Dual-monitor screen rotation not retained on restart (nvidia-settings)

In your case, with your monitors named DVI-I-1 and DP-4 a temporary solution would be to set the following command as a startup application:
xrandr --output DP-4 --rotate right --pos 1920x0 --output DVI-I-1 --pos 0x840
However i do not find this solution satisfying as this should be handled by Ubuntu and/or Nvidia drivers so that the configuration is instantaneously right at startup rather than waiting for this command to run.
For those who have the same issue, with two monitors having the same resolution Hres x Vres, the left monitor horizontal and the right vertical:

Find your monitor names with:
xrandr | grep " connected"

Now let's assume they are called Mon1 and Mon2 (replace with your own names in the subsequent commands).

Calculate the vertical position Vpos defined as the distance between the top of your horizontal monitor to the top of your vertical monitor. You can see below this is defined this way because the origin is at the top left. If you only know the vertical shift Vshift from the bottom, you can easily compute Vpos as:
Vpos = Vres - Hres - Vshift

       0                        Hres           Hres + Vres
    0                            -------------------
                                 |                 |
                                 |                 |
                                 |                 |
                                 |     Mon2        |
  Vpos    -----------------------|                 |
          |                      |  Vres x Hres    |
          |                      |                 |
          |         Mon1         |                 |
          |                      |                 |
          |     Hres x Vres      |                 |
          |                      |                 |
Vpos+Hres -----------------------|                 |
                     ^           |                 |
             Vshift  |           |                 |
  Vres               v           -------------------

Create a startup application (search for "startup" in Ubuntu search) with the command below (replace mon1 and mon2 with your monitor names, Hres with your monitor horizontal resolution, and Vpos with the number as you computed from step 2):
xrandr --output mon2 --rotate right --pos Hresx0 --output mon1 --pos 0xVpos

You should be able to easily generalize to monitors with different resolutions or with different alignments.


My Ubuntu 18.04 LTS Laggy After Reach 90% of RAM and Never Run Faster Again Except Reboot It

I am having a very similar issue, and I've just tried this out, and it seems to be working so far. Computer freezing on almost full RAM, possibly disk cache problem

The answer to the question essentially has you change your swappiness, but it also has you change min_free_kbytes. While I did the same thing in the answer (setting that value to about 6% of my RAM divided by my core count), given you said your computer starts to slow, even at around 90%, I'd recommend setting that value to around 10% of your RAM, divided by your core count.

I had System Monitor open the whole time, and opened a few applications, and it got pretty close to 94%, but never exceeded more than 93%, so I can confirm this works. (For me at least.)


How to query maximum display resolution from command line?

The command xrandr, along with some global options, is used to set the size, orientation and/or reflection of the outputs for a screen. It can also set the screen size.   Entering

xrandr

will display the allowed resolutions, ie

Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096
VGA1 connected 800×600+0+0 (normal left inverted right x axis y axis) 267mm x 200mm
800×600 85.1* +
640×480 75.0 60.0
720×400 70.1


Check permissions of ib*.

If you manually edit the directories for a database that uses InnoDB tables you need to make sure that the ib* files in the root of the MySQL datadir have correct permissions.

Owner and group needs to be mysql.
permissions need to be 644 for the ib* files.

If that does not work: do a mysqldump -u {user} {database} > db.sql of your database and reload the database from command line (mysql -u {user} < db.sql).

In case you have foreign key violations these 2 commands will fix those (and repair the tables):

SET FOREIGN_KEY_CHECKS=0;
SET FOREIGN_KEY_CHECKS=1;


If you're only interested in some lenses, try to How to disable lenses in the Dash

The for-loop in the next section can also be used to re-create the entire database if you've done a bunch or archiving... (E.G. if you've moved a bunch of music or pictures to DVD, USB hard drive, ...)
If you're not interested in any lenses and only in your programs, you might disable zeitgeist altogether!  (This is how I run)

The following line disables the zeitgeist datahub system-wide:

sudo mv /etc/xdg/autostart/zeitgeist-datahub.desktop /etc/xdg/autostart/zeitgeist-datahub.desktop-inactive

Now reboot

This line is just to activate sudo for the next couple of minutes:

sudo ls /home

The following lines are to remove the zeitgeist cache for all users

for szUser in /home/* ; do
  if [ -d "$szUser/.local/share/zeitgeist" ] ; then
    echo Removing $szUser/.local/share/zeitgeist
    sudo rm -rf $szUser/.local/share/zeitgeist
  fi
done

To enable again:

for szUser in /home/* ; do
  mkdir $szUser/.local/share/zeitgeist
done
sudo mv /etc/xdg/autostart/zeitgeist-datahub.desktop-inactive /etc/xdg/autostart/zeitgeist-datahub.desktop


Panasonic Toughbook 55 (FZ-55) No speaker sound on Ubuntu 19.10

I fixed something similar on a semi-rugged Panasonic CF-SX2 by using hdajackretask.

I think your options are:

Wait until fixes arrive by updates.
Wait until someone posts a tested solution somewhere on the internet for your model.
Meddle around with hdajackretask and hope for the best.

When trying out random changes it is very important to write down the initial state of settings for yourself so you can avoid breaking everything further. Still there are probably risks of permanently damaging your hardware.

You have to experiment for yourself what you need overridden for your model. I don't remember the details, but I think you at least need to restart the music app to test changes. Hopefully restarting the whole pc was not required. After finding a change that makes speakers work, I recommend also testing the built-in microphone, sound-out port (headphones) and sound-in port (external microphone) since your changes might have broken those. One way to test microphone for me was using the barely visible audiometer on user portrait at this open-source browser based conference call solution.

CF-SX2 initial state

Without "Show unconnected pins" (without override ticked):

Internal Mic, Pin ID: 0x12; Internal mic
Internal Speaker; Pin ID: 0x14; Internal Speaker
Black Headphone, Front side; Pin ID 0x15; Headphone
Black Mic, Front Side; Pin ID 0x18; Microphone

With "Show unconnected pins" (the ones with override are):

nothing

CF-SX2 solution

Needed to override the following pins in the following ways:

0x17=internal speaker
0x1a=internal speaker
0x1b=internal speaker

Here someone fixed their Panasonic CF-52 Toughbook speaker on Linux Mint by overriding a pin with hdajackretask (0x13=internal speaker).

If you comment your working pin (and maybe initial state as well) then I can alter this answer to be more useful for future readers.


WiFi and Bluetooth will not work on Dell Studio XPS 1645

Please hook up the ethernet temporarily and do:

    sudo apt-get remove --purge bcmwl-kernel-source
    sudo apt-get install firmware-b43-lpphy-installer

Reboot and let us have your report.


command to show list all users and date the logged in

who is the command you want, see man who

$ who -uH
NAME     LINE         TIME             IDLE          PID COMMENT
walt     tty7         2019-08-01 23:39  old         3561 (:0)

If you want older logs, see /var/log/auth.log*. It has more data than just logins, so start with something like:

zgrep login /var/log/auth.log*


How to download source code of package_name into specified directory ？

I am not aware of anyway to specify where it downloads the source to, but I know you could run it as one line to force it to download to a folder of your choice.

If you run your command this way:

cd /tmp && apt-get source pure-ftpd

It will change the present working directory to /tmp then download the source code into the /tmp folder for you.

Or, you could do the line this way with the ability to return to the directory you were just in:

cd /tmp && apt-get source pure-ftpd && cd $OLDPWD

The best is the add this line as a permanent function to ~/.bashrc

apt-get-source(){ cd $2 && apt-get source $1 && cd $OLDPWD; }

Then use it as:

apt-get-source pure-ftpd /tmp

Hope this helps!


How to recursively un-gzip all my files?

Both gzip and gunzip support use of the -r option for recursive operation.

gunzip -r /directory/

Should change all of your files back to their previous format.


If you don't mind using non-free software, apt-getting the flashplugin-nonfree package solved this problem for me:

sudo apt-get install flashplugin-nonfree

Maybe something weird with the flash plugin that ships with Ubuntu?


How to decrease metadata disk usage of journald logs?

First, what you see reported as "on disk" may not be on disk at all. As clarified in a recent bug fix, the new language says "in the file system", which may be in an in-memory file system or disk-backed. By default in Ubuntu 16.04, it's memory-backed, but there's a bug report to make the systemd journal persistent by default in Ubuntu.

Now how to reduce the space. If you're not sure to where to start to find documentation on journald, man -k journald is helpful to see if you have related documentation installed about it already:

$ man -k journald
journald.conf (5)    - Journal service configuration files
journald.conf.d (5)  - Journal service configuration files
systemd-journald (8) - Journal service
systemd-journald-audit.socket (8) - Journal service
systemd-journald-dev-log.socket (8) - Journal service
systemd-journald.service (8) - Journal service
systemd-journald.socket (8) - Journal service

Since you seem to be looking to tune the configuration, man journald.conf is a good place to check. There you'll find docs for several options related to disk space, which you can read the details about there. Here's a summary:

Compress=, enabled by default, compresses the data
SystemMaxUse= and RuntimeMaxUse= control how much disk space the journal may use up at most.
MaxRetentionSec=  The maximum time to store journal entries.

See the mentioned man page for the full docs then edit /etc/systemd/journald.conf.

Finally systemctl daemon-reload && systemctl reload systemd-journald to make your changes take effect.


How can I change the "Memory & threads" limit in ImageJ?

Using Fiji it is possible to change the setting in Edit > Options > Memory&threads.

need to close and re-launch to make the modification effective.


Open Nautilus, the default file manager for Ubuntu (I assume that you are using that since you are fairly new to AskUbuntu)

By default "Move To Trash" option provided in nautilus (by right clicking on file) as follows:

Go to the menus at the top and click Edit->Preferences

In the window that appears, choose the Behavior tab, then click the button to include a Delete Command as shown in the image below.

Following that you should be able to delete a file directly from the  File Manager:

Now you can see "Delete" option (after right-clicking) as follows:

However you can delete files/directories by Delete and Shift+Delete.

In case you don't have write permission for a file or directory Move to Trash or Delete will not work and will be greyed out. This usually is the case for all files outside of your home directory /home/<username>.

Only if you are in desperate need to delete such files from the graphical file manager it is possible to run nautilus as root by sudo -i nautilus but this is not recommended. With a wrong command or accidental mouse move you risk to damage your whole system to a state where it can not even boot.

  Please make yourself familiar with the Ubuntu concept of sudo, the Debian File System Hierarchy, and most importantly permissions before you do anything as root with Nautilus.


For Linksys WUSB6300 do this:

Make sure USB wireless device not inserted

Update the system:
$ sudo apt update
Install required packages:
$ sudo apt install git && build-essential
Download the driver:
$ sudo git clone https://github.com/gnab/rtl8812au
Go to the directory:
$ cd rtl8812au
Do the next commands consecutively:
$ sudo make clean
$ sudo make
$ sudo make uninstall
$ sudo make install

Reboot and insert USB wireless stick

-Persists reboots
-Works with dlink dwa-182 and linksys WUSB6300


How can I duplicate a file x times in a different directory with terminal?

Just prepend the directory name before the filename(s):

i=0; while ((i++ < 100)); do cp index /destination/directory/"index$i"; done

Replace /destination/directory with the actual directory name.


Xubuntu task switcher in Zesty lost its ability to go backwards with ALT-SHIFT-TAB?

I have a similar problem in Ubuntu 17.10. The usual AltTab (switching left to right) works fine but not when trying to switch between windows (right to left) using AltShiftTab nothing happens.
Then I noticed SuperShiftTab does work.

So my guess is the best way to avoid that annoyance is to go for Super instead of Alt or, even better, change the key binding in your keyboard settings.


Installing Ubuntu 14.04.3 from USB - low-graphics

I am in the same situation. I have Asrock Z87 ITX motherboard, Intel 4690S processor and Asus GTX750Ti.

My system already had Ubuntu 14.04 on a small SSD and Windows 10 on a big HDD. I installed bigger mSATA SSD 512GB and wanted to use this chance to make a fresh Ubuntu installation after 18 months of 14.04 LTS updates and after my Hardware enablement update went wrong.

My solution was to take the graphics card out (it is not integrated, like it might be in a laptop). I am using UEFI BIOS without secure boot.

All attempts to use "nomodeset" or "acpi=off" or "nolapic" were not successful (any combination of previous options always ended with a "low-graphic mode error").

Without nVidia graphic card in the system, Ubuntu 14.04 installation was a breeze. Shutdown, put nVidia graphics card back into the system and reconnect the monitor cable. The only issue is what to do after a reboot.

One option is to use "nomodeset". When the system boots, and shows grub menu (use shift key if it does not), select 'e' in order to open edit mode and add "nomodeset". Start Ubuntu, login into the new installation and set the option permanently in /etc/default/grub file. Add "nomodeset" like in this line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset"

After modifying the file, run "sudo update-grub" in order to apply the change.

This solution worked for me. I am not getting "low-graphics error" anymore.


Error in creating java project using netbeans 8.1

Test edit the "netbeans.conf" file located in the "etc" directory where you installed Netbeans and change the parameter "netbeans_jdkhome".

Previous: netbeans_jdkhome="/usr"
Now: netbeans_jdkhome="/usr/lib/jvm/java-8-oracle"

Pointing to the address where java is installed, the address shown is for version 15.10 of Ubuntu. You may have a different directory name where java jvm is installed... for example, java-8-openjdk-amd64 or java-8-oracle

If it not works not reinstalls Netbeans but in box asking the path for java, usually "/usr" change where Java is installed "/usr/lib/jvm/java-8-oracle".


How can I force Déjà-Dup to backup only changed and new files?

As far as I recall, Déjà-Dup will only do incremental updates. Therefore what you are asking for, is exactly what it does already. I'd guess that syncing and comparing just takes a long time. If you want to restore a file via Déjà-Dup from UbuntuOne for example, it will take ages.


Upgrading Ubuntu after official support period has ended

Make sure that the Update Manager notifies you for any new version and not just for LTS versions.

You can do this by going to the settings (found at the bottom of the page) and in the "Notify me of a new Ubuntu Version" choose "For Any New Version"


ssh -X "Xt error: Can't open display: :0.0"

If ssh is able to establish the connection, it will set DISPLAY to the proper value. Since you have X11DisplayOffset set to 10 (the default value), ssh will use the first available display starting at 10. If you see a value that's lower than 10¹, then something is interfering with the normal X11 forwarding set up by ssh, at least by overriding DISPLAY. The value :0 (or :0.0, the part after the dot is irrelevant) indicates the first display that was started on the machine, which in typical cases is the active session (or the graphical login prompt) on the machine's console.

The most likely explanation for the behavior you observe is that one of your shell configuration files sets DISPLAY. The most obvious culprit is ~/.bashrc (which due to a quirk of bash is executed whenever the parent of bash is rshd or sshd, even if the shell is not interactive). Another file that defines environment variables is /etc/environment. If that's the case, the solution is obvious: don't set DISPLAY there. (There are very few cases where you need to set DISPLAY manually.)

There are other exotic explanations. This might happen if you've changed your login shell to screen (a cute idea in theory, but not practical) and you have a shell initialization file that forcibly sets DISPLAY inside screen (not such a good idea). This could also happen if you configured the server to accept environment variables sent by the client (AcceptEnv directive in sshd_config), the client is sending DISPLAY, and the X connection couldn't be established. Or it could happen if you set an environment variable on the server via the command directive in ~/.ssh/authorized_keys. Or xterm could be a script.

¹  Or whatever the value of X11DisplayOffset is in the server configuration, but it's hardly ever changed from the default.


The official repositories for Ubuntu 10.04 contain only Ruby 1.8, but it appears that you're using a manual installation of Ruby 1.9.1. When you install libopenssl-ruby using Ubuntu's package manager, libopenssl is installed for Ruby 1.8 within /usr/lib/ruby/1.8/, but you need it to be installed for Ruby 1.9.1 within /usr/local/lib/site_ruby/1.9.1/.

How you achieve this will depend on how you originally installed Ruby 1.9.1.

If you're not strongly attached to a particular method of installing Ruby, my suggestion is to reinstall it using the Ruby Version Manager (RVM), which is advocated on the official Ruby download page. Installing Ruby using RVM should include the required libopenssl library automatically.

I recommend reading over the RVM installation instructions first (it's not as long as it looks—it's half examples), but this is probably all you'll need to do:

Install dependencies for RVM:

sudo apt-get install git curl

Install RVM:

bash < <(curl -s https://raw.github.com/wayneeseguin/rvm/master/binscripts/rvm-installer )
echo '[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load RVM function' >> ~/.bashrc
source .bashrc

Install dependencies for Ruby:

Scroll up (or run rvm requirements) and look for the line that says For Ruby … install the following:. Copy, paste, and run with sudo the apt-get install … line beneath it.
Install Ruby:

rvm install 1.9.3
rvm use 1.9.3 --default

You could install Ruby 1.9.1 here instead, but Ruby 1.9.3 is the current recommended version and should be compatible with nearly anything that works on other Ruby 1.9.x versions.
Install AtomicTV:

gem install AtomicTV


How to adjust CPU & GPU Fans start temperature in my Ubuntu 19.04 on Dell g5 15 ( 5587 ) laptop?

powersave will control fans on some, not all PCs. thermald may also help.  You may need to install the i8kutils package for Dells.

Once installed, you will need to find which sensors correspond with which fans by experimentation and research, then edit configuration files as explained in the above link to enable control and change the set points.

sudo modprobe i8k force=1 might enable dell_smm devices to appear and sensors to show fan[1,2] rpm so you could configure a desirable thermal profile in /etc/i8kmon.conf . You might need to do force=1 since the laptop is missing from https://github.com/torvalds/linux/blob/a7f89616b7376495424f682b6086e0c391a89a1d/drivers/hwmon/dell-smm-hwmon.c#L952


After searching on a lot of sites and blogs, apparently using an open DNS such as 8.8.8.8 or 8.8.4.4 rather than using automatic DNS solved the problem. I still don't know why the automatic DNS for the router is not working for Ubuntu although it is working fine for Windows.


Ubuntu 18.04 does not wake up from suspend on ASUS Zenbook

I had the same issue - here are some things I've come across in different posts on the topic that you may consider:

Update your graphics driver;
Check your Swap partition size. As answered here, you'd need at least 1.5x the size of your RAM for allocated to your swap partition for hibernation to work. You can check your active swap with swapon -s. I found this page to be very useful on how to manage swap;
Finally what really solved it for me - I switched from Xorg to Wayland. On your log in screen choose Ubuntu on Wayland from the options menu next to the Sign In button.

Hope this helps.


Time zone for Gnome Top Bar Ubuntu 18.10

To change the hardware clock time standard to localtime, use do:

timedatectl set-local-rtc 1 --adjust-system-clock

and

sudo dpkg-reconfigure tzdata

If you want to revert to the hardware clock being in UTC, do:

timedatectl set-local-rtc 0 --adjust-system-clock

Check what you have set by:

timedatectl


I did it this way:

  NOTE: please, read carefully, don't break your operating system.

The Idea: get files that appear after "make" (build). Then search those files on system and remove them.

  Bibliography:
  Uninstall files installed from a source code tar-ball - nixCraft

 - entered to source files of httpd-2.2/ folder.
 # need to clean previous build, and get empty build files snapshot.
 - make clean
 # get empty build snapshot.
 - find . print | tee make.b4
 # build project.
 - ./configure && make
 # get files snapshot after build.
 - find . print | tee make.after
 # get difference before and after build.
 - diff -y --suppress-common-lines make.b4 make.after | tee httpd_orig
 # perform needed formatting.
 - cat httpd_orig | column -t | tr -d '>' | tr -d ' ' | sponge httpd_orig
 # get only files name.
 - cat httpd_orig | xargs -n1 basename | tee httpd_orig_files
 # get system files snapshot.
 - find /  \( -path /boot -o -path /dev -o -path /home -o -path /lost+find -o -path /media -o -path /mnt -o -path /proc -o -path /root -o -path /run -o -path /tmp -o -path /sys -o -path /var -o -path /opt \) -prune -o -type f -print | tee httpd_on_system
 # run python script do remove files created on build project we find on system.
 - python unistall.py

# File: uninstall.py
# Uninstall httpd 2.2 installed from source.
import os

# read file with build project files name.
with open("httpd_orig_files", "r") as f:
    files = f.readlines()

httpd_orig = list()
for line in files:
    # create a list of build files, strip remove newlines.
    httpd_orig.append(line.strip())

# print files name from project build.
print httpd_orig

# open file with files paths on system.
with open("httpd_on_system", "r") as f:
    httpd_files = f.readlines()

for hfile in httpd_files:
    item = hfile.strip()
    filename = os.path.basename(item).strip()
    status = filename in httpd_orig
    if status:
        print "{:<10} {:50} {}".format(status, filename, item)
        try:
            # remove files from system.
            os.remove(item)
        except Exception as e:
            print e


Two things may be happening:

1 - Either you have installed the 32 bit version of Ubuntu (i386) which is unable to "see" 4 gigs of RAM or more (Actually, 32 bit oses usually see about 3,5 gigs of RAM, including Ubuntu, unless you have installed and enabled the PAE - Physical Address Extension enabled kernel, in which case it can see all 4gb, all the way up to 64gb, at least in theory. For information on how to enable the PAE kernel please see:Enabling PAE). If you would like native support of your 4gb, and/or planning to add more in the future, you are better off installing the 64 bit edition of the Ubuntu 12.04 (should be under a name x86_64, or x64, or amd64). If you decide to do so, do not forget to backup the files that are important to you before doing so.

2 - Make sure that the dimms are installed properly. What may also have happened is that one of the two dimms may probably be problematic, in which case, to determine which one of the two is problematic, remove each one of the two and see if the system responds properly to the change. If none of them appears to be problematic, go to solution #1.


Unwanted subdomain requests in the DNS query logs (BIND9)

When you talk of access.log and error.log, I assume you're talking about HTTP server logs.

To make an HTTP request, the process goes something like this (vastly simplified):

the client issues a DNS request to map the host name from the URL to an IP address.
the client makes a TCP connection to the web server at the given IP address.
the server sends back the requested page.

If you aren't seeing any activity in the HTTP server logs, then it means that either (a) the first step failed with the DNS server returning a "no such domain" response, or (b) the client was looking up the host name for some other purpose (e.g. email, ftp, etc).

If you are running a public web site, you'll just have to deal with random people probing for host names in your domain.  Provided you're not relying on obscure host names as a form of security, this shouldn't be a big concern.


I won't copy and paste the entire article, but I think this is what you want:

How to use hibernation without a swap partition
Setting Up Hibernation on Linux SSD Netbooks Without Swap

The first link is a succinct Debian article which should be close enough to get it working on Ubuntu. The second is an article using Kubuntu which should be closer to home but it looks like the same process as the Debian link just spanned over five pages with a bunch of fluff in between.

Pick your poison. :)


I still have Windows XP Professional on my PC. It has no Internet Access, and the CD is not working properly. I don't have a Windows CD. It was installed by the store where I bought it and they did not give me a CD. I can use my phone to install programs on my PC, but it can not boot from a USB.


Play 2 videos in sync on a loop in Ubuntu

You need screen and mplayer, but here is a terribly messy way to get it to work:

`screen -d -m mplayer PATH_TO_VID1` && mplayer PATH_TO_VID2


Adobe Air application not showing an icon in Unity's notification area

Execute in a terminal: gsettings set com.canonical.Unity.Panel systray-whitelist "['all']"


Which package did kernel modules move to between 12.04 to 14.04?

Between LTS 12.04 and LST 14.04, some of the kernel modules moved from linux-image-<version> package to linux-image-extra-<version> package. Install it manually if it has not been installed:

sudo apt-get install linux-image-extra-$(uname -r)


3 monitors using built in graphics & Nvidia card

I have identical configuration. I had to set some things in BIOS exactly as you said to have three monitors. With NVIDIA there was no way for me to setup three monitors working. I gave up and I am using open source NVIDIA driver - nouveau with intel driver for the onboard adapter. It seemed to me as NVIDIA priprietary driver will not cowork with any other driver.

I also had problems not showing the picture on monitor connected to Intel onboard adapter. I changed some BIOS settings and then the picture on the third monitor appeared. Unfortunately, I don't remember the BIOS setting and I don't have the access to that computer right now. I can check tommorow when I get to that computer, but I don't think I will remember, which BIOS setting it was.


Trying to remove apache2/httpd and installing mod_perl

(You could have just run sudo apt-get install libapache2-mod-perl2 and be done.)

It looks like you locally compiled and installed the httpd binary. If you still have the source true where you ran the make command, you can go in there and run sudo make uninstall. Hopefully, it's supported, and it will remove httpd from your system. If that doesn't work, hopefully, the files will have been installed into the folders in /usr/local, and you can remove httpd-related files manually.

Edit: It seems make installed httpd into /bin/httpd. After running dpkg -S /bin/httpd to verify it's not part of a package, you can just remove that file. Other than that, things look fine.


How can I share my connection on Windows 8.1 to VMware Linux Ubuntu

I need to user a bridge connection!

And disable my firewall for VMWare:

"Allow all traffic to / from virtual machines supported by the firewall"


Motherboard, sound and CD Drivers not working after initial boot

Are you downloading the linux driver from Creative and installing as-per instructions ? if so, what does it say when it fails ?

Also, have you tried booting from a livecd containing Ubuntu 13.04 to see if your sound card is supported out-of-the-box by the latest version ?


script to change MAC with suid does not work

If you want to be able to run this and only this script as a normal user without any other sudo rights, or you want to run it with sudo without password typing you can add them to your sudoers.

e.g.
sudo echo "[username] ALL = NOPASSWD: /path/to/your/script" >/etc/sudoers.d/myscript

However this is kinda meh in safety since if someone can edit this script as your user they can run any command as sudo without knowing your password so take care in using it.

Just make sure the script is owned by root and write rights are only at it's owner so no one else can change it.

You can also use chattr to make sure no one can modify your script:

sudo chattr +i script.sh

From man chattr:

  A  file with the 'i' attribute cannot be modified: it cannot be deleted or renamed, no
         link can be created to this file and no data can be written to  the  file.

After all that just run sudo myscript and it should run it with root rights without asking for a password.


Key needs to be typed two times to display

It's not a bug, it's a feature ;) You probably have set a keyboard layout with so called "dead keys". Those keys are mostly not for printing characters themselves, but for modifying the following character. For example, if you press "~" followed by "e", you get "ẽ". This is a simple way to type so called "diacritic characters" that are combined of several glyphs like "é", "ñ", "ô", which are used in many languages. To print ~, `, ^ and others themselves, you can combine them with a space character, thus pressing for example "~" followed by the space key. Your solution, pressing the dead key twice, works as well, but is more complicated for the fingers in my opinion.

If you don't want to use the dead key functionality, you can, as you seem to already have, choose a keyboard layout that doesn't feature them.


website is not showing my wordpress site,

You're not wrong, your bitnami probably has it's own webserver which it starts and also uses it on port 80. Now you installed a package that installed apache2 aswell, which now blocks port 80 since it's using it.

Now your bitnami webserver cannot bind to the - in use - port 80 and fails to start.

Since your configuration is only available at the bitnami one you only get the default page which is provided in /var/www.

Long story short, disable and stop the newly installed apache2 service.

sudo systemctl stop apache2.service && sudo systemctl disable apache2.service

After that run your start script again and it should work.

Question will arise again though how you want the plugin to work if you are using the system to install it but use an externally installed apache2 service. You'll probably need to install the plugin via bitnami aswell.


How to make .bin file from multiple c source code

The source code shown is  not a full distribution.

I suspect you could compile everything there by downloading it, extracting and and using make (there are readmes too) but the things that hold it all together are missing, likely because they're still stock code (ask Sony - they're still obliged to make any unmodified GPL2+ code available) or they're custom written. I suspect whatever is bootloading this is custom made to some degree.

The process of completing the distribution and actually building it into a bin is not something you can "just do". Sony has the secret sauce. You can ask them about the build environment but I'd start by getting the complete source (for everything open source) and see where you stand.

Failing that, talk to the FSF about Sony being non-compliant. Just understand that there are likely parts that Sony has no obligation to share.

I could also be completely wrong. One of these bin files might just be a collection of compiled code (open one up and see - I'd suggest trying to mount one) that just replaces certain components. The base distribution might be completely static.


"fuse" is not a filesystem. It's a bridge to a real filesystem. I would bet the true filesystem is NTFS. Fuse will create a virtual "view" of that NTFS partition giving it what would appear to be Linux ownership and permissions. AN NTFS partition in Linux would in fact run slower than a native Linux filesystem. It would run slower than the same NTFS partition in Windows. All because of this fuse "bridge". Not much you can do about it if you want compatibility with Windows


No.

The Skype FAQ says that the feature is in the works, but hasn't been released yet.

You'll have to wait, or hope that Skype for Linux works, which it probably won't.


Network booting Ubuntu 16.04 Server installer via iPXE w/ NFS on UEFI system

I had the same issue in a debian live booting on nfs. The ipxe documentation refers to the booting case with bios but not with efi, the solution, as you mention, is related to efi.

Add the parameter initrd=initrd_file_name to the imgargs line.

The source of this information is: http://forum.ipxe.org/showthread.php?tid=7522

Although I do not find it in the official documentation, but it works for me on efi.


As stated in the comment, please ask one AskUbuntu question per question.

I'll answer the first two:

  I will be using qt with qt creator and c++; will qt and qt creator automatically install in /opt?

It will not unless you instruct it too through your build system. I assume you'll be using cmake or autotools as a build system, so you'll have to create extra rules for the installation to /opt.

This is one of the reasons we recommend Quickly, as it will handle the packaging and installation to /opt transparently for you.

  Do most frameworks by default install in /opt?

They don't. Most apps are packaged with a build system and the packaging layer on top. The default parameters for build systems in Debian and Ubuntu machines are to install to /usr/share. Installation to /opt is a requirement for all third-party applications that are submitted through the app developer process.


ubuntu 1310 with two NICs: one with dynamic address and one with static address

Delete the default route for eth0:

ip route delete default

Set up a new default route through wlan0:

ip route add default via 192.168.1.1 dev wlan0

Assuming your 97.76.237.0 subnet is a /24, add a new route:

ip route add 97.76.237.0/24 dev eth0 via 97.76.237.65 proto static


command line syntax that will show MySQL details

Server System Variables

To see the values that a server will use based on its compiled-in defaults and any option files that it reads, use this command:

mysqld --verbose --help

To see the values that a server will use based on its compiled-in defaults, ignoring the settings in any option files, use this command:

mysqld --no-defaults --verbose --help

Inside MySQL SHOW VARIABLES will show the current settings MySQL is using. Here is a list of variables.
Inside MySQL status will show information about the install (collation, threads, slow queries and more).

Besides that you can also have a look at /etc/mysql/my.cnf. That file is used to store settings. It holds the port, pid file location, socket etc. Example showing the port number:

more /etc/mysql/my.cnf | grep port
port            = 3306
port            = 3306


LTS releases occur every 2 years, so from 16.04, you will have opportunities to upgrade directly to 18.04 in April 2018, and then to 20.04 in April 2020. It will be generally expected that you would have upgraded to a newer release by then. You will be able to upgrade to 18.04 still at that point though.

You can also re-install a fresh new version at that time if you need to (you may very well have a new PC by then), but it will not be necessary. However, if you do not upgrade by that point, you will no longer be running a supported system, and you may become susceptible to security problems if new ones are discovered in the versions included in the no-longer-supported version of Ubuntu.


How to use ubuntu live disk to reset windows 10 password?

Mount the Windows drive.
Rename C:\Windows\System32\sethc.exe to sethc_bak.exe
Copy C:\Windows\System32\cmd.exe and paste in the same DIR, renaming to sethc.exe
Reboot into Windows.
On the logon screen, press shift 5 times. You should now have an admin CMD prompt.
In the CMD window, type net user your-user YourNewPassword [replacing "your-user" & "YourNewPassword" accordingly.]
Once into the account, delete C:\Windows\System32\sethc.exe, and then rename C:\Windows\System32\sethc_bak.exe to sethc.exe.

I have done this in a VM, and it worked beautifully


stuck in login ubuntu 14.04 after trying everything

It's a temporary answer:

The problem I was experiencing is after recent upgrade, instantly past login I was logged in and then redirected back to login screen.

I've used this: Is there any way to roll back the most recent upgrade?
to roll back most recent upgrade. I've rolled back unity, it didn't help, then I rolled back nvidia-304 and it helped.

Edit:
After update I was struck again with the same problem and found a simpler solution here in comments http://www.linuxslaves.com/2016/05/3-ways-fix-ubuntu-gets-stuck-login-loop.html

I will past the relevant part of the comment by Foxjt:

The general consensus seemed to rotate around problems with the video drivers, so:

sudo ubuntu-drivers devices

This shows the required drivers for my Video card (nVidia G96 GeForce 9400 GT) as nvidia-340.

I ran:

sudo apt-get install nvidia-340

The messages showed that nvidia-304 was being removed and replaced with nvidia-340.

After a reboot, I was able to finally login!!! Hooray!!!


Why do I get these .vimrc errors in Ubuntu 14 after upgrade from Ubuntu 13?

Turns out I didn't have vim, just had vi, due to dependency issues after the upgrade.

tl;dr; - needed older versions of dependencies.  Fixed with:

$ sudo apt-get remove vim-common
$ sudo apt-get remove vim-runtime
$ sudo apt-get update && sudo apt-get install vim
Change .vimrc setting "set filetype off" => "filetype off"

Full Version...

Fix was:

Attempted to do:

apt-get install vim

But got message

...
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 vim : Depends: vim-common (= 2:7.4.052-1ubuntu3) but 2:7.4.335-1~ppa1~s is to be installed
       Depends: vim-runtime (= 2:7.4.052-1ubuntu3) but 2:7.4.335-1~ppa1~s is to be installed
E: Unable to correct problems, you have held broken packages.
$

So then I tried:

$ sudo apt-get install vim-common

Reading package lists... Done
Building dependency tree
Reading state information... Done
vim-common is already the newest version.

Finally, realizing that the messages say the dependency is 2:7.4.052 but I have 2:7.4.335 for vim-common and vim-runtime, in other words I had more recent versions.  Realizing this the final fix was:

$ sudo apt-get remove vim-common
...
$ sudo apt-get remove vim-runtime

Then I was able to do;

$ sudo apt-get update && sudo apt-get install vim

This fixed all the issues except for one line

set filetype off

which I changed to

filetype off


Try to reset the BIOS by e.g. removing the CMOS battery and see if that works. It could also be defective RAM. I've had that if I had bad RAM the computer wouldn’t get past the BIOS loading screen.


Wireless always disabled (either by Ubuntu or hardware switch) - Dell L502X (12.04)

You said you've tried rfkill, but this worked for me,

http://www.dkvermalinux.in/2012/05/ubuntu-1204-lts-wifi-problem-hardware.html


Which aliases do you find most useful or helpful to your Ubuntu experience?

Here are some that I like:

#Opens current directory in a file explorer
alias explore='nautilus .'

#Opens current directory in a file explorer with super user privileges
alias suexplore='sudo nautilus .'

#Opens current directory in Ubuntu's Disk Usage Analyzer GUI with super user privileges in the background
alias analyze='gksudo baobab . &'

#Opens a GUI text editor in the background. Can obviously be replaced with your favorite editor
alias text='gedit &'
#Same as above with super user privileges
alias sutext='gksudo gedit &'

#Opens a file with whatever program would open by double clicking on it in a GUI file explorer
#Usage: try someDocument.doc
alias try='gnome-open'

#lists contents of current directory with file permisions
alias ll='ls -l -sort'

#list all directories in current directories
alias ldir='ls -l | grep ^d'

#self explanatory
alias ..='cd ..'
alias ...='cd ../../'

#show aliases
alias a='echo "------------Your aliases------------";alias'
#Apply changes to aliases
alias sa='source ~/.bash_aliases;echo "Bash aliases sourced."'
#Edit Aliases
alias via='gksudo gedit ~/.bash_aliases &'


How to you paste in List-Mode with Nautilus in Gnome3? In other words... Where do I rightclick to "Paste"? (Not "Paste into Folder...")

You must right click on parent folder, in your case .config button and choose Paste into Folder Button.


Laptop Heating in ubuntu , no issue in windows what to do?

Are you using the default video drivers under Ubuntu?  Sometimes the custom drivers from the video card manufacturer are actually unstable and cause heat problems.
use the
    dmesg | less

command and look for anything that says it taints the kernel. This is often a big clue that you have installed custom drivers.
Also, what sort of laptop did you use, and how much memory do you have?
Are you using SSDs or spinning disk drives?
What is the output of the
    swapon -s

command (shows swap space allocated and used)
What is the output of the
    w

command (shows the load on your system)
what is the output of the
    df -h

command (shows the disk free on your root partition)


HEVC/H265 videos not playing in SM Player

SMPlayer by default uses mplayer executable as its backend. You would need it to use mpv player instead.

Install mpv player first.

sudo apt-get install mpv

Then open SMPlayer and go to its options. Change the location in Mplayer/mpv executable to

/usr/bin/mpv

That should fix it. Make sure you have SMPlayer 15.9 installed.


from PyGObject:

  If you want to write a Python application for GNOME or a Python GUI application using GTK+, then PyGObject is the way to go.

Apparently PyGTK is made available through PyGObject which can be installed with:

sudo apt install python-gi python-gi-cairo python3-gi python3-gi-cairo gir1.2-gtk-3.0


The program 'sed' is currently not installed. You can install it by typing [sed: not found]

Besides copying the binary from another machine and hoping it is the correct version, this can also be solved by using apt or apt-get to install the sed package and passing the --reinstall option so that the .deb file will be downloaded and installed even though Ubuntu's package manager thinks it is already present.

sudo apt install --reinstall sed

This works with apt-get instead of apt, too. It uninstalls and reinstalls the package in a single step. The situation in this problem is that the se package is already installed but the executable has been deleted, so reinstalling solves that. Without the --reinstall flag, the package manager assumes nothing has to be done, because the package is installed already.

You can run sudo apt update first if you want, though it will not typically be necessary in this case, unless you've modified your software sources without doing so. You can pass the --purge flag too if you want but it's unnecessary here, since that just causes conffiles for the package to be removed when it is uninstalled.

sed is a utility that programs are generally allowed to assume exists and to rely on themselves. As you noticed, the scripts that run when installing, removing, or upgrading software can use sed. That's the source of your specific error messages. In theory  APT or dpkg could rely on it directly and be unable to reinstall it. In practice, this does not appear to happen, and I don't expect it to. I've tested this on Ubuntu 16.04 LTS.

I cannot think of any situation where replacing the binary fixes the problem but reinstalling neither works nor shows an error immediately (see comments on the post). Although I cannot be 100% sure that these instructions would work for you--because perhaps more was broken than documented in the question--they should generally work at least as reliably as manually replacing /bin/sed for others who experience this problem.


Oracle-Java8-Installer: No installation candidate

NOTE: This answer no longer works, as the WebUpd8 PPA has been deprecated since Oracle has changed licensing and access restrictions to the Oracle Java codebase.  Details at http://www.webupd8.org/2014/03/how-to-install-oracle-java-8-in-debian.html

The mistake is that you used instructions on how to install java on Debian.  Not Ubuntu.

As root, go to this folder: /etc/apt/sources.list.d
Locate this file: webupd8team-java.list and delete it.
Execute sudo apt-get update for the system to remove any reference to that update server.
Execute sudo add-apt-repository ppa:webupd8team/java to add the correct ppa to your system.
Execute sudo apt-get update again and you should be able to install everything correctly.

I would recommend you installed oracle-java8-set-default too, in order to make this java package the default java on your system.


Font settings not working in Xfce keyboard layout panel plugin in 16.06

I have solved this on my 64bit install by overwriting the /usr/lib/x86_64-linux-gnu/xfce4/panel-plugins/xfce4-xkb-plugin with the version from trusty, and by creating a symbolic link @libxfce4util.so.6 pointing to @libxfce4util.so.7 like this:

sudo ln -s /usr/lib/x86_64-linux-gnu/libxfce4util.so.7 /usr/lib/x86_64-linux-gnu/libxfce4util.so.6


It provides a web interface to the Squid cache manager. See the Squid Wiki for instructions on setting it up.


This error doesn't appear to be related to updating your system.

Once you have booted, click on the Continue button for your error message which should make the message disappear (you may be asked to enter your password to submit the error message if you keep the option 'Send an error report' enabled.

Open a terminal through ONE of the following methods (taken from https://help.ubuntu.com/community/UsingTheTerminal)

Dash -> Search for Terminal
Dash -> More Apps -> 'See More Results' -> Terminal
Dash -> More Apps -> Accessories -> Terminal
Keyboard Shortcut: Ctrl + Alt   + T

Then type: sudo apt-get update && sudo apt-get upgrade

Enter your password when prompted.


Is it possible to have different desktop sessions each with different settings?

Different users can keep different theme configurations. You can create and remove users on the terminal with sudo adduser mynewusername and sudo deluser mynewusername. This way you'll be able to switch between sessions with completely different configurations.

When you create new users they can't use the sudo command by default. If you wish to give the new user access to sudo for installing and removing software from the system you need to add mynewusername to the sudo group. You can do it with the following command:

sudo addgroup mynewusername sudo


Remove the currently installed drivers and install the latest stable drivers supporting GT 755M.

Open a terminal and execute :

sudo apt-get purge nvidia*
sudo reboot

After restart of the system ...

Open a terminal and execute :

sudo apt-get update
sudo apt-get install nvidia-352 nvidia-prime
sudo reboot

You can switch between the graphics with NVIDIA X Server Settings from the tab PRIME Profiles.


TVShow Renamer Run Solely Through Bash/Terminal

FileBot is a command-line tool that you can use in your shell scripts: http://www.filebot.net/cli.html


How to change default permissions on automounted usb flash, formatted in NTFS?

Mount NTFS partition in a USB drive with custom permissions and owner

Assumption: the USB drive is seen as sdb1, modify to match the drive letter and partition number in your case. The general syntax is sdxn, where x is the drive letter and n is the partition number as seen by for example sudo lsblk -f

You can use the following command line method in order to get other permissions and ownership than the default.

Create mountpoint (only if you want a new mountpoint)

sudo mkdir -p /mnt/sd1

Unmount (only if already mounted)

sudo umount /dev/sdxn   # general syntax
sudo umount /dev/sdb1   # modify to match your case

Check your userID's uid number (it is usually 1000, sometimes 1001 or 1002 ...)

grep ^"$USER" /etc/group

and use that number if you want to grab ownership (default is root).

Example of mount command line that should give you something that is close to what you want,

sudo mount -o rw,users,uid=1000,dmask=007,fmask=117 /dev/sdxn /mnt/sd1  # general syntax
sudo mount -o rw,users,uid=1000,dmask=007,fmask=117 /dev/sdb1 /mnt/sd1  # modify to match your case

Example with full permissions for everybody (convenient, but not safe, when there are several users),

sudo mount -o rw,users,umask=000 /dev/sdxn /mnt/sd1  # general
sudo mount -o rw,users,umask=000 /dev/sdb1 /mnt/sd1  # modify to match your case

Check permissions and owner of the directories and files

ls -ld /mnt/sd1
ls -ld /mnt/sd1/*

Test

sudo bash -c "echo 'Hello World' > /mnt/sd1/hello.txt"  # test writing with sudo
cat /mnt/sd1/hello.txt                   # test reading (as user)
ls -l /mnt/sd1                           # check permissions of the content
rm /mnt/sd1/hello.txt                    # test removing (as user)
echo 'I am a user' > /mnt/sd1/user.txt   # test writing (as user)

If this does not work

If this does not work, you may find a solution or at least an explanation at the following link,

Can't format my usb drive. I have already tried with mkdosfs and gparted: Analysis of the problem


Launch eset libc library before samba daemon

So in the depths of /etc/init.d/smbd you'll find the following line which is what is actually launching smbd:

if ! start-stop-daemon --start --quiet --oknodo --exec /usr/sbin/smbd -- -D; then

The popular idea for passing through an environment variable is with env so you'd end up with:

if ! start-stop-daemon --start --quiet --oknodo --exec /usr/bin/env LD_PRELOAD=@LIBDIR@/libesets_pac.so /usr/sbin/smbd -- -D; then

Note that I expect they want you to replace @LIBDIR@ with the correct path to libesets_pac.so.

An alternative is creating a new launcher for smbd as /usr/local/sbin/smbd:

#!/bin/sh

LD_PRELOAD=@LIBDIR@/libesets_pac.so /usr/sbin/smbd

And then just alter /etc/init.d/smbd to call /usr/local/sbin/smbd.


Can I Adjust/Reduce My Partition Size for Ubuntu?

Yes, there is a way to resize your partitions. However, depending on the different partitions you have and their locations, it might be a long process to resize. Nonetheless, here's what you can do, and what I always do. This method uses a utility called GParted.

Before we begin, it is advisable that you take a backup of your data.

Step 1

Boot up from the USB/CD that you used to install Ubuntu, as if you were installing it from scratch. But instead of choosing to "Install Ubuntu", you'll choose "Try Ubuntu". This will boot into the Ubuntu on your USB/CD, not the one you installed. Connect to the internet, and install GParted. GParted is a utility that helps you partition disks. To install it, open up a terminal using Ctrl+Alt+T and then type:

sudo apt-get update && sudo apt-get install gparted && gksu gparted &

Step 2

GParted should come up. My GParted looks like this:

The top right states the hard drive we're currently viewing. In my case, it's /dev/sda. In your case, it most probably will say the same thing, or something else like sdb instead of sda. If you have any other external hard disks or USB sticks connected to your computer, they will also be listed in that drop down menu. It is very important that you make sure you choose your internal hard disk from that drop down menu. To be on the safe side, disconnect any other USB device and refresh GParted by hitting Ctrl+R.

Now, the list at the bottom shows the partitions in this hard disk. In my case, /dev/sda2 is my Window's partition, because it is of type ntfs, and it's fairly big in size (180 GB). My Ubuntu partition is the one that says type ext4, which is also the one that has a mount point of /. So, identify your Windows and Ubuntu partitions the way I did it.

Step 3

Now we do the resizing. It's as simple as right clicking on the partition and selecting "Resize/Move". Do that on your Ubuntu partition, and resize it. Don't worry, the resizing won't actually happen when you hit OK, it'll queue up all the operations so you can "apply" everything in the end. So what you're going to need to do is (1) resize your Ubuntu partition, (2) move the empty space so that it's after your Windows partition, and (3) resize your Windows partition and "expand" it to take over that empty space. Once you're done, take a look at the little diagram showing the partitions and make sure that everything looks okay; that there is no empty space lurking around. If you're satisfied...

As aforementioned, this process can take a LONG time. It's because of the resizing and moving of partitions around. It all depends on how big your partitions are, and how much space is being used. It once took me more than two hours to complete. But, it could only take you 20 minutes. If you want to, you can post a screenshot before applying so we can take a look at it. But again, if you're satisfied and willing to go forwards...

...hit the check mark in GParted to start applying all of these actions. Once done, reboot, and remove the USB/CD, and boot normally into your desired OS.


Without a backup you have virtually no chance. The effort is not worth it. Re-install your system and avoid these actions in the future. Linux is robust, but Linux forgives mistakes very rarely.

/lib – Essential libraries for the binaries in /bin and /sbin
/bin – Essential command binaries that need to be available in single user mode
/sbin – Essential system binaries

Read this:

Re-install Ubuntu without losing data in home folder

What's a good back-up strategy for 1 desktop PC?

Sorry to be the harbinger of bad news.


Google Chrome - Profile could not be opened correctly error

I had this problem too.

anyways. do:

cd ~/.config/google-chrome

then run

sudo rm -rf *

WARNING: THIS WILL MAKE CHROME RESET EVERYTHING! YOU WILL LOSE ALL BOOKMARKS!

This should fix this.


XKB method

XKB may not be the best way to change this device's behavior, but it should be possible in traditional X environments.  Newer XKB contexts like Wayland or kmscon may not provide the granularity needed to configure separate XKB layouts on arbitrary devices.  It also won't function under the traditional console.

Applying a udev hwdb override to make this change should work under all of these.

Under traditional X environments, setxkbmap takes a -device flag and xkbcomp uses -i:

  -device device

  Specifies the numeric device id of the input device to be updated with the new keyboard layout.

Use xinput -list to find the device id numbers.

To prove this functional, use the setxkbmap ... -print to generate a basic layout, save it to a file, then load that with xkbcomp filename.xkb $DISPLAY.  You may need to disable GNOME/KDE's keyboard settings daemons while testing.

$ setxkbmap -layout us -option '' -print > f2toctrl.xkb

Edit the file f2toctrl.xkb -- we're only changing the xkb_symbols line:

// generated with `setxkbmap -print` and modified
// load: xkbcomp -i DeviceID# filename $DISPLAY
xkb_keymap {
    xkb_keycodes  { include "evdev+aliases(qwerty)" };
    xkb_types     { include "complete" };
    xkb_compat    { include "complete" };
    xkb_symbols   {
        include "pc+us+inet(evdev)"

        // existing key definition (see `xkbcomp $DISPLAY - | grep -A 3 FK02`)
        // key <FK02> {
        //    type= "CTRL+ALT",
        //    symbols[Group1]= [ F2, F2, F2, F2, XF86Switch_VT_2 ]
        // };

        // patterned after ctrl:nocaps option
        // see /usr/share/X11/xkb/symbols/ctrl
        replace key <FK02> { [ Control_L, Control_L ] };
        modifier_map  Control { <FK02>, <LCTL> };

    };
    xkb_geometry  { include "pc(pc105)" };
};

Now load it (replace N with the device id you found in xinput -list):

$ xkbcomp -i N f2toctrl.xkb $DISPLAY

You can verify your changes with xkbcomp -i N $DISPLAY - | less, and test the button physically in various applications to make sure it's being recognized.

For normal (non-DE) X environments, the loading command can be added to ~/.xinitrc or other windowmanager startup scripts.  You'd need to add that override to the system's XKB database for use with most Wayland compositors and DEs like GNOME/KDE, but in those contexts I'm not certain how you'd apply the override to only the pedal device.  If that were feasible, I'd create /usr/share/X11/xkb/symbols/pedal to hold the Ctrl override demonstrated above (and potentially other useful overrides for the device).

A very simplistic layout file might look like this:

// /usr/share/X11/xkb/symbols/pedal

// convert F2 key operation to Ctrl
default partial modifier_keys
xkb_symbols "basic" {
    name[Group1]= "USB Pedal as Ctrl";
    replace key <FK02> { [ Control_L, Control_L ] };
    modifier_map Control { <FK02>, <LCTL> };
};


I met a same problem, and found your question by search engine.
I solve the problem by moving the option "-lm" to the last part of the command.

Please try the following command:

gcc -Wall filex.c -o filex.out -lm


How to disable module tun on ubuntu 12.04 LTS?

The tun feature is build static into the ubuntu kernel, so you can't remove it.


How do I remove a partition from elements external hard-drive?

Open disks from dash, delete the partition that's already on the drive by pressing the - sign, Only if no longer needed.

Create a new EXT4 partition, by clicking the + sign,  and format the drive.

Once the partition is created, click on the little wheels to format the drive.


how to list file names when searching for strings passed by cat with pipe

This is a canonical Useless Use of Cat. Use grep directly:

grep -R pam_ck_connector.so /etc/pam.d/

With the -R flag, it will recursively search the directory. If, for some reason, you don't want to search subdirectories and only want to print filenames, then do:

grep -l pam_ck_connector.so /etc/pam.d/*

The -l flag is for printing only the filenames.


Ok so I found an answer after a few hours.

It seems that the dbus daemon is not launched for the remote ssh session.

So using the existing DBUS_SESSION_BUS_ADDRESS was failing, but I found a solution HERE:

$ ssh -X user@pc1 "gnome-terminal -e 'dbus-launch --exit-with-session bash'"
$ nautilus

I starts up a new session bus or find the existing bus address on the X display, so that the aplication can communicate with the gvfs daemon.


How do I do a memory dump of all terminated processes?

One solution from over on ServerFault direct quote:

I've made a script that accomplishes this task.

The idea commes from James Lawrie's answer and this post: http://www.linuxforums.org/forum/programming-scripting/52375-reading-memory-other-processes.html#post287195

#!/bin/bash

grep rw-p /proc/$1/maps | sed -n 's/^\([0-9a-f]*\)-\([0-9a-f]*\) .*$/\1 \2/p' | while read start stop; do gdb --batch --pid $1 -ex "dump memory $1-$start-$stop.dump 0x$start 0x$stop"; done

put this in a file (eg. "dump-all-memory-of-pid.sh") and make it executable

usage: ./dump-all-memory-of-pid.sh [pid]

The output is printed to files with the names: pid-startaddress-stopaddress.dump

Dependencies: gdb

end quote

The only thing to add is a loop to iterate over all PIDs.


There is a background task scheduler named cron that runs tasks at specific times.

The log entry you see in syslog is the cron daemon running its hourly tasks.

run-parts is a utility to run executables in a directory. Hence

run-parts --report /etc/cron.hourly

runs all executable files in the directory /etc/cron.hourly

Take a look at /etc/crontab. There is an entry

17 *    * * *   root    cd / && run-parts --report /etc/cron.hourly

telling to run the command in question at 17 minutes past every hour.

For more details see the man-page of run-parts and crontab


How do I make a syslinux file for an ubuntu partition that is not where syslinux is

I would adivse you to firs start at some official sites to understand how syslinux works:

http://www.syslinux.org/wiki/index.php/The_Syslinux_Project

http://en.wikipedia.org/wiki/SYSLINUX

As of 2010-10-19, Ubuntu 10.10 (Maverick Meerkat) uses Syslinux 4.01 with GFXBoot.c32 (now officially included) and includes several special patches to allow gfxboot to use some configuration directives that were originally intented to be used only with the simple menu modules (menu.c32/vesamenu.c32).


Does your proxy require authentication? If yes, then your apt.conf file should look like this

Acquire::http::Proxy "http://username:password@server:port";
Acquire::https::Proxy "https://username:password@server:port";
Acquire::ftp::Proxy "ftp://username:password@server:port";
Acquire::socks::Proxy "socks://username:password@server:port";

Note :
Mozilla Firefox works fine because it accesses the proxy from network setting and asks authentication when you open firefox.


There are not any specifics to go on here, but I will offer an educated guess based on 11 years using UBUNTU and other Linux distributions. You say this is happening on just one of a field of wifi signals available to you. That suggests that the problem is upstream of your machine. I have run into similar glitches with wifi connected to providers with oversold bandwidth. Somehow the provider times you out and drops the connection. You can log back in when band width becomes available again on the provider's equipment. So, I don't think this is a problem with your hardware or software.


Ubuntu 14.10 and Macbook pro 6,1 and the touchpad

You can do this by manually editing the file

/etc/X11/xorg.conf.d/50-synaptics.conf

If its not there, create one

vi /etc/X11/xorg.conf.d/50-synaptics.conf

But you should read this link Synaptic touchpad before starting.

For more info on this, see the manual

man synaptics


How to change the color of the window outline in spread and switcher?

In Ubuntu 14.04 you can change the window spread highlight color by editing your theme unity.css (if it has one) For example using the default ambience theme.

Browse to the directory /usr/share/themes/Ambiance/gtk-3.0/apps/, and edit unity.css as root.

sudo gedit /usr/share/themes/Ambiance/gtk-3.0/apps/unity.css

Find:

-UnityDecoration-glow-color: rgb (221, 72, 20);

Change the rgb (red, green, blue) values to your desired color! You can also use a hex value like so:

-UnityDecoration-glow-color: #ffffff;

Save the file, and log out then back in to see changes.

HUMOR** If your wondering why I didn’t say to back up the file before editing. It's because I'm a long time Windows user. We tend to try first ask questions later. ROFL, Seriously back up files before making any modifications, or better yet copy your theme to your home folder ~/.themes.

cp -R /usr/share/themes/Ambiance ~/.themes/Ambiance


Hide from other users the folders they do not have read and execute permissions

Remove the read permission for others (or group, if user2 is part of user1's primary group) from the directories in the tree:

chmod o-r /home/User1 -R
chmod o+r /home/User1/Music/Aerosmith/Rocks -R

As long as the execute permissions remain, User2 will be able to traverse the directory tree, but not see the contents.


Firefox on Lubuntu opens half of its height on startup and then maximizes

The solution for me is to go into about:config and turn the following to false from true:

layers.offmainthreadcomposition.async-animations

and

layers.offmainthreadcomposition.enabled

A couple of related links:

https://www.mozilla.org/en-US/firefox/40.0beta/releasenotes/ mentions "Improved scrolling, graphics, and video playback performance with off main thread compositing (GNU/Linux only)".

And the Arch wiki has more: https://wiki.archlinux.org/index.php/firefox_tweaks#Enable_OpenGL_Off-Main-Thread_Compositing_.28OMTC.29


Wine is not an emulator. And RemoteKeys is pretty old software that works by manipulating the Windows API and inserting itself in-between the application layer and the API using undocumented Windows calls.

As Wine just emulates the documented Windows API, this kind of software doesn't work and will not ever work (even when you would file a bug report).

You would get the same kind of behaviour if you would try to install Norton Anti-virus from 15 years ago: It just wouldn't work...  ;-)


K20Xm TESLA CUDA drivers (nvidia-430, 440 etc.) failing to install on Dell T7400 and Dell T7500 running Ubuntu 16.04 LTS

There are many CUDA installation answers here, but basically, you get your Nvidia drivers from the standard repositories, and avoid all the CUDA dependency nonsense on these obsolete drivers offered by the Nvidia run/deb packages by just taking the deb file and unpacking it (not installing). The 10.x debs just contain other deb files, delete the unwanted Nvidia ones.  Then again just unpack them all.

You should wind up with a complete set of the CUDA files (bin and lib) in your local directory, with no package manager tie-in.  Change your PATH and LD_LIBRARY_PATH to include them. The one thing you still might need would be the old gcc/g++ version required by CUDA -- install them, and simply add links to the old versions in your cuda/bin directory.  DO NOT change the system-wide compiler default with the update-alternatives.  Your system will update and maintain kernels and Nvidia drivers without issue.  You will never get a CUDA update unless you explicitly do it yourself.


Python corrupted: how do I clean a failed install or reinstall a fresh instance?

I'm trying to do the same thing, because of a similar (I belive) bug. But the reinstall process just doesn't work. Here is my question:
Update Manager won't open (error related to pythonverbose)


It worked for me:

use rufus
choose "MBR partition schema for UEFI"
write in DD image mode


How do I create a customized Ubuntu Live CD?

You can try Ubuntu Builder

  Ubuntu Builder is a simple tool to create your own distribution. It allows to download, extract, customize in many ways and rebuild the ubuntu images. You can customize i386 and amd64 desktop ISO images.


How to login in terminal using ctrl+alt+ f1-f6?

Your username is the one before the @ mark on prompt.

Like, mine is ronnie@acer-TM-PLAY. So, my username is ronnie
and the password you know.

When you enter Ctrl+Alt+Fx keys You have to enter that username and the password assigned to it.

Hope it helped


Go to Chrome Menu ⇒ Settings ⇒ Appearance section, unmark Use system title bar and borders.


Videos requires to install plugins to play media files of the following type: application/x-subtitle-unknown decoder

The easiest way to resolve this issue is to install VLC player. VLC contains just about every codec needed to play videos.

sudo apt-get install vlc browser-plugin-vlc

The website can be found at https://www.videolan.org/vlc/download-ubuntu.html


Scripts for hybrid graphics discreete card disable on startup

I'm using

chmod -R 705 /sys/kernel/debug

chown -R $YOURUSERNAME:$YOURUSERNAME /sys/kernel/debug/vgaswitcheroo

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

in my rc.local and it works often for me (not always though).


What's the maximum filename length in encrypted ext4 partition?

This is a known bug about encryptfs for along time. As you can see this is a huge bug and whishlist. They are struggling with to support this for 12.04. I couldn't see a neat solution but there is a workaround. But those files are missing right now. A PPA is being set up but there are'nt any package right now.

So, I can't see a direct solution for this problem. Maybe you can ask John Johansen for a new kernel which is for Oneric.

Note: I couldn't read all the comments, there is a possibility that I missed something. ie, there could be a solution or this possible solution (Johansen's) could harm your files.


There is pyNeighborhood which is a gui for mounting samba shares and available in the software centre for download.

There is a good article located here on how to set it up and use it.

First install cifs utils

sudo apt-get install cifs-utils

Alternatively, the basic terminal command is :

mount -t cifs -o username=USERNAME,password=PASSWD //192.168.1.88/shares /mnt/share

If you'd like to see your mount in Nautilus it would be good to create a subfolder first in /media/USERNAME/ for example:

mkdir /media/paul/cifsShare

also, password could ommited in the mount command for example (will also demonstrate file/folder modes):

sudo mount -t cifs //nas-server/cifsShare /media/paul/cifsShare -o username=paulOnNAS,iocharset=utf8,file_mode=0777,dir_mode=0777,soft,user,noperm

in this case you'll be asked for the password (actually for 2 passwords) on the mounting moment.

Have a read through the Samba documentation here on how to do it and set it up correctly to mount on start up etc.


how to fix spelling mistakes in the man page

The quickest way would be to email the current maintainer listed within the man page.

In this case, it is Kenneth Loafman "kenneth@loafman.com"

Or, you could log into Launchpad and submit a bug to the duplicity team:

Personally, I would send the report to Launchpad as this may have a better chance of hitting a wider audience and getting the desired results. YMMV.


Can I turn off PHP and HTML caching both within an Apache virtual host conf file?

It is possible to configure apache to ignore caching in these various contexts:

server config - used in httpd.conf,
virtual host,
directory -  used inside Directory, Location, Files, If, and Proxy containers in the server configuration files,
.htaccess

In your case its option 2 in this format CacheDisable url-string | on:

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    CacheDisable on    # OR
    CacheDisable "/foo_files"  # OR
    <Location "/foo">
        CacheDisable on
    </Location>
</VirtualHost>

Source:

https://httpd.apache.org/docs/2.4/mod/mod_cache.html#cachedisable

http://www.serverlab.ca/tutorials/linux/web-servers-linux/improve-website-performance-by-enabling-caching-in-apache/

https://www.digitalocean.com/community/tutorials/how-to-configure-apache-content-caching-on-ubuntu-14-04


How to connect to a machine behind a firewall using VNC?

If the sys admins in your laboratory are any good, you can't connect to your work PC from home. Firewalls are in place to prevent exactly that.

Ask them about a 'VPN Login' which stands for 'virtual private network'. If they enable that for you, you could connect you PC at home to the network at your laboratory, being 'virtually there'. You could then connect as if you were in the laboratory as you have tested already. (And also ask them how to set up your computer at home to use the VPN.)

If your admins are not good, you could give it a try. You can make a simple test: go to WhatIsMyIPAddress.com from the PC in the laboratory you want to connect to and from another PC in your laboratory. If they both show you the same IP address, you can not connect. (All your laboratory PCs share the same internet IP, so when connecting from the outside, the system doesn't know which one to connect too. You need your admins' help.)

There are ways to circumvent this problems, but they are quite complicated, involve a lot of work on both sides (your PC at home and your laboratory PC), pose a risk to your network infrastructure and you might really get in trouble with your admins. Do you really want to know?


Ubuntu 12.04 Desktop CentrifyDC problems

Finally, problem resolved by making a script in /etc/network/if-up.d/

sudo vim /etc/network/if-up.d/centrify

with content:

    #!/bin/sh

if [ "$IFACE" = lo ]; then
        exit 0
fi

/etc/init.d/centrifydc restart
initctl emit centrify-connected

after I typed:

sudo chown root /etc/network/if-up.d/centrify
sudo chgrp root /etc/network/if-up.d/centrify
sudo chmod 755 /etc/network/if-up.d/centrify

And then I modified /etc/init/lightdm.conf with right permissions (chown root, chgrp root, chmod 644), and I added only one boot condition.

sudo chown root /etc/init/lightdm.conf
sudo chgrp root /etc/init/lightdm.conf
sudo chmod 644 /etc/init/lightdm.conf

then

sudo vim /etc/init/lightdm.conf

and I added only one boot condition.

# LightDM - light Display Manager
#
# The display manager service manages the X servers running on the
# system, providing login and auto-login services
#
# based on gdm upstart script

description "LightDM Display Manager"
author      "Robert Ancell <robert.ancell@canonical.com>"

start on ((filesystem
           and runlevel [!06]
           and started dbus
           and (drm-device-added card0 PRIMARY_DEVICE_FOR_DISPLAY=1
                or stopped udev-fallback-graphics)
           **and centrify-connected)**
          or runlevel PREVLEVEL=S)

stop on runlevel [016]

emits login-session-start
emits desktop-session-start
emits desktop-shutdown

script
    if [ -n "$UPSTART_EVENTS" ]
    then
        # Check kernel command-line for inhibitors, unless we are being called
        # manually
        for ARG in $(cat /proc/cmdline); do
            if [ "$ARG" = "text" ]; then
        plymouth quit || :
                stop
        exit 0
            fi
        done

    [ ! -f /etc/X11/default-display-manager -o "$(cat /etc/X11/default-display-manager 2>/dev/null)" = "/usr/bin/lightdm" -o "$(cat /etc/X11/default-display-manager 2>/dev/null)" = "/usr/sbin/lightdm" ] || { stop; exit 0; }

    if [ "$RUNLEVEL" = S -o "$RUNLEVEL" = 1 ]
    then
        # Single-user mode
        plymouth quit || :
        exit 0
    fi
    fi

    exec lightdm
end script

post-stop script
    if [ "$UPSTART_STOP_EVENTS" = runlevel ]; then
        initctl emit desktop-shutdown
    fi
end script

Be very careful when you do this !


Why does nfs-kernel-server only pretend to stop?

Maybe your nfs-kernel-server file got trashed in /etc/init.d

I'm running 14.04 server and here is a pastebin of mine

http://paste.ubuntu.com/9651994/

If nothing wrong there on your end, you may need to purge and reinstall.

Edit: I just stopped mine and then checked the status and it said it was not running. I then did

 ps aux | grep nfsd

And it was definitely not running. So like I said, I think your issue is the /etc/init.d/ nfs-kernel-server file.

After further thought, if it were me I would just

 sudo apt-get --purge remove nfs-kernel-server

And then install again with

sudo apt-get install nfs-kernel-server

Unless your on 14.04 server, then just use my pastebin.


Use https://launchpad.net/~seriy-pr/+archive/network-manager-l2tp

sudo apt-add-repository ppa:seriy-pr/network-manager-l2tp
sudo apt-get update
sudo apt-get install network-manager-l2tp-gnome
sudo service xl2tpd stop
sudo update-rc.d xl2tpd disable


You can always confirm which graphics card is being used with: prime-select query.

You can change to Intel iGPU using:

sudo prime-select intel

Then change back to GTX 940M using:

sudo prime-select nvidia

But in both cases you have to reboot for the changes to take effect and the other Graphics to be used.


Setting up remote access through Landscape

You can manage that computer via Landscape. To try it out, go to https://landscape.canonical.com and request a free trial. There is no need for a fixed IP.


How do I run a simple Zenity script after disconnecting from WiFi?

If you're using Network Manager (opposed to the command-line /etc/network/interfaces file), you should use the Network Manager dispatcher scripts instead.

Simply place your script in the /etc/NetworkManager/dispatcher.d/ directory, similar to the if-down.d approach. Scripting with Network Manager dispatcher scripts is rather easy and I suggest to read this (basic) example based as posted on the Arch Wiki:

#!/bin/sh

INTERFACE=$1  # The interface which is brought up or down
STATUS=$2     # The new state of the interface
USERNAME=gert # ENTER YOUR USERNAME HERE

case "$STATUS" in
    'up') # $INTERFACE is up
    # you could do something here...
    ;;
    'down') # $INTERFACE is down
    # Check for other active interfaces and only act on all down
    if [ ! `nm-tool|grep State|cut -f2 -d' '` = "connected" ]; then
        /bin/su -l ${USERNAME} -c 'DISPLAY=:0 /usr/bin/zenity --info --text="all network interfaces down"'
    fi
    ;;
esac

For acting on a specific network, see this answer.

And make sure to restart Network Manager to pick up with this new script.

sudo service network-manager restart


Default login credentials are not working Ubuntu 20.04 on Raspberry Pi 4

If you installed the correct Ubuntu version from here and followed the tutorial here, and you are sure that installation is not corrupted, you could try to reset the password.

mount the sd in rw mode on a linux system
chroot to the mounted sd
use the passwd command to change the user password
reboot

OR

mount the sd in rw mode on a linux system
edit the password file i.e.: /mnt/etc/shadow

Editing the password file:

You'll find a row containig

<your_user>:<hashed_password>:14589::::::

like

pippo:$1$9fsdljkel!nFDSfdfasL.blablabla1!54M:14589::::::

just remove "$1$9fsdljkel!nFDSfdfasL.blablabla1!54M" and obtain

pippo::14589::::::

This way user "pippo" will have a blank password.
Don't try to modify root user because he can't login directly on Ubuntu OS.
Once logged on the system just set the password for that user and check if it is set correctly.


Need compatible USB WiFi adapter for Ubuntu 13.10

There is a list of supported wifi adapters here

I have very good experience with the netgear wpn111
and the Conrad wlan stick n300 mini.

Also almost all Intel adapters are supported.


How can I get out of low graphics mode on 12.04?

I have recently received a similar issue with my System 76 Pangolin Performance laptop.  The folks at System 76 told me to run the following commands:

sudo chown lightdm:lightdm -R /var/lib/lightdm
sudo chown avahi-autoipd:avahi-autoipd -R /var/lib/avahi-autoipd
sudo chown colord:colord -R /var/lib/colord

These commands did the trick for me.

While I believe these commands/users might specific to System 76 it's worth checking the ownership of the directories (if they exist).  Also it would be useful if you edit your post to provide the company that makes your laptop and graphics card as a reference if this does not solve your problem.


Ubuntu on 32-bit UEFI (only) based tablet pc

So far you're doing everything right, you just need to modify the USB so that it will boot on a 32-bit UEFI only system.

While Windows is running or on another machine, insert the USB and find a directory called /EFI/BOOT. This needs to contain a bootia32.efi file (even if there is one there already it might not be one that works - last time I found one but had to replace it)

click here to download a bootia32.efi file that worked for me recently.

Drop this file into the right place (remember all the file and directory names are case sensitive) and your USB should boot, given appropriate UEFI settings (secure boot off, USB first or selected in boot menu)


Bought new computer, downloaded Ubuntu, want to wipe Windows 10 and get started

Create a live USB of Ubuntu using universal USB installer which you'll get from pendrive linux.com.  Disable secure boot and fast startup before installing ubuntu. Boot using live USB by pressing the appropriate key on bootup (F2 or F12) and click install ubuntu option. Check the internet connection and click on first option Erase disk and Install Ubuntu. That's it, in the next reboot you'd have your ubuntu working.


Monitors wont go to sleep and screen won't lock in 16.04

I solved my problem by running unity-tweak-tool and removed check disabling "Desktop Lock". Choose System, then Desktop icons, then click Security tab. Make sure that there is no check against Desktop lock.


You cannot upload a version older or equal to, a version you've already uploaded to a PPA. My advice would be to live with the mistake, and don't make the same mistake in the future. Be sure everything is right, before you upload something to a PPA.

You can use sbuild or pbuilder to run test builds locally in a chroot, to help ensure everything builds properly, before uploading.


How to make an Ubuntu down load bootable

Burn the image to disk, then when you boot to DVD drive, just simply follow the instructions to wipe the hard drive and install Ubuntu.


Ubuntu 10 or 11 installation on MacMini Server 5,3

I haven't actually gotten around to installing, but I booted from an 11.10 USB flash drive that I made. Most hardware was supported, from the HDMI out to ethernet.
I didn't actually install because I was unable to get WiFi and sound to work. If you are planning to use the machine as a true and pure server, it should be fine (especially headless).

Note: on Mini 5,3 i7 2.0 GHz quad with 16GB RAM


Unable to acess SQLite database in Ubuntu using PHP under Apache

The package that you need to have installed is php5-sqlite View on Ubuntu  Packages

You can check if it's installed using a phpinfo(); page. Like this one :

//phpinfo.php, show all PHP info

<?php
    phpinfo();
?>

If you see the module loaded, then the issue is somewhere else. If you can't see the SQLite module, then you should check your php.ini configuration file.


Accessing other drives on an AWS EC2 instance?

tmpfs is a virtual memory filesystem based on your RAM
udev supplies Dynamic device management using virtual files

Those volumes aren't using actual disk, and can't be used for your needs.

Note: If you'd like to convert additional RAM and to use it as temporary disk-space (AKA RAM DISK), you can do it using the following command:

$ sudo mount -t tmpfs -o size=10M tmpfs /mnt/mytmpfs

While using part of your RAM as RAM DISK might work, it will consume that part of your RAM allocated as DISK and your programs won't be able to use it as RAM anymore.

You'll need to make sure that there is enough RAM left for your tasks/processing after you allocate that RAM DISK

In order to have more disk storage and still be able to use your RAM for your programs needs - the simple solution will be to add disks / use other machine with larger disk, or any other AWS solution for having additional disk-storage in your machine.

More info from Ubuntu Man pages:

man tmpfs:

  NAME

   tmpfs - a virtual memory filesystem

  DESCRIPTION

   The  tmpfs  facility  allows the creation of filesystems whose contents
   reside  in  virtual  memory.   Since  the  files  on  such  filesystems
   typically reside in RAM, file access is extremely fast.

   The filesystem is automatically created when mounting a filesystem with
   the type tmpfs via a command such as the following:
   $ sudo mount -t tmpfs -o size=10M tmpfs /mnt/mytmpfs

man udev:

  NAME

   udev - Dynamic device management

  DESCRIPTION

   udev supplies the system software with device events, manages
   permissions of device nodes and may create additional symlinks in the
   /dev directory, or renames network interfaces. The kernel usually just
   assigns unpredictable device names based on the order of discovery.
   Meaningful symlinks or network device names provide a way to reliably
   identify devices based on their properties or current configuration.


How to restore grub2 after failed burg installation?

Boot into the Ubuntu Live CD and run a few commands in a new Terminal window.

First, identify which is the Ubuntu partition:

sudo fdisk -l

Next, mount it (replacing sda2 with the appropriate partition number):

sudo mount /dev/sda2 /mnt

And finally, reinstall Grub (replacing sda with the appropriate hard drive):

sudo grub-install --root-directory=/mnt /dev/sda

Now, run this:

sudo update-grub

This should detect your Ubuntu installation and add it to the Grub menu.

Reboot without the CD, and Grub should now load Ubuntu!


I don't know for sure those images are prepared this way, but I would think the way you want to do this is to use the debootstrap program, which is the debian tool used to initialize a directory tree to contain the bare minimum set of files/packages to have a usable debian/ubuntu system.  This is the tool used to do a by-hand install from another unix like OS, or to set up a chroot or pbuilder or other type of image.  Either format a filesystem, mount it, and point debootstrap to that location, or create a regular directory that you will later convert to a filesystem image with e.g. mksquashfs.  You can chroot into the directory and install additional packages after the debootstrap if you wish.


XAMPP opt/lmapp/lampp start script is doing nothing

This is happen when you don't give the correct path for the script. You should start XAMPP using:

./lampp start

or

/opt/lampp/lampp start

If you are not logged as root, you can use:

sudo /opt/lampp/lampp start

And if you add your /opt/lampp directory to your PATH, after you can start it with:

sudo lampp start


Open the terminal and type:
sudo apt update
sudo apt install make

If that doesn't work see How do I restore the default repositories?.


The best is to download it from ubuntu itself: http://www.ubuntu.com/download
If your on a windows machine you can choose the Windows installer. If your on an Ubuntu machine, download the iso file and then there are two options:

Burn the .iso to a CD/DVD or
use the Startup Disk Creater and create a startup up USB stick.

You can also follow a step by step guide for installing Ubuntu
http://www.ubuntu.com/download/help/install-desktop-latest

Cheers,

Erwin


Change desktop environment from terminal?

Install GNOME Shell normally as you would (ignore the change DE at login screen bit).
I assume so far you logged on using the startx command. So once you installed GNOME 3, try logging on using gnome-shell (or try gnome-session if that doesn't work).

PS: You might also want to look at this question, maybe it will be helpful to you.


How do I set up a domain name to SSH into my webserver?

as long as you use dyndns (http://manpages.ubuntu.com/manpages/bionic/man1/dyndns.1.html) correctly there's no need to additionally setup anything and you will be able to connect to the hostname via domain name. I had this running with my own domain some time ago and it worked fine every time the router IP changed. You could just use the domain name then, since it was already updated on the DNS side.


How can I install a previous version of ICU?

It's a general thing that some software will require a particular version of libicu , and also that having more than one version is without issues :
All files have unique names : libicudata.so.52, etc.

So you can often just install a package without conflicts. icu52 : http://packages.ubuntu.com/search?suite=default&section=all&arch=any&keywords=libicu52&searchon=names → libicu52


Why am I given the option to also encrypt my home folder after I've selected system encryption?

You are being offered 2 layers of Encryption.

The first is LUKS. With LUKS your entire installation (except /boot) will be encrypted, including your home directory.

The second is ecrptfs and is used to encrypt your home directory.

In general there is no need to use the two together, but, you could if for example you have multiple users and you wish to keep data encrypted between users or from root access.

When you use LUKS, when you boot, the data in your /home will be decrypted and as long as the system is running, the data can be read by root and other users.

https://wiki.ubuntu.com/SecurityTeam/Policies#Permissive_Home_Directory_Access

If you so desire , you can restrict access to the data in your home directory by adjusting the permissions or by encrypting your home directory as well.

If you encrypt your home directory, your personal data will remain encrypted when the system boots and will only be decrypted when you log in.

HTH


Netbeans doesn't start, Java fatal error, unless sudo

Playing with the netbeans_jdkhome variable I had the feeling I didn't have the right java installed, so I installed it as described here and then I modified the /etc/netbeans.conf

And then I solved, (i just had another warning saying that one file inside my ~/.netbeans, so I run nautilus with sudo and try to fix it again but graphically)

Ps: do NOT use the netbeans version from the repo, it is broken, better download the last and working one directly from the official site


Ubuntu Server 10.04 will not connect to the internet

It's because the virtual machine was configured to use the virtual network cable, since you've moved it to physical hardware the connection isn't available. You will need to edit your connection to use the new network connection as it's default.

Step #1 = In terminal type "sudo nano /etc/network/interfaces". It should say "# The primary network interface","auto eth0","iface eth0 inet dhcp". Change all
the "eth0" entries to say "eth1". Exit using "cntrl + x" and press "enter" to save (ignore the options listed when saving, just press enter).

Step #2 = In terminal type "sudo ifup eth0".

Step #3 = In terminal type "ping example.djun.net". If succesful your screen will fill with somthing along the lines of "64 bytes from ip-" related outputs.
press "cntrl + c" to stop pinging. You are done! If you didn't successfully ping the server the proceed to next step.

Step #4 = In terminal type "sudo ifdown eth0", then in terminal type "sudo ifup eth0". Now retry pinging by typing in terminal "ping example.djun.net". You
should be done!


Ubuntu upgrade from 12.04 to 14.04 failed - Dell

Try to remove all the PPA's from your PPA list. Then do a sudo apt-get update && sudo apt-get upgrade


How do I access Empathy after is has been "started hidden"

The solution is the following command:

empathy -h & disown; sleep 20; killall empathy


Ubuntu Start Page in Firefox Language changed suddenly

Looks similar to these:

http://ubuntuforums.org/showthread.php?t=1669853
http://ubuntuforums.org/showthread.php?t=1352219

Try typing in about:config into the url bar, then adjusting this:

intl.accept_languages


Avro phonetic isn't working on Ubuntu 20.04 for bengali typing

I have solved this issue by this steps

Logout your profile
Login
Now try the same method avro phonetic will appear

If still not resolved then restart your computer , then repeat the steps and it will work.


Problem with install Oxygen-Transparent theme on Kubuntu

If you try to do:

sudo apt-get install kde-workspace-dev

It will show something like this:

kde-workspace-dev : Depends: libkwinglesutils1 (= 4:4.8.5-0ubuntu0.3) but it is not going to be installed
                    Depends: libkwinactiveglesutils1 (= 4:4.8.5-0ubuntu0.3) but it is not going to be installed

Then again:

sudo apt-get install libkwinglesutils1 libkwinactiveglesutils1

And Now you can try again your former command:

sudo apt-get install kdebase-workspace-dev libxrender-dev libx11-dev git


How to cause xfce4 whiskermenu to invoke when super is pressed?

Whiskermenu has the xfce4-popup-whiskermenu command.
Whiskermenu will pop up when you run this command.
(I don't know how to assign a shortcut to the command in Unity.)


Autoconnecting to bluetooth device on startup and autochanging audio output

Important note: due to changes in the d-bus protocol introduced with Bluez5 bt-autoconnect <= 0.2.2 will at present only work with Bluez4.

bt-autoconnect
There is a python tool bt-autoconnect designed to connect to an existing audio headset as soon as it becomes available. This is useful in case we do not want to load the pulseaudio module-switch-on-connect in our default.pa (see this question).
It will also connect a known device with the Bluetooth adapter (disable this if you want to connect manually), and it will be able to switch the audio sink to the Bluetooth sink without interrupting playback of an audio stream.

In case only one Bluetooth audio device is registered in Bluez settings we can choose "Auto" to autodetect this device. If we had paired more than one device we may need to specify the device by its MAC. If we do not specify the MAC bt-autoconnect will take the first device in the list which may not be the one we want.
If we choose to add bt-autoconnect to the Startup Applications it will start at login minimized to its Application Indicator only
In the Application Indicator menu we are able to switch between HSP (low quality telephony) profile with headset microphone enabled, or A2DP high quality audio profile where the microphone will not be available, provided this is supported by our headset.


Batch/Multi rename only files with a specific number range

Using rename

A generally useful tool for this type of activity is rename from the perl package.  It applies a perl substitution to the file name:

rename 's/file/file0/' file[0-9][0-9].ext

How this works:

s/file/file0/

This is a perl substitution command.  It replaces the occurrence of file in a file name with file0.
file[0-9][0-9].ext

This is the list of files that rename is to operate on.  [0-9] means any number from 0 to 9.  [0-9][0-9] means any two numbers, one following the other.

The manpage for rename is here.

Note: This requires the perl version of rename.  There is also a rename utility that is part of util-linux but it works differently.

Using bash

This approach uses a for loop combined with pattern substitution:

for f in file[0-9][0-9].ext; do mv "$f" "${f/file/file0}"; done

How it works:

for f in file[0-9][0-9].ext; do

This starts a loop over each file name that matches the glob file[0-9][0-9].ext.
mv "$f" "${f/file/file0}"

This renames the files using the bash's pattern substitution.  It replaces file with file0` in the file name.
done

This marks the end of the for loop.

This approach requires bash (or other advanced shell).

bash is the default interactive shell and this approach will work under bash.  Thus, this should work on the usual command line.


no booting device after installing Ubuntu

I had a similar issue, this has to do with Secure Boot permissions:

Press F2 at boot and go into BIOS.
In security create a password for logging into bios. Then a bunch of options will become available to you.
One of the options is to pick or load a uefi file for secure boot.
Go into that and you should find grub in there.
It will add grub as a possible place to boot from using secure boot.
Save and restart and come back but this time go to the boot tab.

You should now see your newly added boot option.


Accidentally deleted all my partitions after Ubuntu 14.04 installation

testdisk is a great tool. I had your same situation one year ago, testdisk helped me to recover too many files, but remember that is better to use  testdisk using Ubuntu in Live mode, try to recover your files using  testdisk as soon as you can.

open your terminal and type

sudo  testdisk

then enter your password and select the first option "create" to create a logo file
select the HDD that you want to search for delete files
the program will chose it self the correct option for you, if your computer have EFI support it will select it for you, if you are using a Mac select Apple partition map, if you are using an Intel PC or AMD PC select the first option "Intel/PC partition"
select analyse your hard disk for partitions
select tip QUICK SEARCH to let testdisk find all your partitions, be carefully while you navigate in the terminal the later D means Delete

testdisk will ask for search for partition created under Windows Vista or later. select the correct answer tipping Y for yes or N for no
after explorer your disk It will show you all your partitions, select the partition that you have been deleted/formatted

then select DEEP SEARCH, after scan the partition that you have been selected, it will  ask you to select the destination, is recommended to select an external device like External Hard Drive.

Check this link in my Google+ https://plus.google.com/u/0/100263103486581717464/posts you can see step by step how to use testdisk. If you have any question or you did understand what I wrote just ask.