Can I use C170 Logitech Webcam in Ubuntu 14.04

The good news is that this device should be automatically recognised and setup by Ubuntu. It has the tick of approval and demonstrated full working order with Linux from the Linux Hardware Guide. So to 'install' simply plug it in and you should be right to go.

Once you have physically plugged the device in and it has been recognised by Ubuntu you can test it out with cheese or guvcview. Install these as follows:

sudo apt-get install cheese guvcview

Cheese will automatically detect your webcam and display live video stream and from there you can take photographs or record live streams. Other possible applications under Ubuntu that can utilise your webcam are vlc, MPlayer and Skype. Have a look at the Ubuntu Community Docs link in my 'References' for a bit of a steer into getting these ones running.

References:

Can I use a logitech C170 webcam on Ubuntu 13.04?
Ubuntu Community Docs: Webcam


Ubuntu won't boot after initializing the Build Environment for Android

You have uninstalled quite a few important packages including ubuntu-desktop and xorg. This is the reason why you have no GUI. Still you have a shell running.

Before rebooting, switch to first terminal CTRL+ALT+F1 Log on. Then run

 sudo apt-get install ubuntu-desktop xorg

Agree to remove libgl1-mesa-dri


Power setting changes not being saved on suspend/reboot

I believe a more appropriate way to do this is to create a file:

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

Use nano or kate or leafpad if you don't have the text editor gedit. Add the parameter values:

options snd_hda_intel power_save=XX power_save_controller=YY

Where XX and YY are the desired values.

Proofread carefully, save and close the text editor. Reboot.


How do I safely delete a program in Ubuntu?

Assuming you followed the instructions on the github, I would suggest that you use ppa-purge to remove the 'deadsnakes' ppa

sudo apt-get install ppa-purge

sudo ppa-purge ppa:fkrull/deadsnakes

Update your path to remove the path extensions added as instructed at the github, and most of lime should be inactive.

As for removing it entirely, the manner in which it was installed may require looking into the makefiles to determine what directories need to be deleted.


Network Issue After upgrade to UBUNTU 18.04

Click on Network Setiings...Upper right...

Then open Identity....

Strategy and Test....

STRATEGY

The strategy is simple... Ping a series of diffent sizes, and this will help narrow down the MTU size. A ping is 28 bytes on it's own. A typical LAN connection has an MTU of 1500 bytes. So we need to remember to subtract 28 from the MTU we really want to test. For example, if we want to test an MTU of 1500, first ping and set the size to 1473, this should fail as we are sending a ping that is 1501 bytes in size, with the Do Not Fragment option set. you should get an output similar to the following:

jon@JonM-LabPC:/$ ping -c 2 -M do 8.8.8.8 -s 1473
PING 8.8.8.8 (8.8.8.8) 1473(1501) bytes of data.
ping: local error: Message too long, mtu=1500
ping: local error: Message too long, mtu=1500

--- 8.8.8.8 ping statistics ---
2 packets transmitted, 0 received, +2 errors, 100% packet loss, time 1006ms

We can see the error "Message too long", followed by the actual MTU size. Please be aware that not all Linux distros will have this same output... For Checkpoint's Gaia, you will get something similar to this:

[Expert@R7730StandAlone:0]# ping -c 2 -M do -s 1473 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 1473(1501) bytes of data.
From 172.26.176.150 icmp_seq=1 Frag needed and DF set (mtu = 1500)
From 172.26.176.150 icmp_seq=1 Frag needed and DF set (mtu = 1500)

--- 8.8.8.8 ping statistics ---
0 packets transmitted, 0 received, +2 errors

So, depending on the output you get, you can further validate that the MTU is 1500 by sending a ping that is exactly 1500 bytes in size, rather than 1501. You would just set the size to 1472. This will be the MTU for 99% of internal LAN connections, and most residential cable modems.

Just Keep going up till correct MTU is found....

steve@steve:~$ ping -c 2 -M do 8.8.8.8 -s 1468
PING 8.8.8.8 (8.8.8.8) 1468(1496) bytes of data.
1476 bytes from 8.8.8.8: icmp_seq=1 ttl=118 time=26.3 ms
1476 bytes from 8.8.8.8: icmp_seq=2 ttl=118 time=26.7 ms

--- 8.8.8.8 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1001ms
rtt min/avg/max/mdev = 26.311/26.525/26.739/0.214 ms

steve@steve:~$ ping -c 2 -M do 8.8.8.8 -s 1469
PING 8.8.8.8 (8.8.8.8) 1469(1497) bytes of data.
ping: local error: Message too long, mtu=1496
ping: local error: Message too long, mtu=1496

--- 8.8.8.8 ping statistics ---
2 packets transmitted, 0 received, +2 errors, 100% packet loss, time
1029ms

PING 8.8.8.8 (8.8.8.8) 1468 (1496) bytes of data.

When this message is received, you have determined MTU....

ping: local error: Message too long, mtu=1496
ping: local error: Message too long, mtu=1496


How can I shutdown the system every day at a specific time

Yay! Figured out how I did it!

The file /etc/rc.local evidently runs on bootup. Adding the line sudo shutdown -h 16:30 and then following that line with exit 0 shut the system down each day at that time if it was on.


Software Update problem libplacebo18 on ubuntu 18.04

I fixed it by force overwriting the package

sudo dpkg -i --force-overwrite /var/cache/apt/archives/libplacebo18_1.18.0-1~bionic1_amd64.deb

And then I used this command to fix any broken packages.

sudo apt -f install


I'm installing Ubuntu on a laptop with a 32 GB SSD and 500 GB HDD. How should I partition them?

Recommendation

SSD;

Make one partition taking up the entire SSD for /.

HDD:

Make one partition taking up the amount of RAM you have for swap.
Make one partition taking up the remaining space for /home.

Benefits

Fairly easy-to-understand.
Really fast speeds for loading the operating system and programs.
Lots of space for your personal files in your home directory.
Swap gets stored on the HDD instead of the SSD to avoid swapping causing excess wear on the SSD.
Since /home is on its own partition, a clean reinstall of the OS or a clean install of a different OS while keeping your personal files is much easier (though you have to be careful not to accidentally format the /home partition).

Setting it up

When the installer asks for the installation type, choose Something else.
For each device (the lines that start with /dev/), click on the device and click the New Partition Table... button and click Continue to clear away any existing partitions on that device.
On the disk with about 32 GB of free space, click on the free space line and click the + button.
Change Mount point to / and click OK.
On the disk with about 500 GB of free space, click on the free space line, and click the + button.
Change Size to the amount of RAM you have, change Use as to swap area, and click OK.
Click on free space again and click the + button.
Change Mount point to /home and click OK.
Click Install Now, then click Continue.
Continue with the regular installation questions.

If the above steps give a warning about the need for an EFI boot partition

Go back to the partitioning screen
For each device (the lines that start with /dev/), click on the device and click the New Partition Table... button and click Continue to clear away any existing partitions on that device.
On the disk with about 32 GB free space, click on the free space line and click the + button.
Change Size to 500, change Use as to EFI System Partition, and click OK.
On the disk with about 32 GB of free space, click on the lower of the two free space lines for that disk and click the + button.
Change Mount point to / and click OK.
On the disk with about 500 GB of free space, click on the free space line, and click the + button.
Change Size to the amount of RAM you have, change Use as to swap area, and click OK.
Click on free space again and click the + button.
Change Mount point to /home and click OK.
Click Install Now, then click Continue.
Continue with the regular installation questions.
Ignore the warning about existing operating systems using BIOS compatibility mode.


"python -m pip install pynput" VS "pip install pynput"

There is no different. pip is a python modul. Python allows you to start modules directly from shell because it is creating files in /usr/local/bin/pip. You run the same program.


Why can't I get all reviews for this app in the Ubuntu Software Center using the JSON API?

It's not obvious, but the API filter there is using origin to specify whether the app is from the ubuntu archives or a PPA. So for a commercial app, filtering by 'ubuntu' gives zero results. What you want is:

http://reviews.ubuntu.com/reviews/api/1.0/reviews/filter/any/any/any/any/splashtop-streamer/
http://reviews.ubuntu.com/reviews/api/1.0/reviews/filter/any/any/any/any/splashtop-streamer/page/2/

etc.

Note, there's also a tiny wrapper that can keep your code cleaner if you want it:

$ bzr branch lp:~rnr-developers/rnr-server/rnrclient
$ cd rnrclient && virtualenv venv && venv/bin/python setup.py install && venv/bin/python
>>> from rnrclient import RatingsAndReviewsAPI
>>> api = RatingsAndReviewsAPI("http://reviews.ubuntu.com/reviews/api/1.0")
>>> api.server_status()
u'ok'
>>> streamer_reviews = api.get_reviews(packagename='splashtop-streamer')
>>> len(streamer_reviews)
10
>>> streamer_reviews = api.get_reviews(packagename='splashtop-streamer', page=2)
...


Booting impossible cause GRUB rescue won't let me

Looks like a bug in windows installer.

Easy way -

Reinstall ubuntu by replacing lubuntu.
Still facing same issue? Boot up with live ubuntu disk and use boot-repair tool. Click on "Recommended repair ". At end it will give a url, note that down. If these step doesn't fix the issue, post that link here.

Advance Option : If you are know how to customize partition.

Install ubuntu, while installing there will be prompt saying "Replace current ubuntu", "Reinstall Ubuntu" and Something Else

Choose "something else"

Then do the routine assignment of partition mapping. (If you don't what I am saying stick to Easy option)

Make sure boot-loader location is your hard disk not usb disk. (Hard disk most probably will be marked as sda where as usb as sdb)


1/2 solved - Error removing old /etc/fstab entry to mount HDD

This jimmy rigged it.
Create a directory that you will use as the mountpoint for your drive:
mkdir /mnt/mydrive

Mount your drive with this command:
mount /dev/sdb1 /mnt/mydrive


usr/local/chroots/precise does not exist; cannot update.

This means there is no chroot called "precise".

when you do a distribution upgrade, the name of the chroot changes. Since you went from precise to trusty, you need to update crouton so that it knows there's a newly named chroot:

Code:sudo -e ~/Downloads/crouton -u -n elementary


You could try to use a package manager to remove the package, and if you wamt to remove the whole software, maby you can remove it from software center!


Monitor shows 'no signal' after Nvidia driver installation (ubuntu 12.04 amd64)

Select the default ubuntu kernel (usually the top one), and rather than pressing enter, press E to edit.

Press DOWN ARROW until you get to the line that starts with

linux /boot

and press END keys to position your cursor at the end of the that line usually ending with “quiet splash”.

Now type in the additional kernel option nomodeset (please dont make the same typing error I made for this screenshot :-)


Booting from flash, can't escape grub rescue

It sounds like your system boots to the harddrive but fails. When you say "boot to the usb", is that Ubuntu Live on a USB stick? If that doesn't work, have you tried burning a Ubuntu Live CD and booting from it?


Can I run do-release-upgrade to upgrade from 16.04 LTS to 18.04 LTS but not the latest 20.04 LTS?

to verify this please use the following command:
sudo do-release-upgrade --check-dist-upgrade-only

You will know to which release your system will be upgraded


Configuring Wireless Networking in 11.04

If you are using network manager, right click the "Network Manager" icon, hit "Connection Information".  It will show you all those details.

And if I remember correctly, the SSID is the network name (so if the wifi network's name is "IAmTheEvil", then the SSID is "IAmTheEvil").

However, if you are trying to configure your wireless networking, Network Manager is basically "click and connect", just left-click the Network Manager icon, and then choose the wifi network to connect to.  If you don't know the SSID of your wifi, you're kind of out of luck there.


So, after a while of poking around I learned the answer to a degree.

1.) Because it is not enabled by default and/or the driver does not support on Linux

2.) The blob I guess, they can deny things that weren't designed to run certain codecs natively or directly (non-microcode)

3.) Some do, but it's mainly the fact they are new and were not built for yet.

4.) Best way I found was MPV, I think that's what it was called. You can force hardware acceleration even if not supported.

5.) Yes, skylake has been abandoned for newer technology.

6.) Yes, everything has been made with xorg in mind, that's why the setting was called "Hardware acceleration through x-server".

That's as much I could gather on this.


Cannot See Files in Windows 7 with Ubuntu 14 LTS Server

Welcome to Ubuntu and GNU/Linux!

As things stand, Windows won't be able to do anything with your Ubuntu Server files on a number of levels:

1) It won't be able to log into the system. (You would need to use ssh for this) See: SSH on help.ubuntu.com. This won't help you with file transfers directly, but it will  help to manage your server from Windows.

2) It won't by default be able to read the Linux filesystem. (I'm presuming your server has the default ext4 filesystem).

To share files between your Linux Server and your Windows machine, you can use Samba. See this guide How to Create a Network Share Via Samba Via CLI on how to set it up on your Ubuntu Server.


How do I download and install packages without an internet connection?

You can download the .deb files and install them manually, but without a connection you won't be automatically getting dependancies and updates.  That would be like going back to Linux pre-package manager days, about like... 20 years ago.  Perfectly possible, but much easier to get the computer connected and updated/installed.

You can also have a local repository that you take off-line when needed, for example apt-mirror.


How do I open audio settings GUI in Ubuntu 20?

search "sound" in "app search"
click on super key (= windows key on windows keyboard) to get to app search

select "Sound" section of settings app


Laptop sound issue. Speakers are working, but the headphone doesn't

This seems to be a hardware issue. It was working before in both Windows and Linux. Now it doesn't work with Linux either.


ubuntu cannot shutdown without plugging usb device

This could be a BIOS-related issue, can you try:

Edit the grub configuration file with: sudo nano /etc/default/grub
Add acpi_osi=\"!Windows 2012\" kernel parameter into GRUB_CMDLINE_LINUX_DEFAULT line. So it should be changed from:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
To:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=\"!Windows 2012\""
And run sudo update-grub to make this modification take effect.
Shutdown without USB devices plugged.

Reference: https://bugs.launchpad.net/bugs/1288161


Can I share my internet(lan) through Wifi(adhoc) connection via a laptop?

yes you can open network manger from the right side in the panel then click edit connection you will see all connection choose wireless and click add new set everything like ssd and password then go to ipv4 setting make the method "share to other computer"


Keyring no longer prompts for password when SSH-ing

I found this on the Arch wiki: https://wiki.archlinux.org/index.php/GNOME_Keyring

Basically, you run gnome-keyring-daemon -s to get your specific keyring value, then to your .bashrc, add:

SSH_AUTH_SOCK=`netstat -xl | grep -o '/run/user/yourusername/keyring-xxxxxxx.*/ssh$'`
[ -z "$SSH_AUTH_SOCK" ] || export SSH_AUTH_SOCK

This should make ssh ask you for your password through the keyring GUI.


Error while installing nativefier on Ubuntu 18.04

You could try moving to an older version of node and then retry installing it. According to this documentation, it's not an uncommon issue with Ubuntu 18.04 - https://github.com/nodejs/node/issues/19348.


Where does the Mod4+P key binding come from?

It appears to be related to the BIOS: see here and here.

Marius pointed this (here):

  This is hardcoded in gnome-settings-daemon and can be disabled in
  gconf by setting

/apps/gnome_settings_daemon/plugins/xrandr/active

  to false. This workaround probably has a nasty side effect of breaking
  your real video switch key, if you have one.


Computer won't boot without a USB drive?

I had a similar problem when trying to fool around with a similar /dev/sdb device, my problem was that the sdb was trying to "start at boot" i cant remember what i did exactly to change it back. If you can access your desktop then go into the disks program and edit the mount options and remove the "start at boot" check box. Not sure if this will help, if you cant access the desktop somehow obtain a live cd, and you can change a config file somewhere but cant remember where.


Keep highlight tool on in Document Viewer

It is flaky, unfortunately. There currently is no way to keep the highlight on. So indeed, life is not easy if you are reading though a document. You cannot keep your felt tip pen handy in your hand. You each time have to lay it down and close it, and you need to take and open it each and every time again for the next notation.

In Evince 3.30, life has improved somewhat, but in a different way. Evince 3.30 and upwards have an undocumented hotkey Ctrl+h that activates the highlighting, or, if you made a selection, applies highlight to it. This would work somewhat faster already. However indeed, this was only introduced in Evince 3.30, so is not yet available in your version of Evince.

Evince 3.30 also provides a "Highlight Selected Text" option when right-clicking a selection. However, this is a hit and miss. More often, the selection is not applied than applied. It works more reliably when the selection is larger, but selecting a single word, in many cases the word is not highlighted after selecting the option.

In other words, it is rather primitive in the year 2019, and we may need some more years to see the feature mature. It would be worthy filling an issue on this with the Evince developers. It makes sense having the possibility to keep a tool ready rather than to have to activate it each time over and over again.


I am getting two error messages before startup is finished

As far as the

sda clean 9483989/237839829 clean 0438/23989 blocks

message goes, that's completely normal as 16.04 runs fsck on boot. It's just telling you that your ext4 filesystem is clean and there aren't any orphaned inodes or anything like that.

And regarding:

[OK] Started Load/Save RF Kill Switch Status of rfkill1

That message is referring to the physical Wi-Fi / Bluetooth switch on the side of your laptop. There is a way to override the hardware switch IIRC, so that message probably means the kernel is checking the state of the switch so it can respect it.

Bottom line, both of those messages are normal and you have nothing to worry about :)


Disable Sticky Keys' "Locked After Being Successively Pressed Twice" Behavior

I had the exact same issue for a long time.

You can get the behavior you want by using xkbset. You can install it using apt.

sudo apt install xkbset

You can see the available options with

 xkbset -h

So instead of enabling sticky keys through the GUI. Use xkbset. The command given by another question worked for me. Specifically the -latchlock option disables the unwanted behavior.

Currently I use

 xkbset exp -bell -sticky -twokey -latchlock -accessx -feedback -stickybeep -led 9999
 xkbset bell sticky -twokey -latchlock feedback led stickybeep

It seems like restarting your computer will forget the settings. Adding them as a startup script will work.


How to choose where the software is stored when installing via Ubuntu Software Center

You can't. Linux (not just Ubuntu) follows the Filesystem Hierarchy Standard where is defined what the logical place is to store files such that we do not have duplicate files on our system. USC does not choose where to install software.The package you install has information on where files need to go.

If you want to store programs on a different place you need to install it from source. While compiling sources you can then tell it to install in /opt or in your /home. And if that is a general idea you want to explore Gentoo could be a better operating system for you.

  Also is it a problem to store the application to a NTFS partition?

In general: yes. Windows does not provide functionality for the permissions structure Linux uses.


Unable to boot following update to Trusty, get "NMI handler taking too long" mesage

It seems the problem is related to not clearing the control debug register.

CF140 Performance Monitoring IA32_PERF_GLOBAL_STATUS.
CondChgd Bit Not
Cleared by Reset
Problem: The IA32_PERF_GLOBAL_STATUS MSR (38EH)
should be cleared by reset. Due to this erratum, CondChgd (bit 63) of
the IA32_PERF_GLOBAL_STATUS MSR may not be cleared.
Implication: When
this erratum occurs, performance monitoring software may behave
unexpectedly. Errata Intel® Xeon® Processor E7 v2 Product Family 53
Specification Update March 2015
Workaround: It is possible for the
BIOS to contain a workaround for this erratum

There is probably a fix for this included in kernels higher than  Ubuntu-3.13.0-35.61.
This may happen also if you are debugging SMP kernel using kgdb over serial port (over ethernet as well - probably in any configuration) with all CPU's online. I have to disable all CPUs but one if I want to debug smoothly, otherwise it works sometimes and sometimes not.


Certification is available for most areas of Linux but I think you're putting too much focus on it.

People predominately hire people who are competent at what they do, not the hoops they've jumped through to get there. A year of specific industry experience is worth a dozen vague certificates.

Even if you do want to continue down a road of certification-over-experience (which I can understand for somebody without much real-world experience), in order for the certificate to hold any value, it needs to be locked onto a real-world skill. Few companies will hire somebody solely on the basis that they have a "generic Linux certificate". If you want to be a DBA, get certified for MySQL or Oracle. If you want to be a network monkey, look through the various networking certification programmes available.

I'll add that the good certification programs are both quite hard and expensive (especially at the higher levels) and most of them rely on you having real-world experience for your reasoning.

And if you're applying for newly-grad/junior posts, people won't expect you to have put yourself through a certification programme anyway. They're looking to train up people.


From your comment I understand you removed the icon from the Launcher. This does not remove your home folder, only its icon from the Launcher.

To get it back, just open Dash, search for "nautilus" and drag the icon on to the launcher and you're done:


How to speed up Boot Time in Ubuntu 18.04

Boot time is "controlled" by the speed at which the installed programs and services can load. So to speed it up:

Have a faster boot disk (using a faster SSD or similar - faster storage to load the programs from). You have this, so....
Probably DON'T need to worry about faster memory, though more of it and using preload could help with some programs particularly after boot. 6GB should be enough for now!
Removes unnecessary services (or dont install them in the first place)

The latter is the cheapest, and you already found one of the more ideal solutions in systemd-analyze (for newer linux systems). The blame option lists the services that take longest to complete (note, ones like plymouth, have to wait for other services to finish starting to complete, so removing them wont improve boot time by much).

Some services are important to the systems operation, so aren't ideal to remove (e.g. NetworkManager), but perhaps can be configured so no errors occur or it doesnt try and load stuff you may not use (e.g. lvm). If you post the top output of blame in your question we may be able to help with this!

Also, running systemd-analyze plot > file.svg will give you a visual overview of the boot time (as an image file.svg). Other methods are listed here (but surprisingly misses the plot option covered here).

The options you added are explained here. I'm not sure if I've heard of uses for them outside of dealing with weird video hardware, but any speed increase here is from skipping the splash screen. It might increase speed a bit but the output shows its starting up properly (i.e. I wouldn't bother except on a computer without a display in a fixed state).


command line:

wine /dir/to/application.exe

There is also a menu entry in Nautilus called "open with wine windows program loader"

An MSI installer is done with

wine msiexec /i /dir/to/installer.msi

Do not forget to install winetricks and if you want games playonlinux.

And to configure wine: hit super and search for wine.

Mileage may vary per exe file so do check out  WineHQ for tips and tricks regarding software, rating on how well software functions.


If I change my home from ext3 to ext4 when installing will my data be lost?

Yes.  And you should be able to see that because the format box will automatically be checked.  If you want to enable the two main features of ext4 that can be added without reformatting, run sudo tune2fs -O extents,uninit_bg /dev/sda1 and then sudo e2fsck -f /dev/sda1.


18.04: Run zenity in background or not show the terminal

The next tried on 19.10 with 3.32.0-4 version of zenity.

Modified my Viber's .desktop file the next way:

$ cp ~/.local/share/applications/Viber.desktop ~/.local/share/applications/runzenity.desktop

$ gedit .local/share/applications/runzenity.desktop

[Desktop Entry]
Name=ZenScript
Comment=Calendar showing
Exec=/home/user/test/zenscript.sh
Icon=/usr/share/pixmaps/viber.png
Terminal=false
Type=Application

Created ~/test/zenscript.sh script:

#!/bin/bash
/usr/bin/zenity --calendar

Made it executable: chmod +x ~/test/zenscript.sh.

ZenScript application icon appeared in main menu. After clicking it calendar opens without a terminal.


Ubuntu 18.04 LTS Macbook Pro - Live Disk Boot Trouble AND regular boot trouble

I have pretty much the same issue on a mid-2010 MacBookPro 13 that single-boots Ubuntu. 17.10 worked fine. Upgraded to 18.04 by command line and now the graphical OS interface doesn't appear. I can SSH into the machine. I use the machine mostly as a file and web server, and those functionalities work correctly after the upgrade. The Nouveau video driver is in use, and text appears on the screen as described by numoonchld. I can get to text login using Ctl-Alt-F7. This is a Kubuntu installation, which uses sddm as the display manager/greeter. System log shows that sddm starts then exits. As part of diagnosing, I've installed Gnome desktop and it's gdm3 display manager/greeter, and got the essentially same result.  Booting from USB device with 18.10 installation media hangs at some point with text on the screen.  Because I use this machine as a server, I can live without the desktop, but I don't want to.


The reasoning is you're trying to use your log in e-mail address. It requires you to use your assigned name. The quickest way to find this information out is to login to Facebook via a web browser and check out your own profile. It should the web url as facebook . com / YOURNAMEHERE.

Use that given name and your password you used to log in and it should work.


How "Use Hardware Acceleration" option in Chrome affect performance?

Obviously hardware acceleration works great when you have a decent graphics processor. But if for some reason that GPU isn't working so great then hardware acceleration suffers in browsers. It's why when users complain about performance that involves GPU acceleration. First quick fix is turn off the HA setting. Of course the real solution is determining why the GPU isn't doing a good job, or is it simply a matter its barely acceptable to handle the tasks. In my experience most browsers use hardware acceleration by default and rarely have I seen a hardware setup that disables this. I always say use the settings that work the best.


Starting Pre-cache and pre-load apparmor profiles fails on boot

This is a bug in mediascanner2.0 and I have filed bug 1443693 for you.

As a workaround, you can run:

sudo mkdir -p /usr/share/apparmor/hardware/{audio,graphics,video}.d

or alternatively purge the mediascanner2.0 package if you don't need it (assuming that this is a desktop and not a phone).


Error while purging  PPA from Unity 5.0 testing repository

You need to have the ppa enabled in your sources before running ppa-purge or if quiting a ppa-purge attempt. (1st thing ppa-purge does is disable the ppa to be removed

So open your software sources (software-properties-gtk), re-enable the ppa & then update your sources -

sudo apt-get update

There is likely no way ppa-purge is going to do a clean, complete job so before using i'd strongly advise to install synaptic.

Then run your ppa-purge command, your best bet may be to accept the 1st solution, Y,  & then answer Y to any other presented until it does it's thing.

Once finished Do Not log out or restart

Open synaptic, click 'Reload', then  search gnome-session & mark for install if it's not installed. Then search unity & mark unity for install or re-install.

Additionally search nautilus & mark libnautilus-extension1  for reinstall, check & make sure that nautilus & nautilus-data are installed, if not mark also & apply.

If desired you could search ubuntu-desktop and mark for reinstall in lieu of above, just make sure the packages I've mentioned are installed before you log out or restart

Also note that unity-2d may need to be reinstalled

Good luck...


How to install telegram-cli with Persian/Arabic support

Your issue has two reason, first one is gnome-terminal not supported Persian. And the second one is snap not supported Persian.

You can solve this problem, with this ways:

First way (easy way):

sudo add-apt-repository ppa:ali.r/telegram-cli
sudo apt update
sudo apt install telegram-cli

This PPA has packages for Ubuntu 16.04, 17.04, 17.10. And install konsole alongside of telegram-cli, which is support Persian language.

So you can run konsole and then run telegram-cli on it. As you can see it support Persian completely.

Second way (hard way):

Install dependency:

sudo apt install konsole make git libreadline-dev libconfig-dev libssl-dev lua5.2 liblua5.2-dev lua-lgi libevent-dev libjansson-dev libpython-dev

Download sources from github:

git clone --recursive https://github.com/vysheng/tg.git

Configure and compile it:

cd tg
./configure
make

And make a symbolic link to its binary:

sudo ln /bin/telegram-cli /usr/local/bin

And you can use telegram-cli easily in konsole for Persian support.

Optional:

You can make a launcher for this package.

So run this command:

sudo nano /usr/share/applications/telegramcli.desktop

And paste this contents to that file.

[Desktop Entry]
Version=1.0
Name=Telegram Cli
Comment=Command-line interface for Telegram messenger
Exec=konsole --noclose -e 'telegram-cli --enable-msg-id'
Icon=terminal
Terminal=false
StartupWMClass=TelegramCli
Type=Application
Categories=Network;InstantMessaging;Qt;
MimeType=x-scheme-handler/tg;

And run this command:

sudo chmod a+x /usr/share/applications/telegramcli.desktop

So you can run telegram-cli from applications menu.


How to recompile firefox 57 debian package using debuild?

I managed to solve this. There were two problems:

No packages for build-dep

For that the correct way was to add the relevant ppa:

sudo apt-get source firefox
sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa
sudo apt-get update
sudo apt-get build-dep firefox
cd firefox-57.0.1+build2/
debuild -uc -us -b

Compilation error

This was most likely related to the available free space on disk. Firefox requires 30GB of free space and at least 2GB of RAM to compile. I tried on another machine with a lot of resources, and it worked fine.


How to install Android on BQ Aquaris M10 Ubuntu Edition?

This very question was asked and answered on the BQ support forum:

http://www.mibqyyo.com/comunidad/discussion/75471/is-there-any-guidance-i-can-replace-the-ubuntu-with-android-for-m10-fhd/

First you need to download the appropriate firmware:

FHD: http://www.mibqyyo.com/en-download/categorias/aquaris-m10-fhd/

HD: http://www.mibqyyo.com/en-download/categorias/aquaris-m10-hd/

Then, you can find instructions for installing Android here:

http://www.mibqyyo.com/en-articles/2015/09/16/ubuntu-android-installation-process-for-bq-aquaris-e4-5-and-e5/

BQ suggests you need the updated flash tool: https://storage.googleapis.com/otas/2015/Tablets/Freezer%20FHD/Ubuntu/SP_Flash_Tool_exe_Linux_v5.1612.00.100.zip

Note that these instructions are not specifically for M10, but they are the instructions suggested by BQ tech support on the BQ support forum linked to at the top of this answer. Several users there report success using this method.

Discaimer: On the same forum, BQ support say you will not void your warranty by following the instructions, but you should check this yourself if you are worried about such things. Finally, I have not tried it myself and thus cannot vouch for the method's effectiveness.


Launch Nautilus from command line: warnings and errors

This is likely because of:

You have installed nautilus-share package
You have removed the samba package

Clues:

https://codesearch.debian.net/search?q=net+usershare+info&literal=1&page=1&perpkg=1

To fix:

reinstall both packages by sudo apt-get install --reinstall nautilus-share samba


How could one really get sensitive information from a swap partition?

being a "normal" citizen living in western Europe, is it really
  necessary to wipe or encrypt the swap on my computer?

It is a personal judgement, one that depends on how much you value the privacy of your data, and how much you wish to protect your data from being exposed if it were to fall into the hands of an attacker. Suppose you have a laptop, and one day it gets stolen - how likely is that a thief would try to extract passwords or encryption keys or otherwise private data, and do you care? A lot of people do not care, but some do. Admittedly, most thieves would simply sell the laptop for immediate financial gain, but there are cases where an attacker might be motivated to go further in attempting to access the data itself.

  And before
  someone answer "yes", can I have an exemple on how I could test, and
  leak out my own swap, so that I can actually see what kind of data is
  unprotected despite my encrypted home?

The memory of any process could potentially be swapped out to the swap space. Leaking memory can be dangerous - the obvious example being Heartbleed - see How I used Heartbleed to steal a site’s private crypto key. The memory that is exposed by Heartbleed only belongs to one single process, whereas the memory potentially exposed by your swap space belongs to every process. Imagine a process containing a private key, or password list (eg. web browser) being swapped out - those items will appear, in plaintext, in the swap space. Extracting them is a matter of sifting through the memory for particular patterns of data - it could be plaintext ASCII data visible through strings, or it could be more involved, as in Heartbleed (where the test is that some consecutive bytes are a divisor of the public crypto key). If you have an encrypted /home partition, then the obvious thing to look for is a block of data that forms the encryption key that will unlock the user's data.

A working example:

do bash -c 'echo SECRET=PASSWORD > /dev/null; sleep 1000' to create a bash process with some secret data on its stack
do sysctl vm.swappiness=100 to increase swappiness (not necessary, but may make the example easier)
run top -c, press f, enable the SWAP column, press q to go back to top process view, scroll down until you see the bash -c process
in another terminal, save Chimnay Kanchi's program from Linux: How to put a load on system memory? to usemem.c, compile it gcc -o usemem usemem.c, and run usemem & repeatedly in a terminal. This will use up 512MB blocks of memory at a time. (It does not matter what causes the memory to get swapped out, it could be normal system usage, a run away process, or a deliberate attack, the end result is the same)
watch top, wait for bash -c to get swapped (SWAP column value > 0)
now run strings /dev/sdaX | grep SECRET where X is your swap parititon
Congratulations - you just extracted "secret" data from the swap partition. you will see multiple copies of the SECRET text followed by the "password", the copies that include the full command line leaked from the parent bash process, top process, and the 'bash -c' process. The lines that do not include the full command line have leaked from the 'bash -c' process.
To prove that secrets leak from process memory, and not just the command line, add the line unsigned char secret[] = "SECRET=XXXX"; to usemem.c (just below the unsigned long mem; line). Recompile and run usemem & repeatedly, and strings /dev/sdaX | grep SECRET again. This time you will see the 'XXXX' secret being leaked.


What your CPU supports

Your CPU is 64-bit, as are virtually all desktop CPUs made in the last 11 years.

The first AMD CPUs to support 64-bit were the Opteron and the Athlon 64 in 2003.
The first Intel CPUs to support the current 64-bit instructions were the Pentium 4F and the Pentium D in 2005, and the first Intel Core CPU to support it was the Core 2 in 2006.

Most desktop and notebook CPUs made since this have supported 64-bit, with some exceptions in the early days.

You can still install a 32-bit operating system and 32-bit software on a 64-bit processor, but it comes with limitations: you won't be able to utilise 4GB or more of RAM (with some exceptions), a single process won't be able to use more than 2GB (usually) of RAM, and you won't be able to utilise many of the new instructions in AMD64/Intel 64 which can potentially speed up programs.

Is there any reason to install a 32-bit OS?

There have historically been some drawbacks to using 64-bit, but these are all but irrelevant now:

Software compiled for 64-bit is usually a little larger due to using 64-bit pointers instead of 32-bit, but that is offset by the ability to use large amounts of RAM - 8GB is cheap and plenty these days and of course can only be fully utilised by 64-bit software.
64-bit operating systems require driver code to be 64-bit.  At one point in time, manufacturer support for 64-bit drivers was poorer than 32-bit, but this situation is probably the reverse now.


If one of the strings starts with a - you need put -- as the last argument BEFORE the string. This will prevent the options parser from treating the string as a command- line option.

Source

rpl -x'.txt' '0 ' -- '-1 ' /home/administrator/temp/myText.txt

  Also, is there a way to replace all the strings in the text
  that begin with 0 with -1?

As @kos said:

  you'll have to switch to a more powerful tool
  such as sed or perl

But that's another question. ;)


Error when trying to fix "unmet dependencies" on Ubuntu Server 14.04

It fails to stop, so try to stop it manually:

sudo service postgresql stop

Make sure that apt cache is up to date:

sudo apt-get update

Try again to fix:

sudo apt-get -f install

If it doesn't work, wipe postgresql completely. See, what postgresql packages are installed:

dpkg -l | grep postgresql

Then, remove with sudo apt-get remove <package name>. Pay attention to the messages like "THE FOLLOWING PACKAGES WILL BE REMOVED", don't accept if important stuff is listed there.

Try once more to fix:

sudo apt-get -f install

...


How do I use PGP with Thunderbird in 16.04?

install enigmail plugin for thunderbird
https://apps.ubuntu.com/cat/applications/precise/enigmail/

It's OpenPGP extension for Thunderbird. Enigmail allows users to access the features provided by the popular GnuPG software from within Thunderbird.


How to change keyboard layout in Lubuntu 15.10?

Some googling and a test led me to this:

Right click the panel -> Add / Remove Panel Items -> Add -> Keyboard Layout Handler

That adds an icon to the panel, and by right clicking it and selecting "Settings", a GUI tool for managing keyboard layouts shows up.

To add languages, "keep system layout" should be unchecked.


where do I find downloads for other flavors such as Ubuntu Studio, Kubuntu, Xubuntu, etc?

You can download then from http://cdimage.ubuntu.com/  or

from their own sites: http://www.ubuntu.com/about/about-ubuntu/flavours


How to install Ubuntu without a CD and a USB?

Ways to install without CD or USB:

Got net? With a network connection and another machine, you can network boot to an installer.
Install on a hard drive in a machine that DOES have CD or USB and then move the hard drive to the lacking machine.
Floppy! (just kidding).
Other mass storage interfaces For example Firewire, eSATA etc.


If you need to find CD/DVD drives available on your Ubuntu system

# wodim --devices

  Example

wodim --devices

wodim: Overview of accessible drives (1 found) :
-------------------------------------------------------------------------
 0  dev='/dev/sg1'  rwrw-- : 'TSSTcorp' 'CDDVDW SH-S223F'
-------------------------------------------------------------------------

1st check it your cdrom is plugged in or not


How can I transfer my bash history to a new system?

Your bash history is saved in a plain text file, called by default .bash_history.

Unless you modified the $HISTFILE variable you should find it in your home directory:

$ echo $HISTFILE
/home/sylvain/.bash_history

If you keep your home partition when updating or reinstalling your system and if $HISTFILE is saved on this partition, there's nothing else to do.

To transfer the file to a new computer, just save it on a USB drive and replace the existing .bash_history of the target system.

If HISTTIMEFORMAT was set on the "old" system, don't forget to set it again otherwise the timestamps of the new commands won't be saved as comments in the "new" .bash_history file.

In case you would like to merge both old and new with new being saved at the end of the history file, you can use this method:

sudo apt-get install moreutils
cat .bash_history.old $HISTFILE | sponge $HISTFILE


Set suspend idle delay time on terminal on Ubuntu 18.04

To set AC time out, run

gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-ac-timeout <VALUE>

In place of <VALUE> put time in seconds, e.g.

gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-ac-timeout 3600

Similarly, to set laptop battery timeout, run

gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-battery-timeout <VALUE>


can't restore Android Studio window after minimise

This is a IntelliJ IDEA bug: https://youtrack.jetbrains.com/issue/IDEA-196425

Workaround:

In Android Studio goto: Help > Edit Custom Properties
At the end of file add:

suppress.focus.stealing=false

Restart Android Studio, the bug is gone!


"ALERT! /dev/mapper/server--vg-root does not exist. Dropping to shell!"

Follow the steps to mount lvm partitions:

In live session, open a terminal Press Ctrl+Alt+T and run:

sudo fdisk -l

This lists out the partition table of the system and it looked something like this:

Device Boot Start End Blocks Id System
/dev/sda1* 1    4864 39070048+ 83 Linux
/dev/sda2  4865 6691 14675377+ 83 LVM2_member ...

The next step was to access the /dev/sda2 partition. It is an lvm partition.

In order to install the required tools, run the following command.

sudo apt-get update
sudo apt-get install lvm2

Once you are done with this run pvs:

sudo pvs

This will list the volume groups to which our physical volume /dev/sda2 belonged. It would be of the form

PV VG Fmt Attr PSize PFree /dev/sda2 VolGroup01 lvm2 a- 148.94G 32.00M

The field VG: shows the Volume group.

The above output is just an example, showing that we are concerned with the Volume group "VolGroup01".

The next step is to list the information about this volume group:

sudo lvdisplay /dev/VolGroup01

It will throw a bunch of ouput, but the one we are concerned with is LV Name. It will look something like this:

LV Name /dev/VolGroup01/LogVol00

Assuming that the above one is the partition that we need to mount, just use the usual method to mount it:

sudo mount /dev/VolGroup01/LogVol00 /mnt

Now, you can to find the data you were looking for in the /mnt folder.


Permissions issue uploading to server via FTP client despite user having all permissions

The /etc/sudoers file gives you permissions when you are logged on to the server.  When you use FTP you should have permissions for the user to allow to write to the directory or files that you are attempting to write to such as:

drwxr-xr-x  18 jsmith jsmith 4096 Dec  9 12:44 .

This directory is owned by jsmith and jsmith will be able to dump files into it.

if you have this however:

drwxr-xr-x  18 root root 4096 Dec  9 12:44 .

jsmith will not be permitted to write the files there

And BTW, the screenshot link doesn't seem to work.


How can I export a PDF from GIMP with each layer on a new page?

Gimp (2.10) does it already. No extra software or plugins needed.

Import all images/pages as layers.
Go to File → Export As → filename.pdf.
After clicking Export As, a dialog will pop up asking to confirm save options. Select Layers as pages and Reverse the pages order.
Click the Export button.

That's all! Enjoy.


Chrome stop working after upgrade to Ubuntu 20.04

I solved my issue which look like is related to Intel Drivers. This command line solved the issue:
sudo apt purge xserver-xorg-video-intel

Reboot and everything is back being normal.


Mouse scroll doesn't work while moving pointer on VMWare Workstation with Ubuntu 18.04

I don't remember where I found it but someone solved that by
sudo apt remove xserver-xorg-input-libinput && sudo apt install xserver-xorg-input-evdev

which also worked for me :)


How to connect to Internet with USB stick & How to open C Drive, D Drive & E Drive

Ubuntu is not Windows. If you try and do things the same way as in Windows, you will be frustrated.

There is no such thing as a C: drive (or E: drive or...). There are only mountpoints. Like, if you have a USB called 'MYUSB', its contents will be accessible (after mounting, which is done when you click it in the file manager - or you can configure it to auto-mount disks) at the /media/USERNAME/MYUSB/ directory.

The equivalent to Windows "installers" are Debian Packages (file format .deb). Ubuntu has a very intuitive software installation system - no click-click-click installers, no hunting the web for apps - just search for its name in Software and click 'Install'.

If you want to access your Windows drives from Ubuntu, just click on the button named XX-GB Volume in the side panel.

XAMPP consists of Apache, MySQL, PHP and Perl. Perl comes installed, you can install the rest with the command

sudo apt-get install apache2 mysql-server php7.0

Also, Ubuntu automatically decides the place for installed programs.

As for the internet... That'll have to be a separate question - please provide all details about the modem and the "Console-Site-specific browser". If you can see what web address the "Console-Site-specific browser" access upon clicking the shortcut, just visiting there in Ubuntu (and logging in, whatever else) will (most probably) work.


Why doesn't my Nvidia driver support 1280*1024?

You can try disper: disper on launchpad
It's a command line tool for switching between internal and external displays
(You can't use Xrandr with NVIDIA-Drivers. NVIDIA doesn't support it)

Install disper and try
disper -l


Ubuntu Make

Ubuntu Make is a command line tool which allows you to download the latest version of popular developer tools on your installation, installing it longside all the required dependencies (which will only ask for root access if you don't have all the required dependencies installed already), enable multi-arch on your system if you are on a 64 bit machine, integrate it with the Unity launcher… Basically, one command to get your system ready to develop with!

How to use it

Example: how to install Ubuntu Make and then, Android Studio.

Installing Ubuntu Make

If you are on latest development Ubuntu version, first, add the Ubuntu Make ppa:

sudo add-apt-repository ppa:ubuntu-desktop/ubuntu-make
sudo apt-get update

Then, installing Ubuntu Make:

sudo apt-get install ubuntu-make

How to install android-sdk

umake android

And then, accept the installation path and Google license. It will download, install all requirements alongside Android Studio and latest android SDK itself, then configure and fit it into the system like by adding an Unity launcher icon…

And that's it! Happy Android application hacking on Ubuntu. You will find the familiar experience with the android emulator and sdk manager + auto-updater to always be on the latest.

Source: https://wiki.ubuntu.com/ubuntu-make


Some characters are showing as "?" in libreoffice impress

It's not possible to know for sure what's happening in the slide in the question without opening the file, but it looks like in the two dimensional continuity equation there is an embedded image with a transparent background superimposed over unreadable plain text. Moving the embedded image out of the way would make the plain text easier to see. Select the plain text, copy/paste it into a new text file, and use iconv from the terminal to convert it from whatever character set it has into a character set that is supported on your system like utf-8.

If the embedded images in the slide are all that matters, you can delete the plain text entirely. However this wouldn't work in the slide you have provided. Consider the first equation for the two-dimensional continuity. It should look like this.

The second equation should look like this.

You need to replace the images of the first two equations in the slide with new images that look like the two images shown above which I made using TexMaths.

TexMaths

TexMaths is an extension designed to provide LaTeX support in LibreOffice. LaTeX equations can be inserted as images (SVG or PNG formats) and the LaTeX code is saved into the image attribute for further editing. To insert your first equation into a document, simply type a LaTex math instruction in the text field of the TexMaths Equations window and then click on the LaTeX button. Example: x(t) = \mu ^2 (t) should produce the equation x(t)=µ²(t)

TexMaths is open source software licensed under the GPL.

Installation

Install TexLive.

sudo apt-get install texlive texlive-binaries dvipng

Download the TexMaths extension by following the download link at the official TexMaths website. The file to download ends in an .oxt extension.
Open LibreOffice Writer and install the TexMaths extension using the Tools -> Extension Manager menu.
Close and reopen LibreOffice Writer. You will see a four new TexMaths icons in the toolbar. Click on the TexMaths System Configuration icon and fill in the paths of your programs (usually /usr/bin for all).

Usage

Run TexMaths by clicking on one of the TexMaths Equations icons. Select the LaTeX text and click the first icon (marked by an arrow in the below screenshot) to convert the selected LaTeX text into an image consisting of mathematical symbols.

Select a group of mathematical symbols in LibreOffice Writer and copy it. You can also work with groups of mathematical symbols directly in Impress, however in Impress you can't work with groups of mathematical symbols by selecting them on a slide. In Impress you need to select an equation in a new TexMaths window, which is less convenient than copy/pasting the equations from Writer to Impress when you have more than one equation on the same slide. My preferred workflow when I have a lot of equations is to type the whole list of equations in Writer in LaTeX format, convert the equations to .svg or .png images, check each image if it looks OK, and then paste the images into slides, one image at a time.
Open LibreOffice Impress and paste the group of mathematical symbols that you copied from LibreOffice Writer. Select the group of mathematical symbols and drag it to the correct position.

There can be images of mathematical symbols and plain text mathematical symbols together in the same slide, as in the below slide where the large equation in the middle is an embedded image and the highlighted text is plain text.

Example


Display a message when Root Account Accessed by IP

/var/log/auth.log contains quite a bit of what you want. For example, escalating to root using sudo -s generated this entry:

Dec 18 19:31:23 kazwolfe sudo:  kazwolfe : TTY=pts/1 ; PWD=/home/kazwolfe ; USER=root ; COMMAND=/bin/bash
Dec 18 19:31:23 kazwolfe sudo: pam_unix(sudo:session): session opened for user root by kazwolfe(uid=0)

From there, I can look at the who command to get the IP address of pts/1:

kazwolfe  pts/1        2017-12-18 19:30 (2001:db8::4665)

That section in parenthesis is my IPv6 address, and can be used as a log entry. You can also see when I loaded my session.

auth.log will also contain other entries for sudo:

Dec 18 19:33:30 kazwolfe sudo:  kazwolfe : TTY=pts/1 ; PWD=/home/kazwolfe ; USER=root ; COMMAND=/bin/cat data
Dec 18 19:33:30 kazwolfe sudo: pam_unix(sudo:session): session opened for user root by kazwolfe(uid=0)
Dec 18 19:33:30 kazwolfe sudo: pam_unix(sudo:session): session closed for user root
Dec 18 19:33:40 kazwolfe sudo:  kazwolfe : TTY=pts/1 ; PWD=/home/kazwolfe ; USER=root ; COMMAND=/usr/bin/tail /var/log/auth.log
Dec 18 19:33:40 kazwolfe sudo: pam_unix(sudo:session): session opened for user root by kazwolfe(uid=0)

As long as you force your admins to go through sudo, you'll have these log entries generated on every escalation. It is, however, important to note that a root user can obscure or otherwise modify these logs to hide things.

If you'd rather not hook to log files, you can set sudo to always send an e-mail (see man sudoers), though be aware that this may generate a lot of useless emails.

If you do this, your email will contain almost the exact same information as listed above. IP addresses will still need to be queried separately, but you can always use the last command to get the last few logins as well.

Admins will need to be very fast to intercept things, so it'll be hard for them to hide damage (though they may delete emails from your inbox if it's on the same server). That said, these logs will still not provide information about what they did inside of a sudo session (especially if they escalated to a command prompt). Solutions for that are far more complicated.


How to restore Xfce default panel colors?

Go to the xfce settings manager.  In your menu simply search for "Settings Manger".  NB: not Settings Editor.  Then go to Appearance, and select Greybird.  Go to the icons tab and select 'elementary Xfce dark.'  For fonts, your default should be Noto Sans, size 9.

If you want to reset everything in Xfce to default, instead of doing an apt-get remove, do an apt-get purge.  That will clean up your configuration files as well as uninstalling.  Then reinstall.

Edit:

Install the Greybird with the following:

cd ~
mkdir .icons
mkdir .themes
cd .icons
wget https://github.com/shimmerproject/elementary-xfce/archive/master.zip
unzip master.zip
mv elementary*/* .
cd ../.themes
wget https://github.com/shimmerproject/Greybird/archive/master.zip
unzip master.zip
sudo apt-get install gtk2-engines-murrine gtk3-engines-unico


If you right click on your open desktop somewhere and click on the "keep aligned" setting your icons should line back into place.I ve had that problem and that fixed it


GNU GRUB boot loader - Failed to load image

As you've already done, use boot-repair to recover from your corruption.
The Windows Ext2Fsd driver, used to read/write to Linux ext2/3/4 partitions, WILL corrupt partitions. Uninstall it asap.
If you wish to share files between Windows and Ubuntu, create a new NTFS disk partition to do so.
Let's check your file system for further corruption...

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


Ubuntu 18.04 repeated "Anthentification required by Wireless network"?

sudo nano /etc/modprobe.d/rtl8723de.conf

Copy and past this line and save and exit:

options rtl8723de fwlps=0

Reboot.

This should prevent the WiFi card from automatically sleeping and halting connection.


How to restart the Network Manager in 16.04 whenever Wi-fi is enabled?

I know this is an old thread, but on my older laptop I had a pretty crappy WiFi card which had a tendency to disconnect from the WiFi if there was a lot of load (e.g., downloading large files, etc.).

I ended up creating a simple script to check if my internet was still connected, and if it wasn't, then restart the network manager.

#!/bin/bash

ping -c 1 8.8.8.8
received=$?
echo $received
if [[ $received -ne 0 ]] ; then
    service network-manager restart
fi

I created a root cronjob with sudo crontab -e, and set it such that every minute (you can do it more less frequently, but the script is a simple ping so it isn't resource intensive) it would run the script.

So, if my WiFi did go out for some reason, it would only ever be out for about a minute at a time, tops. If you're unfamiliar with cron, I recommend reading this


The raw value for the read rate is meaningless, and basically all drives show really big numbers there.  The normalized value of 118 with a threadhold value of 6 indicates that it is a LONG way from being a problem indicator ( it has to get from 118 down to 6, and the worst it has ever been is 99 ).  This is why the assessment column reports that it is ok.

So, there is nothing wrong with this drive, at least based on that value.


Issue with Software Updater installing new kernel

I would do the following:

sudo apt-get update to update repositories and package information
sudo apt-get dist-upgrade to update packages and their dependencies

This should update your kernel as well.


How to upgrade qBittorrent to the latest stable (upstream) version?

The version of qBittorrent in Ubuntu is always quite old (since it's updated regularly and most feature and minor bugfix updates don't make it into the official Ubuntu version).

But there is an easy solution!

qBittorrent's maintainer (sledgehammer999) maintains a PPA providing stable qBittorrent builds. I recommend using that.

To enable this PPA and install qBittorrent from it (or upgrade the version you currently have to the version it provides), open a Terminal window (Ctrl+Alt+T) and run:

sudo add-apt-repository ppa:qbittorrent-team/qbittorrent-stable
sudo apt-get update
sudo apt-get install qbittorrent

(Or you can run sudo apt-get upgrade in place of the third line--if some version of qBittorrent is already installed from Ubuntu packages, both ways work.)

I use qBittorrent from that PPA--it works great.

Source: qBittorrent Downloads page (Other Binary Packages section)

For more information on PPAs, see:

PPA (Ubuntu community documentation)
What are PPAs and how do I use them?
Are PPA's safe to add to my system and what are some "red flags" to watch out for?


Enter in this website and select the mirror to your convenience.
Then select old-releases and then gcc2 (for 2.95) or gcc3 (for 3.0). You should now see a few versions of gcc compressed.
Now you should click in the one that you want to have and the download will start.
Finally, you have to compile and install from source.


Gnote is a port of Tomboy to C++.

Pros: Faster, smaller memory footprint.
Cons: (Still) No synchronization support (e.g. Ubuntu one), which is a dealbreaker for most people.

You can read about the author's motives here.

  It is the same note taking application, including most of the add-ins
  (more are to come). Synchronization support is being worked on.

Tomboy is not going to be installed by default in Ubuntu 12.04 - I suppose Gnote may take its place some day.


sudo swapoff -a
sudo cryptsetup resize cryptswap1 --size (in sectors)
sudo mkswap /dev/mapper/cryptswap1
sudo swapon -a

If --size is left out, it will use the whole device.
UPDATE - Based on feedback.  Reboot and make sure mint--vg-swap_1 is still 980M.
IF IT IS, do the steps below.  --  Try manually increasing the size of the container first (I don't think that should have been necessary).  Your comment says you are trying to make the swap 4G (+3G), so:
sudo swapoff -a
sudo lvresize -L+3G /dev/mapper/mint--vg-swap_1
sudo cryptsetup resize cryptswap1 --size 7812500
sudo mkswap /dev/mapper/cryptswap1
sudo swapon -a

On the other hand, if mint--vg-swap_1 is now 4G, then run this (allow for the size of the header):
sudo swapoff -a
sudo cryptsetup resize cryptswap1 --size 7808404
sudo mkswap /dev/mapper/cryptswap1
sudo swapon -a

Reference


Open the logind.conf file

sudo nano /etc/systemd/logind.conf

Changed the following line:

HandleLidSwitch=ignore

Laptop lid no longer dictates suspend mode and configuration saves after reboot. This solves all problems save one:
I prefer the internal screen powered off when laptop lid is closed while sustaining signal to the external screen.


Run this command:
sudo shutdown now

This shutdowns the computer but this was the only solution i know.
If you have a better answer then please post an answer to this question.
After a few seconds you should start the computer again and see what happends next.


Brasero and K3b: problems to burn data dvd's with files having spaces in its name

Not being accessible has to do with not all the parts being present...if you want to be able to pull files out of a single part, there are several approaches. note:you can get files out of archive parts with the rar command line utility.  archive manager just doesn't understand how to do it.

You could do some shell script ninjitsu and wind up with archives of about that size that are not split which archive manager will understand.  Short of that, I don't know a way.


How do I catch exception from sed when trying to read a non-existent file and write a handler for it?

sed returns non-zero exit code when it fails. So you need to  test $? after sed (but before the pipes, else their possibly zero exit codes may "overwrite" sed's)


I've noticed when typing sudo gdisk -l /dev/nvme0n1 that nvme0n1 seemed to not be recognized, which made me figure out that there were a partitioning issue, so I launched GParted.
It told me something was wrong and that I had 5Mo that were not used. Before I did not go through with it because I thought 5Mo was not worth the risk of messing with partition but this time I figured I could give it a try and clicked repair. After that sudo gdisk -l /dev/nvme0n1 command worked and I also launched boot-repair to make sure everything was right. Now everything is working as intended.


Whether your HD is failing or not is not clear at all from the output - it could be just one bad sector, which is a common occurrence these days.

Can you please post the full output sudo smartctl -a /dev/sda (change sda accordingly if needed)?


where can i download windows installer for ubuntu or wubi?

It should be e.g. on the  Ubuntu 14.04 iso. See also here:
Windows installer for Ubuntu 14.04 LTS onwards


Don't choose "Erase HD completely" (it will delete your Windows).

The problem here is that Ubuntu does not detect your Windows.

Please indicate your Boot-Info URL if you want further advice.


Why does Chrome on my Ubuntu (on all DE) does not have page actions?

I would look in chrome://extensions/ in Chrome on OSX, because it appears you have an extra extension installed - this one

Here is a screenshot as well - it only works with the extension is enabled:

This might be installed by default, or integrated into Chrome on Mac (I don't know)


Cant install Ubuntu alongside Windows 7 on HP 650 - Cant recognize Windows partition

I had this problem before, if you had windows 8 installed previously maybe is a GPT data left behind by it, try booting ubuntu in "Try Ubuntu without installing it" mode then

Open the terminal and
type sudo gdisk /dev/sdx (change /dev/sdx for the proper access to you disk, use gparted to know which /dev/ is in case you have doubts)
then press X to enter in expert mode in this mode.
then type z to destroy the GPT data,
type Y to confirm the action.

NOW BE EXTRA CAREFUL because then will ask you about blanking MBR and you MUST respond NO (n) if you answer yes it will destroy the current windows partitions, this worked for me.


Your commands are not working because /etc/init.d/smbd and /etc/init.d/nmbd have the following at the start:

if init_is_upstart; then
                        exit 1
                fi

So, as the init in ubuntu is now Upstart (/etc/init.d/ is from SysV), you need to run the start-stop scripts from the directory /etc/init/. /etc/init.d/ still exists for backward compatibility because many programs still use this directory.

To make things easier for you, Ubuntu has service command:

sudo service smbd stop
sudo service nmbd stop

While running as root:

service smbd stop
service nmbd stop

service will first search in /etc/init/ directory and then /etc/init.d/. service is efficient in another sense that if there are two scripts having the same name in those two directories (as in case of smbd and nmbd) the Upstart script (in /etc/init/) will take precedence over SysV script (in /etc/init.d/).

Also your cron entry can be made simpler:

0 22 * * 0-4  service samba stop && service smbd stop && service nmbd stop

&& ensures that the next command is run only if the previous one is successful (i.e. exit code $?=0).


running a bash file states:date: command not found

PATH="/var/log/servers/Game/"

This sets the PATH to just that directory, and I doubt that directory contains date.

Be careful when you use uppercase variable names, you could easily be stomping over a standard environment variable.

Stick to lowercase, and be more descriptive. Consider using, for example:

log_path="/var/log/servers/Game/"
NEWFILE="${log_path}${FILENAME}_${DATE}${EXT}"


How to grep all the strings which end with '.txt'

If you want to list only the matched "strings," you should use the -o option of grep:
grep -o '\w*\.txt\b' myFile

or
grep -Eo '\w+\.txt\b' myFile

The man page explains this option like this:

-o, --only-matching
Print only the matched (non-empty) parts of a matching line,
with each such part on a separate output line.

However, you need to define your understanding of "strings." I assume a "string" is something like a "word" described in the man page:

The symbols \< and \> respectively match the empty string at the
beginning and end of a word. The symbol \b matches the empty string at
the edge of a word, and \B matches the empty string provided it's not
at the edge of a word. The symbol \w is a synonym for [_[:alnum:]] and
\W is a synonym for [^_[:alnum:]].

In the above example, the two-letter sequences mean this:

Seq.
Explanation

\w
any alphanumeric character

\w*
any number (0 or more) of alphanumeric characters

\w+
any number (1 or more) of alphanumeric characters (extended regular expression)

\.
the period (.) character itself (. has special meaning and  it should be escaped)

\b
match end of the word (no more alphanumeric characters after the string txt)

Note: The $ character you used in your question means "end-of-line" and it will cause to match strings txt than happen to appear only at end of lines.


Removing cuda-repo Network Installer and installing the local version

Remove the Network Installer version

with with conf files

sudo dpkg --purge cuda-repo-ubuntu1404

without conf files

sudo dpkg --remove cuda-repo-ubuntu1404

Install the Local Package Installer version with

sudo dpkg --install cuda-repo-ubuntu1404-7-0-local_7.0-28_amd64.deb


How to re-install grub boot loader in Windows?

Checkout this link to recover Grub:

https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows


An incompletely downloaded Ubuntu iso file is not guaranteed to install properly. Next time use wget -c from the terminal to download the Ubuntu iso. wget with the -c (continue) option will continue the download automatically from the place where it was interrupted until the download is finished. wget is such a powerful program that it will even continue the download from the same place where it was interrupted, if you restart the download from a different mirror. wget is often a lot faster than a torrent depending on the relative download speeds of the mirror and the torrent.

If you are using Windows, the DownThemAll! add-on for Firefox also has the continue functionality.


Touchscreen + non-native resolution = misaligned cursor

As you already found out yourself, the mapping from touch screen coordinates to screen coordinates is controlled by a transformation matrix.

Usually, the system assumes that the touch screen spans the whole screen area, which is correct in most circumstances. However, if the display area is larger (e.g. multiple monitors) or smaller than the touch area, you have to modify that transformation matrix.

Traditionally, you'd have to set Coordinate Transformation Matrix via xinput. But since you are using libinput, there are two differences:

The xinput property is called libinput Calibration Matrix
The transformation matrix is calculated differently

Judging by Reinderien's post, "the proper thing is to do an inverse matrix transformation".

I honestly don't know how to do that, but fortunately he provides a script called xcal, which calibrates the touchscreen for you.

Prerequisites:

python3, tkinter, numpy (install by running sudo apt-get install python3 pyhton3-tk python3-numpy in a terminal).

Donwload xcal and execute it.


Can't play .TS format from a Samsung TV recording

There is no application for Ubuntu with a genuine support for Samsung PVR recordings.
PVR recordings from a Samsung TV are encrypted to meet DRM. In order to view them on a device other than the very TV on which they were recorded we would have to decrypt them first.

Doing so may be illegal depending on copyright laws in your country.

Some older Samsung TVs stored the encryption key together with the video files on an attached USB drive but this is not the case in newer series.
For these we need root access to the TV firmware in order to read the encryption key generated from the TV before we can decrypt our recordings. You will find some tools including tools for Linux/Ubuntu from the SamyGo modified firmware support forums.
You may be able to adapt them to your settings better than me because my TV is not supported without also replacing it's firmware (which I did not want to do). Not all series of Samsung TVs are supported however.


If you are on Ubuntu 11.04 or later, you can use the manual keyword and .override files in /etc/init to disable automatic starting:

sudo sh -c 'echo manual >> /etc/init/mysql.override'

manual effectively removes the start on stanza from the job's config.

If you are on Ubuntu 10.04, you can do this:

sudo sh -c 'echo start on never >> /etc/init/mysql.conf'

The last start on in the file will override any previous ones, so this should work, though it assumes there is no event called never.


Do I need to install all the drivers for my Laptop?

A lot of the time, all the drivers you would need are built into the Linux Kernel, however there are some proprietary drivers that would have to be installed post-installation of Ubuntu ( System Settings -> Software and Updates -> Additional Drivers ) .


new 16.04 install doesnt recognize network devices

I'm going to go out on a limb here and suggest either:

your network cable or connector is faulty or not working; or
your network card has not been set to automatically raise the connection when the module loads (or the line is triggered); or
A BIOS setting for your network card is incorrect in relation to the expected operation in the module

Two adapters have been detected by your kernel and modules have been loaded to manage them.  They are called:

eno1
enp3s0f3

It's possible that these are actually the same adapter.  (e.g. I have servers here that emulate and appear as multiple network cards on the same physical interface.)

See here for how adapters are named in current kernels.

The outputs of both ip link and ip a show that the state is "DOWN".  This usually means that the cable is not physically connected.  So I would test your cables and the devices it's connecting to first.  Maybe plug the same cable into another laptop that you know works.

If/when you have discounted it being a cable/hardware fault, you might consider attempting to force the link up (overriding the trigger) like this:

ip link set eno1 up

Then, you can manually assign it an ip address like this:

ip addr add 192.168.0.5/24

(short form: ip a a 192.168.0.5/24)

(Obviously replacing the ip address and range with one relevant to your network.)

Then you can check to make sure it set correctly by calling ip a again and make sure that the state is "UP" and the IP is correct.

Then attempt to ping a device on the network. (Making sure that the device you're pinging has ICMP Echo Reply on - many have it switched off by default these days!)

If it works, then the module for your ethernet card doesn't yet know how to do line detection yet.  This is highly unusual, and I'd probably consider patching your kernel or getting a newer kernel ASAP if it does.

You may also be a victim of module blacklisting.  If the wrong module is being loaded for your network device (because the right one is blacklisted) you may have to edit /etc/modules.conf or the files in /etc/modules.conf.d/ to ensure that the right module loads and/or the wrong one is prevented from loading.

Finally, there may be a bug in the module for your card or a setting in your BIOS (particularly on newer rackmount servers) that control how the network card operates.

I've listed these in the order of decreasing likelihood.  YMMV.


As far as I can see you haven't changed the size. You seem to have 3 "main" partions:

sda 1+2  windows partition
sda 3+4  Fat32 partition
sda 5    Linux partition

sda 5 is shown with 97.2 GB. The sum of all is around 350 gb. So where should that additional space come from?
I would advise to use gparted for resizing partions. I've used it even on devices that had a windows partition. It always worked.


Dual boot only showing Windows8 and not ubuntu.

windows likes to put itself at the top of the boot order. a work around is this:

boot from a live CD. install efibootmgr.

find the file /efi/ubuntu/grubx64.efi. copy it to /efi/boot/bootx64.efi. if the file is there already move it to the windows folder (in case you want to restore windows boot late). this makes grub the default loader.

next use efibootmgr to delete all entries in the boot list. restart you computer, be sure ubuntu is the first OS you boot into so it is placed in the first slot.


How to list any package update on specific time space?

Yes, you can run the following commands which will print timestamps and changes:

cat /var/log/dpkg.log

and

cat /var/log/apt/history.log

I think you are looking for the first one as that should show all changes made through dpkg and not just the manual apt-get commands run like the second one does although they are both helpful.


Remove Unity completely and exchange it with LXDE

All you really need to do is install lxde is this:

sudo apt-get install lubuntu-desktop

The removal of the extra files can be done also if you're short on hard drive space, but if all you need is more speed, that will do if for you (see How can you remove Unity?).
Be sure to choose LXDE when you login.


Problem installing ubuntu 13.10 on Legacy BIOS machine

Your observation that

  When I try to install Ubuntu 13.10, it tries to install in EFI mode i.e.
   (Boot screen - black and with a error message first "Couldn't open '\EFI\BOOT\fallback.efi':14 " )

...clearly belies your earlier claim that the computer doesn't support EFI. You can't get that message unless the computer is booting in EFI mode. It's possible that the documentation doesn't mention it, or the support may have been added in a firmware update after the documentation was written, but you've clearly got an EFI in the computer.

That said, your partition table data also clearly indicates that you've got a BIOS/CSM/legacy-mode installation of Windows, and the best way to get Linux to coexist with that is to boot Linux in BIOS/CSM/legacy mode. Chances are you can do this by using your firmware's built-in boot manager to select the boot option for your boot medium that does not include the string "EFI" or "UEFI." (You can usually access the boot manager by hitting Esc or a function key very early in the boot process. Unfortunately, which key varies from one computer to another.) On an EFI-based computer, you'll often see two options for removable medium, one with the string "EFI" or "UEFI" and the other without; just select the one without that string to boot in BIOS/CSM/legacy mode.

If that doesn't work, try mounting your USB installer and removing the entire EFI directory tree from it. (This is theoretically possible if you're using a CD-R or DVD-R, but it's much harder because you'd need to remaster it.) The EFI boot loader resides in this directory, so without an EFI boot loader, the computer will be forced to boot the installer in BIOS/CSM/legacy mode.


Netflix desktop doesn't launch when I click on it

Clearing the wine browser directory and then re-installing as described by chargedPeptide in the comments for the previous answer worked for me.

The commands are:

rm -rf ~/.wine-browser
sudo apt-get install --reinstall netflix-desktop


Kubuntu 15.10 operations get slow or hang until logout

Did you read this:

http://scarlettgatelyclark.com/2015/kubuntu-kde-5-4-3-bugfix-release-available-now-in-wily-backports/

I'm generally not a big friend of ppa's, but there is actually no other way to receive bugfixes for Kubuntu than using the backports-ppa. Well 14.04 had KDE4 and it's an LTS. Any STS get's only 9 month support, so anyone is taking part in development to a stable release. I have a LTS+ a STS on the PC (that way it's not too frustrating. After Trusty Kubuntu enters a new Aera with Plasma-KF5 & Applications-KF5. Some edges and corners have to be expected in my mind :-) The good thing about the backports-ppa is it will not hinder a system update lateron, as it doesn't contain newer versions than in the next release.

edit2: Upon the answer that this didn't change a lot, I suggest U take a look a the installed Java-Version

$ java -version

If it's OpenJDK-7, just install OpenJDK-8.

Background:
Could as well be this bug (see also bug-duplicates there):

https://bugs.launchpad.net/debian/+source/openjdk-7/+bug/1512760
 title: Java applications leaks shmem chunks

edit3: Just forget my last comment, bugfix was published to the masses yesterday.


ubuntu 14.04 - Samba - How to share from another drive?

It could be the permissions issue. What actually you should do is check your permissions on /media/media/Big Drive/Music:

ls -l /media/media/Big Drive/Music

it could like in your case as this: drwx------- or something like that then proceed like following:

sudo chmod w+r /media/media/Big Drive/Music

but if you want only just let people read files (listen only to music) and not allowing them to write/modify run this:

sudo chmod 774 /media/media/Big Drive/Music


Danger of using an untrusted apt mirror or proxy

You might need to consider the following situation when it comes to apt repository security. You will find your answer below.

You are adding an untrusted repository

Since anyone can create a private-public key pair, so just validating the downloaded contents or apt-index with the public key won't solve the problem when the author of the repository and the owner of the key puts malicious software in the repository.

He would create a key pair. Sign the contents with his private key, then upload the contents to the repository and then upload his public key

Then you add the repository, download his public key and then try to check. Apt would verify it without issuing warning messages. You might feel you are secure, but you are not. Are you sure you believe the person who has uploaded the content?

You added a repository which has content uploaded by a person you know

This might seem safe. You know the person's name and see that he has signed the repository contents and also the index. In this case too you are insecure. Anyone can impersonate the name.

In this case you need to verify the public key. You should be knowing that person's public key and should be sure about it. If you know the person and see that the repository needs a different public key for validating the contents then you should not trust that repository.

You should know the Person's name and his public key pair together to validate the authenticity of the repository. If any of them is wrong, don't trust the repository.

This is the reason why geek and hacker circles have key-signing parties where they meet in person, shoe each other valid identity proof and then establish trust

You know the person, have the correct public key, but apt shows warnings

This might be the case when you are trying to add the repository, but your computer is not getting the correct apt URL. This might be the situation where your DNS is not working properly and someone is trying to trick you into adding the wrong repository by DNS cache poisoning.

If you get a apt warning even when you have the correct public key, then ABORT. Don't go forward. This third case is usually very rare and you should not be worried about encountering this situation.

Conclusion

When you want to add a repository and you want to be very sure you
are adding the correct repository, you need to know the person who
has uploaded the content and should be sure about his public key.
Validate the repository only against his public key and not the one
which repository owner asks you to verify against. This is the
safest mechanism. As mentioned above, it is NOT safe even if apt
doesn't give warnings when adding a repository. The contents might
be malicious.
Even if you are using a well known repository and then
apt complains, then it means that you are not adding the correct
repository. You are NOT SAFE.


Nexus 4 struck at google logo after flashing localy build ubuntu images

Using the standard installation process https://developer.ubuntu.com/en/start/ubuntu-for-devices/installing-ubuntu-for-devices/ with the Ubuntu compiled image for the Nexus 4 is not an option for you?


Java installation and Android Studio AVD problem

I don't think you are supposed to open Android Studio as root anyways, only sudo programs if you really need to, even if you think they are safe.

Anyways, I think this is due to your environment variables not being set when you run the script as root. You may have to set your JAVA_HOME variable in the script (before launching Android Studio)

Run this command in wherever you installed Android Studio (the folder with the studio.sh file and DON'T RUN AS ROOT):
sed -i "1iJAVA_HOME='$JAVA_HOME'" studio.sh

This will make sure that your JAVA_HOME variable is set properly before Android Studio launches.


Not able to mount some partitions but can mount vfat

sdb7 and sdb9 are not FAT partitions so just drop the “-t vfat” from the commands you have used and it should work.


What is the reason for moving the dash button in 11.10?

Quote from Mark Shuttleworth

  In the panel, you’ll see that the top left corner is now consistently
  used to close whatever has the focus. Maximising a window keeps the
  window controls in the same position relative to the window – the top
  left corner. We have time to refine the behaviour of this based on
  user testing of the betas; for example, in one view, one should be
  able to close successive windows from that top left corner even if
  they are not maximised.

  It’s taken several releases of careful iteration to get to this point.
  Even though we had a good idea where we were headed, each step needed
  to be taken one release at a time. Perhaps this might make a little
  clearer the reasons for the move of window controls to the left – it
  was the only place where we could ultimately keep them consistent all
  the way up to a maximised window with the title bar integrated into
  the panel. I’m confident this part will all be settled by 12.04.

  As part of this two-step shuffle, the Dash invocation is now
  integrated in the Launcher. While this is slightly less of a
  Fitts-fantastic location, we consider it appropriate for a number of
  reasons. First, it preserves the top left corner for closing windows.
  Second, the Dash is best invoked with the Super key (sometimes
  erroneously and anachronistically referred to as the “Windows” key,
  for some reason ;-) ). And finally, observations during user testing
  showed people as more inclined to try clicking on items in the
  Launcher than on the top left icon in the panel, unless that icon was
  something explicit like a close button for the window. Evidence based
  design rules.

Paraphrasing Mark
User testing showed that the original location confused people ,so the dash in 11.10 was an attempt to resolve this.

For 12.04 - the dash button remained within the Launcher.


It seems like you messed up some file ownerships while running GUI applications as root using sudo. The following command should fix this and give you back the ownership of all files in your home directory:

sudo chown -R $USER: ~

Hope this fixes it.

For the future:

Never run GUI programs as root using sudo - always use gksudo or at least sudo -H to avoid such problems to come back.
You should run programs as root as rarely as possible anyway.


To install Dropbox, you need to

Download the Ubuntu .deb file from here. Choose 32 or 64 bit depending on your system architecture.
Double click on the downloaded file and install it via the Ubuntu Software Centre.
Run Dropbox by  searching for it in the Dash. The first time it runs it should download some proprietary components.
You should then by able to install nautilus-dropbox with the original command:

sudo apt-get install nautilus-dropbox

Why is this necessary?

When you tried to install Nautilus Dropbox originally, that attempted to install the Dropbox icons for Nautilus, not Dropbox itself. It required the Dropbox program in order to do anything. Dropbox only releases it's program itself (not in the Ubuntu repos), so it was uninstallable with apt-get.


Is there an upper limit to Ubuntu One Storage Subscriptions?

Yes, there is an upper limit. You cannot purchase more than 429.496.728 20-packs. In practice, this is the same as it being unlimited. If you do find that you need to purchase more storage than this, talk to us.


How can i install ubuntu without data loss

A tutorial shows the steps at https://tutorials.ubuntu.com/tutorial/tutorial-install-ubuntu-desktop .

When you get to Allocate Drive Space  choose Something Else. Pick the drive with Windows on it and tell the installer to erase the Windows system (C:) partition only, and not to install to any other drive or partition.

It is common for multiple drive letters to be assigned to space on one drive and the installation program will show you a map of 'partitions' like this. Read up on the program which handles this, gparted. https://www.pcworld.com/article/3050495/windows-10s-hidden-hard-drive-partitions-how-to-find-them-how-to-remove-them.html may also be helpful.


nvidia quadro K1100M issue with Ubuntu 14.04

I have used the following document to configure a M3800 + QUADRO K1100M + Intel HD4600 on Ubuntu 14.04 LTS and everything works correctly and I can switch (manually) from Nvidia to Intel and vice versa. Do not forget to uninstall Bumblebee if you did so.


You can try this:

Reboot the machine and choose for grub's menu "Advanced options for Ubuntu"

Then "Ubuntu, with Linux (your kernel) (recovery mode)"

after that choose "Drop to root shel prompt"

Below you will have a prompt.
Make sure you have write perms in the filesystem.Type:
mount -o remount,rw /
Got to the /etc folder.Type:
cd /etc
Make sure you have write perms in the sudoers file, or type chmod 640 sudoers, then type:
visudo
Here you have a screenshot of the "sudoers" file.

Maybe you have deleted the line "%sudo   ALL=(ALL:ALL) ALL"
Edit the file and save the changes (ctrl+x and shift Y), change the perms of the file with to chmod 440 sudoers
Then exit and "resume normal boot"

I hope this will helpful.

Regards.


I am new to linux/ubuntu and would like to install a driver for my printer

Have you tried the instructions Brother supplies after you click the download button? I have had no issues with them.

The only thing I would mention that the official instructions do not is that I would move the file to a different directory before running these commands. The last time I ran them it created an uninstall script and other stuff you might want to keep. (also because you run the installer as root you can't really delete them anyways, unless you run the uninstaller as root or delete them manually as root from the terminal)


Invalid YAML: mapping values are not allowed in this context: network:

I believe that your yaml file is invalid for exactly the reason you suspected: indentation and spacing. Your file says, in part:
network:
 version: 2
 ethernets:
  eno1:

Notice that the indentation is one space below network:. Compare the supplied templates:
cat /usr/share/doc/netplan/examples/static.yaml

Which says, in part:
network:
  version: 2
  renderer: networkd
  ethernets:
    enp3s0:

Notice that the indentation is, in every case (except nameservers), two spaces. I suggest that you amend your file to:
network:
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      addresses:
        - 192.168.20.6/24
      gateway4: 192.168.20.2
      nameservers:
          addresses: [8.8.8.8,8.8.4.4,192.168.20.2]

Netplan is also very specific in that it allows spaces in the file and not tabs. Follow with:
sudo netplan generate
sudo netplan apply

Please see: https://netplan.io/examples


If this is still an issue, follow this
-- install snap
command: sudo apt install snapd

-- install pycharm
command: sudo snap install pycharm-educational --classic

Once done you'll need to add /snap/bin in the PATH environment variable. (I'll let you know how once i figure it out)
Once done your command to launch pycharm would be pycharm-educational.


How do I add and remove the Workspace Switcher launcher from the Unity launcher?

To disable workspaces completely

See @fossfreedom answer https://askubuntu.com/a/211169

To just remove the icon but still preserve workspaces

Open the terminal and execute:

gsettings get com.canonical.Unity.Launcher favorites

the output will be something like,

['application://nautilus.desktop', 'application://chromium-browser.desktop', 'application://ubuntu-software-center.desktop', 'application://ubuntuone-installer.desktop', 'application://ubuntu-amazon-default.desktop', 'application://UbuntuOneMusiconeubuntucom.desktop', 'application://gnome-control-center.desktop', 'unity://running-apps', 'unity://expo-icon', 'unity://devices']

To remove the workspaces icon from the dock you should just take out 'unity://expo-icon' from that list. Taking it out, for this case the command should be:

gsettings set com.canonical.Unity.Launcher favorites "['application://nautilus.desktop', 'application://chromium-browser.desktop', 'application://ubuntu-software-center.desktop', 'application://ubuntuone-installer.desktop', 'application://ubuntu-amazon-default.desktop', 'application://UbuntuOneMusiconeubuntucom.desktop', 'application://gnome-control-center.desktop', 'unity://running-apps', 'unity://devices']"

(Don't forget the double quotes for the list on gsettings set)

Currently I'm using eight workspaces with the help of Unity Tweak Tool. I like to have multiple workspaces, but didn't like the unremovable Unity Launcher icon that much, even more because it could only resemble four workspaces while I was using eight instead.


I assume you do not want a package comparison but an actual difference between 2 systems.
2 options I can think of:

You could copy the whole 2nd machine and put it in a directory on the 1st machine. Let's assume /opt/ is empty on your machine you could put /etc/ in /opt/etc/ and do a ...
diff -ru /etc /opt/etc

use rsync with the dry-run option from system1:
rsync -navrc --delete /etc/* {system2}:/etc/

-n (or --dry-run), -v verbose, -r recursive, -a archive mode, -c checksum check (must have: it will report false positives without it). --delete to have it show files not present on system1.

Do this for the normal directories (/var/, /home/, /etc/ etc) and not temporary filesystems like /tmp/, /proc/.


20.04 to 20.10 Upgrade made apt autoremove want to delete everything!

From the Ubuntu 20.10 Release Announcement:

Due to the change in desktop environment this release, direct upgrades to Ubuntu Studio 20.10 are not supported. We recommend a clean install for this release:
Backup your home directory (/home/{username})
Install Ubuntu Studio 20.10
Copy the contents of your backed-up home directory to your new home directory.

What you are experiencing is expected behavior. Since you didn't follow the developers' advice (yet), you may encounter other issues.


I've the same problem :
Telegram-WARNING **: 11:54:14.523: Unfortunately, GTK integration conflicts with qgtk2 platformtheme and style. Therefore, QT_QPA_PLATFORMTHEME and QT_STYLE_OVERRIDE will be unset.
Telegram-Message: 11:54:14.528: This can be ignored by setting TDESKTOP_I_KNOW_ABOUT_GTK_INCOMPATIBILITY environment variable to any value, however, if qgtk2 theme or style is used, this will lead to a crash.
Telegram-Message: 11:54:14.528: GTK integration can be disabled by setting TDESKTOP_DISABLE_GTK_INTEGRATION to any value. Keep in mind that this will lead to clipboard issues and tdesktop will be unable to get settings from GTK (such as decoration layout, dark mode & more).
Qt: Session management error: None of the authentication protocols specified are supported

for me it's fixed by refreshing telegram :
sudo snap refresh telegram-desktop


Lubuntu 15.04 - Broadcom wi-fi wont work at all

E: Unable to lock the administration directory (/var/lib/dpkg/), is
  another process using it?

This usually means that another process, typically Update Manager, Software Center or Synaptic is open and has a hold on /var/log/dpkg. Please close whichever it is. Then in a terminal and with a temporary working internet connection, do:

sudo apt-get purge bcmwl-kernel-source

If it is not removed because it isn't installed, that's fine, just continue:

sudo apt-get install firmware-b43-installer

Reboot and your wireless should now be working.


How to setup a desktop to run 3 independent monitors?

Ubuntu natively supports multiple monitors via the settings without any special config (although I can't say 100% it will work with whatever graphics card or cards you are going to use).

I have run various Ubuntu versions on various hardware running multi monitors without any issues. And I have never had to use proprietary drivers, I always use the default drivers. For example my laptop has both a HDMI out and DisplayPort out. So I can use the laptop screen and two monitors and drag windows between the 3 screens as you would expect.


Four /dev/video entries but just one camera

The answer given here https://unix.stackexchange.com/questions/512759/multiple-dev-video-for-one-physical-device  is a good one. I have the same problem with Skype and it started when I upgraded the kernel from 4.4.x to 5.1.x so somewhere in there the uvcvideo module produced a different output. However, has it is pointed out the output of

v4l2-ctl --device=/dev/video* --all

does show that each entry has a different capability, and in the case of my logitech usb camera only 1 has video capture. So this is most likely a bug in Skype, that appeared after the kernel probably fix a bug themselves, that does not only shows the entries that have a "Video capture" capability.


server is running out of space for php-apps (show error for creating temps etc.)

Delete all snapshots of the vm running out of diskspace that you just have on current state and one vdi file
Resize the vdi from initial size to a size you like and can with

VBoxManage modifymedium /home/user/vm/server.vdi --resize x (where x is the desired new total space in megabytes)

Boot VM with GParted ISO-Image and fit logical volumen of the vm to the new size.
Boot VM Ubuntu OS and do

sudo lvresize -L xx.xxG /dev/ubuntu-tt-vg/root

and

sudo resize2fs /dev/ubuntu-tt-vg/root xxxxxxx (where x are the number of blocks)

(might be that the path looks other than /dev/ubuntu-tt-vg/root for example /dev/mapper/ubuntu--vg-root, figure that therefor out with fdisk -l)