Ubuntu Glossary - Dictionary of Commonly-Used Terms

Please edit this CW post to add new info that hasn't been covered. Try to keep it in sensible categories.

All images are clickable to make them larger.

This list was divided in three cateogies:

UI elements and Interaction
Technical
General Jargon

1. UI elements and Interaction

Super

The Super Key is the equivalent to the Windows key on a keyboard, between Ctrl and Alt. We call it the Super Key because on a Mac it's the Command key, on Linux it varies and on Windows it is the Windows key:

Launcher

This is the "Dock" at the side of the screen where you access your applications. You can add and remove programs from it, and it will also show mounted USB pen drives and CDs / DVDs.

See questions tagged launcher

Dash / Show applications

The way to search Ubuntu for applications and documents. This also has the full list of installed applications - whereas the dock has a user defined subset of these.

On Windows, this is the start menu, and on OSX this is Spotlight:

 betanews and  MacStories

Panel / Notification Bar

This is the bar in the top of your screen.

Home Directory

The place with all your files. It will contain Desktop, Documents, Downloads, Music, Pictures, Public, Templates and Videos. It is found in /home/username.

Ubuntu Software

This is the place to install Applications.

It acts as a graphical way to install programs from a safe place. It is like the App Store on OSX or the Store on Windows 8 +

Unity / Desktop Environment / Window Manager

The default Window Manager in (Vanilla) Ubuntu. This is what you see when you start up your computer and login:

This is GNOME Shell. Other Desktop Environments include Unity (17.04 and below), XFCE and KDE. There are more.

2. Technical

Dual Boot

Installing both Ubuntu and another Operating system (or version of Ubuntu) on the same computer. This can be achieved by installing on separate hard drives, or by partitioning one hard drive.

When installing Ubuntu, the current operating systems should be detected, and it will offer to install Ubuntu alongside it:

Image to installation types

Flavour / Distribution / Distro

Ubuntu is open source, which means anyone can take the code and change it or modify it and give it to other people. Some distributions include Ubuntu GNOME, Kubuntu, Xubuntu, Lubuntu, Ubuntu MATE and Ubuntu Touch for mobile. The whole list can be found here.

Architecture

The processor type - 32 or 64 bit. This determines the download - either i386 or amd64.

64 bit processors can run 32 bit operating systems and programs, but not the other way round. Most modern computers are 64 bit, hence this is the recommended type to download.

Terminal / Command Line / TTY** and **Commands

The terminal is the graphical interface to the command line, with which you can execute commands.

This could be launching an application like firefox, removing a file with the rm command or searching through a file with cat and grep or sed.

TTY is also a command line - just a non graphical one. Note that you have to login to use this one. In fact, you do with the Terminal - you did it when you signed into your account.

Bash and Shell

Bash is the default shell in many Linux distributions. It stands for Bourne-Again SHell, and is Bourne shell with many additions. Shell is a command interpreter that executes commands.

BIOS

This is Ubuntu independent - the BIOS is built into every computer for setting up the basics - like choosing which hard drive to use and power management.

Repository

A repository is a software archive with programs that support Ubuntu in them. These are split into Main, Restricted, Universe and Multiverse. These simply contain different classes of programs - for example Multiverse is paid software, and Main is supported by Canonical.

See the Ubuntu Wiki for more information

3. General Jargon

Release(s)

Releases, or versions are each new iteration of Ubuntu. Currently, a new version is released every 6 months, in April and October. The version number (for example 14.04) tells you when it was released:

They also have a codename - for example 14.04 is Trusty Tahr. 14.10 was Utopic Unicorn - they go down the alphabet.

LTS - Long Term Support** also **LTS Release

LTS stands for Long Term Support. ¼ of Ubuntu releases are LTS releases - once every 2 years. The cycle is a follows:

16.04 - April 2016, LTS
16.10 - October 2016
17.04 - April 2017
17.10 - October 2017
18.04 - April 2018, LTS
18.10 - October 2018
19.04 - April 2019
19.10 - October 2019
20.04 - April 2020, LTS

The version numbers are simply examples. LTS releases are supported for 5 years from the release date (meaning you can upgrade to the next LTS release, or even the one after that). A non LTS release is supported for 9 months, so you have time to get the next release before it is EoL (see below).

Supported means it gets security and other updates from canonical. It is highly recommended that you use a supported release.

EoL - End of Life

When a release is no longer supported, it becomes End of Life. See above for what changes.

Open source

Ubuntu is open source. This means the source code of it is available for modification or enhancement by anyone.

Package Manager

The package manager (DPKG in Ubuntu) is a built-in utility designed to streamline app management. You can browse, install, and remove software with this.

The software centre uses this - it's a graphical interface for dpkg.

Root and sudo

Root is the equivalent of Administrator in Windows. It has the power to do anything - like erase the hard drive, change config files and adjust the time.

In Ubuntu, there is no "root" user. Instead, sudo is used. Any command with "sudo" before it (for example sudo nano) will be executed as root.

Users in the "sudoers" list can execute sudo commands.

The root home directory is simply /root - it is not found in /home/root.

Any images not attributed are created by a contributor to this post.


Install ubuntu overwriting an old Windows8 trial partition

Personally, i whould remove the expired windows partition and use wubi from the good one to install ubuntu, this way you won't have to worry about grub or annything you dont have the old windows and you whould even be able to delete ubuntu from the software manager in the working windows !

http://www.ubuntu.com/download/desktop/windows-installer


Why did Apache name it's Webservers Apache and Tomcat?

Apache
According to the FAQ in the Apache project website, the name Apache was chosen out of respect to the Native American tribe Apache and their superior skills in warfare and strategy.
Tomcat
Tomcat started off as a servlet reference implementation by James Duncan Davidson, a software architect at Sun Microsystems. He later helped make the project open source and played a key role in its donation by Sun Microsystems to the Apache Software Foundation. The Apache Ant software build automation tool was developed as a side-effect of the creation of Tomcat as an open source project.
Davidson had initially hoped that the project would become open sourced and, since many open source projects had O'Reilly books associated with them featuring an animal on the cover, he wanted to name the project after an animal. He came up with Tomcat since he reasoned the animal represented something that could fend for itself. Although the tomcat was already in use for another O'Reilly title, his wish to see an animal cover eventually came true when O'Reilly published their Tomcat book with a snow leopard on the cover in 2003.
Note: you could find them all on Wikipedia.


Where is the order of names in gdm login screen stored?

As far as I know, there is no easy way to configure the order of names: Names are ordered by their login frequency as returned by ConsoleKit (see the output ofck-history --frequent). The numbers are extracted from the log files in /var/log/ConsoleKit/ directly, so there is no simple way to change them. You could still repeatedly login as one user, though, that would move the user to the top ;)


How do I remap the IJKL keys to arrow keys when I hold Alt down?

There are a several more technical ways to do this that I have seen in other SE posts, but one of the easiest ways would be to install AutoKey. It is a full featured keyboard macro processor and it's easy to define simple macros for such a task.

AutoKey does a whole lot of other things easily and, if you know Python which is used as its macro language, you can get a keypress or phrase to do almost anything your system is capable of.  And, it works with just about any program because, by default, its output appears to be coming directly from the keyboard exactly the same as if you were typing it.

Try it and see if it works for you. We don't currently have any developers on the project, but the support list is active and many people are successfully using it.

I just reread your question more carefully and the bit about the other modifier keys still working makes it more complicated because you would probably have to code a separate macro for each modifier combination with each key (i, j, k, l), but I think it would still work.

If you decide to try it, make sure you have the latest version (0.90.4) as many distros provide older versions that don't work as well.


No.

xorg.conf is just a plain text file that is parsed (ie. the lines in it are read by a script and the script sets all the parameters, options and what else is valid in xorg.conf) so no, you can not use conditions. That line you want included would just be ignored or it would error out since the xorg subsystem does not understand it.

You could do this with a udev rule (Writing udev rules and How do I make udev rules work? will get you started).


"Signing key does not exist" after successful upload on Launchpad

PPA will create a new key(Launchpad PPA for YOUR NAME) for you and signed the related files with this new key.

You may need to wait for a while, to get this new key uploaded to Ubuntu Keyserver(keyserver.ubuntu.com).


Isn't the best answer, but I never enjoy Brasero, usually it won't work. Install K3B (KDE CD Burner)  that work every time for me :)


Strange noise appears from my sound columns after upgrade to 13.10

The issue appears to be caused by incorrect Skype installation ( I have downloaded the Skype from its official web site).

The following line fix the problem permanently:

sudo sed -i 's/^Exec=.*/Exec=env PULSE_LATENCY_MSEC=30 skype %U/' /usr/share/applications/skype.desktop

And this is the source of the fix, and also showing how to install Skype properly on Ubuntu 13.10:

sudo apt-get update
sudo apt-get install skype


How can I get grub2 to boot a different option only on the next boot?

You need to make sure you have GRUB_DEFAULT=saved in your grub config (which is autogenerated, you change this part of it by editing /etc/default/grub). sudo update-grub to make the changes active and then use sudo grub-reboot $1.

grep -i "menuentry '" /boot/grub/grub.cfg

Will give you the menuentries that you can cut-paste in for $1. Or, as you note the options are zero-indexed, so the n-th menuentry can be had by passing (n-1) to grub-reboot.

See eg

How to reboot into Windows from Ubuntu?
https://unix.stackexchange.com/questions/43196/how-can-i-tell-grub-i-want-to-reboot-into-windows-before-i-reboot
https://superuser.com/questions/285755/boot-to-windows-once-from-grub-then-back-to-ubuntu-on-next-boot.

Not tested by me as I don't have a 'Windows 7' install.


Dell first boot failed, result in no session created

Problem solved !
I must have used an old 16.04.2 usb installer  wich didn't provide the right linux kernel and thus did not support the network chipset (I assumed that it was a dell based driver available only on the chiped dell release) ..
The install worked with the latest 16.04.3 !

Thanks !

Simon


sudo apt-get install libopenal1 libopenal-dev

Also see Can't make warzone on the Warzone 2100 forum. Apparently you also need alut (sudo apt-get install libalut0 libalut-dev).


Using date and sha1sum

date -u +%F | sha1sum | head -c8;  echo

date -u +%F

prints the system date and time

E.G. 2015-04-24

-u- UTC instead of CEST
+%F - full date; same as %Y-%m-%d

sha1sum

compute SHA1 message digest

E.G. e1a9d1a9de6f784ae30c6c1d5be9fc897ea5e4ec  -
head -c8

output the first part of files

E.G. e1a9d1a9%

-c8 - print the first 8K bytes

echo

display a line of text

E.G. e1a9d1a9


apt-get purge, install nginx; reports success but not installed (12.04)

The configuration files are provided by the nginx-common package, not nginx. Therefore you have to purge nginx-common:

sudo apt-get purge nginx-common
sudo apt-get install nginx

(nginx depends on nginx-common, removing nginx-common will also remove nginx.)

There is no need to add the nginx PPA just for getting back the configuration files.


Android USB only charges on Ubuntu 20.04/Windows 10 dualboot

I got the solution to this. It seems the auto-suspend setting was causing this problem. I just deactivated it as follows.
Open a terminal window and input:
 cat /sys/module/usbcore/parameters/autosuspend

This should return a value of 2, which means autosuspend is enabled. You can fix this by editing the grub file. Enter:
sudo nano /etc/default/grub

Change this to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.autosuspend=-1"

Press Ctrl + X to save the file, and exit. Next, update grub:
sudo update-grub

When that completes, restart Ubuntu.
After rebooting, log into your account and enter the cat command again:
cat /sys/module/usbcore/parameters/autosuspend

This time, the value returned should be -1. You've disabled autosuspend, so USB devices connected to your laptop should not fail due to power issues.


Is it possible to open terminal from run box and use ' -- ' to run a command to pen a file in some other directory?

You did not say HOW you start that command. If run from command line,
gnome-terminal -- python -i ~/demo.py will work, because the shell will change ~ into your home before the arguments are passed to gnome-terminal. But here in your case, the error message states ~/... : not found : There was no shell to interpret the ~, so it was left as is, and effectively, there is no directory whose name is the sole character ~ in the directory the command happent to be started in.

Either explicitely use a shell to interpret the ~ :

gnome-terminal -- sh -c 'exec python -i ~/demo.py'

or do it yourself and proivde the full path name :

gnome-terminal -- python -i /home/me/demo.py


The main reason for the gray-out (which signals that this one program cannot proceed) is not a general high CPU load but a problem with I/O (this is also known as I/O-Wait).

So when your program tries to write to the disk but for some reason the disk is slow to respond you will get this behavior.


Apache2 not displaying any messages on restart

There is no output if there is no error and you should now use systemctl, e.g.:

sudo systemctl restart apache2

To show the status

sudo systemctl status apache2


Usb external drive on fstab and flush option

Add option  noauto meaning do not mount when "mount -a" is given (e.g., at boot time)

and  nofail do not report errors for this device if it does not exist.

Then it is no problem.


I'm using Proxychains, an easy to use command line tool.
Usage:

sudo proxychains4 apt-get update

You can configure you proxy in the /etc/proxychains.conf

[ProxyList]

socks5  127.0.0.1 12345


There is the pi-rho/dev PPA,
which has up-to-date vim packages.

(The current default version for trusty is 8.0.0134.)

The PPA is available for currently supported releases.


All browsers with one icon in the launcher!

Ok, I gotta it!
What I had to do is to edit (as a root) the file bamf.index set in the path /usr/share/applications.
Just added few lines with the name of the launcher followed by the command you want it to manage.  The example on my case was:

brox.desktop  sensible-browser %u
brox.desktop  /opt/google/chrome/google-chrome %u
brox.desktop  firefox %u
brox.desktop  /usr/bin/opera %u

And its done!


How to download apps from different OS to USB and then transfer to Ubuntu?

Keryx is what you need.

  Keryx is a free and open source tool for easily managing packages on offline Debian based computers including support for Ubuntu and Linux Mint. It provides an easy graphical interface to help install and upgrade software.


Blank Screen upon boot, but no GRUB menu!

When I first tried to get into the GRUB menu on my computer, I found holding shift down as soon as the computer was powered and holding it usually opened the GRUB menu. Have you plugged the USB into another computer and checked it for errors?  It is also possible that the boot sequence is wrong, or there was an error when you updated the BIOS. try going into the boot menu, not the BIOS, when you turn your computer on (probably by holding F5) and see if it says boot from USB.


Brightness setting not remembered on an Asus X54H

1)  Edit etc/rc.local and add the below line

echo 4 > /sys/class/backlight/acpi_video0/brightness

Where 4 is the 50 % of brightness. 8 is the maximum

2) reboot

If brightness still goes back to max go to step 3

3) In terminal  run the following:

sudo -i
mv /etc/init.d/rc.local /root/
update-rc.d rc.local remove
mv /root/rc.local /etc/init.d/
update-rc.d rc.local defaults

If above 3 steps failed to resolve

Then add sleep 10 to rc.local

Example

sleep 10
echo 5 > /sys/class/backlight/acpi_video0/brightness
exit 0


How can I install Ubuntu 13.04 on a Mac (using disk)?

I believe there is a reasonable walkthrough for Mac OS X on burning the image, here, on the main ubuntu.com download pages:

http://www.ubuntu.com/download/desktop/burn-a-dvd-on-mac-osx

From there, you should simply boot off of the burned disc (or, of course, a USB stick), but you'll likely need to have some already unused space available for Ubuntu to fit into.  If you've already allocated/fully partitioned all of your HDD space to the other two OSs, it will be a bit more work to restructure the partitions so you have some unallocated space available first.


AMD Driver / No OpencL platforms found / AMDGPU installation

The solution for me was: Booting into Kernel 5.4.0-54 and the amdgpu-pro Driver 20.20-1098277 on Ubuntu 20.04.2 LTS with deactivated Secureboot


How about wget -b URL

It's on the man page


How do I download an Ubuntu 12.04 image with all updates so far?

If you are going to install Ubuntu 12.04 in September then you need to Download the Ubuntu 12.04.1 edition  (called as Point Release) about to release on 23rd August containing bug fixes and updates integrated till that period.

As far as forward updates are concerned , it depends on Newer version of applications to get released in that time frame , so it would be comparatively less against 12.04.

What are point releases in LTS versions?


Need an applet to report web sites unavailability

You could write a small bash script to throw notifications at you... Something like:

#!/bin/bash

for site in $(cat ~/.sites); do
    if ! ping -c 1 -w 5 "$site" &>/dev/null ; then
      notify-send "$site is down!!"
    fi
done

Your list of sites to check lives in ~/.sites.

Then you just need to cron that up to run. You might need to export DISPLAY=:0 in cron so the notification shows up in the right place.

Note that if you use a DNS intermediary like OpenDNS, if a domain name you ping doesn't exist, it'll hit their no-domain search server. Therefore it's probably safer (though less informative) to use IPs.

oli@bert:~$ ping asasdslfkjsdlff.com
PING asasdslfkjsdlff.com (67.215.65.132) 56(84) bytes of data.
64 bytes from hit-nxdomain.opendns.com (67.215.65.132): icmp_req=1 ttl=54 time=33.1 ms
64 bytes from hit-nxdomain.opendns.com (67.215.65.132): icmp_req=2 ttl=54 time=32.8 ms


Whoever runs odoo must also have an account that has permissions on postgresql.
In the error it shows it says that the user "pythondev" does not exist.
To solve:
sudo su - postgres -c "createuser -s pythondev" 2> /dev/null || true

Then set this user in odoo-server.conf


Is there a form to upload files to MEGA(mega.co.nz) from Ubuntu Server(SSH)?

You can install megatools like so

git clone https://github.com/megous/megatools.git
cd megatools/
sudo apt-get install libtool libglib2.0-dev gobject-introspection libgmp3-dev nettle-dev asciidoc glib-networking#(these are the dependancies I needed, you may need others)
./autogen.sh
make
sudo make install

Enjoy!

More robust way which seems to install all the tools:

sudo apt-get install libtool libglib2.0-dev gobject-introspection libgmp3-dev nettle-dev asciidoc glib-networking
wget http://megatools.megous.com/builds/megatools-1.9.94.tar.gz
zcat megatools-1.9.94.tar.gz > megatools-1.9.94.tar
tar -xf megatools-1.9.94.tar
cd megatools-1.9.94/
./configure
make
sudo make install

Edit To install just the binary on vivid and wily (15.04/15.10), you can just run sudo apt-get install megatools. On earlier versions, you can run

sudo add-apt-repository ppa:megous/ppa
sudo apt-get update
sudo apt-get install megatools

From the Readme:

Tools
=====

megareg      Register and verify a new mega account
megadf       Show your cloud storage space usage/quota
megals       List all remote files
megamkdir    Create remote directory
megarm       Remove remote file or directory
megamv       Move and rename remote files
megaput      Upload individual files
megaget      Download individual files
megadl       Download file from a "public" Mega link
             (doesn't require login)
megastream   Streaming download of a file
             (can be used to preview videos or music)
megasync     Upload or download a directory tree
megafs       Mount remote filesystem locally.

See also http://megatools.megous.com


Using your laptop as loudspeaker for your mobile

You could (as alternative) use your Laptop to listen to music and your mobile to control your music program over your mobile with remuco http://code.google.com/p/remuco/


Cant purge with apt-get, because of dependencies

Here is an older thread :

http://ubuntuforums.org/showthread.php?t=1587462

You could use tweak or synaptic for to remove some of the older kernels.

I would let at least one older kernel of your choice "alive" - cause then you are safe for to boot for sure - in case the newest kernel does not work right after update, or after being malformed somehow.


Will Ubuntu+KVM support an old Intel QuadCore Q8300 + Asus P5QPL

Interestingly there are different versions of the Q8300 CPU. Intel decided to enable virtualization in between. I was wondering but I am running one with VT enabled.
You can enable HW Virtualization in BIOS and check the VT flag using:

 #cat /proc/cpuinfo | grep vmx**

Win10 support can be checked here: http://www.linux-kvm.org/page/Guest_Support_Status


`hostname` result is different from "/etc/hostname" after upgrade

By searching the web, I found that the problem is caused by my wireless modem/router because it is a ZyXEL ADSL2+ modem/router. I do not know why this problem was not seen before this, but the solution that prevents (at least in my case) this unattended host name change is to change /etc/dhcp/dhclient.conf so that the system does not request hostname from DHCP server (that is running on wireless modem/router).

Run

sudo nano /etc/dhcp/dhclient.conf

Find a line similar to below command and coment it out:

send host-name = gethostname()

then find a request command that asks for hostname. it should be a line similar to:

request subnet-mask, broadcast-address, time-offset, routers,

In the list of parameters in front of request command find host-name and delete it.


LXC Is it possible to run a 12.04 container on 14.04

A little more info, this fixed my problem:

sudo lxc-create -t download -n [YOURNEWCONTAINERNAME] -- --dist ubuntu --release precise --arch amd64

I figured this out by reading the template script. There's probably other options available.


Cannot log in to WiFi hotspot on Ubuntu 17.10: Name or service not known

I was having the same problem, for me the following fixed the issue:

sudo systemd-resolve --flush-caches


Spanish keyboard doesn't work in US 18.04

I just solved the problem. I've added my second lang. then removed the first language(English). Tested the keyboard and the second layout was working fine. Then added the first layout and it all went well.


Error: [0.000000] tsc: Fast TSC calibration failed

Try this:

Open a terminal,Press Ctrl+Alt+T

Run it:

sudo -i
nano /etc/default/grub

In the file that opens add to the line that reads:

GRUB_CMDLINE_LINUX_DEFAULT="?????????????"

Which following

clocksource=acpi_pm

To be well:

GRUB_CMDLINE_LINUX_DEFAULT="?????????????clocksource=acpi_pm"

Ctrl + U, paste.Ctrl + O, save file. Ctrl + X, close nano.

Then run:

update-grub
reboot


aria2

aria2c --dir=<your_target_folder> URL

wget

wget --directory-prefix=<your_target_folder> URL

curl

curl -o <your_target_folder>/<your_target_file> URL

Chrome/Chromium

Open the URL chrome://settings/
Click "Advanced settings"
Scroll down until you see the entry "Downloads" and change it to whatever you want.

Firefox

Open the URL about:preferences#general
Scroll down until you see the entry "Downloads" (and change)


Your server's boot disk is damaged.  Boot from a recovery environment (CD or managed), log in as root and start:

fsck -C -M /dev/sda1
fsck -C -M /dev/sda2


Packet is too small ffmpeg converting wav to mp3

The error message appears to be at the very end of the file. Check to see if it still converted correctly regardless of the message. If not here are some things to try:

Update to the latest ffmpeg. Use a current build from the git master branch. This will always be newer than any release and is the first thing to try when encountering an issue. You can download it or follow a compile guide.
FFmpeg supports both native and external GSM decoders. Yours was compiled with --enable-libgsm so you have access to both. Your file appears to be the Microsoft GSM variant, so if you want to try libgsm instead of the native decoder use:

ffmpeg -c:a libgsm_ms -i input.wav output.mp3


How can I set panel to bottom, after installing MATE 1.4?

Instead of deleting the panel as in the other answer, right click on panel then click properties and change the Orientation on the General tab.


Can't install Android SDK platforms. Ubuntu 16.04

If as you say the only problem that you are having is overfilling /tmp and you have plenty of space on your storage device as indicated by the output of df -h it's logical to assume that /tmp is not using your hard drive for storage but instead is probably using RAM which can seem like a great idea at some point but can later impose restrictions such as you are now experiencing.

On my 16.04 system I get

$ df -h /tmp
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda2       106G   11G   90G  11% /

But even this is too restrictive so even the 90GB I show available here is insufficient. According to https://source.android.com/setup/build/requirements you need

  At least 100GB of free disk space to checkout the code and an extra 150GB to build it. If you conduct multiple builds, you will need even more space.

While your system has plenty of space on the /home partition it's definitely a bit restricted on the / (/dev/sda3) partition.

  /dev/sda3        14G  7,2G  6,1G  55% /

If you had a larger capacity hard drive you would likely benefit from resizing your partitions. In effect shrinking /dev/sda4 where your home directory is and growing /dev/sda3 where everything under /which isn't mounted elsewhere is. Another option would be to mount /tmp to a specific location with more space in which case this related post would be useful. In your specific case however you are unlikely to get very far with the limited space you have available. I would do the following.

1) Make sure my system meets all the requirements

2) Obtain a new much higher capacity storage device.

3) Clone my existing system from the old drive to the new drive

4) Adjust partitions as necessary to take advantage of the new space.


I guess you are running your script like: script.sh dir/ or bash script.sh dir/.

The way you pass the directory is causing the problem.

In your script you got a grep command:

grep -c "Author" $1/*

If you pass the directory with tailing slash, the grep command would be run as:

grep -c "Author" dir//*

Example:

grep -c "Author" dir//somefile.dat dir//someother-file.dat

And its result would be similar to:

dir//somefile.dat:5

And your cut command would only return an empty string and pass it to sort:

dir//somefile.dat:5   # < You are asking for second part which is empty

So either run your script like: script.sh dir or change it to something like this:

#!/bin/bash

DIR=${1%/}
grep -c "Author" ${DIR}/* | cut -d \/ -f 2 | sort -nt':' -k2 | sed 's/.dat:/ /g'


No ethernet connection available in Ubuntu 20.04

i had the same exact issue. i was missing drivers for the Ethernet.
Go to Realtek site from the actual Ethernet provider. Download the "2.5G Ethernet LINUX driver r8125 for kernel up to 5.6" and follow the install instruction.
You should be able to use wired connection once your done.


USB 3.0 ports failing intermittently, other USB ports not working

By itself, modifing the grub had no effect on the performance of the USB ports.

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.autosuspend=-1"
GRUB_CMDLINE_LINUX="acpi=force irqpoll"

However, I finally did what I should have done within 30 seconds of realizing that there was a problem with my USB ports and looked up my motherboard (a gigabyte ga-990fxa-ud3). This thread describes a simple solution to the problem which involves going into the BIOS and setting IOMMU to "Enabled".

Together with the grub options, this took care of the problem.


So it turns out they just didn't want to work with my system. GDM3 and Lightdm and Xinerama "1"...
I removed them and went with KDE. Works great with Xinerama. I am able to set window resolutions for certain applications as well so if you want to play a game you can 5760x1080 a borderless window and bam your in business.
KDE Plasma is pretty good... although I find someitmes apps like slack can freeze occasionally. Chromium is unrunnable. Maybe its my plugins idk. As a dev it might become an issue :S


How set the correct hour in Ubuntu Server?

This is what solved the issue for me:

check for all timezones, and find yours

timedatectl list-timezones

"America/New_York" matches my zone, so I ran this:

sudo timedatectl set-timezone America/New_York

...Then check the date

date

voilá


What does `do-release-upgrade` really do?

do-release-upgrade is part of the package “update-manager-core”. The script seems to determine which release you are going to upgrade to, try to find out if it’s supported or not and complain about the latter. – If it’s convinced to work, it downloads the release-specific UpgradeTool and runs it.

Part of the “update-manager-core” package is the file /etc/update-manager/meta-release, where you can find the URL http://changelogs.ubuntu.com/meta-release and there you find the URL for the UpgradeTool to download.

The downloaded UpgradeTool tarball is packaged from the source package “ubuntu-release-upgrader” (before it was “update-manager”). The version corresponds to the latest updates for the target release.

The source has an old README from warty and hoary release times. It discusses what should be done during a release upgrade. It also mentions a link to a more detailed UpgradeTool proposal.

I list here the actions mentioned there and checked if they are actually implemented:

repository related

switch to new sources.list entries
remove unknown 3rd party repositories
possibly swap mirror (not implemented)

package related

check there are no broken packages before upgrading
update current release before upgrading (apt-get update only)
remove and install specific packages
check if {ubuntu,kubuntu,edubuntu}-desktop is installed
get rid of old kernels
have a removal-blacklist and -whitelist
remove or replace obsolete packages which existed in earlier releases

configuration related (possible in quirks: see below)

adding the default user to new groups (not done for the versions I checked)
check some config files

The UpgradeTool is configured for each release using the following files (open them to see!):

DistUpgrade.cfg

UpgradeTool-related configuration
release-related configuration
repositories (e.g. [Sources] ValidMirrors)
custom changes ([Distro] PostInstallScript)
special packages; processed only by DistUpgradeController.py:

[Distro] RemoveObsoletes, ForcedObsoletes, BaseMetaPkgs, MetaPkgs
[meta_package_name] ForcedObsoletes

...and by DistUpgradeCache.py:

[Distro] MetaPkgs, RemovalBlacklist, RemoveEssentialOk, BadVersions, BaseMetaPkgs, PurgeObsoletes, Demotions, KeyDependencies
[Distro and meta_package_name] KeepInstalledPkgs, KeepInstalledSection, PostUpgrade*
[KernelRemoval] *

DistUpgradeQuirks.py

runs (release) specific functions (same file) and plugins (plugins directory)
functions must have specific names (e.g. from_nattyPreCacheOpen()) and plugins special condition attributes (e.g. * or PostInitialUpdate)
one of those functions, StartUpgrade(), is another grab-bag itself: among others it calls _applyPatches(), which goes over the files in the patches directory
all these do pretty much nothing on my installation (i386, packages not older than natty-updates)

more from DistUpgradeCache.py

runs get_kernel_list.sh (not in trusty) and makes sure one kernel is installed
some handling about Nvidia drivers

Checked versions:

natty → oneiric
oneiric → precise
precise → trusty (final as of 2014-04-18)
trusty → utopic (hours before release on 2014-10-23)


There can be only 4 primary partitions, but there can be many more logical partitions.


How can I specify the default save directory for gnome-screenshot?

For 12.04
Via GUI

Install dconf-editor

From the command line, run the command sudo apt-get install dconf-editor

Or click here to install from the Ubuntu Software Center:

Press Alt + F2 and type dconf-editor

Go to org -> gnome -> gnome-screenshot

At "auto-save-directory" type the desired directory in the following format: file:///home/user/Desktop/

A tip for anyone who is using the configuration editor in unity: click on the arrow to the left the org text to expand it.
Via Terminal
Simply run this command, replacing the path with your preferred directory.
gsettings set org.gnome.gnome-screenshot auto-save-directory "file:///home/$USER/Downloads/"


The ldd results are expected, since the "binary" is just an script:

$ file /usr/bin/wine
/usr/bin/wine: POSIX shell script, ASCII text executable
$ head /usr/bin/wine
#!/bin/sh

set -e

wine=/usr/bin/wine32
if test "$(file -b -L "$1" | cut -d\  -f1)" = "PE32+" -o "$WINEARCH" = "win64"; then
    wine=/usr/bin/wine64
fi

if test -f $wine; then

So, what's the solution? Remove them completely and install them. We don't really know how much damage is there so removing and reinstalling is the most safest:

sudo apt-get autoremove --purge wine

The same with any package that doesn't work. You can verify the package that correspond to the binary using dpkg -S:

➜  ~  dpkg -S /usr/bin/wine
wine: /usr/bin/wine


YouTube annotations not working on Firefox 33.0 (Kubuntu 14.10)

I just upgraded Firefox to 34.0 and annotations began to work, so it might be a bug in the previous version (33.0).


Server: access console output from other TTY/terminal

Thank to user4556274 for the link to tmux,

for all like me who never heard of tmux and the concept of terminal multiplexing.

Is a bit like a window manager for the console. Typical use case it to start working from one place on a remote machine, then move(fly) to another place and reconnect from there to exactly pick up your session from before. So it just covers my use case.
However, in order to work you need to start tmux before you start doing stuff in your session. So if you forget, its no help to get back to the other session.

However, from what I read in the net it seems most people with those kind of use cases seem to get a hang of using tmux as a default.

Note: i found most google results more confusing than helpful. They lost me right away. The one that got me the very brief top-top-top-level overview was this one, maybe its also helpful for others.


Reset hibernation delay from command line

Open a terminal and use the following command to know the preferred action that is set, when your system is idle and on ac power.

$ gsettings get org.gnome.settings-daemon.plugins.power sleep-inactive-ac-type
'suspend'

you can see in my system it is set to suspend.

To change the value to 'hibernate' use the following command in terminal,

$ gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-ac-type 'hibernate'

To know the idle timeout or delay before the preferred action, when your system is idle and on ac power.

$ gsettings get org.gnome.settings-daemon.plugins.power sleep-inactive-ac-timeout
0

In my system the time out is never represented by sleep-inactive-ac-timeout=0.

To change it to 20 min (20x60=1200 sec) use the following command,

$ gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-ac-timeout 1200


You need to select USB boot in your motherboard's BIOS.  Usually there will be a screen that says 'Press Del to enter BIOS, F8 to enter Boot Menu'.  Press whatever key corresponds to the Boot Menu, and then select your USB from that.

Also, make sure your computer's BIOS is configured to boot from USB.  This will be a setting in the BIOS, usually labeled 'Boot Order'.


Cannot delete user - entry missing in /etc/passwd - (networked user)

I just had this issue.
I stopped the following services
systemctl stop ntpd smb winbind

created user:
useradd linuxuser

started the services
systemctl start ntpd smb winbind


I have exactly the same machine - a CLEVO based SCHENKER XMG A704 - this is how it works :

First disable hibernation in Windows - open command prompt as administrator and execute :

powercfg /h off.

Also disable Fast startup in Windows -> open Windows Control Panel (old version) -> Power Settings and uncheck Fast startup. In case that it is not visible, enable show hidden settings.
Shutdown the notebook completely, do NOT reboot it (otherwise it always starts Windows).

Boot from the Ubuntu installation media you created and select Try Ubuntu without installing.
Press the E key and add the parameter nouveau.modeset=0 at the end of the linux line.
Press the F10 key to boot into the Ubuntu Live desktop - start the installation of Ubuntu.

After it is  finished, boot the installed Ubuntu system and select the Ubuntu GRUB menu entry.
Press the E key and add the parameter nouveau.modeset=0 at the end of the linux line.
Press the F10 key to boot into the Ubuntu system and first of all install the NVIDIA drivers.

Reboot the Ubuntu operating system ... now you don't have to add the parameter any more.

Note : Set a Space between the last character in the linux line and nouveau.modeset=0 !
After having installed the Ubuntu system, you have to select Ubuntu as the default system to boot in BIOS/UEFI settings. You can select to boot Windows from the GRUB menu afterwards.


Start asus laptop UX32VD with keyboard backlight off

The following worked for me with the Asus N550JV running Ubuntu 13.10, but I think it may also work for you:

(1) Get full permissions on the file we need to control

Open up a terminal (CONTROL+ALT+T) and copy and paste this entire code block into the terminal:

sudo touch /etc/init.d/asus_kbd_backlight.sh && \
sudo chmod 777 /etc/init.d/asus_kbd_backlight.sh && \
sudo echo /bin/chmod 777 "/sys/class/leds/asus::kbd_backlight/brightness" > /etc/init.d/asus_kbd_backlight.sh && \
sudo chmod 744 /etc/init.d/asus_kbd_backlight.sh && \
sudo chown root:root /etc/init.d/asus_kbd_backlight.sh && \
sudo ln -s /etc/init.d/asus_kbd_backlight.sh /etc/rc2.d/S99asus_kbd_backlight.sh

then press ENTER.  It will prompt you for your password.

(This was taken from LeoR's answer here)

(2) Create a startup script that changes the keyboard brightness

Enter the following command into the terminal:

echo 'echo 0 > /sys/class/leds/asus\:\:kbd_backlight/brightness' > ~/.my_startup_file.sh

(3) Call this script at startup

Open up "Startup Applications" (you can find this by pressing the Superkey to get to the Dash and typing Startup)

Click Add, then enter whatever you want for Name, and "sh /home/username/.my_startup_file.sh" for Command.  Note: do not put "sh ~/.my_startup_file.sh".  For example, my username is garrett, so I put "sh /home/garrett/.my_startup_file.sh".


Java from terminal: "Unable to access jarfile Example.jar"

Yes, to run a jar, it has to exist.

While creating it, you have to match the directory structure to the package structure.

For instance, your directories might be:

/home/ellen/proj/java/foo/example/src/example/Foo.java
/home/ellen/proj/java/foo/example/src/example/util/MyList.java

for sources, and for class-files:

/home/ellen/proj/java/foo/example/classes/example/Foo.class
/home/ellen/proj/java/foo/example/classes/example/util/MyList.class

(often you find classes in a ../bin/.. instead of ../classes/.. named folder or source and class files are mixed in the same directories)

corresponding to a package structure:

package example
package example.util

then you should move to the base directory of the hierarchy:

cd /home/ellen/proj/java/foo/example/classes

or set it with the parameter -C jar -C /home/ellen/proj/java/foo/example/classes ...  or from the home jar -C proj/java/foo/example/classes ... as relative path.

You create the jar file for example with:

jar -cf example.jar *.class

and inspect it with:

jar -tf example.jar

Note that there is a manifest file, automatically generated and useful, as a template, where you can add the information of what your main class is, if you have such, but which is pretty strict about what the syntax is (upper/lower case, line breaks).

Manifest-Version: 1.0
Created-By: 9-internal (Oracle Corporation)
Main-Class: example.Main

Such a main class entry has to be added, if you want to run it without specifying the main class:

java -jar example.jar

or else you have to use:

java -cp example.jar example.Main

In essence, a jar file is a zip archive and can be worked on with these tools.

A clean separation of src/ and bin/ files is useful, when you have more than a handful of classes and probably a deep packet structure.

 jar -cf example.jar -C classes .

will then, starting in the directory classes/ include everything which is often what you want. (example/class, example/util/.class, example/net/*class ...)

 jar --help

informs you about the syntax.


Can't install updates nor plugins for Rhythmbox and other software

I could connect to facebook and google for a moment, now I can't anymore. That's why I asume it's a problem with Ubuntu. I'm using a usb wifi antenna, the brand is D-Link. Yesterday I downloaded the Chrome Installer, but today I attempted to install it and it asked for my password, started the install and finally failed.

The internet connection is fine, I have other PCs at home and they are working just fine, with a usb wifi antenna too.


Ubuntu 16.04.7 server latest package updates/upgrades now cause xpdf segmentation fault

Needed to load these libraries:
libpoppler-glib8 libpoppler58 poppler-utils xdg-utils
xpdf is now working.
Seems xpdf is no longer included in Ubuntu 20.04 ?


How to get global application menu for gvim?

Solution 1: Make the global menu for gvim work

To get global menu for gvim and to get rid of the warning message,
add this to ~/.bashrc and restart the terminal:

function gvim () { (/usr/bin/gvim -f "$@" &) }

Solution 2: Disable global menu for gvim

To just get rid of the warning message, you can disable the global menu, at least for gvim:

How do I enable or disable the global application menu?

Answer #133005 -
Several options for how to disable the global menu

For example, add this to ~/.bashrc and restart the terminal:

alias gvim='UBUNTU_MENUPROXY= gvim'

References

https://bugs.launchpad.net/ubuntu/+source/vim/+bug/972968
https://bugs.launchpad.net/ubuntu/+source/vim/+bug/776499
https://bugs.launchpad.net/ubuntu/+source/vim/+bug/987707
https://askubuntu.com/a/132581


Is a NVIDIA GeForce with Optimus Technology supported by Ubuntu?

Even if the Supported Products tab on the driver download page says that GT420M is supported, the Optimus variants are not supported. From the Additional Information tab:

  Some designs incorporating supported GPUs may not be compatible with the Nvidia Linux driver: in particular, notebook and all-in-one desktop designs with switchable (hybrid) or Optimus graphics will not work if means to disable the integrated graphics in hardware are not available.

This Optimus design means that the discrete Nvidia card is wired into the integrated Intel GPU and that it's not connected to a monitor at all. Some hybrid graphics laptops still allow you to choose the Nvidia card in BIOS, but most modern Optimus laptops don't have this option.

I am speaking from experience, I have a GT425M combined with an i5-460M processor. If there is no BIOS or hardware setting for switching / disabling the card, you're throwing away your money. The XPS 15 family does not appear to have any of these features. Although you are able to use the Intel graphics card, you may want to use the Nvidia card as well because you've paid for it which is not directly possible at the moment.

You'd better look for another laptop without Optimus. Optimus is crap and Nvidia refuses to provide better support for Linux. If you are adventurous and buy such a notebook, visit the Linux Hybrid Graphics blog and subscribe to its Launchpad mailing list. Visit their wiki for various ways to get such a card (hopefully) working. One method is called Bumblebee which allows you to render programs on your nvidia card. I currently recommend it over other solutions (disclosure: I'm a developer of it).

Ubuntu 12.10 Quantal will be shipped with the first bits for real support for hybrid graphics laptops, called PRIME. This is highly experimental and in development and probably not stable enough for many people. Only the open-source graphics drivers support this, though Nvidia may release support in the future too if it is not too much work for them. This page tracks hybrid graphics support for Quantal, these are the blueprints for Raring.

If you've installed the driver from nvidia.com

You've made a huge mistake by installing the drivers directly from nvidia.com. If you want to have newer drivers, add the ubuntu-x-swat/x-updates PPA because these will install the nvidia drivers in such a way that your Optimus system does not die.

After installing the nvidia driver from nvidia.com, you may experience loss of all graphics effects, black screen or very slow graphics performance. Uninstallation instructions:

Boot into recovery mode by holding Shift before booting and choosing for the recovery option
In the following menu, choose for netroot.
Uninstall nvidia:

nvidia-uninstall

Remove the configuration file generated by nvidia if any:

rm /etc/X11/xorg.conf

Reinstall the Mesa package for GL:

apt-get --reinstall install libgl1-mesa-glx

When done, reboot with:

reboot

Installation instructions for Bumblebee

If you have installed Bumblebee or Ironhide before, be sure to check the instructions on http://wiki.bumblebee-project.org/Upgrading-on-Ubuntu

Since Bumblebee version 3.0 "Tumbleweed", it can disable the Nvidia card in a safe way to save power (press release). You can also run programs using the discrete card for better performance. Installation instructions:

Enable the Universe and multiverse repository for the Nvidia driver.
1.(optional for 13.10 Saucy) Add a PPA containing recent drivers as the one in the repositories is possibly outdated:

sudo add-apt-repository ppa:ubuntu-x-swat/x-updates

(for 13.04 Raring and earlier, not needed for Saucy and later) Add the Stable Bumblebee Releases PPA:

sudo add-apt-repository ppa:bumblebee/stable
sudo apt-get update

Install Bumblebee using the proprietary Nvidia driver:

sudo apt-get install bumblebee bumblebee-nvidia linux-headers-generic

Reboot or re-login to apply the group changes

If you'd like to run a program on the nvidia card now, use the optirun program:

optirun firefox &

If you are only interested in power savings, replace the last command in step 4 by:

sudo apt-get install --no-install-recommends bumblebee linux-headers-generic

At a later time, you can still use NVIDIA by installing bumblebee-nvidia. If you want to use a 32-bit program, you can still install the required libraries with sudo apt-get install virtualgl-libs-ia32. You have to add linux-headers-generic, otherwise the power saving module bbswitch cannot be built.

Instead of virtualgl, you can also try primus to achieve better performance. The package name is primus and you can use:

primusrun glxgears
# alternative that is nearly the same:
optirun -b primus glxgears

(note: before asking about a 60 fps limit, please read its FAQ.)

See also https://wiki.ubuntu.com/Bumblebee

Notes:

Using acpi_call manually is deprecated. By default, it won't survive suspend.
Do not use ppa:mj-casalogic/bumblebee or the MrMEEE/bumblebee-Old-and-abandoned git, it's not maintained anymore and contains a lot of errors.
Martin Juhl forked the original Bumblebee to Ironhide, but in my opinion it should not be used because the design flaws from the original Bumblebee are still present and the "power management" features are not stable (the wrong methods, _ON and _OFF, are used). Installation is still a mess, your installation may be broken after removing it.

If you do not want to use the nvidia card nor Bumblebee

If you've accidentally installed the nvidia driver (i.e. using the jockey), you've two choices:

Uninstall the driver (package nvidia-current)
Set the default OpenGL libraries as described in this bugreport


How to position windows with compizconfig-settings-manager

.

A) How do I calculate X and Y coordinates?
Start from 0,0 (upper left) and move the desire number of pixels across for the first starting coordinate, then down for the second starting coordinate.

B) Is (0,0) the upper left?
Yes.

C) How (to) calculate coordinates for a window to be positioned in the lower right of my screen?
Your screen resolution minus one is the bottom right; if your screen is set to 1920x1280 then bottom right is (1919,1279). Subtract the size of the desired window from that value for the start coordinates; for example, if you want a 320x180 window positioned at bottom right, it would start at ((1919-320),(1279-180)) or (1599,1099). Don't forget, if you use a bottom panel, to offset for its height as well.


you should actually resize the left pane and make it big enough so it moves your chats to the right

see screenshots below:


comment in the out-commented swap-related line in /etc/fstab:
sed -i '/ swap / s/^#\(.*\)$/\1/g' /etc/fstab

then enable swap again:
swapon -a -v

Option -v tell you more about, whether or not the operation was succesfully


How do I rescue files from the encrypted home folder via live USB stick?

I basically followed this tutorial step by step and then some. For the case that this other site will vanish in the future, I copy the basics here:

Start the computer with a live CD.
Start the terminal and run:

sudo ecryptfs-recover-private

My system was now searching for an encrypted directory. This took about 10 minutes. Maybe five. I didn't watch the whole time.
When it is done, you are asked if you want to try to recover the directory. The directory has the username somewhere in it. I affirmed and went on.
In the next step, I was asked for my login passphrase. That one I still had. So I entered it.
After a few seconds, my encrypted directory with all my treasures in it was mounted in the /tmp/ directory. But I still wasn't able to access it simply with a file manager. So I ran nautilus with root rights by pressing Alt+F2 and entering:

gksu nautilus

Like this, I could open the folder in /tmp/ and copy everything onto my external hard drive.


Upstart job: Pass command with escaped quotes to the exec stanza

The key is in the program that issued the error message: /bin/sh. The sh shell's quoting rules don't recognize "\"". See man sh. Use single quote "'" instead.

exec /srv/l4d2/srcds_run -game left4dead2 -tickrate 30 -maxplayers 8 -ip 192.168.1.1 "+map 'c1m1_hotel versus'" +exec server.cfg


Installing with Software Centre vs apt-get

Ubuntu Software application installation

The Ubuntu Software application has a Graphical User Interface to let you search for programs and give you some information about them, but when you click the 'install' button it is basically running the command sudo apt-get install packagename

As Mark Kirby & JonasCz have already stated, installing from the Ubuntu Software application or typing the sudo apt-get install command are just two different ways of doing the same thing.

One advantage of the GUI method is that it will place a launcher icon of your newly installed program into the Unity launcher for you.

If you use the sudo apt-get install command, and then want the Launcher icon for the program in the Unity Launcher, you need to search for the program with the Dash and then drag it onto the Launcher yourself.

In this case, it would appear that TexMaker and 'texlive-full' are different programs and would have different Launcher icons, so the TexMaker icon from your first Ubuntu Software installation of the program will continue to launch TexMaker and will not have been replaced by 'texlive-full'.

[Incidentally, it's possible that the program TeXstudio (found in Ubuntu Software) may have the functionality that you are after]

Edit:
Upon further investigation (I'm unfamiliar with TexMaker & 'texlive-full') it seems that 'texlive-full' is described as 'TeX Live: metapackage pulling in all components of TeX Live'. Whether this means it installs a separate program called 'Tex Live' or is supposed to add some functionality to TexMaker is unclear to me. There is no mention of 'TexMaker' in the Texlive package information: http://packages.ubuntu.com/xenial/texlive-full

Further Edit: Nick Weimberg has a much clearer explanation in the comments: "TexMaker is a GUI program for writing LaTeX. TexLive is a collection of LaTeX packages that don't include a GUI, but are required for much LaTeX functionality. They are separate software programs and separate packages" - A program that doesn't have a GUI will not always have a Launcher, in which case you would run the program from the Terminal - a command such as programname --help or man programname should inform you of how to use it

Getting the Launcher Icon after a sudo apt-get install command

Open the Unity Dash by clicking the Ubuntu Icon at the top of the Launcher or by pressing the 'Super' key.

The 'Super' key is the 'Windows' key on most PC's or the 'Command' key on a Mac.

If you type the name of the program you just installed into the dash ('tex' should be close enough for it to find it) it should show an icon that you can select to launch the program right there and then. You can also drag the icon onto the Launcher to keep it in the Launcher for easy access.

If you can't find your program by typing the name into the Dash, then at the bottom of the 'Dash page' are a couple of different icons: 'Home', 'Applications', 'Files', 'Videos', 'Music', 'Photos'.

Selecting 'Applications' will let you browse through all your installed applications and you should be able to find it there.

The quickest way to go straight to searching through your applications is to hold Super + A at the same time.


Does rEFInd have a "recovery mode" like there is in Grub2

First, understand that when booting Linux, various options are passed to the kernel to modify how it acts. In most cases it's necessary to pass a root= option to identify where the root (/) filesystem resides. It's common to pass other options, too, although the details vary from one distribution and installation to another. Boot managers, including both GRUB and rEFInd, provide menus that enable you to pass different collections of options by selecting them from menus. For simplicity, the menus seldom show you the details of the options; instead, they summarize the options with names, like "boot 4.2.0 normally" or "boot 4.2.3 in recovery mode." You must examine the boot loader's configuration file to decipher what options any given menu entry passes. Thus, the GRUB "recovery mode" option isn't a GRUB feature per se; it's just a menu entry that boots Linux with extra (and/or omitted) options.

I just checked the GRUB entry for a (pre-release) Xenial installation I happen to have running, and its "recovery" entry specifies, in addition to a root= option, ro recovery nomodeset. To duplicate this in rEFInd, you can do either of two things:

You can hit F2 or Insert twice to enter the boot options editor, and modify the options appropriately. You must ensure that ro recovery nomodeset is present. Depending on the configuration, you might want to remove the quiet splash options, too. You should not modify the root= option or the initrd= option, though.
You can edit /boot/refind_linux.conf and create a new entry (or modify an existing one) that makes equivalent changes to the boot options. This entry will then become available when you hit F2 or Insert once at the rEFInd menu.

The first approach is usable on any system using rEFInd and launching Linux kernels directly (unless the relevant features have been disabled in refind.conf); but manually entering the options is a nuisance. The second option is more convenient if you want to enter this mode even remotely frequently.

Unfortunately, recovery features vary greatly from one distribution to another, which is why this isn't part of rEFInd's standard configuration. rEFInd does provide a "single-user" option in its default menu. This option passes single to the kernel, which tells it to boot into single-user mode. This is more standard than the Ubuntu-specific "recovery mode," but I doubt if it does the same thing. (I honestly have never used Ubuntu's "recovery mode.")

Oh, and rEFInd's shell feature launches an EFI shell; but the shell is a separate EFI binary that you must install yourself. The EFI shell enables you to run arbitrary EFI programs, edit files, etc.

Incidentally, the keyboard issues you note represent quirks of some Macs' (and some other computers') keyboards; the function keys on some keyboards do double duty as something else, such as to control volume, screen brightness, etc. Such keyboards have a "Fn" key to toggle between use as a traditional function key and to control the media (or whatever). This type of setup is most common on laptops, but I've seen a few USB keyboards with similar setups. On some keyboards the function key is the default and other times the media-control function is the default.


Installing tar.gz when there is no configure file

Either this actually contains the binaries, or it uses cmake for it's build system. Try going into the directory and typing cmake .


I am not sure if my answer satisfies you: I have a Acer T231H and updated Ubuntu Oneiric, 32 bit:

The xorg with all applications works out-of-box with one touch point.
Qt4 multitouch demos work out-of-box with 2 fingers.
You can get multitouch work somehow with ginn (translates multitouch gestures into keyboard commands+mouse clicks to the applications)

sudo apt-get install ginn

I don't know if ginn is run after restart automatically. At least I had to start it manually after installation:

ginn

You can tweak the parameters+add more programs:

sudo nano /etc/ginn/wishes.xml


Don't feel bad, we've all been or are all still somewhat noobish at using the terminal. Also, love your use of the term right serious muddle.

All right, down to business :D

Question: Does your PC already have the /dev/sda7 partition created?

Answers:

1) As for how to move the /home partition permanently, read this guide https://help.ubuntu.com/community/Partitioning/Home/Moving and this question: How can I move my /home directory to another partition if it's already part of the / partition?

from the guide:

  This guide offers detailed instructions for migrating your home
  directory into its own dedicated partition.

2) Simple: (do all of this after the previous steps)

Just create the tarball on the original PC (seperate PCs, correct?) and move it over to your current PC with something like a USB stick or data CD.
Extract the tarball on the current PC in the /home folder while deleting the old files (keeping the ones you want, if any)


Usb wifi dropped out / rtl8192eu-linux-driver on UBUNTU 16.04

If you have internet access by any other means (wired or through USB tethering), you can installed the RTL8192EU drivers from Mange's GitHub repo. Here are the steps as described on the GitHub page:
Building and installing using DKMS

Install DKMS and other required tools:
sudo apt-get install git linux-headers-generic build-essential dkms

Clone this repository and change your directory to cloned path.
git clone https://github.com/Mange/rtl8192eu-linux-driver
cd rtl8192eu-linux-driver

Add the driver to DKMS. This will copy the source to a system directory so that it can used to rebuild the module on kernel upgrades.
sudo dkms add .

Build and install the driver.
sudo dkms install rtl8192eu/1.0

Distributions based on Debian & Ubuntu have RTL8XXXU driver present & running in kernelspace. To use our RTL8192EU driver, we need to blacklist RTL8XXXU.
echo "blacklist rtl8xxxu" | sudo tee /etc/modprobe.d/rtl8xxxu.conf

Force RTL8192EU Driver to be active from boot.
echo -e "8192eu\n\nloop" | sudo tee -a /etc/modules

Newer versions of Ubuntu has weird plugging/replugging issue (Check #94). This includes weird idling issues, To fix this:
echo "options 8192eu rtw_power_mgnt=0 rtw_enusbss=0" | sudo tee /etc/modprobe.d/8192eu.conf

Update changes to Grub & initramfs
sudo update-grub; sudo update-initramfs -u

Reboot system to load new changes from newly generated initramfs.
systemctl reboot -i

After the reboot, you can check that your kernel has loaded the right module:
sudo lshw -c network

You should see the line driver=8192eu


SSH connection can be established but sftp connection is denied via terminal or any client

Because into your configuration has a custom ssh port - 4422, you must provide it within the sftp command, for example:

sftp -P 4422 user@1.2.3.4


How to backup the whole desktop — without backing up junk?

You might look at a combination of Backups (Déjà Dup) for your /home, and Timeshift for the system stuff. Otherwise, use Macrium Reflect to clone your entire disk/partition.

The closest thing to a Windows-like restore point is by using Timeshift. I use it to save snapshots to an external USB hard drive. Although it can, it's normally not used for backing up your /home directory, just system-level changes. Use Backups (Déjà Dup) for backing up /home files.

Timeshift is a system restore utility which takes snapshots
of the system at regular intervals. These snapshots can be restored
at a later date to undo system changes. Creates incremental snapshots
using rsync or BTRFS snapshots using BTRFS tools.

More information at https://github.com/teejee2008/timeshift

For pre-19.04 users, add the PPA:

sudo add-apt-repository -y ppa:teejee2008/ppa

And install with:

sudo apt update
sudo apt install timeshift


Evolution keeps asking me for password authentication (gnome shell)

This is a known Bug, see here

I looked through some of the comments and there are a few proposed workarounds.

Remove the account:
Not really a solution. Nevertheless: Go to Settings, Accounts, select the perpetrator and click on remove. A notable alternative E-Mail client is Thunderbird.
Set the period for checking for new mail:
Go to Settings, Accounts, select the culprit, click edit and set the "Check new email every ... minutes" setting to some random time other than "Default", after this you will reportedly be asked for the password only once, right after login.
Reset your keyrings, reinstall Seahorse:
Remove everything in ~/.gnome2/keyrings/, uninstall Seahorse, reboot, enter the password when Evolution asks for it, close Evolution, reinstall Seahorse, open Evolution again, enter the password again, this time Evolutions should remember it. Detailed instructions here. Be careful though, resetting your keyring might not be something you want to do.
Install patches:
This one and this one. I haven't tested them though and the comment is from 2014, and I encountered this bug in 2016 (on Ubuntu 14.04, admittedly), so they might be already incorporated in the official releases and might not actually solve the issue.
Read the comments on the bugtracker:
There are more suggestions for solutions and workarounds in the page linked above, If you're not happy with the points listed here, you might find one that works for you there.


How can I add more space for indicators?

The area will autoadjust in size based on the amount of indicators you have loaded, so the more you add it will just grow.

See this list for a list of available indicators:

What Application Indicators are available?


How to install .deb packages in a custom folder different from root (/) using dpkg?

You probably looking for this:
dpkg-deb -x $YourDebFile $TARGET_DIRECTORY

# Example
dpkg-deb -x <file_name>.deb /opt/corbos-linux/2.4.4/sysroots/x86_64-pokysdk-linux/

Found Here

Update:
---
You can install all `.deb` packages with simple command-line loop.
For Example, this is your current "files and folders" and you want to install all these .deb files to /home/username/testing/ directory:
some_deb_file.deb
another_file.deb
other/
testing/

For this you can run these commands:
ls -1 | grep [.]deb >> all_debs.txt
cat all_debs.txt | while read fn; do dpkg-deb -x $fn /home/username/testing; done
rm all_debs.txt

Code Explanation:

We create all_debs.txt file with all .deb file names inside it. In our case file will look like this: NOTE: If your one package depends on another one, then you can edit this file and order the file names as you want.

some_deb_file.deb
another_file.deb

We loop inside file, taking line ("file name"), and installing it using dpkg-deb -x <file_name> <path> structure.
Deleting file that we created at the beginning.

One line code for nerds :) :
ls -1 | grep [.]deb >> all_debs.txt && cat all_debs.txt | while read fn; do dpkg-deb -x $fn /home/username/testing; done && rm all_debs.txt

Hope it helps! Have a great day! :D


If your "new space" is the result of a new install on a larger hard disk, and you haven't synchronized with U1 on that install yet, then simply logging into U1 there should result in everything under the ~/Ubuntu One folder being downloaded again, and if they were in a separate folder which you synchronized, you simply have to select in the control panel to have that folder synchronized again.

If on the other hand, it is the same install you were using before, and you simply disconnected/uninstalled Ubuntu One, then deleted the folder/files in question, the files may be deleted from the server if you just log in and start syncing again. In this case, I'd recommend running these commands in a terminal:

$: u1sdtool -q
$: pkill -9 ubuntuone
$: mv ~/.local/share/ubuntuone/syncdaemon ~/.local/share/ubuntuone/syncdaemon.old
$: u1sdtool -c

This will stop ubuntuone-syncdaemon, move the metadata out of the way, and restart ubuntuone-syncdaemon and connect. When connected, it should just re-download everything, and if you have any conflicting files in ~/Ubuntu One, or other synchronized folders, create conflict files for them.

If neither of these solutions work, and the files do end up getting deleted from the Web UI view, then ensure the client is fully synchronized with the server (all synchronized folders have the same files and those files are the same in both places), then open a support ticket at https://one.ubuntu.com/help/contact to get more help.


How do you import music on mp3 at 320 kbps in banshee, or any other media player?

I'm assuming you're referring to importing audio from CDs, because importing digital music from your filesystem into Banshee shouldn't change the bitrate.

Open Edit > Preferences
From the Source Specific tab, set the Source to "Audio CDs"
With "MP3 (LAME Encoder)" selected, click the "Edit" button
From there, you should be able to set the bitrate to something higher, like 320kbps


How do I list the content of a directory in the terminal without a command?

He types cp /path/ and then repeatedly presses Tab to get the contents of the directory displayed.


From https://github.com/dequis/purple-facebook/wiki :

The purple-facebook plugin is a replacement for the builtin Facebook XMPP plugin. Facebook is in the process of shutting down their XMPP service, which will inevitably break existing support.

As part of Google Summer of Code (GSoC) 2015, jgeboski worked on a plugin for libpurple to support the newer Facebook Messenger protocol. The plugin is implemented for the development version of libpurple, purple3, which has yet to be released. The purple-facebook project simply back-ports the purple3 plugin to purple2, which is the released version of libpurple.

As of October 18, 2015, jgeboski's GSoC work was merged into the mainline Pidgin project. It will appear in the next major release of Pidgin.

Install instructions:

Add the following line to /etc/apt/sources.list.d/jgeboski.list:

  deb http://download.opensuse.org/repositories/home:/jgeboski/
  ./

Notes:

In this case, replace  with your Ubuntu version: trusty

  deb http://download.opensuse.org/repositories/home:/jgeboski/trusty
  ./

Add the repository key:

  $ wget -O- https://jgeboski.github.io/obs.key | sudo apt-key add -

Update the package index:

  sudo apt-get update

Install the plugin:

  sudo apt-get install


Remove unneeded files from /lib/firmware

You can check the firmware that is used for your system in the kernel log.

grep firmware /var/log/kernel.log

will give you a nice list of firmware that was loaded since the last log rotation (could be several days)

However since i first posted this, I learned that most of the firmware will be loaded by initrd and that usually does not generate a logfile of what it is doing.


slow wifi internet when connected to other bluetooth device

This can be fixed by running in terminal

sudo tee /etc/modprobe.d/iwlwifi-opt.conf <<< "options iwlwifi bt_coex_active=0"

Then reboot and test.


I would like to set 127.0.0.1 in my resolv.conf

You need it in /etc/hosts, not /etc/resolv.conf.

And your host name should already appear in /etc/hosts.

What does it say when you run this from the terminal?

grep '127.0.1.1' /etc/hosts

What about:

cat /etc/hostname


After kernel upgrade, unable to boot with / on lvm

There is a typo in the kernel line for the new entry; it should be:

kernel   /vmlinuz-2.6.32-42-generic root=/dev/mapper/smallvg-filesystemlv ro quiet splash

You have omitted the bolded mapper part!


The settings of Kile (and probably most other KDE apps and KDE itself) are usually stored in the directory .kde/share/config.

To specifically answer your question, I think the settings of Kile are stored in .kde/share/config/kilerc.


Cannot SSH into Ubuntu14.04 Server Remotely

Thanks to muru for this part

Firstly, the ListenAddress syntax is not a pipe-separated list.  You'll need two lines.  For example:

Port 22
ListenAddress InternetIP
ListenAddress ServerIP

The next consideration point is that you need to use port forwarding if your server is behind NAT or a router.  This will need to be configured at your router or firewall device, in order to get from the Internet (Public) IP to the internal (private) IP address of your server.

NOTE: This is NOT the same as an 'allow' rule in the firewall on the server.


How to open an URL from command line to Firefox and "switch to tab"?

You can do it like:
firefox -new-tab "www.duckduckgo.com"


Software & Updates (software-properties-gtk): 'EOFError: marshal data too short'

There are two problems:

GPG missing key error on the http://dl.bintray.com repository
EOFError: marshal data too short when Python3 tries to import urllib to launch software-properties-gtk (the "Software & Updates" settings window)

To resolve the GPG error, please follow @GAD3R's answer or any answer to How do I fix the GPG error "NO_PUBKEY"?

You decided to remove this repository from your software sources, which is also ok if you don't need it any more.

To resolve the Python EOFError, we need to eliminate some *.pyc files. Those are compiled byte code of a script, which gets dynamically created when a Python script runs to speed up future launches. They are faulty and don't match the original script any more for whatever reason. We can simply delete them as they are not really needed and will be recreated on the next launch.

We don't want a massacre but a small and effective removal of the faulty files only. Therefore we look at the error traceback from the software-properties-gtk output and find out that this error always happens when Python 3.4 tries to import urllib.parse. To avoid follow-up errors we simply remove all *.pyc files related to Python 3.4's urllib module:

sudo rm -r /usr/lib/python3.4/urllib/__pycache__


Install adblock using synaptic or through firefox's addons menu?

The version in the Ubuntu repositories will only receive bug fixes during a release cycle, not new features. This version has been tested with your version of Firefox, and is fairly stable.

If you use the unpackaged version via Mozilla Addons or elsewhere, it'll receive all new updates by the maintainer of the addon. These may cause breakage, depending on the level of testing upstream puts their code through. In Adblock's case, I suspect the level of QA is high, so this is not a very pressing concern, but one to take into account nevertheless.

Firefox will refuse to install a newer version of the addon if said version no longer supports your browser version, so you don't have to worry about that.

The main difference is that the Ubuntu-packaged version is feature-stable (its behavior does not change) as well as reliability-stable (it will work consistently) throughout the release, whereas you don't get those guarantees from using AdBlock's extention installed externally.

If you're installing it for more than one user, by all means, use the packaged version. But if it's just for you, I think the locally installed version is fine.


You'll need to install an app called pavucontrol and use it to set the default device for Skype to that headset.


Ubuntu 14.04 - install color scheme for ssh client terminal

Your .bashrc file is not sourced when you log in via ssh. You can load your .bashrc using the following command

source ~/.bashrc

See also this answer from Ayman Hourieh for a more permanent fix.


I founded this workaround - not sure if it works

  As many of you know, Steam on GNU/Linux is coming with some bundled libraries in case the system does not have them, and some of the bundled libraries or drivers are outdated. As a workaround, just delete the files Steam says are broken; this will force Steam to use the system's libs and drivers.

Related to the post you can try (better do an backup before)

rm ~/.local/share/Steam/ubuntu12_32/steam-runtime/i386/lib/i386-linux-gnu/libgcc_s.so.1

  You might have to do this two times, each time representing a different lib.


First remove sudo apt-get remove tlp

install cpu-freq:-

cd && wget -O .laptop-mode.sh http://drive.noobslab.com/data/improve-battery/laptop-mode

chmod +x .laptop-mode.sh && ./.laptop-mode.sh

If You running GPU Nvidia/AMD change setting to Intel Mode.


How to subtract two time stamps along with their dates in bash?

You can use date to convert to timestamp which is seconds, subtract the seconds and then convert back to HH:MM:SS.

Unfortunately, date doesn't read the specified format, so we need to turn around the DD.MM.YYYY to YYYY-MM-DD.

{
A="04.07.2019 23:29:40"
B="05.07.2019 01:15:52"

# Create a function to change DD.MM.YYYY HH:MM:SS to YYYY-MM-DD HH:MM:SS.
convert_date(){ printf '%s-%s-%s %s' ${1:6:4} ${1:3:2} ${1:0:2} ${1:11:8}; }

# Convert to timestamp
A_TS=$(date -d "$(convert_date "$A")" +%s)
B_TS=$(date -d "$(convert_date "$B")" +%s)

# Subtract
DIFF=$((B_TS-A_TS))

# convert to HH:MM:SS (note, that if it's more than one day, it will be wrong!)
TZ=UTC date -d @$DIFF +%H:%M:%S
}

Output:

01:46:12

Using a more general function to subtract the dates:

diff_dates(){
    TS1=$(date -d "$1" +%s)
    TS2=$(date -d "$2" +%s)
    [ $TS2 -ge $TS1 ] \
        && TZ=UTC date -d @$((TS2-TS1)) +%H:%M:%S \
        || TZ=UTC date -d @$((TS1-TS2)) +-%H:%M:%S
}

convert_date(){
    printf '%s-%s-%s %s' ${1:6:4} ${1:3:2} ${1:0:2} ${1:11:8};
}

Usage:

$ A="04.07.2019 23:29:40"
$ B="05.07.2019 01:15:52"
$ diff_dates "$(convert_date "$A")" "$(convert_date "$B")"
01:46:12

or if you already have date-compatible dates:

$ diff_dates "2019-07-04 23:29:40" "2019-07-05 01:15:52"
01:46:12
$ diff_dates "2019-07-05 01:15:52" "2019-07-04 23:29:40"
-01:46:12


Always get permission denied on tar. cannot mkdir: permission denied on my kafka installation

Finally (big thanks to @matigo), After do research, i change the permission on my windows into my users settings to full control, i do this with right click and setting on security based on this article https://www.laptopmag.com/articles/take-ownership-folder-windows-10-using-file-explorer


Windows 7 and Ubuntu 10.10 network controller driver conflict?

In my case, it works well on Ubuntu 10.10 but Win 7 cannot recognize the card. The solution is to cold reboot and wait for a few minutes then turn on and boot into Win 7 ( I googled somewhere but now I forgot). According to some explanation, Ubuntu loads some kind of firmware into the card that Win 7 cannot recognize. Anyway, it worked for me.


How to "remove software from Launchpad PPA" in order to do-release-upgrade?

Referring to your comment about ppa:dhor/myway
The following command line can be used to remove the PPA (the option -r causes removal),
sudo add-apt-repository -r ppa:dhor/myway
sudo apt-get update

Your comment about .../webupd8team/java/ubuntu xenial main
deb http://ppa.launchpad.net/webupd8team/java/ubuntu xenial main

corresponds to (can be removed with)
sudo add-apt-repository -r ppa:webupd8team/java
sudo apt-get update

Please notice that this PPA is discontinued.


ls and cd give no output when used with sudo

The -i option causes sudo to run the command in the shell specified by the target user's (in this case, root's) login shell, as you can confirm for example by running

$ sudo -i sh -c 'echo $HOME'
/root

So it is telling you there is no Downloads directory in root's home. If you want to run commands as root but in the invoking user's environment, use sudo -s instead.


Safety difference between adding a PPA and manually installing a deb package

If you trust the provider, it's OK to install from PPA. The advantage of getting software from PPA is that you get automatic updates, which doesn't happen if you install from a Debian (.deb) package.

About security, there isn't much difference between one method and another. If you install an X package through PPA using apt-get, what happens is basically the download of its .deb and its installation with dpkg.

So, overall, it's better to use PPA over manual installation, due to automatic updates.


Let me suggest you have HelloWorld.class file inside some directory. To run it, you simply should type in this directory:

java HelloWorld

To run jar archive, use -jar key:

java -jar MyProgram.jar

To select java machine, type:

sudo update-alternatives --config java

To install Oracle JDK:

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-jdk7-installer

After installation, you can select it as default java.


Login SSH with .ppk file on Ubuntu Terminal

If you only have .ppk file then it would be useful to create a .pem file and then connect to your server using that.

In you Ubuntu computer, install putty-tools with the following command:

sudo apt-get install putty-tools

Now convert your .ppk file to .pem using the following command:

puttygen yourkey.ppk -O private-openssh -o yourkey.pem

Set the proper permission to use the .pem file with following command:

chmod 400 yourkey.pem

Now connect to your server using the below command:

ssh -i yourkey.pem serverusername@server-ip

Hope it helps.


ubuntu 18.04 boot error ucsi_acpi USBC000:00: PPM init failed (-110)

I installed the latest Nvidia drivers (nvidia-440) for my GPU from tty and the problem solved.


Recovering thunderbird files from quick formatted drive?

I don't know what you need to make such a "recipe" but by default your Thunderbird profile is stored in /home/username/.thunderbird (where username is your username)

Inside this folder will be another folder named with a random-looking alphanumeric string and the extension of .default.  This is your profile folder and contains all your email.


BIOS

You have BIOS N1GET34W (1.11).

Current BIOS is N1GETA0W (1.79). Go to here to download the newer version.

swap

Your /swapfile may be a bit small for your working environment. Let's increase it from 2G to 4G.

Note: Incorrect use of the dd command can cause data loss. Suggest copy/paste.

sudo swapoff -a           # turn off swap
sudo rm -i /swapfile      # remove old /swapfile

sudo dd if=/dev/zero of=/swapfile bs=1M count=4096

sudo chmod 600 /swapfile  # set proper file protections
sudo mkswap /swapfile     # init /swapfile
sudo swapon /swapfile     # turn on swap
free -h                   # confirm 8G RAM and 4G swap
reboot                    # reboot and verify operation


VLC not playing DVD and can't install libdvd-pkg in 20.10

libdvd-pkg is in the multiverse repository; you need to enable that.
:~$apt policy libdvd-pkg
libdvd-pkg:
  Installed: 1.4.2-1-1
  Candidate: 1.4.2-1-1
  Version table:
 *** 1.4.2-1-1 500
        500 [redacted]/us.archive.ubuntu.com/ubuntu bionic/multiverse amd64 Packages
        500 [redacted]/us.archive.ubuntu.com/ubuntu bionic/multiverse i386 Packages
        100 /var/lib/dpkg/status

On my system (not 20.10) this can be done on the "Software and Updates" page.

After enabling multiverse, you will have to enter the following two commands one by one.
sudo apt install libdvd-pkg
sudo dpkg-reconfigure libdvd-pkg


How should I divide my free disk space to setup (swap for) Ubuntu?

I installed Ubuntu multiple time on multiple devices.
and every time I installed Ubuntu on 50 GB free space and made 1GB for swap.
while I install Ubuntu I manually divide my hard drive to get the best specification and settings for me making two partitions one for SWAP and the other for Ubuntu.


This is going to be rather technical but was fun to find out so here goes...

I found a package dphys-swapfile and here is the Source code. Option setup is used to set it up:

setup - tells dphys-swapfile  to compute the optimal swap file size and
(re-)generate an fitting swap file. Default it 2 times RAM size.
This  can  be called at boot time, so the file allways stays the
right size for current RAM, or run by hand whenever RAM size has
changed.

Inside dphys-swapfile is a setting conf_swapsize for a pre-defined size (in Natty this is empty):

size we want to force it to be, default (empty) gives 2*RAM
CONF_SWAPSIZE=

and a setting for a swapfactor...

this is what we want, 2 times RAM size
SWAPFACTOR=2

The actual size is calculated a bit further on:

if [ "${CONF_SWAPSIZE}" = "" ] ; then
  # compute automatic optimal size
  echo -n "computing size, "
  # this seems to be the nearest to physical RAM size, lacks about 60k
  KCORESIZE="`ls -l /proc/kcore | awk '{ print $5 }'`"
  # make MBytes which rounded down will be exactly 1 too few, so add 1
  MEMSIZE="`expr "${KCORESIZE}" / 1048576 + 1`"
  # default, without config file overwriding, swap=2*RAM
  CONF_SWAPSIZE="`expr "${MEMSIZE}" '*' "${SWAPFACTOR}"`"
fi

As you can see the way they calculate it in this package depends on the size of /proc/kcore, then gets divided by 1048576, +1 to round it up and then gets multiplied by swapfactor. From my machine:

So the default for this system would be 1065349120 / 1048576 = 1015+1 = 1016 * 2 = 2032 MBytes.


I dont want to see any folder or application on desktop

To do from cli use-
gsettings set org.gnome.desktop.background show-desktop-icons false

else you can do it directly by serching dconf editor in dash then navigate to
org-gnome-desktop-background

and then uncheck show-desktop icon .
If you cant see the image ,just right click on it and save it and then see.


Can't comment on the previous answer (lack of rep), but to add on to Kam's answer above, you can download the notify-osd .deb file from here, for me I just installed the daily one.

Run sudo dpkg -i filename.deb and you'll find that it'll immediately work with your existing NotifyOSDConfig installed. This will "downgrade" notify-osd (as shown in output), and therefore you will need to blacklist notify-osd from auto-upgrades like the other answer mentioned.


Rebooting the system where virt-manager is installed solved the issue.


I want to go back to ubuntu from elementary OS

I don't know pantheon but if it is a DE as you say, and you just installed it, as you also say, it should just be a matter of selecting the DE you prefer from the "display manager", aka the graphical login screen, assuming you have one. There should be a drop down menu on it somewhere allowing you to select DE. Installing a DE doesn't uninstall other DEs. Not normally at least. If you don't use a display manager, like light-dm or whatever, but start you gui with startx from the command line, try looking at the man page for the DE you like. It will probably tell you what to append to startx to boot into it. If you start the gui one of the other ways, I can't help you.


Ubuntu loads Unity 2D rather than Unity 3D

Answer from a comment to the question:

  Usually the problems occur when openGL support does not work. Please
  check the output of glxinfo | grep rendering - there should appear
  direct rendering: yes - further you can test opengl-support with glxgears. Then you should see rotating gears. If one of this does
  not wort, reinstall your graphics driver. I suggest to install the
  proprietary Nvidia driver as I described here in this
  question


Install the following package:

sudo apt-get install winbind

Edit the file /etc/nsswitch.conf and add wins to the line

hosts:          files mdns4_minimal [NOTFOUND=return] dns mdns4

-->

hosts:          files mdns4_minimal wins [NOTFOUND=return] dns mdns4

Now you should be able to ping your windows hosts using the netbios name.


How to change xfce4.8 windows buttons horizontal size?

The button size is dynamic and they reduce their size alone while the bar is filling. If you want you can insert a separator on each side of the application buttons bar and with the global size reduced the button size will be reduced.


Screen timeout for Ubuntu Server login screen

You can set a boot command line parameter consoleblank to do it. Save a copy of /etc/default/grub first, then add this:
GRUB_CMDLINE_LINUX_DEFAULT="consoleblank=450"

and remember to run sudo update-grub afterwards, then re-boot. the example is for 7.5 minutes. If you already have items on the command line then just add this one. Exmaple:
GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1 consoleblank=450 intel_pstate=passive intel_pstate=no_hwp msr.allow_writes=on cpuidle.governor=teo"

Note that console blanking used to be the default, but it was changed some years ago now to not blank after some time by default.


How to display things programmatically in the panel?

It is called unity indicator. There is page on Ubuntu website: appindicator. Have a look on it. I think it gives you enough information.


How do you make Ubuntu accept files sent over bluetooth

Go to Dash Home search for personal file sharing. If you don't have Unity installed, you can open the program from a terminal with typing gnome-file-share-properties in it.

At the bottom of the box enable Receive files in downloads folder over bluetooth also enable Notify about received file then you're good to go :)


How can I set up postfix without the need of a relayhost?

It sounds like you're talking about two different things.

If you need to configure a relayhost, it is because outgoing access to port 25 has been blocked by your ISP.  Given that the mail servers listen on port 25 by convention, you will almost certainly have to use a relay host of some variety.

My guess as to what the person at the help desk was suggesting was that if you wanted to contact a particular mail server outside the ISP's firewalls, then that mail server should be configured to listen on a second port.  Some reasons you might want to do this is if your company required that all mail be sent via their servers, or you'd set up restrictive SPF rules such that mail sent via your ISP would be rejected.  One thing to keep in mind here though, is that this would just be trading one relay host for another.

If you don't have such an external mail server in mind, then the suggestion about changing the port doesn't really apply.  In that case, relaying via your ISP's mail server is probably the best option.


install open icon library in ubuntu 10.04

You need to check with the installation notes provided with download, other wise most of the time these work fine.

If you have downloaded the .tar.bz2 file, then first place(copy) it where you want to extract, for example on desktop.

Then extract the file by right clicking on the file and select " Extract Here", or from the terminal by giving the command

$ tar xjf file.tar.bz2

Now move in to the folder created, for example

$ cd /home/yourusername/Desktop/folder name

$ ./configure

$ make

$ make install

Use sudo where ever it says permissions denied.


PID's associated with Chromium multiple tabs and windows?

The Chromium browser indeed uses different processes to render your opened tabs:

$ps -aef
[...]
sylvain   6432  2223 20 11:19 ?        00:00:02 chromium-browser --enable-pinch
sylvain   6441  6432  0 11:19 ?        00:00:00 /usr/lib/chromium-browser/chrome-sandbox /usr/lib/chromium-browser/chromium-browser --type=zygote
sylvain   6442  6441  1 11:19 ?        00:00:00 chromium-browser --type=zygote
sylvain   6446  6442  0 11:19 ?        00:00:00 chromium-browser --type=zygote
sylvain   6469  6432  8 11:19 ?        00:00:00 chromium-browser --type=gpu-process --channel=6432.0.2058149686 --supports-dual-gpus=false --gpu-driver-bug-workarounds=1,11,13,15 --disable-accelerated-video-decode --gpu-vendor-
sylvain   6489  6446  1 11:19 ?        00:00:00 /usr/lib/chromium-browser/chro
sylvain   6509  6469  0 11:19 ?        00:00:00 chromium-browser --type=gpu-broker
root      6516     2  0 11:19 ?        00:00:00 [kworker/0:0]
sylvain   6517  6446 10 11:19 ?        00:00:00 /usr/lib/chromium-browser/chro
sylvain   6541  6446  5 11:20 ?        00:00:00 /usr/lib/chromium-browser/chro

In the above example pid 6517 and 6541 are my opened tabs, but like you netstat only returns one network process for Chromium (6432):

$ sudo netstat -tulpn
[sudo] password for sylvain:
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 127.0.1.1:53            0.0.0.0:*               LISTEN      1966/dnsmasq
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      3804/cupsd
tcp        0      0 0.0.0.0:538             0.0.0.0:*               LISTEN      1363/gdomap
tcp6       0      0 ::1:631                 :::*                    LISTEN      3804/cupsd
udp        0      0 0.0.0.0:45410           0.0.0.0:*                           2158/dhclient
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           6432/chromium-brows
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           933/avahi-daemon: r
udp        0      0 127.0.1.1:53            0.0.0.0:*                           1966/dnsmasq
udp        0      0 0.0.0.0:68              0.0.0.0:*                           2158/dhclient
udp        0      0 0.0.0.0:68              0.0.0.0:*                           1715/dhclient
udp        0      0 192.168.1.36:123        0.0.0.0:*                           2956/ntpd
udp        0      0 192.168.1.40:123        0.0.0.0:*                           2956/ntpd
udp        0      0 127.0.0.1:123           0.0.0.0:*                           2956/ntpd
udp        0      0 0.0.0.0:123             0.0.0.0:*                           2956/ntpd
udp        0      0 0.0.0.0:49400           0.0.0.0:*                           933/avahi-daemon: r
udp        0      0 0.0.0.0:538             0.0.0.0:*                           1363/gdomap
udp        0      0 0.0.0.0:631             0.0.0.0:*                           1187/cups-browsed
udp        0      0 0.0.0.0:10080           0.0.0.0:*                           1715/dhclient
udp6       0      0 :::60417                :::*                                933/avahi-daemon: r
udp6       0      0 :::5353                 :::*                                933/avahi-daemon: r
udp6       0      0 :::47845                :::*                                2158/dhclient
udp6       0      0 :::8012                 :::*                                1715/dhclient
udp6       0      0 fe80::3ea9:f4ff:fe1:123 :::*                                2956/ntpd
udp6       0      0 fe80::3e97:eff:fe81:123 :::*                                2956/ntpd
udp6       0      0 ::1:123                 :::*                                2956/ntpd
udp6       0      0 :::123                  :::*                                2956/ntpd

So why?

Chromium uses a multi-process architecture, which isolates render processes from the browser process but...
Chromium maintains a single instance of the resource dispatcher, which is shared across all render processes, and runs within the browser kernel process.
Each render process communicates with the resource dispatcher via IPC.

Sources:

Chrome network architecture in a nutshell
Chromium Inter-process Communication (IPC)


Unable to install new apps after upgrading to 20.04

How do I remove a malformed line from my sources.list?
this thread answered the questions that i had.
I am rather inexperienced in linux as well. I ran into the same issue as you after attempting to install WINE.
I did as one user suggested and used
sudoedit /etc/apt/sources.list
to make edits while in the terminal. Then found line 52 in the sources list and removed it completely.
Then ran
sudo apt-get upgrade
just to make sure everything was fixed.


Can't capture video with cheese. Ubuntu 12.10

I've expirienced exactly the same problems both with cheese and guvcview using Assus N43SN webcam this morning and with bit of research it came out that the issues is related to this one: cheese crashed with SIGSEGV in GI_libc_free().

So installing the missing dependency package gstreamer1.0-pulseaudio solved the problem for me.

To install the package run the following in your terminal, to open the terminal hit Ctrl+Alt+T:

sudo apt-get install gstreamer1.0-pulseaudio

Good luck!


Eclipse not running after upgrading to Oracle JDK 1.7?

It looks like you are running Eclipse 3.7, based on the release notes, it doesn't seem to support Java 7 (1.7.0_09), try 1.6.0_37.

http://www.eclipse.org/eclipse/development/readme_eclipse_3.7.html


Piped commands run with sudo prefix result in indented output

It looks like the issue is related to setting Defaults use_pty in /etc/sudoers, which was added for CIS hardening. Upon commenting out that line the server no longer has the indentation issue.
$ sudo lsb_release -a | cat
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.5 LTS
Release:    18.04
Codename:   bionic

Reading through https://www.sudo.ws/legacy.html, I suspect updating sudo to a newer release will fix the issue.
e.g. this change looks promising

Major changes between version 1.8.27 and 1.8.26:
[...]
If an I/O logging plugin is configured but the plugin does not actually log any I/O, sudo will no longer force the command to be run in a pseudo-tty.


Unable to access desktop after latest NVIDIA update - 14.10

If your computer is configured such that you are offered a purple screen at boot time with choices to boot a previous version, you may be able to boot successfully, and once in, uninstall or alter your nvidia drivers.  I've read that if you are not automatically offered that menu, that booting with the shift key held down will force that menu to appear.

If you need help reconfiguring or disabling your nvidia drivers I can offer you tips which have worked for me though I don't claim to be an expert.


external usb hard drive is not being seen anymore

It sounds like the state of the USB hardware isn't being properly initialized (in the USB logic in the enclosure). I suspect once you've fully booted Ubuntu, if you power cycle your enclosure, give it a few seconds, then plug it in over USB, that you'll be able to use it normally. If not, please post the last 30 lines or so of "dmesg" from about 10 seconds after plugging the drive in.

I suppose it's remotely possible this could be a missing kernel module too, but I really doubt that.


Error using SpeedFan - how can I control fan speed?

SpeedFan is a Windows-only program. It will not work in Linux. There is an application in the default Ubuntu repositories that has similar functionality to SpeedFan called Psensor. Psensor is an application for monitoring hardware sensors, including temperatures and fan speeds.
Install Psensor. Also install lm-sensors to detect your computer's hardware sensors, and detect your computer's hardware sensors by running these commands:
sudo apt install psensor lm-sensors
sudo sensors-detect

Then you will get asked a lot of questions about what hardware you want the program to detect.  It is generally safe and recommended to accept the default answers to all questions, unless you know what you're doing.
In Ubuntu 16.04 and later Psensor detects your computer's hardware sensors automatically without running sudo sensors-detect
Psensor displays itself on the desktop as a little thermometer icon in the notification area in the upper right corner of the desktop. You can right-click the thermometer icon at any time to display the hardware temperatures.


Unsigned repositories after running apt-get update (16.04)

I had accidentally littered busybox symlinks around my own filesystem. This caused apt-key's gpgv-method to fail and that caused the key errors.


My mistake guys: from pavucontrol, Notification Sounds were turned off.