Why aren't file properties shown for MP4 files?

This is a confirmed bug in the Zeitgeist library which provides file info to Ubuntu Apps (including Nautilus) and seems to occur with MP4 files downloaded from Youtube, which are encoded with the Baseline level 1.1 profile. It does not happen with other MP4 files.
The file may play in VLC but that doesn't count since VLC internally includes all codecs.
There's no real fix for this until the bug itself is fixed.
To change the default player to VLC, simply do it from one of the other MP4 files which work, or follow the directions in this answer.
To display thumbnails for these videos, please follow the instructions in this answer.

Above steps effectively makes VLC default player and shows thumbnails properly for all videos (as shown below):


How can I change the icons in Pidgin's IRC user list?

The icons are located in /usr/share/pixmaps/pidgin/emblems/16. You can open them up in an image editor  and modify them.


Is information about a filesystem's bad blocks preserved after formatting a partition?

From the vastcough amount of research I've come across in the last five minutes, for instance this and this (from SU.SE), it would appear that device-wide metadata about bad blocks is stored in the Master Boot Record or GUID Partition Table (the disk's partition table that starts at address 00000000: 0x00).

It seems unlikely it would be stored in the partition's filesystem's table of contents. Anyways, the information will only go away if you write the disk a new partition table, which will irreversably destroy all data on the entire disk.

If you're using a disk that has bad blocks for anything remotely mission-ciritical (or even your own data), that disk is bound to fail irreparably in the near future, and it's cheaper and easier and safer to buy a new disk.


Upgrade 17.10 to 18.04, now receiving login loop

I had a similar problem. NVidia drivers were installed while I had AMD Radeon graphics card. So I logged in through cltr+alt+f1 screen and purge NVidia drivers:

sudo apt-get purge "nvidia*"
sudo update-alternatives --auto x86_64-linux-gnu_gl_conf

Another working solution was to install xubuntu and choose it through gear button on login screen.


Changing Ubuntu Touch default browser search engine

Should be available. Don't know, why not. You can add searchengines by adding xml files into /usr/share/webbrowser-app/webbrowser/searchengines (rootfs must be readwrite). Take an existing one as example and test the right properties because I don't, how exactly you must configure them. It depends on the searchengine.


How to run an executable from a mounted drive?

This ought to be a comment, but it seems that I don't have the privilege to write any, so sorry in advance.

Have you tried to execute the mount command in terminal? This program produces output for every mount point in your system. At the end of every line in the output, the mount flags are listed in parentheses. Check if your mount point has noexec flag set.

If so, you can change it with the following command (for example assuming your drive is mounted in /mnt/cdrom):

sudo mount -o remount,exec /mnt/cdrom

If your mounted drive is a Windows partition (i.e. a partition formatted with NTFS filesystem), then you can mount it executable as described in this post.


Download it here:

https://github.com/tcatm/alfred-json
https://github.com/tcatm/alfred

first install alfred-json:

cd /tmp
git clone https://github.com/tcatm/alfred-json.git
cd alfred-json
sudo apt-get install libjansson-dev cmake
cmake .
make
make install

For some examples: see the README in that GIT repository

To use alfred you need to install batman with the packet

sudo apt-get install batctl

then

sudo  modprobe batman-adv

and install alfred itself:

cd /tmp
git clone https://github.com/tcatm/alfred.git
cd alfred
make
make install

see Install batman-adv under Ubuntu to start a mesh network

You can also create the PPA:  /etc/apt/sources.list.d/90-debian.draic.info.list

deb [arch=amd64] http://debian.draic.info/ wheezy main
deb-src http://debian.draic.info/ wheezy main

To install the alfred daemon (A.L.F.R.E.D - Almighty Lightweight Fact Remote Exchange Daemon) and batadv-vis:

cd /tmp/
wget https://github.com/rubo77/alfred-repository/blob/master/alfred_2014.3.0-11_i386.deb?raw=true
sudo dpkg -i alfred_2014.3.0-11_i386.deb
wget https://github.com/rubo77/alfred-repository/blob/master/batadv-vis_2014.3.0-11_i386.deb?raw=true
sudo dpkg -i batadv-vis_2014.3.0-11_i386.deb


enabling lz4 compression in zswap (ie, making zswap more efficient)

I've found the solution in this Russian Debian Forum. I had to run these extra steps

sudo su
echo lz4 >> /etc/initramfs-tools/modules
echo lz4_compress >> /etc/initramfs-tools/modules
update-initramfs -u
reboot

And run dmesg | grep -i zswap, to see

[    0.715952] zswap: loaded using pool lz4/zbud

Excited to see how the performance improves.

edit:
I have written my steps in this guide. You can check if you face issues enabling zswap.


Cannot get my computer sound to work - please help

Please provide more information. Assuming you're using the desktop, have you tried right-clicking on the little speaker icon in the system tray and selecting 'Sound Settings'? You can do a lot of basic troubleshooting in this area. Looks like you have pulseaudio installed, which should simplify things. From this window, under the 'output' tab, you should see a list of your soundcards. You can click the 'test' button on each to generate some audio.

Make sure, of course, that you have your speakers plugged into the right card! You have multiple cards in your machine, and if pulseaudio is choosing one you don't use by default, that could be the whole problem right there. You may want to research your make and model of pc to see which sound card corresponds to which audio output jack.

Another way to troubleshoot is to get some audio playing in an application, then open your unity dash and type pavucontrol. Launch the PulseAudio Volume Control application. Under the 'playback' tab, you should see a list of software audio sources. Find the one playing your audio, and the output meter should be moving. It will display the sound card being used, and you can click on this button select from your different sound cards. Make sure, again, that any sound card you're choosing actually has the speakers plugged into it.

Good luck!


How do i grant write-permission to a java-program?

I don't think you should ever grant superuser access to anything.

I suggest to copy /etc/apt/apt.conf.d/01proxy to a location that is writable by your java program, and then symlink to it from /etc/apt/apt.conf.d/01proxy. Like this:

cp /etc/apt/apt.conf.d/01proxy ~/etc/apt/apt.conf.d/01proxy
sudo ln -sf ~/etc/apt/apt.conf.d/01proxy /etc/apt/apt.conf.d/01proxy


How to run Windows app on Ubuntu? [NOT wine]

You can also install a SSH-Server on Windows (e.g. https://www.openssh.com/) and than call a programm by SSH from your Linux-Client to the command line on your Windows Host-Machine.

Or use something like https://www.teamviewer.com/de

Or look here: How to connect to Windows PC in graphical mode?


Edit: This answer is about ATA Secure Erase. llformat is just a (misleading) password.

None of these answers is correct. A Low Level Format (LLF) is an instruction sent to the disk. To find out how to do this on Linux, read this hdparm tutorial on unix.stackexchange.com,

How do I perform a low level format of a Sandforce solid state disk?

This is a copy of the answer, current as of July 16, 2014 as provided by no.human.being et al,

  Under unixoid systems you can do it with "hdparm". You need to get
  "root" first, then do the following. This is assuming that the drive
  you want to low-level format is "/dev/sda" and that you have "hdparm"
  installed.

hdparm -I /dev/sda

  The parameter is a capital "i", not a lowercase "l", just in case the
  font is ambiguous. If the drive shows "frozen" you must first
  "un-freeze" it. What you need to do to "un-freeze" it depends on the
  device. Most devices will "un-freeze" if you put the system to
  "suspend to RAM" mode, then wake it up again. If the device shows "not
  frozen", you can proceed.

hdparm --user-master u --security-set-pass llformat /dev/sda

  Then show the device info again with the capital "i" as parameter.

hdparm -I /dev/sda

  It should now display "enabled" under "Security:". This is quite a
  critical step. The device is now secured. If you power it down, it
  will lock and might become inaccessible. When you perform the
  low-level format NOW, security will be disabled again and you can
  continue using the device.

hdparm --user-master u --security-erase llformat /dev/sda

  The device should now be physically wiped.

hdparm -I /dev/sda

  Once more with the capital "i". Confirm that security has returned to
  "not enabled". You can now partition and format the device.


DNS Lookup Slow On LAN After Upgrade to 18.04 LTS

Your computer is connected to the subnet 192.168.7.62/24 (netmask 255.255.255.0) and configured to use 192.168.1.1 as DNS server. Unless you have multiple VLANs in you network with routing in between this could be the issue.

Since you clearly have access to Googles Public DNS (8.8.8.8) you should try using that as your DNS server instead.

Note! You might have to restart your computer for the changes to take effect (or restart networking).

Go into the Network Settings and Edit your connection profile:

Then turn off Automatic DNS so your DHCP server doesn't hand out the (perhaps) faulty DNS server again, and enter 8.8.8.8 manually:


Web pages with charset UTF-8 not decoded properly

Did you check this webpage : https://help.ubuntu.com/community/Locale
Maybe it will help you. What exactly is your browser.


Finally found my way out:

setxkbmap -layout ch fr -model pc105

sorry for the noise!


You need the AMD Catalyst 12+ driver.

From here:
http://support.amd.com/en-us/kb-articles/Pages/AMDCatalyst1211betadriver.aspx

This is the latest one:
http://support.amd.com/en-us/download/desktop?os=Linux+x86


To install the Linux software RAID you need to install the mdadm package.

sudo apt-get install mdadm

If you want to make a software RAID-0 from the three image files, you need to create loop devices for each image files:

sudo losetup /dev/loop1 image1.img
sudo losetup /dev/loop2 image2.img
sudo losetup /dev/loop3 image3.img

After you can create a RAID-0 array from them:

sudo mdadm --create /dev/md0 --level=0 --raid-devices=3 /dev/loop1 /dev/loop2 /dev/loop3


Ubuntu 15.04/15.10 on MacBook Pro 11.1 locks up on sleep

I have not experienced the issue since the last update to this question. It must have been fixed in some update along the line.


There is a current service disruption for some users.

Ubuntu One Service Status


Nethogs → creating socket failed while establishing local IP - are you root?

This is solved by version 0.8.1.

As it's not available in repo nor PPA you need to build it (it is really easy and quickly done).

Fetch and extract the most recent version (as of August 2016, v0.8.5)

wget -c https://github.com/raboof/nethogs/archive/v0.8.5.tar.gz
tar xf v0.8.5.tar.gz
cd ./nethogs-0.8.5/

Install dependencies and build

sudo apt-get install libncurses5-dev libpcap-dev
make && sudo make install

Check and run

nethogs -V
sudo nethogs


Get "grub rescue" message when I try to reboot

[insert face palm here]
When you installed it to the external hard drive a bunch of other stuff (boot files) were on the external drive. So now your boot is messed up. In order to fix this you need some kind of windows recovery drive where you can boot to a console. Then refer to this helpful thread for help on fixing the MBR: https://ubuntuforums.org/showthread.php?t=1335353
You can create a recovery drive from a windows PC on windows 10 (I'm not sure about other versions)


Easy installation/removal of a LaTeX package

I advise to recur to an installation by hand of a tex package only when such tex package is not available in an ubuntu package.

Searching for it with

apt-file -x search '/textcomp.sty$'

I obtain the following results:

texlive-latex-base: /usr/share/texmf-texlive/tex/latex/base/textcomp.sty

and it say the tex package you look for is contained in the ubuntu package whose name is texlive-latex-base, so install it, if not already installed.

sudo apt-get install texlive-latex-base

By the way, apt-file is a command to install separately contained in the apt-file package, and only a convenient and alternative way to search into the repositories the same way as http://packages.ubuntu.com/.


mail from website to external error although lampp dovecot and saslauthd already started at boot. When I restart lampp mail is sent

However in Webmin panel boot httpd service is showing no for auto start. Starting this enables another apache daemon.

Regarding the above, there may be two Apache2 installations in system conflicting each other. This could result one Apache2 instance to run at boot and one more the one Webmin sees.

To check which Apache2 Webmin sees, stop the the one running at boot with:

./lampp stop  (locatated at /opt/lampp)

Then go to Webmin and run the httpd daemon.

When the httpd daemon starts, issue the following in terminal:

ps auxwe

This will print all running processes with their paths. If the running Apache2 instance path is other than the one installed with lampp (the one located at /opt/lampp) then there is a strong possibility that there may be conflict in other services too like MySQL, etc.

Also a good place to check is /var/log/* (check for apache2/* logs, mysql.log and mail.* logs)

The procedure above may be used to find other potential conflicitng services like MySQL, Postfix, etc.

Possible Solutions:

Uninstall one stack, that is either the LAMPP or the rest probable installed by the package manager (apt)
Check the all startup scripts and stop the conflicting services
Check the PHP source and see which service calls or tune it by giving a full path to the executable.


cat and Pipe to Run Command Won't Take Two Arguments

To make xargs run your command once for each line of input, give it the -L 1 option (and remove the -n 1 option, since they are mutually exclusive). The standards document for xargs says this:

-L number
The utility shall be executed for each non-empty number lines of arguments
from standard input. A line is considered to end with the first <newline>
unless the last character of the line is a <blank>; a trailing <blank>
signals continuation to the next non-empty line, inclusive.


How can I send a gnome desktop notification from a .desktop app launcher?

Make the exec line:

Exec=bash -c "/home/nhilton/bin/test_sync.bash && notify-send Success || notify-send Fail"

Whole point is that if and && constructs are shell syntax,  so you actually need a shell there to understand them. Hence the use of bash -c

Mind the single and double quotes and double check other parameters in .desktop file


It seems like there is a bug as many people having the issue including myself on Ubuntu MATE. Please run  $ GTK_IM_MODULE='' synapse into your terminal and that should resolve it for you.

Update

I you could also downgrade to older version that doesn't have have the bug. There I have found an answer by @OccamRazor in in here which works very well when I tested.


Vagrant Up and annoying NFS password asking

The official Vagrant docs now cover this:
https://www.vagrantup.com/docs/synced-folders/nfs.html#root-privilege-requirement

You need to add entries to the /etc/sudoers file, and the way to edit that is to type this at the terminal: sudo visudo

Type your password, and you're editing the file.
You'll want to paste these lines below (depending on whether you are running Vagrant on OS X or Linux.

If you're not familiar with vim, which it opens in, this page helped. Basically, copy the appropriate block of text below. Then, in visudo, go to the spot you want to paste text into the file (the end of the file is fine), and hit "i" to go into insert mode. CMD+V to paste your text. Then, hit ESC, then type :w to save your changes and then :q to quit.

As of version 1.7.3, the sudoers file in OS X should have these entries:

Cmnd_Alias VAGRANT_EXPORTS_ADD = /usr/bin/tee -a /etc/exports
Cmnd_Alias VAGRANT_NFSD = /sbin/nfsd restart
Cmnd_Alias VAGRANT_EXPORTS_REMOVE = /usr/bin/sed -E -e /*/ d -ibak /etc/exports
%admin ALL=(root) NOPASSWD: VAGRANT_EXPORTS_ADD, VAGRANT_NFSD, VAGRANT_EXPORTS_REMOVE

And Linux should have these entries:

Cmnd_Alias VAGRANT_EXPORTS_CHOWN = /bin/chown 0\:0 /tmp/*
Cmnd_Alias VAGRANT_EXPORTS_MV = /bin/mv -f /tmp/* /etc/exports
Cmnd_Alias VAGRANT_NFSD_CHECK = /etc/init.d/nfs-kernel-server status
Cmnd_Alias VAGRANT_NFSD_START = /etc/init.d/nfs-kernel-server start
Cmnd_Alias VAGRANT_NFSD_APPLY = /usr/sbin/exportfs -ar
%sudo ALL=(root) NOPASSWD: VAGRANT_EXPORTS_CHOWN, VAGRANT_EXPORTS_MV, VAGRANT_NFSD_CHECK, VAGRANT_NFSD_START, VAGRANT_NFSD_APPLY

Note that these change from one version of Vagrant to another, so the above might be outdated. The important thing is that the docs now cover it.


Is it possible to control the recording if Audacity is running in the background?

Does Audacity have cli options?

Unfortunately, looking into man audacity, does not show any interesting or relevant options:

OPTIONS
       -help     display a brief list of command line options

       -version  display the audacity version number

       -test     run  self  diagnostics  tests  (only  present  in development
                 builds)

       -blocksize nnn
                 set the audacity block size for writing files to disk to  nnn
                 bytes

However...

simply pausing/continuing Audacity from cli works exactly similarly to pausing/continuing recording

I tested pausing Audacity as a process, with the commands kill -stop <pid> and kill -cont <pid>. It did the job perfectly; it stopped recording immediately, resuming immediately when the process was continued. Even after 6 or seven hours, it stops/resumes recording right away with these commands.

Adding the two commands to shortcut keys does exactly what you describe.

How to use

Add the following two commands to shortcut keys:

/bin/bash -c "kill -stop $(pgrep audacity)"

...to stop (pause) recording, and

/bin/bash -c "kill -cont $(pgrep audacity)"

...to resume, and you have your own shortcut keys to start/stop (actually pause) recording.

Only the initial starting of the recording needs to be done via the Audacity GUI.

Adding to shortcut keys

Choose: System Settings > "Keyboard" > "Shortcuts" > "Custom Shortcuts". Click the "+" and add the two commands above to two different shortcut keys.

Extending options

Of course we can extend options, e.g.

/bin/bash -c "kill -cont $(pgrep audacity) && notify-send Recording"

and

/bin/bash -c "kill -stop $(pgrep audacity) && notify-send Stopped"

...to show a notification on the current state, or even make a panel icon to show the current state. Anything is possible

Additionally, a toggle script, as requested in a comment

The script below will toggle recording. Add it to either a shortcut key or launch it in any other way.

The script reads the current process state from the file /proc/<pid>/status, and decides what the targeted state should therefore be.

Additionally, the script notifies the user what happens in a notification (using notify-send).

#!/usr/bin/env python3
import subprocess

try:
    pid = subprocess.check_output(["pgrep", "audacity"]).decode("utf-8").strip()
except subprocess.CalledProcessError:
    pass
else:
    state = "(stopped)" in open("/proc/"+pid+"/status").read()
    if state == True:
        cmd = ["kill", "-cont", pid]; msg = "Recording"
    else:
        cmd = ["kill", "-stop", pid]; msg = "Pausing"
    subprocess.Popen(cmd)
    subprocess.Popen(["notify-send", msg])

To use it

Simply copy it into an empty file, save it as toggle_record.py
Test run it with the command:

python3 /path/to/toggle_record.py

If all works fine add it to a shortcut key as explained earlier in the answer.


Can I remove the pulsing XFCE logo on logon in Xubuntu 11.10?

In Settings Managaer (accessible from the menu with the XFCE logo as button), go to "Session and Startup".  Then click on the "Splash" tab.  Select the "none" option along the left.  Right now you should have some other option like "Mice" selected.


Why would I want to install a snap if I can install via apt instead?

I can share the results of some experimenting with two versions of LibreOffice 6.1.3.2: one as a snap delivered with ubuntu 18.04 and another one installed from the official ppa. Please keep in mind the values I give below are approximate.

Startup time of an empty Calc spreadsheet

ppa: 1.5 s
snap: 13 s

Conversion time of 13-slides (mostly png pictures) to pdf with impress

ppa: 9 s
snap ~70 s

Disk usage [MB] (expected / real)

ppa: 369 / 483
snap: 507 / 1269

I realize these values depend on the hardware and specific configuration of the system I'm using. However, considering I have used the same laptop, operating system and LibreOffice versions, I believe relative comparison is still informative.

Altogether, on my laptop snap image occupies more than 2 times the disk space and it is almost 10 times slower than the corresponding ppa. In contrast with common opinions subsequent startups of snap application are not faster on my system.

My personal view on the end-user's benefits of snap is related only to system security (no sudo required to install, limited runtime permissions). So if you're running a personal system at low risk, I'd stick to ppa's. In such cases the enhanced security is not worth the cost of much worse performance in the present-day snaps.


mute built-in speakers without muting external output speakers/headphones from command line

From the command line interface of pulseaudio, you can list all sinks (as in "places where sound stream goes away") like this:

pactl list short sinks

0 alsa_output.pci-0000_02_00.1.hdmi-stereo   module-alsa-card.c s16le 2ch 44100Hz SUSPENDED
1 alsa_output.pci-0000_00_1b.0.iec958-stereo module-alsa-card.c s16le 2ch 44100Hz RUNNING

Now, you can work with the separate sinks, and have all the details.

You can use the full name of the sink as arument:

`pactl set-sink-mute alsa_output.pci-0000_00_1b.0.iec958-stereo toggle`

You can instead of the long name, use the index number listed in front of the name (1):

Toggle mute, that is switch between sound on and off:
    pactl set-sink-mute 1 toggle

Switch mute on, that is sound off:
    pactl set-sink-mute 1 1

Switch mute off, that is sound on:
    pactl set-sink-mute 1 0

See pactl help or man pactl for more options.


Ubuntu Server 20.04 hangs on black/blank screen during install on Intel NUC

Look at the specification.
Supported Operating Systems
Windows 10, 64-bit*
This NUC does only run Windows 10, no Linux.
I also run in this trap several months ago.
I could not get it run and sent the NUC back to vendor.


Can I wait for a Broken Package System to be fixed automatically?

In this case 'broken' simply means "The package manager knows that this package cannot be installed," which may slightly different from what you expect.

A 'broken' package could mean many things: Corrupted data, conflict with another package, incompatible version, etc. Each cause of 'broken' gets handled differently, of course.

Example: A new upstream version will fix only some causes. It usually fixes file corruption (very rare). It might --or might not-- fix a file conflict (moderately common). It won't fix most version conflicts (very common).


Thunderbird needs to be open if you want to get notifications.
But you can use addons to "hide" it in the tray.

There is an addon called Minimize to Tray in Thunderbird to achieve that.
Once you've installed it press F9 to minimize Thunderbird to the system tray.
You will keep on receiving the notifications when it is minimized.


Playing Minecraft in Ubuntu - Black lines

You can use Minecraft installer. Run following code:

sudo add-apt-repository ppa:minecraft-installer-peeps/minecraft-installer
sudo apt-get update && sudo apt-get install minecraft-installer

Once installed simply run the app, enter (or register) your Minecraft details and you’re all set

Source: http://www.omgubuntu.co.uk/2013/04/minecraft-installer-for-ubuntu

OR

Step 1 - Files/Programs
Go to the Ubuntu Software Center and install OpenJDK Java 6...
Get minecraft.jar from http://www.minecraft.net/download/minecraft.jar and place in you home directory.
Get minecraft.svg from the attachments at the bottom of this post and put it in the same place.

Step 2 - Terminal
Open the terminal and type: sudo bash
Enter your password (not the root one)
Then type: ls
Check if the files you added are there.
If they are type: chmod a+x minecraft.jar
This will make it run-able
Close the terminal

Step 3 - Open with
Go to the minecraft.jar file and right-click on it
Select preferences and set it to open with OpenJDK Java 6...

Step 4 - Launcher
Add a launcher on the desktop (right-click)
Click on the image and locate minecraft.svg
Name it Minecraft
Set the location as the minecraft.jar file

Source: http://ubuntuforums.org/showthread.php?t=1812767


xfce4-terminal closes without confirmation dialog

I could not find any such option. The closest you can get is by opening multiple tabs, for which XFCE Terminal does ask for confirmation. The option governing this is MiscConfirmClose in ~/.config/xfce4/terminal/terminalrc (which was set to TRUE by default in my system).


Is it possible to downgrade 11.10 kernel version to 2.6?

Seeing that your mean reason is overheating, I'd suggest installing Precise Pangolin A1.
It is the current development version, but seeing it's for an LTS version it will mainly see bug fixes and ironing out the flaws. I've heard from reliable people that the A1 (or Alpha 1) is seeing great improvements in terms of power management.
You can also check out this Google-search: power management ubuntu 12.04


If you have downloaded the  Windows installer , you should then open it to install Ubuntu. You will find detailed instruction on how to install here and "Yes" if you just want to give a try for Ubuntu without leaving Windows on your PC then Wubi is best choice.


Is there a kind of Ubuntu Wiki sitemap or contents index?

Index pages: See http://wiki.ubuntu.com/FindPage

RecentChanges: see where people are currently working

TitleIndex: a list of all pages in the wiki

WordIndex: a list of all words that are part of page title (thus, a list of the concepts in a wiki)

WantedPages: a list of linked, but not existing pages

OrphanedPages: a list of existing, but not linked pages

AbandonedPages: a list of pages that have seen no changes for long

RandomPage: some random pages

PageSize: size statistics

PageHits: hit statistics
For map:

You can use Local Site Map at any page, but for example start at home:

https://wiki.ubuntu.com/Home
At the top, Click on More Actions: button, then select Local Site Map

Like that browse site as tree.
For Search, you can use advanced option with most search engine. Example using Google, You can use site: keyword to search only in Ubuntu wiki.

wubi site:wiki.ubuntu.com


What happens if I disable the PPA of a specific package?

If you disable the ppa of a specific package, without reinstalling the packages it contains, then apt will leave the packages at their currently installed versions until a newer version comes along.

If you would like to completely remove ppa's from your system you should use the ppa-purge tool. This can be installed by running sudo apt-get install ppa-purge and you use it by running:

sudo ppa-purge ppa:owner-name/ppa-name


Try another usb stick. I've had lots of strange experiences with some usb thumbdrives only working with some mb/firmware combinations.


It's pretty simple, just follow the instructions provided at the second link (here).

You need Mono and Latex, so run this command:
sudo apt-get install mono-complete texlive-full

Then download the file provided at that page (TikzEdt_2_1_Linux.tar.gz)

Copy/paste the downloaded file to the location where you want to run it from.

Run:
tar -xf TikzEdt_2_1_Linux.tar.gz

in the same folder as the downloaded file.

Once it's finished extracting, run:
./tikzedt

You should be good to go!


The Bitnami Wordpress Linux Installer is pretty much plug-and-play (depending on how you do it).

If you're installing from your bare OS, all you need to do is grab the install runfile from the download site and then do the following:

Open a terminal with Ctrl+Alt+T
Type cd Downloads and hit Enter.
Find the filename for the install file (at the time of writing, bitnami-wordpress-4.7.3-0-linux-x64-installer.run). For all steps below, I will be assuming the filename is bitnami-wordpress.run. Change this accordingly.
Run the following command to start the install process:

chmod +x bitnami-wordpress.run && ./bitnami-wordpress.run

If the installer asks for root permission, run the following command instead (if needed):

sudo ./bitnami-wordpress.run

Alternatively, I would personally recommend you use the Docker setup for Bitnami Wordpress. How to is much simpler:

Install Docker and Docker Compose, and run sudo apt install curl.
Make a folder or similar to store the config file for Bitnami Wordpress. I personally would recommend Bitnami-WP in your home folder.
cd to the folder where you want the configs to go.
Run these commands:

curl -LO https://raw.githubusercontent.com/bitnami/bitnami-docker-wordpress/master/docker-compose.yml
docker-compose up

Whenever you are done, just cd back to wherever the compose file exists, and run docker-compose down to shut down the install.


Install Ubuntu onto USB stick? (Not installer?)

I have installed it successfully on the microSD card on my phone and plug my phone into any PC and boot it from USB. It's no different to installing it on your laptop..... wasn't for me anyways.


Rsync --delete option doesn't delete files in target directory

Use this command:

rsync --archive --verbose --compress --ignore-existing --delete /var/www/ root@mydomaintest.com:/var/www

You do not need a "*" and should not use it too.

To exclude/include files or directories, you should use this parameters:

--exclude 'to_exclude*'
--include 'to_include*'


I had the same problem running Ubuntu 16.04 on the same laptop (both with and without the power connected).  In desperation I updated the kernel from 4.4 to 4.5.3 (see here and here for instructions) and the problem seems to have gone - both for closing the laptop lid and selecting 'suspend' from the menu.


Is there a way to have sound balance affected by window position?

This is not supported by any system I know of.

But it wouldn't be that hard to do but it would require being able to match up mixer inputs with the windows that they appear to come from (this requirement is the hard part.) and then looking up the location of the window for an input and modifying the mixer balance for that input accordingly.

Using X11 state change notification, it would be possible to update the balance for an input in realtime without polling the window locations.


architecture-independent performance monitor tool

I found a good scholarly tool and framework called MICA : "Microarchitecture-Independent Characterization of Application" which has been developed by Ghent University.

More Info on the GitHub page


Also in Ubuntu, Firefox will auto-complete usernames and passwords, unless you except a specific web page. Opera does not do so, but it has a key-shaped button beside the web badge (or a shortcut-key Ctrl+Enter) to login automatically.

Opera, unlike Firefox or Chrome, won't show saved passwords in Password Manager – I like this security guard.


Cant connect to my VPS from Ubuntu Terminal

You need to convert the PPK key to openssh format. It is quite simple even on Ubuntu:

Install putty tools: sudo apt-get install putty-tools
Convert puttygen mypublickey.ppk -O private-openssh -o mypublickey


How to change the Ubuntu 19.04 GDM3 cursor theme?

While editing the file:

  /etc/gdm3/greeter.dconf-defaults

You may change the cursor theme, size and speed as follows:

# Theming options
# ===============
[org/gnome/desktop/interface]
cursor-theme='Bibata_Ice'
cursor-size=35
[org/gnome/desktop/peripherals/mouse]
speed=-0.8

Here, I'd used the Bibata_Ice theme, with size 35 and speed -0.8.

Off course, the folder with the cursor theme has to be inside:

  /usr/share/icons

Good lucky!


Flash player is completely dead for all operating systems as of 2021. This is also stated in the pepperflash documentation There are some alternatives, such as ruffle, but these do not have full support yet.
However, you could try installing Ruffle:

download the Firefox extension
happy flashing! (only old  (ActionScript 1&2) flash games reasonably supported)


is there any app for backup/ restore installed apps in ubuntu?

Aptik is really good.  By using it and Deja-Dup I have just blown away a system (on purpose) and recreated it in only a hour or so.

Here's a picture of the Aptik screen.

I've used the first 3 buttons to save my configuration and reload it onto the new system.  The 4th button seems to largely duplicate Deja-Dup's functionality, so I didn't use it.  The 5th button I did not use because I don't have any custom themes or icons.

The only problem I have encountered is that a few applications didn't get moved and I had to reinstall them manually: Chrome, Teamviewer, Skype.  I am not sure why this is, in fact I have been looking into that today.  I noticed their ppas don't follow the same naming convention as most, perhaps that is why.

this is not an ad, I am just a happy user. and anyway, it's free


Hi there's two posibilities here, the PSU is not providing enough power to the CPU or the CPU is being overclocked.

https://ubuntuforums.org/showthread.php?t=2205211&p=12996968#post12996968

Basically your hosting provider is being irresponsible with their machines.

I'd recomend letting them know about the hardware fault and suggesting they stop overclocking and change the power supply for the server rack containing your ubuntu.

or just switch hosting service.


how to make Ubuntu One app synchronize outwards only (only remote be updated) (one directional)?

No, there isn't. Ubuntu One file synchronization is a file synchronization service, and not a remote storage or backup service.

However, it is possible to disable the file synchronization service, and write a program which uses the REST API to only do file uploads to the service, rather than synchronization.


After switching from gdm to lightdm my screen turns off when I come to the login

It's hard to know exactly what is going wrong, but here are a couple easy ideas that might help:
To start off, when you can't access a GUI you can switch to a shell command prompt with Ctrl+Alt+F1, where you can log in using your user name (not display name) and password.  It then functions like Terminal would.  You can switch back to the GUI to see if it's working yet with Ctrl+Alt+F7.  So, for the course of the following possible fixes, you'll need to go into Ctrl+Alt+F1 to enter commands if you have no functioning GUI.
Do you inadvertently have both gdm and lightdm running at the same time?  To make sure you do not, use the following command:

sudo killall gdm

Now try to restart lightdm with the following:

sudo service lightdm restart

If you don't want to use gdm at all, you may want to enter the following to uninstall it:

sudo apt-get remove gdm

If gdm is already uninstalled and you're having this issue, try reinstalling lightdm using:

sudo apt-get install --reinstall lightdm

You can also do this with:

sudo apt-get remove lightdm
sudo apt-get install lightdm

If you still can't see a GUI after you have tried all of the above, you may need to install the Ubuntu desktop.  To do this use:

sudo apt-get install ubuntu-desktop

If it has already been installed (you will know this because the second item in the last line of that process will read "0 newly installed"), then you may want to reinstall Ubuntu desktop using:

sudo apt-get install --reinstall ubuntu-desktop

I hope at least one of those ideas works.  If at any point you wish to reboot from the Shell without having to use your power button, you'll need to switch to root and then give the command to reboot.  You'll end up doing this chain of commands:

sudo -s
reboot


Logrotate configuration: it works, but always keeps 'current' log empty

According to this old post on the openvpn-users mailing list :

  openvpn logging is done by redirecting stdout/stderr to the logfile

So the solution is to use the copytruncate option in the logrotate configuration:

  copytruncate

  Truncate the original log file to zero size in place
  after creating a copy, instead of moving the old log file and
  optionally creating a new one. It can be used when some program cannot
  be told to close its logfile and thus might continue writing
  (appending) to the previous log file forever. Note that there is a
  very small time slice between copying the file and truncating it, so
  some logging data might be lost. When this option is used, the create
  option will have no effect, as the old log file stays in place.

This is what I have in my /etc/logrotate.d/openvpn file :

/var/log/openvpn.log {
    weekly
    rotate 12
    copytruncate
    compress
    delaycompress
    missingok
    notifempty
}


try:

apt search libxml2

this command show search from any evidence: repositories and installed packages.

so if you will see for example for trusty:

libxml2/trusty-updates,trusty-security,now 2.9.1+dfsg1-3ubuntu4.3 amd64
[installed]
  GNOME XML library

libxml2-dbg/trusty-updates,trusty-security 2.9.1+dfsg1-3ubuntu4.3 amd64
  Debugging symbols for the GNOME XML library

libxml2-dev/trusty-updates,trusty-security,now 2.9.1+dfsg1-3ubuntu4.3 amd64
  [installed,automatic]
  Development files for the GNOME XML library

so, obviously, if you see this output you are have alot of chances to install version.

However if you need the package strictly by version, try indicate the version alike this:

sudo apt-get install libxml2=2.9.1+dfsg1-3ubuntu4.3
sudo apt-get install libxml2-dbg=2.9.1+dfsg1-3ubuntu4.3
sudo apt-get install libxml2-dev=2.9.1+dfsg1-3ubuntu4.3

OR by indicating target repository:

sudo apt-get install libxml2/precise libxml2-dbg/precise libxml2-dev/precise

After it’s installed, run the following command to hold your installed version, preventing the package manager from automatically updating it in the future:

sudo echo "libxml2 hold" | sudo dpkg –set-selections

With --no-remove option apt-get will exit installation process anytime without any prompts if any packages are to be removed:

sudo apt-get install --no-remove libxml2=2.7.8.dfsg-5.1ubuntu4.9

Other goody: --no-install-recommends which claim the apt-get do not consider recommended packages as a dependency for installing.

Read apt-get precise pangolin manpages

Hope it help you.


I don't think there's an existing solution that offers exactly what you describe. You would have to write a couple of scripts, starting with something like fsniper  that watches for new files and then triggering the addition of this file to a text file tracking all files, copying the file to the harddisk, complaining if the disk is full etc. It is of course feasible, but involves a lot of work and has a lot of pitfalls that existing backup solutions take care of coping with (e.g. handling a crash during the copy of a file).

Another solution (that does not store plain files on the disk and does not allow any nice thumbnail preview) is using a powerful backup solution like bacula , that is built for enterprise grade backups and can cope with backing up to multiple tape drives. You can then adapt such a solution to use harddrives instead of tape drives, as explained here on the bacula wiki

A software that might be useful for your current workflow (manual copying of new files) is “Virtual Volumes View” (short: VVV):

  VVV is an application that catalogs the content of removable
  volumes like CD and DVD disks for off-line searching. Folders and
  files can also be arranged in a single, virtual file system. Each
  folder of this virtual file system can contain files from many disks
  so you can arrange your data in a simple and logical way.

Unfortunately it's not available in the repositories but has to be compiled from source.


That suggests that the host system supports neither VT-x or EPT technologies so trying to turn it on is folly. This is a hardware limitation. You need a computer that supports this CPU feature. I'm not sure what else I can say about it.

If you're certain that your computer does support either protocol, check the BIOS. I know mine allows me to turn it off (it was on by default). Mine is in my advanced CPU settings.

But otherwise, no, there's no fix other than you getting a better computer.


How to setup a virtual host on ubuntu 12.04?

Checkout https://github.com/Aslamkv/vh :)
This tool lets you add and remove virtualhost in Ubuntu by doing every configuration for you. It is simple and easy to use.
Installation

Download the files listed at the link GitHub webpage into any folder and open that folder in terminal
Type in terminal ./install.sh
Type in terminal vh to install a VirtualHost or vhu to uninstall a previously installed one

Disclaimer: I am the author :P


Weird (?) BIOS on Dell G5 5500 Laptop + BitLocker woes

On Windows Check if bitlocker is enabled, if so, disable it. I've disabled secure boot on my Dell Latitude E6430, and it's all ok. Fast start or fast boot are the same I guess, I have it disabled to, it should be in the boot menu in the BIOS. I have Legacy turned on. I don't know how you prepared your installation media, I've used ventoy. Good luck :)


What is the difference between GRUB and SYSLINUX?

This is my final answer, which is based on information found by matching keyword within 2000+ pages in this listing on Ubuntu Wiki. What I found were dated notes of Ubuntu development and specifications (read: words, words, words), so that took me some time to reach this answer.
Ops, wrong naming
To begin with, the naming of boot loaders shall be clarified:

Name with all letters capitalized refers to the boot loader (e.g. GRUB, SYSLINUX)

Name with initial letter capitalized refers to the project name or, several or all variants of the boot loader family (e.g. Syslinux)

In particular, 'Syslinux' is a collection of boot loaders that includes 'SYSLINUX', 'ISOLINUX', 'EXTLINUX' and 'PXELINUX'

Following the naming convention, the question is actually referring to "ISOLINUX" for "El Torito no-emulation" bootloader, not "SYSLINUX". Perhaps the latter is used interchangeably with the former in old days. Nevermind, then.
Brief history
2005: ISOLINUX is choosen for Ubuntu CD boot loader, instead of GRUB.

GRUB has been suggested before as a possible replacement boot loader, but this approach was tried in the Warty live CD where we observed significant regressions in bootability versus the ISOLINUX-using install CD. We feel that sticking with solutions based on ISOLINUX is the most appropriate approach for a long-term-supported release.
-- from CdBootloader - Ubuntu Wiki

2006: gfxboot has been added; This supports information quoted in 2010.

In Dapper, we added gfxboot to our amd64 and i386 CD images, providing a friendly graphical boot menu as the first thing users see when booting Ubuntu CD images on those architectures [...]
-- from PortableGfxboot - Ubuntu Wiki

2009: ISOLINUX (noted as SYSLINUX) is still used for booting Ubuntu CD.

Ubuntu live CDs still boot using SYSLINUX, which does not include support for starting the kernel in graphics mode. This means that live CDs display a graphical boot menu, then switch back to text mode to start the kernel, and will then normally switch back to graphics mode later. As a result, live CDs will currently flicker more than normal installed systems at boot time.
-- from BootGraphicsArchitecture - Ubuntu Wiki

2010: ISOLINUX has been used, but GRUB 2 is needed for UEFI support.

Current Ubuntu CDs use ISOLINUX, with the gfxboot extensions from SuSE implementing graphical menus.
This has proven to be rather difficult to maintain, with only one person in Ubuntu who understands the theming code involved [...]
[Since] GRUB 2 recently had graphical menu support added to it upstream, moving to that has the potential to reduce our maintenance load. It seems likely that we will need to use GRUB 2 anyway in order to support EFI, and having to configure two different boot loaders on our CDs would be undesirable.
-- from FoundationsTeam/Specs/MaverickCDBoot - Ubuntu Wiki
Pursuant to foundations-m-grub2-boot-framebuffer, we will need to look into our ability to support graphical boot menus in EFI. GRUB has some level of support for UGA and GOP graphics.
This requires using GRUB for CD booting, or at least having the bare minimum of configuration to support it [...]
-- from FoundationsTeam/Specs/MaverickUefiSupport - Ubuntu Wiki

Differences found or not
Following brief history, we now understand that:

ISOLINUX was preferred due to GRUB had regressions back then (2005)

ISOLINUX was still preferred despite lack of support for starting the kernel in graphics mode that cause flickering during boot transition (2009)

ISOLINUX has been used with gfxboot to provide graphical menu, which was not implemented or not possible with GRUB back then (2010)

GRUB has been added later to boot with UEFI support since Maverick (post-2010)

Then, I realized that it is not the difference between GRUB and SYSLINUX that made Ubuntu live CD include two boot loaders.
Fundamental reasons
From my reading, these supporting facts actually hinted that:

Ubuntu live CD has been using particular boot loader that had better support for providing graphical menu and theme, and smooth transition to show boot splash. In this case, SYSLINUX (precisely ISOLINUX).

When UEFI systems became increasingly common, then only Ubuntu had included GRUB (precisely GRUB 2) in Ubuntu live CD to boot with UEFI support.

Above all, I believe this answers the question that I had for more than a year and this answer has finally put my curiosity to rest.
TL;DR GRUB and ISOLINUX are both used in Ubuntu live CD for exclusive reasons; Both were included in live CD for better boot experience and hardware support.


vlc installed but not opening when clicked in ubuntu 1404

Open a terminal (Ctrl+Alt+T) and run :

sudo apt-get install libvlc5

If it's already installed, you may also need to link your local libraries to the system libraries :

sudo ln -s /usr/local/lib/libvlc* /usr/lib/
sudo ln -s /usr/local/lib/libx264.a /usr/lib/
sudo ln -s /usr/local/lib/vlc /usr/lib/vlc


GDM stopped starting when booting Ubuntu 18.10

Try this command to choose a login manager:

sudo dpkg-reconfigure gdm3

You should be able to select gdm3.


Is it possible to login as the same user with 3 different environments kde, gnome and unity

If you install all three, you should be able to choose which one to use when you login.  This may be disabled by default in 12.04.  Normally, each user will pick a default environment.  Each desktop manager should have a package with a name ending in desktop that will ensure the dependencies are installed.

Running all three simultaneously requires a bit of magic and more than one screen.  The extra screens can be virtual, or additional physical screen.  Not something I would want to try.


Monitor devices network usage and bandwidth in real time

You could use Wireshark to monitor the network traffic.


Stop Super+M from opening Messaging Menu

Unfortunately the shortcuts for both indicator-applet and indicator-applet-session are not configurable, which causes problems. See bugs #558581 and #554713.

If you are brave and know what you are doing, you could use one of the patches listed in bug report #558581.

You could also use indicator-applet-complete which only uses the Super+S shortcut. See this answer for more details.


Best practices to keep your ubuntu desktop and laptop in sync?

OK. What you need is two separate features. I only know a lot about one, but I will do my best to give you the background to the other.

I have 8 computers in my house, and keeping all my files on all of them is a necessity. Unfortunately, I also have about 25 GB of files to sync, so I couldn't use any on-line storage site - they don't give you enough space (except for copy.com - you can sign up for 2 free accounts, and share the data between them. It will be half on one, half on the other, so if you share everything you have 30 GB of space. Whether or not this is allowed, I don't know. It also means that your data is twice as likely to be hacked into.)
Anyway, another solution which doesn't require your files being stored on-line is Bit torrent Sync. This requires a program to be installed on both computers (it's available for free on Windows, Mac OS X and Linux). You then enter a secure address (which it generates) and it syncs your files across - either via your LAN or the internet, and their servers.
You could also sync the folders with the program files in them, but that could cause instability. In the ubuntu software centre, you can sync installed programs to another computer.
Click on

File -> Sync Between Computers

You then sign up for an Ubuntu Software Centre account (which may be the same as an Ubuntu 1 account). On the second computer, you sign in to this account in the same way,

File -> Sync Between Computers

but then click 'I already have an account'

look at this How-To Geek article for more information.


Access to phpmyadmin in dual booted system?

You can't .. your webserver (apache, nginx .. or other) has to be running. And it only does so when Ubuntu is boooted.

If you want access to ubuntu from windows, you have to run either Windows or Ubuntu as virtual server in the other OS, or run Ubuntu on an other server.


After some search in google I found that miam-player is uptill now supported only upto ubuntu 15.10 and is unsupported in Ubuntu 16.04.

The following article helped me to get to this conclusion:
http://ubuntuhandbook.org/index.php/2016/02/miam-player-open-source-qt5-music-player/

Bad Luck. I have to wait for some time now.


What are the default values for synclient parameters?

Well if you switch user to the guest session it should have the default values and run the command synclient -l >/tmp/touchpadsettings then you can switch back to your user and run synclient -l >~/brokentouchpad Then you can run diff /tmp/touchpadsettings ~/brokentouchpad to see the changes and for all of the values you changed you can run synclient  name of setting = value in /tmp/touchpadsettings. For example in the diff command I could totally turn the touchpad off making it not respond with synclient touchpadoff=1 But in the diff I get on one line synclient touchpadoff=0 on one then synclient touchpadoff=1 on the lower line so run synclient touchpadoff=0 to fix it.


Automatically close application after custom time?

Install gnome-schedule from the Ubuntu Software Center, load the program from Applications > System Tools. Use it to add an entry for the time you want the program to be closed like so:

This will kill all instances of firefox at a certain date/time, you can also have reoccurring events that kill off certain programs at certain times, for instance to encourage kids to not browse the internet or for killing certain games.

It is possible to do this kind of thing from the commandline too, but you need to know how to use crontab -l and how to write cron lines.


How to remove default bookmarks from the "Files" in Ubuntu 20.04 (Nautilus)

The item "Recent" is removed when you disable "File History" under "File History & Trash" in the "Privacy" settings.
You still could also remove "Other locations" by changing "show-other-locations" to "False", i.e. <property name="show-other-locations">False</property> in the resource description (cfr. Can the "Starred" folder be removed).
I am not aware of any possibility to remove the "Trash" icon without going into the source code itself.


You could add your command to the file /etc/gdm/PostSession/Default before the exit 0 line.


Boot from a USB key and then format your drive.


Can't change brightness on Toshiba l755 laptop

You can manually set the brightness from the command line using:

sudo echo 0 > /sys/class/backlight/acpi_video0/brightness

(You change the   value from 0 to 100 for desired brightness.)


error when running sudo apt-get upgrade (linux-headers-generic related)

As of today, the current package for both linux-generic and linux-headers-generic is 5.4.0.52.55 (not 5.4.0.51.54)
I see four possibilities:

You forgot to run sudo apt update. This is the most common reason. Simply do so, and your problem will magically vanish like a morning fog.

If you recently did a release-upgrade, and you have other problems, then you might have had problems with your release-upgrade.
It's common when folks add non-Ubuntu packages, third-party sources, PPAs, and other strange stuff, and then hope that apt can handle it magically. It cannot, which breaks upgrades. This is moderately common with LTS-to-LTS upgrades where folks don't keep track of what they installed two years ago.
If this is what happened to you, then the easy solution is to backup your data and clean-install 20.04 to wipe away all that historical dreck.
Best practice for release-upgrades is to uninstall all non-Ubuntu and wrong-version packages and sources before a release-upgrade; return your system to as close to stock condition as possible. Then release-upgrade, then restore your non-Ubuntu sources and package. Next time, try to do it that way.

On rare occasions, a metapackage (like linux-headers-generic) fails to upgrade. This usually happens when folks or their network connection are inconsistent about upgrades and delay normal apt upgrades for more than a few weeks. It's most often associated with no-space-left-on-device errors. You can test for this by looking at the metapackage version.
In this example, the version number is current (5.4.0.52.55), so my system does NOT have this problem, and the solution below won't help.
$ dpkg -l | grep linux-image-generic
ii  linux-image-generic                        5.4.0.52.55

If your system has an older version number that stubbornly won't change, then use clean to delete the metapackage from your local cache (thereby forcing apt to download a fresh copy) then reinstall the metapackage. Finally run a normal apt upgrade.
sudo apt update
sudo apt clean linux-headers-generic
sudo apt install --reinstall linux-headers-generic
sudo apt upgrade

If your upgrade habit is to use a mixture of GUI and Shell, then it's rare-but-possible that your system might have been caught up in phased updates.
Simply run an apt-update/upgrade from the shell instead of using the GUI tools. Shell tools are not subject to phased updates.
sudo apt update
sudo apt upgrade


How to open two different files using the vi editor?

As noted by Zanna, use multiple arguments to Vi. However, Vi(m) by default doesn't show the files at once. They're loaded into buffers and and you can switch to the next (or previous) buffers using :bn and :bp. If you want to see the files at the same time, use windows (splits):

vim /some/file1 /some/file2 -o # horizontal split
vim /some/file1 /some/file2 -O # vertical split

Or tabs:

vim /some/file1 /some/file2 -p # Open up to 10 files in tabs

However, buffers are what Vim actually uses for manipulating files, tabs and windows are merely ways to visually arrange them. Do get used to using buffers directly, instead of via multiple windows or tabs.

(These options also apply to Ubuntu's vi, which is vim.tiny by default. vim-tiny is built with +windows, so tabs and windows are enabled.)

See also:

Vi & Vim: What is a more efficient way to use buffers?
Open an existing file from Vim
SO: Why do Vim experts prefer buffers over tabs? and Using Vim's tabs like buffers
Vim help: Editing with multiple windows and buffers


How to fix Ubuntu calculator malfunction?

Since the issue happened in both your laptop and desktop, it may be due to automatic update of the snap version of gnome-calculator. Use the following command to shift to the apt version.

sudo snap remove gnome-calculator && sudo apt install gnome-calculator


Run:

sudo apt-cache search libpng*

sample output:

libpng12-0 - PNG library - runtime
libpng12-dev - PNG library - development
fp-units-gfx - Free Pascal - graphics-library units dependency package
fp-units-gfx-3.0.0 - Free Pascal - graphics-library units
libpnetcdf-dev - Development files for the parallel netCDF library
libpnetcdf0d - Libraryfor reading and writing parallel NetCDF files
libpng++-dev - C++ interface to the PNG (Portable Network Graphics) library
libpng-sixlegs-java - Sixlegs Java PNG Decoder
libpng-sixlegs-java-doc - Documentation for Sixlegs Java PNG Decoder
libpng16-16 - PNG library - runtime (version 1.6)
libpng16-dev - PNG library - development (version 1.6)
libpng16-devtools - PNG library - tools (version 1.6)
libpng16-tools - PNG library - tools (version 1.6)
libpng3 - PNG library - runtime
libpnglite-dev - lightweight C library for loading and writing PNG images
pngquant - PNG (Portable Network Graphics) image optimising utility
ruby-oily-png - native mixin to speed up ChunkyPNG
tkpng - PNG photo image support to Tcl/Tk

Then run:

sudo apt install libpng12-dev
sudo apt install libpng++-dev

Edit

The latest libpng can be download from here : libpng-1.6.26.tar.xz , install it as follows:

tar xvf libpng-1.6.26.tar.xz
cd libpng-1.6.26
./configure
make check
make install

You can run ./configure --prefix=/path , path = the path to the directory
where you want to install the binary


Ubuntu Server Installation is Getting Stuck

I eventually got my install to work by removing the RAID card from my server.  I also changed the boot drive to be a plain SATA drive, I was trying motherboard raid 1 for a redundant boot drive, once that was done the install completed.  I was then able to plug the RAID card back in and access the files on the array.


Disk read error. click Ctrl + Alt + Del to restart. Windows 7, Ubuntu dual boot

Your Windows partition was a dyanamic disk,

as described from your earlier pastebin:

  =================== Advice displayed in case of recommended repair

  SFS detected. You may want to retry after converting Windows dynamic >partitioning (SFS partitions) to a basic disk. This can be performed via tools >such as TestDisk or EASEUS-Partition-Master / MiniTool-Partition-Wizard.
  Do you want to continue?

  =================== Default settings

  Recommended-Repair This setting would reinstall the grub2 of sda3 into
  the MBR of sda. Additional repair would be performed:
  unhide-bootmenu-10s

I think the problem was corrected, but to be sure look in windows, in your startbar, type

diskmgmt.msc

to open up disk management
and check whether your disk is listed as dyanamic or basic.

You can take help from this link about it- http://www.sevenforums.com/tutorials/26829-convert-dynamic-disk-basic-disk.html

After your second boot-repair

  Recommended-Repair This setting would reinstall the grub2 of sda3 into
  the MBR of sda. Additional repair would be performed:
  unhide-bootmenu-10s

Grub seems to have been successfully installed.

  Boot successfully repaired.
  You can now reboot your computer.

So check about the Basic Disk/Dyanamic Disk part, and tell us more completely whetever problem you are facing.


Temporarily connect to Internet and run in a terminal

sudo apt update
sudo apt install bcmwl-kernel-source

Disable Secure Boot if you are using UEFI.


Made mistake editing, How can return back?

If you didn't change the preferences for gedit from the default you most likely have the original version still available.

Click on open, select Other Documents at the bottom. In the files window you will find a file with the same name that you used, but a ~ (Tilde) appended to the name. (If you saved veryImportant.txt you will additionally see veryImportant.txt~).

In case you don't see any files with a tilde at the end you must enable the diplay of "hidden files" by pressing CTRLH.

Now open that file and immedialtely save it under another name.


How to install ApkInspector on ubuntu 18.04

You need to clone the repository

cd ~/Downloads
sudo apt install git
git clone https://github.com/honeynet/apkinspector.git
cd apkinspector

and then install all the dependencies from APT:

sudo apt install qt4-default python-sip python-qt4 python-pydot graphviz apktool python-tk python-scipy ipython

then you need to patch it as IPython internals were slightly changed:

sed -i "s/import IPython.ipapi/import IPython/g" androguard/androlyze.py
sed -i "s/from IPython.Shell import IPShellEmbed/#from IPython.Shell import IPShellEmbed/g" androguard/androlyze.py

then launch it and enjoy:

python startQT.py


How do I handle a "No such file or directory" error for a header file from make?

This typically indicates that you haven't installed some dependency of the program you are trying to compile. Depending on the header file in question and the program you are trying to compile, you have a couple of options:

Target software exists in the Ubuntu repositories

Sometimes you want to compile from source a package already provided by Ubuntu (to get a different version, perhaps, or to patch it). If the software hasn't changed too much, you can use apt to get the dependencies:

sudo apt-get build-dep <package-name>

This should install all the packages needed to build the Ubuntu package of that software (which may have fewer or more packages than what your source package actually needs).

If you only need to make some minor change in the source, or apply a patch, you might even be able to save a significant bit of effort by letting apt and dpkg do the legwork:

sudo apt-get build-dep <package-name>
apt-get source <package-name>

This will download the source files of the package, including everything needed to make a package of it. The files will be in a directory named <package-name>-<some-version>. Enter it, make all the changes you want, and then do:

sudo dpkg-buildpackage -b -us -uc

This creates unsigned binary package(s) in the parent directory (cd ..). You can then use dpkg to install these packages:

sudo dpkg -i  <package-name>_<some-version>_<architecture>.deb

Examples:

Changing one build option in a package
Can't edit plugins/sudoers/ins_*.h

Target software is not present in the Ubuntu repositories

You can still try your luck with the specific header file missing. Use either the Ubuntu Packages index (the option to search the contents of packages) or apt-file to search for the file. Sometimes multiple packages may provide similarly named files, in which case, prefer:

Files in /usr/include.
Packages of your architecture (use uname -m to know what your architecture is).
Any specific versions your software depends on (such as Qt4 instead of Qt5) - check the README and INSTALL files in the source (if present).
Packages whose names end in -dev, which typically include headers needed for compiling.

See: How do I find the package that provides a file?


No space left on left on Drive after deleting everything. /dev/sda6 100% used

To increase the size of /dev/sda6 root partition,

Boot Ubuntu live disk and click on try Ubuntu option on startup.Now open gparted partition Editor from dash.And make sure that all the partitions are unmounted.
shrink /dev/sda3 by right-clicking on it and select Resize/Move option.
After shrinking, the unallocated space will be created just below to the /dev/sda3 partition.
Now right-click on the extended partition and select Resize option to add up the unallocated space by extending the dragger.
Unallocated space will comes under extended partition(just below to the /dev/sda5 partition.
Rightclick on the /dev/sda5 partition and select Resize/Move option.Move the dragger to extreme right and then click on Apply,so that the unallocated space comes just below to the /dev/sda5 partition.
Now you can be able to extend your /dev/sda6 root partition.

See also How to extend ext4 with gparted? and Extending my Root Paritition


Intel J1900+Ubuntu 16.04——Occured OS hang-up and freezing

forget any kernel, the problem is the mobo. You only need to change the c state to C1 on the bios.Then you'll never  have any problem with any kernel.


Infinite loop when trying to launch a symbolic-link to a bash script

Resolve symlink before processing the file.
foo.sh
#!/bin/bash

# Mark variable for export.
declare -xi LVL

# Resolve absolute pathname.
filename=$(realpath "$0")

# Strip .sh suffix from file and check for exec bit.
((LVL++ < 1)) && [[ -x "${filename%.sh}" ]] || exit 1

export LD_LIBRARY_PATH="${filename%/*}"

# Run it!
"${filename%.sh}" "$@"

foo
#!/bin/bash
echo "$@"

Now we can  create a symlink:
$ ln -s /path/to/foo.sh bar

Regardless of the symlink's name, it is the file foo that will be executed.


Issue with GPG keys while setting up a proot environment

I have found a workaround for this.
pbuilder-dist  focal amd64 create

The added advantage of this method is that both the distribution and the architecture can be altered.


The menu bar in Ubuntu 14.04 disappeared

Open System Settings, click on "Appearance", click on the "Behavior" tab, then, under "Show the menus for a window", select "In the window's title bar".


How to make LUbuntu connect to Wifi in an identical fashion to Live USB

I didn't find a perfect solution while installed on an undersized USB flash drive - I went back and uninstall / purged wicd, and then re-installed network-manager-gnome, and at that point it started working better than before.  With a larger USB flash drive I would recommend just doing a full install, as then everything works "out of the box".

In general, the solution I ultimately went with was to get a larger SSD instead of using a USB flash drive and do the full install, as USB flash experiences frequent pauses whenever lots of random writes are happening which is an issue SSD does not have.


Bash script: How to execute commands consecutively without waiting for the previous one?

Simply put gedit in the background

#!/bin/bash
gedit &
nautilus


'unmet dependencies' while trying to install python-scipy on Ubuntu 12.10

well I got scipy installed so it's definitely possible. ;-)

I think you have some hiccup in your package system - any problems lately such as crashed or aborted installations? alternatively, it's some dependency problem.

anyway, whenever I encounter this, first I try to install the "unmet dependencies" manually, one after the other, so you can try to install python-numpy, then libgfortran3, then liblapack3, and then try again. a sudo apt-get update before all that can't be wrong, either.


Ubuntu does not show a hard drive partion, cannot open it

Edit: Found a workaround. Open the disks application, click on the partition and press the play button, it immediately gets mounted


New client unable to connect to stand-alone Landscape server

I had copied the servers /etc/ssl/certs/landscape_server_ca.crt locally without renaming it. The solution was to rename it to server.pem

Here is the solution in script form

sudo scp cluster@landscape:/etc/ssl/certs/landscape_server_ca.crt /etc/landscape/server.pem
sudo echo "ssl_public_key = /etc/landscape/server.pem" >> /etc/landscape/client.conf
sudo landscape-config --computer-title "node-0" --account-name standalone  --url https://landscape/message-system --ping-url http://landscape/ping --ssl-public-key /etc/landscape/server.pem

And that did the trick.


I have found a solution, It involved stopping the container I had running with the issue and I created/run a new container with a slightly different config as follows.

 docker run
 --cap-add=NET_ADMIN
 -p 8112:8112
 -p 8118:8118
 -p 58846:58846
 -p 58946:58946
 --name=delugevpn1
 -v /home/docker/deluge/data:/data
 -v /home/docker/deluge/config:/config
 -v /etc/localtime:/etc/localtime:ro
 -e VPN_ENABLED=yes
 -e VPN_USER=xxxxx
 -e VPN_PASS=xxxxxxxx
 -e VPN_PROV=pia
 -e STRICT_PORT_FORWARD=no
 -e ENABLE_PRIVOXY=yes
 -e LAN_NETWORK=192.168.1.0/24
 -e NAME_SERVERS=209.222.18.222,37.235.1.174,1.1.1.1,8.8.8.8,209.222.18.218,37.235.1.177,1.0.0.1,8.8.4.4
 -e DELUGE_DAEMON_LOG_LEVEL=info
 -e DELUGE_WEB_LOG_LEVEL=info
 -e DEBUG=false
 -e UMASK=000
 -e PUID=0
 -e PGID=0
 binhex/arch-delugevpn

This now results in deluge being able to torrent/download again although I still have the tracker status still showing occasionally as "Error: Connection Timed out"


Why USB hardwares are shown wrong in windows 7 32bit installed in virtualbox in the UBUNTU 1110 64bit

There are permissions that need to be put in place for passing USB through VB in Ubuntu 11.10

"Add yourself to the user group vboxusers, then log out and back in, to make use of available USB devices. To do this via the graphical interface, click System Settings/Users and Groups/Manage Groups."

See :https://help.ubuntu.com/community/VirtualBox/USB for more information.


Changing folder permissions to enable PHP to create a file

After looking up the properties.ini file, I found out that my Xampp Apache User was called daemon : apache_user=daemon
apache_group=daemon

Therefore, this :

sudo chown daemon:daemon -R

did the trick !


How to fix gunicorn.service: Failed to load environment files: Is a directory

EnvironmentFile=/home/myname/myapp/env should be a file not as some may expect it to be a folder.
There seems a convention conflict here, between web projects and systemd.


How to move files into /usr/bin in Nautilus without getting permission errors

You can  do it like this:

press Alt+F2 to open the 'Run Application' box
type gksudo nautilus in to the text box and press 'Enter'. This will prompt a password dialog box. Enter your sudo password and it will open nautilus with root privilege. From there you can move/copy files without any permission error.

Note: Just make sure that you don't delete/replace any system files.


Plans to make Android Apps run on Ubuntu abandoned?

The original plans were presented by Debbie Beliveau and Michael Frey. If you want to know what happened to their plans, you'd probably do best to ping them an email. Most Ubuntu developers don't bite and I'm sure they'd be happy to explain.

Actually, I'm curious about this too, so I'll send them both an email now. I'll post back with any response.

There have been rumblings of activity elsewhere since in other distributions but I've never seen anything as positive as the UDS presentation a couple of years ago.

There is a way to run some Android applications inside Ubuntu: you install the Android software development kit and run applications on a virtual device. Far from perfect but perhaps enough for simple needs.


Removing everything from my Ubuntu install, even GUI..?

Install Ubuntu server if you don't want a desktop environment. You can always install Unity later by:

sudo apt-get install ubuntu-desktop

It would run almost similar to Ubuntu Desktop after you install Unity. See this answer here for differences between server and desktop version of Ubuntu.

But this is completely different from what you asked for. For one thing, you can't do anything with just the kernel. What you are asking for is Ubuntu Core. More information here.

If you are comfortable enough with linux and not a beginner, you can try Arch Linux. It is a linux distribution which is an answer to your question, and also it has a very good documentation on how to do what you want.


Adding Ubuntu Studio components to existing Ubuntu Desktop installation

You can add the desired components with

sudo apt install ubuntustudio-photography
sudo apt install ubuntustudio-video
sudo apt install ubuntustudio-graphics

to your Ubuntu desktop.


Arctis 5 Headset, Two Audio Playback devices not visible

Pulseaudio does not detect the second stereo output, and defaults to outputting audio to the chat output device.

I've created a pulseaudio profile which enables the game output as well, put it on my github and even created a deb file so you can install it easily.


Ubuntu 20.04 not pausing processes (high fan spin/battery drain) on sleep mode

I had the same issue with a Ubuntu 20.04 running on a new HP Omen with Ryzen 7 4800H CPU.
To fix it, I upgraded the kernel to 5.6.0-1023-oem:
sudo apt install linux-oem-20.04

Then reboot. No need to upgrade all the way to kernel 5.8 (although that one will work, too, but it is harder to install and won't work with secure boot).
It takes about 25s(!) to go into suspend mode after the lid is closed!


What P.C setup is guaranteed to work with ubuntu?

You can find a list of Ubuntu certified computers at http://www.ubuntu.com/certification/


Where can I find blueprints and a roadmap for multiarch in 12.10?

You can keep yourself updated through

Multiarch-support in Ubuntu Quantal launchpad page , and
Package: multiarch-support at
Packages.ubuntu.com
Blueprints of Multiarch Ubuntu Quantal
Status of Development
Quantal Quetzal Roadmaps


The computer is not a mind reader so it can't automagically know you want to create a new raid array when you plug in two new disks.  You will have to create the new array the same as you had to for the first one.


Desktop theme is damaged after changing Ubuntu theme

I finally found a solution ! If anybody else is having a problem and a reboot won't solve it , i ran: unity
In the terminal. That's the reset command that worked for me.. if not try :unity-reset.
And for nautilus to show the theme again : killall nautilus.

Hope it helps anybody having this problem.


♂ You can create your own whatsapp app
 Creating Your Own Whatsapp Desktop App

 Type terminal sudo -H gedit /usr/share/applications/whatsapp-webapp.desktop
 Copy following text to opened screen
☢ İf you using chromium you need to change /opt/google/chrome/google-chrome with your chromium path (thanks @ascendants)

#!/usr/bin/env xdg-open
[Desktop Entry]
Name=WhatsApp
GenericName=WhatsApp
Comment=WhatsApp desktop webapp
#Exec=webapp-container --store-session-cookies --webappUrlPatterns=https?://*.whatsapp.com/* --user-agent-string='Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.83 Safari/537.36 Edg/85.0.564.44' https://web.whatsapp.com %u
Exec=/opt/google/chrome/google-chrome --app=https://web.whatsapp.com/
Terminal=false
Type=Application
StartupNotify=true
MimeType=text/plain;
# If you want icon, type path of icon
# Icon=
Categories=Network;Application;
Keywords=WhatsApp;webapp;
X-Ubuntu-Gettext-Domain=WhatsApp
StartupWMClass=web.whatsapp.com

 If anyone see 'update your browser' warning, you have to update --user-agent-string on line 6 respect to User Agent String (thanks Gangadhar Jannu)

⌨ Making keyboard shortcut (Optionally)
You can follow the instructions below or just look my other answer about Making Shortcuts topic.

wmctrl command used for focus or create app, type sudo apt install wmctrl to install it

➕ Open shortcut window, click + the bottom of the window
 Set name Whatsapp Chrome
 Finally, keyboard shortcuts to open | create

bash -c "wmctrl -xa web.whatsapp.com || /opt/google/chrome/google-chrome --app=https://web.whatsapp.com/"


Dávid Bartal, I have had the same problem.

Since I installed a package named "python2-lxml", things work normally.

Tip: Inkscape uses python 2.x instead of python 3.x, so install python2 compatible modules. For example install python2-lxml instead of python-lxml.

Good luck!


You can run it through it through the Android emulator

Create and start Android image

Download the Android SDK: https://developer.android.com/sdk/ (Select the Linux
32 & 64-bit entry below SDK Tools Only)
Start the Android SDK Manager (tools/android in the downloaded archive)
Wait for to download the list of available Android tools
Click Install # packages... in the bottom left corner
In the Menu select: Tools -> Manage AVDs
On the left side select: New...
Enter a name next to AVD Name
Select a Device (Nexus 4 is fine)
Select the first entry next to Target
Select CPU/ABI type ARM (armeabi-v7a)
Enter at least 200 MiB as SD Card size
Make sure you check Use Host GPU next to Emulation Options
Click OK
Select your new Android image and click Start... on the left-hand side

Locate game APK

In a search engine of your choice search for Temple Run Android APK
Select the first non-Google result
Make sure you can download a file of type Android Package for there
Copy the URL of the page

Download and install game

In the emulator Android should be running now
Select the Settings application (just like on the phone)
Scroll down until you find Security and click on it
Check Unknown Sources and click OK in the warning dialog
Press the Home Button on the left-hand side of the emulator
Select the Browser application
Paste the URL from the last step
Download the file you have previously found on the website
Click on the top panel and pull it across the screen
Wait for the download to complete then tap on the entry that says Download complete
In the installation screen press Next on the bottom right of the screen
The text of the button will change to Install so click it again
Wait for the installation to complete
Click on the Open button on the bottom right of the screen

You should now have Temple Run running in your Android emulator


Probably the grub points to wrong partition or else your Windows boot files are corrupt / do not exist.

sudo os-prober

This will show list of another bootable OS installed in the system.

sudo update-grub

This will update the grub and correct the wrong entries.


Safe method to install Ubuntu on MBR disk with 4 primary partitions

Those partition you have mentioned are created by windows 8.1, don't delete anything. You actual partition is sda4 (499.6GB) where windows is already installed.

For dual boot, try following the method shown here.


In the /etc/mysql/my.conf file (prior to 16.04) or /etc/mysql/conf.d/mysql.cnf (from 16.04 on), look for the line bind-address.  By default it will be set to bind-address = 127.0.0.1.   Just put that line in comment (add a # in front of the line).


Why does my wireless work during install but not after booting?

Per the suggestion from @rubo77 in the comments, I'll leave my update as an answer.

Reinstalling Ubuntu from the Live USB and choosing to install third party software but not download updates while installing allowed me to access wireless after the install was complete. sudo apt-get update and sudo apt-get upgrade performed as expected, but sudo apt-get dist-upgrade caused bcmwl-kernel-source to crash. It appears upgrading the kernel causes the driver to crash.

I'll mention that my solution was to hold upgrades on the kernel version until Ubuntu 18 was released. I've had no issues since upgrading to Ubuntu 18.


I had the same thing, I had to force shutdown the computer and restart.  I was then able to choose Unity 7 and log in.


When adding a Magnet link in Deluge how can I choose which files in the torrent to download?

This is a limitation of magnet uris vs torrent files. Magnet uris only contain the torrent's infohash and optional the tracker and torrent name, whereas a torrent file will also contain the metadata about the torrent's files. The only way to retrieve the torrent's metadata when using magnets is by connecting and downloading from a peer, which takes time.

In future workarounds for this may well be implemented but currently you will have to add the magnet, wait for the metadata from peers, then choose the files you wish to download.


Ubuntu ("Activation of network connection failed" popup) Problem

Use this command:

sudo apt-get install --reinstall network-manager


How do I set system wide proxy in Ubuntu 18.04?

Set proxy details in Environment variables;
Edit /etc/environment and add following lines (replace username, password, host and port with your proxy details).

http_proxy=http://username:password@host:port/
ftp_proxy=ftp://username:password@host:port/
https_proxy=https://username:password@host:port/

For apt,software center & etc;
edit /etc/apt/apt.conf.d/80proxy (if its not exist create it) and add the following lines

Acquire::http::proxy "http://username:password@host:port/";
Acquire::ftp::proxy "ftp://username:password@host:port/";
Acquire::https::proxy "https://username:password@host:port/";


Wifi Issues on 18.04 (Kernel 4.18.0-15-generic)

On our Ryzen mobo, we don’t have WIFI network under Kernel 4.19.x or Ubuntu 19.04 if Secure Boot is enabled. On custom kernel (unsigned), we must tweak Secure Boot on startup to keep it enabled: Booting in insecure mode.

Since last Grub updates: V1.93.13 & V 8.12

sudo mokutil  --disable-validation

Try disabling Secure Boot in BIOS to see if the device works or scans better. You may also go for the latest stable Kernel (4.20.10) or the latest long-term one (4.19.23). See if you get a better response.

Since Kernel 4.20.3, the WIFi network rarely fails and on Kernel 5.0 it works normally.  Is connectivity enabled in Settings?

Check for the latest there:
https://www.kernel.org/
Get the PPA there:
https://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D

~$ mokutil  --sb-state
SecureBoot enabled

dpkg --list | grep linux-image
ii  linux-image-unsigned-4.20.10-042010-generic  4.20.10-042010.201902150516                           amd64        Linux kernel image for version 4.20.10 on 64 bit x86 SMP
ii  linux-image-unsigned-5.0.0-050000rc7-generic 5.0.0-050000rc7.201902180332                          amd64        Linux kernel image for version 5.0.0 on 64 bit x86 SMP

Network Card

lspci -k | more
…
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 P
CI Express Gigabit Ethernet Controller (rev 10)
Subsystem: Lenovo RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
Kernel driver in use: r8169
Kernel modules: r8169
04:00.0 Network controller: Realtek Semiconductor Co., Ltd. Device b822
Subsystem: Lenovo Device b024
Kernel driver in use: r8822be

To increase speed we are using Adguard DNS (Russian) or Cloudflare DNS. They both have good response.

curl -I http://www.cloudflare.com
HTTP/1.1 301 Moved Permanently
Date: Wed, 20 Feb 2019 00:34:45 GMT
Connection: keep-alive
Cache-Control: max-age=3600
Expires: Wed, 20 Feb 2019 01:34:45 GMT
Location: https://www.cloudflare.com/
Set-Cookie: __cflb=1594113181; Secure; path=/; expires=Wed, 20-Feb-19 23:34:45 GMT; HttpOnly
Set-Cookie: __cf_bm=1e273dcaf653df47ecda89c7783c39cb49c06bad-1550622885-1800-AX7B/ztdd9BR3pmoG+i7Jia3vSqRZ6i8POb6MKW/xcYbvmP3jp51S28spPj/HgDgea1Nqd0qKWSjPILRs9RsArc=; path=/; expires=Wed, 20-Feb-19 01:04:45 GMT; domain=.cloudflare.com; HttpOnly
Server: cloudflare
CF-RAY: 4abce3 …

https://adguard.com/en/adguard-dns/overview.html#instruction

https://cloudflare-dns.com/


12.04-my default python version changed to 2.5

The way you installed python, it will have been installed in /usr/local.

If you want to get rid of the old python:

sudo rm /usr/local/bin/python*
sudo rm /usr/local/lib/python2.5

If you just want it as non-default: make sure /usr/local/bin comes after /usr/bin in your $PATH


The official Dell QuickSet application is a Windows-only application.
Unfortunately there is no Ubuntu alternative.


How to search for specific lines in Linux?

Let's create a test file;

$ seq 100 >file

Now, let's display line 52:

$ sed -n 52p file
52

Or:

$ awk 'NR==52' file
52

Or, if you have the file open in vim, you can type 52G to jump to line 52.

Using nano

Suppose that your file is called file.txt.  To edit the file in nano with line, column, and character count displayed, run

nano -c file.txt

This is what nano looks like with the cursor on line 7 of a 21-line file:


Sorting Pictures by name-column "record date" with nautilus

I did not found a way in nautilus but i found a program called "gThumb" it is a very fast and usefull picture viewer.
With this tool you can view the pictures as a kind of explorer and so you don't have to import something.
To sort pictures you can go to "View" -> "Sort by" -> "sort by record-date" (I just translated in english from my language so there are maybe different words in original)

Hope I could anyone help with this.


Mount /tmp and /home to separate hard drive

To have /tmp and /home on the same partition as each other but a different partition from /, you'll need to do this:

Make tmp and home the two top-level directories on the partition you want to contain them. So if right now that partition is itself /tmp, you'll need to move its entire contents to a tmp directory in its root.

Give the partition that contains tmp and home its own mount point. A reasonable name for this is tmp+home (unless you plan to use that partition for other stuff too) and reasonable locations for it are /, /mnt, and /media. I recommend putting it directly in / and the rest of this answer assumes that's where it is.

Give /tmp+home its own entry in /etc/fstab. (You will see /tmp has its own entry.)

Make /tmp and /home symbolic links to /tmp+home/tmp and /tmp+home/home.

Please note that this will not involve using these instructions for creating a separate /home partition, because in this configuration, /home will be a symbolic link into a separate partition, rather than a mount point for a separate partition.
Furthermore, you'll have to unconfigure your separate /tmp directory (including removing or, better, commenting out its entry in /etc/fstab), since /tmp will no longer be a mount point for a separate partition, but will instead be a symbolic link into a separate partition.
This answer doesn't provide extremely specific instructions (though it should be sufficient, combined with the available documentation). If someone who has experience moving /tmp can weigh in on whether or not it's possible/safe to move /tmp while in the installed system, that would be helpful. I can give detailed instructions for doing this from the installed system or from a live CD, but I don't want to give directions that are ineffective or unsafe (nor directions that are unnecessarily difficult and time-consuming).


Maybe it is related to sleep.
I tried this in /etc/modprobe.d/alsa-base.conf:
options snd-hda-intel position_fix=2

Also sudo alsa force-unload together with killall pulseaudio (in a loop) until I finally unloaded all modules, and then reload via sudo modprobe snd-hda-intel.
Now it temporarily seems to work again.

After another restart, I had the problem again. Again, I did this loop:
$ while true; killall pulseaudio; sudo alsa force-unload; end

and after that succeeded after some iterations, I did:
sudo modprobe snd-hda-intel

That again fixed the problem.
I'm not sure if that position_fix=2 is really relevant. But then I also don't really know what the real problem is.


Community Supported Virtual HDD Ubuntu Configured for VirtualBox?

You could also try vagrant. This is a super easy way to create and work with VM's and Ubuntu releases images that are scrutinized and used by thousands of developers.

Using vagrant is super easy.

Install vagrant
apt-get install vagrant
Add a box of the distro you want
vagrant box add trusty/amd64
Start the VM
vagrant up

UPDATE:

For a simple example check out this project on github. https://github.com/levlaz/braindump

The Vagrantfile installs the VM, syncs folders, forwards ports, and runs a bootstrap.sh script that installs some additional packages in Ubuntu.
The bootstrap.sh is a simple bash script that installs some packgages, and performs various configurations.


Connect Raspberry Pi to Ubuntu Laptop with Damaged ETHERNET PORT

Connect the Pi directly to the router with ethernet cable and get the IP address from the connected device list. Now connect your laptop to the same network via WiFi and use SSH/VNC/RDP to access the Pi.

If you don't have access to the router, connect both devices to the same wifi network and use SSH/VNC/RDP to access the Raspberry Pi.

I don't know if Pi supports Ethernet over HDMI.


How to make chrome use less system memory in ubuntu

Try to install extension "The Great Suspender" in chrome. It suspends automaticaly unused tabs. Maybe it will conserve some RAM for you.


How to recover a HDD with first 4MB deleted?

TestDisk did a wonderful job recovering 12.5k files with only 50 files lost. I used these instructions.

Then I donated to TestDisk, and so should you if it helped you ;-)


Strange partition persists after reinstall

I would try doing sudo umount /media/alex/DBAN. It sounds as if the install media had mounted itself, and had not unmounted after reboot. iso9660 refers to an optical disk's file systems, which in most cases is the installation media.

Also, try checking out your partitions in gparted. That may be able to give some more insight to why it's appearing in the first place.


Not able to setup Tomboy Web for Ubuntu One

The actual problem is with Firefox and not with Tomboy Notes.

As explained in this post, Firefox uses the Exec entry in the .desktop file to figure out which command to use to open links from external applications.

For our problem to be solved we just need to change this Exec entry to firefox %u.


Trouble when opening laptop lid. Only black screen is displayed. Ubuntu 14.04?

This can be a temp. fix by trying to avoid suspending. Do the following: Go to Dash then System Setting, power and the choose When lid is closed do nothing.


Gwenview Doesn't Have Option to Not Show Videos?

The option is still there and in the same place as it is in 18.04: Settings > Configure Gwenview > General.

To deal with "But there isn't a menu bar", pressing Ctrl+M will toggle the menu bar on or off in Gwenview.

Tip:

Ctrl+M does something similar in Dolphin. It toggles the menu bar and the Control icon (☰) which offers the same options but in a vertical format.

To toggle the menu's visibility in Konsole, use Ctrl+Shift+M.


How long should it take to create a bootable USB drive?

UNetbootin is an application in the Ubuntu Software Center that does the same thing as Universal USB Installer if you want to try it using a different app. There is also a version of UNetbootin for Windows. I have also seen UNetbootin stall at 99% more than once for about 2-3 minutes, but it didn't give any error message and it always finished after that.

Should this be a 5-10 minute job or is this something that takes hours to do?

Yes, it should be a 5-10 minute job from start to finish, including the wait at the end.
UNetbootin has been dropped from the Ubuntu 18.04 repositories. When I tested the built-in Startup Disk Creator application in Ubuntu 18.04 as a UNetbootin replacement app with 5 different non-*buntu live .iso images it worked every time.


Run apt-get update before running apt-get install.


Why is there an uninstallable wifi driver where my video driver should be?

Please consult ubuntu-drivers --help. The utility, using the command 'devices', lists devices that it thinks need drivers, not devices that have drivers installed. In your case, it believes, mistakenly, that your wireless device needs backports-iwlwifi-dkms. It obviously doesn't; as you said, your wireless is working fine.

backports-iwlwifi-dkms is available, not installed. That's why you can't remove it; it isn't installed. Both this and the graphical version, Additional Drivers, report the same thing. It is a bug. My laptop also runs an Intel wireless device and I have the same result. I won't take a chance and install backports because, first of all, there is nothing wrong that I need to fix, and second of all, we have seen this several times before and know it's a bug.

I suggest that you look for and add to a bug report here: https://bugs.launchpad.net/

In the case of your graphics card, the utility correctly reports that no additional driver is needed because it's apparently already installed:

Kernel driver in use: nvidia

You can verify the version that's installed with:

dpkg -l *nvidia* | grep ii


Cannot install NVIDIA nForece 630a / GeForce 7025 drivers for ubuntu 19.10

I installed nvidia drivers for such GPU by executing NVIDIA-Linux-x86_64-304.135.run


Is it possible to prevent user from open/save file dialog in Ubuntu 12.04 LTS

The simplest way to do this is to use permissions. The permissions for files and directories on Linux and similar systems have 3 basic levels, the permissions of the file's owner, their group and everyone else.

For example, on my system, I create a new user called foo:

sudo adduser foo

This newly created user belongs to the group foo only (sudo -u foo lets me run commands as the user foo, in this case, groups which lists the groups that a user belongs to):

$ sudo -u foo groups
foo

So, let's create a file:

sudo -u foo touch /tmp/file

And have a look at its permissions:

$ ls -l /tmp/file
-rw-r--r-- 1 foo foo 0 Apr  2 17:49 /tmp/file
---------    --- --- =================================> The file's group
 |  |  |      |=======================================> The file's owner
 |  |  ------> Others (everyone else): read only
 |  |--------> Group permissions: read only
 |-----------> Owner permissions: read/write

So, as you can see in the example above, a file has 3 levels of permissions. Since that was created as the user foo, my regular user terdon cannot write to it:

$ echo "hello" > /tmp/file
bash: /tmp/file: Permission denied

In order to list the contents of a directory a user needs read permissions and in order to move into it, they need execute permission. Therefore, to hide the contents of a directory, simply remove the read and execute rights. Taking /media as an example:

$ ls -dl /media
drwxr-xr-x 9 root root 4096 Mar 25 20:15 /media

As you can see above, the owner, the group, and everyone else all have execute rights to the directory (that's what the x means). What we want to do is make it so that only the owner and group members have access to it, so we will need to remove the read and execute rights from the "other" field:

$ sudo chmod o-rx /media
$ ls -dl /media
drwxr-x--- 9 root root 4096 Mar 25 20:15 /media

As you can see above, /media now has no execute right in the "others" field which means that only members of the group root and the user root themselves can access it.

What all this means, is that you can create users and fine tune them to have access to only specific files. However, be very careful with permissions, changing the permissions of system folders is very dangerous and should not be done. Instead, if you have specific directories you want to hide, just change their permissions and leave the system directories alone. So, in your case, if you have the backend files in /backendan d your mapped network drive somewhere in/media`, just run this command to block read access to these directories:

sudo chmod o-rx /media /foo/

For more info on how permissions can be set, see man chmod or any of the many tutorials you can find online, this one for example.


For me, the problem was solved after updating to kernel 4.18 with ukuu
Ukuu is a program that allows the easy installation and removal of newer or older kernel versions in a graphical way It is easy to use and install: makeuseof.com/tag/upgrade-kernel-ukuu-ubuntu. Of course , you can use command line or download the kernel and install I didn't have any problem with the new kernel but in case you face  problems, you can uninstall it by booting from the old one, using the grub menu
Hope it helps


How do install Ubuntu on VMware Player and have it visible and usable by all users?

This is a Ms-Windows related question.

1) You must create the virtual machine and install it Ubuntu
2) the "VM files" must be in a shared folder for every Windows user
3) you can make the vmdk file to launch de VMWare player, so any user can start it

Are you really sure if WUBI isnt your best option?? you can have a better performance


Managed to install using

https://stackoverflow.com/questions/51731062/php7-1-zip-installation-under-ubuntu-18-04

and hence manually installing libzip4 from here

https://packages.ubuntu.com/xenial/libzip4

However, the schema browser doesn't seem to work.


Managing remote server connections via Nautilus

You could create a Desktop Shortcut File and place them on $HOME/.local/share/applications/ your keyring will still manage the passwords so no plain text passwords.

Bellow is the file content. Name it what_ever_you_like.desktop and add execution permission, place it in the above path for easy menu access. For SSH terminal aliases are probably better.

#!/usr/bin/env xdg-open

[Desktop Entry]
Version=1.0
Type=Application
Terminal=false
StartupNotify=true
Exec=nautilus ftp://ftp.mysite.com/public_html
Path=
Name=A meaningful name
Comment=FTP site Access
Icon=folder-remote

PS: About the 'Nautilus bug' I don't believe it's bug just an unconsidered Use Case.


Why do we need to update applications on our computer even when they work fine?

There may be problems that are not apparent to you, or new features that are being added.

For example, web browsers are often updated with security patches and new features. More specifically, the most recent update of Chrome (google-chrome-stable), had a large number of security fixes. A prior update had an overhaul of the appearance (which I would consider a new feature).


updates not updating due to installation of untrusted packages in 12.04?

Try running

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

It will try and update the sources packages to check for available updates that can be updated in your system.

Untrusted packages errors mostly arise due to missing keys , if that is the case then note the missing keys combination of Numbers and Letters and do

sudo apt-key adv --recv-key --keyserver keyserver.ubuntu.com XXXXXXXXX

Where XXXXXXXXX is the key from the error you get.

Another reason would be the Mirrors not properly synced , running the Update command mostly solves them.


How do i run a shell script, in a shell script with the menu dialog?

Introduction

The following set of files work for me, when all of them are in an own directory. You may want to make your menu system more general.

menu

#!/bin/bash

# this simplified version works with files in its own directory

i=0 # define counting variable
wa=() # define working array

while read -r line; do # process file by file
    let i=$i+1
    wa+=($i "$line")
done < scripts

result=$(dialog --title "List of scripts" --menu "Choose a script from the list" 24 80 17 "${wa[@]}" \
 3>&2 2>&1 1>&3)      # show dialog menu

#clear

if [ "$result" == "" ]
then
 echo "Quit"
else
 item=$(($result*2-1))
 #  test output (to be removed later on)
 echo "$item"
 echo "${wa[$item]}"
 read -p "Press Enter to continue or ctrl C to quit"
 # end of test output
 "${wa[$item]}"       # execute selected item
fi

scripts

./test0
./test1

test0

#!/bin/bash

echo $0 start
echo $0 end

test1

#!/bin/bash

echo $0 start
echo $0 end


You might find this video useful: Creating Your First Ubuntu App. Enjoy!