14.04 LTS login window is hidden until mouse pointer is moved to the right

The login screen is called greeter in Ubuntu. While I can't think of exact fix, I can suggest a work-around. Basic idea is changing the greeter. Now, depending on which desktop manager program you are using , the configuration settings will be different. I assume you have lightdm manager, which is default that comes with Ubuntu. Here's procedure for replacing lightdm's default unity greeter with lightdm-gtk-greeter.

When Ubuntu starts and gets to login screen, press Ctrl+Alt+F2  to get to tty terminal screen. Login with your user name and password.
Enter the following command sudo apt-get install lightdm-gtk-greeter , it will prompt you for password, and after you enter, it will run a bunch of commands, asking also if the size of installation is okay. This will install the lightdm-gtk-greeter on your machine.
After installation is done, we need to alter lightdm's settings so that the default greeter is replaced with lightdm-gtk-greeter. Still in the terminal window enter sudo nano /etc/lightdm/lightdm.conf . This will open configuration file  lightdm.conf in the Nano command line text editor(very useful app, by the way).
Add the following line to this file greeter-session=lightdm-gtk-greeter ; Press Ctrl+O, it will prompt you for file name to write, don't change file name - just press enter. Once it says wrote, press Ctrl+X to exit.
Now the settings have been changed. Reboot the computer using this command sudo shutdown -r now and the window for username and password should be placed in the center of the screen now, which is how gtk greeter normally looks.

This procedure works for a variety of other greeters. However if you have different desktop environment, like gdm, the procedure will be slightly different, but the main premise is the same - entering command line,downloading proper greeter, altering configuration files, reboot. I've listed additional information and links bellow. Let me know if that helps. Cheers !

Sources:  archwiki , askubuntu.com, ubuntu wiki, and some personal experience messing with lightdm settings;

Bonus : here's some of my favorite command line apps in case GUI stuff doesn't work or you can't log into graphical shell

Midnight Commander - file manager; sudo apt-get install mc
elinks command-line web browser; sudo apt-get install elinks
moc command line music player; sudo apt-get install moc and mocp to actually run it;


Change keyboard layout (Dvorak, Qwerty, etc.) in Ubuntu 18.04.1 LTS

You were part way there.

Click one of those English items as shown in your screenshot, such as English (United States). Clicking reveals an additional list of more options. In that secondary list you should see a English (Dvorak) item. Select, then click Add button.

You will now find a en menu on your main screen. Use that menu to choose between keyboard layouts (Dvorak, Qwerty).


From experience, for 12.04 and up almost all webcams work out of the box. I have tested the following and they work perfect:

Logitech C200, QuickCam Pro 3000, Pro C920, C270, C310, C615 and a couple others I do not have with me nearby.
Genius Slim 320, Eye 320 and 2 more that I do not remember ^^.
HP HD 4110 and one more but is not HD.

Apart from Logitech, Genius and HP I have had others that have weird names so I do not remember them.

Even though the list here: https://wiki.ubuntu.com/HardwareSupportComponentsMultimediaWebCameras mentions a group of webcams, there are many more that are not there and actually work out of the box.

There are even lists in the web like the following which list an amount of webcams that work (Although this sites are not updated regularly):

http://www.302found.com/linux_usb_video/

http://www.linuxtv.org/wiki/index.php/Gspca_devices

http://www.ideasonboard.org/uvc/#devices

but you have a very good bet that the webcam you buy will work.

One thing I do have to add is that, for HD webcams that have buttons, for example, to take a picture or open a webcam app, this buttons do not work for the moment. At least on 2 Logitech I tried and an HP. Apart from that they do offer resolutions at 1080 and are perfect.

With regards to the price, at least several that appear in this list I have already tested and work out of the box: http://www.amazon.com/Webcams-Computer-Add-Ons-Computers/b?ie=UTF8&node=172511

And for 25$ or less several here I have already tested and also work: http://www.amazon.com/s/ref=sr_nr_p_36_0?rh=n%3A172282%2Cn%3A!493964%2Cn%3A541966%2Cn%3A172511%2Cp_36%3A1253503011&bbn=172511&ie=UTF8&qid=1347329616&rnid=386442011

Do not pay attention to the mention of "Works with Microsoft Windows". Most hardware works on Linux without the need to install additional drivers.

What I do recommend is after buying the webcam you need to install cheese to test the webcam out. I like cheese because you can change resolutions for video and pictures and add effects to the webcam and see how it performs.


How do I connect using ssh over a direct Ethernet connection?

To establish basic network connectivity between two computers, it's much easier to connect computers using a SOHO network switch (something equivalent to, say, a Linksys SE1500) and then assign static IP addresses to each host. This is a more flexible and robust configuration than a direct link. Definitely worth the ~40 bucks.

If direct link is the only option, http://ubuntuforums.org/showthread.php?t=1543087 has details. The use of a cross-over cable may not be a hard requirement if both computers support Auto-MDIX.

The SSH wiki page should tell you what you need to get SSH running on your desktop. Once you've got a SSH connection established, you can just copy the required files to a known location like your home directory with cp. Example:

cp /var/log/Xorg.0.log ~/


SDL2 not being loaded correctly by Jedi Academy (OpenJK)

This is not the right way to do it, but there are no other answers, and this worked for me. I've always had similar problems locating SDL libs. It helped me to find out where are the libraries installed.

Last time I installed libsdl2-dev, apt-get said (in /var/lib/dpkg/info/libsdl2-dev.list) that the *.so where:

/usr/lib/x86_64-linux-gnu/libSDL2.so
/usr/lib/x86_64-linux-gnu/libSDL2-2.0.so

Usually, programs using SDL will search in /usr/lib/ or /usr/local/lib/, so you can try copying it in those paths and renaming it to libSDL2.so.0, which is the name openjk doesn't find.

Or a symlink:

ln -s /usr/lib/x86_64-linux-gnu/libSDL2.so /usr/lib/libSDL2.so.0
ln -s /usr/lib/x86_64-linux-gnu/libSDL2.so /usr/local/lib/libSDL2.so.0


How turn off External Display, on closing lid in Ubuntu 20.04

I think there is an additional setting.
Depending on what you are running, on the command line try:
gsettings set com.canonical.unity.settings-daemon.plugins.power lid-close-suspend-with-external-monitor true
or
gsettings set org.gnome.settings-daemon.plugins.power lid-close-suspend-with-external-monitor true
or both, if you're not sure...


Is it possible to give sudo access to only a particular command?

Yes.

Make a new group, web (call it what you wish)

sudo addgroup web

Add your developer(s) to the web group (use their login name).

sudo adduser your_developer_user web

Then run sudo visudo -f /etc/sudoers.d/somefile (use a meaningful name instead of somefile).

Add in a line (use the full path of the command):

%web ALL=(ALL) /usr/bin/service apache2 *

The developers can then run

sudo service apache

using their login password.

Do NOT add your admin user to the web group.

See man sudoers for additional information


Ubuntu 12.04 startup is slow and dmesg output seems to lose several seconds

Try install bootchart to figure out bottleneck, where the time gap is spent.

http://www.bootchart.org


What is the best Desktop search engine or software

Gnome-Do is pretty good and has alot of ratings provided obviously you use a gnome interface. Recoll and Catfish look good also but I have never tried them. All of these are in the Ubuntu universe repositories (can be found in the software center) for download. Try em out and give us some feedback.


How can I stop Firefox from dropping volume on new media?

In case someone comes across this question (as did I), there is an answer here: Inconsistent Sound Volume Ubuntu 20.04
Basically, you need to change flat-volumes = no to flat-volumes = yes.
The values "true", "1" and "on" are equivalent to "yes", according to the manpage (https://manpages.ubuntu.com/manpages/focal/man5/pulse-daemon.conf.5.html):

For  the  settings  that  take  a  boolean  argument  the  values  true, yes, on and 1 are
equivalent, resp. false, no, off, 0.

Don't forged to uncomment the respective line by removing the ";" or "#":

The   configuration  file  is  a  simple  collection  of  variable  declarations.  If  the
configuration file parser encounters either ; or # it ignores the rest of the  line  until
its end.

The configuration file is: /etc/pulse/daemon.conf
Other possible locations are: ~/.config/pulse/daemon.conf,   ~/.config/pulse/daemon.conf.d/*.conf and /etc/pulse/daemon.conf.d/*.conf:

The  PulseAudio  sound  server reads configuration directives from a configuration file on
startup. If the per-user file ~/.config/pulse/daemon.conf exists, it  is  used,  otherwise
the  system  configuration  file /etc/pulse/daemon.conf is used. In addition to those main
files,  configuration  directives  can  also   be   put   in   files   under   directories
~/.config/pulse/daemon.conf.d/ and /etc/pulse/daemon.conf.d/.

According to the aforementioned post, rebooting is necessary for the change to take effect.
About the configuration option:

flat-volumes=  Enable  'flat'  volumes,  i.e. where possible let the sink volume equal the
maximum of the volumes of the inputs connected to it. Takes a boolean  argument,  defaults
to no.

EDIT: I tested the solution myself and it worked (Ubuntu 20.04).


How to install ubuntu 18.04 on my existing ubuntu 17.04 LTS with live DVD or USB

Just install the way you installed ubuntu 17.04, (by going to boot options).

It will detect the existing files, and will prompt if you want a clean install or preserve the existing files.


Check whether less than some amount of free disk space from the command line

Just realized that this isn't what was asked for, this shows an alert if the space used is greater than a predefined threshold. I'll leave it for further reference though.

You could use something like the script below

#!/bin/bash
X=
X=$(du -sc | awk 'NR < 2' | awk '{ print $1 }')
if [ $X -gt 999000 ]; then
  message="Already using `du -sch | awk 'NR <2' |awk '{ print $1 }'` KB"
echo $message | mail -s "File System Full Warning" email@address.com
fi

X holds the number of KB used, if greater than 999000 it emails a warning message.


How to use the dd command to copy the content of a folder

It can be done
We need to workaround two problems:

dd doesn't know what to do with directories
dd can only copy one file at a time

First let's define input and output directories:
SOURCE="/media/source-dir"
TARGET="/media/target-dir"

Now let's cd into the source directory so find will report relative directories we can easily manipulate:
cd "$SOURCE"

Duplicate the directory tree from $SOURCE to $TARGET
find . -type d -exec mkdir -p "$TARGET{}" \;

Duplicate files from $SOURCE to $TARGET omitting write cache (but utilising read cache!)
find . -type f -exec dd if={} of="$TARGET{}" bs=8M oflag=direct \;

Please note that this won't preserve file modification times, ownership and other attributes.


Package Manager Error: setting up language-selector-common

This is a known bug.

Update: The bug status is now "Fix Released", so you should expect a fix with the next update to lanugage-selector.


How to change the highlight color of the workspace chooser toolbar applet?

Those colours are part of the colour scheme provided by the desktop scheme. So the only solution I can think of is to go to System -> Preferences -> Appearance and change to a different desktop scheme or customise the current one.


Have you tried reinstalling unity-tweak-tools from a command line? This should reinstall the other packages along with it. As far as removing ONLY the tweak-tools package, I'm not sure how to do that.

delta1071


Facebook chat not working with empathy in Ubuntu 12.04

For the current period (now is August 2013), this seems to be a Facebook new feature compatibility problem. The following links below shows that not only Empathy suffers this "Network Error", but also all (most, probably) IM clients.

It seems that FB has recently changed its authentication scheme. I'm not sure if someone is working out there to address this change so that Empathy will soon be compatible with FB's X-FACEBOOK-PLATFORM SASL authentication mechanism.

The best thing to probably do now (if we are not developers) is to sit down, relax, and wait until we can thank those hard-working programmers in fixing this. (And I suppose that guys both client-side and server-side are now working out for this.)

https://www.facebook.com/help/community/question/?id=10201413884891742
https://www.facebook.com/help/community/question/?id=10152943143300125
https://www.facebook.com/help/community/question/?id=658562000823930
https://www.facebook.com/help/community/question/?id=529872150394426


Automatically gracefully restart of Apache server several times a day but later manually restarting makes thing in working everytime

You'll need to figure out what is sending the graceful restart request. I had the exact same error and behavior and thought it was possibly log rotation, but that wasn't it. In my case it turned out to be Let's Encrypt's "Certbot".
I switched from using Certbot to refresh and update Apache, to using plain http on Apache and Caddy in front of it for SSL termination. So, I didn't need the Certbot/LE certs for Apache directly; however, after the Caddy config, Certbot wasn't able to re-verify and after the 30 days or so since last verification expired, Certbot started trying multiple times a day to refresh, giving up, but still trying to restart Apache, which for whatever reason it was unable to successfully do, causing this issue.
So, check if you have Certbot running (when you don't need it any longer). You can disable Certbot with the info here: How to completely remove "certbot" from ubuntu?


gdm3 .desktop file doesn't start wine 5.0 program

Resolution was to add an /etc/profile.d/wine-env.sh with one line:
PATH=$PATH:/opt/wine-stable/bin

To diagnose, I created a ~/.local/share/applications/env.desktop with:

[Desktop Entry]
Comment=simplest possible application
Terminal=true
Name=wine env
Exec=bash --norc
Type=Application
Icon=gnome-panel-launcher

and determined that there was no path to wine set. I looked in /etc (find-grep) for any file that set a PATH with one of the unique names reported by env in the diagnostic terminal window, read up on profile.d and decided that was as good a place as any to put it. [N.B. file name wine-env was chosen for easy identification; it could have been moo or oink but those were obscure. The .sh suffix is necessary.]


If your PC runs all the time you can try (as root)

crontab -e

to start the cron editor. Cron is a service that executes a script at a configured time or after a time intervall has ended.

Now add a line similar to

# m h dom mon dow    command
  0 1   *   *  0      /root/mybackupscript.sh 2> /dev/null

Then create the /root/mybackupscript.sh:

#/bin/sh
# Very simple backup script
rsync -va /home /etc /media/<user>/anotherdisk

That's it principially. I do not know where your "another disk" is mounted into the directory tree so please modify it to your needs.

cron and rsync is also a very powerful and flexible tools, so don't forget to read the man pages:

man crontab
man rsync


what does ubuntu use instead of /etc/users

/etc/passwd, which is the file that all Unix distributions use.


Connecting to the wireless(WPA) from commandLine

Apply WPA/WPA2 personal settings to device:

wpa_supplicant -B -Dwext -i $iface -c ./wireless-wpa.conf -dd

Also try apply WPA/WPA2 personal settings to device:

wpa_supplicant -B -Dwext -i $iface -c /etc/wireless-wpa.conf -dd

The directory listing could be off.


How to log in after logout in L/UBUNTU live persistent usb?

In 14.04 the username is ubuntu and the password is blank.


Machine check error on ASUS while booting from USB

I encountered the same issue in my ZenBook :

booting on a live debian
trying to boot on the installed system (didn't work, for another reason)
retry to boot on the live system => MACHINE CHECK ERROR and no boot.

I tried to boot another live usb key (with grub, not with syslinux) and it worked

Then I retried to boot my live debian system again => it worked

So it just seemed that the machine check error is coming from the fact that your machine is in a wrong state internally, and booting on something else triggered a reset somewhere ... (like in some pci state or ...)

clearly an Asus bug IMHO...


Anomalous result using bash "set" command

Those 8k lines are mainly completion functions from the bash-completion package. On my old desktop, bash uses almost a second to read through and define all those functions, most of which I never use, so I disable it.

To disable it, edit your ~/.bashrc, locate these three lines near the end, and prepend a # to each of the lines.

if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
    . /etc/bash_completion
fi

Next time you run an interactive bash session, set will only output about 50-100 lines; mostly environment variables and special shell variables.


What is the purpose of `dnsmasq` running listening on `127.0.0.1` interface?

127.0.0.1 is the loopback address, it is not accessible by other machines, just the machine itself. According to the post http://www.stgraber.org/2012/02/24/dns-in-ubuntu-12-04/, this dnsmasq instance exists to improve performance by trying multiple DNS servers if one is too slow.


Cannot successfully source .bashrc from a shell script

A shell script is run in its own shell instance. All the variable settings, function definitions and such only affect this instance (and maybe its children) but not the calling shell so they are gone after the script finished.

By contrast the source command doesn't start a new shell instance but uses the current shell so the changes remain.

If you want a shortcut to read your .bashrc use a shell function or an alias instead of a shell script, like

alias brc='source ~/.bashrc'


Ububtu 14.04 64 bit Network not working after update

Try following this method:

Open up the terminal and type in:

sudo service network-manager stop

Then do:

sudo service network-manager start

This fixed the problem for me. Hope this works for you too :)


Normally in virtual box you are connected to the internet via the host's connection.  So if your host OS is connect it's like being connected via a home network. You should not have to have any other connection.


How to setup proxy authentication only once to the entire system?

Proxy parameters
File /etc/bash.bashrc:
    export http_proxy=http://username:password@proxyserver.net:port/
    export https_proxy=http://username:password@proxyserver.net:port/
    export ftp_proxy=http://username:password@proxyserver.net:port/

File /etc/environment:
http_proxy=http://username:password@proxyserver.net:port/
https_proxy=http://username:password@proxyserver.net:port/
ftp_proxy=http://username:password@proxyserver.net:port/

File /etc/apt/apt.conf:
 Acquire::http::Proxy "http://username:password@proxyserver.net:port";
 Acquire::https::Proxy "http://username:password@proxyserver.net:port";
 Acquire::ftp::Proxy "http://username:password@proxyserver.net:port";

clamav installed, file /usr/local/etc/freshclam.conf
 HTTPProxyServer proxyserver.net
 HTTPProxyPort port
 HTTPProxyUsername username
 HTTPProxyPassword password

wgwt, file /etc/wgetrc:
In line 84 or where says:
 #use_proxy = on

Change to:
 use_proxy = on

And where says:
   #https_proxy = http://proxy.yoyodyne.com:18023/
   #http_proxy = http://proxy.yoyodyne.com:18023/
   #ftp_proxy = http://proxy.yoyodyne.com:18023/

Change to:
http_proxy=http://username:password@proxyserver.net:port/
https_proxy=http://username:password@proxyserver.net:port/
ftp_proxy=http://username:password@proxyserver.net:port/


what does it mean by if If you have a PC with the Windows 8 logo or UEFI firmware, choose the 64-bit download

UEFI firmware is a more modern alternative to the BIOS used in older computers. Windows 8 computers require UEFI because it uses something called secure boot. This means that only programs signed by Microsoft can run during boot up.

This adds special requirements needed to install another OS on the machine. Ubuntu streamlines this in the x64 iso of Ubuntu since every UEFI computer happens to have a 64-bit processor in it.

If your processor supports 64 bit, your computer will run more efficiently using 64bit code. You should choose Ubuntu64


I believe the driver you've installed is incorrect for your 14e4:4727 device. Please get a temporary wired ethernet connection, open a terminal and do:

sudo -i
apt-get remove --purge bcmwl-kernel-source
apt-get update
apt-get install firmware-b43-installer
echo brcmsmac >> /etc/modules
exit

Reboot and your wireless should be operating correctly.


While you are correct if a system has had the malicious code running on it overall it's now compromised and needs to be wiped. It's possible for malware to live beyond a single install, but not very likely.

You can also run debsums to validate the package integrity. It's possible for an attacker to add himself to your /etc/apt/sources.list and similar files so that these signatures are "valid" but unlikely.

Otherwise the code can also be included as a binary "override" somewhere like /usr/local/bin/gnome-login-manager or similar allowing them to inject their code when that program is used.

A kernel module could also have been installed which does the malware. Can also be a chrome extension.


MacBook can’t find WiFi for Ubuntu 18.04

I think I have the exact same hardware (13 inches?) and OS installed, and I too had problems with my wifi card. The easiest workaround is to have an Ethernet connection while you install Ubuntu and check the "install proprietary drivers", but I guess it's too late for that one.

Still, you will need an internet connection through Ethernet to solve this, as you have to download and install the drivers.

If you open "Software & Updates" and go to the "Additional Drivers" tab, what do you see? It should look similar to my screenshot.

Make sure "Using Broadcom 802.11 ..." is selected, probably it says "Do not use this device". Once you click the other radio button and then hit apply, it should download and install the driver.


My Upgrade From ubuntu 12.04 to 12.10 got cancelled due to powercutoff

Press ctrl alt f1 and then login there. after that type as

 sudo dpkg-configure -a


Error while mounting partition with Live CD

This error looks like your HDD is mechanical broken or the filesystem is broken.

Try to start sudo fsck /dev/sda from a terminal in your Live-OS. Maybe the FS can be recovered. Additional to that you can check the SMART-Status of your Drive.

Install the tool via sudo apt-get install smartmontools.
You can check the actual SMART-Status with sudo smartctl -a /dev/sda and you can run a extended test with smartctl -t long /dev/sda

Maybe you get some results shown, so you can decide what' the next step.


The preferred way to upgrade Xubuntu to the newest LTR version is to do:

sudo do-release-upgrade

The manual way you were attempting can be used to upgrade to any version you desire. however, some manual clean up is required after because apt-get will try to resolve the upgrade with the minimal amount of removals.
To manually upgrade:

First run: apt-mark showhold to be sure nothing is being held back.
If you find held packages then remove the hold and update them I find aptitude is the easiest way for marking and updating multiple packages at one time. Aptitude will also suggest removal of orphaned packages (packages that are no longer used by anything).
sudo apt-get autoremove will also remove packages that are no longer used.

After your system is fully up to date in the current version, change you sources to point to the version of Xubuntu that you want.
EX: change "trusty" to 'xenial"

Next run this series of commands:

sudo apt-get update This updates the package list
sudo apt-get upgrade This upgrades packages that can be upgraded without changing other packages. thus easing the dependency resolving in the next step.
sudo apt-get dist-upgrade This upgrades the remaining packages that can be upgraded with a minimal amount of removals.

You now have the new version of Xubuntu, and need to clean up obsoleted packages. Again I find aptitude to be the easiest way to do this.
Open aptitude and it will already have a list of suggested removals (orphaned packages), it is generally safe to remove them.
Now go through the remaining obsolete packages. In most cases, remaining packages have been replaced with another: ie gt4 with gt5 and gstreamer0.1-good with gstreamer1.0-good. The replacements will be under the heading of new packages.
This step is the most critical and why I like aptitude, replacing the obsoleted packages will often break other packages; however the broken package usually also has a replacement package to correct dependencies.
Aptitude will list broken packages and recommend fixes. Check over actions to be performed before committing to them.

When you have finish, clean your package cache:
sudo apt-get autoclean this will remove the package cache for packages that are no longer used.


Can I search in the terminal window text?

Yes, you can.

Go to:

Search -> Find...

Or use the shortcut: Ctrl+Shift+F.

You'll see a search mini-window like:

then this is self-explanatory i believe.


QQ for linux has been stopped and not supported for  a long time already. There are implementations of QQ in WINE for Deepin and Ubuntu Kylin, but there is no (at least no more) Linux-version QQ.

There is also w.qq.com, which is a web-based version of QQ, however it's very limited

Basic idea of my solution is to install Genymotion （ an Android emulator ) and install the Android version of QQ in there. Basic steps are: 1)install VirtualBox; 2) install genymotion; 2) add a device; 3) launch that device; 4) download *.apk file for mobile qq; 5) drag and drop to running android emulator

Step 1 Install VirtualBox

Genymotion uses VirtualBox as backend for virtualization. It will be important to install it.

Go to https://www.virtualbox.org/wiki/Linux_Downloads  and download VirtualBox version for your OS version.

If your OS is 32 bit, download i386 package. If your os is 64 bit - install AMD64 package. (You can find out if you use 32 or 64 bit OSwith the arch or uname -m command; x86_64 means 64 bit, i368 and i686 mean 32 bit).

Drag and drop the downloaded package to Software Center or open the terminal, go to the directory where the package is located with cd directory-name and  install the downloaded package with sudo dpkg -i virtualbox-*.deb

For example, my Ubuntu 14.04 is 64 bit, so I downloaded virtualbox-5.0_5.0.2-102096~Ubuntu~trusty_amd64.deb; it is saved in my Downloads folder. I install it with sudo dpkg -i virtualbox-5.0_5.0.2-102096~Ubuntu~trusty_amd64.deb

Step 2 Install Genymotion

Go to https://www.genymotion.com/ and create account. Genymotion for personal use is free. Download appropriate package for your OS version at https://www.genymotion.com/#!/download

Open the terminal and go to the directory where you downloaded the package. The installation binary will be something like this genymotion-2.5.2_x64.bin. In terminal , do chmod 755 genymotion-*.bin && ./genymotion-*.bin -d $HOME. There will be new directory created, called genymotion in your home directory.

If you prefer to install somewhere else, you can do ./genymotion-* -d /path/to/your/directory

Step 3 Install virtual Android Phone

Go to the folder where you installed Genymotion, launch it. Click ADD button. Select any android version, install it. Once installation is done, select that device and click START to launch it.

Step 4 Download and Install Android QQ version

From your Ubuntu web browser to http://im.qq.com/download/ and download the mobile version of QQ. The file should be mobileqq_android.apk

Open the file manager. Find the mobileqq_android.apk file. Drag and drop it into the running Android emulator.

If you receive an error about incompatible CPU, go back to Step 3 and try different device version.

Step 5  Create a Desktop Shortcut [optional]

Open text editor and create genymotion.desktop. Contents are the following

[Desktop Entry]
Type=Application
Name=Genymotion
Exec=/home/user/genymotion/genymotion
Terminal=false

Save that file to desktop. In terminal , do chmod 755 $HOME/Desktop/genymotion.desktop

Exec= line is important. Make sure it says your actual username, instead of user.

References:

https://www.genymotion.com/#!/developers/user-guide

How can I install a .bin file?

An easy way to create a desktop shortcut?


sudo apt-get install eog-plugins -y

then start eye of gnome, (terminal or not, doesn't matter for now), click
edit / preferences / plugins
Scroll down and check the "slideshow shuffle" box. Close the program.

Then, via terminal you can:

eog /path/to/pictures -s

Where the " -s" switch triggers the slideshow and eog remembers the shuffle plugin.


Try Dropping to the root shell. (Hold shift on startup) Then select the drop to root shell option. Make sure that you did a full upgrade and it wasn't interrupted halfway through or something and if it was then try reupdating from the terminal.


Download VirtualGL (.deb) from: http://sourceforge.net/projects/virtualgl/files/VirtualGL/
Navigate to the folder containing the deb package and install it with:

sudo dpkg -i VirtualGL_*.deb
Run glxspheres:

cd /opt/VirtualGL/bin/

./glxspheres

OR

/opt/VirtualGL/bin/glxspheres


What is the middle-mouse-button alternative when one uses a laptop (only left and right button) with Blender 3d-modeling software installed?

When the emulate 3 button mouse option is enabled, ⎇ Alt LMB will emulate the middle mouse button to orbit around the scene.

⎈ Ctrl⎇ Alt LMB can be used to zoom in/out instead of the  Wheel.

⇧ Shift⎇ Alt LMB can be used to pan the view.

Also ⌘ Cmd LMB should emulate a  RMB on a Mac with a one button mouse.


"No required driver detected for unity" on Dell Mini 1010

Your graphics card seems to be under the minimal requirements for Unity - as per this page.

However, try this. Install UNR (on the HDD). Install this driver (it has 3D support), then restart and see if Unity works. If that does not work, then you are out of luck. GMA500 is a crappy little chipset.


An example of LDPA schema with tables, short and easy to understand.

Skills-1st is a website that has this tutorial that have everything of LDAP Schema Design. It have a html version and pdf too for download.

Also in the OpenLDAP website you can find software, utilities, tools, a Quick-Start Guide and more about the open server.

And I leave this question about set-up a LDAP server.


No panels or menus after upgrading to 14.04

I tried reproducing your trouble by disabling Unity-plugin, after this resetting Unity or its settings didn't work. So, this what I've done trying to get it back:

install Compiz Config Settings Manager if you don't have it:

sudo apt-get install compizconfig-settings-manager

Now, you have to go to Compiz Config Settings Manager and enable Unity-plugin when Compiz manager opened navigate to Unity-plugin or just type in search Unity then click on it and on the left put a tick wait a sec it should get back.

How to get to Compiz Manager and Terminal without Unity interface when nothing's responding even pressing Ctrl+Alt+T ? There's always the way to get around, for example press Ctrl+Alt+Del you'll get System Monitor navigate to File Systems you'll get listed with your HDD subsections and simply click twice on Home section now you should get Nautilus running. Navigate to / and hit the search bar just type Terminal now you can launch Terminal from search result, the same way type CompizConfig and you should get Compiz Manager launcher.

What other ways you can try using Terminal try to purge Unity:

sudo apt-get remove --purge unity

Now reinstall it along with ubuntu-desktop simply type and run:

sudo apt-get update

sudo apt-get install --reinstall ubuntu-desktop

This should automatically install and put Unity back on, you'll be able to see the packages that are going to be installed, if not run:

sudo apt-get install unity

After all may require reboot, didn't occur to me.

if you want or need to reset Unity on Ubuntu 14.04 you can use Unity Tweak Tool to do so, if you don't have it installed:

sudo apt-get install unity-tweak-tool

and to reset run:

unity-tweak-tool --reset-unity

Alternatives, all this stuff I wrote should definately work if everything else is fine including video drivers and you can try it in addition with Gnome for example, simply install gnome-shell:

sudo apt-get install gnome-shell

now reboot, and then at the login screen choose gnome-shell and log in, if everything is ok, it should work 100%, if not, the problem is not only in Unity, it might refer to video drivers issues as well.

These are all ways that I could figure out, so good luck!


Some applications are missing their window controls

Silly, it appears my windows controls were positioned under the global menu bar. I would have thought this impossible, but changing themes enabled me to grab and drag my Gedit window down from under there. Things appear to be working now. So, possible bug, with non-maximized windows hiding their tops behind the global menu bar upon application start? I don't know.

(These app windows do restart hiding behind the global menu bar every time, rather than staying where I last left them.)


Can I send data from my old Windows 7 to Ubuntu?

You can access any partition you can access via Windows via Ubuntu (but not the other way around). This includes your system partition.

If you have an external storage device (usb stick, external hard drive), you can copy your data from the Windows partition to that device. Then remove it from the Windows partition (clean trash). After you did so, boot the PC with a live usb stick, launch GParted, decrease the size of the Windows partition, and increase the one of the Ubuntu partition. Then boot Ubuntu and copy the files back from the usb stick / external hard drive.

But remember that things can go wrong when changing partitions. Make a backup in advance, in case for example the power goes down and you're on a computer without backup power supply. Also, depending on your version of Windows, it may fail to boot after you played with the partitions. But this can be solved pretty easily by inserting the Windows DVD.


This answer is for the packages that you installed in Ubuntu 14.04 by running: sudo apt install eclipse eclipse-cdt g++

Open Eclipse and select Help -> Welcome.
The Welcome screen will appear. In the Welcome screen click Tutorials.
The Tutorials screen will appear. In the Tutorials screen click C/C++ Development.
A Help - Eclipse Platform window will open. Click Create a simple application.
The Help - Eclipse Platform window will jump to the Tutorial: Creating a simple application section. In this tutorial, you will use the CDT to create a simple 'Hello World' application. The tutorial has screenshots to make it easy to follow.

After you have finished following the Creating a simple application tutorial, don't delete the 'Hello World' project that you made so you can use it as reference material for making your next C++ project.


On the command prompt, type startx to see if the gui is displaying again.


Using Ubuntu as an SMTP server for Gmail

NOTE: This answer is written for a 16.04 server, but can be adapted for 14.04 if necessary (replacing systemctl ... commands with proper service commands.)

This is a very complex task to set up.  There's a ton of separate important parts to this, but there's four primary components to a setup here, that is also 'secure':

The ISP of the system being used (residential IPs are typically "bad" for this; you're going to want something at a datacenter with either a VPS or an AWS cloud EC2 instance, or something similar)
Basically, do not use your own network for this.  Set up your SMTP server somewhere else, like Amazon EC2.
However, I strongly recommend getting a separate VPS from somewhere, where you can set the rDNS for the IP address to match the forward DNS you'll have to set.  We'll touch on the DNS later.

The system itself (locked down SSH, firewall, etc.)
We need to pretty much configure the system to prohibit connections on port 25 and without SSL.  We also need to just lock down the system.  We'll do this step last, after we make sure the rest works.

Postfix MTA
This provides SMTP.  We ultimately don't need it to deliver mail anywhere, so we don't need this as an MX record in your site's DNS, but we do need some things set up; we need an A record for the hostname, and we need a reverse DNS record to match (hence a suggestion of an actual VPS instead of an EC2 instance).

Dovecot Core
Normally we consider DoveCot to be a provider of POP3 or IMAP services, but dovecot-core on its own can be used to provide the SASL backend that works without many issues, and interacts with the system users.  That's all we're using Dovecot for, but we'll need to adjust some configurations.

I will not touch on point #1, because I can't control that.  I can however give you guidance on how to set things up.  We're going to do it in a different order from the above list, but we'll still get this all done.

Dovecot Core
dovecot-core is going to be used for the SASL backend.  There's a few things later we'll need to work with for 'secure' sending of mail, but we can start setting up the Dovecot backend.
First, install dovecot-core:
sudo apt-get install dovecot-core

Next, we need to make some modifications to /etc/dovecot/conf.d/10-auth.conf.
Let's disable plain-text authentication, and require SSL for the credentials.  Ultimately doesn't matter from postfix -> dovecot, but this is a good step to do.

FIND: #disable_plaintext_auth = yes
REPLACE WITH: disable_plaintext_auth = yes

Next, we need to enable the 'login' auth mechanism.

FIND: auth_mechanisms = plain
REPLACE WITH: auth_mechanisms = plain login

Then, we need to edit the /etc/dovecot/conf.d/10-master.conf file.

FIND:
 # Postfix smtp-auth
 #unix_listener /var/spool/postfix/private/auth {
 #  mode = 0666
 #}

MODIFY TO BE:
 # Postfix smtp-auth
 unix_listener /var/spool/postfix/private/auth {
   mode = 0660
   user = postfix
   group = postfix
 }

This enables the Postfix authentication backend of SASL in Dovecot.
Finally, for Dovecot, we need to edit /etc/dovecot/conf.d/auth-system.conf.ext:

FIND:
passdb {
  driver = pam
  # [session=yes] [setcred=yes] [failure_show_msg=yes] [max_requests=<n>]
  # [cache_key=<key>] [<service name>]
  #args = dovecot
}

MODIFY TO BE:
passdb {
  args = %s
  driver = pam
  # [session=yes] [setcred=yes] [failure_show_msg=yes]
  # [max_requests=> <n>]
  # [cache_key=<key>] [<service name>]
  #args = dovecot
}

Once this is done, we can restart the Dovecot process:
sudo systemctl restart dovecot

Postfix
Now, for the actual SMTP stuff.  This isn't as hard to configure as Dovecot heh.
First, install Postfix and the ssl-cert package which will create a basic self-signed certificate that is just enough to work with SSL-secured SASL auth for SMTP clients:
sudo apt-get install postfix ssl-cert

When prompted for Postfix site types, just select "Internet Site".
Once that's done, we need to make some modifications to the Postfix files.
Find this line:
smtp      inet  n       -       y       -       -       smtpd

Add below those lines, so that the line looks like this with two additional lines below it:
smtp      inet  n       -       y       -       -       smtpd
  -o smtpd_sasl_type=dovecot
  -o smtpd_sasl_path=private/auth

There is also a huge section starting with submission that is commented out.  Take the entire section, uncomment that section, and make it look like this:
submission inet n       -       y       -       -       smtpd
  -o syslog_name=postfix/submission
  -o smtpd_tls_wrappermode=yes
  -o smtpd_tls_security_level=encrypt
  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_recipient_restrictions=permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination,check_policy_service unix:private/policy-spf,reject
  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
  -o smtpd_reject_unlisted_recipient=yes
  -o milter_macro_daemon_name=ORIGINATING
  -o smtpd_sasl_type=dovecot
  -o smtpd_sasl_path=private/auth

With this now configured, we need to now edit the core settings, by editing /etc/postfix/main.cf.
First, move /etc/postfix/main.cf to /etc/postfix/main.cf.dist:
sudo mv /etc/postfix/main.cf /etc/postfix/main.cf.dist

Next, put the following into a new file.  Make sure to update domain names and hostnames for at least one of your domains:
# See /usr/share/postfix/main.cf.dist for a commented, more complete version

# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = no

# TLS parameters
smtpd_use_tls=yes
smtpd_tls_security_level=may
smtpd_tls_auth_only=no
smtp_tls_note_starttls_offer=yes
# Use an actual certificate.
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
# Use an actual key.
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
#smtpd_tls_session_cache_database=btree:${data_directory}/smtpd_scache
smtpd_tls_mandatory_protocols = !SSLv2,!SSLv3
smtpd_tls_protocols = !SSLv2,!SSLv3
smtpd_tls_mandatory_ciphers = medium
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
tls_random_source = dev:/dev/urandom
#tls_medium_cipherlist = AES128+EECDH:AES128+EDH

smtpd_client_connection_rate_limit = 50
anvil_rate_time_unit = 120s

smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination, check_policy_service unix:private/policy-spf

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
myhostname = mail.somedomain
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = $myhostname somedomain mail.somedomain localhost.somedomain localhost
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all

local_recipient_maps = proxy:unix:passwd.byname $alias_maps

milter_protocol = 2
milter_default_action = accept

queue_directory = /var/spool/postfix

Note that a good portion of the configuration options here are used primarily for a full blown SMTP/IMAP setup with a Dovecot backend.  You can still use this config, as this is pulled from an actual mail server (with some data obfuscated lol), as a base for setting this up to use just the SMTP portion of this for your things.  So ultimately, don't worry about anything else.
Note that I recommend you get an SSL certificate just for the mail server, or if you have a wildcard cert for one of your domains use that and set the mailname to a domain in that certificate.  This way, you aren't using self-signed SSL certs for the SSL/TLS encryption on the connection.  Just my two-cents, you can still use the self-signed for most things if all you're doing is submitting email from an SMTP client like Google's Send Mail As function.
Once you're done here, we need to stop then start the Postfix process:
sudo systemctl stop postfix
sudo systemctl start postfix

We should now be good to go with Postfix and Dovecot SASL.

We need a user to auth with though.
We didn't create a user, and you have only a few options.  In our case, we're going to create a dedicated user for this purpose of SMTP authentication.
We're going to create the user with the following:
sudo useradd --create-home --user-group --shell /usr/sbin/nologin authsmtpuser

We then need to set a password.  You can do this with the following command, and enter the password accordingly.  (Characters won't show up, nor will placeholders when it prompts unfortunately)
sudo passwd authsmtpuser

If you don't do this, and have another username on the box (NOT root) you want to auth with, use that in the script below.

Now we can test things.
Let's test this.  This is a very simple Python 3 script that you can use to 'test' that everything works as we expect it to.  Make sure to update DESTINATION_ADDRESS, SOURCE_ADDRESS, SMTP_USERNAME, SMTP_PASSWORD, and SMTP_SERVER_ADDR here to make sure that this script will properly work.  Save this as test_smtp_server_tls.py somewhere, and remember where we saved this.  (You can create it in /tmp/ if you want so it doesn't persist on your computer after a reboot)
#!/usr/bin/env python3

import email.utils as emailutils
import smtplib
from email.mime.text import MIMEText

DESTINATION_ADDRESS = 'your-address@gmail.com'
SOURCE_ADDRESS = 'smtp-test@yourdomain.com'

SMTP_USERNAME = 'authsmtpuser'
SMTP_PASSWORD = 'your password'
SMTP_SERVER_ADDR = 'ip.add.re.ss'
SMTP_SERVER_PORT = 587  # Don't change this.

# Construct a test message.
msg = MIMEText("This is a test message from your custom SMTP server!")
msg['To'] = DESTINATION_ADDRESS
msg['From'] = SOURCE_ADDRESS
msg['Date'] = emailutils.formatdate(localtime=True)
msg['Message-ID'] = emailutils.make_msgid()
msg['Subject'] = "SMTP Server Mail Testing"

try:
    print ("Establishing SMTP connection with SSL...")
    conn = smtplib.SMTP_SSL(SMTP_SERVER_ADDR, SMTP_SERVER_PORT)
    print ("Established connection.")
except Exception as e:
    print ("Could not establish SMTP connection.  Error was:\n%s" % str(e))
    exit(1)

try:
    print ("Attempting to authenticate...")
    (_, response) = conn.login(SMTP_USERNAME, SMTP_PASSWORD)
    if 'Authentication successful' in response.decode('utf-8'):
        print ("Authenticated with SMTP server successfully.")
    else:
        print ("Could not authenticate with server, response was: %s" % response.decode('utf-8'))
        exit(2)
except Exception as e:
    print ("Could not authenticate with SMTP.  Error was:\n%s" % str(e))

try:
    print ("Sending test message to [%s] from [%s] with subject [%s]..." % (DESTINATION_ADDRESS, SOURCE_ADDRESS, msg['Subject']))
    conn.sendmail(SOURCE_ADDRESS, DESTINATION_ADDRESS, msg.as_string())
    print ("Message queued for sending, please check your destination email inbox and junk folders for the message.")
except Exception as e:
    print ("Could not send email.  Error was:\n%s" % str(e))
    exit(3)

exit(0)

Execute this script with python3 /tmp/test_smtp_server_tls.py (assuming you saved it in /tmp/; change the path if you saved it elsewhere.
Check the destination email address inbox and such.  If all worked, you'll get an email shortly from your server and the custom domain.  It may go to your junk mailbox, so check there if you don't get the message initially.

The system - time to lockdown!
This assumes all the above steps worked, of course.
Time to setup the firewall to prohibit unauthorized access.  Note that I hate ufw, it's not complex enough for my needs, so I have written this answer with iptables - you can do sudo ufw disable to turn off UFW and use direct iptables manipulation.  I also only assume you have IPv4 on the system.
If you already have firewall rules in place, then just add a rule to accept new connections on port 587.
If you don't have a firewall enabled, execute these commands (add additional iptables -A INPUT -p tcp --dport 123 -m conntrack --ctstate NEW -j ACCEPT lines, replacing 123 with the actual port number of any other services on your system you need to accept connections to, such as tcp/443 and tcp/80 for HTTPS and HTTP accordingly, before you do the -j DROP line):
sudo iptables -A INPUT -i lo -j ACCEPT
sudo iptables -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 22 -m conntrack --ctstate NEW -m comment --comment "Allow SSH access remotely." -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 587 -m conntrack --ctstate NEW -m comment --comment "Allow TLS-protected SMTP connections, for sending mail." -j ACCEPT
sudo iptables -A INPUT -j DROP

Once this is all set up, run this command: sudo apt-get install iptables-persistent.  When it asks to save the current rule-sets, hit "Yes" for each.
Make sure your test script above and SSH access still works before you close the SSH connection or the connection to your server!  If all works fine, then the last step is to set up the Google alias and tell it to send SMTP from that domain with a different server.

Google Configuration

If your GMail is under a Google Apps system, and you aren't on a Google Apps plan that lets you use external SMTP servers for mail sending, then you will not be able to do this part.  This is a Google-imposed restriction, and I can't help you there.

From the GMail page, we need to configure things.  Firstly, go into your GMail settings.

Once in your settings, go to the Accounts and Imports tab.
You'll need to 'remove' any set aliases so far, in the "Send mail as", section,
then hit "Add another email address".

Put in your name and the other email address for the other domain in the window that pops up.

Once you hit "next step" you'll get a page like this.  Make sure to enter the IP address of your server properly, and also set the username and password to the ones we created earlier.  Also make sure to select the "Secured connection using SSL" option.  This enforces the need of SSL connectivity to happen before sending mail.  This should look something like this, except with the IP address of your server in the blank space:

Save the setting with "Add Account".  You'll receive an email indicating that you need to verify you want GMail to send mail with that address; it'll send you a link to click, with a verification code.  You can just enter the verification code once the email arrives in the last window that opens during this process.
Once that's done, use GMail to send email to somewhere with the other "From" address selected, and it should send via the SMTP server we just set up!  :)


install base system failed : Ubuntu server and xubuntu alternate installation

I'd do this:

boot from the USB stick
select your language, I'll use English as an example

From the proceeding menu, select:

Check disk for defects

This will verify the installation source is Ok and can be read from the media.  If it fails, reboot the system from the USB stick and this time select:

Test memory

On more than one occasion, I've found issues to with setup failing to read installation files due to bad / flaky RAM.

RAM tests will take a long while to run but if you let it complete at the very least you can rule out bad media and RAM as a source of your issue.


How to remove in correct way qt4 development libraries?

sudo apt purge qt4*

This will uninstall qt4 and it's deps


How can I get data off of a (probably) very corrupt drive?

Boot Ubuntu from a live CD, then sudo apt-get install testdisk. Once installed, you can plug in an external drive to backup recovered data to, then run sudo photorec and follow the instructions.


What advantage does a GPU card offer in an Ubuntu laptop?

First things that comes to my mind:

For playing games - you know Steam came to Linux also we have Wine.
For heavy programs that require 3D acceleration like Blender.
For watching 4k HD Movies.
Newer desktop environments like KDE and Unity offer advanced look and feel of the OS when you tweak the settings but for that you need good GPU.

Generally if you use your laptop only for work or browsing internet and watching normal Movies - you don't need one.


In a nutshell, yes. Adding PPAs and installing software can decrease the security posture of a systems. In general, you should only add PPAs that you know are reputable and well established or trusted.

How likely is a Linux system to be infected? Not too likely.


why ubuntu-13.04-desktop-i386.iso file not running when mount it on windows 7 32bit ?

You should not use Wubi. It has been discontinued as of Ubuntu 13.04. It had many bugs and was unstable in general.

However, if you really want to, you can still run Wubi. Note that you will need to have Windows 7 to run these steps. Wubi is not tested/supported on Windows 8. They do not play nice.

Start by copying the Wubi.exe file from the ISO image to your desktop.
Double-click it.
Follow the install wizard.
???
Profit.

If you can, always install Ubuntu on its own partition. It'll be faster, stabler, and easier to fix if problems come up. There is no guarantee that Wubi will work as expected (or even work at all). You have been warned!


How to Increase the width of Vertical and Horizontal Scroll Bars in Ubuntu 18.04 LibreOffice

I wouldn't apply any changes to the stock theme.
You can override the stock settings. With this method you cann still change the theme and keep your changes.

$ mkdir -p ~/.config/gtk-3.0/
$ touch ~/.config/gtk-3.0/gtk.css

Open the created file in the text editor of your choice and add these lines

scrollbar {
    min-width: 15px;
    min-height: 15px;
}

Both should have the same value. The one will be applied to horizontal the other to vertical scroll bars.

This method will change the width/height for all scrollbars and not just the once in LibreOffice


I seem to have solved this. Here's what I did:

I copied gnome-session.conf from /usr/share/upstart/sessions to
gnome-session.override in $HOME/.config/upstart
I edited gnome-session.override and added umask 0002 on the line before
exec gnome-session --session=$DESKTOP_SESSION
I edited $HOME/.bashrc and added umask 002 to the end of the file

Step 2 made newly created files within the desktop session writable, but the umask for the terminal seemed to remain 0022, which prompted step 3. I repeated these steps for the other users as well.

Comments are very welcome, as I'm not a sure this is the best solution.


How Do I enable My Desktop visual effects

Presumably your graphics card (Intel GM855 I guess) is not too well supported from the kernel in Ubuntu 10.10 (see Intel 8xx Issues). To get an idea on how to solve issues you may also have a look at this thread from Ubuntuforums.

Downloading drivers from a manufacturer website is not recommended for unexperienced users. It is only rarely needed anyway. You would need a detailed how-to for the installation process and an additional proof from the community that it's really working with your Ubuntu release.


Command output to file with dynamic file name

This script should work:

#!/bin/bash

dt=$(date '+%d%m%Y %H%M%S')
DAY=$(date +"%u")
c=$DAY$dt
command > myfile"$c".txt

or this command:

command > myfile$(date +%a).txt


How to make the file manager show file sizes in GiB, MiB, KiB?

You can't do so, mainly because Ubuntu follows the Units Policy.

With base-10

If user expect to see file sizes in base-2 using the default file manager in Ubuntu, forget about it. Most known file managers have been using base-10 for some time already.

File managers that show base-10 a.k.a Metric units (kB, MB, GB):

Nautilus (GNOME, Unity)^1
Caja (MATE; Ubuntu MATE)^3
Thunar (Xfce; Xubuntu)
Nemo (Cinnamon)^3

With base-2

While the policy applies to default file manager in Ubuntu for 10.10 and newer releases, there are file managers that did not follow the same.

File managers that show base-2 a.k.a. IEC units (KiB, MiB, GiB):

Dolphin (KDE; Kubuntu)^2
PCManFM (LXDE, LXQt; Lubuntu)^3
Double Commander (cross-platform)

  Reference notes

  ^1: Nautilus in Ubuntu 10.10+ will now show base-10; previously base-2.

  ^2: Dolphin will show either base-2 or base-10 in KDE Plasma 4; otherwise always base-2 in KDE Plasma 5. Some details at below.

  ^3: The file manager has an option to show either base-10 or base-2.

Notice that file managers that show file sizes in base-2 are often found as platform independent software. This may be influenced by the fact that operating system for consumers, esp. Microsoft Windows, use customary binary prefixes a.k.a. JEDEC units.

As for Dolphin file manager, it is the KDE development platform that allows its application programs to show file sizes in base-2, rather than the file manager itself. Such option has been available in KDE Plasma 4, but went missing in KDE Plasma 5.

We can trace back the history, when the blueprint was registered in late-2008 by Joel Parker. Two years later, the policy was finally implemented in Ubuntu 10.10. For such carefully planned changes, it is very less likely for file manager in Ubuntu to revert the changes. Time will tell.

TL;DR Use a file manager that show file sizes in base-2 (KiB, MiB, GiB) for consistent experience across different operating systems. Very less likely for base-2 to be reintroduced in Ubuntu anyway.


You apparently installed Grub on the USB stick during the install, not the /dev/sda.  You can fix this by installing grub on /dev/sda.

Perform the steps provided here for a different question, but the same resolution (the details of all the steps are in the link)  Click on the link:

Dual Boot don't work on Windows 10:
https://askubuntu.com/a/831175/29012

Perform these steps at the terminal command prompt after booting into the Live media:

Replace /dev/sdaX with the partition where Ubuntu is installed.
Replace /dev/sdX with the drive in your computer which is /dev/sda.

The "$" symbol is the terminal prompt you see where you type the command.  The "$" prompt is a normal user.  The "#" prompt is when running as root.  The prompt will change while performing the steps.  Copy and paste the command that appears after the prompt.  The prompts are showing that the lines are terminal commands.

$ sudo mount /dev/sdaX /mnt
$ for i in /sys /proc /run /dev; do sudo mount --bind "$i" "/mnt/$i"; done
$ sudo chroot /mnt
$ sudo grub-install /dev/sdX

# update-grub
# exit

$ sudo for i in /sys /proc /run /dev; do sudo umount "/mnt/$i"; done
$ sudo umount /mnt
$ exit

Now reboot the computer and you'll be all set without the USB device.


Keyboard backlight command by percentage

Script to increase and decrease brightness:

#!/bin/bash

step=12
file=/sys/class/leds/chromeos\:\:kbd_backlight/brightness

case "$1" in
    -i|--increase) ((val = +step));;
    -d|--decrease) ((val = -step));;
esac

if !((val)); then
    echo "Increase or decrease screen brighness"
    echo "Usage: ${0##*/} --increase | --decrease"
    exit
fi

read -r cur < "$file"
((val = cur + val))

if ((val <   0)); then ((val =   0)); fi
if ((val > 100)); then ((val = 100)); fi

printf '%d' "$val" > "$file"

printf 'Before: %3d\n' "$cur"
printf 'After : %3d\n' "$val"

Could be a lot simpler for a keyboard shortcut, but I decided to make it a stand-alone script with help and args, just for fun :)

To run:

save it somewhere, for example ~/keyboard-brightness
set execute permission: chmod +x ~/keyboard-brightness
~/keyboard-brightness --increase
~/keyboard-brightness --decrease

Now just add them as keyboard shortcuts


Right-click on the Computer icon on the desktop. From the drop-down list, choose Map Network Drive. Select a drive letter that you want to apply to access the shared folder and then type in the UNC path to the folder. UNC path is just a specific format for pointing to a folder on another computer.


Is it a problem if my Windows partition is visible from within Ubuntu?

Yes there is a risk, but it should be small. Just having the partitions mounted will not cause any problems, but if you write data to them or change them then you can cause problems.

For example, if you were to delete all the files in the windows partition while running Linux, you would not be able to boot into windows.

For the most part, things will go along the lines of common sense. Don't delete or change windows programs or components and everyone remains happy.

There are a couple of exceptions. First encrypted files and folders in windows will look like gibberish in Linux. Messing with those will damage them. And if you "suspend" windows and boot into Linux, doing almost any write operation on the windows partition has the ability to cause data loss. (This is one reason you should turn off fast boot in the bios).

Of course "global" disk changes like partitioning and  formatting will cause data loss if not done correctly. Some data recovery or file system tools will cause an issue too.

So in the end,

There are risks, but they are much the same as if you dual booted windows 8 and windows 10 and started monkeying around with "the other" install. Your day to day stuff should be 100% safe, just watch your self as you do file system operations and be aware of write operations. Good advise no matter the OS or file system.


Ubuntu 12.10 unity won't start on startup

After login, Ctrl+Alt+T

cp .config/dconf/user .config/dconf/user.bkp
rm .config/compiz-1/compizconfig/config .config/dconf/user

Then Unity magically will appear.

Logout, login again and enjoy!

PS: some of your config will reset. We need to discover what config need to reset instead of remove .config/dconf/user.

EDIT:
To reset only compiz files:

1) After login, Ctrl+Alt+T

sudo apt-get install dconf-tools
rm .config/compiz-1/compizconfig/config ; dconf reset -f /org/compiz/
unity

2) Logout and login


Is it better to upgrade through the Update Manager or re-install from scratch?

The method you choose doesn't have any impact on system performance. Both are fine, the question is whether you want to start from a clean slate or not.


You need to install "grub" bootloader to your harddrive, not to your USB pen drive.

After this step, you will be able to choose which operating system to boot, you won't need the usb stick anymore to use ubuntu.

Step 1:
Identify your hard disk device entry -> one of /dev/sda, /dev/sdb, etc.
Usually, it is /dev/sda.
If you are not sure, check at the command line (Terminal):

sudo fdisk -l

In the output, first line is important as you'll recognize the size of your hard disk.
If you have the usb stick too, you will have /dev/sda with any partitions like /dev/sda1, /dev/sda2, etc AND /dev/sdb -> your usb stick:

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000e26f3

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048    40962047    20480000   83  Linux
/dev/sda2        40962048   275718143   117378048    5  Linux swap / Solaris

Disk /dev/sdb: 500.1 GB, 500107861504 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773167 sectors
         ......and other stuff ..........

Step 2:
Install grub

sudo grub-install /dev/sda


I've completely screwed up my computer by removing compiz then purging dconf*, is there any way to salvage the situation?

To save your data, boot from a live CD/USB and copy the data to a network share, USB drive, or other device.


Ubuntu prompt styling on WSL2 messed up after changing default user to root

I believe Ubuntu as standard has the root prompt in b/w only.
You can change this in root's .bashrc
Find the following line in .bashrc

force_color_prompt=no

And change it to:

force_color_prompt=yes

Now root prompt should be in color also.


There is a typo in the instructions in

Step 4. Configure the network gateway

Nexts line should read:

To configure the gateway, edit /etc/sysctl.conf file. Find and uncomment the following line:

Note the file sysctl.conf is in the /etc/ folder. Be particular about the leading / before the etc/.

As this is a system file, you will need administrative privileges to edit this file. Open a terminal using Ctrl+Alt+T and enter:

sudo nano /etc/sysctl.conf

This will open the file in a text based editor nano. Find and uncomment the following line:

net.ipv4.ip_forward=1

To save and exit nano Use Ctrl+X Followed by Y, followed by Etner.

Hope this helps


It seems that you have a typo in your sources.list

Edit

/etc/apt/sources.list

Look for the entry with univers

add an "e" to the end. Should be  universe


I have referred to this answer in the past and can confirm that it sufficiently answers your question


How to duplicate all files in a given folder with auto renaming

You could do something similar to Windows behavior, using the --backup=numbered option:
$ ls dir1
apple  banana  carrot  date  egg  fish  grape  ham

then
$ for f in dir1/*; do cp -vf --backup=numbered "$f" "$f"; done
'dir1/apple' -> 'dir1/apple.~1~'
'dir1/banana' -> 'dir1/banana.~1~'
'dir1/carrot' -> 'dir1/carrot.~1~'
'dir1/date' -> 'dir1/date.~1~'
'dir1/egg' -> 'dir1/egg.~1~'
'dir1/fish' -> 'dir1/fish.~1~'
'dir1/grape' -> 'dir1/grape.~1~'
'dir1/ham' -> 'dir1/ham.~1~'

giving
$ ls dir1
apple      banana.~1~  date      egg.~1~   grape      ham.~1~
apple.~1~  carrot      date.~1~  fish      grape.~1~
banana     carrot.~1~  egg       fish.~1~  ham

Note that -f (or --force) is still required to override the default "same file" behavior.


Undoing all the terminal commands in the last 24 hours?

You can't directly undo a command. Unfortunately, Linux does not support this feature.

You can use the command history to list all the previous commands you used.

You have to find the reverse command for all of them (e.g. if you invoked a command sudo apt-get install you have to invoke a sudo apt-get purge).

Unfortunately, not all command have a simple reverse command (e.g. if you run a sudo apt-get upgrade you should find out all the updated packages and downgrade them).

My suggestion is to find out a way to clean the actual situation, for instance, you can try to delete all the packages that you installed. If you want to be sure that you're in a completely clean situation, you have to format the VM.


First you have to install the "basic" snap ubuntu-core, on which all snap applications are running. Open a terminal and execute this command : sudo snap install ubuntu-core
Now you are able to install "normal" snap applications, here an example to install nmap:
sudo snap install nmap ... you can update this snap with : sudo snap refresh nmap

Update with instructions how to download a snap package and install it on an offline computer : First you have to find out the download location of the snap package you want to download. In the example nmapabove it is -> https://launchpad.net/~joetalbott/+snap/nmap/+build/1021.
To install it execute : sudo snap install /path-to-the-downloaded-file/filename.snap

Update with an explanation addressing your question how to find various snap packages :
Unlike the way installing software from repositories, snap packages are designed to work independently on supported Linux systems, so all dependencies are included in each snap.
As a consequence there is not a single snap store where all the snap packages are located.

Everyone can create snap packages and choose the location where they are stored. What you want is possible but not the way it is supposed to work, in these days nearly everybody has an internet connection and in the case of Ubuntu you should use the standard way, just as you do when installing or updating applications from the repositories ... otherwise you have to search.

Here is one location where you can find many snaps to download manually : uApp Explorer.com
As snap packages become more popular over time, many developers offer them as a download alternative to .deb files - this is a current example from the notes application : get-notes.com


I'm not sure what your exact circumstances are but XAMPP is designed for one-person-development. It's a quick easy way to test sites locally. If you want a system wide server that all users can use, perhaps it's time to stop using it for something it wasn't designed, and is time to use a traditional LAMP stack instead.

sudo apt-get install lamp-server^

Note: The ^ on the end isn't a typo - it's how we denote tasks.

That should give you a very traditional LAMP setup which you can then customise as much as you like. For service configuration, I personally like the SliceHost articles (even though I'm not a customer there) as they cover most of the basics about getting Apache, PHP and MySQL playing happily and in a nice sane way.


Nope.

fakeroot never has "real" root privileges. It is used for example while creating a debian installer. It is then to virtually install an application into the debian installer, not into your "real" system.

A debian installer is actually nothing else but a scaled model of your system, with all the files, docs, manpages, possible libraries and executables inside it, exactly arranged like it will be "projected" on to your system if you run the installer.

The role as root of fakeroot is then limited to the environment of your .deb file, to be created. It has no privileges to act as the "real" root.


Forensic tools for disk and image analysis

take a look to DEFT Distribution Based ON Ubuntu

DEFT (acronym for Digital Evidence & Forensics Toolkit) is a distribution made for Computer Forensics, with the purpose of running live on systems without tampering or corrupting devices (hard disks, pendrives, etc…) connected to the PC where the boot process takes place.
The DEFT system is based on GNU Linux, it can run live (via DVDROM or USB pendrive), installed or run as a Virtual Appliance on VMware or Virtualbox. DEFT employs LXDE as desktop environment and WINE for executing Windows tools under Linux. It features a comfortable mount manager for device management.
DEFT is paired with DART (acronym for Digital Advanced Response Toolkit), a Forensics System which can be run on Windows and contains the best tools for Forensics and Incident Response. DART features a GUI with logging and integrity check for the instruments here contained.
Besides all this, the DEFT staff is devoted to implementing and developing applications which are released to Law Enforcement Officers, such as Autopsy 3 for Linux`


You should try to install the lastest drivers for your devices. If you didn't do it yet, follow the next steps:

Click on the Dash
Search for Additional and click Additional Drivers
Wait a bit, and you'll see a list with all the compatible drivers for your computer. You can install your graphics card drivers (I usually install the post-release drivers) and all your other devices.
Check if your soundcard name appears at that list, select the entry for it and click Activate. After a while, you'll have to restart your computer.

I hope it works to you, and tell us soon if it worked OK!


Braid downloaded from humble bundle 3 is not running on 11.04

I ran the following command in terminal to run it as per my monitor's resolution

/opt/braid/braid -width 1024 hieght 786

Thank you Eliah Kagan and everybody else for helping out.


Ubuntu supports multiple user sessions at the same time. That means you can log in user A, then lock the screen and/or switch users and log in as user B in parallel.

Both sessions are open this way and no applications will be closed. You can switch between the open user sessions at any time or open new sessions as other users. Each session stays open until you log out from it.

User A and user B have completely separate sessions which run independently of each other. It is not really possible that another user e.g. starts applications in your session, as you describe, unless maybe if the other user is an administrator and explicitly launched the process under your account.


ubuntu 13.04 claims my root password wrong

Got it working thank you Alaa

Run the command gksu-properties and change the "Authentication mode" to "sudo" and close. Now do gksu bleachbit, or whatever GUI application you want to run as root, and type your password (the one you use for updating and installing)


How to run an executable file from a different directory without cd or modifying the PATH?

You can always use the relative or full path to your executable

When you're in /mnt/f, you can run:

C_F/ex
# or
/mnt/f/C_F/ex


See: http://www.thinkwiki.org

Ubuntu packages:

hdapsd - HDAPS daemon for various laptops with motion sensors
tp-smapi-dkms - ThinkPad hardware/firmware access modules source - dkms version

hdapsd : List of supported Thinkpads | GitHub Sources
tp_smapi: Homepage is ThinkPad Configuration Tools for Linux


Which key combination would allow me to pass parameters to kernel during boot

hold shift to get to the grub menu, then select the entry you want using up and down, then hit e to the edit mode. It has instructions after that on the bottom of the screen.


You can partition it in various ways:

Atleast 30% of the disk for a root partition (containing /boot and other stuff), the rest for each OSs home partition (you can share home partitions and some swap (for a suggestion for the size of the swap, you can try this)
Similar to the above but a extra partition which is shared
Half the disk for each OS's root partition - no swap means you can't hibernate and if your RAM is too small you will run out of memory.

The possibilities are endless... If you want to change things after installation you can use GParted and edit /etc/fstab (carefully!)

Probably not possible, as Fedora uses much newer base packages and stuff than Ubuntu, also Fedora uses RPM packages to install stuff whilst Ubuntu uses DEB files. Copying other some things might work, but not always.


What command do I need to unzip/extract a .tar.gz file?

Type man tar for more information, but this command should do the trick:

tar -xvzf community_images.tar.gz

Also, to extract in a specific directory

for eg. to extract the archive into a custom my_images directory .

tar -xvzf community_images.tar.gz -C my_images

To explain a little further, tar collected all the files into one package, community_images.tar. The gzip program applied compression, hence the gz extension. So the command does a couple things:

f: this must be the last flag of the command, and the tar file must be immediately after. It tells tar the name and path of the compressed file.
z: tells tar to decompress the archive using gzip
x: tar can collect files or extract them. x does the latter.
v: makes tar talk a lot. Verbose output shows you all the files being extracted.
C: means change to directory DIR. In our example, DIR is my_images.


Windows 7 won't boot from dual-boot menu

You need a usb drive and download. the boot repair disk. It handles both secured and non secure boot modes.

There are allot of custom ones. so be careful. I would go to sourceforge.net/projects/boot-repair-cd/

I just had same issue with Windows 10. Worked nicely. Good Luck.


Is there a way to configure the "Super W" effect?

A number ofaspects of the 'Super-W' effect may be configured from CCSM.  The options are found under the Scale addon in the Window Management section of CCSM.


You are trying to set permissions for a file system that isnt recognized. THE SYSTEM FUNCTION that "deletes" is not the system used in a linux based bit unless its emulated.
When you tell it to delete it tries to write to the "trashbin". You are only moving stuff. To remove it you need to access the file system, not raw data. Its going to kick the data back because you are just asking it to move not delete, the delete command isnt within its wheelhouse./ regardless of the command you use.

If you can mount the partition/drive of the server in samba or what ever you like you may be able to use that to delete. Try virtually mounting, with permissions. If you only have read/write but not delete/move your going to have a bad time.


Is 1GB RAM with integrated graphics sufficient for Unity 3D on 12.04?

I'd say 1GB is low, considering that you have 256MB of that dedicated to the integrated Intel graphics!!

What I mean is that, with 12.04 Unity, if you will be doing a decent amount of multitasking, you will start to notice lags with 1GB. Eg Firefox open with 5+ tabs along with 3-4 other programs running in the background, etc. (This is based on my own extensive experience with a 1GB machine).

A stock i386 install of 12.04 desktop with Unity 3D uses about 550-600MB of RAM after boot for me, excluding caches and with near-zero swap usage.

So I believe that an additional 1GB of RAM will almost certainly solve your problem. However, since RAM prices are at historical lows (should also be in Bangladesh), if you can afford it I suggest you "max out" with a 2GB module and future-proof your computer :)

Temporarily, if you do not game, I recommend reducing the integrated graphics share to 128MB. This shouldnt affect the user interface/Unity in any way.


Preseeding does not work properly in Ubuntu 14.04

My suggestion would be to use the server ISO with a preseed file. It seems to behave better with preseeding, but it also allows you to set up a mirror and install any packages you need from the servers. I'm using a similar setup with Packer along a very similar manner to this post. http://kappataumu.com/articles/creating-an-Ubuntu-VM-with-packer.html

As you mentioned the desktop installer for 14.04 changed and now most d-i options need to be converted to ubiquity syntax (the server ISO still uses debian installer aka d-i).

The downside is that there is NOT a ubiquity/pkgsel command, but what you can do is use preseed/late_command somescript.sh and then run some in-target apt-get install openssh-server commands within that script.

https://wiki.ubuntu.com/UbiquityAutomation

There are also some files for Ubuntu Desktop provided by a gentleman on the official Packer Google group.

http://groups.google.com/forum/#!topic/packer-tool/SWhoARVwVnM

I would also suggest checking out the Ubuntu repository on Github under boxcutter, they have some excellent working preseed files for each version of Ubuntu. https://github.com/boxcutter/ubuntu


Ubuntu15.04 installation xboxdrv error with xboxdrv.service

Try the following (after the above installation attempt - when the install fails). It solved the same issue I had while installing ubuntu-xboxdrv:

Go to https://github.com/raelgc/ubuntu_xboxdrv/tree/master/src/lib/systemd/system, right click on xboxdrv.service and select "save linked content as" or "save target as" and save it as "xboxdrv.service" in an easily accessible path.

Open a terminal and navigate to the above path where xboxdrv.service is and run the following command :
sudo systemctl enable xboxdrv.service

Then run sudo apt-get install ubuntu-xboxdrv again.

This should solve the problem.
Credit: https://www.digitalocean.com/community/tutorials/how-to-use-systemctl-to-manage-systemd-services-and-units


Enable SSH Root Login with Password in Ubuntu Server 16.04

You should remove "#" from line "#PasswordAuthentication yes" then restart ssh service. It may resolve your issue.


What's a screenshot application which will auto-upload to imgur?

You can do this with shutter as well, which is available in the repositories. Simply take a screenshot and then click export (see screenshots) and you are presented with a comprehensive number of alternatives, including the option of Ubuntu One.

You can upload to places like imgur, imageshack either as a guest or you can use your account if you have one. See the second screenshot for this, which details the uploading preferences settings of shutter, accessed via edit > preferences > upload tab.

For more details on the shutter project see the official site of this very useful program.


Why is pkexec preferred over gksudo for graphical applications?

Why it doesn't work?

By default pkexec does not allow you to run graphical (X11) applications. From the man page:

 The environment that PROGRAM will run it, will be set to a minimal
 known and safe environment in order to avoid injecting code through
 LD_LIBRARY_PATH or similar mechanisms. In addition the PKEXEC_UID
 environment variable is set to the user id of the process invoking
 pkexec.
     As a result, pkexec will not allow you to run X11 applications
     as another user since the $DISPLAY and $XAUTHORITY environment
     variables are not set.
 These two variables will be retained if the
 org.freedesktop.policykit.exec.allow_gui annotation on an action is set
 to a nonempty value; this is discouraged, though, and should only be
 used for legacy programs.

As stated in the man page, you can make it work albeit I really don't know if this is somehow dangerous or recommended.

To enable gedit for example you can create /usr/share/polkit-1/actions/com.ubuntu.gedit.policy with the following content:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE policyconfig PUBLIC
 "-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/PolicyKit/1.0/policyconfig.dtd">
<policyconfig>
  <vendor>gedit</vendor>
  <vendor_url>gedit</vendor_url>
  <icon_name>accessories-text-editor</icon_name>
  <action id="org.freedesktop.policykit.pkexec.gedit">
   <description>Run "gedit"</description>
   <message>Authentication is required to run Text Editor</message>
   <defaults>
     <allow_any>auth_admin</allow_any>
     <allow_inactive>auth_admin</allow_inactive>
     <allow_active>auth_admin</allow_active>
   </defaults>
     <annotate key="org.freedesktop.policykit.exec.path">/usr/bin/gedit</annotate>
     <annotate key="org.freedesktop.policykit.exec.allow_gui">true</annotate>
   </action>
</policyconfig>

Then pkexec gedit should work as expected:

As you can guess, this will only make gedit work. In theory, if you added allow_gui to "org.freedesktop.policykit.exec" (the default action) this should work for all applications, but in my tests I got the same result as yours.

Why is pkexec prefered?

Here you can find a discussion about the strengths of pkexec.


Ubuntu 20.04 Sever unable to connect to WIFI

Replace the existing .yaml in /etc/netplan with this... keep the exact spacing, indentation, and no tabs... fill in the SSID and password...
network:
  version: 2
  renderer: networkd
  ethernets:
    enp9s0:
      dhcp4: true
      optional: true
  wifis:
    wlp8s0:
      dhcp4: true
      access-points:
        "network_ssid_name":
          password: "**********"

sudo netplan generate
sudo netplan apply
reboot
Connect to Internet via ethernet cable.
sudo apt-get update
sudo apt-get install wpasupplicant
reboot
Disconnect ethernet cable.
Connect via wireless.


Connecting to port 0 is not possible, see

https://unix.stackexchange.com/a/180500/85039

It is a special port allowing programs to obtain random port for outgoing connection, and should not be used for incoming connections

Therefore, use -p 1-65535 for nmap, especially if you are using TCP or UDP scans

As for /24 notation that is entirely different thing: it is called CIDR notation and used to match range of hosts on network. For instance, 192.168.0.0/24 will specify all addresses between 192.168.0.0 to 192.168.0.255


Gnome crashes when I drag to reorder favorites in Activities. Why?

You might be using the default X mouse cursor. Try changing it to something else. For example, sudo apt-get install oxygen-cursor-theme and set it in gnome-tweak tool.


Linux doesn't like Apple because they're all about closed source software while Linux all about open source.  If you dual boot 2 operating systems, that might slow the transfer rate.  Try just running Linux.


No focus in the LibreOffice find dialogue

A commentator above suggested a pretty good workaround:

Go to Tools / Options / LibreOffice / View.
Set Mouse Positioning to "Dialog center".
Restart LibreOffice.

The find dialogue still has the system window border around it but clicking Ctrl + F puts focus in the text field so one can type immediately.


According to my understanding leafname is the last part of the program name (not including the /)

e.g. if you would you like to execute /usr/local/bin/myproc the leafname is myproc.

In order to execute a program in the port reserved area - one should change the leafname to start with !

e.g. /usr/local/bin/myproc should be renamed to /usr/local/bin/!myproc

  Note: If there is no real reason for using ports < 1024 for
  non-system application, it would be preferred to use ports > 1024
  for such application.

Some pieces of code from the source code of authbind

helper.c

 117   if (hport >= IPPORT_RESERVED/2) tophalfchar= "!";

 137   snprintf(fnbuf,sizeof(fnbuf)-1,"byport/%s%u",tophalfchar,hport);
 138   if (!access(fnbuf,X_OK)) authorised();

 145   if (af == AF_INET) {
 146     snprintf(fnbuf,sizeof(fnbuf)-1,"byaddr/%s%s:%u",tophalfchar,np,hport);
 147     checkexecflagfile(fnbuf);
 148   }
 149
 150   snprintf(fnbuf,sizeof(fnbuf)-1,"byaddr/%s%s,%u",tophalfchar,np,hport);

tophalfchar is set to be ! if hport is >= 1024/2 (1024/2 = 512)

The code is checking for the following type of strings:

byport/!hport
byaddr/!np:hport
etc

Detailed info about authbind install/setup/testing


how to send data from phone to ubuntu 12.04 through bluetooth?

Do the following after you have successfully paired your phone and Ubuntu laptop (make sure that the devices are set to visible ).

If you haven't already, then install samba by sudo apt-get install samba
Open dash and type Personal File Sharing
Tick Receive files in downloads folder over bluetooth also enable Notify about received file


Nautilus: "Cannot load supported server method list. Please check your gvfs installation"

Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command below.

sudo apt-get install --reinstall gvfs-backends


Since sudo x11vnc -auth... needs to authenticate via the terminal, putting a sudo command in an autostart script (which is not connected to the terminal) you are guaranteed to fail.

Nothing in my reading of man x11vnc leads me to believe it must be started via sudo.


does live usb 3 work faster than a live usb 2

Short answer: No.

My recommendation:
Get a small (2,5" USB3) external harddisk instead of a USB flash. This will make your system feel 10 times as fast, even if the transfer speed isn't. Or, if you have the cash, get a cheap 64GB external SSD.

The reason is that with normal USB flash media the access times are really slow, with harddisks this is much better, and with SSD disks they are another 10x faster. The raw data rate of the bus (USB2 vs. USB3) also differs, but doesn't matter so much unless you do a lot of raw data transfer (i.e. copying very few very large files).

I have tried all of the above. Summary:

USB3 stick on USB3 port: Works, is usable, boots in ~60 seconds (new install).
USB3 stick on USB2 port: Works, is usable, boots in ~65 seconds (new install).
USB3 disk on USB3 port: Works, is a lot faster, boots in ~40 seconds (new install).
USB3 disk on USB2 port: Works, also a lot faster, boots in ~50 seconds (new install).

When using the harddisk the actual port (USB2 vs USB3) doesn't matter so much in daily usage. I connect it to the USB3 port unless I have to transfer a lot of data to a second USB3 disk, in which case this disk will get the USB3 port.

Here are the raw data rates of the respective combinations:

USB3 stick on USB3 port: ~30 MB/s read, ~10MB/s write
USB3 stick on USB2 port: ~20 MB/s read, ~10MB/s write
USB3 disk on USB3 port: ~75..90 MB/s according to hdparm
USB3 disk on USB2 port: ~25..35 MB/s according to hdparm

But, as I said, these are not the primary concern for a system disk. The access times are much more important.


How to mount Snappy Ubuntu Core writable on an external drive

I figured out a way to do this.  First attach the external drive.  Second using parted make the label writable.  Create an ext4 partition and name it writable. Quit parted and use mkfs -t ext4 -L writable /dev/sd?1. Finally using fdisk delete partition #3 on /dev/sda.  Then reboot.


Impossible to format a 4GB RAW usb flash drive

That flash drive is most likely busted. If you want to see all the errors do ...

dd if=/dev/sdf1  of=~/flashdrive.img conv=noerror,sync

The terminal probably can not buffer all the errors you get.

ddrescue might be an option.


Chromium menus not rendered properly in Lubuntu 16.04

A workaround could be to turn off hardware acceleration in the browser. To do so, go to advanced settings (near the bottom of the page) in Chromium's chrome://settings and turn off "Use hardware acceleration when available".


Under Ubuntu the needed drivers can be downloaded from HPLIP web site.

http://sourceforge.net/projects/hplip/files/hplip/3.15.11/hplip-3.15.11.run/download?use_mirror=ufpr

The downloaded files can be installed with sudo command:

sudo -i
sh hplip-3.15.11.run
hp-setup

The scanner can be used together with XSane, which can be installed by:

sudo -i
apt-get update
apt-get install xsane
hp-scan

After placing a sheet of paper on the scan unit and presses the scan button on the printer, a file hpscan001.png is created in the home directory.


How to drop packets to closed ports instead of reject?

You can do this with iptables , DROP vs REJECT.

Syntax

  iptables -option [Chain] [Rule] -j [Target]

Reject

iptables -P INPUT REJECT --reject-with icmp-host-prohibited

Drop

iptables -P INPUT DROP

NOTE: -j is NOT USED with the -P option, see iptables documentation before editing please - https://help.ubuntu.com/community/IptablesHowTo?action=show&redirect=Iptables#Disabling_the_firewall

Example using port 22 (here we use a -j )

REJECT

iptables -A INPUT -p tcp ! --dport 22 -j REJECT --reject-with icmp-host-prohibited

Or with DROP

iptables -A INPUT -p tcp ! --dport 22 -j DROP

IMO Reject is preferred to Drop

Drop is NOT more secure then Reject (despite what "Shields up" might say).

Crackers will not honor the "time out", so it really does not slow down crackers in any way.
Drop tells/reveals crackers your IP address is present due to the lack of a response.
Take a look at tools such as nmap and map test your computers on your LAN. https://nmap.org/book/man-os-detection.html

See http://bodhizazen.com/Tutorials/iptables

and http://www.chiark.greenend.org.uk/~peterb/network/drop-vs-reject

If you need help debugging iptables, please post your entire set of rules as both the syntax and the order of the rules are critical.


How to reduce high GPU temperature in ubuntu 12.04/12.10/13.04

Couple of checks you need to do:

Eliminate Hardware Issues :
- Using Windows and latest drivers, does your GPU shows normal temperatures.
- Is the laptop fan and vents free of dirt and lint. If not, get it services or using a air blower clean them. (http://www.youtube.com/watch?v=T0BQ6YUFaoY)
- Are you using proper thermal paste on the GPU. Arctic silver etc. are known good ones. Please get this done from a service center.

Use the proper ATI drivers
- At the ATI site, download the latest driver for your card and the architecture (64 bit / 32 bit) and check for temepratures.
- Use the open source driver from the Ubuntu built in drivers.

Switch to low graphics mode
- At Ubuntu login, use the Ubuntu 2D option (if available)

Graphics intensive programs
- Do not load any graphics intensive prorgrams - games etc. on this machine.
- Reinstall compiz. (sudo apt-get --reinstall compiz)

Switch to other Distro
- Debian is the best option. Very stable.

Let us know.

Best Regards,

Gurmeet Arora

.


get a launcher on the unity launcher that shows all connected drives/devices in a quicklist

While this would be a useful tool at present this functionality is not available in Unity.

As such this is better addressed as a feature request and I would look at the Unity Get Involved page for ideas on how best to help and put your idea forward.

You can also join the Ayatana mailing list and contribute ideas etc.

Another good site is Ubuntu Brainstorm which is a popular source for feature requests.


Sandisk USB not detected by Ubuntu 14.04 but detected by Windows 7

It turned out the usb-storage module was not being loaded at startup and so couldn't detect any USB drives.

To try it first, I inserted my usb, opened up the terminal and typed sudo modprobe usb-storage and it was detected.

To make the changes permanent, I edited the file /etc/modules as root and added the line usb-storage

My file now looks like this:

# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.

usb_storage
lp

Source: ubuntuforums


Ubuntu 16.10 VM freezing after package updates

From the comments...

Since you can't get to the Recovery screen, you'll have to boot to a Ubuntu Live image and do the following...

boot to a Ubuntu Live DVD/USB (image in your case)
start gparted and determine which /dev/sdaX is your Ubuntu EXT4 partition
quit gparted
open a terminal window
type sudo fsck -f /dev/sdaX # replacing X with the number you found earlier
repeat the fsck command if there were errors
type reboot


Ubuntu 16.04 firefox 48 Old bug solved returns over and over again

One ore more of your Firefox add-ons or plug-ins are causing problems. You can isolate the add-on or plug-in:

Terminate all running Firefox instances. Use killall firefox if necessary.
Start Firefox in safe mode (firefox -safe-mode).
Disable all add-ons and plug-ins. Restart Firefox in normal mode.
Re-enable a few add-ons/plug-ins and restart Firefox.
If Firefox runs without issues, go back to step 4.

If the just enabled add-ons/plug-ins seem to cause problems:
Start Firefox in safe mode (see steps 1–2).
Disable all but one of the add-ons/plug-ins enabled in step 4. Go back to step 5 and repeat until you can narrow down the issues to a single (or more rarely multiple) add-on or plug-in.

Once you isolated the problematic add-on/plug-in, please open a new question to ask how to deal with that.


"Select-by-word" characters are those characters that define words. They are used to determine which characters to select when doing double clicks.

Eg., if you have a-z@ in this list, a valid word would be a@z. If you then have a string like

333a@z444

and you make a double click over 'a', '@', or 'z', it will only select a@z, because '3' and '4' aren't valid word characters.


Ubuntu fails to boot after kernel update

Both of you answers where helpful.

Yes it is the LP bug 919350 about the Intel i915 and yes the problem was solved with the kernel linux-image-3.0.0-16.

Till the kernel update I edited the GRUB to add i915.modeset=0.

Thank you for your help.


Jacek has the right answer, but just to lay out some of the specifics:

Log into the VM using the KVM GUI
On the VM command line, type in:

systemctl enable serial-getty@ttyS0.service
systemctl start serial-getty@ttyS0.service

You will be asked multiple times to enter your password/accept.

Reboot the VM
Then, from the terminal on your main machine, type in:

sudo virsh console your_vm_name_here

Obviously replacing "your_vm_name_here" with whatever the VM name is.

Then you can "ssh" directly into the VM using virsh.


How can I disable Grub from appearing after selecting Ubuntu in Refind menu?

I don't know about disable it but you can try hiding grub boot menu, it's quite easy to do so.

Press Ctrl+Alt+T on keyboard to open Terminal, paste and run below command then:

gksudo gedit /etc/default/grub

An pop up will ask your sudo password, fill it. This behavior is because you're gonna modify grub config file (which need root privilege).
When the file opens, remove # sign before GRUB_HIDDEN_TIMEOUT=0 and set GRUB_HIDDEN_TIMEOUT_QUIET=true. So it looks like:

GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

Save the file, open terminal and run sudo update-grub

Source: http://ubuntuhandbook.org/index.php/2014/06/ubuntu-1404-hide-grub-menu/


How to mount NAS folders via direct wired connection?

In nautilus menu Go/Network, you should see your NAS. Click on the right icon and it will be mounted.

You can access to it in a terminal here : $HOME/.gvfs/...


Let me throw my practical answer into the ring: Go with ext4. You will see no read/write differences vs. XFS except in extreme edge cases (mass deletions of hundreds of thousands of small files, for example).

You will also find more community support for ext4 at places like AskUbuntu, simply because it is so widely used.

One notable disadvantage of XFS is that it cannot be shrunk (decrease partition size), so you would have to backup, repartition/reformat, restore if you ever wanted to decrease your XFS partition size.


Skype and Steam won't load - Ubuntu 14.04

Maybe this link will help with the Steam issue:

Steam Game Not Loading on Ubuntu 14.04

They mentioned modifying the launch files in a text editor.


Window decoration of emacs23 window on fluxbox is outside screen

I found a workaround which I post as an answer, but I would prefer if someone comes up with a real solution:

When I start emacs like this

emacs23 -g 98x36

I get a viewport that exactly fits my screen and all of the fluxbox window decoration is accessible.

I found out the values 98 and 36 by trying different numbers.


My webcam stopped working, how do I fix it?

It looks and sounds like your webcam has had a hardware failure, the type of image your getting suggests the webcam is covered by something, but it may also be that the webcam is defective now and is giving off noise instead of data.