because NTFS is a poorly documented proprietary file system - this is one of those things that are upsetting you about Windows. Linux will politely refuse to mount NTFS volumes that have not been unmounted correctly (as happens in a crash), because it's less than certain about it's ability to fix problems. You can force them to mount manually, but the best solution is probably to mount them in Windows (sigh) and shut it down properly, which should rectify the problem.

If you need a file system to exchange files with Windows, FAT32 is probably the best choice, since it does have a functional fsck utility. As an older file system, this involves compromise. It's also possible to mount ext2 in Windows, as long as you install additional file system drivers, but if you want to exchange files with machines you don't have admin privileges on, that isn't an option.

But your first concern should really be to diagnose what seems to be a hardware issue.


The file ~/.bash_history holds the history.
To clear the bash history completely on the server, open terminal and type
cat /dev/null > ~/.bash_history

Other alternate way is to link ~/.bash_history to /dev/null
However,
One annoying side-effect is that the history entries has a copy in the memory and it will flush back to the file when you log out.
To workaround this, use the following command (worked for me):
cat /dev/null > ~/.bash_history && history -c && exit


Typically a .cue file will be accompanied by a .bin file that contains the actual image data. If you'd like to convert it to the .iso format, the Iso9660 Analyzer Tool (apt-get install iat) should do the trick:

iat my_image.bin my_new_image.iso


browsers not working properly in ubuntu 12.10

I don't think this has to do anything with Ubuntu. It seems more like a problem of the browser or the internet connection.

Anyway, to install Google Chrome, you should head to http://google.com/chrome and download the 32/64 bit .deb installer.

Once downloaded, open a terminal (Ctrl+Alt+T), go to the directory where the file is downloaded and run dpkg -i file_name.deb.

If you get an error, while installing try running this command first:

sudo apt-get install libnspr4-0d libnss3-1d libxss1 libcurl3

and then reinstall Chrome.


How can I create a new Gnome Terminal profile?

In Gnome Terminal, click "File" → "New Profile"

For more details, see Gnome Terminal help - Manage profiles


Is there a way reverse of what mkdir -p option does?

The reversal of the mkdir -p command would be rmdir -p.  rmdir -p will remove the folder structure up till the folder is not empty.  You should be able to use rmdir instead of mkdir on your command:

rmdir -p $HOME/.local/my/sub/directories/1/2/3

You can also specify wildcards like if your $HOME/.local/my/sub/ contained like directories1, directories2 and directories3 for example, it could be done as:

rmdir -p $HOME/.local/my/sub/directories*/1/2/3

or

rmdir -p $HOME/.local/my/sub/*/1/2/3

If any folder as it is removing them contains data or another folder you will receive an error message that the directory is not empty and stops.

rmdir: failed to remove directory '/home/user/.local/my/sub': Directory not empty

Hope this helps!


Software Update not showing 16.04.4 update

If you have installed all available updates with apt or the graphical software updater, you already have it. Minor versions (eg. 16.04.4) are just updates of the .iso image.


Why in many themes my menus are too white (text and background)?

I found my answer when discovering that (without knowing it) I had installed Gtk+ 2 Theme Change, I selected the same theme there as the one in LXAppearance.

How I exactly got the program I do not recall. Maybe it was installed along with a theme that had an installer or a series of instructions that I followed without taking notice.

The issue looks similar to a Qt-related problem which received a similar solution (see the askubuntu question).

The rule should be:
The theme selected in LXAppearance and that selected in 'Gtk+ 2 Theme Change' has to be the same.
(The quality of the way folders and fonts are displayed seems to have improved too.)

What happens is that I can set correctly a dark-menu theme just through LXAppearance and I can do the same thing for the light-menu themes in Gtk+ 2 Theme Change. But sometimes it happens that setting a darked menu theme just in the later would make the fonts of the menus as dark as the background. So, the rule applies both ways.

The program is available in Software Sources (search Synaptic for 'Gtk+ 2 Theme Change')

On Softpedia here.

And the website of the provider.

It is in Software Center


Ubuntu 14.04 No "Enable Wifi" or "Enable Wireless" Option

You will need to download two packages from the internet, transfer them to USB, and take them to your computer.  The packages are

Broadcom wireless driver

DKMS

Other than these newer links for Ubuntu trusty (14.04) you should follow the instructions as in this answer - use arch to determine which architecture you need, download the .deb files, copy them into a directory in your computer.

Then use sudo dpkg -i *.deb from that some directory to install the two packages, followed by sudo modprobe wl.  This should load the drivers required for your wireless adaptor.


nvidia-cuda-toolkit and nvidia driver version

Closing this issue as the nvidia-340 driver is the only one working for GeForce 9800GT. As I checked on their web-page, newer drivers do not support old graphics cards like mine.


Ubuntu 20.04 on ZFS can't update kernel, bpool missing

Solution
Post install
I am not certain if this can be reliably fixed post-install. One thing I found is if I import bpool with the right vdev, then it shows up and it gets mounted on subsequent reboots since it gets remembered in the pool cache. It seems to be possible to change the ZFS vdev name upon import but I'm not sure how this can be done exactly so I'm not suggesting it. Someone with better ZFS-fu can suggest the correct sequence of commands, maybe involving zpool import ... -d ....
At install time
There's already a fix in the responsible code block in Ubiquity but it isn't part of the current version shipped with the first 20.04 media. You can however grab it once you've booted into the Live desktop environment.

Boot from the Ubuntu installation media.
Choose Try Ubuntu without installing.
Grab that fixed zsys-setup:

sudo wget -O /usr/share/ubiquity/zsys-setup https://git.launchpad.net/ubiquity/plain/scripts/zsys-setup?h=20.10.2

Run the Ubuntu installer and install on ZFS (experimental) as normal.


Right click the Menubar (File Edit View ...) and enable the "Color Box"


Ubuntu Software center Download seems to have stopped

Install Skype Using terminal. Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command below.

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

sudo apt-get update && sudo apt-get install skype

give password.. Packages for Skype will be downloaded and installed automatically.

After completing Process , You can find Skype installed


Every time I turn off or reboot from ubuntu, the boot are lost

Wait until Ubuntu fully supports UEFI ...

After install and reinstall all my OS, ubuntu is doing the same all the times (lost the boot system)...

I found that Ubuntu does not support the "Intel® Rapid Storage Technology", this affect directly the GPT ...

currently only recommend wait out the ubuntu 13.04 (with a rescovery USB close)


If it's a one-off command, you're better of just setting it for that command, i.e.:

IRSTLM=/home/user/irstlm /home/user/irstlm/bin/add-start-end.sh  \
  < /home/user/corpus/news-commentary-v7.fr-en.true.en > news-commentary-v7.fr-en.sb

If it is part of a script use:

export IRSTLM=/home/user/irstlm
/home/user/irstlm/bin/add-start-end.sh < /home/user/corpus/news-commentary-v7.fr-en.true.en > news-commentary-v7.fr-en.sb


first let's reset compiz and gsettings to default. Press Ctrl-Alt-t. In the terminal run:

sudo add-apt-repository ppa:amith/ubuntutools
sudo apt-get update
sudo apt-get install unity-reset

finally

unity-reset

For tweaking ubuntu install: ... ubuntu-tweak

sudo add-apt-repository ppa:tualatrix/ppa
sudo apt-get update
sudo apt-get install ubuntu-tweak

In the dash search for "ubuntu tweak"

Once open, click Tweaks tab, then Miscellaneous, then toggle Overlay scrollbars off


Type «sudo» is not known on line 1 of the sources list

This question already has a general answer

In this case, I just deleted the file by running the following comand on the terminal:

sudo rm /etc/apt/sources.list.d/spotify.list


Is a Skype account needed to talk via SIP?

As far as I know, Skype and SIP accounts are not compatible. So, no you won't need a Skype account to talk via SIP. However, you will need a SIP account. By the same token person at the other end will need a SIP account too, not to mention a working and properly configured SIP client.

Unlike Skype, I found configuring SIP a bit more difficult, particularly because there are multiple SIP service providers and settings may be a bit different for each.

Both Skype and SIP allow calling regular phones and receiving calls from phones. Unfortunately these are not free in either for Skype or for SIP service providers.

If you just want to talk and already have a gmail account, you can try Hangout. It works without any download/install, (tested with Chrome browser). You can talk to people with Android phones and tablets as well as PCs, using WiFi (or wired Internet for PCs). Skype apps are available for phones as well.

In any case, you will need an account somewhere. The account is what identifies you to the other Skype/SIP/Gmail users. If you don't have an account there is no easy way for someone to call you (and you to call someone else without an account).

One alternative is to use Viber. Not that it does not need an account, but it uses your (mobile) phone number as your account number. So anyone who knows your phone number can contact you. See How to install Viber in Ubuntu? for more on Viber. I have never used it, so I don't know much about it.

Hope this helps


Adding a Wine (.exe) file to open/play files in Thunar's 'Custom Actions'

I think the main problem is that the Thunar command %F is probably not going to work when applied to a Wine program. Often the best way with Thunar custom actions is to use a script and apply the correct parameter to that: i.e.

/home/mike/foo_script %F

then the parameter can apply to the script.

The script I have experimented with is at the hydrogenaudio forums, and I have modified it slightly, but credit to that forum. There is a lot of useful information on that forum about foobar.

#!/bin/bash

cd ~/.wine/drive_c/"Program Files"/foobar2000/
if [ "$1" != "" ]; then
filename=`echo z:$1 | sed 's/\\//\\\\/g'`
wine foobar2000.exe "$filename" &
else
wine foobar2000.exe &
fi

Copy the script into a text editor, but make sure you place the correct location of your foobar directory in the script, make it executable and enter its location in the Thunar custom actions dialogue (as in the screenshot below). As you know, select audio files and folders in the other 'appearance conditions' tab.

Once it has been added as a Thunar custom action with the correct parameters, the script further above allows you to add and then play your music in Foobar just by right clicking on a single track or a folder and selecting your custom menu item.

Here is Foobar launched with the custom action and playing a folder of Duke Ellington:

In addition, you could probably modify the script and also use it for other wine applications just by changing the name (foobar2000) of the application and the application folder. Then you could create a new script and another different custom action.


If your media player supports MPRIS, there are commandline tools available to send MPRIS commands over DBus to the player.

mpris-remote (in the universe repository in trusty and later)
playerctl
(others)

MPRIS runs over D-Bus, so you can also use tools like qdbus (from the qdbus package) to send direct queries.  See Controlling Clementine with MPRIS for examples.


Resize images to specific height value in ImageMagick?

According to the documentation of ImageMagick I suggest to use -geometry x600, whereas x600 means that the new image has a heigth of 600 px with the same aspect ratio as the old image.

For a single image you could run:

convert input.png -geometry x600 output.png

If you prefer to convert all images of a folder in one run, switch to it (i.e. cd ~/Pictures/panoramas/) and use

mogrify -geometry x600 *.png

But be careful with that, because it overwrites the original image files. To avoid that you could

create a new folder (mkdir ~/Pictures/panoramas/small)
copy the images into this folder (cp ~/Pictures/panoramas/*.png ~/Pictures/panoramas/small) and
edit the images in this new folder (cd ~/Pictures/panoramas/small && mogrify -geometry x600 *.png).


Are LTS releases close to being expired?

The usual Ubuntu documentation spots haven't been updated yet, but it is expected that 16.04 will be an LTS release, and that it will be supported until 2021. As can be seen on the Ubuntu wiki page on LTS:

  A new LTS version is released every 2 years. In previous releases, a
  Long Term Support (LTS) version had 3 years support on Ubuntu
  (Desktop) and 5 years on Ubuntu Server. Starting with Ubuntu 12.04
  LTS, both versions will receive 5 years support. There is no extra fee
  for the LTS version; we make our very best work available to everyone
  on the same free terms. Upgrades to new versions of Ubuntu are and
  always will be free of charge.

The graph there was last updated before the current latest LTS version was released.


| is called pipe. The pipe operator passes the output of one command as input to another. A command built from the pipe operator is called a pipeline.

In UNIX like operating systems, a pipeline is a sequence of processes chained together by their standard streams, so that the output of each process feeds directly as input to the next one.

Suppose, you have $ command 1 | command 2 | command 3, then

Source: Using Pipes with Linux Commands

For example, if you want to list all files in a folder, you will probably use the following:

$ ls -la

Now, suppose, you want to list only java source files, you would probably do something a follows:

$ ls -la | grep .java

ls -la produces a process, the output of which is piped to the input of the process for grep .java.

You can learn more about pipes and filters here.


16.04 applications opening in upper left corner, can't auto-scale windows at screen edges

Never really found the reason why this happened, but the accepted answer at this post fixes the issue if you install CompizConfig:

Why are windows going to top left of the screen?


Is there any working wifi drivers available for HP Probook 440 G2 for ubuntu 14.04?

Yes, there is a driver. But you need to compile it from source. Run these commands.

sudo apt-get install git
git clone https://github.com/lwfinger/rtlwifi_new.git
cd rtlwifi_new
make
sudo make install

Note: This driver should be reinstalled after each kernel update. If it is a problem for many people, I can make a dkms package and put it into a ppa.


where does gnome-do store its information

In ubuntu the configs are by default in this folder

~/.[programname] (~/.do or ~/.gnome-do)

and maybe the history too (or is specified in the config)

edit: If you do not see files starting with a dot (hidden files/directories), you kann press

CTRL + H

in nautilus


GeForce and Radeon: what is present condition of opensource and proprietary drivers?

What you have mentioned in your post is still relevant today. However the proprietary "fglrx" driver for ati has caught up very much with the proprietary nvidia. So much so that i barely notice a difference between catalyst on windows and fglrx on linux. One area where ATI still lacks is HD video playback where there is no equivalent of nvidia's VDPAU. However with ATI opening up, expect much more work on the XvBA. So what i will recommend is that unless you watch a lot of HD movies. Go for Radeon. I have a 4650 and i am very pleased with its performance.

Unfortunately things are not that rosy on the opensource front. The noveau, radeon and Gallium3d drivers are all fine if all you want to do is compiz and maybe a few indie games. But all the open source solutions ( be it mesa, gallium or anything else) are still miles behind their proprietary counterparts. Right now the best performing Open Driver is the Gallium3D driver for the R600 ATI Chip ( Radeon hd 3xxx series), but its still not mature enough. So unless you have very modest requirements, you will have to go for the prorietary ones.


If you toggle the option to "Erase" when you are formatting a volume, the following things will happen:

The volume will be formatted to the type specified.
A dd if=/dev/zero of=/dev/sdX sort of action will take place, where /dev/sdX is the newly formatted volume. In plain language, the new volume will have a bunch of zeroes written to it.

If you are looking for a more thorough means of wiping a hard drive or making it very, very difficult to recover data, you will probably want to use wipe, srm, shred, or scrub.


How to install the LibreWolf Browser (incl. DRM support)?

According to the LibreWolf Documentation there are several ways, some still considered experimental.

Flatpak, the latest package can be found on Gitlab.
(If you have not setup Flatpak, see Flatpak.org.)

AppImage, the latest package can be found on the same Gitlab page.

Download the AppImage (e.g. LibreWolf-.....x86_64.AppImage)

Make the file executable, e.g. in the properties of the file

Move the file to a folder you like it to be stored and run from

Download and move the LibreWolf-Icon to a folder (use “location” below, e.g. download from https://librewolf-community.gitlab.io/)

To be able to open it from Activities or "Show Applications", generate a Desktop-file:
Open a text file (e.g. with gedit) and add to the file:
[Desktop Entry]
Name=LibreWolf
Type=Application
Exec=PATH-TO-FOLDER-WITH-APP-IMAGE/LibreWolf.AppImage
Icon=PATH-TO-FOLDER-WITH-IMAGE/Librewolf-logo.png
Comment=Secure Browser
Categories=Browser;Internet

Make the Desktop-file executable, e.g. in the properties of the file

Now you can open LibreWolf like other applications

Manual Compilation
See for more details on the project page on Gitlab.

Binary Tarball
LibreWolf is available as a binary tarball. Check out the releases page on Gitlab for downloads.

Debian build
Debian builds are are available externally at bgstack15's OBS build repo, too. The Debian release is unstable and it looks that it does not (yet) work on Ubuntu, see comment in issue Typo in package deps (Ubuntu20.04/Mint 20.X) (#199).

If you find any bug or problem, please report it on the project page on Gitlab and/or help with programming.
Some tips regarding settings you can find here on the project page.
The configuration files you can find here: /home/USERNAME/.librewolf/
How to get DRM Compatibility
Digital rights management (DRM) is enforced off by default (this is needed for Netflix and similar); you can enable it with the following instructions:

Open librewolf.cfg  (e.g. sudo gedit /usr/lib/librewolf/librewolf.cfg)
Under the section Section: User Settings
-- Comment the active lines with // under the subsection User Settings: DRM/CDM - Main
-- Comment the active lines with // under the subsection User Settings: DRM/CDM - Widevine
Restart LibreWolf then open about:preferences and enable Play DRM... under general section
-- LibreWolf will download Widevine and enable it (under about:addons plugins section) you can force the download by clicking Check for updates under the tools button

Browser doesn't restore session after restart
Preferences:

Check Restore previous session
Privacy & Security: Scroll to History, to the right from Clear history when LibreWolf closes find button Settings... and uncheck: Browsing & Download history

Save passwords
Activate Restore previous session (see above) can help.
Otherwise check this Reddit thread.


How do I disable the "Show cursor when ctrl is pressed" option in 13.04?

The option to turn it off should be in the Mouse tab of the Mouse and Touchpad options which is in the settings menu.


Strange thing happening in command prompt

suspend is a bash built-in command, what it does as per the man page is:

 suspend [-f]
          Suspend  the execution of this shell until it receives a SIGCONT
          signal.  A login shell cannot be suspended; the -f option can be
          used to override this and force the suspension.  The return sta‐
          tus is 0 unless the shell is a login shell and -f  is  not  sup‐
          plied, or if job control is not enabled.

Thus your shell is suspended and will be until you send it a SIGCONT signal. The behavior you see is because the shell is not interpreting those characters.

To fix this:

Go to another virtual console (press alt-F3 or something) and log in.
use pkill to send the CONT signal to all processes named bash. This won't affect other running shells but should "unstick" the stuck one.

pkill -CONT bash


How do I install apache, php, and mysql on a usb flash drive in ubuntu?

The only way you can achieve this is if your entire Ubuntu OS is installed on a flash drive. The packages you want to install integrate themselves into your OS as they require common packages to function correctly. You could change the path of your apache directory for example so that your websites reside on your usb if you like: Easy way to change apache www location

If you want to install Ubuntu on a usb have a look at this link: Can I install Ubuntu to my 32 GB USB pen drive?


Dangerous Website May Have Infected System?

Stay calm.

Not all adult sites provide you with malware
If nothing special happened besides a redirect, there is no reason to suspect misbehaviour.
The site is not listed as suspected as far as I checked, for instance with avg

You migtht want to remove your browser history or cookies if you hate the fact that you could be 'linked' to an adult site, but that's more of an "ow no, if someone uses my account and really digs deep, they see this site's address" thing, and not an "ow no, there is something wrong with my computer and they are stealing my creditcard" thing :)


How to fix overscanning with nVidia 9800 GT? On Live Cd it wasn't happening?

This might help you out, but it is for 8400 GS. Overscan Fix for Nvidia Graphics Cards


How to add proxy exemption for a domain in ubuntu?

Use the following command to setup the exemption:

gsettings set org.gnome.system.proxy ignore-hosts "['localhost', '127.0.0.0/8', '192.168.1.0/24', 'npmjs.org', '::1']"

To verify the settings enter this command:

gsettings get org.gnome.system.proxy ignore-hosts

This should be the output:

['localhost', '127.0.0.0/8', '192.168.1.0/24', 'npmjs.org', '::1']


How can I change Ubuntu GNOME into Kubuntu?

To accomplish changing Ubuntu GNOME into Kubuntu, you could upgrade to Ubuntu 17.04 then after the upgrade has gone through successfully, you can run some commands to install KDE then remove GNOME.

After you have upgraded to Ubuntu 17.04, you would need to install KDE first.

To install KDE, you would open up a terminal and type:

sudo apt-get install kubuntu-desktop

After you have done this, you should reboot and then at the login menu you would click the Ubuntu icon next to your username and change it to KDE/Kubuntu (I am unsure what the exact name of it is) as seen in this picture:

After this, to remove GNOME, you would then open up a terminal and type:

sudo apt-get purge ubuntu-gnome-desktop

Alternatively, if you do not want to go through with doing all of this, you could back up your data (possibly to an external device) and then simply do a clean install of Kubuntu 17.04. I am a big fan of clean installs, and this is probably what I would do.


There are at least two ways to change the default gateway on a modern Linux system:

Using the traditional route change default gw gateways_ip ethXAdvantage: Works on all unix like systems.Alternative: route delete follow by a route add. Do not try this when connecting remotely.
Using the ip command.
ip route { add | del | change | append | replace | monitor } ROUTE


My terminal shows only a blank screen--How can it?

No Problem , you can restore it easily.

Just press CTRL+ALT+F1 & login there

then paste as

cp /etc/skel/.bashrc ~/
source .bashrc

Then type CTRL+ALT+F7 to reverse to GUI desktop.


HP Color Laser Jet CP 1217 printer driver for Ubuntu 14.04

According to this site, a plugin is required. http://hplipopensource.com/hplip-web/models/color_laserjet/hp_color_laserjet_cp1217.html Please open a terminal and do:

sudo apt-get update
sudo apt-get install hplip hplip-gui

Now, connect the printer and run:

hp-setup

It should find your printer and install the correct plugin and driver.


Suggest mp3 player having minimum requirements

As Enqueue option looks like the main requirement here, may I suggest that with the help of nautilus-actions, we can have an option like "Add to Playlist".

In case you are interested in the steps to do that, here they are :
1. Please install nautilus-actions if you don't have it already.

   $ sudo apt-get install nautilus-actions

Open Menu -> Preferences -> Nautilus-Actions Configuration.
Click on the "+" icon on the toolbar to add a new entry.
We can name the "Context label" something like "Add to Playlist". Similarly please enter anything of your choice in the Tooltip box. We can also choose an icon for the item (need to mention the path of icon).
Click on the Command tab and enter your favorite music player's path like "/usr/bin/audacious" in the box.
For the Parameters box, I have entered "%U" (without the quotes) and working directory is "%d" (without the quotes)
Save.
Now in Nautilus go to the music directory and select multiple files and click right button and select "Add to Playlist".

This should result in the music player to run and play the selected files. It worked for me in Audacious.

Although this might not be the answer you was looking for, I thought to share my thoughts so that in case you like it you can please give it a try.

EDIT 1 : I am attaching here two screenshots of the nautilus-actions configuration tools. These are the two tabs where I have added the details. I am on Natty. I have nautilus-actions nautilus-scripts-manager and also options like nautilus-gksu installed.

Screenshot 1 :

Screenshot 2:


If you are using Ubuntu 16.04 you will see a little speaker at the very top of your desktop click on that speaker. Here are a few things to look for

Check to see if your sound maybe muted if it is just on tick that box
Check the sound output make sure your audio device is present
While in the sound settings check the sound level to make sure it's at least mid way


Custom LiveCD without Unity still tries to load ubuntu session. (Failed to load session "ubuntu")

Copying user's comment in his question to an answer.

  I figured out the solution with the help of this blogpost:

  http://onubuntu.blogspot.sg/2011/09/setting-gnome-shell-as-default-desktop.html

  But the command should be:

sudo /usr/lib/lightdm/lightdm-set-defaults --session gnome-shell

  Place it in your script to build the LiveCD "after" LightDM is
  installed. This just adds the line user-session=gnome-shell to
  /etc/lightdm/lightdm.conf.


Yes, it is possible.

This link shows you how

The link shows you how to turn off all kind of animations especially the spreading icons on menu, searching, and window animations so you can work faster. To do it, just run this command:

$ gsettings set org.gnome.desktop.interface enable-animations false

Then apply it by pressing Alt+F2 and type  r  and press Enter. This will reset the GNOME Shell to follow your command.

To revert it back (enable animation again), just change the command to:

$ gsettings set org.gnome.desktop.interface enable-animations true


KVM on Ubuntu Server 20.04 on Raspberry Pi4

You can do it, but be aware:

The Pi is usually not powerful enough to run heavy VM Guests well -- you are likely to encounter some performance problems (overheating, lagging). Especially desktops.

Monitor your temperature sensors. Running a VM can heat up your Pi quickly - a proper cooling system is highly recommended to prevent unexpected thermal shutdowns.
Monitor your top and free usage on both Host and Guest if you encounter performance problems.
If you run into performance issues due to your host LXQT desktop, consider a lighter-weight web-based server frontend instead of a complete Desktop Environment (I recommend the cockpit package, which is in the Ubuntu repositories)

The Pi image is customized for your hardware, but the VM application presents a much more generic hardware profile to the Guest. So using a pi-specific image is unnecessary (though you CAN do it).

Consider using a cloud-image for arm64 or armhf Guests instead of a pi-specific image. Cloud images tend to be smaller, and will make migrating the Guest to another Host easier someday.
LXD containers are flexible - an LXD container behaves like a VM for most purposes, but with a fraction of the overhead of the VM application + Guest. LXD can also run real VM images with a bit of tweaking. LXD containers are even easier to spin-up, easier to migrate, and have a smaller disk footprint than VMs.
If the application that you want to run in the VM is available in a Snap already, then Ubuntu Core is a very-lighweight snap-only flavor of Ubuntu. Of course, you could run the same sandboxed snap safely without a VM in the first place, too.
For advanced folks who really want to tweak the gears on a super-lightweight image: Ubuntu Base (instructions)


How to see the command attached to a bash alias?

The type builtin is useful for this. It will not only tell you about aliases, but also functions, builtins, keywords and external commands.

$ type ls
ls is aliased to `ls --color=auto'
$ type rm
rm is /bin/rm
$ type cd
cd is a shell builtin
$ type psgrep
psgrep is a function
psgrep ()
{
    ps -ef | {
        read -r;
        printf '%s\n' "$REPLY";
        grep --color=auto "$@"
    }
}

type -a cmd will show all the commands by that name in order of precedence, which is useful for the ls alias above, where the alias itself calls ls.

$ type -a ls
ls is aliased to `ls --color=auto'
ls is /bin/ls

This tells you that when you run ls, /bin/ls will be used, and --color=auto will be included in its list of arguments, in addition to any other you add yourself.


error while running ruby application at system startup in ubuntu

Your code does

sh /home/ubuntupc/.rvm/scripts/rvm

Which will run rvm with no arguments. What you actually want to do is to include the rvm code in your current script, so replace that line with

source $HOME/.rvm/scripts/rvm


Ubuntu as a Router/Gateway - Unable to access WAN

I was able to resolve this issue by editing /etc/udev/rules.d/70-persistent-net.rules.  By making eth0 my WAN NIC, linux automatically used it's gateway as the default gateway.

/etc/udev/rules.d/70-persittent-net.rules:

# This file was automatically generated by the /lib/udev/write_net_rules
# program, run by the persistent-net-generator.rules rules file.
#
# You can modify it, as long as you keep each rule on a single
# line, and change only the value of the NAME= key.

# PCI device 0x10ec:/sys/devices/pci0000:00/0000:00:1c.4/0000:03:00.0 (r8169)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="FF:FF:FF:FF:FF:F0", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

# PCI device 0x10ec:/sys/devices/pci0000:00/0000:00:1c.5/0000:04:00.0/0000:05:01.0 (r8169)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="FF:FF:FF:FF:FF:F1", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

# PCI device 0x10ec:0x8169 (r8169)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="FF:FF:FF:FF:FF:F2", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"


HDMI with Nvidia propietary drivers on 14.04.1

I get HDMI video working fine with my Sony 32″ LCD TV as external screen. But audio has been a problem for long time. Here is a simple technique to enable audio through HDMI so that you can enjoy the high quality sound through TV or Home Theatre System.

Motherboard: M3N78-EM based on NVIDIA GeForce 8300 Chipset

Operating System: Ubuntu 12.04 Precise Pangolin

Here is my VGA controller information:

$ lspci | grep VGA

02:00.0 VGA compatible controller: NVIDIA Corporation C77 [GeForce 8300] (rev a2)

First we need to ensure that NVIDIA proprietary driver is installed. Ubuntu installed the NVIDIA driver by default while installing (I had opted for third party software installation option during installation). System Settings -> Additional Drivers  should show the dialog as shown below. In shell, you can see “nvidia” for the command “lsmod | grep nvidia”.

Configure the screen connected to HDMI Port. In case of NVIDIA, Ubuntu provided System Settings -> Displays tool does not detect the external Display. But NVIDIA provides a powerful GUI based settings tool, which makes the job easier. This tool can be accessed through dash by typing “NVIDIA” -> “NVIDIA X Server Settings” -> “X Server Display Configuration”. Don’t forget to click “Save to X Configuration File” to save your changes before quitting.

Select the HDMI Audio as output device in Volume Indicator (on top bar) -> Sound Settings… -> Output -> HDMI / Display Port.

The above steps should get the job done. If not you can check status of S/PDIF settings. It should not be muted. You can check with “alsamixer” command. The following screenshot shows S/PDIF muted.

Select the muted S/PDIF bar and press M to unmute it. It should be as shown in the below screen.

It should fix the issue. You should be enjoying the audio over HDMI now. Now you can make it permanent by issuing “sudo alsactl store” command which will save the above settings.

In case you did not get succeed, you may try the following tweak.

Create a file called /etc/asound.conf (if there is a file already, just backup that file) with following content and reboot the machine.

pcm.!default hdmi:NVidia
pcm:iec958 hdmi:NVidia


The 3.13. kernel will be supported for Ubuntu 14.04 till the release EOL, it will get security and bug fixing updates.

New kernels are needed to support new hardware.

If everything works, there is no need to upgrade the kernel.


issue with cp command when i was copying in /var/www

Judging by the error message, /home/index.html is a directory (folder), not a file, and /var/www/index.html already exists and it is a regular file.

To see if /home/index.html is a directory, try:

file /home/index.html

It will probably say: /home/index.html: directory.

If that's the case, you cannot copy a directory over file. Maybe the file you're trying to copy is inside the directory /home/index.html? Then the command would be something like

sudo cp -r /home/index.html/index.html /var/www


i2c-hid i2c-SYN1B7B:01:01 failed to retrieve report from device - problem during boot, device stops booting

This was a known issue with kernel versions prior to 3.14 (see bug report here).  Try updating to the most recent kernel and see if that fixes your problem.  (If you don't know how to do that, see askubuntu page here).

Additionally, I am fairly sure that messing with your swap partition caused this problem, as that shouldn't change the behavior of HID over I2C (my knowledge on this is rudimentary, though, so if anyone knows better feel free to correct me).


Are there plans for a progress indicator?

It IS possible via library called Taskview. See https://github.com/ssickert/TaskView. It already has plugins for lots of apps, we just need an AppIndicator which supports it.


After upgrading to 13.04 Unity interface is not showing

This worked for me:

Press Ctrl+Alt+T to open a terminal window.
At the terminal prompt, type ccsm. If the CompizConfig Settings Manager window appears, skip to step 5. If not, continue with step 3.
Type sudo apt-get install compizconfig-settings-manager. Type your password when prompted.
At the next terminal prompt, type ccsm.
In CompizConfig Settings Manager, select the check box for the OpenGL plugin if it isn't already selected.
Click the Ubuntu Unity Plugin item.
Select the Enable Ubuntu Unity Plugin check box, if it isn't already selected. If it is already selected then uncheck this and again select it.
Exit from the CompizConfig Settings Manager.
Press Ctrl+Alt+Delete. When asked, confirm that you want to log out.
I did a cold reboot at this point. I'm not sure it's necessary, but I'm a bit paranoid.

After this, Unity came up as it's supposed to for me.

I have a 64-bit AMD Phenom CPU and an nVidia GPU; I'm running 64-bit Ubuntu with the nvidia-current driver set, and I've just upgraded to 13.04 (at which point Unity disappeared).


The folder not found in directory on reboot

tmp is a directory used by the system itself for temporary files. It is emptied every time you shut down the computer. So I suggest using some program for recovering files. Perhaps PhotoRec will work.


Is there a tool to encrypt a file or directory?

GnuPG (GPG) can use asymmetric and symmetric encryption. Asymmetric crypto involves a two keys, a public key for encryption and a private key for decryption. See djeikyb answer on this page for asymmetric key usage.

For symmetric encryption, the encryption and decryption keys are equal. It is important to realize that most people are very bad at choosing strong passwords. Thus, an encryption scheme using passwords should use a key-derivation function that takes more resources (time, memory) to slow down brute-force attacks.

For a description of GnuPG's KDF, see this Crypto Stack Exchange post. Example usage of symmetric encryption:

gpg --symmetric < unencrypted_file > encrypted_file

Decryption:

gpg --decrypt < encrypted_file > decrypted_file

Note that gpg caches the symkey by default (documented behavior). In order to avoid that, use --no-symkey-cache option as described in a related answer.

Manual page of gpg.

old answer for users who are able to chose good keys, see note below

For single files, openssl is very useful, especially when sending the file over an unsecured channel (e.g. e-mail). It's free (in money and in freedom), unlike Truecrypt, which is only free in money.

NOTE: the password that you enter here will be processed by one MD5 iteration 1. If you chose a password "123456", then you will have very little security.

Encrypt:

openssl aes-256-cbc -salt -in unencrypted_file -out encrypted_file

You'll be asked for a password, which you have to input twice.

Decrypt:

openssl aes-256-cbc -d -in encrypted_file -out unencrypted_file

Manual page for the enc program.

1 openssl enc uses the digest function defined by the -md option (default md5) and invokes function EVP_BytesToKey() with an iteration count of 1. This can be found in the openssl source at apps/enc.c.


Brightness slider gone, and the brightness is constantly jittering

This is not an direct answer to your question, but is a workaround.

Download the .deb file of Brightness Controller from http://lordamit.github.io/Brightness/. Though It is in Software Center but still is not available for Ubuntu 13.10 (We are working on a newer version which will be submitted for all supported versions of Ubuntu within a month).

It supports controlling brightness up to two displays.


You may not have to reinstall. First thing is to ascertain what you did to your bash and if it was system wide or just for your user ID.

Create a new user ID and see if it works normally. If so there is no damage done to 18.04 just for your old user ID.

Ubuntu keeps a "skeleton" of most configurations that get copied to when a new user ID is created. For .bashrc it is in /etc/skel/.bashrc:

$ llocate .bashrc
ACCESS      OWNER  GROUP  SIZE  MODIFIED      NAME (updatdb last ran: 2018-10-06 10:30:06)
-rw-r--r--  root   root   2188  Aug 31  2015  /etc/bash.bashrc
-rw-r--r--  root   root   3771  Aug 31  2015  /etc/skel/.bashrc
-rw-r--r--  rick   rick   7522  Sep 30 10:10  /home/rick/.bashrc
-rw-r--r--  rick   rick   7492  Sep 30 10:09  /home/rick/.bashrc~

If you modified .bashrc and damaged it there may be a backup called .bashrc~ which you can copy over top.


Permission denied when I try to cd into any folder

Your folders need to have an executable bit ('x') set. You can set it with chmod +x Documents.


Linux operating systems organize the file system in a tree structure. Since you installed the OS to your SSD, that drive is the root of the tree and is mounted at / Where on the tree the HDD is depends on how and where you mount it. It can be anywhere on the tree you desire. (One common location to mount a secondary drive on a home system is /home as that is the location on the tree that by default holds all the users files. For a good overview, see https://help.ubuntu.com/community/LinuxFilesystemTreeOverview


Right-Click on your panel and select Panel > Panel Preferences.

Click on the Items tab and select Windows Buttons.

Click on the Gear on the right for Edit the currently selected item (my icon pack shows it as an eye ball).  Change Window Grouping to Always.

Hope this helps!


Assistance needed for conducting file searches

Yes it's recursive and it starts in the directory that it is currently viewing.  It is also quite comprehensive and will find a string that is part of a filename.  If you play around with the searchbar in Nautilus (the file browser) you will find it quite useful and simple.


Directly installing file from internet with package manager instead of downloading it first (Lubuntu Disco Dingo 64)

The .deb installer, in your usage scenario, is stored in /tmp.

The contents of the temporary folder are deleted during a reboot.


Is Python 2 removed from 14.04 CD images?

For 14.04: server and desktop images
The situation is:

there is no python2 on the server image
but python2 is part of the the desktop image

The logic
I quote:

It is a release goal for Ubuntu 14.04 (Trusty Tahr) that we ship only Python 3 on the touch, server, and desktop images. Don't worry, Python 2.7 will still be available in the archive, and more specifically 'main' for now.

Python 2 is removed from the server images, you are absolutely right! For the server, don't worry python2 is still in the repos and can thus easily be installed.
Now the migration to python3 is not completely finished for the desktop (which involves more python packages than the server). The desktop image thus still has python2.
Source: https://wiki.ubuntu.com/Python/FoundationsTPythonVersions


Its difficult to tell what's wrong by hearing this kind of statement..
 "My Mi-fi would connect to my computer but wont browse"
you have to troubleshoot step by step and use process of elimination
Since you have already confirmed wireless is connected fine,check you have ip address issued by the wireless device/router first.. To check that open a terminal and type

sudo ifconfig

If ip is in the range of wifi device that is issued, then ip is ok. Yet you can't browse then check gateway is ok, .. Use terminal and type

sudo route

if that one also looks good, next it may be DNS issue, try to have a ping .

open a terminal and
ping 8.8.8.8

and also

ping www.google.com ..

This will help you to eliminate dns are ok or not.. If 8.8.8.8 pings are someting similar xx bytes from 8.8.8.8: icmp_seq=3 ttl=56 time=xx ms  and ping www.google.com gives you ping: unknown host www.google.com potentially there could be a dns issue..

If everything works fine, yet cant browse, then use tracert kind of equivalent : to make sure upper level firewall or similar device is blocking/not blocking your path..

(and also if this is a business/working/enterprise environment they may use proxy settings etc )

If these things are too much technical for you , get in touch with your friend who is capable of helping you..


Recover Orphaned RAID 0 from Silicon Image controller with Linux Software RAID?

Had pretty much the same problem with an it8212 "fake RAID" controller, and a couple of disks on RAID0. Surprisingly, mdadm could solve the problem, with a little trial and error, though.
If you know/remember the chunksize (the quantum of each parallel disk read/write for each disk), you can try something like that (don't try it just yet):

 sudo mdadm --build --verbose --run --chunk=64 /dev/md0 --level=raid0 --raid-devices=2 /dev/sde /dev/sdd

If /dev/md0 was already occupied, feel free to use incremental numbers instead of 0.
Of course, /dev/sde and /dev/sdd where the disks in my case, and 64k was my chunksize, but you can easily determine your own configuration with:
    sudo fdisk -l

This lists all partitions of all your physical discs. Those two that interest us should be exactly identical in manner of size, cylinders, sectors, etc.
Furthermore, since parameter ordering definitely matters, the first one (in place of my /dev/sde) should appear to have a partition table (or a part of it, if you had used extended dos partitions), and the second one (my /dev/sdd) would appear to be totally corrupt.  Be careful not to touch your other, non-raid disks, though :-)
OTAH, if both appear invalid, you can stop reading this answer, it wont work for you :-(

Using --build (instead of --create) has the advantage of skipping the creation of superblock information, avoiding risk of data erase, and, most importantly, starting real data from sector 0, thus creating a so called "legacy" assembly, which is what most "fake raid" chipset vendors would do.(educated guess: their superblock info is written on chipset NV memory, therefore they don't really need to write any metadata on the disks).

Now, if you don't remember the original chunk size, trial and error is required...
Try building with a different chunk size each time, then use fdisk -l on /dev/md0 explicitly, and see if partition info is displayed correctly.
If so, try mounting one of the discovered partitions as read-only and verify some data (preferably text), in order to be sure. If not, undo.
To undo mdadm building, and make disk available again, use
    sudo mdadm --stop /dev/md0
     and
    sudo mdadm --remove /dev/md0
Then try again, with different chunk size.

Although mounting would suffice (ability to mount corrupt partitions is extremely rare), here's a somewhat more advanced trick to check correct chunk size, by searching for partition identifier string.
Hopefully, in a valid partition table, the starting sectors of one or more recognizable partitions are described. Again, in my case:

 /dev/sde1   *          63    47118644    23559291    7  HPFS/NTFS/exFAT
 /dev/sde2        47118645   102896324    27888840    7  HPFS/NTFS/exFAT
 /dev/sde4       102896325   980463014   438783345    5  Extended

In almost every case, you can find identifier strings close to the beginning of every type of partition. ie. 'NTFS' itself, in case of NTFS.
Using dd, copy the first few sectors of the disk (/dev/md0), onto a file.

 sudo dd if=/dev/md0 of=testfile bs=1024 count=256 skip=0

This should copy the first (skip=0) 256K of disk data to 'testfile'. Now, using something like:

strings -a -t d testfile | grep NTFS

or x instead of d if you prefer hex, or, more simply,

hexdump -C testfile | less

then, search with '/'

and you can find the position of the string in the entire disk.
Compare that with the calculated partition offset.
For example, in my case, the first ntfs partition started at 63th sector, which leads to an offset of 63*512 = 32256. 'NTFS' string was found at place 32259, so we'd consider this 'a match' (3 bytes post the beginning). (Don't forget to add skip * bs to your calculation, if some non-zero skip is used in dd). Unfortunately, a match doesn't necessarily mean it's the correct chunk size, while a mismatch would mean it surely isn't.


Ubuntu gets stuck in a login loop - Not even Ctrl+Alt+F1/6 working

Follow instructions bellow
1- Use a live Linux cd and chroot to your Ubuntu.
2- Remove nvidia driver using apt-get purge.(apt-get purge nvidia-*)
3- Reinstall ubuntu-desktop package.


How to set password on Initial Boot of Pre-Installed Ubuntu

You would want to set each users account password to expire sometime in the past.

From Official Ubuntu User Management Documentation:

  To easily view the current status of a user account, use the following
  syntax:

sudo chage -l username

  The output below shows interesting facts about the user account,
  namely that there are no policies applied:

Last password change                                    : Jan 20, 2008
Password expires                                        : never
Password inactive                                       : never
Account expires                                         : never
Minimum number of days between password change          : 0
Maximum number of days between password change          : 99999
Number of days of warning before password expires       : 7

  To set any of these values, simply use the following syntax, and
  follow the interactive prompts:

sudo chage username

  The following is also an example of how you can manually change the
  explicit expiration date (-E) to 01/31/2008, minimum password age (-m)
  of 5 days, maximum password age (-M) of 90 days, inactivity period
  (-I) of 5 days after password expiration, and a warning time period
  (-W) of 14 days before password expiration.

sudo chage -E 01/31/2008 -m 5 -M 90 -I 30 -W 14 username

  To verify changes, use the same syntax as mentioned previously:

sudo chage -l username

  The output below shows the new policies that have been established for
  the account:

Last password change                                    : Jan 20, 2008
Password expires                                        : Apr 19, 2008
Password inactive                                       : May 19, 2008
Account expires                                         : Jan 31, 2008
Minimum number of days between password change          : 5
Maximum number of days between password change          : 90
Number of days of warning before password expires       : 14

  Other Security Considerations Many applications use alternate
  authentication mechanisms that can be easily overlooked by even
  experienced system administrators. Therefore, it is important to
  understand and control how users authenticate and gain access to
  services and applications on your server.

Also, check out Automating/Customizing an Ubuntu installation using preseeding.  This looks like what you want to be doing.


you need not to remove gnome(removing may cause more problems and broken package etc), just install kde-plasma-desktop from software center.

its a light weight desktop and does not require must resource, unlike Unity which is a resource eater.

at the time of logging you just select kde session.


Your code is fine, it just that is not how you show the value of a variable.
$b

is just like entering the value of variable b and hitting enter as if that value was a bash command. That's why bash complains being unable to find the command "0".
Try this and see what happens:
x=ls
$ls

As the others said you can "show" the value of a variable b using
echo $b

Hope this helps.


Is there any software equivalant to link shell extension for ubuntu?

The default file manager, Nautilus already has "Make Link" option in right click menu. Click it, and it will give you "Link to filename" link, which you then can place anywhere you want.


starting again the latest process within loop if specific condition isn't met

To attempt to answer your question, following your comments, you could probably include the process which you want to repeat within the if statement, this of course depends on what those processes are doing:

for (( j=1; j <= i; j++ ))
do
# process something as sequential within loop #
if [ ! -f specific_file_$id ]; then
echo " Necessary File not found! "
echo " starting the current process again for the last time "
# process responsible for the creation of specific_file_$id #
fi
done

As the if statement is only triggered if the file doesn't exist, you can repeat the part of the process responsible for the file creation, this will use any variables set within that particular iteration. Once the if statement has completed, the for loop will continue on its next iteration, any further files which aren't created will be treated in the same way.


Restart and resume applications like in OSX

This worked for me when connecting remotely to a machine and logging in/out. Will test in a few hours at home with a full reboot, will edit with my findings

I also found this which seems to do exactly the same.

I have never thought about this feature before and glad you brought it up!

EDIT
I run Gnome 3 and wasn't able to find the setting as mentioned in the first article
The second article also didn't work for me

EDIT 2
Neither article worked for me in Ubuntu 14.04 using Unity or Gnome 3


How to disable integrated webcam on ubuntu?

Try to find the driver for your webcam and unload it. I don't have Dell Inspirion so I don't know what driver you have for webcam. Try to find it with

lsmod

In my case it was uvcvideo. When you find it unload it. In my case the command was:

sudo rmmod uvcvideo

After I removed it, the cheese did not find the device any more and it couldn't work. Then try to load it again. In my case the command was

sudo modprobe uvcvideo

If your driver is not uvcvideo replace it in the commands with your driver name. Make a test too to see that your application does not load the driver. It is a small possibility for that also because root privileges are required to load kernel modules.


Switching node versions on Ubuntu 19 messes up npm

n latest          # switch to the latest version of node
which npm         # check if you have multiple installations should give one
sudo apt-get purge --auto-remove npm
sudo apt-get clean
npm -v            # check if npm is really removed
sudo apt-get install --reinstall npm
exit              # close the terminal for npm is sticky

Open a new Terminal and check with npm -v if done


Files do not appear in synchronized Folders

This is a known bug for ubuntu-one. A fix is committed but did not make it to 11.10. It will be fixed in 12.04.

Possible workarounds are restarting the ubuntu-one synch daemon from Ubuntu One preferences, or issuing the command

u1sdtool -q; killall ubuntuone-login; u1sdtool -c

A system reboot will also force the files to be synchronized. A final alternative is to move the contents elsewhere, add folder to sychronization and then move the contents back in.


Thanks to Erich E. Hoover and his team you can use Pipelight to run Flash, Shockwave, Silverlight and Unity Player in your native Ubuntu browsers.

The steps, reproduced here:

sudo add-apt-repository ppa:pipelight/stable
sudo apt-get update
sudo apt-get install --install-recommends pipelight-multi
sudo pipelight-plugin --update
sudo pipelight-plugin --enable flash


Foxit Reader is not responding on Ubuntu 20.04

I solved it running the installer as administrator. I hope that could be useful for you.


In 16.04.x LTS I would create a swap partition 1 GB or 2 GB, 'just in case' to avoid crashes in the few cases when the RAM is not enough. Edit: Set the swappiness value so it only swaps at the last second, as suggested by @AndroidDev (for example 10 instead of default 60) according to this link: How do I configure swappiness? | Ask Ubuntu

The newest version of Lubuntu will create a swap file instead of a swap partition by default. But it is a short-life version, and I would recommend the LTS version. You can create a swapfile instead of a swap partition, if you wish, but I would not do it.

I think TRIM is used automatically, when the drive is connected via SATA or eSATA, but maybe not via USB (unless built-in in the SSD itself).
I am rather sure that you have to configure noatime yourself, but it is easy. You can also consider turning off journaling (which has both advantages and disadvantages). See this link: Final system tweaks / Installation / UEFI-and-BIOS | Ubuntu Community Help Wiki


Java or Ubuntu Bug? (Problem with Minecraft)

Maybe your problem is that openJDK is not working properly, because that GNU folks make reverse engineering for releasing code, it may not work as espected specially with the newest versions thus in the Minecraft page is told that you must use Java official packages for running minecraft properly.

so the easiest way to install java in ubuntu, is opening  terminal with CTRL + ALT + T and type this

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java8-installer

since you have openJDK1.8 already installed you may want to remove it

sudo apt-get purge openjdk-8-jdk --auto-remove

or just make the original Java as default

sudo apt-get install oracle-java8-set-default

hope this helps


Linux ignores setuid on directories, and uses setgid to set the group of the files created in it. So, when diego creates a file in common, it is owned by the user diego, and group my-group. However, the user's umask determines what the initial permissions of the created file are, and the default is to give only the owner write permissions. Which means diego2 won't be able to modify those files.
Your options are:

Change the permissions on the existing files to add write permissions for group and set umask for both to 0002 so that both users create group-writeable files, which will affect all files they create. That might not be something you want to do. Or,
Use ACLs to add default permissions to the common directory (and also to existing files and directories in it) that allow both diego and diego2 to write to them. (See this U&L answer.)


If I install Ubuntu to a USB with "Universal USB Installer", will my Windows be broken?

No. It will simply make your USB drive bootable. It does not touch your hard disk(beyond downloading an reading the image downloaded). It will not mess up Windows boot. However, if your USB drive is bootable, the boot will then be Ubuntu. When you install fully, however, the bootloader will be replaced with GRUB , which offers a choice between Ubuntu and Windows, as well as many other OSes if they are installed.


If you are running Ubuntu and want to play go on KGS, i.e. online, it is probably best to follow their advice and run

  javaws http://files.gokgs.com/javaBin/cgoban.jnlp

from a command line. IcedTea (or whatever) will download the client and run it automatically.
To run the program Cgoban3 offline you can download the .jar-archive of the program with the command:

  wget files.gokgs.com/javaBin/cgoban.jar

This will save the file cgoban.jar in the working directory.
You will then be able to run Cgoban3 offline with

  java -jar cgoban.jar

The sound may not be working then, which is a Java problem, but let's not get into that now.
The sound and other bugs (?) are the reason why I personally still use method 1 to play online.

Enjoy  your  go!


Can't create new folder or paste anything in my second drive

It is probably a permissions issue.
Have you tried to create a new folder using the command line?
sudo mkdir new_folder

If this works, the problem is the lack of permissions.
You will have to give permissions to your HDD:
chmod u+rw path_to_hard_drive


How do I access Ubuntu after installing alongside Windows 10? (non eufi)

Your problem is that the OS boot manager used by your computer is not set to grub, but to Windows. To fix this you need to get into the BIOS.

In Windows, hit the Windows key and search up "change advanced startup options". Hit "enter".

When the settings window appears, click "Restart now" below "advanced startup".

When the screen appears, click "Troubleshoot" , then "Advanced options", then "UEFI Firmware settings", then "Restart".

When the screen loads up, click "system setup", "setup", or whatever your computer calls the BIOS.

Next, go to wherever the boot options are, and change the OS boot manager from there, making sure the "ubuntu" device is above the "Windows" device.

Exit saving changes, and when you boot into grub you will see both OSs in the list.

Hope this works.


OwnCloud: Permission denied for www-data on mounted drive

drwxr-x---+ 4 root     root      4096 Nov 18 21:56 ..

These are the permissions of the /media/pi folder. As you can see the owner is the root user and other users cannot access the files and folders inside it.

You need to set the owner of that folder to www-data

chown www-data:www-data /media/pi


Error when plugging iPod Touch into MacBook

sudo add-apt-repository ppa:pmcenery/ppa
sudo apt-get update
sudo apt-get dist-upgrade

i did it yesterday, and worked flawlessly for me (4.2.1 iOS)


What does Ubuntu do when I signal undocking to a laptop?

/etc/acpi/events/lenovo-undock or some other similar file corresponding to your laptop defines the ACPI event code for your undock button and maps it to a call to /etc/acpi/undock.sh.

/etc/acpi/undock.sh runs through drivers that correspond to devices that hotplug through your docking station, and signals these drivers to disconnect.


Any way to power on an external HDD without re-plugging it?

You should be able to mount the partition which will power it on. Or use the "standby" option, which will power it down but leave it accessible. When you need to use it again just mount the partition. The little play button under the volumes bar will mount it.


I am not sure what is it that you want. Here are steps on how to create or rename a folder on your desktop in Ubuntu very plainly explained:

1) Right click on your desktop
2) Click "new folder"
3) Name the folder

If you want to rename an existing folder, right click on the folder and click "rename".


How to shut down my pc like it does when it is running out of battery?

I'm not quite sure what you mean but if 'hibernate' means the same as 'suspend' then everything that was on screen should still be there when you wake it up again. But maybe some apps are crashed by this process. The only alternative I'm aware of is going to 'Brightness & lock' in 'System Settings' and telling the screen to 'Turn of when inactive for: 1 minute. This will blank your screen soon but leave everything running.

Maybe you've tried all that but I'm running 16.04 and I'm not aware of any other kind of hibernating mode. I was assuming that a laptop goes into 'suspend' mode when the battery is dying but maybe I'm wrong about that.


Nothing there looks out of the ordinary. It's a log of all authentication and authorization (two very different things) attempts.

dnsmasq is a local DNS cache.

lightdm is your "Display Manager" the thing that prompts for your username and passsword before you login (inside X).

Nothing there suggests spying or key logging or even remote login attempts. Basically it's a bunch of system processes running as system processes and their requests for authorization being logged.


Authentication failed with the correct password and now I cannot use sudo anymore

The sudoers file works normally via group membership of a user.

As default, you have the following configuration in ubuntu:

 # Members of the sudo group may gain root privileges
 %sudo ALL=(ALL) ALL

As I understand your description, you have dropped the group membership for the sudo group.

Hopefully you have left over another account which is member in the sudo group.
If this is true, you can use the following command to fix your user:

 sudo usermod -a -G sudo  USERNAME

If you have given your root user an explicit password (non standard in ubuntu), you can also invoke:

 su -c usermod -a -G sudo  USERNAME

If both isn't possible, you may do the following:

boot your computer with a live/rescue cd (see also https://wiki.ubuntu.com/RecoveryMode)
mount your root partition (aka /) to e.g. /mnt
chroot /mnt usermod -a -G sudo USERNAME


Ubuntu 17.04 installed on a USB flash drive freezes so much

This is the problem with using normal usb's for installing ubuntu. I found the same problem when I installed ubuntu on to a usb. However, as soon as I put it onto my computers hard drive, it sped up a lot.
If you really want to put ubuntu onto a usb, I would get at least a usb 2.0, but probably a 3.0. They are much faster, therefore making the os run faster.
Important:
Make sure that your computer/laptop supports USB 2.0/3.0. Otherwise you won't get any difference in using USB 2.0.
See here for a comparison of the different versions of USB


I mounted the remote directory to my own local machine following this :
https://linuxize.com/post/how-to-use-sshfs-to-mount-remote-directories-over-ssh/

I am working on the remote files as if I am working on my own local machine


Can't enable Wifi in HP Envy with Ubuntu 14.04

Run in terminal

sudo tee /etc/modprobe.d/blacklist-acer-wmi.conf <<< "blacklist acer_wmi"

and reboot.


im using Ubuntu 18.04.2 LTS and want to install win 10 along side. how plz?

Grub is less scary then it sounds, in fact it is incredibly friendly.

Ubuntu having been in this dynamic of dual-booting with windows from the start, has become very experienced with dual booting problematics.

Grub is the bootloader for most linux distributions.

it is faster, more configurable, ect ect ect...

trust it.

as per : Install Windows or Ubuntu first after clean wipe?

you should install windows first (as a complete format of the disk) and then install ubuntu. the other order is too hard for you to do.


Can I install packages by adding the *.deb files to /var/cache/apt/archives and restarting?

While apt does download to /var/cache/apt/archives, it doesn't automatically install packages from there. To install from downloaded package files, just do:

sudo apt install /path/to/debs/*.deb


Is there any open source Microsoft Project MPP viewer?

Project Libre has superseded OpenProj and claims Project 2010 compatibility.

http://www.projectlibre.org/ is the homepage

http://en.wikipedia.org/wiki/OpenProj#Fork_-_ProjectLibre gives some history on how OpenProj forked to give rise to Project Libre.


How to fix Permission Denied (Public key) error?

As you have noted, the Fedora box you are logging in to was not set up to allow password authentication, only public key authentication - this can be seen from the ssh -v result.

So one solution is to add password authentication, as you have done.

The other method would be to take the contents of ~/.ssh/id_rsa.pub on the Ubuntu box and add it to the file ~/.ssh/authorized_keys on the Fedora box.

Now that you have password authentication enabled, you can install the authorized key with this command on the Ubuntu box:

$ ssh-copy-id fedora_box


Black screen when booting Ubuntu 16.04 LTS with Raspberry Pi 2

In my experience with this image on a Raspberry Pi 2, there's no output on the display when the kernel is booting.

I have to wait a few moments until text is visible on the console.


Try "Radio Tray"!
It's quite new and active developed. And really small.. http://radiotray.sourceforge.net/

Development Blog: http://linuxsoftware.blogsome.com/category/radio-tray/


I recall when I installed Wine on my Ubuntu machine (14.04) that I had trouble as well. There were two packages in the Ubuntu Software Center:

Microsoft Windows Compatibility Layer (meta-package)
Wine Windows Program Loader

I think it was the 2nd one that actually worked to get the whole package installed.

EDIT: Check out this answer which explains how to add the Wine PPA: Why should I prefer ppa wine over the wine in the official repository?


ubuntu 14.04 connect to a wifi network using command line

First run iwconfig to see if the wireless extensions are enabled.

sudo su
iwconfig

If you are informed that there is a card, for example wlan0 and wireless interface is recognized as you are going to:

Second to view the available wireless networks run iwlist

sudo su
iwlist wlan0 scan

Networks will show at your fingertips. Note the proper ESSID, which then need to enter.

Third, knowing the ESSID and the network password, run:

sudo su
ifconfig wlan0 up
iwconfig wlan0 essid <ESSID>
iwconfig wlan0 key s:<password_wireless>

In the last command, the s: is to indicate that what is below is a sequence of characters.

If the key is in hexadecimal numbers put the key starting with 0x:

Fourth, you must request an IP address from the DHCP server, or by ifconfig if you give the IP, netmask, gateway, etc.:

sudo su
dhclient wlan0

The steps can be automated script:

sudo su
nano /etc/init.d/wifi-on.sh

A simple text file with the following content:

!/bin/bash
ifconfig wlan0 up
iwconfig wlan0 essid <ESSID>
iwconfig wlan0 key s:<password_wireless>
dhclient wlan0

Control + O. save file. Control + X, close nano.

And you give execute permissions and add the system startup:

sudo su
chmod 755 /etc/init.d/wifi-on.sh
update-rc.d wifi-on.sh defaults


Nautilus keep crashs on mounting samba drives

This is a problem that should be reported as a bug: https://help.ubuntu.com/community/ReportingBugs


https://wiki.ubuntu.com/Touch is the source for official information on special features, new apps, and other details. https://wiki.ubuntu.com/Touch/Devices lists devices officially supported, and also known to but but with community support only.


CDE - The Common Desktop Environment is X Windows desktop environment
  that was commonly used on commercial UNIX variants such as Sun
  Solaris, HP-UX and IBM AIX. Developed between 1993 and 1999, it has
  now been released under an Open Source licence by The Open Group.

CDE project has detailed build instructions in their wiki.

My understanding is that Linux port of CDE is currently an alpha-quality software and has "quite a few known security vulnerabilities". I'm also not aware of any pre-built .debs or a PPA to install CDE from.

  ...it should be made clear that at the moment there are no
  pre-compiled binaries available for systems so at the moment all will
  have to be confident enough to compile from source


Samba error message invoke-rc.d: initscript samba, action "restart" failed

You can restart samba manually by.

sudo /etc/init.d/smbd restart
sudo /etc/init.d/nmbd restart

You may need need to restart windows too or wait for some time clicking refresh to purge windows cache. You may have problem to connect to one samba server with 2 different users.

BTW: samba will always give you problems cause its m$oft. (cannot change ip ports, it not encrypted, so good for local net only) Use ssh if you can. If you just need to copy files winscp.net will do the job.

BTW2: ubuntu (or system-config-samba) guys could handle to restart samba processes cause it's been years already (in 14.10 the problem still persist and I remember it was there before 13.?)


Unable to copy files to Samsung MPS - libmtp error: Could not send object property list

Try installing the following packages:

sudo apt-get -y install libmtpserver-dev mtp-server

This was a workaround I used when I was unable to transfer files to my phone.


Problem has been solved by simply installing with the ISO burned into an actual DVD.


Installing single OS Ubuntu 14.04 in EFI mode

If you haven't already done so, disable Secure Boot on your computer. Then try preparing a CD-R or USB flash drive with my rEFInd boot manager. (Image files for both are available on its downloads page.) Boot to the rEFInd medium. You should see at least one option for a Linux kernel (with a name beginning with vmlinuz) in its menu. Try it. If it boots, install the Debian-package version of rEFInd (either downloaded and installed manually via dpkg or via the PPA described at the bottom of the rEFInd downloads page).


Ran out of space of newly installed HDD?

You have shared /media, which is on / file system. You have 83GiB free there. Is what you're copying around 120GiB in size? If so, the error message makes perfect sense.
When Windows asks for the free space of the share, Samba dutifully reports what's free for /media, which is the root of the share. Windows checks this, and sees that free space is less than size of objects.
A workaround would be to share each drive as an individual share. It appears that this is also known behavior:

Samba daemon does not report correct disk space if the exported path consists from several disks.
For example, it assumes /home is exported on Samba and consists from 3 disks as follows. Samba daemon should report free space of 210GB but actually reports 10GB.

So it seems that this is a known problem with Samba. Easiest workaround is probably to share each drive as its own share. Another workaround would be install samba-dfree


Note down the number of times the condition is true using bash/shell script

If the value 1 or 0 is assigned to the file /sys/bus/drive/prd, you can read it with 'cat` and assign a variable to it.

var=$(cat /sys/bus/drive/prd)

and then count the zeros and ones

...
if [ "$var" == "1" ]
then
  good=$((good+1))
elif [ "$var" == "0" ]
  bad=$((bad+1))
else
  echo "unexpected value"
fi
...

You have not explained anything about the signal, so I don't write any code about that.

Instead I made a small demo shellscript, that may help you see how to make a while loop to count 'good' and 'bad' key-strokes and how to write the result when the measurement is finished.

#!/bin/bash

echo "siganl: as demo, let a key-stroke be the signal"
echo "value:  as demo, a digit key is good=1 other keys are bad=0"
echo "quit the loop with 'q'"
good=0
bad=0
re='^[0-9]+$'
while true
do
 read -sn1 ans
 if [[ "$ans" == "q" ]]
 then
  echo ""
  echo "good=$good"
  echo "bad=$bad"
  exit
 elif [[ "$ans" =~ $re ]]
 then
  echo -n '1'
  good=$((good+1))
 else
  echo -n '0'
  bad=$((bad+1))
 fi
done

Good luck with your own shellscript :-)


Fighting procrastination: how to disable wi-fi for a certain amount of hours without ability to reactivate until countdown ends

U can do it easily using a script!!

Open mousepad/leafpad from the menu,
Type (or copy/paste)

#!bin/bash
nmcli radio wifi off
sleep $(( 60*60*8 ))
nmcli radio wifi on

This will put off wifi for 8 hours. (see above)
Now chmod this script,

chmod +x wifi_off

Replace wifi_off with the name of the file u saved.

Put it in a cronjob

crontab -e

Edit your cron file to look like this

50 20 * * * bash wifi_off

This means it will set off this script at 8.50 pm and put off wifi for 8 hours.

And save it!


Old version of google-chrome starts even if newer is installed

Weird, but a restart solved the problem (after doing all things mentioned in the above question)


Yes, it is trustworthy.

The PPA is run by Matthias Klose (Member of Ubuntu, Canonical Partner Developer, Gnome3 Team, Edubuntu developer, Xubuntu developer, ...) .

References :

Matthias Klose Profile on lauchpad
Debian's packages overview for Matthias Klose


The exec command which is used for shell-level redirection in bash also works in zsh. Try:

exec 2>/dev/pts/2


From man taskset:

  taskset is used to set or retrieve the CPU affinity of a running process given its PID or to launch a new COMMAND with a given CPU
  affinity. CPU affinity is a scheduler property that "bonds" a process
  to a given set of CPUs on the system. The Linux scheduler will honor
  the given CPU affinity and the process will not run on any other CPUs.
  Note that the Linux scheduler also supports natural CPU affinity: the
  scheduler attempts to keep processes on the same CPU as long as
  practical for performance reasons. Therefore, forcing a specific CPU
  affinity is useful only in certain applications.

While this guarantees that the process will run only on a certain CPU (or a set of CPUs), the affinity setting does not guarantee that no other processes will run on those CPUs. To achieve this, I think you can change niceness (or nice level) of the process to its lowest value (1) - see man nice and man renice for details.

Setting the lowest nice level will guarantee that the process will not give the CPU to another task while running - however, the guarantee is not 100% (for example, if you have another process with the same priority in the system, both processess may be scheduled to share the CPU)


How to give access permission to specific folder by specific user in ubuntu.[Terminal]

The following commands will create user X4 and (by default) group X4 and directory X4, and will limit access to directory X4 to user X4 exclusively.

sudo adduser X4
sudo mkdir X4
sudo chown X4:X4 X4
sudo chmod 0750 X4

Note that nothing will prevent X4 from rummaging around elsewhere on the file system. There is no way to prevent that. However, no one except X4 and root will be able to access directory X4.


Why does top report virtual memory and swap space usage differently?

I can't see much from this, but what is important is RES column, which is "resident set size". To quote man top:

      RES  - anything occupying physical memory which, beginning with
             Linux-4.5, is the sum of the following three fields:
             RSan - quadrant 1 pages, which include any
                    former quadrant 3 pages if modified
             RSfd - quadrant 3 and quadrant 4 pages
             RSsh - quadrant 2 pages
      .
      .
      VIRT - everything in-use and/or reserved (all quadrants)

While VIRT column shows 11.740 GB, RES columns is only 120.0 MB.
Large VIRT can amount to all memory mapped cache files and all malloc() generated anonymous mapping that hasn't yet been allocated to a physical memory page, due to Linux's "optimistic memory allocator". Attempt to access some of such pages may still result in SIGSEGV (Segmentation fault) if no physical pages are available.

See the explanation in the NOTES section of man malloc:

NOTES
       By default, Linux follows an optimistic memory allocation strategy.  This means that  when
       malloc()  returns  non-NULL there is no guarantee that the memory really is available.  In
       case it turns out that the system is out of memory, one or more processes will  be  killed
       by  the  OOM  killer.   For more information, see the description of /proc/sys/vm/overcom‐
       mit_memory and /proc/sys/vm/oom_adj in proc(5), and the Linux kernel source file  Documen‐
       tation/vm/overcommit-accounting.

Hope this helps.

gmt42


The standard way to remove an architecture would be through dpkg:

sudo dpkg --remove-architecture i386

Tested on Ubuntu 16.0.4 LTS.

It is also faster & simpler than to add architecture after every deb ... in sources.list.


You need to ensure your charm can relate to rabbitmq-server using the rabbitmq relation. For examples of other charms that already do this, take a look at https://manage.jujucharms.com/interfaces/rabbitmq.

Once you do that, deploying both rabbitmq charm and your charm and running juju add-relation rabbitmq mycharm will trigger a relation hook inside your charm where you can use the relation-get hostname command to get the IP.

For a much more detailed explanation of how relations work, check the excellent link Jorge Castro provided in the comment above.


18.04 Install Problem: KeyError: 'MAJOR' / Subiquity

Vendor confirms it is a driver issue with 18.04.

Chassis Model: X10DSC+

NVMe Model: PM1725A, 800 GB, NVMe PCIe3.0


Is it safe to disable resize_inode on ext4 FS?

It looks like disabling resize_inode is safe, but I don't think it solved my problem. After executing

tune2fs -O^resize_inode /dev/mapper/data-data

system recomended me to use e2fsck. Here is the result:

# tune2fs -O^resize_inode /dev/mapper/data-data
tune2fs 1.41.11 (14-Mar-2010)

Please run e2fsck on the filesystem.

# e2fsck /dev/mapper/data-data
e2fsck 1.41.11 (14-Mar-2010)
/dev/mapper/data-data was not cleanly unmounted, check forced.
Filesystem does not have resize_inode enabled, but s_reserved_gdt_blocks
is 897; should be zero.  Fix<y>? yes

Resize_inode not enabled, but the resize inode is non-zero.  Clear<y>? yes

Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Block bitmap differences:  -(128--1024) ... -(512000128--512001024)
Fix<y>? yes

Free blocks count wrong for group #0 (860, counted=1758).
Fix<y>? yes
.
.
.
Free blocks count wrong (32631947, counted=32649888).
Fix<y>? yes

/dev/mapper/data-data: ***** FILE SYSTEM WAS MODIFIED *****
/dev/mapper/data-data: 23369/2065792 files (2.6% non-contiguous), 496180576/528830464 blocks

Acording to this answer of Hubert Kario, resize_inode is used to allow resize inodes of FS and I am complitly wrong while trying to use it to speed up my disk operations. But the answer of my question is: Yes, it is safe to disable resize_inode.


The configuration files differ dramatically (and annoyingly) between versions.  So trying to copy your /etc/rsyslog.conf file from one system to another probably won't work, especially if you're switching major releases.  (In this case from version 5 to version 7.)

Ubuntu IS Debian under the hood, and rsyslog is rsyslog regardless of the OS it's installed on.  The important point is to make sure you google for instructions specific to your version, or use your package manager to install the accompanying rsyslog-docs package, then read those.  In ubuntu/debian:

apt-get install rsyslog-docs


So I kind of found a solution myself: I changed the permission of the whole directory in the file browser (via right click -> permission), so I managed to recover the data. Thank you.


How do you get a raid with 4 terabytes to give you the full disk amount in ubuntu server

Maybe you have something else configured than raid0. Looks a bit like raid1 cause 2113gb/1024=2,06TB wich might be because of some spare sectors.

If you want to have full size you would need raid0 (stripe), that gives you maximum speed and no extra data safety.

Raid-Levels on Wikipedia

After verifying the correct Raid Type we need to check on the device and how the system sees it.

In your case we have a hardware controller that normally gives raid-arrays as normal drives to the system. I.e. /dev/sdc /dev/sdd etc.

use: sudo lshw -c disk to see the devices Ubuntu sees.

In your case we see that the raid is presented as  /dev/sdc

If you have the desktop envirement setup you could simply use gparted (sudo apt-get install gparted). That looks simply like the diskmanager in Windows and is quite selfexplaining.

If you do not have the desktop set up and running a terminal mode server use sudo fdisk /dev/sdc to enter the terminal partitioning tool.

If you have not setup a LVM this will be the guide to follow: How to resize / enlarge / grow a non-LVM ext4 partition
Just replace the /dev/??? with your /dev/sdc to match it your configuration.

!!! PLEASE ALWAYS NOTE THAT CHANGES TO THE PARTITIONTABLE WILL/MIGHT RESULT IN A COMPLETE LOSS OF DATA ON THAT DRIVE !!!
BACKUP EVERYTHING FIRST!

Hope this will do the trick for you.


Can I get a combined inbox in Thunderbird?

I believe the feature you are looking for is called 'Unified Folders' which works on both IMAP and POP3 protocols.

The official site location: http://kb.mozillazine.org/Global_Inbox#Unified_Folders

Quote from the site:

  Unified Folders (originally named Smart Folders when it was added in
  3.0) is a folder pane view which looks like a global inbox account by merging the contents of all inbox folders (both POP, IMAP and local
  folders) from all accounts. It also shows the inbox of each account as
  a child folder of the unified Inbox account. Any messages in an inbox
  shows up in both the root of the unified Inbox, plus the child folder
  of the unified Inbox for that account.

To use this functionality:

View >> Folders >> Unified

I have verified that this does work on Thunderbird 12.0.1 using Ubuntu 12.04. The KB article I found above it a bit old but still holds correct information about the functionality of the 'Unified Folders'.

If you are just trying to combine the Inbox only and leave the rest as is, it does not look like it can be done but extensions can be made in the future to have this feature in Thunderbird.

Hope this is helpful.


I have used this guide to solve it on my old desktop computer back in the day. You could try it out. The feature is switched OFF by default because it's not working very well.

At least give it a try.

https://wiki.ubuntu.com/X/Config/SVideo

Edit: Using desktop effects is not recomended though, and last time I used it I was using Gnome 2.x


How do I run Minecraft-Console-Client on Ubuntu?

As the readme states, you don't have to build the project from source - just grab the latest development build (MinecraftClient.exe) from:

https://ci.appveyor.com/project/ORelio/minecraft-console-client/build/artifacts

Here's a summary of required steps on Ubuntu:

Install Mono: sudo apt-get install mono-runtime libmono-reflection-cil
Download MinecraftClient.exe from the above link
Run mono MinecraftClient.exe.


Since it seems to me that you have a dualboot setup this thread might have an answer to your problem.

Right here: No sound from laptop speakers in Ubuntu 14.04 after booting into Windows 8.1


Boot your system into a live CD.
Mount your system into the live CD:

sudo mount /dev/sda1 /mnt
sudo mount --bind /dev /mnt/dev
sudo mount --bind /dev/pts  /mnt/dev/pts
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys  /mnt/sys

Log into the mounted system:

sudo chroot /mnt

Install grub:

grub-install --boot-directory=/boot/ --recheck /dev/sda

Reboot your system.


If you're looking for an OS that has low spec requirements, then you're looking at one of three of the Ubuntu derivatives. Take a look at this Ubuntu wiki page for more info

Lubuntu (LXDE)
Xubuntu (XFCE)
Ubuntu MATE (MATE)

All three of these would be a good choice for your laptop's specifications.

I would personally choose one of those three over stock Ubuntu (Unity), Ubuntu GNOME (GNOME3) or Kubuntu (KDE) because they have higher minimum system requirements. However, I run stock Ubuntu (Unity) on a laptop with a Dual Core Core 2 Duo @ 1.6 GHz with 2.5 GB of RAM - so it's up to you.

Once you decide which derivative you're going to go with, you've got to decide which Ubuntu release to go with.

Currently, the supported versions are:

12.04 LTS (And all subsequent .x releases)
14.04 LTS (And all subsequent .x releases)
14.10
15.04

I would personally suggest using either 14.04 LTS (because it's stable and will be supported for 5 years) or 15.04 because it's the newest version. Basically, just ignore 14.10.

As for which architecture to choose, your processor is basically assured to be 64 bit - so I would just suggest downloading the 64 bit version. The 32 bit version will work, but if you have a 64 bit CPU you might as well make use of those extra 32 bits.