Gnuplot - Plot data points on 2D contour plot

Finally it worked, but the following changes had to be made:

Include a space between each line in the data file of points (M_Coord_Plain.txt) because the splot command needs this format.
Delete the unset surface command and replace it with set surface command because the data points are plotted on the surface. However this has as a result the points to seem vague since the corresponding color for zero value (the defined third column :(0) ) is by default dark purple.
So we can use a black and white color palette and define a wide range colorbox range in order to have a big contrast between zero and high contour values.

So the commands to plot the requested plot are:

set pm3d explicit
set surface
set view map  # Set a bird eye (xy plane) view
set contour  # Plot contour lines
set key outside
set cntrparam cubicspline  # Smooth out the lines
set cntrparam levels discrete 3.197,3.552  # Plot the selected contours
unset colorbox
set cbrange [0:7000]  # Set the color range of contour values.
set palette model RGB defined ( 0 'white', 1 'black' )
set style line 1 lc rgb '#4169E1' pt 7 ps 2
splot 'Contours.txt' using 1:2:3 with pm3d notitle,\
      'M_Coord_Plain.txt' using 1:2:(0) with points ls 1 notitle

The resulted plot is this.


Ok, apparently, NGinx can not proxy regular HTTP into HTTPS. Its main author just says: "Use Squid".

Fortunately for us, the SSL-using upstream package-repositories automatically redirect HTTP into HTTPS -- a redirection, which NGinx' proxy will quietly follow.

There is also a patch for NGinx to fill this rather gaping omission, but for the time being we do not need it and can stick with the stock NGinx supplied by Ubuntu.


Why is system asking me to authenticate before shutting down?

Adding this as an answer then:

That's generally a symptom of having a daemon that has been started with sudo.


Ubuntu 13.04 Asus N56 keyboard brightness restarting

Add a delay before the echo command line, like this:

sleep 7

echo 0 > /sys/class/leds/asus::kbd_backlight/brightness

That should change the timing so that all appropriate software components are running before the command is to be executed. Depending on your configuration you can decrease the time value; just make a few iterations in order to determine the shortest delay that will work reliably with your system.


How to edit bluej launch script in Ubuntu14.04?

If you haven't installed a JDK, you have several options.

1. APT and the official repositories

You may install one via apt-get, for that, open a terminal and type:

sudo apt-get openjdk-8-jdk

I recommend this, as it will set everything for you properly and you will be able to upgrade easily.

2. APT and the WebUpd8 PPA

You can also install Oracle's JDK vida the WebUpd8 PPA as detailed here, I believe it will also take care of everything for you.

3. Download directly from Oracle

Finally, you can install Oracle's JDK, but you will need to set set your JAVA_HOME, PATH and alternatives manually.

JAVA_HOME is used by some applications to find your JDK. I'm unsure if BlueJ uses it.

PATH is used by your shell session to know where it can look for any executables.

If you have several JDK versions, lets say you have the OpenJDK from the official Ubuntu repos, plus Oracle's JDK 1.8., both in your PATH. If you call javac, The Debian alternatives system will be used to resolve which one of those javac binaries will be used.

To do this, append this lines to your ~/.bashrc:

export JAVA_HOME=/path/to/jdk
export PATH=$PATH:$JAVA_HOME/bin

Source your bashrc file ( . ~/.bashrc ). Afterwards, update your alternatives (you will only need to do so if you have more than one JDK installed).

--install
  E.g. sudo update-alternatives --install /usr/bin/javac javac $JAVA_HOME/bin/javac 1

--set
  E.g. sudo update-alternatives --set javac $JAVA_HOME/bin/javac

To help you identify which alternatives you may need to update you can use:

update-alternatives --get-selections | grep java

If you really need to edit the launcher, you can edit /usr/share/applications/bluej.desktop:

sudo nano /usr/share/applications/bluej.desktop

or add your own at

~/.local/share/applications/bluej.desktop

But I doubt that is the issue.


How to add entire folder of wallpapers in KDE plasma 5

Dude just find the wallpaper folder in your filesystem and add the images into it might have to do some digging around in the filesystem to find the folder, but you can also open the file manager as sudo then copy your images from the wallpaper folder you have to the default wallpaper folder of KDE.


Can I use other tool than Ubuntu Software Center to open apt links?

Neither gDebi, Synaptic or Lubuntu Software Center support handling the "apt://" protocol/links.
But a very simple graphical apt-get-type installer called AptURL does.

Install it with sudo apt-get install apturl
Set Firefox Preferences to "Always Ask" for apt
Click on a link, and select AptURL:

And the window will pop open:

Installation will take place using a lightweight gDebi-style frontend

The other option is to use a custom script such as green7's answer
But to be browser-independent, what you really need is:

A .desktop file for your script/application, indicating that it handles the x-scheme-handler/apt protocol (see MimeType= lines in aptURL.desktop, ubuntu-software-center.desktop)
And you can set the default by modifying the defaults.list file in /usr/share/applications/


There's a program called NDISWrapper. It's in repo under ndisgtk. It will let you use windows XP drivers pretty seamlessly which is nice.

The broadcom cards are a total headache - the company is d-bags to open source and their proprietary linux drivers are far from reliable.

General recommendation - Wicd instead of Network-Manager. Good time to ditch Unity as well if you are still on it. Wicd has fixed persistent authentication problems, signal strength issues, etc with the Broadcom cards for me before.


Permission denied when trying to run Firefox on USB

did you try to run terminal as root and access the  USB device then run the file? (without sudo ofc), also try give access to folder could help


How can I get Ubuntu 12.04 to act and feel like Ubuntu 10.04?

Step 1. Install Mate, Gnome Flashback, or XFCE

1a. Installing Mate

If you are running 14.04 fellow this instructions.

Click this link to install the Mate package, find it in the Ubuntu Software Center, or type sudo apt-get install mint-desktop in a terminal. There are more instructions here

If you are running 12.04-13.10 fellow this instructions.

Type this in a terminal

# this add the repository
sudo add-apt-repository "deb http://packages.mate-desktop.org/repo/ubuntu $(lsb_release -cs) main"
sudo apt-get update
sudo apt-get install mate-archive-keyring
sudo apt-get update
# this installs base packages
sudo apt-get install mate-core
# this installs more packages
sudo apt-get install mate-desktop-environment

1b. Installing Gnome flashback (formerly Gnome Fallback)

If you are running 14.04 fellow this instructions.

Click this link to install the Gnome Flashback package, find it in the Ubuntu Software Center, or type sudo apt-get install gnome-session-flashback in a terminal. There are more instructions here

If you are running 12.04-13.10 fellow this instructions.

Click this link to install the Gnome Fallback/Panel package, find it in the Ubuntu Software Center, or type sudo apt-get install gnome-panel or sudo apt-get install gnome-session-fallback in a terminal. There are more instructions here

1c. Installing XFCE (XForms Common Environment)

Click this link to install the XFCE package, find it in the Ubuntu Software Center, or type sudo apt-get install xubuntu-desktop in a terminal. There are more instructions here

Ubuntu has an XFCE spin called Xubuntu it is recommended to install it from the official image (.iso) that can be downloaded at this page.

Step 2. Make them look like Ubuntu 10.04.

2a. Making Mate

You need to get the Ambiance Theme so open up a terminal and type this in.

cd ~/Downloads
wget http://dl.dropbox.com/u/72782740/debian/ubuntu/ambiance-mate_12.04_all.deb
sudo dpkg -i ambiance-mate_12.04_all.deb

Or download this file, click here to download and install it though Gdebi, Ubuntu Software center, or...

After it is done install, change the Theme to Ambiance MATE so open the Appearance preferences (located under System -> Preferences) and select the Ambiance MATE theme.

This is how It is going to look like

After that you now need to chance the wallpaper to the 10.04 one. so first you need to get them.  So open up a terminal

cd ~/Downloads
wget https://launchpad.net/ubuntu/+archive/primary/+files/ubuntu-wallpapers_0.31.3_all.deb
sudo dpkg -i ubuntu-wallpapers_0.31.3_all.deb

Or download this file, click here to download and install it though Gdebi, Ubuntu Software center, or...

After it is done install, change the wallpaper to the default in 10.04 so open the Appearance preferences (located under System -> Background) and select the the default in 10.04 wallpaper.

*Sorry I couldn't find a image for this micro-step.

2b. Making Gnome Flashback

You need to get the Ambiance theme if you don't ready have it.  It isn't any different from the stock one that you need.  If you don't have it click here to download it  And just install it though Gdebi, Ubuntu Software Center, or tools like it.  Finally you just need to chance the wallpaper to the one in 10.04 and you do that by just opening a terminal and type in

cd ~/Downloads
    wget https://launchpad.net/ubuntu/+archive/primary/+files/ubuntu-wallpapers_0.31.3_all.deb
    sudo dpkg -i ubuntu-wallpapers_0.31.3_all.deb

Or download this file, click here to download and install it though Gdebi, Ubuntu Software center, or...  And it is no difference into changing it from normal unity. More Info

2b. Making XFCE

Making the panels look like Gnome 2

First,  Remove the the button panel by right clicking on it and select Delete.  Add the Show Desktop, Window Buttons, Workspace Switcher and Trash Applet to the new button panel. Now we are done with the button panel now it is time for the button one so chance the panel size to 24px by right clicking on it and select Panel>Panel Preferences. Rename “File Manager” menu into “Places” by opening the handy terminal and type in sudo nano /usr/share/applications/xfce-settings-manager.desktop  find the entry Name and change the entry into this Name=Settings Manager → Name=System save it and close it. Now Right click on the Panel Select Panel Preferences Than Items. Remove all default items and left 8 eight items : Applications Menu, Separator, Notification Area,  add a  separator between Applications Menu and Notification Area to be Expand by click the item, and click edit item by select Edit the currently selected item button at the bottom of Panel Preferences menu. Then, add two Launcher items and move them to the position after Applications Menu item.  Set them to Show Label Instead of Icon, by clicking Edit the currently selected item>Advanced> Show Label Instead of Icon. Now, edit each launcher and add the two main applications.   For first launcher, add the Places items by clicking Edit the currently selected item>General>Add new item, search and scroll down to get the Places item.  For the second launcher, do the same but put the System item (that we have edited before from the xfce-settings-manager desktop menu).
Now, we have a good looking Gnome 2 panels.

Now We are going to change the theme to Ambiance

You need to get the Ambiance Theme so open up a terminal and type this in.

Add Ravefinity Project PPA
    sudo add-apt-repository ppa:ravefinity-project/ppa -y
 Update package information and install ambiance and radiance themes
    sudo apt-get update && sudo apt-get install ambiance-xfce-lxde radiance-xfce-lxde
 Install other colors variations (blue, green, purple, ...):
    sudo apt-get install ambiance-colors-xfce-lxde radiance-colors-xfce-lxde

Or download this file, click here to download and install it though Gdebi, Ubuntu Software center, or...

After it is done install, change the Theme to Ambiance.

This is how It is going to look like

After that you now need to chance the wallpaper to the 10.04 one. so first you need to get them.  So open up a terminal

cd ~/Downloads
wget https://launchpad.net/ubuntu/+archive/primary/+files/ubuntu-wallpapers_0.31.3_all.deb
sudo dpkg -i ubuntu-wallpapers_0.31.3_all.deb

Or download this file, click here to download and install it though Gdebi, Ubuntu Software center, or...

After it is done install, change the wallpaper to the default in 10.04 so open the Desktop Settings (Right on the desktop -> Desktop Setting) and select the the default in 10.04 wallpaper.

Step 3. Install MDM (Mate Display Manager)

You need to get the Ambiance Theme so open up a terminal and type this in.

 sudo add-apt-repository ppa:noobslab/mint
 sudo apt-get update
 sudo apt-get install mdm mdm-themes

During the installation you will get a window asking you to choose your default DM, like the one in the print screen. Choose MDM.

And That is it!!!

Sources

http://xubuntugeek.blogspot.com/2012/06/how-to-install-ambiance-and-radiance.html
http://namakutux.blogspot.com/2011/11/how-to-make-xfce-looks-like-gnome-2.html
http://xfce-look.org/content/show.php?content=141027
http://linuxg.net/how-to-install-mdm-1-4-on-ubuntu-13-10-13-04-12-10-12-04/
http://www.linuceum.com/Distros/osDesktopConfigXfce.php
http://namakutux.blogspot.com/2012/10/ambiance-mate-theme-for-ubuntu-refined.html
https://launchpad.net/ubuntu/+source/ubuntu-wallpapers
http://www.howtogeek.com/110052/how-to-install-the-mate-desktop-go-back-to-gnome-2-on-ubuntu/
http://www.howtogeek.com/110052/how-to-install-the-mate-desktop-go-back-to-gnome-2-on-ubuntu/
How do I install MATE (the desktop environment)?


Host name reverts to old name after reboot in 18.04 LTS

First edit /etc/cloud/cloud.cfg and set the parameter "preserve_hostname" from "false" to "true" and then edit /etc/hostname.


I've found these bug reports:

https://bugs.launchpad.net/ubuntu/+source/jockey/+bug/626320
https://bugs.launchpad.net/ubuntu/+source/jockey/+bug/658106

You can install the driver manually by installing package firmware-b43legacy-installer


gksu not working in menu mode but works in cli mode

Press Alt + F2 then write : gksu-properties and open it.

The first option should be "sudo"

Authentication mode: sudo

and change the second option from "enable" to "force enable".

Grab mode : force enable

Then retry to open an application with gksu

You can also try the gksudo instead of gksu

Maybe gksudo works better.

Also you can try to create a new launcher

Open a terminal and issue the following commands

sudo apt-get install --no-install-recommends gnome-panel
gnome-desktop-item-edit ~/.local/share/applications/ --create-new

At the opened window complete the appropriate sections

Name: wireshark-root

Command: gksudo wireshark

Comment: anything you want

Find the new launcher and try to open it.

Alternatively you can try to replace the Command: gksudo wireshark

with Command: gksudo wireshark &

maybe the ampersand & helps here.


I don't have a CSS decoder, what software should I download?

Installation of libdvdcss may be what you need:

Install the libdvdread4 package via command line using the terminal:
sudo apt-get install libdvdread4

Then execute:
sudo /usr/share/doc/libdvdread4/install-css.sh

Rebooting may be necessary.

After this, VLC will automatically use it. Some programs may need recompilation.
Source: RestrictedFormats/PlayingDVDs.


hostapd vs netplan: wlan0 not added to bridge at boot

I met the same problem,on boot the wlan0 link set to client mode or so...
see the kernel source br_if.c#L605 here reject bridge func br_add_if
if (dev->priv_flags & IFF_DONT_BRIDGE) {
        NL_SET_ERR_MSG(extack,
                   "Device does not allow enslaving to a bridge");
        return -EOPNOTSUPP;
}

and when wlan device register wireless/core.c#L1305 set the IFF_DONT_BRIDGE flag
    if ((wdev->iftype == NL80211_IFTYPE_STATION ||
         wdev->iftype == NL80211_IFTYPE_P2P_CLIENT ||
         wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr)
        wdev->netdev->priv_flags |= IFF_DONT_BRIDGE;

it seems that networkd register wlan0 in module NL80211_IFTYPE_STATION on boot.
Fine! Here is my resolutions:

Remove wlan0 from netplan, keep networkd unmanaged wlan0 link.
Then,you may noticed that hostapd.conf has field like bridge=br0,using that to bridge wlan0 to br0.

in your case the config are:
etc/netplan/01-netcfg.yaml
network:
  version: 2
  renderer: networkd
  ethernets:
    eth0:
      dhcp4: no
      dhcp6: no
      wakeonlan: yes
  bridges:
    br0:
      interfaces: [eth0]
      dhcp4: yes
      parameters:
        stp: true
        forward-delay: 4

hostapd.conf
interface=wlan0
driver=nl80211
bridge=br0
logger_syslog=-1
...


How to open a 30gb or more wireshark file (.pcap) from system which is having a low configuration?

I've found the solution. The way is to use tcpdump program.

tcpdump -r old_file -w new_files -C 10

10 - is the size of new files in million bytes. 10 Mb in this example


Can't get Intel HD Graphics 530 (Skylake i7 6700) to work

Installing Linux Mint 17.3 Rosa solved it!

Somehow, Mint 17.3 enabled i915_bpo driver automatically. Here's lshw output:

    *-display
         description: VGA compatible controller
         product: Intel Corporation
         vendor: Intel Corporation
         physical id: 2
         bus info: pci@0000:00:02.0
         version: 06
         width: 64 bits`
         clock: 33MHz
         capabilities: pciexpress msi pm vga_controller bus_master cap_list rom
         configuration: driver=i915_bpo latency=0

If you're still running 17.2, you might have some luck with trying to install i915_bpo manually.


I have some questions before installing ubuntu 14.04

For cursor flickering go to System Settings > Displays.In the Displays window, you will see an Unknown monitor. Click it and disable it. Voila! Mouse flickering should be gone.

If everything else looks fine then you can proceed with installation of Ubuntu 14.04. Also looking at your system specs I really dont think there would be a problem.


How do I fix boot problems after installing Ubuntu 14.04 alongside Windows 8.1?

Did you have an abnormal shutdown, that can cause data corruption. If Windows you run chkdsk, but for an ext formated partition you run fsck.

From liveDVD/Flash so everything is unmounted,swap off if necessary, change example shown with partition sda8 to your partition(s)
e2fsck is used to check the ext2/ext3/ext4 family of file systems. -p trys fixes where response not required

sudo e2fsck -C0 -p -f -v /dev/sda8

if errors: -y auto answers yes for fixes needing response, also see man e2fsck

sudo e2fsck -f -y -v /dev/sda8


Have a look at dh_fixperms. Either don't run it or use chown after you call dh_fixperms. I guess that another way would be to run chown in postinst.


We have to enable the volume control buttons:

sudo gedit /etc/rc.local

and add the line:

cp /sys/devices/platform/thinkpad_acpi/hotkey_all_mask /sys/devices/platform/thinkpad_acpi/hotkey_mask


Broadcom BCM5787M stopped working as of the update I did today

I had the same problem with my HP laptop, the wireless stopped working after an update. I think all I did to fix it was install the driver again because in the update they stop supporting most broadcom drivers, so you need to revert back to an older version. I'm not sure if this is any help, but it is what I concluded after 5 hours of searching the web trying to fix my internet connection. Try searching in google your device model number (broadcom BCM5787M). And make sure if you're using wireless, download the wireless driver, not the Ethernet driver.

If you don't have to update the drivers, search for a key that disables/enables the wireless on your device, the update might have switched it off, so a simple press of the key may help.

If all else fails, you can either continue to search the web for an answer, or just reinstall ubuntu and don't update everything, just update a few things (don't ask how, because I don't know) and that may help.


How to map right shift to slash using xmodmap?

You can use the following command:

xmodmap -e "keycode 62 = slash question slash question" #this will make Shift_R to act as slash

To get this change for every session, after you have run the previous command, create a file called .xmodmap with the new keymaps, using the following command:

xmodmap -pke > .xmodmap

Then, create a file called .xinitrc in your home directory, containing the following line/command:

xmodmap .xmodmap


Ubuntu 12.04 and 13.04 installs fail if Secure Boot (UEFI) is enabled on Toshiba Tecra R950

I've experienced dual-booting with dual-boot and UEFI. Here's what I did:

Disable Secure Boot from BIOS (Keep it disabled, as it prevents booting once installed)
Install Ubuntu normally
Open up a Terminal from the live CD and run:

sudo apt-get install boot-repair
sudo boot-repair

Choose the recommended option and follow the instructions it gives you
Reboot
Your computer should boot straight into GRUB, with Ubuntu as the main option


How to move multiple files with rsync while showing progress?

You can use the Coreutils Progress Viewer progress . After installing it1, simply send your mv process to the background and provide progress with its PID:

mv -t /path/to/file1 /path/to/file2 & progress -mp $!

Use progress -w to show a list of all running coreutils processes with their progress. See man progress and its github page for more options and examples.

Further reading with a lot of different approaches:
How can I move files and view the progress (e.g. with a progress bar)?

1: If you’re using Ubuntu 14.04 you’ll unfortunately have to build the software yourself, see the above linked github page.


Very good question. As I understand it, libido is responsible for the non-menuitem items in the indicator menus. I mean the calendar, media controls, etc. If I understand correctly, you should be able to add menu items as usual, like the "Time & Date Settings..." item.


Running a script at startup with rc.local (permission denied)

# ls test.sh
-rw-r--r-- 1 root root 0 nov 27 13:40 test.sh

# ./test.sh
-su: ./test.sh: permission denied

To solve:

# chmod +x test.sh

Change test.sh for /path/to/myscript.sh


You can check your external monitor output using xrandr

xrandr -q

Now let's assume your monitor is connected using HDMI1 port

xrandr --output HDMI1 --primary

For making it persist run:

tee -a $HOME/.xprofile <<< "xrandr --output HDMI1 --primary"


My boot partition is filling up. What's the solution?

You can boot the livecd and use gparted to resize it, or remove it instead.


14.04 & Intel HD Graphics: undefined symbol: drm_intel_get_reset_stats

Ouch! Well, I wasn't on 14.04 back then, but a:

sudo apt-get install --reinstall xserver-xorg-video-intel libgl1-mesa-glx libgl1-mesa-dri xserver-xorg-core
sudo dpkg-reconfigure xserver-xorg
sudo reboot

would have fixed it too!


Tried everything, finally had to disable UEFI and reload 13.04, with option nomodeset.

The only difference that I have noticed is that the driver listed in the details in settings now says Vesa: Intel etc.


Upgrade to Ubuntu 20.04 fails because of PPAs. How to proceed?

Ok, I found this answer, which suggests to search the logs for a line like this:

2013-10-17 15:00:30,543 ERROR Dist-upgrade failed: 'The package 'xubuntu-desktop' is marked for removal but it is in the removal blacklist.'

For future readers, this is what I did. I ran a search like this:

sudo apt install ack-grep
ack "ERROR Dist-upgrade failed" /var/log/dist-upgrade/

which gave this output:

ack: apt-clone_system_state.tar.gz: cannot open file for reading
main.log
115:2020-05-28 13:59:48,248 ERROR Dist-upgrade failed: 'The package 'postgresql-12-postgis-3' is marked for removal but it is in the removal blacklist.'

20200528-1350/main.log
117:2020-05-28 13:48:27,555 ERROR Dist-upgrade failed: 'The package 'postgresql-11-postgis-2.5' is marked for removal but it is in the removal blacklist.'

I then uninstalled those packages:

sudo apt purge postgresql-12-postgis-3
sudo apt purge postgresql-11-postgis-2.5

and after that the upgrade is now continuing to install..


Nautlius: add mouse right-click action to compute MD5 sum

You can work with a nautilus script.

Create the scripts directory if it does not yet exist

mkdir -p ~/.local/share/nautilus/scripts/

Place your script into that directory and make it executable (chmod +x <name_of_script> or via your file manager: right-click file, properties). Any executable script you put there will be available under an entry "Scripts" in your right-click menu.

In your script, you can use the variable NAUTILUS_SCRIPT_SELECTED_FILE_PATHS to retrieve a newline-delimited list of selected files (i. e., one file path in case you selected a single file). You will also need to display the output: this can be done by piping the output of the command to zenity. This simple script will already cut it:

#!/bin/bash
set -eu -o pipefail
md5sum "$NAUTILUS_SCRIPT_SELECTED_FILE_PATHS" | zenity --text-info


Create blank disk image for file storage

Yes.

This is a step-by-step guide to create a custom image starting from scratch;

I'll assume the following:

The image size should be 100 MiB
The image partition table should be MBR
The image should contain a single FAT32 primary partition

Creating the blank image

Create the blank image:

dd if=/dev/zero of=image.img iflag=fullblock bs=1M count=100 && sync

ubuntu@ubuntu ~/tmp % dd if=/dev/zero of=image.img iflag=fullblock bs=1M count=100 && sync
100+0 records in
100+0 records out
104857600 bytes (105 MB) copied, 0.0415825 s, 2.5 GB/s
ubuntu@ubuntu ~/tmp % tree
.
└── image.img

0 directories, 1 file

Mounting the blank image

List the already busy loopback devices:

losetup

ubuntu@ubuntu ~/tmp % losetup
NAME       SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE
/dev/loop0         0      0         0  1 /cdrom/casper/filesystem.squashfs

Mount the image on the first available loopback device:

sudo losetup loop1 image.img

ubuntu@ubuntu ~/tmp % sudo losetup loop1 image.img
ubuntu@ubuntu ~/tmp % losetup
NAME       SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE
/dev/loop0         0      0         0  1 /cdrom/casper/filesystem.squashfs
/dev/loop1         0      0         0  0 /home/ubuntu/tmp/image.img

Partitioning / formatting the blank image

Run gparted passing the loopback device as an argument:

sudo -H gparted /dev/loop1

Click on "Device" -> "Create Partition Table...":

Click "Apply":

Click on "Partition" -> "New":

Select "fat32" from the drop-down menu:

Click "Add":

Click the green tick:

Click "Apply":

Click "Close":

And close Gparted.

Unmounting the image

Finally, unmount the image from the loopback device:

sudo losetup -d /dev/loop1

ubuntu@ubuntu ~/tmp % sudo losetup -d /dev/loop1
ubuntu@ubuntu ~/tmp % losetup
NAME       SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE
/dev/loop0         0      0         1  1 /cdrom/casper/filesystem.squashfs

You can use the created image for whatever purpose you want; for example, you can use it as a virtual USB drive:

sudo losetup loop1 image.img

Opening Files:


Can no longer open a password protected Libreoffice .ods

Happened to me too following an update to 3.4.5.

I also run 3.4.5 at work on a Win XP installation and this issue isn't there so it's either Linux centric or a Ubuntu packaging problem.

I only have 1 password-protected file (ironically it contains all my passwords which I'm in the process of moving to keepassx) but it was irritating nonetheless. I got round it by installing calligra suite which will open them. No good for sharing with MS users as it won't save in word format, but at least you will be able to open the files and re-save them with passwords if you stick with odf.


Browse to /usr/share/applications/
Copy the .desktop file of the application you want to your desktop.


AWS Ubuntu14.04 Instance mktemp fails on upgrade

I just solved the same problem on a Debian machine. It's not a memory problem (I figure that out after cleaning up over 2Gs of memory).

You may be simply missing the /var/tmp directory.

  failed to create file via template '/var/tmp/mkinitramfs-FW_XXXXXX'

ls -l /var/tmp
If it's not found then do sudo mkdir /var/tmp
Run the vmware-install.pl again.

And if you want to clean up your disk to free up memory, run

su /usr/bin/bleachbit

That'll free up a lot space taken up tmp and cached files. You can run Bleachbit from your pull down menu (sorry I'm on a Debian machine so I don't know where is it is on Ubuntu).  But that's not as root, so you'll get a lot of access denied statements.

Good luck


Open Terminal.  Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command below.

sudo gedit /var/lib/polkit-1/localauthority/50-local.d/hibernate.pkla

Copy and paste the following code in file:

[Re-enable Hibernate]
Identity=unix-user:*
Action=org.freedesktop.upower.hibernate
ResultActive=yes

It will appear in the power menu!


SOLVED: How can you set high priority on "games" permanently?

It seems you are able of detecting your process and changing its priority using "Gnome system monitor", when you are changing a process priority you are actually changing its nice level. A nice level can be between "-20" highest priority and "19" the lowest.

so we should somehow renice (change the nice level) the game process.

You can simply use other answer suggestion and use renice command to do it, however there are other options too.

reniced

one is to use reniced to install it use:

sudo apt install reniced

then you can use regular expression to define rules in this file:

/etc/reniced.conf

You can add something like:

-20n ^game-process

change "game-process" with your game's process, now whenever you run sudo reniced it's going to renice all process defined in /etc/reniced.conf.

and

the other option is to use and to install it:

sudo apt install and

It's job is to activates itself in certain intervals and renices process according to their priority and CPU usage. [read manual]


Ubuntu 14.04 setting static IP for server on VirtualBox

To have a static IP for your server, you have to understand your network configuration. If you are the one managing the IP network, you have to use one of the free IP. Otherwise, please ask your network admin for a static IP and use that.

address (enter the IP you got from admin)
netmask (enter the subnet mask)
network (you can identify your network from the IP you got)
gateway (This also you have get from the admin)
dns-nameservers (this can be 8.8.8.8 or whatever admin gives you)

Except, IP address, everything else can be copied from another machine from your network which is configured with static IP.


'Error: Read-only file system', even with root privileges in Bash shell

By default, filesystems are mounted with the readonly (ro) option when in recovery mode. You will need to re-mount / in read-write (rw) mode:

mount -o remount,rw /


First, go to the installation directory, and fire it up with ./studio.sh

For >= v2.0

There is an option to add a shortcut in Android Studio's "main menu" (option highlighted in blue):

For < v2.0

There is an option to add a shortcut in Android Studio's "main menu":

3) To open it in the future, just search for "android studio" in the Dash:


Cannot deploy JavaFX app (Can't build artifact - fx:deploy is not available in this JDK)

I have worked quite a few hours to fix this. The solution removes all the error messages when trying to run the javafx application as well as trying to execute the jar file outside IntelliJ.
You need to edit the Manifest file.
Also to add library + having a proxy (so to  speak) main class executed in order to execute correctly.
Difficult to explain. But without the last part nothing goes if you have "extends Application" in your Main class.
Maybe you want to have a look: https://www.youtube.com/watch?v=D4D7daAmpV4


How do I change language on Firefox 60.0.2 (64 bit)?

Use the Firefox interface in other languages with language packs

-Go to https://support.mozilla.org/en-US/kb/use-firefox-interface-other-languages-language-pack to d download you language and install it.

Then change the language.

-In the address bar type about:config (accept the risk)

-Type intl.locale.requested in the Search field.

-Double-click the intl.locale.requested preference.

-Enter the code of the language you want to use as the string value or leave it blank to use the language of your system.

-Click the Firefox menu three horizontal bars button then exit.

When you start Firefox again, you will see the interface in the new specified language.


Yes. (Not on some of the laptops, just to be complete if you change your mind later on)
No, Windows cannot boot from an "additional" hard drive: Windows MUST boot from the first partition on the first hard drive. (And it has been like this from DOS 2.11, the first DOS I used.  Microsoft has a near-monopoly and can dictate how things must be done!)
Yes:  There is a way to "fool" Windows that it's booting from the first partition on the first hard drive by changing BIOS settings (but it cannot be an external (USB) HDD).  As this site is about Ubuntu, the exact details for this Windows tomfoolery is better asked on http://superuser.com, a sister-site of Ask Ubuntu.


Joomla Files/Folders Permissions in Ubuntu

the find command returns a list of files, and the -exec parameter executes on each listed file the command chmod 644. The brackets allows the user to specify where in the command is used the listed filename...

the \; is used to specified the end of the command (in this case, the end of the chmod command)

see man find:

   -exec command ;
      Execute  command;  true  if 0 status is returned.  All following
      arguments to find are taken to be arguments to the command until
      an  argument  consisting of ';' is encountered.  The string '{}'
      is replaced by the current file name being processed  everywhere
      it occurs in the arguments to the command, not just in arguments
      where it is alone, as in some versions of find.  Both  of  these
      constructions might need to be escaped (with a '\') or quoted to
      protect them from expansion by the shell.  See the EXAMPLES sec-
      tion  for examples of the use of the '-exec' option.  The speci-
      fied command is run once for each matched file.  The command  is
      executed  in  the  starting  directory.    There are unavoidable
      security problems surrounding  use  of  the  -exec  option;  you
      should use the -execdir option instead.

http://unixhelp.ed.ac.uk/CGI/man-cgi?find


libgcc_s.so.1 must be installed for pthread_cancel to work

The bug seems unsolved to the date (oct 30). Switch to proftpd instead. It is not difficult to migrate the user database from vsftpd into proftpd.

At least is what I had to do in order to have my server up an running again (and asap)!


after upgrade to 20.04 jpilot icon missing from aps

The JPilot package is not available for 20.04 LTS, but you still can download and install it manually from 18.04 LTS repository:
cd ~/Downloads
wget http://archive.ubuntu.com/ubuntu/pool/universe/p/pilot-link/libpisock9_0.12.5-dfsg-2build2_amd64.deb
wget http://archive.ubuntu.com/ubuntu/pool/universe/j/jpilot/jpilot-plugins_1.8.2-2_amd64.deb
wget http://archive.ubuntu.com/ubuntu/pool/universe/j/jpilot/jpilot_1.8.2-2_amd64.deb

sudo apt install ./libpisock9_0.12.5-dfsg-2build2_amd64.deb ./jpilot-plugins_1.8.2-2_amd64.deb ./jpilot_1.8.2-2_amd64.deb

and use it as before.


The ClamTk update message is for the GUI. You can check what version you have now, by clicking on the "yellow star" icon. Go to the home page, then download the update and install version 5.26, and any appropriate add-on files, then close and re-open ClamTk to confirm that the update message is gone.

For virus signature updates, first click the "Scheduler" icon and confirm that you have updates configured. Then click the "Update" icon to manually update the virus signatures.

The red circle icon is a different problem. Usually it's broken packages. Start Synaptic and go to the Edit menu, and select "Fix broken packages". Repeat this until it doesn't complain any more. Reboot the computer and the red circle icon should be gone. If it isn't, more work needs to be done on your system.


sudo apt-get install -f doesn't fix broken packages. And now?

Try running the following commands:

 sudo dpkg --configure -a --force-all
 sudo apt-get clean
 sudo apt-get update


Did you upgrade your grub properly? I'd use super grub disk to fix it.

http://www.supergrubdisk.org/


Upstart script is not run (there is no syntactical error)

Your echo command writes to STDOUT. At the time your job runs, STDOUT is not pointed to anywhere useful.

echo "testjob ran at [`date`]" >>/tmp/myjob.log

will save the output.


Is there any legal things I need to discuss with Canonical before publishing an Ubuntu-based distribution?

You have the right to modify and redistribute Ubuntu under the GPL.

As long as you don't infringe any trademarks like 'ubuntu' or 'buntu' for example calling it 'Jorge ubuntu' without permission, or claim to be officially endorsed or assiosiated with Ubuntu / Canonical then you should be fine.

You should read this link for clarification and contact Canonical if you are unsure.
  They were very helpful when we asked permission to use their trademarks.


Software Center doesn't show files installed

I don't think you can do it in the Software Center. If you install the Synaptic Package Manager then you can see which files were installed by right clicking the package, select Properties then choose the Installed Files tab.

The Synaptic Package Manger is available in the Software Center.


What determines which virtual console the graphical interface is run on?

X uses the first free virtual terminal, and the first six are now allocated for gettys by upstart from /etc/init/tty[1-6].conf, and traditionally by init from /etc/inittab.

To choose a specific virtual terminal for X, you pass it the parameter 'vtXX' (see X -help) , where XX is the desired terminal number. There are a bunch of ways to pass parameters to X, but that is stuff for another question. :)


Volume issue with Bluetooth paired device


Ubuntu 14.10 no desktop after kernel update to 3.18.1

After the updataion of Kernel if we find any difficulties try with updating the GRUB using the below command,

sudo update-grub
sudo reboot

Hope this helps.


Rosa Image Writer on Kubuntu 20.04 is missing kdesu

That software has not been updated since 2016 according to their web site.
Here is a list of some possible replacements: ROSA Image Writer Alternatives for Linux
According to the above list, UNetbootin is very popular. You can find UNetbootin's official website here.


Realtek rtl8812au WiFi broke after 20.04 kernel update

Reboot and use the Grub menu Advanced Options to boot into the 5.4.0-58 kernel.  Then in terminal sudo apt remove linux-image-5.8.0-38-generic linux-generic-hwe-20.04
sudo apt autoremove
sudo apt install linux-generic
Reboot


Ubuntu 16.04 unity desktop environment doesn't load after fresh install

I solved the problem following these steps:

Activated the proprietary Nvidia graphics driver instead of the nouveau open-source one.
Unfortunately this made my Ubuntu fail to boot, so I had to follow these steps to get it to work: https://askubuntu.com/a/391608/281857
At this point Ubuntu was booting but there was still no launcher, top bar, etc. However I could right-click on the desktop to open a Terminal, and ran Fix 5 detailed by this answer: https://askubuntu.com/a/481620/281857


You don't need to register on wush.net. Just try sudo apt-get install subversion, or this http://itp.nyu.edu/physcomp/Tutorials/OpenBTSInstallation


Ubuntu 15.04 disconnects from virtual networks after wakeup

Making it work manually

I have solved this problem typing the following command in a terminal after wake up:

sudo ifconfig vboxnet0 192.168.50.1/24

I'm not really sure if 192.168.50.1 is the VirtualBox default IP, but it's the one that my Virtualbox is using, if yours is using another you have to replace the IP.

Making it work automatically

To make it work automatically while the system wakes up I have created a file in the folder:

/lib/systemd/system-sleep/

The content of that file should be something like this:

#!/bin/sh
ifconfig vboxnet0 192.168.50.1/24

Make the file executable with:

chmod a+x /lib/systemd/system-sleep/name_of_file.sh

Since it's a root file, you'd need to be sudo to create the file, but we don't need to include the sudo in the script.

Hope it's helpful!

NOTE: Just tested on Ubuntu 15.10


Ubuntu stuck at black screen with pink diagonal lines after selecting "Try Ubuntu." (Update - Still need help)

Try reburning the disk, and if that doesn't fix it it may be a problem with the graphics card or something. You could try using lubuntu or a puppy linux livecd to copy the files off the disk as well as it doesn't require nearly as much graphics work.


have you tryed to use this ??
% sudo apt-get install vlc browser-plugin-vlc
or this
% apt-get install miro

i think if you was connecting with internet your problem will fixed  :D


Installing packages and saving the output from apt in a log file

Yes you have to use tee to accomplish that.

sudo apt-get install <package-name> | tee Log.txt


Changing keyboard rate for initial keypress in Ubuntu?

This is easy with dconf editor. (To install run sudo apt-get install dconf-tools). Open dconf editor and navigate to:
org>gnome>settings-daemon>peripherals>keyboard

The location for keyboard delay has been updated to:

org>gnome>desktop>peripherals>keyboard

Changing the delay to 200ms worked well for me.


Xubuntu Thunar Menu Bar disabled, now lost forever

The shortcut for disabling and enabling the menu bar in my German version is Ctrl+M.

Try that.


I unlocked the 'Files' button/icon from my unity launcher and now it disappearead and I cannot restore it or get it back

I just tried it. When you start files again its icon appears way down on the launcher so you probably will not see it:

Move the mouse pointer to the lower end of the launcher and those icons get expanded


Can I use same external drive to backup and install new version?

The answer to your question is a clear "NO".

You should never ever use the same external drive for data-backup and as booting-device.

For this purpose, i really recommend, to use two different media.

For data-backup, I would recommend, that you use your existing external harddrive.
As boot-device, you can either use a fresh and clean DVD (which you burnt the iso-image on) or otherwise - as I do it - a usb-stick. For this purpose, a usb-stick with 8GB space is just enough.

So prepare this usb-stick as your boot-media.

For this purpose, the safest way is, to your unetBootin. I always use that and it took me to clean installations.

Greetings
Andrea


Is my windows 8.1 still available or not ? I tried dual booting with Ubuntu 14.04

Your problem description is not entirely clear to me.

But The correct procedure for dual booting is pretty simple.

First install windows in a partition. Then install ubuntu in another partition. And use ubuntu grub to access your desired operating system while booting.

And if you have done in this way, your windows partition should be fine.


Sounds like a job for gnome-search-tool.

It can perform partial matches on the file name and search on more options:

File content
Modification date
Size
File emptiness
Owner/Group
Name pattern exclusion
Name regular expression match
Hidden and backup files

It can also:

Follow symbolic links
Exclude other filesystems

You can define a a location to search. In my example I have two .gpl files in that directory but only one containing the word Server.


What network manager to use for the Xfce4 Panel to see my current conection state?

You can try a program to manager wireless networks called wicd:
** Instalation**
sudo apt-get install wicd
Configuration

Configuration of Wicd is extremely simple, and automatic for wired
clients.
To configure a wireless connection: Open the Wicd network
manager in Applications > Internet > Wicd Network Manager, or you may add it as a launcher to Xfce Panel.

See if the wireless network you're looking for shows on the list. If it is a hidden network, click the down arrow next to the Network button, and type in the ESSID of
the network.
If the network you want to connect to is listed, press the "Connect" button next to it. > If you get the message "This network requires encryption to be enabled." hit OK

Source
You can also try network-manager network-manager-gnome


I should have 20GB of swap space, but I apparently have no swap space at all

I think that what happened is that when you installed the new Linux distro, you told it to use the old swap partition and it was formatted.

Since partitions are nowadays referenced in /etc/fstab by their UUID, if the partition was formatted, it now has a new UUID and Ubuntu can't find it anymore.

The quickest solution would be to find the new UUID (sudo blkid | grep swap) and update /etc/fstab accordingly, but beware, if both OSes share the same swap partition, hibernating one OS and boot into the other will wipe your hibernated session (since all memory contents is written in the swap partition when hibernating). As long as you don't use hibernate, this will be OK though, but the best choice would be to allocate a swap partition for each OS.


How does one provide sudo file read access privileges to a Wine application?

you can try CAP_DAC_READ_SEARCH capabilty while doing setcap. Which will eventually allow your appication to read all the files of any user


I am not aware of an alternative; the alternative is to construct your interfaces in code.


Audio over HDMI Distorts on AMD Graphics Card (Orca Screen Reader Sound Distorts as Well)

Same problem here. Not a solution, but a workaround is to kill & restart the sound deamons:
pulseaudio -k && sudo alsa force-reload

That is at least better than restarting the entire PC. Unfortunately, with the latest update, the problem seems to be worse in the sense that the deamons often won't start (they seem to be ignoring the kill when they are occupied or something similar).
Generally I won't have this issue until I suspend, possibly with sound still playing. I think it might be some kind of bug entering an invalid state after the system wakes up.


Cannot preform FTP uploads, "Connection timed out"

Your server is refusing connection, if you are sure about all the details of it try using passive mode, some servers require it.


Lubuntu either fails to install grub or fails to boot after what seems to be successfull instalation

If your UEFI-set up netbook does not want to boot, you can try to solve the problem afterwards while booting into a SystemRescueImage and there trying as root with chroot, grub-install and update-grub to install and configure your grub2. See https://wiki.debian.org/GrubEFIReinstall how to do that.

Alternatively you can try to disable SecureBoot: search for "Disabling SecureBoot in the BIOS" in your search engine (with the quotes).

There is also a Boot-Repair available, which might help: Search for "boot repair ubuntu" in your search engine (without the quotes).


Can I adjust computer display size to fit broken screen?

It's easy try this

Use xrandr -q to see what resolutions are available for your display.
To change it just write in terminal:

xrandr -s 1024x768

See  reference


There are a number of options:

Use the --remove flag, similar to how the PPA was added:
sudo add-apt-repository --remove ppa:whatever/ppa

You can also remove PPAs by deleting the .list files from /etc/apt/sources.list.d directory.

As a safer alternative, you can install ppa-purge:
sudo apt-get install ppa-purge

And then remove the PPA, downgrading gracefully packages it provided to packages provided by official repositories:
sudo ppa-purge ppa:whatever/ppa

Note that this will uninstall packages provided by the PPA, but not those provided by the official repositories. If you want to remove them, you should tell it to apt:
sudo apt-get purge package_name

Last but not least, you can also disable or remove PPAs from the "Software Sources" section in Ubuntu Settings with a few clicks of your mouse (no terminal needed).


Ubuntu 12.04 upgrade problem (The package system is broken)

Open the file /etc/apt/sources.list and disable all the unstable or third-party repositories. Then run sudo apt-get update && sudo apt-get upgrade.

Also, as mentioned in the snippet you provided, you might have to run sudo apt-get install -f.


Open the CompizConfig Settings Manager.

Go to Window Management > Place Windows, enable it, and in "Placement Mode" choose Centered.


Very likely you did not stop uTorrent process - utserver.
It will be running until stopped even if you deleted all uTorrent files.
Restart and it should be gone.


After some findings I see that one should extend the .vdi disk using this line:

VBoxManage modifymedium <name_of_vm>.vdi --resize 8000

You can create a new virtual disk and associate it with the virtual machine to provide the extra space:

VBoxManage createmedium --filename <name_of_vm>.vdi --size 8000

Basically the above steps is what was left out, but in your case you did it a bit wrong. The steps aught to have been:

Resize using VBoxManage
Use gparted iso file in Virtualbox to boot and resize.
Resize the physical volume: sudo pvresize /dev/location/of/device
Make the assigned space available with lvresize command
Now I have added link and hopefully you will need only the first two commands I gave.

Source:

https://oracle-base.com/articles/vm/virtualbox-extend-disk-and-file-system

https://technology.amis.nl/2017/01/30/ubuntu-vm-virtualbox-increase-size-disk-make-smaller-exports-distribution/

http://derekmolloy.ie/resize-a-virtualbox-disk/


Applications menu filled with lots of LSP apps after upgrading to Ubuntu 20.10

The best (and I think only safe) way to fix this is to bring up the Menu Editor by typing "edit" after clicking on the menu/start button.
Navigate to LSP Plugins and choose to not have it show from the menu.
You can also choose to have the CALF plugin thingie to not show if you have that but don't use it. Cheers!


I want my Ubuntu server 18.04 to shutdown every night at a certain time? How can I do this?

Edit the system crontab:

sudo vi /etc/crontab

Add the following line to the bottom of the file:

0   23   *   *   *    root     shutdown -h now

Save the file (ZZ in vi).
That should run the command "shutdown -h now" every night at 23:00.


Recent upgrade of openjfx broke my installed application

As it turns out, Canonical decided to ship a new version of openjfx. (Incidentally, is there a place where one can see such version changes/decisions?)

The relevant information can be found in /var/log/apt/history.log:

Start-Date: 2019-04-29  07:10:19
Commandline: apt upgrade
Requested-By: tannerli
Install: [snip]
Upgrade: [...]
openjfx:amd64 (8u161-b12-1ubuntu2, 11.0.2+1-1~18.04.2)
openjfx-source:amd64 (8u161-b12-1ubuntu2, 11.0.2+1-1~18.04.2)
libopenjfx-java:amd64 (8u161-b12-1ubuntu2, 11.0.2+1-1~18.04.2)
libopenjfx-jni:amd64 (8u161-b12-1ubuntu2, 11.0.2+1-1~18.04.2)
[...]

There's an open bug at LaunchPad and quite a few similar questions on various StackExchange sites concerning this, this one for example. None of those fit my specific needs. Seems there is no real solution to this day, only a

Workaround

Explictly downgrade all openjfx packages to the previous version:

$ sudo apt install openjfx=8u161-b12-1ubuntu2 libopenjfx-java=8u161-b12-1ubuntu2 libopenjfx-jni=8u161-b12-1ubuntu2 openjfx-source=8u161-b12-1ubuntu2

Hold back the affected packages, so that the next apt upgrade won't break things again:

$ sudo apt-mark hold libopenjfx-java libopenjfx-jni openjfx openjfx-source

This will show up as info when you're upgrading next time:

$ sudo apt upgrade
[...]
The following packages have been kept back:
  libopenjfx-java libopenjfx-jni openjfx openjfx-source
0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.


Accessibility testing the web for the blind and low vision in Linux

Orca Screen reader is preinstalled, launch it by orca or searching dash for orca. See the wiki page for it.


Sound increasing and decreasing randomly in XMoto

I had solved the problem.
Looks like the problem was with my led button to increase the sound, over the keybord.
Ubuntu detects it as a input device.
Xmoto try to detect the input devices to able joysticks so this fake joystick make the sound crazy.

Running

  sudo ln -s /dev/input/js0 /dev/js1

and

sudo ln -s /dev/input/js1 /dev/js0

solves the problem to me.

js0 device is my led button.
js1 device is my joystick.


How can I play mp4 and avi files in a Movie Player?

VLC Media Player - available from the Software Centre!


Dual boot Ubuntu and an ubuntu based distro

just boot with a live-cd and at installation you can create a partition. Then at boot you will be able to choose which operating system you will run.

you don't have to do anything before you start installing.


cron.daily seems to run but doesn't log any activity

What are the 20-minute jobs?  It looks like you pasted /etc/crontab, and it has no 20-minute entries.

What is the contents of /var/log/cron.log?

Do the permissions on /etc/cron.daily look right?  (e.g. should be at least r-x root)

Do the scripts inside /etc/cron.daily have execute permissions?

What does

run-parts --test --report /etc/cron.daily

print?

What happens if you add a new script in that directory that does something trivial that you can verify, e.g.

date >> /tmp/date.out

What does /etc/syslog.conf contain?  It should be something like:

cron.*                          -/var/log/cron.log

If it's cron.notice or cron.warn or cron.err rather than cron.*, then not all activity will be logged to /var/log/cron.log.


If you are asking for community version of Cinelerra, there is a PPA as @Brett Howard said. It worked on my current system. Just used these:

sudo add-apt-repository ppa:cinelerra-ppa/ppa
sudo apt-get update
sudo apt-get install cinelerra-cv

The updating process after installing the PPA is automatic:

sudo apt-get update
sudo apt-get upgrade


Additional partition of FAT32 created (size 512 MB) after installing ubuntu 20.04 in my Lenovo Laptop

I wouldn't delete it. Installing Ubuntu normally creates two partitions, one big one and then a small one. Most of Ubuntu is on the big one, but some of the instructions that the computer follows in order to be able to read the big one might be in the small one.

And now, for the longer explanation of what I think that partition is (trying to make it understandable, but I'm not sure what you and other readers know or don't know in advance, so I hope this is clear and isn't dumbing down )

I don't think the UEFI (the code that runs when you turn on the computer and figures out what should run next and reads that from a disk and runs it) knows how to read ext4 or NTFS, so some code is stored on a FAT32 partition, and that code contains the instructions on how to read the other partitions.

That is, I'm guessing it's the "EFI boot partition": ''EFI boot partition'' and ''biosgrub'' partition

I don't know how much of Ubuntu is stored on the small one. But at least some part of GRUB (the programme that shows a menu so you can choose when to boot Windows and when to boot Ubuntu) would have to be on a FAT partition.

In general, I wouldn't delete stuff without at least having some clue what it is and where it might have come from.


How can I remove a previously applied Fade effect in Kdenlive?

To remove the fade effect, click on the clip to which you applied the fade effect (In this case I used "Fade to black", visible as the red triangle at the end of the clip), and then delete the effect in the "Effects stack" tab by clicking the "X". Here's a screenshot:

Make sure you have "Effect stack" checked in the "View" menu for this to work. I hope I understand your question right, let me know if you haven't and this is not what you want to do.


How can I fix Libreoffice after apt autoremove broke it?

Installing LibreOffice with GUI
Open Software Center, search for LibreOffice, and install it.
Using CLI
Open a terminal and enter the command
sudo apt install libreoffice

And why did autoremove did something like that?!?

This is not supposed to happen. I have no idea why this happened. From the log, it seems that you were using the LibreOffice PPA, but that should not cause the issue either. I am using that PPA too, but autoremove never suggested to remove LibreOffice.


How to change address and name of the computer in linux Ubuntu

So the problem is with the nameserver(s).
After updating to 12.04 there is no resolv.conf file, these settings are being configured in /etc/network/interfaces

For instance if this was you resolv.conf
    nameserver 10.10.10.10
    nameserver 10.10.10.20

No you need to rewrite it like this in /etc/network/interfaces:

dns-nameservers 10.255.255.10 10.255.255.20


Making Canon LBP6000 printer work under Ubuntu 14.04 64-bit

I followed Masroor/bain instructions; after installing EVERY SINGLE (hidden) DEPENDENCY, I was able to get it to work, but ran into the "kill ccpd once every boot" issue.

If you go here and look at the very end of the page, they say:

Only one ccpd process running after system startup
For normal operation two ccpd processes should be running in a system. The ccpd daemon depends on running cups daemon before forking the second process. You can use the following method to workaround the problem:

Enable the cups init script (update-rc.d cups defaults).
Instruct the ccpd init script to run after the cups init (update-rc.d ccpd defaults 99), or add "sleep 10 && /etc/init.d/ccpd start" in /etc/rc.local script.

I removed all runlevels for ccpd and added the sleep command to rc.local.


How do I get to the update settings window when the system is up-to-date?

You need to launch the "Software & Updates" application instead of the "Software Updater" application. Search for "Software & Updates" in Activities overview and launch it.

Alternatively, as @mikewhatever pointed out in comments, you can launch the application by running the software-properties-gtk command in Terminal.


How does apt-get/aptitude update determine what package lists to update?

When I first tested the touch hack, I was surprised that apt-get used the local file mod time to inform the http server what to download--but that's obviously the case (or the hack wouldn't work).

The downloaded Release file contains a reliable date and these files are crytographically signed, and are therefore quite trustworthy, but the hashes aren't used to determine what package files to download.

With the timestamp approach now in use for package files, there's nothing special needed from the mirror site. We owe the Debian project for the design. It's helpful to mirror owners to keep Ubuntu identical to Debian and keep things vanilla and therefore easy to manage.

This design normally works fine, as far as I know. This is just a bug which should be fixed as far as I'm concerned, but the bug is in Canonical private code so outsiders like me can't help patch it. I hope they do so soon as we are abusing the hospitality of those running Ubuntu mirrors, in addition to causing unnecessary expense for some Ubuntu users who must pay for bandwidth by the gigabyte.

There is an http protocol mechanism for using an etag to represent a served item, but it's not used for apt-get. Such a tag could contain the hash from the Release file.

It's the large number of packages included in Ubuntu releases which make this bug so significant.

From the signed (and therefore checksummed) Release, there are hashes for these files, and in these files hashes for versions of packages and from there checksums for files. Since the package files contain the version numbers, and since they don't change, the bug doesn't cause redundant package upgrades.


When you copy the script into place, don't forget to make it executable and owned by root:

sudo chmod +x /etc/init.d/celeryd
sudo chown root:root /etc/init.d/celeryd

Once you have installed that, you can set it to start automatically on boot with:

sudo update-rc.d celeryd defaults
sudo update-rc.d celeryd enable


How can I get bash to evaluate a PM2 command stored in a Variable?

Try either of these lines:

var="sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup systemd -u username --hp /home/username"

$var

var1=$("sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup systemd -u username --hp /home/username")

$var1

The error on the one you used happens because expressions don't expand in single quotes, use double quotes for that:

var='sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup systemd -u username --hp /home/username'
$var


You basically need some development packages to compile Gnuradio from source. From the error you posted I would install the following packages, open a Terminal a type:

sudo apt-get update
sudo apt-get install libasound2-dev libxi-dev

You'll probably have to get several other -dev packages to compile it though.

Take a look at the source package page, they're all all listed as build-depends.


How can I make text in Android Studio readable?

This is due to an unrecognized font.

See the below image for a guide as to how to change the font.

Or, in text:

In Android Studio, go to File > Settings
In Settings, go to Appearance and Behavior
Select the Appearance sub-menu
Check the Override default fonts option.
Set your overridden font to Ubuntu with size 15 (or whatever you prefer)


Ubuntu GUI SMB share with password inaccessible from Windows 7

Solution
The problem was that the Windows 7 machine attempted to authenticate with NTLMv1 while it was disabled on Ubuntu 20.04 in favor of NTLMv2.
The fix is to force NTLMv2 for client connection on the Windows machine: set HKLM\SYSTEM\CurrentControlSet\Control\Lsa!LmCompatibilityLevel to 5 or 3: https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc960646(v=technet.10).
Another but less secure fix is to enable NTLMv1 in /etc/samba/smb.conf with ntlm auth = yes. Note that NTLMv2 has additional protection against replay attacks: https://miriamxyra.com/2017/11/08/stop-using-lan-manager-and-ntlmv1/.
How I found it

Set log level in /etc/samba/smb.conf with log level = 5. Although, log level = 2 would've been enough.

Compared logs of a failed connection from Windows 7 and a succeeded connection from Ubuntu 20.04 itself:

From Windows:
[2020/07/17 12:11:17.453906,  2] ../../libcli/auth/ntlm_check.c:429(ntlm_password_check)
  ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user gsovetov
[2020/07/17 12:11:17.454843,  2] ../../source3/auth/auth.c:343(auth_check_ntlm_password)
  check_ntlm_password:  Authentication for user [gsovetov] -> [gsovetov] FAILED with error NT_STATUS_WRONG_PASSWORD, authoritative=1
[2020/07/17 12:11:17.454887,  2] ../../auth/auth_log.c:635(log_authentication_event_human_readable)
  Auth: [SMB2,(null)] user [WORKGROUP]\[gsovetov] at [Fri, 17 Jul 2020 12:11:17.454866 MSK] with [NTLMv1] status [NT_STATUS_WRONG_PASSWORD] workstation [RHN] remote host [ipv4:192.168.1.72:49609] mapped to [WORKGROUP]\[gsovetov]. local host [ipv4:192.168.1.252:445]

From Ubuntu:
[2020/07/17 12:09:36.639590,  3] ../../auth/auth_log.c:635(log_authentication_event_human_readable)
  Auth: [SMB2,(null)] user [WORKGROUP]\[gsovetov] at [Fri, 17 Jul 2020 12:09:36.639576 MSK] with [NTLMv2] status [NT_STATUS_OK] workstation [GSOVETOV-MATE] remote host [ipv4:192.168.1.252:55250] became [GSOVETOV-MATE]\[gsovetov] [S-1-5-21-1148495091-2039333689-3294533319-1001]. local host [ipv4:192.168.1.252:445]
  {"timestamp": "2020-07-17T12:09:36.639644+0300", "type": "Authentication", "Authentication": {"version": {"major": 1, "minor": 2}, "eventId": 4624, "logonId": "0", "logonType": 3, "status": "NT_STATUS_OK", "localAddress": "ipv4:192.168.1.252:445", "remoteAddress": "ipv4:192.168.1.252:55250", "serviceDescription": "SMB2", "authDescription": null, "clientDomain": "WORKGROUP", "clientAccount": "gsovetov", "workstation": "GSOVETOV-MATE", "becameAccount": "gsovetov", "becameDomain": "GSOVETOV-MATE", "becameSid": "S-1-5-21-1148495091-2039333689-3294533319-1001", "mappedAccount": "gsovetov", "mappedDomain": "WORKGROUP", "netlogonComputer": null, "netlogonTrustAccount": null, "netlogonNegotiateFlags": "0x00000000", "netlogonSecureChannelType": 0, "netlogonTrustAccountSid": null, "passwordType": "NTLMv2", "duration": 7842}}

Found how to enable NTLMv1 for incoming connections in Samba: https://nelsonslog.wordpress.com/2018/08/31/ubuntu-18-samba-and-ntlmv1/.

Found how to enable NTLMv2 for client connection on Windows: https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc960646(v=technet.10). A recommended value is 5: https://support.microsoft.com/en-us/help/4090105/how-to-audit-domain-controller-use-of-ntlmv1-and-ntlmv2. (I'm not sure what's the default value. It might be me who changed this setting a few years ago and forget about it.)


How can I set view preferences to sorted by reverse date modified?

There's an additional parameter default-sort-in-reverse-order that doesn't appear to be accessible from the in-application preferences menu, but can be set in the dconf database - I think this will do you want.

There is a GUI dconf-editor that allows you to modify such hidden settings - it's not installed by default but available by installing the dconf-tools package. Alternatively you can set it from the command line using gsettings

$ gsettings set org.gnome.nautilus.preferences default-sort-in-reverse-order true

If the dconf-tools package is installed, there is an equivalent dconf command line

$ dconf write /org/gnome/nautilus/preferences/default-sort-in-reverse-order

You can revert the change any time with

$ gsettings reset org.gnome.nautilus.preferences default-sort-in-reverse-order

or

$ dconf reset /org/gnome/nautilus/preferences/default-sort-in-reverse-order

Note that it applies to whatever the default sort order is, so for example if you change back to sort-by-name that will be reversed as well - there doesn't seem to be a way to specify the sort direction individually.


Go to System > Administration > Additional Drivers and see if you have a disabled proprietary driver. If any error occurs during enabling of proprietary driver go to Synaptic Package Manager and search for broadcom or bcm. There are lots of alternative. In my case bcmwl-kernel-source package worked. I also recommend you to see as well as paste which wireless card you have with lspci | grep wireless. Be sure to stay wired during this.


Disable -s (i.e. -s) keyboard shortcut in 12.04

If you're in Unity 3D, you can go to

gff --no-gui -setparam="CCSM/Expo/Keyboard\ Shortcut/*" setflag("disabled")

OR in human terms/you don't know what gff is: Open up CompizConfig-Settings-Manager, then go to "Expo", then inside the first tab "Keybinds" there should be a keybind called "Activate", click on the pencil next to it, and write "disabled"


The ClamAV-Test-File file is like an EICAR file: it's used to test the behaviour of your anti-virus solution.

These kinds of files offer you the possibility to simulate a virus infection without actually infecting your system as they only contain the signature of a virus.


Why won't my WiFi work with a Belkin USB dongle and WPA2?

Try using wicd instead of native network-manager. I had similar issues, mostly related to bizarre unexpected wifi disconnections - after upgrading to 11.04. I never had this problem on earlier versions of ubuntu to be honest.


Multi-threading in application designed in quickly

When asking programming questions, it is always best to provide a minimal working example and not just code snippets.

Without a working example to play with, I have the following suggestions:

Use a thread to walk the directory tree and put your results in a second separate treemodel (not connected to a treeview). This means you have two treemodels, one connected (which gets rendered to the screen) and one not connected (which therefore does not get rendered)
Add a timeout of a few seconds, which does calls a function that detaches and deletes the first treemodel, copies the second treemodel to a new one, which now serves as the "thread" treemodel and attaches the second tree model.

The reason why you see the GUI hanging is that the file walker takes very long and every time you add a file, a lot of overhead in Gtk is called. By adding a full treemodel, this overhead is only called one time. And by using a thread for the file walking, your GUI stays responsive.

As for the threading part in Gtk, you might want to look here: https://stackoverflow.com/questions/8120860/python-doing-some-work-on-background-with-gtk-gui

A couple of notes to your code:

Python has a build-in file walker, which might be faster but is certainly shorter than your code: os.walk
If you want to use your code instead, remember that Python has a build-in recursion limit. Depending on the size of your file system, you might want to replace the recursion with a trampoline like construct


If you see there ,you have installed Java Run time Environment which is actually needed to run Java based software in your system.

for example If you place java filename then it will execute that particular java file.

but javac belongs JDK which stands for Java development Kit , which you need If you would like to do programming on Java.

To get install Java for programming you can install openjdk-7-jdk with

sudo apt-get install openjdk-7-jdk


How to capture audio in Ubuntu from a stereo device?

You probably want a USB Audio Interface. Not all of them work equally well on Linux though, it may be worth checking here if there is driver support:

http://www.alsa-project.org/main/index.php/Matrix:Main


Is there any fix for ATI HD 4350 With Unity?

I have an ATI Radeon HD 4350 in my Desktop.

My advice is not to use the Official ATI drivers. The "default" open source drivers work perfectly for me, both with Ubuntu's normal interface and in Unity. Unity is not sluggish, does not freeze, or have corruption of the window borders for me.

To deactivate the Official ATI drivers you need to go to System->Administration->Additional Drivers (but if you installed them using some other method, you may have to do uninstall them differently).


It appears that the libcurl library must be built with c-ares support at compile time. From a cursory glance at the curl launchpad page This doesn't appear to be a dependancy of libcurl under Ubuntu, so it looks like you are left compiling and statically linking to your build of the libcurl library. This seems like a more appropriate question for StackOverflow.


TL;DR: Running hash -r or just starting a new shell usually fixes this problem.
If the file is actually gone, then the shell probably just still has it hashed.
First I suggest you verify that /usr/local/bin/cpan really is gone:
ls -l /usr/local/bin/cpan

If there is something there, then you didn't fully uninstall. If there is nothing there, then you will get this message:
ls: cannot access '/usr/local/bin/cpan': No such file or directory

Assuming you got that message, but bash is trying to run /usr/local/bin/cpan when you type in cpan and press Enter, the problem is most likely that bash still has that path hashed. Rather than looking up where external commands are every time, shells typically hash their locations. So you can fix the problem by telling bash to "rehash," by running:
hash -r

Or just start a new shell.
If that doesn't work, check if it's an alias or shell function.
If the file is neither still present nor still hashed, then most likely cpan is an alias or shell function that acts as a wrapper for /usr/local/bin/cpan. To ascertain this, run:
type -a cpan

If it's an alias or shell function, that will show the definition. Then you can unset it with unalias cpan if it's an alias, or unset -f cpan if it's a shell function.
You will ultimately want to remove the definition from whatever startup script contains it. Usually it will be in the .bashrc file in your home directory. Aliases are sometimes defined in .bash_aliases. (Occasionally people define aliases and shell functions in .profile, .bash_profile, or .bash_login, even though this is not a very good practice.)
If that doesn't work, consider how you're running cpan or what shell you're in.
If the file is gone, not still hashed, not an alias or shell function, and type -a doesn't reveal the problem, then most likely you are either (a) not running cpan directly through that command, or (b) using a shell other than bash.  In the former case there is no way to answer without further details.
The latter case seems unlikely since your shell calls itself bash, though every once in a while someone ill-advisedly makes a symlink called bash to a shell that isn't (which isn't advisable). The truth is, I'm mainly mentioning this for the benefit of other readers. Based on that message, you're almost certainly using bash.
However, in case you're not or might not be, run echo "$BASH_VERSION" to see if you're running bash--this should be unset in other shells--and echo "$SHELL" to see what your default shell is. Rehashing works differently--or is at least achieved differently--in other shells.
Some other Bourne-style shells, like zsh, have a rehash command that you would run instead of hash -r. That is also how you would cause rehashing  to occur in csh and tcsh.


How do I increase the size of swapfile without removing it in the terminal?

First disable swap file:

sudo swapoff /swapfile

Now let's increase the size of swap file:

sudo dd if=/dev/zero of=/swapfile bs=1M count=1024 oflag=append conv=notrunc

The above command will append 1GiB of zero bytes at the end of your swap file.

Setup the file as a "swap file":

sudo mkswap /swapfile

enable swaping:

sudo swapon /swapfile


16.04 How do I stop Mongo 3.x.x and 4.x.x from complaining about WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'?

Mongo complains because using transparent hugepage and always defraging it is not optimal for it's performance.  Do your research if you need more info.

A clean permanent solution is to install sysfs and add the setting there.

:~# apt install sysfsutils

add these two lines to /etc/sysfs.conf:

kernel/mm/transparent_hugepage/enabled = never
kernel/mm/transparent_hugepage/defrag = never

reboot


Searching for a tabbed SSH client with multi-execution support for Ubuntu

The best solution i found by far is byobu (maybe running in your client machine in your situation). Its a terminal app based on tmux (also can use screen instead) and can achieve what you want and has other great features like notifications which make it nearly an imperative for me (I use it also on my Arch based systems).

You can make splits on the same window, and also make multiple windows.
Then you can enter a command(s) to all windows (with Ctrl+F9) or splits (with Shift+F9).
Handles multiple (de)atachable running sessions (instances).
Also you can set profiles to start byobu sessions with certain config (splits, windows, commands like ssh...).
Notifications _(updates, reboot required...) and systray-like "indicators" (cpu, mem, entropy, wlan strength...).

Check this post from the father of this great tool (Dustin Kirkland from Canonical cloud staff), with a simple but usefull video tutorial.


How to bulk-extract objects from swf (Adobe Flash) files with swfextract?

Use this one-liner

swfextract --outputformat "extract_%06d.%s" -a 1- file.swf

If you want to extract to a dir content, make that dir first:

mkdir content
swfextract --outputformat "content/extract_%06d.%s" -a 1- file.swf

Works fine.

See the docs.


Wireless adapter hard blocked: rfkill unblock all not working

Try getting the event ID first by running rfkill event (press CtrlC to exit rfkill afterwards).

Then run rfkill unblock xxxxxxxxxx.xxxxxx, replacing xxxxxxxxxx.xxxxxx with the event ID from the previous command.

This will release the block.


Yes, it's expected, because your home is /home/user. /home is just the container for the home folders.


How do I install the Command Line Interface?

You don't have to install the command-line interface. You have two options:

From the Ubuntu Desktop, press the Ctrl+Alt+T keys to open a terminal (CLI).
Or to open a true Linux console (TTY), press Ctrl+Alt+F1 and login. To switch back to the desktop, press Ctrl+Alt+F7 (or Ctrl+Alt+F8).


Virtualbox stuck on purple loading screen

Changed my UEFI bios settings to turn on CPU virtualisation and used a 64-bit OS and it fixed my problem.


Wifi Disabled in Ubuntu 16.04 and Windows 7 dual boot

You must have accidentally disabled the wireless by hardware switch/button.

The hardware switch is usually a combination of Fn+F10 or some other function keys. Look for the wireless radio/Wi-Fi/Airplane symbol on the keys of the first row on the keyboard (My latitude has it on PrntScrn key). They can be used to toggle the wireless.

If this doesn't work, check your BIOS to see if WLAN is disabled.

UPDATE FROM COMMENT BELOW:

Dell Latitude E6530 Wifi Hardware Switch is a slider on the right hand side of the keyboard just above the CD drive.


Why is the +8 timezone called GMT-8 in the filesystem?

The Etc/GMT... zones are there for backwards compatibility only.  Their zones are inverse from the usual expectation such that they conform to the POSIX specification, as described in the Wikipedia entry for the TZ database.

The only legitimate uses of these zones (other than backwards compatibility) is for ships at sea.  All populated locations on land have named time zones.  For example, you may be in the "Asia/Shanghai" time zone.

You can see a list of the time zones and their current offsets here.

See also, "Time Zone != Offset" in the timezone tag wiki on StackOverflow.


Why is my window resizing in the wrong direction?

I see you already got another answer but thought I should clarify my answer with the specific steps and also add the steps to RECREATE the condition since you and Neilen were not able to originally use my "fix".

You may do these steps to correct the reverse resizing motion:

1: Alt-F8

2: Press the Down Arrow once.

3: Press the Return Key.

Now you will find that you may click on the bottom edge of the window and resize it as normal.

You can also RE-CAUSE the problem to occur resulting in "reversed motion" of the bottom edge of the window during resizing by doing the following steps:

Alt-F8
Press the Up Arrow once
Press the Return Key.

I hope this helps clarify my work-around and makes the problem reproducible for others to fix this odd behavior!  I'm using Ubuntu 14.10.

Mike


Ubuntu 14.10 on MacBookPro4,1 nVidia 8600m - cannot load binary drivers

I discovered that there is a way to do it - after finding a clue here: http://korrekt.org/page/Note:How_to_install_%28K%29Ubuntu_14.04_on_Macbook_7,1#What.27s_the_problem_with_EFI_on_this_Macbook.3F:

  (K)ubuntu will not ask if you want EFI or BIOS mode during installation. It will
  just use the same mode that you have used to boot the installer. Once
  you installed Ubuntu in this mode, it will be hard to change. In fact,
  both modes have their own dedicated boot loaders that work differently
  (package "grub-pc" for BIOS and package "grub-efi-amd64" for EFI).

  How to boot in BIOS mode. Thus, you must make sure that your installer
  boots in the right mode. For me, this worked by booting from a CD/DVD.

  ...

  At least in my boot loader, it seems to be impossible to boot from a
  non-EFI USB stick. I could use USB sticks to boot, mainly to use a
  live system to try and fix my installation, but these were always EFI
  USB sticks that were then booted in EFI mode.

The solution is to burn a CD/DVD instead of using a USB stick. In this way it is indeed possible to force the Mac firmware to boot in BIOS mode, and Ubuntu will take from this that it should install the BIOS version of GRUB. Everything flows from there. However, based on my understanding, it is not possible to do this without a full reinstall.

I hope this helps someone else.


Change between user and root without password

It sounds like you want these users accounts to be able to sudo to root with out providing a password.  If this is the case, this is actually quite easy.
You can create a file in /etc/sudoers.d to define the sudo behaviour and also to define sudo perimissions.
Say you have an account named a account defined named lindsay.  You want Lindsay to have sudo access, without needing to type in her password when using sudo.  To accomplish this you would do the following:

Create a new file in /etc/sudoers.d using your favourite text editor.  In my example I'll create a file in this location named lindsay since that'll help to remember what this is for later.
Add the following single line of text to the newly created file and save the changes.

lindsay ALL=(ALL) NOPASSWD:ALL

Next we need to set permissions of 0400 on this file:

chmod 0400 /etc/sudoers.d/lindsay

That's it!  Our user Lindsay will now be able to sudo to root without re-authenticating by typing in her password.  You can find more details about the syntax and some examples in the link below.
Be aware of the security implications of doing this since you are intentionally weakening the security of your Ubuntu installation.
Cheers!
Sudoers - Community Help Wiki


Add printer (and similar things) as standard user with sudo rights

The permission you had posted indicate a highly configured custom Linux. Standard Ubuntu groups are very different.

This is not unusual for a workplace computer but it may lead to unpredictable results in standard procedures. It may for example be that your administrator had blocked any access to external drives or printers.

Nevertheless you can see whether your root (sudo) permissions are sufficient to add yourself to the lpadmin group to be able to add a printer to the system.

sudo usermod -aG lpadmin <USERNAME>

Other groups of interest may be plugdev, sambashare, cdrom, fuse. For all groups and privileges read the corresponding list in the Ubuntu Wiki.


why ffmpeg command producing error in Ubuntu terminal?

The path /usr/local/bin/ indicates, that you have installed a custom version of ffmpeg. The version you have installed with apt-get install is located at /usr/bin/ (without the "local" part). To execute the version apt-get has installed, run

/usr/bin/ffmpeg

You can remove /usr/local/bin/ffmpeg or mark it as non-exexcutable with sudo chmod -x /usr/local/bin/ffmpeg. Run hash -r so the change takes effect in the current shell. Log out and log back in so that the change takes effect for every graphical application.

As soon as /usr/local/bin/ffmpeg has been treated with one of the above mentioned method, simply calling ffmepg will start the one at /usr/bin/ffmpeg by default.

Edit Added information from @Ramchandra_Apte on how to do this without a complete reboot.


So internet is not acessible from 1 computer but is working from othe computers? On this computer, you have ubuntu and you cannot connect to the internet using any browser?

"suddenly lost.." implies it was working and now it isnt

Can you ping yahoo.com?
Can you ping DNS server?


It seems as though you are missing proper address of the files you are moving.  I cannot see the full line of what you are trying but I would say that to move the files you should use:

sudo mv ~/Desktop...

or

sudo mv /home/username/Desktop ...

Alternatively, if you are already in the folder that contains /Desktop you could do

sudo mv ./Desktop....

That is, what you are missing is what comes before /Desktop as what you currently have there is saying that at the root of your file system there is a folder called Desktop which, in most installations, this is not the case as the Desktop folder is under the user's home folder (i.e., inside /home/username/).

(LinuxRev: permissions should not be an issue as he is trying as a sudo.)

A quick search search for "How to move files and folders from linux terminal" shows many sources including this one: HowTo: Move A Folder In Linux Using mv Command


try using fsck
steps:
but first login as root

sudo su

then:

fsck /dev/ur-drive

you can also force fsck upon system boot
do:

touch /forcefsck

dont forget that uh must do all these steps with your root privilages.

then reboot ur system and hold down the SHIFT key which will open the grub menu
form which uh must select the ADVANCED OPTIONS FOR UBUNTU

after that select the RECOVERY MODE.
then select fsck it will pop-up with some dialogue box..
select yes .
you can then select normal mode to bootup ur system in the normal mode.


https://www.ubuntu.com/legal/terms-and-policies/intellectual-property-policy

You are looking for option number 3 in the above link. It depends on how you going to post the system image.

Any modification to system image will requires approval of Canonical team before you distribute.

You are also bonded to the other terms and condition of ubuntu page.


NFS Network Drive Added to /etc/fstab, only root has permissions

To make files actually accessible, you could use the admin interface on your NAS to set their owner to your user ID on your Linux machine, or you could try the uid=... and gid=... mount options in the /etc/fstab entry; see man 8 mount:

uid=value, gid=value and umask=value
Set the file permission on the filesystem.  The umask  value  is  given  in octal. By  default, the files are owned by root and not readable by somebody else.


How can I hide mounted volumes when I still want USB volumes to appear on the desktop?

Add them to your /etc/fstab and they will be hidden:

LABEL=fedora    /mnt/fedora ext4    noauto,rw,noatime,errors=remount-ro,norelatime,user_xattr,acl   0   0
LABEL=FAT32     /mnt/FAT32  vfat    noauto,rw   0   0
LABEL=xp        /mnt/xp     ntfs    noauto,rw   0   0
LABEL=seven     /mnt/seven  ntfs    noauto,rw   0   0

They need not be mounted at all, noauto acheives that.
Do not mount them under /home if you use other file managers.
They will still appear if you mount them under /media. Useful for eSata bay drives.
This behavior is neither xfce nor thunar-specific, it affects all file-managers that employ gvfs.


Why does the Spotify client render certain pages completely black?

A while back, Spotify enabled hardware acceleration by default in the desktop client. On certain systems (not only Linux), incompatibility with the graphics drivers causes some content to fail to render. The suggested solution is to disable hardware acceleration in the clients' Preferences (Edit > Preferences):

Applying this change requires a restart of the Spotify client. If this causes a "Failed loading skin" error, uninstall spotify (sudo apt-get remove spotify-client) and remove /opt/Spotify (sudo rm -rfv /opt/Spotify). Reinstall Spotify (sudo apt-get install spotify-client) and the issue should be resolved; hardware acceleration should now be disabled.


Bars do not disappear watching videos full screen

Double clicking on the title bar maximizes the window.  That is not the same as full screen mode.  To enter full screen mode you need to click on the button that says full screen mode, or right click in the display area and choose the full screen option from the menu.


you can use  Control Blur  Extension to Control the Blur Effect.

Blur Sigma Value set to 0

Blur Sigma Value set to 4

Blur Sigma Value set to 100

you can follow the installation instructions from this  post

Or you may use this wonderful extension  Extension


Wiped Windows and installed Ubuntu 18.04 on Acer Travelmate P but can't find bootloader

Try to repair the boot with Boot-repair using the USB with UBUNTU LIVE.

https://help.ubuntu.com/community/Boot-Repair


How can I completely reverse all changes by npm in Ubuntu

This will be messy ...
The simplest solution that I have found to this problem when trying to "fix" a broken development server that couldn't be formatted and rebuilt from scratch due to "management" is this:

remove the globally installed packages
delete the locally installed packages from the various /home directories and /root
remove Node

Here's the basic process:

Open Terminal (if it's not already open) or SSH into the machine (if you don't have physical access)
List all globally installed packages:
npm list -g --depth 0

Uninstall the global packages one by one with:
sudo npm uninstall -g <package-name>

If you'd like to also do this for locally installed packages from your account, you can do this:
npm list
npm uninstall -S <package-name>

The -S flag will also remove the reference in your package.json file
Remove the following directories:⇢ /etc/npmrc⇢ /home/youruser/.npmrc⇢ /root/.npmrc⇢ ./.npmrc in any project directory next to package.json (search by using locate .npmrc)
Remove the Node package:
sudo apt remove nodejs --purge
sudo apt remove npm --purge

Finally, remove the straggling files and directories:
sudo rm -rf /usr/local/bin/npm \
            /usr/local/share/man/man1/node* \
            /usr/local/lib/dtrace/node.d \
            ~/.npm \
            ~/.node-gyp \
            /opt/local/bin/node \
            /opt/local/include/node \
            /opt/local/lib/node_modules

... and the modules:
sudo rm -rf /usr/local/lib/node*

... and the include modules:
sudo rm -rf /usr/local/include/node*

... and the files in the local /bin:
sudo rm -rf /usr/local/bin/node*

Enjoy a 15-minute break, because you're done

At this point, you can reinstall Node and its package manager if you wish to start over with a clean slate.


This is at least a partial answer to my question. It turns out that I have dropbox in use (for some years now). Since 15.04 if I click on dropbox and click "Open Dropbox folder", it will reproducibly remove the shortcuts on my desktop.

I have been using this click for a long time and only since 15.04 has the problem appeared. I think I need to report the bug both to Ubuntu and Dropbox because I have no way of knowing which side is causing the problem.

At least now I know what to avoid doing to prevent my desktop shortcuts from being removed.

Thanks to Ask Ubuntu for having a place to ask questions. In this case no one was able to help me, but it is very helpful to at least be able to ask. It sure beats banging your head against the wall....


TPM is Trusted Platform Module, you can disable it in BIOS.
Go to Bios settings and search something like secure chip or secure boot and set it to disable.

after that, press F10 and restart pc.

roema


Quick search shows that it's been removed as "un-maintained, buggy, and superseded by backportpackage from ubuntu-dev-tools": https://bugs.launchpad.net/ubuntu/+source/prevu/+bug/948191

See if backportpackage from ubuntu-dev-tools suits your needs


How to make Lenovo Ideapad S10-3s netbook hibernate?

swapon -s will display how much swap you actually have mounted at the moment.

It is possible that you have a 3GB swap partition but for some reason it isn't being mounted.  It'll also tell you if there is anything abnormal about your swap usage.  If you continue to have problems, tell us the output of this command.

The swap partition is mounted in /etc/fstab (typically).

Another thing to keep in mind is that if you selected to encrypt your home directory during the Ubuntu install, your swap partition will also, by default, be encrypted.  Due to the way this is done it's no longer possible to hibernate (it would be difficult to have disk encryption but also allow hibernation and still be secure, and Ubuntu's chosen method of home directory encryption does not support it).

Edit: as seen in the comments, it became apparent that this user had both zRam-based swap (which is like compcache) and disk-based swap, and solved his/her problem by installing zramswap-enabler.


How to create a Live USB key for a SUSE distro on Ubuntu?

If the .iso is a "hybrid mode" image (like most Ubuntu and Debian images these days, have no idea about SUSE), then you can just write it directly to the USB just as if it was a CD-ROM drive.  For instance, using dd.

dd if=imagefile.iso of=/dev/sdc oflag=direct bs=1048576

If the .iso is not a hybrid mode image, then you can use UNetBootin, available from Ubuntu's repositories, which is an easy way to burn an ISO (for a Linux distro) to a USB key.

UNetBootin does not restrict you to using it with Ubuntu only - it will allow you to use an .iso you have previously downloaded, and that .iso can be of any distro.


Is it safe to use apt-btrfs-snapshot for complete system restore on new machine?

OK, I tried it out in a VM. Here's the general gist of what I did:

Create an Ubuntu 18.04 VM in VirtualBox, with a 20 GB disk. Install using the desktop ISO image, and (of course) configure using btrfs instead of accepting the defaults.
Boot into the new system, install apt-btrfs-snapshot. Install some other things too, I did Docker because that's one of the things I wanted to make sure is backed-up. The idea is the backed-up system needs to be obviously different from a fresh install so that we can tell if this actually works.
Make a reference snapshot with sudo apt-btrfs-snapshot snapshot.
Remove the disk from the VM, and create a new disk and install Ubuntu 18.04 on it following the same process as before.
In the new VM, also install apt-btrfs-snapshot, but nothing else (because we're going to restore our backup anyway).
Shutdown the VM, then attach in SATA slot 1 the disk from the first VM. Boot back into the VM and make sure the new instance has booted and not the backup disk (you can check if the things you installed are there or not - they should not be there in the new instance).
Manually mount the root of both the new and backup btrfs disks - I did this through entries in /etc/fstab but it can just be done with mount commands.
Find the name of the snapshot in the backup that you want to restore, something like @apt-snapshot-2018-08-01_08:48:31 - there will be a number of these in the root of the btrfs filesystem.
Make a btrfs subvolume of the same name in the new disk, with a command like sudo btrfs subvolume create /path/to/new/btrfs/@apt-snapshot-2018-08-01_08:48:31
Copy everything across from the backup to the new empty subvolume, something like sudo cp -ar /path/to/old/@apt-snapshot-2018-08-01_08:48:31 /path/to/new/btrfs/
Finally, check the new subvolume is seen with sudo apt-btrfs-snapshot list and then, assuming it is listed, set the restored image to be used on boot, with: sudo apt-btrfs-snapshot set-default @apt-snapshot-2018-08-01_08:48:31
Power off the VM and remove the backup disk. Reboot, and then check the restore has worked. In my case, it did - in particular the Docker images I had tested before the backup worked on the restored machine.

So it seems like it does work to restore to a fresh install from a root subvolume snapshot, as long as the hardware is similar.


Unity Tweak Tool (unity-tweak-tool) can be installed from the default Ubuntu repositories in Ubuntu 13.04 and later, but it is not available in the Ubuntu Software Center for Ubuntu 12.04. The application that is most similar to Unity Tweak Tool in the Ubuntu Software Center in Ubuntu 12.04 is MyUnity.

MyUnity allows one to configure and tune Unity with a pleasant and comfortable graphical interface. MyUnity is a third-party application, not an official part of the Unity project.

sudo apt-get install myunity

The GUI looks like this:


Apache failed to start LSB: Apache2 web server

I also encountered the same error (while working with Saltstack) and managed to solve it. There are four ways.

For some reason your /etc/apache2/envvars is missing:
To solve this, you can create the file manually and add the default envvars content below

sudo vim /etc/apache2/envvars

# envvars - default environment variables for apache2ctl

# this won't be correct after changing uid
unset HOME

# for supporting multiple apache2 instances
if [ "${APACHE_CONFDIR##/etc/apache2-}" != "${APACHE_CONFDIR}" ] ; then
    SUFFIX="-${APACHE_CONFDIR##/etc/apache2-}"
else
   SUFFIX=
fi

# Since there is no sane way to get the parsed apache2 config in scripts, some
# settings are defined via environment variables and then used in apache2ctl,
# /etc/init.d/apache2, /etc/logrotate.d/apache2, etc.
export APACHE_RUN_USER=www-data
export APACHE_RUN_GROUP=www-data
# temporary state file location. This might be changed to /run in Wheezy+1
export APACHE_PID_FILE=/var/run/apache2/apache2$SUFFIX.pid
export APACHE_RUN_DIR=/var/run/apache2$SUFFIX
export APACHE_LOCK_DIR=/var/lock/apache2$SUFFIX
# Only /var/log/apache2 is handled by /etc/logrotate.d/apache2.
export APACHE_LOG_DIR=/var/log/apache2$SUFFIX

## The locale used by some modules like mod_dav
export LANG=C
## Uncomment the following line to use the system default locale instead:
#. /etc/default/locale

export LANG

## The command to get the status for 'apache2ctl status'.
## Some packages providing 'www-browser' need '--dump' instead of '-dump'.
#export APACHE_LYNX='www-browser -dump'

## If you need a higher file descriptor limit, uncomment and adjust the
## following line (default is 8192):
#APACHE_ULIMIT_MAX_FILES='ulimit -n 65536'

## If you would like to pass arguments to the web server, add them below
## to the APACHE_ARGUMENTS environment.
#export APACHE_ARGUMENTS=''

## Enable the debug mode for maintainer scripts.
## This will produce a verbose output on package installations of web server modules and web application
## installations which interact with Apache
#export APACHE2_MAINTSCRIPT_DEBUG=1

Then restart apache service as usual.

sudo service apache2 restart

If your envvars file is ok then it may be a case of missing packages. Reinstall the missing packages using below command, then restart the Apache service.

sudo apt-get -o DPkg::Options::="--force-confmiss" --reinstall install apache2
sudo service apache2 restart

Alternatively you can uninstall Apache and all its config files then reinstall it.

sudo apt-get purge apache2
sudo apt-get install apache2

And finally if all the options above don't work, you can try installing package libapache2-mod-php7.0 or disable the PHP7 module by running

sudo a2dismod php7.0


Slow boot after installing separate distro

I think that the additional partition with the Debian installation is not related to the slowdown. The most likely causes are: corruption of your Ubuntu installation, or bad system updates. The easiest solution is to avoid debugging things at this point. As you haven't invested many hours in configuring your Ubuntu install, I recommend just formatting over and then reinstalling Ubuntu. Also, just to rule out Windows interference, it's currently best to change partitions from within Windows.