Find the application starter file (.desktop) of the application you are interested in.

Lets say I want to find the icon of Firefox. The desktop file is located at /usr/share/applications/firefox.desktop.

Drag the desktop file into your text editor and find the name of the icon it uses:

Note the line Icon=firefox. This implicitly says the icon's file name is firefox.png.

Almost all the icon themes are stored at /usr/share/icons. Very few programs will put their icons in /usr/share/pixmaps  Those are the two directories usually the operating system will seek for the icon file, in order.

Since we want to find firefox.png I'll open up my Terminal and execute the command:

find /usr/share -iname "firefox.png"

Result:

As you can see the icon we seek is /usr/share/pixmaps/firefox.png
The path depends on the icon theme you use. The icon sizes most application launchers tend to use are 64x64, 128x128 or 256x256. It depends.

You might also want to read freedesktop.org standard icon lookup method.


the r5u870 project have been updated. you could go to the project home page and get the new url. the project is hosted on github now.

the x86 version works. you can download it by clicking "download zip" in the right area  of the github page, and other steps are just same as before.

if you are using the x64 version of linux, you may try the master branch on github, but it may not work, since the author said he doesn't have a x64 machine to develop and test.


how to remove environment variables set for QSTK?

Open your favorite editor, for example gedit (Super key gedit Enter). Then open /home/xxxxx/.bashrc using the File menu. Delete that first line. Save the file. Now, start up a new terminal window and see if the problem is gone.


Is it possible to do a fully unattended major version upgrade to Ubuntu?

Upgrading from 14.04 to 18.04 unattended on such environment is like trying to hit a fly with a trebuchet. Sure it's possible, but you can bet how big is the chance to succeed. I mean, of course you can force every change to go with defaults and with a little bit of luck maybe your system will be upgraded properly, but don't expect it will not be required to fix some stuff "by hand".

Anyway, if you want to make it, first you should have a clone of your environment in a separate network. For bare-metal (dedicated or in-house servers) dd or rsync might become handy. Also read about clonezilla live CD system, that has all you need for cloning stuff. For virtual machines or containers it's easy to make a clone or snapshot. It's also possible on LVM partitions.

Once you have a clone or mirror-like environment you can test the upgrade process and automate it for production. Keep in mind that you should not skip any LTS on the way. First upgrade from 14.04 to 16.04, then from 16.04 to 18.04.


Resizing a partition did not update the df output

Making the partition larger manually, doesn't grow the file-system. You wil have to run something like:

sudo resize2fs /dev/mmcblk0p2

for extX file-systems.


Stop airplane mode from starting bluetooth

Same issue here. Running 18.04.3 (Gnome) on a Thinkpad X230

Steps to reproduce:

In Apps->Settings turn on Wifi, turn off bluetooth
Hit Fn+F5 -> Airplane Mode gets enabled, both Wifi & BT are off
Hit Fn+F5 again, both Wifi and bluetooth are switched on

Expected behaviour would be Wifi on, bluetooth off as it was.

Seems to be a known issue with Gnome:

https://bugzilla.gnome.org/show_bug.cgi?id=787800

Remapping the hotkey to toggle only Wifi instead of Airplane Mode would sound like an option, but it seems Airplane Mode is being activated automatically whenever both Wifi and BT are switched off..

https://gitlab.gnome.org/GNOME/gnome-shell/issues/131

Which is a little bit of a bummer for people who rarely use bluetooth and rarely travel by plane :)


After set to default in gnome-tweak-tool and disable of attach dialog window to parent window in "Window settings" I fixed it....


Allocating space for Ubuntu in dual boot installation - what are "files" and "ubuntu"?

My Question is : what is the purpose of the space I'm allocating?

The space you are allocating is for the installation of Ubuntu. The installation process will create one or two partitions it needs for the installation of the operating system.

  By this I mean: will programs be installed to "files" or "ubuntu"?
  what differentiates "Files" from "Ubuntu"? Will I be able to access
  "files" ?

I am guessing that you have created an big NTFS partition next to your Windows 10 installation to either keep your files or to install Ubuntu. Ubuntu cannot use NTFS partitions. It uses a different partition scheme that Windows cannot create. Depending on the version you are trying to install, it may also need a swap partition. All these will be created in the part marked as "Ubuntu" by shrinking the NTFS partition you have created. The part marked as "files" will the the shrunk NTFS partition.

Yes, you will be able to read and write to the NTFS partitions from either Windows or Ubuntu. No, Ubuntu installation will not put anything in this partition.

If you do not want an additional NTFS partition, and want to allocate the whole of the big partition you have created previously to Ubuntu. You have to boot Windows again and delete this partition and keep this place unallocated.

When you start Ubuntu installation again, it will find this unallocated space in the disk and create all the partitions it needs. It won't show you the slider then.

Hope it helps


Building xar source error: no libcrypto?

There is a fix for this now, it only requires some small changes. You can read about it in the Github issue.

Here's what you need to do:
In configure.ac, line 332 is:

AC_CHECK_LIB([crypto], [OpenSSL_add_all_ciphers], , [have_libcrypto="0"])

Replace it with:

AC_CHECK_LIB([crypto], [OPENSSL_init_crypto], , [have_libcrypto="0"])

Note that the only change is to the second part in brackets. You can see an example of this change here.

Then run ./autogen.sh. After that you can continue install with make and sudo make install.


Ubuntu One says it's always synchronizing

"Standoff" means the connection is half-dead. After a short delay you should see syncdaemon trying to reconnect; as this seems to not be the case, please consider restarting syncdaemon (u1sdtool -q; u1sdtool -c). If the problem persists, please enable debug and file a bug.


Sound not working after suspend on Lenovo T400

Not exactly sure how the problem got fixed. But I will list the set of things I have done so that it may help others.

1)Most importantly - check the sound settings - Output Volume, Mute/UnMute, In Output section and in settings for selected device - make sure speakers are selected in connector,try changing different profiles in hardware section (mine is Analog stereo duplex)

2)I know this is weird solution - But try once :) In some blog, I have read that after suspend some problems may appear - wireless going off, sound not working etc and best solution is to reboot the computer. If it still doesn't work, Suspend it again! I am not saying this works but try once.


how to connect to a wifi (wpa/wpa2) in ubuntu server 14.04

You can do this via system start using the /etc/network/interfaces configuration.

From terminal,

sudo nano /etc/network/interfaces

To setup dynamic addresses:

auto wlan0
iface wlan0 inet dhcp

To setup static addresses:

auto wlan0
iface wlan0 inet static

Input your credentials:

wpa-ssid <network>
wpa-psk <password>

For static addresses you can supply:

address <address>
netmask <netmask>
gateway <gateway>
dns-nameservers <nameserver1>, <nameserver2>

Final result:

auto wlan0
iface wlan0 inet static
address 192.168.1.10
netmask 255.255.255.0
gateway 192.168.1.1
dns-nameservers 192.168.1.1, 8.8.8.8
wpa-ssid NETGEAR
wpa-psk password


Is there a utility for hopping in and out of a CLI?

Yes, use can use tmux or, the older screen. The following are excerpts of their respective man pages:

tmux:

 tmux is a terminal multiplexer: it enables a number of terminals to be
 created, accessed, and controlled from a single screen.  tmux may be
 detached from a screen and continue running in the background, then later
 reattached.

 When tmux is started it creates a new session with a single window and
 displays it on screen.  A status line at the bottom of the screen shows
 information on the current session and is used to enter interactive
 commands.

 A session is a single collection of pseudo terminals under the management
 of tmux.  Each session has one or more windows linked to it.  A window
 occupies the entire screen and may be split into rectangular panes, each
 of which is a separate pseudo terminal (the pty(4) manual page documents
 the technical details of pseudo terminals).  Any number of tmux instances
 may connect to the same session, and any number of windows may be present
 in the same session.  Once all sessions are killed, tmux exits.

 Each session is persistent and will survive accidental disconnection
 (such as ssh(1) connection timeout) or intentional detaching (with the
 'C-b d' key strokes).  tmux may be reattached using:

       $ tmux attach

screen

   Screen  is  a  full-screen  window  manager that multiplexes a physical
   terminal between  several  processes  (typically  interactive  shells).
   Each  virtual  terminal  provides the functions of a DEC VT100 terminal
   and, in addition, several control functions from the ISO 6429 (ECMA 48,
   ANSI X3.64) and ISO 2022 standards (e.g. insert/delete line and support
   for multiple character sets).  There is a scrollback history buffer for
   each virtual terminal and a copy-and-paste mechanism that allows moving
   text regions between windows.

   When screen is called, it creates a single window with a  shell  in  it
   (or  the  specified  command) and then gets out of your way so that you
   can use the program as you normally would.  Then, at any time, you  can
   create new (full-screen) windows with other programs in them (including
   more shells), kill existing windows,  view  a  list  of  windows,  turn
   output  logging  on  and off, copy-and-paste text between windows, view
   the scrollback history, switch between windows in whatever  manner  you
   wish,  etc.  All  windows  run their programs completely independent of
   each other. Programs continue to run when their window is currently not
   visible  and  even  when  the whole screen session is detached from the
   user's terminal.  When a program terminates, screen (per default) kills
   the  window  that  contained it.  If this window was in the foreground,
   the display switches to the previous window; if none are  left,  screen
   exits.

Both of these programs will enable you to log on to a server, launch a process, then log off and leave it running. When you want to check on it, you log back on to the server and reconnect to the running tmux or screen session and it is as though you never left. You can install both of them from the Ubuntu repositories:

sudo apt-get install screen

or

sudo apt-get install tmux

You can find a nice Q&A comparing the two programs on our sister site, Unix & Linux.


How to run dell command-configure with the terminal?

To make the binaries from dcc discoverable without having to type the full path every time, open the file ~/.bashrc and add the following to the end,

export PATH="/opt/dell/dcc:$PATH"

Then when you open a new terminal, simply cctk will look for and execute this file in /opt/dell/dcc.

As for the actual usage, you’ll have to read the manual or help guide to understand how it works. usage error means the program was executed, but did not have the required command line arguments passed to it.


If you are going to compile manually, you have to install all the depenencies and -dev packages manually.

For gtk+ the command is

sudo apt-get install libgtk-3-dev libgtksourceview-3.0-dev

You also need who knows what else. Check the README for dependencies and search for them and the -dev packages in the ubuntu database.


How to remove all lines in a file containing a string from another file

Use the following grep expression:

grep -vFf file_B file_A

Here is a test:

$ cat file_A
bird, snake
dog, cat
rabbit,fox
eagle,dove

$ cat file_B
dog
dove

$ grep -vFf file_B file_A
bird, snake
rabbit,fox

-f will read the patterns from a file (one per line), file_B in this case
-F will consider the patterns read from file_B as fixed string, meaning no further pattern operation will be done on the patterns
-v will print the non-matching lines i.e. the lines of file_A that does not contain the petterns from file_B.


Since your /var is an LVM logical volume, you could increase its size by using another disk’s space. However, you are using /dev/sdb as an unpartitioned disk. You should:

Back up the data from /dev/sdb somewhere,
partition your /dev/sdb drive,
restore the original data to one partition and mount it as /mnt/data and
use another partition as a physical volume which your logical volume /var can utilize.

Alternatively, you can make /mnt/data a logical volume, too. In this case, the physical volume on /dev/sdb could be either a partition or the whole unpartitioned disk. I’d still prefer to create a partition there, even a single one. The partition table does not take much space and the drive will have a more flexible setup – you can see the difference right now.

See also

How do I add an additional hard drive?
How can I add a new drive to an existent logical volume?


xubuntu 12.04 vlc 2.0.3 dual monitor refresh different rates problem

Based on my own experience with 12.04, performance seems to degrade on multi-display desktop, regardless of your refresh rates or any other display settings for that matter.  Though using single or single display desktop (multi-display desktop, one workspace for each display) will maintain normal FPS during video playback or rendering.

Because you mentioned both ATI and Nvidia having this issue, I'm going to assume it might be something specific with Xubuntu and running any dual display desktop.  I'm curious if other variants of Ubuntu has this issue also.


Not able to authenticate during sofware installation

I installed policykit-1-gnome . Now everything is working fine.


Ubuntu 18.04 iso without desktop environment

You can use the mini iso.  https://help.ubuntu.com/community/Installation/MinimalCD

It basically includes nothing except the base system by default, you have to specify all packages to install.  If you don't want a desktop, simply don't install one.


how to locate them and remove them?

One way to do it would be using the command find

sudo find / -iname '*thunderbird*'

Like this you will parse all the file system and will see every element that contains the expression "thunderbird"

Alternativly we have fd-find in our repositroy which is faster then find (because it uses multithread)
 It is not installed by default, you can install it with apt

sudo apt install fd-find

Syntax is lighter and output is colorized

fd thunderbird /

You can also use locate

locate thunderbird

To remove a file use the rm command


Partitioning an EMPTY hard drive for Windows 10 and Ubuntu 16 dual-boot from gparted

Install always and only as UEFI.

Under BIOS you have limitation to 4 partitions, you don't have such limitation under UEFI.

You than leave the unalocated space for LINUX!
 16GB for Linux Boot
for Linux Swap your size of  installed  RAM + 8 GB
for Linux Home as much as you are able,
for Windows you shall have the partition created for by windows installation and for Windows 10 "recovery"
When installing Windows I always separate partition for Windows + all the software about 120 GB to 160 GB, and max for my "archives" (my all personal files). I was able under (UEFI) Windows to partition
as many as 16 plus partitions, for Windows swap (all "moving" files known as Temporary Internet files) and other Microsoft crap files (including all the latest factory drivers) I reserve about 16 GB.
Before I complete installation after installing Windows I routinely decrapify Hard Disk always using PrivaZer
All my software not related to WINDOWS OS is always installed in a DEDICATED FOLDER so I don't have to ever search for in the case I need to access it!!

https://privazer.com/en/PrivaZer_free.exe

I also  under Linux purge the Windows System Volume Information leaving the only partition log file and getting rid of all other Microsoft crap files.


Run a command for a specific amout of time

The timeout command is built for precisely this. To run your cvlc command for 1 minute:

timeout 1m cvlc-command

The time period can use the strings d for days, h for hours, m for minutes and s for seconds. If no time measurement letter is given, the default is seconds.

A useful option is --preserve-status which will make the timeout command exit with the controlled command's status code, even if it is killed. If this option isn't used, the status code will be that of the controlled command if no timeout occurred, or 124 if the command timed out.

Another useful option if you need to be very sure the service has stopped is to use --kill-after=<time> which will send another kill signal to the command if the command has not stopped by the new limit set by time


USB stick made with UNetbootin missing BOOTMGR.

If you're using some linux distro to make the live USB, you can use the commands given in the following link:

How to make an Ubuntu live USB stick in Fedora?

If you're using Windows, you can try any other Live USB creating software such as YUMI (Your Universal Multiboot Installer) or LinuxLive USB Creator.


Installing Ubuntu One in Windows 7 - hangs at "Getting information, please wait..."

Ubuntu one on windows 7 is really buggy.  I use Ubuntu 1 now and love it but too buggy on windows 7.  Use windows mesh instead.  It's free like Ubuntu 1 up to 5GB and even syncs removable devices.  Windows hotmail/live account required.


How do I get emacs to open in the terminal when it is being used as the config editor?

From @steeldriver comment:

git config --global core.editor "emacs -nw"


Failed to fetch *.deb Size mismatch, then packages with unmet dependencies

Today I ran some software updates.
Next, I tried re-installing it. Voila, the game is now succesfully installed.

Nice!
Now off to play a little amnesia!


I can no longer reach Ubuntu Desktop and instead get "GNU GRUB VERSION2.03..."

Choose Ubuntu from the grub menu with the arrow keys and hit enter.

Login to Ubuntu, open User Accounts, Unlock your account and flip the switcch for auto login.

If this doesn't solve your problem, drop me a comment with the details of what happened that you didn't expect.


Taskbar extensions not working in Ubuntu 18.10 with gnome 3.30

I could finally make it work. I think gnome-extension page have old one. I referred
the github repo and there was a issue and patch for that. I clone the repository and copy it to extension folder. After I logout and login it worked perfectly. Use following commands.

git clone https://github.com/jimmytheneutrino/gnome-shell-extension-taskbar
cp -r gnome-shell-extension-taskbar/ ~/.local/share/gnome-shell/extensions/TaskBar@zpydr

Before copy ,remove any old versions from gnome-shell-extension-taskbar/ ~/.local/share/gnome-shell/extensions/TaskBar@zpydr.


I think 14.04 used upstart for daemon jobs.
Upstart can be very simple, for example, create a file inside of /etc/init/

sudo nano /etc/init/<filename>

inside the file put:

exec <command>

Then, to start that command as a daemon, do start <filename>


How do I install development tools for 12.10?

Do not copy my commands, you must type them in and use your tab key becuase my kernel may be different than yours.  I explain play by play:

Open up a terminal and type:

sudo apt-get update

This update gives your computer a heads up of files you may need.  But no files download, only information on what can be downloaded.  If you didn't do this first, you may not have the latest link to security updates or the latest versions of software.

As you type, press the tab key, to finish your command.  Start typing the command that will install build-essential.  Once you get this far stop:

sudo apt-get install linux-headers-

The next part that should appear will be your Linux kernel.  So open another terminal and type this:

uname -r

You should see something like this:

3.2.0-23-generic

Now go back to the other terminal and press tab as type.  You should see your kernel pop up.  Choose that one.

sudo apt-get install linux-headers-3.2.0-23-generic

Now type a space and add build-essential (don't forget use your tab for completion).

sudo apt-get install linux-headers-3.2.0-23-generic build-essential

Now hit enter and files will download that help you compile code.


That looks like an X86 device, so you might find the Intel NUC images might work there.


LDAP configuration: slap_init no backend for

Reconfigured slapd after a hundred of reinstalations, now it runns smoth as nothing else in this universe like nothing was ever wrong... Hope I can edit this answer in the future and provide you with an answer.

SchoolGuy


You need debootstrap chroot.

Install packages on the host computer.

sudo apt-get install debootstrap
sudo apt-get install schroot

Create a configuration file for schroot.
Run debootstrap.
Check the chroot.
Now you can use whatever you want, including installation using

apt-get

The detailed instructions and more information can be found in the above link

Another useful link can be found here.

A simpler instructions:

Create a chroot environment into which you will install your packages:

debootstrap precise fakeInstallation

Replace "precise" with your Ubuntu version name, and "fakeInstallation" with directory you want to chroot.

Now you have created a fake installation in the fakeInstallation directory

chroot fakeInstallation

Now you can use apt-get install within the fakeInstallation directory


Ubuntu 11.10 with KDE installed does not prompt for elevation for privileged ops in all apps

Do you have the polkit-kde-1 installed ?

A bug report: https://bugs.launchpad.net/ubuntu/+source/policykit-1-gnome/+bug/867737


How can I disable access to the Snap Store?

You could firewall off the store by setting all the host names the store uses to 127.0.0.1 in your /etc/hosts file. That way you get to keep the ability to build and install snaps locally, but snapd will never reach the store.

Adding 127.0.0.1     api.snapcraft.io to /etc/hosts will likely be sufficient.


The User fossfreedom mentioned in a comment a link to launchpad.

In this link is a statement that the fcron project is not under developement any more, also the homepage of fcron itself shows that there was no release since May 2010, also there was a gap of three years to the release before.

I could not find a quick way to contact the developement team to ask if the project is really abondoned, so I assume it is and try to live with cron until I find another solution.


How to set default browser on Ubuntu Touch?

open the Settings utility, move to the Details tab, click on the Default Applications and then select your preferred web browser through the Web drop-down.


Why doesn't 12.10 give me an option to Install beside windows 7?

While Installation choose "Something else" and setup your partitions manually:

and follow

https://www.youtube.com/watch?v=m5Jxfj6tu_U
https://www.youtube.com/watch?v=qBCHsgry2RQ

check out tutorial on how to install dual boot system
How to install Side by Side Boot on Windows XP


Upgrading Firefox fails. lzma error: compressed data is corrupt

Here's how I fixed it.

cd  /var/cache/apt/archives
sudo rm firefox_32.0+build1-0ubuntu0.14.04.1_i386.deb
sudo apt-get update
sudo apt-get upgrade


Script to convert .wma to .mp3 command not found

As first make sure you have ffmpeg and libav-tools installed, this you can do by typing in terminal (ctrl+alt+t):

apt-cache policy ffmpeg libav-tools

This should get you an output like the following if both are installed:

ffmpeg:
  Installed: 7:2.8.6-1ubuntu2
  Candidate: 7:2.8.6-1ubuntu2
  Version table:
 *** 7:2.8.6-1ubuntu2 500
        500 http://archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
        100 /var/lib/dpkg/status
libav-tools:
  Installed: 7:2.8.6-1ubuntu2
  Candidate: 7:2.8.6-1ubuntu2
  Version table:
 *** 7:2.8.6-1ubuntu2 500
        500 http://archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
        500 http://archive.ubuntu.com/ubuntu xenial/universe i386 Packages
        100 /var/lib/dpkg/status

If you get in one of the lines beginning with Installed: an entry (none) install the package with sudo apt-get install <package-name>.

Now only a few corrections to the script itself:

#!/bin/bash

cd "$1"
find . -type f | grep wma$ > wma-files.txt

readarray -t files < wma-files.txt

for file in "${files[@]}"; do
    out=${file%.wma}.mp3
    probe="$(avprobe -show_streams "$file" 2>/dev/null)"
    rate="$(echo "$probe" | grep "^bit_rate" | sed "s:.*=\(.*\)[0-9][0-9][0-9][.].*:\1:" | head -1)"
    ffmpeg -i "$file" -ab "$rate"k "$out" && rm "$file"
done

You can call this then with ./script.sh /path-to-your-music.


14.04 resumes to black screen, no response

I read some posts mentioning that USB keyboard and mouse could be related. After some experimenting, I finally found a solution:

Before suspending the laptop, I unplug my mouse (it's wireless, so I
just remove the receiver)
Once it is suspended, I put the receiver back in
Resuming with the receiver inserted works

I probably didn't try all possible combinations but this has reliably worked for me.


Repeated 'authentication required' for wifi

Changing the router's configuration helped. Changed the mode to Wireless-G and security mode to WPA2 Personal. Problem seems to be solved.


Partition 256 GB SSD for dual Boot, Windows 10 + Ubuntu 19.04

You are a bit limited on disk space on the SSD so I recommend dropping the /home partition altogether and going with a single partition for everything in your Ubuntu operating system. New installations of Ubuntu 17.04 and later create a swap file instead of a swap partition by default, so a single >= 25GB partition for Ubuntu is all you need. This feature makes more efficient use of valuable disk space on SSDs.
You can also add the 128 GB SD card to /home by following the instructions in How to increase space in /home, by adding an extra hdd? or How can I give space on another drive to my Ubuntu partition?. This will allocate to your Ubuntu installation 100GB on the SSD (plenty of room to install applications) + 128GB on the SD card making a total of 228 GB for Ubuntu and the remaining 156GB of disk space on the SSD will be allocated to Windows 10 by the Install Ubuntu alongside Windows 10 option in the Installation type screen of the Ubuntu installer. You won't need to do any manual partitioning because you will only be making one new partition in the Installation type screen of the Ubuntu installer.


How would you go about backing up a remote Ubuntu VPS via SSH?

SSH Public Key Authentication

The first thing you want to do is start with ssh public key authentication. This will let your script use SSH without a password.

All that the server needs is SSH installed, and public key authentication set up for the user that will be running the backup script from the RasPi.

Here's a good tutorial for public key authentication: https://hkn.eecs.berkeley.edu/~dhsu/ssh_public_key_howto.html

Option 1: SSH and Tar

You can compress the tar.gz from the server and transmit it directly over ssh with something like this:

ssh root@remoteserver.example.com "tar -czvf - / 2> /var/log/sshbackup" > vpsbackup.tar.gz

This will make the VPS tar and gzip all files on / and transmit it over SSH to store in vpsbackup.tar.gz on the RasPi. A log of the most recent backup will be kept on /var/log/sshbackup on the VPS.

Option 2: Rsync

Sending an entire .tar.gz over SSH is inefficient... Files that don't change will still be transmitted. A better solution is to use rsync, but this makes it difficult to make a .tar.gz that preserves permissions. If you have enough storage space on the RasPi, you can just store the backup files as plain ol' files. Then you can have a script tar.gz them if you want to keep multiple past backups.

The server needs rsync installed. This will run over SSH, so you still use the public key authentication, and keep the encryption. You will need to run this command as root and have public key authentication and SSH logins for root enabled to preserve permissions. Your destination (or at least a temporary destination) should be a Linux filesystem. If you're storing these backups on a FAT or NTFS partition (e.g. on most external hard drives), you can make a loopback filesystem (see http://www.walkernews.net/2007/07/01/create-linux-loopback-file-system-on-disk-file/) for temporary storage. The tar.gz file can be stored on any partition, because it preserves permissions on its own.

An example rsync command:

rsync -a --delete --exclude=/dev --exclude=/sys --exclude=/proc --exclude=/tmp remoteserver.example.com:/ /path/to/backup/destination/

be careful when using --delete, especially as root! It will delete any files in the destination directory that do not exist on the backup source. You should only use --delete when syncing to a dedicated backup directory being used only for that VPS. You should also make sure there is no possibility of your script syncing to the wrong destination (e.g. if /path/to/backup/destination is determined by a shell variable)

rsync will only transfer files that are different between the source and destination. If you have large files, it will also only transfer parts of the file that have changed (for this to work, you must add the -c flag). This means you are using minimal bandwidth, but it'll use more CPU and slow down re-sync preparation times as both sides need to first checksum files to determine which blocks to transfer. If you do use the -c flag and you have large files (such as database files) and/or a flaky connection, consider adding --partial --append, which enables you to resume transfers after a connection is interrupted.


Their note is mentioned in download section is as :
Note: These binaries are just the artifacts of the builders and have not undergone any QA, thus they should be considered unsupported.
It means that do not provide binaries and are considered unsupported so there is no other workaround then building the source.


Wine is upwards compatible with software requiring >= earlier versions of Wine. Wine 3.x fulfills the dependency requirement for software that requires Wine 1.x.


juju-quickstart: error: bad API response: cannot upload charm to provider storage: 500 INKApi Error

Figured out the issue.

After the environment is bootstrapped, changes to the environments.yaml file don't seem to take effect. The settings are pushed into the *.jenv file for that environment. Because I was using quickstart, the settings were pushed in prior to any changes made. The solution is to "juju destroy-environment --force", modify the environments.yaml file based on your needs, then perform a "juju bootstrap".

I stumbled on this when I unplugged my computer from the network, and removed ALL proxy settings everywhere and attempted to deploy a local charm. It still tried to use the proxy for 10.0.3.1. A "grep -r 'myproxy.com'" pointed to the *.jenv file.


No, you don't have to force it. Xorg server automatically loads it if it exists. You may think of it as a static override configuration.

Keep in mind that Xorg will load dynamic setting then falls back to default if xorg.conf for missing item.

man xrog.conf

  When the Xorg server is started by the “root” user, the config file
  search locations are as follows:

   <cmdline>
   /etc/X11/<cmdline>
   /usr/etc/X11/<cmdline>
   $XORGCONFIG
   /etc/X11/$XORGCONFIG
   /usr/etc/X11/$XORGCONFIG
   /etc/X11/xorg.conf
   /etc/xorg.conf
   /usr/etc/X11/xorg.conf.<hostname>
   /usr/etc/X11/xorg.conf
   /usr/lib/X11/xorg.conf.<hostname>
   /usr/lib/X11/xorg.conf

man Xorg

  CONFIGURATION

  Xorg typically uses a configuration file called xorg.conf and
  configuration files with the suffix .conf in a directory called
  xorg.conf.d  for  its    initial setup.  Refer to the xorg.conf(5)
  manual page for information about the format of this file.

  Xorg  has  a  mechanism  for automatically generating a built-in
  configuration at run-time when no xorg.conf file or xorg.conf.d files
  are present.    The current version of this automatic configuration
  mechanism works in two ways.

  The first is via enhancements that have made many components of the
  xorg.conf file optional.  This means that information that  can  be
  probed  or    reasonably deduced doesn't need to be specified
  explicitly, greatly reducing the amount of built-in configuration
  information that needs to be gen‐    erated at run-time.

  The second is to have "safe" fallbacks for most configuration
  information.  This maximises the likelihood that the Xorg server  will
  start  up  in    some usable configuration even when information about
  the specific hardware is not available.

  The  automatic  configuration support for Xorg is work in progress.
  It is currently aimed at the most popular hardware and software
  platforms sup‐    ported by Xorg.  Enhancements are planned for future
  releases.


When performing a soft reboot using the restart button, what should I see in my /var/log/syslog?

In that situation, you should use the 'top' command. That will show you the programs that are currently using resources.


Logitech t650 wireless touchpad gestures

In kernel 3.19 (as included with Ubuntu 15.04 Vivid) the Logitech HID++ driver got rewritten to improve support for certain Logitech devices. This shifted processing of events from the hardware (the touchpad) to software (the Linux input driver stack).

This results in the Logitech T650 touchpad not sending keyboard events such as Back for three fingers. Since there is no multi-touch driver that processes gestures, you do not get the event either.

Workarounds:

Install a kernel version before 3.19 (or just the hid-logitech-dj driver from previous versions).
Enable both reporting of gestures as well as raw events. Since the events reporting is very sluggish after this method, I won't explain it here.

A forward solution should recognize the multi-touch functionality of the Logitech T650 touchpad and then generate appropriate events for gestures.


chrootkit suspicious files and directory detected

Are these files/directories related to a software package (or several software packages)?

for thing in /usr/lib/debug/.build-id /lib/modules/4.4.0-93-generic/vdso/.build-id /lib/modules/4.4.0-92-generic/vdso/.build-id /lib/modules/4.4.0-91-generic/vdso/.build-id ; do
    /bin/ls -ld $thing
    /usr/bin/dpkg -S $thing
done

YMMV, but on MY Ubuntu 16.04.3LTS, this shows:

$ for thing in /usr/lib/debug/.build-id /lib/modules/4.4.0-93-generic/vdso/.build-id /lib/modules/4.4.0-92-generic/vdso/.build-id /lib/modules/4.4.0-91-generic/vdso/.build-id ; do
>     /bin/ls -ld $thing
>     /usr/bin/dpkg -S $thing
> done
drwxr-xr-x 229 root root 4096 Aug 14 17:54 /usr/lib/debug/.build-id
python-bzrlib-dbg, tclcl-dbg, python2.7-dbg, libfltk1.3-dbg, graphicsmagick-dbg, python3-tk-dbg, python3-gdbm-dbg:amd64, libglib2.0-0-dbg:amd64, libkf5wallet5-dbg:amd64, libtk8.6-dbg:amd64, libtcl8.6-dbg:amd64, libc6-dbg:amd64, atanks-dbg, ballz-dbg, lyx-dbg, liblqr-1-0-dbg, ntfs-3g-dbg, python3.5-dbg, evolution-dbg, freeglut3-dbg:amd64, libgd-dbg:amd64, libgdk-pixbuf2.0-0-dbg:amd64: /usr/lib/debug/.build-id
drwxr-xr-x 5 root root 4096 Aug 28 18:31 /lib/modules/4.4.0-93-generic/vdso/.build-id
linux-image-4.4.0-93-generic: /lib/modules/4.4.0-93-generic/vdso/.build-id
drwxr-xr-x 5 root root 4096 Aug 15 19:30 /lib/modules/4.4.0-92-generic/vdso/.build-id
linux-image-4.4.0-92-generic: /lib/modules/4.4.0-92-generic/vdso/.build-id
/bin/ls: cannot access '/lib/modules/4.4.0-91-generic/vdso/.build-id': No such file or directory
dpkg-query: no path found matching pattern /lib/modules/4.4.0-91-generic/vdso/.build-id

I don't have linux-image-4.4.0-91-generic installed.

This is a False Positive result from chkrootkit, and shows the difficulty with any prepackaged set of "Am I rooted?" tests. While the tests may have been fine at the time of packaging, they lag behind the changes in the environment being checked. Given the high possibility of False Positive results, this type of tool should ONLY be used as a first step, a trigger to further investigation. Understanding must come before action.


Easy way to install TeX Live (and TeX Studio) in Ubuntu 12.04

It's probably best to download an .iso image of a TeX distribution from CTAN, texlive2013.iso for example - it's ~2GB. Put this into your Downloads folder.

Just ensure that you have the perl-tk package installed before using the GUI. If not, open a terminal and go:

$ apt-get install perl-tk

Then create a mount point:

$ sudo mkdir /mnt

Change the current directory, mount the .iso and start installation

$ cd ~/Downloads
$ sudo mount -t iso9660 -o ro,loop,noauto texlive2013.iso /mnt
$ cd /mnt
$ sudo ./install-tl --gui=perltk

This opens up a nice GUI. You can to decide what to install in Installation collections. Also change the Create symlinks in system directories  as in the screenshot so that the directories will be all laid out for you. This means you won't need to poke around and modify your system files post-installation.

After installation, close the terminal and open a new terminal:

$ sudo umount /mnt

Check if everything is OK:

$ tex --version

TeX 3.1415926 (TeX Live 2013)
kpathsea version 6.1.1
Copyright 2013 D.E. Knuth.

Try processing a .tex file and preview a PostScript file.

$ latex sample2e.tex
$ dvips sample2e.dvi

You can also make a .pdf file:

$ pdflatex sample2e.tex

If you want to modify settings or get more packages, do this in TeX Live Manager 2013:

$ sudo tlmgr -gui

To install a LaTeX editor, (e.g. TeX Studio), download the relevant .deb file into Downloads folder and install

$ cd ~/Downloads
$ sudo dpkg -i texstudio_2.7.0_i386.deb

You may need to install libpoppler-qt4-3.deb first.

References:

TUG documentation

TeX Live docs

Starlinq blog


How to make windows steal focus when links are opened

I was able to fix this using Compiz config settings manager

Install ccsm:

sudo apt install compizconfig-settings-manager

General Options > Focus & Raise Behaviour
Set Focus Prevention Level to OFF


How to install new Skype in Ubuntu 17.10 and later

Updated 1-2-2018

Canonical has announced that Skype is now available as a Snap, so it can be installed direct from the Ubuntu-Software or by using snap:

snap install --classic skype

or you can use the link: https://snapcraft.io/skype

Old Method

If you prefer to install it with Debian package manager use the old method:

Refer to the  https://www.skype.com/en/get-skype/ page. Then choose the option

  get Skype for linux Deb

then a .deb file will be downloaded. Open the terminal, refer to the folder where the .deb was downloaded (Or right mouse click in the folder and choose open in terminal). Then run:

sudo dpkg -i skypeforlinux-64.deb

if it showes any problem run: sudo apt install -f

when it finishes delete the skypeforlinux-64.deb file.


Sound output problem on HP pavillion g6 2229TU in ubuntu 10.04

Two things i have found useful from community help and i will paste here. The full debugging link is here. here are the explanations I find relevant

6. Is the sound card physically installed and recognized by your hardware?

Open a terminal and type

lspci -v | grep -A7 -i "audio"

This should output some information about your audio hardware. An example is below.

00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 02)
        Subsystem: Toshiba America Info Systems Device ff01
        Flags: bus master, fast devsel, latency 0, IRQ 22
        Memory at dc440000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: <access denied>
        Kernel driver in use: HDA Intel
        Kernel modules: snd-hda-intel

Most people, especially laptop users, have a built-in sound card for their computer on the motherboard. If yours is built-in and isn't showing up in this step, then you probably need to enable it in your BIOS. When you first reboot your computer, there's usually a key sequence listed telling you how to enter the BIOS configuration screen. Since all BIOS's are differenct, you'll need to sort through your BIOS and enable the built in sound card. If you need help with this, you should ask at ubuntuforums.org.

If you are not using a built in sound card, and this step does not show your audio card, the card may be seated incorrectly on your motherboard, or may be bad or otherwise incompatible with your motherboard. You will probably want to test the card in another computer to see if it works there.

7. Is my sound card supported by the Ubuntu sound system?

Ubuntu uses the Advanced Linux Sound Architecture (ALSA) for managing sound output. There is a listing of all of the sound cards supported by ALSA at http://www.alsa-project.org/main/index.php/Matrix:Main . You should look for the information that was listed by the command in the previous step. If it happens that your sound card is not supported by ALSA, you have two options: obtain a new sound card that is supported by ALSA, or contact the ALSA developers and request support for your sound card.


menu not showing in apps when maximized 12.10

Let't take it step by step:

The reported missing wm is referring to the window manager. Ubuntu 12.10 uses Unity as wm.
Instead of autoremove you should use:

sudo apt-get purge appmenu-gtk appmenu-gtk3 appmenu-qt

I also recommend you to use the unsettings tool to make more deeper customizations. To install it, type:

sudo add-apt-repository ppa:diesch/testing
sudo apt-get update
sudo apt-get install unsettings

After that you can run it with unsettings.

NOTE

In your case reinstall the uninstalled packages first with:

sudo apt-get install appmenu-gtk appmenu-gtk3 appmenu-qt


Change console initial path after mount /home directory from an ext4 partition

The problem solved by rebooting the system.

Although the guide mention it is enough with running the command sudo mount -a, it seems there were still old dependencies that were not updated with that command, so after rebooting the system, console initial path changed to the one expected and even the removed files started going to the rubbish folder, and were not removed permanently as it was happening before.


What's the difference between install-powerpc and install-free-powerpc? "install-free"?

The "install-free" option from yaboot adds apt-setup/restricted=false apt-setup/multiverse=false to the kernel command line. These two options disable non-free or multiverse software during the installation.


GParted partition resize using a broken USB flash drive failed halfway through

I wouldn't trust the results of a partition resize operation that was done with a USB flash drive that could not be inserted firmly into the USB port. That model of USB flash drive costs less than $5 USD for the 16GB model, and you should have thrown it out as soon as you saw that it was broken.
The laptop's Ubuntu partition is corrupted, and it's possible that some data on the Ubuntu partition has been lost. GParted didn't do anything to change the Windows 10 partition, so the files on the Windows 10 partition are still OK. Your best course of action to avoid descending into chaos is to backup your personal files on the laptop's Ubuntu partition from another bootable Ubuntu live USB flash drive, delete the Ubuntu partition with a bootable Ubuntu/GParted live USB (but don't delete the Windows 10 partition(s)), and reinstall Ubuntu.


recover data using a laptop running Ubuntu, but won't load

You can boot with Ubuntu LiveUSB and copy your data anywhere you like.


System shutdown after entering my username and password

I have a similar issue. I managed a workaround by -

selecting the "Ubuntu, with Linux 5.0.0-32-generic" instead of the default "Ubuntu, with Linux 5.0.0-45-generic" in the Advanced Boot options.

I'm running 18.04 and am dual booting windows.
I am very new to Ubuntu. I have no idea why this is happening, I have a hunch that it is an issue with the graphics drivers.

Update -
I updated my graphics drivers and all is well now. It boots up normally.


Maybe a software can help like KeyTouch.

Also, some keybord come with a program for this kind of thing.

Hope this help.


You can use Synaptic (or any other application that needs to run as root) under Wayland by first entering this command in the terminal:

xhost +si:localuser:root


Unable to get package manager to work in Ubuntu 11.04

Try 15.04 (late Beta) or 14.04 LTS.

The version number is the date. 11.04 was release in April, 2011. This is now an unsupported version of Ubuntu. Supported ended for this version in November, 2013.

LTS (Long Term Support) releases are released every two years. The last one was 14.04. There are six month releases as well for those that want the latest versions but they are not supported for quite as long a period of time. A very nice graph of this is available on wikipedia.


Absolutely, but it is recommended to install a lighter version of Ubuntu as because your hardware seems a little old. It is recommended to install Lubuntu or Xubuntu for this kind of hardware.

And as is reported at ARCH:

Sound should work out of the box.
There shouldn't be any problem with wifi but IF there is any problem, then the solution has been stated also at ARCH.


How can I download pictures to an IPad 2

I don't have an ipad, but on android, you have to manually find the file(s) and download them. Also, you may want to check if your picture file is being synced to ubuntu one.


JUJU ERROR machine is already provisioned

You may have to cleanup the machine manually before being able to add it again. I am assuming it was no longer in use before you removed it from the gui.

I would try:

sudo apt-get remove juju*

And if not enough, I would try cleaning unused directories and files (those in my case):

sudo rm /etc/systemd/system/jujud*
sudo rm -rf /var/lib/juju
sudo rm /usr/bin/juju-run


How to install elementary OS AppCenter on Ubuntu?

If you're on Ubuntu 16.04 LTS you can install AppCenter from elementary OS PPA.

Step 1: Add the PPA

sudo add-apt-repository ppa:elementary-os/stable
sudo apt update

Step 1.1: For releases newer than 16.04LTS

If you're on an Ubuntu release newer than 16.04 LTS, use the following Daily PPA instead:

(I have had success with daily on 16.04 as well)

sudo add-apt-repository ppa:elementary-os/daily
sudo apt update

Step 2: Add elementary Apps repo

AppCenter is supposed to add this repository automatically, but that may not always happen. Add the repo and it's key:

sudo bash -c 'echo "deb http://packages.elementary.io/appcenter $(lsb_release -sc) main" >> /etc/apt/sources.list.d/appcenter.list'
sudo wget -O /etc/apt/trusted.gpg.d/appcenter.asc http://packages.elementary.io/key.asc
sudo apt update

Step 3: Install AppCenter

Then all you have to do is install the appcenter package:

sudo apt install appcenter

If the installation fails due to unmet dependencies on 16.04 LTS, add this PPA for PackageKit

sudo add-apt-repository ppa:ximion/packagekit
sudo apt update

and try again to install. When it's installed successfully, the launcher for AppCenter should show up in App Dash.

Or you can just launch it from the terminal as:

appcenter

Or:

io.elementary.appcenter


df reports an ext4 partition is full, but there is no data

It could be that some process still has deleted files open. If this is the case then they will not appear in the du output but would still be counted in the df output.

One quick way to check for these is to list /proc as user root (hint sudo su should get you a root shell). Any open, but deleted files will have (deleted) at the end of the symbolic link target name.

ls -l /proc/*/fd/* | grep deleted | grep /home

should give you a list of any files open. Once you have that then an ls -lL of the specific file should give you the size of the file.

As an example (using /tmp on my system because there are no examples on /home here) I see a few files owned by user mysql.

richm@viking:/$ sudo su
root@viking:/# ls -l /proc/*/fd/* | grep deleted | grep /tmp
lrwx------ 1 root     root     64 Oct 13 06:30 /proc/1489/fd/11 -> /tmp/ibwmCqpg (deleted)
lrwx------ 1 root     root     64 Oct 13 06:30 /proc/1491/fd/12 -> /tmp/ib9MTMQi (deleted)
root@viking:/# ls -lL /proc/1489/fd/11
-rw------- 0 mysql2 mysql2 0 Aug 24 14:09 /proc/1489/fd/11
root@viking:/# ls -lL /proc/1491/fd/12
-rw------- 0 mysql mysql 1320 Oct 15 13:40 /proc/1491/fd/12

If you have any processes with large deleted files open then stoping the process should be enough to reclaim the disk space. Alternatively a reboot should do the same thing.


Where can I find a list of compatible audio cards?

Maybe the hardware compatibility list on linuxcompatible.org can help you.

Maybe this can help too: Sound Cards & Drivers - linux-sound.org

Here is another list: Sound cards - Linux Hardware Compatibility HOWTO


Text editor to handle extremely large files

There is a graphical vim - gvim - that may be more acceptable to you than the less graphical versions. I haven't tried it on large files though.

But it really comes down to personal preference. vi could do the job, but you're not comfortable using it. That's fine, but you might not like anything suggested either. So just try a few until you find one that works both for your large files and yourself.

The problem you will find is that no editor will work well if it doesn't have the system resources available to do its job. There are limitations that may stop you no matter what editor you try - for example a 32bit system will cause problems for all editors past a couple of hundred meg. A lot of the better known editors will have tricks like disabling features, increasing swap space, etc, to allow large files to be edited.


I have two wallpapers (side by side) on one screen. help!

Your question isn't very clear and is hard to understand. Ubuntu by default will only use one wallpaper for each screen. If you go to "System Settings" -> "Appearance". You will find all of your wallpaper settings.

Note: most of the wallpapers have a max resolution of 2048 x 1280.

It's hard to answer your questions since I can't replicate the issue, Ubuntu by default uses one wallpaper for all screens. I know KDE by default has a different wallpaper per screen, so you will need to change the wallpaper explicitly for each screen.

Here is a related thread.

Maybe if you reverse engineer the instructions on that post you can solve your issue.


Ubuntu versions 15.04 and newer perform a quick file system check on the root disk and report the result on the screen.

  The message
  /dev/sda2: clean, 286631/6111232 files, 2586472/24413952 blocks
  has the following meaning:

  The partition that was checked is "/dev/sda"
  The file system is "clean", i.e. there are no inconsistencies
  "286631/6111232 files": The file system has been created to allow a maximum of 6,111,232 files, and currently there are 286,631 files,
  "2586472/24413952 blocks": The storage capacity of the file system is 24,413,952 blocks (probably 4096 bytes each), and 2,586,472 blocks currently are in use.

  This is an informational message confirming that the file system is ok. There is nothing that needs to be resolved or repaired.

See the link https://answers.launchpad.net/ubuntu/+question/293967. There you will find a more information.


First, you need to backup all your data.   Organize you data all at one location (folder).  Windows XP Professional, Backup utility is installed by default, which is very helpful to create a backup copy of your important files.

Click Start  >  All Programs  >  Accessories  >  System Tools  >  Backup

Click Next and then choose Back up Files and Settings

Click all the folders you want to backup.

Choose the backup type, Destination and Name

Windows XP does not support writing the backup file to a CD directly, so create the backup file in the same hard disk and burn it in a CD or DVD.

Go to the Ubuntu website to download Ubuntu.  Choose the 32bit version. Burn the ISO to a CD.  Since you have Windows XP, you can use Free ISO Burner , once that is done, boot from the newly created CD, make sure that you system is set to boot from CD.

When you get to the Installation Type screen, choose erase and install.

Continue the installation following the on screen instructions.


Network printer appearing twice under "Settings > Printer"

The second print queue disappearing implies that it is being auto-setup by cups-browsed. It should reappear when cups-browsed is restarted. This part of remote configuration is working correctly and as designed.
The first queue is not set up by cups-browsed but by the GTK printing sub-system. I am guessing that the screenshot shows a GTK application. (You did not say what the application is).
GTK gets remote printers all by itself. It does not use CUPS but deals directly with the printer. My guess is that when CUPS is stopped (systemctl stop cups) the first entry still does not disappear.
The issue of GTK not using the correct CUPS APIs may be seen as a bug. There is nothing you can do about the first entry without severely crippling your whole printing system, which is what some of the advice in @User24601's link advocates. Users will have to live with it until the GTK maintainers decide to fit in with what CUPS provides.
Informative links are here and here.


You could use GNU sed's lowercase \L extension:

sed -r 's/([^ \t]+\s)(.*)/\1\L\2/' file

Explanation

-r use ERE
s/old/new/ replace old with new
([^ \t]+\s) save some characters that are not space or tab, followed by a space or tab
(.*) save any number of any characters
\1\L\2 print the first saved part unchanged, then the second saved part lowercased


Is it possible to change Unity Panel fonts or font size?

This not the best way as it involves changing the size for all applications, but it's the only way I know.

Press Alt + F2 and type gnome-appearance-properties.
Start the Appearance Preferences application from the search result.
Go to the Fonts tab.
Change the Application Fonts font settings.


I don't mean to sound rude, but if you're so new to Ubuntu, why do you think you're better qualified than Ubuntu developers to decide which update is worth it? Updates for release Ubuntu versions only include bugfixes and security fixes, you'll generally want all of those.

If you wish to inspect changelogs, they can be found on pages like https://launchpad.net/ubuntu/quantal/+source/python-keystoneclient/ for every source package.


Lock screen not working in xubuntu 18.04

After not finding a good answer how to solve the locking issue on Xubuntu 18.04, I stopped using the supplied locking mechanisms in Xubuntu (namely the gnome-screensaver and light-locker) and installed i3lock from the distro's repos.

This locker is very simple and can be used wihout any switches (you can set a background image and a few other options, none of them are critical).

The only downside I see is that I can't seem to make it lock the session on system suspend and that it doesn't show the keyboard layout, but as long as you remember which layout you've used before locking the screen, you're OK. Layout switching keyboard shortcut you use in the session works also in the i3lock, so that's OK, too.

BTW, it seems to be enough to have only the one line invoking i3lock in the /usr/bin/xflock4 file.


Cannot install packages. "Warning: untrusted versions..." plus "method driver /usr/lib/apt/methods/http could not be found"

I decided to manually install apt from http://packages.ubuntu.com. That fixed everything. It repopulated both /etc/apt and /usr/lib/apt/methods.


If I cat file to other file is there way to get them separate again?

With cat file_b >> file_a you are just appending the content of file_b to file_a. No format change, no other manipulation (1)(2).

You can go back by just removing the last bytes of the files; probably something like

 head --bytes=-$(wc --bytes file_b | cut -d" " -f1) file_a > old_file_a

should work.

Explanation:

wc --bytes file_b

returns the length of file_b in bytes (and the name of the files, like "5678 file_b")

wc --bytes file_b | cut -d" " -f1

gets rid of the file name in the output of wc by keeping just the first field ("5678"). Then we use a process substitution to put that number as an argument to head:

head --bytes=-5678 file_a

outputs all the contents of file_a but the last 5678 bytes.

Footnotes:

(1) In the OP example, I doubt that the pic2.png file is still a valid PNG file...

(2) Included in "other manipulation" is the fact that there is no recording of the original length of the file or any marker that separate the two files. If after the cat you delete file_b you have no way to separate them again without knowing the length of the original files. An archiver format (tar, zip, rar) is doing exactly this bookkeeping for you (and compress and checksum and other thing, sometime).


Ubuntu App store doesn't show any installed application

Try removing and reinstalling gnome-software. As Fix Ubuntu Software Center not loading issue in Ubuntu 16.04 LTS advises, you can do this by running:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get autoremove gnome-software
sudo apt-get install gnome-software


how to execute a command after resume from suspend?

You can place your scripts in the /etc/pm/sleep.d directory to have them run after suspend.  You will need to add a conditional to make your script run only during resume and not during the suspend process as well.  For example, your touchpad script would look like:

case "${1}" in
    resume|thaw)
        DISPLAY=:0.0 ; export DISPLAY
        xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Two-Finger Scrolling" 8 1
        xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Scrolling" 8 1 1
        xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Pressure" 32 10
        xinput set-int-prop "SynPS/2 Synaptics TouchPad" "Synaptics Two-Finger Width" 32 8
        setxkbmap -layout gb
        xkbset m
        xkbset exp =m
        su $USER -c "sleep 3; /usr/bin/xmodmap -e "keycode 135 = Pointer_Button2"" &
;;
esac

Be sure your script is marked globally executable and change $USER to the corresponding username.

You can find more detailed information in the pm-suspend manpage (man pm-suspend) or by looking at the documentation in /usr/share/doc/pm-utils (particularly /usr/share/doc/pm-utils/HOWTO.hooks.gz).


Music transfer from Ubuntu 16.04 to iOS 10 iPhone 6+

The iPhone OS, called iOS, is constantly updated.  With each update, it tends to break compatibility with the libimobiledevice.  This is why you can't use your iPhone with Ubuntu to transfer music, etc.

Accessing the pictures of the iPhone is more or less USB Storage-class communication, which doesn't change between revisions of the iOS.  The core OS handling for music, however, changes, which breaks the compatibility.

The only way to transfer your music to your iPhone is, unfortunately, to be using iTunes, on either a Windows or a Mac machine.  I do this from within a Windows VM within my Ubuntu system, passing through the USB for my iPhone right to the VM so it can be used (I use VMware, but VirtualBox will work for those who don't pay money to VMware for their stuff).


If you already have a cdrom, you should not mount another image as "cdrom". You have 2 possibilites:

unmount your /cdrom (with sudo umount /cdrom). I would not recommend it. If you want to restore your old cdrom, you have to remember the path in /dev.
make a new directory (preferrably in /media, but this is not necessary): sudo mkdir -p /media/anyNameEvenCdrom and after this sudo mount -o loop matlab2011a_64.iso /media/anyNameEvenCdrom


New Ubuntu Software Store (20.04) is too slow

The new Software Store offers the "good old" apt-managed applications and the new snap format. What you want is probably use the apt-packaged-versions of applications, which is possible.

Snaps are canonicals way to provide sandboxed applications. This has some positive and some negative implications. You can detect whether you are looking at a snap packaged app by the following indicators:

there is a channel given in the details section which may be changed by a dropdown-menu at the top left in the windows header.
currently (this will likely change) only snaps seem to have icons. Also if you search for an application, note that snaps seem to be listed first, and after that come the apt packages.
it is indirectly visible in the "source" because its a different format.

If you search for VLC and want the good old VLC the way you installed it until now, scroll to the bottom of the search and you will find it. It is the same as sudo apt install application in the terminal.

You will wonder about what the difference is. So here I try to give a short list:

Snaps take more time on their first startup. It's getting a lot faster next time, but is still not perfect.
Snaps have permissions you can give or deny within the software store, similar to smartphones.
Snaps usually are way larger. So in case you have a device with not so much space, consider not always using snaps. But you can mix them! The reason for the size is that snaps are often packaged together with their depencencies and therefor can not as easy share dependencies with other applications. Actually, sometimes this is very useful! Because sometimes some dependencies can not be installed the same time on a machine, which can cause conflicts with different applications. As far as I know canonical has plans to improve the snap system to make this less problematic.
Snaps are easy to update, allow you to install newer versions on Ubuntu and even try beta releases and similar things. If you update an application, it will store the last version in case you want to go back.

Summary

If you have a device where disk space is rather rare, avoid snaps.
If you want an application where it is important to always get the newest version, consider snaps when an alternative is to add an ppa. Very useful if you stay on Ubuntus LTS versions.
If you do not fully trust an application but need to install it for whatever reason not in a VM or something, consider a snap to at least limit what it may do on your system, if there is no other way.

To me, the software store does not feel finished. Categories load apps relatively slow on first sights, and no images for apt packages is weird. They are trying to push their snap format heavily and that is okay, but the usability of the store is unfortunately very low, which is probably the reason for your confusion.


VirtualBox 4.12 Shared clipboard not working in Ubuntu14.04

Started working after running: sudo apt-get install virtualbox-guest-dkms and enabling bidirectional shared clipboard.


Can't install package libglib2.0-dev because it depends on some unknown version

Try to do it with aptitude:

sudo aptitude install libglib2.0-dev


Calculation percentage of my data for different number ranges

Using awk:

awk '
    # Count occurencies
    {
    if ($1 < 0.3) a++
    else if ($1 > 0.7) c++
    else b++
    }
    # Print Percentage of count/NR (num records)
    END {
        printf "< 0.3: %.2f%%\n",a/NR*100
        printf "> 0.3 and < 0.7: %.2f%%\n",b/NR*100
        printf "> 0.7: %.2f%%\n",c/NR*100

    }
' file


My ati Radeon X1200 graphic card is not installed how do i install it

The wording of that dialog may be confusing you.  You do have a video driver installed by default - an open source driver named 'radeon' (also sometimes referred to as the -ati driver.)

The other driver that's being offered is a proprietary closed-source driver called AMD Catalyst, aka "fglrx" which stands for "FireGL and Radeon for X".  Like others have mentioned it only works for newer AMD cards, and unfortunately your X1200 (of the R6xx generation) is no longer supported by AMD with this driver.  -fglrx is needed for getting the maximum performance and full feature support out of AMD graphics cards.

However, contrary to what others have said, the open source -ati driver is fine for ordinary computer use - which is presumably what you're after since you're using a somewhat older graphics card.  It's quite stable, with reasonable performance good enough for basic gaming, desktop compositing and so on.  Plus then you can have a warm fuzzy feeling that you're using open source rather than closed source.  ;-)


Unable to install libpq-dev in ubuntu 16.04

Please try these commands, starting with cleaning the temp files, configure all unpacked but un-configured packages, then fix broken package dependencies, update, and install libpq:

sudo apt-get clean
sudo dpkg --configure -a
sudo apt-get -f install
sudo apt-get update
sudo apt-get install libpq-dev


How do I change Show Workspace Selector hot key in Workspace Matrix on Ubuntu 18?

From https://github.com/mzur/gnome-shell-wsmatrix/issues/47:

$ sudo cp ~/.local/share/gnome-shell/extensions/wsmatrix@martin.zurowietz.de/schemas/org.gnome.shell.extensions.wsmatrix.gschema.xml  /usr/share/glib-2.0/schemas/
$ sudo glib-compile-schemas /usr/share/glib-2.0/schemas/

Then use gsettings or dconf to set org.gnome.shell.extensions.wsmatrix-keybindings workspace-overview-toggle.


Sony WH1000-XM4, no microphone input through bluetooth connection on Ubuntu 18.04

Not a complete answer but only HFP/HSP supports both sound and mic at same time the other profile does not support mic at all.


I just read over the instructions again and realized that I have to install those packages listed as not found.

I will mark this as answer as soon as possible.


Adding a program to the launcher with a script

First get the list of applications from the launcher:

$ gsettings get com.canonical.Unity.Launcher favorites

Make an array of the items.
Then have your install script add your application to the array
Then have your script add the items from the created array to this command with item comma separated:

$ gsettings set com.canonical.Unity.Launcher favorites "['app1','app2','app3','your program.desktop']"

The app# is the applications from the array that you are including in your installer script.

Replace your program with the name of the *.desktop launcher you created.

Update:
The procedure is listed above.

This is a command line that will append your application to the launcher

gsettings set com.canonical.Unity.Launcher favorites "$(gsettings get com.canonical.Unity.Launcher favorites | sed "s/]/,'Your Program.desktop']/")"

Add the above commandline to your install script.  Replace the bold Your Program.desktop with the program you created.  This will not clobber what your current icons.  It'll append.


Difference between 'cd' and 'cd ..' in unix /linux

Difference between commands

The difference is that cd is a single command, no arguments. If there is no arguments, cd will go to your home folder by default. Now, by contrast .. always means "one directory up" or parent directory. So when you do cd .. it will go up one level. And this is always true, with exception of / folder, because there is nowhere else to go. Here's a demo:

$ pwd
/etc
$ cd ..
$ pwd
/
$ cd ..
$ pwd
/

Using this knowledge in practice

So where are the two commands useful ? cd will jump back to your home directory, which is the same as doing cd ~ or doing cd $HOME. This means that if you are somewhere very very deep in directory tree, you can quickly and easily go back to home directory. Here's an example:

$ pwd
/sys/class/block/sda1/holders
$ cd
$ pwd
/home/xieerqi

With .. you can also do cool things.  Let's say I am in /sys/class/block/sda1/holders folder and I want to quickly go to up 3 levels. So we can do this:

$ pwd
/sys/class/block/sda1/holders
$ cd ../../../
$ pwd
/sys/class

What also can be done is to make a function out of this. We can navigate easier by specifying a number of levels to go up.  Here it is:

goup() {
    num=$1
    while [ $num -ne 0 ]
    do
        cd ..
        num=$(expr $num - 1 )
    done
}

Knowing that cd .. goes up one level, why not specify how many times we want to repeat cd .. ? That's exactly what this while loop does. And here it is in action:

$ pwd
/sys/class/block/sda1/holders
$ goup 4
$ pwd
/sys


Software and updates stuck on "Applying changes" after I select the drivers, tried doing it from terminal still doesen't use them. Plus TOR

Here an example how to run the Tor browser bundle, for the current 64 bit Linux download :

wget -c https://www.torproject.org/dist/torbrowser/6.5/tor-browser-linux64-6.5_en-US.tar.xz
unxz tor-browser-linux64-6.5_en-US.tar.xz
cd tor-browser_en-US/
./start-tor-browser.desktop

Can you try this and report back ?


Modifying brightness control shortcut key bindings

have you tried using xbacklight

sudo apt-get install xbacklight
# increase brightness
xbacklight -inc
# decrease brightness
xbacklight -dec

(edit: since you want to go below the normal min brightness use the script below)
if that does not work you can edit this script or control it manually:
http://pastebin.com/HzzHrS2g be sure to read the commends at the top of the scriptYou will need to edit lines 5 through 7


mini.iso doesn't appear in Startup Disk Creator

according to this site: http://www.maketecheasier.com/install-a-minimal-ubuntu-on-old-laptop/

"You won’t be able to create a USB startup disk with this iso file, so the only way is to burn it into a bootable CD."

BUT IT'S DATED...

EDIT:

Based on quick google search, Unetbootin should work fine:
https://apps.ubuntu.com/cat/applications/unetbootin/

Just select your mini.iso...

I CAN CONFIRM, IT DOES WORK! (15.04)


https://github.com/bookkojot/mp4fixer

This tool solves exactly this problem. Worked for me. There are a few simple steps involved, instructions are enclosed. You need a short properly saved video on the same machine with the same kazam to use as input so it knows what the headers should look like. And you get the mp4 from the movie.mux.


How to tell if 13.04 will run slowly on my computer

The main reason for this is that "Unity 2d" is removed in 12.10, and if you don't have proper graphics support (or a really good processor) Unity3D will run slow.

This is because Unity3D will be running through LLVMpipe, which basically runs all the graphics on the main processor.

The website mentioned on the error box states:

  If you choose to continue anyway, Ubuntu will try to run using
  software rendering (via LLVMpipe). While llvmpipe is pretty good on
  modern CPUs, if your video card is old your CPU is likely old too, and
  it may result in unusable performance.

  Alternatives may include sticking with an old ubuntu release or
  switching to one of the lighter weight derivatives or Debian. For
  12.04 and 12.10, ubuntu-classic (no effects) is also a feasible option. To do this, install the gnome-session-fallback package, and
  then on the login screen click the gear icon and select
  "Ubuntu-classic (no effects)".

How to tell if your are running the 2d or 3d: Am I using Unity or Unity 2D?

If you are running 3D currently I may mean that the new drivers don't support the card on your machine, or if there is a chance of getting graphics drivers working it probably won't be easy, and these problems will likely continue in 13.04.

So probably the best options:

Stick with 12.04 (still use the version of unity you are using)
Or, Move to Xubuntu, Kubuntu, Lubuntu and upgrade (other desktops, will not look like unity)


What is the difference between traceroute and mtr?

Since this is Ubuntu-oriented site I have made a comparison of similar tools available on this distribution.

From their respective MAN pages:

Traceroute

  traceroute tracks the route packets taken from an IP network on their
  way to a given host.

Example Output (trimmed):

$ traceroute 1.1.1.1
traceroute to 1.1.1.1 (1.1.1.1), 30 hops max, 60 byte packets
 1  192.168.1.1 (192.168.1.1)  0.265 ms  0.248 ms  0.239 ms
 2  * * *
 3  X-X-X-X.X.X.pl (X.X.X.X)  21.871 ms  22.061 ms  25.072 ms
 (more data here)
 10  one.one.one.one (1.1.1.1)  24.072 ms  22.439 ms  21.497 ms

MTR

  mtr combines the functionality of the traceroute and ping programs
  in a single network diagnostic tool.

In short MTR does traceroute continuously and presents it in nice formatted table.

Example output:

$ mtr 1.1.1.1 -c 5 --report
Start: 2019-08-09T15:13:28+0200
HOST: blackhole                   Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 192.168.1.1                0.0%     5    0.2   0.1   0.1   0.2   0.0
  2.|-- X-X-X-X.X.X                0.0%     5    9.7   9.0   8.4   9.7   0.5
  3.|-- X-X-X-X.X.X                0.0%     5    9.6   8.6   6.2   9.8   1.5
  (more data here)
  10.|-- one.one.one.one            0.0%     5   12.8  13.4  10.7  18.9   3.3


How do I find the version of linux-generic that matches a particular version of the kernel?

Uninstall all kernel versions > 3.13.0-125-generic.

Then you put the kernel on hold. Speaking in broad strokes, pinning has to do with repository preferences not package preferences, or at least in this case it is far easier to put the kernel on hold.

See : How can I avoid kernel updates?

And https://help.ubuntu.com/community/PinningHowto

  Pinning is a process that allows you to remain on a stable release of
  Ubuntu (or any other debian system) while grabbing packages from a
  more recent version.

  Note however that the processes described below will only work if
  things like libc6 versions match, so you should probably not do this
  on an Ubuntu system. I strongly recommend you look at UbuntuBackports
  before doing this.

Pinning is used as a last resort and in some ways does the opposite of putting a package on hold. It marks the stable repositories as preferred and allows you to pull in a few packages . This can cause significant breakage however and should be done only as a last resort. backports, ppa, and compiling from source are all preferred to pinning.

If you do not understand the term "things like libc6 versions match" you should not be pinning . Note also the warning "you should probably not do this on an Ubuntu system."


Want to run a .py program as in terminal at start up

Use gnome-terminal:

gnome-terminal -e "python /path/to/file.py"


From the official wikipages for clamav to set clamav up we have two modes:

Manual mode and is setup and used accordingly

Install:

sudo apt install clamav clamtk

Usage:

sudo clamscan [options] [target file or directory]

Daemon mode and is setup and used accordingly

Install:

sudo apt install clamav-daemon

Usage:

sudo clamdscan [options] [target file or directory]

Information from wiki

Run ClamAV as a Daemon

Install clamav-daemon. You can then use clamdscan where you would previously have used clamscan. Lots of programs, especially e-mail servers, can connect to a ClamAV daemon. This speeds up virus scanning as the program is always in memory.

The clamav-daemon package creates a 'clamav' user; in order to allow ClamAV to scan system files, such as your mail spool, you can add clamav to the group that owns the files.

Let ClamAV listen for Incoming Scans

There are cases where you may want ClamAV daemon to act as a scanner for other systems, so you don't have to run everything locally on the system.

To do this, you simply have to modify the clamd.conf file and add TCPSocket PORTNUMBER and TCPAddr IPADDRESS arguments to the clamd.conf file and reload the daemon. The daemon will then accept connections to it via the IP address and Port combination you specify.

Check to find if Clamscan is running

Look for it in the processt list, or use this handy shortcut: ps ax | grep [c]lamd


Laptop doesn't boot after subsequnt Ubuntu update

My hunch is that your firmware settings have been damaged. AFAIK, the only way to repair this is from within the firmware setup utility, so you'll have to keep trying until you can enter that tool. (If you can get Ubuntu to boot, you may be able to enter the firmware setup tool by typing sudo systemctl reboot --firmware-setup.)

Once you're in the firmware setup utility, select the option to restore everything to the defaults. This should do as I've suggested, and with any luck that will clear up the problem. Unfortunately, it's also likely to render Ubuntu unbootable. There are several ways to recover, but the least intrusive (and therefore the least likely to cause a recurrence of the problem) is:

Download the USB flash drive or CD-R version of my rEFInd boot manager.
Prepare a boot medium from the rEFInd file you download.
Boot with the rEFInd boot medium.
In rEFInd, boot Ubuntu.
In Ubuntu, open a Terminal and type df /boot/efi. Note the disk device and partition; for instance, it might be /dev/sda2.
In the Terminal, type sudo efibootmgr -c -d /dev/sda -p 2 -l \\EFI\\ubuntu\\shimx64.efi -L ubuntu, changing the -d and -p options to match the disk device you identified in the previous step. Note that -l is a lowercase L, not a digit 1.
Reboot and hope it works.

Alternatively, instead of steps #5-6, you could install rEFInd to your hard disk using the PPA or Debian package.


"Upgraded" 16.04 to 17.04 Now unable to change mouse speed

I had the same problem and struggled for quite a while until finding the solution. Most other tutorials tell you to set the property "Device Accel Constant Deceleration".

However, my mouse and as it seems yours too uses libinput.

So the property is a bit different and is called "libinput Accel Speed" https://www.mankier.com/4/libinput

Try setting the speed with the following command:

xinput --set-prop 10 'libinput Accel Speed' -0.8

NB: The values are betwean -1 and 1


How do you change the highligter for files?

This a change in the theme or the color scheme. You must either edit it, or use a different one.


A better solution would be to generate a trimmed image.

Trimming  different images may raise different problems... We have to tune some parameters. Try:

convert input.png -border 1x1 -fuzz 15% -trim output.png


Full install that went well, wont boot, not even from my usb stick. Really confused!

The issue you have could be the one with Syslinux not booting on some systems. I had the same issue recently on a netbook, while never had it before anywhere else. While it booted and installed fine at first from the stick, it wouldn't boot neither from stick nor from the harddisk afterwards.

What I did is to grab the newest Syslinux 4.05 from http://www.syslinux.org/wiki/index.php/The_Syslinux_Project and update the 4.04 on the stick with it, by using syslinux.exe like described on that page under Windows. Right after that, I could boot again from the stick and repair the installation.

Maybe that helps in your case too.


Software updater - is there a way to change when exactly "display weekly" happens?

There is not a way specify times (or days) in the Software & Updates control panel.
Generally, it shouldn't be necessary for most folks: The displayed packages don't include time-sensitive security patches (your settings are to install those automatically right away). The only upgrades displayed will be non-time-sensitive bugfixes and backports.

The actual Software Updater application is available from the terminal at any time: update-manager

If you really want update-manager on a timer, you can use a cron job or a systemd timer. However, trying to run the application (which requires a $DISPLAY variable) that way might be more complex than is worthwhile for some users.


Ubuntu 20.04 LTS - Grub Customizer messed up my Grub

It seems you have overdone it and done something that the resolution of the grub menu can't handle. Did you see the following warning and ignore it? Anyway, follow the instructions in this image to solve the issue.


Is it possible to Make UBUNTU portable on my HHD

Yes, just install it on Portable HDD, and you'll have no problems.


How to remove Gnome theme completely from Ubuntu 13.04

as you said If you install it from software center , then from the software center it self you can remove that theme and its very easy one click operation.

Just type what you would like to remove in  the search box of askubuntu and it will list that application and by clicking at that application you can see uninstall button and that will take you to the removing of theme from your system.

for example


2017 macbook Trackpad is not working in Ubuntu 20.04

I have the same problem as you on a mid-2017 Macbook Pro (Macbook14,1). I've installed Windows 10 through bootcamp and I have a linux partition also installed (Ubuntu 20.04 LTS) which I triple boot with rEFInd 0.12.0. I wish someone would at least respond to you, kinda stinks. My trackpad worked for the first day then just quit for some reason in ubuntu. Hopefully we can get an adquate answer.
This is what I've found:
https://victorleungtw.com/2020/04/24/install-ubuntu-macbook-pro.html
https://github.com/roadrunner2/macbook12-spi-driver
Our macbook doesn't have the T2 chip (according to apple's T2 website), so use the drivers for the 12-inch Macbook. If you can get this to work, please get back to me.
EDIT:
I decided to be the guinea pig because I'm somewhat impatient. Turns out the drivers work! Here's the exact commands you'll need to use:

Open a terminal window and type sudo -i to become root.

Type the following commands:
echo -e "\n# applespi\napplespi\nspi_pxa2xx_platform\nintel_lpss_pci" >> /etc/initramfs-tools/modules
 apt install dkms

 git clone https://github.com/roadrunner2/macbook12-spi-driver.git /usr/src/applespi-0.1

 dkms install -m applespi -v 0.1

This worked for me about 20 mins ago. The only problem left is that it doesn't disable the trackpad when typing, so you may accindentally click something whilst typing using these drivers. I've seen a bug fix driver with keyboard detection included on github, so I'll try to find them again to post here.


I use this solution:

In /boot/grub/grub.conf find menu entry of Ubuntu and remove this two lines:

load_video
gfxmode $linux_gfx_mode

Then save the file and reboot.
It was helpful for me.


OK, so it's really Firefox fault. New capability in FF60(*). Found the "Customize" entry in the Tools menu (stripes icon) and the "Title bar" choice was unchecked.

At least my gut feeling that it was due to something else was right...

(*) Thanks to @pomsky for pointing this out


Dual booting on a laptop with SSD and HDD

Although this question is asking for answers which are primarily opinion based, the official documentation does state that you only need a certain amount of partitioned space for your installed operating system.

With that said, you should certainly have enough space.

I recommend you use 2/3 of the total disk space for the OS you plan to use the most, including any swap partition if the OS uses swap.


I'm the developer of the software mentioned above by Lynob (Lagrangian analysis tool named Ariane).

As mentioned by steeldriver the problem is due to the lack of the static netcdf library (*.a) for the Fortran interface of NetCDF in Ubuntu 16.04.

I made a bug report about this problem here: https://bugs.launchpad.net/ubuntu/+source/netcdf/+bug/1698368.

To solve the problem:

be sure that netcdf library is intalled (ls -rtl /usr/lib/x86_64-linux-gnu/*netcdf*)
be sure that netcdff is also
installed (ls -rtl /usr/lib/x86_64-linux-gnu/*netcdf*)
download the last version of the Ariane software: Ariane-v2.2.9_00.tar.gz (http://stockage.univ-brest.fr/~grima/Ariane/download/download.html).

After decompressing the package, then submit:

./configure
make
make check
make install


Why are notifications appearing in the invisible black zone above my monitor?

Unfortunately this is a bug, and the inability to configure the position of notify-osd to prevent it happening is a feature.

Luckily, in the spirit of open source, someone has created a patched version that can be configured and positioned manually:

http://www.webupd8.org/2011/05/configurable-notifyosd-bubbles-for.html


Installing Ubuntu first time, having problem to install Asus drivers!

If your computer is 64 bit, make sure you downloaded the 64 bit image.
(This must be a comment but I don't have rights to comment)


Cannot mount Windows 98 SE share over SSH to Ubuntu 14.04

You're running the mount command as root and haven't specified a different username. You can add username=user to the -o list (where user is the username on target machine):

sudo mount -t cifs //192.168.0.2/uniserv /tmp/uniserv/ -o username=user,sec=lanman,servern=Uniplus1

If you want to connect to the share as a guest, use guest instead of username=user in the -o list:

sudo mount -t cifs //192.168.0.2/uniserv /tmp/uniserv/ -o guest,sec=lanman,servern=Uniplus1

If the server gives information about ownership and permissions, mount.cifs will try to respect it. Otherwise, all files and directories in the share will be owned by root, and accessible only by root. If you don't want that, you can add use the uid and or gid arguments to specify user or group IDs. A common way is uid=$UID. For example:

sudo mount -t cifs //192.168.0.2/uniserv /tmp/uniserv/ -o guest,uid=$UID,sec=lanman,servern=Uniplus1

The UID environment variable is a bashism (also in zsh), so if you're invoking this command from a shell that doesn't support it (such as dash, which provides sh in Ubuntu), use $(id -ru) instead (or manually put in your actual user ID number from /etc/passwd):

sudo mount -t cifs //192.168.0.2/uniserv /tmp/uniserv/ -o guest,uid=$(id -ru),sec=lanman,servern=Uniplus1

Source: Mainly man mount.cifs.

If you'd prefer to perform the mount operation itself as a regular (non-root) user, How do I mount Samba share as non-root user may help.


FYI: unlocking a Kingston SSD by use of hdparm, after setting a user password appears to be impossible.

NOTE: The drive will appear as locked next time you reboot after setting your password. Until then, security will only appear as enabled.

Whether trying the very user-password you just set, or other variants, such as "", "NULL", NULL or a row of 32 spaces, either as a user-password or as a master-password, will not unlock your drive, but instead give you an Input/output error.

sudo hdparm --user-master m --security-erase "" /dev/sda

will, however, do the job (that's m as in master, since in Kingston's case the master-password is apparently NULL by default).

The very same master password ("") that returns the Input/output error for the security-unlock command, works just fine with the security-erase command.

So don't lock your ssd unless you really intend to erase it, 'cause it's far from certain whether you'll be able to unlock it.

I've been reading reports of similar issues and I've even stumbled across a patch, which I have, however, not tested.


Why are the Python dependencies listed by Ubuntu different than what apt-get installs

These are recursive dependencies.

The dependency graph (manually drawn and therefore overly simplified, only including the packages you mentioned) would look something like this:

python
├── libpython-stdlib
│   └── libpython2.7-minimal
├── python2.7
│   ├── libpython2.7-stdlib
│   └── python2.7-minimal
└── python-minimal
    └── python2.7-minimal

You see, each dependency is just a regular package that can have more own dependencies. You can get that information on https://packages.ubuntu.com by clicking the links of all dependency packages (those with the red dot) and repeating that recursively for each entry. It's a tiresome task, unfortunately.

The easiest way to find out what packages need to be installed is to just run the sudo apt install PACKAGE command and look at its output. Or if you want to be safe nothing happens yet and you just get the information, you can simulate the installation only:

apt -s install PACKAGE

There is also apt depends PACKAGE to list direct dependencies (and other relations) of packages, but if you add --recurse to get indirect dependencies too, the list becomes too long to be readable as there are tons of duplicates and irrelevant entries displayed along. --important helps a bit with that, but not too much. Also keep in mind that usually you already have many of these dependencies already installed because something else depends on it, so again this would not tell you what you need to install additionally.


.sid files are handled through "MIME", a multimedia extension to, of all things, E-mail.

walt@bat:~(0)$ mimetype *.sid
*.sid: audio/prs.sid
walt@bat:~(0)$

Read man update-mime and man mailcap. You may even wish to less /etc/mailcap, but meanwhile:

walt@bat:~(0)$ grep audio/prs.sid /etc/mailcap
audio/prs.sid; audacious %s; test=test -n "$DISPLAY"
audio/prs.sid; totem --fullscreen %s; test=test -n "$DISPLAY"
walt@bat:~(0)$

This shows that there are two choices for playing files with mimetype audio/prs.sid (and here's the command), filename *.sid.


How can I see system logs while booting up ubuntu?

To see the boot messages while Ubuntu is booting, press the ESC key after the GRUB menu. This way you can see where Ubuntu gets stuck and figure out how to fix your machine without having to use a command line or a recovery disk.


You need install build tools at first:

sudo apt-get install build-essential git ncurses-dev subversion zlib1g-dev m4 automake autoconf

And do not extract their toolchain to /opt at all. It will not work. It requires newer version of m4 and some other stuff.
The firmware is based on OpenWRT, so it can compile toolchain on its own.

Then extract the DSL-AC88U_FW_V1_10_06_Build591_GPL_official.tar.bz2 archive and go to firmware directory

cd ~/Downloads/GPL_DSL_AC88U_v11006_build591/DSL-AC88U_FW_V1_10_06_Build591_GPL_official

# download package with broken link
wget http://lmde-mirror.gwendallebihan.net/latest/pool/main/m/mklibs/mklibs_0.1.34.tar.gz -O dl/mklibs_0.1.34.tar.gz

and compile both the firmware and the toolchain with

make V=s

Notes:

the compilation on my 18.04.2 LTS machine failed, I did not get any factory/sysupgrade images.
extracting the toolchain to /opt does not help:

cd /
sudo tar -xf ~/Downloads/GPL_DSL_AC88U_v11006_build591/DSL-AC88U_FW_V1_10_06_Build591_GPL_official/crosstools-arm-gcc-4.6-linux-3.4-uclibc-0.9.32-binutils-2.21-NPTL.Rel1.2.tar.bz2

and ends with

  autom4te: need GNU m4 1.4 or later: /opt/toolchains/crosstools-arm-gcc-4.6-linux-3.4-uclibc-0.9.32-binutils-2.21-NPTL/usr/bin/m4
  aclocal-1.11: autom4te failed with exit status: 1
  Makefile:950: recipe for target 'aclocal.m4' failed


Can I check whether my webcam's LED is software or hardware controlled?

Short of writing an exploit, you can contact the webcam manufacturer. Past that, you might be able to open your camera up, and take a look, but this can always be problematic.

In most cases on modern webcams, the camera light is controlled by the webcam's onboard firmware. Without having access to the firmware, this makes our life somewhat difficult, as you'd have to extract it from the chip or try to get a compiled image.

However, there's still a concern - even webcams with hardware controlled lights may still be manipulated into turning on without enabling the light (or without you noticing the light). Software like Metasploit have special functions that turn the webcam on, take a photo, and immediately turn it off. Depending on your camera's  hardware, this could happen too fast for the light to register - this was a known issue on MacBook Pros once upon a time.

If you're truly paranoid about your webcam being used against you, it's best to either unplug it (instead of disabling it through software) or use some privacy guard device.


I think that the best solution would be reinstalling all MATE components with commands:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install -f
sudo dpkg --configure -a
sudo apt-get install --reinstall grub2-themes-ubuntu-mate \
     ubuntu-mate-desktop^ ubuntu-mate-artwork ubuntu-mate-default-settings \
     ubuntu-mate-icon-themes ubuntu-mate-wallpapers-complete human-theme \
     gir1.2-mate-panel libmate-desktop-2-17 libmate-menu2 \
     libmate-panel-applet-4-1 libmate-sensors-applet-plugin0 \
     libmate-slab0 libmate-window-settings1 mate-accessibility-profiles \
     mate-applet-topmenu mate-applets mate-applets-common mate-backgrounds \
     mate-control-center mate-control-center-common mate-desktop \
     mate-desktop-common mate-desktop-environment-core mate-dock-applet \
     mate-gnome-main-menu-applet mate-icon-theme mate-icon-theme-faenza \
     mate-indicator-applet mate-indicator-applet-common mate-media \
     mate-media-common mate-menu mate-menus mate-netbook \
     mate-netbook-common mate-netspeed mate-netspeed-common \
     mate-notification-daemon mate-notification-daemon-common \
     mate-optimus mate-panel mate-panel-common mate-polkit \
     mate-polkit-common mate-power-manager mate-power-manager-common \
     mate-screensaver mate-screensaver-common mate-sensors-applet \
     mate-sensors-applet-common mate-session-manager mate-settings-daemon \
     mate-settings-daemon-common mate-system-monitor \
     mate-system-monitor-common mate-terminal mate-terminal-common \
     mate-themes mate-tweak mate-user-guide mate-utils mate-utils-common \
     plymouth-theme-ubuntu-mate-logo plymouth-theme-ubuntu-mate-text \
     python-mate-menu ubuntu-mate-artwork ubuntu-mate-default-settings \
     ubuntu-mate-icon-themes ubuntu-mate-libreoffice-draw-icons \
     ubuntu-mate-lightdm-theme ubuntu-mate-themes ubuntu-mate-wallpapers \
     ubuntu-mate-wallpapers-common ubuntu-mate-wallpapers-complete \
     ubuntu-mate-wallpapers-utopic ubuntu-mate-wallpapers-vivid \
     ubuntu-mate-wallpapers-wily ubuntu-mate-wallpapers-xenial

I collected this list on my Ubuntu 16.04.3 LTS MATE system.


How do I make the USB monitor Lenovo Think Vision lt1421 work?

As far as I can tell the general consensus appears to be that if you could get a driver wrapper working then maybe...

I gather, although I could be wrong, that this uses DisplayLink technology and that there should be an open source driver... somewhere: http://www.displaylink.com/news/news/news150509.htm

Which would mean that you want: xserver-xorg-displaylink

If this is the case then there is some advice here on how to get the drivers working: How To Make Ubuntu 13.04 Work With DisplayLink Monitor?

However your mileage may vary, I've got zero way of testing any of this out and I am just making an somewhat educated guess.


Edit your Java arguments (Profile Settings) for starting the game and get rid of CMSIncrementalMode (-XX:+CMSIncrementalMode). If your using Java 8 you don't really need any arguments. If you have not installed Java Look here...Install Java 8


Unable to run a sequence of commands using SSH

You are basically running ssh host "var=value; echo $var". The shell performs variable expansion before ssh received the command. Thus, the actual command as received by ssh becomes:

var=$value; echo

In order to avoid the shell eating your dollar, use single quotes:

ssh host 'var=value; echo $var'

Considering your command, it looks like you are trying to use the output of one command in the last one. For that to succeed, you must make proper use of command substitution:

  ssh host 'output=$(sudo virsh list --all | awk "/running/{print \$2}" | tail -2); sudo virsh dominfo $output'

Or even:

  ssh host 'sudo virsh dominfo $(sudo virsh list --all | awk "/running/{print \$2}" | tail -2)'

This assumes that sudo is configured not to ask for a password, otherwise you will get an error such as:

sudo: no tty present and no askpass program specified


Error in Exporting and importing Database in MariaDb from Ubuntu 14.04 LTS Command Terminal

These import and export data commands needs to be used  directly from command terminal like

Import Data Command

sudo /opt/lampp/bin/mysql -u root -p sachin_db_copy < /home/sachin/Downloads/cl134_sachin_db.sql;

Export Data Command

sudo /opt/lampp/bin/mysqldump -u root -p sachin_db_copy > /home/sachin/Downloads/cl135_sachin_db.sql


Accidentally removed libstdc++6, most programs not working

According to the packages web page, dpkg should be able to work without libstdc++6 (unlike apt).

So you should be able to download the correct version libstdc++6 for your architecture manually and install it using dpkg -i, e.g.

sudo dpkg -i libstdc++6_5.4.0-6ubuntu1~16.04.10_amd64.deb

In the case you cannot use your normal web browser on the machine in question, get the right URL elsewhere and download the file using wget, e.g.

wget http://security.ubuntu.com/ubuntu/pool/main/g/gcc-5/libstdc++6_5.4.0-6ubuntu1~16.04.10_amd64.deb

According to the following error:

apt-get: error while loading shared libraries: liblz4.so.1: cannot open shared object file: No such file or directory

you seem to have more missing required packages.

Check which package provides the file, download it and (re)install using dpkg like before. For liblz4.so.1, you need liblz4-1. Repeat this procedure with each file while APT complains about missing files.

One more thing… Your command invocation

root@server:~# sudo apt-get screen

indicates you are both logged in as root and using sudo. These two things are redundant, you need just one of them at a time.


Running a process through SSH command and keeping it alive

Like xenoid pointed out in the comment, redirecting the stdout/stderr to anywhere other than the screen fixed the problem.


Can't extend root partition using gparted

Make sure that you have a good backup of your important Ubuntu files, as this procedure can corrupt or loose data.
Keep these things in mind:

always start the entire procedure with issuing a swapoff on any mounted swap partitions, and end the entire procedure with issuing a swapon on that same swap partition

a move is done by pointing the mouse pointer at the center of a partition and dragging it left/right with the hand cursor

a resize is done by dragging the left/right side of a partition to the left/right with the directional arrow cursor

if any partition can't be moved/resized graphically, you may have to manually enter the specific required numeric data (don't do this unless I instruct you to)

you begin any move/resize by right-clicking on the partition in the lower part of the main window, and selecting the desired action from the popup menu, then finishing that action in the new move/resize window

Do the following...
Note: if the procedure doesn't work exactly as I outline, STOP immediately and DO NOT continue.

boot to a Ubuntu Live DVD/USB
start gparted
right-click on /dev/sda9 and select move
move the entire /dev/sda9 partition all the way to the left
resize the right side of /dev/sda9 all the way to the right
click the Apply checkmark

Reboot the computer.