How to update cryptsetup till version 1.6.1?

1.3 System specific warnings

Ubuntu as of 4/2011: It seems the installer offers to create LUKS partitions in a way that several people mistook for an offer to activate their existing LUKS partition. The installer gives no or an inadequate warning and will destroy your old LUKS header, causing permanent data loss. See also the section on Backup and Data Recovery.

This issue has been acknowledged by the Ubuntu dev team.

Update 4/2013: I am still unsure whether this has been fixed by now, best be careful. They also seem to have added even more LUKS killer functionality to the Ubuntu installer. I can only strongly recommended to not install Ubuntu on a system with existing LUKS containers without complete backups.

  Update 11/2014: There seem to be other problems withe [sic!] existing LUKS containers and Ubuntu as well, be extra careful when using LUKS on Ubuntu in any way, but exactly as the Ubuntu installer does.

(source)


How can I check what was installed for an apt package?

The following command will list all files installed by the package autojump:

dpkg -L autojump

It is a dpkg command because dpkg is actually responsible for installing packages, apt just a frontend that runs dpkg.

For completeness, there is also the reverse command:

dpkg -S file

This will give you all packages which contain something named file (this can also be a single part of a path).


How do I uninstall Ubuntu from a computer?

DO NOT RUN sudo rm -rf / --no-preserve-root on systems with systemd

When running the command on a UEFI computer (2012 or newer) you are deleting all the UEFI firmware variables which can cause your PC to be bricked and cannot be repaired without a motherboard replacement on some devices.

Here is what happened to one Linux user : An Ubuntu command bricked my system?

So don't try what the other answers talking about rm -rf / say since it only works on legacy BIOS machines. I am typing this from a UEFI laptop which can also be bricked by the command.

Proper Method for UEFI devices.

Boot an Ubuntu Live USB / CD and open GParted. Then delete all the partitions and click apply.

Please note that after this, most of your data can still be recovered easily using professional tools.

Proper Method for UEFI devices if you have private data

As @ByteCommander says, download DBAN (Darik's Boot And Nuke), burn the ISO to a disc / USB and tell it to erase the disk

After performing this, all data is irreversibly gone!


Desktop disappeared using GeForce 470 gtx

Purge ANY nvidia settings, go to nvidia website and download latest .bin driver pack. In order to install it you have to boot from recovery options and use command line.


pip3 packages are getting installed in /home/user/.local/python3.8/site-packages/ but not able to use them at all

First try to force reinstall the package. I am unsure why every file is empty but something must have gone wrong when you first installed the package. An empty file would explain the import error message you are seeing.
pip3 install --upgrade --force-reinstall <package>
I would not recommend invoking pip with sudo as this can modify your system's Python packages which in general should only be manged by your system package manager (e.g. apt-get, yum, etc.). Modifying system Python packages has the potential to break other system components that depend on them.


Amd intergrated Graphics drivers for ubuntu

Search for Additonal Drivers using Unity Dash (~ Start Menu). If there are any drivers available for your video card, they will show up here. I recommend fglrx over fglrx-updates, since the latter tends to have bugs.


Tablet pen doesn't work correctly when in portrait mode

Are you using magick-rotation?  I just fixed the same problem.

Here's the way to update the wacom driver that could be responsible for that mess :

https://answers.launchpad.net/magick-rotation/+faq/1603


A more feature filled mintmenu like applet for Xubuntu 12.04

Can't help you on a native xfce menu, but MATE is available on PowerPC.  See http://ubuntuforums.org/showthread.php?t=1918246&page=29&p=12573621#post12573621 .  I've had the Mint Menu working in Xubuntu on PowerPC, but its annoying scrolling drives me nuts!  You have to upgrade to xfce 4.10 for it to work.

I've compiled most of MATE 1.6, just python-caja that is currently defeating me http://forums.mate-desktop.org/viewtopic.php?f=16&t=1660 .


There is already a bug. This was a problem inherited from Debian, but then it was solved there (in Debian).

And now apparently everything gets down to a problem with repositories (curl is in main while the needed libraries are in universe, and this goes against the policies for the main section).

If you want to recompile it I suggest you to follow this answer on this website.


Changing Razer keyboard's RGB settings on startup

After doing some research, I found the answer to my problem.
According to Open Razer documentation https://github.com/openrazer/openrazer/wiki/Using-the-keyboard-driver ,
In order to change my keyboard's RGB settings I had to rewrite the appropriate files in /sys/bus/hid/drivers/razerkbd//
One has to write the command  echo -n -e "\xFF\x00\xFF" > /sys/bus/hid/drivers/razerkbd//matrix_effect_static , where you can replace xFF\X00\xFF by any hex code you wish.
Finally write a shell script with this command and have Ubuntu execute it on startup.


How to get hp printer to select correct trays on samba shared printer

I would suggest opening a terminal and issue this command sudo apt-get install hplip-gui This package contains utilities with graphical user interface (GUI) for
 HPLIP: HP Toolbox, HP Fax etc.


zeptoweasel solved it in his question:

  SOLUTION: For future reference, the problem turned out to be that the BIOS was in UEFI mode. I switched it to CSM mode and reinstalled, and that fixed the problem.


blocksize error when mounting ufs drive in 12.10

I kind-of have a solution. -ish.

What I did was find an old netbook (an eeepc) and ran the nas4free livecd from it. This allowed me read/write access to the freebsd external hard drive, but nas4free has some issues with ntfs sometimes (so I didn't want to risk losing data by trying to connect it).

So, with a live version of nas4free running on my network, I connected my wife's ntfs external hard drive to my ubuntu laptop, connected to the nas4free box via the network and transferred files that way.

It's slow going, but it at least allows me to pull files off the ufs-formatted external hard drive.


Assuming you are running Ubuntu 14.04 or later, I suggest you get a temporary internet connection, open a terminal and do:

sudo apt-get install bcmwl-kernel-source

Reboot and your wireless should be working.


Ubuntu distro upgrade - does it install new kernel?

Yes, upgrading installs a new kernel. However, it seems as though the old kernel is still installed (the currently running kernel won't be automatically removed on upgrade), and for some reason you are still running it. Did you do a full reboot? Is the old kernel set as the default in grub? You can reboot, select the new kernel at the grub menu, remove all the old kernels, and the install the new graphics driver.


Is it possible to do a lossless conversion from m4v to webm?

I would like the properties of the input file to be the same for the output file, so that I do not have a noticeable quality change.

You're going from a lossy codec to another lossy codec. That means you will lose quality no matter what, unless you set the target bit rate so high that the quality loss won't be noticeable (even if it's still there).

The downside is, of course, that the file size will increase. How much, you ask, will it increase? No one can tell. It depends on how good the quality of your input video is, and how easy the video is to encode.

To force a bit rate during conversion, do the following, e.g. for constant 1 MBit/s:

ffmpeg -i in.m4v -c:v libvpx -b:v 1M -c:a libvorbis out.webm

The libvpx encoder can also work with variable quality, using the -qmin, -qmax options:

ffmpeg -i in.m4v -c:v libvpx -qmin 10 -qmax 42 -c:a libvorbis out.webm

Use lower values for both parameters to achieve better quality. Usually FFmpeg would set them to 2/31, but WebM needs a different scale here AFAIK.


KDE Accessible always open and unclosable

That tray icon is a manifestation of package kaccessible.  I don't see any obvious way to keep the app (which "provide[s] accessibility services like focus tracking and a screen reader") but disable the icon; you might consider filing that as a bug if it's still a problem.  If you don't need kaccessible, uninstall it and then quit KDE Accessible via the icon and it'll stay gone.


How to use the same Python for Windows and Linux on Windows subsystem for Linux

You can use the version of python used in windows by typing in python.exe instead of python3. This is not recommended and there's no real reason to do so because you'll face several problems with

CR/LF line endings
Running python in this way does not preserve the path, hence, say you have test.py in the current WSL folder and run python.exe test.py. Python will be started in its root directory and will be unable to locate test.py

Python behaves identically, like in the case of pip freeze e.t.c and will produce the same output if you're running in the same virtualenv and hence just using the ubuntu version of python will work fine.

As of 18.04, WSL ubuntu has Python 3.6.5 preinstalled, and you can see both the windows and ubuntu python being used below


Understanding the output of df -h command

You have only one actual partition /dev/sda3.

You should not touch the udev and tmpfs partitions.

tmpfs is a virtual memory filesystem based on your RAM
udev supplies Dynamic device management using virtual files

More info regarding udev and tmpfs you can find in this answer.

/dev/loop partitions are a mounted snap-file which is based on SquashFS read-only file system

You can check what is the content of /snap/core/3748 and /snap/spotify/5 folders.
Anyway - those are very small files (160M and 84M) - so removing them won't save much disk space.


Video output to monitor is cut after installing Ubuntu 11.10

OP reported solving the problem

  after some searching I found a fix that worked for me by Francisco Martinex askubuntu.com/questions/97475/


May I use UbuntuOne to share files from my business?

If you want a perfect answer you should ask it on the U1 support page. But the terms of services seem not to exclude what you want.

Acceptable use and conduct
All usage of the services must be legal and not infringe any third party's rights. You must not take any action or use the services in any way that might bring Canonical into disrepute, affect the ability of Canonical to provide the services, be illegal, or encourage illegal activities. You may not use the services in any manner that might be libellous or defamatory (more info on what that means), that contains threats or incites violence towards individuals or entities, or that violates the privacy or publicity rights of any third party. Some services have usage limitations as indicated at https://one.ubuntu.com/plans, and you may not exceed these. As part of the services, you may store data on Canonical's servers or those of Canonical's suppliers. You should ensure that this data is not in breach of any applicable law and does not breach any individual's data protection or privacy rights. You shall indemnify Canonical in full for any loss, cost or damages suffered by it as a result of your use or misuse of the services.

Technically if the amount of downloads get out of hand you could be affecting the ability of Canonical to provide the services.


I'm a little confused about which hard drive is usb and which isn't, but if it were me I'd try to install a fresh Ubuntu onto whichever HD is physically inside the new computer (not a fan of USB HD's for a system drive, not as reliable it seems). Using a Ubuntu live iso/cd/usb, and with the old USB HD not even plugged in.

Then with the new Ubuntu in the new HD & new computer working, you could move your $HOME from the old drive onto the new Ubuntu (if you want to keep your old settings).

Here's a quick guide to copying an old home folder to a new one, https://help.ubuntu.com/community/Partitioning/Home/Moving#Copy_.2BAC8-home_to_the_New_Partition It's basically copy the files with the same permissions & owner (but the owner can be changed with chown later anyway). A file manager like Nautilus or Thunar or any one should work fine instead of rsync too.

Plugging an old HD (with an old OS) into a new computer doesn't always work, the hardware differences could be too great. (An 80GB HD could be from a 10 year old single cpu computer, the AMD APU's are 3 years old or so & could be 8 core?)

And this page has info on migrating Ubuntu from one HD to a new HD, only on the same computer. It might work for your case, but because of the hardware changes it may not be ideal https://askubuntu.com/a/40454/129271


Having trouble running setup-environment (YOCTO) in a Ubuntu 32-bit VM

The file is in the current directory . not the parent directory .. so you are simply using the wrong address

MACHINE=smarch-samx6i ./setup-environment build


How do I install and use the latest version of GNOME?

Installing from the Software Center (11.10 and newer)

Open the software center search for "gnome shell" and install it, or just click this button:

After it installs, log out.

For 11.10

at the login screen click the little gear icon and select "GNOME" from the menu.

For 12.04 and 12.10

At the login screen click the icon show and select "GNOME" from the menu.

After that just put in your password and login:

The login manager will remember the last session you went into so you only need to select GNOME once, after that you can just login normally.

Customizing it further

You can also use the fallback mode if you prefer an old-school experience:

How to revert to GNOME Classic Desktop?

And if you use auto logins you might need to tell lightdm to always use shell:

How can I use gnome shell by default instead of unity?

Other Goodies to install with it

gnome-documents
gnome-boxes

Command Line Instructions:

 sudo apt-get install gnome-shell

Where to report problems:

Discussion about GNOME3 packaging (Mailing list link on the bottom left): https://launchpad.net/~gnome3-team

Most problems and issues with this set of packages can go on this list, it should be the first place you report problems and issues.

Bug reports that are NOT packaging related: https://bugzilla.gnome.org/

If GNOME3 isn't working well it could be packaging related, so please don't just randomly report bugs to GNOME unless you are confident that it's an upstream GNOME problem.
If you're not sure if you should report the bug upstream then ask someone either on IRC or on the mailing list above if you need help determining if something should be reported to GNOME.


The problem that you are having is that you need JRE (Java Runtime Environment)  on your computer to use Matlab. To install, execute the following commands AS ROOT:

java -version

This will check to see if you have java installed. If not, proceed to the next steps.

sudo apt-get update
sudo apt-get install default-jre
sudo apt-get install default-jdk

What this will do is install the Java Runtime Environment, and also the Java Development Kit, incase of future use of more advanced software. After that, you're done! You should now be able to successfully install Matlab.


How can I install the Atheros AR8161 drivers without an internet connection?

Try download file from the following link on another PC and copy it to your machine via USB Key. http://security.ubuntu.com/ubuntu/pool/main/l/linux-backports-modules-3.2.0/linux-backports-modules-cw-3.6-3.2.0-33-generic_3.2.0-33.18_amd64.deb

Then install this package.  Reboot your computer.  At that moment, probably, you can connect to internet.If you can't, try the following command and restart:

sudo modprobe alx

Note: I assumed that your Ubuntu 12.04 is using default 3.2.0-33 kernel version.  If it false, you must download different package.  For learning your kernel version,try uname -a command on Terminal.


Accidentaly deleted contents of the home folder

If all that you've done is rename the account, the home folder may still be there under /home/oldusername/.

To check this, open a terminal and enter sudo ls -al /home/oldusername/.

If you see your 'lost' files, enter sudo cp -r /home/oldusername/* /home/newusername/


Can Swap Files be located in separate partitions, such as an old Swap Partition?

You can format the partition in "EXT4" and use it as normal partition, and then create a swap file there like in :

https://support.rackspace.com/how-to/create-a-linux-swap-file/

However, you have to mount this new partition at startup by adding it to the fstab file because a partition created after installing ubuntu will not be automatically mounted unless you add it to the fstab partition, so in summary you will mount the new partition then you will mount the swap file into the new partition, which is a very bad idea.

Why don't you just collapse this partition with any other partition and create the swap file into the root partition for example!


OK. The first problem (reboot problem after installation was completed) occurred because I set acpi=off during the installation because Ubuntu got stuck in loading purple screen. After many tries I could pass by the purple screen by chance without setting acpi=off! Then after installation, Ubuntu was restarted without any problem.

The second problem (shutdown and restart problem after Ubuntu was booted for the first time from hard disk) was because of Nvidia driver. I did

sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
sudo ubuntu-drivers devices
sudo apt-get install nvidia-361

And now everything is fine :-)

UPDATE

As I said I could not pass by the purple screen during the installation and I found what the problem was. I had connected a USB 2.0 flash drive to a USB 3.0 port for installing Ubuntu. Today I connected a USB 3.0 flash drive to the USB 3.0 port and I booted Ubuntu with that and the problem was solved (I don't need to wait for a chance or set acpi=off to boot Ubuntu). But unfortunately I am getting a new problem and it is I cannot reboot or shutdown Ubuntu .


Why is ThunderBird downloading older messages even when only last 6 months are set for synchronization?

Unfortunately no !
It's a big issue that TBird developers just do not seem to care about.

It just does not make sense for Tbird to download every email since the beginning of time onto each computer on which you set it up.


Broken dependency after upgrading ubuntu 14.04

This is the clue,

secrets.tdb exists in /var/lib/samba and /var/lib/samba/private, aborting samba-libs preinst
rename one of them to allow the install/upgrade to continue

So moving  the file /var/lib/samba/secrets.tdb to another location will solves your problem,

sudo mv /var/lib/samba/secrets.tdb ~/Desktop

And then run the below command to fix dependencies,

sudo apt-get install -f


Im dualbooting windows 10 and ubuntu 16.04. but i use grub2 as a boot manager, and if i mess up i usually just use boot-repair. you can do more than program java in windows. i haven't come across something i could not do in windows, but some things are easier in ubuntu.
your questions already has been answered.
How to create UEFI-only bootable USB live media?


How do I schedule waking up from hibernation?

When hibernating, the operating system is off and can't do anything. It's the computer's BIOS that does the waking up, so it's only possible if your computer's BIOS supports it. With some BIOSes, you can configure a scheduled wakeup quite easily.

Press the key that gets you into "setup" or similar when the computer first boots up (often F2 or Del) and see what options you have.

Alternatively you may be able to configure the BIOS to wake from Ubuntu, if the BIOS supports waking and allows the OS access to configure it. This guide is quite comprehensive:
http://www.mythtv.org/wiki/ACPI_Wakeup


INFO Bootstrapping environment : ERROR No matching node is available

Basically question still with no response beacuse of the error is not common when we plan to integrate juju and maas in a existing infrastructure.
The answer could be one of the next propositions:

Wake-on-LAN for virtual machines does not work, MAAS supports "virsh".
Need to have nodes that are in the "ready" state before they can be allocated to a user.
Need to run and boot at least once, during which time they signal to the maas server that they are ready

Still one notice and will be nice if someboy had sure idea if juju bootstrap requires more than 2 nodes ???

Hopefully will help !!!


How is 'rm -rf /' able to delete all files in the system?

It doesn't matter that /bin/rm is deleted. It's only being run once and by that point it's all loaded in memory, as is everything else required to keep sending deletes to the filesystem and disk.

Sidebar/Update: Per David Hoelzer's answer (and mentioned in the comments), the inode the hardlink /bin/rm used to point to would remain right up until rm finished (because Linux holds in an open state) but that fact is irrelevant; the state of the disk doesn't matter at all.

The binary is loaded into memory before it is run. Even if you could manually destroy the rm disk data, it wouldn't affect or stop the deletion from completing (assuming you don't otherwise make the disk unavailable).

No idea what an inode or hardlink are? This is the answer where I worked it out.

Anyway, this is also why you can delete the package for the current kernel without the computer imploding. As long as you install a different version, it'll be able to boot up.

Again, this works because rm is only called once. The following would fail after /bin/rm died because it calls it once for every filename:

find / -exec rm {} \;

That said, find / -exec rm -rf {} + and find / -print0 | xargs -0 rm -rf would also both likely fail because they both have argument limits, meaning they would only delete a number of files before being called again. At some point along the journey, /bin/rm could expire (and be released) before the rest of the files were deleted. It's not guaranteed though. If /bin/ were the last directory entered, these methods could work.


There is usually a "wake up" key on the keyboard ('Fn key or else). Does it work after you open the lid?

In some cases iti s just the display driver that does not light up the screen. Again, using the keyboard keys that change screen luminosity could light up the screen.


How can I prevent my system from crashing or becoming unusable due to high RAM usage?

If a process eats too much memory then the system should protect itself through the OOM killer, wich is a standard feature in any Linux system.

As estated in the best answer so far to How does the OOM killer decide which process to kill first?

  If memory is exhaustively used up by processes, to the extent which
  can possibly threaten the stability of the system, then the OOM killer
  comes into the picture.

  NOTE: It is the task of the OOM Killer to continue killing processes
  until enough memory is freed for the smooth functioning of the rest of
  the process that the Kernel is attempting to run.

  The OOM Killer has to select the best process(es) to kill. Best here
  refers to that process which will free up the maximum memory upon
  killing and is also the least important to the system.

  The primary goal is to kill the least number of processes that
  minimizes the damage done and at the same time maximizing the amount
  of memory freed.

  To facilitate this, the kernel maintains an oom_score for each of the
  processes. You can see the oom_score of each of the processes in the
  /proc filesystem under the pid directory.

  $ cat /proc/10292/oom_score

  The higher the value of oom_score of any process, the higher is its
  likelihood of getting killed by the OOM Killer in an out-of-memory
  situation.

If your system crashes then I'd suggest to fine tune the OOM policy by adjusting the oom_score of your processes.

It is unlikely that the OOM killer was disabled but, to make sure, check if this command returns 0:

$ sudo sysctl vm.overcommit_memory
vm.overcommit_memory = 0

References:

http://www.oracle.com/technetwork/articles/servers-storage-dev/oom-killer-1911807.html
https://superuser.com/questions/1150215/disabling-oom-killer-on-ubuntu-14-04/1150229
https://unix.stackexchange.com/questions/153585/how-does-the-oom-killer-decide-which-process-to-kill-first
https://www.kernel.org/doc/Documentation/sysctl/vm.txt


Spotify not starting since updating to 15.04

This is caused by  libgcrypt . You can solve this by:

wget http://security.debian.org/debian-security/pool/updates/main/libg/libgcrypt11/libgcrypt11_1.5.0-5+deb7u3_amd64.deb

sudo dpkg -i libgcrypt11_1.5.0-5+deb7u3_amd64.deb

If this doesn't work then purge spotify and install again from this repository.

sudo apt-get purge spotify*

Then

sudo add-apt-repository "deb http://repository.spotify.com stable non-free"
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 94558F59
sudo apt-get update
sudo apt-get install spotify-client


Ubuntu-Server Upgraded to Ubuntu desktop, How do I change it back?

not sure about the newest version, but "apt-get remove ubuntu-desktop --purge" was how I did it the last time I messed up.


How to have an encrypted partition/folder without any cleartext at all?

An ecrypted partition or directory encrypts the data on the disk. The data on the disk is never in cleartext. As long as the partition or directory is open or mounted you see the data in cleartext, but on the disk it remains encrypted. Essentially the full disk encryption or filesystem encryption software sits between the disk and the programs which read or write the files, and encrypts or decrypts the data on the fly -- that's why such software is sometimes called OTFE, On The Fly Encryption. Since the data appears in cleartext while the partition or directory is mounted, such systems are said to protect data at rest.

In your example, the file folder/file is encrypted as soon as you write the first character into it. It appears in cleartext because the directory folder is mounted; while it is mounted, the eCryptfs software translates automatically between the ciphertext on the disk and the cleartext presented to the programs. You are right that this is not the only way that an encrypted partition or subtree can  possibly work, but as far as I know all encrypted filesystems work in this way.

If you want to encrypt one or more files without leaving any plaintext visible and maintaining access to the ciphertext then you cannot use software which appears as a filesystem; you must use software which encrypts or decrypts files. GnuPG is free and widely used.


Eclipse version on Ubuntu 14.04 (Trusty Tahr)

The version of software in the repository is the latest tested stable version which may not necessarily be the actually latest stable version from the developer.  Most of the software in the repository is a few versions older than the latest released version of the actual various developers.

You might consider going to the developer's site of your favorite applications and getting the very latest reversions from them.  Keep in mind that the version on the developer's site might not be fully supported yet with your Ubuntu current Ubuntu version.

While the latter might be true, this isn't something I have experienced by getting the latest from the developer.

I alway install the latest version of Eclipse (being one of my favorite applications) from the developers site:

https://www.eclipse.org/downloads/

You probably already know by your reference to the latest version.

The version for linux includes the binary which will work directly from the archive extract.  You can extract the tar to /opt/eclipse and run the exec from there.


You are using fbdev driver currently. Try to remove nomodeset from your kernel boot options [1] and upgrade kernel to a latest one [2] to use amdgpu or radeon drivers.

[1] How do I add a kernel boot parameter?

[2] https://wiki.ubuntu.com/Kernel/MainlineBuilds


Sublime Text does not launch under gksudo

Have found this, although there is no answer about what makes sublime behave like this. In short, use -w argument.

As for the second question, I think you are looking for a PATH environment variable. Here is some info.


I got the solution for my issue. The below changes are required specially for raspberry pi 2(armhf) which avoids the program to run infinite.

https://code.google.com/p/cvblob/issues/detail?id=23

go to /home/pi/cvblob/cvBlob

  In cvLabel.h file

const char movesE ... const char movesI ...

to

const signed char movesE ... const signed char movesI ...

  and in cvBlob/cvcontour.cpp , line 84:

change

const char cvChainCodeMoves[8][2] = { { 0, -1},

to

const signed char cvChainCodeMoves[8][2] = { { 0, -1},


Quickly will create a folder wherever you invoke it from. Just make sure you change the current directory to the location where you want it to create the folder containing your new app first, and then run the quickly create command.

So for example, if you want to create a test app that you're not going to keep in the /tmp folder, you can run it with:

cd /tmp
quickly create ubuntu-application TestApp

Then Quickly will create the app under /tmp/testapp


How to verify if my microphone input is dead or ubuntu not detected it yet? I can hear music but i cant record audio

Parts of this answer comes from: Sound doesn't work with Intel 5 Series/3400 chipset

Maybe you are experiencing an issue with your sound engine. Make sure you are using the appropriate sound profile for your case.

In this image we are choosing the appropriate sound device. Which will offer several sound profiles, based on the abilities of the sound device itself. Of those, we should at least choose one of those that mentions a sound input: "Analog Stereo Output + Analog Mono Input" is working for this case but you may have 4.0, 5.1 Sound profiles plus Analog Mono Input. Any of these that features a Mono Input will do the trick.

In this window we are going to choose the right place from where the computer is going to gather sound. Let's say:  the place where the microphone is plugged in.

You can enter the sound preferences by clicking the Main Menu, then hit "System", "Preferences" and finally choose "Sound"

Give this a try and please inform if you face additional issues (like: having not "plus Analog Mono Input" sound profile).

Good luck!


The folowing text is mostly copied from:
https://wiki.ubuntu.com/Audio/UpgradingAlsa/DKMS

HDA driver is the driver for internal "HDA Intel" sound cards (if your computer is from 2005 or newer, you almost certainly have a "HDA Intel" sound card for handling internal speakers, headphone jacks and microphones). USB or Bluetooth sound will not be affected.

DKMS is a method to recompile kernel modules locally whenever the rest of the kernel changes. This means that you do not add a ppa: instead you download the package once and install it, confirm that it fixes your problem, and you're done. When you install a new kernel, as you regularly do if you have the updates repository enabled (this is recommended), DKMS will automatically recompile your existing DKMS package to fit the new kernel.

You can use this method if the latest ALSA snapshot works for you currently, and you just want the what's currently the latest (without having to stay updated with newer snapshots).


how to install both qt5-qmake and qt4-qmake

I could not find a reliable way though some say that qtchooser works but it doesn't work.
What I do as a workaround is to install qt4 at first then install qt5, to revert back to qt4 just remove qt5-default, it will use qt4. To switch back to qt5 just install qt5-default. It's a tiny deb package lower than 500kb.

EDIT:
When you attepted to remove qt5-default it will automatically install qt4-default

EDIT2:
What I did yesterday to use latest version of qmake, I downloaded 32 bit offline installer from http://download.qt-project.org/official_releases/qt/5.2/5.2.1/qt-opensource-linux-x86-5.2.1.run then set executable flag and installed it to /home/$USER/Qt5.2.1, it doesn't install it into system path. To use qmake to create makefile you need to specify the path/home/$USER/Qt5.2.1/5.2.1/gcc/bin/qmake -Wall ../project.pro worked for me

EDIT3: I found an easier way to switch between qt4 and qt5 using environment variables

To switch to qt4

 export QTCHOOSER_RUNTOOL=qtconfig
 export QT_SELECT=4

EDIT4:

As I get experienced about programming I come across more simple solutions.

You don't need to switch  between QT4 <-> QT5 at all.

Install QT4 and QT5 packages from Ubuntu repositories and then locate qmake

locate qmake

I am running Ubuntu 14.04.3 32 bit so my qmake paths are:

/usr/lib/i386-linux-gnu/qt4/bin/qmake
/usr/lib/i386-linux-gnu/qt5/bin/qmake

All you can do to build your project is to run

for qt4:

/usr/lib/i386-linux-gnu/qt4/bin/qmake

or for qt5:

/usr/lib/i386-linux-gnu/qt5/bin/qmake

in your source directory where project*.pro file exist.

Then to compile it with make command.


why does speedtest display other country

This probably means that your IP address seems to be in America, or that there are no Speedtest servers in your area.


Wifi Signal and Disconnecting Problem in Ubuntu 19.04

Open terminal enter gedit admin:///etc/default/grub
Once the file is opened go to the line that has "quiet splash" and add pcie_aspm=off inside the quotes so
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
becomes
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=off"

save and exit gedit and do sudo update-grub then reboot


None of my games are working in wine 1.5

Ok since your error is very general, I am going to give you the following links which I have updated to solve some of the problems you might be having:

To install Wine follow this link: How do I install wine?

To configure wine with additional packages that are needed to have a working Game follow this link: How do I install Half-Life 1 and 2?

To be able to use wow and other apps follow this link: Adjusting resolution for individual Wine programs

And to correctly solve many of the video problems follow this link: How do I install the Nvidia drivers?

With this, you should be set to a working Wow (And many other games for that matter)


Error installing two PHP Versions Ubuntu 12.04 with Plesk 11.5

It turned out the php 5.5.10 Version i downloaded from php.net was currupt. A new download and new install solved my problem.


Can I upgrade a wubi 10.04 install using a 11.04 install image

You can only upgrade a Wubi install while booted into that install, so either using update manager, or from the alternate desktop CD image (cdromupgrade).

You cannot do it from Windows or by booting an Ubuntu CD/USB.

You can only upgrade to 11.04 from 10.10 - so you'd first need to upgrade from 10.04 to 10.10, but note that there are some problems with the wubi upgrade to 10.10 (bug 653134 and bug 610898). These have been fixed for 11.04, but until the fix is backported to 10.10 you will likely suffer booting problems. You can find a solution for these problems here: Wubi megathread

With any upgrade I recommend backing up beforehand. With Wubi you can just copy the virtual disks (usually just the root.disk) in Windows beforehand. It's a good idea to copy C:\wubildr as well.


Removing a deb package installed from thirdparty

You can remove any software installed via a .deb packages with the apt-get remove command

First open a terminal session with Ctrl+Alt+T and type in:

  sudo apt-get remove google-chrome-stable

This should remove the package from your system.

Additionally, to see a list of locally installed and obsolete packages either run the command

sudo apt-get install aptitude
aptitude search '~o'

or install Synaptic with sudo apt-get install synaptic and click on the Status button on the left panel and select Installed (local or obsolete). See screen capture below for reference.

Both options will show you the list of all .deb installed packages.


Problem with international keyboard on 13.10

I just discovered that the problem was with system language. If you use English as the primary language, the '+c doesn't work as when the primary language is set to Portuguese-Brazil. Now, with pt-br as primary, it works as expected.


It asks you to open a terminal and open either ~/.bash_profile or your ~/.bashrc and type the following at the end of the file:

source ~/.local/bin/bashmarks.sh

This will execute the contents of ~/.local/bin/bashmarks.sh in the current shell everytime you start a new instance of bash.

See this question for more on what source does:

What does source do?


dell vostro 1000 broadcom wireless connection

I have a Vostro 1000 with the same wireless card and I found that Ubuntu detects the card but does not install the correct drivers.

Use lspci command to display the details about hardware. It will display all of PCI connected hardware. Look the information for wireless card in the list, the match must be with this identifier [14e4:4312].

$ sudo lspci -v

05:00.0 Network controller: Broadcom Corporation BCM4311 802.11a/b/g (rev 01)
    Subsystem: Dell Wireless 1490 Dual Band WLAN Mini-Card
    Flags: bus master, fast devsel, latency 0, IRQ 18
    Memory at c0200000 (32-bit, non-prefetchable) [size=16K]
    Capabilities: [40] Power Management version 2
    Capabilities: [58] MSI: Enable- Count=1/1 Maskable- 64bit-
    Capabilities: [d0] Express Legacy Endpoint, MSI 00
    Capabilities: [100] Advanced Error Reporting
    Capabilities: [13c] Virtual Channel
    Kernel driver in use: b43-pci-bridge
    Kernel modules: ssb

$ sudo lspci -nn

05:00.0 Network controller [0280]: Broadcom Corporation BCM4311 802.11a/b/g [14e4:4312] (rev 01)

To solve the problem install the correct driver for this wireless card and remove the incorrect driver (bcmwl) which Ubuntu installed by default.

$ sudo apt-get update
$ sudo apt-get install firmware-b43-installer
$ sudo apt-get remove bcmwl-kernel-source
$ sudo reboot

And I had the wireless card working again! Because I upgraded the Ubuntu version and with the last it worked fine after installation.

Or if you prefer It can be done with Synaptic:

Get b43-fwcutter, firmware-b43-installer
Uninstall bcmwl-kernel-source (installed by default)

I hope it helps.


OSError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/pelican-3.6.3.dist-info'

Although it is possible to install it as a global site-package, I think it is better to look into python virtual environments.

1. use virtualenv:

Install virtualenv using sudo

apt-get install python-virtualenv

then you can create a virtual environment:

virtualenv pelican

and activate it:

. pelican/bin/activate

(note the dot+space at the begining). You can then run

pip install pelican markdown

to install it at this virtual environment. After done working with this you can run

deactivate

to deactivate the environment. When you want to work on your project again, you'll have to activate that environment again.

2. virtualenvwrapper

virtualenvwrapper is a tool for making it easier to manage multiple virtual environments. You can install it by typing

sudo apt-get install virtualenvwrapper

then create a virtual environment using

mkvirtualenv pelican

and install your packages

pip install pelican markdown

You can then deactivate this environment with

deactivate

When you want to work with this environment again run:

workon pelican

Installation as a global site-package

If you insist to install it as a global site-package run

sudo pip install pelican markdown


How can a mini PC be stopped from being detected as a laptop with a battery?

I'm an upstream kernel developer and the author of the kernel-patch linked from the original post.
I just discovered this thread today, this is a known issue with some of these Intel Atom x5-Z83xx based boxes, they use an AXP288 PMIC and often the BIOS does not turn off the fuel-gauge (battery
monitoring) part of this chip.
The driver for the AXP288 fuel-gauge contains a list of devices like this:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/power/supply/axp288_fuel_gauge.c#n679
And it will automatically disable itself for devices on this list.
So the proper fix for this, which will make future Linux versions work out of the box, without needing manual configuration, is to add your device to this list.
I can do this for you, but I need some information about your model to be able to do this.
Please as a regular user in a terminal run:
grep . /sys/class/dmi/id/* 2> /dev/null

On the device and then copy and paste the output here, or send me an email with it at "Hans de Goede hdegoede@redhat.com".
That will give me the info which I need to add your device to the no-fuel-gauge list.


You can restore default keyboard layout settings. You can find it under System>Keyboard>Layout Settings .. Restore Defaults ..


Selective crop in pages of a PDF document

use PDFCrop,

see for instructions:
http:// manpages.ubuntu.com/manpages/gutsy/man1/pdfcrop.1.html

it includes these examples:

EXAMPLES

pdfcrop --margins 10 input.pdf output.pdf

pdfcrop --margins ’5 10 5 20’ --clip input.pdf output.pdf

AUTHORS

pdfcrop has been written by Heiko Oberdiek.  This manual page has  been
written  by  Frank Küster for the Debian/GNU Linux distribution and may
be freely used, modified and/or distributed by anyone.

OR

install Adobe Acrobat Pro in Wine:

https:// appdb.winehq.org/objectManager.php?sClass=version&iId=4922

you can download a version of Acrobat Pro 7 with serial number from the Adobe web site from:
https://helpx.adobe.com/creative-suite/kb/cs2-product-downloads.html#

Mind their comment though:

Adobe has disabled the activation server for CS2 products, including     Acrobat 7, because of a technical issue. These products were released more than seven years ago and do not run on many modern operating systems; Adobe no longer supports them.
Adobe strongly advises against running unsupported and outdated software. Only customers who legitimately purchased CS2 or Acrobat 7 and need to maintain their current use of these products may use the serial numbers provided during the download.


How do you print/recall the definition of a function in bash

With the type command:

dennis@lightning:~$ foo() { echo "hi"; }
dennis@lightning:~$ type foo
foo is a function
foo ()
{
    echo "hi"
}


Windows 10 scanning and repairing drive (E:) which contains my Ubuntu 18.04 LTS

Windows won't give a drive letter to a partition with a filesystem type it can't read, so since it's working on drive E:, it's not doing anything to your Ubuntu partitions.

It's doing something to one of your other NTFS partitions. You have five NTFS partitions total.


wget does not download all the files, and links aren't converted

the coorect command is wget -r -k -np http://bbc.com/news

r   for recursive
k   for convert link after download
np  for no parent


how to proceed installation of ruby compass?

I think you have to install ruby-dev first. Try installing that package and then try installing compass again.

  apt-get install ruby-dev


Why is Resume from Sleep sometimes 5-10 seconds and other times 1+minutes?

Closing the lid will cause the machine to suspend to RAM. After you resume you can look at the kernel messages to see what part of the resume is taking so long.

For example:

dmesg | grep "PM: resume"

[   60.006935] PM: resume of drv:hub dev:1-1:1.0 complete after 177.408 msecs
[   60.006945] PM: resume of drv: dev:ep_00 complete after 177.306 msecs
[   60.006953] PM: resume of drv:usb dev:1-1.4 complete after 172.034 msecs
[   60.006985] PM: resume of drv: dev:ep_81 complete after 177.417 msecs
[   60.162766] PM: resume of drv:scsi dev:host1 complete after 334.403 msecs

you may be able to observe a device in the log that is taking too long to resume, which could be the root cause.  I suggest filing a bug against the "linux" package.


Unity in 12.04 with vmwgfx (VMWare player 4.0.3)

I have Sony Z11 notebook with 2 video cards, Intel & nVidia. VMWare Player+Ubuntu+Unity 3d (compiz) works great on nVidia (faster one), while Intel shows exactly the same symptoms as yours. I haven't got it working on Intel, but this fact shows that the problem might be in the host OS video driver incompatibility with the VMWare Player/Ubuntu guest. Maybe you could try to update host video driver to the latest version.

My system setup:

Notebook: Sony VPC-Z1190X
Host OS: Windows 7 Ultimate 64-bit
Videocard 1: NVidia GeForce GT 330M / Driver 190.24
Videocard 2: Intel GMA HD / Video BIOS 2120.0 / Driver 8.15.10.2021

VMWare: Player 4.0.3
Ubuntu: 12.04 64-bit
Unity/Compiz: latest from repository.


Notification bar broken after upgrade 16.10 -> 17.04

Simple to fix globally for all apps (skype, slack, google hangouts, etc). Simply do:

sudo vi /etc/environment

and add

export XDG_CURRENT_DESKTOP=Unity

and then reboot or relogin


Can't install (stuck on copying files) Ubuntu on MSI GS63VR 7RG (most recent as Q4 2017) w GTX1070 MQ

Did you try also Ubuntu 17.10? It has newer kernel (4.13.0).
I was able to install it, without issues on my  MSI GS63VR 6RF.
I can try to help you.

Gabriel


"focus follows mouse" does not respect the window orders while closing a window

I suggest also turning off /apps/metacity/general/auto_raise.

The focus will still go to the "other" window, but the windows' stacking order remains the same, which makes it easier to refocus on the (new) fully exposed top window (just move the mouse over it, of course).


How do I convert a RAID 4 array to RAID 0?

You can change the current configuration directly to a RAID with mdadm -G -l 0 /dev/md127.  Since a RAID 4 with only 4 of 5 members is essentially a RAID 0 without a parity stripe, the conversion will occur instantly.  If there was a parity member, it would be dropped, but since it's already listed as "Removed", it will simply be dropped, Raid Devices decremented to 4, and state should be "clean".

From the mdadm query printed above, you can see that the member size is 1TB and the volume size is 4TB, so the volume should be usable as is, even without the parity member.  You will then need to grow the partition with parted and perform filesystem resize operations per usual.


wifi is not working after updating 11.10

This one solved my problem: https://askubuntu.com/a/76557/34563


How do I access my Windows partition using the command line?

First you need to know the partition your Windows is. For that you can use the command

cat /proc/partitions

Then you need to make a folder, where the partition will be mounted to:

mkdir /mnt/win

Next

mount /dev/*** /mnt/win

Then

cd /mnt/win


Ubuntu 12.04 Server Load Installer Components From CD

Its simple, You should try to make Bootable USB again. The software that you used to make bootable usb was not successfully made it bootable. This time try Startup Disk Creator to make USB Bootable.
For this contact any person having Ubuntu installed in his/her system. Or use your previous Live Ubuntu CD/DVD (if you have).


How to generate uptime monthly report in linux?

There is a tool called "tuptime" that generates information on "uptime" but with a lot more information compared to the single line "uptime" shows.

From their github page:

  Basic Installation and usage

  Clone the repo

git clone https://github.com/rfrail3/tuptime.git

  Copy the tuptime file located under latest/ directory to
  /usr/bin/ and make it executable

cp tuptime/src/tuptime /usr/bin/tuptime chmod ugo+x /usr/bin/tuptime

  Assure that the system pass the prerequisites

python 3.X

  Run first with a privileged user

tuptime

Extra added by me: change the owner and group of typtime to your user with:

sudo chown $USER:$USER /usr/bin/tuptime

and you can run it without sudo/root access.

From the link one of the keypoints it shows is:

  It register the times in a sqlite database. Any other software can use it. The specs are in the tuptime-manual.txt. Also, it have the option for output the registers in seconds and epoch (-s) or/and in csv format, easy to pipe it to other commands.

So if you can code you could create your own reports. Or even connect the database to something like jasperstudio and create a template.

Otherwise the command tuptime will show this:

System startups:    1   since   21:54:09 24/09/15
System shutdowns:   0 ok   -   0 bad
System uptime:      100.0 %   -   21 minutes and 30 seconds
System downtime:    0.0 %   -   0 seconds
System life:        21 minutes and 30 seconds

Largest uptime:     21 minutes and 30 seconds   from   21:54:09 24/09/15
Shortest uptime:    21 minutes and 30 seconds   from   21:54:09 24/09/15
Average uptime:     21 minutes and 30 seconds

Largest downtime:   0 seconds
Shortest downtime:  0 seconds
Average downtime:   0 seconds

Current uptime:     21 minutes and 30 seconds   since   21:54:09 24/09/15

or tuptime --table will show a tabled output:

No.      Startup Date                              Uptime       Shutdown Date   End                   Downtime

1   10:15:27 08/08/15                          42 seconds   10:16:09 08/08/15    OK                 16 seconds
2   10:16:26 08/08/15                          49 seconds   10:17:15 08/08/15    OK                 16 seconds
3   10:17:32 08/08/15            5 minutes and 47 seconds   10:23:19 08/08/15    OK                 16 seconds
4   10:23:36 08/08/15                           9 seconds   10:23:45 08/08/15   BAD                 42 seconds
5   10:24:28 08/08/15   2 hours, 9 minutes and 27 seconds   12:33:55 08/08/15    OK  41 minutes and 44 seconds
    . . .

The tuptime manual mentioned has loads of good information.

You can send the output to a file by adding >> /home/$USER/Downloads/tuptime.log to the command. That text file could be sent to clients.


What is needed to automatically run Cron tasks created with Gnome Schedule?

You need to specify what your default output display is.
(Sorry, the above reference is in German. I could not find anything else.)

A) In the cmd field, introduce:
 either
     DISPLAY=:0 /usr/bin/notify-send test
or
     export DISPLAY=:0; /usr/bin/notify-send test
and report on result in a comment below if needed.

B) You may also try running your GUI cmd notify-send as an "X application". You can select that out of the unfolding menu, in the field directly below yr cmd field.

WHY it is so:
"Gnome Schedule" is based in part on crontab, but crontab doesn't know about yr general user's environment variables. To get more information on that, do (in terminal):

$ man 5 crontab

As a result you need to specify:

what yr stdout (i.e. yr standard display) is within the cron-job itself.
the path prefix of yr cmds, whenever said cmd-executables are not found in /usr/bin/. Concretely for notify-send, it is in  principle superfluous to prefix its full path. Do so anyway for all cmds as a healthy habit...

HTH.


ARM Ubuntu won't let me change my resolution

I had this problem and this is how I fixed it. Open a terminal window and type

    nano /boot/firmware/usercfg.txt

(note you will need to run it with sudo, alternatively use any text editor). Then you can add the settings to set display resolution. Mine looks like this:

    # Place "config.txt" changes (dtparam, dtoverlay, disable_overscan, etc.) in
    # this file. Please refer to the README file for a description of the variouszn

    # configuration files on the boot partition.

    [HDMI:0]
    hdmi_group=2
    hdmi_mode=82
    hdmi_drive=2

    [HDMI:1]
    hdmi_group=2
    hdmi_mode=82
    hdmi_drive=2

Note the two groups HDMI:0/1 this is because RiP4 has two hdmi outputs and they can be configured individually. Also see that the hdmi_group=2 refers to computer monitors, 1 would be for television screens. hdmi_mode=82 refers to my resolution which is 1080p 60Hz. To find a full list of mode numbers that corresponds to resolutions and rates, you can go here:

https://www.raspberrypi.org/documentation/configuration/config-txt/video.md

Refer to hdmi_mode section.

Once these changes are made, you can restart.


Suddenly some of my keys stopped working (g, h, the upper arrow)

test the keys in  a live session it could be a hardware issue
Live-session


Refresh display settings - using xrandr / Laptop screen off, external screen on

You can use the following command:

xrandr --auto && xrandr --output --left-of

or

xrandr --auto && xrandr --output --right-of

depending how your screen are arranged in System Settings → Displays.

See man xrandr for more info.


Thanks for the hint with the console message; it saved me having to plug-in a monitor to the console of a test server (keyboard sufficed...)

That said, up to at least 14.04, Ubuntu supported a nobootwait option for fstab entries, which would achieve what you want; smth like this:

UUID=8b481900-fb7a-4e9e-929c-e940a6b913a4 /data   ext4   nobootwait  0  2

Alas as mentioned in this other question, the nobootwait option was removed in 16.04 with currently no viable substitute other than the /etc/rc.local workaround described in the other answer.


Solved it by myself. If you have an Asus you have to disable "Secure boot control". I read somewhere that it may causes some troubles but it is the only solution that works for me.


Everything in UI is widened after installing Ubuntu 20.10

Check your monitor resolution
And set it to real value of your monitor
https://help.ubuntu.com/stable/ubuntu-help/look-resolution.html.en
If you still have trouble with gpu drivers then try pop os or manjaro. They have better gpu detection and automatic Installation of gpu drivers


How to tell Ubuntu not to check link to directory?

I found a simple way to make broken link work again. Instead of rechecking the link it is easier to remake the link. (Yes I know..LOL..I have little experience in Linux). When the partition is mounted I have done this in Terminal (CTRL+ALT+T) writing the command:
ln -s -f "path_to_Target" "path_to_Link/LINK_NAME"
ln command is used to make soft or hard links.
The -s option is to make "soft link" and the -f option is to "force" making it so that it does not give me an error because the link already exists. The ln command is described in more detail here.
Next stage is to make the link run the command by itself when clicked. I posted another question for this.


What is the significance of the group created along side a user?

This is a "user private group scheme" issue.

  In order to allow more flexibility, most Linux systems follow the
  so-called user private group scheme, that assigns each user primarily
  to his or her own group. This group is a group that only contains this
  particular user, hence the name "private group". Usually this group
  has the same name as the user login name, which can be a bit
  confusing.

http://tldp.org/LDP/intro-linux/html/sect_03_04.html

  What does this have to do with UPG?

  UPG sets the default umask to 0002 so that group users can write to
  files. This would be undesirable and dangerous if everyone belonged to
  one group (like the “users” group in SUSE) — but when each user is in
  their own group, the additional group permission is moot until you
  write into an SGID directory.

http://www.oreillynet.com/onlamp/blog/2006/09/using_user_private_groups.html

More: http://en.wikipedia.org/wiki/Filesystem_permissions#User_private_group


cat

is made for copying textfiles

dd

is used for a bit-for-bit copy


After ubuntu 19.04 update, sound card cannot be detected

found this  solution here https://superuser.com/a/1509313/1151609

it worked for me

Here is a copy of the original post from hopeseekr

sudo vim /etc/default/grub
Find GRUB_CMDLINE_LINUX_DEFAULT and add snd_hda_intel.dmic_detect=0 to the end
of it. (ex: GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3
snd_hda_intel.dmic_detect=0")
sudo grub-mkconfig -o /boot/grub/grub.cfg
Reboot the system.


How to launch Brackets from terminal with sudo privileges?

Use sudo:

sudo -i brackets

It will launch as a root instance. Make sure to use -i, it prevents root owning any of your home folder.

To launch in a certain directory, first cd to that directory, like this:

cd /path/to/folder

Then launch it with the same command:

sudo -i brackets


Onboard is an option.
http://manpages.ubuntu.com/manpages/bionic/man1/onboard.1.html,
https://launchpad.net/onboard,
https://askubuntu.com/a/1162219/226614.
If you have KDE, I think it comes with a built in on screen keyboard.


Ubuntu Menu and Launcher not showing after 2/16/2018 update

This doesn't sound like the bug linked in the OP's question or the close candidate in the comments section: 2/15/18 compiz update broke unity. It sounds more like this common problem: Unity doesn't load, no Launcher, no Dash appears

This is especially true due to comments in deep within my proposed link stating the guest session works perfectly just not the normal user. The OP here has same scenario.

Try the simple solution there by opening a terminal and typing:

rm -rf ~/.config/compiz-1/compizconfig/*
sudo reboot

Some users say it works right away while someone else says the reboot is necessary.


If you go to a TTY and type sudo pkill X that might work (it does anyways).  Still looking for a fix, though.


How to read the following ffmpeg instruction?

I would like to understand how to read the following ffmpeg instruction

Your ffmpeg command is semi-obfuscated by scripting so the actual command is not known, but here's an explanation of each option:

-i indicates the input.
-r 1 sets output frame rate to 1. This is not needed if you want to output a single image or if you want to output all images. In this example it is used to output one frame per second which would skip many frames.
-s qvga sets output width x height to "qvga" which is an alias for 320x240.
-t 1 sets the output duration to 1 second. This is not needed if you want to output a single image or if you want to output all images. It is often added by rookie users trying to output a single image but -frames:v 1 should be used instead.
-f image2 An often superfluous option used to set the output format or muxer. It is used if your output name is ambiguous (perhaps due to scripting). Otherwise, ffmpeg will automatically choose the proper muxer for image outputs.

  how can l adapt it to get all the frames of a given video ?

The simplest, unscripted command to get all of the frames is:

ffmpeg -i input %04d.png

This will output 0001.png, 0002.png, 0003.png, etc. If you want more than a numerical sequence you can use something like output_%05d.png which would result in output_00001.png.

For more info see FFmpeg Documentation: Image Muxer.


So it would seem that installing a game via Steam using the compatibility tool reconfigured my gdm3 in a way that was absolutely broken on reboot.
Please note that my nvidia linux drivers were not installed. That may have contributed to the issue.

The quick fix was switching to lightdm. The longer fix is apt-get
purge 'nvidia*', uninstalling gdm3, reinstalling gdm3, reinstalling
the nvidia drivers. This fixed it and now my visuals are snappy and
fast.

I prefer gdm3 to lightdm aesthetically. I think I would only run lightdm on a low spec machine or microcontroller.


A manual install should be the last step to take if all else fails.

First look in the Ubuntu software repositories (Synaptic is nice for this) if the module is available there. Most (if not al) packages have a python- or python3- prefix depending on the Python version you use.

If it is not available, try with pip. It's not installed by default, do so with sudo apt-get install python-pip or sudo apt-get install python3-pip
Installing packages is as easy as sudo pip install mypackage (or pip3).

If for some reason the above steps don't work, look for a setup.py file inside the package. If there's one, try to install with sudo python setup.py install

Should there be no setup.py file, you can manually copy the module in your PYTHONPATH. Run this command to see where Python searches: python -c "import sys; print sys.path"


How To Install Multiple Fonts At Once From .zip Files?

This is a one-liner in a terminal. Open a terminal with Ctr+Alt+T and run the commands below. Replace <your_font_zips> with the folder name, where you have placed your zip font files.

cd <your_font_zips>
# next command extracts all TTF and OTF files into your `.fonts` folder.
unzip "*.zip" "*.ttf" "*.otf" -d ${HOME}/.fonts
# next command rebuilds font cache
sudo fc-cache -f -v

If you want to remove the fonts again, then simply delete the TTF files in your .fonts folder and rebuild the font cache.

More about fonts and Ubuntu here.

And yes, you need all TTF files.

TTF and/or OTF

I quote:

  OTF is more likely to be a “better” font, as it supports more advanced
  typesetting features (smallcaps, alternates, ligatures and so on
  actually inside the font rather than in fiddly separate expert set
  fonts). It can also contain either spline (TTF-style) or Bezier
  (PostScript Type 1-style) curves, so hopefully you're getting the
  shapes the font was originally designed in and not a
  potentially-poorer-quality conversion.

Source


The issue is not the IFS, it's because in bash (and certain other shells) the RHS of a pipeline is executed in a subshell.

A simple alternative is to use process substitution to keep the read in the parent shell:

read -r device blocks used available use_percent mounted_on < <(df -k | grep /dev/mmcblk0p1)

See Bash: Variable assignment doesn't seem to 'stick'


Based on the tags in your question (qt & c++), I assume you intend on using the Qt framework. Thankfully, there is a library available for Qt that can do this for you. And the best part is that the library is already included in the main archives.

The library I'm referring to is called QCA - Qt Cryptographic Architecture and is available through the libqca2  and libqca2-dev  packages. You will also want to install the libqca2-plugin-ossl  package, which provides runtime support for the OpenSSL functions.

  Note: before going any further, I should point out that QCA is only available for Qt 4.x at the time of writing and may not work with Qt 5.x.

Rather than going into a lot of detail on using the QCA library, I will instead point you to this example which demonstrates how to use the AES128 algorithm to securely encrypt a message with a passphrase and then decrypt it later with the same passphrase.


I found izx's answer here to be your best option.

If you aren't too comfortable editing these files there is an app called Grub Customizer which can modify a lot of grub settings. You can read more here - definitely worth a try.

Good luck!


Wine may need 32-bit library.
You can install it with
sudo apt-get install libncurses5:i386 libncurses6:i386

and then retry.


Ubuntu 12.10 installation problem via usb

The Solution
Reinstalling GRUB will fix this. This question explains how:

How can I repair grub? (How to get Ubuntu back after installing Windows?)
I know your problem isn't that Windows was just installed. But the fix is the same.

Or if you prefer, you can use any of these methods:

Grub2/Installing - Fixing a Broken System

If you experience any further problems booting your new Ubuntu system, please go ahead and edit your question again (then you can comment on this answer to let me know).
Everything you need to know to fix this problem is there...but in case you're interested in what is wrong and why that will fix your situation, I've included an explanation below.
The Problem
The error message is actually telling you that it tried to boot via Ethernet and failed. This makes sense--to boot successfully from the fourth device in the boot list, PCI Lan, you'd have to have a boot server running on a local network.
This error message is useful to us not because it tells us it failed to boot from PCI Lan, but because it tells us it tried. That means it was unable to boot from all of the boot devices that are set before it in the list.
It makes sense that it didn't boot from USB--the Ubuntu live USB was disconnected, and you've reported that when it is connected, it boots. And it makes sense that it didn't boot from the CD/DVD drive--you probably didn't put a bootable disk in that drive.
The question is, why didn't it boot from the hard disk? We know the hard disk works, since it worked before, it worked when you installed, and you can access it from an Ubuntu live system. And it looks like the system was installed.
For the BIOS to move down on the boot device list from the hard disk, the disk must have appeared not bootable at all. That is, the problem isn't that the installed operating system begins to start and has a problem. Rather, the installed operating system cannot even start. Its boot loader, GRUB, is nowhere to be found.
While most installations go without anything going wrong, this is actually one of the more common installation problems. It can occur if you manually tell the installer not to install GRUB to the master boot record of the first hard drive, if it identifies the first hard drive incorrectly (its idea of first isn't necessarily what the BIOS tries to boot first), if it thinks a suitable boot loader is already in place (and is wrong), and possibly for other reasons.
Reinstalling the GRUB2 boot loader to the master boot record of the drive that the BIOS is trying to boot almost always solves this problem. When someone with a working Ubuntu system installs a Windows system alongside Ubuntu, the Windows installer will overwrite the master boot record with its own boot loader, which does not detect and provide an option to boot Ubuntu. That's what your situation has in common with that of users who've just installed Windows beside Ubuntu.


Laptop fan constantly running at a high speed

I also own a Dell Inspiron 15R laptop, but with an i3 processor and 6GB RAM and running Ubuntu 14.04. I was experiencing the same issue you are and would like to offer you the solution the fan issue on my computer.

I found out via the forums about an application called TLP, which is an autonomous power management tool. Once installed, it began to work immediately and my fans began to run normally. Slightly skeptical, I restarted my computer a few times to verify that the problem was resolved, and it was. My fans were not running at max speed and remaining as such once my computer displayed the GRUB menu and thereon, as they were before I installed TLP.

This site will guide you through installing the application.

UPDATE

I have discovered that TLP was not a complete solution to this issue, or my fan issue. However, I recently found a solution to my fan problem, which seems identical to yours, and I posted it on my thread, https://askubuntu.com/a/537538/311982. But I will post my answer here, for convenience.

  Fan speed is normalized by editing the line

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

  in the grub configuration file found at /etc/default/grub so that it reads

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=!Windows 2012".

  Follow these steps to try this solution:

  Open a terminal, type sudo gedit /etc/default/grub, and press ENTER
  Enter your login password and press ENTER (the password will not be displayed as you type it)
  Edit the line,

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

  such that it reads,

  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=!Windows 2012".
  Click "Save", wait a few moments for the file to save, then close the text editor.
  In the terminal, type

  sudo update-grub

  and hit ENTER
  Finally, shut down your computer. Shut it down completely, so don't "restart" it.

  Once you turn your computer back on and select the linux operating system whose grub file you edited earlier, your fans should be working normally. This solution has worked for me on Ubuntu, Linux Mint, Elementary OS, and LXLE on a Dell Inspiron 15R 5520 laptop.

-Jordan


Any alternative to nautilus-image-converter for dolphin?

Yes, there is a third-party plugin available. Download it from here by switching to File Tab https://www.linux-apps.com/p/1126887/ or from this direct link

Now extract it and go to its directory. From terminal use these commands:

sudo cp src/kim_*.desktop /usr/share/kservices5/ServiceMenus/
sudo cp src/bin/kim_* /usr/bin/
sudo chmod a+rx /usr/bin/kim_*
sudo chmod a+r /usr/share/kservices5/ServiceMenus/kim_*.desktop
sudo mkdir /usr/share/kim
sudo cp COPYING /usr/share/kim/kim_about.txt
sudo mkdir /usr/share/kim/slideshow/
sudo cp src/slideshow/* /usr/share/kim/slideshow/
sudo mkdir /usr/share/kim/gallery
sudo cp src/gallery/* /usr/share/kim/gallery

Now restart dolphin. It'll be in the Actions menu.


I think your issue might be related to this bug: https://bugs.launchpad.net/ubuntu/+source/apt-cacher-ng/+bug/1020995. I have tried to use the mirror feature on Ubuntu 14.04 also and gave some errors.

You can backup your /etc/apt/sources.list file

sudo mv /etc/apt/sources.list /etc/apt/sources.list.orig

and create a new one with following content. Replace the ro.archive.ubuntu.com with initials from your country (e.g fr, de, us etc).

#############################################################
################### OFFICIAL UBUNTU REPOS ###################
#############################################################

###### Ubuntu Main Repos
deb http://ro.archive.ubuntu.com/ubuntu/ precise main restricted universe multiverse

###### Ubuntu Update Repos
deb http://ro.archive.ubuntu.com/ubuntu/ precise-security main restricted universe multiverse
deb http://ro.archive.ubuntu.com/ubuntu/ precise-updates main restricted universe multiverse
deb http://ro.archive.ubuntu.com/ubuntu/ precise-proposed main restricted universe multiverse
deb http://ro.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse

###### Ubuntu Partner Repo
deb http://archive.canonical.com/ubuntu precise partner

###### Ubuntu Extras Repo
deb http://extras.ubuntu.com/ubuntu precise main

Then run:

sudo apt-get update
sudo apt-get install openssh-server


How can I use the 16.04 gui on 20.04 LTS?

Ubuntu 16.04 defaulted to the Unity 7 desktop.
Ubuntu 17.10 & later use the GNOME desktop by default.
Use
sudo apt install ubuntu-unity-desktop
to install (add) the Unity 7 desktop on your system.  You can select which you use at login.


Brightness Controls not working on Sony Vaio VGN FZ31S NVidia G8600M

here some solution in heberw (עברית-למקרה שאתה דובר (: ): http://www.fxp.co.il/showthread.php?t=10255235&p=94282824#post94282824

also here is the source from the end of the comment there: Vertical Scroll doesn't work on a Sony Vaio VPCEB1S1E


How to get the default theme using python "Gtk" (not "gtk")?

It is Gtk.IconTheme.get_default() in the gobject-introspection bindings.


Software not running in wine 1.7 ubuntu 15.04

FAQ : "6.1 How do I run an application once I've installed it?"  at https://wiki.winehq.org/FAQ


How to import Rhythmbox podcasts into Banshee?

I am not sure how to get the old podcasts out, but adding the podcasts and re-syncing can be done as shown below:


Installed the latest nvidia drivers and ubuntu won't start anymore :(

You can uninstall the driver: How can I uninstall Nvidia proprietary drivers? - and then install the one from the repos (you can use the "Software & Updates" app).

"All went good but when I restarted" = all went good until I tried to use the driver.

You shouldn't be surprised, even the tutorial you mentioned says "they don’t risk uploading a piece of software that has yet to be proven stable". If a driver is available in the repos - it means it is generally safe to use. If a driver is made available by the vendor - it could mean anything: from "tried & tested" to "go & try & mess up your system as you like".


Message during boot: (process:301): GLib-WARNING **: getpwuid_r (): failed due to unknown user id (0) at boot

It has nothing to do with fixing filesystem errors, though it is a rather generic error and hard to diagnose.  It could be something serious, but most of the time it's not if GDM is coming up just fine.

There is a bug about it here: https://bugs.launchpad.net/ubuntu/+bug/531027 which shows just how generic it can be, feel free to add yourself to the "I am affected by this" list.


How a Script exit when a software does not install properly?

APT returns a non-zero value when the installation fails.
The return value of the apt is stored in the global variable $?
We can use that variable to detect installation failures. Eg:

sudo apt-get update

for software in vim linphone linphone-common linphone-nox git dpkg-dev
do
   sudo apt-get install $software -y

   if [ $? -ne 0 ]  #If apt returns an error, do the following...
   then
       echo "ERROR($?):Failed to install $software"
       echo "Exiting installation..."
       break
   fi
done


I have installed C drive Windows 10, I want to install this C drive format and install Ubuntu

If you only want Ubuntu and not Dual boot with Windows, the safest way to do this is:

Create a Unallocated Space via Windows OS, install Ubuntu on it in Dual OS mode.

After being done with installation, delete Windows boot entry from grub, then delete or format your Windows Volume with any suitable utility like Gparted etc, & you're done.

Why Install in Dual OS Mode and why not just deleting Windows Partiton right there from Ubuntu Installation?

Just to be there in a safer side. If anyhow, Ubuntu Installation fails you'll not have a Computer with no OS.


Under ubuntu 20.04 no sound from Chromium for non-console logged in user

If you use pulse-audio things now seem to work. They did work with firefox and vlc but not chromium (per this post). However sometime later after some magical update things started to work. So for now this issue is resolved for myself.


My problem was solved after trying time after time to install Ubuntu every time the installation crashed on "who you are" after typing my name and password then trying over and over again it went well and I could end sucessfully my installation, I even try to install Fedora instead but it didn't even read my pen drive... hope it help other people!


Why is the "Software" application not showing the same results as "Software Updates" or even apt?

GNOME Software is for modern Android/iOS entertainment-oriented newbies, not for techies and old-school users. Such users need only games, YouTube and media-player. They do not need build-essential, texlive, development packages and so on. They need only to play, consume and watch :)

You can read some thoughts about software installation in modern Ubuntus on community.ubuntu.com.
At present time the best are aptitude, apt, Muon and Synaptic.


Does Xenial provide boost asio only at version 1.10, even though other boost libraries are 1.58?

You are confusing libasio as being part of boost. It is a separate library. The boost asio header is included in the versioned libboost1.58-dev package in xenial.


What is the right way to install nodejs on Ubuntu 16.04?

Please type this command on terminal.

             sudo apt-get install nodejs

To check the version of Node js

             nodejs -v

To remove the Node js

             sudo apt autoremove


to fix it simply open the terminal and run these commands

rm ~/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libstdc++.so.6
rm ~/.local/share/Steam/ubuntu12_32/steam-runtime/i386/lib/i386-linux-gnu/libgcc_s.so.1

Steam should then work properly.But make sure not to install the proprietary AMD drivers as they are very bad for the stability of the OS compared to the open source drivers.If you are getting low performance with the open source drivers then simply upgrade the Mesa version by adding the xorg edgers ppa

sudo add-apt-repository ppa:xorg-edgers/ppa

After that type this in order to upgrade the Mesa version

sudo apt-get update & sudo apt-get upgrade

Then reboot and the new Mesa driver should be loaded.


How can I change the settings of read only pendrive?

The USB pendrive is seen like this:

$ sudo parted -ls

Warning: Unable to open /dev/sdb read-write (Read-only file system).  /dev/sdb has been opened read-only.
Model: SanDisk Cruzer Switch (scsi)
Disk /dev/sdb: 16.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

and

$ sudo lsblk -f
NAME           FSTYPE  LABEL UUID                                   MOUNTPOINT
sdb
└─sdb1         ntfs          80060C87060C8100                       /media/pm/80...
sr0

sudo lsblk -m
NAME                      SIZE OWNER GROUP MODE
sdb                      14.9G root  disk  brw-rw----
└─sdb1                   14.9G root  disk  brw-rw----

and is mounted as

$ df -h
Filesystem                   Size  Used Avail Use% Mounted on
/dev/sdb1                     15G  8.7G  6.3G  59% /media/pm/80060C87060C8100

with read-only permissions. There can be different reasons for the read-only status.

If there are important files on the USB pendrive, please back them up (copy them to another drive) before you start any repair actions.

Maybe the NTFS file system is damaged and needs to be repaired with Windows tools, either the graphical tool in Windows or with

chkdsk /f X:

where X: is its volume ID as seen by Windows. See this link for more details,

Repair the partition table and file system of a pendrive

After trying to repair the file system, you can try again in Ubuntu. If it still does not want to mount it read-write, you can try according to the following AskUbuntu answer,

Mount NTFS partition in a USB drive with custom permissions and owner


About IT++

  IT++ is a C++ library of mathematical, signal processing and
  communication classes and functions. Its main use is in simulation of
  communication systems and for performing research in the area of
  communications. The kernel of the library consists of generic vector
  and matrix classes, and a set of accompanying routines. Such a kernel
  makes IT++ similar to MATLAB, GNU Octave or SciPy.

Writing and reading data from files

  Here we will use the it_file class to store some data. The program
  write_it_file.cpp looks as follows: ... When you run this program you
  will obtain a file called it_file_test.it in your current directory.
  You can read the file into Matlab/Octave to view the data by using the
  following commands:

itload('it_file_test.it')
figure(1);
clf;
plot(a)

And then they give an example of a C++ program to read an .it file. So it seems your options are:

Use Matlab
Use GNU Octave
Write a reader in C++


If you are using Xubuntu, open Theme Configuration. If you have only installed Xfce from another desktop environment, then you can paste sudo apt-get install gtk-theme-config in terminal to install. Launch the application and change the top category Custom highlight colors to your preferred colors. Log out and log in again. This should fix the issue on Ubuntu Software Center.

To fix the YouTube Like/Dislike text, go to the gtkrc file you downloaded with this theme. I installed for my testing by going here. Then I named the file .gtkrc-2.0 and placed it in my home directory for it to be activated on my system. However, you may have the file in another location. Open this file. Go to the line that starts with gtk_color_scheme (line 60 in my file). Change this fg_color: #EEEEEC to this fg_color: #686A6A or whichever darker color you prefer. This color matches the hexadecimal number for the little thumbs up/down icons on YouTube. You may need to log out and in again for changes to take effect. However, this was not necessary for me. I only needed to restart Firefox.

If things are still not optimal after these changes, I fully understand where you're coming from on this. I always want my themes to be 100% perfect to my liking. It is great that with enough knowledge and persistence you can make things just as you like. You may want to try out a few other of these themes if you haven't done so already. Numix Dark Theme is probably pretty nice. I've also seen Spatry talk about some cool themes. If you dig into the config files after installing a full theme, then with enough persistence you can usually figure out how to change little aspects. My previous post here may be of interest.


How do I install Ubuntu Core 16 on the Beaglebone Black?

Beaglebone Black is not an officially supported platform. One of the Ubuntu Core team members has published a developer image that can be used to explore and learn.


How to compile C++ source code ("iostream.h not found" error)?

You should use #include <iostream>, not iostream.h; the .h form is very old and deprecated since years.

You can read more than you probably want to know on the .h vs non-.h forms here:
http://members.gamedev.net/sicrane/articles/iostream.html

(Plus, you should write std::cout or have a line using namespace std; otherwise your next error will be about the compiler not finding a definition for cout.)


Why can't I watch video after installing the original ffmpeg fork from Jon Severinson's PPA?

Jon Severinson's ffmpeg is NOT Ubuntu's ffmpeg!

Last year, some of the ffmpeg developers split off and started their own version ("fork") of ffmpeg, called libav. For various reasons, Ubuntu ended up choosing libav as the version to include in Ubuntu 12.04. See this question for more info.
Both ffmpeg and libav are actively developed, in parallel, right now. Jon's PPA contains the latest original ffmpeg packages, not the libav ones (which are in the official Ubuntu repository)
Both sets of packages have different, incompatible and confusing versioning schemes -- and this is a problem because they also share some of the same components, dependencies, etc. due to their shared heritage. libav 0.8.x is as "new" as ffmpeg 0.10.x!
Right now, Ubuntu applications are set to depend on the libav versions of software.
But when you install Jon's ffmpeg, Software Center/apt gets confused because the audio/video player needs dependencies, but different versions of those are already installed!
Bottom line: if you install Jon's ffmpeg, you have to be prepared to separately install or build from source your preferred audio/video players. ffmpeg and libav cannot co-exist on an Ubuntu installation at this time (unless you install one of them manually).
So, unless you need some particular feature only implemented by ffmpeg, stick to libav since it's the officially supported fork and is as new and actively developed as ffmpeg.


Battery Time To Empty Incorrectly Estimated

The default battery indicator in Ubuntu can be inaccurate on some laptops due to the systems bios not showing the remaining time correctly.

One solution for this is to get a better battery indicator called battery-status that is available by ppa for installation.

Type the following commands in a terminal;

sudo add-apt-repository ppa:iaz/battery-status && sudo apt-get update
sudo apt-get install battery-status

After installation go to Cog -> Startup Applications;

And add following command to the list

/usr/lib/battery-status/battery-status --indicator

Then restart your system, there is a good guide with screenshots on OMG!Ubuntu!


How can I connect USB to TV (via AV port)

I think you might be talking about a cable to be used with a digital camera, not a computer.

does yours look like this?

or this:

This cable is meant to connect a digital camera to a TV. It's useless with computers

There are adaptors, such as the one in the first image, that do this job. A few of them work well with Ubuntu, you should carefully select one that does if you're going to buy one, because may of them have problems.

But, I think you're probably not talking about this thing. So, no, a simple cable will not work.


You may do the below two things:

[1] Go to Startup-Applications from the main menu on the top, and disable all unneeded services such as bluetooth-monitor, sharing-service, etc.

(Sometimes, all startup items are hidden from view by default for security purposes. If that is the case, then issue below command in a terminal, and then open the startup applet:

sudo sed -i 's/NoDisplay=true/NoDisplay=false/g' /etc/xdg/autostart/*.desktop

)

[2] Login in Ubuntu-2D mode instead of the default one.

[3] In your virtual machine settings, check how much RAM you have actually allocated to your vm. It also helps to check 3d-acceleration and other settings and disable the ones you don't use.

I'm sure you will lose some of the sluggishness after you do this.


If you have any other working computer, go ahead and download the Ubuntu version you have installed. Burn it to a disk and boot it up. When it prompts you to try it or install it, click install it and it will detect your Ubuntu version, giving you a bunch of options. You're gonna wanna go ahead and choose "Reinstall Ubuntu XX.xx". This won't delete any personal files, as the image shows:


Lowering screen max brightness with Ubuntu 18.04

This cannot be done the way you want to do this as this is a Linux Kernel Read-Only value:

There is no code that will read the value of max_brightness and act upon it: the kernel just publishes whatever the maximum value for your hardware is.

If you would try to force the kernel into still accepting writes, it will throw an Input/output error.

Maybe there is a way to:

Intercept the keypresses individually and then refuse to go higher, but that would mean posting a new question and referring back here as to why you'd want to do that.
ask Linus Torvalds himself to attend to your bug, but there's very little chance in him solving this in the near future... ;-)


Trying to setup https on qbittorrent web UI

Try this, it worked for me.

Using a Let's Encrypt certificate requested via certbot (see here).

certbot certonly --standalone --preferred-challenges http --must-staple --redirect --hsts --uir --staple-ocsp --rsa-key-size 4096 --domain subdomain.doman.com

And the certs are stored here:

root@server:/etc/letsencrypt/live/subdomain.doman.com# ll
total 12
drwxr-xr-x 2 root root 4096 Mar 20 14:10 ./
drwx------ 3 root root 4096 Mar 20 14:10 ../
-rw-r--r-- 1 root root  692 Mar 20 14:10 README
lrwxrwxrwx 1 root root   53 Mar 20 14:10 cert.pem -> ../../archive/subdomain.doman.com/cert1.pem
lrwxrwxrwx 1 root root   54 Mar 20 14:10 chain.pem -> ../../archive/subdomain.doman.com/chain1.pem
lrwxrwxrwx 1 root root   58 Mar 20 14:10 fullchain.pem -> ../../archive/subdomain.doman.com/fullchain1.pem
lrwxrwxrwx 1 root root   56 Mar 20 14:10 privkey.pem -> ../../archive/subdomain.doman.com/privkey1.pe

I had to copy the "cert.pem" and "privkey.pem" file to the following path (qbtuser is the user who runs the qBittorrent daemon)

mkdir /home/qbtuser/.config/qBittorrent/ssl
cd /home/qbtuser/.config/qBittorrent/ssl
chmod 0700 *.pem
chown qbtuser:qbtuser *.pem

root@server:/home/qbtuser/.config/qBittorrent/ssl# ll
total 16
drwxrwxr-x 2 qbtuser qbtuser 4096 Mar 20 15:52 ./
drwxrwxr-x 4 qbtuser qbtuser 4096 Mar 20 16:34 ../
-rwx------ 1 qbtuser qbtuser 2321 Mar 20 15:59 cert.pem*
-rwx------ 1 qbtuser qbtuser 3268 Mar 20 15:59 privkey.pem*

Troubleshooting:

journalctl -f -u qbittorrent.service

systemctl daemon-reload && systemctl restart qbittorrent


My WiFi connection keeps getting dropped, and then requiring password, over and over again

I would try these two things.

Forget the connection. And then disable the wallet system. That is the Plasma version but I think that Ubuntu has something similar. Then reconnect and try again.
Second thing is search for other drivers for your WiFi hardware.  In Plasma it is in System Settings under Driver manager.


Where is isc-dhcp-server configuration files in Ubuntu 14.04?

In Ubuntu 14.04, it should be /etc/dhcp/dhcpd.conf. The following command will list all installed files from isc-dhcp-server package and filter /etc configuration using grep.

$ dpkg -L isc-dhcp-server | grep /etc/

/etc/dhcp
/etc/dhcp/dhcpd.conf
/etc/init.d
/etc/init.d/isc-dhcp-server
/etc/init
/etc/init/isc-dhcp-server.conf
/etc/init/isc-dhcp-server6.conf
/etc/apparmor.d
/etc/apparmor.d/usr.sbin.dhcpd
/etc/apparmor.d/dhcpd.d

Through GUI, Open Synaptic: Right click on isc-dhcp-server → Properties → Installed Files.


Restrict Deluge to tun0 only but allow Deluge Web UI over eth0

This will force deluge to only use the vpn tunnel with exception to your local subnet.

iptables -A OUTPUT -m owner --uid-owner deluge ! -d 192.168.1.0/24 \! -o tun0 -j REJECT

The logic is that it blocks all OUTPUT anything that isn't the VPN tunnel with exception to the local subnet.

Make sure you verify what user your deluge uses. and adjust the subnet to match yours.  Also verify within ifconfig that your tunnel name, in my example, tun0


D6000 Dock with Displaylink DisplayPort output not working

Ensure secure boot is turned off in the BIOS (I also enabled legacy support - not sure if this is required)


Move Chromium button layout from right to left

Issue no longer present on Chromium 55.0.2883.87 (Developer Build) Built on Ubuntu , running on Ubuntu 16.04 (64-bit).


How to make a custom command available in sftp

You're treating SFTP and SSH as if they're the same.
That's your problem here; they aren't the same.

SFTP is very deliberately locked down for handling files and nothing else.

The only way I can imagine doing what you suggest is by replacing /usr/lib/openssh/sftp-server with something else that does support a remote command syntax. I don't know any drop-in replacements that will. You would also need a client that knew what to do... This is asking a lot.

I'd suggest using SSH (if you have access) when you need to fire commands off. It can also do some limited file moving but that's really not what it's for.


Best way to switch workspaces is

Ctrl+Alt+←↑→↓

and

if you want to switch an opened application to other workspaces:

Ctrl+Shift+Alt+←↑→↓


This issue is related to Screen blinking on moving cursor from one monitor to another and was fixed by updating kernel to upstream


When does diff use | in a side by side diff?

This is the best description of "incomplete line" I could find:

When the last line of a file ends with a new line character it is a "complete line". Otherwise it is an "incomplete line".

For example, suppose F and G are one-byte files that contain just f and g, respectively. Then diff F G outputs:
1c1
< f
\ No newline at end of file
---
> g
\ No newline at end of file


How to connect Samsung Tab 2 10.1 to Ubuntu 12.04?

Look on the setting of the device itself. I had a similar issue with my Galaxy Player and after beating my head against the wall for 2 hours, I started looking at the device. In Settings/Wifi and Bluetooth/USB, changed from Media Player to Mass Storage. This worked for me, your mileage may very.


WCH CH355 Quad serial card not assinged ttyS* after reboot / upgrade

After many many many hours of rebooting and Google searches I finally found an answer.

I bought a different serial card for $17.

The WCH 355 card is in the documentation that I found as being supported.
The card would be found about every 5th reboot. I can only guess that there is some register that comes up random and maybe every 5th reboot it was recognized.
( It was always recognised under windows )

So for $17 it would have been better to just buy a new card immediately.

I am posting this for someone else to find when they buy this card.


Install Python 3.7 packages in Ubuntu 20.04

Rather than building from source or using packages from different Ubuntu versions I would recommend using the Deadsnakes PPA. This provides both newer and older versions of Python than are in the Ubuntu archive, and keeps those versions up to date with bugfix releases.


Apache + php7.2-fpm: 503 Service Unavailable

In my case, this solved it:

service php7.2-fpm start
systemctl enable php7.2-fpm


simple-scan fails to warm up the scanner

I have the same scanner and works every time and never had any real trouble with it. The scanner is powered by USB only and there lies the most likely cause of your trouble. Some laptops only provide limited power to most of the USB ports and some cables with some age and/or wear might have lost the ability to provide the power needed.
When using a laptop, try to check the USB ports. Most laptops have some ports with an icon of a lightning bolt that suggests the port is capable of providing enough power for USB devices that need it. Also, try another cable or if none available, try clean the connectors to make sure they are dirt free.

Most trouble for these USB devices comes simply because they get underpowered and give weird results or behave badly at moments they just need for a little more.

Good luck!


Can I virtualize a pre-installed Windows 7?

There is a section in the VirtualBox User Manual explaining how to use a real disk or partition in a virtual machine.

I tried once, and it works. The only problem I had was the video card driver: when switching from the real installation to the virtual one and back, I have to disable/enable the GuestAdditions video card driver, if i recall well (it was long time ago).


Monitor stutters after forcing larger resolution

After reading this article on Medium I downloaded umc which I used with the --rbt option to generate the mode line instead of cvt. I adjusted the frame rate to get close to the same pixel clock that was used when it was working (but stuttering) which was 222.75.

This lead me to use

> umc 2560 1440 55 --rbt

# 2560x1440x54.97 @ 81.250kHz
Modeline "2560x1440x54.97"  221.000000  2560 2608 2640 2720  1440 1443 1447 1478  +HSync -VSync

that has a pixel clock of 221.00.

After adding this mode it worked like a charm, with the correct resolution and without any lag or stutter.

The whole process and solution seemed kind of random though...


Ubuntu 20.04 how to start viber-mtd minimized at tray?

As a workaround, you can use devilspie to auto-minimize Viber windows whenever they are opened:
First, apt install devilspie, and put the following into ~/.devilspie/viber-minimize.ds:
(if (is (application_name) "Viber <your viber number>")
    (begin (minimize))
)

then simply set devilspie to start at boot, and Viber to start up after that. To ensure this you could set this script to run at boot:
#!/usr/bin/env bash
devilspie &
/snap/bin/viber-mtd.viber

Note that once you start a Viber instance, un-minimizing it from tray will work as expected, devilspie won't interfere (it only acts on newly-opened windows, not opened-but-minimized ones).


This is a bug in Unity.  Please mark yourself as affected here:
https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1451613


Prevent VLC from starting a new instance every time a media file is opened

Open Vlc, Go to Tools Menu -> Preferences-> Interface-> Instances->

Choose Allow only one instance


Restore boot-loader after resize dev/sda1 using gparted

If a resize or move operation is cancelled then the file system can be left in an inconsistent or broken state.  This can result in data loss and the inability to restore the ability to boot from a broken file system.

I recommend restoring from backup, or if you do not have a backup then try to recover the file system / important data before proceeding any further.


Unable to access external hard drive - "Not authorized to perform operation" - Ubuntu 18.04

If you happen to have chrome-remote-desktop installed as a Chrome Browser Extension there's a good chance that is the cause of problem.

If so, see Automount when clicking on disks in GUI file manager suddenly stopped working in Ubuntu 18.04 for solution.


With help from this question and its answers I was able to get this working (currently resilvering).  To any ZFS developers reading this, the operation of replacing a disc should be made much easier/full (and fool) proof.  After the initial setup and on a long enough time line the only operation every ZFS user will eventually have to do is replace a disc.  But I digress.

In my case I didn't want to replace my drive, I only wanted to clear its faults and get it back online fault free so I could determine if the disc actually needed to be replaced.  My reasoning for wanting to do this was 1.) the system had been on for nearly a year without a reboot so bit rot is a possibility 2.) the number of errors was fairly small.

The trick it seemed for me was to delete the partitions from the disc in question.  First I needed to determine which device to operate on.  You could determine this via process of elimination using zdb, but I used lshw to get all the info I needed at once.  Basically I wanted to correlate the the device zpool status was telling me had failed to a /dev/sdX device (if you are not familiar with less just use the up/down keys to show more/less and the q key to quit).

root@server:/# lshw|less
...
              *-disk:2
                   description: ATA Disk
                   product: ST3000DM001-1CH1
                   vendor: Seagate
                   physical id: 0.2.0
                   bus info: scsi@0:0.2.0
                   logical name: /dev/sdd
                   version: CC24
                   serial: Z1F1J33Y
                   size: 2794GiB (3TB)
                   capacity: 2794GiB (3TB)
                   capabilities: 15000rpm gpt-1.00 partitioned partitioned:gpt
                   configuration: ansiversion=6 guid=52d25a12-120a-1c40-92a1-0be436c2d642 sectorsize=4096
                 *-volume:0
                      description: OS X ZFS partition or Solaris /usr partition
                      vendor: Solaris
                      physical id: 1
                      bus info: scsi@0:0.2.0,1
                      logical name: /dev/sdd1
                      serial: f25724a4-dd55-764c-af34-9479521854b9
                      capacity: 2794GiB
                      configuration: name=zfs
                 *-volume:1
                      description: reserved partition
                      vendor: Solaris
                      physical id: 9
                      bus info: scsi@0:0.2.0,9
                      logical name: /dev/sdd9
                      serial: 89eeeedb-e3a0-4940-8a50-d3d7506ad603
                      capacity: 8191KiB
...

Here I can see that /dev/sdd is the disc I wanted.  I then deleted the partitions from that disc:

root@server:/# fdisk -l /dev/sdd

Then just follow the onscreen prompts for deleting the partition.  Here is a good guide.  After that the following command finally worked:

root@server:/# zpool replace tank 12956315685006632708 /dev/disk/by-id/ata-ST3000DM001-1CH166_Z1F1J33Y

The guid (that long number) was obtained using the zdb command.  I think in the end I might have been able to use the online command instead of replace, but I didn't try that.