Why isn't ethernet bridging working with OpenStack?

First, forget virbr0 -- that's added by libvirt and is irrelevant.

For an "all-in-one" Openstack server with one NIC, there should be no need for another aliased virtual interface. As discussed in the Openstack guide, you should bridge br100 to your public IP address (eth0), and let Nova create instances and bridge them to br100.

e.g. add the below to /etc/network/interfaces, modify as appropriate for static:

auto br100
iface br100 inet dhcp
    bridge_ports        eth0
    bridge_stp           off
    bridge_maxwait   0
    bridge_fd            0

The allowable private IP subnet has to be configured via the --fixed-range option in nova.conf, and the --flat_network_bridge option set to br100.

  Please paste your nova.conf in the question to help with further troubleshooting!


Problem connecting with USB 3G Viettel in 12.04

Step by Step guide to use Huawei E1550 USB stick on Ubuntu:
1. Plug in Huawei E1550 USB modem to USB port. You can notice its icon is loaded on Desktop.

Type following command at command prompt: gksu gedit /etc/udev/rules.d/15-huawei-e1550.rules
It will open gedit. Type following lines in it and then save it and close the file:

SUBSYSTEM=="usb"
SYSFS{idProduct}=="1446"
SYSFS{idVendor}=="12d1"
RUN+="/lib/udev/modem-modeswitch --vendor 0x12d1 --product 0x1446 --type option-zerocd"

Restart the computer. After restart click on "Network connection" icon in the top panel. You will see new menu item under "Mobile Broadband" category.
Click on that new entry. It will open a New Mobile Broadband Connections dialog. Click Forward to continue.
Select you country (Singapore in my case) and click Forward. Then select service provider from the list and click forward. Then choose your Billing plan and click Forward. Then finally Click on Apply to save setting.


This happens because the PSU can't supply enough power to do both things at once - powering the CPU has a higher priority than charging the battery.


installing software package for any user account and root user

Programs installed from the Software Center or apt-get should be installed globally (system wide) and will be available to all users.

This is because they are not installed in a particular user's home folder but in the usr folder.

Each user will have their own file in their account to save there preferences and data except any user logged in as a guest, as their data is deleted on logging out.

.sh and .bin files that install without root will only be available by the user that installed it unless the folder that it is installed in is made available to all users via the sharing options via the mouse right click or the command line chmod.  This is because programs that install without root only install into the home directory of the user that installed them.

source


Ubuntu 14.04 only has 2 ways to display my folders. Can I get the other option back?

If you're talking about the Compact view:

Then no, not using the default file browser, Nautilus.
You can install Nemo, which does retain this option:
sudo apt-get install nemo

You can set Compact view as the default. Go to the Edit menu, then click on Preferences:

Set View new folders using: to Compact View.


Have to reinstall ubuntu 16.04 repeatedly

It sounds like you've got a hard disk problem. The first thing is to perform a file system check...

boot to the GRUB menu (where you select which OS to start)
choose Advanced Options
choose Recovery mode
choose Root access
at the # prompt, type sudo fsck -f /
you can ignore errors about the time/date/superblock
repeat the fsck command if there were other errors
type reboot


Have you toggled the hardware wifi radio button?


How can I uninstall my current java and install sun java 1.6

1.) If you’ve already installed OpenJDK (Or in Ubuntu generally it is already installed). Remove it by running this command:

sudo apt-get purge openjdk*

2.) Then:

sudo add-apt-repository ppa:webupd8team/java

Then update:

sudo apt-get update

3.) Select which version you want
To install Oracle Java 8:

sudo apt-get install oracle-java8-installer

To install Oracle Java 7:

sudo apt-get install oracle-java7-installer

To install the Java 6:

sudo apt-get install oracle-java6-installer


nslookup finds ip for a hostname in .local domain, but ping does not

I believe this is caused by mdns - multicast dns, for autoconfiguration of the .local domain.

If you check in /etc/nsswitch.conf, you will probably see:

hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4

mdns4 is what is doing multicast dns. Try changing this to:

hosts: files dns

And see if it makes any difference. If it makes it work, you can remove mdns permanently with:

Try apt-get remove libnss-mdns

Which will do the nsswitch.conf change for you as well.

Alternatively, don't use .local - use .lan or something instead.


Recursive subvolume deletion (snapshots are just read-only subvolumes) is not yet available in btrfs-tools.  In order to delete the top-level, you must first delete the lower levels.

You can get a list of the subvolumes with the btrfs subvolume list command.  The -o option should let you filter the results to just the ones you care about, but feel free to experiment.  You should then be able to go down the list and delete all the sub-subvolumes, after which you should be able to delete the toplevel subvolume, and then you're done.


You have a typo in your lightdm.conf file

greeter-session=unity-gretter

should be

greeter-session=unity-greeter


Is there a way to make some entries in history "sticky"?

I used to be heavily reliant on using CtrlR to recall previously entered commands – both commonly used commands and long complicated ones. I encountered very similar issues to those you describe.

To overcome these problems, I modified my Bash configuration so that when the shell exits it appends to the history file rather than over-write it:

shopt -s histappend

However, if the shell didn’t exit cleanly (as in a hard reset), I’d still lose the history for that session so I added the following to save the history after each command is entered.

PROMPT_COMMAND='history -a'

Shell aliases

In the end, I came to embrace shell aliases as the best way to save the commonly used commands and those long complicated ones that take time to get right. As long as they’re saved to my aliases file, they’ll always be available to me – even years later.

I store all my aliases in ~/.bash_aliases and then source that file from  my .bashrc as suggested by the default .bashrc provided by Ubuntu:

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
    . ~/.bash_aliases
fi


matlab.desktop file you downloaded and put in /usr/share/applications/ says:

#!/usr/bin/env xdg-open
[Desktop Entry]
Type=Application
Icon=/usr/share/icons/matlab.png
Name=MATLAB R2011a
Comment=Start MATLAB - The Language of Technical Computing
Exec=matlab -desktop
Categories=Development;

I think you should change the Exec line with your installation folder.


Script / Shortcut to switch display priority?

It turned out I already wrote it, as part of this question. Since it is another question, below an outtake of that one:
#!/usr/bin/env python3
import subprocess

# Look up the currently set primary screen, set it to the other one
scr_data = subprocess.check_output(["xrandr"]).decode("utf-8").splitlines()
scrs = [[l.split()[0], "primary" in l] for l in scr_data if " connected" in l]
for screen in scrs:
    if not screen[1]:
        subprocess.Popen(["xrandr", "--output", screen[0], "--primary"])

It toggles (switches between the two) the primary screen.
To use:

copy the script into an empty file, save it as toggle_primary.py

Add it to a shortcut key: choose: System Settings > "Keyboard" > "Shortcuts" > "Custom Shortcuts". Click the "+" and add the command:
  python3 /path/to/toggle_primary.py


Windows 7 partition D: to unallocated space?

Answer copied from comments:

Your "free space" is allocated to an extended partition (that's why the whole thing is green), but within the extended partition, you can make logical partitions - and the free space space is currently not allocated to logical partitions (hence "unallocated").

Ubuntu can and does work fine with extended partitions...


How to make package installation automatic?

The configuration files are managed by ucf and you can set system wide configuration via editing /etc/ucf.conf For reference, here's an unedited example from one of my Ubuntu 16.04 installations:

#
# This file is a bourne shell snippet, and is sourced by the
# ucf script for configuration.
#

# Debugging information: The default value is 0 (no debugging
# information is printed). To change the default behavior, uncomment
# the following line and set the value to 1.
#
# DEBUG=0

# Verbosity: The default value is 0 (quiet). To change the default
# behavior, uncomment the following line and set the value to 1.
#
# VERBOSE=0

# The src directory. This is the directory where the historical
# md5sums for a file are looked for.  Specifically, the historical
# md5sums are looked for in the subdirectory ${filename}.md5sum.d/
#
# conf_source_dir=/some/path/

# Force the installed file to be retained. The default is have this
# variable unset, which makes the script ask in case of doubt. To
# change the default behavior, uncomment the following line and set
# the value to YES
#
# conf_force_conffold=YES

# Force the installed file to be overridden. The default is have this
# variable unset, which makes the script ask in case of doubt. To
# change the default behavior, uncomment the following line and set
# the value to YES
#
# conf_force_conffnew=YES

# Please note that only one of conf_force_conffold and
# conf_force_conffnew should be set.

If you wish to keep your currently installed versions of all configuration files you can simply edit this file and remove the comment marker # from the line that contains # conf_force_conffold=YES

For more precise handling, it's worth mentioning that you can control specific configuration files with ucf. That however is beyond the scope of this answer.

Source:

http://manpages.ubuntu.com/manpages/xenial/man5/ucf.conf.5.html


Perhaps writing the commands to a shell script, making it executable and running it with sudo will do what you need.

However what you are doing is very dangerous. Allowing potentially untrusted command line to be executed as a root is a disaster waiting to happen. Look up "shell injection" type of vulnerabilities. Then perhaps consider reviewing what needs to be done and then redesigning it without the need to run any command as sudo.


What to do if this dialogue comes in terminal in ubuntu 16.04

Tab down to the <Ok> field and press Enter.


How do I make Shotwell regenerate all the thumbnails?

This shell script will regenerate your thumbnails of sizes 128px and 360px so you'll see at least something in viewer.

sqlite3 ~/.local/share/shotwell/data/photo.db \
  "select id||' '||filename from PhotoTable order by timestamp desc" |
  while read id filename; do
    for size in 128 360; do
      tf=$(printf ~/.cache/shotwell/thumbs/thumbs${size}/thumb%016x.jpg $id);
      test -e "$tf" ||  {
        echo -n "Generating thumb for $filename ($tf)";
        convert "$filename" -auto-orient -thumbnail ${size}x${size} $tf
        echo
      }
    done
  done


How to run a script when opening OpenBox?

If it doesn't exist, create a file in your ~/.config/openbox directory called autostart or autostart.sh (both should work).  If the openbox directory doesn't exist, create that as well.

In this file, you put in all your executables that you want to run when openbox starts.  Ensure you put an ampersand after every command, otherwise, openbox will lock up waiting for the executable to end.

Here is an example of an autostart file:

tint2 &
plank &
volti &

As you can see, with the ampersands, the autostart script will be able to continue executing the next lines.

If you would like to see more on how to completely setup an openbox desktop, including running applications in the autostart file, see this video


Have updates to version 15.04 brought some ATAPI usage with them?

The answer is NO, at least, the problem had no relation to the recent updates of Ubuntu 15.04.

In one of answers at AskUbuntu for similar problem, which I cannot find now, someone mentioned that the lens of a CD-ROM may need cleaning.

I removed the cover of my CD-ROM, and though I doubt that the dust was the cause of the problem, because there was no dust inside and lens seemed clear, but for some reason, after I cleaned the lens with a soft napkin and reconnected the device to the desktop, the drive began to work correctly (before this I was unable to write), and these messages have gone.

I hope, this can be helpful to someone, who might find himself in a problem like mine.


How to eliminate the lock screen so the login form displays instead?

Have you tried just typing without the form being displayed?  For me (18.04.2 LTS), that causes GDM to display the login form.


You might consider using conky which is a great lightweight system monitor that can not only monitor your battery state but many, many other functions of your computer.


Wifi P2P wpa_supplicant - failed to create p2p device interface

Does your wifi device support p2p-client/p2p-go interfaces? You can check under interfaces by doing "iw list"

     Supported interface modes:
     * IBSS
     * managed
     * AP
     * AP/VLAN
     * monitor
     * P2P-client
     * P2P-GO
     * P2P-device


How to drag an image to the side panel to open with Chrome

This is because Chromium does not announce that it can open .png files in its .desktop file but Firefox does. Compare the MimeType lines in /usr/share/applications/firefox.desktop and /usr/share/applications/chromium-browser.desktop.

Please report this bug by running ubuntu-bug chromium-browser


How do I set up an OpenGL programming environment?

As far as I know OpenGL is a graphics library. The IDE choice depends on the language you want use OpenGL in.

Anjuta is a perfect IDE for C and C++

sudo apt-get install anjuta

then you have to download OpenGL library:

sudo apt-get install freeglut3 freeglut3-dev libglew1.5 libglew1.5-dev libglu1-mesa libglu1-mesa-dev libgl1-mesa-glx libgl1-mesa-dev

after that you should include libraries (in folder gl/*) into your code


Bash error "no such file or directory" when I type cd usr/bin/python3.7

As pointed out in a comment from AlexP, you did not include the / at the beginning. Even if you did that, you would still not succeed. You are trying to change directory cd to a file. Type

ls -l /usr/bin/python3.7

The output should be something like that

-rwxr-xr-x 2 root root 4464400 nov 28  2017 /usr/bin/python3.5

For a directory you see a letter d at the beginning of the line, like this

drwxr-xr-x   2 root root 90112 aug  7 06:49 bin

You will see, that python3.7 is a file not a directory. You can change to a directory

cd /usr/bin

but not to a file like /usr/bin/python3.7.


Ubuntu upgrade problem Xenial to Zesty [solved]

The problem was not a display driver issue. Instead it was because /etc/fstab used names instead of UUIDs.

The clue was in the boot log which showed things on the lines of "A start job is running for /dev/mapper/ubuntu--vg-root" (and others).


Apache 403 Forbidden Error - Can't access webserver

It is not the configuration, but the file permissions themselves. You need to chmod your web root directories to 755 and web files to 664.

A far better solution is to use the user module in apache, which allows user to host files inside a public_html folder in home directory.

for further information see:

Apache symlinked to home directory - Permission Errors


Both QT5 and QT4 are in main Ubuntu repository for 14.04

You can simply install QT4 as

sudo apt-get install qt4-default libqt4-dev qtchooser qt4-designer


WiFi is not detecting in compaq presario c700

It's a Broadcom wireless LAN card.  Try the following in terminal:

sudo apt-get update
sudo apt-get install bcmwl-kernel-source

This should blacklist the non-working device module in '/etc/modprobe.d/blacklist-bcm43.conf' and install the working one.  If you are still having problems, have a look at the community help pages for the broadcom devices.

Desktop support for 10.04 LTS runs out in April next year.  You might consider 12.04 LTS because the driver module support may be better, and it will be supported until April 2017.


Emulate apt-get from third-party sources with dpkg

Assuming you can boot a live system I guess in your case it might be the best procedure, to perform your tasks in there and then transfer your downloaded packages over.

The following is regarding using a live-dvd (with a stick it should be more easy as long as you made it use the free space as persistent storage).

Boot your live-dvd and select 'try ubuntu', when finished attach a usb-stick. Open gnome-disk-utility, find your usb-device and unmount it, also write down it's device-path (for this example we will use /dev/sdb1).

Now open a terminal with Ctr-Alt-t and type sudo mkdir -p /var/cache/apt/archives/ this will take care that this directory truly exists.

In the same terminal, you now mount the usb-stick to that point sudo mount /dev/sdb1 /var/cache/apt/archives (be sure to use the correct device).

So now we will add the repository holding the software you want:

for classic deb-archives:
sudo echo "deb http://archive.getdeb.net/ubuntu xenial-getdeb games" >> /etc/apt/sources.list.d/getdeb-games.list add the pgp-key wget -q -O- http://archive.getdeb.net/getdeb-archive.key | sudo apt-key add -
for ppa's: sudo apt-add-repository someppa/ppa

Now we update our package lists sudo apt-get update and download the packages sudo apt-get install -d warsow; the -d options makes apt-get only download the package and all dependencies.

Voila finished, all your needed packages are now on your stik. Reboot into your normal system, attach the stick, open a terminal and cd into the stick and there issue sudo dpkg -i *.deb to manually install all packages and then run sudo apt-get install -f to clean everything up.

This procedure can bring in newer versions of already installed packages depending what repositories you use, so be careful, what you download and install. With third-party repositories there is also always the probability to catch yourself a flu or a virus, so think about what you do.


Copying only files without extension via scp

scp server:~/Area?? location/in/my/computer

will get you all files named "Area__", as "?" globs for a single char.


Go To Meeting on Ubuntu: Possible, and if not, which alternative?

OpenMeetings

  Openmeetings provides video conferencing, instant messaging, white board, collaborative document editing and other groupware tools using API functions of the Red5 Streaming Server for Remoting and Streaming.

Mikogo

  Mikogo is a desktop sharing tool full of features to assist you in conducting the perfect online meeting or web conference.
  Take advantage of the opportunity to share any screen content or application over the Internet in true color quality with up to 25 participants simultaneously, while still sitting at your desk.

Yugma

  Yugma free web conferencing allows anyone, anywhere to instantly share their desktop and ideas online with others. To start hosting your own meetings, sign up today for FREE. Your Yugma Free web conferencing account allows you to invite up to 1 attendees with 30 minutes meeting limitations.


Possibly, you are missing some environment variables. Maybe some entries in your $PATH? How about the following. Create a script, say /home/user/testidea.sh (where user is your actual username, of course), containing

#!/bin/bash

/opt/idea/bin/idea.sh 2> /tmp/idea.err > /tmp/idea.out

Make it executable

chmod a+x /home/user/testidea.sh

And replace the respective line in the idea.desktop file by

exec=/home/user/testidea.sh

Maybe that will work, but if not, at least (hopefully) you will find what is wrong by inspecting /tmp/idea.err and /tmp/idea.out.


When will Firefox 5 be in the official repositories?

You wil get firefox 5 in the official channels in the next 24 hours.

If you want it before that use the PPA. It's easy and it is fairly safe.
If you change your mind about PPA check out How do I install the latest stable version of Firefox?


Gtk version problem while installing themes to Ubuntu 12.10

Ruled it out being a web browser issue from the start, tried 2 web browsers. It was simple. The themes didn't work. Also have to run sudo add-apt-repository ppa:upubuntu-com/gtk3. Seemed to have fixed my problem. Best document to get a custom gtk3 theme running on Ubuntu 12.10. I found a few others, but this one break it down as simple as it gets. You don't even have to move the themes files any where with these steps. I have to admit, I was starting to hate this OS but seems like everything on this OS is actually pretty easy, just need to find the right steps. At this point I have everything set up and starting on the fun stuff, setting up lamp and figuring out how to use all that. Anyone have any pointers on setting up Python?


How to install numpy and scipy for python 2.7.12, Ubuntu 16.04?

To install it for python 2.x, this works for me on ubuntu 18.04:
sudo apt-get install python-scipy


Unable to Get a Working Desktop Launcher for a Python Program

I am not sure if this is really necessary, but when I made a bash script I launched the script with this command "bash $$$$$$$.sh". The only reason that I mention this is that the .py extension is not on the script name in your desktop launcher. May be nothing, worth a look and a try.    Craig


For 3 times you can just run:

cat file file file > new_file

And here is a trick if you're lazy like me and you don't want to re-type the file name N times. Type cat then the filename, Press Ctrl+W, then Ctrl+YSpace N times, finally type > new_file.

However it's a better idea to use a simple "loop" in combination with cat command.

3 times example:

for i in {1..3}; do cat file >> new_file; done

Or as you asked in comments:

limit=3
for ((i=0; i<limit; i++)); do cat file >> new_file; done

Change '3' to any number you want.

Result:

jplg3350.18i
jplg3360.18i
jplg3370.18i
jplg3350.18i
jplg3360.18i
jplg3370.18i
jplg3350.18i
jplg3360.18i
jplg3370.18i


Firstly, let's address the processes.  These're two unrelated processes.

Firstly, dhclient is being used alongside NetworkManager on your system to get the IP address dynamically for eth1 connections.  That's not a keyserver.

Secondly, gpg-agent tends to be started on desktop instances when you logon via a GUI, to handle GPG requests for decryption, encryption, signatures, etc. within the GUI.  This way, you get nice GUI prompts from GPG for your password instead of other prompts.

What's missing here is that you don't tell us if you enabled the root user or anything. If you did, and you don't have sudo privs on any other users and you use separate permissions and such, then you could have been breached.  But usually, gpg-agent isn't a backdoor, it's only listening locally.  (Any launch of gpg-agent though can open such a command though, in this case it's on the root user so someone may have logged in as root via the GUI).

As to whether this is a backdoor or a breach, we can't reliably answer that without direct inspection of the system, network traffic, etc.  It's not able to be determined solely from what is stated here whether it's a breach or not.


Install tomcat 9 on ubuntu server 18.04.3

Did you check the /opt/ directory to ensure that the tomcat folder is there? That error can indicate that there is no directory the command is referencing.

For example, it cannot change permission on a directory that does not exist.

Try this instead:

Create a new group for tomcat-

sudo groupadd tomcat

Now create a new user, in this case called tomcat. Make the user a member of the tomcat group. Make that users home directory /opt/tomcat and give it a shell of /bin/false

sudo useradd -s /bin/false -g tomcat -d /opt/tomcat tomcat

Source:https://www.digitalocean.com/community/tutorials/how-to-install-apache-tomcat-8-on-ubuntu-16-04


DisplayPort with Targus 2k Dock and Dell E6230

The Targus 2K appears to be a DisplayLink device, searching a bit brought me to this page with the following statement:

  Rotation is not supported due to missing functionality in the generic modesetting driver

It's not clear to me when this article was written and if it's still up to date, I have to guess it is still correct and there is nothing that can be done about that.


I deleted trusted software providers from authentication in software and updates

You can add Public Keys to your apt keychain using apt-key.  It is up to you to determine whether or not to trust the keys and import them.  Here is how you would do it:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv 886DDD89 7F0CEB10 C300EE8C

Where keys are separated by spaces.
You may use full keys, or the last eight characters, as show above.
This example would import Tor, NGINX and MongoDB keys.


Home directory locked after login, content replaced by “Access-Your-Private-Data.desktop”

I found a weird solution, I removed the entries in my account's crontab:

I had some lines like this my crontab:

@reboot sleep 60 && mkdir -p /run/shm/project1_cache /run/shm/project1_logs
@reboot sleep 60 && mkdir -p /tmp/project1-test-dev

In my home, I have added some symbolic links that point to these directories (I put the cache and logs directories in the RAM in order to speed up Symfony).

I moved these commands to a script launched with Gnome Shell's startup applications manager and it works as before.

I don't understand why this resolved my issue but it works for me.


3rd and 4th serial port not configured on startup

If you want to boot with this configuration applied on the serial port you can modify the

/var/lib/setserial/autoserial.conf

to modify the configuration of the ttyS3, including the sentence you used to reconfigure it correctly.

The autoserial.conf file is used on the boot process by /etc/rc0.d/K19setserial script.

Here's my own file

/dev/ttyS0 uart 16550A port 0x03f8 irq 4 baud_base 115200 spd_normal skip_test
/dev/ttyS1 uart 16550A port 0x02f8 irq 3 baud_base 115200 spd_normal skip_test
/dev/ttyS2 uart 16550A port 0x03e8 irq 4 baud_base 115200 spd_normal skip_test
#/dev/ttyS3 uart 16550A port 0x02e8 irq 3 baud_base 115200 spd_normal
/dev/ttyS3 baud_base 115200 auto_irq skip_test autoconfig spd_normal


software and updates can't connect internet

Go to software and updates
Select Other Software
uncheck all ppas
click close
click reload

Go to Lite Welcome

Good luck!


Just use chromium, you extract it from zip and, in my case, ./chrome --no-sandbox


How do I write raw bytes to a sound-device?

This script is a thin wrapper around PulseAudio's Simple API. It allows you to write samples to the default output:

#!/usr/bin/env python3

import random
import ctypes
import struct

class NoiseMaker (object):

    PA_SAMPLE_U8 = 0
    PA_STREAM_PLAYBACK = 1

    def __init__(self, rate, channels):
        pat_sample_spec = ctypes.c_buffer(struct.pack("LLB",
            self.PA_SAMPLE_U8, rate, channels))
        self.pa = ctypes.cdll.LoadLibrary("libpulse-simple.so.0")
        self.s = self.pa.pa_simple_new(0, "App", self.PA_STREAM_PLAYBACK,
            0, "App Noise", ctypes.byref(pat_sample_spec), 0, 0,0)

    def write(self, data):
        self.pa.pa_simple_write(self.s, data, len(data), 0)

    def __del__(self):
        self.pa.pa_simple_free(self.s)

one_second_noise = bytes(random.randint(0, 255) for i in range(44100*2))
NoiseMaker(44100, 2).write(one_second_noise)

The rate (44100) defines how many samples there are in a second of real time. It expects bytes in the range of 0-255 inclusive, which is defined by PA_SAMPLE_U8 (equivalent to 'Unsigned 8-Bit' as shown by Audacity, for example). If you have more than one channel, it expects alternating samples for each of them. So, one second of noise has 44100 samples per channel = 88200 samples, where the (modulo 2 = 0) ones are for the left channel.

Please note that this script runs only on Python 3


How do I find the boot parameters used by the running kernel?

You can run cat /proc/cmdline.

Example:

[01:31] ~ $ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-2.6.38-7-generic root=UUID=025c4231-b7bb-48bf-93e9-d20c5b5ce123 ro crashkernel=384M-2G:64M,2G-:128M quiet splash bootchart=disable acpi_enforce_resources=lax vga=792 vt.handoff=7


Where does ubuntu store information on all installed programs

At the bottom of the screen of software-center there is a link "Show NNNN technical items". Click that link.

At the top right there is a search box. Type the name of your package there.

And to answer your actual question: the information about installed packages is stored in /var/lib/dpkg and can be queried with dpkg-query -l (or various other frontends). There is no separate backend for each frontend. That is also why you get errors about a locked database when you try to run two dpkg frontends at the same time, like synaptic and software-center.


When you mount a volume using the Nautilus GUI file manager, the operation is handled by the gvfs daemon rather than a traditional mount command.

You can call gvfs-mount manually from the command line in which case the volume will be mounted in exactly the same way (without the need to explicitly create a mount point) at the default gvfs location - either /media or /media/username - plus the device label. For example

$ gvfs-mount -d /dev/sda1
Mounted /dev/sda1 at /media/28C68BC3C68B8FAC

To unmount, use the mountpoint and volume label

$ gvfs-mount -u /media/28C68BC3C68B8FAC/


What configuration is correct for Static IP?

Ok, I am not sure why, but I got it to work. I am not going to mark it as the answer until I am conviced that I solved the issue.

First what I did was go to this tutorial, and noticed that they have search cyberciti.biz in their /etc/resolv.conf file, followed by the dns servers they want to use. Remembering that this "search" line is similar to the one that was automatically generated in my copy of the file, I formatted the file to look like this:

search hsd1.nh.comcast.net
nameserver 68.87.71.226
nameserver 68.87.73.242

These DNS number I had to get from this website (I use comcast).

I restarted the computer and magicly I can ping Google! Also, the search line has been removed from the /etc/resolv.conf file, but I think that's ok.

Also, I don't know if this helps/hurts, but I put in the line

dns-nameservers 68.87.71.226 68.87.73.242

in my /etc/network/interfaces file, as the last line.

I will update this post if this turns out to work or not.


How to fix "some packages could not be installed ... unmet dependencies" installing Java?

Sure thing. In the command line type in software-center now search for java. That should fix all your problems.

Also I recomend installing synaptic as your package manager to assist you with individual packages.


Others have pointed you to How do I run memtest86+? because it's not reasonable for Linux to fail in this way. An operating system, be it Linux, MacOS, or Windows, will read and write memory in much the same way. However, it's possible for one operating system or program to appear functional on defective memory because they load different things into different memory regions.

In basic terms memory addresses 0 - 10 might work fine, but 11-20 might not, because of a hardware defect. This error could be with your memory sticks, motherboard, or the CPU itself - all of which have different roles in memory and bus management.


Dual Boot Ubuntu on HDD and Windows on SDD, tried installing but grub not working

Maybe you can try this software, it cleaned every problem I had before with the GRUB stuff.
https://help.ubuntu.com/community/Boot-Repair
Install the software:
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair

Then run it and follow the instructions according to your problem:
$ boot-repair

I hope it helps, and welcome!
(Please try the solution before voting it as answer)


Ubuntu disk partioning issue: not enough space

You are most likely running VirtualBox as root, which causes it to store disk images and virtual machines in /root, which is part of the / filesystem, which is your 20GB SSD that has ~7GB of free space.

The easy solution is: don't run it as root, run it as your own user. There is no advantage I know of in running VirtualBox as root.


Can I use Ubuntu with windows 7 starter?

How can that be the problem? You can install any operating system you want in your hard drive, given that it has enough free space. Just back up your files!


what do the parameters uid and gid with /etc/fstab do?

Mount options for Microsoft (and similar) file systems to set the owner and group

From man mount,

Mount options for fat
       (Note:  fat  is  not  a  separate  filesystem,  but a common part of the
       msdos, umsdos and vfat filesystems.)

       ...

       uid=value and gid=value
              Set the owner and group of all  files.   (Default:  the  uid  and
              gid  of  the  current process.)

There is a similar text for ntfs. See the following link for examples, where uid is used,

How do I use 'chmod' on an NTFS (or FAT32) partition?


How to map Ctrl+S in vim on gnome-terminal?

You can disable Ctrl-S in a terminal by:

stty stop undef

You can put this line in your ~/.bashrc file to make the change permanent. You can also reenable Ctrl-S with:

stty stop ^s


Where is the difference between using `pdfimages` from poppler-utils and using the one provided by xpdf-utils for image extraction?

They are forks: used to be the same but someone decided to go another direction. Poppler-utils is the favored one. Debian already removed xpdf-utils from the code base. From Ubuntu bug #697119 and debian bug #622343 they also are in conflict with each other due to sharing the same file names.

xpdf-utils seems to be better at some things but from the 2nd link: "These minor regression bugs should be submitted against poppler (preferably upstream poppler) where they can actually get fixed."

Poppler is used in Gimp and Evince so that seems to be your best bet.


https://github.com/docker-archive/docker-snap/issues/22
mentions that the daemon.json file should be in this folder :

/var/snap/docker/current/etc/docker/daemon.json

or

/var/snap/docker/current/config/daemon.json

to take into account the changes you then need to
sudo snap restart docker


Will the MSI R7770 work on Ubuntu 12.04?

From my own experience with the same GPU (HD 7770) the Radeon driver doesn't provide what you'd call good support especially in the kernel version of Ubuntu 12.04, for that I used Catalyst which you can install as explained here:

What is the correct way to install proprietary ATI Catalyst Video Drivers (fglrx) directly from AMD?

If you don't want to use Catalyst for whatever reason, you can upgrade your kernel which will include better suport for newer cards from the Radeon driver, you can update it as explained here:

How to update kernel to the latest mainline version without any Distro-upgrade?


Can I use ddrescue & Testdisk in ubuntu to create image to recover data?

Recover from a cloned copy or image

Yes, it is a good idea to make a cloned copy or an image with ddrescue and do the recovery job on the cloned copy. It reduces the risk, that the recovery attempts will damage what is still possible to recover on the drive.

Links

Accidentally did dd /dev/sda - See also the other answers.

Repair the partition table and file system of a pendrive - scroll down to find 'Advanced repair of a partition table, file system and/or recovery of files'


The best player I've seen is Miro player. It can play from a lot of sources, torrents, podcasts and feeds. You can browse from thousands of chanels directly from Miro or from their website, so far all popular channels I've seen are there.

Watch their presentation at getmiro.com

You can install it from the ubuntu software center.

good luck!


Uninstalled Kubernetes but I keep getting: "unable to resolve host slave-node"

This usually happens when the hostname is different from the host name, you should modify the name in the following path /etc/hosts


Solved the problem using this solution:

  I have fixed this issue doing the following:

  Installing the libs:

apt-get install libxi-dev libxmu-dev

  (Re-)moving the Qt libs inside the Genymotion installation
  directory:

mkdir QtLibs && mv *Qt*.so* QtLibs

  This last command will make Genymotion use the system's Qt libs.


Upgrade package that was installed with apt-get to version in .deb file

Download the new version of your software, cd into its directory and then simply run:

sudo apt install package.deb

The apt utility can handle installing .deb files while handling their dependencies too.

Just make sure the package.deb that you are downloading has been created for your Ubuntu version, for example do not install a deb file which is created for zesty on xenial.


'sudo' not found in Turnkey linux Ubuntu install

Whilst Turnkey Linux is based on Ubuntu (and is binary compatible - and in fact is mostly constructed of vanilla Ubuntu packages), it isn't strictly Ubuntu and has a number of customisations.

So sudo is not installed by default in TKL appliances. On a desktop it is a really good idea to have the root account disabled and use sudo instead (as Ubuntu is by default). IMO (and the TKL dev's) this rationale does not apply to servers.

With this setup sudo is generally not required. For general admin just use root (and so no need for sudo). If you want additional users you probably don't want them having admin (sudo) privileges anyway.

So to install curl (or any other command) just omit the sudo eg

apt-get install curl

If you want sudo then just install it

 apt-get install sudo


Delay an application at /etc/xdg/startup

Typically to delay a .desktop that is autostarted you'd add a line like this, example here of 4 sec's

X-GNOME-Autostart-Delay=4

Just to note, the .desktop you posted above has X-GNOME-Autostart-enabled=false so it shouldn't be autostarting quake. It it is truly set to false & guake is autostarting then look in ~/.config/autostart/ for another .desktop for quake to add above line to.


What to do when you don't get answers from Launchpad?

Ask the same question here on AskUbuntu. I don't mean to denigrate the efforts or expertise of the Launchpad Answers folks—and for extremely technical, project code-related questions they may be the best to ask—but the community here is more vibrant and less fractured, and the software more attuned to preventing good questions from falling down the cracks.

Follow the FAQ, and you're nearly certain to get some sort of resolution here.


Ubuntu 18.04, fresh install, cannot install build-essential!

Try this:

sudo apt-get update
to update your package list.
Then

sudo apt-get autoclean
to clean up any partial packages.
Then

sudo apt-get clean
to clean up the apt cache.

sudo apt-get autoremove
will clean up any unneeded dependencies.

If while doing this you can identify the broken package this code will very forcefully remove it.

sudo dpkg --remove -force --force-remove-reinstreq build-essential

source


When you open a patch file in emacs, you can put the cursor on a hunk and hit C-c C-c to jump to the corresponding location in the patched file and it will tell you if the patch has already been applied or not.  Then you can use C-c C-a to apply the hunk.


Switch to a console (not a terminal!) by using Ctrl + Alt + F1

dpkg-reconfigure compiz
compiz --replace
unity --reset
unity --replace

Switch back to your desktop with Ctrl  + Alt + F7.

Maybe a reboot of the system is necessary.


Cursor running wild, then crashes on an Asus G73sw

OP Solved problem :

  Radical but efficient: i've disabled the touchpad using the following command: "xinput set-prop 14 "Device Enabled" 0", and created a launcher for it. It seems to work.


Unity dash: Sorry, there is nothing that matches your search

E: Unable to locate package unity-place-applications

  E: Unable to locate package unity-place-files

unity-place-applications and unity-place-files   are no more available in Ubuntu 14.04 instead use unity-lens-applications and unity-lens-files which is founded in universe repository, so first enable it(if it's disabled for some reason else skip it to the last command)

sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu $(lsb_release -sc) universe"

Now update software sources

sudo apt-get update

Now you can install it :

sudo apt-get install unity-lens-applications

sudo apt-get install unity-lens-files

Try to do this:

    mkdir local.OLD
    mkdir gnome.OLD
    mv .local/share/applications/*.desktop local.OLD/
    mv .gnome/apps/*.desktop gnome.OLD/

Then logout, login and check the result now.


Problems with a Radeon HD 5450 card on Ubuntu Server

Ah - you're right, mikewhatever! I thought I needed some sort of (simple) video card, but there actually is a simple one on the mother board. Removed the card and the fqlrx-driver and used the on-board card instead. Problem solved. Thanks! :-)


How to start a service living on a Windows partition

Finally I figured it out. It is in fact a mounting option (exec). Now my fstab looks like this and it works all pretty fine.

UUID=E24E8DDC4E8DAA3D /media/nelson/data                  ntfs   users,defaults,exec 0 0


How to make a bootable flash from my already installed Ubuntu?

Welcome to AskUbuntu, Jeff!

I haven't tried it myself, and I don't know if it's been tested with your version of Ubuntu, but it looks like there is a way!

The steps are a a bit too long and too involved for me to include here, so I'll just include the link to the Ubuntu Community Wiki page that hosts the instructions.

https://help.ubuntu.com/community/MakeALiveCD/DVD/BootableFlashFromHarddiskInstall

I hope this helps!


How to list and remove files only if multiple conditions are met

With bash, you could run something along the lines of

for a in *240p.mp4
do
   b=${a/240p/480p}                     ## replace 240 by 480
   if [ -f "$b" ]                       ## if x-480p.mp4 exists
     then   mv "$a" "REMOVE_$a"         ##   rename x-240p to REMOVE_x-240p
   fi
done

And if you are happy with the REMOVEd list

rm REMOVE_*


How to put YAD form fields value into variable after submit?

As shown in this post, to parse the parameters of a form from YAD in the bash/shell on Linux you can:
VAR=$(echo $YAD_OUTPUT | awk 'BEGIN {FS="," } { print $1 }')

Where:

VAR is the name of the variable where you want to store the value of the YAD entry.
$YAD_OUTPUT is self-explanatory. In your case, you named that variable "OUTPUT"
FS="," is the separator value. In your case, ",".
$1 is the position of the first --field. In your case, the content of $default_jpg (/).

Here is the corrected example:
#!/bin/bash

default_jpg='/';
default_mp3='/';
default_resolution='1920:1080';
default_filename="/";

OUTPUT=$(yad \
  --title="JPG and MP3 to MP4" \
  --form \
    --text="Options" \
    --separator="," \
    --field="JPG:FL" \
    --field="MP3:FL" \
    --field="Resolution" \
    --field="MP4 (Output):SFL" \
    --button="Create MP4":1 \
    "$default_jpg" \
    "$default_mp3" \
    "$default_resolution" \
    "$default_filename" \
) accepted=$?

if ((accepted == 1)); then
  jpgfile=$(echo $OUTPUT | awk 'BEGIN {FS="," } { print $1 }')
  mp3file=$(echo $OUTPUT | awk 'BEGIN {FS="," } { print $2 }')
  resolution=$(echo $OUTPUT | awk 'BEGIN {FS="," } { print $3 }')
  filename=$(echo $OUTPUT | awk 'BEGIN {FS="," } { print $4 }')

  echo $jpgfile $mp3file $resolution $filename
fi

The start of this answer is to help Google to find this solution.


Which one is good Traffic shapping / Traffic Monitoring?

I think L7-filter would do it (But I have not used it) http://l7-filter.sourceforge.net/


Ubuntu Desktop 12.04 LTS does not work with Radeon Generic PnP display

I have the same problem with ATi Radeon 6750HD. When you get the option to boot into Ubuntu, press Enter and quickly hold left Shift key. Choose Ubuntu recovery mode. It will give you a set of options. Select Resume normal boot and you are good to go.


Very frequently there's a substantial lag issue if you have an nVidia graphics card. If you don't know what card you have use lspci in terminal.

If you do have it then get into classic and update the driver to the most recent version. The difference is immediately apparent after a quick restart.


How to create a virtual network interface in Ubuntu?

USE CASE: To create a persistent VIP address in a server to function as a 'loopback' address

Change to /etc/systemd/network/ directory

user@server:~$ cd /etc/systemd/network/

Create two files, 'vip.netdev' and 'vip.network'

user@server:/etc/systemd/network$ touch vip.netdev vip.network

Show the newly created files

user@server:/etc/systemd/network$ ls
vip.netdev  vip.network

Edit the two files with your favorite editor to reflect the detail below

user@server:/etc/systemd/network$ more vip.netdev
[NetDev]
Name=vip
Kind=dummy

... and ...

user@server:/etc/systemd/network$ more vip.network
[Match]
Name=vip

[Network]
Address=172.16.1.23 (or whatever address you so choose)
Mask=255.255.255.255
Broadcast=172.16.1.255 (match the Address x.x.x.255)

Enable the newly created VIP interface w/out rebooting the server

user@server:/etc/systemd/network$ systemctl restart systemd-networkd

Show the newly create VIP interface

user@server:/etc/systemd/network$ ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.16.1.16  netmask 255.255.255.0  broadcast 172.16.1.255
        inet6 fe80::20c:29ff:fe9b:703f  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:9b:70:3f  txqueuelen 1000  (Ethernet)
        RX packets 244  bytes 32605 (32.6 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 653  bytes 51807 (51.8 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 411  bytes 66247 (66.2 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 411  bytes 66247 (66.2 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

vip: flags=195<UP,BROADCAST,RUNNING,NOARP>  mtu 1500
        inet 172.16.1.23  netmask 255.255.0.0  broadcast 172.16.255.255
        inet6 fe80::d0a7:56ff:fe83:95ff  prefixlen 64  scopeid 0x20<link>
        ether d2:a7:56:83:95:ff  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 7  bytes 490 (490.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

... or ...

user@server:/etc/systemd/network$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:0c:29:9b:70:3f brd ff:ff:ff:ff:ff:ff
    inet 172.16.1.16/24 brd 172.16.1.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe9b:703f/64 scope link
       valid_lft forever preferred_lft forever
3: vip: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether d2:a7:56:83:95:ff brd ff:ff:ff:ff:ff:ff
    inet 172.16.1.23/16 brd 172.16.255.255 scope global vip
       valid_lft forever preferred_lft forever
    inet6 fe80::d0a7:56ff:fe83:95ff/64 scope link
       valid_lft forever preferred_lft forever


I found several how-to's just by running a Google search:

http://www.enderunix.org/docs/eng/daemon.php

http://www.netzmafia.de/skripten/unix/linux-daemon-howto.html

http://code.activestate.com/recipes/66012-fork-a-daemon-process-on-unix/

http://cjh.polyplex.org/software/daemon.pdf

I hope they can help you on your way.


From here, I was able to figure out that the name server was not set properly in my configuration file and after setting it, I could make it run.

auto wlan0
iface wlan0 inet static
address 192.168.1.9
netmask 255.255.255.0
gateway 192.168.1.1
wpa-ssid my_ssid
wpa-psk my_ssid_password

dns-nameservers 8.8.8.8
dns-search lan
dns-domain lan


Do I need to install a package to use Wayland on Cosmic?

Simple search on packages.ubuntu.com gives the result - you need to install one package:

sudo apt install gnome-session-wayland


Brightness automatically goes to full whenever I log in

This can often be fixed by adding a setting to your Grub configuration. Try this:

Open Terminal (if it is not already open)

Edit the Grub configuration file:
$ sudo vi /etc/default/grub

Note: Feel free to use any text editor you prefer, so long as you are editing the file with sudo.

Find the line that starts GRUB_CMDLINE_LINUX_DEFAULT and add acpi_backlight=vendor. This should give you a line that looks similar to this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Note: Your line may be longer with additional settings if you have an Nvidia video device or other hardware.

Save the file and update Grub:
$ sudo update-grub

Reboot.

This should resolve the issue.


control panel to see running applications

Open System Monitor using the Dash to view your running applications/processes. This essentially does the same thing as Windows Task Manager.  It is a graphical GNOME program, its name if you want to invoke it from a terminal is gnome-system-monitor.

For the command line, you have several options from a simple ps -aef (just prints a list) to top (a scrollable list) or even htop (fancier than top, not installed by default):


Can I show icons in System Monitor on Ubntu 18.04?

The System Monitor that is pre-installed on Ubuntu 18.04 is installed via the snap package, not from the traditional apt repo. You can verify that by running snap list, the output should contain gnome-system-monitor.

The snap execution environment doesn't see any of the icons on your system (local or system-wide). So this is somewhat an expected behaviour.

As a workaround you may remove the snap applications by running

snap remove gnome-system-monitor

and install the traditional one by running

sudo apt install gnome-system-monitor


Ubuntu 17.04 slow boot on SSD with dual boot

I could find a fix that a Reddit user posted, it was actually a bug:

  In Ubuntu 17.04, there is a bug in the installer when using home
  folder encryption - a swap partition is referenced but 17.04 now uses
  a swap file.

  Open /etc/crypttab in a text editor and change the following:

  cryptswap1 UID=XXXXXXXX

  to this:

  cryptswap1 /swapfile

Now my Ubuntu boots in like 6 seconds :-)


Ubuntu 19.10 fractional scaling cursor issues

Assuming you can use xrandr there is a hacky way to fix this:

xrandr --output <external-monitor> --scale 0.9999x0.9999

Example:

xrandr --output eDP-1 --scale 0.9999x0.9999

This fixed a similar issue I had with flickering cursor.


Can't change my package manager on new install of Ubuntu 16.04 LTS

Ok, from the description and your added info, I think it is because you are trying Ubuntu(live USB), so not all software repos are enabled. By default, live session only select main and restricted software as below pic:

The software you wanted - clementine or synaptic are both in "Community-maintained free and open-source software".

So you can enter in Dash - "software" then choose "software & updates"; or a command line way in Gnome Terminal - run "software-properties-gtk";

Then tick the checkbox before "Community-maintained free and open-source software (universe)"; then close this dialog, let it update software list; Then you can use "sudo apt install clementine" to install clementine and use "sudo apt install synaptic" to install synaptic.

Or by commands:

$ sudo apt-add-repository universe
$ sudo apt update


Can I set the scrolling speed when I mouse over the launcher?

Just to clarify the three ways to scroll with the Mouse over the Launcher

Mouse Wheel
Mouse Cursor at the Top/Bottom will enable Auto-Scrolling
Click & Drag

There does not appear to be any current way to edit the speed however there is an auto-scroll bug that might be relevant here.


Installation of Serato DJ in WINE failed

The system requirements for Serato DJ requires Windows 7.

Using the command winecfg I changed my windows from XP to Windows 7.

I no longer get the installation failure.


How can I order desktop icons to fit in the grid?

When you right-click on the desktop, click on "Keep Aligned" so that it is checked before you organize it by name.  Unless I am wrong, this should realign them to the grid.

It appears that there is a grid, it's just small.  Try dragging icons around and you'll see that they snap to the small grid instead of just staying where you leave them.


How can I set that Alt-TAB to switch windows only on the current workspace?

In compiz manager in the Ubuntu Unity Plugin in the Switcher tab the Key to start switcher has to be disabled. And after one of application switcher plugin has to be enabled.


Howto reset locale-settings for new users system wide to another locale

This question has many duplicates.
The file you want to look for is /etc/default/locale.
You can also check man localectl and man update-locale. One more alternative is dpkg-reconfigure locales.


Flash player does not work probably with Arabic language

Since Adobe will not update flash for Linux.

  Adobe will no longer provide new releases of Flash Player for Linux
  after version 11.2, the company has today announced.

  Google will, instead, take over the implementation of Flash Player via
  a new plugin API called ‘Pepper‘.1

Consider using HTML 5 instead of flash for You Tube.  It doesn't have that problem.  As you see in the below image, it doesn't have the problem.

1Source:OMG


local development LAMP server: routing external requests through SOCKS proxy

@adempewolff, Good question, but one thing I'm not clear is that

  2) set up ssh tunnel from guest OS, route all traffic through local
  SOCKS proxy (easy with Ubuntu but looks like it might be a touch
  harder with Xubuntu)

What do you mean by this, a touch harder with Xubuntu? SSH is almost shipped with every Linux distros, just set up a tunnel with ssh, then configure it as the globe socks v5 proxy, things may get done.

UPDATED ANSWER:
global proxy may available on weird Xubuntu
http://proxychains.sourceforge.net/
edit proxychains.conf as follows,

[ProxyList]
# add proxy here ...
# meanwile
# defaults set to "tor"
socks5  127.0.0.1 9050

execute proxychains /etc/init.d/apache2 start to launch your apache server.


It will be usable with Mir as SDL has added support for Mir.

  With Mir and SDL playing nice together, games using it will run natively under Unity 8 on Mir – no fuss, no hassle, and no discernible difference from that of the traditional X server.

Mir is the display server used in last ubuntu versions developped by cannonical

Reference: Some of Linux’s Most Popular Games Will Run Natively On Mir


I am really not quite sure about upstart scripts cause I never did one.

But If you want to run a script or command even you close your terminal or logout of your user account then you better use nohup command.

Syntax :

nohup  My_first_initd_script

Then you can close your terminal or logout from your PC but it will run. And you want to start the same from the system startup then add this command in/etc/rc.local

Let me know if any issues.


Tried to install Ubuntu. It failed. Now I'm at a GRUB screen. What is this and how do I resolve it?

I'd try to repeat from the beginning.
Try the first answer in here: How do I install Ubuntu?

Especially the first 7 steps or so may solve your problem. If you think you did everything there right and used the official download source and the downloaded iso was not damaged, maybe an other answer here can help you.

Note that you eventually have to call the boot manager with pressing F11 or DEL while booting to select your usb boot device and start installation, instead of booting into your broken installation. (Note: This is what helped the questioner. See comments.)

To assure a correct download, you can use a bittorrent downloader application to download the iso. This is especially useful if you have a slow or unreliable internet connection. You can find the .torrent files for ubuntu here: http://www.ubuntu.com/download/alternative-downloads


How can I boot from my bootable USB flash drive to install Ubuntu?

To boot from USB you need to prepare it. Directly copying the image to USB won't make it bootable.

Two most used software that helps to create USB bootable

Universal USB installer
LILI

Once USB is prepared, you need to open BIOS and select the USB drive as first bootable disk. Then it will boot using the USB.

For wubi installer 12.10, you need to download wubi installer. Copy the iso image to same directory as installer and execute wubi.exe as admin. Installation from wubi.exe inside the iamge is blocked due to few bugs.

Caution : Windows 8 preinstalled laptop require special steps.


Fade out Label / Button / Status Bar with GTK

Well, the great thing is, it works with Ubuntu 12.10 and GTK 3.6 (is it that version number? IDK).

So basically what I am doing is setting my status bar container to INSENSITIVE via Gtk.StateFlags.INSENSITIVE).

This property is styleable via CSS. Here is my source:

def poll_for_motion(self):
    if (self.was_motion == False
            and self.status_bar_visible
            and self.buffer_modified_for_status_bar):
        self.status_bar.set_state_flags(Gtk.StateFlags.INSENSITIVE, True)
        self.status_bar_visible = False
        self.buffer_modified_for_status_bar = False
        return False

    self.was_motion = False
    return True

def on_motion_notify(self, widget, data=None):
    self.was_motion = True
    if self.status_bar_visible == False:
        self.status_bar_visible = True
        self.buffer_modified_for_status_bar = False
        self.update_line_and_char_count()
        self.status_bar.set_state_flags(Gtk.StateFlags.NORMAL, True)
        GObject.timeout_add(3000, self.poll_for_motion)

And the css that complements it:

#status_bar_box GtkLabel:insensitive {
     color: rgba(255,255,255,0);
     transition: 500ms ease-in-out;
}

#status_bar_box GtkButton:insensitive {
    background: rgba(255,255,255,0);
    transition: 500ms ease-in-out;
}


You have:

Active: failed (Result: exit-code) since Mon 2017-07-24 13:06:05 IST; 9min ag

Failed means not running thus you are getting:

Failed to connect to 127.0.0.1:27017...

try running:

sudo service mongodb restart


Why does printf report an error on all but three (ASCII-range) Unicode Codepoints, yet is fine with all others?

The three working characters are the three printable ASCII characters that are not in the C basic character set. The reason why these characters are forbidden in C is that it would be hard on compilers: they would need to perform the \u interpolation before lexical analysis, which I think would break in a few corner cases, and would be impractical in many compilers anyway (because characters outside the basic set are only required to be allowed in a few places).

Having the same forbidden characters doesn't make sense in a shell utility. I suspect this is a bug, and $, @ and ` should not work either. The reason not to support them is again to make it easier to parse strings. For example, if you want to determine that there is no special character in a string you're going to put into a database query, you can check that the string doesn't contain ', and not worry about it containing \u002a.

Consider using recode as suggested in the GNU coreutils manual, or (more portable in practice) Perl or python.


Ubuntu 14.04 has visual artifacts and freezes

Your screenshot is displaying repeating patterns of video artifacts which are characteristic of video RAM artifacts. If the RAM in your graphics card is failing, sometimes just a small fraction of the RAM goes bad while the rest of the RAM continues to work properly. This can result in a screen that looks like a fraction of the screen has glitchy, repeating patterns of video artifacts, while the rest of the screen is rendered properly.

In order to further diagnose and possibly solve the problem:

Check for a missing proprietary graphics card driver. Open the terminal and type:

ubuntu-drivers devices

This command will identify the recommended proprietary graphics driver from the default Ubuntu repositories.
Test if the visual artifacts also occur in situations that require a lot of video RAM, for example while browsing and playing a YouTube video in Firefox.
If your graphics card is removeable, temporarily remove it in order to check if the graphics card is causing the glitchy, repeating patterns of visual artifacts. Graphics cards that are intended more for ordinary day-to-day use than for gaming are relatively cheap to replace.
Read the answer to this question: What causes this graphical glitch in my web browser? which has a screenshot with a graphical glitch that looks similar to yours.


Hollow Progress Bars in Ubuntu 13.04 Software Center

I don't suppose anything is broken here. Maybe ubuntu just moved away from the completely orange-filled progress bar to this swanky version for software center.


My machine runs Ubuntu Desktop 15.04 and I want to separately run Ubuntu from an external encrypted hard drive

The easy way of doing this is to:

remove the existing boot drive from your machine
remove the the external drive from its enclosure and insert it into your machine
Boot a LiveDVD
install it as you want
move the freshly installed HDD to the external enclosure.

Then when you want to boot that, just go into your BIOS and boot from the external HDD.

To keep the system updated, you need to follow this official documentation

The more complex solution would be:

Hook up all drives
remove UEFI and convert to BIOS boot.
Boot a LiveDVD
Install Ubuntu
take "something else"
Take care to put the boot manager (grub) on the external hard drive together with its system files
Install everything you want
shut down the machine
remove the external drive

The result is the same: externally bootable HDD that needs off-line updates.


Can I run bash commands from an Ubuntu HTML5 App?

What is the web server serving the apps? You can always put shell scripts in the /cgi-bin/ folder and invoke the URL.


The orig. issue was likely caused by the unity plugin becoming unset, going back into ccsm & re-enabling the unity plugin may of fixed


First of all you need the absolute path to command , in my case:

/usr/local/bin/stockfish

Directory i just pressed button at the right that point to scid in your home directory :

~/.scid

Notice that if you have done steps on stockfish page the final step is :

./stockfish

But to use it as i did do one more step :

sudo make install

This give the output directory .


Error on installing eclipse from software center

The problem so called error is in SWT lib, that means your JDK is not installed properly .

Reinstall Java as shown here.

and then

Install Eclipse as shown here.

hope it helped you.


How can I set the shortcut for "Redo" from Ctrl+Shift+Z to Ctrl+Y?

Since you explicitly ask for a system- or at lease session-wide solution in the comments: this cannot be done in a way that doesn't break lots of other things.

The Ctrl+Z, Ctrl+Y, and Ctrl+Shift+Z shortcuts that you mention are handled on the application level. Although it's possible to intercept and “translate” them before they ever reach an application it would interfere with many other things, e. g. applications that bind these to unrelated actions.1

Instead I recommend that you change the on the application level. Many applications without a distinct interface to change keyboard shortcuts still allow changes to them through their toolkit configuration, e. g.

GTK+ applications and
KDE applications.

1 If you still want to try it please look at xmodmap or xdotool. Relevant questions are:

Make shortcut for navigational functions
Create custom keyboard shortcut to send Super+2


Is There a Modern Gesture Solution On Kubuntu 20.04

touchegg now uses libinput since version 2.0.
As for KDE, I found this config file for touchegg and KDE that you might enjoy:
https://github.com/NayamAmarshe/ToucheggKDE
Here is an overview of this new version and of what would be needed for direct kde support:
https://www.youtube.com/watch?v=o74_ddzi1kw


How do I backup all Gnome Tweaks configuration?

From the terminal, execute the following to save your gnome settings:

cd ~
dconf dump / > saved_settings.dconf

Keep the saved_settings.dconf file in a safe place so you can use it after you upgrade.
From the terminal, execute the following to restore your gnome settings:

cd ~
dconf load / < saved_settings.dconf

(I suggest doing a test to make sure this works for you:
Save the settings as shown above in step 1. Then make a few test changes using Gnome Tweaks. Finally restore the settings, as shown above in step 2. If everything restores to the way you had it before, you can use the saved file to restore settings after you upgrade.)

Note: There may be some settings that have changed between Ubuntu versions, and you will need to fix those manually. However, per vanadium's comment below, most settings will transfer over just fine.


How to prevent system from gettin Freezed on launching any software?

Ubuntu is too heavy for this old computer.

I would suggest installing Lubuntu 14.04.

1 GB of RAM is just enough. And Ubuntu graphical effects drain all CPU and GPU resources.

Minimal requirements just let OS start and work some way. They do not guarantee any comfortable work.


Ubuntu 14.04 USB installation drive not recognized during boot(Dell Latitude D630)

As the D630 is an older model I don't believe UEFI has anything to do with it. Double check system requirements here I would avoid unetbootin as in my experience success is rare. I've had excellent results using dd to duplicate the iso to a USB flash drive. The process to do so can be found in here. Basically you just connect the flash drive you wish to install the image to and insure it's not mounted then issue the commands which you will need to edit as explained below. DO NOT copy and paste. Read the entirety of the answer and insure you have the device name correct before proceeding.

sudo dd if=YourUbuntuImageName.iso of=/dev/XdY
sync

Where YourUbuntuImageName.iso is changed to the name of your Ubuntu iso image and /dev/XdY is changed to the device name of the flash drive you want the image duplicated onto. dd uses a default block size of 512 bytes which you don't have to change. If you want a progress report during the "burn" you can install dc3dd with sudo apt-get install dc3dd and substitute dc3dd for dd in the command. The output of mount and sudo fdisk -l can be useful in determining the device name.

This will result in a USB bootable installer for Ubuntu. Boot from it using BIOS (I believe the D630 will let you choose the device to boot from if You repeatedly tap F12, to get the boot options menu) having booted from the installer, install Ubuntu normally choosing as the target the flash drive you wish to install to.

Installing Ubuntu to a flash drive is no different from installing it to any other drive. Your BIOS determines which device is booted from. You can create your own "persistence" with normal partitioning methods if you want home on a separate partition but installing Ubuntu normally to a flash drive will result in persistence of settings and installed apps (just as installing to a hard drive would) anyway so it's not truly necessary. Here's where you make the changes on a Dell D630 to allow USB Boot. F2 at Dell Logo should get you to the BIOS.

Sources:

Experience

https://www.winhelp.us/computer-boot-order.html


How Can I install Ubuntu on Galaxy Nexus

Ubuntu for Phone, has not been released to install in Samsung Galaxy Nexus phones yet.  It has been rumored that it will be released towards the end of Feb 2013 as a developer platform.  This means that it will not be 100% fully functional for general public yet.

Ubuntu for the Nexus 7 TABLET is available now.  This is the Ubuntu Desktop version not for Gnex Phone.


after updating, my laptop doesn't turn on

You need to run fsck manualy.  boot with a dvd or pendrive and got to a terminal.

Then type  fdisk -l you should get an output like

Device       Start       End   Sectors   Size Type
/dev/sda1     2048   1050623   1048576   512M EFI System
/dev/sda2  1050624   1550335    499712   244M Linux filesystem
/dev/sda3  1550336 468860927 467310592 222,9G Linux LVM

whith "/dev/sda*" or "/dev/sdb*" or something like

Disk /dev/mapper/ubuntu--vg-root: 213 GiB, 228665065472 bytes, 446611456 sectors

if you use lvm partitions
Then you can run fsck with

  fsck /dev/sda1

or

fsck /dev/mapper/ubuntu--vg-root


How do I install Ubuntu 12.04 on an Asus g74sx- bbk7?

You can try Ubuntu's Windows installer (Wubi) if you are running Windows.


I would like to try installing Ubuntu onto my laptop and don't know how

Here is the way to install ubuntu using a usb stick.

Download the Ubuntu iso file. The latest version of ubuntu is
available here
Download rufus and create a bootable usb drive of ubuntu.
Restart windows and boot from the usb device. Press F12 to get the boot menu.

Then you can install or try ubuntu os. Step by step instructions are available here

In the installation, you can configure or format partitions. In that window you can format the windows partition.


problem in size with /var/log file is 110GB

That is a directory and those commands deal with installed packages. They are unrelated. logrotate can be used to remove, compress, and/ or send logs to your email. What you need is up to you. Learning how to read the man pages is very helpful and, yes, it does take some getting used to. Those files are very important, please do not just delete them. Read the man page (at the command prompt: $ man logrotate), search the internet and post back with what you think you want to type and get an explanation from someone about what it will do. Also read the apt-get manual page ($ man apt-get) to see what they both do, as a reference. And, the habit of typing 'whatever' into the command line can be hazardous to your computer and your sanity.


As suggested in comments, converting .jpg to a .png file fixed the issue.

.png is a more native file format for Linux and .jpg is a more native file format for Windows. That said the file conversion software may have removed "noise" from the .jpg file when converting it to .png format. If there was "noise" what it was is anyone's guess. If you are in a similar situation and you must have .jpg file format you can still convert it to another .jpg file with a bit of file compression and may also be successful.


How to enable AVX2 extensions on a Ubuntu guest in VirtualBox 5?

I was asking myself the same question. I read through major parts of the VirtualBox documentation a while ago and remember that SSE4.1/SSE4.2 is well documented, but AVX2 is not, though it is expected to be exposed to a guest since VirtualBox 5.0 Beta 3.

Here are the flags of /proc/cpuinfo on a 14.04 host:

flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
       pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
       pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl
       xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64
       monitor ds_cpl vmx est tm2 ssse3 fma cx16 xtpr pdcm pcid sse4_1
       sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c
       rdrand lahf_lm abm ida arat pln pts dtherm tpr_shadow vnmi
       flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms
       invpcid xsaveopt

and here on a VM hosted by VirtualBox 5.0.14

flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
       pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm
       constant_tsc rep_good nopl xtopology nonstop_tsc pni pclmulqdq
       ssse3 cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx rdrand
       hypervisor lahf_lm abm

I searched the Internet and downloaded the source, which brought me to this ticket where frank (Frank Mehnert, I assume) explains how to disable AVX and this ticket noted in the changelog as a reason to disable AVX2 passthrough temporarily as of 5.0.2. So there was a reason to disable it and you should be careful.

I ran VBoxManage setextradata "$vm_name" VBoxInternal/CPUM/IsaExts/AVX2 1, booted my VM and AVX2 was enabled:

flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat
       pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm
       constant_tsc rep_good nopl xtopology nonstop_tsc pni pclmulqdq
       ssse3 cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx rdrand
       hypervisor lahf_lm abm avx2

To check I ran x265 in the VM:

x265 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX AVX2 LZCNT

I was looking around if something else could be enabled, grep -r -i "search_term" . in the source did bring up some results for the search terms pIsaExts, pExtFeatureLeaf, pFeatures, pCurLeaf and pCpumCfg but adding keys either had no effect or the VM refused to start. Speaking of which, to view all the extra keys you set run:

VBoxManage getextradata "$vm_name" enumerate

and to delete a key just run the same command you did to set the key but without a value, example:

VBoxManage setextradata "$vm_name" VBoxInternal/CPUM/IsaExts/AVX2

Instead of just grepping through the source it would be better to read and understand the projects' source code organization.


You can also use 7digital. Ubuntu One was using 7digital as music provider, but with different agreements for territorial limitations. If 7digital is available for your country, you may even find many more musics available for purchase.

7digital for Nederlands : http://nl.7digital.com/


You don't need to change the GID of the users.

You need to set the directory permissions to sticky, so that every file created under it, will be owned and writeable by that group by default.

sudo chown root.sharers /path/to/directory
sudo chmod g+sw /path/to/directory


Is something wrong with my partitioning?

There is nothing wrong with this setup

Without knowing what you will be using your laptop for and what programs you will install, it is hard to say if this partition scheme is right for you.

For most home use, I recommend a simple three partitions system:

/ This is the system partition for the OS. As little as 30GB may be fine. If you think you will install a lot of software, or develop web pages, you may want more.
/home This is where all your personal files including data, music, movies, etc. will go. This will also contain your personal configurations.
swap this is needed by Ubuntu to run smoothly. It is used as virtual RAM. 2GB to 4GB may be fine. You may want to put double your physical RAM if you want to hybernate your laptop. Hybernate is disabled by default as it does not work in all systems.

I don't have any use for a separate /opt partition. But, if you install a lot of software manually, this may be useful. If you decide to get rid of it, you may allocate this space either to /, where the /opt folder will be. Or you can allocate it to /home.

I also don't find it useful to have the two drive_1 and drive_2 partitions. I would allocate that space to /home.

However, these are personal preferences. Other people will tell you other things.

Hope his helps


How to disable autohiding for launcher in Unity

First of all, install the Compizconfig settings manager from Ubuntu Software Center or just run following command: sudo apt-get install compizconfig-settings-manager
Start it under System -> Preferences menu, find “Ubuntu Unity Plugin” and click into its configuration page.

Then change AutoHide Launcher to: Never

How can I configure Unity?


Just updated to lastet Viber version and it became huge.

The reason is that 1920x1080 px  on 13" screen has dpi of 166, what I have set in my xfce settings.
A lot of apps powered with electron or other custom magic treat dpi over 140 as "retina" and double rendering size.

Viber settings screen cannot go UI scaling under 100%, so you can do it manually.

New solution (works for Viber >= v7.0)

Try running Viber from the terminal by specifying the QT_SCALE_FACTOR as follows:

  QT_SCALE_FACTOR=0.6 /opt/viber/Viber

As a permanent solution, ensure the following line is in place in the Viber starter shortcut file (.desktop):

  Exec=env QT_SCALE_FACTOR=0.6 /opt/viber/Viber

The Viber .desktop file is usually located at /usr/share/applications/viber.desktop. A locally editable copy can be placed in ~/local/share/applications/.

Old solution (works for Viber < v7.0)

Install sqlitebrowser from official repo, use it to open ~/.ViberPC/config.db

Go to table CommonSettings and modify Value of ScalingRatio to something under 1.0, I used 0.6.


Can't Connect to a PPTP VPN Server from Ubuntu 18.04 Linux

I had the same issue. I fixed it by clearing up all firewall rules (see https://serverfault.com/questions/200635/best-way-to-clear-all-iptables-rules how to do that with iptables).
It seems that the firewall I was testing recently left some rules in place, which started to block the VPN communication.


Printing one sheet with duplex enabled fails HP psc 2510

As my printer recently 'died' answering this question won't be needed anymore for me.


I had the same issue

sudo apt-get --reinstall install ubuntu-session
sudo apt-get --reinstall install yaru-*

worked for me, but I had to restart to finally see Yaru listed in the tweaks tool.

Here is the reported bug to track the 'official' solution:


Can't visualize web service of wireless cameras using Chromium

Unfortunately there is no easy way to use ActiveX in Ubuntu, the short answer is no. Wine browser seems to use Gecko, and IEs4Linux has been abandoned (and I'm not sure ActiveX even worked with that). Google Chrome only supports ActiveX in Chrome browser in South Korea in windows, because the major South Korean banks have been running their web apps with ActiveX for a long time. Apparently it's possible to run Chrome for windows in Wine, but even then if you get Google's patched Chrome for the South Korean market, I don't think it would be available in any language other than Korean. If your computer can handle it, I'd recommend running XP in VirtualBox, otherwise you may want to dual-boot and grab the photos from your cameras that way and store them on a shared partition. It might be less of a hassle to just use a memory card reader, I certainly hope you're not relying on this ActiveX feature for productivity.


RDP unable to connect Remmina/Ubuntu 14.04

Open Remmina. Right click the malfuntioning connection and click edit.
Under the Advanced tab set Security -> RDP.


12.10 extended desktop executed programs start

I found a solution:
On compiz-config-manager there is a windows placement option, where can enabled some function.


20.04 fails to authenticate Wifi (Realtek RTL8723BE)

If you have the latest drivers you can try this.
Remove and reinsert the module with following setting:
sudo modprobe -rv rtl8723be
sudo modprobe -v rtl8723be ant_sel=2

This will usually set your Wlan interface down. So set it up again.
sudo ip link set <interface> up
sudo iw dev <interface> scan

You can make this persistent with these commands:
echo "options rtl8723be ant_sel=2" | sudo tee /etc/modprobe.d/50-rtl8723be.conf

This setting + having the latest driver fixed my problems.


Why do my windows occasionally stop taking keyboard input after alt-tab?

It turns out the shortcut Ctrl-S freezes keyboard input. This can be undone with Ctrl-Q.


How do I  accept inbound connections for a specific program?

You may want to take a look at this help.ubuntu.com post on the firewall, particularly the "ufw Application Integration" section.


VNC doesn't work with display switched off

I suffered the same issue:
Ubuntu 18.04 with x11vnc. Turn off monitor and VNC client at the other side freezes, turn on again and it works fine.
Fix/Workaround: replace the HDMI to HDMI cable from pc to monitor with a DVI to DVI cable from pc to monitor. Now turning off and on the monitor does not influence the VNC client anymore.
Do not ask why, it just works now.


I want to capture a specific colum from a command output using python 3

Your way to get the output of system calls is quite outdated. Use

subprocess.check_output()

instead:

#!/usr/bin/env python3
import subprocess

f = "/home/jacob/Desktop/output.txt"

lines = subprocess.check_output(["dpkg", "-l"]).decode("utf-8").splitlines()
with open(f, "wt") as out:
    for l in lines:
        if l.startswith("ii"):
            out.write(l.split()[1] + "\n")

Replace f with the actual path of the output file.

Output file:

...
...
apg
app-install-data
app-install-data-partner
apparmor
apport
apport-gtk
apport-retrace
apport-symptoms
appstream
apt
apt-transport-https
...
...

Note

The solution above will create a file, ending with an empty line. If that is an issue somehow, use the solution below.

#!/usr/bin/env python3
import subprocess

f = "/home/jacob/Bureaublad/output.txt"

lines = subprocess.check_output(["dpkg", "-l"]).decode("utf-8").splitlines()
open(f, "wt").write(
    "\n".join([l.split()[1] for l in lines if l.startswith("ii")])
)


Thanks @user535733, I got into contact with Lenovo and since I still have warranty, they are replacing my SSD. So its a hardware problem, not something to do with Ubuntu.


I think memory is locked on its adapter else formatting the memory would repair it


Facebook and flash - why doesn't facebook recognise that I have flash installed?

You're using the 64bit beta, and it looks like Facebook's version check code isn't accepting it. I get the same message in Facebook with that version of Flash on Firefox and Chrome. I don't think there's anything you can do but go back to the release version. Unless there's a Firefox extension that fakes plugin versions?

For what it's worth it's easier to disable different versions of a plugin on the fly in Chrome/ium on its about:plugins page.


How do I run multiple Ubuntu versions on a single machine?

In general:
 yes, of course!

How to:

Your Ubuntu Live-CD-Installer (And a live-stick) will ask you while Installing if you want to install alongside or upgrade, click at 'install alongside' and you got it.

Screenshot from here


If you are asking for 11.10 or 12.04, you most likely need to install dconf-editor and look under /org/gnome/settings-daemon/plugins/keyboard instead, though I'm not sure what exactly you're hoping to find there. You can only alter the plug-in's loading priority, and whether it is active.


Stripping Ubuntu 10.04 Server down to JeOS like setup?

I think what you want is called Ubuntu Core.

  Ubuntu Core is a minimal rootfs for use in the creation of custom images for specific needs. Ubuntu Core strives to create a suitable minimal environment for use in Board Support Packages, constrained or integrated environments, or as the basis for application demonstration images. It is available for the i386, amd64, and armel architectures.

Here's a build example. Hope this helps.


Are you looking for an IDE for a specific language? Or an "all-in-one" IDE? Check out Anjuta and QT Creator. Also see this list of alternatives to Visual Studio for Linux

EDIT: QT Creator has a good GUI designer called...take a guess...QT Designer. Is that what you're looking for?


Certain characters not rendering on Ubuntu title bar and Mozilla gmail and some other sites

I wish I had an answer.  I don't have enough of a reputation to leave a comment, so I will ask my question here.  What hardware are you running on?  What display driver are you using?  I have similar problems on a t450s which uses the Intel Broadwell HD Graphics 5500.  Example screen shots.

Notice the missing u in Buffers and the missing s in Lisp from the emacs menu bar in emacs menubar screenshot.  What I can't show you is that if I click on the menu item it will show all the letters, because, I think it is in a different font.

Notice the garbled entries in my thunderbird list of email subjects in the thunderbird screen shot.  Also the missing folder names.  This is not a thunderbird issue, but a rendering issue.  I can click on them and they open up.

Is this anything like what you are experiencing?


Lighttpd starts but doesn't work. lighttpd.pid Permission Denied

Well the whole question is moot.

I did not set my php5-fpm socket connections properly. Solved with the following.

First,
sudo nano /etc/php5/fpm/pool.d/www.conf

  Now change the listen line to look like this.

    ;listen = 127.0.0.1:9000

    listen = /tmp/php5-fpm.sock

Second,
sudo nano /etc/lighttpd/conf-available/15-fastcgi-php.conf

Now you just have to restart your php5-fpm -> sudo /etc/init.d/php5-fpm reload

And,
sudo /etc/init.d/lighttpd restart

Reference:

http://www.zimbio.com/Linux/articles/IssTANdRWZQ/How+install+Lighttpd+PHP5+MySQL+Ubuntu+12
http://kywk.github.io/endroid/linux/ubuntu_LLMP-setup.html


I use a small hack.

You need xbacklight. Try running it from terminal (Ctrl+Alt+T), and if the package is not already installed, it suggests you to install. Follow the instructions.

Commands you need to know. (Use a number instead of <...>) Aren't they self-explanatory?

xbacklight +<increment>
xbacklight -<decrement>
xbacklight =<value>

Usually the range is 0 to 100. Running with no arguments shows the current value.

It is now as simple as setting the corresponding command to run automatically.
Simplest way:
Open Startup applications (Search in dash) and add an entry with command xbacklight =25. Use your preferred value instead of 25.
More complicated way:
Cook up a bash script to detect time of the day and then set the backlight value, and set it to run on startup. Left as an exercise to the reader.
Even more complicated way:
Detect light from webcam and the precise position of your favorite electron, destroy universe, rebuild it, and then set backlight to your favorite number. Set it to run on startup.


This worked for me:

sudo dpkg -i --force-overwrite /var/cache/apt/archives/libdrm-amdgpu1_2.4.85-0~x~padoka0_i386.deb
sudo dpkg -i --force-overwrite /var/cache/apt/archives/libdrm-amdgpu1_2.4.85-0~x~padoka0_amd64.deb
sudo apt-get install -f
sudo apt-get upgrade


How to mount an encrypted partition image from an external drive?

You want to use

  ecryptfs-recover-private - find and mount any encrypted private directories

  SYNOPSIS
         ecryptfs-recover-private [--rw] [encrypted private dir]

  DESCRIPTION
  This  utility  is  intended  to  help  eCryptfs recover data from their encrypted home or
         encrypted private partitions.  It is useful to run this from  a  LiveISO  or  a  recovery
         image.   It  must  run  under  sudo(8)  or  with  root permission, in order to search the
         filesystem and perform the mounts.

Telling it which directory to decrypt is optional too, it will search everywhere if it's omitted (but that could be pretty slow).

It's actually a shell script, so you could see  it yourself (or run manually if you desired) with

less `which ecryptfs-recover-private`


Do I need unencrypted files underneath encrypted overmount?

Looking at the unmounted encrypted home directory of a non-logged-in user, I see some unencrypted files (well they're really directories and links):

$ /bin/ls -la /home/walt
total 12
dr-x------  3 w3   walt 4096 Apr  9 22:12 .
drwxr-xr-x 13 root root 4096 Sep  1  2015 ..
lrwxrwxrwx  1 walt walt   56 Oct 22  2011 Access-Your-Private-Data.desktop -> /usr/share/ecryptfs-utils/ecryptfs-mount-private.desktop
drwx------  7 walt walt 4096 Jan 16  2013 .cache
lrwxrwxrwx  1 walt walt   30 Oct 22  2011 .ecryptfs -> /home/.ecryptfs/walt/.ecryptfs
lrwxrwxrwx  1 walt walt   29 Oct 22  2011 .Private -> /home/.ecryptfs/walt/.Private
lrwxrwxrwx  1 walt walt   52 Oct 22  2011 README.txt -> /usr/share/ecryptfs-utils/ecryptfs-mount-private.txt

You don't need any other files. You could delete the files with something like find /home/user -maxdepth 1 \( \! -type l -a -type d \) -exec echo rm {} \;, remove the echo when you are thrilled with the results of the find


I want to synchronize accounts & desktops between the Ubuntus in my home

Im no expert but for your set up it sounds like you will need a central "server". Distributed syncing will not work as all computers may not be on at once. If you had one computer which was on all the time and had a large amount of storage you would have a number of options.

You could mount the users /home folder over the network.

A better option would be to set up rsync scripts that incrementally sync:

on node login from server -> node
on node logout from node -> server

You may also have to look at an app called Unison in the software centre but ive never used it and I think it could be quite old.


Unable to connect to scanner (simple-scan & Brother DCP-L2530DW)

This did the trick
sudo apt purge ippusbxd

references
https://bugs.launchpad.net/hplip/+bug/1871011
https://bugs.launchpad.net/ubuntu/+source/ippusbxd/+bug/1876289


"MapiLogonProvider: Network error" with Exchange MAPI Connector

I have eventually found the reason for this. We have a multi-server exchange setup, and its important to use the address of the exchange server in the configuration that has your mail, and not the server that's configured to do outlook web access.


Is it good practice to run applications with sudo?

You need to understand what sudo does. Quoting the Wikipedia page :

  sudo (/ˈsuːduː/ or /ˈsuːdoʊ/) is a program for Unix-like computer operating systems   that allows users to run programs with the security privileges of another user (normally the superuser, or root

To explain further, it gives your program access to the core, sensitive files of your computer. Let me give you an example.

Try running touch /etc/abc.txt and you will be thrown an Access Denied error message, because the first "/ " in the path says that it is in the root directory and hence normal users cannot access it. To make the above command work, you will need to elevate your privileges and that is exactly what sudo does. Try running the above command with sudo and you can see the file will be successfully created.

Using sudo for everything is NOT a good practice. You should elevate the permission level of any program only if absolutely necessary. If you keep adding sudo to all the programs, there is a high chance that you'll mess up with the core files of your computer. And yes, No programs get root permission by default.


Are python bindings for OpenCV 2.4.3 available?

OpenCV 2.4 is orginial proposed for Raring (13.04) and the same is backported for previous version.

You can download the python bindings for OpenCV 2.4 from here

python-opencv_2.4.2+dfsg-0exp2ubuntu1_amd64.deb
python-opencv_2.4.2+dfsg-0exp2ubuntu1_i386.deb

But make sure you have met the dependencies mentioned here

I am not sure whether OpenCV2.4 will work well with Python 3.2.3. You can try your luck.


Is there any program for ubuntu which handles pptx file properly?


I'm running Ubuntu on my Nexus 7, do I have access to the same packages as if I'm running Ubuntu on my Desktop?

No Not Exactly, The Nexus 7 is an ARM based platform, therefore uses a different package archive than your common x86 Desktop. If the desired package is not available for ARM, then it will not be available to download.

As there are some Nexus 7 specific packages. These packages are found in the nexus 7 ppa (ppa:ubuntu-nexus7/ppa).  The Nexus 7 PPA is enabled by default when you install. We are currently in the process of migrating all our changes upstream into Raring Ringtail (13.04). When that switch occurs, most updates will come from the main Raring repositories.


Why does apt say an enormous 16.7 GB additional disk space is needed?

I got the same message on 14.04 (not sure which container) though I tried to apt-get upgrade, not dist-upgrade.
It showed me exactly the same 16.7 GB. Anyway I proceeded with the upgrade and everything went well. Only some 30 MB of additional space were used instead of 16.7 GB. So it's definitely a bug.

EDIT: A month has passed and here's what I got today on 16.04.2

apt-get uprgade
...
2 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 3,008 kB of archives.
After this operation, 16.7 GB disk space will be freed.
Do you want to continue? [Y/n]

The same 16.7 GB but now it will be freed.


automatic mount any external drive under /media with read/write access to everyone

Well, here we can use the same trick that fstab uses for Optical media (aka CD's and DVD's):

/dev/sr0        /media/cdrom0   udf,iso9660 user,noauto     0       0

The first column indicates the file system, I'm sure your USB's will have fixed values, so lets presume that everything after sda is a USB, and since you can only have 4 USB's at the same time, the list goes from sdb, sdc, sdd and sde.

$ ls /dev/sd*
/dev/sda   /dev/sdb   /dev/sdb3  /dev/sdb6  /dev/sdc  /dev/sdf
/dev/sda1  /dev/sdb1  /dev/sdb4  /dev/sdb7  /dev/sdd
/dev/sda2  /dev/sdb2  /dev/sdb5  /dev/sdb8  /dev/sde

(In my case I use a memory reader, so my USB drivers start from sdg but lets continue.)

Now, we assume each USB have one and only one partition, so the lines we need, for our fstab, are:

/dev/sdb1
/dev/sdc1
/dev/sdd1
/dev/sde1

Then you said your mount points has to be fixed, so after you have created your directories, lets add them:

/dev/sdb1 /media/HDD1
/dev/sdc1 /media/HDD2
/dev/sdd1 /media/HDD3
/dev/sde1 /media/HDD4

Since you can have almost all type of file systems, lets use the auto so fstab guess the file type to use:

/dev/sdb1 /media/HDD1 auto
/dev/sdc1 /media/HDD2 auto
/dev/sdd1 /media/HDD3 auto
/dev/sde1 /media/HDD4 auto

Ok, now lets boil down to the options, which will be the very same for CD's with the plus of read/write permissions:

/dev/sdb1 /media/HDD1 auto rw,users,noauto,allow_other,umask=0
/dev/sdc1 /media/HDD2 auto rw,users,noauto,allow_other,umask=0
/dev/sde1 /media/HDD3 auto rw,users,noauto,allow_other,umask=0
/dev/sde1 /media/HDD4 auto rw,users,noauto,allow_other,umask=0

rw tells that we want read and write permission, users allows any user to mount a device, noauto prevents that the driver gets mounted automatically when mount -a is called, like it does at boot, preventing boot ERRORS and WARNINGS, allow_other allows other but the user that mounted the driver to have the same permissions, and umask=0 prevents the defaults umask from being applied.

Now the only 2 left fields are pretty much just about the dump order and fsck order, which could be in 0 both, leaving us with the final result:

/dev/sdb1 /media/HDD1 auto rw,user,noauto,allow_other 0 0
/dev/sdc1 /media/HDD2 auto rw,user,noauto,allow_other 0 0
/dev/sdd1 /media/HDD3 auto rw,user,noauto,allow_other 0 0
/dev/sde1 /media/HDD4 auto rw,user,noauto,allow_other 0 0

With this, each time that you plug a USB device it will being automagically mounted in the mount point without the intervention of the user. You should modify according to your necessities.


Is there a task switcher (Alt+Tab) for Xfce that allows to select application using a mouse click?

You can use Skippy-XD for this. It is a full-screen task-switcher for X11 similar to Mac OS X's Exposé feature, and works nicely with Xfce. To install latest development packages (recommended), use the Skippy-XD PPA (daily). In Xfce 4.10 you can easily bind skippy-xd command to Alt + Tab in Settings > Keyboard > Shortcuts.


Ubuntu 16.04 Skylake not able to shutdown and restart

I have Dell i7559 with i7-6700HQ and GTX 960M.

After a fresh install (boot directly to the installer with nomodeset, update all packages before logging in, # dpkg-reconfigure compiz), I got this cpu lockup issue.

Then I installed Nvidia driver 364.19 from https://launchpad.net/~graphics-drivers/+archive/ubuntu/ppa and everything (shutdown, reboot and suspend) works fine now.

Hope this helps.


how can I upgrade from version 11.04 to a newer one?

General solution for such situations is to do several dist-upgrades to the next release until you reach supported version. For your issue, you need to update to 11.10 release then to 12.04. Then you have to decide if you want to have LTS version or the latest one which is 13.04. Of course, you need all transitional releases to be downloaded and burned to CDs, or you have to use Ubuntu old-releases site to make transitional upgrades.


how to recover from ubuntu 12.04 boot crash

At this point and time since you mentioned battery and power messages and you have a loop flashing a message,unplug your coputer and REMOVE the external battery pack if possible.This may clear your memory of any corrupted data (flashing loop) and residual bytes of corrupted memory.Afterwards place your install disk in your CD drive,then turn on.Your system will look at your disk and hopefully pull necessary data to boot up.
Warning Do Not Reinstall at this time.See if your system repairs itself as it boots up with your disk in the drive.At minimum you should be seeing different screens,hopefully with a solution.My experience with Linux/Ubuntu systems,not windows,is it tries to self heal itself as long as it can pull uncorrupted data from an external source.
 Please do not reinstall unless necessary.If you think it through you will find the Linux products are built in a logical manner.The su and sudo are not as scary as they appear.


How do I install a Lexmark Pro200 printer driver for Ubuntu 12.10?

Open the Printers app
Click Add.
Select Network Printer
Wait about 2 secs for it to show up.

If it doesn't show you, enter the IP address of the printer and hit the Find button.

Ubuntu has always found my printers with no trouble at all.