Disconnected is simply not a use case for Ubuntu Core.
Ubuntu Core is designed for online use. Ubuntu Core is designed to be Snap-only (no debs).

Snap packages, and their associated infrastructure, are designed for frequent, secure online upgrades...which does not seem like what you want.

There is no secure offline or manual install/upgrade method. (There are offline methods, but they are hacks).

You don't get an opportunity to audit Snap packages before they upgrade.

You cannot easily run your own Snap repository.

You can build your own Snaps using the Snapcraft tool...but the build will go to the public Snap Store instead of to your own private Snap repo.

Ubuntu Core requires your Ubuntu One ssh key during first login. There is a workaround for that, but it's an insecure hack.

For a secure alternative to Ubuntu Core for a not-on-public-network system, consider using Ubuntu Server. It's much more flexible and customizable, can be secured, and can be more easily adapted to your use case using available tools.


16.04 LTS - Black Terminal, Black Borders - Intel onboard graphic card

Got some help elsewhere: turns out there was a problem of some 3rd party PPAs colliding: In Synaptic I unchecked every ppa but the oibaf/graphics-drivers, did "sudo apt-get update" and tried to purge the ppa:oibaf/graphics-drivers again - worked and after a reboot: yes, indeeed, everything back to normal.


Cant open nautilus or gnome terminal on 19.04

Mainly it appears that there's a bug, not sure what it is. It uses masses of system resources which is why you can't open nautilus. I found a reinstall worked

sudo apt-get install --reinstall nautilus

I also found that installing unity worked for other services like terminal.

sudo apt install ubuntu-unity-desktop

It's a work round that works until they fix gnome


Open a Terminal and go to the folder where you downloaded the deb file an type:

sudo dpkg -i ./google-chrome-stable_current_i386.deb

It will install the package system-wide.


I finally found a solution for the NFS mount problem. Looking for similar questions at Stackoverflow I arrived at this post

I applied the suggestion to install and run rcconf

sudo apt-get install rcconf dialog
sudo rcconf

In rcconf I marked statd as selected (it was unmarked) and rebooted the main node (NFS server). Then I restarted each node, entered in recovery mode, modified fstab so they could boot (commenting any NFS entry). When the node was up I restored fstab and mounted NFS filesystems.

When entering in recovery mode I had to remount the filesystem before editing fstab, it was not writable before

mount -o remount,rw /

nano /etc/fstab

then resumed normal boot.

In a terminal I uncommented NFS imports from /etc/fstab and run sudo mount -va

Now, mounted filesystems appear, they can be listed and a file created/edited in a node appears on all nodes.

Of course, there should be a better and more general solution for NFS properly booting but this has worked for me.

Hope it helps someone.


unable to change brightness on amd integrated gpu

You may have better luck with the tool light. It works also where xbacklight doesn't. It is available in the standard ubuntu software repositories of at least version 20.10, so you can install it with
sudo apt install light

If that does not work on your Ubuntu version, you can install it according to the instructions of the application's Github page.
It is a great tool. You can set a minimum brightness so that you will never fully darken the screen. I use it with much satisfaction on the default Ubuntu desktop to increase/decrease the brightness in smaller steps, with the commands
light -U 1
light -A 1


How to Activate wifi in Toshiba Satellite C655?

you have a ath9k

ath9k is a completely FOSS wireless driver for all Atheros IEEE 802.11n PCI/PCI-Express and AHB WLAN based chipsets.

AR9002:

*      AR9220 (>= 2.6.27, an AR9280 card over PCI)
*      AR9280 (>= 2.6.27)
*      AR9281 (>= 2.6.27)
*      AR9285 (>= 2.6.29)
*      AR9287 (>= 2.6.32)

have you tried install this :

sudo apt-get install linux-backports-modules-wireless-maverick-generic


Different version between OpenSSH and OpenSSL in Ubuntu Server

The current OpenSSH does not build against OpenSSL 1.1.0. There is a whole thread about it in the upstream mailing list explaining the reasons why they did not want that.

If I see right, you installed the new version, but dynamically loaded libraries still stayed there.

The supported OpenSSL versions are written in the INSTALL file in git repository.


Are there alternatives to software center?

Yes, there is an alternative to the Ubuntu Software Center named appgrid. It's a very lightweight application center for Ubuntu and it will let you purchase applications too. You can install it in Ubuntu with these following commands:

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

It was only a 100KB download for me.

Comparison between appgrid and Ubuntu Software Center:

Feature                                                | appgrid  | Ubuntu Software Center
-------------------------------------------------------+----------+-----------------------
Programming language                                   | Python 3 | Python 2
Warm start to home screen                              | 2.7s     | 20s
Warm start to details screen (eg opening an apt: link) | 2.3s     | 30s
Full database build                                    | 58s      | 6min24
Initial database size                                  | 36.7MB   | 96.5MB
Memory usage after startup to home screen              | 20MB     | 53.6MB
Lines of code (including tests)                        | 5900     | 56960

You can sign in with Ubuntu One ID also:


Why is this command that is in my PATH not being found?

The MythTV backend doesn't have access to X, so it won't be able to run things like xset without setting the environment up properly first. The instructions here are for restarting the frontend via a script that runs via irexec, but it should be easy enough to follow and insert your poweroff script in there.


Increasing Partition or deleting Ubuntu dual boot Windows 10

How you access your computer's built-in boot manager is very much a computer-specific thing. With most computers, you do it by hitting Esc, Enter, or a function key (usually a high-numbered one, like F8 or F10) at boot time, before GRUB has loaded. Chances are you used this same keystroke to get the Ubuntu installer to boot. Sometimes that stops working or is disabled, though, in which case you need a workaround. Some possibilities for this include:

Keep trying -- Sometimes the keystroke used to access the boot manager is finicky, in which case you might need to try it several times before you can get it to work. This is even worse if you don't know what keystroke it is. Try checking your manual, looking for messages at boot time, or asking on a forum for your computer or motherboard to learn what keystroke you should be using.
Reset the firmware to the defaults -- You may be able to boot into the firmware setup utility by typing sudo systemctl reboot --firmware-setup in Ubuntu or by using another key sequence at boot time. You can then select an option to reset the firmware options to their defaults. This will usually re-enable the keystroke to access the boot manager. Unfortunately, it's also likely to remove the ubuntu boot entry you use to boot Ubuntu, so you'll need to restore it with Boot Repair, efibootmgr, or some other tool.
Disable "fast start" in the firmware -- Some EFIs have a feature called "fast start" or something similar, which disables full USB initialization, thus cutting off access to external media. If you can get to the built-in boot manager but it doesn't show your USB drive, disabling the EFI's fast start feature can help. Note that the name of this feature is not standardized, so you may have to go hunting. Sometimes it's referred to as a level of USB initialization, in which case you'd set it to full USB initialization. Note also that this feature is unrelated to the Windows Fast Startup feature, which has an entirely different effect.
Install rEFInd -- My rEFInd boot manager should show options for booting external media, although sometimes they appear only after you hit the Esc key in the rEFInd menu. Installing rEFInd to your hard disk, though, means that it will take over as the default boot manager from GRUB, which you might not want. Even if you prefer to keep using GRUB, you might consider installing rEFInd, then uninstall it or set GRUB/ubuntu back to the default position using efibootmgr's -o option once you've done what you need to do with rEFInd.


Screen brightness not adjusting on Lenovo ThinkPad E585 Ubuntu 20.04

I had a similar problem that was solved by updating to the latest linux kernel (5.7 should also be okay), which includes better support for AMD graphics. I used this guide to update my kernel to 5.8. Hope that helps!


Run chrome webpage as desktop application

This might not be what you're looking for. But if you want to pin a Google Chrome website to the desktop as a web application you can do the following:

Click the 3 dots on the top-right corner
Click More tools
Click Create shortcut...
Select the Open as window checkbox

Hope I helped!

Chrome > Version 70

Update for new versions of Chrome, where no Open as window checkbox appears:

Click the 3 dots on the top-right corner
Click More tools
Click Create shortcut...
Click Create
Navigate to chrome://apps
Right-click on the new app
Click Open as window


i did this before in my desk computer .
follow this steps :

install windows on the SSD .
install ubuntu partitions on the specified amount of the HDD drive.
format the left amount with NTFS or FAT32 file system .
finish the installations

note :
you can format the shared partition while installing ubuntu or after .

your partitions should look something like this :

SSD (windows) :

C:\
D:\

HDD (ubuntu) :

sda1 - Ubuntu (EXT4)
sda2 - Swap
sda3 - Shared partition between Ubuntu and Windows (NTFS or FAT32 Format)


Kubuntu staring cura appimage after each login despite it not running during logout. How to fix it?

Search for clues in the /proc/<PID> directory. Each process has it own directory in /proc/. Get the processes #,
 then navigate there and look around. Other commands such as ps -auxf, and pstree could help find the culprit.

If that isn't helping then try "System settings->Desktop Session [Start with an empty session]" . Maybe after a few closed sessions you may be able to re-enable [Restore Previous Session].

I had an issue with a stubborn app doing the same thing. I feel the Plasma Desktop Restore Previous Sessions may have a few kinks that may need some more tweaking with how that behavior is handled.

If I am correct cure is a 3d slicer for generating G-code for 3d printers. It could potentially be another related app calling it.


shell script for wifi connection via terminal

I've made this:

#!/bin/bash

## Restores the screen when the program exits.
trap "tput rmcup; exit"  SIGHUP SIGINT SIGTERM

## Saves the screen contents.
tput smcup

## Clears the screen.
clear

## Loop through available interfaces.
while read interface; do                    # While reads a line of the output
    i=$((i+1))                                  # Only God knows what does this (view note 1).
    type=$(cut -f2 -d ' ' <<< $interface)       # Saves the interface type to check if is wifi.
    status=$(cut -f3 -d ' ' <<< $interface)     # Saves the status of the current interface.
    interface=$(cut -f1 -d ' ' <<< $interface)  # Selects the INTEFACE field of the output.
    if [[ "$type" == "802-11-wireless" ]]; then # If is a WiFi interface then:
      interfaces[$i]=$interface                     # Adds the current interface to an array.
      echo "$i: $interface ($status)"               # Prints the name of current interface.
    fi                                          # Ends the if conditional
done < <(nmcli device | tail -n +2)         # Redirects the output of the command nmcli device to the loop.

## If there is only one interface
if [[ "$i" == "2" ]]; then
    iface=1 # Selected interface is the only one
    clear   # Quick and dirty workaround for make disappear the interface list.
else
    ## Prompts the user for the interface to use.
    read -p "Select the interface: " iface
fi

## If the entered number is valid then...
if [[ "$iface" -le $i ]]; then
    read -p "Enter the SSID or BSSID: " b_ssid # Prompts the user for the ESSID/BSSID
    read -p "Enter the password: " pass # Prompts the user for the password
    output=$(nmcli device wifi connect "$b_ssid" password "$pass" iface wlan0 --timeout 10) # Tries to connect
    wget -q --tries=5 --timeout=5 --spider http://google.com &> /dev/null # Is connected to Internet?
    if [[ $? -eq 0 ]]; then
            echo "You're connected." # Is connected to Internet
            exit 0
    else
            echo "Error. $output" # Anything goes wrong
            exit 1
    fi
else
    echo "Invalid interface entered. Exiting..."
    exit 2
fi

## Note 1: this line increments $i


PowerPC Mac G5 bootloader hangs at quiesce

I ran into the same problem, didn't find any info on a solution but got it to work now.

I found out it's some kind of data flush/update command so I guessed that setting the clock to a realistic time/date (since the comp is old and the battery probably dead the date resets to lika 1909). After I set my clock straight (with a live CD) the boot process did not get stuck. Try it. Might work for you too. :)


How to share folders using Oracle, Windows and Ubuntu

You need to create a shared folder on the "host" that is shared by the "guest" Go to https://www.virtualbox.org/manual/ch04.html#sharedfolders for more information as it is rather detailed. The online user manual is here https://www.virtualbox.org/manual/UserManual.html


Since matplotlib2tikz is on PyPi, you can install it by

sudo -H pip install matplotlib2tikz


Amd graphics card installation error on ubuntu 15.10

You have all the prerequisites installed already the problem is that in newer versions of the kernel the version.h file has been relocated.
You can locate it with

locate version.h

Which most likely will come up with this location for your version.h file for that version of the kernel "/usr/src/linux-headers-4.2.0-18-generic/include/generated/uapi/linux/version.h". But since we already know which kernel version and what distro you are using all you have to do is link the missing file to the folder and start the installation again.

sudo ln -s /usr/src/linux-headers-4.2.0-18-generic/include/generated/uapi/linux/version.h /lib/modules/4.2.0-18-generic/build/include/linux/version.h

That should work. Unless AMD is still not supporting that version of the kernel.


How do I get duplex printing working on a Samsung SCX 3201 G?

I had the same problem on Samsung SCX 6322 DN Series and this was sorted by installing the driver from the manufacturer.


nvme SSD problems - Cannot format - HDPARM permision denied

This definitely seems like a hardware issue, but if you'd still like to try formatting it, then I recommend using mkfs. In order to do this, you need to open up a terminal (Ctl+Alt+T or search in applications menu). Run the following fdisk command, and pay close attention to the size of each device. You should be looking for a device that is roughly 240GB, and it should be an actual device (not a loop), which should look like /dev/sdX, where 'X' is the letter of the drive. The second line of the blocks should identify the Disk Model, and your SSD will likely say KINGSTON SA1000M8240G. I'll refer to the corresponding device as /dev/sdX from now on, and just make sure to replace the 'X' with the proper letter.
sudo fdisk -l

In order to format the drive, you'll either use mkfs.ext4 if you plan to use it for Linux, or mkfs.ntfs for Windows. Alternatively, if you plan to use it as an external drive, I suppose you could format it to FAT32 with mkfs.fat -F 32. I'll list each of these commands for you below
sudo mkfs.ext4 /dev/sdX

sudo mkfs.ntfs /dev/sdX

sudo mkfs.fat -F 32 /dev/sdX

If you run into an issue describing the device being mounted, simply unmount the drive.
sudo umount /dev/sdX

You shouldn't run into permission errors here, but let me know if you do, and I'll try to figure out how to approach the problem from a different angle. If your SSD still has problems after a format, then it's probably best to send it in for warranty.


Not possible to see ubuntu 12.04 from the update manager

If you are able to use the internet, and your network is working, then try this: Open Update Manager, press Settings button and on te first tab, change the server where it says "Download from: ". I had the same issue, and for me it was automatically set to Germany. I selected Main server, and it's fine now:


How can I backup VPS server while it is running?

If you've got a good deal of time on your hands, and can leave your system online, you can do a remote rsync down to your system.

rsync --recursive --progress user@host:sourcedir /path/to/save/backup/on/local/machine

That should do what you want, but it'll take up a ton of space on your computer, because its literally a copy of the data on your VPS.  Note you might want to run this with the root user, if you want a total copy.  Also, this won't preserve the permissions, it'll just give you a copy of the files.

About the Arguments Used Above
In case you're curious as to what the arguments for the rsync directory:

user@host:sourcedir:  user means the username to use on the VPS (in this case, probably root).  host means the connection address you use for your VPS.  sourcedir means the directory you want to copy from.  In your case of a full VPS backup, you would probably want this to be /.

/path/to/save/backup/on/local/machine/:  You've got several different options with where you want to store your backup when its on your local drive.  In any case, you will want to make sure you can access this, so you would probably end up with something like /home/user/VPSbackup/ where user is your local username on the local system (not on the VPS)

The --recursive argument will copy all files in every subdirectory from sourcedir.

The --progress argument will show you the progress of each file as its being downloaded (can be helpful in certain cases), because it can show you the time left to download each file (it'll flood your terminal screen, but that's not necessarily a bad thing if you want to see the progress).

Most  importantly...
BE VERY VERY VERY CAREFUL!
An rsync in which you switch the user@host:sourcedir and the /path/to/save/ arguments will OVERWRITE your VPS with old data or no data.  This can also lead to you breaking things if you specify the wrong /path/to/save/.


Webapps on Chrome - not Chromium - with Ubuntu 13.04

If you mean the unity web apps, the simple answer is no. But you might be able to get the folders where the Chromium-based extensions are, and copy them to your Chrome profile folder. If you want more help, just ask. (I haven't tried this)


Where are words stored when using the "Add word to dictionary" feature within a text editor?

It would depend on the text editor or the application itself.

For ghostwriter the configuration area is:

~/.config/ghostwriter/dictionaries/personal

for Libreoffice the configuration area is:

~/.config/libreoffice/[version #]/user/workbook

Replace [version #] with the version you are running.  Ubuntu 16.04 ships with version 4.  So the area would be:

~/.config/libreoffice/4/user/workbook


15.10 install and now my pc doesn't allow me to do anything, please help?

you could try installing gnome- there may have been a problem with unity in the install? that command would be:

  sudo apt-get install gnome

and then do the startx thing?
Do you have any other information than that?


ubuntu-distro-info from the distro-info  package provides information about all Ubuntu releases.

You get an overview of all releases with

ubuntu-distro-info --all --fullname

For the "current" version

ubuntu-distro-info --stable --fullname

For the current LTS release

ubuntu-distro-info --lts --fullname

For currently supported releases

ubuntu-distro-info --supported --fullname

(This strangely includes the current development version although it is not supported yet)

To get the number of days till EndOfLive you add --days=eol (shorter -yeol)

ubuntu-distro-info --supported --fullname --days=eol

To get the number of days till the current development version will be released you can use just -y or --days

ubuntu-distro-info --latest --fullname --days


Windows Network Drive with samba disk looks disconnected after start up

I solved this issue with net use command and one small script. You can add unlimited shares in same way:

:CHECKFOLDER1
net use S: \\server1\share /Y
timeout /t 5 /nobreak > NUL
IF NOT EXIST S: GOTO CHECKFOLDER1

:CHECKFOLDER2
net use S: \\server2\share /Y
timeout /t 5 /nobreak > NUL
IF NOT EXIST T: GOTO CHECKFOLDER2

Insert the above code in .bat file and put in startup folder. To open this folder, press Win+R and type shell:startup command.

In the future, this script will run automatically on startup and try to "mount" these shares in every 5 seconds. It will exit, if shares are available.


How to burn .iso file to external hard-drive

I understand that you want to use your external hard disk as your installation source, in exactly the same way you would use a DVD or USB stick. If this is the case, a simple command can do what you want but warning, it is a very strong command and incorrect use may and will destroy data completely, so use it very carefully:

sudo dd if=iso_file_path of=/dev/sdx bs=4M && sudo sync

where x is your external hard disk letter.

Make sure the external drive is not mounted when you run this command.
Make sure you use the correct drive letter otherwise you will wipe all data on whatever drive the letter you use refers to, even if it is your system drive, without any prior notice or verification.

You will not see any progress indicator while the .iso is being copied. Just wait for the prompt to reappear after the copy is complete.

After this, you should be able to boot your system from your external drive by using it as boot media from your BIOS's boot menu.


If this is in Firefox, try to install Flash-Aid.


Try to check if your function keys are working.
If not you can use Brightness Controller, a free and open source app.

It is not available on the Ubuntu Software Center in Ubuntu 10.10 so you have to install it from the .deb package.

Let me know if the .deb package is working in Ubuntu 10.10.


I have  found a workaround.

With Super Grub 2 Disk you can boot machine from CD.

Download from:
http://www.supergrubdisk.org/category/download/supergrub2diskdownload/
Select the (ISO) format.
Burn the ISO to CD using image burning software.
Power on the machine with the CD in the drive to boot.


Can't convert files using winff: Error opening filters!

Your ffmpeg filters have problem, just reinstall it, that should solve problem

sudo apt-get autoremove --purge ffmpeg
sudo apt-get install ffmpeg

You might also need to install winff after this,

sudo apt-get install winff

Try converting after this it should work, if it doesn't then you might be trying to use a filter that has a dependency unfulfilled. Try converting directly from terminal and tell if you encounter same error,

ffmpeg -i videoFile.mkv -vcodec copy -acodec copy VideoFile.mp4


Can i make my bootable usb have a persistent storage after creating it without it?

Changing Live Pendrive to Persistent Pendrive
This works both with BIOS and UEFI.
Many people prefer a Persistent Pendrive that will save changes;

Create a Live Pendrive using Rufus or similar;

Boot the pendrive toram to make the drive editable:
Press Shift when booting; press Esc from Language; press F6; press Esc;
Type a Space and toram after quiet splash ---, and press Enter.

Create a casper-rw file:
sudo dd if=/dev/zero of=casper-rw bs=1M count=512
sudo mkfs.ext3 -L casper-rw -F casper-rw

(where count=512 is the persistence size in megabytes, with a max of 4GB).

Move the new casper-rw file from home to the root of the Live Pendrive;

Add a Space and persistent after quiet splash --- in the following files:
/isolinux/txt.cfg, (for BIOS boot persistence Rufus);
/syslinux.cfg, (for BIOS boot persistence UNetbootin);
/boot/grub/grub.cfg, (for UEFI boot persistence).

Shut down and reboot the persistent drive.

It's also possible to turn a Live USB into a Full-Install USB which has some advantages, except it won't install Ubuntu: Can Ubuntu be installed to the pendrive it was booted from?


That card should be enough for running Arma 2 - not in high resolution or with lots of details, but it should run just fine (it was released in 2009). NVIDIA is probably the best bet for graphics card on Linux, because they recently started cooperate with Valve on Steam for Linux and the result are new NVIDIA drivers with much better performance.

The problem is that Arma 2 is not yet supported by Steam and it might never be, so your only current option is running it through Wine, and well, see the support page for yourself - current status is garbage.

Linux is good for indie games (Braid, Swords & Soldiers and other gems from HumbleBundles), but not yet fit for mainstream AAA games. Steam for Linux and Steambox might change that (and I sincerely hope they will), but for now, you'll be much better of with Ubuntu and Windows dualboot.


How do I move window to specific workplace via keyboard?

That's either a bug or a consequence of a tweaked environment.

To verify the keyboard shortcut visit the gear in the upper right hand corner,
select system settings -> keyboard -> shortcuts -> navigation.
Move Window one workspace to the [direction] should be defined. If it is and
you're still having problems then try resetting unity to defaults.

To reset unity to it's defaults: unity --reset:

How do I reset my Unity configuration?

Once that's done: CTRL+ALT+SHIFT [ARROW] will take the active window and place
it on the desktop you're pointing to. CTRL+ALT [ARROW] just switches the
current desktop.

UPDATE:

After clarifying the bug with the user. I found out that this is actually a known bug.

https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/348848
https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/291854
http://osdir.com/ml/ubuntu-bugs/2011-06/msg40967.html

It looks like it's getting lost in the wishlist status. I would recommend filing a new bug to bring fresh attention to it. I agree that it's a bug. If it isn't an option then it should be removed from Navigation shortcuts to begin with. I think I will to, this would be very useful.


No "Choose OS" screen after co-installation of Ubuntu 12.04

You didn't specify your boot manager of choice.

  If you want windows to manage the boot menu, it wouldn't recognize
  Ubuntu directly without a 3rd party boot manager like easybcd.
  If you want Ubuntu to manager the boot menu, you need to load
  grub2.

Source: https://superuser.com/questions/392033/no-boot-menu-after-installing-ubuntu

Grub needs to be fixed (Re-Installed).  The link below shows you how to do just that.

Click here for a step-by-step instructions for using Grub.

Reinstall / Recover GRUB from Ubuntu live CD / USB


Internal HDs that don't contain the OS aren't accessable unless I try to manually browse them

Go to Disks again and click in a drive/partition (except for the one Ubuntu is on), then the two cogs and Edit mount options.

Set automatic mount options to false and tick the mount on startup to have the drive mount when the computer is started.

Now in the terminal type sudo mount -a to test if it will mount successfully, also click the mount (play icon) in disks to test if it will mount.

Ext4s will most probably have a mount error when 'Show in interface' is ticked due to a bug and outstanding fix. Turning it off should fix it, but then you will have to go to the mount location directly to open it, since it won't display in the interface - you can add a bookmark to the mount location to overcome this (temporally until this is fixed).


Kubuntu 20.10, after installing Snap app, no position in menu

so according to Internet, the problem is my default shell - ZSH. (strangely it affects Plasma as well...)
i could see links to my apps:

ls -l /var/lib/snapd/desktop/applications

but this variable was not pointing there:

echo $XDG_DATA_DIRS
/usr/share/plasma:/usr/local/share:/usr/share

i had to edit /etc/zsh/zprofile and add at the end of that file:

emulate sh -c 'source /etc/profile.d/apps-bin-path.sh'

which adds snap directories to $XDG_DATA_DIRS


Shutter's --selection command line option is missing

I've removed a previously activated PPA for shutter, which appears to have an unstable  Beta version of Shutter. Works now.


Proper installation method for play on linux

playonlinux is now in Official ubuntu Repository . You can install playonlinux with its dependencies as:

sudo apt-get install playonlinux binutils bzip2 cabextract curl gettext-base gnupg icoutils imagemagick mesa-utils netcat p7zip-full python python-wxgtk2.8 unzip wget wine x11-utils xterm


Kubuntu 18.04 LTS keyboard not working after installing synaptics

Here's how I uninstalled synaptics without a keyboard:

I wrote out two commands and emailed them to myself from another computer.

sudo apt remove xserver-xorg-input-synaptics
<sudo password>

and

Y

The newlines are interpreted as 'Enter' by the shell. I could then copy and paste these into the terminal with the touchpad controls to remove the offending package.


ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' After Upgrade Ubuntu 20.04

I encountered the same error. The issue was that my.cnf contained "NO_AUTO_CREATE_USER" under sql_mode. This has been removed in MySql 8.0.
I had the following in my /etc/mysql/my.cnf:
sql_mode = 'STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'

Removing NO_AUTO_CREATE_USER fixed this.


How to Enable AMD-V virtualization on Lenovo G585

You have to enable it in your BIOS.

Unfortunately, some vendors cripple / disable options in your BIOS. Very frustrating.

First thing you should try is to update your BIOS. If that does not work you will have to write your own. I had to do this for my laptop, frustrating.

See https://www.bios-mods.com/

Be careful as you can brick your box doing this.


Adding an existing user to another group

Have you tried doing this with adduser instead? The Ubuntu Help page recommends not using useradd.  I think what your trying to do could be done like this:

adduser newuser
(automatically makes home folder)

adduser newuser olduser (this adds newuser to the olduser group)

Hope that helps.

EDIT:

This should at least help you figure out if the problem is related to usermod or not. Try to add the user and change groups without using useradd or usermod.


You're probably wanting to install the xorg package, which provides the standard X11 implementation on Ubuntu.

Try: sudo apt install xorg


Since wvdial is on the installation CD, you can enable System -> Administration -> Software Sources -> Ubuntu Software -> Installable from CD-ROM/DVD -> Cdrom with Ubuntu 10.04 and then install it via Synaptic.

In the long run, though, you should have a way to install software upgrades and packages that aren't included on the CD. For this I recommend using Keryx, which is essentially a relay for your package manager over a USB drive. Updates can be downloaded using an internet-connected computer running Windows, OS X, or Linux.


QtiPlot on Ubuntu 16.04 cannot find Python configuration files

It is well known bug https://bugs.launchpad.net/ubuntu/+source/qtiplot/+bug/435918 that can be solved by changing the qtiplotrc.py file.


How to configuration Msql 5.7 to provide another access to the database

if the user with the password can login locally but cannot remotely due to Access denied for user 'user'@'his_ip'  then
GRANT ALL ON dbname.* TO 'user'@'his_ip';

If he can't even connect then check firewall and if mysql listen that interface:
netstat -plnt | grep 3306


How to pin a web link to the Unity launcher?

Unity simply does not show launchers of type Link

The simple truth is that the Unity Launcher refuses to show launchers of the type Link.

Adding a link to the launcher

There is however also no reason at all to make the launcher specifically a link, since you can make the launcher of typ Application do anything you like. To add a link, create a simple launcher like:

[Desktop Entry]
Type=Application
Name=Tutanota Webmail
Exec=xdg-open https://app.tutanota.com
Icon=/home/daniel/Pictures/tuta-icon.png

and add it to ~/.local/share/applicatons, log out and back in, to open the link from Dash in your default browser, or

[Desktop Entry]
Type=Application
Name=Tutanota Webmail
Exec=firefox https://app.tutanota.com
Icon=/home/daniel/Pictures/tuta-icon.png

to open it in e.g. firefox.

However, issue!

Note that the disadvantage of using a single, dedicated launcher to launch a link is that the window that will appear, will be grouped under the icon of your default browser, not under the icon of your link. Or worse, your other browser windows might be grouped under your Link icon in the launcher.

Better option

It is therefore better to add your link to the existing firefox (or other browser's-) icon.

copy the firefox launcher from /usr/share/applications to ~/.local/share/applications:

cp /usr/share/applications/firefox.desktop ~/.local/share/applications

Open the file with (e.g.) gedit, Look for the line starting with:

Actions=

Add "Tutanota Webmail" to the line:

Actions=NewWindow;Tutanota Webmail;

Add to the very bottom of the file a section:

[Desktop Action Tutanota Webmail]
Name=Tutanota Webmail
Exec=firefox https://app.tutanota.com

Now save the file, log out and back in. A new entry appears:


Find the UUID of your connection using

$ nmcli con

Note that this lists not just physical connections but also the Wireless connections defined (SSIDs).

Put some simple script like this in your /etc/NetworkManager/dispatcher.d/ directory:

#!/bin/bash

# Specify your connection UUID you like to trigger on below.
MYCON_UUID=397bdb70-2a89-415e-b3e9-09ca0b704fc1

if [ "$CONNECTION_UUID" == "$MYCON_UUID" ]
then
    # do your scripting you need to do here:
    mount -t sshfs ...
fi

Don't forget to set the right permissions to make it excutable (i.e. chmod +x trigger-sshfs-on-vpn.sh). It can be any type of script, a Bash script is probably sufficient for your purpose.

NetworkManager just executes all the scripts in this directory providing some environment variables you can use for scripting. In this case you probably just need CONNECTION_UUID.


Why do the packages "yum" and "yum-utils" exist in the repo?

The whole life of this package is presented on https://tracker.debian.org/pkg/yum .

It is removed from Debian unstable because of Python 2 deprecation.

See https://tracker.debian.org/news/1101794/removed-343-3-from-unstable/  and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=951299 .


Why is Aegisub no longer available in Ubuntu?

I could find no hints as to why Aegisub has vanished although I believe that it was dropped from Debian Buster (which Bionic Beaver is based upon).

Update: fkraiem has found the relevant Debian entry and the relevant bugreport.

Notwithstanding Debian's issues on 'Buster' I have managed to compile my own copy of Aegisub on Bionic Beaver. This is good solid option for you to regain access to this application without using a 3rd party repository.

As it is an older application some massaging of the source with sed has been required, otherwise there are really only 2 simple steps to take:

1. Dependencies and build tools:

Copy and paste this entire code block into a Terminal window to download and install some required dependencies and build tools:

sudo apt-get install build-essential checkinstall libx11-dev libwxgtk3.0-gtk3-dev \
libfreetype6-dev pkg-config libfontconfig1-dev libass-dev libboost1.62-all-dev \
liblua50-dev libasound2-dev libffms2-dev intltool

2. Download, compile and install the source:

Copy and paste the following lines into a Terminal window to download, extract, modify, compile and install the Aegisub source:

mkdir -v $HOME/aegisub_build && cd $HOME/aegisub_build
wget http://ftp.aegisub.org/pub/archives/releases/source/aegisub-3.2.2.tar.xz
tar xvf aegisub-3.2.2.tar.xz && cd aegisub-3.2.2
sed -i 's/$(LIBS_BOOST) $(LIBS_ICU)/$(LIBS_BOOST) $(LIBS_ICU) -pthread/' tools/Makefile
sed -i '46 a\#include <unicode/unistr.h>' src/utils.cpp
CPPFLAGS="-DU_USING_ICU_NAMESPACE=1" ./configure && make -j 2
sudo checkinstall -D --install=yes --fstrans=no --pakdir "$HOME/aegisub_build" \
   --pkgname aegisub --backup=no --deldoc=yes --deldesc=yes --delspec=yes --default \
   --pkgversion "3.2.2"

The sed magic has been drawn from many sources, looks like Arch and Slackware are both keeping the application alive :).

3. Screenshot:

And a final screenshot demonstrating Aegisub successfully running on my Bionic system:


Find out how many times a specific function is used in command line terminal

Bash keeps a history of the last N commands you have run in ~/.bash_history (by default, see the value of $HISTFILE) and you can see this list by running history:

 $ history | head
    1  test.py file.txt outf
    2  cat outf
    3  test.py file.txt outf
    4  cat outf
    5  test.py file.txt outf
    6  cat outf
    7  cat file.t
    8  cat file.txt
    9  rm file.tex
   10  test.py file.txt outf

Those are the first 10 commands in my history. As you can see, the format is "command number" followed by the actual command. So, to count the times you have used man, you could do:

history | awk '$2=="man"' | wc -l

That will run history, awk which here will print only those lines whose second field is man, and then pass these lines to wc which counts them. If you need to run this often, you could make it into a little function. just add these lines to ~/.bashrc:

countCom(){
    history | awk -vcom="$@" '$2==com' | wc -l
}

Then, to count man, you would do:

$ countCom man
4460

However, this will count the number of times you have run man in the entire history of your shell. It isn't only since opening the current terminal. This is usually what you want since seeing just the handful of commands you've run since opening this terminal is rarely if ever helpful. After all, those are a subset of the whole.

If you really need this to be per-terminal, you could run history -c when you open a new terminal. This will clear the history for this terminal so that next time you run history, you will only see the commands since opening this terminal.

Unfortunately, you cannot add the history -c command to your shell's initialization files (~/.bashrc for example) because the history is read after reading the init file, so it has no effect there. So if you really need the history for this terminal and this terminal only, you will have to run history -c manually.


How to create a new file via touch if it is in a directory which doesn't exist?

There is the command install which will accomplish what you are asking for.

install -Dv /dev/null this_dir/new.txt

(source: Bash command to create a new file and its parent directories if necessary)

Explanation:

install is used to copy files and set attributes (see man install)
-D tells the command to "create all leading components of DEST except the last, or all components of --target-directory, then copy SOURCE to DEST"
-v causes to show every creation step (can be omitted of course)
/dev/null is the source, from where to copy
this_dir/new.txt is the target of the copy operation.

@rchard2scout has thankfully pointed out that

  The install command is part of GNU Coreutils, which has been marked as "Essential". That means it'll basically always be available.


How do I rebuild a package to include debugging information?

You can do this in just a few steps:

Get the necessary tools and build dependencies:

sudo apt-get install devscripts fakeroot
sudo apt-get build-dep <package>

Set the build options:

export DEB_BUILD_OPTIONS="debug nostrip noopt"

Build the package:

fakeroot apt-get source -b <package>

Install the package:

sudo dpkg -i <package>*.deb


vsftpd: 500 OOPS: config file not owned by correct user, or not a file

I don't know if you still need this, but I had the same problem recently I Google around and found This Page. The major difference I found was that I was trying to start the server by typing:

# vsftpd

Instead of:

# systemctl start vsftpd

in the terminal. I hope this helped.


Chrome embed VLC Player couldn't playback MP4

There no longer is a VLC Multimedia Plugin, it's been split off to Vlc Web Plugin

So if you're using a ppa see if they have the package. Otherwise it's available in 12.04, package name browser-plugin-vlc

What you've been enabling/disabling is the Totem Mozilla plugin which encompasses the 2 plugins in screen below that I have greyed out by disabling.

By & large the totem plugin is quite good, may even be better than the vlc one, only experimenting & personal use case would tell.

To fully enable the totem plugin install the ubuntu-restricted-addons package or -extras as mentioned.

gstreamer plugins themselves are not used by vlc

If you do end up with this vlc browser plugin you probably should disable any other totem based plugin in chrome


I think the problem is due to a conflict with the lilo package, which appears to be installed on your system.  The default boot loader for Ubuntu is Grub2, you probably don't need lilo.

Try sudo apt-get remove lilo.  Then try, eg. sudo dpkg --configure initramfs-tools.  The error messages should go away.


Maximizing a Window moves minimize,maximize and close button to the left

To clarify the question, I believe this relates to the Unity interface in Ubuntu 11.04.  If the window controls are switched to the right of the screen, they function correctly when an application is running in a window.  However, if the application is maximized, the window controls switch to the left side of the screen.

While this may be considered to be a bug, since the user has indicated a preference for the "normal" (i.e. historical) location of the window controls by changing the system configuration, it is apparently a designed-in feature, related to positioning the controls in the top panel.

See http://www.omgubuntu.co.uk/natty/panel where it is stated that "When you maximize an application, the window controls (Close, Minimize, Maximize) are moved into the panel to give you more vertical working space."


You can use the famous ImageMagick which is also available as Ubuntu package or for MacOS.
It has a lot of options to crop an image, described in its documentation.


firefox still showing up in bleachbit after removal

Yes: as you suspected, BleachBit shows the Firefox section only if the Firefox configuration files exist on your system, so you can run this command to delete the Firefox user profile

rm -rf ~/.mozilla/firefox

Then you can delete the Firefox cache using BleachBit. Recent versions of Firefox have it under another directory tree.

As Soren A pointed out, removing a package normally using APT does not remove its configuration files.


How do I autostart docker container at system reboot?

It is a very common use case to add the restart policy on an existing container.

This could be done with the following command:
docker update --restart {no,on-failure,unless-stopped,always} container_name

More details: Docker - Start containers automatically


Startup applications got messed up - Dropbox and Redshift not loading automatically

As I understand, you use Ubuntu 12.04 Desktop

Ok. First of all, delete changes you made.

update-rc.d -f dropbox remove

Dropbox is added to autostart if dropbox.desktop file exists in ~/.config/autostart. Here is my dropbox.desktop file:

[Desktop Entry]
Name=Dropbox
GenericName=File Synchronizer
Comment=Sync your files across computers and to the web
Exec=dropbox start -i
Terminal=false
Type=Application
Icon=dropbox
Categories=Network;FileTransfer;
StartupNotify=false

It should be runnable(or ubuntu says it's untrusted launcher), so run chmod a+x dropbox.desktop.

Also as @Chris said, he use CLI script to install dropbox and it was saved in ~/myscripts/ which is not included in PATH variable. So he moved this script to /usr/local/bin.


Exact steps for configuring a remote ssh terminal

The linked answer is about SFTP, which is more complicated. Configuring ssh server is much easier.

Step 1 :  Install OpenSSH package if not installed

sudo apt-get install openssh-server

Step 2 : Add to your /etc/ssh/sshd_config

PermitRootLogin no

Step 3 : Restart sshd service.

sudo service ssh restart

Step 4 : Generate key pair on the computer from where you want to access your machine and copy the public part to your machine:

ssh-keygen -f ~/.ssh/id_rsa
ssh-copy-id -i ~/.ssh/id_rsa your_machine


Interface's manual configuration problem

Let's turn it other way ... if I only want to change the HW ADDR of a unique eth0 served by an dhcp server.
Which file should I modify ? the same one (etc/network/interface)
cause in there will be only
auto eth0
init dhcp

...

anybody ?


From https://libreboot.org/faq/#amdpsp:

  This is basically AMD's own version of the Intel Management Engine. It
  has all of the same basic security and freedom issues, although the
  implementation is wildly different.

Effectively, PSP is an isolated, low-level, proprietary co-processor that cross-checks your BIOS firmware with its own. If the BIOS firmware doesn't contain AMD-PSP firmware, then your computer will not boot.

AMD PSP isn't something that you run- it runs at boot, and while you use your computer. As a matter of fact, it can be quite unsafe- once a cracker gains access to the PSP, he/she can effectively control most, if not all, aspects of your hardware.

You may want to give this a read: https://libreboot.org/faq/#intelme


How to give specific port to Apache in Ubuntu 12.04 and port for mysql

Simple , you can do it with listen  command.
I mean open your terminal with CTRL+ALT+T then type as

sudo gedit /etc/apache2/httpd.conf

Then make the line as

Listen 8000

save & close.
restart your apache server.
now your apache will start listening to port number 8000.


Do I need to install NVIDIA drivers if I have an integrated graphics card?

Yes, you need Nvidia drivers to install nvidia-prime that will power off the Nvidia adapter.

If you don't have nvidia-prime both adapters will consume power, and you will also have graphics glitches too.

Another option is to use an opensource bumblebee, but it does not work well on the modern releases.

I see no problem in installing Nvidia drivers for that purpose.

You have the drivers installed, so keep using them.


Depending on which desktop you wish to install, you install the the meta-package that installs all the necessary packages. You can use apt-get or aptitude to do this.

sudo apt-get install ubuntu-desktop

installs the Unity desktop

sudo aptitude install kubuntu-desktop

would install the KDE desktop

Other desktop meta-packages are xubuntu-desktop, ubuntu-gnome-desktop, lubuntu-desktop, and edubuntu-desktop .


Enabling 3D acceleration VMware 9 Ubuntu 13.04

Open the VMX file:

vim winxp.vmx

And add these to the end:

mks.gl.allowBlacklistedDrivers = TRUE

try to boot the machine with 3D enabled.


Persisting keyboard light state on boot/shutdown

This utility may satisfy you: https://launchpad.net/~poliva/+archive/lightum-mba

Hope it could be polished and merged to standard Ubuntu some time later.


Is it possible to backup installed software installers?

Thanks Gladen.
Software installed from online repos "installs automatically" and comes along with its own libraries or may share libraries from other already installed softwares.
Most times we only watch the progress of the whole activity but dont really care/even know where it goes.

Backing up sorces is good and backing up "setups" is great


How to automatially detect status of the network interface with NM

Thanks a lot! This is what I did:
sudo nano /etc/NetworkManager/dispatcher.d/02-events

With the content:
#!/bin/sh -e

if [ "$1" = "eth0" ] && [ "$2" = "down" ] ; then
echo "eth0 is down!" >> /home/matej/dispatch.txt
fi

if [ "$1" = "tun0" ] && [ "$2" = "down" ] ; then
echo "VPN is down!" >> /home/matej/dispatch.txt
fi

if [ "$1" = "tun0" ] && [ "$2" = "up" ] ; then
echo "VPN is up!" >> /home/matej/dispatch.txt
fi

Make it executable:
sudo chmod +x /etc/NetworkManager/dispatcher.d/02-events

Restart NM:
sudo service network-manager restart

This works as expected, but when I unplug the ethernet cable, there is around 10 seconds timeout, before NetworkManager detects an event. Could this be shortened to let's say 5 seconds?


Sony, HP, and many laptop vendors are hard-coded to only boot Windows.

There are several work-a-rounds that suggest you move the grub grubx64.efi or shimx64.efi file on top of the Windows /EFI/windows/bootmgfw.efi. However this isn't recommended because Windows Update will restore bootmgfw.efi and you'll be back to only Booting windows.

Instead, I suggest renaming the fallback /EFI/Boot/bootx64.efi and boot hard drive entry or use rEFInd.

Make sure you backup the entire EFI partition before making changes.

You have several options available:

I. Move and rename the grub files grubx64.efi or shim64.efi (for secure boot) to this folder/file /EFI/BOOT/BOOTX64.EFI

Rename /efi/boot/bootx64.efi, copy shim or grub into /efi/boot and name it bootx64.efi  Then boot hard drive entry. New versions of Boot-Repair automatically do this with 'Use the standard EFI file' in advanced options. It also backs up current bootx64.efi which is probably just a copy of Windows .efi boot file.

From live installer mount the efi partition on hard drive:
Mount efi partition. check which partition is FAT32 with boot flag. Often    sda1 or sda2 but varies.

sudo mount /dev/sda1 /mnt

only if not already existing,

sudo mkdir /mnt/EFI/Boot
sudo cp /mnt/EFI/ubuntu/* /mnt/EFI/Boot

If new folder created, the bootx64.efi will not exist, skip this command

sudo mv /mnt/EFI/Boot/bootx64.efi /mnt/EFI/Boot/bootx64.efi.backup

Make grub be hard drive boot entry in UEFI. If not existing, may have to update UEFI also with efibootmgr.

sudo mv /mnt/EFI/Boot/grubx64.efi /mnt/EFI/Boot/bootx64.efi

If need be, add a new UEFI hard drive boot entry:
See also

man efibootmgr

If ESP is sda or default drive & partition entries:

sudo efibootmgr -c -L "UEFI Hard drive" -l "\EFI\Boot\bootx64.efi"

If ESP is not sda1, sdX is drive, Y is efi partition, also NVMe drives :

sudo efibootmgr -c -g  -w -L "UEFI hard drive" -l '\EFI\Boot\bootx64.efi' -d /dev/sdX -p Y
sudo efibootmgr -c -L "UEFI hard drive" -l "\EFI\Boot\bootx64.efi" -d /dev/nvme0n1 -p 2

(This is the same as what Boot-Repair used to do in II. Not now recommended:
Rename /efi/Microsoft/Boot/bootmgfw.efi and copy grub or shim into /efi/Microsoft/Boot and name it bootmgfw.efi  Then boot Windows entry to boot to grub menu. You have to manually add a grub menu entry to boot renamed Windows efi file. Grub2's os-prober entry boots bootmgfw.efi entry which is now just grub, so it will not work.

Users who manually moved efi files around see post #6.

http://ubuntuforums.org/showthread.php?t=2101840
http://ubuntuforums.org/showthread.php?t=2219452
http://ubuntuforums.org/showthread.php?t=2221498&p=13012109#post13012109

II. If you ran Boot-Repair's fix for "buggy UEFI" with an older copy it's best to undo it. And then make the change above to use bootx64.efi
To undo and to rename files to their original names, you just need to tick the "Restore EFI backups" option of Boot-Repair.

Any rename either manually or with Boot-Repair will need to be redone after a Windows update as it will restore Windows files.

III. Edit Windows BCD, one alternative to Boot-Repair's rename to make shim have Windows name.
Some systems work better to register grub/shim from inside Windows - for those that keep resetting Windows as default.

Grub not showing on startup for Windows 8.1 Ubuntu 13.10 Dual boot

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

https://coderwall.com/p/vfyqkg

IV. If Description has to be Windows, then change UEFI description. This really only works for those with just Ubuntu, and no Windows install at all.

sudo efibootmgr -c -L "Windows Boot Manager" -l "\EFI\ubuntu\shimx64.efi"

Restore or a new Windows UEFI entry - assumes default sda1  add -p 2 if sda2 (see man efibootmgr -d drive & -p partition options):

sudo efibootmgr -c -L "Windows Boot Manager" -l "\EFI\Microsoft\Boot\bootmgfw.efi"
sudo efibootmgr -c -L "Windows Boot Manager" -l "\EFI\Microsoft\Boot\bootmgfw.efi" -d /dev/nvme0n1 -p 1

V. Some install rEFInd which seems to be another workaround and has nice boot icons.

http://www.rodsbooks.com/refind/index.html

http://www.rodsbooks.com/refind/secureboot.html

PPA available to make it easy to install in Ubuntu

http://www.rodsbooks.com/refind/getting.html

VI. Restore Ubuntu UEFI entry
sdX is drive, Y is efi partition , if sda2 for example

sudo efibootmgr -c -L ubuntu -l "\EFI\ubuntu\shimx64.efi"  -d /dev/sda -p 1
sudo efibootmgr -c -L "Ubuntu" -l "\EFI\ubuntu\shimx64.efi" -d /dev/nvme0nX -p Y

VII. Change boot order with efibootmgr:

Change boot order using efibootmgr

VIII. Uninstall UEFI entry:

Uninstall Grub and use Windows bootloader
Change boot order using efibootmgr


Starting from a standard Ubuntu 13.10 install, add the following:

Update the system (manually)

sudo apt-get update && sudo apt-get upgrade

sudo apt-get dist-upgrade

(Optional) If you need to remote access (to this platform)

sudo apt-get install openssh-server

Add some tools, used below

sudo apt-get -y install vim curl build-essential

Set to auto-update, for security updates

sudo vim /etc/apt/apt.conf.d/10periodic

.. by replacing existing file contents with:

APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Download-Upgradeable-Packages "1";
APT::Periodic::AutocleanInterval "5";
APT::Periodic::Unattended-Upgrade "1";

Disable 'Guest' login account

sudo /usr/lib/lightdm/lightdm-set-defaults -l false

(Optional) Add 'Ubuntu Tweak' tools/app

sudo add-apt-repository ppa:tualatrix/ppa && sudo apt-get --quiet update

sudo apt-get -y install ubuntu-tweak

Load ALL video, audio codecs, etc.

curl ftp://ftp.videolan.org/pub/debian/videolan-apt.asc | sudo apt-key add -

echo "deb ftp://ftp.videolan.org/pub/debian/stable ./" | sudo tee /etc/apt/sources.list.d/libdvdcss.list

sudo apt-get update

Install VLC, Mplayer, and Ubuntu restricted extras

sudo apt-get -y install vlc vlc-data vlc-plugin-pulse browser-plugin-vlc

sudo apt-get -y install mplayer

sudo apt-get -y install ubuntu-restricted-extras

Install full DVD capabilities

sudo apt-get -y install libdvdcss2 libdvdnav4 libdvdread4

sudo /usr/share/doc/libdvdread4/install-css.sh

The should cover most things you needed ..


Is it safe to remove Python 2.7.15rc1 from Ubuntu 18.04?

Run

apt purge -s python2.7

where -s is a simulation of what would happen.

and see for yourself what else you will lose.

On my system, Kubuntu 18.04, here's what I see:

The following packages were automatically installed and are no longer required:
  gir1.2-appindicator3-0.1 gir1.2-gtk-vnc-2.0 gir1.2-keybinder-3.0 gir1.2-libosinfo-1.0 gir1.2-libvirt-glib-1.0 gir1.2-spiceclientglib-2.0
  gir1.2-spiceclientgtk-3.0 gir1.2-vte-2.91 libgovirt-common libgovirt2 libgtk-vnc-2.0-0 libgvnc-1.0-0 libkeybinder-3.0-0 libphodav-2.0-0
  libphodav-2.0-common libspice-client-glib-2.0-8 libspice-client-gtk-3.0-5 libusbredirhost1 libvirt-glib-1.0-0 spice-client-glib-usb-acl-helper
  syslinux-common virt-viewer xsltproc
Use 'apt autoremove' to remove them.
The following packages will be REMOVED:
  boot-repair* boot-sav* boot-sav-extra* glade2script* kubuntu-settings-desktop* python* python-asn1crypto* python-cairo* python-certifi*
  python-cffi-backend* python-chardet* python-cryptography* python-dbus* python-enchant* python-enum34* python-gi* python-gi-cairo*
  python-gobject* python-gobject-2* python-gtk2* python-gtkspellcheck* python-idna* python-ipaddr* python-ipaddress* python-libvirt*
  python-libxml2* python-libxslt1* python-mutagen* python-openssl* python-pkg-resources* python-psutil* python-qt4-dbus* python-requests*
  python-six* python-urllib3* python-xdg* python2.7* ranger* recoll* terminator* trash-cli* virt-manager* virtinst* zim*
0 upgraded, 0 newly installed, 44 to remove and 0 not upgraded.

I won't be removing python2.7.

Looking further into this, one can find out what is present in a clean installation of Ubuntu 18.04, as opposed to an upgrade from an earlier version, by looking at /var/log/installer/initial-status.gz. I have such a system.

From a terminal window, run:

$ zgrep "Package: python2.7" /var/log/installer/initial-status.gz

The search will be empty indicating that no package containing the string python2.7 was installed.

In your case, since you upgraded from 16.04 to 18.04:

If you do have python-2-7-15rc1 on your system, it means it was retained from your previous system as part of the upgrade or that you subsequently installed software that depended on it.
Either way, removing such a package in 18.04 is safe with the caveat that programs depending on it that you installed (a) when using the previous system (before the upgrade) or (b) after the upgrade maybe removed.
Keep in mind that during the life of 18.04, if you install something like calibre or gimp or variety or virt-manager, doing so will bring python2.7 back.


It seems like a hardware problem with the disk.

Please execute the GUI scan-disk / check-disk and fix the disk.

More info here: how-to-run-a-checkdisk

After the disk will be fixed, you can check if the directory exists, and if so - remove it.


To your second question:

Each storage drive has an UUID
(Wikipedia Link) which stays the same until you change the partition (like changing filesystem, etc.). So you can use the uuid instead of sda1/sdc4/...

On the ubuntu site, there's a good explanation how to use uuids, how to find them out, and so on:
Using UUID.


Cannot get an access to one of my user accounts

You can use passwd command:

sudo passwd username

you'll prompt for password enter it then you'll be prompt to enter new password for that user

sudo passwd test
[sudo] password for test:
Enter new UNIX password:
Retype new UNIX password:

man passwd

DESCRIPTION
       The passwd command changes passwords for user accounts. A normal user
       may only change the password for his/her own account, while the
       superuser may change the password for any account.  passwd also changes
       the account or associated password validity period.


Disable unattended upgrades:

sudo dpkg-reconfigure unattended-upgrades

Select "no" when asked "Configuring unattended-upgrades" then select "ok".

More information on unattended-upgrades can be found at:

wiki.debian.org

help.ubuntu.com


Why can't I run Alice3 in my computer with Ubuntu 14.04;

The application is probably looking for its files in the current directory, so instead of running sh ~/Alice3/alice3.sh, change to the containing directory

cd ~/Alice3/

and then run

sh alice3.sh

If you don't want to invoke the application using sh, you can make the launch script executable using chmod +x alice3.sh and then run it from the Alice3 directory using ./alice3.sh


I had even tried to install Windows, which had no problem, but I still couldn't install Ubuntu after that.

The solution was to run mke2fs with some params (my colleagues ran it so I'm not sure what the params are).


OpenConnect VPN on Ubuntu 18 set up like the default of OC on Fedora Workstation? Need PA GlobalProtect VPN

As far as I know you cannot setup an GlobalProtect VPN connection inside the GUI. You have to use the terminal to setup the connection, which is actually quite easy:

Open the Terminal by STRG+ALT+T and enter the following command:

openconnect --protocol=gp vpn.url-to-your-server.com

Then the you will be ask all necessary information to setup the connection. Once done, the connection is established.

To safe your time to enter manually the command, create a file on your desktop and name it vpn.sh with the following content:

#!/bin/bash
openconnect -b --protocol=gp vpn.url-to-your-server.com

Safe it. Now you can just click on it, enter the details and to connection will be established automatically.


Unity 3D doesn't work on ubuntu 12.04 LTS in virtual box hosted by Windows 7 64bit

Ok guys. I have solved the problem.

This are some steps I made to fix it.

Uninstall the guest additions ( again ... )
Restart
After restart I went into System settings -> Additional Drivers and I enabled virtual box driver ( It starts downloading guest additions ). When I tried to install it from the VirtualBox menu ( Install guest additions ) it didnt work.
After another restart the name of this driver has been changed into Oracle VM VirtualBox Additions for Linux Module

NOTE that when I tried to disable / enable drivers with installed guest additions system crashed ( only reset helps ) and refused to start. ... and most cofusing ... it was looking enabled.

Regards


Experimenting a bit more, I was able to locate the alternate ffmpeg binaries installed by other programs using locate and egrep:

locate mpv | egrep 'ffmpeg$'
locate imageio | egrep 'ffmpeg$'

And then use alias to redirect the ffmpeg command to the most up-to-date binary without breaking other dependencies.


Custom terminal function to change text case

That is not too complicated:

Copy the script below into an empty file, save it as change_case (no extension) in ~/bin (you may have to create the directory). Make the script executable
You may have to log out/in, especially if the directory did not yet exist (or alternatively, run: source ~/.profile)
Open a terminal window, test it by running the command:

change_case custom this is a test case to see if all in the script works

output:

This is a Test Case to See If All in the Script Works

I tested it with all options from your question (upper, lower, sentence, custom) and all should work as your example.

The script

#!/usr/bin/env python3
import sys

string = sys.argv[2:]
opt = sys.argv[1]

excluded = ["in","by","with","of","a","to","is","and","the"]

if opt == "lower":
    print((" ").join(string).lower())
elif opt == "upper":
    print((" ").join(string).upper())
elif opt == "sentence":
    print((" ").join(string).title())
elif opt == "custom":
    line = []
    for s in string:
        s = s.title() if not s in excluded else s
        line.append(s)
    print((" ").join(line))


Ubuntu 15.04 Nvidia NVS 5200m not working and mini display port not working

So update, on Ubuntu, it cannot work with unity or Light DM.

using ubuntu-gnome I have it working like a charm albit some serious screen tearing and no sync to vblank option in the nvidia settings manager.


Can I get the Firefox 4 button icons from Windows XP to display in Ubuntu?

Install the theme Strata RELOADED from the Mozilla addons repository. That should do the trick.


I created the launcher and downloaded the icon from a website. You can download that icon here.In link I have provided 4 icons for the google services. You can choose whichever one you like.


Apache on 18.04 LTS | Change where web files are stored and served from?

Well, if you know apache on windows, configuration is the same, you have a bunch of config files that tell apache which domains to serve, where to find content, who may access, etc. You can change the config any time you want. During installation some default settings will be put into /etc/apache2/ to get you started which you can change to your liking.

In ubuntu the structure is probably different from what you are used to in WAMP. Put your vhost definitions into /etc/apache2/sites-available/ and run a2ensite site-name (site-name is the name of your file in sites-available) and reload apache service (sudo systemctl reload apache2.service). Inside your vhost, just point DocumentRoot or an Alias to your second partition. You may need a <Directory /path/to/document/root> definition to allow access to your document root.

Alternatively, you can just mount your second partition to /var/www which is the default location for apaches document root. This will put your web files automatically on your second partition without changing any of the default apache configuration.


Are the dark toolbars also coming to gtk2 applications?

You can already have that in Natty. It is unlikely that it will be an official 'backport' since that's not Ubuntu's way.

All credits go to James Schriver/Dashua from launchpad.
Only for Natty.
From OMG Ubuntu:

Global dark toolbars

Put together by Dashua, the following Natty-only PPA contains a modified version of the Ubuntu light themes that applies this ‘dark toolbar’ style to all of your installed GTK+ applications.

As this ‘style’ is very much in-progress it doesn’t work correctly with all applications. Bear this in mind before installing, and make a back-up of the original Ambiance theme in case you wish to revert.

Also provided via Dashua’s PPA is a patched version of Nautilus-Elementary.

Getting the changes

You can upgrade your version of Ambiance and Nautilus with these unsupported changes by adding ppa:dashua/ppa to your software sources (see the Technical details about this PPA on how to add a PPA).

Once added, run the Update Manager to apply the relevant updates. Select Ambiance in the Appearance Properties window for the theme to take effect. You may need to log out and back in in-order for changes to Nautilus to appear.

Also note that this version of Ambiance has Faenza set as the default icon set. If you don’t wish to use the Faenza icon pack you can change. Click the customize button in Appearance Preferences, go to the icon tab and choose an icon set of your choosing. The default Ubuntu icon set is Ubuntu Mono Dark.

And it will look like this:


Replace Default Qt version paths in:

/usr/lib/x86_64-linux-gnu/qtchooser/default.conf
or in newer releases /usr/lib/x86_64-linux-gnu/qt-default/qtchooser/default.conf:

/opt/Qt5/bin
/opt/Qt5/lib

Check:

qtchooser -print-env

Reference: man qtchooser


How to use the latest version of flash on Ubuntu?

Do this.  Ensure that universe is included in your software resources and, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command below.

sudo apt-get update
sudo apt-get install browser-plugin-lightspark

Also you can check out Ubuntu Packages, to manually install using a .deb file.


Move launcher from one monitor to another in Ubuntu 16.04

Go to System Settings > Screen Display

Find Launcher placement and select the display you want to put the launcher on.

Other than that you could personalize your unity interface with Unity Tweak Tool.


How to fix slow wireless with Intel 4965 AGN?

(answer in progress)

The iwl4965/iwlegacy driver has had a number of regressions in the past, but they've usually been fixed.

The high invalid misc number may be related to your low throughput.

Please try/test/answer a couple of things, and ask me for a howto when needed:

Do you experience this problem with the Ubuntu 12.04 Desktop Live CD (which runs kernel 3.2.0-23, IIRC)?
Can you try using wicd instead of NetworkManager?
Can you compile and try the latest iwl4965 driver from the compat-wireless tree?
What is the manufacturer/model number of your router?
Does your laptop have bluetooth?


Why can I not password protect specific URL paths?

You can but you do need to follow the rules as described:

The AuthUserFile directive sets the name of a textual file containing the list of users and passwords for user authentication. File-path is the path to the user file. If it is not absolute, it is treated as relative to the ServerRoot.
Each line of the user file contains a username followed by a colon, followed by the encrypted password.
For mod_auth_basic, use the utility htpasswd which is installed as part of the binary distribution, or which can be found in src/support. See the man page for more details. In short:

Create a password file Filename with username as the initial ID. It will prompt for the password:
htpasswd -c Filename username

Add or modify username2 in the password file Filename:
htpasswd Filename username2

Security
Make sure that the AuthUserFile is stored outside the document tree of the web-server. Do not put it in the directory that it protects. Otherwise, clients may be able to download the AuthUserFile.

You need to create the password file using htpasswd.


Does the change to Mir affect other Ubuntu derivates like Xubuntu or Kubuntu?

It's complicated :)

No it won't is the short answer. Canonical wants to move to Mir. Their effort to continue supporting X will be minimal once Mir starts working well. X will then have to be developed and supported by the community (that's us). The story is that the Kubuntu developers are not inclined to move to Mir. So Kubuntu will either stay with X or continue to move to Wayland.

However, no one believes that the dust has settled on this. On the one hand, KDE/Kubuntu will have to start supporting both X and Wayland so that will be a heap of extra work. On the other, we will all have to see how well Mir actually works. If it isn't up to scratch to replace X in the coming months, Canonical may have to extend support for X longer.
So let's just wait and see.


How to get video output through HDMI on 18.04? [Intel HD Graphics card]

I am updating this question 8 months later.
The problem solved by itself when I upgraded to Ubuntu 20.04.


setting global font scaling (which will affect menu bars, editors, such as gvim)

This setting is under the "Display Setting" in System Settings. You can get to it by searching "Display". Here is what it looks like:


java.lang.NoClassDefFoundError: javafx/application/Platform despite JavaFx added as Maven dependency

You're trying to run JavaFX 11, which is build using Java 11+ (class file version 54.0+, if I recall correctly) with a Java 8 runtime (which only supports class file version 52.0).
You either need to switch to a more recent Java version, I'd recommend the following:

AdoptOpenJDK (no bundled JavaFX, Maven dependency required)
BellSoft (select Full JDK, then #JavaFX is even part of it, no Maven dependency required)
Zulu OpenJDK (also supports bundled JavaFX)

I'd also recommend to use both the latest Java and JavaFX version (16 was just released).
Or you choose a Java 8 distribution with JavaFX bundled within:

again Bell Soft has something
Zulu OpenJDK also has Java 8 LTS version with and without JavaFX

Is manipulation of settings unavoidable on Linux (e.g. JAVA_HOME, ... ) and every Linux users is familiar with that so I don't to worry about it ?

It's avoidable:

With Java 8 you can create an "app" from your code with the javapackager utility contained within the JDK. The result is a directory containing the executable and the full runtime required. The users don't need to install anything.
With Java 14+ you have the jpackage tool (the other one was removed and so superseded with this one). That can do basically do the same but in conjunction with the Java 9+ module system.
With GraalVM 21 (Java11 variant) you can even create a single executable file from your code. No JVM, no runtime, just one (rather large) file - can be cross compiled on Linux, Windows, Mac, Android, iOS.

Links:

javapackager in Java 8
jpackage in Java 14+
GraalVM and Gluons Maven plugin for JavaFX builds

Is there any way to bundle JavaFx within my .jar, knowing i'm limited to JRE 1.8

Not with JavaFX 11 and later version. But you can still do it with the Java 8 variant  from BellSoft.
But why are you limited to Java 8?

Should I package my app with other stuff like suggested in the following post: How to ensure that JavaFX is installed (espacially on Ubuntu)?

No... I mean, not necessarily. It depends on what you want.
I'd use a more recent version and use the GraalVM road (which is the hardest, but doable, once you have your build set up and running).
Btw: the javapackager or jpackage tools are able to create .debs or .rpms.

#edit: Updated links and descriptions, added Zulu OpenJDK as an option.


Trying to install reactjs globally in Ubuntu 16.04 lts

open your terminal
all you need to is just add

  sudo npm install -g create-react-app

after that, you can cd into the folder you want to create your project and run the command

  create-react-app my-app

All done.


How to assign the ' Web Browser Shortcut' to Synapse?

I don't have these keys so I can't try it. You can try to remove this shortcuts ("Launch Web Browser") and add a new shortcuts with key XF86WWW and command synapse.

Or remove the shortcut for "Launch Web Browser" and use XF86WWW in Synapse.


Do you have an installer for Windows 7? Because if you do I would recommend you to install Ubuntu first and leave some space for Windows. Then install Windows and repair install the blootloader using a software called Easy BCD.


Which laptop tools does Ubuntu come with?


How do I remove Mobile Broadband connections that don't appear under "Edit Connections..."?

NM connections are stored in /etc/NetworkManager/system-connections/

I assume the bug is https://bugs.launchpad.net/ubuntu/+source/gnome-bluetooth/+bug/822311


apt-get update stuck: Connecting to security.ubuntu.com

This worked for me, courtesy of Zach Adams (https://zach-adams.com/2015/01/apt-get-cant-connect-to-security-ubuntu-fix/):

  Turns out this is an issue where
  connecting over IPv6 on some servers causes them to get stuck at this
  point. The fix is really simple.

Open /etc/gai.conf

Under the line

# For sites which prefer IPv4 connections change the last line to

Uncomment the following line by removing the #:

# precedence ::ffff:0:0/96 100

  This will allow you to still use IPv6 but sets IPv4 as the precedence
  so that apt-get won’t get stuck.


18.04 server remastered ISO preseed finish-install "left unconfigured"

I was able to bypass this issue, I can't say it's really a fix since I never found the cause for certain.

In my preseed file my late_command was like so:

d-i preseed/late_command string /bin/sh -s /final/setup.sh

I included a exit 0 line at the end of the script but something was still causing a failure status, even though all the commands in the script were successful.
Changing only the way the late_command is invoked made the finish-install scripts complete successfully.

d-i preseed/late_command string /bin/sh -c "$(cat /final/setup.sh); exit 0"


Running "ubuntu-support-status" throws an exception

Well, thanks to @cl-netbox and @Videonauth, I have solved the problem.

Apparently, even though python-apt was up to date, some other package (that it probably depends on) wasn't, and that was the cause of the issue.

Simply running

sudo apt dist-upgrade
sudo reboot

Fixed the issue.


Ubuntu Core Pi Installation: x509 certificate has expired or is not yet valid

I got this message today and was hoping to find an answer here :-(

I think what happened for me is that my Ubuntu id was very old (2010) and I hadn't used it since maybe 2014.

I had to delete my Ubuntu account and recreate it on their site (https://login.ubuntu.com). Sadly this meant I lost my original username (when I tried to re-use it it said it was already in use).


Upgrading to 10.04 broke my TrueMobile 1150 wireless

Running the following command appears to have fixed the issue.

sudo dpkg-divert --rename /lib/firmware/agere_sta_fw.bin

I did this per https://bugs.launchpad.net/ubuntu/+source/linux/+bug/498336/comments/93


chkrootkit scanner detected possible KLM Trojan

Is this anything to worry about?

No, it is a false positive and a long standing bug in chrootkit. You will see the message any time the lkm check reports hidden processes inaccessible by the readdir command. If you have something like ClamAV, MySQL, Exim or MailScanner running you are bound to see this warning.

Easiest check: run chrootkit a couple of times with as many services stopped (ie. mysql, clamav etc). If the results vary it is a clear indicator it is a false positive.

By the way: rkhunter has a better check for lkm.

Some random topics about this message: stackexchange, cpanel.net, Linuxquestions.org and all state this is bogus and a bug.

Something extra: the command ./chkproc -v will show the process ids (PID) for the message you get and you can use that to find the program that is connected to this process with cd /proc/{PID}/ && cat cmdline

In case this is convincing enough you can stop reading. If you want to know about your machine and how things work keep reading.

  So what do you need to know about your system to be able to tackle this problem?

Firstly: The best rootkit detector is you. Knowing what services are active on your machine, knowing what scripts are running on your machine is what keeps your system clean and safe. And yes it will take a bit of time to fully understand a Linux system.

Secondly: There is a bit of malware targeting Linux but it is rare. For the simple reason that although Linux is very portable it is not that portable. The differences between distributions (how ever so small), libraries, different kernels and compilers make executing random code on random machines extremely difficult. And the people that are into malware are in it for financial gain. So they focus on Windows for the very simple reasons that it is closed source, has a lot of holes that depend on Microsoft to take action to fix them. (simplified :) )

Now for the warning you see about a possible LKM Trojan installed. LKM stands for Linux Kernel Module and is one of the core modules in Linux. Kernel modules are loaded into matching kernels and if the two do not belong together the modules will not load.  This is one of the basic security features of a Linux system that you can use for tracking down malicious code (1).

Some basic things about kernels (2):

uname -r shows your kernel.
the kernels installed can be viewed in /boot.

rinzwind@schijfwereld:/boot$ ls
  abi-3.16.0-22-generic         initrd.img-3.16.0-29-generic
  abi-3.16.0-23-generic         initrd.img-3.16.0-30-generic
  abi-3.16.0-24-generic         memtest86+.bin
  abi-3.16.0-25-generic         memtest86+.elf
  abi-3.16.0-28-generic         memtest86+_multiboot.bin
  abi-3.16.0-29-generic         System.map-3.16.0-22-generic
  abi-3.16.0-30-generic         System.map-3.16.0-23-generic
  config-3.16.0-22-generic      System.map-3.16.0-24-generic
  config-3.16.0-23-generic      System.map-3.16.0-25-generic
  config-3.16.0-24-generic      System.map-3.16.0-28-generic
  config-3.16.0-25-generic      System.map-3.16.0-29-generic
  config-3.16.0-28-generic      System.map-3.16.0-30-generic
  config-3.16.0-29-generic      vmlinuz-3.16.0-22-generic
  config-3.16.0-30-generic      vmlinuz-3.16.0-23-generic
  grub                          vmlinuz-3.16.0-24-generic
  initrd.img-3.16.0-22-generic  vmlinuz-3.16.0-25-generic
  initrd.img-3.16.0-23-generic  vmlinuz-3.16.0-28-generic
  initrd.img-3.16.0-24-generic  vmlinuz-3.16.0-29-generic
  initrd.img-3.16.0-25-generic  vmlinuz-3.16.0-30-generic
  initrd.img-3.16.0-28-generic
kernel modules are installed in /lib/modules in a subdirectory matching your kernel.

So based on (1) and (2) the next step is to reboot into another kernel. The offending module was compiled against a specific kernel and will not be able to compile itself into the other kernel (simply because the headers do not match).

The amount of directories and files that can be affected when you have a rootkit are limited (a rootkit needs to be started from somewhere). There are 2 directories and a group of files that will be targeted ...

/etc/init.d/

Do an ls -ltr /etc/init.d (it will list them in order they have been last changed) and check for unknown services. Normal services will have sane names. These services can be started by the system or manually.

rinzwind@schijfwereld:/etc/init.d$ ls
acpid                   hwclock.sh             reboot
alsa-utils              irqbalance             resolvconf
anacron                 kerneloops             rsync
apparmor                killprocs              rsyslog
apport                  kmod                   saned
atieventsd              lightdm                sendsigs
avahi-daemon            lvm2                   single
bluetooth               mountall-bootclean.sh  skeleton
bootmisc.sh             mountall.sh            smartmontools
brltty                  mountdevsubfs.sh       speech-dispatcher
cgmanager               mountkernfs.sh         sslh
cgproxy                 mountnfs-bootclean.sh  sudo
checkfs.sh              mountnfs.sh            thermald
checkroot-bootclean.sh  networking             udev
checkroot.sh            network-manager        udev-finish
console-setup           ondemand               ufw
cron                    php5-fpm               umountfs
cups                    pppd-dns               umountnfs.sh
cups-browsed            procps                 umountroot
dbus                    pulseaudio             unattended-upgrades
dns-clean               rc                     urandom
grub-common             rc.local               uuidd
halt                    rcS                    x11-common
hostname.sh             README
/etc/rc*/

The startup and kill scripts are located in /etc/rc[0-5,S].d. In general the files here have numbers and a sane description (these files are executed in alphabetical order when started and in reversed order during a kill. Watch out for scripts consisting of random numbers and letters. Here is a list (these are valid scripts).

rinzwind@schijfwereld:/etc$ ls rc*/
rc0.d/:
K01alsa-utils    K01lightdm            K01unattended-upgrades  K05umountnfs.sh
K01atieventsd    K01php5-fpm           K01urandom              K06networking
K01bluetooth     K01pulseaudio         K01uuidd                K07umountfs
K01cgmanager     K01resolvconf         K02avahi-daemon         K08umountroot
K01cgproxy       K01speech-dispatcher  K03sendsigs             K09halt
K01cups-browsed  K01sslh               K04rsyslog              README
K01irqbalance    K01thermald           K05hwclock.sh

rc1.d/:
K01alsa-utils    K01irqbalance     K01speech-dispatcher  README
K01atieventsd    K01kerneloops     K01sslh               S01dns-clean
K01bluetooth     K01lightdm        K01thermald           S01killprocs
K01cgmanager     K01php5-fpm       K01ufw                S01pppd-dns
K01cgproxy       K01pulseaudio     K01uuidd              S02single
K01cups          K01saned          K02avahi-daemon
K01cups-browsed  K01smartmontools  K04rsyslog

rc2.d/:
README        S01uuidd       S02kerneloops         S04cups
S01apport     S02acpid       S02rsync              S04cups-browsed
S01cgmanager  S02anacron     S02smartmontools      S04pulseaudio
S01dns-clean  S02atieventsd  S02speech-dispatcher  S04saned
S01php5-fpm   S02cgproxy     S02thermald           S05grub-common
S01pppd-dns   S02cron        S03avahi-daemon       S05ondemand
S01rsyslog    S02dbus        S03bluetooth          S05rc.local
S01sslh       S02irqbalance  S03lightdm

rc3.d/:
README        S01uuidd       S02kerneloops         S04cups
S01apport     S02acpid       S02rsync              S04cups-browsed
S01cgmanager  S02anacron     S02smartmontools      S04pulseaudio
S01dns-clean  S02atieventsd  S02speech-dispatcher  S04saned
S01php5-fpm   S02cgproxy     S02thermald           S05grub-common
S01pppd-dns   S02cron        S03avahi-daemon       S05ondemand
S01rsyslog    S02dbus        S03bluetooth          S05rc.local
S01sslh       S02irqbalance  S03lightdm

rc4.d/:
README        S01uuidd       S02kerneloops         S04cups
S01apport     S02acpid       S02rsync              S04cups-browsed
S01cgmanager  S02anacron     S02smartmontools      S04pulseaudio
S01dns-clean  S02atieventsd  S02speech-dispatcher  S04saned
S01php5-fpm   S02cgproxy     S02thermald           S05grub-common
S01pppd-dns   S02cron        S03avahi-daemon       S05ondemand
S01rsyslog    S02dbus        S03bluetooth          S05rc.local
S01sslh       S02irqbalance  S03lightdm

rc5.d/:
README        S01uuidd       S02kerneloops         S04cups
S01apport     S02acpid       S02rsync              S04cups-browsed
S01cgmanager  S02anacron     S02smartmontools      S04pulseaudio
S01dns-clean  S02atieventsd  S02speech-dispatcher  S04saned
S01php5-fpm   S02cgproxy     S02thermald           S05grub-common
S01pppd-dns   S02cron        S03avahi-daemon       S05ondemand
S01rsyslog    S02dbus        S03bluetooth          S05rc.local
S01sslh       S02irqbalance  S03lightdm

rc6.d/:
K01alsa-utils    K01lightdm            K01unattended-upgrades  K05umountnfs.sh
K01atieventsd    K01php5-fpm           K01urandom              K06networking
K01bluetooth     K01pulseaudio         K01uuidd                K07umountfs
K01cgmanager     K01resolvconf         K02avahi-daemon         K08umountroot
K01cgproxy       K01speech-dispatcher  K03sendsigs             K09reboot
K01cups-browsed  K01sslh               K04rsyslog              README
K01irqbalance    K01thermald           K05hwclock.sh

rcS.d/:
README             S03udev              S08checkroot-bootclean.sh
S01console-setup   S04brltty            S08kmod
S02alsa-utils      S04mountdevsubfs.sh  S08urandom
S02apparmor        S04procps            S09mountall.sh
S02hostname.sh     S04udev-finish       S09networking
S02mountkernfs.sh  S05hwclock.sh        S10mountall-bootclean.sh
S02resolvconf      S05lvm2              S10mountnfs.sh
S02ufw             S06checkroot.sh      S11mountnfs-bootclean.sh
S02x11-common      S07checkfs.sh        S12bootmisc.sh
a startup script.

In general Ubuntu uses bash in a terminal and dash when booting. echo $SHELL will show you what shell is being used. For bash the hidden files to check for weird scripts or weird lines of code are...

/etc/profile
/etc/bashrc
/etc/bash.bashrc

~/.profile
~/.bash_profile

These are the 5 common ones. Any machine can have more though. Besides that you might also include

/etc/crontab
crontab

The last one for both your user and by doing sudo su. "crontab" you can list with crontab -l.  Watch for scripts that are not general Linux or created by you.

If you happen to have a second system life becomes a lot easier: you can simply compare all the files above with the second machine.


Java 9 is still in development and does not have a stable release yet. Remove it and replace it with Java 8, probably the error will be gone then.

sudo apt-get purge openjdk-9*
sudo apt-get install openjdk-8-jre


Black screen after login after update (Intel GPU)

Maybe try the following first to update your intel driver:

sudo add-apt-repository ppa:glasen/intel-driver
sudo apt-get update
sudo apt-get install xserver-xorg-video-intel

This may also be down to certain chipsets needing KMS in order to run X and a desktop environment such as GNOME, KDE, Xfce, LXDE, etc. KMS is supported by Intel chipsets that use the i915 DRM driver.

Dont use nomodeset or modeset=0, as it throws off KMS and you wont
be able to do anything.
sudo nano /etc/initramfs-tools/modules and add in the i915 and
intel_agp drivers, save, and rebuild by running update-initramfs
-u


How do I change an existing path to a binary so that it points to a newly installed updated version?

Names of executable files are search for in the folders that are listed in your PATH setting, and in that order.
/home/vanadium/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

An executable installed in .local/bin will thus take precedence over executables with the same name placed in the other folders listed.
1. Per "best practices," where should I put the new, unpacked run-binary?
Definitely keep the one you want to use in .local/bin/. If you want to use the same command to launch it, then remame the previous version (e.g. .local/bin/run-binary-versionnumber) or move it to another folder, or, better, see next point.
2. How do I update /home/john/.local/bin/run-binary so that "run-binary" executes from the newly installed location after doing #1 above?
If you want to keep previous versions of your executable around, good practice is to place each version in its dedicated folder, or perhaps, if it is a single executable, in the .local/bin folder but with a distinct name, e.g run-binary-versionnumber. Then, you can create a symbolic link in .local/bin that is named how you typically want to run it, e.g. run-binary.
That way, the version of your choice will be started when you run run-binary. You still can easily run other versions by giving the specific name run-binary-versionnumber.
You can create symbolic links with the file manager, or with the command
ln -s ~/.local/bin/run-binary-versionnumber ~/.local/bin/run-binary


Moving from Windows to Ubuntu. What programs to use?

First of all, welcome to Ubuntu! :-)

So, all the software you mentioned in your list have an equivalent in Linux. I really suggest you spend time reading one of these links I offer you below:

Linux software equivalent to Windows software
List of free and open source software packages
List Of Open-source Programs (LOOP): 1, 2

I'm sure you will have great suggestions apart from those lists. It was there that I chose to use the following equivalents:

gimp for images (.jpeg, .png, .gif)
OpenOffice.org for create and manipulate Microsoft Office docs
Telepathy for Messangers (QiP, ICQ, Msn, etc) with Skype available
Mozila Firefox replacing Iternet Explorer

For all other software you have an equivalent in Ubuntu, and you can easily search and install using the tool Ubuntu Software Center, see a screenshot below (from wikipedia):


Laptop display "unknown" and can't detect external displays

This problem was solved by the OP:

  For those with the same problem, that's how I solved it: Open console
  (ctrl alt t) type in nvidia-settings A window will pop up, and just
  play around there till it works... Was pretty hard for me with only
  half of my pixels working, had to permanently move the window around
  to be able to read all the stuff but I got it down.


Mime.cache root shell, -can not log in desktop

Problem solved!
Before deleting mime folder I had its backup just in case with the name of mime_back.
Now, I remount the system to read-write mode with the following command.

mount -o remount,rw /

and then deleted the recent version of mime with rm -rf. Finally, rename the backup mime folder. And it worked.


Is it possible to make shutdown impossible?

Create a alias for shutdown
Edit sudoers and negate the allow with a exclamation mark, !SHUTDOWN .

Edit:  /etc/sudoers

Add these lines to Command Aliases section.

Cmnd_Alias     SHUTDOWN = /sbin/shutdown,/sbin/reboot,/sbin/halt,/sbin/poweroff

# User privilege specification
root   ALL=(ALL:ALL) ALL, !SHUTDOWN

# Allow members of group sudo to execute any command
%developers  ALL=(ALL:ALL) ALL,  !SHUTDOWN

Ref.: https://www.tecmint.com/disable-shutdown-and-reboot-commands-in-linux/


Thanks to all who have posted trying to help me sort this out.  I wanted to update all on the current status and explain what I did to put the system in its current state.  You will notice in the original post that I tried sudo service ssh start, etc. and obtained various unhelpful errors.  Eventually, I did

#touch /etc/ssh/sshd_not_to_be_run

and then

# killall sshd

a few times.  At this point sshd stopped restarting (as you would expect).  I then ran

sudo service ssh status
ssh stop/waiting

sudo service ssh start
ssh stop/pre-start, process 22510

sudo service ssh status
ssh stop/waiting

sudo service ssh stop
stop: Unknown instance:

sudo service ssh status
ssh stop/waiting

sudo service ssh start
ssh stop/pre-start, process 22579

sudo service ssh status
ssh stop/waiting

These results are expected given the presence of sshd_not_to_be_run file.  After subsequently removing this file I was able to run:

sudo service ssh status
ssh stop/waiting

sudo service ssh start
ssh start/running, process 25063

sudo service ssh status
ssh start/running, process 25063

sudo service ssh stop
ssh stop/waiting

sudo service ssh start
ssh start/running, process 25141

sudo service ssh status
ssh start/running, process 25141

sudo service ssh stop
ssh stop/waiting

sudo service ssh start
ssh start/running, process 25247

It looks like things are in order for now.  If anyone has any ideas about tests that I could to to help ubuntu sort this out (I have seen several other posts on the web that indicate the errors I was originally getting) I would be happy to do them and post results.  Thanks again for all of your help.


Is concurrent execution of "sudo apt-get install", "sudo snap install", and "pip install --user " recommended?

The system will not allow executing apt install more than once at a time. it will error out on the 2nd one because it can not lock a special file. Reason: apt remove and  apt install can have conflicting actions. One package could need to remove something that the other action would need. "Dependency hell" is what we called that.

"snap" can do it but you need a special feature:

snap set system experimental.parallel-instances=true

There will be no problems: "snap" is designed to be independent of everything. There is no dependency issue here: all snaps install their own software.

"pip" can do it too.

xargs --max-args=1 --max-procs=4 sudo pip install < install.txt

it will install the packages that are in "install.txt" (each line one package) and it will install (in this example) 4 at a time. Be careful: this can get nasty with dependencies. pipenv install package packages is supposed to fix the dependencies problem but has a serious drawback: it creates a file and a lock file that takes long to create so not much gain in speed. But it does install in parallel when done.

Assuming you meant to use each of these 3 at the same time (and not one of these 3 more than once at the same time): You can have 1 of each of these running at the same time where snap and pip can do parallel installs. Also with a note to take into account: it is possible to use apt to install a package that also can be installed with pip. Do that at the same time and it could spell trouble.

As said in comments: always do a sudo apt update before installing new software.

  Is concurrent execution of “sudo apt-get install”, “sudo snap install”, and “pip install --user ” recommended?

No but "recommended" is not really a show stopper :)


From personal experience I can say that running games (especially newer ones) through wine, although possible, can be a very frustrating process.  Even if you eventually get them to run, there will be some reduction in performance.

There are some comercial tools (crossover comes to mind) for running windows applications on linux, but I have never tried them.

I found that installing a windows partition purely for gaming was a much simpler solution. I use an old 160GB HDD for my windows partition and that seems to do the trick nicely.  If you are worried about running out of HHD space then buy a small(ish) second hand HDD.

Also if you only keep games on your windows partition, and not important files, then it is not too critical if the installation breaks and you have to re-install.

EDIT:

In terms of partitioning layout.  I have a separate 160GB HDD for windows, and a 250GB HDD for linux.  I have separate root, var, swap and home partitions, sized at 20, 10, 4.5 and the rest GB each.

I recommend reading this wiki entry: https://wiki.archlinux.org/index.php/Partitioning

Although it is not specific to Ubuntu, the principals still apply.


To rename, you do not need a script. There is the rename command that allows to rename with a single command. It is installed by default. Consult man rename for how it works. Useful for first learning is among others, this website.


can't install nvidia-driver-toolkit on Ubuntu 20.04 LTS - needs uninstallable package

I think you might have added PPAs or changed your sources.list in "/etc/apt/sources.list". If so, try first to get your sources.list to its original state (for ubuntu focal) which supposed to be something like:
deb http://archive.ubuntu.com/ubuntu/ focal main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ focal main restricted universe multiverse

deb http://archive.ubuntu.com/ubuntu/ focal-updates main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ focal-updates main restricted universe multiverse

deb http://archive.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ focal-security main restricted universe multiverse

Yours might not be exactly the same but just make sure that all mirrors belong to  focal.
Then list your packages sources using the command:
sudo apt-cache policy

Now if you find any PPAs related to nvidia/cuda try to remove it using the command:
sudo add-apt-repository --remove ppa:<ppa_name>/ppa

Then try to purge any nvidia or cuda related packages
sudo apt-get --purge remove "*cublas*" "cuda*" "*nvidia*"

And make sure that there are no cuda files are in /usr/local/cuda. If so remove them.
Finally, clean the cache and remove unneeded packages using:
sudo apt-get clean
sudo apt-get autoremove

Now try again the following and hopefully it will work:
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install nvidia-cuda-toolkit


Can't install software using apt-get install : hash sum mismatch and failed to fetch errors

You can try:

sudo apt-get -o 'Acquire::http::No-Cache=true; Acquire::http::Pipeline-Depth=0;' install NAMEHERE

apt bug explained here: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=810796


Ubuntu Virtual Host cant connect to MS-SQL Server

It's most probably due to cached config.

Please try

php artisan config:clear


How to install latest package version of a ppa?

I looked at the repo's Packages.bz2 file for 12.04 and 16.04 and saw that there Packages.bz2 were not updated to point to the latest version of chromium available in the repo.

Maybe the maintainer forgot to do it

So I would recommend you to use another ppa or wait beacuse the repo's devel section which ,if I am right means that the update is still in testing process and not ready as considered by the maintainer .

And as you asked how can you install then you may use these commands:
cd /etc/apt/sources.list.d
sudo nano canonical-chromium-builds-ubuntu-stage-xenial.list
and change the line : deb http://ppa.launchpad.net/canonical-chromium-builds/stage/ubuntu precise main
to deb http://ppa.launchpad.net/canonical-chromium-builds/stage/ubuntu xenial main
and then run sudo apt update && sudo apt install chromium-browser

Before editing the source file
After editing the source file