How to report a bug and contribute a fix for juju

There are several starting points worth checking out: README.md and CONTRIBUTING.md files in the juju-core source (https://github.com/juju/juju) explain how to install and build juju from source and set up your Github account as needed. Whenever you have a question, there are several ways to get in touch with the juju-core team:

on IRC channels #juju-dev and #juju on FreeNode (most developers hang out there daily);
subscribe and send questions to the users and developers mailing lists (juju@lists.ubuntu.com and juju-dev@lists.ubuntu.com);
checking AskUbuntu for questions which might be relevant (a lot of team members answer questions tagged with "juju" regularly);
searching and reporting juju-core bugs on Launchpad (https://bugs.launchpad.net/juju-core) or (if you don't have a LP account - https://github.com/juju/juju/issues).

For more detailed answers to the typical steps in the workflow (file a bug, propose a patch, get code review, submit the patch), take a look at Juju @ github – The Life of a Bugfix.

In the near future some steps of the process will be automated and get easier for contributors, so in the mean time I hope this helps!


How to go back to node version 5 from node version 6?

you can use n module to help you achieve change,upgrade and remove node versions.
Start by installing the n package

$ sudo npm install -g n

after that you can install many version of node as you like and activate only one of the using the cmd :

$ n  v5.11.1

this will either activate the v5.11.1 version if you already install it , or if it doesn't find it it will install and activate it to be the current version that you will work with


Terminal copy and paste commands: Break of consistency

This shortcut existed in terminals as an interrupt shortcut far before the era of graphical interfaces and copy/paste.

However, I understand your frustration. When switching from GUI universes like Windows and years of copy/pasting with Ctrl+c it's difficult to change your habits.

Depending on the terminal software you use, you can change this comportement and swap the usage of Ctrl+c and Ctrl+Shift+ c.

Alternative solution you can use like I did the Autokey software to achieve this.

  AutoKey is a desktop automation utility for Linux and X11. It allows you to manage collection of scripts and phrases, and assign abbreviations and hotkeys to these. This allows you to execute a script or insert text on demand in whatever program you are using.

When you create a new entry in Autokey, choose Script
In the textarea, paste : keyboard.send_keys("<shift>+<ctrl>+c")
In the Hotkey input field, select Ctrl+c
In the Window filter, select your terminal emulator by clicking on Set, then Detect window properties, then clicking on your terminal app, and finally by choosing "Window class". It will restrict this hotkey to these categories of windows.

You can do also the same, for Ctrl+v and Ctrl+Shift+c

I was a heavy user of Autohotkey on Windows. Autokey is far less powerful and is badly unmaintained since years. However, on my distribution (Xubuntu), it still works partially, and I use it mainly for text expanding and to override shortcut definitions in applications.


Found the answer!  I had to delete the ".curlew" directory out of my home folder.  Apparently the settings from Xenial didn't carry forward properly to Bionic.  Deleting, and allowing curlew to rebuild it fixed the problem.


If you have a list of files to download, just save it as a file (let’s call it files.txt) and then run this command:

< files.txt xargs -I{} wget https://s3.amazonaws.com/edx-course-spdx-kiczales/HTC/{}

  So what would the approach be, on Linux/Ubuntu, for downloading the files with the AWS CLI?

There is a lot of ways with wget being one of the most basic ones.

  but secondly, can this be done with just a bash script?

Why, if a single command can do this?

  Is there a way to print all the files in a directory if you only have access to the files?

If the owner is blocking that (as in this case), you cannot do it simply. How did you get the list of files you presented in your question actually?

  I would love if there was a bulk approach to downloading files from a (AWS) server.

You are barking up the wrong tree, you should ask the owner of the server instance. You cannot easily access any Linux server in the world just by knowing it is a Linux server. Yes, there are black-hat hackers trying to do so but Linux is designed to be secure, so not allowing that.


Mount Network Shares for Plex - Ubuntu 16.04LTS

The way you entered username and password looks incorrect to me.
Your fstab line to mount a CIFS volume should read:

//nas.local/video/Movies /home/magwezie/Plex/Movies cifs rw,username=xxx,password=xxx 0 0

The mount options should be separated by , (not space), their names and values should be separated by = (not :). You may also include the last two parameters – dump and pass but they’re optional. They should be both 0 (default value) for a network drive.

See man fstab for details (emphasis mine):

  The fourth field (fs_mntops).

  This field describes the mount options associated with the filesystem.

  It is formatted as a comma-separated list of options. It contains at least the
  type of mount (ro or rw), plus any additional options appropriate to the filesystem
  type  (including performance-tuning options). For details, see mount(8) or swapon(8).

Look also at man mount.cifs to see how individual options should be formatted, e.g.:

username=arg

  specifies the username to connect as. If this is not given, then the environment variable USER is used.

Host identification – another possible problem

Moreover, I recommend using IP address instead of a hostname like nas.local. The hostname in the local network might be discovered later and not be available during boot.


PlayOnLinux displays weird looking window on 18.04 for MS Office installation

This might be a bug in the MS Office install script or particular wine version / used library.

You can have a workaround: After you created a drive go to options with highlighted virtual drive and hit Open a shell button.

From that shell window run wine setup.exe and see if your window renders correctly.

PlayOnLinux downloads and uses an older wine version for its Word 2010 setup by default and your system may have a different wine version which can cause the graphics to load incorrectly, try to change it in the settings of your virtual drive in PlayOnLinux from configure -> Office2010 -> General -> Wine version


You need to run this command:

gsettings set com.canonical.Unity.Panel systray-whitelist "$(gsettings get com.canonical.Unity.Panel systray-whitelist | sed -e "s:\[:\['gcdemu' ,:")"

which will add cdemu application to Unity panel whitelist.


Performance improvement of Ubuntu on soc board

as @Aditya Patil suggest the best way is to install everything on ssd.
But if you doesn't want to re-install ubuntu u can move some directory on otherpartition.

To do this I suggest you to start a live cd , then mount two disk in this way:
(I suppose sda are your standard disk and sdb the ssd disk)

mkdir standard-disk
mount /dev/sda1 standard-disk
mkdir quick-disk
mount /dev/sdb1 quick-disk
cp -vfr standard-disk/usr/* quick-disk/
rm -vfr standard-disk/usr

Then modify the standard-disk/etc/fstab file adding this line

/dev/sdb1  /usr ext4 defaults,noatime 0 2

Obiouvsly you can repeat this action for other partition; for example if your /dev/sda2 is your home dir you can move it to /dev/sdb2, then add a fstab line like above.


The permissions of /var/www can be found by executing the command:

stat -c "%a %n" /var/www/ It returns 755 /wav/www/

Owner can read and write and execute, Group can read and execute, and Others can read and execute.

But root owns /var/www so you either have to be root to add files, or change the permissions so anyone can write.

See this answer for more details what those permission actually mean.


Ubuntu touch - How to open .doc word documents in googlemail

Document Viewer can open doc files, but only latest few versions. If you already have Document Viewer which doesn't work, try updating it first.


Assuming creating a new xorg.conf file would help, try the following:

Xorg -configure

After your xorg.conf file is created successfully, you can follow the steps your document is referring to.

P.S. More information about your operating system and what you've tried so far may be helpful to share here if this doesn't work.


Is there a graphical ssh-agent in 10.04 LTS Server?

The program your coworker is looking for is ssh-askpass:

  under X, asks user for a passphrase for ssh-add

This is integrated into Gnome in the package ssh-askpass-gnome (which will interface with Gnome Keyring, so you can save the ssh key decryption password in the keyring, and it will be supplied as needed) - note that it should already be installed if the metapackage ubuntu-desktop is.


Should I download Java's tar.gz or rpm to do offline java installation?

RPM is Redhat, Fedore, CentOS so unusable.

You need, preferably, a DEB version or otherwise the tar.gz version.

I would advicw to use a personal archive as explained here:http://www.webupd8.org/2012/06/how-to-install-oracle-java-7-in-debian.html

Install method for java 7:

su -
echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee -a /etc/apt/sources.list
echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu precise main" | tee -a /etc/apt/sources.list
apt-key adv --keyserver keyserver.ubuntu.com --recv-keys EEA14886
apt-get update
apt-get install oracle-java7-installer
exit

You can then install this...

sudo apt-get install oracle-java7-set-default

"To automatically set up the Java 7 environment variables"


First set any color from settings>background>background>color

I use https://www.color-hex.com/ this website for choosing colors.

then run below commands

gsettings set org.gnome.desktop.background color-shading-type 'horizontal'

you may put 'vertical' also

gsettings set org.gnome.desktop.background primary-color '#456789'
gsettings set org.gnome.desktop.background secondary-color '#000000'

Example

pratap@pratap:~$ gsettings set org.gnome.desktop.background color-shading-type 'horizontal'
pratap@pratap:~$ gsettings set org.gnome.desktop.background primary-color '#456789'
pratap@pratap:~$ gsettings set org.gnome.desktop.background secondary-color '#000000'
pratap@pratap:~$

replace any color you want in above commands.

Horizontal Grading

Vertical Grading


Laptop screen blank after suspend, though external monitors working

open a terminal, and use xrandr command to get identity of displays:

$ xrandr

Screen 0: minimum 320 x 200, current 2304 x 2048
LVDS-1 connected primary 1366x768+417+1280 ...
VGA-1 connected 1280x1024+1024+256 ...
HDMI-1 connected 1024x1280+0+0 left ...
tell xrandr to revive laptop screen

$ xrandr --output "LVDS-1" --auto

By the way, often laptop screen and external monitors are all blank on resume from suspend, when the system requires a password. It seems that nothing will revive the screen. It is possible to enter the password blindly, and the screens will come on. But you might be able to revive the screens so you can see what you are doing when entering the password, by pressing the "Fn" key.


It seems this is possible. There's too much to post here, but there's a lenghty tutorial, with videos on the LoL forums. This method uses Wine to run the game.


Problem installing Java using Software Center and Terminal

If you need more information about installing java here is the documentation

I supposed that you mean the Oracle (Sun) Java 6

Do the following if you are planning to install the jre

$ wget http://download.oracle.com/otn-pub/java/jdk/6u34-b04/jre-6u34-linux-i586.bin
 $ chmod u+x jre-6u34-linux-i586.bin
 $ ./jre-6u34-linux-i586.bin
 $ sudo mkdir -p /usr/lib/jvm
 $ sudo mv jre1.6.0_34 /usr/lib/jvm/
 $ sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jre1.6.0_34/bin/java" 1
 $ sudo update-alternatives --install "/usr/lib/mozilla/plugins/libjavaplugin.so" "mozilla-javaplugin.so" "/usr/lib/jvm/jre1.6.0_34/lib/i386/libnpjp2.so" 1
 $ sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/lib/jvm/jre1.6.0_34/bin/javaws" 1

If you are planning to install the oracle java 6 jdk 32-bit

$ wget http://download.oracle.com/otn-pub/java/jdk/6u34-b04/jdk-6u34-linux-i586.bin
 $ chmod u+x jdk-6u34-linux-i586.bin
 $ ./jdk-6u34-linux-i586.bin
 $ sudo mkdir -p /usr/lib/jvm
 $ sudo mv jdk1.6.0_34 /usr/lib/jvm/
 $ sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.6.0_34/bin/java" 1
 $ sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.6.0_34/bin/javac" 1
 $ sudo update-alternatives --install "/usr/lib/mozilla/plugins/libjavaplugin.so" "mozilla-javaplugin.so" "/usr/lib/jvm/jdk1.6.0_34/jre/lib/i386/libnpjp2.so" 1
 $ sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/lib/jvm/jre1.6.0_34/bin/javaws" 1

And this important

 $ sudo update-alternatives --config java
 $ sudo update-alternatives --config javac
 $ sudo update-alternatives --config mozilla-javaplugin.so
 $ sudo update-alternatives --config javaws


Simply use the date command to redirect into file and it will be created:

date > example.txt

A prefered way would using the >> append operator:

date >> example.txt

Both the redirection operator (>) and the append operator (>>) will create the target file if it doesn't exist. You never need to create it first and write to it later.


Unable to connect to wireless network on my sony F15218 laptop with ubuntu 12.04 lts 64 bit

Run in the terminal:

echo "blacklist brcmutil" | sudo tee -a /etc/modprobe.d/blacklist.conf

Then:

sudo gedit etc/modules

and  from that file remove brcmutil then save the file and reboot.

Reset the modem and router remove your network from network manager and reboot the computer to allow network manager to find your network.


Why can't I completely remove any applications?

this has just worked for me:

sudo dpkg --purge [package name]


use the WUBI installer to install Ubuntu thru Windows 8 there is an excellent guide at this link
http://apcmag.com/how-to-dual-boot-windows-8-and-linux.htm
then get the WUBi installer at UBUNTU
and double click and follow the instructions
you might also consider AOMEI as partitioner and partition a separate drive for WUBI to install on


how to rename wlp2s0 to wlan0 in ubuntu 17.04

To get an ethX and wlanX back, edit the grub file.

$ sudo nano /etc/default/grub

Look for GRUB_CMDLINE_LINUX and add the following net.ifnames=0 biosdevname=0.

From:

 GRUB_CMDLINE_LINUX=""

To:

 GRUB_CMDLINE_LINUX="net.ifnames=0 biosdevname=0"

Generate a new grub file using the following command.

$ sudo grub-mkconfig -o /boot/grub/grub.cfg

Generating grub configuration file ...
Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported.
Found linux image: /boot/vmlinuz-4.4.0-15-generic
Found initrd image: /boot/initrd.img-4.4.0-15-generic
Found memtest86+ image: /memtest86+.elf
Found memtest86+ image: /memtest86+.bin
done

Restart PC


How do I start x11vnc via bash script on startup, not login?

Assuming that you can create a script that does the operations you would like to do at startup you can then:
 1. Create the script (e.g. runX11vnc.sh)
 2. Copy the script to /etc/init.d
 3. Run the following commands:
sudo update-rc.d runX11vnc.sh defaults
sudo chmod +x /etc/init.d/runX11vnc.sh

The script should now run on startup.


Is there a way to find the executable name for an application so I can launch it in a terminal?

(1) If you know the name of the program

Try on the command line:

find /usr -name 'evince'

Most programs are in the /usr/bin directory.

Then you can type on the command line:

/usr/bin/evince

This will start the evince program.

To know the hierarchy of the Linux filesystem (what is where) you can check the page about the Linux Filesystem Hierarchy on The Linux Documentation Project site

(2) If you don't know the name of the program.

Step 1: Open a terminal and list all running processes with their PID - process identifier number:

ps -e

Step 2: Start your program

Step 3: Switch to the terminal and type again:

ps -e

Step 4: Trial and error to find the process of your program.

Ubuntuone-syncd is in both lists with PID 2911. Ps is the process of the ps⁻command in the terminal. There are three possibilities left:update-notifier, aptd and evince.

On the command line for those 3 possibilities

man name_of_the_process

or

info name_of_the_process

or

name_of_the_process -h

Replace name_of_the_process by the real process name.

In this case if we type

evince -h

we get:

So evince is the GNOME Document Viewer we were looking for.


dpkg-reconfigure grub-pc no option to select boot device

This appears to be due to a change introduced to avoid potential corrupted systems.  I've filed a bug report about this as this just bit me during a RAID failure.
Update: The bug has been confirmed and triaged as high priority against basically all supported versions of Ubuntu.
Update #2: Fix has been released for Focal and Groovy!  I'm hoping someone on the Ubuntu team is tracking Bionic.
Update #3: Fix has been released for Bionic!


You can run a nmap scan (from inside and outside your LAN) and see if you can access the ports your server is listening on are available from outside

sudo apt install nmap #to install nmap
nmap -p 32400,32469,7003,17500,445,1093,139,5900 YOUR_SERVERS_IP_ADDRESS

then you can list your iptables rules to see if there are ports blocked from your firewall

sudo iptables -L

if so, you can add your services using ufw (Documentation) profiles (one for Plex media server) or just specify the ports manually an open them.


Hidden files is just for files which start with a period. That does not help.

There are tools to recover images, I think it was PhotoRec that I used successfully in the past.

The less you use that partition, the greater your chances that your files are still there.

Could it be that you enabled volume compression in the NTFS options?


In extended desktop mode, the computer sees multiple monitors as a single large desktop. If your window manager places desktop icons on the left, then they will jump to the far left-hand monitor.

However, if you use KDE as your desktop manager/window manager, you can use "FolderView" as your desktop setting. This way, you can arrange icons exactly as you wish on either monitor and they will stay put.

I have tried most of the major desktop environments, including Cinnamon, Gnome 2, Gnome Classic (Gnome-Session-Fallback), Gnome 3, KDE, LXDE, MATE, Unity, and Xfce. Among these, KDE is the only one I have tried that enables me to use my right-hand monitor as the primary display while also keeping my desktop icons on the right-hand display.

If you want to stay with Xfce, a workaround I have used in that desktop environment is to install screenlets and use the folderview screenlet to put a window on my right-hand monitor that is set to the Desktop folder. This way, I can see the icons that are on the far-left in the screenlet window. With this screenlet, I can also open, copy, paste, or delete files that appear in the Desktop folder.


"Apply" button stays grey in Synaptic Package Manager

is a synaptic known bug please simply select an app to install and you can apply changes


I too am frustrated with this and have not found a way to truly disable, though I know of a quicker way to reset. Instead of going to view you can go to the bottom of the screen beside your scale % and there is a xx.xx° which can be clicked and you can click reset or what I do, 0 then Enter on numpad (a bit quicker for me)


LAMP charm in a LXC container configuration query

"It also allows you to specify a Bazaar branch. It will clone the branch into the webserver and copy the contents to /var/www"

By this I meant the /var/www inside the instance. the instance is contained nwithin a lxc container. To access this juju ssh into the instance:

  juju ssh lamp/0

then check /var/www inside the instance. Your laptops /var/www will not be created


Unable to burn because of medium write error

Memorex media tends to give a lot of errors on Macintosh computers. I highly suggest going out and purchasing some Verbatim DVD's. They are reliable and tend to work with success most of the time.


[UEFI][GRUB] Boot repair keeps adding MokManager.efi to boot menu

First, know that MokManager.efi is a tool for managing Machine Owner Keys (MOKs), which are Secure Boot keys used by Shim to enable you to boot OSes of your choice when Secure Boot is active. If Secure Boot is active on your computer, you probably should have MokManager installed and accessible from GRUB, so that you can boot emergency tools of your choice should the need arise. If Secure Boot is inactive or unsupported on your computer, MokManager is dead weight -- but it's not a lot of dead weight, so I wouldn't worry too much about it. (You'll find far more useless cruft in any out-of-the-box Linux distribution, and few people go digging through all those files to clean it out.)

That said, my guess is that Boot Repair is finding the MokManager.efi binary in files installed from the shim package. Specifically, the file is /usr/lib/shim/MokManager.efi.signed (it's renamed to omit the .signed extension when it's copied to the ESP). If you really don't need Secure Boot, you could try removing that package -- but other packages may depend on it, so you may need to remove more than just that one. OTOH, if you're running Boot Repair from a live CD, it's conceivable that it's pulling MokManager from there rather than from your regular installation, so removing the files from your regular installation may be ineffective. For similar reasons, editing your local GRUB configuration files might not do much good.

  Placed the memtest86+, config, System.map, initrd and vmlinuz files in both, /boot and /boot/efi of the FAT32 boot partition.

The "FAT32 boot partition" is known as the EFI System Partition (ESP). If you're using GRUB, there's no need to copy most of those files to the ESP, and certainly not to the boot or boot/efi directory on that partition. Neither of those directories exists by default on the ESP. Note, though, that the ESP is normally mounted at /boot/efi, so from your description, you may have copied those files to /boot in your normal Ubuntu distribution and/or to the root of the ESP. (It's critical to understand mount points when dealing with the ESP. The EFI may see a file as fs0:\EFI\ubuntu\grubx64.efi, but that file would likely be /boot/efi/EFI/ubuntu/grubx64.efi in Ubuntu. You "erase" the mount point from the complete Ubuntu file path to determine where the file is on the partition itself. The EFI has no idea of what the Ubuntu mount point is, and so accesses the file without using the Ubuntu mount point.)

Of those files, most of them belong in the Ubuntu /boot directory, which is not on the ESP. (In some cases, /boot is a separate partition itself.) Various memtest86+* files should go in /boot, too, placed there automatically by the memtest86+ package. There should be no need to adjust any of these. If you've been copying those files to achieve some specific goal, perhaps you should share that goal, since it's unlikely that you're doing the right thing unless you've omitted some critical details (such as if you're planning to use gummiboot/systemd-boot on your computer).

Generally speaking, all of this stuff should Just Work. If it's not working, then something is wrong, and the actions you've described are unlikely to help, so knowing what's wrong is critical for helping you. If you simply want to remove MokManager from your GRUB menu, I recommend you not bother -- and if you insist on trying, copying your kernel and other files will not help; you need to adjust the GRUB configuration files and run update-grub. (I'm afraid I don't know precisely what you'd do to remove MokManager.) Alternatively, you could switch from GRUB to any of the several other EFI boot loaders for Linux.


Using Hibernation in Ubuntu 19.04 (not enough swap file)

Hibernation requires swap space on a separate partition. Although it also can work on a swap file, the swap file must be contiguous and the offsets indicating the physical location of the file must be specified, so setup is more complex.

If you want to try hibernation, create a swap partition first. The size of the swap partition should be at least the size of your computer RAM: hibernation involves that all content of RAM is written out to SWAP space before the system shuts down; on restart, the contents os read again from the SWAP space into RAM.

Be aware that hibernation may not work properly on your computer, even if you have set up proper SWAP space. This is because computer manufacturers tend not to document how they implemented power management. As a result, hibernate does not work well on quite a lot of hardware.


Dual booting Ubuntu 12.04: UEFI and Legacy

This is probably a Secure Boot issue, at least in part. (Selecting the correct EFI-mode boot option may be part of the issue, too.) On the one system I've got that can handle Secure Boot, enabling it and trying to boot from a disc that can boot in either EFI or BIOS mode, but without a valid Secure Boot signature, results in a BIOS-mode boot, even if I tell the computer to boot in EFI mode. This behavior exactly matches your description of what's happening to you. Furthermore, you say this is a new computer with Windows 8 installed, which means that it almost certainly shipped with Secure Boot active.

If I'm right, you have three options for how to proceed:

Disable Secure Boot in your firmware -- this is the easiest method if you're familiar with setting basic firmware options, but you'll need to track down the right  one.
Install using a distribution that's been signed with a Secure Boot key -- Ubuntu 12.04's installer has not been so signed, AFAIK, but I suspect that Ubuntu 12.10's has been. I'm not positive of that, though. (I've not yet tested it on my Secure Boot-capable PC.) Fedora 18 is supposed to be signed, but it's not yet been released, and I'm not sure of the status of whatever pre-release version is out there.
Create your own Secure Boot keys, sign everything yourself, and use Secure Boot in that way. This is the hardest approach by far.

For more information on all of these approaches, see this Web page I wrote on the subject. Note that the Web page says nothing about OS installation. Most of the issues and procedures would be the same for OS installation as for anything else, but modifying files on an installation CD is trickier than modifying files on a USB flash drive, so keep that in mind when you're considering your options.

Addition: I can think of a number of reasons why you might be getting an "Operating system not found" message even when booting in EFI mode with Secure Boot disabled. I suggest you check the following:

Check your Secure Boot setting again. Yes, I know you said you've disabled it, but firmware settings can be tricky sometimes. It's worth double-checking.
Using gdisk or parted, verify that the USB drive you're using has a valid GUID Partition Table (GPT) with an EFI System Partition (ESP; identified as partition type code EF00 in gdisk, or by a "boot" flag in parted). If the disk uses an MBR partition table, a fussy firmware might reject it. Likewise if it lacks an ESP.
If the disk uses a hybrid optical disc/hard disk configuration (as some installation disk images do), it could be that a fussy firmware will reject it. In this case, backing it up, creating a fresh GPT on the disk with a new ESP, and restoring everything on a file-by-file basis might get it working.
Mount the ESP and look for a file called EFI/BOOT/bootx64.efi. (Case shouldn't matter; but see below.) This is the boot loader file. If it's absent, the disk won't boot. You'll need to figure out what happened to the file and restore it.
Although the FAT filesystem used on ESPs is case-insensitive, I've encountered one badly broken EFI with case sensitivity issues. Messing with the filename case might fix it, but there are a lot of possible variants.
Check that the ESP uses FAT32, not FAT16. Most EFIs seem to be happy with both, but the spec does say the ESP should be FAT32, and I know of one implementation that's unhappy with a FAT16 ESP.

You could also try booting something else in EFI mode. One possibility is rEFInd, which is an EFI boot loader that, if you can get it to boot, it may be able to detect and run the Ubuntu installer's boot loader. There's a CD image of rEFInd, but that really is a CD image, not a USB image. To create a USB image, you'd need to download the binary file and install it manually. Tip: There's a new install.sh script that's available here. (It's destined for the next release, but that release isn't finalized yet.) This version of the script includes a new option, --usedefault, that can be used to help create a bootable USB flash drive. You'd use it like this:

sudo ./install.sh --usedefault /dev/sdc1

This example should create an EFI-bootable USB flash drive on /dev/sdc1, provided that partition is an ESP on the USB flash drive. Note that you must partition the disk and create a FAT ESP before running install.sh.

One more possibility is to install in BIOS mode and then sort it out later. You can install rEFInd, gummiboot, or an EFI-enabled version of GRUB after installing in BIOS mode. You might need to jump through some hoops with renaming boot loaders to get things working, but if you can't get your installer to boot in EFI mode, this may be your only option.


Bluetooth and wifi are not working in ubuntu 20.04

Get this Intel utility which tests compatibility.
https://downloadcenter.intel.com/download/26735/Intel-System-Support-Utility-for-the-Linux-Operating-System
It will tell you whether any Intel based card is compatible.  NO AX200 chip-based card is compatible.  I've tried 2 now.  Canonical really screwed the pooch with the 20.04 release.


What does this `iptables -t filter -X` command mean

All of this is answered by the manpage (see man iptables on the command line):

-F, --flush [chain]
    Flush the selected chain (all the chains in the table if none is given).
    This is equivalent to deleting all the rules one by one.

-X, --delete-chain [chain]
    Delete the optional user-defined chain specified. There must be no references
    to the chain. If there are, you must delete or replace the referring rules
    before the chain can be deleted. The chain must be empty, i.e. not contain any
    rules If no argument is given, it will attempt to delete every non-builtin
    chain in the table.

And though you didn't ask, the small bit on -t here (I remvoed a large portion of the data here, because it can all be read in man iptables):

-t, --table table
    This option specifies the packet matching table which the command should
    operate on. If the kernel is configured with automatic module loading,
    an attempt will be made to load the appropriate module for that table if it
    is not already there.


Could not open directory '.dbus/': Permission denied

It seems like your ~/.dbus/ folder is owned by root instead of by your own user.

If this is the case, you can:

Remove that folder, using:

sudo rm -rf ~/.dbus

Or:

Change the ownership to your-username / your-user-group using:

sudo chown -R your-user-name.your-user-group-name ~/.dbus/

Note: replace your-user-name.your-user-group-name with the actual values, e.g. if your user is sal and your group is also sal than it will be: sal.sal

As @Pablo Bianchi added in the comments below, $USER environment variable holds your-user-name (and in Ubuntu your-group-name is usually equal to your username) hence in most cases you can run the following command:

    sudo chown -R $USER.$USER ~/.dbus/

More info regarding Ubuntu environment variables can be found here


What is 'AHCI mode' - HP ProLiant MicroServer Gen8

AHCI is the standard interface for SATA controllers.  Other options usually include IDE mode, where the controller pretends to be an old IDE controller for compatibility with older operating systems, and RAID, which means fake raid support.  Fake raid is actually just an AHCI controller that has bios code and windows drivers to implement raid in software.  For more information, see http://wiki.ubuntu.com/FakeRaidHowto.  Unless you are dual booting with Windows, it is best avoided and you should stick with conventional linux software raid, which is better supported.


New Ubuntu install on new laptop is unable to find wifi adapter

Connect to the internet and run in a terminal
sudo apt install rtl8821ce-dkms

and reboot.
This will install a driver for this adapter.


How to install delegate libraries for Image Magick 7.0.7

It looks like you have simply skipped some of the required Bionic Beaver development libraries. Once these are installed you should be good to go!

1. 'Development' Files:

Easiest way to generate the required list of development libraries is to make sure you have the 'Sources' box ticked in 'Software & Updates' and then run the following command from a Terminal:

apt-get -s build-dep imagemagick

This simulated run (-s) will give you an eye-watering number of files to install (240mb download on a clean Bionic Beaver install). I have done this already for you so simply run the following single command to load up the required development files:

sudo apt-get install autoconf automake autopoint autotools-dev build-essential chrpath \
cm-super-minimal debhelper dh-autoreconf dh-exec dh-strip-nondeterminism doxygen \
doxygen-latex dpkg-dev fonts-lmodern g++ g++-7 gcc gcc-7 gir1.2-harfbuzz-0.0 graphviz \
icu-devtools libann0 libasan4 libatomic1 libbz2-dev libc-dev-bin libc6-dev \
libcairo-script-interpreter2 libcairo2-dev libcdt5 libcgraph6 libcilkrts5 \
libclang1-6.0 libdjvulibre-dev libexif-dev libexpat1-dev libfftw3-bin libfftw3-dev \
libfftw3-long3 libfftw3-quad3 libfile-stripnondeterminism-perl libfontconfig1-dev \
libfreetype6-dev libgcc-7-dev libgdk-pixbuf2.0-dev libglib2.0-dev libglib2.0-dev-bin \
libgraphite2-dev libgts-0.7-5 libgvc6 libgvpr2 libharfbuzz-dev libharfbuzz-gobject0 \
libice-dev libicu-dev libicu-le-hb-dev libicu-le-hb0 libiculx60 libilmbase-dev \
libitm1 libjbig-dev libjpeg-dev libjpeg-turbo8-dev libjpeg8-dev liblab-gamut1 \
liblcms2-dev liblqr-1-0-dev liblsan0 libltdl-dev liblzma-dev libmime-charset-perl \
libmpx2 libopenexr-dev libpango1.0-dev libpathplan4 libpcre16-3 libpcre3-dev \
libpcre32-3 libpcrecpp0v5 libperl-dev libpixman-1-dev libpng-dev libpotrace0 \
libptexenc1 libpthread-stubs0-dev libpython-stdlib libquadmath0 librsvg2-bin \
librsvg2-dev libsigsegv2 libsm-dev libsombok3 libstdc++-7-dev libsynctex1 \
libtexlua52 libtexluajit2 libtiff-dev libtiff5-dev libtiffxx5 libtool libtool-bin \
libtsan0 libubsan0 libunicode-linebreak-perl libwmf-dev libx11-dev libxau-dev \
libxcb-render0-dev libxcb-shm0-dev libxcb1-dev libxdmcp-dev libxext-dev libxft-dev \
libxml2-dev libxml2-utils libxrender-dev libxt-dev libzzip-0-13 linux-libc-dev m4 \
make pkg-config pkg-kde-tools po-debconf preview-latex-style python python-minimal \
python2.7 python2.7-minimal python3-distutils python3-lib2to3 tex-common \
texlive-base texlive-binaries texlive-extra-utils texlive-font-utils \
texlive-fonts-recommended texlive-latex-base texlive-latex-extra \
texlive-latex-recommended texlive-pictures x11proto-core-dev x11proto-dev \
x11proto-xext-dev xorg-sgml-doctools xsltproc xtrans-dev zlib1g-dev

On top of these development files we can add a few more to round out the ImageMagick installation, checkinstall to assist in packaging and a few more -dev files to build some delegates not seen in the standard Ubuntu package. The following is again a single command:

sudo apt-get install checkinstall libwebp-dev libopenjp2-7-dev librsvg2-dev \
libde265-dev libheif-dev

2. Download , compile & install:

Then run the following single command to download the latest ImageMagick and successfully build it:

mkdir $HOME/imagemagick_build && cd $HOME/imagemagick_build && \
wget https://www.imagemagick.org/download/ImageMagick-7.0.7-37.tar.bz2 && \
tar xvf ImageMagick-7.0.7-37.tar.bz2 && cd ImageMagick-7.0.7-37 && \
./configure --with-rsvg && make && \
sudo checkinstall -D --install=yes --fstrans=no --pakdir "$HOME/imagemagick_build" \
     --pkgname imagemagick --backup=no --deldoc=yes --deldesc=yes --delspec=yes --default \
     --pkgversion "7.0.7-37" && \
make distclean && sudo ldconfig

Where I have indicated: ./configure --with-rsvg && make you can substantially speed up the compile by adding something like the following: ./configure --with-rsvg && make -j 4, adding in an integer commensurate with the number of cores available from your processor...

3. Test the installation:

Testing this version reveals your required delegates safely installed:

andrew@ilium:~$ identify --version
Version: ImageMagick 7.0.7-37 Q16 x86_64 2018-06-01 https://www.imagemagick.org
Copyright: © 1999-2018 ImageMagick Studio LLC
License: https://www.imagemagick.org/script/license.php
Features: Cipher DPC HDRI OpenMP
Delegates (built-in): bzlib cairo djvu fftw fontconfig freetype heic jbig jng
jp2 jpeg lcms lqr lzma openexr pangocairo png rsvg tiff webp wmf x xml zlib
andrew@ilium:~$

And now you have the very latest ImageMagick installed on Bionic Beaver with all of the delegates that you required and a few extra ones for good measure:).


/etc/php/5.6/fpm/php.ini should be the right file.  Did you restart your webserver after making/saving that change?  For apache on ubuntu its sudo service apach2 restart.  If you are using a different OS/webserver, just google for the restart command.


Ralink RT3090 wifi hard-blocked on IdeaPad S205

Some genius made this PPA featuring rt5390sta driver at version 2.4.0.4 which after a couple of restarts finally made the WiFi work. (The download they reference at the official Ralink website doesn't seem to exist anymore)

It isn't maintained anymore and the kernel module build throws a bunch of warnings, made the thing work though, so whatever.

I recommened adding this line to your sources, offering the latest version, intended for natty:

deb http://ppa.launchpad.net/markus-tisoft/rt3090/ubuntu natty main

You then need to

sudo apt-get install rt5390-dkms

and add these lines to /etc/modprobe.d/blacklist.conf:

blacklist rt2800pci
blacklist rt2800lib
blacklist rt2x00usb
blacklist rt2x00pci
blacklist rt2x00lib
blacklist rt2860sta
blacklist rt3090sta

...or read my source for solving this.

EDIT Okay, I lied. It stopped working a few minutes later. Had to give up on Ubuntu on that machine unfortunately.


What does apt-get --fix-missing do and when is it useful?

Ok, in order:

(1) -m ignore missing or fix missing packages (as opposed to -f broken packages). These options are synonyms for the same option. (Since to fix it ignores from here it takes its own weirdness  :-) )
(2-3) When you install/upgrade with apt-get upgrade or with apt-get install somepackage, usually apt tries to update dependencies. This means that it may find that some packages need new or updated versions of existing packages, and so on in a cascade of dependencies. If some of those packages are missing or fail the integrity check, it seems to  suspend this package, and wants you to go to handle the result following the handle method of the requiring package, if possible. Often it stops installing this package.
(4)  With apt-get update you download what is needed to rebuild the list of dependencies.
After that you can try apt-get install --fix-missing again, in the hope that the updated list fixes the problem by itself.
This can be very useful at times, such as when you add a source for packages in your /etc/atp/sources.list,
or when the package index files have been updated.

Not all the programs you can use under Ubuntu came from the official Ubuntu repositories, and are updated with the same versions -- this is rare.

Moreover, there are many reasons why an installation can be abruptly interrupted (A kill signal, a power shortage, a failure of graphic driver...)  In those situations, apt-get update may not work, so you first need to fix the problem with apt-get install --fix-missing or with some dpkg  commands.

You can see apt-get install --fix-missing as a light and friendly version of commands like dpkg-reconfigure --all or dpkg.


Open the dconf Editor. Then, go to com > canonical > indicator > sound (tree at the left of the window). After that, ensure that the checkbox corresponding to visible is checked to see the sound indicator.


VLC is able to ignore the region value with most drives. However, it must be set to something:

sudo apt-get install regionset

Place the DVD in your drive and in your case, run:

regionset /dev/sr0

Then set the Region from 1 to 8:
See https://en.wikipedia.org/wiki/DVD_region_code#Region_codes_and_countries


How to get a log of at what points in time a directory was modified?

There's no such logs. You can only see last modification time with stat command. That said, you can use inotifywait command from inotify-tools package.  Example of its usage can be found on one of my other answers. Alternatively, you could use watchdog Python package. An example of usage is shown in watchdog's documentation. The output looks as so:

2018-11-10 21:32:45 - Modified directory: ./.config/Qlipper
2018-11-10 21:32:45 - Modified file: ./.config/Qlipper/qlipper.ini.lock
2018-11-10 21:32:45 - Created file: ./.config/Qlipper/qlipper.ini.yJ1483

You can start this as command python3 watchdog_example.py >> /var/log/my_directory.log & from /etc/rc.local and viola - you've got yourself a directory event logger that just works.


install bumblebee it will solve the problemwith the GPU drivers  worked for me  a few months ago on the same laptop https://wiki.ubuntu.com/Bumblebee#Installation


Sounds like you had an external drive of some sort attached and somehow told it to be permanently mounted.  You need to find the reference in /etc/fstab and either delete it or, preferably, comment it out.

Post the contents of the file on here if you are unsure...

From the terminal, type the following commands:
cd /etc
sudo cp fstab fstab.150209
sudo gedit fstab

Now, in front of the line which starts UUID=65E3E80C574F48DA   /media/nuc/500GB ... type the # character.  It should now look like:

#UUID=65E3E80C574F48DA   /media/nuc/500GB ...

Save the file and reboot.  if there are any problems you still have the original fstab in fstab.150209.  Once you are happy that all is well you can use   sudo gedit /etc/fstab/ and delete the line you have just commented out.  Or, if it feels safer, leave it be...


Why is the monospace font of Ubuntu different from the monospace font of openSUSE?

"Monospace" is not actually a specific font. Fontconfig goes through its configuration as well as the various properties of all installed fonts to determine which are monospace fonts and uses the one with the highest priority when an application asks for "Monospace". Same with "Serif" and "Sans".


Why do I seem to type faster on my Ubuntu Virtual Machine (in Terminal)?

Concerning deleting (and changing the cursor position with arrows), the slickness may come from different delay and rate settings of the autorepeat (that is also called typematic).

In ubuntu you can adjust these with the xset command.

For the Mac, the answer to this question will make things slicker. Don't forget to log out your session and log in again for the changes to take effect (in the terminal and all other text fields).


gcc versions later than 5 are not supported while compiling ethminer

This solved my problem:

sudo rm /usr/local/cuda/bin/gcc
sudo rm /usr/local/cuda/bin/g++
sudo apt install gcc-5 g++-5
sudo ln -s /usr/bin/gcc-5 /usr/local/cuda/bin/gcc
sudo ln -s /usr/bin/g++-5 /usr/local/cuda/bin/g++


Unzip the file (right click then uncompress or unarchive) and then double click on the .deb file which will open the softwares manager.


Open "Files," navigate to the folder you want to share, right-click it, choose "Properties," switch to the "Share" tab, tick "Share this folder," adjust other options on the tab as needed and, finally, click the "Create Share" button. Its icon will now indicate (two arrows) that it is being shared.


The reason why you are unable to connect with the adb is because your phone must not have USB debugging installed.

You cant connect through adb unless you somehow enable it.

As a semi solution, you could go and get a dirt cheap screen repair, and even if it doesn't last, you can at least enable the USB debugging!

Good Luck


The problematic theme is most probably the default radiance theme.
You need to edit

 /usr/share/themes/Radiance/gtk-3.0/apps/nautilus.css

make a backup by copying it to nautilus.old

 $ cp /usr/share/themes/Radiance/gtk-3.0/apps/nautilus.css  nautilus.old

now edit with your favourite text editor (requires SU permissions).
using nano:

$ nano /usr/share/themes/Radiance/gtk-3.0/apps/nautilus.css

Find the lines:

/* desktop mode */
.nautilus-desktop.nautilus-canvas-item {
color: @bg_color;
text-shadow: 1px 1px alpha (#000000, 0.8);
}

change to

/* desktop mode */
.nautilus-desktop.nautilus-canvas-item {
color: #000000;
text-shadow: 1px 1px alpha (#ffffff, 0.8);
}

to temporarily check if it worked, you may use

$ killall nautilus
$ nautilus

Logoff and back-in to complete the procedure.


With Kernel 3.5.0-21 the wireless card Realtek RTL8723AE-BT stop working

I assume you installed the driver by downloading and compiling the Realtek package. When a new kernel is installed by Update Manager, you must recompile:

cd Desktop/RT8723  <--or wherever you compiled the package
sudo su
make clean
make
make install
modprobe rtl8723e
exit

Oops! It errors for me, too. You might try this package: http://www.kernel.org/pub/linux/kernel/projects/backports/2012/12/04/compat-drivers-2012-12-04.tar.gz

./scripts/driver select rtlwifi
make
sudo make install
sudo modprobe rtl8723ae

You 'make clean' because the module was compiled originally against your specific versions of kernel, headers, gcc, etc. When updates are installed, the various files built in the compile process may or may not work correctly with, for instance, a newer gcc version, so wipe it all out and start fresh: make clean.


MSI-6837D laptop goes to hibernation when the lid is closed

Perhaps it is a option in your BIOS.

To see if this is the case you should reboot your laptop. As soon as you see any text on the screen you should press either F1, F6 or F10 (it varies from laptop to laptop, but often is says something like "Press F1 for Options" when the laptop is booting. Then you will enter the BIOS control center.

From there you will most likely have a lot of configuration options, and they all look different depending on which laptop you are using, so unfortunately I can't give specific instructions however a such option as "Behavior when lid is closed" is probably going to be under "Power" or "Display".


APT complains about bad signature and security when adding repository and packages cannot be installed

The system says that there is unsigned repository "http://id.archive.ubuntu.com/ubuntu artful".

Try this command:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3B4FE6ACC0B21F32

It must solve your problem.


Successfully installed Ubuntu Asus laptop. After booting Windows system won't Ubuntu

My hint is:

1) Disable fast startup on windows

2) If it still doesnt work, boot in your live usb on try ubuntu, install boot-repair and launch it:

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair


What does it mean when the system monitor reports a program as using over 100 percent CPU?

100% CPU usage represents full usage of one CPU core.

Anything above 100% represents a multithreaded process utilizing more than one core.


The Transmission issue got fixed in this commit


How do I check where devices are mounted?

There are at least three programs I know of that list device mount points:

mount - mount a filesystem  (used for general mount info too):

$ mount
/dev/sda3 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
...
/dev/mapper/lvmg-homelvm on /home type btrfs (rw,relatime,compress=lzo,space_cache)
/dev/sda5 on /home/muru/arch type btrfs (rw,relatime,compress=lzo,space_cache)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
systemd on /sys/fs/cgroup/systemd type cgroup (rw,noexec,nosuid,nodev,none,name=systemd)

df - report file system disk space usage

$ df
Filesystem                1K-blocks      Used Available Use% Mounted on
/dev/sda3                  30832636  11993480  17249912  42% /
none                              4         0         4   0% /sys/fs/cgroup
...
/dev/sda5                  31457280   3948600  25396496  14% /home/bro3886/arch

lsblk - list block devices

$ lsblk
NAME                    MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda                       8:0    0 465.8G  0 disk
├─sda1                    8:1    0   100M  0 part
├─sda2                    8:2    0  58.5G  0 part
├─sda3                    8:3    0    30G  0 part /
├─sda4                    8:4    0     1K  0 part
├─sda5                    8:5    0    30G  0 part
├─sda6                    8:6    0 339.2G  0 part
│ └─lvmg-homelvm (dm-0) 252:0    0   1.2T  0 lvm
└─sda7                    8:7    0     8G  0 part [SWAP]
sdb                       8:16   0 931.5G  0 disk
└─sdb1                    8:17   0 931.5G  0 part
  └─lvmg-homelvm (dm-0) 252:0    0   1.2T  0 lvm

Of these three, mount lists all the mountpoints, AFAICT. The others have their weaknesses.

findmnt suggested by @webwurst is now my favourite tool for the job. It's a Swiss Army knife when it comes to output control (newer versions can output in JSON too):

$ findmnt /
TARGET SOURCE    FSTYPE OPTIONS
/      /dev/sda1 ext4   rw,relatime,errors=remount-ro,data=ordered
$ findmnt / -no source
/dev/sda1
$ findmnt / --json
{
   "filesystems": [
      {"target": "/", "source": "/dev/sda1", "fstype": "ext4", "options": "rw,relatime,errors=remount-ro,data=ordered"}
   ]
}
$ findmnt / --df
SOURCE    FSTYPE  SIZE  USED AVAIL USE% TARGET
/dev/sda1 ext4   40.2G 25.8G 12.5G  64% /


Sound only from Subwoofer, Ubuntu 16.04, Laptop Asus G750

Try to use alsamixer on your command line and find out which channels are de-/activated.


Are you sure the firewall is the problem here? There could be some other problem.
Maybe your simple server is only listening on localhost (127.0.0.1 in IPv4, or ::1 in IPv6). That would explain your nmap results. You can check this using ss. Grab yourself a terminal and do a ss -ltn | grep 2794. If the fourth column (which is the column 'Local Address:Port') reads something like 127.0.0.1:2794 or [::1]:2794, your simple server is listening on localhost only.
If this is the case, you have several options. You could use a proxy server to forward traffic from the Internet to your simple server. You could use an iptables rule to forward the TCP connection. Or (and this is probably the easiest option) you could change your simple server so it listens on all interfaces. Do this by specifying it should listen on 0.0.0.0 (IPv4) or :: (IPv6).


You asked:

Is it possible to do this through an emulated USB(similar to PowerISO)?

You can install directly from the ISO image if you use Wubi. Here's two ways:
Put the ISO Image in a Folder with the Installer
Download wubi.exe and put it in a folder with the ISO image and (preferably) nothing else. Make sure the Wubi installer is for the same Ubuntu release as the ISO image.
Then just run wubi.exe; assuming the ISO image is uncorrupted, it will find and use its contents automatically.
Mount the ISO Image
If you have a Windows utility like Virtual CloneDrive, Daemon Tools, or PowerISO that lets you mount ISO images on a virtual drive, you can mount the ISO image, then run wubi.exe from inside the virtual drive. (It's a file in the ISO, so if you use this technique, you don't have to--and should not--use a separate copy of it.)


Ubuntu 20.04.1 randomly freezes on MSI GF75

Possible cause for this bug:
https://forums.developer.nvidia.com/t/bug-report-455-23-04-kernel-panic-due-to-null-pointer-dereference/155506
Possibly fixed by driver 460.56. I have not had the chance to try it yet (I'm still at 460.39 with Ubuntu 20.04, RTX 3070), and I get random freezes too.


Opening a PDF File by script, printing it, and closing it

This will do the job:

Firstly:

Install a PDF printer, run the following in the terminal:

sudo apt install cups-pdf

Secondly:

In the terminal, cd into the directory containing your PDF files and run the following command:

find . -maxdepth 1 -type f -name '*.pdf' -exec lpr -P PDF {} \;

Done:

The printed files are located in your home directory under a directory called PDF.

Important notice:

When you install the PDF printer in the first step above ( by default ) it is named PDF as the name that identifies the printer in the system and the command in the second step above should work fine with no errors.

However if that is not the case on your system or if you had to remove and add the printer again, the name of the printer might change and you will get an error like lpr: No such file or directory. To solve this you need to find the new name for your PDF printer. This is how to do it:

Type this in the terminal and hit enter:

lpstat -s
You will see output like this:

device for CUPS-PDF-Printer: cups-pdf:/
Your printers name is now CUPS-PDF-Printer and you need to modify the command in the second step accordingly, like so:

find . -maxdepth 1 -type f -name '*.pdf' -exec lpr -P CUPS-PDF-Printer {} \;

Explanation - as requested by user3140225:

{}

Contains the output of the find command.

To see it in action:

Please run find . -maxdepth 1 -type f -exec echo {} \; from within a directory that contains some files in it.
Then run find . -maxdepth 1 -type f from within the same directory.

The output is the same.

\

Prevents the semicolon ; after it from being interpreted as a shell punctuation which will prematurely terminate the command.

;

Indicates the end of the argument part for -exec which is needed for it to work correctly.


./configure: Mono version not recognized during MonoDevelop config

You likely need mono-devel installed though that may not be the end of your configure issues. Maybe just go ahead & run

sudo apt-get build-dep monodevelop


Cannot purge or remove failed Google-chrome-stable installation on Ubuntu 16.04

That guide is a bad one, since Chrome's .deb file handles all that setup for you and even does it properly (like using a file in /etc/apt/sources.list.d rather than polluting /etc/apt/sources.list).

First, undo the damage

Open a terminal by pressing Ctrl+Alt+T
Open the messed up file for editing by running:

sudo nano /etc/apt/sources.list

Remove the lines you added, which should be:

deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main
wget https://dl.google.com/linux/linux_signing_key.pub

Press Ctrl+O to save
Press Ctrl+X to exit
Check for errors in the Apt sources by running:

sudo apt-get update

If you get any errors, let me know by commenting below this answer

You can then install Chrome much more simply

Open a terminal by pressing Ctrl+Alt+T
Download the installer by running:

wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb

Install Chrome by running:

sudo apt-get install ./google-chrome-stable_current_amd64.deb

Delete the installer by running:

rm google-chrome-stable_current_amd64.deb

Start up Chrome to make sure it installed properly by running:

google-chrome & exit


Turn off Microsoft Explorer Touch Mouse Haptic feedback?


Is it possible to install a Windows 10 software in Ubuntu?

At least for .appx files it seems possible, see Is it possible to run Windows 10 UWP apps on Ubuntu?
Download appx file from store via https://store.rg-adguard.net/ (you have to save the file via the context menu).
unzip -d <output-dir> <file>.appx

Then check for the executable and run it with wine.
Hope it helps :)


How to create a ubuntu bootable USB to run on Windows using a MAC

First make absolutely sure that the USB key is not mounted (if it is, unmount it).  Next you should use

sudo diskutil list

To see if the USB key shows up.  If it does, then the "problem" is that it isn't formatted.  This is not actually a problem, you can proceed to use it.

If the USB key does not show up, there may be driver or hardware problems.  In either case, it's probably simplest to buy a new, working USB key.

Once you have a working identified USB key you can use a command like

sudo dd if=./xbmc-9.11-live-repack.img.dmg of=/dev/rdisk<NUM> bs=1m

where  is the number of the disk that diskutil shows you.  Be very careful not to use one of your other disks where you might cause damage.

Here's a blog posting with a more extensive explanation of the procedure


That depends on a setting in Firefox. You can configure Firefox to automatically open, save or ask what to do for various type of files:

Edit -> Preferences -> Applications Tab

Tell your friend to right click the download link, and select "Save link as...", instead of left clicking.


If you don't want to upgrade/install those packages, is actually very easy. If you don't use them just uninstall them:

sudo apt-get remove <packages to remove>

To prevent that they try to get installed/upgraded you could put them on hold:

echo <package> hold | sudo dpkg --set-selections


To set up the Laptop Lid Close Action you have to install Advanced Setting (or the Gnome Tweak Tool).I suppose you have installed it ( if not you can do that from USC (Ubuntu Software Center) under either tweak or Advanced Settings.), so here what you have to do,

Press the super button and type in tweak or advanced and choose the Advanced Settings. When it opens choose the shell tab;

choose you desired on both on AC and on battery

I dont know if xmonad effets this but you may even need to check your settings in

/etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla

Make sure you have two settings in there

[Enable hibernate by default in upower]
Identity=unix-user:*
Action=org.freedesktop.upower.hibernate
ResultActive=yes

[Enable hibernate by default in logind]
Identity=unix-user:*
Action=org.freedesktop.login1.hibernate
ResultActive=yes

You can read more about the file and its settings here.

Hope it helps


Type into terminal:

unity --version

Hopefully that's exactly what you want.

Alternatively, click on the Applications tab in the Unity Launcher and search "Synaptic". You should see "Synaptic Package Manager", open it, and then search "Unity" in the search bar (or Quick Filter, as it's called). Your version should be listed underneath the "Installed Version" column.


Bookmarks in File, aka Nautilus only open home directory

A proper bookmark, made by pressing CtrlD or other means of adding bookmarks, will create an entry in the Bookmarks section of the sidepane. This entry will remember the location you were in when you created the bookmark. The entry under the Network section is due to Nautilus remembering the location and other connection settings for the server.

Here, the lab entry under the Bookmarks section opens in my ~/Downloads directory, because that's where I bookmarked it.


It is strange that you have a zfs.img image file while you have not installed the zfsutils-linux package. You are running LXD 2.0 (deb package) which requires the zfsutils-linux package in order to create a ZFS loop file.

To verify that ZFS it not used, run sudo zfs list and sudo zpool list. You should get command not found.

If you are sure that the ZFS loop file is not used, then you can move it to another location, and then reboot your computer. If LXD still works, then you are sure that the containers are not located in the ZFS loop file.


The iso file, is an image of the disk, it was meant to be burned directly into the CD/DVD, without modification, nor uncompressing (actually the iso is not compressed itself).

You need some software to burn the iso into the disk (Windows Vista onwards can burn ISO without help). Just right click the file and look for "Burn to Disk" or "Burn Image".

There are tools for almost all OS's to burn ISO's:

Windows: has both built-in and ImgBurn.
Mac OSX: Disk Utility.
Linux: has Brasero (just to mention the most popular... I think).


GUI not showing after installation of 11.10 on virtual machine

In vM do you have 3d and 2d checked in the vm settings.
what is the vm graphics memory set at i usually set at 128,
When starting the machine does boot to a terminal. From the terminal log in with your user name and password sudo apt-get install update then try sudo apt-get install ubuntu-desktop


fsck
Let's start by checking your file system...

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

SMART
Your SMART Data looks fine. No disk problems.
snaps
You have a lot of snap applications that are increasing your boot time (35.392s snapd.service, and all dev-loopxx devices). See snap list. Consider uninstalling snap apps, and reinstalling the binary (.deb) versions of the same app, if available.
You'll probably have to keep these snaps...
Name                  Version                     Rev    Tracking         Publisher   Notes
core                  16-2.49.2                   10958  latest/stable    canonical✓  core
core18                20210309                    1997   latest/stable    canonical✓  base
gnome-3-28-1804       3.28.0-19-g98f9e67.98f9e67  145    latest/stable    canonical✓  -
gnome-3-34-1804       0+git.3556cb3               66     latest/stable    canonical✓  -
gnome-system-monitor  3.38.0-17-g38c1ce1d62       157    latest/stable/…  canonical✓  -
gtk-common-themes     0.1-52-gb92ac40             1515   latest/stable/…  canonical✓  -
gtk2-common-themes    0.1                         13     latest/stable    canonical✓  -
snap-store            3.38.0-59-g494f078          518    latest/stable    canonical✓  -
snapd                 2.49.2                      11588  latest/stable    canonical✓  snapd


How to extract matrices from QtOctave to LibreOffice Calc?

You should be able to use the octave csvwrite or dlmwrite to write your matrix to a comma-separated variable file, which you can open / import into LibreOffice Calc

csvwrite('mymat.csv', m)

or equivalently

dlmwrite('mymat.csv', m, ',')


Windows7 machine cannot access Linux share folders via Samba, help please

After breaking my head for a long time, it was the firewall.
Try (you or whoever sees this ticket) to disable firewall and check if it is working:
sudo ufw disable


Causes of files disappearing and ways of prevention?

While this 'could' be a failing disk, the fact that no other directories were affected makes me think that it's more likely something else. Once (or twice), I've accidentally deleted EVERYTHING on my drive and it acted exactly the way you are describing this. Most of the files were gone instantly but a good portion didn't go away until all processes which used them also quit. In summary, my guess is that your brother ran something like:  cd ~ && rm *


How to clone my Lucid (10.04) + root as an image for further re-installation?

Try REMASTERSYS. It's help me a lot with backup the whole system including your home folder data (Music, Pictures, etc). It's also creating LiveCD/LiveUSB mode,. Hope this help you :)

http://www.remastersys.com/


You can set your JAVA_HOME in /etc/profile as Petronilla Escarabajo suggests. But the preferred location for JAVA_HOME or any system variable is /etc/environment.

Open /etc/environment in any text editor like nano or gedit and add the following line:

JAVA_HOME="/usr/lib/jvm/open-jdk"

(java path could be different)

Use source to load the variables, by running this command:

source /etc/environment

Then check the variable, by running this command:

echo $JAVA_HOME

Update

Usually most linux systems source /etc/environment by default. If your system doesn't do that add the following line to ~/.bashrc (Thanks @pje)

source /etc/environment


Interestingly, (I learned it from a video on YouTube) when you suspend your system and turn it on back you will start to hear the sound. I've tried just now when I was searching for a solution and it's working.


From the code you shared, you are not executing apt-get as root. Try this:

jan@jan-Satellite-C855:~$ sudo apt-get install -f

or you could switch user to root and then run it:

jan@jan-Satellite-C855:~$ sudo -s
[sudo] password for jan:
root@jan-Satellite-C855:~# apt-get install -f


Does GNU awk accept intervals specified using braces in regular expressions?

From the manual:

  Initially, because old programs may use ‘{’ and ‘}’ in regexp
  constants, gawk did not match interval expressions in regexps.

  However, beginning with version 4.0, gawk does match interval
  expressions by default. This is because compatibility with POSIX has
  become more important to most gawk users than compatibility with old
  programs.

Since Ubuntu 12.04 has GNU awk 3.1.8 and 14.04 has 4.0.1, you must be on 12.04 (or another such old release).

Set POSIXLY_CORRECT for POSIX behaviour:

$ echo "a{2,3}" | POSIXLY_CORRECT=1 gawk '/a{2,3}/ {print}'
$ echo "aa" | POSIXLY_CORRECT=1 gawk '/a{2,3}/ {print}'
aa

Or, use the -r option if you want to keep GNU extensions and use interval expressions:

  -r
  --re-interval

  Allow interval expressions (see Regexp Operators) in regexps. This is
  now gawk’s default behavior. Nevertheless, this option remains (both
  for backward compatibility and for use in combination with
  --traditional).


./configure output in terminal but also in file with 2>&1?

Read man bash, especially the "Redirection" section.

2>&1

redirects STDERR (the error stream) to the same place that STDOUT is going.

What do you mean "no longer where it needs to go internally"? The STDERR and STDOUT streams are produced by ./configure as it goes about its business. How you process STDERR or STDOUT after the script outputs it generally won't affect the script (except lots_of_output | read_a_byte_an_hour).

What do you want gedit to process? Where is gedit going to write the edited file?

You could

./configure 2>/tmp/stderr >/tmp/stdout

then gedit either file.

If you want to save, STDERR along with STDOUT, and process it later, see man tee, and do:

./configure 2>&1 | tee /tmp/logfile | later_processing ...


Check out this question, it might be just what you're looking for.

Boot up a live cd or usb, and go into try ubuntu mode. Open file explorer, and see if you can find your Ubuntu partition. If you can't find it, open a terminal by pressing Ctr-Alt-T on your keyboard and type in:

sudo su
gparted

In the window that opens up, find your hard drive, and note its /dev/sdX. The X here is for example, you have to replace it with whatever lowercase letter you got when you found the drive in gparted. Then, in the terminal, run this:

mkdir /media/ubuntu/Ubuntu
mount /dev/sdX1 /media/ubuntu/Ubuntu
nautilus /media/ubuntu/Ubuntu

Remember to replace X with the appropriate letter.

These commands mount your Ubuntu partition so you can view the files. Now you should have a file explorer window open with the root directory of your Ubuntu installation open. Open the folder home, and go into your user folder. Now you can plug in a backup drive and copy all the files over. Then when you install Ubuntu again, you can copy the files over.

If you don't see a home directory in the folder you opened, then probably /home was located on /dev/sdX6. In that case, can mount it by typing the same commands above but replacing /dev/sdX1 with /dev/sdX6 and /media/ubuntu/Ubuntu with /media/ubuntu/Home. It's always good to make backups.

If /dev/sdX6 is the home partition, you can do a reinstall without wiping it. Start the install by clicking the Start Install icon on the Desktop, and once you get to the Something Else screen designate /home to be on /dev/sdX6. Just don't format the partition! If you do, you will lose all your files.

But first, what's wrong with your computer? Does it turn on? What do you see? Do you get an error message? Do you get to the grub menu? Do you get to the startup screen?

Most of the time, you can repair the installation without having to reinstall. To help us help you better, could you edit your question or reply to this answer explaining exactly what the problem is.


How to make anthy type unicode characters?

I don't know if there is such a feature in any of the Anthy engines available for Ubuntu, but I think it's worth mentioning that you can use code points to type Unicode characters.


This is because the chromium in 19.10 has been transitioned to a snap.

The reason is the same as this other bug affecting chromium, and that the Firefox snap also has the same issue.


How can I access a tty from the terminal?

Some options:

sudo chvt 1 will bring you to the first virtual console. Putting this in a .profile should not be very useful.
Snooping on a running virtual console is allegedly possible with ttysnoop.


Ubuntu Studio 16.04 w/xfce4:

System settings-> Power manager -> Security tab.

Uncheck "Lock screen when system is going for sleep" (sic).

This worked on both my systems (Laptops: old Sony, fresher Dell).

I also removed X-screensaver, though I'm unsure if this was really necessary.

I imagine it's not too different on any other X-window flavor - disable the screen lock on suspend/sleep in power manager security settings.

Hope this helps.


**tmux** in gnome terminal with sliding cursors in each pane

This is not possible. GNOME Terminal has a fixed UI structure, and makes its text grid canvas available for applications to write characters on. There is no way an application (e.g. tmux) could add other UI elements such as a scrollbar there.

(On macOS, iTerm2 has something called "tmux integration". I don't know what it is, never tried, but it might include this feature you're looking for. None of the terminal emulators I'm aware of have it under Linux.)

Note that even with a single tmux pane only, the scrollbar is unusable (or depending on the graphical theme, probably not even visible). tmux switches to the so-called alternate screen of the terminal, which does not have a scrollback buffer. tmux offers its own means for scrolling – which also works when tmux presents multiple panes –, consult its documentation to find out what it is (sorry, I don't know off the top of my head).

If you don't need any of tmux's features apart from the paned layout (multiple terminals next to each other), you might consider using Tilix or Terminator instead of GNOME Terminal. All these three (and many more) emulators are based on the VTE terminal emulator widget, so the actual terminal emulation behavior will be exactly the same, only the UI around it will be substantially different.


Help interpreting fdisk after boot problems

Your HDD uses GTP which is useful if the HDD is bigger than 2 TiB. Use GParted instead of fdisk -l. It will provide the same information.


VMplayer not enough memory after upgrade to 17.10 (artful aardvark)

Based on this method, I've used the following commands to solve similar issue:

cd /tmp
git clone https://github.com/mkubecek/vmware-host-modules.git
cd vmware-host-modules
git checkout workstation-14.0.0
tar cf vmmon.tar vmmon-only
sudo cp vmmon.tar /usr/lib/vmware/modules/source
sudo vmware-modconfig --console --install-all

In this way it compiles and works correctly.


Command substitution doesn't work when it's the input to `read`

Command substitution is a shell expansion, and Bash doesn't perform expansions on the input to read.
This is a good thing, because read is supposed to capture whatever nonsense (or brilliance) the naive (or expert) user typed.
Try entering any input that the shell would usually expand, and you will find the same thing happens...
$ var=~          # ~ was expanded before assignment
$ echo $var
/home/zanna
$ read -r var
~
$ echo $var
~

There are some sort-of exceptions to this - read treats backslash characters as escapes

The backslash character ‘\’ may be used to remove any special meaning for the next character read and for line continuation.

This is almost never what you actually want (you want read to capture whatever the user typed including any backslashes), so you should habitually use the -r flag with read (like I have done in my examples):

-r
If this option is given, backslash does not act as an escape character. The backslash is considered to be part of the line. In particular, a backslash-newline pair may not be used as a line continuation.

The other exception is that the input is split into fields in a way similar to word-splitting, so you can assign to multiple variables:
$ read -r var
one two three
$ echo $var
one two three
$ read -r baa ram ewe
one two three
$ echo $ram
two

Quotes are from this section of the Bash manual - scroll down to find read, or run help read in the shell for a shorter version.


Adding a third bootable OS to 16.04 and Windows 10

It's workable.  The Ghost is an image backup/restore system.  You can backup a partition and restore it to a different disk or partition.  Restoring the OS to a partition is similar to installing the OS on a different partition.

The integration to Grub is the same as before.  When you have multiple drives and partitions with different Operating Systems on the drives, run grub-update to add the other OS's to the grub menu.

$ sudo update-grub

Windows XP has some limitations.  You may have to perform some special considerations to accommodate those limitations.  You may have to boot legacy to ensure the migration.  It may have other problems such as being limited to only primary partitions.

Only Windows XP 64-bit editions are supported on GPT partitions.  I believe XP also has a problem with LVM partitions.

Windows XP was designed during the era of substantially lower performance hardware.  With this in mind, you might consider running XP as a VM and get basically the same performance it had when it was released.


Is it possible to have f.lux (software that adjusts display's color temperature) on Ubuntu 14.04?

May I suggest RedShift?

It's more maintained than flu.x, it has more options and it works perfectly with Ubuntu 14.10 x64 and Ubuntu 15.04 x64.

It can be installed from the repositories (12.04, 14.04, and newer):

sudo apt-get install redshift gtk-redshift

You may optionally create a configuration file for RedShift. It is NOT created automatically, so you'll have to create it using gedit ~/.config/redshift.conf.

This is how my redshift.conf file looks like:

; Global settings for redshift
[redshift]
; Set the day and night screen temperatures
temp-day=4500
temp-night=3500

; Enable/Disable a smooth transition between day and night
; 0 will cause a direct change from day to night screen temperature.
; 1 will gradually increase or decrease the screen temperature
transition=1

; Set the screen brightness. Default is 1.0
;brightness=0.8
; It is also possible to use different settings for day and night since version 1.8.
brightness-day=0.9
brightness-night=0.7
; Set the screen gamma (for all colors, or each color channel individually)
gamma=0.8
;gamma=0.8:0.7:0.8

; Set the location-provider: 'geoclue', 'gnome-clock', 'manual'
; type 'redshift -l list' to see possible values
; The location provider settings are in a different section.
location-provider=geoclue

; Set the adjustment-method: 'randr', 'vidmode'
; type 'redshift -m list' to see all possible values
; 'randr' is the preferred method, 'vidmode' is an older API
; but works in some cases when 'randr' does not.
; The adjustment method settings are in a different section.
adjustment-method=randr

; Configuration of the location-provider:
; type 'redshift -l PROVIDER:help' to see the settings
; ex: 'redshift -l manual:help'
[manual]
; set these values if you've set the location-provider to manual instead of geoclue
;lat=51.522698
;lon=-0.085358

; Configuration of the adjustment-method
; type 'redshift -m METHOD:help' to see the settings
; ex: 'redshift -m randr:help'

[randr]
screen=0

If you need to, compiling it manually is also quite easy. Here is the official repository: https://github.com/jonls/redshift

Just make sure that you've installed all the dependencies specified in the travis.yml file before running the bootstrap executable file.

Instructions here: https://github.com/jonls/redshift/blob/master/HACKING.md

For Ubuntu 15.04 users: it could be that you won't be able to use redshift because of some missing dependencies. Try to compile it by getting the code directly from github.

sudo apt-get install build-essential libxcb-randr0-dev
./bootstrap
./configure --enable-randr
make
sudo checkinstall

...or just install if you don't want to use checkinstall.
The libxcb-randr0-dev package should satisfy the dependency to use randr as an adjustment method. Otherwise try to enable vidmode by doing:

./configure --enable-vidmode


Why don't you try this command:

dpkg --force-depends --remove x11-xkb-utils

It came from comment number 5 of this bug report.


error no such partition. Grub rescue mode

You can boot up the Windows install disk and choose Repair Windows option, or you can use a live Ubuntu to do the same thing, like described here: https://help.ubuntu.com/community/RestoreUbuntu/XP/Vista/7Bootloader.
Or try this alternate method: How to restore Windows 7 MBR without a CD.


Does DPKG support for verifying GPG signature for Debian package files?

Short answer: No, dpkg does not support signature verification. Also No because such signatures are a poor measure of trustworthiness in the scenario you describe.

Neither dpkg nor apt can decide if a source is a trusted source. As the human, it's your job to decide if a source is worthy of your trust or not. There is no magic token-of-trustworthiness that is only issued by the good-internet-elves. (And if there were, how could you tell it wasn't a clever fake? Bad actors can sign files, too)

NEVER add a source to apt that you do not trust. Apt depends upon you to make wise decisions.

Distros control the chain-of-trust from upstream source, building and signing packages. That's one reason that a wise choice of distro is important. The right distro has the software you need, so you don't go wandering across the internet (mis-)gauging the trust of all the software you gather from each site

Apt verifies that packages from your authorized sources are not corrupted nor substituted during download to you. Apt tracks sources and dependencies. Apt does NOT gauge trustworthiness.

Dpkg merely installs whatever apt tells it to install, and in the order apt dictates. Dpkg used to use debsigs, a long-disused early signature method. Today, dpkg does all sorts of checking...but on the filesystem and on the package and on it's own functioning.

If you tell dpkg to install a deb full of malware, dpkg will do exactly what you instructed it to do. Dpkg is like a toaster - you can misuse a toaster and burn down your house. The dpkg developers believe that folly by the human  --bypassing the protections of human sensibility, distro, and/or apt-- is a human problem, not a dpkg bug.

CONSIDER CAREFULLY adding non-Ubuntu packages. They might break your system. They are unsupported here.

Note: debsigs are an early and long-disused signature method built into dpkg. They were superseded long, long ago by distros and apt.


How to reduce size of the vertical panel icons in xfce4?

it turns out you can do this by increasing the number of rows while reducing the row size.


is it possible to use android SDK's windows version on linux?

I strongly recommend installing Android SDK again in Ubuntu. At the cost of using some additional disk space, it will save you a lot of time and also give better stability and performance. This also might even result in saving disk space if you find that Android SDK works so much better in either Windows or Ubuntu that you could uninstall Android SDK in the other OS in order to save disk space. Saving disk space is a legitimate concern especially if you are installing Android SDK on an SSD where disk space is at a premium in order to get better performance from the application.


Simply

current_dir=/home/akshay/UCS
source_dir=/lib/python2.7/lib-dynload/
echo "$current_dir$source_dir"

And then export it

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$current_dir$source_dir


Cannot run ubuntu emulator on ubuntu12.04

This problem was also reported on Launchpad and forums:

https://bugs.launchpad.net/ubuntu/+source/goget-ubuntu-touch/+bug/1331177

http://ubuntuforums.org/showthread.php?t=2208424

There are two suggestions currently but neither one worked for me:

installing libudev1:i386
using --use-raw-disk key

I've recreated the emulator image and this .device file contains only one line:

i386


After much discussion, and deliberation here, I found what the issue was.

In my main nginx.conf I was setting the listen directives to both port 80 and 443

Once I removed them, and added them to the VHost configurations, it started working.


You can do that using xclip (package xclip, not installed by default):

xclip -out -selection primary | xclip -in -selection clipboard


system-config-printer broken after update to 14.04

Modifying system files is not a good idea, instead check first that you have the latest version of the corresponding package:

dpkg-query -W system-config-printer-gnome

It should return:

system-config-printer-gnome    1.4.3+20140219-0ubuntu2.1

Then try to re-install the package using apt-get:

sudo apt-get update
sudo apt-get install --reinstall system-config-printer-gnome


Bash script for 'apt-get update' with automatically insert password

You can do with

#!/bin/bash
echo password | sudo -S apt-get update

From man sudo and from Stackoverflow

  -S, --stdin
                   Write the prompt to the standard error and read the password
                   from the standard input instead of using the terminal device.
                   The password must be followed by a newline character.

If your password has special characters then use single quotes around the password like echo 'p@ssowrd'.


How can I install the crond service on an ubuntu server 16.4?

To check the status of cron run:

service cron status

Instead of "crond"


Here's an ugly workaround that I don't have a LUKS container to test on:

udevadm info /dev/mapper/files--vg-main

Where /dev/mapper/files--vg-main is the device you are checking for.
if [ $? -eq 0 ] then the command was successful meaning the device exists and you can mount it.

else you'd have to loop and check again.

As a side note you can find some useful udev debugging ideas on this page.


In my case, the problem was due to the Event Calendar widget.
Referring to the answer at Kubuntu desktop freezes after installing event calendar widget I opened a Terminal via keyboard shortcut, and entered the following
cd ~/.local/share/plasma/plasmoids
mv "org.kde.plasma.eventcalendar" "org.kde.plasma.eventcalendar.old"

I then entered plasmashell to test it, and it works.
People upgrading Kubuntu are advised to disable Event Calendar beforehand.


I always get "No such file or directory: apache2: could not open error log file /etc/apache2/$ apache_log_dir /error.log" how cat I fix this

Look at your vhosts-files in /etc/apache2/sites-available/<vhost>. In these files are defined where to find the error log for a specific website (not the global log) i.e. "default".

There are two variables to do this and per default they look like this:

ErrorLog ${APACHE_LOG_DIR}/error.log
CustomLog ${APACHE_LOG_DIR}/access.log combined

Make sure that /var/log/apache2/ exists before you start apache!


The issue was from a bad update with the PPA. Once I followed the instructions everything started working. If it wasn't for me noticing my server hasn't updated in a while I wouldn't have stumbled upon this.


How to delete all directories with a particular name?

It's not clear --- under the directory dir_a you can have only one directory named Debug. Or are you saying that you have dir_a/Debug, dir_a/dir_b/Debug, dir_a/dir_c/Debug and so on?

You can list all directory named exactly Debug under the directory dir_a with:

cd dir_a   # or whatever you need to go there
find . -type d -name Debug

this will list all the directories named Debug under the current directory. To delete them (double check, this IS NOT UNDOABLE):

find . -depth -type d -name Debug -exec rm -r {} \;

-depth will list Debug/Debug/ before Debug/ to avoid errors.

In detail:

find . -type d -name Debug will search all directory under the current one (.) for entries which are both directory (-type d) and have the name "Debug" (-name Debug).
The added -depth flag make the search depth-first (it means that "deeper" matches are found before "shallow" ones).
-exec ... \; tells find to execute the command in ... for each match. (The semicolon is quoted because otherwise the shell will interpret it).
In the command ... above, the special symbol {} is substituted by the current match.

So in plain English it is: find every directory under this one which name is "Debug", depth first, and for each one execute the command rm -r followed by the full name of the directory.


Now I know why I didn't understand...  Routing is done on a network level and not on a port level.  You need to sub-segment your network in 3 separate networks and bind each network to each network card and then have your router route the packets to the correct Ethernet port.

As each network card has its own network address, any packets coming in with a certain address will also go back out on that network.

E.g.:

eth0: 192.168.100.0/24 LAN
eth1: 192.168.101.0/24 Access Point
Eth3: Default gateway/24: ADSL modem

Then all traffic that is not for 192.168.0.0/16 will go out to the Internet and all local traffic will stay local.

To do port forwarding you have two options:

If you add an additional piece of hardware like a Big-IP between the router and the server, that will be able to inspect the packets and depending on ports send stuff to Eth0 and Eth1 by changing the IP address on-the-fly and then the server will then again send it out on the correct interface, and the BigIP will then convert it back to whatever it was...
You can also drop the router entirely and use the server as a router to accomplish the same thing, and then you just use iptables to inspect the packets and route them around.

But what you're trying to do is impossible (only using a hardware router and software routing in the server) as there is no notion of "HTTP/FTP" as that is on a port level...  :-(


How to copy files into /usr/local/? (permission denied)

There are a couple of different ways

Open Nautilus with sudo by typing sudo -H nautilus in terminal then copy the files as you would normally. Warning: I would close nautilus straight after so you don't accidently use it for moving normal files.
Open terminal and type sudo cp file1 /usr/local/ obviously replacing file1 with aptana
Add open as admin option to nautilus and open the local folder by right clicking and selecting open as administrator.


This works:

network:
  version: 2
  renderer: {renderer}
  ethernets:
    {networkname}:
      match:
        macaddress: {mac address}
     wakeonlan: true

and it is a lot more lines than you have in your yaml file. Looks like macadress is mandatory/adviced for WOL.

See also the Common properties for physical device types.


For more predictable results you have to install all needed build-dependencies for current version of Boost package by running

sudo apt-get build-dep boost1.67

and then try to compile the newest.


ubuntu error installation in SONY VAIO model VGN-T330FP

Sounds like video drivers to me.

Maybe try the command line based installation and then add a windows manager of your choice afterwards like XFCE?


Zenity alternative for Bash scripts in package sources?

Yad (yet another dialog) is a fork of Zenity with many improvements, such as custom buttons, additional dialogs, pop-up menu in notification icon and more.

You can install yad using the following PPA,

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

See example demonstrations how to use yad in shell scripts.


Bluetooth settings are controlled from configuration files in /etc/bluetooth. For input devices we can define a timeout before a connection will be disconnected. To disable this open /etc/bluetooth/input.conf as root in an editor and either comment out the following line by adding # (as it is done in the example below), or set timeout value to 0:

#IdleTimeout=30

Other timeouts that can be set in /etc/bluetooth/main.conf may not be affected in your case as they only play a role when a service may be interrupted (e.g. by bad signal strength) and will not be reconnected in case a timeout is set here. Default values for timeouts in main.conf are:

DiscoverableTimeout = 0
PairableTimeout = 0
PageTimeout = 8192


Ubuntu Desktop Installation Partition Sizing Formula

To my experience a formula describing partition sizes in % are no use here. Absolute values I would recommend are

4 GB Swap
10-15 GB for OS depending on how much software you want to install
the rest for the home partition.

It should be sufficient for beginner to experienced user, I don't know what exact demands real power users have.


Looking for Ubuntu wallpaper with blue night sky, squid, and astronaut?

Found it. Posting for others.
https://www.reddit.com/r/wallpapers/comments/9qmpam/encounter_3840x2400_by_lazardjin_ubuntu_1810/


Extended display not working for Lenovo Thinkcentre (Intel Xeon)

The Intel integrated graphics drivers are usually installed automatically when they're found, as they're part of the xserver-xorg-video-intel package, but you can confirm they're in place by trying to install the package again:

Open Terminal (if it's not already open)
Install the drivers:
sudo apt install xserver-xorg-video-intel

Note: You may see a message like "xserver-xorg-video-intel is already the newest version". If you do, then carry on to the next step.
If the driver is installed but Ubuntu can't see it, you may need the mesa-utils package as well:
sudo apt install mesa-utils

Reboot
Confirm the UNCLAIMED message is gone:
sudo lshw -C display

So long as the video device is properly loaded — and the total resolution of both displays does not exceed the maximum for the video card — then you should be able to extend your desktop across both displays


Bricked GRUB after deleting a partition on my hard disk

You can re-install grub by booting the Ubuntu live CD or USB and following the instructions on this page:

http://howtoubuntu.org/how-to-repair-restore-reinstall-grub-2-with-a-ubuntu-live-cd

Hope this helps
Jim


Start services only when really required

You could probably use knockd to do it if you really wanted to.  I also have quite a few daemons installed for various uses, and I tend to just disable them starting on bootup and manually start them when I need them.  The command to do so would be:

sudo update-rc.d $serviceName disable

and then the obvious

sudo service $serviceName start

when you actually want it running.

The knockd conf I can think of off the top of my head would look something like:

[ApacheHTTP]
    sequence = 80
    seq_timeout = 10
    command = /usr/bin/service apache2 start
    tcpflags = syn
    cmd_timeout = 10

etc, etc for all of the services you want.  This will not automatically stop them, however.  You can add a line that says 'stop_command = /usr/bin/service apache2 stop' if you want, but this could shut it down without you wanting to.


I cannot install aptitude tool on ubuntu 16.4

You need to write sudo before your installation. And then enter you password to install aptitude tool.


If format my system and install ubuntu as only OS what will to happen hard disk drives?

If you install Ubuntu as the only operating system on the hard drive (install option "use all of the hard drive" then it will repartition your hard drive and format it completely.  It will warn you of this, however you have to read the screen carefully. You should back up all of your important data to an external hard drive from which you can recover your data after you have installed Ubuntu.

Ubuntu/Linux doesn't treat hard drives and partitions the way Windows does - there are no drive letters (C:, D:, E: etc), instead all storage devices (hard drives, USB pendrives etc) are given a letter scheme in a device name so that the device names become /dev/sda, /dev/sdb, /dev/sdc and so on.  Furthermore, each partition on the hard drive is given a number so the first hard drive with say three partitions would be /dev/sda1, /dev/sda2, /dev/sda3 etc.

These drives are all mounted seamlessly within the / (root) file system, so the main boot drive is usually accessed as /, while a separate partition used to put all user data on will usually be mounted to /home.

You don't really need to know how to partition the hard drive.  As soon as you tell the installer to use whole drive it will partition it and do all the set up for you.

If you select "do something else" at this point instead then it's possible to specify partitions, and even move partitions up or down, and resize them.  It would be quite possible to copy all of your important data onto one of the other partitions and leave it there until after the installation, and copy it to your /home afterwards and re-use the space to grow your main data partition to take up all of the hard drive. You would need to move the data before you start the install; the partitioning program will not move data from one partition to another.  This would be an advanced topic however, and I'd still strenuously recommend that you back up all of your important data to an external drive.


You need to know that some programs like Firefox have a special memory place for their "clipboard", while ubuntu has another. you CAN use the clipboard from firefox to another programa in ubuntu only while you have Firefox OPENED. You can not close Firefox if you want to maintain the information you have in the Firefox Clipboard.

This also applies to other programs that do not share the same memory place. Closing the programa you copy from can make the following problems:

Copy some info and when you select to paste there is no PASTE option available.
Select by dragging the mouse over some text and when you want to paste using the middle scroll button there is nothing to paste.

So at the end you need to have the source program you are copying from opened. Also selecting something by dragging on it and highlighting what you want is different from selecting COPY option. They sometimes have different memory places (Depending on the program). For example in Firefox, highlight something and open gedit and paste using the middle scroll button. It will work. No close firefox and test. No do the same but right click and select COPY.

That way you know how programs relate when using the clipboard or their own clipboard.

Wish there was a universal clipboard.

Another HINT for you is to download glipper. Which saves anything you highlight or copy to a list from where you can grab anytime you want the info.


Mounting a disk as read-write isn't necessary to format the disk. Unmount it, if mounted, with:

sudo umount /dev/sdd1

Then you should be able to delete the partition with GParted and create a new one.

Make sure you are using sudo in front of the commands you mentioned.


If you've followed the instructions here, you should probably have installed bumblebee-nvidia and primus, right? I believe primus gives a better performance over virtualgl. The latter is still the default, though, so you should run optirun with the -b primus option: optirun -b primus glxgears. See if you get a better performance.

Also, have a look on this post, which is very enlightening: https://askubuntu.com/a/36936/169250

EDIT: Try to update your nvidia drivers:

sudo add-apt-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get install nvidia-331
sudo apt-get --purge autoremove #this should remove old drivers
sudo apt-get reinstall bumblebee bumblebee-nvidia

EDIT2: Apparently, you'll need to change a configuration file. See here (under Updating Drivers): https://wiki.ubuntu.com/Bumblebee#Installation

And it seems that running optirun nvidia-settings you can probably see if the nvidia GPU is working.


How do I choose the right parameters when using badblocks?

Since your drive has a 4096 byte physical sector size, you want to use -b 4096.  I don't think the -c argument makes much difference, so just leave it alone.

Also the drive's internal SMART test is better and faster than badblocks, so using smartmontools or the disk utility to run that instead is a better idea.


I had/have a very similar problem as what you describe.
Or maybe not exactly the same, I'm not so sure from your description.
In may case, the video would completely hang. It would maybe play 1 sec or so and then just hang. Moving the mouse sometimes plays a few more frames. It's somewhat strange.
I thought this is a problem with my graphics somehow (also because it noticed the problem since a Nvidia graphics driver update, and I had other graphics problems before, like this).
I thought this is an issue with Chrome but Firefox has the same problem.
Also disabling hardware acceleration in Chrome or doing sth like that did not help.
But then I switched the audio (I attached some Bluetooth headset), and suddenly all the videos play fine again, without any hang.


Try to update to the 4.4 kernel version (for this you can follow the answer here). This solved the problems with the touchpad i had on my asus X555UA, but i still have problems with the internl mic and the jack.


Blinking black pattern of dots and lines on the screen

The solution to this issue is to install intel graphics driver.
Here's How:

Goto this link and download the .dep package suitable for your OS version (eg. Linux Graphics Installer for Ubuntu* 13.04, 64-bit)
Install the signatures listed on the above link (warning there are two types - one for Ubuntu and another one for Fedora)
Double click on the .dep package you have downloaded in the first step
Double clicking the .dep package will start up Software center. wait a few second for it to load the Installation program
Click Install
After the installation has been completed, reboot your machine.

If this answer is the solution, please mark it as your accepted answer.
Thank you, and hope this helps :)