How big is your swap partition/file? You need 1.5 times the amount of your system RAM to be able to hibernate. Less than this means hibernation will not work.

Eg: If you have 8GB RAM, then you will need 12GB of swap space to be able to hibernate.

Why is this? Well, hibernation physically turns your PC off, which means the contents of RAM which cannot survive a lack of power, must be dumped somewhere before switching off. When you come out of hibernate, the data is re-copied back into RAM before "resuming" the system.

Since PC's now come with gargantuan amounts of RAM as standard, hibernation is not really very practical anymore, particularly when you consider that going in and out of hibernation on a modern PC takes longer than shutting down and booting it from SSD.

With improvements in power management such as offered by Intel's Haswell chipset, you're far better off suspending rather than hibernating because it could happily sit there for a week in suspend mode while using one-tenth of bugger-all power.


Uninstall kubuntu-desktop from ubuntu 18.04

If you installed it via sudo apt-get install kubuntu-desktop you can uninstall it by

sudo apt-get remove kubuntu-desktop --autoremove

To be safe, run the reconfigure on your login manager.

sudo dpkg-reconfigure gdm3

After that, you might need to reboot your machine.


Problem with proxy settings while trying to install a package

From my experience, terminal does not respect gnome system settings.

When we had a coporate proxy, we needed to set those in .bashrc.
So, set your proxy in ~/.bashrc by adding these lines to the end of the file and try again (it might be enough to set http and https proxy only, but you never know...) :

export http_proxy=http://1.2.3.4:5678/
export ftp_proxy=http://1.2.3.4:5678/
export socks_proxy=socks://1.2.3.4:5678/
export https_proxy=http://1.2.3.4:5678/

.bashrc is executed every time you start up a terminal. So do not forget to close and reopen your terminal after saving .bashrc.

Good luck and have fun.


Thanks to the help of terdon, the output of grep -H PATH ~/.profile revealed the login-loop problem:

~/.profile:PATH=/usr/local/bin

instead it should've been:

~/.profile:PATH=/usr/local/bin:$PATH

@terdon, @Braiam: Thanks a lot for your help!


You can check GParted -> Information for more details (source). It is likely your partition table is violating some of the rules of ms-dos partition tables.


Try the same command but without the [...] around split, they are there in the manual page to indicate that the -split argument is optional:

latex2html -split 0 cv.tex


Yes, you can.
Exactly how to do this will depend on your situation.

Here's a bare-bones way to do it:

Load the kernel module.

/sbin/modprobe tun

Create the tunnel device

cd /dev
sudo MAKEDEV tun

This will create /dev/net/tun .

Use openvpn to create tun0 .

sudo openvpn --mktun --dev tun0

Optionally, edit /etc/network/interfaces, and bring up tun0 .

sudo ifup tun0


You will have to manually review and debug they Apparmor Profile you copied from Arch. My guess is that you can review and make a few (minor) changes.

If you can not do this, then I suggest you put the profile into complain mode and run aa-logprof

sudo aa-complain /etc/apparmor.d/usr.bin.skype

Open and use Skype. Close Skype.

Then run aa-logprof

sudo aa-logprof

Review and accept the changes.

I suggest you review the final profile ;)

Then re-enable the profile

sudo aa-enforce /etc/apparmor.d/usr.bin.skype

See:

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

https://wiki.ubuntu.com/DebuggingApparmor


When you issue a command or execute a shell script in any Unix-like operating system, you start, or create, a process. In short, a process is an instance of a running program. Attributes of processes include a process-id (pid) and a parent process-id (ppid), and there are others. Processes are also associated with a terminal (tty) from which they were executed, unless they are daemons.

I suggest you read more about processes and their attributes at the Unix School or at these university user-pages. (All of these pages and more were found with Google, so it is unclear why you were unable to find them.)


When not overwriting existing data, the file tables are cleared and all of the diskspace is opened up for future writing.  The data is still there, but won't be seen by the new filesystem.  The old data will become corrupted and overwritten over time.  This is typically faster, and fine for a normal user.

When overwriting existing data, every bit of the device is written over with a zero.  This is preferred when the contents of the disk were confidential, or the drive is being given to another person.  In this way, the data is more securely destroyed (not entirely) and would be much, much harder to get off the disk.


Wallpaper in each workspace and right-click problem

No.

And to make it possible to save my answer ("no" is a bit short) this a possible workaround that changes your actions to open a file on the desktop from 1 move with the mouse and 1 click on an icon to 2 clicks on icons and 1 mouse move:

You need to use places>desktop to get to your desktop icons.
So you can add in an option to show desktop from the launcher. Rightclick desktop (w/o compiz wallpaper active ;) ) and choose 'add launcher'. See image...

(command nautilus "/home/your_username/Desktop")

Add in an icon, move this launcher from desktop to ~/.local/share/applications and pin this to the launcher.


The browser app is the boringly named "webbrowser-app", from the README:

  webbrowser-app is a lightweight web browser tailored for Ubuntu,
  based on the Webkit rendering engine and using the Ubuntu UI components.

Code is here:

https://launchpad.net/webbrowser-app

Session from UDS is here (thanks Radu):

http://summit.ubuntu.com/uds-1303/meeting/21621/appdev-1303-apps-webbrowser/


Change the path of images in the Shotwell database

Shotwell stores it's data in a SQLite database. You can change the path as follows:

Close Shotwell;
Make a backup of ~/.local/share/shotwell/data;
Open the database with the command sqlite3 photo.db (you may need to install sqlite3 first with the command sudo apt install sqlite3;
At the prompt (sqlite>), type a command like this:

update PhotoTable set filename =  replace(filename, '/old/path/', '/home/me/new/path/');


Custom keyboard layout not showing in Settings

I think you have to add the entry also to the file evedev.xml, something on the line of:

    <variant>
      <configItem>
        <name>kinesis</name>
        <description>My special kinesis</description>
      </configItem>
    </variant>

Near where the other variants for the se layouts are defined.

...and/or modify the correspondent base.xml, base.lst files.

I really do not know exactly how it works, thanks to the quite sparse documentation, but I managed to have my Spanish variant working (tested in Xubuntu but should work in all DE... modulo bugs).

And yes, removing *.xkm files is needed too. And yes, the .xml file should be generated by the .lst file, but I am unable to find how.


I found a solution :

from Ubuntu destop, press Ctrl+Alt+F2, you will swith to a TTY teminal.
Enter your user name and password.
type : DISPLAY=:0 gnome-terminal this opens a terminal in your Ubuntu desktop.
Return to Ubuntu destop by pressing Ctrl+Alt+F7.
Type in the terminal

sudo apt-get install dconf-tools

dconf reset -f /org/compiz/

setsid unity

then reboot.


Security Issue: Ubuntu 20.04 missing power setting to lock screen when lid closed

Please go to Settings -> Privacy -> Screen Lock and enable item Lock Screen on Suspend - it works well.


USB 3 devices are sometimes tricky, and do not work with some combinations of operating system and computer hardware. So it is a good idea to try in different USB ports and in different computers, if possible also with Windows or MacOS.

The tools that I know, need to see a USB pendrive as a mass storage device (typically /dev/sdx), where x is the drive letter a or b ...
You can search for the drive with the following commands

sudo lsblk -f
sudo lsblk -m

But it is not necessary to be able to mount it (and see the file system) in order to repair it. You can try to wipe the first megabyte with mkusb. See the following links

pendrive lifetime

how to repair a pendrive

If wiping the first megabyte does not work in any USB port of at least two different computers, it is probably damaged beyond repair.


If you want to use rEFInd but trim the number of options rEFInd itself shows, editing the entries as shown by efibootmgr won't work. In fact, using efibootmgr on a Mac is unlikely to have any desirable result, since Macs are weird in how they manage boot programs.

Instead, you need to manage your boot entries in one of the ways that rEFInd supports, such as:

Deleting unwanted boot loader programs from the hard disk.
Using the dont_scan_volumes, dont_scan_dirs, or dont_scan_files options in refind.conf to blacklist specific partitions, directories, or filenames from rEFInd's auto-detection.
Deleting filesystem drivers to prevent rEFInd from scanning particular partitions.
Adjusting the scanfor line in refind.conf to prevent scanning for certain broad classes of boot programs, such as BIOS-mode boot loaders (by removing hdbios from the list).
Using dd to delete BIOS boot loaders from specific partitions or from the hard disk's MBR. This method is potentially dangerous, though.

Chances are one of the first two or three options will do what you want to do, but it's not clear from your description which one will work best for your situation. For instance, if you've deleted Manjaro or Ubuntu completely but still see boot options for them, chances are you've got leftover boot loaders for these OSes in the EFI System Partition (ESP), and deleting those files may be in order. OTOH, if you're seeing entries for an OS that you're booting in some other way, perhaps one of the dont_scan options would work better.

Note that in some cases rEFInd will produce multiple entries for one distribution, and these should not be trimmed. The reason is that rEFInd may detect multiple kernels. You can see the exact filename beneath the icon when you highlight an entry. If the filenames take the form vmlinuz-{version} but differ in their version numbers, this is what you're seeing. You should keep such multiple entries because sometimes a new kernel doesn't work properly, and having multiple kernels can therefore provide a fallback in case a new one doesn't work. If all your kernels work, you can get rid of older entries by uninstalling the older kernel package with dpkg, apt-get, synaptic, or some other tool. That's a variant on the first option. Just be sure that whatever's left actually boots successfully.


Bash script to limit the number of logins

Edit your /etc/sshd_config on the server side and change the line:

#MaxSessions 10

to

MaxSessions 20

See man sshd_config:

 MaxSessions
         Specifies the maximum number of open shell, login or subsystem
         (e.g. sftp) sessions permitted per network connection.  Multiple
         sessions may be established by clients that support connection
         multiplexing.  Setting MaxSessions to 1 will effectively disable
         session multiplexing, whereas setting it to 0 will prevent all
         shell, login and subsystem sessions while still permitting for-
         warding.  The default is 10.


Program runs slow after boot in Ubuntu 20.04

Linux propably uses the powersave mode for the CPU (frequency goes only up, if xour CPU usage is high). You can use a cpupower to change it. (The CPU will use more Energy and Laptops will have shorter battery life)


Canon printer won't print some black part

This could be a couple of things but the fact it prints well in Libre Office and Firefox would probably eliminate any bugs in 12.04 as being the cause as it only occurs in acrobat.

Am I correct in saying that the i560 has 2 black cartridges in the print head?  I know it sounds obvious but do they both have ink or have you checked them for blockages?

If you check all above and are still having issues then you should try printing the test page in RGB mode.  The last thing to try is to print the test page in Grayscale rather than color.


Intalling Ubuntu with Windows 8 on 32 bit System with UEFI

According to your Boot-Info, your Windows8 is not using UEFI (it is installed in Legacy mode). So you must install Ubuntu normally (Legacy mode, not UEFI).

The Boot-Info confirms that your computer is 32bit, so you must install Ubuntu 32bit. (Ubuntu 64bit won't work on this pc)


File, Edit buttons have dissapeared from ubuntu desktop

Open your terminal (Ctrl+Alt+T) and run this command:

sudo apt-get update && sudo apt-get install appmenu-gtk indicator-applet-appmenu indicator-appmenu

That will install the packages to make application menus appear in the top panel.


Incorrect memory displayed on ubuntu using free commands

free displays RAM and swap memory usage.

To display the usage of your hard disk in a terminal, you can use

df -h

-h is used to display the results of df in human readable format, i.e. in MB and GB.

Note, however, that df will only display the mounted partitions. If you want to display the size of all partitions (either mounted or unmounted) on your computer, you can use

lsblk


Ubuntu 16.04 + Nvidia Driver = Blank screen

Where/When do you get the blank screen? Is it when the grub menu should appear upon boot, or when the Ubuntu Unity login screen should appear? If it's the latter, try the following:

Add nomodeset on your Ubuntu grub entry. Highlight the entry you use to boot, press e, then add replace

...ro    quiet splash ...

with

...ro    nomodeset quiet splash ...

If that boots to the login screen correctly, press Ctrl + Alt + F2, login, then run sudo prime-select intel. Then reboot and see if that fixes it.

Also, how are you installing NVidia drivers? DOuble-check at nvidia.com if you're using the correct ones.


If you have a standard keyboard, you should be able to type Ctrl and hold down the F1 key (simultaneously).

You should then see a screen prompting you for:

A userid
that userid's password

if you don't see that information on your screen, keep cycling through the different  (where "x" = the number of the Function key at the top row of your keyboard).

During some installations, you can "cycle" much in the same way as above and you'll see install-related output.

HTH

~Rick


How can I map the Apple Magic Mouse two-finger swipe to a web browser's back and forward functions?

I have set up this and many other gestures with touchegg. Install it via:

sudo apt-get install touchegg

Configurate touchegg via its configuration file located here:

~/.config/touchegg/touchegg.conf

Configuration for your desired gestures would be the following.

<touchégg>

<settings>
    <property name="composed_gestures_time">15000</property>
</settings>

<application name="All">

    <gesture type="DRAG" fingers="2" direction="LEFT">
        <action type="SEND_KEYS">Alt+Right</action>
    </gesture>

    <gesture type="DRAG" fingers="2" direction="RIGHT">
        <action type="SEND_KEYS">Alt+Left</action>
    </gesture>

</application>

It's important to follow the last hint of the FAQ if you want to setup two or three finger gestures.

 synclient TapButton2=0
 synclient TapButton3=0
 synclient ClickFinger2=0
 synclient ClickFinger3=0
 synclient HorizTwoFingerScroll=0
 synclient VertTwoFingerScroll=0

Create an executable shell script and fire it up on startup.

This deactivates the two and three finger taps and clicks of the synaptics driver as well as the two finger scrolling. If you want to keep the two finger tap to be the right mouse button click and the two finger scrolling you have to do it with touchegg as well.

I think the magic mouse reports itself as a trackpad as stated here.


You can use the following command to put the tarball on the other drive:

tar cvf /<mount_point_of_dev_sda>/<archive_name>.tar /media

If you want to gzip your tar file add 'z' to tar options (tar czvf) and append.gz at the end of the .tar file.


I fixed this problem using Gnome Tweaks.

Install Gnome Tweaks from Ubuntu Software
Launch Tweaks
Select Keyboard & Mouse
For Overview Shortcut select Right Super (instead of Left Super)


Can someone give me a better idea of what I did when I installed Ubuntu? It's working but strangely

Congratulations on taking the time to try Ubuntu.

When you selected 'install alongside other operating system', the installer may have  automatically resized the Windows C: partition and used that space. Sounds like it allocated 80 GB for Ubuntu.
I would recommend installing gparted  on Ubuntu to see how your hard drive got partitioned. (Note that if you try to perform operations on your Ubuntu partition while running Ubuntu from that partition, you'll probably run into errors.)
Ubuntu can see your Windows partitions without a problem, but Windows can't see your Ubuntu (GNU/Linux) partitions. This is because of the way filesystems work: each partition has a table of information about files, including where the actual file data is on a hard disk. There are different types of formats for storing this information, hence the term filesystem types. Windows (by default) stores data in the NTFS filesystem, whereas Ubuntu stores data in the ext4 filesystem (by default). The problem arises because while Ubuntu has software that tells it how to read NTFS filesystems, Windows doesn't have the equivalent software for ext4. Because of this, Ubuntu can read Windows filesystems, but not the other way around. I think there might be third-party programs for Windows to see Ubuntu partitions; try Googling "read ext4 on windows".
You should be careful with dual-boot. If something goes wrong with Windows it can be a pain to make the bootloader work again for someone still getting the hang of Ubuntu. Ubuntu is definately worth the trouble in the long run though.


How to start a GUI software on a remote Linux PC via SSH

Yes. You just need to run export DISPLAY=:0 (or whatever the remote display is numbered as) in your ssh session and programs run will run on the remote display. A quick example:

oli@bert:~$ ssh tim
oli@tim:~$ export DISPLAY=:0
oli@tim:~$ firefox

Firefox is now running on tim's display.

However when you close your ssh session, most of the time the remote application will close. If you want to disconnect from ssh but leave the application running you need to launch it in a special way using something like screen (keeps the ssh session running in the background) or nohup, or another method. For more information on this there was recently another question on it.

You can shorten this all down into one command that will connect, export the display in-line and start the application in a way that won't close it after the ssh session dies:

ssh tim "DISPLAY=:0 nohup firefox"


You can use a very useful bash alias for that. Edit or create the file ~/.bash_aliases.  Then state your aliases like below, entering one alias per line.

Here are a few examples

alias www='chromium-browser'
alias wwwproxy='chromium-browser --proxy-server=a.b.com:1234'
alias myserver='ssh myname@mysshserver.com'

Then, in your terminal, you can call these shortcuts

$ www
    -- Opens chromium with a blank or home page
$ wwwproxy disney.com
    -- Opens disney.com in chromium using a proxy
$ myserver
    -- connects to your ssh server


See man usermod:

   SYNOPSIS
      usermod [options] LOGIN

   -d, --home HOME_DIR
       The user's new login directory.

       If the -m option is given, the contents of the current home
       directory will be moved to the new home directory, which is
       created if it does not already exist.

   -m, --move-home
       Move the content of the user's home directory to the new location.

       This option is only valid in combination with the -d (or --home)
       option.

       usermod will try to adapt the ownership of the files and to copy
       the modes, ACL and extended attributes, but manual changes might
       be needed afterwards.

   -l, --login NEW_LOGIN
       The name of the user will be changed from LOGIN to NEW_LOGIN.
       Nothing else is changed. In particular, the user's home directory
       name should probably be changed manually to reflect the new login
       name.

So you want

sudo usermod -m -d /home/new_login_name old_login_name
sudo usermod -l new_login_name old_login_name

The first command will move your login directory; the second command will edit the relevant files that reference your name (/etc/passwd, /etc/shadow, /etc/groups) of old_login_name to new_login_name.  You didn't ask, but you may also want to change your group name as with groupmod in an analogous fashion (sudo groupmod -n new_group_name old_group_name).


In the search, type "configure wine" and run the application.
Open the Audio tab and set all the drop down lists to System Default.
Once changed, test the settings.

If this doesnt work, try going through the list of all you audio devices and select which ever ones work.


Installed Ubuntu 20.04 (replacing Windows 10) fails to boot

You should try disabling Secure Boot, and for Ubuntu, the right file to boot is grubx64.efi.

Secure Boot is put in place by OEMs to prevent unsigned drivers and EFI shells from being used.


How to change the monitor's refresh rate?

You should be able to use xrandr. Calculate the needed modelines for your resolution and refresh rate:

cvt 1600 900 75

(Here my example resolution is 1600x900.) Now create a new mode with xrandr:

xrandr --newmode "1600x900_75.00"  104.00  1600 -hsync +vsync

Add the new mode to xrandr:

xrandr --verbose --addmode VGA-0  "1600x900_75.00"

and activate it

xrandr --output VGA-0 --mode "1600x900_75.00"

Note that your values will be different. In particular, your monitor might not be VGA. Run the xrandr command with no arguments to find out the name of your monitor and use that instead. Running xrandr -q will display a list of available outputs.

Here's some more information on xrandr.


In my case the problem was that the downloaded ISO is defective.
In order to check the ISO file, run an md5sum for the ISO in the terminal, for example:

md5sum lubuntu-14.04-desktop-i386.iso

and verify that the calculated hash matches with the given hash appropriate to your Ubuntu version which can be found here on the Ubuntu help wiki

Re-download the image if necessary, and try again.


Google Chrome 64bit window drags on resize

Looks to me like a problem with your video drivers. You could try installing proprietary  drivers (from Nvidia or ATI) using the Additional Drivers tool, to see if that clears up the issue.

You mentioned that you tried the 64 bit, 32 bit and Chromium, I assume they all do this but never Firefox. This would imply that it's something (a library, perhaps) that Chrome uses, but Firefox doesn't. You could also check to make sure that you've got everything up to date (Use the Update Manager or sudo apt-get update; sudo apt-get upgrade in terminal.)


I think it's because the cache contains the URL specific scheme of representation characters, %3a is ASCII code 3A in hexadecimal, which is character ":" and if you query that installed package eg with command dpkg -s x11proto-damage-dev | grep Version you can see that it contains ":"

Version: 1:1.2.0-1

So indeed, that ":" is encoded as %3a ...


After multiple more kernel updates that I couldn't get to work. I did something I didn't want to do, but technically solved the problem. I upgraded to a non LTS build. I've upgraded to 17.04 and not having problems. No idea what the problem was but it's gone now.


vino: no such schema of "org.gnome.Vino"?

Consider to install vino package with

sudo apt install vino

as it contains needed file.


Chrome not showing fonts for github website

Okay, so after a day, I was finally able to solve this issue. The font I have installed by putting in ~/.fonts folder was not working. I went to that folder from the file manager and it failed to display fonts from the .ttf file and also clicking on Install gave an error Install failed.

I have dual boot Ubuntu 16.04 with Windwos 10. So what worked is installing Segoe UI fonts from the Windows/fonts directory. Open the windwos installation drive in file manager, navigate to windows/fonts folder. Search segoeui, open each of the search result and click on top right corner Install. After doing it all, run fc-cache -fv  and log out. Now login to see the Segoe UI fonts all over!

Hope this helps someone.


Why can i not approve activities in Landscape when installing packages?

The only activities that require approval are the ones with a status of unapproved. If you try to approve any other activity type, it will fail with that error message which is misleading in that regard. It should say that some of the activities that you selected don't require approval.


I had the same issue, here is what my exim4 paniclog looked like:

$ sudo cat /var/log/exim4/paniclog

2014-02-01 21:36:51 socket bind() to port 25 for address 127.0.0.1 failed: Address already in use: daemon abandoned
2014-02-01 22:03:33 socket bind() to port 25 for address 127.0.0.1 failed: Address already in use: daemon abandoned
2014-02-01 22:33:19 socket bind() to port 25 for address 127.0.0.1 failed: Address already in use: daemon abandoned
2014-02-01 22:36:33 socket bind() to port 25 for address 127.0.0.1 failed: Address already in use: daemon abandoned
2014-02-01 23:03:51 socket bind() to port 25 for address 127.0.0.1 failed: Address already in use: daemon abandoned
2014-02-01 23:14:31 socket bind() to port 25 for address 127.0.0.1 failed: Address already in use: daemon abandoned
2014-02-02 11:09:48 socket bind() to port 25 for address 127.0.0.1 failed: Address already in use: daemon abandoned

This problem was apparently solved by deleting the paniclog file


No internet using Intel Wireless-AC 9462 on Ubuntu 20.04?

I suggest that you try a driver parameter. From the terminal:

sudo -i
echo "options cfg80211 cfg80211_disable_40mhz_24ghz=Y"  >  /etc/modprobe.d/cfg80211.conf
exit

Reboot. If there is no improvement, please make a few changes in the router's setup.

WPA2-AES is preferred; not any WPA and WPA2 mixed mode and certainly not TKIP. Second, if your router is capable of N speeds, you may have better connectivity with a channel width of 20 MHz in the 2.4 GHz band instead of automatic 20/40 MHz, although it is likely to affect N speeds. I recommend a fixed channel, either 1, 6 or 11, rather than automatic channel selection. Also, be certain the router is not set to use N speeds only; auto B, G and N is preferred. After making these changes, reboot the router.

EDIT: We note dozens, perhaps hundreds of lines of:

  changed bandwidth, new config

There are many reports of this behavior and it seems always to prohibit the wireless from working at all. Let's try to stop it. From the terminal:

sudo -i
echo "options iwlwifi 11n_disable=8" >>  /etc/modprobe.d/iwlwifi.conf
modprobe -r iwlwifi
modprobe iwlwifi
exit

Is there any improvement? If not, there are other parameters that we may try that are increasingly restrictive.

EDIT 2: Your device and driver look first for version -50 of the firmware and, not finding it, then -49 and then it finds and loads -48 which is the latest found in the Ubuntu package linux-firmware. There is, however, a version -50 available. Let's load it:

cd /usr/lib/firmware
sudo wget https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/iwlwifi-QuZ-a0-jf-b0-50.ucode
sudo modprobe -r iwlwifi
sudo modprobe iwlwifi

Now, let's check to see what version loaded:

dmesg | grep firmware

Look for later timestamps; the firmware load that occured when the computer first boots will be around 4.00 or so; we are interested in the most recent entries; that is, 50.00 and probably much higher.

Is there any improvement?


Customize the notification center appearance

I Dont have Ubuntu 20.04 Installed. I have tested this in gnome-shell 40.
In any gnome-shell theme for your version. Searching the below content and editing it to your preferred values will bring the changes you are looking for.
/* Popovers/Menus */
.popup-menu-boxpointer, .candidate-popup-boxpointer {
  -arrow-border-radius: 12px;
  -arrow-background-color: #353535;
  -arrow-border-width: 0px;
  -arrow-border-color: #202020;
  -arrow-base: 0px; # I have edited this
  -arrow-rise: 0px; # I have edited this
  -arrow-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.5); }


How do I change my default Java directory?

After recently installing Oracle Java following the same instructions, I ran into a similar error. The link to the java executable appears to be missing in your /usr/bin.
To resolve this, I would manually create the link:

$ sudo ln -s /etc/alternatives/java /usr/bin/java

You may have to change /etc/alternatives/java to point to the correct location, but this is the default based on the instructions you followed.


The way redis works is that the data is stored in RAM, not on the disk.

/var is not mounted in RAM, its content persist between reboots.

Usually web servers store their pages in /var/www, database managers store data in /var/lib/name (/var/lib/mysql, for example)...

It's absolutely normal applications store data inside /var.


Problem with downgrading nginx - can't remove dependencies

Dependency issue solved with using official nginx Docker images


Internal SD card reader not mounted/detected lenovo y50

Run in terminal

sudo apt-get install exfat-fuse exfat-utils


How can I install the driver for my EPSON NX430 printer?

SCANNER you need see http://download.ebz.epson.net/faq/linux/faq_ls_00002.html

iscan-data_1.26.0-1_all.deb
iscan_2.29.3-1~usb0.1.ltdl7_[amd64 or i386].deb
iscan-network-nt_1.1.1-1_[amd64 or i383].deb

[copied from http://download.ebz.epson.net/faq/linux/faq_ls_00007.html]

Configure Image Scan! for Linux to connect to your device by editing
/etc/sane.d/epkowa.conf. You need administrative privileges to do
so. Read the instructions in the file about network configuration
and add an entry for your device like this =>>>>
net IPADDRESSOFTHESCANNER 1865
Finally, disable the conflicting epson2 SANE backend. You can do so
by changing the line consisting of "epson2" to "#epson2" in
/etc/sane.d/dll.conf. This will require administrative privileges.

PRINTER

epson-inkjet-printer-escpr_1.3.1-1lsb3.2_[amd64 or i386].deb after
you install the driver go to System Settings/Printers and add your
printer it should work

tested Ubuntu 13.10 amd64 used krusader to navigate through the folders


How to setup transparent ssh when there are multiple servers

Use

ProxyCommand ssh -W %h:%p Tom@my_host_machine

or just

ProxyCommand ssh Tom@my_host_machine nc %h %p

netcat does not accept username as a argument.


How can I use the in-built function alert in Gnome Schedule?

If you look into your ~/.bashrc file youll find the alias which defines alert.

# Add an "alert" alias for long running commands.  Use like so:
#   sleep 10; alert
alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"'

Example:
Try as input in your manual terminal:

notify-send "Hello World!"


Recover Windows 7 boot after installing Ubuntu 14.04

Test this:

Insert the Windows 7 installation disc into the DVD drive and restart the computer.

If prompted, press any key to boot from the Windows 7 installation DVD.

Select your language preferences and click on Next.

Click on Repair your computer.

Select which operating system you want to restore and the click on Next. If Windows 7 is not listed here, or it is blank, then it is ok. Click on Next anyway.

Select the system recovery option you want to do:

Startup Repair

System Restore

System Image Recovery

Windows Memory Diagnostic

Command Prompt

If you managed to recover Windows 7, will have lost Grub should reinstall.

Insert the Ubuntu Desktop live-disc into the DVD drive and restart the computer.

Select Try it.

Open a terminal.

Run it:

sudo -i
fdisk -l
#Suppose fdisk informs your partition / is /dev/sda3, continue running
mount /dev/sda3 /mnt
mount --bind /dev /mnt/dev
mount --bind /dev/pts /mnt/dev/pts
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
chroot /mnt
grub-mkconfig -o /boot/grub/grub.cfg
grub-install --root-directory=/mnt /dev/sda
grub-install --recheck /dev/sda
umount /mnt
reboot

That's it.

Sources:

http://windows.microsoft.com/en-us/windows/what-are-system-recovery-options#what-are-system-recovery-options=windows-7

https://wiki.archlinux.org/index.php/GRUB


Ubuntu server 14.04.1 LTS wont install any packages after reboot

In your /etc/network/interfaces file you need to add your dns servers.  Try editing like below:

auto eth0
iface eth0 inet static
  address 192.168.0.10
  netmask 255.255.255.0
  network 192.168.0.0
  broadcast 192.168.0.255
  gateway 192.168.0.1
  dns-nameservers 8.8.8.8 4.2.2.2

Then run

sudo service networking restart

Try to ping

ping google.com


Create video with an image and audio file using ffmpeg

Use:
ffmpeg -loop 1 -i image.jpg -i audio.mp3 -c:v libx264 -tune stillimage -c:a aac -b:a 192k -vf "scale='iw-mod(iw,2)':'ih-mod(ih,2)',format=yuv420p" -shortest -movflags +faststart out.mp4

The scale filter example is a fancy way of making the width and height to be divisible by 2 which is needed for this particular encoder when outputting YUV 4:2:0 (4:2:2 and 4:4:4 are not supported by most players, so that is why you see so many examples using yuv420p).
A simpler method is to crop or scale like crop=550:764, but the above command will work with any input size.


I found a solution!
I used http://rufus.akeo.ie/ to make my live USB and upon reboot I was able to successfully set up my Ubuntu installation.


File names in non-latin script changing in question marks

You didn't tell us how those files were created, but it sounds as an encoding issue to me, i.e. the file names are probably encoded in something else but UTF-8.
Consider this series of commands:
~$ mkdir test
~$ cd test
~/test$ touch ภาษาไทย
~/test$ ls
ภาษาไทย
~/test$ LANG=C
~/test$ ls
''$'\340\270\240\340\270\262\340\270\251\340\270\262\340\271\204\340\270\227\340\270\242'
~/test$


Dual Boot Setup Into Existing Win-10 Machine

welcome to ask ubuntu.

I think you're overthinking a bit what it is ubuntu does these days.

lately things have been going much better regarding windows 10 / ubuntu 18 + dual booting, so you should disregard these other questions.

here is the process I used with my brand new windows 10 asus gaming laptop that led to a clean dual boot with grub 1st and boot.ini loaded when you select the "windows 10" option in grub, it works flawlessly and both parties leave the other alone :

on windows open up powershell with administrative priveledges
(that's right click on the icon, "run as Administrator"). type:
powercfg -h off
plug in your ubuntu USB key (make sure it is uefi
mode, rufus is a good tool to make uefi boot keys)
then open up
settings go to "Recovery" and select "Restart Now" under "Advanced Startup"


postfix setup as a cloud mail gateway with exchange 2013 internally

Check the Postfix documentation regarding mail forwarding domains. This may fix your issue with outside email systems getting mail to your Exchange system.

The same document covers virtual domains with mailbox stores.

This may give you some leads on how to configure Postfix to accomplish what you're trying to achieve. I do believe however that since Postfix is primarily an MTA, getting it configured to act as a replica of your Exchange system is going to be challenging.


The problem here is that you are attempting to run a Windows executable on a non-windows filesystem. The BiosAgentPlus_568.exe is not capable of running under Linux, though it may work under Wine. If this is from here, then you may need to add that to a USB Stick or CD (not sure if that is a self-extracting piece of software or not) and try booting using same.

Unless there is a reason to update the BIOS that is driving that demand, it is probably not worth the risk and effort. Your BIOS should generally only be updated when required, or when there is some compelling reason to do so (some functionality added that is available to you, etc.).

If you are not familiar with updating BIOS and the risk, probably not worth the risk, as a failed BIO update is worse than no BIOS update. Proceed with caution.


How to complete `mariadb-server`'s installation without being stopped at "Enter the password"?

Well, thanks for your help, but below lines worked for me.

export DEBIAN_FRONTEND="noninteractive"
sudo debconf-set-selections <<< "mariadb-server mysql-server/root_password password $PASSWORD"
sudo debconf-set-selections <<< "mariadb-server mysql-server/root_password_again password $PASSWORD"

sudo apt-get install -y mariadb-server python-mysqldb


Black Screen after login Ubuntu 18.04 Nvidia 418

Switch to LightDM

sudo apt-get install lightdm

That was the only thing that worked for me.

Here is another interesting (non) solution:
Once the black screen comes up, log in from somewhere else and kill Xorg. Now you're back to the tty. Press ctrl-c to finish killing Xorg. Gdm restarts and will work this time.


Please check this page
He gives some nice info that helped me with a problem similar.

gksudo gedit /etc/init/network-manager.conf
Under stop on stopping bus, add
kill timeout 1

He also advises to

sudo apt-get autoremove modemmanager

But that step wasn't necessary for me.

Of course this might be trick for production environments.
Use it only for personal computers and things like that


How to I change the root foldername that shown in Nautilus

Go to system settings, under system click Details, then click Overview on the left and were it says Device name you can edit what is shown for the root drive under Nautilus. This will change the hostname to Computer also after reboot so just change your hostname to what you want it to be using
gksudo gedit /etc/hostname and gksudo gedit /etc/hosts. After reboot Nautilus will show the drive as Computer and your hostname will be whatever you have set it to be, you can check this by just typing hostname in terminal.


Download files with wget from a list but save with a specific naming pattern

You could always use a shell loop:

while read url; do wget -O foo_$((++i)).json "$url"; done < list.txt

The file list.txt is your list of URLs, one per line. This is read by the while loop, each URL is saved as $url, wget downloads it and the -O flag tells it to save to a file called foo_N.json where N is the current value of $i. Since $i is incremented in each iteration ($((++i))), this will result in a increasing sequence of file names.


Using Snap on Ubuntu for Windows 10 Error

snaps use snapd which requires systemd which is not available under WSL.

https://forum.snapcraft.io/t/windows-subsystem-for-linux/216


Well i could close the question but just found the answer here: https://help.ubuntu.com/community/ApacheMySQLPHP (The community help has gotten better)

Anyway the faster way was to edit the file of apache from /etc/apache2/sites-available/ in my case it was 000-default. Change all the /var/www entries (in my case 2) to the directory you want www to be in. This is the way without the virtual Hosts which is also mention in that link.


How can I show notes on my laptop in LibreOffice Impress?

This should work more or less out of the box:

Make sure you have the presenter console extension installed:
apt-get install libreoffice-presenter-console
plug your external display or beamer to the laptop
unset the display mirroring in the Ubuntu display settings
in Impress, go to Slide Show/Slide Show Settings and choose the correct presentation display from the list.
start the presentation (e.g. hit F5)

You should now see a different screen on your laptop and the external display or beamer. The laptop version should also show any slide notes you have (click on the notes button at the bottom).

Notes:

This is also valid for OpenOffice.org. In that case the package to install is openoffice.org-presenter-console.


We can actually ignore the error when you run only fluidsynth

This works: fluidsynth -F ./test.wav GeneralUserGSv1.471.sf2 test.mid

I still encounter this error message: fluidsynth: warning: Failed to pin the sample data to RAM; swapping is possible.

Specific instructions for my use case is in my repo.


How can I adjust the transparency of the Status Bar (top panel)?

example panel transparency
For example 100% transparency...

A useful option if you are using transparency is the option just below - Transparency Maximized Toggle (called Opaque panel for maximized windows in Unity-Tweak-Tool)
Switching on this option will not display the top panel as transparent if the window is maximised i.e. with 100% transparency but this toggle switch-on:

Nautilus is maximised and therefore the top-bar does not remain transparent.
13.04
The panel transparency can be defined with unity-tweak-tool

12.04
(click to install)
The panel transparency can now be defined in MyUnity


How do I insert an umlaut on the u in ubuntu?

UPDATED

I have worked it out.

Firstly, set your Compose Key to Right Alt (Alt Gr on my keyboard) so that it doesn't interfere with the short cuts for copy, paste and many other combinations.

then go to your document and

press the Alt Gr button
release it
then type in u
followed by "
which gives you a ü

Hope this helps


I just followed a previous post with a similar issue: askubuntu.com/questions/110672/… and it worked.  I did get a the following warning:

  Reading package lists... Done W: GPG error: http://ppa.launchpad.net
  oneiric Release: The following signatures couldn't be verified because
  the public key is not available: NO_PUBKEY 531EE72F4C9D234C

but it seems to get the java updates.


You have a mess of local and global python modules.
Remove problematic with
pip3 uninstall pyqt5

and retry.


Windows Server 2008 R2 Standard Terminal Server and Ubuntu 11.10 - how do I backup from my own pc on remote desktop?

You may try remmina rdp client.
I think it allows to use shared folders between the server and client.


for the ubuntu motd, you can disable it in

  /etc/default/motd-news

just change ENABLED=1 from 1 to 0

By doing a

grep -ERi "motd" /etc

we can see how linux has become a mess!

In /etc/ssh/sshd_config there is a "PrintMotd no" option, but even if it is set to no, there is a motd displayed indeed.

In /etc/update-motd.d/ there are 11 files!

There are a few things related to motd in
/etc/pam.d/sshd and in /etc/pam.d/login

Probably by reviewing those last 2 files, you'll get a clue how to fix your issue.

good luck ;)


Why do I need to connect to a VPN to use SSH outside of work?

Whether you will be able to ssh into the server directly, or need to connect to VPN first, it depends on how the organization has configured their network.
If the network is configured so that the ssh service on the server is exposed directly to Internet (which in fact is standard on many universities I had contact with - at least their "main" server which provides eg. email for employees is available directly via ssh), then you will be able to log in directly via ssh without the need to VPN first. On the other hand, if the network is configured so that ssh service is available only for internal network, you need to first connect to VPN.
I don't think that the second approach (with the need to connect to VPN first) is more secure than the first one, because ssh connection is encrypted by itself, and normally the server should use the same company-wide single sign-on authentication as the VPN uses, which means if you know the credentials to ssh into the server, you also know the credentials to login to VPN, and vice versa. However, some network administrators prefer that approach.


How do I switch from 11.10 back to 10.10?

There is no newer version of maverick. Only LTSes get minor releases like that.


If I’m trying to run the same script in ten different directories in a row, will this way work and is there a more concise command sequence?

Some notes:

Don't parse ls. Assuming you want to use all the directories in the current folder, so

for dir in */        # note the trailing slash

IMO "dir" is a better varname than "i".
if not every directory is wanted, you can spell them out

for dir in dir1 dir2 dir4 ...; do ...

or use a glob pattern that will match the wanted dirs

for dir in dir[1-46-9] ...; do ...

or use an array to hold them, and iterate over the array

dirs=(dirA dirB dirE dirG)
for dir in "${dirs[@]}"; do ...      # those quotes are required.

Quote your variables
This pattern is fine: cd dir; do stuff ...; cd ...
You could also create a subshell so the effects of cd vanish when the subshell exits.
It's conceivable that cd fails.

So, here's a slight alternate take

for dir in */; do
    ( cd "$dir" && echo 2 | ./scriptname.sh )
done


Is it possible to install gnome-shell extensions like in Fedora 15?

You have to enable the extensions using gnome-tweak-tool.

If you continue to get errors, please remember the the version of GNOME Shell in the repositories is a bit behind because of the fact that this version of Ubuntu is still in development, and not all packages are up to date as yet.


Try using the 64-bit version instead of the 32-bit version. The 64-bit version handles UEFI better than the 32-bit one.


Navigating windows folder on Ubuntu partition

The location of the directory is usually /media/< Partition name >

You can check the mounted partitions and their mount points by running the command

df

or the command

mount -l | grep dev/*

And then you can cd to that directory using the terminal.

Note: Ubuntu usually mounts the partitions when you click on them in Nautilus, the file manager. So remember to click on it before running df


Will Juju support start/stop of existing units?

This is a super-interesting question. Yes, I think it would be a valuable addition to Juju, and would encourage you or others to work up a patch. As someone said, the underlying cloud infrastructure would need to support this operation, but even MAAS could turn physical machines on and off without releasing them.

Inviting a patch doesn't mean it would land but I think it's interesting enough to mock up the CLI and API extensions needed, and perhaps work up a prototype just for EC2 showing what's needed in core and in the provider.


Surface Pro 4 Type Cover Not Working Ubuntu 16.04

Good eve,
I've learned the hard way.  I have yakkety running on SP4.

The very short version:
update kernel to latest v4.10-rc8 (release candidate).  The keyboard / mouse both function (!).

There's also a program called ukuu I highly recommend you install to EASILY update your kernel.

Everything works after you reboot.

HTH,

MarkB (triple booting WIN10, Ubuntu, Mint)


Is there a way to set the (max) amount buffer / cache an Ubuntu server reserves from RAM?

There is no real need to limit the amount of RAM used for caching, as this memory is only reserved for caching but will get used if your applications will need more RAM.

A good read might be found at https://www.linuxatemyram.com/ (I'm not affiliated with this site) It might clear up a bunch of insecurities and concerns on your side I hope.

As to how to limit the caching amount I lack the knowledge to give you there a profound answer, but the website I linked states that there is no way to limit the disk caching amount.


Adding white to a transparent background in GIMP

As Amanthety points out in the comments, first thing to do in Inkscape would be to go to File -> Document Properties and set the background color to white (by default it's transparent). To do this, click on the color bar next to "Background color" and set the A (alpha) value to 255. This makes the color opaque instead of transparent. Or, as Charles Green correctly comments, create a white object under your logo. Both solutions will have as a result a white background.

Concerning sizes:

go to File -> Document Properties and set the size there
and/or, if
you export the SVG to PNG (File -> Export PNG image) you can set the
image size of the PNG in pixels in the export dialog.


SOLVED (sort of). I was never able to completely boot live from USB. Although I now have Linux installed on the internal HDD (I still have windows on the SSD). Once I got the HDD installed, I had an extra drive. So I was able to experiment with the installation process without worrying about rendering my entire system unusable. I was able to install via NetInstall (mini.iso). I found that my usb drive was becoming unresponsive during the boot process. One time when it became unresponsive, I simply unplugged it and plugged it back in. The system recognized my usb drive once again and the installation process continued. It might have worked the same for a normal install. But I was already trying the NetInstall at that point.


Pls set volume using alsamixercommand and select the appropriate device using F6 key. Most of the user missed the default device selectionsenter image description here


How to reduce bubble-notification time in empathy?

I don't know if Empathy uses the NotifyOSD bubbles (I don't use Empathy), but if it does, maybe this can help:

First install patched NotifyOSD:

sudo add-apt-repository ppa:leolik/leolik;
sudo apt-get update;
sudo apt-get upgrade;
sudo apt-get install libnotify-bin;
pkill notify-osd;

Then install NotifyOSDconfig:

sudo add-apt-repository ppa:nilarimogard/webupd8;
sudo apt-get update;
sudo apt-get install notifyosdconfig;

Run NotifyOSD from launcher or menu and configure your bubbles.

All this from here: http://www.webupd8.org/2010/05/finally-easy-way-to-customize-notify.html


Newer versions of MAAS, including your new version, use the ISC dhcp server.  A separate package maas-dhcp acts as a wrapper, running its own instance of the dhcpd in a customized configuration.

As you'd expect, maas-dhcp depends on isc-dhcp-server.

Why the change?  If I recall correctly, the main reason for the switch from dnsmasq to the ISC server was that the former was considered a bit of an unknown at larger-scale deployments, whereas ISC's dhcpd is a proven component.


How to allow another user in a group to read a file

Don't add Cedric to group jack, because that is Jack's personal group. It's a security violation.
In addition to that, in new versions of Ubuntu, the default access to home accounts and files will be 600 for files and 700 for folders, i.e. groups and others can't access the area at all. This is recommended for security, because in previous versions, anyone could access (but not modify) anyone else's data.
You can explicitly set this in older versions of Ubuntu for all of the various home folders as follows:
sudo chmod --recursive go= /home/

A side effect of this is that no matter how you set your secret file within Jack's folder, no one can access it. That's a Good Thing (as Winnie the Pooh might say), both for security and because Jack's folder is personal to Jack.
So…
The right way is to create a brand new folder, not in Jack's area, that all permitted people, and only permitted people, can share.
You specify who may share with a new common group created just for the purpose. You assign the file's ownership to Jack, who can write to the file, and the file's group to the new common group, whose members can read but not modify the file.
Here are the steps. For this example, I've used the folder /home/secshare and the group name secacc, but you can choose a different name for both the folder and the group name (they can have the same name as each other, if you like).
sudo groupadd secacc                           # Create the new security group.

sudo mkdir /home/secshare/                     # The folder to hold the security file.
sudo chown jack:secacc /home/secshare/         # Jack owns the folder. Group has access.
sudo chmod u=rwx,g=rx,o= /home/secshare/       # Jack: rw. Group: r. Others: none.

# Create the file.
echo secret5cd51b | sudo tee /home/secshare/secret7b079

sudo chmod g=r,o= /home/secshare/secret7b079   # Owner: rw. Group: r. Others: none.

# Assign Jack as the owner, and secacc as the group.
sudo chown jack:secacc /home/secshare/secret7b079

# Double-check permissions.
sudo ls -l --directory /home/secshare/
> drwxr-x--- 2 jack secacc 4096 Feb  8 11:48 /home/secshare/
sudo ls -l /home/secshare/
> -rw-r----- 1 jack secacc 13 Feb  8 11:48 secret7b079

# Assign both Jack and Cedric to the group secacc
sudo usermod --append --groups secacc jack
sudo usermod --append --groups secacc cedric

At this point, Jack has full access to both the folder and the files within.
Cedric belongs to group secacc and therefore has read-only access to both the folder and the files within.
Pedri, who doesn't belong to the group secacc, has no access to the folder, and no access to the files within (even if the files within have full read-write access to everyone — test it for yourself).


Keyboard stops working on a Dell Inspiron 7110

When it happens to me I usually click on the touchpad (not the mouse) and it resumes working.

Bad bug, btw, Ubuntu's getting worse and worse.


Desktop broken: no launcher and no windows

I sort of had the exact problem with Unity after I installed nVidia drivers in 12.10.
I installed nVidia driver, rebooted and had a very low resolution and no Unity.

A friend of mine (an Ubuntu expert!) fixed it for me. He uninstalled the nvidia drivers. (I guess this would help) the he installed Nouveau and everything was fine.

I hope it helps :-)


11.04 -> 11.10 update problems (Power, Display, Resolution)

Fist question can be answered here

Other display related question could be better troubleshooted if you did a reinstall on your nvidia drivers and started a new configuration.


Does flash player on Google Chrome support video acceleration with nvidia drivers?

Information about Stage Video

Stage Video technology was introduced in version 10.2 of Adobe Flash Player (blogs.adobe.com) and it does support Nvidia's vdpau. The Flash Player (called Pepper Flash plugin) in Chrome is essentially a repackaged Adobe Flash Player.

Making it actually work is another matter and as far as I've read experiences from forums, the effectiveness of it varies. Also, not every Flash video actually supports Stage Video.


How to stop a upstart job when another is starting?

You can add stop on service starting stanza to the services that you want to stop whenever the backup event fire up. Something like this:

# this is my test service

start on runlevel [2345]
stop on runlevel ![2345]
stop on backup starting
start on backup stoping

exec service --daemon

you must replace backup with the name of the service that starts using upstart. There's also the fire event stanza but this is a bit more complicated since it requires you to modify both, the service you are stoping for backups and the service that is starting to do the backup.


Ubuntu 12.04 "connecting" for 30 seconds, then gives up and says I'm disconnected

Please do:

gksu gedit /etc/modprobe.d/blacklist.conf

a little window will open enter your user password then remove:

blacklist brcmsmac

blacklist bcma

from the blacklist file that opens then save gedit and close.

Then do:

sudo apt-get purge bcmwl-kernel-source

sudo modprobe bcma

sudo modprobe brcmsmac

If it does not connect do:

sudo dpkg-reconfigure resolvconf

There are 22 wireless networks in your area and that makes it very difficult for network manager to connect to one.


How to change index in OptionSelector immediately (without animation)?

You can see a copy of the OptionSelector qml here it uses UbuntuNumberAnimation when it's not expanded. There's no option for switching it off and if the feature is required you're going to have to patch upstream and wait a while for new versions of the library.

You could make your own open selector widget though, remove the animation part and make sure you rename it for use in your code. I recommend this route.


Installing Media Explorer 0.3.6.1 on Ubuntu 12.04

Install the prerequisites (I started from the list in itnet7's answer):

sudo apt-get install intltool libclutter-1.0-dev libsoupcutter-dev libmx-dev libgrilo-0.1-dev libgstreamermm-0.10-dev libclutter-gst-dev liblircclient-dev  libtracker-sparql-0.14-dev libavahi-glib-dev librest-dev libavahi-client-dev tracker
Download the latest media-explorer 0.3.6.1 and extract it in one step:

wget -O- https://github.com/downloads/media-explorer/media-explorer/media-explorer-0.3.6.1.tar.xz | tar -xJ
Fix the configure file because it does not recognize the deprecated soname in the latest clutter libraries, and because it depends on the old tracker-sparql-0.12 library instead of the latest 0.14:

cd media-explorer-0.3.6.1
sed -i -e "s/\`\$PKG_CONFIG --variable soname_infix clutter-1.0\`/eglx/g" configure
sed -i -e "s/sparql-0.12/sparql-0.14/g" configure

Configure, compile and install Media Explorer with:

./configure --prefix=/usr && make && sudo make install
Start tracker to index content with tracker-control -S, and start Media Explorer from the Launcher (or just media-explorer):


Sorry, it's a little late, but I just finished implementing it and I think you'll love it.

This answer will unstuck you, but probably not the way you intended to be unstuck, but better. Doing OLED brightness changes with ACPI hooks is simply a compromise. If you change the brightness instantly, you compromise smooth brightness changes, if you do smooth brightness changes, you compromise reliability (because now you can press the function key twice before the previous changes apply and thus get flickering), and night light is simply not supported, because the "color correction" is updated only when you press the brightness keys.

This repository is a much better solution for both your slider and your startup issues. And now you can have night light too :)

It works by watching for changes in brightness (the normal brightness you adjust using your slider or whatever normal method you use) and applying them to the OLED panel. It does require a little tweaking, but it's worth it.

After switching to this solution, I noticed the nice dimming effects my desktop environment provides when I'm away from my laptop for a while, and also the brightness fade effects on the lockscreen. These are little things that you can't get with ACPI hooks


I recommend letting Kubuntu add the printer. Then when its done you add another one with your name and all the details you want. Test it from an application and from the print test page.  Then delete the printer you don't want. You can add the same printer with different details as many times as you want. If another one keeps coming back then you may have a network loop.  Another printer is sharing your printer back to you.


cannot find/read/delete new notifications on lock screen

Press super + m and you get to the menu you need.
You can see/read the messages and delete them.


Is the name of a private Linux computer discoverable in its LAN?

There are several services that do hostname broadcast as part of their offerings, generally you can't rely on a system having any of them installed.

samba - windows compatible network shares and discovery
avahi - bonjour/DLNA/UPNP announcement and discovery

if you have the IP address of the computer (as found by arp) and it runs ssh then you could do this to ask the computer what its called

ssh user@ip.ad.dr.es hostname


modprobe nvidia throws error: could not insert 'off'

So, IMHO, nvidia did some changes to their install. For everyone trying to get bumblebee work with their nvidia driver, you have to know that:

Now nvidia library is located in /usr/lib/x86_64-linux-gnu
blacklist-nvidia.conf file is located in /lib/modprobe.d/

The answer was in blacklist-nvidia.conf, which stil had alias nvidia off uncommented.


Ubuntu Live ISO booting from DVD or Pendrive: different GRUB menus

Startup Disk Creator, UNetbootin, Universal and others, all have different boot screens. The creators of the various USB installers would probably be in violation of copyright, (or at least good taste), if they copied each others screens exactly, even if they are open source.

I have found that some of the installers work better than others, but none have destroyed my hard drive or any USB drives yet.


Operating system boot manager for Ubuntu 16.04

Open a terminal, type sudo nano /etc/default/grub, and press Enter.
In the file that opens up find the line GRUB_DEFAULT. Now the value of that line should be set to 0, change it to 1.

Save the file pressing Ctrl+o, press Enter to confirm, and Ctrl+x to exit.

Run the command sudo update-grub.

The next time you restart the PC, if you don't touch anything when the boot menu shows, it should automatically start Windows.

Note that the value of GRUB_DEFAULT starts the OS identified in the boot menu starting from 0.


Disclaimer: not an expert, this is what i would do.

start by disconnecting your laptop from the internet
power up
check all ports open with nmap -PN 127.0.0.1 (and close them later if unneded)
get which services/apps are using ports with sudo netstat -tulpn
check which services are running on start

with that info i will start looking for anything suspicious.

You can take a look at rkhunter.

If it's only your account which is compromised (and not the root account), i will try to create a new one with sudo access and work the process from there.


Touchscreen, WebCam and Screenlight not working!

Try the instructions here:
https://help.ubuntu.com/community/Webcam/Troubleshooting
helped me with my Acer V5, at least with guvcview I know my webcam is supported... hm, but still black in Skype. Good luck!


Home directory lost the execute permission flag. What can cause this?

Even though you've said it didn't happen with human intervention, the most likely cause is that someone recursively changed permissions higher up in the filesystem, and the command affected more than was expected.  An example would be running chmod -R a-x /home/someuser, which would affect directories as well as regular files.

It may have been a custom script that ran the chmod command - check your crontab to see if there are any scheduled jobs that may have done it:

crontab -l


How to open the desktop of Ubuntu machine?

if you ssh'd with the -X option you can launch GUI programs through X11 forwarding. Then just start the GUI program you're interested in. For example, to explore the filesystem GUI:

ssh -X user@serve.whatever

...after connection...

nautilus .

This is really bad practice though, the X11 connection is slow, and you'll hate it. Better to just get comfortable with the CLI.


The process is:

Launch chrome
Right click on it in the launcher and select lock to launcher

And you should see chrome still there after you closed it.


How do I install JDK 8 with NetBeans(Cobundle) on 16.04 Ubuntu?

Open terminal (Ctrl + Alt + T)
Change the current directory path where you have downloaded the .sh file in terminal using following command

cd path/to/downloaded-file
Take Read/Write/Execute permission by typing following command in terminal for the downloaded .sh file

sudo chmod 777 downloaded-file.sh
Run the file by

./downloaded-file.sh

Done!


Question seems to be related to creating a Kiosk Mode Ubuntu session. If this is the case, you have several options.

Ubuntu: you have two options here. First, you can just install a light version of Ubuntu and customize it such as it becomes a kiosk. Or you can start from a full ubuntu desktop and customize it to become a kiosk. Naturally, the former is better in terms of resource use. There are plenty of guides online, so it would be a bit redundant to write all the steps here. This guide is an example (for 14.04, but it should work for 16.04 too).
Purpose built kiosk OS: there are a several options around of open-source OS that are basically just a Kiosk mode. As such, they are very light in resources requirements. A few examples: Porteus Kiosk, Symphony OS and Instant WebKiosk.


Updating Quantal 12.10 to Raring 13.04 broke seahorse-nautilus

That would be bug 697895 in the Gnome Bugtracker

So far all you can do is confirming the bug over there and wait. /:


Micro SD card shows wrong capacity and files disappear. Can it be fixed?

The explanation is based on my experience and knowledge : Crossing portable storage solution from different architecture/OS may corrupt the partition table. A corrupted partition table can prevent from using the existing partition or creating new working partition.

Solution with ubuntu computer :

Insert SD card in the computer and open a terminal

lsblk

Find the sdcard in the output. Unmount any mounted filesystem, for example:

udisksctl unmount -b /dev/mmcblk0p1
sudo apt-get install parted
sudo parted
(parted) select /dev/mmcblk0
(parted) print
(parted) mktable msdos
(parted) mkpart primary fat32 1 31300

The last number depends on your SD card. To know that number you need to look at the second line of the print information. mine was 31.3GB so I entered 31300 which is in MB. It is up to you to find this information or to write back here.

(parted) print
(parted) quit
mkfs.fat /dev/mmcblk0p1

You should have a working SD card now.

Some notes on the commands:

(parted) means that you are still in the parted utilty.
/dev/mmcblk0 is a guess since it can vary from a system to another. Use the correct label for your sdcard
Be careful to carefully select the right device with parted. If you are not sure that you are selecting the right one come back here and ask.


Turning Off Automatic Brightness in Ubuntu 17.10

What if you try to set and control brightness via xbacklight?

Basic commands of xbacklight are:

sudo apt install xbacklight
xbacklight -get
xbacklight -set insert-here-a-percentage-value-from-1%-to-100%

I had the same issue after installing nVidia drivers and the brightness control was gone. With xbacklight you can even gradually increase or decrease brightness and add the relative commands (see help) to keyboard shotcuts.


Make a Python program executable from its icon

Although your question might be on the edge for more than one reason (too broad, off topic, more than one subject per question, on the edge of a number of almost-duplicates), I'll answer the question(s).

The first question: about running a (text-only) script "from an icon", as you mention it:

Your script is text-only, and needs to be run in either Idle or a terminal window. That means that if you want to run it by double-clicking from an icon, you'd need to create a .desktop file, in which is defined to run the script inside a terminal window.
These .desktop files are part of practically all GUI applications installed on Ubuntu by the way.

A very basic example, fit for your script:

[Desktop Entry]
Name=Test
Exec=/home/jacob/Bureaublad/test.py
Terminal=true
Type=Application

The most interesting lines are:

Exec=/home/jacob/Bureaublad/test.py

in which the command to run your script is defined.
Read more on how to create the command, the script being executable or not, using the shebang, language extension, see here.

and the line:

Terminal=true

That says the script needs to be run in a terminal window.

You can extend your .desktop file with a.o. an icon and a lot more options, depending on what you are using it for exactly, see here.
How to use the .desktop file

Paste the code above in an empty file, save it as test.desktop. Edit the command in the line Exec=/home/jacob/Bureaublad/test.py, according to the link I added to create commands to run a script.
If you use the file from your desktop, make it executable with the command:

chmod +x /path/to/Test.desktop

Alternatively, you can copy (move) the .desktop file to ~/.local/share/applications to make it available in Dash. Globally installed applications store their .desktop files in /usr/share/applications. In the last two directories, there is no need to make the .desktop file executable.

About the example lines you don't understand

The lines:

#!/usr/local/bin/python
#!/usr/bin/env python

are shebangs; the first line of a script, telling the shell how to run it if the script is executable, and you run it without python before the path to the script. Since you use python3, the shebang in your scripts should normally be:

#!/usr/bin/env python3

More on this, and the relation between shebang and command in the link above.
CHMOD X (?) chmod +x is probably what you mean. As explained above, you can make a file executable with the command:

chmod +x /path/to/file


How do I setup software RAID 0 or JBOD with BTRFS?

Read more about Raid here: RAID levels

You could use 4+4GB space, if you run it as raid 0, so 8gb in total. The risk of failure will be like 10 times higher with this configuration.

You could also run JBOD instead of RAID 0, which will result in 12GB of usable space.

What I would recommend: Mount the SD-Card as /home. This will give you 4GB for the system, and 8GB in your home, where all your user specific data is beeing stored.


fatal: unable to access “…”: gnutls_handshake() failed: Handshake failed

I get "gnutls_handshake() failed" message as well.
You could try to compile git with OpenSSL instead of gnutls using Paul N. Baker's shell script.

This shell script works for me.


How to make the shutter top panel icon to be permanent?

To have the shutter icon in your tray every time you login, you have to add it to your startup applications.

Since you probably don't want to see its window every time you login, add --min_at_startup to the call.

Start the program 'Startup Applications', click 'Add', enter a name and description of your choice in the dialog. Then, as command, enter:

/usr/bin/shutter --min_at_startup

and click the dialog's 'Add' button. Once you logout and in again, the shutter icon should be in your tray.


Try first:

sudo apt update

and then

sudo apt install carla-git


Error while installing Android Studio, no JDK found

To solve this error I had to do the following:

Install the Default JDK

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

Set the JAVA_HOME Environment Variable

Get the JDK path here:

sudo update-alternatives --config java

Edit the environments file

sudo nano /etc/environment

And add the JAVA_HOME path to the end of the file:

JAVA_HOME="/usr/lib/jvm/java-8-oracle"

Then reload the environment with

source /etc/environment

After that I was able to start the Android Studio setup without the error.

Source: How To Install Java with Apt-Get on Ubuntu 16.04


Which is the best package to draw drawings in python?

I don't know if the packages you listed would work, but I remember using gtk.gdk.Pixmap() and gtk.DrawingArea() to draw.


VLC, Totem etc very slow frame rate/choppy but Firefox VLC plugin works fine

I've been having similar issues with VLC lately in 14.10. I use firefox with no plugin (all disabled) and mp4 plays fine as well. Switching to parole media player seems to work just great but not as many options as VLC (playback speed etc).

One thing you can do for your intel chip is to first install vdpaudrivers http://www.webupd8.org/2013/09/adobe-flash-player-hardware.html and in your vlc settings there is an option for hardware acceleration. make sure that box is selected and you can even specify to use the VDPAU va gl acceleration if i'm not mistaken.

Here's how to install the drivers:

sudo apt-get install i965-va-driver
sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install libvdpau-va-gl1

Another way to run VLC with hardware acceleration is to use the following command (after installing the drivers):

VDPAU_DRIVER=va_gl vlc

or

VDPAU_DRIVER=va_gl totem

or

VDPAU_DRIVER=va_gl parole

It also helps to install the intel-linux-graphics installer. You can do that with the following commands:

wget https://download.01.org/gfx/ubuntu/14.04/main/pool/main/i/intel-linux-graphics-installer/intel-linux-graphics-installer_1.0.7-0intel1_amd64.deb
sudo apt-get install gdebi
sudo gdebi intel-linux-graphics-installer_1.0.7-0intel1_amd64.deb
sudo apt-get -f install
sudo intel-linux-graphics-installer

Finally, it really doesn't hurt (it helps) to have all the opengl support you can find. The synaptic package manager can help you search for and locate opengl packages. Just pay attention to what get's uninstalled if anything and never accept changes before reviewing to make sure installing stuff isn't going to uninstall something important in the process.

more info: https://01.org/linuxgraphics/downloads


Tkinter is a wrapper around the Tk widget set.  According to http://wiki.tcl.tk/3158, Tk does not support bidirectional text rendering, which would explain why the Urdu characters were displayed left to right.

Unless you've got a particular attachment to Tk, I'd suggest using a more modern graphics toolkit like GTK or Qt.  If you must use Tk, you'll probably be stuck needing to manually reorder characters to presentation order.


I have to prevent termination of a process

Optimize the services running on your VPS to suit the RAM available or upgrade the available RAM to provide for the services.

You could resort to adjusting the oomkiller. See the accepted answer here Set OOM killer adjustment for process on startup?


Why doesn't GNOME 3.10 work in Ubuntu 14.04

It might help to install all of ubuntu GNOME:

sudo apt-get install ubuntu-gnome-desktop

It will pull in gnome-session like Githlar suggested, and also all other things that may be needed for a smooth experience.


From man sudoers:

  sudoers uses time stamp files for credential caching.  Once a user has been authenticated, the time stamp is updated and the user may then use sudo without a password for a short period of time (15 minutes unless overridden by the timeout option).  By default, sudoers uses a tty-based time stamp which means that there is a separate time stamp for each of a user's login sessions.  The tty_tickets option can be disabled to force the use of a single time stamp for all of a user's sessions.

The "timeout" above refers to timestamp_timeout,
also explained in man sudoers:

  timestamp_timeout

  Number of minutes that can elapse before sudo will ask for a passwd again.  The timeout may include a fractional component if minute granularity is insufficient, for example 2.5.  The default is 15.  Set this to 0 to always prompt for a password.  If set to a value less than 0 the user's time stamp will never expire.  This can be used to allow users to create or delete their own time stamps via sudo -v and sudo -k respectively.

To modify the default setting of timestamp_timeout,
edit the sudoers configuration using the sudo visudo command,
and add a line near the top of the file like this:

# timeout after 30 minutes (instead of the default 15)
Defaults timestamp_timeout=30


Yes, AND No.  I have run late-ish variants of Ubuntu, 12.04 and higher on computers with less than 1g of RAM, but if I recall correctly, I had difficulty performing the installation due to the low memory.  In the end, I installed the OS on a separate computer with more RAM and then moved the drive to the computer with the lesser quantity of RAM and it worked.  I would not go so far as to say it worked terribly well, but it worked.

In my experience Pentium 4's actually run pretty well with Ubuntu, provided they have enough RAM.  My definition of enough might not be someone else's.  In my experience, the cutoff is about 1.25gb, below which the system is annoyingly slow and prefers to have only one application loaded at a time.  My advice to you would be to see if you can add 1gb of RAM to your machine.

I would guess that your 512 is made up of two 256 modules.  I would advise you to take one of them out and replace it with a 1gb, thus upgrading to the minimum I outlined and spending a minimum of money.  If you can afford to purchase two such modules and expand your memory to 2gb, I would advise doing so.

Had you listed the brand and model of your machine, I probably would have looked up a favorable price for you on Amazon.com


Reinstall all dependancies of a single package

You need a bit of text processing to feed the actual command to apt-get. The following should do :

sudo apt-get install --reinstall $(apt-cache depends package | \
     grep -Po 'Depends:\s+\K[^ ]+$' | tr '\n' ' ')

Replace package with the actual package name. You can also do a --dry-run before proceeding to be sure of the actions.

It has couple of parts :

apt-cache depends package will find the dependencies of package
grep -Po 'Depends:\s+\K[^ ]+$ | tr '\n' ' '' will get us only the name of the dependencies in a space separated form
So the command substitution pattern $(apt-cache depends vim | grep -Po 'Depends:\s+\K[^ ]+$' | tr '\n' ' ') will feed the name of the packages to apt-get install --reinstall.

Example using vim :

$ apt-cache depends vim | grep -Po 'Depends:\s+\K[^ ]+$'
vim-common
vim-runtime
libacl1
libc6
libgpm2
libpython2.7
libselinux1
libtinfo5

$ sudo apt-get install --dry-run --reinstall $(apt-cache depends vim | grep -Po 'Depends:\s+\K[^ ]+$' | tr '\n' ' ')
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
  libc-dev-bin libc6:i386 libc6-dbg libc6-dev libpython2.7-minimal
  libpython2.7-stdlib python2.7 python2.7-minimal
Suggested packages:
  glibc-doc glibc-doc:i386 locales:i386 python2.7-doc
The following packages will be upgraded:
  libc-dev-bin libc6 libc6:i386 libc6-dbg libc6-dev libpython2.7
  libpython2.7-minimal libpython2.7-stdlib python2.7 python2.7-minimal
10 upgraded, 0 newly installed, 6 reinstalled, 0 to remove and 506 not upgraded.
Inst libc-dev-bin [2.19-0ubuntu6.5] (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [amd64]) [libc6-dev:amd64 ]
Inst libc6-dev [2.19-0ubuntu6.5] (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [amd64]) []
Inst libc6-dbg [2.19-0ubuntu6.5] (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [amd64]) []
Inst libc6 [2.19-0ubuntu6.5] (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [amd64]) [libc6:amd64 on libc6:i386] [libc6:i386 on libc6:amd64] [libc6:i386 ]
Inst libc6:i386 [2.19-0ubuntu6.5] (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [i386])
Inst libacl1 [2.2.52-1] (2.2.52-1 Ubuntu:14.04/trusty [amd64])
Conf libc6 (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [amd64])
Conf libc6:i386 (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [i386])
Conf libacl1 (2.2.52-1 Ubuntu:14.04/trusty [amd64])
Inst libselinux1 [2.2.2-1ubuntu0.1] (2.2.2-1ubuntu0.1 Ubuntu:14.04/trusty-updates [amd64])
Conf libselinux1 (2.2.2-1ubuntu0.1 Ubuntu:14.04/trusty-updates [amd64])
Inst libtinfo5 [5.9+20140118-1ubuntu1] (5.9+20140118-1ubuntu1 Ubuntu:14.04/trusty [amd64])
Conf libtinfo5 (5.9+20140118-1ubuntu1 Ubuntu:14.04/trusty [amd64])
Inst libgpm2 [1.20.4-6.1] (1.20.4-6.1 Ubuntu:14.04/trusty [amd64])
Inst python2.7 [2.7.6-8] (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64]) []
Inst python2.7-minimal [2.7.6-8] (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64]) []
Inst libpython2.7 [2.7.6-8] (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64]) []
Inst libpython2.7-stdlib [2.7.6-8] (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64]) []
Inst libpython2.7-minimal [2.7.6-8] (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64])
Inst vim-common [2:7.4.052-1ubuntu3] (2:7.4.052-1ubuntu3 Ubuntu:14.04/trusty [amd64])
Inst vim-runtime [2:7.4.052-1ubuntu3] (2:7.4.052-1ubuntu3 Ubuntu:14.04/trusty [all])
Conf libc-dev-bin (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [amd64])
Conf libc6-dev (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [amd64])
Conf libc6-dbg (2.19-0ubuntu6.6 Ubuntu:14.04/trusty-updates [amd64])
Conf libgpm2 (1.20.4-6.1 Ubuntu:14.04/trusty [amd64])
Conf libpython2.7-minimal (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64])
Conf python2.7-minimal (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64])
Conf libpython2.7-stdlib (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64])
Conf python2.7 (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64])
Conf libpython2.7 (2.7.6-8ubuntu0.2 Ubuntu:14.04/trusty-updates [amd64])
Conf vim-common (2:7.4.052-1ubuntu3 Ubuntu:14.04/trusty [amd64])
Conf vim-runtime (2:7.4.052-1ubuntu3 Ubuntu:14.04/trusty [all])


virsh list lists the given names of the VMs, not the hostnames. You can give a VM a name with --name option at virt-install command. I guess your host was given a random name, because no name was specified when creating it.
To display the hostname of a VM (domain as QEMU and KVM say) you can use following command at your case:
virsh domhostname instance-00000005

Or more spefically:
virsh domhostname DOMAINNAME


Doesn't work on Chrome for me as well.  However, firefox is not an issue. You can also use VLC locally to view the stream or on your cell provided it's connected to the same LAN.  Chrome may be trying to connect to https://localhost instead of http://localhost.


Trick installer to use btrfs root with compression

An easier way to do this is to alter the mount command of the live environment.

Boot as usual to the live session.
Move the mount executable to another location:

sudo mv /bin/mount /bin/mount.bin

Edit a new file using sudoedit /bin/mount and save the following script into it (alter the options as you like; here we have added compress):

#!/bin/sh
if echo "$@" | grep -q -- "-t btrfs"; then
    /bin/mount.bin "$@" -o compress
else
    /bin/mount.bin "$@"
fi

You can also match block devices like /dev/sda1 instead of -t btrfs and chain elifs to use different mount options for different devices and filesystems.
Copy the original permissions over to the new script:

sudo chmod --reference=/bin/mount.bin /bin/mount

Install as usual and your btrfs partition will be mounted with the specified options (here, compress).
After the installation is finished, before exiting the live envirement, alter the /etc/fstab of the newly installed system to match the specified options, so it will use the same options on new boots.

I used: defaults,noatime,compress-force=lzo,space_cache as mount options.

This works with quantal daily (30/6/12).

I used the btrfs partition as / and a swap partition.

Credits go to this post (in this thread), which in turn cites this blog post.


Which option ("internet site", "internet with smarthost", "satellite system") should I choose in postfix configuration?

Main options explained

Internet site: Mail is sent and received directly using SMTP.

This option requires you have a fully qualified domain name and full access to modify DNS records for this domain name as this method requires adding a MX record and a reverse DNS for it to send and receive emails.

Internet with smarthost: Mail is received directly using SMTP or by running a utility such as fetchmail. Outgoing mail is sent using a smarthost.

This option requires you have a fully qualified domain name but not necessarily full access to modify DNS records for this domain name. You pay for mail service providers or smarthosts to send emails on your behalf and provide a rout / method to delver incoming emails to your machine either by handling the MX and other DNS records for your domain name or by receiving them on their servers and provide you with mail server address, port and credentials so that you can periodically fetch incoming email using different protocols like POP and IMAP.

Satellite system: All mail is sent to another machine, called a 'smarthost', for delivery.

This option does not require you to have a fully qualified domain name nor access to modify DNS records. This is what serves your purpose as described in your question.
Setting up an email relay
1. General settings
You can reconfigure postfix and choose the correct option like so:
sudo dpkg-reconfigure postfix

In the configuration screens, you will see:

General type of mail configuration: From this choose Satellite system.

System mail name: Inter your machine's hostname which will most likely be displayed by default.

SMTP relay host (blank for none): Doesn't matter at this stage as you will set it again when you modify /etc/postfix/main.cf so leave the default.

Root and postmaster mail recipient: Leave it blank to have local emails to postmaster which is defined in /etc/aliases delivered to /var/mail/nobody or set the system user to receive it instead... This has nothing to do with relaying emails. This is to handle emails sent locally to for example root@localhost or other local users accounts that might be in /etc/aliases which will have something like this:
# See man 5 aliases for format
postmaster:    root

Other destinations to accept mail for (blank for none): These are hostnames that your postfix installation will accept emails for them... So leave this at the default which will be all possible hostnames for your current machine only.

Force synchronous updates on mail queue?: This tells postfix to implement some sort of internal journaling system which will slow it down but only needed when your file system is not a journaled filesystem which is not the case with Ubuntu's ext4 filesystem... So choose No.

Local networks: Similar to "Other destinations to accept mail for" above... This is a security feature so that other hosts on your network or outside it cannot send emails through your postfix instance... So leave it at default.

Mailbox size limit (bytes): Self explanatory... I recommend you leave it on default i.e. unlimited.

Local address extension character: Leave it on default as email providers will base their specific instructions for postfix integration on this being default.

Internet protocols to use: Leave it on all unless you know what you are doing... all should work fine.

It is worth mentioning that if you edit /etc/postfix/main.cf afterwords then it does not matter what option you chose during the initial configuration above and many guides advise choosing different options... compare this and this... Those guides however do not explain this point clearly and it might cause some confusion.For example one guide tells you to choose Internet Site then afterwords tells you to modify /etc/postfix/main.cf and set relayhost which will change postfix from standalone mail server to a relay mail server i.e. as if changing the option to Satellite System!
For the relay option /etc/postfix/main.cf will contain something with relayhost set to an e-mail provider like this:
relayhost = [smtp.gmail.com]:587
smtp_use_tls = yes
smtp_sasl_auth_enable = yes
smtp_sasl_security_options =
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt

2. Email provider's specific settings
After that follow your email provider's specific instructions for postfix integration like:

these easy instructions for setting up postfix with relay to Gmail.

these easy instructions for setting up postfix with relay to Yahoo.

The process should be similar for other email providers if they offer this feature. If your e-mail account is with another provider, please refer to their documentations regarding relayhost address, port, security and authentication.
Please, pay attention to specific relay e-mail provider requirements like for example enabling less secure apps for Gmail or otherwise postfix will be denied access and connection to Gmail.
Extra resources

Please also see this related answer.
Reverse DNS.
MX record.


How to import numpy as standard user from server?

this sounds like your $PATH isn't pointing to those executables.

try running the following as root and then as as user

echo $PATH
which python
echo $PYTHONPATH

this will tell you which python installation you are using and where it is looking for installed python files.

It sounds like your user accounts are not pointing at the same python setup. Its best with python to only use root to update the system packages as most distros require specific python versions for some of their internal tools.

Have a look at Virtualenv installations for your user accounts , this way you can have a custom setup for each user that will not conflict, its also easier to migrate that user to other machines as the python setup will be entirely in its homedir.


You need to import the certificate in your browser of choice.  In chrome, you can find this under advanced settings -> manage certificates -> import your certificate.


Will I encounter any problems if I change the App switcher to another using CCSM. 15.10 64 bit

I thought of a very simple way. Testing in Guest session. In the end is just about disabling conflicting key bindings of previous settings.


Install Ubuntu 13.04 alongside Windows XP Pro - No option

assuming your guess of hard disk(80 gb) beeing unpartitioned......
on your windows right click on my computer icon select the manage option.
a new window will appear in which select storage devices->disk management.
your 80 gb partition will be displayed .
right click on the partition ,select the option shrink volume to your required size.
format the new partition.
now insert ubuntu live cd and you will get the option "install along side of windows" option.
hope it will work.


How I can extract files, name.iso.001 name.iso.002 and so on

cat name.iso.001 name.iso.002 so on > newName.iso

does the job almost all the time.
Otherwise there is utility called lxsplit

sudo apt-get install lxsplit

I never used lxsplit but I think the way you use it to join is:

lxsplit -j name.iso.001


Try this:

apt list --installed | grep "xxx"

Edit: Alternatively, as Chev_603 wrote, you can do this:

dpkg -l | grep "xxx"

Edit 2: about apt list, see man apt. Looking at man apt-get shows that apt-get does not have the list --installed option.


i dont know if i understand that right or no,but upon what i understand that while you was importing new ppa or repos you mess up with your old one.so that link may be solve your problem


How to set an image background for file manager (caja file manager)

You have to use Caja GUI:

Edit → Backgrounds and Emblems and then drag needed Pattern or Color

to the Caja window of interest. You can use your custom image by clicking on Add a New Pattern (image should allow patterning).

To reset the background setting you have to drag Reset pattern or color to the window.

Notes:

the background will be shown in Icon View and Compact View.
you have to set 'background-image' path by using gsettings:

gsettings set org.mate.caja.preferences background-set 'true'
gsettings set org.mate.caja.preferences background-color ''
gsettings set org.mate.caja.preferences background-uri 'file:///usr/share/caja/patterns/dots.png'

also you have to set 'background-color' by using gsettings:

gsettings set org.mate.caja.preferences background-set 'true'
gsettings set org.mate.caja.preferences background-uri ''
gsettings set org.mate.caja.preferences background-color '#E5E5E5'

to remove background programmatically use:

gsettings set org.mate.caja.preferences background-set 'false'


You could try the following command.

unity --reset-icons

That will reset all icons to default and if that fails reset Unity .

unity --reset


Open network settings, then select your internet access point using the orange arrow...

then click "Settings" to configure your advanced internet settings.


Look at Beaglebone Black which is an open source HW running Angstrom. You can also run Android on Beaglebone Black. It is a TI sitara ARM Cortex A8 Application processor. (BTW I believe Angstrom and Yocto project have merged)

Also Freescale and other vendors have ported Linux to ARM Cortex A8 processor.

Atmel has ported Android to an ARM Cortex A5 processor (SAMA5D3).

Since Ubuntu is built for desktop and server applications you might have to over come some  challenges to get Ubuntu working for Embedded applications. I have seen Ubuntu running on a ARM Cortex A8, but I am not sure if it is a preferred choice.

BTW Raspberry PI is very popular in Europe.

Hopefully this will get you started.

Like to hear from to community on this topic.

References

Ubuntu Server for ARM
Beaglebone Black
Raspberry pi


How do I set up a kiosk that uses java and plays a . jar file only?

You can do this very easily using Workbench, a web-based Linux configuration and build system created by my company, RapidRollout (I am the founder). Workbench has built-in support for configuring a Java application to run as a kiosk application like you describe. In fact, we made a YouTube video showing how to create a Space Invaders arcade console using Workbench, which you can watch here. I think that is pretty close to what you are looking for.

Hope this helps.

-Forest


It seems like there was an update for VmWare which broke it. You can install VirtualBox, I guess, it supports same virtual hard disc. More information about migrating is here and Oracle official instructions are here - since you can't boot VmWare, you will have to modify steps from official instructions.

To answer to other questions, no internet connecion is required to start Ubuntu since most devices uses wifi connection, which connects after OS boot. And no, it doesn't matter if you use another mouse in another USB.


Move wireless passwords to another computer

As @Alaa mentioned, you'd want to copy your system connections to the new computer. Just doing a quick copy of files from /etc/NetworkManager/system-connections/ will suffice.  If it doesn't work double check that permissions are rw for root only.

If you have any VPN connections, you'd want to do that for /etc/NetworkManager/VPN as well.

User-specific ones are stuck in your keyring. If you want, you can copy that to a remote location and drop it onto your new system.


Ubuntu 12.10 can't see eth0 after update from 12.04

I started the root prompt from recovery mode in the oldest version of all installed kernels. That was a bad idead. I tried recovery mode with the newest kernel and ethernet started working. From there on I could install nvidia-current, and now I'm all set!


Now it is named "Disks". Search for it in the Lens. (command gnome-disks)

And more options are as follows:


Radeon HD6870 fan goes frenzy after unsuspend

I have managed to fix it with the following script:

#!/bin/bash
sudo aticonfig --pplib-cmd "set fanspeed 0 20"


Ubuntu 12.04 - Trouble with UFI Boot on Macbook Pro Retina (late 2013)

You need to boot in to OSX and install rEFInd in OSX, Macs dont reconize any version of linux by default, so your need to install it on your OSX partition. After that you reboot your mac and rEFInd should pop up


Assuming that you are using Ubuntu 20.04.1 LTE
sudo apt-get update
sudo apt-get install ibus

Then restart the system

Open the “Language support” window (you can search for it)
Language support
Choose “IBus” from the keyboard input method system under the language tab.
Click the “Install/Remove languages...” button and check the
“Sinhala” language in the popup box and apply it.
Check Sinhala
Open the "settings" -> “Region & Language” window Click the “+” Plus sign on the Input sources section.
Region & Language
Choose “Sinhala” on the popup box to view available keyboard methods.
Add new keyboard input method
Then Select “Sinhala (wijesekera(m17n))” at the bottom. You are done.
Add wijesekara unicode input layout

To Swithc keyboard =  [Win] + [Space bar]
සිංහල =  i+s+x+y+,
සඳහා = i+ [alt+ o] +y + d
ශ්‍රේණිය  = f+Y+`+a+K+s+h
සංගීතය = i+x+.+S+;+h
Sometime combined letters are not work in Libre office.
Ex. න්‍ද = k+[] + o


Icon size/spacing settings for Ubuntu 17.10

For Ubuntu 17.04 (and 17.10) with Gnome Flashback: Go to Files (file manager app), go to the Desktop folder, hold control + scroll mouse wheel. This changes the sizes in both the window and on the desktop.
original answer from: Ondra Žižka Jun 27 '17 at 14:10 at
How to resize the icons of the desktop?
(added the 17.10 part...)


How can I change the color of each bar in a bar graph using open office?

By first click we can select the chart bars as a whole. Then by performing a second click on one of those bars to select one of them we can change the Format Data Point -> Area by right click context menu:

There is admittedly a bit of mouse click acrobatics needed but once you have the timing it is pretty fast. This was tested with Libre Office but should also work in Open Office.


Change command from

sudo iwconfig wlan0 channal 1

to

sudo iwconfig wlan0 channel 1


How can I use chromecast with Ubuntu touch (phone)?

Currently, on most of the devices, it's not supported to do so, and there is no way to install and enable the Cast extension in the Ubuntu Browser.

However, you can set up a Libertine container and install Chromium in it, with the Terminal app or over ssh/adb:

$: libertine-container-manager create --id xenial --name 'Chromium'
$: libertine-container-manager install-package -i xenial -p chromium-browser

Then, install the Desktop Apps Scope from the store, and it should show Chromium to launch. You should then be able to install the Cast extension in it. Note though, the E4.5 is very limited in CPU and RAM, and so you may not actually be able to run Chromium reliably enough for this purpose on that device.


Error mounting ESP prevents installation

I suggest you should use Gparted to format the particular partition you wish to use to reinstall Ubuntu. Format as ext3 or ext4 not vfat. Ubuntu file systems are based on ext file systems. If it was Windows then NTFS would be used.

Try that and see if you are able to install Ubuntu


How to use ubuntu dash as online search engine?

Yes, you can do this. Open your terminal and paste these lines one by one.

sudo add-apt-repository ppa:scopes-packagers/ppa
sudo apt-get update
sudo apt-get install unity-lens-answers

Then restart your computer for the changes to take effect.


After an new update the system is working ok again.

The first time I had to:

ifconfig eth0 up
dhclient eth0

When you have connection then try to update the system. Hopefully it will be solved in next update.

Important.  Set the "proposed" repository turned off.