How to reinstall all networking drivers?

If your network configuration is somehow messed up it's better to clean its configuration files, rather than reinstall anything.

Of course you can purge packages related to network, like network-manager, remove its configfiles, then install again, but it's really dirty way of doing it.

DANGEROUS STUFF BELOW: dreaded dragons, hot plasma, don't copypaste it

mkdir ~/network_fix \
&& cd ~/network_fix \
&& dpkg -l | grep -E "^ii(\ ){1,3}network-manager" | awk '{print $2}' | while read -r pkg ; do apt download $pkg ; done \
&& sudo apt-get purge network-manager \
&& sudo rm -r /etc/NetworkManager

then reinstall it

cd ~/network_fix && sudo dpkg -i *.deb

You may want to do the same with netplan.io in modern ubuntus, depending on what setup you're using.

Also you can revert changes done inside some generic configfiles like /etc/network/interfaces, /etc/hosts, /etc/resolv.conf, etc.

One way of doing it is to rsync anything network related from another system with same distro, f.e. installed on virtualbox, or from live CD.

However there is also whole big story about systemd in this case, but this is something beyond my nerves...

But nevertheless, you want to do some crazy things :) So I'd recommend describing what the problem is in the first place, before going wild.


After installing Ubuntu I get an initramfs error

sda5
/dev/sda5 is not being found. Edit your question and show me sudo blkid and cat /etc/fstab.
BIOS
Fujitsu Lifebook LH531
You have BIOS version 1.08. There's a newer BIOS available, version 1.15, available here.
Note: Verify that I have the correct web page for your model #.
Note: Have good backups before updating the BIOS.
Update #1:
Reinstalled Ubuntu and it boots properly now. BIOS still needs to be updated.


Use gparted to change the partitioning of your system.

You will have to enlarge the extended partition (/dev/sda2) to fill out the whole disk.
Then move the swap partition sda5 to the end (right) of the extended partition.
After that, shrink the extended partition back to its original size by moving the left border, so it resides at the end of the drive and does not contain any unpartitioned space besides the swap partition.
Finally enlarge the main partition sda1 to cover all unpartitioned space.

You have to apply the changes in gparted by clicking the green tick. If it causes errors, try it again with applying the changes after each step.


Broadcom BCM4352 Wireless not working with 16.10

We have found that, even though it is properly blacklisted, bcma loads anyway!! Let's correct it in rc.local.

Please do:

gksudo gedit /etc/systemd/system/rc-local.service

Put in the following:

[Unit]
 Description=/etc/rc.local Compatibility
 ConditionPathExists=/etc/rc.local

[Service]
 Type=forking
 ExecStart=/etc/rc.local start
 TimeoutSec=0
 StandardOutput=tty
 RemainAfterExit=yes
 SysVStartPriority=99

[Install]
 WantedBy=multi-user.target

Proofread carefully, save and close the text editor. Next:

gksudo gedit /etc/rc.local

Place the following:

#!/bin/sh -e

modprobe -r wl
modprobe -r bcma
modprobe wl

exit 0

Proofread carefully, save and close the text editor. Next:

sudo chmod +rx /etc/rc.local

sudo systemctl enable rc-local

sudo systemctl start rc-local.service
sudo systemctl status rc-local.service

If there are no errors, reboot and test.


The package "libpango" has a problem, blocking installation of other packages, how do I fix it?

Finally it was solved with

  sudo aptitude reinstall libpango1.0-0

Actually i don't understand what it did. It removed a lot of packages then every thing was back to normal after

  sudo apt-get update

I hope this answer helps somebody else


Apache server A attempts conn to mysql server B. times out

We changed the ip of the machine to a different ip range within our institution. from a private range to a public ip. it now connects. We're now investigating this private range. Thanks for everyones help!

https://serverfault.com/questions/200774/apache-server-a-attempts-conn-to-mysql-server-b-times-out-what-am-i-missing/201308#201308


how to input chinese characters into a ubuntu 14.04 server edition with no GUI?

A "headless" server cannot display anything -- not Latin letters, not Chinese characters; it is headless. It is your terminal / web browser / whatever application you use locally which displays the characters. You are looking at the wrong end of the pipe; for example, the picture below show how a program on the server will send the character <U+7F51> (网, wǎng, "net", "network") to an application on the local machine:

User     Local machine                  Headless server
        ______________                    ____________
 ( )   |  __________  |                  |            |
 /|\   | | Terminal | |  \xE7 \xBD \x91  |            |
/ | \  | |          | |<-----------------|  <U+7F51>  |
  |    | |    网    | | (UTF-8 encoding) |            |
 / \   | |__________| |                  |            |
/   \  |______________|                  |____________|


How can I pass command output as first argument to next command

There are two solutions:

Run sudo /mnt/c/twit/venv/bin/pip install requests directly
Run sudo $(which pip) install requests


am I right to assume that Unity is just the theming scheme of Ubuntu? (Pretty much like Aero on Windows 7?)

"Unity" is Ubuntu's default desktop environment, like the old Gnome and KDE you may remember. In a very simplistic way, sure, it's a "theming scheme" like Aero.

  Am I right to assume that Ubuntu now uses the Unity 3D?

No, Ubuntu's Unity has nothing to do with the Unity 3D gaming engine.

Just Unity usually refers to Unity 3D, which is prettier but requires a reasonably modern video card; Unity 2D is the version for low-end computers.
If you prefer the "classic" pre-9.10 Ubuntu experience, try installing the gnome-session-fallback, which will show up on your login screen as Gnome-Classic
For lots more info on Unity and pretty pictures, see http://unity.ubuntu.com/about/


Ubuntu 15.10 won't boot for no evident reason

If you go into recovery mode then to the root command prompt and type

mount -o rw,remount /

then

vi /etc/default/grub

Look for a line that  says

#GRUB_CMDLINE_LINUX=

Change it to

GRUB_CMDLINE_LINUX="text"

Save the file and run

update-grub

Now when you boot it will boot to the command prompt login.

Once logged in it should be running ...

you can try startx  and see if it locks up again. If it locks then you can look into your video drivers but at this point I don't have enough information to go by .. maybe when it comes to that point  someone else can suggest something...

setting it up the way I suggest will at least let you boot into your normal Ubuntu (though without a GUI) so you can easily edit it without having to use the recovery mode. Once you figure out the issue and fix it and startx boots you into GUI without an issue you can re-edit /etc/default/grub comment out that line we changed and do sudo update-grub and it will boot back into the GUI at bootime


Ubuntu on Dell Latitude E5520 working slow

If you experience this problem mostly when using Firefox, try disabling "Global Menu Bar integration" from Firefox add-ons. This, supposedly, is a more common issue if you have a lot of bookmarks. I had a very similar problem, and disabling that add-on fixed it for me.

Bug that I refer to > https://bugs.launchpad.net/ubuntu/+source/unity/+bug/987060

If you notice Firefox, unity-panel-service and hud-service taking up a lot of RAM and CPU, this is likely your problem. I noticed that your resources seem to be fine in what you posted, but that is only an instantaneous report and might not be an accurate account.

Hope that helps.


Connecting to VPN disconnects other connections

This is probably down to the server configuration of your company. Do you have control of that? It sounds like it is pushing down a default route to ensure all traffic (including your IM and video streaming traffic) traverses the company network. If you don't want this behaviour then you probably want "split-tunneling". I'm not an OpenVPN user but a quick search threw up this thread which might help:

OpenVPN split tunneling


please refer to this, if you can still see sda partitions there is hope,
How do I point grub back to a working Ubuntu (btrfs !)

You can use any method available for you at the moment to see the partitions, fdisk, bootinfo etc. After you identify that you have the partitions you should proceed to mount and boot them with grub. Most is explained in the link.

If you have access to the grub> prompt you can do:
ls
see what is the output, normally "(hd0) (hd0,msdos2) (hd0,msdos1)", then follow after you recognize the right one do:

 set prefix=(hd0,1)*/boot/grub
    set root=(hd0,1)*
    insmod normal grub
    normal
    insmod linux grub
    linux /boot/*
    root=/dev/sda1* grub
    initrd /boot/*
    boot


FPM uses php.ini syntax for its configuration file - php-fpm.conf, and pool configuration files
You may add the directive to php-fpm.conf

sudo nano /etc/php/7.2/fpm/php-fpm.conf

Insert a line (example for 10M)

upload_max_filesize = 10M


Error installing Ubuntu 14.04 the failing step is select and install software

Just gone through this myself.

I had to try several different USB sticks before I found one that worked.

I also found that it only worked if I created the installation disk from within an existing Ubuntu installation.


Downloading wine-x64 when opening Software Center

I found that the cause of this were remaining wine "addons". The solution was to enter:

  "sudo dpkg --purge pipelight-multi gnome-exe-thumbnailer"


How can I work around "something wicked happened resolving" mirror errors?

It seems its a DNS resolve problem..

To solve this edit your /etc/resolv.conf (sudo nano /etc/resolv.conf) and add the google public DNS addresses like this:.

nameserver 8.8.8.8
nameserver 8.8.4.4

Do the ping test again on a known server and if that passes do a apt-get update..

Hope this helps, if not say so, gl. ;)


how to change a user home directory to adirectory that already exits?

The message is only informational - the change should be accepted regardless.

Ex. given

$ getent passwd testuser
testuser:x:1001:1001:,,,,testuser@foo.com:/home/testuser:/bin/sh

then

$ sudo mkdir /home/foo
$ sudo usermod -m -d /home/foo testuser
usermod: directory /home/foo exists

however the home directory was successfully changed

$ getent passwd testuser
testuser:x:1001:1001:,,,,testuser@foo.com:/home/foo:/bin/sh

And just to be sure:

$ su - testuser
Password:
$ pwd
/home/foo


Ignoring file 'google.list.save.1' in directory '/etc/apt/sources.list.d/' as it has an invalid filename extension

Nothing to worry about. .save file is created when you edit files with nano. Somethimes when you force quite the editor save file is left over. When you delete google.list.save.1 it will remove the error  in apt


Why is there a problem in Firefox connecting to a particular site securely?

I would say that's a problem. First make sure you've installed any updates by opening the Update Manager and doing a refresh. Install any updates, restart Firefox and try again. It also might be worth trying another browser, like Google Chrome (just to see if it has the same issues).

If it's still showing as a security issue, that could well mean that there is somebody or something between you and the website trying to eavesdrop or interfere with the communication between your browser and the server.

I'm speculating and it could just be an out-of-date certificate that needs to be updated. If updating doesn't help, you should edit your question to include the details about the certificate. Firefox should be able to tell you why it's not happy.

But I would approach this suspiciously. It never hurts to be too suspicious when your online credentials are at risk.


Ubuntu:Unable to correct problems, you have held broken packages

First ensure your system's libraries are update by running:

$ sudo apt update
$ sudo apt upgrade

Then manually install the Depends that are displayed in the error message.

Then install the package as normal.


Terminal opening two instances of Sublime instead of one

Add these lines in Preferences -> Settings - User. It worked for me in Sublime Text 3.

{
    "hot_exit": false,
    "remember_open_files": false
}

But, when we open Sublime Text from dash/search, all the projects/folders from the previous session are removed. You will get a new blank instance of Sublime Text.


How to connect two PCs with nomachine? What goes where?

The following wiki guides should tell you what you need to know:

https://help.ubuntu.com/community/FreeNX
https://help.ubuntu.com/community/NomachineNX


You don't mention which desktop environment you're using, but you can install krfb, which lets you connect to your desktop.

I'm not sure if this will work with unity (since this is a KDE-based application), but it does share your main screen, and does not start a "second" VNC session. It also lets you connect without having to interact after the session ends.


How to set custom lock screen time in Ubuntu 18.04

Open Terminal and run:

gsettings set org.gnome.desktop.session idle-delay 1800

to set the "Blank screen" delay to 30 minutes or 1800 seconds (or set any value in seconds). You can use $((30*60)) to use minutes directly.

Note: After making the change, in Settings → Power → Power Saving → Blank screen it will show "Never" as there is no entry for 30 minutes.

To lock: The number of seconds after blank screen activation before locking the screen (default: 0)

gsettings set org.gnome.desktop.screensaver lock-delay 0

Needed: Set this to TRUE (default) to lock the screen when the blank screen goes active

gsettings set org.gnome.desktop.screensaver lock-enabled true


No sound in .mp4 file converted with x264

Just use dmMediaConverter, (a ffmpeg gui) it is the ideal tool for this.


Failed to set MokListRT: out of Resources : import_mok_state()

I solved this problem.

Create a Live USB/CD of Ubuntu 17.10
Boot this USB/CD in UEFI mode (the problem doesn't happen with this version)
Open terminal and use this command: sudo mokutil --reset
Try to boot with the system you want to install
If you get this another error "Failed to open \EFI\BOOT\mmx64.efi", change the file name of "grubx64.efi" to "mmx64.efi" (localte on /efi/boot on USB/CD)
Boot again and you will see no errors (I hope so).


google-musicmanager Couldn't connect to Google Play

I ran into this issue as well - I had already installed Google MusicManager at some point, and blew it up when I installed an update.

My solution was to COMPLETELY remove it and its configuration.  First, removing it completely via apt:

sudo apt-get purge google-musicmanager-beta

Then, tracked down all remaining files that referenced it and removed them, including within my own profile:

cd /
find . -iname '*musicmanager*'
rm <anything that was found above>

Then I reinstalled, and it came up with initial setup dialogs and worked properly.  Note that there have been comments that for people with two-factor auth using the feature to just click "Yes" on the phone doesn't work - I had it send me a text message with an auth code instead and it authenticated just fine.


Can't boot to USB after installing Ubuntu

I found it.

There was another sub-menu - Hard Drive BBS Priorities.

I went in there and selected the USB and disabled the others.


Is there anything to gain from having a 4k screen with 200% scaling vs. a FullHD screen?

Yes!

4k at 200% does actually not work as described in the question; to make it work like that you could simply operate the 4k screen with a FullHD resolution.

The 200% scaling works differently. Unfortunately I am not well versed enough in the inner workings of ubuntu's display management to be able to explain how exactly it works, but from my experimentations I can say that yes, it does indeed render most things in a hidpi mode, where fonts - and icons, in some cases - are rendered with a higher resolution. Practically all of the "standard", builtin ubuntu GUI, including preinstalled applications, are rendered at double size, at the given resolution. This includes the system settings, file browser,  I can provide a few images and highlight the differences between 100% and 200% scaling, to make things clearer.

The Dock

Closeup comparison of a launcher icon in the dock. Left is 100% scaling, right is 200% scaling. The left half has been scaled up x2 in gimp for comparison purposes.

Not much to add here. As you can see, the icon has visibly more detail with 200% scaling.

Gedit

Closeup comparison of chrome and text body of the standard text editor. Left is 100% scaling, right is 200% scaling. The left half has been scaled up x2 in gimp for comparison purposes.

Icons, labels and text body are all rendered with visibly more detail.

Gimp

Comparison of GIMP, a foss image manipulation program. Left is 100% scaling, right is 200% scaling.

Here it gets funny. Text elements are all rendered at twice the size, as expected. The icons however, are not, which might make them potentially too small to use on a very high dpi screen, despite the scaling. Notable is that the size of the image preview is not affected by the 200% scaling, which is certainly correct behaviour.

PyCharm

Closeup comparison of PyCharm, an IDE developed by JetBrains. Above is 100% scaling, below is 200% scaling, respectively. The above has been scaled up x2 in gimp for comparison purposes.

As the answer expresses interest in a JetBrains IDE specifically: PyCharm works very well with the 200% scaling. All user interface elements - icons, text elements, menu bars - are scaled up, rendered with visibly more detail.


Using sed with pattern grouping to capture the desired portions:

your_command | sed -r 's/.*_T([0-9]+)_s([0-9]+)$/\1 \2/'

([0-9]+) is the first captured group, [0-9] matches any number between 0-9 and + indicates one or more match of the preceding token [0-9] in this case
([0-9]+) is the second captured group
In the replacement pattern the two captured groups are referenced by \1 and \2 respectively.

Example:

$ cat file.txt
exp_70_T8_s1
exp_71_T8_s5
exp_72_T8_s10
exp_73_T10_s1
exp_74_T10_s5
exp_75_T10_s10

$ sed -r 's/.*_T([0-9]+)_s([0-9]+)/\1 \2/' file.txt
8 1
8 5
8 10
10 1
10 5
10 10

Change the replacement pattern to meet your need, for example without any space:

your_command | sed -r 's/.*_T([0-9]+)_s([0-9]+)/\1\2/' file.txt

Answer to the edited question:

For _T:

your_command | grep -Po '.*_T\K\d+'    ## Using grep
your_command | sed -r 's/.*_T([0-9]+).*/\1/'   ## Using sed

For _s:

your_command | grep -Po '.*_s\K\d+$'    ## Using grep
your_command | sed -r 's/.*_s([0-9]+)$/\1/'    # Using sed


Why am I getting notices about File Manager needing to restart?

Pcmanfm has the option of two pane and tree like in Windows. It is very light and fast to use. Hope it helps.


How to restrict the NTFS Linux partition on Windows in Dual Boot systems

You can simply unmount the Linux NTFS partitions in Windows. Here is how:

Press Win + R and run this command - diskmgmt.msc.
Right click the partition you wanna unmount, then remove the drive letter from it.

Done! It'll do the thing.


This bug made using emacs and IntelliJ Idea a nuisance under Ubuntu 18.04 LTS. I found a simple workaround.

You can verify how Alt and Shift are not being detected simultaneously by running

$ xkbwatch

Notice how the blinky lights change for ALT and for SHIFT individually but not for both at the same time.
The output of setxkbmap -query:

rules: evdev
model: pc105
layout: us,us,us
variant: ,intl,
options: grp:alt_shift_toggle,grp_led:scroll
         ^^^^^^^^^^^^^^^^^^^^
         THIS IS THE PROBLEM

We will now unset ALTSHIFT toggle, so that it is not prematurely captured.

$ setxkbmap -option -option grp_led:scroll
            ^^^^^^^
            DELIBERATELY EMPTY

The first empty -option erases all options, the second one just
carries over an option we want to keep. Additional -option clauses can
preserve other preexisting options.

You can still change to next/previous input source with whatever is configured in Ubuntu Settings/Keyboard/Typing. In my case it is Super+Space (Super=Windows key in PCs).
Repeat step number 2 again and notice how ALT and SHIFT now play together simultaneously.

I am now a happy Emacs and IntelliJ user.
This is a single command workaround.


Isn't it as simple as:
Navigate to the menu, click Mode and then choose Programming ?


Short Answer

At least for my case, it turns out you can force a restart and then repair packages.

Details

I followed @SauravKumar's advice in the comments and forced the system to restart. On reboot, the computer got to the purple screen where it selects which OS to run. If I chose the default Ubuntu, it started loading and then went to a black screen and didn't respond to the keyboard at all.

So I then booted in recovery mode and chose the check packages option. It found out that I was using a different version of etc/default/rcs than the package maintainer. I chose to update it (the default is don't update) and then resumed booting and now it's running fine. Just to make sure, I rebooted again, and it works after a regular reboot too.

Update to 13.10: success!


Power failed during 16.04 LTS to 17.10 upgrade after successful download of files

It appears as if something has been broken due to the power failure mid-upgrade. Here are some steps to try:

Run fsck

The first thing to try is to boot into /bin/bash, you can do this by:

  reboot
  edit grub:

  edit the grub entry by pressing 'e'
  edit the kernel line by pressing 'e'

  add the following at the end of the kernel line: init=/bin/bash

  press enter to save and 'b' to boot

  The init=/bin/bash statement boots straight into a shell, so no password is required.

From here

After you get the root shell, run:

fdisk -l

to get a list of all disks and sizes. Find the one where your install lives(likely /dev/sda1), and run:

fsck /dev/sda1

or replace /dev/sda1 with your install location.

If you're already here, you can also try:

mount -o remount,rw /
dpkg --configure -a

If you're lucky, and on ethernet, you can try:

ifconfig eth0 up
apt update
apt install -f
apt upgrade

Use an older kernel

It's likely that the kernel was updated during the Ubuntu upgrade process. In this case, try booting into an older kernel. You can do this by:

  While booting when GRUB appears with entries select the second entry i.e., Advanced options for Ubuntu there you can see different older kernel versions which was installed previously, you can select one among them which works good for you.

this answer
If this does fix your problem, resume the upgrade. I would recommend running the following first:

sudo apt update
sudo dpkg --configure -a
sudo apt install -f
sudo apt upgrade
sudo update-grub

some help from here

Live CD

If all else fails, boot from a Live CD, and copy your files(/home/usernamehere) to an external drive. Then, re-install, and copy all your files back over. You can get some help here, but the main points are:

  You have to find your hard disk, which is listed on the left side of any file browser window, near the top. Mount that (or if there's more than one volume listed, mount the one for your Ubuntu system, or if you're not sure, mount them all and go through them to see). As Mark Rooney commented, you can just click on it to mount it. Then find the home folder in there.

  That will probably be sufficient to enable you to copy your files out. Remember that copying them, say, to the desktop of the live CD system would be useless, as they would go away when you reboot. Instead you must:

  copy them to an external drive or USB flash drive (but if you're booted from a USB flash drive, not that one, unless it has a persistent area and you really know what you're doing), or
  put them on another machine on the network, or email them to yourself, or otherwise store them on an Internet server (for example, with a service like Ubuntu One), or
  burn them to a CD/DVD.


code is still using old IP even though server nslookup showing new IP

I know this can be counter-intuitive, but (assuming you're using Chrome) open Developer Tools. (Click the Hamburger->More Tools->Developer tools) Then click the config gear to the top right and check "disable cache while devtools is open".

Refresh the page with devtools open and see if that gets you to the solution. That will force the browser to pull fresh files from the server each time and help you rule the client's side out. The Network section of devtools when you refresh may help as well. I'm thinking it's the browser's cache.

(Unsure if this is the case, but I could imagine Chrome resolving and storing the IP in cache and only resolving again if that IP doesn't have the file, or a similar mechanism, to minimize unnecessary look-ups.)


Is there a synapse like search bar as a desktop widget for Gnome desktop fallback mode?

Indicator-Synapse is a new attempt at presenting results from the powerful application/file launcher Synapse.

To install in Ubuntu 12.04:

sudo add-apt-repository ppa:elementary-os/unstable-upstream

sudo add-apt-repository ppa:birdie-team/stable

sudo apt-get update && sudo apt-get install indicator-synapse libkeybinder-3.0-0

For other releases please check:

http://www.omgubuntu.co.uk/2013/09/spotlight-like-tool-coming-to-pear-os-other-distros


How to change background color of pop out menu of the top bar of Ubuntu 18.04 lockscreen and unlockscreen?

from the standard ubuntu.css file the below part is what you are looking for. Concentrate on "green" color.

.popup-menu-boxpointer,
.candidate-popup-boxpointer {
  -arrow-border-radius: 3px;
  -arrow-background-color: green;
  -arrow-border-width: 1px;
  -arrow-border-color: #1f1f1c;
  -arrow-base: 24px;
  -arrow-rise: 11px;
  -arrow-box-shadow: 0 1px 3px black; }

Edit: Concentrate on Blue & Yellow colors in below.. Hope you can manage further..

/* Popovers/Menus */
.popup-menu {
color: blue;
  min-width: 15em; }
  .popup-menu .popup-sub-menu {
    background-color: blue;
    box-shadow: inset 0 -1px 0px #2c2c28; }
  .popup-menu .popup-menu-content {
    padding: 1em 0em; }
  .popup-menu .popup-menu-item {
    spacing: 12px; }
    .popup-menu .popup-menu-item:ltr {
      padding: .4em 1.75em .4em 0em; }
    .popup-menu .popup-menu-item:rtl {
      padding: .4em 0em .4em 1.75em; }
    .popup-menu .popup-menu-item:checked {
      background-color: #3a3a34;
      box-shadow: inset 0 1px 0px #2c2c28;
      font-weight: bold; }
    .popup-menu .popup-menu-item.selected {
      background-color: rgba(238, 238, 236, 0.1);
      color: yellow; }


How to change file text content only with Shell Script commands?

Expanded version of my comment:

You can use sed to edit your file. In general you need:

sed 's/STRING/REPLACEMENT/g'

In your example the following code should work for you:

With explanation:

sed -i                # the -i option allows you to read from and write to the same file
's/none luks,discard/ # the part you want to replace
\/dev\/disk\/by-label\/MON_LABEL_ICI:\/keyfile luks,keyscript=\/lib\/cryptsetup\/scripts\/passdev/g'
                     # the part you want to insert. Note, that the / characters
                     # have to be escaped with \/
 input.txt           # your input file

as one-liner without comments to copy-paste:

sed -i 's/none luks,discard/\/dev\/disk\/by-label\/MON_LABEL_ICI:\/keyfile luks,keyscript=\/lib\/cryptsetup\/scripts\/passdev/g' input.txt


I can't see the password when I enter it in Terminal wth the command "su"

but it requires the "su" command

No it does not. It needs "sudo".

  but it remains blank

What did you expect? Inputting passwords is always going to be hidden so nobody behind you can see what you insert.

Regarding the link in your question: please do NOT use installers for operating systems other than Ubuntu (or Debian). Installers for Redhat or SUSE do NOT WORK on Ubuntu.

Regarding installing Java: before the command you are suppose to use to install java you put the command sudo and when asked for a password you insert the password for your user. If you have more than 1 user make sure you use the admin account; by default that is the user Ubuntu was installed with unless you changed it afterwards.

The default repositories have a JDK. Install can be done with:

sudo apt update
sudo apt upgrade
sudo apt install default-jdk

And for latest version from oracle you could use this how-to.


dell wifi is installed but not working Ubuntu 14.04

I just formatted the whole system and installed the Ubuntu once again and it Additional driver worked and WiFi is working one again.


What does the command 'sudo sh -e ~/Downloads' do?

This is a page describing the sh command.

The sh command runs or processes jobs through the Bourne shell.
The -e flag: If not interactive, exit immediately if any untested command fails. The exit status of a command is considered to be explicitly tested if the command is used to control an if, elif, while, or until; or if the command is the left hand operand of an "&&" or "||" operator.

Also see man sh.


ChrUbuntu on external hard drive (lsblk not found)?

From the ChrUbuntu blog it seems that you can only boot from a USB stick or SD card. However I have not encountered this error. Did you type shell after opening a new console tab (ctrl-T) in Chrome? Maybe you're not in developer mode and running a developer kernel (dev channel)? Maybe you need to upgrade to the latest version of Chrome OS.


SteelSeries mouse not recognized as mouse on Ubuntu

According to this bug report, a firmware update of the mouse will fix your problems.


Changing extension of multiple files in Ubuntu 12.04

The rename command is already installed, you don't need to add anything else.

rename takes Perl code as its first argument. Most concrete use cases of renaming consist of a regexp replacement: s/REGEXP/REPLACEMENT/. To remove the existing extension, replace everything starting at the last . character.

rename 's/\.[^.]*$/.txt/' /path/to/directory/*

If your files have no extension (no . in their name), you can either use $ (which matches the end of the file name) as the regexp, or append .txt to the name.

rename '$_ = "$_.txt"'  /path/to/directory/*

This doesn't change the content of the files, it only renames them. If your data isn't in the format you want, that's a completely unrelated problem.


Firefox YouTube videos often refuse to load after a certain duration into the video

It's a Flash problem, not a Firefox problem…

I use the following workaround (this is not a solution, maybe someone else will have a better idea, but in the mean time, it'll help):

Note the time you're stuck in the video
Do a hard refresh Ctrl+F5
Play the video again and click on the time just before you had the problem.

This seems to work in 90% of all cases.  If not, I just note the time, quit Firefox, saving all tabs, wait for 3 seconds, start Firefox up again and continue again.  This brings you up to 99% of all cases solved.

Then there's always log off and log on again (99,9%) and reboot (99,99%)


Configure a container for using it with juju

The documentation for the local provider can be found here:
https://jujucharms.com/docs/2.0/clouds-manual

There are ways, that have not been fully tested, to use manual provisioning to use containers not started by juju, but this is not advised at this time.

Ignore the admin-secret, and this is actually being moved out of the environments.yaml file.  You only need it to log into the juju-gui.  Other than that it is used by the internal system.

Zookeeper is no long used with the newer versions of juju (> 1.0).

The root-dir is useful if you are using an encrypted home dir, or you just want the log files and mongo database stored elsewhere.


Should all hosts be set to network boot at all times or after they have been registered and allocated as a service, should they boot to disk?

You should leave PXE booting on at all times.  MAAS will tell the machine to local boot as appropriate depending on what state it is in.

I don't know why your agent isn't restarting between reboots, it sounds like a juju bug but I am not a juju expert (I work on MAAS).  After you do a juju bootstrap, the node installs itself and you'll see it reboot at the end of that.  You should see messages going to the console saying the agent is starting up.  That reboot is no different to you rebooting it manually later so I suspect that something went wrong during installation and the installer didn't manage to tell MAAS to turn off the "netboot" flag.  Can you see any obvious errors on the console when it installs the node during deployment?


You can also use lsof aka "List open files": https://en.wikipedia.org/wiki/Lsof


Why can't sudo find a command after I added it to PATH?

You have to add the path to the sudo path.

Run the command sudo visudo

you will see a line like this:

Defaults        secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:$

Now add the path of your command here and this should work.

For example:

$ sudo storm
sudo: storm: command not found

Now add the path as above:

$ sudo visudo

secure_path="......:/opt/storm/bin"

save and exit.

now sudo storm will just work normally.

Note You should also add the path to the default path in /etc/profile.


You can mount Google Drive on Ubuntu using ocamlfuse via Nautilus.But this does not provide syncing

GUI Sync tool:
Open source GUI tool for GDrive sync : ODrive
There is a snap package for Odrive sudo snap install odrive
Dunno if you can select a specific drive folder for sync

CLI Tool:
Open source CLI tool for clouds rsync : RClone
RClone usage for Google Drive: https://rclone.org/drive/
It can select a specific drive folder for sync


Try the option 'export to html'. From your 'root note', click the 'gears' icon, and select 'export to html. At the bottom of the dialog that opens asking you where to save the file, you get two options to tick: 'export linked notes', and 'include all other linked notes'. The first is presumably what you want. Also tick the second option if you want Tomboy to follow all the links in the linked notes (and not only those in your 'root note'). Then print from the page that opens in your web browser.

You might have to enable the 'export html' add-in from the Tomboy preferences.


Why can't Chromium suddenly access any partition except for /home?

If you do a search back you can see whatever I learnt about it in this thread https://discourse.ubuntu.com/t/call-for-testing-chromium-browser-deb-to-snap-transition/11179/ . I'll also point you to https://bugs.launchpad.net/ubuntu/+source/chromium-browser/+bug/1832711 where I filed a bug about issue accessing my NFS shares

where Olivier Tilloy (osomon) states

  If you connect the removable-media plug, you should be able to access
  files and directories mounted under /mnt and /media. That won’t
  resolve your issue with NFS shares seamlessly, but maybe you can mount
  them there?

Looking at that bug report I ran

snap connect chromium:removable-media

then I reported that drag&drop worked like it did before switch to snap.

I didn’t change my mounts as I didn’t want to, but I added a few extra mount entries in /etc/fstab to load the my shares in /mnt/ too for the directories (NFS for me) that I wanted to be able to access in chromium. After that I had no issues.

Please note as this was all done 13-June-2019, my memory is a now little faded… but what I did works for me equally well on my now Ubuntu 20.04.


Most desktop environments (generic)

xdg-open file2open.xxx

GNOME (generic)

until Xenial (16.04):

gvfs-open file2open.xxx

starting with Artful (17.10):

gio open file2open.xxx

(xxx = some file extension). With this command the default app for xxx will be invoked (for example evince if you want to open PDF).

Application-specific

Using Evince, GNOME’s default document viewer:

evince file2open.pdf

Using Okular, KDE’s default document viwer:

okular file2open.pdf


Can I drag and drop from Evince to Thunderbird?

In the options menu in the upper right of the evince window, click on the 'share' symbol (the third one in the row):

This opens an empty mail window with the pdf as attachment. From there you either write your mail or you can drag and drop the attachment from one mail window to the other.


Is there a way I can block a folder from Gnome and/or Unity search?

OK, so; I formatted my HDD again, just to start from scratch again. Here's the whole story:

After successfully installing Ubuntu 11.10 i386 on my Lenovo T400 ThinkPad;

Install dependencies (needed for Google Chrome and Gnome Shell)

sudo apt-get -f install

Install Gnome Shell

sudo apt-get install gnome-shell

Install Gnome Tweak Tool

sudo apt-get install gnome-tweak-tool

Once installed, it should show up as "Advanced Settings" in the menu.
Optional Install Gnome Contacts

Note: not included in Ubuntu, but somehow shows some contacts in DASH as search results; but won't open anything when clicked, unless you install this.

sudo apt-get install gnome-contacts

Optional Install Gnome Sushi (a MacOS X'-ish spacebar file previewer)

sudo apt-get install gnome-sushi

Here's the important part, as of now, if I dare search "hard"... I'll get a mixed bag from hardware apps to other kind of hard stuff I wouldn't want to be shown in there.

So, let's install Activity Log Manager:

Install Activity Log Manager

sudo add-apt-repository ppa:zeitgeist/ppa
sudo apt-get update
sudo apt-get install activity-log-manager

After this, I added "the folder" to the "pseudo-blacklist", and no luck. That's because this would only block it out of the Activity Log. Not Dash, and not search.

Install Activity Journal

This one is nothing but the GUI for Zeitgeist.

At this point; nothing has happened. Dash still shows whatever I'd browsed before, and whatever I browse now, will show.

Remove the "recently used" file, and turn it into a folder (right?)

rm ~/.local/share/recently-used.xbel
mkdir ~/.local/share/recently-used.xbel

After this last step; Dash won't shoe your previously browsed files, and, won't show your new browes files, plus, activity log manager won't be tracking whatever you set it to.  No more "Recently opened" section in Dash, and now the beautiful Activity Journal will actually be useful!

Done! This actually worked for me, at least has until now (just a couple of hours), hopefully, it'll stay that way. If it stops working, I suppose I'll let you know.

Apparently, Sean Houlihane was right, thanks man.


Why not simply create one VM, configured as you like and clone it. Seems like a reasonable alternative. You might also find this related post interesting.


How to program a one click indicator (add middle click functionality)?

Short answer is that you can't. Clicking on indicator icon only brings up the menu. What can be done is to set the middle (scrollwheel) click ( on touchpads that's right and left click pressed together ), which is done by setting Indicator object's secondary activate target.

Here's an example of something I use within my own launcher-list-indicator on lines 152 and 153:

152         last = self.get_last_menuitem(self.app_menu)
153         self.app.set_secondary_activate_target(last)

When user presses middle click over idicator item, it will activate the specific menu-item without bringing down the menu.

What you also can do as alternative, is to use scroll events, something like that:

86         self.app.connect("scroll-event", self.set_next)


Okay, it is working now.

Steps:

Completely remove everything that has to do with nvidia, bumblebee and dependencies.
Update to kernel 4.7.2 (Not sure if this was the key)
Installed nvidia-367 through the additional drivers interface, rebooted.
Added ppa:bumblebee/testing.
Installed bumblebee, bumblebee-nvidia, primus and prime-indicator through synaptics.
Ran sudo prime-select intel and rebooted.
Modified /etc/bumblebee/bumblebee.conf, replacing 'current' with '367', rebooted.

Now I can switch globally using prime-indicator or run a specific app using primusrun.


Unable to install Ubuntu after graphics drivers(NVIDIA) update failure in Ubuntu 16.04 Virtual machine

The following solved the problem.

Delete all the temp files (search for %temp% in Windows Menu Search Box) then empty trash bin.
Restart laptop/pc


Dual Monitor not recognized in Xubuntu 14.04

Update:

I just realized that even though our laptops are similar (E6440 vs E6430), we have different integrated video cards (yours has ATI, mine Nvidia), so my original answer is practically useless to you. However, I did have the same issue as you in that I could not get extra monitors to be recognized or configured and xrandr was not reporting anything useful.

So, that being said, I believe your issue is with your driver. I couldn't find which driver is appropriate for your card, but perhaps you will have better luck finding it.

Here is Ubuntu's list for Radeon Drivers:
https://help.ubuntu.com/community/RadeonDriver

Here is a wiki for installing ATI binaries:
https://help.ubuntu.com/community/BinaryDriverHowto/AMD

I hope that helps.

Edit: Old answer below, for reference.

I had a similar problem. I have a Dell Latitude E6430 running Ubuntu 14.04 with Gnome 3.10 and GDM.

#uninstall bumblebee and nvidia drivers
sudo apt-get purge bumblebee* nvidia*

#reinstall nvidia 331
#(the only driver that apparently works correctly with my video card)
sudo apt-get install nvidia-331 nvidia-settings nvidia-prime

#restart
sudo reboot

After rebooting, xrandr was able to detect all my display ports again and my previous settings found in ~/.config/monitors.xml were loaded automatically.

You may also consult this page for more help with further configuration:
http://xmodulo.com/install-configure-nvidia-optimus-driver-ubuntu.html


Run a program background even close the ssh connection

There are various options you have to achieve this.

append & to the command you run.
run nohup command & and then press enter
Use supervisor


I had lots of problems via upgrading ubuntu versions. I recommend you just do a clean install not an upgrade. It will do it correct.I had 12.04 and upgraded it to 12.10 but everything goes wrong. Now I just installed 13.04 and everything working fine.

Do it a try.


What is the role of /proc/fs/jbd2/sda6-8/info in Ubuntu?

According to wiki.kernel.org FAQ

/proc/fs/jbd2/partition/info file shows the average statistics from the /proc/fs/jbd2/partition/history file since the file system was first mounted.

Executing cat /proc/fs/jbd2/partition/info gives:

56 transaction, each upto 2048 blocks
average:
 0ms waiting for transaction
 57671ms running transaction
 0ms transaction was being locked
 28ms flushing data (in ordered mode)
 14ms logging transaction
 2383 handles per transaction
 6 blocks per transaction
 7 logged blocks per transaction

Also the purpose of  /proc/fs/jbd2/partition/history file  is to provide information on the behaviour of the ext4 journaling layer (JBD2).

cat /proc/fs/jbd2/partition/history gives:

R/C  tid   wait  run   lock  flush log   hndls  block inlog ctime write drop  close
R    7102  0     5000  0     1424  4     68681  5     6
R    7103  0     5000  0     1644  4     64579  9     10
R    7104  0     5000  0     856   32    38719  11    12
R    7105  0     5000  0     1052  0     47142  12    13
R    7106  0     5000  0     1172  16    56028  11    12
R    7107  0     5000  0     1416  4     71047  11    12
R    7108  0     5000  0     1640  4     81125  5     6
R    7109  0     5000  0     1616  4     77314  6     7
R    7110  0     5000  0     1640  0     76111  5     6
:
:


Unable to install Ubuntu 12.04.03 Server in VMware Workstation 10

Found the problem.

Its seeems to be related to my BIOS. I did an update of it. And then Iw as able to
perform the installation without any other issue!

Nothing else was changed! Just the Bios update!

I now have Ubuntu running in a VM.

Thanks to all.


Installing packages remotely via bash script in ubuntu

That is very odd: the error seems to be generated by firefox needing to access X functionalities (which is normal), but those export commands should be sufficient to make it work (if you have a running X session on the hosts).

The only tips I can give to you is to replace the export line like this (you should only need one):

#export DISPLAY=:0.0
export DISPLAY=:0

or try to explicitly set the display on each command:

su user1 -c 'DISPLAY=:0 firefox -no-remote -CreateProfile firefox18'


Screen shuts down when trying to install or try ubuntu?

I have the y410p, and had a similar problem. I managed to figure out that the screen brightness is defaulting to all the way down every time I reboot. I hold down Fn+Up arrow key (yours may be different) and it comes back. I haven't figured out how to fix this yet...more pressing concerns unfortunately.  Whine and popping in the speakers on battery power, etc.


GDM does not prompt for password and doesn't let me log in

In text mode edited

/etc/gdm/custom.conf

setting AutomaticLoginEnable=true

Now at least it will log in automatically


Note: Some releases of the kernel aren't capable of using zswap. See bug #1315203.

According to the kernel documentation, zswap can be enabled by setting zswap.enabled=1 at boot time. Zswap is is still an experimental technology,

  NOTE: Zswap is a new feature as of v3.11 and interacts heavily with memory
  reclaim.  This interaction has not be fully explored on the large set of
  potential configurations and workloads that exist.  For this reason, zswap
  is a work in progress and should be considered experimental.

so it would be wise to only enable it temporarily at first:

Hold down Shift at boot to enter GRUB's menu.
Edit the commands for Ubuntu to include zswap.enabled=1 at the end of the linux line.
Press F10 to boot.

If you want to enable zswap permanently, edit the GRUB configuration file to include zswap.enabled=1 at the end of the GRUB_CMDLINE_LINUX_DEFAULT entry.


How can I run the slideshow in a specified order?

gwenview:
This is probably the best image viewer available at the moment. Built for KDE4, Gwenview comes with support for virtually all image formats out there, tools to do basic editing, tree-like file browser, support for tags, thumbnail previews, cropping, image rating system, slideshow, fullscreen mode, support for plugins and two view modes (Browse and View).
Let's install and use it:
sudo apt-get install gwenview

Now select your images and right-click on and choose Open With ► Gwenview

When the Gwenview GUI opens, select  Sort By ► Date under the View menu

Now your added images are sorted by date, just go to the View menu and select Start Slideshow
Don't forget: before Start Slideshow you should select all added images in the Gwenview window to select to show in Slide show mode. cool!
Also here are a lot of Ubuntu Photo Slide Show applications.


Will Ubuntu 14.04 release security updates for openssl 1.0.1 even after 31st December 2016 or will they move to openssl 1.0.2

The answer to your question appears to be that security updates will be released (backported) as needed through the duration of Trusty LTS support.  There are currently no plans to release  openssl 1.0.2 for Trusty. According to the posts here only security patches will be released for 1.01 after 2016-12-31. It seems the latest source available is 1.0.1e available here

Why?

Marc Deslauriers (Ubuntu Security Engineer) states:
"Ubuntu doesn't typically update to newer software versions. Like most other Linux distros, we backport security patches to the versions of software we ship, whether or not there is still upstream support for it."

So the commitment to security is there.

If you feel the need to upgrade regardless you can obtain the source on this page and compile it yourself. Installation instructions are included in the archive but it's pretty straight forward even if you've never compiled code before.

Note that I'm not recommending this as a course of action, I'm simply attempting to be thorough in covering the possibilities.

  $ ./config
  $ make
  $ make test
  $ make install

Sources:

https://www.openssl.org/source/

Installation instructions included in https://www.openssl.org/source/openssl-1.0.2j.tar.gz

As an alternative you could upgrade to xenial (16.04) which has version 1.0.2g already available or as Seth Arnold (Member Ubuntu Security Team) states here

"16.04 LTS's openssl package is based on a 1.0.2g starting point. If running 16.04 LTS is not an option then perhaps the backportpackage command from the ubuntu-dev-tools package could help you."


I found the problem , Download the latest version of Gradle. Gradle on Ubuntu's repo can't be used to build openjfx8. However the following link can be helpful to build Openjfx.

https://github.com/hgomez/obuildfactory/wiki/How-to-build-and-package-OpenJDK-8-with-OpenJFX-on-Linux

Thanks to H.Gomez for Obuildfacory     :) .....


Windows 7/Ubuntu 12 dual boot deleted for Windows 8 installation. How to make grub rescue go away?

If you have your Windows 8 disc, you can get to the recovery options and access a command prompt by inserting the disc and booting from it. Refer to your motherboard manual for steps to change the boot order of your hardware from within the BIOS so your CD/DVD drive boots first.
Once you have chosen to repair Windows with your installation disc, open a command prompt and type the following commands:

bcdedit /export C:\BCD_Backup
C:
cd boot
attrib bcd -s -h -r
ren C:\boot\bcd bcd.old
bootrec /RebuildBcd

Another Method

If that does not work, try these in this order:
bcdedit /export C:\BCD_Backup
C:
cd boot
attrib bcd -s -h -r
ren C:\boot\bcd bcd.old
bootrec /FixMbr
bootrec /FixBoot
bootrec /RebuildBcd

I have had success myself with these steps in the same situation. Best of luck!
( For an image tutorial of the above, please see http://www.sysnative.com/forums/showthread.php/3894-Manually-Fix-the-Boot-Configuration-%28Windows-7-Vista%29 )
-Mike


Perhaps the user account is not added to the www-data group.
Verify that the user account is in the www-data group by running the following command:

groups USER

(where USER is the username of the account) and checking if www-data is in the list of groups returned.

If not, add the user to the www-data group by:

sudo usermod -a -G www-data  USER

and verify again.

Reference: Add a User to Group www-data


There is no default LD_PRELOAD variable, or, in other words, it is empty. You can revert to that state by typing

unset LD_PRELOAD

LD_PRELOAD is not to specify the libraries found in the regular case; it is just here to specify an order of library loading that is different from the regular one (determined by ldconfig(8)).


First, I recommend that you establish a baseline for signal strength. Please run the terminal command:

nmcli dev wifi list

Please take note of the Signal reading for your router. Now let's try a driver parameter:

sudo modprobe -r 8821ce
sudo modprobe 8821ce rtw_ant_num=1
nmcli dev wifi list

Is there any improvement in the signal? If not, try:

sudo modprobe -r 8821ce
sudo modprobe 8821ce rtw_ant_num=2
nmcli dev wifi list

I suspect that one of these settings will result in a noticeable improvement. Make the driver parameter permanent:

sudo -i
echo "options 8821ce rtw_ant_num=X"  >  /etc/modprobe.d/8821ce.conf
exit

...where X is the setting that you find offers the greatest improvement.


How to completely remove Ubuntu 12.04 LTS from a windows 7 dualboot?

You have to remove grub using this post.

After it you will be able to boot only windows
Delete Ubuntu partition by right click on my computer . choose Manage > disk management > select Ubuntu partition > delete using right click.


Ubuntu 14.04 completely freezing after logging in when 2 monitors plugged in

Try pressing Ctrl+Alt+F2 straight from your login screen, logging into your user, and typing

sudo chown -R user:user .

replacing user with your username.  It could be that there are some configuration files which have been accidentally taken over by your root user.  If this fails, try creating a new user and see if you can log into the desktop with the new user.


Are features like Trim for SSD's Included for 16.04?

Yes, TRIM is now supported in the kernel and through daemons in Ubuntu. No need to worry. You can read more and check for yourself here: How to enable TRIM?


I had exactly the same problem. The solution was quite simple. Install the driver for my video card Gforce 9600GT.


Grub not defaulting to latest kernel in 12.10

OK, the newest kernel (v23) was installed today and everything has now suddenly reverted to normal i.e. the latest kernel is found by default.

So, not quite sure what caused the previous blip - never experienced that before and my PC config hasn't changed for several years - but it seems to have resolved itself before I got around to trying to find grub on my data disk and moving it.

One quick question though... Popey mentioned that he thought the 12.10 grub list just showed "Ubuntu" rather than the kernel version. Mine definitely still shows version numbers the same as always. Is that a problem?


My ethernet is not been detected in Ubuntu 12.04

Yep... you need a driver. The best plan is to get the driver on your windows machine, then boot to linux and compile it. You can follow the steps found in this guide at the Ubuntu Forums:

Download the driver and expand it into a new directory. cd to the
top directory in the expanded directory.
sudo make clean modules
sudo make install
Verify that a new file named r8168.ko exists in the directory
/lib/modules/3.2.0-24-generic/kernel/drivers/net/ethernet/realtek/.
blacklist r8169.
Edit /etc/initramfs-tools/modules and add a line with "r8168" in it.
sudo depmod -a
sudo update-initramfs -v -u -k  uname -r
Reboot


I usually do it using the setting panel: Setting>Displays like you can see here


Does Ubuntu desktop enable remote SSH access by default

No, all services are "opt in". You need set ssh up before you can use it. And that would be to install a server version for ssh. When you install the server though you "opt in" by default.

  How do I check the status of SSH access in mys system?

16.04 with systemd: systemctl status sshd. In case your system uses upstart, check in this file exists: /etc/init/ssh.conf.

  How can I disable the access?

You can always purge the ssh package when it is installed. If enabled stopping and disable-ing the service is possible too.

systemctl disable sshd

In case your system uses upstart: sudo mv /etc/init/ssh.conf /etc/init/ssh.conf.disabled


Set a scheduled time for software updates

Edit the systemd timers for apt

There are three settings to change:

/lib/systemd/system/apt-daily.timer

This provides your daily apt update, refreshing the package database.
Change this section:

 [Timer]
 OnCalendar=*-*-* 6,18:00   // Try *-*-* 02:17 for nightly at 0217 (2:17 am)
 RandomizedDelaySec=12h     // Delete this line - you don't want delay
 Persistent=true            // Keep this line

/lib/systemd/system/apt-daily-upgrade.timer

This provides your daily Unattended Upgrades, installing security upgrades. The previous job MUST run first - calculating the upgrade requires reading the package database. Change this section:

 [Timer]
 OnCalendar=*-*-* 06:00     // Try *-*-* 03:17 for nightly at 0317 (3:17 am)
 RandomizedDelaySec=60m     // Delete this line - you don't want random delay
 Persistent=true            // Keep this line

/etc/cron.daily/apt-compat

This job adds additional randomness to apt. The purpose is to avoid overloading mirrors by distributing job across time randomly. You accomplished the spirit of this goal by setting the other apt jobs to an unusual time (like 17 minutes past the hour).Change this section:

 # delay the job execution by a random amount of time
 random_sleep               // Comment out this line by adding a '#' in front.


Cambria appears only in italics in LibreOffice

From http://www.webupd8.org/2013/07/how-to-download-and-install-windows-81.html

  If you need the Cambria (regular) font, you'll need to convert it to
  TTF because the font is available as a TrueType Collection (TTC) and
  unless you convert it, you won't be able to use it in LibreOffice for
  instance. To convert it to TTF, you need to install FontForge:

sudo apt-get install fontforge

  And then, open a terminal and run the following command (the commands
  below assume you've followed our exact instructions and extracted the
  fonts under ~/sources/fonts):

cd ~/sources/fonts/
fontforge -lang=ff -c 'Open("cambria.ttc(Cambria)"); Generate("cambria.ttf");Close();Open("cambria.ttc(Cambria Math)"); Generate("cambria-math.ttf");Close();'


Just run the Python interpreter of the version you want, with pip as module to execute, like:

python3.6 -m pip install some_package

That way you can be 100% sure the interpreter you launch your scripts with is the same as for which you manage pip packages. No system modifications necessary.

The pip executable is not exactly defined to be any fixed version anyway, whatever updates next would likely override it again. Plus it sometimes breaks for other reasons like version incompatibilities anyway. I'd usually not use it directly at all, except maybe for when you're in a venv (Python virtual environment) where it's exactly defined what it is.


How to avoid duplicate entries in .bash_history

From the bash man page:

  HISTCONTROL

    A colon-separated list of values controlling how commands  are  saved  on
    the  history  list.   If  the  list of values includes ignorespace, lines
    which begin with a space character are not saved in the history list.   A
    value  of  ignoredups causes lines matching the previous history entry to
    not be saved.  A value of ignoreboth is  shorthand  for  ignorespace  and
    ignoredups.   A value of erasedups causes all previous lines matching the
    current line to be removed from the history  list  before  that  line  is
    saved.   Any  value  not in the above list is ignored.  If HISTCONTROL is
    unset, or does not include a valid value, all lines  read  by  the  shell
    parser are saved on the history list, subject to the value of HISTIGNORE.
    The second and subsequent lines of a multi-line compound command are  not
    tested,  and are added to the history regardless of the value of HISTCONTROL.

So put the following line in your ~/.bashrc:

export HISTCONTROL=ignoreboth:erasedups


How to get native notifications on chrome?

Well it's already available nativly without installing any additional applications. If you have the latest dev channel of Google Chrome browser. If you don't want to install Dev channel then all you need to do is wait until it comes to Google Chrome stable.

How to enable it in Chrome Dev?

chrome://flags/#enable-native-notifications

Go to this URL and enable the flag by toggling it Enabled. And restart the browser.

And then notifications should technically work! It works as expected on Gnome but Unity seems to have a problem with it!

Can't complaint as its feature from Dev channel of Google Chrome.

Download Chrome Dev

Related Article


Changing WiFi MAC address on Raspberry Pi 4 Model B with Ubuntu 20.04.2 LTS

I gave up on utilising netplan and I decided to directly configure systemd-networkd renderer. Here is the solution.
vi /etc/systemd/network/00-default.link

[Match]
MACAddress=original MAC

[Link]
MACAddress=spoofed MAC
NamePolicy=kernel database onboard slot path


This is intentionally the default behaviour: allowing you to minimise ("close") Rhythmbox and control it from the Sound menu.

To work around this you need to "quit" Rhythmbox by selecting File->Quit in the menu, or using the keyboard shortcut Ctrl+Q.

Related Question:

Is there a plugin for Rhythmbox to exit on close?


Ubuntu 16.04 Remmina connect to Mac with different display resolution

Have you tried the left-most button in the Remmina interface? When you hover your mouse over it, it says "Resize the window to fit in remote resolution". I'd love to show you a screenshot of it, but I don't have the reputation to add images. :P I have Remmina v1.1.2 and it works fine when accessing a Mac.


First and foremost
You have to make sure your EUFI is disabled at the BIOS. The EUFI stands for Unified Extensible Firmware Interface. To do that visit this link
Second thing to do
Download grub repair and run it and follow the on-screen instructions.
To do that visit this link
On the final note
You need to restart your system for changes to take effect.


How do I resize the Xfce 4 panel on Xubuntu?

Right click on the panel.
Go to

Panel → Panel preferences
Go to tab Display.
In the section Measurements tweak Row Size (pixels).


running gnome-terminal with no window border on startup in xubuntu 12.10

You can do that stuff with devilspie. Install the devilspie package, and write the following configfile (save as ~/.devilspie/gnome-terminal.ds)

(if (is (window_role) "borderless")
  (begin
    (geometry "+0+0")
    (maximize_vertically)
    (undecorate)
  )
)

Now you just run devilspie when you log in (e.g. by adding it to startup applications), then whenever a window with the role "borderless" appears, it will be moved to position (0,0), maximized vertically, and decorations removed.

You specify the role of gnome-terminal with the --role option.

gnome-terminal --role=borderless


How to use theming in QML for Ubuntu Phone

Unfortunately the documentation does not explain how applications should be themed, especially that this part is not fully implemented. However applications can still load theme files where they alter the system defined styles and specify their own ones.

There is no specific rule where to put the application-specific theme file yet. However, it should be in a place the application knows and can access. The theme can be loaded using the Theme.loadTheme(url) function, where url is the URL/URI to the .qmltheme file. For example, assuming the theme file is in the "theme" folder relative to the application's folder, you should have Theme.loadTheme(Qt.resolvedUrl("./theme/mytheme.qmltheme"))
I'm not sure I understand what you meant on "reference" in here. Do you refer to how a styled component will know which style to use, or you refer to how the QML-elements providing the visuals will be linked to the styled component?


there is nothing special about installing Android Studio in Ubuntu, installing Android Studio is straight forward.

first, you need JRE installed, you can install JRE by following command:

$ sudo apt-get install openjdk-8-jre

and then just download zip file of Android Studio and then extract it where ever you wanted to install it.

and then run this command while staying inside extracted folder:

$ ./bin/studio.sh

To uninstall, just delete installation folder and .android folder OR you can look at this long answer: Install and Uninstall with Screenshot and Full Details

$ sudo rm .android

It is just simple.

Thanks.


Use the gnome-tweak-tool to change your GTK3 theme.

Download from https://launchpad.net/~gnome3-team/+archive/gnome3/+sourcepub/1775469/+listing-archive-extra


OP posted:

  I tried to manually start Tor (by typing /usr/sbin/tor in the terminal) and afterwards Vidalia and it works perfectly.

From the documentation of Vidalia:

  I Can't Start Tor

  The most likely reason that Vidalia could not start Tor is because
  Vidalia is looking for your Tor installation in the wrong directory.
  You can tell Vidalia where Tor is located by updating the Tor
  Executable option in the general configuration settings.   Another
  possible reason that Tor cannot start is because there is already
  another Tor process running. Check your list of running process and
  stop the previous Tor process, if you find one. Then, try running Tor
  again.

  If that did not help, check your message log to see if Tor printed any
  information about errors it encountered while trying to start.

  Vidalia Can't Connect to Tor

  Vidalia manages Tor by communicating with it via Tor's control port.

  The most common reason that Vidalia cannot connect to Tor is because
  Tor started, but encountered an error and exited immediately. You
  should check your message log to see if Tor reported any errors while
  it started.

  If Tor is listening on a different port than Vidalia expects, Vidalia
  will be unable to connect to Tor. You rarely need to change this
  setting, but if there is another service running on your machine that
  conflicts with Tor's control port, you will need to specify a
  different port. You can change this setting in Vidalia's advanced
  configuration settings.

  Tor Exited Unexpectedly

  If Tor exits immediately after trying to start, you most likely have
  another Tor process already running. Check the message log to see if
  any of the last few messages in the list are highlighted in yellow and
  contain a message similar to the following:

connection_create_listener(): Could not bind to 127.0.0.1:9050: Address already in use.
Is Tor already running?

  If you find an error message like the one above, you will need to stop
  the other Tor process before starting a new one with Vidalia. On
  Windows, you would need to look for tor.exe in your Task Manager. On
  most other operating systems, the ps command can help you find the
  other Tor process.

  If Tor had been running successfully for awhile (that is, longer than
  a few seconds), then you should check the message log for information
  about any errors Tor experienced before it exited. Such errors will be
  highlighted in either red or yellow.


Ubuntu itself does not provide any specific version of the operating system dedicated to a specific laptop's "brand".

The ones which come with a laptop are mostly same ISO that Ubuntu provides or a tweaked one by the laptop manufacture.

You can have access to all available ISOs from here.


How can I replace pcmanfm with dolphin in Lubuntu 18:04?

As you discovered, it's easy to swap applications. Unfortunately, you also discovered that it doesn't mean that applications have parity.
With LXDE and LXQt, as odd as this might seem, the file manager is responsible for managing the desktop. Not so with Dolphin, where KDE's Plasma does more of the heavy lifting (and ultimately kind of ties together all the separate pieces of their desktop environment in integrated ways, for better or for worse). So if you use any other file manager, you're going to consider how to deal with the desktop, if that's important to you. Some can still handle it (e.g. Nautilus), some have separate solutions (e.g. XFCE's Thunar has a separate xfdesktop package), and there are some separate packages that can handle it on their own (e.g. idesk).
You may want to try Lubuntu 20.04, which uses LXQt, which is vastly improved over LXDE in terms of functionality. I don't think it will get you the console integration you're looking for (which, in Dolphin, is via KParts, something exclusive to KDE), since it seems like discussion of the subject ultimately decided against it, but it at least uses the same GUI toolkit. LXQt is also way more responsive to bugs and feature requests.


Remove or hide magazines from the Software Center

There is no way to remove the Magazines from searches I'm afraid.  And the reason why you will see them so often is they make use of he keyword search system that USC offers developers.  Magazines cover a lot of subjects.


How can I get chromium-browser to run fullscreen (not kiosk) in 12.04?

For people finding this now, you can start Chromium fullscreen from the command line by executing:

chromium-browser --app=http://example.com --start-fullscreen

Tested on Ubuntu 14.04 LTS


Unable to locate GNOME Shell settings or version. Make sure it is installed and running

I also faced this problem after customizing my desktop many time I tried to solve it  and i got it.
The problem comes from desktop customization when you download lightdm from gdk3 it will change your gnome setting and stop it from your PC/Laptop.
The solution is:

just update your laptop: sudo apt-get update
logout from top-right corner.
Then clik on setting icon below of user login.
then Select on gnome/gnome-clasic/ubuntu/  (whatever option you want to select)
then enter the password and login
optional --> remove unwanted application which you have installed to solve this problem.

thanks if you facing problem then comment here.


Segfaults and "Read-only filesystem" after a dist-upgrade

For anyone stumbling across this question, it seems the underlying problem was I'd run out of disk space part way through a kernel update, so the initrd image file hadn't been created.  So as soon as I tried restarting, all I got was a kernel panic error.

To fix:

Burned a copy of Xubuntu to a USB
Booted to the USB and chose the "Try Xubuntu" option
Opened terminal - found something I didn't need and deleted it (in my case, I had 3GB of Docker files sat in /var/lib/docker that were easily replaceable
cd into /boot and make a note of the last working Kernel (for me, it was 3.13.0.43)
Restarted - selected Advanced Boot Options (or whatever) at the GRUB menu and selected the kernel above
System boots as normal (yay!) - ran sudo apt-get update && sudo apt-get upgrade
Let Ubuntu do it's thing
Reboot again as normal
Fixed!

There may have been something on screen about having to run a dpkg command before I could upgrade, because of the previous botched update - I'm quoting a lot of this from memory.  Either way, I recall just running exactly what it told me to and all was good.

So yeah. Moral of the story - don't underestimate how big you may need your / partition to be, and keep an eye on disk space!


UBUNTU 16.04 Server, How to Setup exim4 to reject dangerous files

Exim is a low level mail transport agent, it's not designed to look at the content of messages. If you google 'ubuntu exim4 spamassassin clamav' you can find out how to install the type of filters you need to achieve this.


How can I force a format of an external HDD that Gparted and Disk Utility can't see?

GParted or KDE Partition Manager require an unmounted drive to operate.  Given your system is detecting the drive, but refusing to mount it, you should be able to select Device, New Partition Table after selecting the correct device in either partition manager and clear everything up in about one minute, plus the time it takes to create the new filesystem.


How to change the address bar back to tabs from input text in nautilus?


Try from a terminal: sudo apt-get install ubuntuone-installer ubuntuone-control-panel-gtk

Make sure you have the "universe" repository check in "Software Sources"

As noted in my comments, you probably want this though:

sudo apt-get install ubuntuone-client-gnome


Rocket League thinks controller is plugged in. There isn't one

the default steamos-xpad-dkms controller driver that comes installed on ubuntu and its official flavours can cause problems. I recommend following the instructions listed in the first answer of this thread to blacklist the old steamos controller driver.


How to change all file associations (MIME-types) of one particular application in KDE?

FreeOffice sets its file associations in ~/.config/mimeapps.list (also in /usr/share/applications/defaults.list but they get overriden by ~/.config/mimeapps.list).

You can use the following sed command to replace the FreeOffice entries with the respective LibreOffice ones in ~/.config/mimeapps.list:

sed -i -e 's/textmaker-free18/libreoffice-writer/g' -e 's/planmaker-free18/libreoffice-calc/g' -e 's/presentations-free18/libreoffice-impress/g' ~/.config/mimeapps.list

The above apply to all Ubuntu desktop environments, not only KDE.

Edit

In OP's case ~/.config/mimeapps.list does not override /usr/share/applications/defaults.list. In this case one has to run the same sed command for the /usr/share/applications/defaults.list file:

sed -i -e 's/textmaker-free18/libreoffice-writer/g' -e 's/planmaker-free18/libreoffice-calc/g' -e 's/presentations-free18/libreoffice-impress/g' /usr/share/applications/defaults.list


How to set hibernate/shutdown timers? XFCE power manager not having an effect in Lubuntu

Try turning off Light Locker. You can find it in Preferences > Light Locker Settings. Turn the "Enable light-locker" to Off. This may be what is turning off your screen after 10-15 minutes.

Are you using a laptop or desktop? If you are using a laptop, please note that there are different settings for battery power or plugged-in.

Also make sure in the "Display" section of Xfce Power Manager you have the Screen set to blank never.

I do not believe you can set the computer to shutdown after a period of inactivity using Xfce Power Manager.

I can recommend a way to schedule shutdown for a certain time everyday:

For a one-time shutdown, go into the terminal (press CTRL + Alt + T or open Accessories > LXTerminal) and enter this command:

sudo shutdown -h 03:30

(Replace 03:30 with your desired time in 24:00 format)

If you would want your computer to turn off at a certain time every day, you could enter this command in LXTerminal (press CTRL + Alt + T or open Accessories > LXTerminal):

sudo crontab -e

Which might say it is creating a file and might offer the choice of text editor. (If you get to choose, I'd recommend "nano").

In nano, press the down button to go to the last line in the document and enter this line:

30 3 * * * poweroff

Replace 3 with the hour and 30 with the # of minutes past the hour you would like the system to shut down. (Note: The spacing between the numbers, asterisks, and command is important here.)

Once you've entered this command, press (CTRL + X) to exit nano, and enter Y to save the new file.

Please let me know if you have questions or would like some clarification.


I've recently gone through this process on a Sony Vaio T13 preloaded with Windows 8, in short I cheated and installed Ubuntu on a virtual machine (VirtualBox) which was a straightforward process detailed description here.


The Gnome Classic in 11.10 is Gnome Panel 3. It has been ported to GTK 3, so there's no reason not to support it. The question of development is mostly a question of popularity. Gnome Panel 2 have been very popular, but I'm not entirely sure that's because of the panels themselves, but because of the large number of available applets that is available for it. From a users perspective, these were quite nice, but from a developers perspective, the technology they were based on, are horribly outdated. So the question remains if anyone is going to actually port them to the new platform. If that happens, then I think Gnome Panel 3 can have a good future, but it requires quite a bit of effort and somebody has to do the work.

Because of this, I am a little bit sceptical that it will "take off". It seems more likely to me that people who want a similar environment to Gnome 2 will move on to Xfce, which already has a community and some momentum. I don't think Gnome referring to it as a fallback helps create enthusiasm to rebuild the Gnome 2 experience on Gnome 3.

But this is pure speculation. It's impossible to tell how this will unfold.


Very strange, probably is an old Firefox bug already noted on Bugzilla's Bug 629312.
The solution might be to set the Firefox gfx.color_management.mode option in about:config to 0.This may solve the problem in your computer but not - obviously - in other machines: to mitigate the problem on remote machines use Web Safest Colors or Web Safe Colors.
For the images, you can use GIMP to change the colour's hue; there is also a web safe image mode in Image -> Mode -> Indexed... that may solve the problem for some images (it's ugly but works).
Please note that using only those safe colors will enhance the accesibility of your website, it's always a good practice; you'll need an extra bit of patience, the world is full of software bugs.
Comment under here if you need more help and don't forget to press the up arrow if I'm of any help.
Have a nice evening.


How to find/install build dependencies for building GStreamer plugins?

Since you try to compile a package from source that's also in Ubuntu, you can try this:

sudo apt-get builddep gst-plugins-bad-multiverse0.10

However, this does not guarantee that you will get the right versions of the dependencies in older Ubuntu releases.


"grep GetConnection() CustomerRepository.cs"
is right to complain, as "(" is specially interpreted by the shell and doesn't make sense the way you use it.
Escaping "(" as "(" and ")" as ")" is a good thing to do, but putting the whole argument into quotes would be even better:
grep 'GetConnection()' CustomerRepository.cs

As for your second try,
sed -e 's/GetConnection()/GetConnection(_connectionString)/' CustomerRepository.cs

sed replaces each line according to your command, and puts out every line not regarding if your substitution toke place or not.


I just tried, and was able to boot the Ubuntu desktop 16.04 AMD64 image, written to a USB flash drive, with Secure Boot active on an HP EliteDesk computer. Thus, I can say with some certainty that this image is properly signed for Secure Boot. Several possible causes of your problem spring to mind, some of which you could correct but others you could not:

Image CPU type -- Check that you're using the correct image file, and in particular, that it's for the correct CPU type, which should be AMD64 for the vast majority of computers. (AFAIK, i386 images never supported Secure Boot "out of the box.")
Image damage -- Use the md5sum utility to verify the integrity of your download. (See here for more on how to do this.)
Improper image preparation -- Some tools, such as YUMI/Pen Drive Linux, create USB flash drives that can be booted in BIOS/CSM/legacy mode but not in EFI/UEFI mode. If you used such a tool, your disk might not be bootable in EFI mode. This isn't a Secure Boot issue per se, but you might be mistaking it for one. Try using Rufus, UNetbootin, or dd instead. In fact, even if you used one of these tools, switching to another one might be necessary, since there can be system-to-system quirks and incompatibilities.
Computer boot manager issues -- You might be unable to access your computer's built-in boot manager, or you might be selecting the wrong option in the boot manager. For instance, many EFIs present two options for removable media, one of which boots in BIOS/CSM/legacy mode and the other of which boots in EFI/UEFI mode. If you select the former, the disk might not boot if Secure Boot is active; you must select the option that includes the string "UEFI."
Non-Secure-Boot regression -- You could be seeing a problem that's unrelated to Secure Boot, such as a new kernel bug. Filing a bug report would be in order in this case, but you'll need to track down the problem with more precision first.
New Shim or GRUB bug -- Finally, you might have encountered a new bug with the Shim or GRUB package. If you're convinced this is what happened, you should file a bug report. You might be able to work around it temporarily by swapping out the EFI/BOOT/bootx64.efi file from the 16.04 image with the same file from the 14.04 image; however, before you do this, you should back up your working /boot/efi/ directory tree from your 14.04 installation, since the installation is likely to replace your working shimx64.efi binary with a non-working one. (bootx64.efi and shimx64.efi are the same file; they're just named differently on the installation image vs. an installation to disk.)

It would also be helpful if you describe in more detail what you're doing and what's not working. You claim that the image is not signed, and I'm working under the assumption that this is because you've tried to boot it and can't get it to boot, but even with that assumption, there are details that could be important, such as any error messages you might be seeing. If there's any evidence that GRUB has launched, then that would tend to support a post-GRUB problem. Thus, describing exactly what's happening is important to better diagnose the problem. (If necessary, take a video, post it to YouTube, and post a link to it here.)


How do I set up an Ubuntu virtual machine inside Ubuntu?

You can run an Ubuntu virtual machine inside an Ubuntu host.

You can use these:

Oracle Virtualbox

which is available in software center and

Vmware Workstation

which you should download the bundle and install it yourself.

Note: VirtualBox is free, while VMWare Workstation is paid.

if any other question please ask..


Is it better to install software through software center or compile it myself?

Manual compilation
pros:

if you are developer, you can change anything you want and implement new features in the software

cons:

You shold be developer, that's not easy.
And you should well understand alien code and know programming languages
And you should track your software manually

Command line
pros:

more informative installation process
shows errors in the case if they appear. You can simply copy them and search solution in the Internet.
possible to manually remove locks

cons:

you should know the exact name of the package
you should type commands and know what are you doing
you should track self-compiled packages manually

GUI
pros:

You have a big choice of available packages
Easy to learn
Shows a lot of information about packages
Handles all packages automatically

cons:

progress is less informative
in case of errors you should do a screenshot and optionally edit it in graphic editor before posting to forums.
if some installation left lock inside directories /var/lib/apt/lists, /var/lib/dpkg, /var/cache/apt/archives you should use Terminal
some software is not accessible and you should search for it in the Internet


User rights for non admin users on ext4 data partition

The answer to this is to set the sticky bit (t) of your directories.

You set the sticky bit recursively on your data directory by:

sudo chmod -R +t /media/data

This restricts the right to delete or rename a file only to the owner of a file, although the directory might be publicly readable and writeable.

The permissions string will after that look like e.g. rwxrwxrwt if the owner user, group and every other user all have full permissions (read, write, execute), whereas only each specific file's owner may delete or rename it.


How can I change what time Deja Dup does its backup?

That feature is on the wishlist, for now you can try setting the schedule to monthly in the preferences and setup your own schedule using crontab and deja-dup --backup.


update firefox to firefoxx 57 on ubuntu 16.04 LTS

i found a solution

i visited mozilla website and downloaded the latest version of firefox

extracted the .tar.bz2

typed this command in terminal sudo apt-get remove firefox

runned the firefox executable

and this solved the problem :)


how to change the value of system files without opening them?

It's perfectly possible to do it with sed, match for the line and change the value:

sed -i '/^PermitRootLogin/s/yes/no/' /etc/ssh/sshd_config

^PermitRootLogin matches the line starting with PermitRootLogin
s/yes/no changes the value of the option from "yes" to "no"


US international keyboard with dead keys (Ubuntu 18.04)

I used 'international with AltGr dead keys' or something like that in 16.04. I could keep the right Alt key depressed to add an accent to just a single letter, and have , ' and " work normally otherwise.

In 18.04 it seems hidden. In "Region & Language" I selected a US keyboard first, and then I could add the "English (intl. with AltGr dead keys)" - after which I could remove the plain US keyboard.

Note that I also moved from IBus to XIM method (it's under Manage Installed Languages - ???) while I did that - no idea if that helped with this change, but I could change it back to IBus anyway.


Application menu missing on menu bar / windows title bar after upgrade to 16.04

After some digging around I found this thread describing the same issue (but for 14.04).

The solution is simply:

sudo apt-get install indicator-appmenu

Don't ask me why it was missing..


Open the Dash and search for system monitor. Go to process tab and see which process is taking up CPU/Memory (by clicking on CPU/Memory tabs). If its taking high cpu/memory for long period, kill it and check if system is fine. Mostly its because of some rogue process
Do you have any graphics card ?


Ubuntu-Core Snappy ssl-certificate error

You will need to check the time on the system. Most probably your Rasp is issuing the wrong time to the OS and the Certs become void. Issue the    date    command and check the time. If it is wrong issue

 sudo date new_date_time_string

where new_date_time_string has to follow the format MMDDhhmmyyyy.ss which is described below:

MM is a two digit month, between 01 to 12
DD is a two digit day, between 01 and 31, with the regular rules for days according to month and year applying
hh is two digit hour, using the 24-hour period so it is between 00 and 23
mm is two digit minute, between 00 and 59
yyyy is the year; it can be two digit or four digit
ss is two digit seconds. Notice the period . before the ss

With the proper time in place. It should most probably solve the issue.

Source: What is the command line statement for changing the System clock? && I ran into the same problem with my Beaglebone


No application in unity dash after upgrade packages in ubuntu 13.10

To fix this issue, you can probably just run sudo dpkg-reconfigure -A. Your problem is likely that your Dash configuration wasn't updated properly, so it cannot see any apps. Running the command will reconfigure Ubuntu, so any problems with your configuration files will be flushed out there.


The php-pear package is in the official Ubuntu archive.


If you don't have any apache2 configuration that you need, Try to resolve this by removing all apache2 files and configuration and install a new default configuration.

Try the following command to uninstall and remove configuration files.

(You need to stop the apache service before you uninstall):

sudo apt-get purge apache2*

And install it again by typing:

apt-get install apache2


There is an alternative to launchpad for a deb repository?

A repository is just series of directories. It's commonly on a web server (over http) but it doesn't have to be. The full process of doing this is long:

Create and upload a GPG signing key
Build and sign your packages
Set up a web server to host these things
Use something like Dak or Reprepro to set up the directory structure and export that to the webserver.

The result is a real repository that you control. The difference from a LP repo is there's no shortcut for adding your signing key to the client computers. You'll have to get them to use the old-fashioned method:

wget -q http://path/to/key.asc -O- | sudo apt-key add -

And then add the repo (add-apt-repository can add http://... addresses).

And even after that, you need to guarantee uptime. If you can't keep the repo up you're going to cause 404 warnings on clients' machines. Nobody likes that.

Debian has the best documentation on how to do this:

https://wiki.debian.org/HowToSetupADebianRepository
https://wiki.debian.org/SettingUpSignedAptRepositoryWithReprepro


Auto mounting shared folders with VirtualBox

I just had a similar thing in KVM with a shared folder as 9p file system.

The solution if you can't use an /etc/fstab entry is to edit the guest OS' /etc/rc.local and insert your personal mount command (without sudo!) before the exit 0 line.

The file would then normally look like this:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

mount -t vboxsf src /home/patrick/src

exit 0

Make sure you edit the file as root (e.g. with sudo nano or gksudo gedit).


how to activate touchpad in portege r200

Are you sure that touchpad is turned on? Go to "System Setting"(search in dash)>"Mouse and Touchpad". From there you can active touchpad if it's disable.


Usb devices stop working as soon as applications access powered usb webcam

Dock
HP Elite Thunderbolt 3 65W Dock
We updated the dock firmware using the updaters found here.
BIOS
HP Z-Book 15 G3
You have BIOS version "N81 Ver. 01.16", dated Jun 18, 2017... N81 is the family ROM code.
There's a newer BIOS available, version 01.52 Rev.A, dated Nov 1, 2020, and can be downloaded here.
Note: Select Windows OS to see the BIOS update.
Note: Confirm that I have the correct web page for your model #.
Note: Have good backups before updating the BIOS.


Why am I unable to create a shared folder?

A good way to share a folder between two linux computers is to make one of them an SSH server. You can make the Ubuntu computer an SSH server by installing openssh-server.

sudo apt install openssh-server

Then you can connect remotely from the other computer via the simple command line tool ssh to log in an run remotely or sftp to transfer files.

ssh user@IP-adress

or to be able to run GUI application programs remotely

ssh - X user@IP-adress

or transfer files

sftp user@IP-adress

for example

ssh sudodus@192.168.0.2

You can use GUI tools, for example the file browser Nautilus or the dedicated tool Filezilla with the text

ssh://user@IP-adress

for example

ssh://sudodus@192.168.0.2

in the box for location of the directory you want to see. You can save it as a bookmark, and manage the remote directory seamlessly.

If you have a Windows computer, you can install Filezilla for Windows or WinSCP and connect to the remote directory in the same way.

If you are working locally in your own local network behind a firewall you can do it with password authentication, but using keys increases the security if the system is accessed via the internet or if other people have access to the local network. It is also more convenient to use keys because you need not type the password to get access.

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

https://help.ubuntu.com/lts/serverguide/openssh-server.html


Xubuntu Xenial 16.04.3 LTS Completely Freezes when I start Virtualbox 5.0.40_Ubuntu r115130

I have the same issue with the latest kernel available: 4.13.0-36.
So I have reverted to using the latest kernel that works without any issues: 4.11.0-14

$ aptitude search 4.11.0-14 | grep ^i
i A linux-headers-4.11.0-14         - Header files related to Linux kernel versi
i   linux-headers-4.11.0-14-generic - Linux kernel headers for version 4.11.0 on
iBA linux-hwe-edge-tools-4.11.0-14  - Linux kernel version specific tools for ve
i   linux-image-4.11.0-14-generic   - Linux kernel image for version 4.11.0 on 6
i   linux-image-extra-4.11.0-14-gen - Linux kernel extra modules for version 4.1
i   linux-signed-image-4.11.0-14-ge - Signed kernel image generic
i   linux-tools-4.11.0-14-generic   - Linux kernel version specific tools for ve

I let the latest kernel be, so that I continue to get upgrades, and whenever I boot the system I select the 4.11.0-14 version by entering the grub menu.

Every now and then, when there are updates in new kernel versions, I test whether this has been fixed. No success so far.


how to take rcp to take daily backup of database from my ubuntu server to my local system?

First, don't just rsync a database, or anything else that's getting actively written to. You're likely to get an unusable copy. This is true for most databases, mail spools ... practically any "live" data. This is why you test your backups!

PostgreSQL has an extensive chapter on backup and restore, which would be a good starting point.

For basic use a nightly pg_dump backups is generally sufficient. If you need more, look into running hot standbys, WAL archiving with PgBarman, etc.

You actually can rsync a PostgreSQL database so long as:

You run pg_start_backup() first
There's nothing writing to the destination other than the rsync
You run pg_stop_backup() afterwards *and copy the required archive files from pg_xlog.

Because of the need to copy archives, it's usually best combined with WAL archiving.

Start with basic pg_dump dumps:

pg_dumpall --globals-only; plus
pg_dump -Fc for each database

If you need more, I've given you some info on where to look to find what fits your needs best.


Cronjob disappears whenever I restart apache2

Oops! You've fallen afoul of the fact that Ubuntu (Debian?) handles root crontab not via /var/spool/cron/crontabs/root (which is the file you create, with crontab -e), but through /etc/crontab, which offers the system more flexibility, and, via a slightly different format, the ability to run periodic jobs as any user.

From /etc/crontab:

# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

So, abandon crontab -e as root, and follow /etc/crontab

I haven't figured out why /var/spool/cron/crontabs/root gets deleted, but since it's not the Right Way, I don't think it matters.


You can use:

udisksctl mount -b device_name

where device_name is the name of a storage device and should look something like /dev/sdb1.

Using lsblk or sudo fdisk -l command you can find out all storage devices attached to your system.


How to get Silverlight and Flash 10+ to work in Chromebook and Ubuntu 12.04 with Firefox

First, you should not be installing .rpm on Ubuntu.

Second, to install flash

sudo apt-get install flashplugin-installer

Silverlight is not available for Linux. The closest is moonlight or pipelight

See How to enable Moonlight/Silverlight 5 on firefox?

Not sure if it works on alternate browsers. Last time I tried moonlight is was a bit buggy.


My name no longer appears on gnome-panel


How can I use Pearson's ePEN java applet on Ubuntu?

Update for 2017 marking season
Since Firefox have dropped support for plugins, you need to download the Firefox ESR (Extended Support Release). I recommend using this just for running ePEN. Assuming you downloaded it to Downloads, run
cd ~/Downloads
tar xf firefox*
cd firefox
./firefox

When prompted to "set Firefox as default browser", I recommend saying No. Note that running this version instead of the globally installed one, it will still use and update your profile, so you won't see much difference to your usual firefox experience.
Follow the original answer as below.

I have a working solution (tested in 64-bit systems: Ubuntu 16.04, Xubuntu 16.04 and Ubuntu MATE 16.04), but my attempts to make the applet work using OpenJDK-8 and the IcedTea-8 plugin were unsuccessful. If anyone can find a method that avoids using Oracle Java, that will be a big improvement on this answer.
I've only tested this fix in Firefox - please comment with info on how it works in other browsers
Step 1: Install Oracle Java for example using this ppa (I used version 8):
sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java8-installer

Step 2 install required libraries
sudo apt-get install libswt-gtk-3-jni libswt-gtk-3-java

Step 3 for 64-bit systems: Go to the exam2score site, log in, click mark student responses and and then 'activate java' answering 'run' 'allow' etc to any security warnings that pop up*. When trying to run the applet you will get an error from the java console: 'Unsatisfied Link Error cannot load 32-bit SWT libraries on 64-bit JVM' To fix this, copy the swt-gtk-3.8.2.jar file to the correct place:
sudo cp /usr/lib/java/swt* /usr/lib/jvm/java-8-oracle/jre/lib/ext

Step 3 for 32-bit systems: (not tested as I can only boot 64-bit Ubuntu, but figured out from my original process. Please comment if you have tested): Loading the applet will fail with a message from the java console: 'unable to load libraries' with a path along the lines of /home/(username)/.swt/lib/linux/x86 you can fix it by making this symlink:
sudo ln -s /usr/lib/jni/libswt-* ~/.swt/lib/linux/x86/

*you can get rid of security warnings permanently by telling Firefox to always allow java to run on this page and by setting a site exception in the Java Control Panel security options (search for Java in the dash)
(Note: staring at this and this and related posts for several hours helped me figure out this mystery)

Additional update for 2017 marking session
For some of my papers, I was blocked from logging in: at the login page I would be redirected to the browser health check and could not proceed. The original error was:

This browser is not supported. You must use Internet Explorer 11.

I got around that one by installing the User-Agent switcher Add-on and setting the user agent to Internet Explorer on Microsoft Windows. However, I still got the redirection, now with a complaint about my java version. I got around it in an inelegant fashion:

after selecting the paper, grab the actual login page address before it redirects (try taking a screenshot).
enter about:config in the URL field
find javascript:enable and toggle it to false to disable JavaScript
open a new tab and enter the URL of the login page (eg https://wwb.exam2score.com/epen-webapp/jsp/login.jsp)
log in with your credentials. It succeeds, but the page features are broken, so...
return to your about:config tab and toggle javascript:enable to true
return to your exam2score tab and refresh the page.


Cannot connect to ubuntu folder in windows

Windows cannot "see" a linux folder. They each use different technologies to store data. Windows uses NTFS and Ubuntu uses ext4. Your best bet would be to use something like ftp to transfer files inside your network.
That said, if you download WSL2, you will have a linux environment inside Windows. You may be able to use bash from inside WSL2 to connect, and even mount your folder.