Is it possible to access source code or a config file of a terminal command, to read how it works and even customize it on local computer?

Quick Answer:

Research the terminal command.

There's no absolute set rule of where the variables or details are stored.  If you don't know the details of a terminal command, you'll have to look it up to be sure.

Most terminal commands, especially the commands that have lots of options, have manuals that are installed on the system by default, which makes this looking up easy.  That also includes the shell for the terminal commands which in the case of Ubuntu is bash by default.

Before the internet was so popular for performing the not knowing that you refer to, people relied much on the libraries, books, and manuals.  People had many books and manuals in their home.  The went to the bookstore and library often.  I used to spend many hours in the library, almost always had two or three books checked out for home research (or programming and commands).  It's been around 20 years since I went to the library to do research.  I do from time to time go to the library for some seminars, or meetings.  I also belonged to two computer clubs, who shared information.  Both clubs published monthly newsletters which included important computer and programming information.

If you don't have access to the Internet you can use the manuals that are already your computer for the terminal commands.

Thank of a terminal command and type this:

$ man [terminal command]

You can research bash and the import command (from your question) with:

$ man bash
$ man import

Both manuals will show you lots of information that you can research without the internet.  They also include a glossary which you can use words from those manuals to do further research.

To know the details of the variables of a command, you'd have to research the particular command.  Some of the same commands might even have various flavors or variations which might store some of it's variable or details in a different area depending on the Linux distribution or the maintainer of the specific command.

How to download the source code of Ubuntu's commands and applications:

You can download the source code of the commands by adding the source to your repository.  You can find this by:

 Goto Software & Updates ->
(click on the tab) Ubuntu Software ->
 (put a check mark on) Source code

Use this command to get the source package you want to download:

$ sudo apt source <package name>


How to make window topbars dark in ubuntu 13.10 and Cinnamon?

In Cinnamon, you need to go to "Themes", then "Other Settings" and then "Window Borders". If you only have Adwaita, then you need to install some GTK themes, not shell themes and then you can change the top bar.


Find out the total system installation size

Try df -h.

It will show information in the form

Filesystem      Size  Used Avail Use% Mounted on


I succeeded by inserting at the end of the ~/.zshrc file the following command:
if [ `tput colors` != "256" ]; then
  exec bash -l;
fi

So, if the environment does not support 256 colors, bash is launched.


Problems with Qualcomm Atheros AR9285 Wireless Network Adapter

Let's get the driver to load automatically on boot. Open a terminal and do:

sudo -i
echo ath9k  >>  /etc/modules
exit

Reboot. Check:

iwconfig
dmesg | grep ath

Please post the result here and let us have the link in your reply. http://paste.ubuntu.com


17.xx kernel errors due to Ubuntu kernel, or possible hardware problem?

As per @Terrance, I visited https://bbs.archlinux.org/viewtopic.php?id=228604 and found this:

That comes from the intel driver and I'm not sure if it's still some driver bug lurking somewhere or because of an hardware bug or limitation. It used to be much worse and manifest itself even your the intel iommu off, as you can probably find by googling for similar problems, and it affected many generations of intel igpus.

That said you really want to disable the iommu for the igpu because if you use it some power saving feature is turned off automatically due to a hardware bug, there is even a message on dmesg about that. You can still use the iommu for everything else though, just use intel_iommu=on,igfx_off in your kernel parameters line.

I added intel_iommu=on,igfx_off to my /etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_iommu=on,igfx_off"

and did a sudo update-grub, rebooted, and so far, no more drm errors!


Try resetting the root password, this is only a temporary fix lmfao, read my post and you'll know why, reset the password and it'll work for a few days atleast


how to make unity available on login-screen

Make sure you also installed the unity-greeter package.

You can install it via sudo apt-get install unity-greeter from the terminal. Or search for this packages with your preferred package managemetn tool.


How to make gnome classic the default desktop using command line tools?

1) Edit your ~/.dmrc file

nano ~/.dmrc

It should look something like the example below. There may be several lines relating to keyboard layout, language, etc, but you can ignore those.

[Desktop]
Session=gnome

2) Replace gnome with whatever you want, in this case gnome-classic.

3) Save with Ctrl - O and then Ctrl - X to close.


Is there a way to install SSDT (SQL Server Data Tools) on Ubuntu?

No. These are Windows tools to be used on a Windows machine.
From Microsoft docs:

Use existing SQL tools on Windows with SQL Server on Linux
Tools that currently run on Windows such as SSMS, SSDT, and PowerShell, also work with SQL Server 2017 on Linux. Although they do not run natively on Linux, you can still manage remote SQL Server instances on Linux.
See the following topics for more information:

SQL Server Management Studio (SSMS)
SQL Server Data Tools (SSDT)
SQL PowerShell

so ...

Still after a lot of searching, I couldn't find any solution. I have already installed SQL Server 2017 on my Ubuntu machine, but now I need your help for installing these services :)

You need a Windows machine; if that was not the case you would be able to use their tools without any connection to Microsoft.
Possible method: install virtualbox in your Ubuntu desktop, Windows in there and the tools in there and then connect to your SQL server.


Dual Boot Windows and Ubuntu Insert Media Tool Error. Can you help me?

Is the installation supposed to be a dual boot of windows 7 and Ubuntu? If so, the grub from Ubuntu should be able to detect the Windows 7 and add it to the startup options. Or maybe you already notice the Windows 7 during installation of Ubuntu.

I had a very similar issue several years ago but it was actually my own fault. I set up a dual boot of windows 7 and Ubuntu and used the grub as the boot manager instead of Windows's. Later I tried to uninstall Ubuntu by deleting the Ubuntu disk within Window 7 and of course I was doomed as the grub was deleted as well. However I found some information saying that I can modify the MBR to manually point to the loader of the remaining Windows 7. Can't remember if I used a Windows 7 installation disk to enter recovery mode but I remember the modification was in the black screen. Anyway it worked out for me eventually.


Is it possible to reveal the Gnome3 launcher just by moving the pointer near the left hand side?

Did you try flicking the pointer to the very upper left corner of your screen? That's how it works in Debian, at least.


Try running these commands on the terminal

sudo dpkg --clear-avail

sudo apt-get update

think this will resolve the issue.


I uninstalled virtualbox, do I get the allocated storage I gave it back?

With VirtualBox, you allocate yourself a Virtual Hard Disk as you mentioned above.

You mentioned you allocated 9.5GB to Windows. Simply delete this Virtual Drive and all of that space is given back to you.

As the answer from user146001 mentions, in your Home directory, you enable "Show Hidden Files" (or press Ctrl + H to see hidden files) and find your .VirtualBox folder. In there, go to your HardDisks folder and simply delete the .vdi files, as these are the files of your virtual drives.

You can go about this via the terminal or via the file manager.

Please visit this link more information on VirtualBox and visit here for alternative (or even recommended) ways of removing Virtual Hard Disks.


Which ubuntu-minimal image can be used for Azure

according to https://ubuntu.com/blog/minimal-ubuntu-released
On Dockerhub, the new Ubuntu 18.04 LTS image is now the new Minimal Ubuntu 18.04 image. Launching a Docker  instance with docker run ubuntu:18.04  therefore launches a Docker instance with the latest Minimal Ubuntu.
you can find the docker hub for ubuntu here : https://hub.docker.com/_/ubuntu
for 18.04 this is the dockerfile ubuntu uses to build the docker image (lcick on bionic in this page)

https://github.com/tianon/docker-brew-ubuntu-core/blob/74249faf47098bef2cedad89696bfd1ed521e019/bionic/Dockerfile
i.e.
FROM scratch
ADD ubuntu-bionic-core-cloudimg-amd64-root.tar.gz /

# a few minor docker-specific tweaks
# see https://github.com/docker/docker/blob/9a9fc01af8fb5d98b8eec0740716226fadb3735c/contrib/mkimage/debootstrap
RUN set -xe \
    \
# https://github.com/docker/docker/blob/9a9fc01af8fb5d98b8eec0740716226fadb3735c/contrib/mkimage/debootstrap#L40-L48
    && echo '#!/bin/sh' > /usr/sbin/policy-rc.d \
    && echo 'exit 101' >> /usr/sbin/policy-rc.d \
    && chmod +x /usr/sbin/policy-rc.d \
    \
# https://github.com/docker/docker/blob/9a9fc01af8fb5d98b8eec0740716226fadb3735c/contrib/mkimage/debootstrap#L54-L56
    && dpkg-divert --local --rename --add /sbin/initctl \
    && cp -a /usr/sbin/policy-rc.d /sbin/initctl \
    && sed -i 's/^exit.*/exit 0/' /sbin/initctl \
    \
# https://github.com/docker/docker/blob/9a9fc01af8fb5d98b8eec0740716226fadb3735c/contrib/mkimage/debootstrap#L71-L78
    && echo 'force-unsafe-io' > /etc/dpkg/dpkg.cfg.d/docker-apt-speedup \
    \
# https://github.com/docker/docker/blob/9a9fc01af8fb5d98b8eec0740716226fadb3735c/contrib/mkimage/debootstrap#L85-L105
    && echo 'DPkg::Post-Invoke { "rm -f /var/cache/apt/archives/*.deb /var/cache/apt/archives/partial/*.deb /var/cache/apt/*.bin || true"; };' > /etc/apt/apt.conf.d/docker-clean \
    && echo 'APT::Update::Post-Invoke { "rm -f /var/cache/apt/archives/*.deb /var/cache/apt/archives/partial/*.deb /var/cache/apt/*.bin || true"; };' >> /etc/apt/apt.conf.d/docker-clean \
    && echo 'Dir::Cache::pkgcache ""; Dir::Cache::srcpkgcache "";' >> /etc/apt/apt.conf.d/docker-clean \
    \
# https://github.com/docker/docker/blob/9a9fc01af8fb5d98b8eec0740716226fadb3735c/contrib/mkimage/debootstrap#L109-L115
    && echo 'Acquire::Languages "none";' > /etc/apt/apt.conf.d/docker-no-languages \
    \
# https://github.com/docker/docker/blob/9a9fc01af8fb5d98b8eec0740716226fadb3735c/contrib/mkimage/debootstrap#L118-L130
    && echo 'Acquire::GzipIndexes "true"; Acquire::CompressionTypes::Order:: "gz";' > /etc/apt/apt.conf.d/docker-gzip-indexes \
    \
# https://github.com/docker/docker/blob/9a9fc01af8fb5d98b8eec0740716226fadb3735c/contrib/mkimage/debootstrap#L134-L151
    && echo 'Apt::AutoRemove::SuggestsImportant "false";' > /etc/apt/apt.conf.d/docker-autoremove-suggests

# verify that the APT lists files do not exist
RUN [ -z "$(apt-get indextargets)" ]
# (see https://bugs.launchpad.net/cloud-images/+bug/1699913)

# make systemd-detect-virt return "docker"
# See: https://github.com/systemd/systemd/blob/aa0c34279ee40bce2f9681b496922dedbadfca19/src/basic/virt.c#L434
RUN mkdir -p /run/systemd && echo 'docker' > /run/systemd/container

CMD ["/bin/bash"]


How to run "systemctl" + $ + "apache" $=stop,start,restart as non sudo/root user?

Create a Cmnd_Alias in /etc/sudoers like:
Cmnd_Alias APACHEADMIN = /usr/bin/systemctl start apache2, /usr/bin/systemctl restart apache2, /usr/bin/systemctl stop apache2

Then add a line for the user privilege:
jsmith  ALL = NOPASSWD: APACHEADMIN


mount cifs share on terminal fails (using password or kerberos krb5 ticket)

I recommend you use fstab for mounting.

Try to check the logs to troubleshoot the causes of your problem, try this command to display the list of files which could display the mount logs:

grep -e mount -e ext4 -lR /var/log 2> /dev/null

For me, the mount logs were in /var/log/syslog it may be different for you.

Now you need two terminal tabs open, enter the command on one tab: sudo tail -f /var/log/syslog

And on the second tab, try to mount the system with the following command:

mount -t cifs -o user=USER,domain=DOMAIN,cruid=USER,sec=krb5 //HOST/Share /mnt/tmp

If you go back to your first tab you should be able to see some log errors.
For me the errors were(for you it may be different):

   kernel: No dialect specified on mount. Default has changed to a more secure dialect, SMB2.1 or later (e.g. SMB3), from CIFS (SMB1). To use the less secure SMB1 dialect to access old servers which do not support SMB3 (or SMB2.1) specify vers=1.0 on mount.
   kernel: CIFS VFS: protocol revalidation - security settings mismatch
   kernel: CIFS VFS: session ffff90a6a2959000 has no tcon available for a dfs referral request
   kernel: CIFS VFS: cifs_mount failed w/return code = -5

Depending on your error logs, you may be able to get away with adding vers=1.0 to your mount command and this could work but it is the less secure version of smb. Otherwise, you could workout what the solution is based on the error you get.

What you could also try is configure the Samba server inside /etc/samba/smb.conf similar to this (it works for me):

[username]
   comment = Username's developer directory
   read only = no
   locking = no
   path = /var/www/username
   guest ok = no
   writeable = yes

Then on the client, add the following line to /etc/fstab

//server/username /mountpoint cifs vers=1.0,username=username,iocharset=utf8,uid=your_profile_uid_on_the_server 0 0

Use sudo mount /mountpint
See how this goes, hopefully this information will be useful to you.


SCP from an Ubuntu device to an Ubuntu VM in Windows

Not sure what error it's throwing for you, might be a syntax error.
If you are logged into the Ubuntu VM then it should be as simple as scp username@ipaddress:file.txt /some/place/local/. The man page for SCP is confusing and not very clear.

Have a looksee at this page for a few examples: http://www.hypexr.org/linux_scp_help.php


Mouse skipping with Ubuntu 18.04 on Dell Inspiron 3558

After exhausting various resources, I decided to try a different flavor of Linux. I installed LinuxMint 19.1 (Tessa). OMG, what a huge difference. I have been running it daily for over a week now. Not only did it solve my mouse skipping issue, the laptop now runs sooo much faster. I hope this info is helpful to others.


Ubuntu 12.10 - Problems with installing Nvidia Drivers

I used a combination of the info in the link below and a bit of luck!

http://www.dedoimedo.com/computers/ubuntu-quetzal-nvidia.html


You need to resize these images:

sudo convert /usr/lib/primeindicator/intel.png -resize 24x24 /usr/lib/primeindicator/intel.png
sudo convert /usr/lib/primeindicator/nvidia.png -resize 24x24 /usr/lib/primeindicator/nvidia.png


Share network with second ethernet port ubuntu 17.10

You need to define a bridge. As Ken Sharp posted, this is in the documentation.

network:
version: 2
renderer: networkd
ethernets:
     enp1s9:
        dhcp4: false
     enp1s10:
        dhcp4: false
bridges:
    br0:
        interfaces: [ethernets]
        dhcp4: true
        parameters:
            stp: false
            forward-delay: 0

This should in theory work. I've not tested it, as I don't have a box with netplan avaialable.


Where could I find drivers of ATI Radeon 2400 HD?

Go to the AMD website.
Select the appropriate categories in their drop downs (see image)
Click "View Results". You found the driver. Congratulations!

To install them:

Run in terminal:

sudo sh ati-driver-installer-10-3-x86.x86_64.run

Note:-if the filename is different, then change the name. You will be asked for your password.
Select the first option, then click next, then use all the recommended options.
To get sound working right click on the sound icon on the top right, click sound preferences. Go to Output and select the RV630 or whichever your one is.
If the sound still doesn't work, go into a terminal window again and type:

killall pulseaudio
sudo alsa force-reload

Source: Ubuntu Geek. Google is your friend.


Why linux can't deal with hybrid graphics easily?

Hybrid graphics a set of two graphic cards with different abilities and power consumptions.

The (Old) Basic Switching Model -

This approach involves a two graphic card setup with a hardware multiplexer (MUX). It allows power save and low-end 3D rendering by using an Integrated Graphics Processor (IGP); or a major power consumption with 3D rendering performance using a Dedicated/Discrete Graphics Processor (DGP). This model makes the user choose (at boot time or at login time) within the two power/graphics profiles and is almost fixed through all the user session.

The (New) Dynamic Switching Model -

In this approach, the DGP and IGP are plugged to a framebuffer and there is no hardware multiplexer. The IGP is always on and the DGP is switched on/off when there is a need in power-save or performance-rendering. In most cases there is no way to use only the DGP and all the switching and rendering is controlled by software.

The problem with dynamic switching in Linux -

At startup, the Linux kernel starts using a video mode and setting up low-level graphic drivers which will be used by the applications. Most of the Linux distributions then use X.org to create a graphical environment. Finally, a few other softwares are launched, first a login manager and then a window manager, and so on. This hierarchical system has been designed to be used in most of cases on a single graphic card.

Therefore, the kernel has to be indicated that the graphic switching has to be done in a dynamic manner by means of a driver. However, most manufacturers like Nvidia and AMD are focused more towards the Windows side since it is more popular due to the number of games that are designed for it and the user base. It is basically a vicious cycle in which linux gets stuck.

Reference : Arch Wiki


All SFTP sessions are encrypted and authenticated by the server's host key.

If you already generated your key files, You may add it going Edit -> Setting -> SFTP and Add KeyFile

If not, You may access the server just typing like this:


No, Canonical has stopped shipping free CDs since April 2011. You might want to refer to the above link in the comment as to why they stopped shipping free CDs.


The hardware information that you had provided in your earlier question says that you are using Ubuntu 12.04 on a machine that has a NVIDIA GEFORCE GT 520MX graphics adapter.

Install the NVIDIA drivers in an alternative way, but first remove all NVIDIA related software you have had installed ... this includes bumblebee ... it will be replaced with nvidia-prime.

Highlight the Ubuntu entry in the GRUB boot menu and press the E key.
Add nouveau.modeset=0 to the end of the linux line - press F10 to boot.

On login screen press Ctrl+Alt+F1 - enter user name and password - execute :

sudo apt-get purge nvidia* bumblebee
sudo reboot

Install the stable NVIDIA drivers for GEFORCE GT 520MX from the official Ubuntu repositories :

Highlight the Ubuntu entry in the GRUB boot menu and press the E key.
Add nouveau.modeset=0 to the end of the linux line - press F10 to boot.

On login screen press Ctrl+Alt+F1 - enter user name and password - execute :

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

Update addressing the comment under your question that you are using Ubuntu 15.04 now :

Generally you should use the drivers from the official Ubuntu repositories. But when you have problems with these drivers ... you can install the drivers from the GPU Drivers PPA.

Uninstall the currently installed NVIDIA drivers 352 :

Highlight the Ubuntu entry in the GRUB boot menu and press the E key.
Add nouveau.modeset=0 to the end of the linux line - press F10 to boot.

On login screen press Ctrl+Alt+F1 - enter user name and password - execute :

sudo apt-get purge nvidia*
sudo reboot

Install the latest official stable NVIDIA drivers 358 :

Highlight the Ubuntu entry in the GRUB boot menu and press the E key.
Add nouveau.modeset=0 to the end of the linux line - press F10 to boot.

On login screen press Ctrl+Alt+F1 - enter user name and password - execute :

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt-get update
sudo apt-get install nvidia-358 nvidia-prime
sudo reboot


OpenTLD MatLAB mex error, OpenCV library

It looks like the provided compile.m is hard-wired for a particular version (and location) of OpenCV:

if isunix
    disp('Unix');

    include = ' -I/usr/local/include/opencv/ -I/usr/local/include/';
    libpath = '/usr/local/lib/';

    files = dir([libpath 'libopencv*.so.2.2']);

I was able to get it to compile and link on 64-bit Ubuntu 16.04 with the standard libopencv-dev 2.4.9 from the repository by making the following changes:

if isunix
    disp('Unix');

    include = ' -I/usr/include/opencv/ -I/usr/include/';
    libpath = '/usr/lib/x86_64-linux-gnu/';

    files = dir([libpath 'libopencv*.so.2.4'])

NB I did not attempt to test the resulting mexa64 objects


How to remove proxy set in the office when working at home?

You most likely have http_proxy set either as a system-wide setting (either in /etc/profile or in /etc/bash.bashrc) or as your private setting (in ~/profile, ~/bashrc or wherever your sysadmin decided to put it).

You can get-rid of that per bash session using unset:

unset http_proxy
unset https_proxy

Or you disable it permanently when you locate where exactly it is being set.


Differences between grep, fgrep and egrep

See man grep:

  The  variant  programs  egrep,  fgrep  and  rgrep are the same as grep -E, grep -F, and grep -r, respectively. These variants are deprecated, but are provided for backward compatibility.

And

Pattern Syntax
   -E, --extended-regexp
          Interpret PATTERNS as extended regular expressions (EREs, see below).

   -F, --fixed-strings
          Interpret PATTERNS as fixed strings, not regular expressions.

   -G, --basic-regexp
          Interpret PATTERNS as basic regular expressions (BREs, see below).
          This is the default.

   -P, --perl-regexp
          Interpret PATTERNS as Perl-compatible regular expressions (PCREs).
          This option is experimental when combined with  the  -z  (--null-data)
          option, and grep -P may warn of unimplemented features.

Prefer grep -F whenever you have no pattern to match as it is a lot faster.
Use grep -E and especially grep -P only when Basic Regex does not fullfil your needs as the matching will be slower.


How to install ffmpeg 3.0 on Ubuntu 15.10

I found this as a working solution for 16.04.

sudo add-apt-repository ppa:jonathonf/ffmpeg-3
sudo apt update
sudo apt upgrade
sudo apt install ffmpeg

More information can be found here.


Portable monitors that work with Ubuntu/Linux

Yes I use one of those Asus monitors daily with my 2017 XPS 13, it works well.

I had to get to grips with xrandr and use 2x scaling on it.

I use mine in portrait orientation and unfortunately the supplied protective cover that doubles up as a stand does not work well as a stand in portrait, so I bought a folding plate stand off eBay that works admirably, and folds flat to maintain portability.

I'm using Kubuntu 18.04.
It will not fit in a 13" laptop bag for my XPS 13 but it does fit in a 15" laptop bag.

It's handy needing only one USB-C cable but it does make the laptop fans more likely to come on. Under simple editing they don't, but an app I use sometimes running under wine makes the fans come on after a few minutes when I have the monitor connected, but not otherwise. Nothing bad though...I use both daily.


update-grub warning regarding GRUB_DEFAULT title name

The Grub-manual states:

  Previously it was documented the way to use entry title. While this still works it’s not recommended since titles often contain unstable device names and may be translated

Your entry-title contains a device-name (/dev/nvme0n1p2). Devices names may change if you remove or add a drive or reconnect the existing drive to a different slot.

In such a case the menu-entry-titles in /boot/grub/grub.cfg would be updated when you run 'update-grub' and this would make the default (which remains the same) invalid. Thus you get a warning, you can still use it if you want and knowing what you're doing, never add or remove drives.

It's recommended to use the menu-entry-ID instead which does not contain a device name but the UUID of the partition you want to boot from, that's much more stable.

You don't need to use the two-level-identifier. I just copied the identifier of my first menu-entry from /boot/grub/grub.cfg and set

GRUB_DEFAULT='gnulinux-simple-06a41c79-a7ff-4fd2-86eb-fb4f510bf31a'

and then ran sudo update-grub which finished silently (no error, no warning), also no problems during reboot.


How to install Postler (From elementary)

Check me here, but I believe Elementary OS provides updates/software for 10.04 and 10.10.  That is, unless something has changed as of late, 11.04 is likely not supported.


You can get similar behavior with the compose key. The compose key can be set under System Settings -> Keyboard -> Layout -> Options -> Compose Key. Now, to type ü, press compose, release compose and then proceed as you would in Windows.

Edit: Misread slightly, you'd need to make the keys dead before doing this, which for me, they were by default.


If I create two files with same content , should their hashes be the same?

Aren't there any property of the files that could be responsible to produce different hashes using SHA 256 ?

  Creation time is same.modification time is different.

mtime and other file properties is not a part of file content. The "file content" is whatever you can read with "read" C function. You can also use, for example, hexdump -C myfile, which uses read function internally, to see the content of a file "myfile". So if it's the same, hashes would also be the same.


Take a look at this Ubuntu Documentation.


How do I turn off automatic switching of windows?

seems following extension was activated. I don't remember installing it. I had to disable it .


The PPA you added to install Flareget does not have any software for Ubuntu 13.10 (saucy).

You will have to the the Flareget software somewhere else.

First, lets remove the PPA so that apt can work without errors.

sudo apt-add-repository --remove ppa:upubuntu-com/flareget-i386
sudo apt-get update

Now, download the .deb installer for Flareget from here: http://flareget.com/download

Double click on the .deb file you download and Ubuntu Software Center will install it for you.


if you're still interested in an answer, in the months since you posted this question in November 2015, I have started being the maintainer of the most popular version of LibHand that was uploaded to GitHub.

We have moved the repository to https://github.com/libhand/libhand/

As of writing LibHand should compilation and run fine on modern Debian (and derivatives such as Ubuntu) if you follow those instructions.

  Satisfying software dependencies under Debian/Ubuntu

  The following instructions allow compilation of LibHand without too much trouble on all versions of Debian/Ubuntu currently supported by the Debian Project and Canonical.

  See the 'Supported platform' section of README.md for exact OS versions LibHand currently supports.

sudo apt-get install build-essential cmake git libogre-1.9-dev libglu1-mesa-dev libxt-dev libopencv-dev tcl tk libboost-system-dev libboost-filesystem-dev

  On Ubuntu 12.04 and Debian Wheezy, there is no libogre-1.9-dev package available, so substitute with libogre-dev (which is v1.7.4 on those systems).

  On a fresh Ubuntu 12.04/14.04/16.04 install, if apt-get is unable to locate the OpenCV (libopencv-dev) and OGRE packages, append 'universe' to your sources.list, run sudo apt-get update and try again.

  Compiling libhand and pose_designer

git clone https://github.com/libhand/libhand
mkdir build
cd build
cmake ..
make
# Collate libhand build artifacts into local "dist" directory (for external applications to link against)
make install
# Ensure path exists first: on 32-bit, x86_64 is replaced with i386. Replace OGRE version with whatever was installed (likely OGRE-1.9.0, OGRE-1.8.0, or OGRE-1.7.4).
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/lib/x86_64-linux-gnu/OGRE-1.9.0
./hand_cpp/source/pose_designer

(Source)


How to download Ubuntu updates to a flash drive, and use it to update other PCs?

Try the apt-offline package:

Description: offline APT package manager
apt-offline is an Offline APT Package Manager.
apt-offline can fully update and upgrade an APT based distribution without
connecting to the network, all of it transparent to APT.
apt-offline can be used to generate a signature on a machine (with no network).
This signature contains all download information required for the APT database
system. This signature file can be used on another machine connected to the
internet (which need not be a Debian box and can even be running windows) to
download the updates.
The downloaded data will contain all updates in a format understood by APT and
this data can be used by apt-offline to update the non-networked machine.
apt-offline can also fetch bug reports and make them available offline.

Here's an example of shell usage. It's easy to learn.  From the same page, here is how to use it:

Using apt-offline:
You generate a signature on your Debian box at home and carry the signature file on a removable medium (Probably a USB Stick).(e.g. "apt-offline set /tmp/apt-offline.txt")
Now you take the USB Stick (with the apt-offline.txt signature file) to the office machine which could be running any linux version, or as I mentioned above, even Windows.
There, you could run apt-offline giving it the signature file. (e.g. "apt-offline get C:\apt-offline.txt")
apt-offline would generate you an archive file or a folder with all the data.
That data can be copied on a removable media. The removable media can be attached back to the disconnected Debian box at home and installed. (e.g. "apt-offline install /tmp/apt-offline.zip")

Here's the manpage

...or you can make things SUPER-easy with the apt-offline-gui package.

This package contains the graphical user interface to apt-offline.


Every directory contains a . and a .. entry.
. means the directory itself. It is called the current directory.
.. means the directory's parent directory, that is, the directory that contains it.
There is one directory that is not contained by any other directory: /. So / is special--like all other directories, it contains a .. entry, but its .. entry is itself. So for /, and only for /, .. and . are equivalent.
These directory entries are handy for a variety of purposes. For example, you can change directory to the parent of the directory you're currently in with the command cd ...
You may have seen . in the context of running programs or scripts. In a Unix-style shell, when you run a command by name, the shell doesn't automatically try to run a program by the name in the current directory. (This is surprising to some users coming from Windows, where traditionally that would happen.) The main reason for this is security--if someone creates a program in their directory that has the same name as some system administration tool, and you run that tool while in their directory, they could have just tricked you into running their program.
So, to run a program that is not in your PATH, you must call it by some name that has a / in it. To run a program in the current directory, you can use ./program. (You cannot use /program, because that is an absolute path and means "the file called program in the root directory, /.")


ppa.launchpad.net does not support https

As the packages you download from launchpad are all cryptographically signed just like with every other debian repository, a man-in-the-middle attack is not really feasible. apt checks the signature of the downloaded .deb files and any tampering would lead to an invalid signature. Invalid signatures cause an error prior to installation. So I don't see this as a major problem from a security perspective.
One could argue that it is a violation of privacy as anyone listening in on the connection could see which software you are installing. Therefore, an HTTPS connection would indeed be preferable.
As for your last question regarding if they couldn't just add the certificate and be done with it, we both don't know how the infrastructure behind ppa.launchpad.net works. For a single server things are often that simple. But I doubt that we are talking about a single simple server. The infrastructure is probably more complicated than that and therefore the setup may be more complicated. There are also issues regarding server load to consider, as encrypting all outgoing traffic requires a lot more CPU cycles than just delivering it. Depending on the volume of traffic they receive this may cause significant load on the server which they might not want to handle. But please bear in mind that this is just speculation on my part and the reasons might be entirely different.


Why could I not export variables permanently?

profile is only read when you login, have you tried a login shell bash -login,bash -,logging out and then back in or just plain old rebooting?

You can use .bashrc if want it every time you spawn a shell.


You're essentially within a container or host, and only have rights to the instance, and not the host. Without knowing the credentials, or IP location of your Hyper-V host, you do not have much to go off. Apart from an NMap scan on your logical network, or perhaps checking your netstat for communication, you're going to struggle.


Can I do something with my partitions so I can install Windows alongside Ubuntu?

Use gparted to resize the Ubuntu partition, and then create a new partition with the NTFS file system. Then install windows from the CD to that partition (it will automatically pick that up as the partition to install to). You may need create an Ubuntu liveCD, and use it to reinstall grub, as windows will have replaced grub with its bootloader. (I can provide a link on how to do this if necessary). TL;DR make sure there is an NTFS partition somewhere on the disk.


Packages go missing after bootup and certain indicators don't seem to install anymore

To install the Unity indicators that are included with the basic Ubuntu Unity installation, run the following command.

sudo apt-get install indicator-appmenu indicator-application indicator-sound indicator-bluetooth indicator-datetime indicator-keyboard indicator-messages indicator-printers indicator-power indicator-session telepathy-indicator

Xfce offers a different set of indicators than Unity. Also, the network-manager indicator is not the same as the "network-indicator". The Unity network-manager indicator is part of one of the complete indicator packages included in Unity. (Unity8 is for Ubuntu touch) Furthermore, xfce4 now offers a panel indicator that specifically displays the complete group of Unity indicators.

Right click on your top panel and select add new item to panel.

You can safely remove Unity8 and all dependencies by running the following commands:

sudo apt-get purge unity8
sudo apt-get autoremove
sudo apt-get autoclean

Finally, if you don't use lightdm or gdm and you are using the startx command to start xfce instead of signing in normally, certain indicators and features won't be available.


Two great resources for RegExp: Debugexx and regular expressions 101

(<form[^\a]*</form>|<FORM[^\a]*</FORM>)

Debuggex

regular expressions 101

(method="[a-zA-Z]*|METHOD="[a-zA-Z]*)

Debuggex

regular expressions 101


How to remove/hide $RECYCLE.BIN and System Volume Information folders?

Create a text file .hidden on your hard drive, and add folders you wish to hide, like this:

found.000
$RECYCLE.BIN
RECYCLER
System Volume Information
pagefile.sys


It sounds like your hands get too close to the touchpad when you type, accidentally triggering mouse clicks. In the settings for the mouse and touchpad, there's a setting for deactivating the touchpad while typing; make sure that one is checked.


Probably at line 20 of /etc/apache2/sites-enabled/zzz-deny-generic.conf is present something like:

 ServerName *

According to Apache documentation, ServerName syntax is:

 ServerName [scheme://]fully-qualified-domain-name[:port]

As I can understand this last configuration file would deny any request that is not matched by previous VirtualHost.

Depending on your specific situation you could remove ServerName directive.


`gnome-screenshot -a` doesn't copy anything to the clipboard on Ubuntu 18.04

I'm apparently very bad at reading documentation, the command should be

gnome-screenshot -a -c

to copy to the clipboard, which is the behavior I wanted.


Everything that belongs to the user is stored under

/home/<username>

In most cases configurations are "hidden", that means they have a dot . in front of them.

You can see them in a console with the command

ls -la

or you open your file manager in ubuntu go to your home folder and press

<CTRL>-h

this should show them.


I solved the problem by creating a port-forwarding on my router.


How do I safely uninstall unused ubuntu installs

Did you use only update-grub2 after deleting the partition? If that is the case then after deleting another partition, try sudo grub-install /dev/sdx where sdx is the HDD where the current Ubuntu installation resides.e.g. sda if first hard disk. Then do a sudo update-grub2. In this way, you'll be sure that you are updating the grub from current installation and not the other one.


Where should I place templates and config file in debian hierarchy

I made a blog post about creating your own debian packages at:

http://www.leaseweblabs.com/2013/06/creating-custom-debian-packages/

To save you from some reading, the directory structure should be like this:

DEBIAN

control (required)
templates (optional)
preinst (optional, chmod 0755)
postinst (optional, chmod 0755)
prerm (optional, chmod 0755)
postrm (optional, chmod 0755)

… (files to be installed at specified location)

Make sure the permissions and locations are like this, and it should work :)


refer the ubuntu installtion guide http://www.ubuntu.com/download/help/install-desktop-latest


Have you tried in preferences? Check the Startup Applications and see if orca is enabled.


fstrim is managed by systemctl, not cron, and is defined by a systemd service unit called fstrim.service and a timer unit called fstrim.timer.
$ locate fstrim.service
...
/usr/lib/systemd/system/fstrim.service

Please use
$ systemctl status fstrim.timer

to check for the status of fstrim. It will show something like ...
● fstrim.timer - Discard unused blocks once a week
     Loaded: loaded (/lib/systemd/system/fstrim.timer; enabled; vendor preset: >
     Active: active (waiting) since Wed 2021-01-27 02:23:22 CET; 1 day 21h ago
    Trigger: Mon 2021-02-01 01:02:07 CET; 3 days left
   Triggers: ● fstrim.service
       Docs: man:fstrim

jan 27 02:23:22 discworld systemd[1]: Started Discard unused blocks once a week.

If that is not the same for you... the ssd might not be compatible.


No sound (dummy output) on Inspiron 7000 using Ubuntu 16.04

Finally I found how to solve the problem. First I reverted all the changes in the system configurations, as installation of alsa, pulseaudio and config files, disabled the fast boot in BIOS options, then I updated the BIOS following this tutorial from DELL website and turned off the computer for some hours, now the sound is working.


Wifi network Connection detection takes too long time in Ubuntu 12.10

Update the System.

 sudo apt-get update

After this command try whether your wifi working or not. If not means do the following

Then you have to remove the bcmwl kernel source:

 sudo apt-get remove bcmwl-kernel-source

Then again install :

 sudo apt-get install bcmwl-kernel-source


Is there any certificate manager available by OS in Ubuntu (i.e. Windows Certificate Manager)?

On Kubuntu 19.10 there is Kleopatra. I did not try on other version.


Your workflow (for 1.24 git cebc20a) should most likely be like that

Add
Inserting your command and the label for your command
Push another time add / Pushing enter should also work
OK

You could use that feature for e.g. adding some code formating tool.


If your system has duel graphics card and optimus enabled you need to turn off the discrete graphics card. Otherwise both are enabled and lead to high temperature.
Instruction for installing Bumblebee to turn off  discrete  GPU and enable only when required
Ubuntu docs link for updated info

Type the following in terminal,
sudo add-apt-repository ppa:bumblebee/stable
then
sudo apt-get update

For more up-to-date nvidia drivers, you need to add another PPA. As of 12.04, this is still necessary for Nvidia GT 6xxM cards. It may be optional for the GT 4xxM and GT 5xxM series on 12.04. When in doubt, just install it. The command is:

sudo add-apt-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get update

To install Bumblebee using the proprietary nvidia driver:
sudo apt-get install bumblebee bumblebee-nvidia linux-headers-generic

Reboot.

If you just want to disable nvidia card, no need to learn followings
Usage Instruction :
To run a program with nvidia card, use optirun command prefixed in terminal.
Like to run glxspheres with nvidia card type
optirun glxspheres
To run firefox type : optirun firefox &
Note: If you intend to run 32-bit programs like Wine and using Ubuntu 11.10 Oneiric or later, install 32-bit libraries with:
sudo apt-get install virtualgl-libs:i386 libgl1-mesa-glx:i386 libc6:i386
Linked Questions:
How well will Nvidia Optimus cards be supported in 12.04?
Is a NVIDIA GeForce with Optimus Technology supported by Ubuntu?
Can't use nvidia card/driver on optimus notebook


xrandr always has a VGA-1 or VGA-2 without physical display

I don't have a Thinkpad 530 to double-check, but it looks like your mainboard sees a phantom VGA where there is none.

Look in /sys/class/drm for a list of video outputs of the E530.

There should be one labelled as card0-VGA-1. Remove the card0-, that's the name of the output in question.

The fix should be to edit /etc/default/grub, you have to add video=VGA-1:d between the quotes in the GRUB_CMDLINE_LINUX line (the 12th line).

So, if your video output was VGA-1, change
GRUB_CMDLINE_LINUX="" to
GRUB_CMDLINE_LINUX="video=VGA-1:d"

After you finish editing, don't forget to run update-grub.


Trouble Booting Ubuntu from bootable USB

I have encountered this problem couple of times myself, while installing linux distributions (e.g. Ubuntu 16.04 LTS ). And most of time I have managed to resolve it by changing the utility used to create a bootable USB.
since you have not mentioned the method you chose to create the bootable USB, my recommendation is to give Rufus a try, in case you have not already.
For me personally Rufus has been the savior of the day, and it's quite easy to utilize.
Hope this helps


Intel NUC no sound over hdmi terminal commands

Per the error, apt just isn't a command. You need apt-get and you'll need to prepend that with sudo to run them as root. So the last two commands should read:

sudo apt-get update
sudo apt-get install oem-audio-hda-daily-dkms


lightdm doesn't run the display-setup-script script

Using Ubuntu, the best way to get your user account to have the right resolution for your dual monitor setup is as follows:

Delete monitors.xml from ~/.config/
Open Screen Display in System Settings
Set appropriate screen settings (use XRandR or ARandR beforehand if need be)
Then the big one - Hit Apply

You'll notice after doing the above that monitors.xml is rewritten, and whenever you login your dual monitor setup will work.

Secondly, to get the login screen to work correctly the process you need to follow is as is this answer. The tricky part is ensuring your permissions are correct - On top of setting the correct permissions for the symbolic link,  you also need to make sure Others are able to access the monitors.xml file as well as the ~/.config folder.

The beauty of this setup is, as opposed to trying to brute force some xrandr commands, that whenever you change your resolution/monitor set-up in Ubuntu, your login screen will follow suit.

For both of the above to work you need to make sure you remove any references to xrandr commands at startup.


Can one still download 10.04 netbook edition

You can get images for netbooks with ARM processors: http://old-releases.ubuntu.com/releases/ports/releases/lucid/.

However, please be warned that there is no support for discontinued releases and any questions opened here will be closed as off-topic. You may be able to get assistance on Ubuntu Forums, though.

There is no intel .iso there. For that you need to use one of the isos mentioned here:

https://askubuntu.com/a/183716/1992
https://askubuntu.com/a/183605/1992


gconftool-2 -s -t string /apps/metacity/general/button_layout menu:minimize,maximize,close , and try rebooting system
or

Interesting as

gconf-editor >Apps > Metacity > General > button_layout shows
close,maximize,minimize:menu


Wireless connection won't auto connect when VPN is set to auto connect

I was having the same issue with Ubuntu/Linux Mint and I found it was related to my wireless driver.

See if you have a realtek card with lspci

02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8188EE Wireless Network Adapter (rev 01)

If followed these steps to fix:

sudo apt-get install linux-headers-generic linux-headers-$(uname -r) build-essential dkms git
git clone https://github.com/FreedomBen/rtl8188ce-linux-driver
cd rtl8188ce-linux-driver
make
sudo make install
sudo cp -r firmware/* /lib/firmware
echo "options rtl8188ee ips=0 fwlps=0" | sudo tee /etc/modprobe.d/rtl8188ee.conf


Where are file properties stored on the actual file system?

This may not be a complete answer, but this is what I was able to find from my research.

File attributes are stored in inodes and the 'inode tables' are generally scattered throughout the file-system. In general, to find where you have the inode tables (at least in ext3 filesystem), you can run:

sudo dumpe2fs /dev/<device> | fgrep 'Inode table'

and you can do a hexdump of the raw data at the block where the inodes resides (Note I've not tried this command!):

sudo dd if=/dev/<device> ibs=4096 skip=<inode block> count=1 | hexdump

Replace the <device> and the <inode block> with the block offset to the inode table you want to look at.

source: LinuxQuestions, SO question


Btrfs Quotas for Hierarchy in Filesystem

So I found the answer, I will post my example code for creating a Parent\Sub hierarchy.
If someone has any questions you can ask me here, I will try to answer them.

    sudo mkdir test

sudo btrfs subvolume create test/a
sudo btrfs subvolume create test/b
sudo btrfs subvolume create test/c
sudo btrfs subvolume create test/d

sudo btrfs qgroup limit 5M test/a
sudo btrfs qgroup limit 6M test/b
sudo btrfs qgroup limit 7M test/c
sudo btrfs qgroup limit 8M test/d

sudo btrfs qgroup create 1/1 test/
sudo btrfs qgroup limit 15M 1/1 test/

sudo btrfs qgroup assign 0/278 1/1 test/
sudo btrfs qgroup assign 0/279 1/1 test/
sudo btrfs qgroup assign 0/280 1/1 test/
sudo btrfs qgroup assign 0/281 1/1 test/

##TEST##
sudo cp ~/file4MB /test/a/4MB
sudo cp ~/file4MB /test/b/4MB
sudo cp ~/file4MB /test/c/4MB
sudo cp ~/file4MB /test/d/4MB
cp: error writing '/test/d/4MB': Disk quota exceeded

ls -lh test/a
total 4.0M
-rw-r--r-- 1 root root 4.0M Oct 18 12:22 4MB
ls -lh test/b
total 4.0M
-rw-r--r-- 1 root root 4.0M Oct 18 12:23 4MB
ls -lh test/c
total 4.0M
-rw-r--r-- 1 root root 4.0M Oct 18 12:23 4MB
ls -lh test/d
total 2.9M
-rw-r--r-- 1 root root 2.9M Oct 18 12:23 4MB


NVIDIA 173 drivers/nvidia-settings are never loaded on boot

You have to explicitly save them.

Try running nvidia-settings with root privileges:

gksu nvidia-settings

Then go to "X-Server Display Configuration", setup your resolution and possibly meta-modes and click "Save to X Configuration File"

Close Nvidia-settings. They are now saved.


Why are many operations or commands in Ubuntu not allowed normally when you can just do the same thing by typing sudo?

Security! ;-)

Only admin users can do sudo and even those have to provide a password, i.e. if you leave your screen for a minute, nobody can do sudo without the password.


How do I make Banshee re-scan for cover art?

Try typing in a terminal:

banshee --fetch-artwork

This will make banshee download missing covers.


Ubuntu one changes 'Date modified' to time and date of sync

From the Ubuntu One documentation, it appears that this is intentional:

  Ubuntu One does not keep track of the metadata like file modified
  dates, therefore the file system will see that newly synchronized
  files have a last modified date of the synchronization, not when the
  content of the file was last modified.

It seems silly to me too though...


udhcpc and VLAN settings on embedded systems

I'm afraid that you are not going on the right way. Your computer must be already in the right VLAN before it will be able to make communication with the switch. Until your computer is set to the right vlan, you will not able to use a DHCP client in order to get an IP address.

You should use vlan tagging directly on the switch port instead.


Ubuntu 14.04 closed all programs and locked

The problem that you are facing might be due to memory hipe, hard disk bad sector or bios releated issues. Hence please check the system log and kernal logs to check what exactly the issue is and proceed based on it.

  tail -f /var/log/syslog

Note: gnome-system-log tool can be used if you are using gnome.

To check kernal messages - dmesg(/var/log/kern.log)


Converting Red Hat syntax to Ubuntu for networking

The hostname from /etc/sysconfig/network is set in /etc/hosts file

127.0.0.1  onyx.boisestate.edu  onyx

and you could add it as:

132.178.208.159 onyx.boisestate.edu  onyx

The Ethernet interfaces from /etc/sysconfig/network-scripts/ifcfg-ethX are set in /etc/network/interfaces file like the following:

auto eth0
    iface eth0 inet static
    address 192.168.0.1
    netmask 255.255.255.0
    network 192.168.0.0
    broadcast 192.168.0.255

auto eth1
    iface eth1 inet static
    address 132.178.223.159
    netmask 255.255.240.0
    network 132.178.208.0
    broadcast 132.178.223.255
    gateway 132.178.208.1

Hope this helps!


Download your chosen windows file
right-click, select 'open with' and choose wine.

To view installed programs, search for 'wine' in the dash and run 'Browse C: Drive' - which is the same as the C: drive in windows.


Free unallocated space can be added to swap but not ext4

Try booting into Windows and seeing if it's possible in the Disk Management Tool
Which looks like this:
Windows Disk Management Tool Screenshot


Logitech M720 Triathlon is not connecting by bluetooth to Ubuntu Gnome 16.04

I think I just solved it. I booted into Ubuntu with Bluetooth off and installed Blueman from the software center. Then I connected the mouse and it worked. I took it around 5 or 10 seconds after pairing to move but it did eventually.


update-initramfs runs scripts in init-premount?

I had a similar problem, so I poked around in other scripts included in initramfs.
Apparently, the "trick" is in a script header which should look like this:

 #!/bin/sh

 set -e

 case $1 in
 prereqs)
     prereqs
     exit 0
     ;;
 esac

The case statement is the important part.

It is mentioned in this documentation, but it doesn't state that you have to include this header even if you do not require precise ordering.


Make bootable image from non-bootable to use with qemu

Actually, the image is correct, but qemu-system-arm can't launch it if we don't set an adapted kernel (with " -kernel kernel-qemu ")...

Now it's working, with the classic image (that seemed to be not bootable).


Linux Driver for >2TB drives that are already formatted by Windows DiscWizard?

My recommendation is to bite the bullet: Back up the disk, repartition it, and restore the data. I admit that I know nothing about this DiscWizard software, but I know from experience that such things tend to be non-standard and to be unusable outside of their designed environments (in this case, Windows).

Moving forward, see my answer to this question (which it seems you've also answered). You can get access to the disk in other ways via tools like DUET or Clover, or by using an (ugly and dangerous, but at least somewhat well-understood) hybrid MBR.


Installing Qt Creator 3.1.2 on Ubuntu 14.04 LTS

The manual method links to a specific version of Qt Creator. Installing from a PPA would install whatever version it currently provides, and the Ubuntu SDK PPA offers updates - so it might be have some bug fixes (which may in turn create more bugs).
Installing using apt, which you would if you use a PPA, automatically selects the version for your architecture, so you should get 64-bit by default, unless you specifically call for 32-bit.
Well, a manually installed program updates itself only if the program supports it. So taking care of updates is easier with PPAs than manually installed apps, in general. However I do not know whether Qt Creator offers updates within the program.
gcc-4.9 is yet to arrive in Ubuntu 14.04. The PPA supports whatever version is currently in the release it targets, which would gcc-4.8.x.
The converse - KDE is linked with Qt, because it is built on Qt. Qt Creator runs fine with Ubuntu.


Here's a Perl solution. This should be much faster for thousands of files:
perl -e '@bad=grep{/(\d+)\.end/ && $1 % 12 != 0}@ARGV; unlink @bad' *

Which can be further condensed into:
perl -e 'unlink grep{/(\d+)\.end/ && $1 % 12 != 0}@ARGV;' *

If you have too many files and can't use the simple *, you can do something like:
perl -e 'opendir($d,"."); unlink grep{/(\d+)\.end/ && $1 % 12 != 0} readdir($dir)'

As for speed, here's a comparison of this approach and the shell one provided in one of the other answers:
$ touch file.{01..64}.name.{00001..01000}.end
$ ls | wc
  64000   64000 1472000
$ time for f in ./* ; do file="${f%.*}"; if [[ $((10#${file##*.} % 12)) -ne 0 ]]; then rm "$f"; fi; done

real    2m44.258s
user    0m9.183s
sys     1m7.647s

$ touch file.{01..64}.name.{00001..01000}.end
$ time perl -e 'unlink grep{/(\d+)\.end/ && $1 % 12 != 0}@ARGV;' *

real    0m0.610s
user    0m0.317s
sys     0m0.290s

As you can see, the difference is enormous, as expected.
Explanation

The -e is simply telling perl to run the script given on the command line.

@ARGV is a special variable containing all the arguments given to the script. Since we're giving it *, it will contain all the files (and directories) in the current directory.

The grep will search through the list of file names and look for any that match a string of numbers, a dot and end (/(\d+)\.end/).

Because the numbers (\d) are in a capture group (parentheses), they are saved as $1. So the grep will then check whether that number is a multiple of 12 and, if it isn't, the file name will be returned. In other words, the array @bad holds the list of files to be deleted.

The list is then passed to unlink() which removes files(but not directories).


You can print all non-ASCII lines of a file using my Python 3 script that I am hosting on GitHub here:

GitHub: ByteCommander/encoding-check

You can either clone or download the entire repository or simply save the file encoding-check and make it executable using chmod +x encoding-check.

Then you can run it like this, with the file to check as only argument:

./encoding-check FILENAME if it's located in your current working directory, or...
/path/to/encoding-check FILENAME if it's located in /path/to/, or...
encoding-check FILENAME if it's located in a directory that is part of the $PATH environment variable, i.e. /usr/local/bin or ~/bin.

Without any optional arguments, it will print each line and its number where it found non-ASCII characters. Finally, there's a summary line that tells you how many lines the file had in total and how many of them contained non-ASCII characters.

This method is guaranteed to properly decode all ASCII characters and detect everything that is definitely not ASCII.

Here's an example run on a file containing the first 20 lines of your given install.en.txt:

$ ./encoding-check install-first20.en.txt
     9: Appendix��F, GNU General Public License.
    14: (codename "���Xenial Xerus���"), for the 64-bit PC ("amd64") architecture. It also
    18: ���������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������
--------------------------------------------------------------------------------
20 lines in 'install-first20.en.txt', thereof 3 lines with non-ASCII characters.

But the script has some additional arguments to tweak the checked encoding and the output format. View the help and try them:

$ encoding-check -h
usage: encoding-check [-h] [-e ENCODING] [-s | -c | -l] [-m] [-w] [-n] [-f N]
                     [-t]
                     FILE [FILE ...]

Show all lines of a FILE containing characters that don't match the selected
ENCODING.

positional arguments:
  FILE                  the file to be examined

optional arguments:
  -h, --help            show this help message and exit
  -e ENCODING, --encoding ENCODING
                        file encoding to test (default 'ascii')
  -s, --summary         only print the summary
  -c, --count           only print the detected line count
  -l, --lines           only print the detected lines
  -m, --only-matching   hide files without matching lines from output
  -w, --no-warnings     hide warnings from output
  -n, --no-numbers      do not show line numbers in output
  -f N, --fit-width N   trim lines to N characters, or terminal width if N=0;
                        non-printable characters like tabs will be removed
  -t, --title           print title line above each file

As --encoding, every codec that Python 3 knows is valid. Just try one, in the worst case you get a little error message...


Trying to rar all subdirectories in a directory, not raring sub directories with folders in them

Using the -r flag will add subdirectories:

for dir in */; do rar a -r "${dir%/}.rar" "$dir"; done


Yes, you can convert it to an external drive, just after connecting it go to terminal and run this command:

  sudo os-prober

this should find the Windows on your other drive. then use:

  sudo update-grub

and whenever you boot the computer you will see Windows beside Ubuntu in the grub menu.


Installing matlab on Ubuntu 12.04 32bits

Unfortunately, MATLAB 2013a is not compatible with Linux 32 bit. The last release of MATLAB to be compatible with this platform was R2012a.


How to speed up boot time of Ubuntu when you find a possible cause in "dmesg" output?

Systemd is responsible for booting process. You can improve it by disabling some services or trying to fix your configuration. To check how much time services take in your boot process you can run:

systemd-analyze blame

For graphical detailed view of your boot procedure you can generate a plot image:

systemd-analyze plot > bootimage

Now you can open bootimage with eg. eog or different image viewer and check how much time services are taking (and eg. where system stops when booting). It will look like this:

As we can see e.g virtualbox.service is taking 62ms which is very nice but mounting my F3 disk is not so fast. I can consider to disable automounting (it's kinda bad example because systemd is lanuching services in parallel mode and this service is not slowing boot time, nothing depends on it but this is how it works). (In your dmesg output there is something wrong with mount options. You can check in /etc/fstab)

If you want do disable any service it is good to know if something else is not using this service as dependency. You can check it on e.g virtualbox.service example :

systemctl list-dependencies virtualbox.service --reverse

The output shows there aren't any service files related. So if I don't need it I can stop and disable it without any complications:

sudo systemctl disable virtualbox.service --now

If you find some services in your system which are taking long time to load first read about what it is exactly doing and then try to fix related configuration files or if you don't need it disable it.


Most of the UI elements are missed (Xubuntu or XFCE4 over Ubuntu Server on VirtualBox)

Dealt with this recently. The following fixed it for me:

sudo apt-get install gnome-icon-theme-full tango-icon-theme


problem after installation of ubuntu on virtual machine

You seem to have left your installation media still attached to the guest machine. Remove it using the gif image below as a guide:


Is it possible to convert abw to docx or doc offline

You should be aware of the Abiword's supported formats list and save your files according to the best strategy about file formats and conversion. Pay special attention to the part that says AbiWord cannot export Microsoft Word documents at the moment.

There are better tools for working with Microsoft's proprietary formats. WPS Writer from WPS Office (formerly Kingsoft Office) handles almost all the aforementioned files


Change disk from NTFS/exFAT/HPFS to LinuxLVM (0x82) without formating

You cannot properly change filesystem types without formatting.  Filesystem types cannot be switched readily like that.  This applies for every operating system - Windows, Linux, and MacOS - and is not a limitation specific to one OS or file system type.

If you want to store Timeshift backups on the disk, you need to back up the data you don't want to lose either to your computer or to a different disk, format the drive to be LinuxLVM, and then copy your files back.  If this is your OS disk, then you'll have to format then reinstall.

There's no other way around reformatting the partition unfortunately, as you can't switch between filesystem types without that reformat step.  (NTFS, exFAT, HPFS, LVM, etc. don't speak the same 'language' when it comes to how partitions and the filesystems work at the raw byte level in terms of what is stored where for disk information, file allocation tables/journals, etc.; this is why the reformat step is necessary to change the file system types)


Yes , it is possible if you have satisfied minimum requirements:

750MHz CPU or better
512Mb RAM or more
HD video card
Keyboard, mouse, speakers, sound card

Don't forget to change boot priority in BIOS
What are you using to write image to USB stick?


how to open PDF file at specific page in the terminal?

Evince is a PDF viewer able to open PDF files at a specific page using the terminal with the following command:

evince -i 5 "path/to/document.pdf"

where -i option specifies the page of the document, 5 in this example, and the second argument specifies the path to the document to open.

Okular is a PDF viewer able to open PDF files at a specific page using the terminal with the following command:

okular -p 5 "path/to/document.pdf"

where -p option specifies the page of the document, 5 in this example, and the second argument specifies the path to the document to open.

Acrobate Reader is a PDF viewer able to open PDF files at a specific page using the terminal with the following command:

/opt/Adobe/Reader9/bin/acroread /a "page=5" "path/to/document.pdf"

where page=5 is the argument that specifies the page of the document, 5 in this example, and the second argument specifies the path to the document to open.


After upgrade to 16.04, wifi signal strength jumps from perfect to zero and back

I did the following and the connection is good so far (with some drops of strength, which I still cannot explain):

Plug off and back on the router.
See what usb wireless adapter you have by running lsusb in the terminal.
Install the driver for the wireless adapter and also make sure that the power management for this device is off. I have Realtek Semiconductor Corp. RTL8188EUS 802.11n Wireless Network Adapter and this post took me through all the steps.


What is the recommended disk partition for kubuntu 14.04 manual install and dual boot with Windows 8.1 64 bit?

In my experience, I always tend to go overboard with the size of the root partition. I also tend to assign 40-50 Gb to root, but I'm beginning to doubt that much space is actually necessary (correct me if I'm wrong). I'm currently running Kubuntu 14.04 on a new machine for about 6 months, and have installed as much software as I'll ever need (VirtualBox, wine, Calligra, Krita, etc.), but most apps' user data winds up in /home's hidden folders.

My system is only using about 10 of the 50 Gb...Perhaps the next time I'll try giving only 30 Gb to root, and keep those extra 20 for downloads, movies, etc. Your /home partition should definitely be the biggest, and as to your 16Gb swap...I'd say that's way beyond what you'll be needing. People used to recommend making swap double or triple your RAM capacity, but that was back when ram was measured in MB ;)

You won't be using your swap unless you used up all your RAM, which isn't all that likely. I have 8Gb of RAM, and even with Virtualbox using 4 of them, + tons od¡f apps in the background,  (Firefox, Thunderbird, Ktorrent, Libreoffice, etc.), some of them fairly memory hungry, I've never reached anything near 8Gb, so my 4Gb swap aren't particularly being put to good use...


Internal speakers and internal mic not working

So everything is working now. It was a problem of controls and settings. I played around with it, choosing OFF for one of the profile options and then speakers worked again. Also for the mic I turned the right speaker to zero and the left down to 30% and the sound is fine now. But I still don't understand what the PROFILE is on the audio settings and why it has to be off, or what the different options mean:
bult-in audio analogue stereo
and
digital stereo HDMI output


How to enable "mirror" feature in the display settings using command line?

I'll presume that your monitors have the same resolution. Check for the names of your monitors with

$ xrandr --query
Screen 0: minimum 320 x 200, current 3840 x 1200, maximum 32767 x 32767
LVDS1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 382mm x 215mm
   1920x1080      60.0*+   59.9
   1680x1050      60.0     59.9
   1600x1024      60.2
   1400x1050      60.0
   1280x1024      60.0
   1440x900       59.9
   1280x960       60.0
   1360x768       59.8     60.0
   1152x864       60.0
   1024x768       60.0
   800x600        60.3     56.2
   640x480        59.9
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 connected primary 1920x1200+0+0 (normal left inverted right x axis y axis) 518mm x 324mm
   1920x1200      60.0*+
   1920x1080      60.0 +
   1600x1200      60.0
   1680x1050      60.0
   1280x1024      60.0
   1280x960       60.0
   1024x768       60.0
   800x600        60.3
   640x480        60.0
   720x400        70.1
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

So here, mine are LVDS1 and DP1. If both are active, then simply run

xrandr --output DP1 --same-as LVDS1

If only one is active, then run

xrandr --output LVDS1 --auto --primary --output DP1 --auto --same-as LVDS1


How to run a script after or before hibernate

You can run commands before and after hibernation or suspension (note there is a difference; hibernation is to disk, suspension is to memory) by creating a script in /etc/pm/sleep.d:

#!/bin/bash

case "$1" in
  hibernate)
    # put commands to run on hibernation here
    ;;
  thaw)
    # put commands to run when returning from hibernation here
    ;;
  suspend)
    # put commands to run on suspend here
    ;;
  resume)
    # put commands to run when returning from suspension
    ;;
esac

The filename of the script will dictate the order in which the scripts run compared to other scripts in sleep.d. Within your script, your commands will run in whatever order you put then in the script.


Can I expand my /boot without upsetting the system?

Maybe you can avoid this instead? It looks like your partition is big enough. Is it ok to remove old kernels? What is the kernel you are currently using? (uname -r) It might output something like 2.6.35-24-generic. And which kernels are installed? (ls /boot | grep vmlinuz), which might output something like

vmlinuz-2.6.35-22-generic
vmlinuz-2.6.35-24-generic

In this example, you know you are using 2.6.35-24, so look for 2.6.35-22.

dpkg -l | grep 2.6.35-22

The output tells us which names to use for removing them

ii  linux-headers-2.6.35-22 2.6.35-22.35
    Header files related to Linux kernel version 2.6.35
ii  linux-headers-2.6.35-22-generic 2.6.35-22.35
    Linux kernel headers for version 2.6.35 on x86/x86_64
ii  linux-image-2.6.35-22-generic 2.6.35-22.35
    Linux kernel image for version 2.6.35 on x86/x86_64

Now we can

sudo apt-get remove linux-headers-2.6.35-22 linux-headers-2.6.35-22-generic linux-image-2.6.35-22-generic

to make room for the new kernel to be installed.


Generally, if you are using Network Manager, the /etc/network/interfaces file need only contain the loopback interface. Network Manager is supposed to handle all other details for us. I suggest you right-click the NM icon and select 'Edit Connections...' Select Wired and Wired Connection 1. Be sure that Connect Automatically is checked:

If you are still having the issue, please try:

sudo apt-get install ethtool
gksudo gedit /etc/rc.local

Add the following above 'exit 0'

ethtool -A eth0 autoneg off

Proofread carefully, save and close gedit. Is it working as expected now?

If it is still not working as expected, install the replacement r8168 driver:

sudo apt-get install --reinstall linux-headers-$(uname -r) linux-headers-generic build-essential dkms
wget http://media.cdn.ubuntu-de.org/forum/attachments/44/18/3005217-r8168- dkms-8.029.00.tar.gz
sudo tar xvf 3005217-r8168-dkms-8.029.00.tar.gz -C /usr/src
sudo dkms add -m r8168-dkms -v 8.029.00
sudo dkms build -m r8168-dkms -v 8.029.00
sudo dkms install -m r8168-dkms -v 8.029.00
echo "blacklist r8169" | sudo tee -a /etc/modprobe.d/blacklist.conf
sudo modprobe -rfv r8169
sudo modprobe -v r8168

I realize there are later versions of r8168 available, however, I am not confident that the later versions work with your earlier kernel in Ubuntu 12.04. Then try rebooting to see if the ethernet starts on boot correctly.


How can I make sure that my hard drive is correctly mounted so that Backup works?

General description how to mount via /etc/fstab
You can mount the target partition for the backup via a line in /etc/fstab.
Mounted all the time
If the target partition is in an internal drive, and/or you want the partition to be mounted all the time, you can use the instructions in this link,
How to create partition for data?
Connected and mounted only during backup
If the target partition is in an external drive, you can add the mount option noauto so that you need not have it connected and running all the time.
This means that you can mount it manually with a command line (in a terminal window) before starting to use it, and the mount will be controlled by the line in /etc/fstab in a reliable way.
In the line add noauto after defaults like this: defaults,noauto as the fourth field in fstab. See man fstab for more details.
The examples in the link would be modified to
if ext4 file system
UUID=a3b3f4a4-3d6e-4d4e-7e1a-c2f0de792f90 /media/sindre/Backup ext4 defaults,noauto 0 2

if ntfs file system
In this case you might add some mount options instead of 'defaults'
UUID=56CA491D4B13782A /media/sindre/Backup ntfs noauto,rw,users,umask=022 0 2

and of course you should use your own data for the UUID and mount point.
This new line with be used after reboot.
Mount and unmount
These commands will work, when the line is there in /etc/fstab

before backup:
  sudo mount /media/sindre/Backup

after backup you can unmount
  sudo umount /media/sindre/Backup

When successfully unmounted, you can turn off and disconnect the drive.
Details
Create a mountpoint (only once)
sudo mkdir /media/sindre/Backup

Edit a line similar to one of the lines above into /etc/fstab. Use this command
sudo blkid

to identify the UUID of the data partition. Use it without quotes. Start the editor (nano)
sudo nano /etc/fstab

and add/edit this line modified with your data partition's UUID and file system.
Edit
I noticed/realized that you have wrtten the UUID of the drive in the second edit of your original question. I have edited it, and I suggest the following /etc/fstab file,
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
/dev/mapper/ubuntu--vg-root /               ext4    errors=remount-ro 0       1
# /boot was on /dev/nvme0n1p1 during installation
UUID=0602af3b-b971-4014-91c1-dcb6fe7cec18 /boot           ext4    defaults        0       2
/dev/mapper/ubuntu--vg-swap_1 none            swap    sw              0       0

# 1. the backup drive from your example (original)
#/dev/disk/by-uuid/5898e1d1-0683-4076-b854-64394cc1c973 /mnt/5898e1d1-0683-4076-b854-64394cc1c973 auto nosuid,nodev,nofail,x-gvfs-show 0 0

# 2. the backup drive with small modifications from your example
#UUID=5898e1d1-0683-4076-b854-64394cc1c973 /mnt/5898e1d1-0683-4076-b854-64394cc1c973  ext4 auto,nosuid,nodev,nofail,x-gvfs-show 0 2

# 3. close to what I suggested at first in my answer (select and modify to fit what you need
#    uncomment alias remove the # character from the beginning of the line that you want to use)

#UUID=5898e1d1-0683-4076-b854-64394cc1c973  /media/sindre/Backup  ext4  defaults,noauto  0  2

I suggest that you try example #3, the last line by uncommenting it (remobe the # character from the beginning of the (last) line.
Feel free to try and/or modify any of the three candidate lines, but use only one of them each time. The other two should be 'commented away' with a #.


fresh ubuntu server 20.04 system clock cant synchronize

My router has a firewall section where you can allow traffic in/out/both by port to 'all addresses'. It also has port forwarding. I had only completed the former and apparently I needed both. Does NTP protocol communication really initialize from the NTP server? I would have thought your own device (from behind the firewall) would ask what time it is and NTP server would be allowed to reply back through the firewall. Is that not the case?


How should I proceed after black screen during Ubuntu upgrade?

Temporary Fix
To get the system to boot:

After turning on your PC, hold the right SHIFT key to get to the GRUB bootloader.
Once GRUB is open, press the “e” key to edit the first highlighted entry “Ubuntu”.
Move your cursor down to the line that starts with “linux”, and use the right arrow key to find the section with the words “ro quiet splash”.
Add “nomodeset” after these words.

nomodeset
Feel free to remove “quiet” and “splash” for more verbosity to troubleshoot the boot process.
Press “CTRL + X” or “F10” to boot.
The system should now boot

For permanent fix


Installing Ubuntu in shrinked unallocated space

You don't delete unallocated space, its space thats empty. The reason you can't create a new partition is because you reach your 4 primary limit or 3 primary 1 extended limit on MBR. It would be easier for use to see your drive format, Open cmd and type "diskmgmt.msc" then post a picture.

I'm going to guess your layout since there usally similar. There could be a 199mb "SYSTEM" partiton, then windows, then recovery, and last tools. You could convert the tools into a logical partiton, then shrink the windows partiton and move it behind the tools. Last you would create a new partition, in which you would install ubuntu in. Ease Partiton is free and makes things alot easier (note: it can't read ext4). As always Backup your data!


Chose which version of python to use
python 2.x
python setup.py install

python 3.x
python3 setup.py install

Change the system's default python version
sudo update-alternatives --config python

Additional Information
How do I make the terminal run python 3.1?


Ubuntu 15.10, logitech mx anywhere mouse pairs but doesn't do anything

In a related thread the user Tobi just updated his answer for Ubuntu 15.10, which worked for me perfectly: Logitech MX Anywhere 2 mouse pairs but doesn't do anything

In fact the PIN-less pairing method of the MX Anywhere 2 is not very well implemented in Ubuntu 15.10.
This commands have to be run to make the pairing work:

hciconfig hci0 sspmode 1
hciconfig hci0 down
hciconfig hci0 up


Determining the source of memory cache usage

To find out about "memory cache" use slabtop, using -s you can sort the output and c is for the cache size, so use:

sudo slabtop -s c

For me most of the cache is related to inode_cache

And about "swap",
You can use status  file in each process directory in /proc to find out which one of them is using the swap.

For specific program:

cd /proc/$(pgrep -x programname)
grep -i swap status

To get a list of all process cache size:

cd /proc
find -maxdepth 2 -iname status -exec grep -i -e name -e swap {} \; -exec echo "---" \;

the output would be similar to:

---
Name:   atd
VmSwap:        0 kB
---
Name:   rsyslogd
VmSwap:        0 kB
---
Name:   cron
VmSwap:        0 kB


The fallback fonts are decided by Fontconfig; it consults the configuration in /etc/fonts as well as the glyphs provided by all fonts to determine or decide which particular font is used to provide the character. You can right-click on a character in Character Map to see which font has been used to backfill the character.

Newer versions of GNOME Character Map can restrict display of glyphs to a specific installed font, but you will have to use something like FontForge in order to view available glyphs in a compact format.


Use different default applications to open .txt and .ply files

The issue you have is that if you run a mimetype command on your .ply file, you'll obtain that it's a text/plain type. So, when you choose your default software for your file, you, in fact, choose for that mimetype.
These files are considered as plain text files.
According to that thread,

Create a file anywhere (let's go for $HOME/ply-mime.xml)
Copy paste that in it

    <?xml version="1.0"?>
<mime-info xmlns='http://www.freedesktop.org/standards/shared-mime-info'>
    <mime-type type="application/extension-ply">
        <comment>.ply file</comment>
        <glob pattern="*.ply"/>
    </mime-type>
</mime-info>

Run in your terminal xdg-mime install ply-mime.xml. Now, you can do your "Select Default software for". It might need you restart your computer. I'm not sure.

You can delete $HOME/ply-mime.xml


Can't find packages: eid-mw eid-viewer in Ubuntu 18.04

You can download the 16.04 smart card reader .deb files from Ubuntu 16.04 and double-click each .deb file to install it manually in Ubuntu 18.04.

Run the following commands in Ubuntu 18.04 to install dependency packages:

sudo apt update
sudo apt install pcscd libpcsclite1 libpcsclite-dev libusb-0.1-4

Manually download these three .deb files from the official Ubuntu website.

libacr38
libacr38ucontrol0
libacr38ucontrol-dev

The software for reading the Belgian electronic identity card (beidgui) has been discontinued in Ubuntu since later releases than Ubuntu 12.04, but the source code for beidgui is still available from its GitHub webpage which also has instructions for installing it.

This repository contains the software and viewer for the Belgian electronic identity card. With this, you can:

Communicate with secure websites that require eID authentication
Sign documents and emails using your eID
Using the viewer, read the identity data on eID cards, verify their validity, and store them for future usage
Using the provided API, do all of the above in custom applications of your own.


Chrome asks for password to unlock keyring on startup

From the manpage:

  --password-store=<basic|gnome|kwallet>
  Set the password store to use. The default is to automatically detect based on the desktop environment. basic selects the built in, unencrypted password store. gnome selects Gnome keyring. kwallet selects (KDE) KWallet. (Note that KWallet may not work reliably outside KDE.)

The easiest way to fix that in the launcher is to copy the .desktop file to your home folder and edit it (google chrome users should copy the appropriate file):

cp /usr/share/applications/chromium-browser.desktop ~/.local/share/applications

Then edit the new file such that the Exec line reads like this:

Exec=chromium-browser --password-store=basic %U

If you have any other Chromium app installed, their .desktop files should also be in ~/.local/share/applications, edit them accordingly.


What makes mysql service autostart, while it's disabled in BootUp-manager?

AFAIK MySQL differs from other services. For instance:

sudo update-rc.d nginx disable # Works
sudo update-rc.d mysql disable # Does not

I don't know how BootUp Manager (bum) works, but it wouldn't surprise me that it is not capable to manage MySQL.

To disable MySQL from startup you will have to manually do it, for that see: How to stop mysql from running at boot time?

Again, no sure if this is a bug on that tool or not (no sources for say so).


Have MacOS-like window animations on Ubuntu 19.04

I was looking for the same and finally found similar one, it's called 'Compiz like magic lamp'. link: https://extensions.gnome.org/extension/3740/compiz-alike-magic-lamp-effect/


I bet if you umount /dev/sdd2, you will see another 12GB /home folder


Touchpad doesn't work after installing Ubuntu 14.04

My laptop has a function to turn off the touchpad, FN + F7. For some reason it's turned off by default on startup. However, we're working, so we're golden, that can be solved later.


Mount Windows share as guest from command line

You need to add the version to the options depending on the cifs version you use. So that would be for v1.0:

sudo mount -t cifs -o rw,guest,vers=1.0 //192.168.1.1/Fab-EXT4 /media/MichelNAS/

There is also vers=2.0 and vers=3.0


The apache2 configtest failed: Segmentation fault (core dumped)

I have successfully solved this problem by using this command: sudo a2dismod php7.0 then i restart apache2, it work normally.


I used "non- mac" version Ubuntu to install Trusty Tahr on my mac. Try this

http://www.penguinsecurity.net/wp/2014/05/01/enable-wireless-in-ubuntu-on-macbook-pro/

http://www.penguinsecurity.net/wp/2014/04/28/install-ubuntu-14-04-lts-trusty-tahr-on-macbook-pro-retina-2013/

I also tried mac version 13.10 last year on my Retina mac and it worked as well but with some tweaks.


How do I fix a ASUS Eee PC to run Ubuntu 18.04 with "This kernel requires an x86-64 CPU, but only detected an i686 CPU"?

Stock Ubuntu is 64 bit only but the flavors like Kubuntu and Lubuntu have 32-bit versions.

https://www.ubuntu.com/download/flavours

And for an old eepc you should use a lightweight OS like https://lubuntu.me/downloads/


To enable the grub menu to select the kernel, you have to comment the line in /etc/default/grub

  #GRUB_HIDDEN_TIMEOUT=0

Then you have to run update-grub and reboot and the grub menu should appear.


gnome-session-fallback not working in Ubuntu 14.04

compiz flashback and metacity started to work properly after running

dconf reset -f /org/gnome/gnome-panel/


MAAS error failed [3/7] (00-maas-03-install-lldpd, 99-maas-01-wait-for-lldpd, 99-maas-02-capture-lldp)

Worked out by using own "commissioning script" to install lldpd among other things.

This boils down to this command:

apt-get install -y --force-yes --allow-unauthenticated lldpd


Here is one solution that seems to work and is (relatively) straightforward and (largely) GUI-based:

Install GRSYNC from the Ubuntu apps directory (or through apt-get install).
Install "Scheduled Tasks" / Gnome-Schedule using CLI / terminal:

sudo apt-get install gnome-schedule

Mount your NAS / external hard drive so that Linux recognizes it as if it was another hard drive. (NOTE: detailed instructions are available on the Ubuntu wiki named MountWindowsSharesPermanently - if someone wants to make this a link, it would be great - I'm only allowed to post 2 links). These steps assume you are accessing an unprotected / public folder. The wiki contains more information on different scenarios.

Install cifs-utils: sudo apt-get install cifs-utils
Create a mount folder for the NAS folder you are mounting in the 'media' folder. You can do this either through your file manager (you may have to access it as super-user) or through CLI: sudo mkdir /media/what-you-want-to-call-your-nas (e.g. "/media/seagatecentral")
Add your NAS to the /etc/fstab file. You can do this either by browsing to it in your file manager (again, with super-user status) or through CLI: sudo nano /etc/fstab.

Add this line:

//servername/sharename  /media/what-you-want-to-call-your-nas  cifs  guest,uid=1000,iocharset=utf8  0  0

Servername: the name of your NAS 'server' (easiest is to use the IP address, and assign it a static IP address in your router settings. If you can't do this you may be able to identify the non-IP address server name by browsing to it in your file manager).
sharename: the folder you want to mount (e.g. on Seagate Central, a default "Public" folder is created that could be used here, or another one like "MyName/Backups" so it would read "//ip-address-here/MyName/Backups")

Remount your drives so the new 'drive' will show up: sudo mount -a

Create a backup using GRSYNC - most of the options are fairly straightforward, so setup the type of backup you want (NOTE: you are not scheduling it yet). A quick guide is available at dedoimedo.
Find the rsync command generated by GRSYNC: go to File --> Rsync Command Line (or just press Alt+R). Copy the entire command.
Create a scheduled task using Gnome-Schedule. This is fairly straightforward as well. In the "Command" field, paste the rsync command you copied from GRSYNC. For more information on Gnome-Schedule, you can check everydaylinuxuser.

You should be all set now.


The command to disable menus with icons is:

gconftool --set /desktop/gnome/interface/menus_have_icons --type bool false

The command to disable buttons with icons is the same as you note:

gconftool --set /desktop/gnome/interface/buttons_have_icons --type bool false


changing individual letter position with bash

You can do it using tr command. A search for "ROT cypher Bash" leads me to caesar-cipher.sh.

Note that the commands are case sensitive.

Caesar cipher encoding:

$ echo "THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG" | tr '[A-Z]' '[X-ZA-W]'
QEB NRFZH YOLTK CLU GRJMP LSBO QEB IXWV ALD

Caesar cipher decoding:

$ echo "QEB NRFZH YOLTK CLU GRJMP LSBO QEB IXWV ALD" | tr '[X-ZA-W]' '[A-Z]'
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG

It can also be adjusted to ROT13 instead:

$ echo "THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG" | tr '[A-Z]' '[N-ZA-M]'
GUR DHVPX OEBJA SBK WHZCF BIRE GUR YNML QBT

$ echo "GUR DHVPX OEBJA SBK WHZCF BIRE GUR YNML QBT" | tr '[N-ZA-M]' '[A-Z]'
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG

In your case it would be:

tr '[A-Z]' '[X-ZA-W]' < file

Also from another source to decode (reverse the order of patterns to encode):

ROT-3 = tr 'd-za-cD-ZA-C' 'a-zA-Z'
ROT-4 = tr 'e-za-dE-ZA-D' 'a-zA-Z'
ROT-5 = tr 'f-za-eF-ZA-E' 'a-zA-Z'
ROT-6 = tr 'g-za-fG-ZA-F' 'a-zA-Z'
ROT-7 = tr 'h-za-gH-ZA-G' 'a-zA-Z'
ROT-8 = tr 'i-za-hI-ZA-H' 'a-zA-Z'
ROT-9 = tr 'j-za-iJ-ZA-I' 'a-zA-Z'
ROT-10 = tr 'k-za-jK-ZA-J' 'a-zA-Z'
ROT-11 = tr 'l-za-kL-ZA-K' 'a-zA-Z'
ROT-12 = tr 'm-za-lM-ZA-L' 'a-zA-Z'
ROT-13 = tr 'n-za-mN-ZA-M' 'a-zA-Z'
ROT-14 = tr 'o-za-nO-ZA-N' 'a-zA-Z'
ROT-15 = tr 'p-za-oP-ZA-O' 'a-zA-Z'
ROT-16 = tr 'q-za-pQ-ZA-P' 'a-zA-Z'
ROT-17 = tr 'r-za-qR-ZA-Q' 'a-zA-Z'
ROT-18 = tr 's-za-rS-ZA-R' 'a-zA-Z'
ROT-19 = tr 't-za-sT-ZA-S' 'a-zA-Z'
ROT-20 = tr 'u-za-tU-ZA-T' 'a-zA-Z'
ROT-21 = tr 'v-za-uV-ZA-U' 'a-zA-Z'
ROT-22 = tr 'w-za-vW-ZA-V' 'a-zA-Z'
ROT-23 = tr 'x-za-wX-ZA-W' 'a-zA-Z'
ROT-24 = tr 'y-za-xY-ZA-X' 'a-zA-Z'
ROT-25 = tr 'z-za-yZ-ZA-Y' 'a-zA-Z'


You will have to delete partitions of your disks to install Ubuntu, so first backup whatever data you need and then delete the partitions that will give more than 4.4 GB of data.

To backup, first "Try Ubuntu". You will get an option in the beginning of the installation process to try it, copy all important data and then install Ubuntu. You will have to delete partitions that will give you more than 4.4 GB of data.

See this question for the complete instructions on installing Ubuntu:

How to install Ubuntu


Error with Update Manager and Software Center

A hash mismatch is usually a sign of a broken mirror, so yes, changing mirror was a good approach to take. You can try switching back in a day or two, it may be fixed.

I don't know why you are getting an error on the i18n/Index file, but that's not very important, so you can happily ignore it.

I suggest running rm /var/lib/apt/lists/partial/* /var/lib/apt/lists/*, then trying to update the lists again.

You can do the same operation with these commands:

sudo rm -rf /var/lib/apt/lists/*
sudo apt-get update


How much space will the Ubuntu 10.04 netbook take after installation......is it compatible with the Archos 9?

Had a quick look around this seems to be quite a comprehensive guide on how to do it

http://www.ossramblings.com/installing-ubuntu-archos-9-tablet

In that guide they use a netbook install of Ubuntu not sure how much space that takes up normally but I know the system requirement for the desktop version is 5Gb so would think the netbook version would be a bit less.


How to use a driver for Ubuntu with a higher kernel version(2.6.36) on ubuntu with lower kernel version (2.6.30))

That's a pretty old kernel... Which release of Ubuntu are you running? Can you possibly upgrade to a newer version? It would help you reach your goal...

Many easycap bugs have been fixed in the newer kernels.

Barring that, you may be able to find a newer kernel if you enable the backports and/or testing repositories if you haven't already done so.

Finally, you could compile your own mainline kernel.


Probably Ubuntu Software Center or Synaptic is already open. If so, close those programs, and retry.

If nothing changes, close the session (log out) or reboot and retry.


CUDA instructions ask to stop GDM but it doesn't exist

I had similar problems when installing in 11.10 (I don't know if 12.04 is supported).

To exit the GUI, use sudo service lightdm stop (Ubuntu now uses lightdm instead of gdm).

Once you have exited the GUI, and before you run the install script, make sure to completely unload nVidia's kernel module. To do this, I used "dkms", but I don't remember the commands used.


How to stop running pidgin at logins and disable window hiding feature?

Try this,

Close all running applications then go to System → Preferences → Startup Applications.
Click on the Options tab, check Automatically remember running applications when logging out.

Close and reboot.

NOTE:

If you want your windows to stop minimizing when your away status changes, then Goto Tools → Plugins and then uncheck Iconify on Away plugin.

Alternatively you could stop using musictracker so your status stops periodically changing.


Booting Ubuntu 14.04.3 - black screen with blinking cursor, then returns ASUS BIOS utility menu

Ultimately, I wiped my flash drive and put it in FAT format. Then, I followed this link: http://computers.tutsplus.com/tutorials/how-to-create-a-bootable-ubuntu-usb-drive-for-pc-on-a-mac--cms-21187?utm_source=Tuts+&utm_medium=website&utm_campaign=relatedtutorials&utm_content=sidebar&WT.mc_id=Tuts+_website_relatedtutorials_sidebar which worked!


When you get options. Force Quit and Wait, press on Wait. Sometimes the dialog box opens again with same options, press wait again


I suspect it is because you have another session open (someone else logged in) Before you attempt shut down again, click on the user applet and see that no one else is logged in. If they are Shutdown and restart will only log you out.


Which Ubuntu Source file implements the management of the nx bit?

You could try to start here.

Example how to start

There is line of code:

#define X86_FEATURE_NX      ( 1*32+20) /* Execute Disable */

I already has cloned git repo of linux kernel, it was cloned when the last commit in master branch was 14186fea0cb06bc43181ce239efe0df6f1af260a. So something may be changed right now.

Trying to find all files that use this X86_FEATURE_NX in the linux kernel git repo:

$ for i in *; do find "$i" -type f | xargs grep -l "X86_FEATURE_NX"; done
arch/x86/kvm/vmx.c
arch/x86/kvm/svm.c
arch/x86/kernel/head_32.S
arch/x86/include/asm/cpufeature.h


You can also hover your mouse over the title of the program, here Firefox. Then the menus will show.

This is actually a feature of Ubuntu, in order to save the most space possible. This vetical space is indeed more useful for browsing for example.


What you see is the a UEFI BIOS. Unlike the legacy BIOS, there's MBR where the bootloaders always try to overwrite each other. Instead, bootloaders are installed in the form:

<EFI system partition>/efi/{vendor}/{file}.efi

The EFI partition is a small, FAT32 formatted partition usually located at the beginning of the hard drive. It stores the bootloaders for all the UEFI compatible operating systems you have installed.

Once a UEFI compatible operating system is installed, it copies the bootloader to the EFI partition and creates an entry in the NVRAM which points to the bootloader. In your case, ubuntu points to

<EFI system partition>/efi/ubuntu/grubx64.efi

Windows, for example, creates an entry called "Windows Boot Manager" pointing to

<EFI system partition>/efi/microsoft/bootmgrw.efi

So, with a UEFI BIOS, you can use its boot menu to select your operating systems, set the default operating system to boot, etc.

Also, Ubuntu 11.04's installer has a bug where it will reformat your EFI partition. So, if you have Windows installed, it will no longer boot. You'll have to install Ubuntu first, then Windows.

EDIT: One more thing :) If you want Windows to show up in the boot menu, you have to boot the install DVD in UEFI mode. There should be an option for that if you look in your BIOS settings.

Hope this helps


You can use find to run different commands on regular files and directories by filtering them with the -type option. This runs recursively on everything inside ./Movies:

# all directories become 755 (rwx r-x r-x):
find ./Movies -type d -exec chmod 755 '{}' \;

# all files become 644 (rw- r-- r--):
find ./Movies -type f -exec chmod 644 '{}' \;


Why isn't Nvidia handling all graphics smoothly?

If you are using laptop with Optimus technology, and you almost certainly are, nvidia-prime is an absolute ... of a driver (just a personal opinion). It doesn't support vertical sync, that is where image tearing is coming from. Citing Nvidia:

  There is no synchronization between the images rendered by the NVIDIA GPU and the output device. This means that the output device can start reading the next frame of video while it is still being updated, producing a graphical artifact known as “tearing”. Tearing is currently expected due to limitations in the design of the X.Org X server.

I suggest you to use Bumblebee driver. It will give you some performance penalty, but given that you say that you are not a gamer, you won't notice it. I used it for years with same generation CPU and GPU as yours (second gen core CPU and Fermi GPU) and it worked flawlessly all the time.

It may take some time to setup though, especially for the first time... For starters, refer to Bumblebee wiki.


How To Hide Mounted Drives From Ubuntu 18.04 Desktop?

Open Terminal and run the following command:

gsettings set org.gnome.nautilus.desktop volumes-visible 'false'

Alternatively, if you have (GNOME) Tweaks installed, you can use it to disable 'Mounted Volumes' under Desktop:

This won't work for Ubuntu 19.04 and later as desktop icons are handled by a GNOME Shell extension instead of Nautilus for those releases.


if you know by a fact your windows7 and users folder were in the same partition and you can still see your files, there is a good chance your that everything is fine and you only overwrited the boot during installation in a wrong manner. try installing again paying attention to the options, click on "manual" opposed to "guided use entire disk" and choose your first hard-drive to receive the boot loader, use or create different partition or hard drive for linux instalation. the instalation should take care of putting a menu(GRUB menu) on the screen when you reboot with windows 7 and linux to be chosen from. maybe you had some error after installation that  before installing the boot loader


How to remove "." from a filename in Perl?

The match group /(…)/ contains anything inside the parentheses.
If you don't want the dot to be part of it, then put it outside
the parentheses: /\.([^.]+)$/.

#!/usr/bin/env perl

use strict;
use warnings;

my $filename = 'Test.txt';
$filename =~ s/(.*)\.([^.]+)$/$1$2/;
#               ^^    ^^^^^
#               $1     $2
print "filename: '$filename'\n";

# prints "Testtxt"


What does "Open a console/terminal" mean?

Open the terminal by searching for it in the Dash, or use the keyboard shortcut Ctrl + Alt + T.
In the terminal use the command cd to change the present working directory to a new directory (directory is used as a synonym for folder). For example, to change directory to your Desktop type the command:
cd ~/Desktop

followed by pressing Enter. So if you downloaded the file to your Downloads folder, you would use the command:
cd ~/Downloads

to change the present working directory to this location.
You can also type cd in the terminal followed by a space character and drag the folder icon of the directory that you want to change to from the file manager into the terminal, and then the full path to that directory will be automatically entered into the terminal for you.