Can you determine which packages are not being used at all when running a specific program

You can check which files were accessed by a program using strace:

-e trace=file
   Trace all system calls which take a file name as  an
   argument.   You can think of this as an abbreviation
   for  -e trace=open,stat,chmod,unlink,...   which  is
   useful   to   seeing   what  files  the  process  is
   referencing.  Furthermore,  using  the  abbreviation
   will  ensure  that  you don't accidentally forget to
   include a call like  lstat  in  the  list.   Betchya
   woulda forgot that one.

So, something like:

$ strace -fe trace=file -o log /bin/bash -c ''
$ awk -F\" '!a[$2]++&&/\//{print $2}' log | xargs dpkg -S 2>/dev/null | awk -F: '!a[$1]++{print $1}'
bash
libtinfo5
libc6

Be warned, though: this output is not particularly useful one way or the other:

It doesn't tell you which packages aren't used by a command, because the use could be by some way other than accessing a file (or maybe it accessed a file which was created by a package but not recorded in dpkg's database).
It doesn't tell you which packages could have not been used by a package. For example, if I ran an interactive bash session, the number of packages is a lot higher, mostly because the completion scripts provided by those are also being counted. The list even includes GRUB! And GRUB clearly isn't needed by bash.

What you should do is start with ubuntu-minimal and install only those things needed for the program to run over and above that (you'll know which ones are needed when the program dies of mysterious errors).


"An uncaught exception was raised:Invalid version string 'GNU/Linux'" when creating bootable USB stick

You could try using UNetbootin, the Ubuntu package is called unetbootin.


That's because in that command your trying to do that as the user not the admin group user

do it like this

ldapmodify -D "cn=admin,dc=imageek,dc=yesyouare" -W -x -f huehuehue.ldif

-x for unencrypted i don't know what your using ssl or tls so use it like this it will ask for ldap admin user password in opensure or redhat the admin user that has write access to the DIT is called manager.

and edit the ldif file like this

dn: uid=onepunchman,dc=imageek,dc=yesyouare
changetype: modify
replace: userPassword
userPassword: newpunchword_bwahaha


This is a problem related to a recent stable release update in Ubuntu 12.04.  We know that it's affecting a large number of users, according to the statistics on errors.ubuntu.com; but we have not yet been able to reproduce the problem ourselves so can't propose a solution.  Please file a bug report by running 'ubuntu-bug libnspr4' from the affected system, and attach the output of this command:

  sudo apt-get -oDebug::pkgProblemResolver=true install -f

(There will be a lot of output; you will want to redirect it to a file with '> logfile 2>&1'.)


Ndiswrapper is wrong. To start that module on boot run

sudo tee -a /etc/modules <<< "rt5592sta"
sudo update-initramfs -u


Programs requiring SUDO authentication not launching from Unity search launcher and Synapse [Ubuntu, 16.04]

Maybe authentication-agent is not running. Run the following command to run the agent

/usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1

If it works then run that on startup.


Neo/AdNW/KOY Keyboard Layout - Mod4 broken

KDE Plasma desktop
To solve the issue using the KDE plasma desktop, you have to go to the advanced keyboard settings in the system settings. As you already mentioned, the first thing you need to do is to disable CapsLock, which resolves the conflict with the Mod3 button. Then you have to open the "key to choose 5th level" submenu and select the corresponding modifier keys that you want to use as your Mod4 (Also see this link). For Neo, ADNW or KOY it is the < and Alt Gr key. If i remember correctly, Alt Gr is referred to as right Alt in the menu). For me, this solved the problem in Ubuntu 20.04 and I can use the KOY layout without noticing any problems so far.
It is a little bit confusing that the modifier key got the number 4 while the option talks about level 5, but it works. However, there is a small catch. If you use another layout in parallel during the learning process, enabling the Mod4 key disables the functionality of the Alt Gr key for other layouts, since it is a global setting.
After a quick search, I read that this can be solved using a bash script, but I didn't try it yet, because enabling/disabling the key in the options is quick enough for me and I only switch during my learning periods.
GNOME
As mentioned by schwupp in the comments, the gnome settings do not provide the advanced keyboard settings menu. However, if one runs gnome-tweaks (you need to install it and/or gnome-tweak-tool), you can navigate to the "Keyboard & Mouse" submenu and hit the Additional Layout Options button. Another menu will pop up where you find the submenu item "key to choose 5th level". Select the "right Alt" and < option. You can also set the CapsLock behaviour there.


You can change some grub options by editing the /etc/default/grub file. One thing to try could be to change the GRUB_TIMEOUT value there to some larger value, like 30 or so, then it should wait for 30 seconds hopefully giving your screen enough time to show the menu.

After editing the /etc/default/grub file, run the update-grub command:

update-grub

and then reboot.


Ubuntu Studio 19.04 laptop won't wake up from suspend

Okay, it's a recognized bug in the AMDGPU open source graphics driver (see https://bugs.freedesktop.org/show_bug.cgi?id=110258). The fix is available as a patch here: https://cgit.freedesktop.org/drm/drm/commit/?h=drm-fixes&id=72cda9bb5e219aea0f2f62f56ae05198c59022a7

I needed to recompile my kernel (something I'd never done before and took a long time - for other newbies this guide is quite helpful https://wiki.ubuntu.com/Kernel/BuildYourOwnKernel) but this solved the issue and the computer now wakes up from suspend. Hopefully this fix will be included in future Ubuntu kernels.


Ubuntu Touch calendar app: events imported from Google displayed on 2 days

I have just performed an update of this calendar app with the latest update sent out today and this appears to of resolved the issue of the double dots. I have performed a sync and the dots have not returned. I can only take it that this issue has been resolved, thanks to the hard work of the app development team and pomsky for their updates. Cheers guys.


Run crontab -e to edit your current crontab.

Add the entry there. Save and exit the editor.

* * * * * /usr/bin/env > /tmp/env.output

This will run the command every minute.


Virtualbox: resolvconf in ubuntu 12.04 host breaks DNS in WinXP guest

From https://forums.virtualbox.org/viewtopic.php?f=7&t=49519#p226989

Run on the host:

VBoxManage modifyvm "VM name" --natdnshostresolver1 on


You're executing the query without checking whether its return value is sane. You may get clues as to why this is failing by looking at the return value from this:

$result = $db->query('SELECT * FROM sysconfig');

Remember that $result will be FALSE if the query didn't execute successfully. So after that line you can do:

if (!$result) {
  echo($db->lastErrorMsg());
}


Ubuntu systematically losing wired connection

Installing the r8168 driver will fix it.


How can I remove the DRM from a Kindle book?

I'll leave the legalities, and ethicalness of this up to the lawyers, but my understanding is that it's illegal to break DRM, but legal to make a single backup of DRM material you have a legal right to have access to.

The answer to the question I believe is found by combining two separate works:

First this package: Calibre
Coupled with this plugin: DeDRM

The directions are detailed at the plugin link.


Run your virtual machine and go to menu. Find option: Install guest additions. If it is installed succesfully reboot your virtual machine. Now it should work in better graphics mode. More info.


Why do I see two VGA compatible controllers on my PC?

You see two because you have two. It's called ATI Dynamic Switchable Graphics.

One on-CPU Intel for energy-efficiency
One discrete card (an ATI/AMD Radeon HD 6470M in your case) for rendering.

This is a very similar setup to the Nvidia Optimus and it carries similar issues under Linux, only it seems there hasn't be as much effort go into fixing the situation as there might have been with Nvidia... There are some pretty hacky guides out there:

http://ubuntuforums.org/showthread.php?t=1930450
https://wiki.archlinux.org/index.php/hybrid_graphics#ATI_Dynamic_Switchable_Graphics

Looking at the Arch guide there, it looks like this is going to get better with the open drivers now they've landed power management but really, until then you're stuck hacking in the proprietary driver with the first guide.

You could just ignore this until things are "better" (14.04 should give you a better base) but until then your ATI card is going to be running at full power.


GRUB menu option only shows black rectangle

I managed to boot Ubuntu on this XPS13 by pressing F12 at the Dell screen after power on, and fixed the GRUB issue using:
$ sudo nano /etc/default/grub

Comment out or remove the broken theme line:
#GRUB_THEME="/boot/grub/themes/Crunchy-simple/theme-tropical.txt"

Optionally use a working theme.
GRUB_THEME="/boot/grub/themes/dark_squares/theme.txt"

Ensure readable GRUB menu on QFHD screen:
GRUB_GFXMODE="1024x768"
GRUB_CMDLINE_LINUX_DEFAULT="video=1280x720"

Ctrl+X and answer Yes to save and exit Nano.
Optionally remove some old kernel GRUB menu entries and free up /boot space after updating to the latest kernel in Synaptic:
$ sudo apt autoremove
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED
  linux-headers-5.4.0-31 linux-headers-5.4.0-31-generic linux-headers-5.4.0-34 linux-headers-5.4.0-34-generic linux-image-5.4.0-31-generic linux-image-5.4.0-34-generic linux-modules-5.4.0-31-generic
  linux-modules-5.4.0-34-generic linux-modules-extra-5.4.0-31-generic linux-modules-extra-5.4.0-34-generic
0 to upgrade, 0 to newly install, 10 to remove and 0 not to upgrade.
After this operation, 718 MB disk space will be freed.
Do you want to continue? [Y/n]

The rest can be cleaned up manually.
Use working GRUB config for this OS:
$ sudo update-grub
Sourcing file `/etc/default/grub'
Sourcing file `/etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found theme: /boot/grub/themes/dark_squares/theme.txt
Found linux image: /boot/vmlinuz-5.4.0-38-generic
Found initrd image: /boot/initrd.img-5.4.0-38-generic
Found linux image: /boot/vmlinuz-5.4.0-37-generic
Found initrd image: /boot/initrd.img-5.4.0-37-generic
Found linux image: /boot/vmlinuz-5.4.0-32-generic
Found initrd image: /boot/initrd.img-5.4.0-32-generic
Found Fedora 32 (Workstation Edition) on /dev/mapper/fedora_localhost--live-root
Adding boot menu entry for UEFI Firmware Settings
done
$ reboot


The fifth field of /etc/passwd is known as the GECOS field, it is reserved for saving user's name and comments. The entries you are seeing solely depends on how you add the user using adduser command.

I will give your answer by just showing two examples of adduser:

FIRST CASE:  Just the Full Name is given, No other info:

$ sudo adduser foobar
Adding user `foobar' ...
........Truncated.............
passwd: password updated successfully

Changing the user information for foobar
Enter the new value, or press ENTER for the default
    Full Name []: foobar foobar
    Room Number []:
    Work Phone []:
    Home Phone []:
    Other []:
Is the information correct? [Y/n]

$ getent passwd foobar
foobar:x:1002:1002:foobar foobar,,,:/home/foobar:/bin/bash

As you can see in the 5th field the comments that i have not given any input are kept blank with commas , separating them.

SECOND CASE: All info are given:

$ sudo adduser foobar
Adding user `foobar' ...
Adding new group `foobar' (1002) ...

..........Truncated...............
passwd: password updated successfully
Changing the user information for foobar
Enter the new value, or press ENTER for the default
    Full Name []: foobar foobar
    Room Number []: 10
    Work Phone []: 1010
    Home Phone []: 1234
    Other []: spamegg
Is the information correct? [Y/n]

$ getent passwd foobar
foobar:x:1002:1002:foobar foobar,10,1010,1234,spamegg:/home/foobar:/bin/bash

As you can see all parts of 5th field are now populated with the comma separated values given as input.

CHANGING VALUE: If you want to change the value of the comment field to something else you can use usermod command with -c (--comment) option:

$ sudo usermod -c "spamegg" foobar

$ getent passwd foobar
foobar:x:1002:1002:spamegg:/home/foobar:/bin/bash

Or the better way as @muru suggested in the comment, use chfn. If you are logged on as the user foobar (in this example), then you can use just chfn, or as root sudo chfn foobar. It will prompt you for entering values one by one again, you can also change any individual value by using appropriate option of chfn. Check man chfn for details.


Run these commands sequentially in terminal.

sudo apt-get install dvd+rw-tools

growisofs -Z /dev/sr0=/path/name.iso

If you get input/output error or I/O error example
[ PERFORM OPC failed with SK=4h/TRACK FOLLOWING ERROR]: Input/output error
/dev/sr0: "Current Write Speed" is 8.2x1352KBps.)

Use this command
growisofs -dvd-compat -speed=2 -Z /dev/sr0=/path/name.iso

I know speed is quite slow but its quite stable configuration and its most likely to work, but you can experiment with the values
I tried this method on DVD-R x16 dvd on my dvd writer HL-DT-STDVDRAM GT33N, LE01, max UDMA/66
NOTE: This method did help many users but in my case ,the image did get burned onto dvd, as i could notice the colour difference, but for some reason the disc still shows as blank, and my bios isn't recognizing that the DVD contains Ubuntu live CD


What is the default call of keyboard shortcuts in GNOME?

If you have a windows key on your computer hold that down for a couple seconds. hope that helps :P


Open file /etc/mysql/mysql.conf.d/mysqld.cnf and add 1 line disable_log_bin after [mysqld]
ie.
[mysqld]
disable_log_bin

and upload it.
restart mysql service with sudo service mysql restart.
it's done


You need to actually install the system before attempting to transfer data. Nothing is saved permanently when running in a live media session as in "Try Ubuntu"


Can not install Ubuntu after manually deleting partition

I figured out the problem.

For all users with Acer Aspire 5560G, hope this helps.

Press F2 when system starts to go to Settings. Change the graphics from "switchable" to "integrated".

Since this particular laptop has dual graphics, ubuntu installer was unable to use the graphics with "switchable" mode. Now it should work.


You could uninstall from the Software Centre - navigate to the page of the app you want to uninstall. At the top right, there will be a "Remove" button.

Alternately, you could use the terminal and use

sudo apt-get remove <app_name>


Installation difference between from source and apt-get?

The difference is that apt installs generic binaries and manages their versions.

When compiling a source package you are entirely on your own because apt cannot manage the package.

However, compiling a source package and installing it yourself is useful if you need features that can be had only by compiling the package yourself.

Sometimes developers will provide features that can only be used in software if a certain compiler switch is used. And sometimes specific processors can perform better if certain compile flags are used.

However, in most cases the features that can be enabled are for debugging purposes and will never be needed even by hard core users. And the binary version that apt is configured to use is already optimized for your processor.

Possible situations where you would need to compile the source yourself would be:

There's a version of the software available that has features or fixes you need but the package hasn't been updated in your repository yet.
You're compiling the software to use on a computer with a different architecture.


After installing xubuntu, I did not get a boot loader, help?

First, reset BIOS to the default settings:

Turn on the computer and immediately press the F10 key repeatedly, about once every second, until the HP Computer Setup opens.

Then, under the Main menu, use the down arrow key to select Restore Defaults. Select "yes", click "yes" to save. Reboot.

Next, disable secure-boot

Immediately press the Escape key repeatedly during startup, about once every second, until the HP Computer Setup opens. (I think you have to press F10 here)

Then, on the Advanced tab, use the down arrow key to select Boot Options, and then press Enter.

On the Boot Options page, use the down arrow key to select Secure Boot, press the Enter to uncheck the box if it is already checked.

Click Save to save the change. Then click yes.

The Computer Setup Utility closes and the computer restarts.

Next, immediately press the Escape key repeatedly during startup, about once every second, until the Startup Menu opens.

Press F9 to open the Boot Device Options menu, use the up or down arrow key to select the USB CD/DVD drive, and then press Enter. The computer starts Windows.

Insert the bootable USB, CD, or DVD into the CD/DVD drive (or USB plug) and then press the power button to turn the computer off, wait about five seconds.

Finally, press the power button again to turn the computer on and the CD DVD or USB should startup bootrepair.

If boot repair has not fixed the issue:

Start the computer and boot windows.

Open an Administrator Command Prompt window. Type the following command exactly as it is written here, verbatim and press enter:

bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi

Then, reboot and you should be able to boot into Ubuntu.

Now, run boot repair from your installed version of Ubuntu and not from the live disk or USB.

After Ubuntu boots, you will need to install boot-repair and then run it. To do so, open a terminal and type the following commands:

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

Finally, enter your password when the system prompts to start boot-repair. Select default or recommended fix.

The user with the same laptop model in the following linked (where I got alot of this info from) post also recommended using Grub Customizer to iron out the grub settings if you want to customize or edit them. I would suggest taking a look at the following post for more info.

How can I make Ubuntu the default boot option on a newer laptop (UEFI)?

and

For more info, the HP BIOS instructions were derived from here.


How do I change the plymouth bootscreen?

To change between the installed themes you should do:

sudo update-alternatives --config default.plymouth
sudo update-initramfs -u

The first will list available themes to choose from, the second command with update initramfs with a new theme.


Why TEST = Hello with blanks doesnt work in the terminal?

Makefiles are read and processed by the make program, whereas shell scripts are read and processed by a shell interpreter - they have different variable assignment syntax and parsing rules.
There's nothing to say a shell couldn't parse assignments with whitespace around the = as make does - in fact, some shells (notably csh) do so, for example
#!/bin/csh

set test = hello
echo "$test"

however the POSIX /bin/sh and Bourne-derived bash, as well as ksh and zsh do not allow it.


what is the pincode when pairing a JBL Charge 2+?

According to the quick start guide the code is 0000, so you must have other problems with your connection.

Edit - that link appears to be for a Charge, this link for the Charge 2 does not show any code at all.

Edit 2 - neither does this manual for the Charge 2+.


Try this my friend : Grub customizer. with this tool you can customize your ubuntu grub. Download from here: https://launchpad.net/~danielrichter2007/+archive/grub-customizer/+files/grub-customizer_3.0.4-0ubuntu1%7Eppa1p_i386.deb

After install please running it , Go to appearance tab and custom ur background boot as u want it from there.


Not sure how you can troubleshoot like this. Also I apologize, I am not able to comment.
Try to disable the NetworkManager and use wpa_supplicant and dhclient manually. Don't run wpa_supplicant with the -B argument to run in the background, that way you can see what it says when you disconnect.
Its going to be something like this

echo `wpa_passphrase ssid passphrase` >> /etc/wpa_supplicant.conf
wpa_supplicant -iinterface -c/etc/wpa_supplicant.conf
dhclient wlan0

Now when you disconnect look at the error it gives you. Also check the lease time when you use dhclient.


messed with my audio settings and now I can't record sound while recording my monitor

Some info HERE

Make sure the audio device is Pulse

Try this Pulse Audio Volume Control HERE

PulseAudio info HERE

Try uninstalling and reinstalling, open terminal and enter:

sudo apt-get purge simplescreenrecorder

then:

sudo apt-get install ppa-purge

ENTER

sudo ppa-purge ppa:maarten-baert/simplescreenrecorder

ENTER

sudo add-apt-repository ppa:maarten-baert/simplescreenrecorder

ENTER

sudo apt-get update && sudo apt-get install simplescreenrecorder

ENTER


What is "'gtk2' Qt style" in Lubuntu 19.10?

One solution is to install qt5-style-plugins.

The following additional packages will be installed:
  qt5-gtk2-platformtheme qt5-style-plugin-cleanlooks qt5-style-plugin-motif
  qt5-style-plugin-plastique
The following NEW packages will be installed:
  qt5-gtk2-platformtheme qt5-style-plugin-cleanlooks qt5-style-plugin-motif
  qt5-style-plugin-plastique qt5-style-plugins

Once installed, open LXQt Appearance again. The gtk2 style is now available.

(A log out and log in seems needed to make pcmanfm-qt use the dark theme.)

The image shows various Qt applications (featherpad, konsole, pcmanfm-qt, and LXQt Appearance) themed dark.


Force Ubuntu server locale to Windows client

you might find your answer and lots of other useful info by following this link

Ubuntu Server Guide - Windows Networking

Good luck and keep us posted.


How to fix an error using a colorscheme for gvim?

I'm not quite sure about that error message but seems like your vimrc file cannot find your colorscheme.

Have you tried using color scheme from your home folder ?(/home/your_home_folder/.vim/colors/ir_black.vim)

If you have some colorscheme files in that folder then you can activate from edit->ColorScheme->ir_black.
If you want "ir_black" as your default gvim cholorscheme put "colorscheme ir_black" in your vimrc file (/home/your_home_folder/.vimrc).

And the reason you are seeing lot of gap between each character is the font that you are using in your vimrc is not available in computer.


The package that owns /etc/samba/smb.conf is samba-common - You should be able to copy the config from /usr/share/samba/smb.conf if /etc/samba/smb.conf is missing & then run dpkg --configure samba-common


Ubuntu 13.10 Amd Radeon HD 4870 No Drivers or Fglrx tools

I do not think that AMD is supporting the 2xxx,3xxx,and 4xxx cards anymore.  There are legacy drivers for them, but they do not work for the newer kernels after 12.04.  There is a work around for them but from what I read, it is a 50/50 chance of it working, and you probably have to rework it after system updates. It might break your system also, use at your own risk.   I think your best bet would be to use the open source drivers, unless you must have the Radeon drivers for your system, you could reinstall 12.04. Colin


If you choose "Switch Account" from the power menu at the lock screen...

then press the physical power button...

you should get the option to restart the computer by default.


How do I create a YAML file in order to set a static IP for my /etc/netplan directory? Server 18.04 LTS

That is exactly what I suggest that you do. Here is a sample file to get started: Can't change Ubuntu 17.10 to use a static IP

Of course, substitute your exact details here. Also, indentation, spacing, etc. are crucial. Proofread carefully.


My graphics is working again.
Out of sheer despair I followed an advice found somewhere to switch from wayland to xorg (I've never heard of wayland):
In /etc/gdm3/custom.conf I uncommented WaylandEnable=false.

That did it. I'm back to a screen resolution of 1680x1050 which is A LOT better than 800x600!

I hope this survives the next update ;-)


USB live error, "cannot open output file F:\autorun.inf"

I don't know why the menu looks exactly like it does, but a live USB flash drive, even with a persistent area, still provides the same boot options as a normal live USB flash drive with no persistent area.

So, to use the system on the USB drive, select Try Ubuntu without installing. It should work fine.

In case something went wrong in the creation of the live USB, I recommend testing its persistence first before assuming it works. For example, you could create a file on your desktop. Then shut down and reboot, and see if the file is still there. If it is, you should be good to go.


After system repair, snapd service is not running/fails to restart

A brute force fix:
sudo apt purge snapd snap
sudo apt install snapd snap

Followed by manual re-installation of all snaps.
If anyone can suggest a better fix, you are welcome.


how to create wifi hotspot in Ubuntu 14.04

You have to go in System Settings > Network and then in the Wireless section, click on "Use as hotspot".

After the security notification, it will show you the network name and the wep key needed to connect to this network (those informations can be customized).

For more details, you can also check : http://www.howtogeek.com/116409/how-to-turn-your-ubuntu-laptop-into-a-wireless-access-point


One way to fix this, would be to use the 'apt' version of gnome-calculator instead of the 'snap' version:

sudo snap remove gnome-calculator

will remove the snap version of the calculator, and the 'apt' version is already installed on your system.  Just open the activities....


How do I set up a default GNOME and KDE desktop for every new user I will create?

I've done this once when working on a live cd, and would suggest copying from home to skel, and then testing, and modifying individual files as needed from that point. Another thing, try using Virtual Box and a mock installation first before you do this on an actual system, just to be safe.

For GNOME you can also set defaults in Gconf Editor (gconf-editor command) by right clicking on a value and choosing to set it as default.


Error in the simple shell script ( i.e.+ : unexpected `end of expression' )?

I think the most likely explanation is that your dirsize variable is empty.

For example, in bash

$ foo=3; bar= ; echo $(( $foo + $bar ))
bash: 3 +  : syntax error: operand expected (error token is "+  ")

while in AT&T ksh

$ foo=3; bar= ; echo $(( $foo + $bar ))
ksh:  3 +  : more tokens expected

and in BSD mksh

$ foo=3; bar= ; echo $(( $foo + $bar ))
mksh:  3 +  : unexpected 'end of expression'

Note that all of these shells allow "bare" variable names like (( foo + bar )) in expressions, and this form may be preferable since it treats empty variables as zero values. From man bash:

   Shell variables are allowed as operands; parameter  expansion  is  per‐
   formed before the expression is evaluated.  Within an expression, shell
   variables may also be referenced by name without  using  the  parameter
   expansion  syntax.  A shell variable that is null or unset evaluates to
   0 when referenced by name without using the parameter expansion syntax.

So for example

$ foo=3; bar=7 ; echo $(( foo + bar ))
10

$ foo=3; bar= ; echo $(( foo + bar ))
3


I'm not sure if it updates automatically or how that works. I just installed Unetbootin on a fresh 13.10 install today and it gives me 6 different variations of 12.04 to choose from. So maybe

Alternatively, you could just go to:

http://www.ubuntu.com/download/desktop

Select 32 bit or 64 bit and download the ISO file onto your computer. Then open up Unetbootin, choose Disk Image instead of Distribution, find the file you just downloaded and install it.

Hope that helps!


The process is the same as accepting any other call in Skype. When someone calls you with Skype, just click Answer or Answer with Video. If the call is a conference call, than you will be able to see and hear all of the participants once you have joined.


You should see the command chmod and id.


How to install an older version of a package not entirely intended for your Ubuntu version?

Remove the PPA and installed packages from it. Now try manually adding the trusty version of the PPA:

sudo add-apt-repository "deb http://ppa.launchpad.net/developer-name/ppa-name/ubuntu/ trusty main" (where developer-name and ppa-name are placeholders).

This should work, assuming the PPA has support for the trusty release, however it has not been tested on our end. If the command fails (which it might), you can undo it with the same command, but add the --remove tag after it.


Ubuntu/Linux tools to put Ubuntu on USB (for testing or installation)?

Many live CD images are actually hybrid CD/USB images, so they can be copied directly to either a CD or USB drive with dd and will work either way.  This is true of all Ubuntu and Debian official live CD images over the last few years, and may be true of other distros.

dd if=cdimage.iso of=/dev/xxx

Where /dev/xxx is the USB drive.

In cases where that doesn't work because the image is not a hybrid CD/USB image, unetbootin is the best way I can think of.


How to set Konsole key bindings in 16.10?

In konsole, you can go to settings -> edit current profile -> keyboard to modify your key bindings. You can also use your own defined keyboard with mappings specified in your own keymap file.


I can't do anything in APT: "E:Type 'sudo' is not known"

Welcome to Ubuntu, you will be good to go with a little more experience.

I assume you manually edited the file /etc/apt/sources.list.d/spotify.list and you now have a typo in the file.

Open the file in any editor (sudo nano /etc/apt/sources.list.d/spotify.list ) and fix it.

If you  do not know the syntax, post the contents of the file here.

See also : How do I remove a malformed line from my sources.list?


Can you tell whether I have a hardware or software problem with a DVD-ROM drive?

I think it is an encryption problem.
You may need libdvdcss

Search for it synaptic or

sudo apt-get install libdvdcss2 libdvdread4 libdvdcss-dev


Recover GRUB-EFI after installing Ubuntu on a Mac

You can use Boot Repair. It will regenerate your GRUB installation. To install it:

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt install --assume-yes boot-repair
boot-repair

If you cannot access to Ubuntu anymore, use a live CD/USB: https://ubuntu.com/tutorials/try-ubuntu-before-you-install#1-getting-started
and select the "Try Ubuntu" option. Then install there Boot Repair and follow instructions.


Where can I find good quality LXD Documentation

LXC vs LXD

Blog posts are nice & informative and good to read to get started but good documentation they do not make once you've gotten started.  If you are like me, you may be fairly clear on the difference between Docker & LXC/LXD after reading only a few commonly-found blog posts on this..  But the difference between the older LXC project and the new LXD project were not at all clear to me, and most pages I found just don't do a good job explaining it in a way I could understand.  Mostly they try to clear the confusion between an application container (Docker) and an operating system container (LXC/LXD).  Then I found this blog post:  Where does lxd fit in

As you may know by now, all of these tools (Docker/LXC/LXD) use common kernel features like namespaces and cgroups, it's just a question of how userspace decides to use them.  A summary of the above post focused on the evolution of LXC vs LXD, based on my understanding:

LXC originally was created to test the new kernel features; as such it was a mishmash of shell scripts and C programs (still used today via the "old" LXC command line tools).
Then this was refactored into a library.  Existing LXC userspace command line tools use this library now.
LXD is a ground-up way of interfacing with this library that's unencumbered by backwards-compatibility with the old LXC command-line tools.  So it's easier to use and more capable.

If anyone (like a maintainer) sees some errors above, please feel free to correct my answer. :)

Some notes on libvirt-lxc

Also, in case you are considering libvirt-lxc (e.g. if you are already using libvirt with KVM):

Red Hat deprecated this: https://access.redhat.com/articles/1365153
Upstream says they will still work on it: https://www.redhat.com/archives/libvirt-users/2015-August/msg00026.html
Even though libvirt-lxc has lxc in the name, it does not actually use lxc and instead directly uses the kernel features.  So don't confuse this libvirt driver with lxc despite the naming confusion.  Reference: http://libvirt.org/drvlxc.html  (Note that I think proxmox does use lxc proper, but not the newer lxd tools).
Stéphane Graber suggests that using libvirt with containers is a poor fit, and that while somebody could conceivably write a libvirt-lxd, he thinks it is also a poor fit.  In summary: libvirt is designed to manage VMs and containers are not VMs, so things get messy and you only support a common denominator of features.  Reference: https://lists.linuxcontainers.org/pipermail/lxc-devel/2014-November/010820.html
To reinforce the previous, it's not so easy to create new containers with libvirt-lxc.  For example, you have to give it a path to an EXISTING rootfs for a new container you want to create, and there's no support in libvirt-lxc to spin that up.  So that leaves you doing things like using external tools like lxc-create to create a new container from a template, and then make a new libvirt-lxc container using that existing dir just created, which then leaves me asking: "why fuss with libvirt-lxc instead of just using lxd directly?"

LXD documentation

Back to your question, I've tried to bring together all the reference documentation on LXD I could find.  There is some nice documentation here:

https://github.com/lxc/lxd/tree/master/doc

In particular:

configuration.md has a nice reference list of possible configuration options.
imagehandling.md talks about how operating system images are cached locally.
lxd-ssl-authentication.md discusses the REST API and how it's exposed over both a local UNIX socket, and optionally on HTTPS, and how this is secured.
storage-backends.md discusses the limitations & configuration of each storage backend.
userns-idmap.md lxd by default uses unprivileged containers which means that container UID/GID must be mapped to a host UID/GID; this discusses that.
A lot of the remaining documentation isn't as critical to read, or is more geared towards developers.

The above links are from master branch of lxd upstream so you might want to check the doc directory for the sources of the package you actually have installed, so you don't accidentally use some new feature that you don't have installed yet.

There aren't really many man pages, but here is what I found included in the lxd and lxd-client packages:

LXC(1) - client program to communicate with server daemon.  Currently (5/14/2016) rather useless and uninformative.  Hopefully in the future a series of manpages can be made for this tool, much like the btrfs manpages.
LXD(1) - server daemon command line.

Of course, there is also the server guide page: https://help.ubuntu.com/lts/serverguide/lxd.html

Finally, remember that lxd is based on the lxc library (but not the old lxc command-line tools).  This means that lxc configuration can still be directly done, e.g. using raw.lxc configuration option in lxd.  Therefore some reference to the underlying LXC configuration is useful, but remember it should be avoided if possible to avoid a conflict with LXD (e.g. if you set the same configuration item in both LXD & LXC).  You can dig through the manpages to find those if needed: https://linuxcontainers.org/lxc/manpages/


You may also try pre-installed vdi files.

Check this url:

http://virtualboxes.org/images/ubuntu/

At the time being 10.04 is the latest vdi


How can I edit this code for user input and to end at 0?

Since you're using bash, you can make use of some features that might not be available in POSIX /bin/sh. For example:

read accepts a prompt string, eliminating the need for a separate printf

read -p 'Type in a whole number!: ' x

you can use arithmetic expressions like (( x > 0 )) in place of [ x -gt 0 ] test brackets, and postfix decrement like ((x--))
bash has an until construct that might be more idiomatic for a count down

So for example:

#!/bin/bash

read -p 'Type in a whole number!: ' x

until (( x == -1 )); do
  printf '%d\n' $((x--))
done

ex.

$ ./myscript
Type in a whole number!: 5
5
4
3
2
1
0


What errors are you getting? Did you purchase the domain name you are trying to use from a source such as NameCheap or something similar?


Look & Feel:

GTK+ and Java Swing Applications do not play well at all together when it comes to look and feel. I am afraid we'd have to wait for Java 8 for a proper fix.

For the time being, if you're not using Kubuntu but Ubuntu and Unity, you have to switch to the native look and feel which is Metal.

Go to your netbeans directory (ex: /home/user/netbeans7.2/etc) and open the file : netbeans.conf

then add the following line to netbeans options:

-J-Dswing.aatext=true -J-Dawt.useSystemAAFontSettings=lcd --laf Metal

Source: http://hanynowsky.wordpress.com/2012/04/27/netbeans-ide-look-feel-under-ubuntu-12-04/

Global menus:
Java Swing applications cannot benefit from Global menus integration for now. For the same reason: GTK/Swing implementations. Even Eclipse IDE is blacklisted for now even though it's SWT and not Swing based. Same goes for Emacs and Lotus notes.
Nevertheless, you can activate Global Menu support for Java Swing applications by using Java Ayatana Library and for netbeans install the corresponding plugin : http://hanynowsky.wordpress.com/2012/05/12/integration-of-java-swing-applications-with-unity-global-menu-in-ubuntu-12-04/
By the way, it would be ideal if OpenJDK crowd include this same library in OpenJDK's next version so that Swing Application get support for Global Menu out of the box.

Slowliness:
I use Netbeans IDE frequently on my machine and it's not slow at all compared to Eclipse.
It might be an issue with the version packaged for Ubuntu Software Center (repos). I don't recommend it. Instead, download Netbeans 7.1.2 from Netbeans.org and install it locally on your home directory. You'll notice that it's faster than the version in repositories. Slowliness might also occur when you're using OpenJDK instead of Oracle JDK (Tested).


Ubuntu 13.04 can't open software & updates / software sources

According to warning it seems to be a bug because some of the apps in repositories didn't updated/read correctly. As the post suggest you should consider to launch a bug.

But before that it is not bad to give a try to fix the problem. I suggest you to completely remove software-center and install it again, if you don't mind.

Please follow execute following commands in terminal to remove/install:

sudo apt-get autoremove software-center
sudo apt-get --purge remove software-center
sudo apt-get autoclean && sudo apt-get autoremove
rm -r ~/.config/software-center
sudo apt-get update
sudo apt-get -f install software-center

Just in a case, install synaptic and check whether you'll be able to open Software & Updates through that. Also check whether you have some broken or residual pacakges.

I wish it would help you to fix your issue.. Reply if something goes wrong..


How to create php files in /var/www folder?

Open /var/www/

cd /var/www/

Create the file

sudo touch hello.php

Open the file

sudo vi hello.php

Enter write mode (we were in command mode initially) by pressing a (note that vi is case sensitive)

After that, press Esc (to change to command mode) and type :wq. Check if everything is fine with cat hello.php.

However, it's probably a better idea to use editors such as vim or nano as work with them is a lot simpler than that.


Ubuntu Chromium browser - how to define zoom percentage via command line launch?

Run the following in command line to set the Chromium browser zoom percentage to 79%

chromium-browser --force-device-scale-factor=0.79


Boot fails after showing ubuntu screen and just sits on screen showing [OK]. Tried removing fglrx but still can't get it to go

I had reinstalled the system but likely the stated answer of:

sudo service lightdm restart

will do the trick from having a similar error on another computer.


My screen is disabled for a long time after I click "Install to harddisk"

You need to disable "apic" as well as acpi.
When editing the boot options, use both acpi=off and noapic.
You can edit the boot options by pressing F6 on the boot screen (hit Escape when the little picture of a keyboard and a person shows up):

In addition to displaying a popup menu, the F6 key also activates in-line editing of the boot command. Pressing F6 brings up the popup menu. Pressing ESC, whether selections were made or not, removes the popup window but opens the boot command for editing.
The phrase "Boot Options" is fixed on the left side of the screen. The command scrolls off to the left to leave the right end available for appending. The user may add additional inputs after the "-- ". Allow one space between each additional input.

At the end of the boot options, append both the avove arguments.


Google Chrome opens window underneath current window

If you have several windows open in google chrome you should see a small arrows next to the google chrome icon in the launcher.IN this example i have 2 windows open thus showing  2 arrows

To get a Quick view of all windows currently  open,  left click on the icon and you will see something like the below picture,which shows all current open windows.Click again to go back to original window or click on the window you wish to open. This also works for other programs for example having several gedit pages open.

If i go to google chrome settings/extensions/get extensions the chrome web store opens in another tab for me


How to initialize TP-Link WN725N V3 at startup every time Ubuntu 18.04?

Well I have rebooted x number of times x5. It's fixed. If you see a question mark the first time do not fret just reboot again.

The problem does not seem to be with my exact adapter or any particular WIFI adapter. Maybe works for anything plugged into USB and beyond.

This issue is a gadget/driver binding thing. Never heard of it.

I can't take credit the answer is here Ubuntu doesn't bind usb device after reboot

pretty simple even for a noob. It was my first time using nano.

control+o to save

control+x to exit


Simple VJ software for background video in live concert

Here are a few:

freemix
FreeJ
LiVES
veejay


Run lsusb -t, it'll show all your USB devices in a nice hierarchy as well as the speed of each port.


I had this same issue.  Disabled NetworkManager-wait-online.service and that will cut down on some of the time.  Otherwise if you can update to 18.10 that is what solved it for me.


How do I move mouse's arrow with 1 index finger on topside of touchpad while other index finger touches left bottom area of the touchpad?

Copying /usr/share/X11/xorg.conf.d/40-libinput.conf to file 90-libinput.conf in the same folder and updating 90-libinput.conf as follows fixes the problem:
Section "InputClass"
     Identifier "libinput touchpad catchall"
     MatchIsTouchpad "on"
     MatchDevicePath "/dev/input/event*"
     Driver "libinput"
         Option "Tapping" "True"
         Option "DisableWhileTyping" "True"
         Option "TransformationMatrix" "4.000000 0.000000 0.000000 0.000000 4.000000 0.000000 0.000000 0.000000 1.000000"
EndSection


"Failed to start network default" error when trying to juju bootstrap an LXC environment

This happens because you're likely not a member of the libvirtd
  group. You can confirm this by running groups in the command-line. If
  libvirtd isn't in that list you'll need to do the following:

sudo usermod -a -G libvirtd <YOUR_USER>

  Once you've added yourself to the group you can either log out/back in
  or just run:

newgrp libvirtd

  This will set up that terminal session (and you user for that terminal
  session) to be a part of the libvirtd group. From here you should be
  able to run juju bootstrap.

How do I configure juju for local usage?


How do I become an Ubuntu Partner so I can build devices?

Welcome to Ask Ubuntu, a community-driven Q&A site where we answer software questions about the Ubuntu Operating System.
Though there are some Canonical employees here, most of us are not, so you'd be better off redirecting your question directly to Canonical, the company behind Ubuntu as your question is off-topic here...
;-)


VirtualBox running Ubuntu distro - troubleshooting

As memory serves me, switching TTY's should fix the problem. In your case, your host key is set for left-command, so it would be Left-command + F1, followed by Left-command + F7. It's a bug.

update: on your Mac, you may have to Left-command + fn + F1 and then Left-command + fn + F7


How do I allow SFTP with a password BUT not SSH?

Here is a possible answer:

https://serverfault.com/questions/354615/allow-sftp-but-disallow-ssh

Link describes the use of

Subsystem sftp internal-sftp


Automatic say yes to make ext3 file system on disk with mkfs.ext3

You should probably not make a filesystem on an entire disk. Instead, you should make it on a partition on the disk (which would be something like /dev/sdc1 rather than /dev/sdc). If you don't already have a partition you can make that first. The partition can (essentially) be the size of the whole disk, if you like. Even when you only want one partition on the disk, you still need to actually make the partition. Many utilities and applications (and people!) will not work, or will behave strangely, if your filesystems are not on partitions.

If you really know what you are doing and you're sure you want to make a filesystem that is not part of any partition, you can do make mkfs.ext3 do this without prompting the user, by using the -F flag. This is almost always preferable to simulating interactive input with a pipe (it's simpler, more self-documenting, and what if something unexpected happens and the question is something else, like the device already being mounted?). On the other hand, in some situations (with some utilities) you may find you have to pipe y or yes to a utility, so it's a good technique to be aware of.

From the description of the -F flag in man mkfs.ext3:

  Force mke2fs to create  a  filesystem,  even  if  the  specified
  device is not a partition on a block special device, or if other
  parameters do not make sense.   In  order  to  force  mke2fs to
  create  a filesystem even if the filesystem appears to be in use or is
  mounted (a truly dangerous thing to do), this option  must be
  specified twice.

So, you can use mkfs.ext3 -F /dev/sdc.

But, to reiterate, you should probably not do this at all because filesystems should almost always be created on a partition.


At first you should know that RedShift is packaged in all Ubuntu versions.
To remove locally installed stuff use:
sudo python3.8 -m pip uninstall redshift-gtk
sudo rm /usr/local/bin/redshift
sudo rm /usr/local/bin/redshift-gtk

So you can simply install RedShift from repository with:
sudo apt-get install redshift redshift-gtk


Error running updates: GPG error: http://repository.spotify.com stable InRelease

Looks like Spotify has changed the keys. You can solve this problem by running the following command in the terminal:

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys D2C19886

Refer the official update and installation instructions.


Design justification and analysis is available here.


asks for password when trying to format unencrypted HDD

i resolved it by reinstalling Ubuntu.
If anyone had an answer it wont hurt to share in case someone else gets the same issue


virtualenv is activated but pip freeze return all system packages

Ubuntu packages virtualenv in a different way. While in other environments when you create a new virtualenv, it is empty, Ubuntu packs a lot of packages inside a newly created virtualenv.
Anthony Sottile made some interesting videos on this topic and also explains how to get virtualenv not from Ubuntu package manager, but from scratch - and turns out, this one is able to create new virtualenvs with zero packages inside.
curl --location --output virtualenv.pyz https://bootstrap.pypa.io/virtualenv.pyz

You can then do a python3 virtualenv.pyz venv - and into this venv you can install virtualenv. And then put it on your path. Sounds complicated? It is well worth it.
This uptodate virtualenv is up to 10 times faster than the one from Ubuntu packages and it has zero packages inside a new virtualenv.
I recommend to watch this video...
https://www.youtube.com/watch?v=OXmYKh0eTQ8&ab_channel=anthonywritescode


How do I select 3,000 out of 10,000 files in file manager?

There is no easy method to do that from a stock file manager. You can do it with Shift +  Arrow Up (or Arrow Down) but you will need to select the amount of files yourself.
Command line:
This will copy (cp) 3000 files (-n 3000)  to /opt/ (-t "$directory"):
cd /dir/with/files/
find . -maxdepth 1 -type f -print0 | head -z -n 3000 | xargs -0 -r -- cp -t "/opt/" --

Change 3000 to another number if needed
Change /opt/ to your desctination.
Use mv -tf to move instead of cp -t when you know cp does what you want (the mv is needed to clear the 3000 files)


I am a Sixth Form student who needs to use 3D CAD software for my project. Any clue on how to do this?

Try OpenSCAD

  OpenSCAD is a software for creating solid 3D CAD models. It is free
  software and available for Linux/UNIX, Windows and Mac OS
  X.OpenSCAD

To install, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo apt-get install openscad


Getting log file of system ON & OFF history

Maybe You're looking for ~/.xsession-errors?

Also take a look at ~/.bash_history.


You appear to have been affected by this bug in gdm3 You may wish to subscribe to it so that you get notified when it's repaired.

To confirm, issue the command cat /etc/X11/default-display-manager which should output the full path of your display manager. You might go so far as to change display managers as a workaround. This should get you a bit farther, hopefully this and a reboot will solve the too many open files problem as well..


Disable HDMI audio on ubuntu studio 19.04

This problem is happening to a lot of people including me in Ubuntu 19.10 due to a bug 1847570 PulseAudio automatically switches to HDMI sound output on login.

The only solution that worked for me was by Selmi in this question:

Open a terminal
Run sudo nano /etc/modprobe.d/blacklist.conf
Add blacklist snd_hda_codec_hdmi to the end of the file on its own line
Save the file (CTRL+O) and exit (CTRL+X) nano
Reboot.


Internet not working on Ubuntu 14.04.01 LTS

Using

  route -n

and also nm-tool:

I could see that eth1 had become set as the default, and was pointing to the gateway address.
Our setup required eth0 to be the default. This was resolved using:

sudo ip route change to default dev eth0 via 172.21.0.1

where 172.21.0.1 is the gateway address.


Ubuntu 17.04 with GNOME stuck in login loop

Try install gdm
crtl + alt +f2(login)
sudo apt install gdm
sudo dpkg-reconfigure gdm
sudo service lightdm stop
sudo service gdm start


First, install the TightVNC server  sudo apt-get install tightvncserver.
Set up the VNC server for the user you wish to log in as. When you run "vncserver" for the first time, it will ask you to set a password. only allow SSH tunnelled or VPN connections. To launch programs or a session when your VNC session starts, modify ~/.vnc/xstartup. Here is an example.

#!/bin/sh

xrdb $HOME/.Xresources
xsetroot -solid black
/opt/azureus/azureus &
k3b &
icewm-session &

Copy the following into /etc/init.d/vncserver. The easiest way to do it is to copy it to your clipboard, run sudo -i && cat > /etc/init.d/vncserver && exit in a terminal, paste it in, and type CTRL-D. Be sure to change the USER variable to whatever user you want the VNC server to run under.

#!/bin/sh -e
### BEGIN INIT INFO
# Provides:          vncserver
# Required-Start:    networking
# Default-Start:     3 4 5
# Default-Stop:      0 6
### END INIT INFO

PATH="$PATH:/usr/X11R6/bin/"

# The Username:Group that will run VNC
export USER="mythtv"
#${RUNAS}

# The display that VNC will use
DISPLAY="1"

# Color depth (between 8 and 32)
DEPTH="16"

# The Desktop geometry to use.
#GEOMETRY="<WIDTH>x<HEIGHT>"
#GEOMETRY="800x600"
GEOMETRY="1024x768"
#GEOMETRY="1280x1024"

# The name that the VNC Desktop will have.
NAME="my-vnc-server"

OPTIONS="-name ${NAME} -depth ${DEPTH} -geometry ${GEOMETRY} :${DISPLAY}"

. /lib/lsb/init-functions

case "$1" in
start)
log_action_begin_msg "Starting vncserver for user '${USER}' on   localhost:${DISPLAY}"
su ${USER} -c "/usr/bin/vncserver ${OPTIONS}"
;;

stop)
log_action_begin_msg "Stoping vncserver for user '${USER}' on localhost:${DISPLAY}"
su ${USER} -c "/usr/bin/vncserver -kill :${DISPLAY}"
;;

restart)
$0 stop
$0 start
;;
esac

exit 0

Make the script executable with sudo chmod +x /etc/init.d/vncserver.
Finally, connect to your server with a VNC client on port 590X, where X is the value of "DISPLAY" in the vncserver script. On OS X, I like to use Chicken of the VNC. On Windows and Linux, the TightVNC client works nicely.

Source


I do not believe we have something like that.
This will show when a system was installed:
$ sudo tune2fs -l /dev/sda1 | grep 'Filesystem created:'
Filesystem created:       Sat Jun 14 18:29:43 2014

Replace /dev/sda1 with the device name you need (1st column of df / will show you what you want). But I do not believe I ever saw a command to show how long a system has been turned on or off.
uptime

will only show how long the current uptime is.
This will list the last 1000 reboots/shutdowns:
last -1000 reboot shutdown

But that lacks the moment the system was turned on after a shutdown.
edit:
How about an approach like this (it will list the hours a disk has been active):
 smartctl --attributes /dev/sda | grep Power_On_Hours

Replace /dev/sda with your device name and install it with sudo apt smartmontools if not available yet. Not totally perfect as it assumes you started using the disk when the system was installed.


locate: ignore .git .svn and hidden folders in general when using wildcard

I have found this locate -i '*testhack*' | egrep -v "\/\." | head -n 256 but using only locate, although it seems faster than using regexes with locate.


Bridge does not get IP from DHCP server on boot

I believe for your bridge section, it should look like:

It is bridge_ports not bridge-ports

auto br0
iface br0 inet dhcp
    bridge_ports eno1
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0
iface eno1 inet manual

More information can be found here.

Example from my system:

$ cat /etc/network/interfaces
# The network interface
auto br0
iface br0 inet dhcp
   bridge_ports eth0
   bridge_stp off
   bridge_fd 0
   bridge_maxwait 0
iface eth0 inet manual
auto lo
iface lo inet loopback

$ ifconfig
br0       Link encap:Ethernet  HWaddr 00:21:85:94:46:a4
          inet addr:10.0.0.100  Bcast:10.0.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:195 errors:0 dropped:0 overruns:0 frame:0
          TX packets:211 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:39400 (39.4 KB)  TX bytes:27433 (27.4 KB)

eth0      Link encap:Ethernet  HWaddr 00:21:85:94:46:a4
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:278675 errors:0 dropped:0 overruns:0 frame:0
          TX packets:263759 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:110002223 (110.0 MB)  TX bytes:408874062 (408.8 MB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:64269 errors:0 dropped:0 overruns:0 frame:0
          TX packets:64269 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:23474196 (23.4 MB)  TX bytes:23474196 (23.4 MB)

Hope this helps!


If you want the update to continue then you might want to try the following:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade

the last command should continue the installation process

If you see any issues, run this

sudo apt-get -f install


Ubuntu equivalent of the Cisco Anyconnect vpn client

There is a package called openconnect which does the job. To install it:

sudo apt-get install openconnect vpnc

and to run it, so that you can access the restricted network (eg through your browser):

sudo openconnect vpn.hostname.com

and enter the username and password when prompted on the command line. Or to input them automatically all in one go:

echo 'the!!password' | sudo openconnect -u 'the!!username' --passwd-on-stdin vpn.hostname.com

To send the script to the background so that you can continue using the command line:

Ctrlz

then

bg

(for background).


Try using the -z test:

if [ -z "$1" ] && [ -z "$2" ]

From man bash:

-z string
   True if the length of string is zero.


You can open it in your favorite text editor, or use a tool like cat or less.

For example:

    cat /etc/script.pl


Why can't I get a screen resolution higher than 1024x768

EDITED: I just saw this typo on your question, it was VGA1 not VGA-1 in your command line, retry and let me know ;)

it seems that your problem was somehow common Like here

The thing I would suggest is to download the latest Ubuntu driver of your express chip-set from the Intel website G41 Download Page


In the end, i did not choose to update my libc6 to a newer version to support the R 4.0 because change in libc can cause some problems.

What i did was to look for a older version of glmnet from the archive and installed it with my older version of R (3.2.3) and it worked perfectly!


Can't connect to Internet via Ethernet wire

There might be a problem with your network services. Try resetting them:
Open the terminal by pressing Ctrl+Alt+T and then type in: sudo service networking restart.
After the command has run, restart your machine, and it will reconfigure the settings upon restart.

However, there are issues whereby Ubuntu writes "Booting Up without full network config"...a second restart will do the trick.

If this doesn't work, and the problem continues to persist afterwards, open the command line and type in this:
echo on | sudo tee /sys/class/net/eth0/device/power/control

This should resolve it, and ethernet is bound to work afterwards.


Difference between key (recv-keys), signing key, and fingerprint in APT/PPA system

I'll start with your last question.

ppa:ansible/ansible is a special format that refers to Launchpad PPAs and can be used in Ubuntu and Ubuntu derivatives (at least). In terms of functionality, a PPA is just a regular repo. However, this exact format can't just be added into /etc/apt/sources.list, since apt doesn't recognize this format. Therefore, the URL to the repo has to be added. For example, the URL for ppa:teamName/archiveName is http://ppa.launchpad.net/teamName/archiveName/ubuntu.

Typically, either Software Updater or the terminal is used to add a PPA. Software Updater recognizes the PPA syntax. In terminal, apt-add-repository recognizes the format and is typically used to add a PPA. This also gets the public key that is used to sign the repo. If, for some reason, it isn't able to, you'll get a similar warning that you got when running sudo apt-get update.

As for the fingerprint, the full fingerprint of a public-key is a 40-character alphanumeric representation of the public key. Launchpad shows the full 40 characters. However, typing or remembering 40 characters is difficult, especially when there are multiple public keys. Therefore, typically the last 8 or 16 characters are shown. apt is showing the last 16 characters of the fingerprint, and apt-key list (which uses gpg behind the scenes) is showing the last 8. The format to show in gpg can be configured.


Does Ubuntu support "@reboot" in crontab?

@reboot is supported in Ubuntu. The reason why your entry

@reboot /var/kiosk/btest.sh

doesn't work in /etc/crontab is because it's missing the user field. The correct syntax would be

@reboot root /var/kiosk/btest.sh


The boot loader will load the kernel, the kernel would attempt to run init, not find it and panic.

The way out of it is to reboot, edit the boot parameters, add init=/bin/bash and boot that way. The kernel will use bash as init. This will give you a chance to run commands and fix the system.

Correction
Apparently the kernel (file init/main.c) does:

if (!try_to_run_init_process("/sbin/init") ||
    !try_to_run_init_process("/etc/init") ||
    !try_to_run_init_process("/bin/init") ||
    !try_to_run_init_process("/bin/sh"))
        return 0;

panic("No working init found.  Try passing init= option to kernel. "
      "See Linux Documentation/init.txt for guidance.");

So it would find /bin/sh (which is a link to dash) and that will give you a shell and a chance to fix it without using the init=/bin/bash boot parameter.


You have to know that VirtualBox is just Virtual, so many things can be different.

Reboot your virtual machine and when you see Oracle's logo , click the screen (focus there) and then hold down Shift until Grub menu appears.


I understand your suspicions but I use Hubstaff (for Windows) and don't have anything to worry about.

You can remove Hubstaff on Linux by navigating to the Hubstaff folder and dragging the "uninstall-Hubstaff.sh" file to a terminal window. A new support article will be published on this soon.

Hope this helps!


The XFCE desktop settings for the panels are stored in your home in ~/.config/xfce4/ and you should have the default home files for new users in /etc/skek/.

So you could "reset" your settings by copying the files from /etc/skel/.config/xfce4/ to your /.config/xfce4/ directory.

Then just logging out & in again should reload your desktop (reboot not required).

Using XFCE's own settings windows to change things (themes in Appearance, Desktop, etc) should work.

Since you said there are no files in /etc/skel/.config/xfce4/, you should be able to just erase your current xfce4 files in ~/.config/xfce4/ (possibly using a 2nd account, in case erasing the files while you're logged in might cause them to be re-written on logout) and things should be reset on the next login.


Update to 20.10 failed according to lsb_release -a

User jos from the comment section is right. If you have the groovy repos in your /etc/apt/sources.list and do
sudo apt update
sudo apt dist-upgrade

you have technically an up-to-date Ubuntu 20.10 installation, regardless of what the text file says in /etc/lsb-release.
I don't know how you ended up with wrong lsb-release info. I would recommend you to cleanly install Ubuntu 20.04, as pointed out in your other question thread, as this gives you gives you a lot more possibilities currently to try things out easily with your Dell XPS 13, since Dell is officially supporting that release for that machine.


Find every word, otherwise a message from grep should appear

You can do this (somewhat inefficiently) using grep inside a shell loop. Given

$ cat file1.txt
6 rahul
4 anil
8 ravi
9 sagar
3 pravin

Then

$ for k in 8 9 2; do grep -q "$k" file1.txt || echo "$k not in file"; done
2 not in file

Alternatively, you could do something like this using awk:

$ printf '8\n9\n2\n' | awk '
    NR==FNR{a[$1]++; next}
    {delete a[$1]}
    END{for (k in a) print k " not in " FILENAME}
  ' - file1.txt
2 not in file1.txt


What is the meaning of the output of the command 'sensors'?

Sensors is reporting values found in Linux virtual file system directory:

/sys/class/thermal/thermal_zone*/temp

You can find them out yourself (even if Sensors isn't installed) using:

$ paste <(cat /sys/class/thermal/thermal_zone*/type) <(cat /sys/class/thermal/thermal_zone*/temp) | column -s $'\t' -t | sed 's/...$/.0°C/'
INT3400 Thermal  20.0°C
pch_skylake      -47.0°C
SEN1             52.0°C
SEN2             48.0°C
SEN3             55.0°C
SEN4             58.0°C
B0D4             54.0°C
x86_pkg_temp     54.0°C

Notice the pch_skylake sensor has gone crazy. Whilst researching the problem I found this question and posted this answer.


Run this in a Terminal (Ctrl+Alt+T):

unity --replace

That works for me on Ubuntu 12.04.


Install Ubuntu alongside Windows 10 with legacy bios?

Well, I am a new 'Ubuntuan' (permit me to use that word) too!

This is my first answer on the forum, I hope to give it a good try.

From what you said, i presume you have a working windows 10 OS!

Download the Ubuntu ISO image from the Ubuntu website here.

Download Rufus to setup a USB drive to be used as boot manager.

Open rufus after download
Select the drive you want to install on.
Select the partition scheme for both legacy and UEFI modes
Leave file system and cluster size as default
In the Create bootable disk using option, select ISO Image, then click the icon beside to pick the Ubuntu ISO Image you downloaded.
Then click start to start the operation.

You should know when the process is done.

However, due to Windows Fast Boot options, your computer might boot directly into Windows 10 without booting from the Ubuntu Boot manager you created (Which i assume is connected to your system). You can force your system to load your external drives by Reordering the Boot Options in your BIOS setup. And some computers will give you access to select which drive to boot from when you press a specific key (mostly F12 or ESC key) immediately your computer powers on.

Then select the USB Bootable manager you created, and UBUNTU should load then.
Follow the download process to install Ubuntu and enjoy freedom for life!
Thanks.


Use sudo nano /etc/apt/sources.list. It will open the file in an editor in the terminal window. It works like a GUI editor, except that the mouse doesn't work and you use the arrow keys to move around.

With nano, commands are listed on the bottom, where ^ means Ctrl. So, to save or Write Out the file, you press Ctrl+O, and to exit, you press Ctrl+X.


Is there any way to check the battery percentage of Apple wireless peripherals?

There isn't a GUI for read wireless mouse or keyboard battery data.

You can find useful information on sysfs under /sys/class/power_supply/. For example the Apple Wireless Keyboard is under /sys/class/power_supply/hid-78:CA:39:4E:6F:C7-battery/. In the device directory there is a file named capacity, this is a capacity in percents.

So in summary, for reading Apple Wireless Keyboard battery capacity you should do:

cat /sys/class/power_supply/hid-78:CA:39:4E:6F:C7-battery/capacity

Note that hid-78:CA:39:4E:6F:C7-battery can be different for your device.


How can I always include "Applications" in the filter results of Unity Dash?

Clicking on the Filter Results tab of the Unity Dash allows you to see your filter options or to modify your filter options.

The filter options you see are a toggle.  You can tell which ones are toggled on by the white border around the selection.  If there isn't a white border, then it's toggled off.  If it's off clicking the selection will toggle it on.

If you have a white border around your Applications it will be toggled on.  It will always include "Applications" in the filter results until you click the applications button again and turn it off (by removing the white border).

If you type something in the search area that that has a match for one of your filters (in this case you applications) you will see it in the search results under that category.  If the match comes up empty, the category will not show.  It will only show if a match is found.

You have the letters voko in your for your search.  You are not seeing the Applications category because it's not finding a match for voko in the application search.  Because you have the Files & Folder filter turn on, a match for your voko search has been found.  So the category for that match is displayed.  If you keep narrowing your search (for instance placing a bunch of x's) until there isn't a match, your dash results will be blank.  You will neither see your Applications nor the Files & Folder category displayed.

The Applications filter is showing you applications that were installed with a *.desktop extension that has an entry in default locations like /usr/share/applications and ~/.local/share/applications.


Ubuntu 12.04 Wireless won't connect with gnome network manager or wicd

Your wireless device uses the driver rt73usb. Some drivers have trouble with mixed mode WPA and WPA2 networks. Please try setting your router to WPA2 only. Some drivers have trouble with 80211N; try setting your router to B and G speeds but not N. Finally, you might do:

gksudo gedit /etc/modprobe.d/rt73usb.conf

Add a single line:

options rt73usb nohwcrypt=Y

Proofread, save and close gedit. Reboot and give us your report.
Edit: gksudo for gedit, never sudo.


Apache doesn't process Korean Characters in Pretty Permalink

From this article here try these steps:

Backup your /etc/apache2/conf.available/charset.conf

sudo cp /etc/apache2/conf.available/charset.conf /etc/apache2/conf.available/charset.conf.bak

Open charset.conf in your favourite editor:

sudo vim /etc/apache2/conf.available/charset.conf

Add the following lines in there:

AddDefaultCharset off
AddCharset ISO-2022-KR .iso2022-kr .kis
AddCharset ISO-2022-CN .iso2022-cn .cis
AddCharset Big5 .Big5 .big5

Reload your apache server:

sudo service apache2 reload

Now test it.


What is the difference between target="font" and target="pattern" in fontconfig?

From:

https://lists.freedesktop.org/archives/fontconfig/2007-December/002787.html

  Applications typically work like this:

  Convert user's font request to a fontconfig pattern;
  Apply fontconfig configuration on it using target="pattern";
  Get a sorted list of fonts matching that pattern from fontconfig. The list is returned as a set of fontconfig patterns itself;
  Choose the font to use (typically the first one having the requested character);
  Apply fontconfig configuration on the font pattern using target="font".

  So, what it means is that for example if you want to turn off antialiasing on Bitstream Vera Sans for sizes less than 7.5, you should do that using target="font". If you do it with target="pattern", it will turn off aa for all fonts if the request is Bitstream Vera Sans, regardless of whether you have that font installed or not.

  If you want to write fallback rules such that DejaVu Sans be substituted for Bitstream Vera Sans, that's done with target="pattern", because you want to modify the request.

And also from:

https://lists.freedesktop.org/archives/fontconfig/2003-March/000128.html

  Use the font target for all changes to how a particular font is rendered and pattern target for changes in how a font is selected from those available.


Why can't I move files from my Ubuntu desktop to other folders?

The reason you cannot drag files is due to limitations in the support of desktop icons. Since a few Ubuntu versions, icons on the desktop are not anymore provided by nautilus file manager (aka "Files"). Instead, a Gnome Shell extension "Desktop Icons" has been created for that. This extension is rather new and still quite limited in its capabilities, in particular with respect to the interaction with the file manager.
This has happened because Gnome Shell does not support desktop icons. They consider the desktop not to be the appropriate place for folders and launchers. Most of the time, it is covered by your applications. Instead, users are encouraged to place frequently used launchers on the Dash, and launch applications from the Application overview. For files, users are encouraged to work from Files, or from within the applications, rather than placing a range of files in a single Desktop folder.
Consequently, at some point, Gnome developers removed the code to provide desktop icons from the file manager. Therefore, Ubuntu used an older version of nautilus file manager in Ubuntu 18.04, in order to continue providing desktop icons. Nowadays, they ship with an up-to-date version of nautilus, and support desktop icons through the Gnome Shell extension. Hopefully, with time, the extension will improve in replacing the former functionality of nautilus with respect to icons on the desktop.


sudo add-apt-repository 'deb [arch=amd64] http://it-mirrors.evowise.com/ubuntu/ bionic universe'
sudo apt update
sudo apt install libtk8.5
If this does not work reply and I'll try to fix it.
Best Regards And Good Luck!


newest Gnome installed, but how to access it?

Are you used to an older layout? The desktop selection menu is in the top right now.

https://askubuntu.com/questions/527912/cannot-choose-gnome-fallback-after-unistalling-mate-desktop


You can clone the entire system and then restore it on another PC, but it will completely replace the PC running the same version of Linux (Mint 15 Mate) with your cloned system. If that is something you want to do, see this link, which will guide you through installing and using gddrescue, which you can install with sudo apt-get install gddrescue.

If you just want to back up settings and installed packages, see this AskUbuntu question.


MTP access to my phone LG-E900 (Optimus 7; Windows Phone 7.8) from Ubuntu?

I had the same problem. After looking for a solution, I installed Kubuntu 13.10 64bit. After that I ran a sudo apt-get update and sudo apt-get dist-upgrade. Restart and connect your device and you will see how you can do anything with it; Dolphin will do a good job with your cellphone.


Why Ubuntu Installation asks to disable Secure Boot?

If you don't disable Secure Boot, you will be unable to install 3rd party kernel modules, like proprietary video or wireless drivers.

We don't know if you need any 3rd party kernel software or not.

You can keep it enabled if you don't need them. Another limitation will be that hibernation doesn't work in Ubuntu with enabled Secure Boot.

Secure Boot is a mechanism in UEFI that checks signatures of OS kernel and doesn't let to load unsigned OS's or modules.

Nothing terrible will happen if you disable it. It is not a very useful feature in practice.


After maunual apt-get upgrade, Software Updater still wants me to update

man apt-get:

  upgrade is used to install the newest versions of all packages
             currently installed on the system from the sources enumerated in
             /etc/apt/sources.list. Packages currently installed with new
             versions available are retrieved and upgraded; under no
             circumstances are currently installed packages removed, or packages
             not already installed retrieved and installed. New versions of
             currently installed packages that cannot be upgraded without
             changing the install status of another package will be left at
             their current version. An update must be performed first so that
             apt-get knows that new versions of packages are available.

TL;DR: Some of the upgrades require the installation of new packages, and apt-get upgrade won't do that. You may consider apt-get dist-upgrade.


I would suggest LUbuntu. This is a version of Ubuntu with the graphic desktop LXDE/LXQT.

The requirements for this version of Ubuntu is:

Memory (RAM): for advanced internet services like Google+, YouTube,
Google Drive, and Facebook, your computer needs at least 1 GB of RAM.
For local programs like LibreOffice and simple browsing habits, your
computer needs at least 512 MB of RAM.
Processor (CPU): the minimum specification for CPU is Pentium 4 or
Pentium M or AMD K8. Older processors are too slow and the AMD K7 has
problems with Flash video.

You can obtain more information and download it from: https://lubuntu.net/lubuntu-18-04-bionic-beaver-released/


Openvpn unrecognized option tls-version-min

You are running an old version of openvpn, namely v 2.3.2, which does not support that option.
Make sure you have at least version 2.3.6 installed.

I assume that you do are still running 14.04 LTS and will have to do the release upgrade via do-release-upgrade and the upgrade the package or manually install openvpn from source.


It is an SSH session when SSH_CLIENT, SSH_AUTH_SOCK, SSH_CONNECTION and/or SSH_TTY is defined. If you want to make it work across su commands add them to env_keep in sudoers.

See https://unix.stackexchange.com/questions/9605/how-can-i-detect-if-the-shell-is-controlled-from-ssh/9607#9607 for more methods.


How to create and export a vmware image using vmbuilder

Although there are scripts available that can supposedly convert them, I don't trust them so I will show you the manual route here

The easiest way to do this is using QEMU directly. Power down the guest, then run the qemu-img -O vmdk /path/to/guest/disk /path/to/new/disk.vmdk command to convert the disk format (see below).
Next, use virsh dumpxml vmname to dump out an XML description of the guest.
Now, when creating a new VM in vSphere Client, just try and make the hardware at least as close as possible to the XML, and instead of creating a new disk image, just add the vmdk generated by the qemu-img command above.
This should do what you want

qemu Version Problems
Running these commands on Ubuntu 12.04 will give you no end of confusing version problems. In my experience, 1.5.3 gives good results. Follow the instructions here (obviously changing the order and commands to match your situation), if you get stuck.


You can install LAMP running one command:

Install tasksel

Select LAMP Server,

Follow the installation process.

After the installation is completed, you can test your localhost the way you did.

To check PHP is working

sudo   gedit  /var/www/info.php

And paste in this PHP information code:

<?php
    phpinfo();
?>

Save it and exit.

Restart Apache 2:

sudo /etc/init.d/apache2  restart

You can test PHP runing the info.php file:

http://localhost/info.php


World of Warcraft crashes when entering the game

You can try reducing all you video settings to the lowest possible and pray that works, seems like your video drivers are running low on crowded spaces. You should at least make sure that the software you are trying this is stable and not beta.


SD card is recognized but won't mount "can't read superblock"

Before you try anything else, copy the entire device to a safe place:

sudo dd if=/dev/mmcblk0 of=/var/tmp/safeplace bs=1024k

If dd gives you errors, something may be wrong with your device, or the card reader in your machine. Have you tried reading it on some other machine (I assume the answer is "yes", so read on!)

Next, use try reading the partition table:

sudo parted -l /dev/mmcblk0

What is the partition type?

If it's vfat, maybe the superblock is corrupted; try sudo fsck.vfat /dev/mmcblk0p1 (check the man page for options).
Did you actually create it on a linux machine? If not, maybe it's an exFAT filesystem. Try:

sudo dd if=/dev/mmcblk0p1 bs=16 count=1 | hd

and see if the first few bytes are 'EXFAT'.  If so, install the fuse-based exfat:

sudo apt-get install exfat-fuse

and try mounting manually if the GUI won't automatically recognize it.

If this still doesn't work, well, we'll have to dig deeper :)


Keyboard shortcut to kill uWSGI process in mac terminal

In your startup.sh you can add exec before uwsgi.

#!/usr/bin/env bash
service nginx start
exec uwsgi --ini uwsgi.ini

After that you will be able to do Ctrl+C to stop it.

Source


Ipython is using python 3.5 instead of 2.7

The first line of /usr/local/bin/ipython is "#!/usr/bin/python3" I could edit that line to use python instead of python3 or it was as simple as run with:

python /usr/local/bin/ipython


How do I change the length of time the lock screen appears for?

Ubuntu 17.04 and earlier (Unity)

Open System Settings, click Brightness & Lock and select a value for the screen turn off option, Turn screen off when inactive for:

Choose your time delay in the drop-down menu.

Ubuntu 17.10+ (Gnome Shell)

Check this question.


Why doesn't duply work when set as a cron job?

So, based on the comments, follows the answer to my own question.

Error log

A useful (essential) first step was to get an error log.

The syntax to obtain one is:

/bin/duply calendar backup > /tmp/duply.log 2> /tmp/duply.error.log

Cause

Luckily the log files pointed out why:

  duplicity missing. installed und available in path?

So I added to the cron file the same PATH value I have in shell session and the issue disappeared. I didn't think it was required to add PATH to the crontab file because PATH during the cron job is /usr/bin:/bin, and duply resides in /bin.

Now the crontab file starts with:

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games


Turn an external hard drive into a live usb

The UUI looks for USB flash drives and there is a diference between USB flash drive and USB HDD. To be able to use your USB HDD as a live HDD, open UUI and ensure that the "Now showing all drives(BE CAREFUL)" check box is checked. Then you should be able to view your USB HDD in the drop down. Be very careful while using this option because it will list all the drives and you dont want to end up formatting any other drive

Image source: PendriveLinux.com


Steam doesn’t load beacause of missing GTK modules

You can try removing pinned_libs_32 and pinned_libs_64 folders from steam folder.
If you installed the .deb package from the official site, you can do:
cd ~/.local/share/Steam/ubuntu12_32/steam-runtime
mv pinned_libs_32/ bak-pinned_libs_32
mv pinned_libs_64/ bak-pinned_libs_64

Now try to run steam


Where is the power off button in Ubuntu 18.04 LTS ?

If you click on the top right corner, it will show you a drop-down menu.

In that place, the power button  is placed.

on login screen

in desktop session

It will open the menu with Cancel, Restart and Power Off:


Like stated, screen would help.

screen /dev/ttyUSB1 2400

Note, you need to be in dialout group or issue connection from root account.


How can I put old Ubuntu CDs to good use?

I would use them, possibly with a clear plastic coating/wrapper, as a 'set' of drink coasters for entertaining. I had some old CDs that I printed labels for that read (in proper album cover art fonts) "This is a Coaster, Vol. I" and "This is a Coaster, Vol. II", etc. They made me smile all the time and I got some great comments from guests. It would rank up there with the hard drive clock as far as geek decor.


when i do an update, I get these warnings

No, it's nothing serious.

The programmers forgot to add a few lines of code that are needed now but not in previous releases.  But that just causes this warnings to be displayed.


acpi problems make wakeup every midnight

Disabing ACPI should be a last resort, in case you've almost given up. Check your BIOS settings whether you have a scheduled wakeup, it's called Resume by Alarm on AWARD BIOSes.


How set the Message of the Day (MOTD) as Ubuntu Server?

It looks like the /etc/update-motd.d directory can no longer have links to the scripts. (This happened to the Cronjob directories a number of release back, and is part of the security stuff I would guess).

If you list the directory (ls -l /etc/update-motd.d) you will see the following

50-landscape-sysinfo -> /usr/share/landscape/landscape-sysinfo.wrapper

If you want the System information back just copy the script into /etc/update-motd.d with the following command.

$ sudo cp /usr/share/landscape/landscape-sysinfo.wrapper /etc/update-motd.d/52-landscape-sysinfo

Note that when landscape fixes the problem you will get two copy of the script and then you can just delete the file.


Is there any program similar to Guitar pro available ?

Guitar Pro has native Linux version. Similar open-source app is Tuxguitar. You can install it from the Software Center.


I need a chroot user to now have ssh public key access

There is more than that. If you want to allow users ssh into chroot, you need to provide them at least shell and its dependencies. These files need to be copied into chroot.

You can find out what are the required shared libraries for bash using ldd (if your user has different shell use that one):

ldd /bin/bash

You will probably be able to see the errors that should guide you in the log. If not, give a try to running sshd in debug mode.


How large a checksum file can md5sum handle?

md5sum doesn't has limitation of  checksum files or number of files, but maybe the problem is that md5sum can not handle subfolders.
Try to install md5deep, which allow to make checksum for subfolders recursively and works smoothly with large number of files.


According to the answer in the thread below, pip should be already installed as you are using Python 3.4+

https://stackoverflow.com/questions/6587507/how-to-install-pip-with-python-3

In case you don't have it installed, try running the command below

sudo apt-get install python3-pip


I have had exactly the same problem with my T540p on Ubuntu 14.04 for the past two months and It's been a week that I (manually) upgraded the kernel to (the official) 4.1.3 and eventually the problem is gone. Previously, I was using 3.19.x.  I guess, that's because newer (> 4.0.0 version) kernels have better support for Realtek wireless cards!


Remove openjdk-7-jre but apt-get requires to install openjdk-6-jre, etc

This is more likely to an stupid dependency, so you shall tell apt-get not to install anything while removing JRE7:

sudo apt-get --purge autoremove default-jre default-jre-headless icedtea-6-jre-cacao icedtea-6-jre-jamvm openjdk-6-jre openjdk-6-jre-headless openjdk-6-jre-lib icedtea-plugin sun-java6-fonts fonts-ipafont-gothic fonts-ipafont-mincho ttf-telugu-fonts ttf-oriya-fonts ttf-kannada-fonts ttf-bengali-fonts icedtea-7-plugin openjdk-7-jre python-renderpm python-reportlab python-reportlab-accel

If I have to guess, some package depends/recommends/suggest default-java or a virtual package and this cause that while you try to remove one the other gets installed.


Problem with initial Ubuntu 14.04 startup

Try taking a look at /etc/default/grub file. Open command line (Ctrl + Alt +T  or Ctrl +Alt + F1), and type cat /etc/default/grub .  Specifically, at this portion:

Try altering GRUB_DEFAULT , GRUB_HIDDEN_TIMEOUT, GRUB_TIMEOUT, GRUB_CMDLINE_LINUX_DEFAULT just like mine.

Also, /var/log folder has quite a few logs that can help you troubleshoot issues. Specifically in this case you're interested in dmesg file and boot.log file. I'd suggest you read those and/or attach to your question. To do that you can do cat /var/log/dmesg > ~/dmesg_log.txt , which will output a copy of dmesg log into your home directory. Same thing with other logs


There are a some places you should try checking.
First I would try the Additional Drivers where you can enable third party closed software.

Another place would be to check with your USB model to see if the manufacturer has support for Ubuntu at all.

Also do:

sudo apt update
sudo apt upgrade

I found this in git hub : https://github.com/jurobystricky/Netgear-A6210

follow the instillation in the bottom in git hub

it always helps to have everything up to date, or breaks, but hopefully helps.


Turtle Beach X12 HeadSet Mic Not Working?

change the settings option in Sound Preferences > Hardware to Input+Output.


Maybe it would be a better idea to install the drivers from Ubuntu's official 'Additional Drivers' utility rather than forcing AMD's packages to install (which might not always actually work in 14.04 as you've now found):

Press the Super (Windows) key, type in 'drivers' and click on 'Additional Drivers'.

Install the proprietary AMD driver that they recommend.


Can't open 32-bit Machinarium - can't read file type

On the website it says that they only have a 32 bit version for linux, so are you sure your downloading it for the correct os?

Thanks, hope this helps!


I can't uncheck "Manage Windows Without Launcher"

Docky can have multiple docks, on the side, top or bottom of the screen, but it requires at least one of those docks to manage those windows that don't have a launcher on any dock. So you will have to select the dock you want to "Manage Windows Without Launcher" and check the box. Then when you select the dock that previously "Managed Windows Without Launcher" it will be unchecked.


Upgrading From Ubuntu 18.04.2 to 19.04 Using DVD

There is an option called Repair Ubuntu that can be accessed from the Boot Menu while a Bootable USB or DVD is connected. As you said GUI Login is no longer working, have you checked the following link, Help Ubuntu? How about that option?

Moreover, there is no such thing called Disco Dingo is the Latest and Bionic Beaver is the Old one. Bionic is an LTS Version which is comparably more stable than Disco Dingo which has a shorter life term and as well as support.


How do I deny a particular user from getting root ( through su ) in a terminal by changing the /etc/pam.d/su ? Pam based controlling is required

This is what /etc/sudoers does with the help of some groups.

By default, if a user is a member of group admin or group sudo, they'll have the ability to run commands as the root user. So, we can just remove the user from these two groups:

sudo gpasswd -d sudo user1
sudo gpasswd -d admin user1

Note that this will not take effect immediately. user1 must log out and back in for this change to take effect.

To give user2 access to root, you may add them to either of these groups. Personally, I prefer to add them to the sudo group, like so:

sudo usermod -aG sudo user2

Again, user2 needs to log out and back in for these settings to take effect.

Note, though, that it may be possible for user1 to have a record in the /etc/sudoers file, in which case you need to delete that record.

When editing /etc/sudoers, never edit it by hand! Instead, use the visudo command, which will validate that you're not going to accidentally break your config irreversibly. Execute this with the sudo visudo command.


firefox not preserving the home page settings after restart

Here you go , Firefox have provided a Guide for you.

It consists of several cases that can cause the issue you got.

The problem seems to appear due to user don't have enough permissions to save his settings to  prefs.js file. so locate the file and change the permissions to the file as

to locate the file

locate prefs.js

then you will get some output similar to this

/home/jai/.mozilla/firefox/gvj89mfl.default/prefs.js

take the firefox prefs.js path from your home folder.

then

chmod 755  <path to prefs.js file>

will resolve your issue.

https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save#w_unable-to-save-any-preferences-or-settings


Duplicate icons for manually created GNOME launcher items

To save sifting through the thread mentioned by @earthmeLon, you need to do the following:

Launch the application
Fire up a terminal and run xprop WM_CLASS. Click on the window of the the application that is running with a duplicate icon.
You'll get some output like WM_CLASS(STRING) = "Navigator", "Firefox". Choose one of the classes, eg Firefox in this example
Add the class as the value of StartupWMClass in the .desktop file. For example, StartupWMClass=Firefox
Save the .desktop file, close the application and re-open it. There should now only be 1 icon in the launcher


Ubuntu 14.04 LTS: Shows error "System program problem detected", See details

Can you open a terminal:

CTRL+ALT+T

then type:

sudo apt-get update

any errors will show up there, and it tries to give you ideas as to how you might fix them as well.

Chris


How to set a new cyclic wallpaper in ubuntu 11.10?

I believe you would have to script it...I looked at the /usr/share/backgrounds folder, which is the folder for the default backgrounds and it has a folder in it called contest.

In it there is an xml file (open in gedit to view or edit it).
It seems to contain information on how long a picture will be shown and what picture it will transition to.

So I'm pretty sure you could just swap the filenames and paths in the xml file and tweak the duration and that should do it.
Never tried it myself though.

The precise location of the xml file is  /usr/share/backgrounds/contest/background-1.xml

EDIT: WHOOPS just looked at the other article posted as duplicate and it seems to have the answers you need
How do I create a desktop wallpaper slideshow?


"postgres: command not found" / after regular install of postgres and configure new data directory

postgres execution command is psql and not postgres

postgres is the username

info from pgGettingStarted

  To test your connection using psql, run the following command:

psql -U postgres -W


Test this:

First, plug in the fax modem to an available USB 2.0 port.
Open a terminal: press Ctrl+Alt+T.
Run it:

sudo -i
apt-get install efax-gtk
modprobe usbserial vendor=0x0572 product=0x1329
dmesg | tail  -n 100

You are looking for something similar to this:

  usb 2-1: Product: USB Modem
  usb 2-1: SerialNumber: 35680336
  cdc_acm 2-1:1.0: ttyACM0: USB ACM device
  usbcore: registered new interface driver cdc_acm

You are interested in the serial address that Ubuntu has assigned to the USB fax modem. I’ve highlighted that information above in bold type.
The only thing you now have left to do is to plug in one end of a modular phone cord to the other end of the USB fax modem, and the other end of the modular phone cord into an available modular phone jack.
In efax-gtk select File Settings from the menus. On the second tab, you will need to enter the serial address that Ubuntu assigned to your fax modem when you set it up.

Source: http://efax-gtk.sourceforge.net/README


It not that likely to be MBR this far in - either a drive problem or random corruption, back it up quick if you haven't already!

Then you'll want to run fsck & badblocks over it:

sudo -i
fsck -t ext4 /dev/sdb1 # or whatever partition it is..
e2fsck -c /dev/sdb

The man page for badblocks recommends to do it this way, not directly. If it's got SMART monitoring then look at the logs & run tests for that as well.


How to make sudo use a separate password?

If I understand you correctly, you would like to set up a universal password that all users would have to input in order to execute a command as root with a sudo command.

Example:

Account-A = Password-1
Account-B = Password-2
root          = root-password

If Account-A or Account-B enters the command:

sudo apt-get autoclean

Then the subsequent output:

[sudo] password for root:

would be the same for both users.

This is typically NOT the preferred method of security through the use of sudo as implemented by Ubuntu.

This is not the recommended method of password implementation

For security reasons, Ubuntu does not enable a root user account. Unlike Debian, Ubuntu disables the root account.

You have been Warned this is not recommended!

Here's how it's done:

First, open a terminal and type the following command to set up a root password:

sudo passwd root

You will be prompted for your user-password to execute sudo. You will then be prompted to choose a password for root. You will then be prompted to re-enter the newly chosen password for root.

Next, change the default editor to nano instead of vi with this command:

sudo select-editor

You will be asked to choose an editor. Type the number that corresponds to "/bin/nano" and press enter.

Then, execute the following command to edit your sudoers file. You must use the visudo command to edit the /etc/sudoers file. Do NOT edit this file using gedit, do NOT use vi, DON'T use nano or leafpad or any other text editor because you risk locking yourself out of the sudo command completely for all users if there is a synatax error. Using visudo will fix syntax errors or alert you without saving the changes.

sudo visudo

Scroll down to the first line that begins with the word "Defaults" and press enter. Move up to the newly created blank line and insert the following line:

Defaults        rootpw

Use the tab key between the two words and do not use spaces!!

Press ctrl + o to write out the changes to the file. When asked to save the file as "/etc/sudoers.tmp", delete ".tmp" and press enter to save the file as "/etc/sudoers" instead.

You will now be prompted for the root password whenever any user executes a command with sudo.

Refrences:

wiki.archlinux.org/index.php/sudo

how-do-i-make-sudo-ask-for-the-root-password

set-sudo-password-differently-from-login-one

Debian documents "sudo_configuration"

help.ubuntu.com/community/Sudoers

wiki.debian.org/sudo


switch user not working in Xubuntu 14.04

This is fixed in package whisker-menu but still not in package xfce4-panel. It appears that 'actions' is hardcoded to execute gdmflexiserver which only works if gdm is used instead of lightdm, which in turn is the xubuntu default.

You have, as always, several options:

Drop the actions item or disable user switch there and enable and use it in whisker-menu
Switch to gdm (apparently already installed)
Create a deviation from /usr/bin/gdmflexiserver to a script that calls dm-tool switch-to-greeter, like whisker-menu already does
Recreate 'actions' with a custom dropdown launcher duplicating all necessary commands

If I remember correctly, previous versions of lightdm would provide a gdmflexiserver compatibility hack that is no longer around.


How to install new software on Ubuntu 12.04 LTS?

Just type this on your terminal:

sudo apt-get install [package name]

And you also can install a new software on Software Center. It is easy to use.