how to remove my key (ssh-keygen) when I do not know hostname? (But I know other things)

Nothing to do, except remove the keys you created (~/.ssh/id_rsa and ~/.ssh/id_rsa.pub). A quick summary of how SSH works and the purpose of the various files.

SSH without passwords works with "assymetric keys".
This requires a pair of keys that you generate, one private  (~/.ssh/id_rsa) and one public (~/.ssh/id_rsa.pub).
During the login process, SSH uses you local private key to do something that can be checked on the other system using your public key.
The public key doesn't need to be kept securely. On the other hand the private key should never leave your local system. You can protect it with a password if you think your local system (and its backups) isn't secure enough and someone else could get access to the key.
To identify yourself on other systems, you give them your public key. On these other systems, the userids that you can login to have your public key added to their ~/.ssh/authorized_keys file, which, as its name implies, collects the public keys of all the people that can log in as that userid. This is done either manually with an editor or using the ssh-copy-id utility.
As an added protection (mostly useful when you use a password login AFAIK), the systems you connect to have an identifier. This identifier is sent to your system during the login process. If the identifier is not in your known_hosts file (which is the case the first time you connect to them), you are asked if you accept that identifier, and if so, it is added to your local ~/.ssh/known_hosts. Normally this identifier should never change, so if you are asked again later to accept the identifier, better ask confirmation to some admin.

So, where you are: you have just generated a couple of public/private keys on your local system.

As long as they aren't used anywhere you can just erase them, sight unseen.
If you copied the public key on a system, you can remove it for cleanliness, but it is not a security risk as long as the private key hasn't been compromised.
If someday you suspect that your private key has been compromised (you keep it without a password and somebody accessed your system or your backups), then you should in earnest have the matching public keys removed from the authorized_keys of ids/systems where you copied it (from that point of view, the known_hosts file is a good clue of which systems hold a copy of your public key). Then
you can generate a new pair, and copy the new public key to the necessary systems.
Normally you have no local ~/.ssh/authorized_keys unless you also login on your local system using SSH (but this is rare, and is best avoided)
One case where you want to remove a host from the known_hosts file, is when the identifier of that host changes for legitimate purposes (host is reinstalled or upgraded and the old identifier gets lost in the process, but you should be told by an admin). You then want to be able to add the new id to your known_hosts but this cannot be done as long as the previous id is there. One solution is to erase known_hosts but you'll have to re-accept the keys of all your remote hosts, or you use ssh-keygen -R <host> to remove only the relevant obsolete key.


Should I install 11.10 daily release now or rather wait?

You can do either. Both installs are very similar (I haven't had any problems with the beta) and you will just pick up any remaining updates with your next update. The Beta won't leave any unnecessary files.

You will need around 1.5-2hrs for the download and install, so if you have time, you can easily do it now.

Follow these instructions to update now:

How do I upgrade to the development release (aka. Ubuntu+1)?


How to install Proteus( simulation software) for ubuntu

Proteus is not available for Linux natively.

Although you may be successful in running it through WINE, there is no guarantee that all the features will work, especially since it is a software that requires a lot of libraries to simulate various microcontrollers etc.

The best option to run Windows software which do not have Linux ports is to install a Windows OS, either on a separate partition or as a virtual machine.

Otherwise, you may wish to look at alternatives to Proteus on Linux.


Remove only 1st page from a LOT of pdf files

You can do this with a free program called pdftk, available here.

You can use the following commands to take every PDF in the current directory and copy them to the ‘trimmed’ directory with the first page removed:

mkdir trimmed
for i in *pdf ; do pdftk "$i" cat 2-end output "trimmed/$i" ; done


Authentication Failure when using any VNC Viewer (Windows) with VNC Server on Ubuntu 12.04

I'm not sure if it's OS specific,but I uninstalled Ubuntu and then installed CentOS and followed similar instructions for setting up VNC client - then everything worked.  Unfortunately no definite solution to the original problem.


dpkg: error processing package ubuntu-make (--configure):

Remove the ubuntu-make:

sudo apt-get remove --purge --auto-remove ubuntu-make

Show the available python3-argcomplete versions:

sudo apt-cache showpkg python3-argcomplete

Install the correct python3-argcomplete version (in my case):

sudo apt-get install python3-argcomplete=0.8.1-1ubuntu2

Reinstall ubuntu-make:

sudo apt-get install ubuntu-make


How do I increase the size of Ubuntu which was installed through Wubi?

Even if you found the steps to migrate and resize your WUBI installation, the maximum size is 30GB -by design limitation; which you are already configuring.

If you need a bigger size for your Ubuntu installation, then The answer will be backing up your system\data > perform another installation on a dedicated partition or perhaps a virtual machine > restore your data to.

You can also migrate your WUBI installation to a partition by following this article http://help.ubuntu.com/community/MigrateWubi

But I'm afraid I didn't try it before


Awk script returns "Bad Interpreter" error

The line is not complete and points to the wrong directory, it should be:

#!/usr/bin/awk

Thats called the 'magic-line' or 'shebang' and tells the shell what program is needed to interpret the script.

An other way to run awk is (pointed out by @Knud larsen):

awk -f file.awk [file to be processed]


How to fix: cannot install minitube-ubuntu after full update / upgrade to 14.04?

Once I've disabled PPA http://ppa.launchpad.net/mc3man/trusty-media/ubuntu, the minitube-ubuntu could be installed.


Why are the MeMenu and the messaging applet two separate things?

Answered by MPT in the Ayatana mailing list:

  Only because no-one has done the design work necessary to work out how
  to merge them.

So, hopefully, they can be merged at some point.


Have you started the installation procedure yet?

Shortly after choosing the language you want to install Ubuntu in you are asked if you either want to install Ubuntu next to Windows or want to substitute the existing OS. By taking the first option ubuntu will be installed into a new partition that will be set up.

You also can create your own partition (that is the third and last choice of the installation client) and install Ubuntu into that.

Either way you will not be able to install the system into the same partition as your Windows OS.


How can I change the default color for all the text in the system manually

To change the color on a tty you can use setterm. Example:

setterm -background black -foreground green

If you want this when you log in you can add it to .bashrc otherwise you need to manually do this every time you log in to a tty.

Colors:

[grey||bright][black||red||green||yellow||blue||magenta||cyan||white]

There are more options in the man page.

edit: This will not work if you are already using another color scheme.
You might also be interested in color coding for directories (dircolors): What do the different colors mean in ls?


Screen doesn't turn back on after powersave

Open the Unity Dash and look for "Additional Drivers". Once the program opens, if there are proprietary drivers available for your graphics card besides the X.org driver, try using them. After installing one, you will need to reboot for changes to take effect.


How Do I Create Mime Types For New Documents (Command Line)?

The correct solution can be found --> here <-- , but a foo version is provided below to directly answer the question.

Please pay very close attention to the use of application-x-foo, x-foo, and foo as they change throughout.

Note: When updating the Ubuntu tutorial, it's probably better in an example to distinguish between the foo application, foo the extension and foo mimetype to avoid confusion moving forward. i.e. lmms uses *.mmpz and x-lmms-project, which helped a lot in figuring this out.

 Get a scalable SVG icon (example provided)

wget http://soqr.fr/testsvg/zebra.svg -O ~/Desktop/application-x-foo.svg

 Create a mime-ingest file in XML format:

<?xml version="1.0" encoding="UTF-8"?>
<mime-info xmlns='http://www.freedesktop.org/standards/shared-mime-info'>
<mime-type type="application/x-foo">
<comment>Foo File</comment>
<glob pattern="*.foo"/>
</mime-type>
</mime-info>

 Save this to ~/Desktop/x-foo.xml
 If not already, create a desktop file:

[Desktop Entry]
Version=1.0.0
Encoding=UTF-8
Name=FooGazi
GenericName=Foo Application
Comment=This is my Foo Application
Exec=/usr/bin/foo
# Please change, system-shutdown.svg used only as example
Icon=/usr/share/icons/Humanity/actions/48/system-shutdown.svg
StartupNotify=true
Type=Application
MimeType=application/x-foo;

 Save this to ~/Desktop/foo.desktop

 Deploy the mime description

sudo xdg-mime install --mode system ~/Desktop/x-foo.xml

 Deploy the application launcher

sudo cp ~/Desktop/foo.desktop /usr/share/applications

 Deploy the SVG icon

sudo cp ~/Desktop/application-x-foo.svg /usr/share/icons/gnome/scalable/mimetypes/

 Register the application launcher with the registered mimetype

sudo xdg-mime default foo.desktop application/x-foo

 Update the mime cache

sudo update-mime-database /usr/share/mime

 Update the icon cache

sudo gtk-update-icon-cache /usr/share/icons/gnome/ -f

 As a habit, I also add the appropriate line to /etc/mime.types but please confirm whether or not this is still needed and edit this post to reflect that.
 Log off and then back in.  Both the icon and the association should work.


It seems like I had accidentally added an incorrect foreign architecture to my computer when using the "dpkg --add-architecture" command at a previous date. Below is the incorrect command I had entered:

  sudo dpkg --add-architecture i3836

That is why binary-i3836 was a reoccurring issue. I used the command below to fix the issue:

  sudo dpkg --remove-architecture i3836

I can use sudo apt-get update fine now.


Upgrade to 11.04 failed, how do I repair when it won't even boot?

Right after your bios spalsh press shift that will show your bootloader menu called grub menu which will have something like this listed.

Ubuntu, with Linux 2.6.38-10-generic
Ubuntu, with Linux 2.6.38-10-generic(Recovery Mode)

Try recovery mode and see what errors you get during the boot process Or

press e during grub listing and replace quiet splash with text where you see it. Basically some screenshots with further information on bootloader can be found here. If you have some filesystem errors you may check your filesystem from live-usb or gparted/Disk-Utility from live-usb.

P.S. If you don't mind resetting the configurations, I think using new install is less tedious than recovering. Having said that if you have different home partition, your old settings can be used as well after you install the application for the settings that is. You should recover/backup your important data as @Philippe recommends.


Try right click on panel => panel preferences and changing the row size. This should automatically resize the icons in the panel.


snapcraft build issue: GLIBC wrong version

Figured out the problem, the issue was that I was trying to run $ snapcraft to build but when I used cleanbuild it worked and no errors.

$ snapcraft cleanbuild


Some times when i close the lid of my laptop I get black screen

I personally had this issue solved with a driver update (on a laptop with mixed Intel / nVidia graphics; I updated both the Intel and the nVidia drivers).

If this doesn't solve the problem for you or you can't update the drivers for any reason, the best I can give is a better workaround, i.e. once opened the lid to switch to a TTY with Ctrl+Alt+F1 and then to switch back to the X environment with Ctrl+Alt+F7.


Here are a couple of things to try:

Boot to a Live USB to make sure you still have data, etc. on your main drive.
Use Gparted to make sure the boot flag is still there.
Use Gparted to create a small 4GB or so partition and reinstall Ubuntu to that partition, or to another drive, internal or USB.  (I did this once and accidentally repaired a non-booting drive.)

Edit:

If you have a separate partition for /home, you could try reinstalling Ubuntu on top of where you already installed it.  Your /home will be preserved as long as you don't format it in the process.


Unable to locate package libnginx-mod-http-lua

You are using Ubuntu 16.04, but libnginx-mod-http-lua is in the default Ubuntu repositories for Ubuntu 18.04 and later.


The RAID normally done in BIOS is not full RAID, it is basically "RAID Assistance". It is there to help Windows do RAID as Windows cannot do full software RAID on it's own without some sort of hardware assistance. Linux on the other hand can do software RAID on it's own without any hardware assistance. Trying to use the "RAID Assistance" actually gets in the way and confuses the software RAID. It is generally recommended not to use this "RAID Assistance" when using Linux. (I learnt this one the hard way) As far as I can tell this "RAID Assistance" feature in BIOS's does not bring any performance advantage, it is merely a "compatibility layer" for Windows.


Unable to start X service in ubuntu 20.04 with gtx 1080ti and k80 on board

OK. I found the solution to my case. In short, the reason of X server not starting is that the auto-configuration of X server fails to find the correct display device, i.e. gpu. And this can be fixed by manually set the device in a config file. In particular,

sudo nvidia-xconfig This will generate a config file at /etc/X11/xorg.conf
Next, input command lspci, and find the BusID of the gpu you want to connect your monitor to. Here in my case:

06:00.0 VGA compatible controller: NVIDIA Corporation GP102 [GeForce GTX 1080 Ti] (rev a1)

the BusID is 6:0:0.

Next, in xorg.conf find the following

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BusID          "PCI:6:0:0" # make sure the ID matches the VGA device ID
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

and make sure the BusId in the Device section matches the result of your gpu BusID as shown in step 2.

reboot

Now you should be good to go ;).


Are you sure you hasn't configured BOTH sslh and openvpn to use port 443?
Please check it. Proper way would be to set up openvpn to listen on some other port (say, 0.0.0.0:18000) and configure sslh to redirect openvpn connections to 127.0.0.1:18000. This way you will be able to connect to openvpn directly should sslh fail for whatever reason, but also will be able to use sslh to serve openvpn on port 443.

Also, you might want to post your config for both here.


error in first step of of Ubuntu Deb Pack Installation

Here is the explanation:

Your ‐ isn't really a -, although they look exactly the same! The one in your example is a UNICODE U+2010 whereas what you need is a UNICODE U+0045 (ASCII 45).

Here is a test with your ‐:

$ echo "‐" > test
$ hexdump test
0000000 80e2 0a90

And here is the regular -:

$ echo "-" > test
$ hexdump test1
0000000 0a2d

This command works:

sudo sh -c 'echo "deb http://www.openfoam.org/download/ubuntu $(lsb_release -cs) main" > /etc/apt/sources.list.d/openfoam.list'

or the longer version:

VERS=$(lsb_release -cs)
sudo sh -c 'echo "deb http://www.openfoam.org/download/ubuntu $VERS main" > /etc/apt/sources.list.d/openfoam.list'


Ubuntu 16.10 - new possibilities from desktop to IoT. Can someone explain what is making this version so special to IoT solutions?

See this article for information:
https://insights.ubuntu.com/2016/10/13/canonical-releases-ubuntu-16-10/

Snap packages are able to be packaged for many platforms, embedded systems included. MAAS 2.0 allows better server deployment, etc.


Online upgrade from 12.04 to 14.04 stuck

I had this problem as well but I figured out a way around it.

After the upgrade has stalled look for the process called "frontend" in the process tree of "python->sudo->trusty->trusty->...->...->frontend" that the upgrade-manager is running under. Once you kill this sub-process the installation process will start again and complete cleanly.

This is related to something involving updating of the man-db. It is not related to subversion, or python, or whatever was being unpacked. That was just the last bit in the logs. The problem is something related to man-db and (probably) perl.

Recommending a fresh install as a first course of action is not exactly helpful. That's what you do when problem solving fails. It isn't a solution.


apt-rdepends saith "yes, you can have Nautilus without samba. Even without tango. You want fries with it?":

$ apt-rdepends nautilus|grep -i samba
Reading package lists... Done
Building dependency tree
Reading state information... Done

Just to sure:

sudo apt-get install --no-install-recommends --simulate nautilus

No samba there for me on Xenial 64. Try it for yourself. If there isn't a surprise, do it again without the "--simulate" if you want nautilus.

Steeldriver's comment re recommend vs. depend is totally to the point -
the "--no-install-recommends" avoids stuff you don't have to have. Strictly speaking samba per se isn't even a recommend on my system - I just purged samba to test out of curiosity. But samba-dsdb-modules and samba-vfs-modules are. Still not depends though.

I'm not even sure why I had samba, because it didn't drag anything I remember ever using with it when I purged it. I guess I'll leave it off. Glad I dropped in to this thread.

Wait a second - I see you already HAVE Nautilus. Did you try:

sudo apt-get purge samba

or even

sudo apt-get purge samba*

?

That ought to do it without taking Nautilus. If it does take Nautilus, just re-install Nautilus with the --no-install-recommends as described above.


You do not need to compile it.
Simply use package from repository:
sudo apt-add-repository universe
sudo apt-get update
sudo apt-get install searx

Then run it with searx-run.


Lubuntu Wine IDM set up with Chromium help needed

As it is possible to install and run Windows applications with Wine this should usually not be needed, and it may also lead to instabilities due to an often not 100% compatibility (see Wine database for compatibility issues).

Many Windows programs have their native Linux counterparts, and I strongly recommend searching for these before we decide to give up, and use a Windows program with Wine. Ever so often you may also find that you simply do not need to install any additional application, because Ubuntu already had the best choice installed for you.

A good place for searching is the Ubuntu Software Center, but also we do have many questions here to give advice on applications to replace the Windows counterparts. For a download manager recommendation see:

What download managers are available for Ubuntu?

You will soon find that applications provided from the Ubuntu repositories will nicely integrate with the desktop, i.e. you will easily be able to select any of these applications for standard actions such as downloading, or opening a certain file type.

This will not be the case for Wine applications. In case you really do need a Windows application for a given task we then have to manually define a .desktop file to announce this application to the system. For doing so see the following question:

How does one create a custom application launcher for Wine installed apps?


It doesn't work because /var1/ and "var2" are, respectively, a regexp constant and a string literal.
You can use the value of var1 as a dynamic regexp or computed regexp and the value of var2 as a replacement string by writing gsub(var1,var2) i.e.
$ awk -v var1="$Linea_SF" -v var2="$Linea_EF" '{gsub(var1,var2);}1' "$FILE"
H224:N3-S105:O4H

(you don't need cat ... | since awk can read files directly).


Installing Ubuntu (any distro) onto a iMac G4

There are sometimes community ports, but Ubuntu is not officially supported on Power PC. Please refer to the official wiki for more information.

However, this Ubuntu iso release has the Power PC port that will hopefully work for you.


Postfix can send but not receive mails - Recipient address rejected

Quite honestly - error states quite clearly, where is the problem.
In your virtual mailbox table.

It says that user hasn't been found there, hence incoming mail hasn't been accepted.

I see you're using ldap for virtual users/mailboxes and aliases records - so first of all check if you can connect to your ldap server and, if so - whether your ldap records are in proper order.


bin/bash: bad interpreter: No such file or directory

You’re missing a leading slash making the shebang an absolute path:

#!/bin/bash
# ↑ here

In your case, the shell seems to be searching for ./bin/bash.

The shebang (and also executable permission) is only taken into account if you’re running the script as a program:

$ ./test1.sh

It is ignored if you directly run the interpreter and provide your script as an argument:

$ bash test1.sh

See also: https://askubuntu.com/a/850387/250300


Does Ubuntu 11.04 recognize and work easily on a tablet?

First of all, it would be nice to have the tablet specs of the laptop that you are talking about.

However, I have experienced nice results when installing previous versions of Ubuntu (9.04, 9.10, 10.04, etc.) when installing to an HP Pavilion tx1000, whose characteristics can be reached by clicking here.

In those experiences, everything in the tablet started working right out off the box.

Unfortunately I can't say for Dell or other brands but although everything may work with no hassle at all, you can experience some issues when trying to calibrate the tablet, or even more when trying to use the on-screen keyboard, which was for me the hardest issue that I had to face with the tx1000.

The procedure for installing in a Tablet Laptop is exactly the same as for a desktop or common laptop, but if your tablet brand or make are different than those that I have mentioned over here, you should look for a different answer. Sorry if so.

Good luck!


Trying to copy file from desktop to usr/share/audacious/skins using terminal. What am I doing wrong?

Check desktop is a typo. It should be Desktop. Try to copy as

sudo cp -r /home/noyfb/Desktop/Grey /usr/share/audacious/Skins/

or to move

sudo mv /home/noyfb/Desktop/Grey /usr/share/audacious/Skins/

Also check, the folder is grey or Grey. You mentioned it differently in your question.

-r is necessary, thanks to @jobin.


How do I get the Guayadeque icon to work with the indicator applet in Gnome Classic?

YAY! I found the problem! It was so simple I actually feel dumber for finding the solution. :P

The "Notification Area" applet is what controls the "legacy" icons. It also fixed a few other icons that were missing for other apps.


I have the same exact problem, trying to install ubuntu mini but they dont include wifi module in their mini iso. I have the following solution

1) Use a live ubuntu desktop iso to boot
dd a normal desktop ubuntu iso to a usb
boot the computer with that live usb

sudo cfdisk /dev/sda
sudo mkfs.fat -F32 /dev/sda1
sudo mkfs.ext4 /dev/sda2
sudo mkfs.ext4 /dev/sda3

cd /tmp && wget http://archive.ubuntu.com/ubuntu/pool/main/d/debootstrap/debootstrap_1.0.114ubuntu1_all.deb
cd /tmp && dpkg -i debootstrap*.deb

sudo mkdir -p /mnt/usb
sudo mount /dev/sda2 /mnt/usb
sudo mkdir /mnt/usb/boot
sudo mount /dev/sda1 /mnt/usb/boot
sudo debootstrap bionic /mnt/usb http://hk.archive.ubuntu.com/ubuntu/

sudo mount -o bind /dev /mnt/usb/dev
sudo mount -o bind /dev/pts /mnt/usb/dev/pts
sudo mount -t sysfs /sys /mnt/usb/sys
sudo mount -t proc /proc /mnt/usb/proc

sudo cp /etc/apt/sources.list /mnt/usb/etc/apt/
sudo chroot /mnt/usb apt-get update

sudo chroot /mnt/usb apt-get -y install grub-efi-amd64 sudo make git ssh linux-firmware linux-image-generic nano intel-microcode curl software-properties-common unzip network-manager net-tools wpasupplicant
sudo chroot /mnt/usb apt-get -y install alsa-utils pulseaudio

# add your packages here, Install your driver here
# sudo chroot /mnt/usb apt-get -y install papirus-icon-theme cpanminus gexec libcpan-distnameinfo-perl libcpan-meta-check-perl libfile-pushd-perl liblocal-lib-p$
# sudo chroot /mnt/usb apt-get -y install xorg openbox obconf lxterminal conky tint2 feh pcmanfm xarchiver chromium-browser gmrun
# sudo chroot /mnt/usb apt-get -y install viewnior ttf-wqy-microhei
# sudo chroot /mnt/usb apt-get -y install transmission-gtk rar unrar zip evince scrot

sudo chroot /mnt/usb passwd

sudo echo -e "/dev/sda1  /boot       vfat    umask=0077      0       1" | sudo tee -a /mnt/usb/etc/fstab
sudo echo -e "/dev/sda2 /               ext4    errors=remount-ro 0       1"  | sudo tee -a /mnt/usb/etc/fstab
sudo echo -e "/dev/sda3 /home               ext4    defaults        0       2"  | sudo tee -a /mnt/usb/etc/fstab

sudo chroot /mnt/usb
# Following in chroot environment
apt-get install grub-efi-amd64
grub-mkdevicemap
grub-mkconfig -o /boot/grub/grub.cfg
update-grub
grub-install --target=x86_64-efi  --bootloader-id=grub_uefi --efi-directory=/boot

sudo shutdown -r now

To get online

sudo nmtui

This is sort of like how you install arch. You can use arch wiki as a references

2) Use debian mini so with firmware
https://cdimage.debian.org/cdimage/unofficial/non-free/cd-including-firmware/
But of course this will install debian instead.


Create randomly encrypted swap when installing 14.04.1?

Thank you, liquidat. That was not quite what I was looking for, but it did help me figure it out. Here is what I did, which seems to have worked:

At installation, set up three partitions:

/dev/sda1: 512 Mb Ext2, mapped to /boot.
/dev/sda2: 4096 Mb unused partition, of type Linux (0x83).
/dev/sda3: Remaining space encrypted Ext4, mapped to / (file system root).

This installed Ubuntu without a swap space. After installation, I followed the instructions from Encrypted Swap Partition for 14.04 to install a randomly encrypted swap partition in /dev/sda2. I modified the commands slightly to follow the example from my 12.04 installation:

$ sudo cryptsetup -d /dev/urandom create sda2_crypt /dev/sda2
$ sudo mkswap -f /dev/mapper/sda2_crypt

Add/edit the following line to /etc/crypttab:

sda2_crypt /dev/sda2 /dev/urandom cipher=aes-cbc-essiv:sha256,size=256,swap

Add/edit the line in /etc/fstab:

/dev/mapper/sda2_crypt none swap sw 0 0


How to download software for Ubuntu from Android?

You can successfully install software without an Internet connection if the software is fully packed with all met dependencies of which is something very hard to achieve!

Otherwise, you have to manually install all dependencies which is something very painful as most packages need many dependencies of which these dependencies packages need other dependencies in order to work (the chain goes on).

The only possible solution to this is using Portable Package Manager like CamicriCube or Kery, but the problem is they are not available for the Android OS!


There are plenty of installation guides on the website; I think you should take a look at those.

Besides, it looks like the package is available in the repository, so you can install it with

sudo apt-get install moodle

Take a look at this Step-by-step Installation Guide for Ubuntu. Still, if you insist on installing from source, their own documentation for Installing Moodle may help. Try those and comment/ask for help with any problems you encounter following the instructions.


What application is needed to find an email host

Use dig command from dnsutils package, if it's not installed then install it using:

sudo apt install dnsutils:

And to use it:

dig -t mx hostname.com

For example:

$ dig -t mx gmail.com  +short

20 alt2.gmail-smtp-in.l.google.com.
40 alt4.gmail-smtp-in.l.google.com.
10 alt1.gmail-smtp-in.l.google.com.
5 gmail-smtp-in.l.google.com.
30 alt3.gmail-smtp-in.l.google.com.


LibCurl: how do I compile the example code?

copy the source file to a directory where you have write permissions (so that the compiler is able to create the executable) e.g.

mkdir ~/src && cd ~/src
cp /usr/share/doc/libcurl4-doc/examples/ftpget.c ./

compile and link the file using gcc

gcc -Wall -o ftpget ftpget.c -lcurl

This will create an executable called ftpget which you should be able to run from the current directory using ./ftpget


type French accents with US international keyboard

Use the keyboard layout called English (international with Alt Gr dead keys). (Do this by going to System Settings > Keyboard > Layout settings, and then add the layout you want with the + button on the bottom.)

This way, the keys to input the characters ', ", `, ~, and ^ become "dead keys" while you hold pressed Alt Gr. After releasing the key combination with Alt Gr, no characters will be print (hence "dead"), but inserting a letter afterwards will yield a variation of the base character of the letter, in accordance with the dead key you pressed before; for example, é, ë, è, ẽ, and ê for e (respectively). (If you have no explicit Alt Gr key, just use the rightmost Alt key.)

So in summary, to insert a symbol

press and hold Alt Gr,
press the modifier key / key combination; e.g., `,
release all keys pressed so far, and
press the base character key; e.g., E for è.

Note: You can also enter an acute accented vowel by just pressing Alt Gr + (vowel).

(Source: this post on french Ubuntu forums.)


Alright, reinstalling did work:
I used:

  sudo apt install --reinstall thinkfan


Desktop lagging and general problems with an ATI X1550

In the dash.. when you type AMD do you see the the AMD Catalyst Control Center (Administrative)? If 'yes' login and click on 'Display Options' and 'Tear Free'. You want to disable 'Tear Free'.


SED or something to delete everything after first space up to `|`

With sed:

$ stat --printf='%A|%U|%G|%s|%y|%N\n' /etc/profile | sed 's/ [^|]*//'
-rw-r--r--|root|root|575|2015-10-23|'/etc/profile'

Which simply replaces a space followed by non-| characters with nothing.


Not sure what browser you are using, but if Firefox, have you tried something like Greasemonkey ? That might be a good place to start. You can control the way web pages display utilising that add-on.If you go the user scripts, might find one that can work for you as well.

HTH


How do I open .cpp file from the github directory?

You can open the file in any text editor. Try:

nano file_name.cpp


Default folder/file created ACL permissions not correct

you have to set the default for the user also:

setfacl -R -d -m user:ftpaccess:rwx html

the above command will set the default for the existing folder recursively, if you want apply this ACL for files and folder remove the -d options.


How to move grub from one disk to another?

@oldfred's comment and linked worked perfectly.  It did reset some of the customizations I had, but I was able to fully disconnect the old hard drive.  For reference, if you are having issues after copying or moving a disk, look at this post for more information that should help.


How do I find the gear icon to change from GNOME to Unity in 17.10?

It's hidden a little bit:

In my VM login, you can see the standard screen - after I choose a user, you can then see the 'gear' icon... as shown below


See https://wiki.ubuntu.com/Membership

  "Contributions are valued and recognised whether you contribute to artwork, any of the LoCoTeams, documentation, the forums, the answers tracker, IRC support, bug triage, translation, development and packaging, marketing and advocacy or anything else."


Set system clock to local sidereal time (the time needed for astronomy)

What you seem to be looking for is called "Apparent solar time" and will not be part of the OS. You may be able to use a Search Engine to locate an application or algorithm that will help you calculate this based on GPS coordinate.

I did a quick check on Google and saw that the National Oceanic & Atmospheric Administration has a web page at http://www.esrl.noaa.gov/gmd/grad/solcalc/ that may help you with this.


How to make an executable require root password?

Rather than touching the current shell script, you can make a wrapper to call it with more permissions.

Save the script from below, make it executable (e.g. chmod +x mysudowrapper.sh), and use it like this:

./mysudowrapper.sh /path/to/originalscript.sh

Then make the originalscript.sh only runnable by root:

chown root:root /path/to/originalscript.sh
chmod go-x /path/to/originalscript.sh

Test it:

/path/to/originalscript.sh
bash: /path/to/originalscript.sh: Permission denied

Via wrapper script as above should work. From here you should be all set.

#!/bin/bash
# Wrapper to run commands with sudo. Uses gksudo in a GUI environment, falls back on
# plain sudo in non-GUI environment.
# Info: http://askubuntu.com/a/244690/88802
# Author(s): Gert van Dijk
# Disclaimer: No warranties whatsoever. I'm not responsible for any damage here.
# Purpose of this script is to *demonstrate* a wrapper to run other commands.

GKSUDO=/usr/bin/gksudo
SUDO=/usr/bin/sudo
gui_sudo () { # Run command with a GUI-capable sudo-wrapper
    $GKSUDO -- $SUDO "$@"
}

plain_sudo () { # Run command with the plain sudo wrapper
    $SUDO "$@"
}

has_gui () { # Checks for whether GUI is available via the $DISPLAY environment
    if [ "$DISPLAY" != "" ]; then return 0; else return 1; fi
}

has_args () { # Checks for valid amount of arguments
    if [ "$1" != "" ]; then return 0; else return 1; fi
}

print_usage () { # Prints usage
    echo "Usage: $0 <command> [args]"
}

if has_args $@; then
    if has_gui; then gui_sudo $@; else plain_sudo $@; fi
else
    print_usage; exit 1
fi


Ubuntu 18.04 Bluetooth Discovery not working [0cf3:e004]

My Dell Inspiron 15 7000 laptop updated to LTS 18.04.04 after which the Bluetooth adaptor stopped playing. Selecting the "On/Off" GUI toggle didn't work, and I had the "no default controller available" message as you have. I used GRUB to enter system settings and disabled my on-board camera. Et voila...BT returned. I don't know linux well enough to debug this, but I hope that it may help eliminate things for you.


How to remove pre-installed ubuntu and and install another OS?

Wipe the HD first using Diskpart from Windows 7 DVD: SSD / HDD : Optimize for Windows Reinstallation

Follow these tips to get a purrfect clean reinstall - use the ones which apply: re-install windows 7

SOURCE : http://www.sevenforums.com/installation-setup/150731-install-windows-7-over-ubuntu.html


I am unable login in grooveshark via , i am not a premium user, do you think that is the reason

"User ***@gmail.com doesn't have a Grooveshark Anywhere account"

It's what it shows when I try to log in with my Grooveshark account. So yes, it seems you need to be premium to use Grooveshark through Clementine.


Installing boot repair or start-up manager may solve your problem.. In these softwares there is an option to fix the resolution of GRUB.. All the best

Either add ‘ppa:yannubuntu/boot-repair’ to your Software Sources via the Software Centre or, for speeds-sake, add it using a new Terminal session:

sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair

To install Start-up manager  do the following
In a terminal, if the universe repository is enabled, run:

    sudo apt-get install startupmanager

Source:https://help.ubuntu.com/community/StartUpManager


Your problem sounds like this bug:

https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/848164

Although the bug hasn't been fixed yet, a couple solutions have been posted.  This one includes a step-by-step guide:

http://www.thefanclub.co.za/how-to/how-auto-connect-ubuntu-1204-gsm-mobile-broadband-connection-on-boot-startup-service

Regarding the power issues, I suspect the computer isn't going to sleep, although you can check power management settings by going to System Settings... (accessible by clicking the gear icon in the upper-right side of the screen) --> Power.

My suspicion rather is that your screen is going to sleep.  You can adjust this by going to System Settings... --> Brightness and Lock.  I wouldn't recommend completely disabling turning off your screen, but maybe instead set it to a longer time.  You could also  disable having to re-enter your password by turning Lock to off.


Two Ubuntu partitions with different swap partitions

It's a waste of space - when installing the second Ubuntu you could've just pointed it to the existing swap partition. Actually, I even think the installer automatically configures an existing swap partition to be used if it can find one.

To fix the situation (well, if you consider it a problem), you need to open /etc/fstab file of one of the ubuntus, locate the line which mentions "swap" and change the device name (or partition UUID) there.

The line would look something like

# /dev/sda2
UUID=69222dd6-31ea-488e-a4c1-8f5a5fbba098 none            swap    sw              0       0

so you can change it to

/dev/sdb5 none            swap    sw              0       0

or, even better, find the UUID of the swap partition and use it instead:

sudo blkid /dev/sdb5
/dev/sdb5: LABEL="SWAP-sdb5" UUID="69222dd6-31ea-488e-a4c1-8f5a5faac456" TYPE="swap"


I can't test on my laptop but,

  NOTE: IOMode "wb" is ignored when employing blockio as it performs no caching.

  WARNING: IOMode=wb could lead to  serious  data  loss  from  an  unexpected  system failure (power loss, system crash). Use at your own
  risk!

If you are using blockio switch to fileio as this link documents:

http://manpages.ubuntu.com/manpages/trusty/man5/ietd.conf.5.html


16.04: Virtualbox Installation in Chromebook

I re-flashed my Acer Chromebook with SeaBIOS and installed the latest Ubuntu on it (18.04). It works fine, though it doesn't have 'sleep' mode. I'm not sure if that is due to the hardware or the 'SeaBIOS'.

Maybe that's an option rather than using Virtualbox.


Ubuntu 14.10 keeps freezing without real reason

Try when switch to tty2 ALT+F2 login and reinstall Xorg

sudo apt-get install --reinstall Xorg

any change?


i want to run single o.s ,how to install ubuntu?

If you really want to get rid of Windows do as Ed Manet said, the thing is that you have to be sure to repartition the booting hdd, it´s plain simple using the Ubuntu GUI while installing. I will recomend to NOT USE the manual partition method unless you know what are you doing.


Why does bluetoothd show version 5.37 after installing Bluez 5.45?

If you look at the contents of the bluez package you'll note that bluetoothd and bluetoothctl are seperate programs, not to be confused with the version of the package. It's not uncommon for a collection for programs in a package to have their own separate versions. In order to insure that you aren't using an out pf date version of one of the aforementioned programs you could use which to insure that you are launching the one that you installed by checking the location against the file list shown in the first link that I provided. You'll see that which bluetoothd should respond with /usr/sbin and which bluetoothctl should respond with /usr/bin/ if you get those results odds are good that nothing is wrong. Unless you've used a PPA or installed bluez by compiling it yourself, in which case your question requires further detail.


Ubuntu 16.04 - only connecting to ethernet, no wifi option

modprobe: ERROR: could not insert 'wl': Required key not available

This is the subject of a recent and still open bug in Ubuntu: https://bugs.launchpad.net/ubuntu/+source/bcmwl/+bug/1572659

It appears that the only solution so far is to enter the computer's BIOS and turn off Secure Boot.

To do so roam around the options after booting your windows machine in F12 mode, until you find a Secure Boot switch and turn it off. Then exit and boot Ubuntu normally

Secure Boot is a security standard developed by the PC industry to help make sure that your PC boots using only software that is trusted by the PC manufacturer

Reboot. Your wireless should now be working.


Installing ubuntu os on a different drive than windows os during dual boot setup

Yes, it can be done.  My main PC has Windows 8.1 installed on one physical drive and Ubuntu 14.04 LTS installed on a different physical drive.  There is a third physical drive which is accessible from either OS.  This all works great.

However, both OS's did store their EFI boot information in the same partition on one of the drives.  I do not know if it has to be this way. I had created an EFI partition on Ubuntu's physical drive, but the installer used the one on the Windows physical drive. I was told this might happen, and it did.

I have the shared physical drive formatted as ntfs, because this started out as a Windows PC.  This may be required anyway, because I don't think Windows can use an ext4 formatted partition.  I am not 100% sure of that though.

As you can tell, I am certainly no Linux expert, but with a great deal of study and prep, and the help of people on this site, I managed to do this installation without any problems.  Some of the advice I followed was in answer to this question.


In Code::Blocks if you are using the GNU gcc compiler, you will probably need to add the -pthread compiler flag to both the compiler and linker options (under `Project --> Build options...)


Uninstall Ubuntu from dual boot (separate drives) with Windows 10, fix Windows boot

I hope that you didn't deleted ubuntu yet. You need first to open gparted (sudo apt-get install gparted) , go to your hard disk with windows and ubuntu , and delete boot flag from ubuntu partition and set it to windows. Now it will boot directly in windows. Now in Windows , you need to delete the ext4 partition (with ubuntu). For partition on windows see this tool : http://www.partition-tool.com/


With sed you can do:

ping 192.168.1.1 | sed -n 's/.*time=\([^ ]*\).*/\1/p'

That simply looks for the longest stretch of non-space after time=, uses parentheses to capture it so we can later refer to it as \1 and just replaces everything on the line with whatever was captured. The -n (don't print by default) along with the /p (print if this worked) at the end of the substitution operator ensure we only print relevant lines.

I wouldn't use sed for this though, other tools are simpler here. For example:

grep

ping 192.168.1.1 | grep -Po 'time=\K\S+'

Perl

ping 192.168.1.1 | perl -lne '/time=(\S+)/ && print $1'

awk

ping 192.168.1.1 | awk -F'[= ]' '/time=/{print $(NF-1)}'


How to create a link file with custom picture?

Create a application launcher. For this save the following to a file with .desktop extension. Make it executable (chmod +x filename)

[Desktop Entry]
Encoding=UTF-8
Name=askubuntu.com
Type=Link
URL=http://www.askubuntu.com
Icon=/usr/share/pixmaps/firefox.png

change /usr/share/pixmaps/firefox.png to your icon, http://www.askubuntu.com to your link


Be sure you have the ports open to public. I use ufw and can see the status of my ports with the command ufw status. Reference: UFW Essentials: Common Firewall Rules and Commands | DigitalOcean
check that your sites-available are also in your sites-enabled
How To Configure the Apache Web Server on an Ubuntu or Debian VPS | DigitalOcean

After changes be sure to restart your apache2 server. Your router also needs to allow access to the ports on your computer. You can pretty much follow the guides on the VPS type servers. They are the same for a local hosting computer.


Google Chrome vanished from applications launcher

Open Terminal (press Ctrl+Alt+T or search for "Terminal" in the Dash) and write:

google-chrome &

This should work, otherwise it will show the problem. If it launches, you can lock it's icon on the launcher just by moving it towards (I usually place it above Firefox).


Should I get rid of these packages or should I not?

If your computer is working as you like, and does not currently 'crash and burn', it should be fine to remove those packages. To quote the manual for apt-get (man apt-get):

  autoremove
       autoremove is used to remove packages that were automatically installed to satisfy dependencies for other packages and
  are now no longer
             needed.

The problem with this is that is it thinks those packages are no longer needed, as packages with those packages as dependencies are not installed, etc. This is only designed to remove supposedly unneeded packages, with the flaw that they are sometimes wanted (e.g. skype-bin). Those packages also only amount to 0.1 Gigabytes, so will not take up loads of space.

If you want to remove some you think you don't need, you can remove them individually with sudo apt-get remove .... Leaving them installed should be fine, it is rare that something just being installed to cause damage.

And if you do decide to remove those packages, hopefully reinstalling them afterwards should resolve any issues - just make a note of what will be removed.


Creating a virtual machine to test things is a briliant idea, I wish more people would do that instead of corrupting their main install. If it is possible for your use case, most probably YES, but you're not being very specific. If you know you want an extra partition on forehand, you can create it during install of the VM. VirtualBox is a good application for running VM's and it is in the standard repositories.

The fun about virtual machines is that you can completely mess up things inside a VM, while your host OS stays up running stable. Worst case scenario is that it runs somewhat slower because the VM is using a lot of CPU or (disk) IO.

Personally I always have a few VM's installed, just to test things.

In many modern PC's you can enable VT-x or AMD-V extensions, which will dramatically improve performance of virtual machines. Refer to the manual of your motherboard for this.


How do I make an entire directory executable?

Another good option is Incron. It works on inotify with specifiable conditions for a given location.

So I can say watch this folder, when you see a file created, run a command.

Just as a sample incrontab...

/path/to/scripts IN_CREATE chmod +x $@$#  # <--- this arcane bit is path ($@) + file ($#)

One could similarly use the path/file as arguments to a bash script to allow it to filter by .py extensions if needed.


How to re-size partitions without space directly in font of them?

You have to do this in steps.

First add the unallocated space to the extneded partition, sda4 -> apply changes

Next you have to move your partitions one at a time until the unallocated space is adjacent to your / partition. You have to do it is steps -> move a partition, apply changes ... move a partition -> apply changes


How to add Top Bar menu; File, View, History, Tools...for applications in 18.04?

The feature you are describing is called Ubuntu Global Menu.

It's available here:
Gnome Global Application Menu(HUD for Gnome)

There are a number of ways to install it.  But I found the most convenient way is to use the Chrome Extension interface.

You can do this by adding the Chrome support extension to Ubuntu 18.04 with this command:

$ sudo apt install chrome-gnome-shell

Then turn on the feature from Chrome.  You'll have to reboot to make the changes come into effect.

I tested it on both a fresh install of Ubuntu 18.04 LTS and an Version upgrade to 18.04 LTS (from 14.04 LTS).  They both worked fine.

After the reboot, you can turn the feature on and off from the Chrome Extensions page without rebooting.

There are some comments concerning problems in the past when it was still in the development.  As far as I can see the bugs has been worked out.  The recent comments are positive.


Bluetooth mouse has jittery polling rate

Removing the usbhid module does not disable my mouse, so it does not affect bluetooth.  Some threads (1, 2) mention that setting /sys/kernel/debug/bluetooth/hci0/conn_max_interval, conn_min_interval and conn_latency should work, but they do not for me. Setting the same parameters via hcitool does work. Connect the mouse, and obtain the handle from the bluetooth connection with hcitool:

# hcitool -i hci0 con
Connections:
    < LE 12:34:56:78:9A:BC handle 3585 state 1 lm MASTER AUTH ENCRYPT

Then set low values for min, max and latency as above:

hcitool lecup --handle 3585 --min=6 --max=7 --latency=0

hcitool notes the factor for min and max is 1.25ms, so this should accept polling rates with an interval of 7.5ms - 8.75ms.

As the settings only apply to the bluetooth connection, the solution immediately stops working after the mouse disconnects, so if anyone has a more permanent solution I would love to hear about it!


Ubuntu 11.10 running in windows 7 (wubi) AND on a separate partition

Whenever you install Ubuntu in a dual boot (non-Wubi), it replaces your Windows bootloader with Grub. Grub's bootloader is more complex than Windows' and has to load up modules from the Ubuntu partition. So, if you delete the partition, Grub will fail to load successfully, and will be unable to boot Windows. Instead you'll see a grub rescue prompt.

So the first step in uninstalling is to replace the Grub bootloader with a Windows equivalent.

To install a Windows bootloader, boot Windows and create a Repair CD. Boot from the repair CD (or from your original Windows DVD) to a repair prompt and run:

bootrec /fixmbr

(If you use Windows XP then the command is: fixmbr)

If you can't boot Windows and can't create a repair CD, you can install something like lilo which works the same. Boot from an Ubuntu CD/USB and select "Try Ubuntu", connect to the internet and drop to a terminal (Ctrl+Alt+T):

sudo apt-get update
sudo apt-get install lilo
sudo lilo -M /dev/sda mbr

Note, when you install lilo it will popup a big warning. You can ignore this - Tab to OK and hit enter. Also, if you don't boot from /dev/sda change as appropriate.

Once you're replaced the bootloader, make sure that the computer boots straight into Windows. After that you can go and delete the Ubuntu partition and swap partition and reclaim the space etc.

Edit

If you install Ubuntu as a dual boot and find that Windows no longer boots, then run the bootinfoscript. If you see something like this:

sda1: __________________________________________________________________________

    File system:       ntfs
    Boot sector type:  Grub2 (v1.99)
    Boot sector info:   Grub2 (v1.99) is installed in the boot sector of sda1
                       and looks at sector 856028928 of the same hard drive
                       for core.img. core.img is at this location and looks
                       for  on this drive. No errors found in the Boot
                       Parameter Block.
    Operating System:
    Boot files:        /bootmgr /Boot/BCD

Then it means that grub has overwritten the Windows boot sector and Windows cannot boot. Sometimes it just goes straight back to the grub menu, but not always. First, file a bug as this should never happen, and then fix it either by booting from a Windows repair CD and, from a repair prompt, run:

bootrec /fixboot

Or, from Ubuntu, you can recover the backup boot sector... First install testdisk:

sudo apt-get install testdisk
sudo testdisk

Then restore the backup boot sector using this guide to the testdisk screens:

First   screen:  Select "No Log" and press enter.
Second  screen:  Select the hard drive containing  the Windows system partition and  choose "proceed".
Third   screen:  "intel"
Fourth  screen:  "advanced",
Fifth   screen:  Select the Windows system partition  and choose "boot"
Sixth   screen:  "BackupBS"
Seventh screen:  type "Y" to confirm

Edit 2

If you run the bootinfoscript and see something like:

sda2/Wubi: _____________________________________________________________________

    File system:       ext3
    Boot sector type:  -
    Boot sector info:
    Mounting failed:   mount: wrong fs type, bad option, bad superblock on /dev/loop0,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

Then it indicates some internal file system corruption in the root.disk. What you need to do is fsck the root.disk. (I'd also recommend running chkdsk /f in Windows beforehand for good measure because there could be corruption there as well).

In your particular case you can mount and fsck the root.disk from your other install:

sudo mount /dev/sda2 /mnt
sudo fsck /mnt/ubuntu/disks/root.disk
sudo umount /mnt

Note: you can supply options to fsck such as -fvy. (force/verbose output/answer yes to all prompts).


Is there a way to install apt packages which doesnt require root permissions atleast, without sudo rights, and inside the home folder?

You may download the package directly with apt, and extract the files with dpkg, but with most bigger programs, you have to manually adjust tons of config files to match the different environment.
apt download <apt package name>
dpkg -x <package file name> <destination directory>

For example:
apt download x11-apps
dpkg -x x11-apps_7.7+7_amd64.deb ./


Doing an ssh-add upon ssh/slogin if key is not in ssh-agent?

I worked out a solution for this via the bash shell.

Add to .bashrc:

check-ssh-add() {
if [ "$DESKTOP_SESSION" == "" ]; then
  if [[ `ssh-add -l` != *id_?sa* ]]; then
    ssh-add -t 5h  ## 5 hour ssh-agent expiration
  fi
fi
}

slogin() {
check-ssh-add
/usr/bin/slogin $@
}

ssh() {
check-ssh-add
/usr/bin/ssh $@
}

scp() {
check-ssh-add
/usr/bin/scp $@
}

sftp() {
check-ssh-add
/usr/bin/sftp $@
}


How do I download things from the source repository?

First - create a working folder to download the source in

mkdir ~/working_dir
cd ~/working_dir

The simplest way is to use the syntax apt-get source [foo] where [foo] is the package name.

For example - if you wanted to see the source of nautilus you would use

apt-get source nautilus

basic development tools

Obviously - if you are intent on playing with code changes you need a few extras.

sudo apt-get install devscripts build-essential fakeroot

building packages

To get install the development packages and dependencies use the syntax

sudo apt-get build-dep [foo]

Finally - to build the debian package

debuild -us -uc


Ubuntu 14.04 Disable automatic network connection until after login

If you enable All users may connect to this network when creating a network profile, then that profile is always available, even if no one's logged in. And Network Manager will try to connect to it even before you log in. If you disable it, it will only connect when you log in. This has the effect that no other users (logged in or not) can connect to it if you are not logged in.

Sometime in the distant past, the text was "Available to all users", I believe, but that seems to have changed.


Thank you for your answer, I found it, the problem was my partition table was wrong, I solved using Device===>Create a partition Table===>GPT and work well.

Solved problem.

Thanks to all.

gparted


Trouble with Dual Booting Windows 8 and Ubuntu 13.04

while installing ubuntu you have to mount the partition you want it to install on as / (root drive). you can have more partitions for /home, /usr, /var and any other folders / subfolders you would want to keep if you reinstall / change linux distribution.

hope this helps


The panel date/time Applet doesn't show the evolution agenda's events

You can enable the calendar in the second tab of the date & time preferences (which you can access from the item at the bottom of the menu).


How do I change the color of the Unity upper panel?

Method 1
The top panel (for which the proper term is "menu bar") in Unity gets its theme from the currently set GTK+3 theme. Notice that depending on whether you select Ambiance or Radiance the color of the menu bar changes to match your window titlebars. So, one option is to simply find, install, and select a different GTK+3 theme. However, this also changes the theme for the rest of your desktop.
Method 2
An alternate solution you may try requires a little bit of work, but could potentially give you a lot of control over how the end result looks. The following method describes how to change the appearance of the menu bar by making it transparent and modifying your wallpaper to get the look you want:

Change your menu bar opacity using the configuration tool of your choice. You can do this using CCSM if you're brave enough, or you can use a safer alternative. In this example, I'm using Ubuntu Tweak. Once Ubuntu Tweak is installed, click the Tweaks button in the toolbar, and select Unity under the Desktop category. Look for an option near the bottom for "Panel opacity", and turn it down; the lower, the better.

Note: if you turn the panel opacity all the way down to 0.00, you will should get the best effect (i.e. complete transparency) needed for the rest of these steps, but you run the risk of running into this bug, which will turn your global menu text an ugly black color until you increase the opacity again. If you encounter this bug, please mark yourself as affected there.

Create a panel background of your choice. There's many ways you can do this (and the next step) using the image editing software of your choice. (My personal recommendation is GIMP, though it has a bit of a learning curve.) You'll want your panel background to be 24px high (the height of the menu bar), and as wide as your display in pixels. If you desire, you can find a pre-made panel background online instead and skip to the next step.

Tip: If you are unsure what resolution your display is for this step or the next, you can easily check by clicking the Displays... option under the power cog in the top-right corner of your screen and looking at what is currently selected under Resolution.

Get a wallpaper that is the same size as your display and overlay the panel background at the top. The idea here is to create a new wallpaper which will fit your display in such a way that you can see your custom panel background right along the top of the screen underneath the menu bar, giving the appearance that the menu bar actually looks like that. Again, feel free to use the image software of your choice.

Set your customized wallpaper as your new desktop background. You can change your desktop background under Appearance > Look in System Settings by either going through the power cog or by right-clicking your desktop and choosing "Change Desktop Background" from the menu. Alternatively, you can simply double-click your newly-created background file in your file manager to open it in Image Viewer and select Image > Set as Desktop Background from the global menu or HUD.


Evolution : relaying denied in ubuntu 14.04.1

This error is a very common error which comes from the mail server you are trying to send email through.

Possible reasons include

username / password for server not set
you use the mailserver of your ISP but are connected through another ISP

Call your ISP / the server admin and ask them how to proceed.


drive not working in clean ubuntu 14.04.1

Test this:

Open a terminal,Press Ctrl+Alt+T

Run it:

sudo -i
chmod -Rf 777 /media/private
chmod -Rf 777 /media/project


Found the answer I used in 17.04:

How to disable systemd-resolved in Ubuntu?

It was systemd-resolved causing the DNS resolution problem. Following the instructions there to disable the service (and direct NetworkManager to use a different resolution service) has brought everything back up again.


How do I install no-ip DUC on ubuntu 14.04?

no-ip Ubuntu 14.04

sudo apt-get install noip2

could not found the package in a repository. So, to install noip2 you have to:

sudo -i
cd /usr/local/src/
wget http://www.noip.com/client/linux/noip-duc-linux.tar.gz
tar xf noip-duc-linux.tar.gz
cd noip-2.1.9-1/
make install
rm /usr/local/src/noip-duc-linux.tar.gz

To config defaults noip2 with capital C

sudo /usr/local/bin/noip2 -C

To change time interval noip2 with capital U

sudo /usr/local/bin/noip2 -U 120

To restart

sudo /usr/local/src/noip-2.1.9-1/debian.noip2.sh restart


This tutorial is a step-by-step configuration of NAT with iptables:

Source: http://www.howtoforge.com/nat_iptables


SCP over SSH with no password - cannot get it to work

It seems like you have copied the root key to the remote server, while the regular user key wasn't copied correctly.

ssh and scp should provide the same feedback (with the difference of login-into-remote-server vs. copy-file-into-remote-server)

When the key-pair will be copied as required to the remote server, the scp command will be:

scp local-file-name user@remote-host:/full/path/remote-file-name

In order to copy the user key to the remote server, you can use ssh-copy-id

  Note: You should replace the mykey in the below command, with the
  filename of your key-file

Copy the key to a server

Once an SSH key has been created, the ssh-copy-id command can be used to install it as an authorized key on the server. Once the key has been authorized for SSH, it grants access to the server without a password.

Use a command like the following to copy SSH key:

ssh-copy-id -i ~/.ssh/mykey user@host

This logs into the server host, and copies keys to the server, and configures them to grant access by adding them to the authorized_keys file. The copying may ask for a password or other authentication for the server.

Only the public key is copied to the server. The private key should never be copied to another machine.

Test the new key

Once the key has been copied, it is best to test it:

ssh -i ~/.ssh/mykey user@host

The login should now complete without asking for a password. Note, however, that the command might ask for the passphrase you specified for the key.
Troubleshooting


Unable to login after modifying .profile

When you log into recovery mode with grub, you'll have to remount / as readwrite, like:

mount -t ext4 /dev/sda1 / -o rw

you should look at the fstab

cat /etc/fstab

to see if you are supposed to use /dev/sdaX or /dev/sdbX or UUID or Device-by-id syntax.  where X is the partition of /.  After you do get in, I recommend creating a secondary account.  Make sure to add it to the additional group "wheel" or "root", but not as the main group.  Also, make sure you use visudo to add this user to the "sudoers".

Additionally, you can type

sudo passwd

to unlock your root account to prevent having to go through all this trouble again. Please do not log into your desktop as root.


Why doesn't "osinfo-query os" detect Ubuntu 18.04?

You could always take it from the GitLab site then replace it.

Might need to install the git, osinfo-db-tools, intltool and make first

sudo apt install osinfo-db-tools intltool make git

Clone the osinfo from the GitLab page

git clone https://gitlab.com/libosinfo/osinfo-db

Go to the osinfo-db folder

cd osinfo-db/

Prepared the os files

./prepare-release.sh

During the prepare it showed the following line:

osinfo-db-import --root /home/terrance/builder --system osinfo-db-20180830.tar.xz

So, I went to that folder cd ~/builder and it contained a usr folder.  All I had to do was copy that folder to the root and it updated

cd ~/builder
sudo cp -Rv * /

And now it detects Ubuntu 18.04

terrance@terrance-ubuntu:~/builder$ osinfo-query os | grep -i ubuntu
 ubuntu10.04          | Ubuntu 10.04 LTS                                   | 10.04    | http://ubuntu.com/ubuntu/10.04
 ubuntu10.10          | Ubuntu 10.10                                       | 10.10    | http://ubuntu.com/ubuntu/10.10
 ubuntu11.04          | Ubuntu 11.04                                       | 11.04    | http://ubuntu.com/ubuntu/11.04
 ubuntu11.10          | Ubuntu 11.10                                       | 11.10    | http://ubuntu.com/ubuntu/11.10
 ubuntu12.04          | Ubuntu 12.04 LTS                                   | 12.04    | http://ubuntu.com/ubuntu/12.04
 ubuntu12.10          | Ubuntu 12.10                                       | 12.10    | http://ubuntu.com/ubuntu/12.10
 ubuntu13.04          | Ubuntu 13.04                                       | 13.04    | http://ubuntu.com/ubuntu/13.04
 ubuntu13.10          | Ubuntu 13.10                                       | 13.10    | http://ubuntu.com/ubuntu/13.10
 ubuntu14.04          | Ubuntu 14.04 LTS                                   | 14.04    | http://ubuntu.com/ubuntu/14.04
 ubuntu14.10          | Ubuntu 14.10                                       | 14.10    | http://ubuntu.com/ubuntu/14.10
 ubuntu15.04          | Ubuntu 15.04                                       | 15.04    | http://ubuntu.com/ubuntu/15.04
 ubuntu15.10          | Ubuntu 15.10                                       | 15.10    | http://ubuntu.com/ubuntu/15.10
 ubuntu16.04          | Ubuntu 16.04                                       | 16.04    | http://ubuntu.com/ubuntu/16.04
 ubuntu16.10          | Ubuntu 16.10                                       | 16.10    | http://ubuntu.com/ubuntu/16.10
 ubuntu17.04          | Ubuntu 17.04                                       | 17.04    | http://ubuntu.com/ubuntu/17.04
 ubuntu17.10          | Ubuntu 17.10                                       | 17.10    | http://ubuntu.com/ubuntu/17.10
 ubuntu18.04          | Ubuntu 18.04 LTS                                   | 18.04    | http://ubuntu.com/ubuntu/18.04
 ubuntu4.10           | Ubuntu 4.10                                        | 4.10     | http://ubuntu.com/ubuntu/4.10
 ubuntu5.04           | Ubuntu 5.04                                        | 5.04     | http://ubuntu.com/ubuntu/5.04
 ubuntu5.10           | Ubuntu 5.10                                        | 5.10     | http://ubuntu.com/ubuntu/5.10
 ubuntu6.06           | Ubuntu 6.06 LTS                                    | 6.06     | http://ubuntu.com/ubuntu/6.06
 ubuntu6.10           | Ubuntu 6.10                                        | 6.10     | http://ubuntu.com/ubuntu/6.10
 ubuntu7.04           | Ubuntu 7.04                                        | 7.04     | http://ubuntu.com/ubuntu/7.04
 ubuntu7.10           | Ubuntu 7.10                                        | 7.10     | http://ubuntu.com/ubuntu/7.10
 ubuntu8.04           | Ubuntu 8.04 LTS                                    | 8.04     | http://ubuntu.com/ubuntu/8.04
 ubuntu8.10           | Ubuntu 8.10                                        | 8.10     | http://ubuntu.com/ubuntu/8.10
 ubuntu9.04           | Ubuntu 9.04                                        | 9.04     | http://ubuntu.com/ubuntu/9.04
 ubuntu9.10           | Ubuntu 9.10                                        | 9.10     | http://ubuntu.com/ubuntu/9.10


Ubuntu : Firefox performance too bad for JS intensive websites

Off the bat I must say there are many differences in browsers and may handle JS differently due to the fact that Firefox and Chome are entirely different builds by different company's they are not created equally.

With a fully updated OS and a fresh copy of Firefox there is little you can do if problem persist.

Fully update your system

sudo apt-get update
sudo apt-get upgrade
sudo apt-get diso-upgrade
sudo update

Remove Firefox and reinstall it. - you will lose all data in browser
if it is not backed-up.

sudo apt-get purge firefox

Delete .mozilla/firefox/ in your home directory, should it still be there.

Delete .macromedia/ and .adobe in your home directory, these can contain "Flash Cookies" stored by the browser

sudo apt-get install firefox
sudo apt-get update

Check internet speed in both firefox and chrome is it the same ?
Do what I do forget Firefox and just use chrome. JK

you can not compare Firefox on windows to Firefox on  Linux they are built entirely different where there is an issue on a Linux box may not mean the same problem happens in windows. It is my experience that main stream programs and devices seam to work better on windows due to the fact that company's build products more torts windows systems first simply because they are more popular.

If a fresh copy and full update doesn't work it must be an issue with the Linux version of Firefox and will hopefully get fixed with a future update from Mozilla.


Ubuntu software center - Purchased software - How to still download?

Gnome software center  and Ubuntu software center are just software to allow you to download and install other software.  The software it shows will be the same in both (well, there will be different libraries). 3rd party software is likely to be available in gnome software center too, maybe you need to open the "partners" repository to get it shown?

(you did not tell what the software is; add it to the question and the answer is likely to be more targeted to your problem).

The old Ubuntu Software center is listed in the 17.04 package list but it will install the 16.04 package since there is no newer version. Direct download to DEB file. That probably still works (have not tried it ;) )

Regarding paid software: you also get support from the seller of your software. And they are likely to have their own repository, their own debian installer and their own download site.


I don't think $JAVA_HOME is set by default.
Normally it is set within the file /etc/environment for every user.
Otherwise you can set it in $HOME/.bashrc for yourself:

export JAVA_HOME=/path/to/sdk/basis/directory


Sysinfo is what you are looking for in Ubuntu 18.04 and earlier. It is a graphical user interface application that supplies information about the hardware in your system including CPU, memory, graphics card and the motherboard. You can install Sysinfo using the Ubuntu Software Center, or else open the terminal and type:
sudo apt-get install sysinfo

In Ubuntu 20.04 and later install System Profiler ( sudo apt install hardinfo ) instead of Sysinfo.


The /etc/resolv.conf file is generated from the files stored in the /etc/resolvconf/resolv.conf.d directory when sudo resolvconf -u is ran.

If you make any changes to these files:

terrance@terrance-ubuntu:/etc/resolvconf/resolv.conf.d$ ls -l
total 8
-rw-r--r-- 1 root root   0 Jun  3  2015 base
-rw-r--r-- 1 root root 151 Feb 25  2017 head
-rw-r--r-- 1 root root  33 Jun  5  2016 original
-rw-r--r-- 1 root root   0 Jun  5  2016 tail

The changes will be reflected when you run the resolvconf -u command for update.  I actually put my DNS information in the original file and I leave all the other files alone:

terrance@terrance-ubuntu:/etc/resolvconf/resolv.conf.d$ cat original
search local
nameserver 10.0.0.1

Then after running the sudo resolvconf -u command we can see my changes in my /etc/resolv.conf file:

$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 10.0.0.1
search local

EDIT: One more thing you may have to check and change is the line dns=dnsmasq found in the /etc/NetworkManager/NetworkManager.conf file.  You can copy and paste the following line to disable using the dnsmasq from the NetworkManager.

sudo sed -i 's/dns=dnsmasq/#dns=dnsmasq/' /etc/NetworkManager/NetworkManager.conf

After running the above line, reboot the computer for the new changes to take effect.

Hope this helps!


Try running

sudo blkid

on the command line while more than one being plugged in. The partition/volume should have a unique identifier.

Alternatively, you could also use the device serial, if provided by the manufacturer.

Run lsusb -vvv and identify the device, then look for the iSerial field, e.g.:

Bus 004 Device 005: ID 059f:1049 LaCie, Ltd rikiki Harddrive
Device Descriptor:
  bLength                18
  [...]
  iManufacturer           2 LaCie
  iProduct                3 Rikiki USB 3
  iSerial                 1 00000000d49425f030b6
  [...]


Messed up my 12.04 graphics: Falsely installed NVidia drivers on HD Graphics

Try re-installing (or install if missing)

xserver-xorg-video-intel

These are the drivers for Intel, hopefully a re-install will fix the settings that Nvidia borked.


The transcode package bundles an image stabiliser plugin vid.stab. Their video demo certainly looks convincing (if a little vomit inducing).


No Legacy Boot: Recovery media only functions on Dell and Alienware systems error

Removing hidden Ubuntu partition allows to install Elementary OS.


Why doesn't dpkg -L show files under /usr/lib for this package?

Files created by package-specific installation-scripts are not listed.

From man dpkg:

dpkg-query actions
              See  dpkg-query(1)  for  more  information  about  the following
              actions.

              -l, --list package-name-pattern...
                  List packages matching given pattern.
              -s, --status package-name...
                  Report status of specified package.
              -L, --listfiles package-name...

From man dpkg-query:

-L, --listfiles package-name...
              List files installed to your system from package-name. When mul‐
              tiple package-name are listed, the requested lists of files  are
              separated  by an empty line, with the same order as specified on
              the argument list. However, note that files created by package-
              specific installation-scripts are not listed.


After logging in, there's a black screen and my cursor, nothing else! in Ubuntu 12.10

Just for completeness, this problem also occurs when you mistakenly installed the "nvidia-319-updates" package, but you do not have an nVidia graphics chip on your system.
In my case this package was an indirect dependency from package "libopencv-dev".

So, when you're running on an ATI or Intel grpahics chip for example, and you installed openCV (package libopencv-dev), OpenGL gets broken and you'll get a black screen with mouse cursor after logging in. To resolve in this case, just remove nvidia's packages:

sudo apt-get remove nvidia-*

See this bug on launchpad for more details


Why are my Firefox control buttons disappearing?

It doesn't Disappears , it just Looses focus .

Like here in Top-Left Corner , when Mouse is not hovering over it

And when you browse your mouse over it , it is visible.

You just have to Double-Click on the Empty space in the Top-panel right to Firefox-title or any other Maximized window  to Resize in older always.


14.10 upgrade failed now no user profiles and screen config is hosed

Boot from a live-CD or USB, take a look at the files of your hard drive after mounting the corresponding partition.

Maybe the password file got messed up, but from what you described, much more went wrong with your upgrade, so reinstalling (if that is an option) might save you hours of troubleshooting.


Is there a faster way to erase a pen (USB) drive using dd command?

You can set the blocksize to 1M. That is way faster.

sudo dd if=/dev/zero of=/dev/sdd bs=1M && sync


Ubuntu 17.10 doesn't shutdown properly: eth0: failed to remove key

Try this:

gksudo gedit /etc/default/grub

then change the following line from:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

To:

GRUB_CMDLINE_LINUX_DEFAULT=""

And then, update the grub and reboot using :

sudo update-grub
sudo reboot

Otherwise:

Upgrade the kernel to a newer version, since it is a bug; more details here


External wireless dongle ASUS USB-N13 keeps dropping connection since 16.04 update

There are a very few drivers that both claim the same device, The driver 8192cu that you installed from dkms and the driver rtl8xxxu are two examples. They both claim your wireless device and, no doubt, conflict. Let's blacklist one and see if your wireless now performs as expected. Please open a terminal and do:

sudo -i
modprobe -r rtl8xxxu
echo "blacklist rtl8xxxu"  >>  /etc/modprobe.d/blacklist.conf
exit

It may take a reboot. Any improvement?


Connect to wireless network with Ubuntu 17.04

When you create a virtual machine with VMware, you can use one of several types of network connections.

bridged networking, where the VM has direct access to the network. Here the VM must acquire a different IP address (e.g. from a DHCP server) and may require bringing the network interfaces up/down (e.g. by using ip link
or ifconfig) in the VM each time you change of network.
NAT, where the VM connects to the network (and internet) through the host system. Using this type of connection, the VM is not accessible from the outside.
host-only, where the VM connects only to the host system.

I think you must use a NAT connection. using this connection, your VM will have network/internet access while the host system has access. If you need to access servers/services in the VM you may configure a port forwarding for NAT.

If you need information on bringing interfaces up/down, please look here.


Installed some Gnome Shell Extentions with apt (deb package) - Howto enable them?

Once installed the extensions with those commands, try to restart the gnome-shell by Alt+F2 type restart and Press Enter..

Then open extensions app or tweaks to control them..
Alternatively logout and logback in is also a way..
I just relogin, once the two commands you mentioned are ran.


You can use systemd timer.

your.timer

[Unit]
Description=Starts ntp after boot

[Timer]
OnBootSec=60s
Unit=ntp.service

[Install]
Target=multi-user.target

Also you should disable ntp.service and enable your.timer


sed: -e expression #1, char 10: extra characters after command

First you don't have to use pipe between the variable assignment text= and the sed command. You need to replace with the command delimiter ;.

Second, you can get the error because part of the replacement text is interpreted by sed.
You actually need to quote the replacement string. This can be done with the bash parameter expansion operator @Q.

text=$(head -n2 test.txt)
sed -i "1i ${text@Q}" output.txt

As mentioned in the bash man pages:

  ${parameter@operator}
  ...
  Q     The expansion is a string that is the value of parameter quoted in a format that can be reused as input.

Obviously inserting before line 1 is the same as doing:

head -n2 text.txt > /tmp/temp.txt
cat output.txt >> /tmp/temp.txt && mv /tmp/temp.txt ouput.txt


You have to install virtualbox so that the genymotion application will work.

avinash@avinash-Lenovo-IdeaPad-Z500:~/softwares$ sudo chmod +x genymotion-2.1.0_x64.bin
avinash@avinash-Lenovo-IdeaPad-Z500:~/softwares$ sudo ./genymotion-2.1.0_x64.bin
Installing to folder [/home/avinash/softwares/genymotion]. Are you sure [y/n] ? y

- Trying to find VirtualBox toolset .................... OK (Valid version of VirtualBox found: 4.3.6r91406)
- Extracting files ..................................... OK (Extract into: [/home/avinash/softwares/genymotion])

Installation done successfully.

You can now use these tools from [/home/avinash/softwares/genymotion]:
 - genymotion
 - genymotion-shell

avinash@avinash-Lenovo-IdeaPad-Z500:~/softwares$

After the genymotion.bin file was installed, a genymotion directory was created.Go inside that folder and double click on genymotion application to work.


From the description of the package php5-mysql(version 5.3.10-1ubuntu3.2) :

  This package provides modules for MySQL database connections directly from
  PHP scripts.  It includes the generic "mysql" module which can be used
  to connect to all versions of MySQL, an improved "mysqli" module for
  MySQL version 4.1 or later, and the pdo_mysql module for use with
  the PHP Data Object extension.

So, the package php5-mysql does contain support for MYSQLi extension.


Ubuntu not booting after using Ubuntu-Tweak's janitor function

If you happened to have edited/modified/deleted something related to X.org then the answer provided by Jobob will help:

Remove existing xorg using the following command

sudo apt-get remove --purge xserver-xorg

Install xorg using the following command

sudo apt-get install xserver-xorg

Reconfigure xorg using the following command

sudo dpkg-reconfigure xserver-xorg

And if you have an Nvidia or Ati card, I would also suggest to reinstall the driver as shown in How do I install the Nvidia drivers?


Anything I do with apt runs "setting up razercfg"

You have left razercfg in a non-working state (installed,  not configured). The other two packages depend on a working razercfg. This makes the packaging system unhappy/inconsistent, so it tries to configure razercfg every time you invoke it, and fails, leaving razercfg installed, not configured.
Manual intervention is necessary. There are two different ways to resolve the problem: configure razercfg correctly. OR remove razercfg.
Reconfigure:
sudo dpkg-reconfigure razercfg qrazercfg qrazercfg.applet

OR
Remove from system:
sudo apt purge razercfg qrazercfg qrazercfg.applet


I think you actually don't really want the menu to appear each time you boot, so by following this, you can have it only show the menu on pressing shift while booting.

Open the grub configuration by typing:

sudo -H gedit /etc/default/grub

Now, if you don't really want the grub menu even appearing without your consent, just add this line to the file:

GRUB_HIDDEN_TIMEOUT_QUIET=true

and then change:

GRUB_TIMEOUT="5"

to:

GRUB_TIMEOUT="0"

Save this file, run the following command:

sudo update-grub

and then after a reboot you should be able to see the change.


there is no package yet , but it will soon https://launchpad.net/~w-rouesnel/+archive/openssh-hpn


Is this the tutorial you're following? The error you included suggests SHA256SUMS.gpg isn't there.  Do you have both files, SHA256SUMS.gpg and SHA256SUMS, in your current directory?  I would make sure both files are there and look like this:
$ ls -l SHA*
-rw-rw-r-- 1 userid userid 204 Feb 11 14:07 SHA256SUMS
-rw-rw-r-- 1 userid userid 833 Feb 11 14:07 SHA256SUMS.gpg


According to the License Agreement on use of AVG AntiVirus Free Edition, the AVG license grants you permission to use AVG AntiVirus Free Edition "solely ... on a single computer". The definition of solely which is "not involving anyone or anything else; only" seems to be restrictive enough that it fully excludes installing AVG on more than one computer. I think that "anything else" would also exclude installing AVG on both OSs of a single computer with a dual boot. I think that the words "anything else" mean that you can install AVG on one operating system for personal use and that's it. Unlike the ClamTk antivirus application from the Ubuntu Software Center, which you can install on as many computers as you like.

Installation

Visit the Download AVG AntiVirus Free 2015 website.
Under the AVG AntiVirus Free - for Linux header download the .deb file for installing AVG AntiVirus in Debian-based systems like Ubuntu.
Users of 64-bit Ubuntu should enable MultiArch if it isn't already enabled by running the following command in the terminal:

sudo dpkg --add-architecture i386

Double click the AVG .deb file to open it for installation in the Ubuntu Software Center. This is the easiest way to install AVG AntiVirus in Ubuntu.


PostGIS Broken Package: Unmet Dependencies - liblwgeom-2.1.8

I can confirm the bug for Ubuntu 12.04 LTS with the same PPA.

The following worked for me on Precise (mainly using "dpkg -r" to remove liblwgeom-2.1.7):

sudo service postgresql stop
sudo dpkg -r liblwgeom-2.1.7
sudo apt-get -f install
sudo service postgresql start


for i in 1 2; do
  echo variable${i}_case$i
done

should do what you want. Substitute 1 2 with the numbers or strings you need. Dependent on the values of $i you may need to quote it like so: echo variable"$i"_case"$i".


login loop 19.04 works wayland but not x

Ok, not a definitive answer to may own question - I gave up and reinstalled. However, while reinstalling, I reinstalled the touchpad-indicator utility at some point in the process. This disabled my wifi. Removing it re-enabled my wifi. I didn't investigate thoroughly but I suspect the login loop might have been caused by failure in touchpad-indicator which may have some compatibility issues with very latest updates to 19.04. But this is just a conjecture.


Type .quit or use Ctrl+D.

Type .help to get a list of available commands.


Android sdk manager not showing up ( Ubuntu )

Ok i figured out the problem , in order to make adt bundle work i need to install Java 6 instead of 7 so the below command worked for me

sudo apt-get install openjdk-6-jdk


Do I have to worry about "error: superfluous RAID member"?

As mentioned here by Fussy Salsify this seems to be a bug of update-grub script with spare device in one of the RAID arrays. As mentioned here a patch has been applied and should come to Ubuntu at some time.

Boyd Stephen Smith Jr. said he thinks this error report may be just cosmetic here and Vladimir 'φ-coder/phcoder' Serbinenko submitted a patch that seems to just change the error report to "spares aren't implemented".

Also there is a bug report at launchpad (#816475) and a possible workaround that involves changing the partitioning. The importance of this bug is undecided at launchpad but looks like it caused some real problem to Björn Tillenius that could not upgrade/install grub. So looks like you should be careful.


Try wvdial:

sudo apt-get install wvdial to install via the terminal

or install it using the Software Center:


Why is there a discrepancy between disks and df?

TL;DR they are measuring different things

Longer version:

Storage usage on Linux file systems (any file system really) is actually very complicated.  I recommend Googling for differences in df and du for some classic examples of tools measuring different things that a novice (not criticizing, we all have to learn) might think should be the same.

Here is a good example.  Say you notice you are low on space by checking with both du and df and they match.  Great!  Then you delete a large file and check again.  If a process has a handle to that file you will now see different results.  du will no longer see the file and immediately reflect the change.  df will only show the difference once the process accessing the file terminates.

I also recommend playing with lsof.  Under the covers all these tools use various strategies and rules for determining "usage" because they are solving different problems, and that's useful once you understand their intents.  The disks application is the same in that it is making assumptions about the definition of "used space" and therefor gives results accordingly.

Hope that helps!


I eventualy used pam_warn to get the unknown user as well as the ip of the connecting user.


Network connections appear unclaimed after purging linux-images

I suggest you reboot into an earlier linux-image by selecting it at the GRUB menu as I linked above. Afterwards, reinstall the faulty version:

sudo apt-get install --reinstall linux-image-3.13.0-45-generic

When finished, reboot and test.


There is no SPICE protocol in vinagre for Ubuntu

SPICE wasn't available in Vinagre because it used to be compiled without support for it. Reading the Debian bug report it appears that this choice was related to the fact that libspice-client-gtk is only available on i386 and amd64, and not on other architectures.

However, since version 3.12, Vinagre is now built with the right build-dependencies and hence has SPICE support. You can find it in Utopic.


Can't boot into Ubuntu, keeps returning to GRUB

Reinstalling the GRUB2 boot loader to the Master Boot Record often solves this sort of problem (assuming you're describing a grub> prompt with a flashing text cursor instead of a menu where you can select what OS you want to boot). You can reinstall GRUB2 to the MBR using any of the methods detailed at https://help.ubuntu.com/community/Grub2#Reinstalling_GRUB2.


How do I determine which processes are accessing a usb device?

I managed to solve the problem by removing the battery panel plugins, notifiers, indicators as well as native battery power management.

Note that using the third party UPS management solution was necessary for my case, but generally Ubuntu provides good options as well.

Contention for the hid device was corrected by doing the following:

disable upower
    sudo apt-get remove upower --purge

disable indicator power backend
    sudo vi /usr/share/upstart/sessions/indicator-power.conf

change
    exec /usr/lib/x86_64-linux-gnu/indicator-power/indicator-power-service

to
    #exec /usr/lib/x86_64-linux-gnu/indicator-power/indicator-power-service

remove unneeded packages
    sudo apt-get autoremove --purge

reboot.

This allows the tripplite poweralert daemon to communicate properly with the UPS.

Also, for reference, it is possible that during contention before the native power services are disabled that the power alert console is left in a corrupt state.

This is corrected by:

stop the power alert daemon:
sudo killall -9 pald

Deleting the dat files from:
/var/tripplite/poweralert/data/

Restart or daemonize pald as you choose.
The java app should now run correctly and connect every time.

Hopefully this helps somebody some day.
-c


Postifx receives mail but won't send mail out

In main.cf add relayhost =smtp.some_mail_server.com

This host can be smtp server of your provider

Restart postfix after this.


Thunderbird occasionally does not display notifications on new mail arrival.

Have you tried the following extension?

https://addons.mozilla.org/it/thunderbird/addon/gnome-integration/?src=search


This can be accomplished with symlinks. But first, you need to setup your system so that the D: partition is automounted every time you boot Ubuntu.

Run sudo blkid to see the UUID (Universally Unique Identifier) for all of your partitions. Then you will have to edit your fstab with this information.

fstab is a file located in /etc/ which determines which drives and partitions should be mounted every time the system starts. Before you do anything else, make a backup of the one you have:

sudo cp /etc/fstab /etc/fstab.backup

Then, edit fstab (with for example sudo nano or gksu gedit) and add this line:

UUID=<UUID of your D: partition> /media/Media ntfs defaults 0 0

Make sure that the mount location, /media/Media, exists before doing this, then reboot.

Now it's time to create symlinks. You will need to remove the personal folders first, as otherwise the symlinks will be placed inside them instead of replacing them. Make sure to backup any files you have there before running these commands:

rm -rf ~/Videos && ln -s /media/Media/Tesla/Videos ~/Videos

Repeat for all the folders you want to appear in your Home directory.


How can you mount a Windows 10 partition that is not bootable and is still "in use" due to the hibernation issue

In order of preference...

repair the "Lenovo" problem that won't let you boot Windows, then boot Windows, then fully shutdown Windows
boot a Windows Repair disc and run chkdsk (or repair) on the hard drive
(and I hate to recommend this...) use sudo ntfsfix /dev/sdxx. See man ntfsfix for more information about this command.


find -type f ! -name '*.c'

finds every file whose file name is not (!) ending in .c.

To play it safe, either use -ok instead of -exec or execute rm with the -i option:

find -type f ! -name '*.c' -ok rm {} +
find -type f ! -name '*.c' -exec rm -i {} +

If you're absolutely sure you can automatically delete all findings with -delete (always as the last option!) instead of calling another program:

find -type f ! -name '*.c' -delete

As always: Backup your data and delete with care.


How can I resize root and home partitions?

You'll have a worry free resizing only if you have unused space in between root and home. As far as I know the newest Ubuntu which is 20.04 can work without a swap partition as it's able to do the same with swap file. I don't know much in detail though. So you can remove the swap partition and extend the root by another 10GB which is released from swap. This would be the easiest for you. Another solution is to take a backup of /home. Then delete swap and home and do a re-partition. This can be done running the Live CD and once partitioning is done, you can copy data back to /home. As a thumb rule, when you partition your disk instead of allocating the space at the beginning of the unused space, you may use end of the space. This will help you easily resize the root partition in future.
Consider a 200 GB disk

root (/) 30 GB
20 GB unused space
swap based on RAM (Usually double the size of RAM 8x2=16) but this
is optional now.
home (/home) remaining space (134 GB)

Hope this helps.


Installing VMware player: "chmod: cannot access... no such file or directory"

To install VMware Player 6, you need first to do some prerequisites.  Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo apt-get install build-essential linux-headers-`uname -r`

Then go ahead and download VMware Player 6, the file will download to your Downloads folder.  Once the download is done, navigate to the Downloads folder, and:

cd Downloads
chmod +x VMware-Player*
sudo ./VMware-Player-6.0.0*

During the installation when asked for a license number, skip that unless you got a key for player plus which is a paid product.VMware


Download the Ubuntu 13.10 .iso and make either a bootable DVD or USB Flash Drive to install from, then during install select the Upgrade existing Ubuntu option from the list and hopefully it will use what is available to give you a fully working installation...


This answer includes steps taken in comments above, with additional steps to backup bookmarks in Firefox and purge and reinstall the package.

Troubleshooting steps

In Terminal, type firefox -P -no-remote and hit Return or Enter key.

If successful, this will prompt you with a list of Firefox user profiles. If it did, try to create a new profile and run Firefox using that.
If step 1 failed, confirm that Firefox is really not running by using strace firefox command* in Terminal.

If Firefox exits by itself, the last several lines contains only exit_group(0).

In contrast, Firefox that exits normally upon user action (by clicking on Close x button or using Alt+F4 combination key) will contain close(8) close(7) exit_group(0) in the last three lines of *above command.
Optionally, backup your bookmarks by copying the bookmarkbackups directory that is found under ./mozilla/firefox/PROFILEDIR to somewhere for later use.

In which, PROFILEDIR may look something like XXXXXXXX.default for the profile that Firefox has created by default.
Remove the .mozilla directory which is found under the Home directory of current user.

  $ rm -rf ~/.mozilla

Purge the package (this is preferred than apt-get remove command, in case the package that has been downloaded earlier is corrupted when upgrading Ubuntu)

  $ sudo apt-get purge firefox

Install the package that is downloaded new

  $ sudo apt-get install firefox

Finally, run Firefox as usual.

Restore bookmarks in Firefox

If you have done step 3, you can now restore your bookmark from the freshly installed Firefox. You will be using one of the files inside the bookmarkbackups directory.

In Firefox, open the bookmark manager a.k.a Library (either by Alt+B > Show All Bookmarks or using Ctrl+Shift+O key combination will do).
In Library, click on Import and Backup button and select Restore > Choose File....
Navigate to the bookmarkbackups directory you had copied earlier.
Select the latest *.json* file found inside the directory and click OK.

It will take a few moment, depending on your bookmark file size. The restored bookmark is found under Unsorted bookmarks > YYYYMMDD.

Whereby, YYYYMMDD is part of the filename of *.json* file you had selected earlier and it is also the date the bookmark backup that has been created in your older install of Firefox.

Compatibility notes

The troubleshooting steps should be applicable to recent Firefox releases on any Ubuntu releases, not just 12.04. I have decided to provide generic answer, since other earlier questions and answers didn't have this kind of advice.


how to network in ubuntu client on windows host?

The easy way is to use VirtualBox Shared Folders, and the longer way is by setting up your virtual machine in "Bridged Adapter" mode so that it shows up as another machine on your local network.

Shared folders are pretty easy to set up and use, especially if you use the "auto-mount" feature that VirtualBox has built in.

There is a lot of information available on both setup types, so do a search around the web, and then if you have more specific questions I can try pointing you to further resources.

Couple of places to start:

https://forums.virtualbox.org/viewtopic.php?t=15868
https://help.ubuntu.com/community/VirtualBox/SharedFolders


you are talking about a file server with apache

Just do as follows.

Open your terminal and do as below

sudo apt-get install apache2

then

sudo service apache2 start

Just open your browser and type as localhost and press enter.

If you see

You have installed your webserver successfully.

Now we have to setup a file server for you.

Now open /var/www/html location and make a folder with any name and  place some files of yours.

Then restart/reload apche2 and then in the browser type as

localhost/ and you see your folders.

But to make your friends/people to see your files. we have a lot of work to do like

We need  a website name for that
If no website name then we have to choose one and add it in your /etc/hosts file and your friends /etc/hosts file.
Make a virtualhost entry in /etc/apache2/apache2.conf file


The Ubuntu live-CD uses a custom interface (ubiquity), but underneath that (or directly, if you use the alternate/server CD) is debian-installer ("d-i") from the Debian project, on which Ubuntu is based.

The live-CD provides a full running linux environment (and the alternate install a minimal live environment) in memory. From this the new, empty drive is mounted and a minimal system copied into it. You can look through the d-i code to find the scripts which perform each part of the process (you might also want to look into the debootstrap tool).