I have had the same problem after each restart. I don'n know clear solution, but workaround.

$ ps -ef | grep pulse
gdm       1293  1164  0 11:12 ?        00:00:00 /usr/bin/pulseaudio --daemonize=no
root      1460     1  0 11:12 ?        00:00:00 /bin/sh /snap/pulseaudio/9/bin/pulseaudio
root      1687  1460  0 11:12 ?        00:00:00 /snap/pulseaudio/9/usr/bin/pulseaudio --exit-idle-time=-1 --disallow-exit=yes --system -F /snap/pulseaudio/9/etc/pulse/default.pa -p /snap/pulseaudio/9/usr/lib/pulse-8.0/modules -n
haripra+  3268  2078  3 11:15 ?        00:00:08 pulseaudio --start
haripra+  3578  3257  0 11:20 pts/0    00:00:00 grep --color=auto pulse

If I kill (e.q. $sudo -kill 1460 etc.) the processes, Pulse audio started, bu still even if the connection from pulse to the sound HW is established, Pulse not know about streams and applications.

In the Settings, test speakers works, but there is still no sound. After restart, the problem is back.

According this page Establishing connection to PulseAudio. Please wait ...

$ pulseaudio --check
$ pulseaudio -D
E: [pulseaudio] main.c: Daemon startup failed.

1) Reinstall PulseAudio and Alsa libraries according for examamle here: No Sound In Ubuntu And Linux Mint

In fact i used different way - Synaptic package manager. Install Pulse Audio Volume Control.

2) Delete in your home ~/.config/pulse directory. This is the key step.

3) Restart system.

Don't try

To change manually anything on this Tab:

Attend to change configuration causes, that there will be again the same problem described above and you must repeat step 2) and 3).

Also to check sound in Settings -> Sound Test speakers probably doesn't work. But streans are visible (Applications Tab) and sound is back.


Under Ubuntu, the pulseaudio daemon 'hogs' the audio devices. Instead of killing it, you can make it swallow your application's OSS output like this:
padsp ./yourApp

If that doesn't work, here's a link bug report on how the fedora guys overcame a similar problem with audacity:
https://bugzilla.redhat.com/show_bug.cgi?id=445644


You might have a process cd'd to there, or reading/writing there. Use sudo lsof +D /dev/sdX (where "sdX" is your disk. Also read man lsof. Or use fuser, part of the psmisc package. Read man fuser.


Ubuntu keeps resetting HDD APM level to 1 on wakeup from suspend

Still haven't found the correct solution.
As a workaround I create an executable script:
/lib/systemd/system-sleep/sleep-sdb.sh

#!/bin/sh

case $1/$2 in
  pre/*)
    ;;
  post/*)
    hdparm -B 254 -S 120 /dev/sdb
    ;;
esac

Found here:

https://bugs.launchpad.net/ubuntu/+source/gnome-disk-utility/+bug/1511703
https://bugs.launchpad.net/ubuntu/+source/hdparm/+bug/199094
https://wiki.archlinux.org/index.php/Power_management#Hooks_in_.2Fusr.2Flib.2Fsystemd.2Fsystem-sleep


How can I set coolbits nvidia Ubuntu 18.04

In Ubuntu MATE 18.04 possible solution is to edit config in /usr/share/X11/xorg.conf.d, namely file 10-nvidia.conf. Here is how it looks in my case for example:

Section "OutputClass"
    Identifier "nvidia"
    MatchDriver "nvidia-drm"
    Driver "nvidia"
    Option "AllowEmptyInitialConfiguration"
    Option "Coolbits" "12"
    ModulePath "/usr/lib/x86_64-linux-gnu/nvidia/xorg"
EndSection

I just installed nvidia-prime via Additional Drivers GUI and then edited this file to add Coolbits option and it worked with no issues.

I assume it should work the same for main branch of Ubuntu.

I edit my input options using file 40-libinput.conf in same directory as well.


Relevent files not showing up in Dash after restore

Im not familliar with crashplan BUT we will try to restore everything without losing any data this it will NOT wipe your disk it will just REinstall all software again plus upgrade.

Press Ctrl+Alt+F1

Type your Username and Password

sudo service lightdm stop
sudo apt-get update
sudo apt-get install --reinstall ubuntu-desktop
sudo shutdown -r now

Hope it helps


When installing packages that are external to aptitude (i.e. using sudo dpkg -i packagename.deb), dependency errors often occur.

In most cases, this can be fixed by running the following command immediately after the dpkg installation has failed:

sudo apt-get -f install

This command essentially tries to resolve any outstanding dependency issues.

It could also simply be that the package You are trying to install ins incompatible with Your Ubuntu version.


This should fix the issue:

sudo apt-get install -f
sudo apt-get remove postgresql-8.4
sudo dpkg --configure -a
sudo apt-get install postgresql-9.1


Got back Hibernation option, but cannot resume from Hibernate

I assume you have installed Debian in a way that it uses it's own separate swap partition. If you have not, I would suggest doing so (create another swap partition and change the /etc/fstab files accordingly), because too different operating systems writing to the same swap partition may discard hibernation data stored on the partition by the other OS.

Then you have to ensure that the OS you want to use hibernation on (usually both), writes to the correct partition. This is configured in the /etc/initramfs-tools/conf.d/resume file. You have to put the UUID of the correct swap partition in there (use sudo blkid /dev/$device_name to get the UUID). Finally you need to update the initial ramdisk:

sudo update-initramfs -u -k all

That should fix it.


can't paste the project file into the htdocs on ubuntu

I guess you want to use change the owner of the folder. Use chown ("change owner") instead of usermod:

  sudo chown -R root.xamppusers /opt/lampp/htdocs


I finally solved it by following Helder's fix here: https://www.turnkeylinux.org/forum/support/20090724/fix-apt-get-could-not-resolve-archiveubuntucom

That is, change the order of the options for line 'host' in '/etc/nsswitch.conf'.
Move 'dns' to the beginning of the row.


Directly start Windows 7 (ubuntu dual boot)

Oldfred's comment is valid, but requires elaboration. Before going further, you should know your boot mode (BIOS vs. EFI). If you don't know whether your computer is booting in BIOS mode or in EFI mode, look for a directory called /sys/firmware/efi in Ubuntu. If that directory is present, you've booted in EFI mode; and if it's absent, you've booted in BIOS mode. See this page of mine for more on this subject. Once you know your boot mode you can begin considering solutions:

BIOS Mode -- If your OSes were both installed in BIOS, your options are limited, but the details depend on your disk and boot loader configurations:

One Disk -- If you have one disk, then only one OS's first-stage boot loader resides in the Master Boot Record (MBR; that is, the first sector) of the disk, which controls the boot process. If you're booting straight to GRUB, then GRUB's first stage is presumably on the MBR (although there are some rare alternative configurations). Thus, you'll need to restore the Windows boot loader to the MBR to boot it directly, then restore GRUB. I'm not a Windows expert, but typing BOOTREC /FIXMBR in a Windows Command Prompt window should put the Windows boot loader on the MBR. See this page for basic information on this command, and ask on a Windows forum if you need more advice. The easiest way to restore GRUB is to use Boot Repair from an Ubuntu emergency disk. Another way to restore GRUB is to back it up before you begin (with sudo dd if=/dev/sda of=~/sda.mbr bs=440 count=1) and then restore it when you're done (with sudo if=/path/to/sda.mbr of=/dev/sda); however, this approach runs a small risk of serious damage if you make a mistake, and you'll need to be familiar enough with your emergency disk (used for the restore) to locate the sda.mbr backup file. Most people are better served by using Boot Repair.
Multiple Disks -- If your computer has multiple disks, it might boot in much the same way as on a single-disk system; however, it's also possible to put the Windows boot loader on the first disk's MBR and GRUB on the second disk's MBR. If this is your configuration, then you may be able to boot to Windows without using GRUB by pulling up your computer's built-in boot manager. You typically do this by pressing Esc, Enter, or a function key just after you power on the computer (before the GRUB menu appears). This is the same tool you probably used to boot from the Ubuntu installation medium. It should show options to boot from each of your hard disks, and selecting the Windows disk should boot Windows.

EFI Mode -- If your OSes were installed in EFI mode, then the firmware's built-in boot manager is a more sophisticated variant of the one I just described for the BIOS multi-disk configuration. This menu should have an option that's called "Windows Boot Manager." Select it to boot Windows directly rather than going through GRUB. This will be a one-time boot; when you next reboot, GRUB should appear. Again, this will work only if you installed in EFI mode.
Mixed Mode -- Although rare, mixed-mode configurations are possible. In such a setup, Windows is installed in EFI mode and Ubuntu in BIOS mode or vice-versa. The fact that you're booting Windows through GRUB implies that this is not how your system is configured; I'm mentioning it only for completeness or in case somebody else in the future reads this answer and has such a setup. In this case, the firmware's built-in boot manager is likely to enable a one-time boot to Windows without involving GRUB. If Windows is installed in EFI mode, the relevant entry is probably called "Windows Boot Manager"; and if Windows is in BIOS mode, it's likely named after the disk on which Windows is installed.

In most of the preceding cases, using the computer's built-in boot manager will get the job done. Unfortunately, there's no standardization about how to get to this tool. If you don't know how to access it, you may need to consult your computer's manuals or just try rebooting. Sometimes you'll see a prompt, like F10 - Setup, at some point during the boot process. If not, try hitting random keys -- it's usually something in the F8 to F12 range, but it could easily be something else.

If you've got a one-disk BIOS-mode installation, your task is harder, since you'll need to temporarily replace GRUB, as noted earlier, in the MBR. Be sure to read the pages to which I linked above, in the "One Disk" bullet point, and if you have any questions, ask them before you start digging a hole for yourself.


Problems updating Python from the repositories today (Feb 25, 2021)

This is a known issue that happened today, February 25, 2020.
There was an emergency case where the archives were out of sync.  To quote the Mirrors team:

we know about the missing python 2.7 packages.  We had to react quickly to a serious regression, and should be publishing normally soon.

Regression information is not available, however, but we can safely state that this was because they yanked the bad packages out fast before things propagated, and then the sync systems got up to date after they fixed the regression.
As of around 11:30AM UTC-5, the archives should be syncing properly and this issue should be "resolved" now automatically.


Upgrading from 12.04.3 LTS to 14.04.1 LTS failure

You have to reinstall the update manager. First, remove/purge it:

sudo apt-get purge update-manager-core update-notifier-common

Then have a look at the console output. If it tells you, that some directories could not be removed, delete them manually. In my case:

rm -rf /var/lib/update-manager
rm -rf /var/lib/update-notifier

If you are on 13.04 or later, you should also do this to clear cached update messages:

sudo rm /var/lib/ubuntu-release-upgrader/release-upgrade-available

Then update your sources:

sudo apt-get update

Reinstall the update manager:

sudo apt-get install update-manager-core update-notifier-common -y

Only if you are currently on an LTS and want to upgrade to latest LTS, make sure that in /etc/update-manager/release-upgrades you have set:

Prompt=lts

Otherwise (upgrading any version to a newer version) set:

Prompt=normal

Now dist-upgrade should work:

sudo apt-get dist-upgrade


Making sure a bash script is run as script-specified user

Just put this line after #!/bin/bash:

[ "$USER" = root ] && echo "This script shouldn't be run as root. Aborting." && exit 1

This is roughly the equivalent of:

if [ "$USER" = root ]; then
    echo "This script shouldn't be run as root. Aborting."
    exit 1
fi


Selection and toggles are not highlighted in Ubuntu 18.04 LTS

After upgrading from 16.04 to 18.04 I had the same issue. I fixed it with the following:

sudo apt purge arc-theme
sudo apt install arc-theme

Note: be aware that this will completely remove arc-them including any customizations.


increase /dev/sda1 size which is mounted to / (root)

Use the GParted application to resize your partitions. You can open the application, right click the partition that is mounted on / and resize it to fill your disk space.


No Wifi connection on HP elitebook 8570w with Intel Ultimate -N 6300

We see the dreaded firmware error in your log:

  Microcode SW error detected.  Restarting

Let's install the latest firmware and see if it helps:

wget http://mirrors.kernel.org/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.161_all.deb
sudo dpkg -i linux*.deb

Reboot and tell us if you connect.


Auto-Invoke Update Manager to update everything and shutdown after system idle for x minutes?

There are a few packages that may help with this:

unattended-upgrades installs security updates automatically
powernap suspends or shuts down the computer when there are no processes running from a given list

Although finding the right list of important processes may be difficult... powernap is more targeted at servers.


Using Ctrl + Alt + F4, I was able to access the CLI and discovered errors similar to those found within this question.

I deleted the Oibaf entries from /etc/apt/sources.list.d.

This had no effect. As this was not the only repository I had newly been working from, I added the repository again to maintain continuity in troubleshooting.

Following luke's solution here I still had the same issue.

I was able to login to the desktop again after running the following command:

sudo apt -f upgrade

Note:

For some implementations of the amd drivers, they can be reverted by entering

amdgpu-pro-uninstall


Does Ubuntu 12.04 LiveCD run Unity 2D or 3D or selects which one to run adaptively?

As with an installed system,

/usr/lib/nux/unity_support_test

will be used to determine whether the system is capable of running Unity 3d. If it is not, logically Ubuntu 2d will be started.

    /usr/lib/nux/unity_support_test -p

returns a nice little overview that tells you more about the hardware capabilities of your GPU.


First, make sure you've followed the instructions available here: Can I install Microsoft Office? If so, how?

If you tried that but it doesn't work, the first thing I'd recommend is trying to add a Microsoft Exchange account ("Settings"->"Online Accounts").
Secondly, you could run MS Outlook 2010 32-bit through Wine.
Finally, you could run it in a Windows virtual machine using VirtualBox.

If none of these works, maybe you should consider switching to Mozilla Thunderbird. Just sayin'...


Migrate root filesystem from btrfs to ext4

You can rsync the files to another, but it won't boot (as you've observed). However, it's not difficult to set the new drive to boot after you've copied the files. The exact method depends on which boot loader you want (grub, gummi, etc.), how you've configured your partitions (do you have a separate /boot partition?), if you're using partition tables or GPT, and if you're using EFI or MBR.

That's too many variables for me to cover, but you can find instructions online if you search. The Arch wiki pages tend to cover this in great detail, for example.

In case you're unsure, I suggest you choose GPT, EFI, no separate /boot partition, and gummi. If your system is old enough it may not support those choices.


Ubuntu as Gateway - Client PC no internet

You need to use IPTABLES to do the trick.
You need to forward the traffic from one interface (your 10.0.0.1 interface to the 192.168.129 interface).

Run the following rules:

#/sbin/iptables -t nat -A POSTROUTING -o ens33 -j MASQUERADE
#/sbin/iptables -A FORWARD -i ens33 -o ens34 -m state --state RELATED,ESTABLISHED -j ACCEPT
#/sbin/iptables -A FORWARD -i ens34 -o ens33 -j ACCEPT


VIm : copy all file to paste it in web browser

You can use xclip. Lets say you have a file named file.txt and you have edited the file using vim and saved it. Now running the following will copy the content of the file to the clipboard:

cat file.txt | xclip -selection c

Now you can just paste the content of the file by any usual method.

Remember, in this solution you need to save the changes you made before copying to clipboard.


Does btrfs support per user quota?

No, it doesn't.

  If I move the /home/... folders to a btrfs partition, can I still enable per user quota? That is, each user should be able to use a limited amount of storage.

Yes, the trick is to use a subvolume for each home.

Btrfs supports subvolume quotas since Linux Kernel 3.6.

(Note that Ubuntu Precise has 3.2, Quantal has 3.5, Raring has 3.8, and note that you can install the Raring Hardware Enablement Stack on Precise, to have an updated kernel.)

Instructions to enable quotas are in the Btrfs FAQ, "How do we implement quota in BTRFS?". Subvolumes created after btrfs quota enable support quotas automatically. Subvolumes created before btrfs quota enable need manual intervention to support quotas.

Mount the btrfs filesystem
Enable quota: btrfs quota enable mountpoint
(If the filesystem already contains subvolumes, enable their quota support:)

List the subvolume IDs with btrfs subvolume list. The number that follows ID (at the beginning of each line) is the subvolume's id.
Create a qgroup with btrfs qgroup create 0/subvolume-id path-to-subvolume (don't forget to replace the subvolume-id with the correct id)
Rescan the subvolumes, since the quota settings have been changed: btrfs quota rescan

Create new subvolumes that you need: btrfs subvolume create mountpoint/subvolume-name
Limit the subvolume usage: btrfs qgroup limit 100G path-to-subvolume
Profit.

Finally, set up /etc/fstab to mount the subvolumes automatically at boot:

  UUID=uuid-of-the-filesystem /home/mountpoint btrfs defaults,subvolid=subvolume-id 0 0

Alternatively, you may use LABEL=label or /dev/sdxn to refer to the btrfs filesystem.

To apply the changes to fstab without rebooting: mount -a


Taskbar pinning of apps are not being seen And Grub theme installing Problem

To keep your apps to dock, at first open your app, and when it's icon appear on dock just right click on icon and select keep in dock

To copy themes to folder open your terminal (ctrl+alt+t) and enter following
gksudo nautilus

this will open the file manager with superuser but in safe way.

now you can copy from desired folder and paste to the folder you want.

OR go to this link It have explained 3 different ways.


You got a lot going on there. Honestly no clue what juju is or how you bootstrap localhost with it, or why you have different subnets that are on the same VLAN? Which looks like is your problem here. Try to break down big problem to the basic components which are failing. Looks like you're trying to ping your lxdbr0 interface (10.14.162.1) from your ens160 (192.168.10.1) which are both on the same ethernet segment. So the router just responds with hey dummy the 10.14.162.1 is right here on the same segment so you can address it directly https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol#Redirect


KeepNote does not work on 20.04, without installing obsolete software to make it work. Also, KeepNote was last updated in 2012.
Try CherryTree. It's a flatpak app, and it's installable from the Software store, and it'll import your old KeepNote database files.
A hierarchical note taking application, featuring rich text and syntax highlighting, storing data in a single xml or sqlite file. Cherrytree is not just about having a place to write notes and to-do items and keeping them organized, it's also a place you can store links, pictures, tables, even entire documents. It can be your one program for all the miscellaneous information you have and want to keep. All those little bits of information you have scattered around your hard drive can be conveniently placed into a Cherrytree document where you can easily find it.
The Main Features:
 • Rich Text supporting Images, Tables, Code Boxes, Hyperlinks and Anchors, Spell Check, Lists
 • Syntax Highlighting supporting many programming languages
 • Password Protection, Powerful Find and Replace utilities, TOC generator
 • Print, Save as PDF, Export to HTML, Export to Plain Text
 • Import from Several other Note Taking Applications

CherryTree home page: https://www.giuspen.com/cherrytree/
KeepNote home page: http://keepnote.org/


I got this solved , you just need to mount the /proc filesystem inside the chroot :

sudo mount -o bind /proc /chroot/proc

then inside chroot , install java

#install java
apt-get install oracle-java7-installer


How can I see background process in Ubuntu? And kill unnecessary processes?

From the terminal, ps -ef will list all the processes. See man ps. See man kill, man 2 kill, man  killall, man nice, man pkill, man renice, man 7 signal, and man skill to mess with processes. However, simply killing a process that you think is useless may be a mistake. The system might restart the process, or something you depend on might depend on the process you killed. Learn what the processes do, and look at /etc/init/ and /etc/init.d, /etc/rc?.d, man service to see how processes are started by the system.


What are the system created files in $HOME?

These files and folders contain user specific setting. Desktop behavior and Application setting of each user is not same. These settings are stored in their home directory in hidden files and directory.

If you backup your whole home directory including the configuration files and folders, after restore,your settings also will be restored to its previous state.


After installing coffee script the coffee command is found but does nothing

Apparently npm coffee script is broken. I've tried in my system using both, global and local installation and do not work. Luckily you can use coffeescript package from apt-get:

sudo apt-get install coffeescript

In my case installed version 1.4.0. Is a fair price for having something working:

coffee --version
CoffeeScript version 1.4.0


Pressing the powerbutton does not do anything in Ubuntu (no menu)

Command-line method:

Open a terminal by first pressing Alt+F2 and the typing "terminal") and type the following:

gsettings set org.gnome.settings-daemon.plugins.power button-power "interactive"

Graphical method:

For a graphical way to get the menu, you need to install dconf-editor; install it from the software center by typing the name of the application or from a terminal using sudo apt-get install dconf-editor and then open the application by first pressing Alt+F2 and then typing dconf-editor.

On opening the application, from the left side menu go to org -> gnome -> settings-daemon -> plugins -> power and then in "button-power" choose "interactive".


Ubuntu software center crashes every time I try to open

Remove the file:

sudo rm /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_i18n_Translation-en%5fIN

and update the the package database again:

sudo apt-get update

You can also remove the entire folder: /var/lib/apt/lists

sudo rm -r /var/lib/apt/lists
sudo apt-get update


Epson scanner requires libjpeg version 6 -where & how can I find this?

OK, I found it. It's a package called libjpeg62, available here or here. Second link appears newer and specially for Ubuntu. The scanner started saving as JPEG as soon as I installed the package and rebooted.

PS, sorry for the duped account. Dear namesake Jorge Castro, can you merge them?


How can i setup and configure sendmail SMTP server to send bulk emails in UBUNTU?

Here's a tutorial ripped straight from : https://www.tecmint.com/setup-postfix-mail-server-in-ubuntu-debian/

It uses Apache2, PHP5, PostFix and SquirrelMail.

In a terminal type :

sudo apt update && sudo apt install apache2 php5 postfix dovecot-imapd dovecot-pop3d squirrelmail -y && sudo ervice postfix restart && sudo service dovecot restart && sudo squirrelmail-configure && sudo cp /etc/squirrelmail/apache.conf /etc/apache2/sites-available/squirrelmail.conf && sudo a2ensite squirrelmail.conf

choose internet site :

enter qualifier domain name of your choosing :

for dovecot you'll have to accept the self-signed certificate :

enter hostname, ("localhost") :

type "2" :

now type "1" : here you'll have to enter your domain name (you need a domain name)

Go back to the main menu by writing “R” and hitting the enter key, write “4” in order to configure the general options. You see “Allow server-side sorting”? Enter “11” and change it from “false” to “true” by entering “y”. Now hit the Enter key, and enter the “S” key in order to save the configuration file :

In order to start using squirrelmail webmail, you’ll have to create a new user, to do so, run.

sudo useradd myusername

Replace “myusername” with the user name you want, create a password for the new user by running.

sudo passwd myusername

Create a home folder for the user in /var/www/html/myusername and make it default home directory.

sudo mkdir -p /var/www/html/myusername
usermod -m -d /var/www/html/myusername myusername

then add rights to this newly created user :

sudo chown -R myusername:myusername /var/www/html/myusernam

now you can open up a new tab in your browser and you can go to the domain name you entered + /squirrelmail.

it will show this :

go ahead and log in with the newly creeated account.

now you should be able to bombard your mails.


Unable to boot USB on GIGABYTE motherboard

The answer was extremely simple. @oldfred provided it with his comments to this question. The boot device (after hitting F12 to bring up the boot menu during Post screen), turned out to be the Sandisk Cruzer listed first under +Harddisk table.

I had never entered that part of the boot devices screen. I had only looked at USB devices. Booted right up from the Flash drive (USB Sandisk Cruzer).


Can i run ubuntu from USB and save all information?

If you already have Ubuntu installed you can use the Startup Disk Creator which will install Ubuntu to a USB Stick. You'll need to make sure you first download the ISO (If you want the best compatibility use a 32bit ISO). In the Startup Disk dialog you can sepcify how much space you want reserved for saving things like new software, documents, and settings. After doing so choose the Disk drive you want to use and the ISO then Make Startup Disk.

Everytime you plug in the USB select "Try Ubuntu" instead of install in the boot menu. That will drop you in a live session and your data will be saved to the extra space specified during the creation stage.


Why is the size of my .Private folder so large?

Since its contents are encrypted, you are unlikely to be able to tell much by looking at the files in ~/.Private directly.

Instead, you'd be better off looking at the unencrypted view of those same files in ~/Private.  The ecryptfs system has quite a low overhead, so if ~/.Private is large it is likely because you've placed a lot of data in ~/Private (or a program running on your behalf has done so).


How to connect internet across a static IP network?

It is possible that your home internet does not use 192.168.1.*. You could change the configuration on your router to use 192.168.1.* addresses. You should check the user manual for your router to learn how to do this.


Video Players malfunction in various ways

I was able to find the answer in this Youtube video:

https://www.youtube.com/watch?v=wN9tGhmRvns

Which recommends disabling hardware accelerated decoding in VLC's settings panel.


a package wants me to use a system mail name

The application is asking for your domain name for emailing.  If you have a domain that you are on, you would just type that in like:

example.com

But if you don't have a domain that you are part of, the hostname of your computer would be the domain name.  To get your hostname, it is either the name right after the @ in the terminal prompt, or you type in hostname from the prompt to get your hostname:

terrance@terrance-ubuntu:~$

terrance@terrance-ubuntu:~$ hostname
terrance-ubuntu

Hope this helps!


Unable to update variable in bash script

To update a variable in bash, you must use this syntax:

VAR="some stuff$VAR"

But, since you are using a pipe, the while loop is executed in a sub-shell, you variable is lost.

To correct this, you must have the syntax:

while read f
do
done <<< $(input)

So in your case:

REF_SEQ=""

while read f;
do
    name=$(echo ${f}| xargs -I {} basename {} )
    REF_SEQ="${REF_SEQ}${name} "
done <<< $(find . -name "*.txt" -maxdepth 1 -type f)

echo "Full Sequence:  ${REF_SEQ}"


No wired or wireless networking available on Ubuntu 12.04 (wired work from LiveUSB)

Additional Drivers sometimes offers to install the wrong drivers! Please open a terminal and do:

sudo apt-get remove --purge bcmwl-kernel-source
sudo modprobe b44

Now your ethernet should be working. Hook it up and do:

sudo apt-get install linux-firmware-nonfree

Upon reboot, both should be working fine.


How to make my computer accessible over the internet through a machine that does have a public IP address

If you have a Middle Machine somewhere on the Internet where you can SSH into it both from Desktop and Laptop (the machines don't need to be on the same network at all), you can forward the traffic through Middle Machine quite easily:

Step 1 - SSH from Laptop to Middle Machine:
Laptop --------SSH-----> Middle Machine

Step 1b - set up a TCP tunnel back to Laptop:
Laptop --------SSH-----> Middle Machine
      <--RemoteForward--

Step 2 - SSH from Desktop to Middle Machine:
Laptop --------SSH-----> Middle Machine <--SSH-- Desktop
      <--RemoteForward--

Step 2b - set up a TCP tunnel through Middle Machine:
Laptop --------SSH----->   Middle Machine   <--SSH-- Desktop
      <--RemoteForward-- <--LocalForward--

Step 3 - SSH from Desktop through Middle Machine and RemoteForward to Laptop:
Laptop --------SSH----->   Middle Machine   <--SSH-- Desktop
       <--RemoteForward-- <--LocalForward-- <--SSH--

See this answer on SuperUser on how to set this up (in that answer, Middle Machine is named serverpc, Laptop is officepc, Desktop is homepc). There is some extra network and CPU overhead due to the fact that you're running SSH-through-SSH, but it is surprisingly usable.

All this can be done as normal user using vanilla SSH in default configuration. You can also use all the features of SSH in the final tunnel from Desktop to Laptop - SSHFS, X forwarding, agent forwarding, you-name-it.


Cannot boot from USB or DVD _Ubuntu 14.04 LTS

Are you sure that you've gone through the whole process of making a bootable usb without any errors? How did you set your boot sequence?


Mir-libs and mir-kiosk on RPi3 with Ubuntu Core

I happened to be trying this just last week, and stumbled across a bug which I presume was causing your problems:

https://forum.snapcraft.io/t/opengl-interface-change-in-master-broke-gles-on-the-pi-devices/1947/5

There is a workaround mentioned there, but a newer core snap has the proper fix integrated.

So I'd recommend using the Daily/Edge RPi3 image available here (it also has reliably working wifi).
Next install the core snap from the edge channel, and then you can follow Alan Griffith's guide.

-G


xfce4: "sudo startxfce4" - all good, but only "startxfce4" - fail. Why?

Ok as they said on thread suggested this is a duplicate of... try installing xfce-desktop and then try to start your environment. Also check if there's a xinitrc file under $HOME/.config/xfce4/xinitrc since that is configuration file that startxfce4 script reads from when run.
If it's absent or empty, check /etc/xdg/xfce4/xinitrc since that configuration file is run when you do sudo startxfce4. What you can do and is suggested by startxfce4 man page is to copy contents of xinitrc from /etc into the one that's in your home directory.

cat /etc/xdg/xfce3/xinitrc > $HOME/.config/xfce4/xinitrc

Then try to start your xfce DE. Hope it helps.


I have same problem here in my Ubuntu 11.10 box. Last year the FileZilla main developer was told about Filezilla Unity integration, but it said that he does not want to do it becasue he does not use Unity at all. However, he will accept patches, he said, but may be none has done one at this time yet.

You can see the thread here:
http://forum.filezilla-project.org/viewtopic.php?f=1&t=21610

So I think this problem has only solution: get rid of Unity, or get rid of Filezilla.


Probably yes; I've done the same, if you run fsck over USB it can take all day + for a big drive.
Leave it running, or else dismantle it & use a SATA link - it will be much faster in the end!


I had the same problem and I resolved in this way:

cd /etc/init.d
sudo gedit killwlan
paste into:

   modprobe -r wl

   modprobe -r bcma

and save the file;
cd /etc/rc0.d
ln -sT /etc/init.d/killwlan S16killwlan
cd /etc/rc6.d
ln -sT /etc/init.d/killwlan S16killwlan
cd /etc/init.d/
sudo chmod 755 killwlan

In this way you stopped wifi kernel modules (that cause the halt of system) before shutdown procedure.


Attempting to dual boot Ubuntu and Windows 7 on Sony Vaio with Insyde H2O BIOS

Broadly speaking you have three options:

Manually install an EFI boot loader for Linux. This is the easiest solution in principle, but it can be tricky to get working in practice.
Re-install Ubuntu, but figure out how to get your computer to boot the installer in EFI mode rather than in BIOS mode. Chances are this can be done by fiddling with options in your firmware, but the details vary so much from one system to another that it's hard to give simple and definitive advice.
Wipe your hard disk, set your firmware to BIOS mode, and install both Windows and Linux in that mode. This will be a pain to do, but in some cases people in your situation end up resorting to it in the end.

To get started with the first option, I recommend using a USB flash drive. Partition it with GPT and create an EFI System Partition (ESP) on it. (An ESP has its "boot flag" set in GParted or has a partition type code of EF00 in gdisk. In either case, it uses a FAT filesystem -- preferably FAT32 -- and it's usually 100-500 MiB in size.) On the ESP, create an EFI/BOOT directory and place your boot loader program there with the name bootx64.efi. For instance, you could put ELILO there. In the case of ELILO, you'd also need to copy a Linux kernel and initial RAM disk to the drive and create a configuration file. The point of all this is that you can mess with the USB flash drive on another computer, stick it into your target system, and tell the firmware to boot from the USB drive in EFI mode. If it doesn't work, you can fiddle with it and try again. Repeat that until it does work. Once you get something that will boot your Linux installation, you can copy those files over to the ESP on your hard disk (/dev/sda1) and use the efibootmgr program to register the boot loader with your firmware.


Will 11.04 use other filesystem than ext4?

Short answer: no, we're sticking with ext4 by default.

However btrfs support has been improved for 11.04 (btrfs can be your boot partition). It may well be adapted as a future release's default - see the Ubuntu's Development Manager's blog post from last year on the subject.


You have to make all your changes one step at a time. First of course you have to be running from a live CD with all the partitions unmounted, including swap. You can unmount them from gparted if need be.

Resize the extended partition (/dev/sda2) , free space in front , adjacent to /dev/sda1
Apply changes.
Resize /dev/sda1
Apply changes.


What you are trying to accomplish is impossible. The WUBI runs from inside Windows. It creates a virtual partition in a big file inside Windows partition (such as C:). The bootloader is tricked to look inside the Windows partition for the Ubuntu partition that is actually a file.

By destroy Windows 8 if you mean to reformat the Windows partition, then you will lose your Ubuntu installation as well. Without Windows and a Windows partition, there is no way to install WUBI.

Create a live USB either from within Windows by http://www.ubuntu.com/download/help/create-a-usb-stick-on-windows OR from within Ubuntu:

http://www.ubuntu.com/download/help/create-a-usb-stick-on-ubuntu

Boot your computer from the USB stick and install Ubuntu overwriting Windows and everything else.

Before you do this, make copies of all your personal data, music, photos, and whatever else you value. in an external hard drive.

Hope this helps


Can I make a screen switch from one computer to another by cli?

If making the screen sleep works, then almost certainly the toggle- script below will work:

#!/bin/bash
# --- set your monitor below
monitor=VGA-0
# ---
if [ -z "$(xrandr | grep $monitor | grep +)" ]; then
  xrandr --output $monitor --auto
else
  xrandr --output $monitor --off
fi

The script toggles on/off a monitor, to be set in the head of the script:

# --- set your monitor below
monitor=VGA-0
# ---

How to use

Copy the script into an empty file, save it as screentoggle.sh
In the head of the script, set the monitor, like in the example. Use xrandr to find the name of your monitor
Add the script to a shortut key: Choose: System Settings > "Keyboard" > "Shortcuts" > "Custom Shortcuts". Click the "+" and add the command:

sh /path/to/screentoggle.sh

Now if you toggle the screen off on one computer, it will be available on the other.

Note

You probably need to add (and run) the shortcut on both computers, since the screen will only switch if the screen is set to --auto on at least one computer.


Unable to login after Ubuntu 18.04 fresh install

Switch the login display manager from gdm3 to lightdm. LightDM is a more lightweight login display manager than gdm3. In some Linux Mint releases lightdm is the default login display manager, and since Linux Mint does not have this login problem and Ubuntu 18.04 does, I suggest that you try using lightdm in Ubuntu 18.04.

Open the terminal and type:

sudo apt install lightdm
sudo dpkg-reconfigure lightdm
sudo reboot

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


How can I change the size of Unity 2D launcher icons?

11.10
There  is a way to make the icons smaller, however the icons are surrounded by backlit that's always 54x54 px and you can't shrink that, it's hard coded.
What you can do is this:


Above solution works fine, but to make it compatible with MySQL reference manual solution (single options file and --defaults-group-suffix) /lib/systemd/system/mysql@.service should look like this:

# MySQL systemd service file

[Unit]
Description=MySQL Community Server
After=network.target

[Install]
WantedBy=multi-user.target

[Service]
User=mysql
Group=mysql
PermissionsStartOnly=true
ExecStart=/usr/sbin/mysqld --defaults-group-suffix=@%I
TimeoutSec=600
Restart=on-failure
RuntimeDirectory=mysqld
RuntimeDirectoryMode=755

BTW, there is no /lib/systemd/system/mysql@.service in Ubuntu by default, so it has to be added manually (and it doesn't work if you just copy /lib/systemd/system/mysql.service to /lib/systemd/system/mysql@.service).


slapd with back_sock does not create a socket

The purpose of back_sock is to connect to an another socket that already exists. It's documented in the slapd-sock(5) manpage. It certainly does not create any socket.

If you review your logs, you'll only see errors when an action is attempted, because the sock backend opens the socket each time it needs to do some action, and closes it afterwards. You'll see an entry could not open socket in your logs if the socket cannot be opened for each action.

If you're trying to make slapd listen on a socket instead, you need to modify /etc/default/slapd, and adjust/add the slapi:// URL (remember you'll need to encode slashes as %2f, see slapd(8) for more details).


Cannot get outside VPN (same settings work on Debian)

You need to edit your VPS's route and add a default gateway. And also you have to make sure that you have enabled ip forwarding by echo 1 > /proc/sys/net/ipv4/ip_forward.

Edit:There must be a row in routing table saying that if no destination was found for packets, then it must be routed to default gateway; This is mine:

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         192.168.1.1     0.0.0.0         UG    0      0        0 eth0

you can add a new entry for default gateway using route add default gw 192.168.1.1. Make sure that routing table is currect in both VPS and client


How do I get my Canon MX420 printer working?

Original source : http://www.ubuntubuzz.com/2011/06/download-install-canon-printer-driver.html

Type the following command in terminal (Cntrl-Alt-T)

sudo add-apt-repository ppa:michael-gruz/canon

sudo apt-get update

sudo apt-get install cnijfilter-mx420series

All the best.

In case of any error please post it here.

Edited

to configure the printer you can use lpadmin

Restart the CUPS daemon by typing

  sudo /etc/init.d/cups restart
  OR sudo service cups restart

Register the printer to the spooler by typing

  for usb = /usr/sbin/lpadmin -p [printer_name] -m [PPD_filename] -v cnijusb:/[USB_port] -E

like

  sudo /usr/sbin/lpadmin -p MX420USB -m canonmx420.ppd -v cnijusb:/dev/usb/lp0 -E

for LAN
For a LAN connection

like

/usr/sbin/lpadmin -p [printer_name] -m [PPD_filename] -v cnijnet:/[MAC_address] -E

  sudo /usr/sbin/lpadmin -p MX420LAN -m canonmx420.ppd -v cnijnet:/00-00-85-AB-C1-23 -E

3.Set the default printer

/usr/sbin/lpadmin -d [printer_name]  like

  sudo /usr/sbin/lpadmin -d MX420USB

4.unblacklist usblp module by typing

  sudo nano /etc/modprobe.d/blacklist-cups-usblp.conf
  Add a # in front of the line with "blacklist usblp" - Note this might cause problems where you are running multiple printers from the same system where CUPS manages those printers directly

5.check the printer status by typing

cngpijmonmx420 [printer_name] like

  cngpijmonmx420 MX420USB

if there is no error,then your printer is ready....... if error we can resolve it...


Do you have the hard drive set in the BIOS/UEFI as a boot option? Sounds like maybe it is still trying to boot the USB or otherwise.


Install Ubuntu 14.04 while display is distorted

Thanks for the help. I created a live DVD and ran the installation from there versus the USB and everything worked perfect. Maybe I had dorked up the way I created the USB.


I needed to add mce=off at the end of the kernel command inside grub. Thanks for all the help though!

More information on my issue was found here https://www.phoronix.com/scan.php?page=news_item&px=Linux-Boot-Threadripper-Zen2MCE


Can't upload and connect to networks, network error(?)

I changed the mtu to 1300 in the Network Connections and the problem solved.
(Thanks for the Hungarian Ubuntu Facebook group.)


Dell OpenMagage web server "crashes" after logging in

Had the same problem too with Ubuntu 16.04. Problem is the /home folders are encrypted.

Each time you login, dsm_om_connsvc.service crashes.

The solution is then, to decrypt the /home folders (to do with every one of your home folders if you want to back them up and you have stuff in them) and to remove the encryptfs utility like this :

back up your home dir :

sudo cp -rp /home/username /home/username.backup

log as an other account you created with a password and sudo rights and do this :

sudo rm -rf /home/username
sudo rm -rf /home/username.backup/.ecryptfs

remove the encryption utility :

sudo apt-get remove ecryptfs-utils

then restore your backup home folder:

sudo mv /home/username.backup /home/username

now restart OMSA :

/opt/dell/srvadmin/sbin/srvadmin-services.sh restart

and login with your username and password should work.

I helped myself with this link (to remove the encryption from your system) :

https://www.howtogeek.com/116179/how-to-disable-home-folder-encryption-after-installing-ubuntu/


How do I unassociate executables with wine?

Right click on .exe file> under properties> opens with> select the application> add or remove.

Make your selection then close.


Allwinner A10 crane board (mk802+) to run Ubuntu Server

Pay attention that the MK802+ has an A10S, not an A10 like MK802. Although rootfs is very similar, kernel is NOT. I'm running linux-sunxi sun5i (not sun4i like you mentioned) for about a month without any problems.


do you have SuperGrubDisk (http://www.supergrubdisk.org/)? This could help troubleshout. If it's more aptitude-related, have you tried stuff like apt-get update or apt-get clean?


How enable/disable WiFi adapters individually under 10.04

For your first problem you can disable it by blocking the driver from loading. Use lsmod to find the driver it uses and then add blacklist that-driver to /etc/modprobe.d/blacklist.conf (on a new line). Bit of a sledgehammer approach but it would disable it.

I don't know if this would actually disable the hardware so it might still eat battery.


Ubuntu Boots Up in Emergency Mode and I'm Too Much of a Potato to Diagnose

Lets first check your file system for errors.

For 17.10 or older...

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

For 18.04 or newer...

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


There's no easy way to recover these files.  Gimp does not save data automatically in case you forget to save.  If the application crashes, there's no way to save the data before closing the error; so, you should save all of your data after every accepted step, unless you don't care if you lose your work.

Plugin research revealed two promising links, which are both very similar.  The "linux-only" link was junk and isn't mentioned here.

Short, untested, open-source attempts (both done in python):

http://www.gimpusers.com/forums/gimp-developer/11718-autosave-plugin - more officious and seemingly robust.
https://www.mail-archive.com/gimp-developer@lists.xcf.berkeley.edu/msg18118.html - better tabbing.

According to the author of the (2), GIMP does not want to have an auto-save feature because it makes your privacy more secure: advanced users don't have the "secret hidden tmp directory" to spy on unsuspecting beginners.

data-privacy

The more officious code says that it saves all open documents to the prescribed location every 30 minutes.  Thirty minuets is a wide gap: I want to recommend 10 seconds, but perhaps the auto-save process is processor-intensive, and it might even interrupt your work-flow.  If it does not interrupt your work flow, you should get it down to less than 5 minutes because that's about how long an old laptop battery lasts if you forget to plug it in and don't get/have battery alerts  (like in Ubuntu Mate).

data-integrity


Show Downthemall addon download manager for firefox

Try clicking on the Open Menu button in the top bar:

Then, click on the Customize button:

You should see the DownThemAll Download Manager somewhere there. Simply drag and drop the icon to your task bar or into the Menu! Then, you can just click that button and you're good to go!

I don't use DownThemAll myself, so I don't have it installed and can't be entirely certain that will fix your issue, but it should.


Packages of graphic card driver for GeForce GTX 960M by Ubuntu 14.04

I don't have enough rep to comment. I got Xubuntu 15.10 working on my Inspiron 15 7559, which has a GeForece GTX 960M, with functional suspend mode and the ability to switch between integrated and discrete graphics.

See my answer here:

Graphics and sleep issues on Dell Inspiron 15 UHD

Another similar question:

Infinite login loop with Nvidia proprietary graphics

Edit: Removed duplicate content. I learned it is bad practice to post duplicate answers to related questions. Fixed link


How to make Ubuntu ask for password when mounting partitions?

According to the Ubuntu ManPage Repository, pklocalauthority - PolicyKit Local Authority makes a distinction between user authentication (to make the user in front of the system prove he really is the user) and administrator authentication (to make the user in front of the system prove he really is an administrator)

Therefore you can use this policykit to provide administration authentication for mounting all (internal and external) devices.

To do so, follow these steps:

Open a terminal(CTRL+ALT+T) and type:

gksu gedit /var/lib/polkit-1/localauthority/10-vendor.d/com.ubuntu.desktop.pkla

In line 4, look for ResultActive=yes and change it to:

ResultActive=auth_admin_keep

Save and Close the file.

Ubuntu will now require a password when mounting all drives (internal and external drives).

For specific partitions:

In 10.04 and newer versions, mounting all devices (internal and external) are allowed without asking for password unless it was defined in the filesystem table (fstab) file.

Therefore, to make Ubuntu prompt users for sudo password when mounting specific partitions, you need to edit your fstab file.

To do so, follow these steps:

Open a terminal and type:

gksu gedit /etc/fstab

At the last line, add the UUID of your partition with the defaults option.

You can find out the UUIDs of partitions by running blkid in the terminal.

For example:

$ sudo blkid
/dev/sda1: UUID="5474ce02-5c07-4002-a0e7-10c8bc5dba2c" TYPE="ext4"
/dev/sda2: LABEL="windows" UUID="7355DDFB0563F31F" TYPE="ntfs"
/dev/sda5: LABEL="data" UUID="7e3fbc57-03fe-4742-bb72-756f31852059" TYPE="ext4"
/dev/sda6: LABEL="films" UUID="a319fb28-3061-404f-abbc-6519cf81c6c9" TYPE="ext4"
/dev/sda7: LABEL="tv" UUID="5D10E5D66886BCCF" TYPE="ntfs"
/dev/sda8: UUID="12d16683-5530-454e-809b-1a30ed47a8c9" TYPE="swap"

Now that you know the UUID, you can add it to the fstab file. But first, you need to create a mountpoint where the partition will be mounted.

You can do that by running:

sudo mkdir /path/to/dir/name-dir

In my example, I want to mount the partition under /media/data:

sudo mkdir /media/data

Now, I can simply add the line below to make sure that Ubuntu prompts for a password when the "data" partition is mounted:

UUID=7e3fbc57-03fe-4742-bb72-756f31852059 /media/data   ext4 defaults 0 0

Save and Close the file.

Note:

The defaults option uses the default options that are rw, suid, dev, exec, auto, nouser, and async.

The user allows normal users to mount the device, whereas nouser lets only the root to mount the device.

For detailed information, visit How to edit and understand /etc/fstab.


Ubuntu 16.04: After minimizing a window, it cannot be maximized again

I was having the same issue and the comment on the question nailed the answer.

I enabled the other workspaces (desktops) by going to Settings > Appearance > Behavior > Enable Workspaces.  All the lost windows came back immediately.


Problem installing Grub on bios_grub partition

Unless my math is faulty, you are working with a 60 Gb HDD and you want to reserve 38+ Gb as file storage.

Best case, this old notebook is going to offer disappointing performance and you'll be starved for file and swap space.  Consider the following:

Copy the ntfs files onto a thumbdrive or external drive and free up the whole 60 Gb for your solo Lubuntu installation.

Then, do a clean Lubuntu installation which includes letting the installation process partition and format the HDD based on it's own recommendations.

I think you got yourself in trouble by installing Lubuntu while trying to work around a way too tiny HDD that already had data on it.  Let's remove that from the process. If you do a clean install everything should work just fine.  Fine, that is, bearing in mind that your Dell is 11 years old so it's performance may be rather sluggish.

You might be able to kludge your way towards fixing your current installation roadblock.  However, finding a way to eliminate grub from the picture is not an option for you.  But my advice would be to bite the bullet and just install the OS cleanly and correctly.


Make sudo not ask for password for n minutes after login

Here's an idea for how it could be done.  NOTE: this is a hack; use only if the words passwordless sudo make your eyebrows want to crawl all the way up your skull.

The premise is: we cannot pass login credentials to sudo.  So the question is how to have a NOPASSWD sudo for only the first few minutes of a login.  We can do that by starting the login shell in NOPASSWD mode, and spawning a background process in .bashrc which after some minutes undoes the NOPASSWD.

# somewhere near the bottom of ~/.bashrc
sudo -n /bin/bash -c "$HOME/nopasswd-sudo 60s 12h <&- >&- &"

Of course the script itself must be started with NOPASSWD sudo, or we would be still be prompted for a password.  And the script must reinstate the NOPASSWD rule when the bash session ends, so that NOPASSWD is set for the next login.

Here is the script $HOME/nopasswd-sudo that will do that:

#!/bin/bash

SUDO_FILE="/etc/sudoers.d/$(basename "$0")-${SUDO_USER}"
SUDO_RULE="${SUDO_USER} ALL=(ALL:ALL) NOPASSWD: ALL"

[ -z "$SUDO_USER" ] &&
     echo "$(basename "$0"): must be invoked with sudo" >&2 &&
     exit 1

# Trap exit to recreate SUDO_FILE for next login
trap "echo '$SUDO_RULE' > '$SUDO_FILE'; exit 0" EXIT

# First time around just exit, creating the SUDO_FILE
[ -f "$SUDO_FILE" ] || exit 0

# After $1 (default 5m) remove SUDO_FILE to end NOPASSWD sudo
sleep ${1:-5m} && rm -f "$SUDO_FILE"

# Wait until our parent exits, and we will exit via the trap
# If after $2 (default 12h) still alive, we assume we missed the HUP
sleep ${2:-12h}

On its first run (which must done from the command-line, not from .bashrc), the script creates the file /etc/sudoers.d/nopasswd-sudo-$USER containing a NOPASSWD wildcard for the logged in $USER:

{username} ALL=(ALL:ALL) NOPASSWD: ALL

Then on every login it starts and waits in the background until the passwordless time is up, after which it removes the file, and the next sudo will require a password.

After that it waits indefinitely (actually, up to 12h, to prevent lingering orphans that missed their parent's HUP signal), or until its parent, the login shell, ends.  Just before it exits, its EXIT trap recreates the NOPASSWD file.

Tip for the adventurous: remember to always keep a separate root shell open while you mess with login scripts or sudo rules.  You wouldn't be the first to lock yourself out.


UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY

Try this:

You would have to use the live-dvd/usb.

You would boot the live-dvd/usb with your PC.

And run fsck from a terminal:

sudo -i
umount /dev/sda7
fsck /dev/sda7 -y


Laptop runs too hot, the fan runs silent

Depending on the laptop model your fan may be controllable via software, such as the fancontrol package, pwmconfig or by directly putting values into the /sys/classes/thermal/cooling_device*/cur_state values. However, testing with the latter it seems these values didn't cause the fans to get turned on. My understanding is that these are part of the ACPI subsystem and many vendors expose some details in the "tables" but don't honor the writes - so the fans don't actually get turned on.

For some vendor specific laptops (Dell) there are utilities that make specific requests to the fan controllers that do work, but I am not aware of any that do this for Samsung devices.

  I did used to have the option to run the fan 'silently' (i.e, slower).

It's possible that by setting certain power configurations as you did in Windows is how the fan controller is determining when to turn on and off. In Linux these are often known as "governors" and can be modified using the cpupower command.

Another interesting side note is that if you "soft" shutdown from Windows sometimes it leaves the fan controller in a strange state, with some users reporting that their fan works in Linux when they use a full shutdown followed up with a real power button press when rebooting: Source


Unfortunately, the latest version of the python2.7 package available in the Natty repositories is 2.7.1-5.

2.7.3 is only officially available for Precise 12.04.  You would have to compile this yourself for 11.04, or search for a PPA containing it.

To find out the latest version of a package available for a specific release, simply go to:

http://packages.ubuntu.com/release-name/package-name

where the release-name is natty, oneiric, etc.

To find out all available versions of a specific package and the releases they correspond to, look at:

http://packages.ubuntu.com/search?keywords=package-name

or at:

https://launchpad.net/ubuntu/+source/package-name


Screen tearing issue with HP 15 (AMDGPU)

I did some of dirty attempt, and finally resolved my own problem. However, this answer only applies to xorg, not wayland as screen tearing doesn't appear when I'm using it.

First, make sure that your packages are up-to-date, as it's essential.

Since I'm using Unity, playing around with ccsm by toggling on Force complete redraw on inital damage and Force full screen redraws (buffer swap) on repaint seemed like resolving it. I don't know if GNOME also uses compiz.

I realized that there was something wrong with my config file;

Option "TearFree" "true"

That is the correct string, since the option only accepts boolean input(?). Previously, I tried playing with DRI and TearFree setting; using only one of them renders to unaccessible desktop. I don't have an idea why.

Reboot and the screen tearing is gone!


I would like to delete an accidental post I did on paste.ubuntu.com while using Bootrepair

I believe you can email rt@ubuntu.com and ask them to remove the post, but don't expect a quick removal. rt@ is the alias for their internal ticket handler (Request Tracker).1

1Source: Answer to the question Can I get an @ubuntu.com email address for the Ubuntu-related event I'm organising? by Oli


How do I temporily locally set example.com to resolve to 127.0.0.1 without modifying the hosts file

Your question seems somewhat vague, so I have prepared two separate answers for you:

If what you're asking is whether or not you can write DNS records from the server /etc/hosts file, the answer is no. You can change /etc/hosts all you like, but it will only affect the server's view of the corresponding IP address, not the Internet's view of the IP address. That is the purpose of DNS -- to resolve a domain name to a specific IP address Internet-wide. Source: Wiktionary definition of DNS
If what you're asking is whether or not you can alias an IP address to a domain name, the answer is yes. Editing the /etc/hosts file does just that. In all likelihood, the best way to do that temporarily is simply to sudo nano /etc/hosts, add the alias in question, such as 127.0.0.1 box.example.com, and later remove it. To alias an IP without administrative priveleges, as per your request, I honestly do not believe that it is possible. If I come across any information to the contrary I will update my answer immediately.


Please guide me, to configure qt on lubuntu 13.10

Install .run files

sudo sh [FILENAME].run

Or

sudo ./[FILENAME].run

Install .deb files

sudo dpkg -i [FILENAME].deb

Or

Install Gdebi with

sudo apt-get install gdebi

Then right click on the file and select open with Gebi package installer.

I have posted some guides here and here


Apt-mirror for amd64 did not include focal/main/dep11 and focal/main/cnf/Commands-amd64

apt-mirror is not maintained and has several bugs for missing files for newer releases.  You can either patch the installed version or install a fork with incorporated patches
Browsing the bug reports, you'll see the reported issues

https://github.com/apt-mirror/apt-mirror/issues/

One such fork

https://github.com/Stifler6996/apt-mirror


super + space does not change language ubuntu 18.04 unity

With Ubuntu 18.04 switching to GNOME, it seems that even the default Unity shortcut to switch keyboard layout isn't supported anymore.

I experimented different customized shortcuts for Next/Previous Input Source in Settings > Text Input, and found that shortcuts using space require either ctrl or shift to work, e.g. ctrl+shift+space. So the defaults  super+space and super+shift+space simply don't work at all.

Solution

You are still free to choose usual combinations like super + N or modifier-based combinations like alt + shift (Windows-style). Be careful with shortcuts relying solely on alt and super though, as they may open the Command, Launcher or Keyboard Shortcuts pop-up depending on how long you hold them.

For instance, on my Japanese keyboard I'm using ctrl + muhenkan, as it's also possible to reuse special keys.


What are the default permissions for the /usr/share/applications folder?

All files inside /usr/share/applications are owned by root:root. Here's the proof:

% sudo find /usr/share/applications ! \( -user root -a -group root \)
%

So to fix that just run:

sudo chown -R root:root /usr/share/applications


Integrating Internet Download Manager, which installed in Virtual Box, with Firefox or Chromium, installed on Ubuntu 12.04 (host OS)

I used to use IDM on XP.  I really doubt if it will work from a VM, as the VM is pretty separated from the host system.

If you use Firefox, I'd recommend trying out "DownThemAll!", a download manager plugin.  I've been using it, and it works very well for me.  You can download all links on a page, or a selection of links, like IDM.  It seems fast, and so far, has worked well for me.

I don't know if it's available for any other browsers, though.


Make sure you have logged back in (the changes happen only when you start a new shell). Additionally, try using .bash_profile instead of .profile. To test without logging back in, you can source the file directly by typing:

. ~/.profile


intel-microcode n dmesg microcode reported on ubuntu 18.04

The microcode is loaded from your initrd (initial ramdisk), so to ensure your package is installed in your initrd/initramfs, the following command will re-create it

`sudo update-initramfs -u`

Note however

  The date displayed does not correspond to the version of the
  intel-ucode package installed. It does show the last time Intel
  updated the microcode that corresponds to the specific hardware being
  updated
  https://wiki.archlinux.org/index.php/microcode

The intel-ucode in my 'archlinux' quote refers to your intel-microcode package in Ubuntu.
(I didn't find a Ubuntu reference, which is why I've used Arch's)

I did find on the Ubuntu Wiki 'Firmware Test Suite - microcode test'

  This test checks to see if the firmware is loading that latest microcode
  for the CPUs
  https://wiki.ubuntu.com/FirmwareTestSuite/Reference/microcode

which should put your mind to rest; just run the test :)


version 11.4.0.323 seems to have this issue resolved.


After some searching I found that vm has own firewall settings that has to be changed in VM Inbound Security Rules to allow access via port 80 (by default only ssh is allowed).


Cancelled upgrade from 11.10 to 12.04, refusing to upgrade again

You can continue the upgrade by running sudo dpkg --configure -a in a terminal.


Speakers and headphones at the same time when using a DV6-2170

I would first check to see if Ubuntu is detecting both (Headphones and Speakers) in the system settings:

If you see something like one the following images, then you know both were detected:

In my case I have support for my headphones and my stereo output. If in one case I would like to disable sound for the speaker, I would first select the output I want to disable and then disable the option (Marked by the green circle). This way sound will not come out of that output connection. The same goes for input devices. Here is another image of how 12.10 looks. Notice that I have both, the Speakers connection (Analog Output) and the Headphones:

The same case applies here. You select the device you want to mute and click on the mute button.

For cases where this options do not show or sound is still coming from the speakers when you have your headphones connected then follow this steps:

Type in dash terminal or ter for short and press Enter

In the terminal type alsamixer and press Enter

Inside the alsa mixer app, using your arrow keys, move left or right to any of the options that will show in your mixer window. Pressing up or down you can adjust the volume for that specific connection or pressing M you can mute the connection. What you will be doing here is looking for the one that mutes your speakers but leaves your headphones still with sound.

Now for your case, it seems your headphones are not getting detected correctly. The only option your computer shows is "Speakers" which are the internal ones. When you connect the headphones, the sound comes out of both (Speakers and Headphones) because it thinks they are the same. If you have already upgraded Ubuntu I would suggest to see what the command dmesg outputs. Type dmesg on a terminal and see if there is anything related to sound.

UPDATE: After looking at your dmesg and other information (Provided by Mr Jeeblez himself) and seeing that you have the Intel 5 Series/3400 Series Chipset High Definition Audio, searching I found a bug report that was made for said motherboard. You can find the bug report in
https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/580233

The solution was to do the following:

In the terminal type: sudo gedit /etc/modprobe.d/alsa-base.conf
At the end of the file paste the following:

alias snd-card-0 snd-hda-intel
options snd-hda-intel model=dell-m4-1 enable_msi=1

Save and Reboot.

NOTE: If this does not work, change in the second line the part about:

model=dell-m4-1 --> model=hp-m4.


How to admin samba 4 domain controller from Mac client

As far as im aware there isn't any software to administer GPO (Group Policy Objects) from a mac and requires windows.

One way would be to install Vmware Player and install a windows machine inside of that and use it to administer users and GPO's.

Underneath active directory it uses LDAP to authenticate users, so if you aren't interested in administering GPO's you could use a tool like LDAP browser MAC to manage your users.

You may also need to set up LDAPS to change users passwords and you can find a guide to that on the samba wiki (Google "ssl certificate samba")


Have Unattended-Upgrade perform check before restarting

You can use the configuration in this file (thx @muru):

/etc/apt/apt.conf.d/50unattended-upgrades

and this line:

Unattended-Upgrade::Automatic-Reboot "false";

In a shell I would do that:

sudo sed -i 's/^Unattended-Upgrade::Automatic-Reboot "true";$/Unattended-Upgrade::Automatic-Reboot "false";/g' /etc/apt/apt.conf.d/50unattended-upgrades

Create a script for that and start you program inside the script. If it's finished revert the changes.

Or you can use this file:

/etc/apt/apt.conf.d/10periodic

and this line:

APT::Periodic::Unattended-Upgrade "0";

"0" means disabled
">0" is the time interval in days.

This disables auto-update system-wide.


thor27's steam-login without entering Big Picture

The file containing such configuration is called steam-de, the newest version of which is located at https://github.com/thor27/steam-login/blob/master/steam-login/usr/bin/steam-de.

Notice the content of line 63:

parameters='-tenfoot -enableremotecontrol'

Those are the parameters that make Steam open in Big Picture mode, but luckily the author made it easy to alter.

Firstly, you need to locate steam-de on your machine. Go to the terminal and type whereis steam-de. You may find, as output, something like steam-de: /usr/bin/steam-de /usr/bin/X11/steam-de.

Now we edit the file. In this case, we run:

sudo nano /usr/bin/steam-de

Then, change the aforementioned parameters argument to parameters=''. Save (that's Ctrl+O on nano) and exit (Ctrl+X). If you run sudo nano /usr/bin/X11/steam-de, you will notice your change has carried on to that file.

Now just run steam-login as usual and it will boot in windowed mode.

By the way, you may also want to comment line 88, prefixing it with a #; it will look like this:

# zenity --error --text "Ops! Steam had some trouble to run. That can be a problem with steam itself or with your configuration."

This will prevent steam-login from showing an error dialog when you exit steam from the windowed mode. It should, instead, just go straight back to lightdm.


Installing Ubuntu over Windows 10 on a drive with only a few gigs of free space?

If you're installing Ubuntu over Windows, you're overwriting the OS on the hard drive so all 30 GB will become available to Linux. Installing with a USB drive like you said will work fine.


With GNOME 3.0 and Ubuntu 11.10, things changed compared to the accepted answer to this question.

You can find more details at "Creating custom URL handlers in Ubuntu 11.04, 11.10, GNOME 3.0".


with a live session of Ubuntu 18.04 how to access all folders with root previliges those are inside a disk having Ubuntu 18.04 Installed.?

In the live session, you can open a terminal window and run commands with the prefix sudo, for example

sudo copy path2/file1 path2/file2

to copy file1 with root privileges.

In standard Ubuntu you can open a terminal window with the hotkey combination

ctrl + alt + t

In a live session you need no password to run via sudo, but in an installed system, you need the password for your user ID to run via sudo.


Archive manager that extracts into new folder named after archive

In Ubuntu a right-mouse-click (contexmenu) on a .bz .gz .7z .bz2 etc always unpacks to a folder in my experience. The program used is....fileroller.

Also take a look at this: Is there an 'Extract to...' context menu option for the Archive Manager application in Nautilus?

If all else fails:  file-roller -h  filename
the -h option forces the creation of a directory in which the files are unpacked. The name of the directory is the same as the archive name minus the filename extention. see: man file-roller


You have to install some dependendent packages:
sudo apt-get install gconf-service gconf-service-backend gconf2 \
gconf2-common libgconf-2-4 libpython2-stdlib libpython2.7-minimal \
libpython2.7-stdlib python-is-python2 python2 python2-minimal python2.7 python2.7-minimal

But to keep problem reproducible I would recommend to install deb-packaged version instead:
cd ~/Downloads
wget https://desktop-download.mendeley.com/download/apt/pool/main/m/mendeleydesktop/mendeleydesktop_1.19.4-stable_amd64.deb
sudo apt-get install ./mendeleydesktop_1.19.4-stable_amd64.deb

as it does this for you and will install desktop-shortcut with icon.


Ubuntu 16.04.3 LTS customization applies after login only

This is because you are using user settings, instead of using them globally and they apply only after logging in with the specific user. Put the same settings in your display manager settings and everything will be fine.

Edit: I guess you are using lightdm as it's the default display manager for ubuntu, in that case you can put your monitors.xml in /var/lib/lightdm/.config/ so your monitors resolution and order will work at the  login screen.
As for the wallpaper on your login screen check this link.


Less output does not show output in terminal after quitting it

seq 1 100 | less -X

see: man less

-X or --no-init
Disables  sending  the  termcap  initialization and deinitialization strings to the terminal.
This is sometimes desirable if the deinitialization string does something  unnecessary, like clearing the screen.


Can apps created using Quickly for Ubuntu be used in other linux distros?

Yes, you can
By default quickly uses pyGOBJECT for creating applications, It is a cross platform so you can use these apps in other linux distros. But you may need to make tiny changes in the code because there are some ubuntu specifc features like application indicator which is not available in other distros.


Unable to uninstall Ubuntu or delete partition

You may need to buy a Windows CD to get Windows back since you said that the entire disk is devoted to Ubuntu.

The reason you cannot reformat the hard drive is that you are using the operating system from the hard drive; the formatting program recognizes this and prevents you from removing the operating system from under itself.

Run the program, Diskmanager, and check the number of partitions on the drive; if you only have 1, then you need to buy a Windows CD.
If you have 2 or more, then the restoration copy of the Windows installation may still be on the drive. To utilize this, you will need to create a bootable CD (or USB drive) with gparted. It's very easy to make a bootable CD (instructions are provided at the web site), and a little more difficult to make the bootable USB (some computers also won't boot from USB). gparted will allow you to reformat the Ubuntu partition as NTFS.

This is the part I don't know about. How to access the restoration partition to get the original copy of Windows.


I assume you mean you want to use LibreOffice's Spanish-language user interface, and enable its editing features for Spanish (e.g. spell-checking).

Make sure the language packages are installed. To do this, open the Language Support dialog (from the menu or by running gnome-language-selector), click "Install / Remove Languages...", make sure the box for "Spanish; Castilian" is ticked:

Then, if needed, press "Apply Changes".

Don't change the order of the languages (i.e. leave English on top) in the main Language Support dialog; this means that the default language for all applications will be English.

After doing this, make sure the packages libreoffice-l10-es (Spanish UI), libreoffice-help-es (if you need the help in Spanish), and a Spanish spelling dictionary are installed. (I'm not sure whether Language Support dialog installs these for you.)
Open any LibreOffice application, and browse to Tools > Options > Language Settings > Languages:

Change "User interface", "Locale setting", "Default currency", and default document language (as desired) to your desired national variety of Spanish, and press OK. (You must close and reopen LibreOffice before the language will change.)

This will change the language only for LibreOffice, leaving other applications in English.

If you meant you want the Spanish-language tools (for writing documents in Spanish) but still want the English UI, do the same, but leave "User interface" as English.


How to change the Bus / Dev in order to allow xsane to work

As you stated in your comment:

The problem was solved. lsusb to verify where the usb is located.

Then, sudo chmod a+w /dev/bus/usb/$Bus/$Dev


Package lkl was only used for an (now) old release of Ubuntu. The package on launchpad shows only Hardy.

So if you want this you need to install the source code from here. Download it, open a console and extract the files from the archive. The following commands should install it:

cd lkl
./configure
make
make check (not required but it does some tests).
sudo make install

to install the package program and you should have the command lkl on your system.


Low graphics performance with Intel HD graphics

You have 60 FPS because of VSync. Switch off in System settings -> Compiz settings -> OpenGL -> VSync


I think you will notice a difference if you install the fonts-nafees package from the Ubuntu archive and switch to an Urdu locale. fonts-nafees includes the Nafees Nastaleeq font.


Your easiest solution would be to backup data and reinstall, your might also find these answers relevant: How to Reinstall Ubuntu on Acer C7 Chromebook


You can pass variables in either using the -v command line option:
date="2020-12-11"

cat /var/log/dpkg.log | awk  -v date="$date" ' / installed / && $0 ~ date {print $5}'

or via the ENVIRON array in the case of environment variables
export date="2020-12-11"

cat /var/log/dpkg.log | awk  -v date="$date" ' / installed / && $0 ~ ENVIRON["date"] {print $5}'

See for example Pass shell variable as a /pattern/ to awk


Before to follow this answer, you may reflect a little at the fact that can be illegal to monitor someones keystrokes (of course without permission).

Assuming you're talking about one of these Ubuntu releases and not about Ubuntu One that is a cloud service, go in terminal an run next command:

sudo apt-get install logkeys

This will install Logkeys Keylogger on Ubuntu.

Before to start keylogging process first time, create a log file in your home directory or wherever you want:

touch keylogging.log

Use Logkeys to start keylogging process:

sudo logkeys --start --output keylogging.log

Now your keylogger is running in background and you can close the terminal. The output will be stored in the keylogging.log.

To stop keylogging, kill logkeys process:

sudo logkeys  --kill

To read keystrokes recoreded by keylogger, use:

strings keylogging.log

Read official documentation for more options.


Don't have the new 'Software' Store in Ubuntu 16.04 LTS

Have you tipped the check box to download updates during install?
If not try to make an update.

sudo apt-get update
sudo apt-get upgrade

But normaly it should be installed, except the case of a beta build


You would be able to setup the PC as an IPv6 router, if you have a IPv6 subnet for it to use.
To enable IPv6 routing you only need to setup the IPv6 address on the second interface of the PC and enable IPv6 forwarding.

Enable IPv6 routing on Linux
(you may need to modify [or disable] the firewall on the PC if you got one)

echo 1 > /proc/sys/net/ipv6/conf/all/forwarding

(edit /etc/sysctl.conf to config during boot)

If you want to use automatic IPv6 address assignment
Install and configure radvd .

You also have to configure your router/ADSL box with a IPv6 route to the new IPv6 subnet configured on the PC.

Also you can find an easier solution HERE


remote access between ubuntu desktops 16.04, no connection

I'm no expert at this but I've been experimenting with remote access on my local network recently and I think the problem is the IP address that you are entering into the 'Server' field.

It's probably the correct IP address for using with an ssh connection but it wants a VNC server address.

In case this is helpful for others, I'll go through all the steps that got it to work for me using the VNC Server option.

Keep in mind that, as far as I can tell, using ssh is a far more secure way to access a remote machine than using VNC. If it's just over your local network then it shouldn't be too much of a security worry, but I've not yet had any luck getting Remmina to work using the SSH tunnel options despite being able to connect fine using ssh from the Terminal.

Firstly I went to the computer I wanted to access remotely and searched in the dash for Desktop Sharing.

From there I could choose to 'Allow other users to view your desktop' and 'Allow other users to control your desktop'.

(You're also able to choose whether you want the remote machine to have to acknowledge that this is okay before allowing access and/or whether you require the user to enter a password before access is granted.)

Once this was enabled, when I went to my other machine and opened Remmina Remote Desktop Client, I created a new profile and selected the Protocol to be VNC - Virtual Network Computing.

Next to Server the option to 'Browse the network to find a VNC server' was now enabled and clicking on that dotted icon showed two options for the same machine using IPv6 or IPv4 protocols.

Selecting one (either of them should work fine) will now fill the Server option with something like:

[YourRemoteComputerName.local]:5900

I initially filled in the 'User name' and 'Password' fields but that isn't necessary for it to work.

Change the Name field at the top to allow you to save the profile, hit Connect and you should now have remote access to your other machine.


Hardy, the long term version from 2008 has 1.19. I know it is not the same as 1.20 but I guess it is the closest you can get using canonicals blessed bits. Try to download the three files from the right side of this page: http://packages.ubuntu.com/hardy/tar and use dpkg-buildpackage to make a package suitable for your distribution. After that, you need to force the installation with dpkg -f -i because you're probably downgrading.

I am left wondering why would you do such a thing. Is 1.22 giving you a hard time?


How does ubuntu terminals autocomplete work?

An almost identical question was asked in StackExchange:
How does bash tab completion work?

I have been spending a lot of time in the shell lately and I'm
wondering how the tab autocomplete works. What's the mechanism behind
it? How does the bash know the contents of every directory?

The top voted answer:
There are two parts to the autocompletion:

The readline library, as already mentioned by fixje, manages the command line editing, and calls back to bash when tab is pressed, to enable completion. Bash then gives (see next point) a list of possible completions, and readline inserts as much characters as are identified unambiguously by the characters already typed in. (You can configure the readline library quite much, see the section Command line editing of the Bash manual for details.)

Bash itself has the built-in complete to define a completion mechanism for individual commands. If for the current command nothing is defined, it used completion by file name (using opendir/readdir, as Ignacio said).
The part to define your own completions is described in the section Programmable Completion. In short, with
complete «options» «command» you define the completion for some command. For example complete -u su says
when completing an argument for the su command, search for users of the current system.
If this is more complicated than the
normal options can cover (e.g. different completions depending on argument index, or depending on previous arguments),
you can use -F function, which will then invoke a shell function to generate the list of possible completions.
(This is used for example for the git completion, which is very complicated, depending on subcommand and sometimes
on options given, and using sometimes names of branches (which are nothing bash knows about).

You can list the existing completions defined in your current bash environment using simply complete, to have an impression on what is possible. If you have the bash-completion package installed (or however it is named on your system), completions for a lot of commands are installed, and as Wrikken said, /etc/bash_completion contains a bash script which is then often executed at shell startup to configure this. Additional custom completion scripts may be placed in /etc/bash_completion.d; those are all sourced from /etc/bash_completion.


How can I make DNSMASQ bindings in human readable format?


Booting Ubuntu from USB stick on Lenovo IdeaPad g580 (i5)

I've had some similar boot issues with my Lenovo IdeaPad Y500, especially with booting from an ISO burned on DVD (but also using USB boot). Assuming there are some similarities between the two laptops, I would suggest the following:

Power off the laptop & remove the USB stick
Boot the machine from the "Novo" button
Once the "Novo" menu appears, insert your USB stick
Select "Boot Menu"
If the ISO was properly written, you should see a bootable USB drive in the boot menu.

If the above doesn't work, I would explore your BIOS settings, and try enabling, or disabling secure boot to see if that works.

I hope that helps!


Alright, found an answer myself somehow. Apparently, new versions of KDE Plasma use another file than mentioned in the older answer. The new file is located at /usr/share/plasma/desktoptheme/(themename)/metadata.desktop and works pretty much the same way with the only difference that it is theme-specific.

The steps I suggest are:

Copy the desktoptheme you are currently using to a folder with a custom name. (For example, copy Breeze /usr/share/plasma/desktoptheme/breeze to /usr/share/plasma/desktoptheme/canobreeze or so)
Edit the metadata.desktop's defaultWallpaperTheme to the wallpaper you prefer.
(Optional, but handy) Edit the metadata.desktop's name to something you like. This is to differentiate between your theme and the original one.
Set the defaultWidth and defaultHeight. You can find the available sizes at /usr/share/wallpapers/(wallpapername)/contents/images. Please note: not all wallpapers shipped with plasma have the same sizes. For example: the Next wallpaper has a lot of sizes, while Canopee only has one. IF THE SIZE IS NOT SET CORRECTLY THE WALLPAPER WON'T WORK!!!
Look in the System Settings for 'Workspace Theme' (or in plasma search 'Plasma Theme').
Set the theme to your own, modified version (it has the name specified in the metadata.desktop file)
And there it is: when you create a new activity or connect a new screen, you will get your custom wallpaper.


How do I configure the automatic suspend setting?

I'm running ubuntu 14.04 and this steps would help you with your issue. If you are running a different version of Ubuntu the steps might change.

On your "System Settings", click on "Brightness & Lock". On "Turn screen off when inactive for:" from the pull-down menu select "Never".


You can try the command below to force re-detection of disks. I have seen the command cause issues with externally-mounted LUKS partitions, so if you have any of those, I would suggest dismounting them before trying this command

sudo partprobe


Installing Kubuntu 15.10 x64: An error occurred while restoring previously-installed applications

It looks like the issue stemmed from the fact that when choosing the partition on which to install Kubuntu, I was deleting then creating a new one. I instead selected the partition, clicked on "changed", marked as to be formatted and to be mounted as \: this time, it worked.


Razer Orochi bluetooth mouse connects but doesn't work (ubuntu 16.04)

It magicaly works now! Maybe some recent updates made it work, or something magical has happend. I had lag issues but this answer has solved my problem.

EDIT:
The problem was I am using bluetooth speakers and it's not possible to use both at same time.


No.
Not using apt-get, GCC 2.x predates Ubuntu !

I managed to locate GCC 2.95 at http://archive.debian.org/debian-archive/debian/pool/main/g/gcc-2.95/
You could download the appropriate version and install using the dpkg -i pathto/filename.deb command. Who knows if it will work, or have any issues with dependencies and then you would for sure need to use apt-pinning to prevent Ubuntu installing a more modern version - really not worth even trying IMHO.


I want to bridge my ethernet to my wifi, but there is no ethernet port listed. What can I do?

You can try ifconfig -a, after that youu can see ethernet port. Now we need to bridge

ifconfig eth0 0.0.0.0
ifconfig ath0 0.0.0.0   #ath0 is wireless interface name
brctl addbr br0
brctl addif br0 eth0
brctl addif br0 ath0
ifconfig ath0 up
ifconfig eth0 up
ifconfig br0 up

Now you can access internet.


Ubuntu drains battery very fast compared to Windows

You can use either laptop-mode-tools (which come pre-installed) or TLP, but not both at the same time. There is no big practical difference between the two, the consensus appears to be that TLP is somewhat more advanced, while laptop-mode-tools is somewhat more stable.

You can use powertop (sudo powertop) to see your biggest energy consumers, and to check (under "Tunables") if laptop-mode-tools/TLP are working properly - most parameters are supposed to switch to "Good" once the laptop is unplugged. Sample:

Some minor parameters (like VM writeback timeout, swappiness etc.) which are not auto-adjusted can be adjusted manually. Google will help you to find out how.

However, if your laptop has AMD/Nvidia graphics, power drainage is probably caused by the opensource X graphic driver. In which case, as much as we all like opensource, you have no option but to install proprietary video drivers (fglrx/bumblebee respectively). You will easily find the how-to's on the web.


Ubuntu 19.10 Login Loop After Installing Proprietary Nvidia Drivers

Fix

The problem was with GDM display manager and the Nvidia driver, seems they still do not play well together even in 19.10.  I wasn't able to determine the root cause of the problem, however what worked for me was to install lightdm and change the grub command line on startup.

On the login screen press:
• Ctrl + Alt + F2 to enter the terminal and log in.
• Edit /etc/default/grub. I did it with sudo <yourtexteditor> /etc/default/grub.
• Change the line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to GRUB_CMDLINE_LINUX_DEFAULT="nomodset".
• Update this grub edit with update grub (tyvm @jake).
sudo apt-get install lightdm
• reboot

After installation, I was able to login as normal with the NVIDIA driver installed (nvidia-driver-435).

Reference: Login loop with fresh 19.10 install


Processing triggers result in "skipping file because of errors", expected: '='

In modern Desktop Environments menu files are not necessary. Therefore you can ignore the error message. A working desktop file is important.

But you could try to fix your menu file via

sudo nano /usr/share/menu/wxmaxima

and add the following

?package(wxmaxima):\
    needs="X11"\
    section="Applications/Science/Mathematics"\
    title="wxMaxima"\
    longtitle="GUI for the computer algebra system Maxima"\
    icon16x16="/usr/share/pixmaps/wxmaxima-16.xpm"\
    icon32x32="/usr/share/pixmaps/wxmaxima-32.xpm"\
    command="/usr/bin/wxmaxima"

After that start

sudo update-menus


Is there a way to install Ubuntu completely on a portable external HDD and boot into it on any computer/laptop?

No
Each computer / laptop you want to run Ubuntu on can have different video cards and drivers meaning the kernel boot parameters might need changing.
Better option
Your best bet would be to make a Live-Boot USB with persistent storage.


Chrome sound not working on Ubuntu 15.04

Reinstall alsa and pulseaudio

sudo apt-get remove --purge alsa-base pulseaudio indicator-sound
sudo apt-get install alsa-base pulseaudio indicator-sound
sudo alsa force-reload

Then restart Chrome


At what point is the ~/.bashrc file created?

In most cases, the initial user files (including .bashrc) are created when the user is created. They are copies of the files stored into the 'skeletal' directory, named /etc/skel. There are two main commands:

useradd is the back-end command, if you using it directly (without any options) just a system user (and its group) will be created:

$ sudo useradd new-user
$ ls -la /home/new-user/
ls: cannot access '/home/new-user/': No such file or directory

useradd will create a home directory and populate it with a copy of /etc/skel if the -m --create-home option is supplied. Thanks for this comment to @jwodder.
The option -s --shell will change the name of the new user's login shell. No matter what the new user's login shell is, the entire content of the 'skeletal' directory /etc/skel will be populated into the new user's home directory.
A different 'skeletal' directory cold be defined with the -k --create-home option.
The configuration file of this command is /etc/default/useradd.

adduser is user-friendly and interactive front-end of useradd. This command will copy the files from /etc/skel to the user's $HOME directory by default:

$ sudo adduser new-user
Adding user `new-user' ...
Adding new group `new-user' (1002) ...
Adding new user `new-user' (1002) with group `new-user' ...
Creating home directory `/home/new-user' ...
Copying files from `/etc/skel' ...
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
Changing the user information for new-user
Enter the new value, or press ENTER for the default
        Full Name []: New User
        Room Number []:
        Work Phone []:
        Home Phone []:
        Other []:
Is the information correct? [Y/n]

$ ls -a /home/new-user/
.   ..   .bash_logout   .bashrc   .config   examples.desktop   .profile   .Xdefaults

The configuration file of this command is /etc/adduser.conf.
The default value for the new user's login shell is deteminated by the variable DSHELL=. It could be specified also via the option --shell. No matter what the new user's login shell is, the entire content of the 'skeletal' directory /etc/skel will be populated into the new user's home directory.
The SKEL= variable in this file specifies the default directory containing 'skeletal' user files.
The option --no-create-home will force the command adduser to do not create a user home directory, respectively the content of the 'skeletal' directory will not be copied.
If called with one non-option argument and the --system option, adduser will add a system user... A home directory is created by the same rules as for normal users. The new system user will have the shell /bin/false (unless overridden with the --shell option), and have logins disabled. Skeletal configuration files are not copied. ...from the manual page.

Additionally, when the user is created with any GUI tool as User Accounts, the result is identical to that of the command adduser.

References:

What is the difference between adduser and useradd?
What's the difference between "adduser" and "useradd"?
Home directory not being created
AddUsersHowto - Ubuntu Documentation Community Wiki
What is the *nix command to view a user's default login shell?
Terminal command for listing available shells


Added new partition to system, "permission denied" when running programs

You can access files on your newly created ext4 partition, but you cannot run programs. When you do, you get a "Permission denied" error. This suggests two possibilities, as reverendj1 has suggested:

The files might not have execute permissions. To give a file execute permissions from the command line, run:

chmod +x filename

If you just want to give execute permissions to the owner of the file:

chmod u+x filename

To give a file execute permissions in Nautilus (the file browser), right-click on the file and click Properties. Click the Permissions tab. Check the box that says Allow executing file as a program, and click Close.

The partition may be mounted with noexec. To check this, run mount and see if noexec is listed next to the relevant entry. Since you're mounting from /etc/fstab, you can remove noexec there.

In addition, please note that:

Usually, though not always, executables should be stored in the normal places: /bin, /sbin, /usr/bin, /usr/sbin /usr/local/bin, /usr/local/sbin, /opt/bin, ~/bin. Are you sure you really want executables on that drive. You may want to edit your question to provide more information about what you want to accomplish.
To run a program from the command-line that is located in the current directory by specifying its relative path, you must precede it with ./:

./program
If you are launching a .desktop file rather than an application then:

It does not need the executable bit set.
You should not attempt to run it as though it is itself a script or program, but instead like this:

xdg-open application.desktop

If these are Windows executables that you're running with Wine, they don't actually have to have the executable bit set. If they don't, you can right-click them and click open them with Wine Windows Program Loader, or launch them from the command line like this:

wine program.exe

(I see this provides very similar advice to a previous answer, so I've decided make this community-wiki.)


Just how much "heavier" might be Ubuntu 18 when switch to Gnome3?

You can always switch DE if you don't like the default one. Perhaps even to the Unity (although the gist is that Canonical gonna move development resources out of Unity, but may be community step in).

On the topic: AFAIK Gnome is heavier on GPU, which you didn't mention ☺  Also looking the benchmarks from 14 April 2017 Unity is a tiny bit faster than Gnome (make sure to read the text too — the first benchmark, where Gnome looked like performed terribly, have had a technical problem). Also note that I am not using Gnome myself (I am on i3), but I've occasionally saw on IRC people complained about lags in some of Gnome menus. If you see the same: this is irrelevant to GPU, and is a bug which hopefully be(was?) fixed.

But that's about short-term. In the long-term, of course, Gnome is/will be refactored, improved, etc — so I'm sure its performance will get better. The more that after Canonical have officially switched to Gnome, Gnome would be developed by at least Canonical and Red Hat. You can peek at development for gnome-shell and mutter (the WM).

Overall performance-wise it's always worth upgrading the system. E.g. by using 14.04 you're limiting yourself to mesa 10.1 which is terribly outdated. Last bugfix release (not even features) for 10.1 was June 24, 2014, and last bugfix release for whole 10 series (the 10.6, to be specific) at October 3, 2015. Although in 2016/2017 there were a bunch of cool improvements, both CPU and GPU wise, in graphics drivers.

Same for the kernel: 3.13 version — that sounds like a bad joke! As of writing the words latest kernel is 4.12. Just skim through releases here to see how much improvements you're missing. New IO and power governors, improvements to file systems, drivers, core, memory management, network sybsystems, overall refactoring, atomic changes to GPU drivers… You're really missing a lot of performance improvements.


I had the same problem. I installed Ubuntu 20.04 for "penguin" container. However, in /etc/apt/sources.list.d I had cros.list and cros-gpu.list, there were some Debian sources, which I commented out (using '#')
cat cros.list
#deb https://storage.googleapis.com/cros-packages/84 stretch main

cat cros-gpu.list
#deb https://deb.debian.org/debian stretch-backports main
#deb [arch=amd64,i386] https://apt.llvm.org/stretch/ llvm-toolchain-stretch-7 main

Then I did:
sudo apt-get update && sudo apt-get upgrade && sudo apt-get install steam

and all "libgl1-mesa*" stuff was resolved and installed, no dependencies issues.


Add

 alias ls='ls --hide="*~"'

to your ~/.bashrc, ~/.bash.aliases or where ever you define your shell aliases.