How to correctly enable Desktop Cube in Unity 3D?

This is what I invented and tested with more than 20 PCs. Note that you actually NEED a video card that can render this and to have the drivers correctly installed. Look for the answer in the following links to install the drivers correctly:

How do I install the Nvidia drivers?

How can I update my NVIDIA driver?

Can not install Nvidia driver

What's the difference between the nvidia-current, and nvidia-current-updates packages?

Install Compiz Config Settings Manager

(Note: What are some of the issues with CCSM and why would I want to avoid it?)

sudo apt-get install compizconfig-settings-manager

NOTE: If you have 12.10 or above you need to also install the compiz-plugin package. So instead of the final terminal line mentioned above, it would be:

sudo apt-get install compizconfig-settings-manager compiz-plugins compiz-plugins-extra

If you do not install the compiz-plugins you will not see the cube or rotate plugins in the compiz plugin list.
Open Compiz Config Settings Manager and go to Preferences

Select Plugin List Tab

Disable Automatic Plugin Sorting and accept the warning that will appear after trying to disable it.
From the Disable Plugins List, Enable the following plugins: cube, rotate
From the Enable Plugins List, Disable the following plugins: wall
Go back from the Preferences menu to the Main Compiz Menu and select General Options

Go to Desktop Size tab and change the Horizontal and Vertical Virtual Size to 4:

How it looks in 12.04 or below

How it looks in 12.10+

DONE

There is no need to restart the PC or logout or anything additional to this steps. In this case it works on Nvidia, Ati and Intel cards.

If you want to add more Effects you would do them in the Preference options but you need to be careful which Plugins have problems with others. In this case they are working excellent.

HOW TO TEST IF IT IS WORKING?

Simply leave CTRL+ALT pressed and then with the Arrow keys press -> or <- to rotate Right or Left, respectively.

You can also (If you mouse has support for a third middle button), leave the middle button pressed while in the desktop (Without selecting anything else) and move your mouse around.

I will need to test it even further to say that it is stable but so far am typing this with the Cube effect activated, could drag a video I was watching to another virtual desktop and no problems.

On 12.04 watching Family Guy

On 12.10 watching Game of Throne + AskUbuntu

On 13.04 watching (actually crying) Fringe:

Lastly, you can just download My Compiz Profile to import using the CCSM Import option and have the configuration that is mentioned in this post.

HOW TO GO BACK TO DEFAULT?

If this is giving you any video errors or glitches, then you need to go back to the defaults. I would try to run ccsm again and simply put the "Wall" plugin back from Disabled to Enabled in the Preferences Menu and then Activate the "Automatic Plugin Sorting". Or just set all plugins to automatic by enabling the Automatic Plugin Sorting option again. Now logout/login just in case any of them gives an error or weird behavior. If you can't open the Compiz Settings Manager go to the terminal and type ccsm.

Options to reset Compiz and/or Unity to default (In case of an error) are:

For 12.04 and Below - unity --reset
For 12.10 - How do I reset my Unity configuration?
For 13.04+ - unity-tweak-tool --reset-unity
Remove Launcher Custom Icons - unity --reset-icons

UPDATE - Confirmed working on at least 10 PCs and 5 Laptops. All laptops are HP ranging from DV6000 up to DV9700. The desktop PCs are all Intel Core 2 Duo and all have Nvidia cards. The laptops only the last 2 have nvidia cards. The rest are intel.


Make sure, libpam-gnome-keyring is installed on your system

sudo apt-get install libpam-gnome-keyring

Also you should have a login keyring in ~/.gnome2/keyrings/login.keyring

---Edited by OP to cover another situation.

I installed LXDE on my Ubuntu 14.04 system and started getting this keyring popup again when I took a backup.  libpam-gnome-keyring was already installed on this system!  To fix it, I had to add a line of text to two files, like this:

To /etc/pam.d/passwd add:

password optional pam_gnome_keyring.so

And to /etc/pam.d/login add:

session    optional     pam_gnome_keyring.so        auto_start

This will unlock the keyring on login when I log in through LXDE.


How do I recover my desktop settings after accidentally changing my home directory?

Do this

usermod -d /home/your_home_directory USERNAME

chown -R USERNAME /home/your_home_directory
This will recover your settings.


/etc/hosts file overwritten in persistent live USB

General discussion about persistent live systems
Some system settings are set up and some programs are started before the overlay system for persistence has started. This happens for the linux kernel and for the kernel's hardware device drivers. Maybe this is also what is happening to the /etc/hosts file. I have tampered with that file in installed systems, but not in persistent live systems, so I don't really know, if there is an easy solution to the problem.
Possible solutions

An obvious, but not so easy solution is to install Ubuntu (install like into an internal drive) into a USB drive. Such a system will behave like any installed system. See this link and links from it.
If you don't want identical installed systems, it should be possible to set up a master installed system with the OEM method, clone it and then finish the installation in each computer making the systems unique with user names and passwords, host names etc.

Another alternative might be to [automatically] backup /etc/hosts to a 'safe place', and at boot restore it [also automatically]. This could be done with scripts and maybe involve cron. But there should be a reason for /etc/hosts to bounce back (unless it is a bug). Maybe things involving the network and /etc/hosts happen early about in the boot process, before the overlay system is activated, and in that case, this workaround will not work.

Yet another alternative is to try a persistent live system made from another linux distro in order to check if the /etc/hosts bounces back to default after reboot.

Test with Debian 9.6.0
mkusb can create persistent live drives from Ubuntu and Debian iso files. So it is natural for me to try a Debian persistent live system. I have the iso file
debian-live-9.6.0-amd64-cinnamon.iso

which is new (downloaded January 2019). I made and tested a persistent live system, and it preserves /etc/hosts after reboot :-)
user@debian:~$ cat /etc/hosts
127.0.0.1   localhost debian
192.168.0.4 xw8400
::1     localhost ip6-localhost ip6-loopback
ff02::1     ip6-allnodes
ff02::2     ip6-allrouters

user@debian:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 9.6 (stretch)
Release:    9.6
Codename:   stretch

user@debian:~$ uname -a
Linux debian 4.9.0-8-amd64 #1 SMP Debian 4.9.130-2 (2018-10-27) x86_64 GNU/Linux
user@debian:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            7.8G     0  7.8G   0% /dev
tmpfs           1.6G  9.4M  1.6G   1% /run
/dev/sdb4       2.0G  2.0G     0 100% /lib/live/mount/persistence/sdb4
/dev/loop0      1.9G  1.9G     0 100% /lib/live/mount/rootfs/filesystem.squashfs
tmpfs           7.8G     0  7.8G   0% /lib/live/mount/overlay
/dev/sdb5       8.4G  2.3G  5.8G  28% /lib/live/mount/persistence/sdb5
overlay         8.4G  2.3G  5.8G  28% /
tmpfs           7.8G     0  7.8G   0% /dev/shm
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           7.8G     0  7.8G   0% /sys/fs/cgroup
tmpfs           7.8G  4.0K  7.8G   1% /tmp
tmpfs           1.6G   20K  1.6G   1% /run/user/1000
/dev/sdb1       4.2G   23M  4.2G   1% /media/user/usbdata

user@debian:~$ sudo lsblk -fm
NAME   FSTYPE   LABEL                 UUID                                 MOUNTPOINT                                 NAME     SIZE OWNER GROUP MODE
loop0  squashfs                                                            /lib/live/mount/rootfs/filesystem.squashfs loop0    1.8G root  disk  brw-rw----
sda                                                                                sda    238.5G root  disk  brw-rw----
├─sda1 ext4     root                  2093f8d6-7840-4256-8edc-4db97e865784                                            ├─sda1 232.5G root  disk  brw-rw----
└─sda2 swap     swap                  4b882c9f-4867-4c5c-8eb7-c84ef03f4786                                            └─sda2     6G root  disk  brw-rw----
sdb                                                                                sdb     14.9G root  disk  brw-rw----
├─sdb1 ntfs     usbdata               51B99954568550BA                     /media/user/usbdata                        ├─sdb1   4.2G root  disk  brw-rw----
├─sdb2                                                                                ├─sdb2     1M root  disk  brw-rw----
├─sdb3 vfat     usbboot               3FAC-E416                                                                       ├─sdb3   244M root  disk  brw-rw----
├─sdb4 iso9660  d-live 9.6.0 ci amd64 2018-11-10-11-54-14-00               /lib/live/mount/persistence/sdb4           ├─sdb4     2G root  disk  brw-rw----
└─sdb5 ext4     persistence           9d044926-15cd-4e1b-911d-ceb8e7101cf3 /lib/live/mount/persistence/sdb5           └─sdb5   8.5G root  disk  brw-rw----
sr0                                                                                sr0     1024M root  cdrom brw-rw----

I don't know if things will work as they should with Debian persistent live and your Apache web server,

if /etc/hosts and the corresponding network settings work as intended, and
if other things in Debian, for example hardware drivers work with your computers,

but I think it is worth trying with Debian.


Either change to /var/www/html/example.ca/public_html moving the files there to actually be looking in the correct directory you have it configured for, for the files. Or change the DocumentRoot /var/www/html/ to DocumentRoot /var/www/ so it will be serving the files up where you try to access them with the first /var/www/example.ca/public_html. You need to restart the web server for the configuration changes to take effect /etc/init.d/apache2 reload. Edit, that is the command to reload on my Debian based systems it may be different in others. And I would add a http://123.456.789.0 (your IP) or the domain you have, should show you the Apache is working page or that index.html you have put there according to your posting. It needs the http://123.456.789.0/public_html as the address to access the files in the /var/www/html/public_html/ directory of the web server, an index.html file in that directory should just load in a brower as its default homepage for that site.


You will have no real benefits of re-building a kernel, unless there are patches in a newer kernel version which are needed for your hardware, that aren't included in the version you have installed. But in general, there is no good reason to recompile a kernel from what is shipped in the distro.


No Shadows under menus on application decoration borders and unity panel

it has been reported on Launchpad (Ubuntu's bug tracker) here: https://bugs.launchpad.net/ubuntu/+source/gtk+3.0/+bug/1574693.

And a fix has been published in the xenial-proposed repository (see below for a link on how to enable it), so it should be available to the main repository in your updates in a few days if all goes well:

  Hello Albert, or anyone else affected,

  Accepted gtk+3.0 into xenial-proposed. The package will build now and
  be available at
  https://launchpad.net/ubuntu/+source/gtk+3.0/3.18.9-1ubuntu3.1 in a
  few hours, and then in the -proposed repository.

  Please help us by testing this new package. See
  https://wiki.ubuntu.com/Testing/EnableProposed for documentation how
  to enable and use -proposed. Your feedback will aid us getting this
  update out to other Ubuntu users.

  If this package fixes the bug for you, please add a comment to this
  bug, mentioning the version of the package you tested, and change the
  tag from verification-needed to verification-done. If it does not fix
  the bug for you, please add a comment stating that, and change the tag
  to verification-failed. In either case, details of your testing will
  help us make a better decision.

  Further information regarding the verification process can be found at
  https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you
  in advance!


latest update to 16.04 broke my wireless network

You have installed the wrong driver. With a working internet connection, open a terminal and do:

sudo apt purge bcmwl-kernel-source
sudo apt update
sudo apt install firmware-b43-installer

After it completes, reboot and your wireless should be working.


The server  https://w3s.webmoney.ru:443 is not trustworthy.

% curl https://w3s.webmoney.ru:443
curl: (60) server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none
More details here: http://curl.haxx.se/docs/sslcerts.html

curl performs SSL certificate verification by default, using a "bundle"
 of Certificate Authority (CA) public keys (CA certs). If the default
 bundle file isn't adequate, you can specify an alternate file
 using the --cacert option.
If this HTTPS server uses a certificate signed by a CA represented in
 the bundle, the certificate verification probably failed due to a
 problem with the certificate (it might be expired, or the name might
 not match the domain name in the URL).
If you'd like to turn off curl's verification of the certificate, use
 the -k (or --insecure) option.

Run

curl --insecure https://w3s.webmoney.ru:443

and it works.

From man curl

-k, --insecure
    (SSL) This option explicitly allows curl to perform "insecure" SSL
    connections and transfers. All SSL connections are attempted to be
    made secure by using the CA certificate  bundle  installed  by
    default. This makes all connections considered "insecure" fail unless
    -k, --insecure is used.

Add trusted certificates with

Add the path to the certificate to

/etc/ca-certificates.conf

use a path relative to /usr/share/ca-certificates
Run sudo update-ca-certificates

For further instructions read man update-ca-certificates

Taken from the comments:

  FYI: The same site has SSLv3 and SSLv2 enabled - it's BAD and not trustworthy at all because of that


Does the Gluglug ThinkPad X200 work with Ubuntu?

The Libreboot X200 comes with Trisquel GNU/Linux pre-installed. http://shop.gluglug.org.uk/about/

Trisquel is based on Ubuntu. Trisquel 7 "LTS" is based on Ubuntu 14.04 LTS, I believe. My understanding is that Trisquel is Ubuntu with every last bit of non-Free software ripped out (plus other features like its own "...customized version of the GNOME Flashback desktop environment"). https://trisquel.info/en/wiki/documentation See also the wikipedia entry for Trisquel.

Given the above, I would not foresee any problems running Ubuntu, though I cannot advise on current Ubuntu RAM requirements.


Where can I find the SHA256 hashes of Ubuntu images?

Currently only MD5 hashes are securely available. If you believe it is necessary to provide SHA256 hashes as well, please file a bug against the Ubuntu website.

Your report will be significantly more well received if you refrain from shouting profanities at those from whom you are seeking help.


I came across this problem a while back. From what I understand, the kernel is preventing lm-sensors from looking at fan usage, so I modified my GRUB settings to allow lm-sensors to access this information. First, open the configuration file:

sudo gedit /etc/default/grub

Then set the GRUB_CMDLINE_LINUX option to the following:

# This allows fan usage to be read by lm-sensors
GRUB_CMDLINE_LINUX="acpi_enforce_resources=lax"

Save the file and close, then update your GRUB settings:

sudo update-grub

Executing sensors in the terminal should show your fans' RPMs now.  It may be the case that not every fan for your machine is being shown - for my machine, none of the ASST_FANs are shown.

Perhaps I could solve this issue by making a configuration for your mobo, as described here, but I am happy with the information I have been able to get with the adjustment to the GRUB configuration.


the 396 version is beta version delete completely that version and reinstall the stable version i gues it was 390 it may work


Ubuntu 14.10 Intel Wireless 7260 - Bluetooth not working

In case anyone still needs help on enabling Intel 7260 Bluetooth under Linux. For the notebook version of the adapter, there are youtube videos about taping over the last pin, which seems to turn it on. I have the internal Pcie card, which requires that you hook up the USB cable (included with the adapter). The USB jack polarity is important, and can inadvertently be reversed, so check for that. My card was immediately recognized and Bluetooth works flawlessly once the cable was attached. That's on a Gigabyte AB350 Gaming 3 with Ryzen cpu and Kubuntu 18.04.


Unable to get exclusive lock, apt-get busy

You probably aborted an install at some time or another. The Following will release any lock you have. Just be sure you don't have software center open or are installing anything.

sudo fuser -cuk /var/lib/dpkg/lock; sudo rm -f /var/lib/dpkg/lock
sudo fuser -cuk /var/cache/apt/archives/lock; sudo rm -f /var/cache/apt/archives/lock
sudo rm /var/lib/dpkg/lock;sudo dpkg --configure -a


Why does Chromium take up 1 GB in my .config and can I reduce that size?

The File System folder is the storage for the FileSystem API, which lets websites and Chrome extensions store files inside your browser.

According to "Hard Drive filling up? Check Chrome's File System folder" on Ghacks, it can be cleared with this procedure:

  Warning: note that this will sign you out of nearly all websites and lose all data that websites store inside your browser, so you can, for example, lose some documents or saved games on some sites if they store those inside your browser instead of on their web server.

Go to the URI chrome://settings/clearBrowserData.
Select All time for Time range.
Check the box next to Cookies and other site data.
Click the Clear Data button.


Hiding desktop top panel through a shortkey. Is this possible? ( I am not talking about "auto-hide".)

<Super>+o or <Super>o  is how we assign shortkey in "Dash to panel" extension for autohiding the short key.

  (Note: u can select any other alphabet in case of "o")

And I think, there is no command to hide the top panel bar.


Ubuntu sits behind a corporate proxy/firewall -- how can I install packages?

For temporary proxy setting..I mean only for the current session run below command:

export http_proxy=http://yourproxyaddress:proxyport

To add this proxy setting permanently edit apt.conf file

gksudo gedit /etc/apt/apt.conf

And add below line:

Acquire::http::Proxy "http://yourproxyaddress:proxyport";


How can I edit the color of search bar in nautilus gtk3?

i found a solution for my problem in

/usr/share/themes/Ambiance-Purple/gtk-3.0/gtk-widgets.css

i change this

/***********
 * infobar *
 ***********/
.info {
    background-image: -gtk-gradient (linear, left top, left bottom,
                                     from (shade (#dbdbdb, 1.04)),
                                     to (shade (#dbdbdb, 0.96)));

to this

/***********
 * infobar *
 ***********/
.info {
    background-image: -gtk-gradient (linear, left top, left bottom,
                                     from (alpha (#dbdbdb, 0.0001)),
                                     to (alpha (#dbdbdb, 0.0001)));

sorry guys but new users aren't allowed to post images you can see them here


Xubuntu 14.04 - Strange "Log Out" button behavior

You can check the settings to your Whisker Menu by clicking on your Whisker Menu, then go to Settings, then Panel.

Click on the Items Tab, then on the Whisker Menu

Click the gear to the right.

Then click on the Behavior Tab, and make sure the appropriate boxes are checked and configured correctly

Hope this helps!


Everything should be located in the /etc/skel folder.

You need to create a link on the desktop for all users:

mkdir -p /etc/skel/Desktop
cd /etc/skel/Desktop/
vi shortcut.desktop
    [Desktop Entry]
    Version=1.0
    Name=ShortCut
    Comment=Visit ShortCut
    GenericName=ShortCut
    Exec=firefox http://intranet.ShortCut.com
    Terminal=false
    X-MultipleArgs=false
    Type=Application
    Icon=firefox
    Categories=Internet
chmod +x shortcut.desktop

That will create a link on the desktop.

Here's few articles that will help you for what you need:

How do I apply a custom Gnome-shell theme for all users?
How to ensure that all new users have the same profile settings as the current user?
http://www.linuxhowtos.org/Tips%20and%20Tricks/using_skel.htm
http://humanreadable.nfshost.com/sdeg/etc_skel.htm
http://www.linfo.org/etc_skel.html
http://www.booser.com/etc-skel-directory.html
http://www.thegeekstuff.com/2009/06/useradd-adduser-newuser-how-to-create-linux-users/#more-552


Ubuntu laptop Linux blocking Embedded Linux board Linux domain

Not sure about windows but you need to either run a DNS server, use some sort of network announcement such as Avahi - https://help.ubuntu.com/community/HowToZeroconf , configure your router, or edit /etc/hosts

sudo nano /etc/hosts

Add a line

  pyng_ip_address pyng

See http://manpages.ubuntu.com/manpages/zesty/man5/hosts.5.html


While I wouldn't recommend it (unless the use case explicitly calls for it), you can use something like the following in a shell script:

"echo PASSWORD | sudo -S COMMAND"

Where PASSWORD is the user password, and COMMAND is the command to run at the elevated permissions level.

Note that the -S option is important, as it redirects input from term to standard input. See Sudo Manual for additional details.


I had the same problem..
If you have just like me added SDK to a existing QT installation.
It is maybe necessary to add next repository!

1) Close QT

2) Open terminal and enter "sudo add-apt-repository ppa:ubuntu-sdk-team/ppa"

3) Update your system

4) Read for example http://itsfoss.com/install-configure-ubuntu-sdk/

5) Open QT or Ubuntu SDK (i don't see any difference between them)

6) creat a kit armhf-ubuntu-sdk-15.04 or armhf-ubuntu-sdk-14.10, depending on your phone

I created a new project (simpleui) and can run it on my phone.

Meizu MX4 Ubuntu Edition using armhf-ubuntu-sdk-15.04 kit


i recommend you to re-install grub

here is some documentation on how to do so:

https://help.ubuntu.com/community/Grub2/Installing#Reinstalling_GRUB_2


Not really an answer to your scripting problem, but I recommend using the unattended-upgrades  package. It is specifically designed to do just that. You don't have to worry about updating at a peak hour, because unattended-upgrades is run with a random delay (max 30 minutes) because otherwise the servers are being crushed.

If you still want to change the time your updates are done, it is useful to know that the unattended-upgrades is in cron.daily. You can change when cron.daily is executed by editing the /etc/crontab file, for more information see this question.

If you want more information about setting up automatic updates in general (including some pointers on how to write your own cron job) see the Ubuntu help page on AutomaticSecurityUpdates.


Could Google Chrome cache be causing hard drive corruptions?

Yes, it can. I already twice had an extent problem with Chrome cache on SSD formatted to btrfs.

I used this answer to diagnose the issue.

find /mnt/mountpoint -xdev -inum xxxxxxxx

shown me a file from Chrome cache. After I deleted the file the problem has gone.

I think the same happens on ext4.

The SSD is new and reports no problems in SMART.

This must be a Chrome issue, because I have no other disk issues.


Problem booting Ubuntu on external hard drive

If the computer is booting in EFI mode, as your "UEFI" tag and the symptoms imply, then you should first be aware of the cause of the problem: External media normally boot using the default/fallback boot filename, which is EFI/BOOT/bootx64.efi on the EFI System Partition (ESP) on x86-64/AMD64 systems. Most OS installations are to internal disks, which boot using customized entries stored in NVRAM. External media can also boot with such entries; but some EFIs delete entries that they can't see when you boot, so customized entries for external media can disappear if the external medium is unplugged while the system boots another OS.

Three solutions occur to me:

The most straightforward solution is to move/rename your boot loader. Ubuntu installs its boot loader as EFI/ubuntu/shimx64.efi and EFI/ubuntu/grubx64.efi on the ESP, which is normally mounted at /boot/efi in Ubuntu. Rename EFI/ubuntu on the ESP to EFI/BOOT on the ESP. You must then rename shimx64.efi to bootx64.efi. (If your system does not use Secure Boot, you may optionally rename grubx64.efi to bootx64.efi instead of renaming shimx64.efi.) This solution has the advantage that your external disk should be bootable on most EFI-based computers of the same architecture as the original computer.
Install my rEFInd boot manager to your internal disk's ESP and set it as the default boot program. You could do this in Ubuntu by unmounting the external ESP from /boot/efi, mounting the internal ESP to /boot/efi, and installing the Debian package (but not the PPA version). Do not edit /etc/fstab. Once set up in this way, rEFInd should launch on every boot, even when your external disk is unplugged; but because rEFInd builds its boot list on every boot, ignoring NVRAM entries, Ubuntu entries will appear only when the external disk is plugged in. This solution has the advantage of per-boot adaptability. You can even set rEFInd's defaults so that Ubuntu is the default boot option when the external disk is plugged in but Windows takes top spot when the disk is removed. One caveat: If you're using Secure Boot, you'll have to jump through some extra hoops to get it working. Copying the EFI/ubuntu directory tree from the external ESP to the internal one before installing rEFInd, then deleting EFI/ubuntu from the internal ESP, should do the job.
You can re-install GRUB to an ESP on an internal hard disk. To do this, you'll need to unmount /boot/efi from Ubuntu, mount an internal disk's ESP to /boot/efi, and re-install GRUB. You may want to update your /etc/fstab, too. This approach can be tricky, though; some GRUB configurations rely on a GRUB configuration file in /boot/grub, and if yours does this, /boot will also need to be on the internal disk or else GRUB will stop working when you unplug that disk, which means you won't be able to boot anything except by using the computer's built-in boot manager. I haven't been following the details of where Ubuntu stores its GRUB configuration file, so I'm not sure how likely you are to run into this problem.

Personally, I'd go with one of the first two solutions, since I'm not entirely sure where Ubuntu stores its grub.cfg file these days. That third option might be viable if you know that file gets stored on the same ESP as GRUB, or if you're willing to create a /boot partition on your internal disk.


Not able to scp file to AWS EC2 instance - the same pem key works fine for my colleague

I used ssh command to get connected to AWS EC2 to test if pem file was valid. I was able to get connected successfully. I disconnected from SSH.
After my first connection scp started working. I am not sure how my first SSH connection solved my problem of scp.
I would appreciate if any one can explain.


How to setup Qt Creator to compile Windows executables?

I found a much easier solution: simply install Qt Creator under Wine.

I had to use winetricks to get the VC++ 2008 runtime files installed first but after that, it worked perfectly.


How to install Edubuntu package in Ubuntu?

Install the metapackage called edubuntu-desktop, then logout and select Edubuntu as session.


Convert software RAID fileserver from Windows to Ubuntu

What you will need first is to get the drivers of your RAID controller compatible for Ubuntu, I would run a LIVE USB Ubuntu and install the drivers there and test later if your 6 HDDs are visible, if you do, I would do the installation of the OS in your SSD drive (I would keep also just incase an image backup of your windows using Clonezilla)


PKCS#7 signature not signed with a trusted key problem, pc not booting graphically

If you are a beginner, this is just about the toughest spot you can be in. This will help.
I had this problem today after an update.  I could see the XFCE desktop did try to start, but it was failing to launch the display manager (either gdm3 or lightdm failed).  End result was Black Screen with that message you saw. I'll be shocked if your problem is not caused by proprietary drivers, probably Nvidia.
I felt lucky to get out of this. When the Black Screen of Death happens, I was not able to get a terminal with Alt + Ctrl + F2. Old time Linux skills came in handy.
In my case, it turned out that the Nvidia drivers were not signed in the expected way. I found posts about corrections proposed for kernel, but I was happy to just get rid of Nvidia drivers so  the computer might start. I'll run without them for a while.
Here's what I did to fix. Use power button to restart. As the system is restarting, hit the Esc key over and over. Pay attention, stop hitting Esc as the small menu appears.  If you accidentally hit escape there, you'll get bumped to grub menu and that's tough to navigate.  I restarted a couple of times to hit Esc just at the right moments.  You arrive at a menu with 3 lines.  The 2nd line is Advanced Ubuntu Options, which is just choosing kernels or recovery modes. Cursor down to recovery mode, pick that, then another menu.  I choose the "root" session.  I do have a root password, I hope you do too.  If you log in with password, you'll be root.
List all files with Nvidia. Prompt will be pound sign.
# dpkg -l | grep nvidia

and then purge those files (whatever name) one by one
# dpkg --purge  ???

It may refuse because of dependencies, but keep trying.
You probably won't have network access at that point, so apt-get installing things won't work.


I found a working solution to the problem.

You need to edit the file /etc/default/grub

$ sudo gedit /etc/default/grub
Go to the line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" and edit it to:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i8042.nopnp=1 i8042.dumbkbd=1"
Update grub

$ sudo update-grub
Reboot your computer.

Source


Are you sure you're not mistaken on speed units?

Keep in mind that speeds shown for WiFi and LAN networks are most of the time represented in Megabits.

But browser and file manager tend to show speed values in Megabytes.

For example for standard WiFi on 2,4 GHz modem the top speed is 72 Mbps, which is around 9 MB/s. But in real world there are many obsticles for WiFi signals, that slows down the speed over it to much less speeds, like 40-50 Mbps, which gives you  only 5 to 6 MB/s.

The reason why WiFi works unstable and slower than LAN is because of the signals from different WiFi networks interfering with each other. On this frequency there is a narrow range of channels on which WiFi can work.

So the solution for your will be to either connect your laptop over wired LAN, or upgrade your WiFi modem to a 5 GHz device, which has much better performance.


Exists some Ubuntu 16.04 known bugs/issues site?

yes! here is Ubuntu's official bug tracking website

https://bugs.launchpad.net/


From what you’ve said, it sounds like VirtualBox is open.

Sometimes, especially on laptops, you can get a “phantom” screen - when Ubuntu thinks there’s a screen connected to the HDMI output (or equivalent) when there’s nothing there.

Ubuntu may still try to display applications on this phantom screen. Try disabling the external screen to avoid this issue. When you do disable it, all of the applications on that screen should move to the only screen connected - the real screen.


I found it.

The configure script was not able to find library links properly. I am writing this, in case there's anyone who has the same problem as mine.

./configure COMPILED_BY="name <email>" LIBS="-lboost_system -lboost_thread"

This solved my problem, and here's some other solutions. [POV-Ray Newsgroup


How to make the terminal autocomplete based on previously entered commands?

To get the behavior you are after, add these lines to your ~/.inputrc (create the file if it does not exist):

"\e[A": history-search-backward
"\e[B": history-search-forward

Then, open a new terminal and it will work as expected. This behavior is controlled by the settings in /etc/inputrc and ~/.inputrc. You can read more about them in the Readline Command Names section of man bash:

   non-incremental-forward-search-history (M-n)
          Search forward  through  the  history  using  a  non-incremental
          search for a string supplied by the user.
   history-search-forward
          Search  forward through the history for the string of characters
          between the start of the current line and the point.  This is  a
          non-incremental search.


How can I change ports on an Docker container?

All you have to do is -p 127.0.0.1:8080:8080 and that would connect the container port to the host port which both happen to be the same number. I personally prefer having the IP address there as well, just for self-documenting the code.


How to make sure that Qt5.4.2 is installed properly

You might have both versions installed, use whereis command to find about all available instance of a program:

whereis command-name

e.g:

whereis qmake

it will tell you if any other version was available, then you can use absolute path to find about its version, like:

/usr/local/bin/qmake -v


Keyboard layout ignored in initramfs since kernel 4.4.0-34. How to use non-US layout?

I had the same problem on a fresh install* of ubuntu 17.10.

This bit of information by F.Raab was proven very useful:

  However /usr/share/initramfs-tools/hooks/console_setup do not generate /etc/console-setup/cached.kmap.gz and just use the existing one, in contrast to Debian. I assume that the generation has to do once right and then it should work again and then call ´update-initramfs -u`.

It seems the file /etc/console-setup/cached.kmap.gz was missing on my system, and apparently, the responsible programs do not create it.

The steps that did work on my system:

cd /etc/console-setup
Find a file to use as template: ls | grep kmap (search for filenames containing 'kmap' in current folder). I choose cached_UTF-8_del.kmap.gz.
Create a duplicate of the template file and call it cached.kmap.gz: sudo cp cached_UTF-8_del.kmap.gz cached.kmap.gz(except NVIDIA drivers enabled via software & updates and grub quiet splash disabled because of shutdown bug)
run sudo update-initramfs -u so cached.kmap.gz can be integrated in the boot sequence.

(I tested that cached.kmap.gz whas being used by running stat cached.kmap.gz before and after step 4 and comparing the access timestamps.)

After reboot, cryptsetup would accept my LUKS pasphrase in my preferred keyboard layout, instead of QUERTY.

(That means cached_UTF-8_del.kmap.gz already contained the correct layout. If above method does not work for you, you may try your luck with one of the commands at Change keyboard layout (English UK) on command line to English US or https://apps.ubuntu.com/cat/applications/language-selector-gnome/)

I'm on kernel 4.13.0-32-generic' (check usinguname -r`). Upgrading the kernel might mitigate the issue as well, but I did not want to do that as I feared that would result in conflicts with the NVIDIA driver again. (Why I had to leave Fedora; after almost every kernel update, my system would turn unstable again, and I don't have the skills and time to solve that.)

* except NVIDIA drivers enabled via software & updates and grub quiet splash disabled because of shutdown bug


fglrx Radeon HD 4550 xorg.conf tweaks 2D performance

I have an mobility radeon hd 4650, in xorg.conf, section device :

Section "Device"
    Identifier  "aticonfig-Device[0]-0"
    Driver      "fglrx"
    Option      "RenderAccel" "true"
    Option      "AllowGLXWithComposite" "true"
EndSection

In section "Screen" I put

   Option      "AddARGBGLXVisuals" "True"

Try this, and see if something works better ...

when I run glxgears:

34947 frames in 5.0 seconds = 6989.268 FPS

good luck


Cannot perform SMART data and Self-Test on external hard drive

I had the same problem. In my case, S.M.A.R.T had been working properly on the device for years while using Ubuntu 12.04, and then under Ubuntu 14.04 it happened exactly what you tell in the question.

The problem is related to a new kernel module that was introduced in Linux Kernel 3.15 called uas (USB Attached SCSI) (see release announcement).

That module is now the responsible of managing USB Mass Storage Devices. There is a thread where people complain that uas in kernel 3.15 is causing their USB devices to fail. Another one says that it might be the cause of S.M.A.R.T problems.

Fortunately, those problems seem to be gone at kernel 3.19 (which I am using), as my device is being detected correctly. Only the S.M.A.R.T problem remains.

To fix it, you need to disable the use of uas module for the given device.

Disable uas without rebooting

First, unplug all USB devices that might be using it. Then, remove the uas and usb-storage modules:

sudo modprobe -r uas
sudo modprobe -r usb-storage

Then, load usb-storage module with a parameter that tells it to not use uas for a given device:

sudo modprobe usb-storage quirks=VendorId:ProductId:u

VendorId and ProductId must be replaced by your device vendor and product id, which can be obtained with lsusb command (they are the characters after ID).

For example, I have the following device:

Bus 002 Device 011: ID 0bc2:3320 Seagate RSS LLC SRD00F2 [Expansion Desktop Drive]

So my vendor id is 0bc2, and my product id is 3320. My command is:

sudo modprobe usb-storage quirks=0bc2:3320:u

The last u tells usb-storage to ignore uas for the device (see source).

At this point, you can insert the USB device, and it will know not to use uas, making S.M.A.R.T work properly. You will see lines like these in dmesg when inserting the USB device:

usb 2-2: UAS is blacklisted for this device, using usb-storage instead
usb-storage 2-2:1.0: USB Mass Storage device detected
usb-storage 2-2:1.0: Quirks match for vid 0bc2 pid 3320: 800000
scsi host12: usb-storage 2-2:1.0

Make the change permanent

The previous quirk will only last until you reboot the system. To make it persistent, you need to follow the steps described here, which I copy below:

First, create a file named ignore_uas.conf in the /etc/modprobe.d/ directory with the following content:

options usb-storage quirks=VendorId:ProductId:u

As before, substitute VendorId and ProductId by your device vendor and product id obtained from lsusb.

Next, regenerate your inital ramdisk:

mkinitcpio -p linux

or, on newer Ubuntu versions:

sudo update-initramfs -u

Finally, reboot your computer.

Edit:
More background on the issue, and another way to get around it without disabling uas (which has better throughput than usb-storage) can be found here: https://www.smartmontools.org/ticket/971#comment:12

It seems that kernel is blacklisting SAT ATA PASS-THROUGH on some devices when running in uas mode, as they have broken firmware.

So, the blacklisting can be disabled (at your own risk) by using the previous method I mention in the answer, but removing the final u from the quirk, ie:

quirks=VendorId:ProductId:

Please note, however, that I have not tested this approach.


Efficient way to copy multiple files using the GUI

I'm sure this a general Linux/Unix behavior since the same thing will happen on a Mac. (Pretty sure it happens with Windows as well.) Every file copy operation is independent and added to the I/O queue and the OS will attempt to execute them simultaneously rather than sequentially even if the destination is the same. Going to a USB device can exacerbate the situation even further since the data throughput is considerably slower than the hard drive; then add the overhead of maintaining the directory information on the USB drive with multiple I/O executions running and it just bogs.

Stick with the Control-click route: if you make a mistake, Control-click the mis-selected file again and it will de-select it.


Cannot uninstall MongoDB on Ubuntu 18.04

When you purged/uninstalled MongoDB, /var/log/mongodb and /var/lib/mongodb were removed automatically. When you tried to remove those "removed" files explicitly, it threw errors,

rm: cannot remove '/var/log/mongodb': No such file or directory
bash: /usr/bin/mongod: No such file or directory

Just because there were indeed no such files.

Moreover after you uninstalled MongoDB, there was still a file /etc/systemd/system/mongodb.service which is used to start/stop/restart MongoDB service via systemctl. Since MongoDB was already uninstalled but that file was still there and it was unable to run that service, thus showed Active: failed.

Remove that file using:

sudo rm /etc/systemd/system/mongodb.service

And you are done. Try checking its status or starting using:

sudo systemctl status mongodb
sudo systemctl start mongodb

You'll get an error like "Service not found". Now there is no service MongoDB in your system


You can always use Wubi. It will install Ubuntu inside your windows partition.


How do I change which mirror I get updates and software from?

Quite easy:

Open the Software & Updates (you can also start this using the software-properties-gtk command)
Find the Download From dropdown and select Other

Choose the server you want:

If you click Select Best Server, the USC will go through a load of tests to find the server that's fastest in your location. Generally it will be a server close by.
For a lot more information on this, see the Ubuntu Community Documentation on Repositories


Tried to change few setting, once I've configured Nvidia X server settings to run on the Intel GPU (and not on Nvidias), the fans seems to be getting quiet, and temps went down.


Ubuntu 14.04 doesn't detect second monitor

Open Additional Driver , then try to use X.org X server. Or if you already use that you can switch to a new driver corresponding to installed VGA card. Most of the times X server works but I don't guarantee about other drivers to respond properly.
Then, in Displays check that both displays are ON.


It is very simple. You need MS Windows to maintain an ntfs volume. Do not use the nfts file format if you only have Ubuntu, and if you are not intending to connect the drive periodically to a Windows system, except if the data on the drive is discardable (I use an ntfs drive for my television, for example) and you are prepared to format now and then (it has been several years since I checked and reformatted my drive.
Background
ntfs remains a proprietary file format developed by Microsoft. While Linux has basic tools to check the ntfs file system, it does not have the capability of Windows tools to check the partitions, and thus may not be able to handle more serious problems with the file system.


Installation of libsasl2-modules-gssapi-mit failed : unmet dependencies

libsasl2-modules-gssapi-mit <- depend on libsasl2-modules

case 1 : libsasl2-modules-gssapi-mit instead of libsasl2
case 1 result is libc6 <- depend on ubuntu-desktop

I guess.. The CDH release target is ubuntu server. (none gui).


I know this is a few months old but perhaps others ending up here from Google can use this advice.

You can add the following to your ~/.ssh/config file. If this file does not exist, you can create it.

host yourpi.local
    IdentityFile ~/.ssh/id_rs

Where yourpi.local is the DNS name or IP address you've configured Deja Dup to use for backups and id_rsa is the name of your private key file.

This will fix your issue with Deja Dup and also remove the need to pass -i to your ssh command if that is currently how you invoke it.

Good luck!


The underlying problem is that Qt5's QMimeDatabase changed DjVu MIME type from "image/vnd.djvu" to "image/vnd.djvu+multipage". It's already fixed in qpdfview 0.4.16 but it's not yet available in any repository at the time of writing despite being released 9 months ago.

Workaround is to build the updated package yourself:

wget https://launchpad.net/qpdfview/trunk/0.4.16/+download/qpdfview-0.4.16.tar.gz
sudo apt build-dep qpdfview
apt source qpdfview
cd qpdfview-0.4.14
uupdate ../qpdfview-0.4.16.tar.gz
cd ../qpdfview-0.4.16
dpkg-buildpackage -us -uc -nc
cd ..
sudo dpkg -i qpdfview_0.4.16-0ubuntu1_*.deb qpdfview-djvu-plugin_0.4.16-0ubuntu1_*.deb


Trying to write the perfect VPN kill-switch bash script - have a question about wlp3s0 traffic. Ubuntu 18.04

The wlp3s0 is your physical adapter, the tun0 is created on top of this adapter. The reason you see traffic on wlp3s0 is because tun0 is tunneling traffic over wlp3s0. The packets are being encrypted when they reach tun0 and are sent via wlp3s0 to the Openvpn server.

If you stop traffic via iptables on the wlp3s0 you will loose your vpn tun0 connection as well.


xfce4-terminal on Plasma change window color/style to dark

try this
to open directly this^ setting window, run:
kcmshell5 style

If this^ not help - try this :
https://wiki.archlinux.org/index.php/KDE#GTK_application_appearance
https://wiki.archlinux.org/index.php/Uniform_look_for_Qt_and_GTK_applications


How to run a program from the command line and still be able to work on the command line while it runs?

Just add a & after the command. This will make the command run on the background.

Notice that you will still get the output of it, so you may want to redirect the output to /dev/null or to some configuration file.

E.g. in order to redirect both stdout and stderr:

java myProgram > /dev/null 2>&1 &


Yes. Ubuntu by default support VNC. Try using Terminal Server or Remote Desktop Viewer.


What's the monitor-sensor file in the /bin folder of ubuntu? What does it do?

based on the file /bin/monitor-sensor you can simply search for package details

for Example: https://packages.ubuntu.com/search?mode=filename&suite=eoan&section=all&arch=any&keywords=monitor-sensor&searchon=contents

the Package is iio-sensor-proxy (2.8-0ubuntu1)

then you can do apt show iiiio-sensor-proxy

pratap@i7-4770:~$ apt show iio-sensor-proxy
Package: iio-sensor-proxy
Version: 2.8-0ubuntu1
Priority: optional
Section: utils
Origin: Ubuntu
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Ritesh Raj Sarraf <rrs@debian.org>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 167 kB
Depends: libc6 (>= 2.7), libglib2.0-0 (>= 2.39.90), libgudev-1.0-0 (>= 146), systemd
Homepage: https://github.com/hadess/iio-sensor-proxy
Task: ubuntu-desktop-minimal, ubuntu-desktop, ubuntu-desktop-minimal-default-languages, ubuntu-desktop-minimal-default-languages, ubuntu-desktop-minimal-default-languages, ubuntu-desktop-minimal-default-languages, ubuntu-desktop-minimal-default-languages, ubuntu-desktop-minimal-default-languages, ubuntu-desktop-minimal-default-languages, ubuntu-desktop-default-languages, ubuntu-desktop-default-languages, ubuntu-desktop-default-languages, ubuntu-desktop-default-languages, ubuntu-desktop-default-languages, ubuntu-desktop-default-languages, ubuntu-desktop-default-languages, kubuntu-desktop, lubuntu-desktop, ubuntustudio-video, ubuntustudio-publishing, ubuntukylin-desktop, ubuntu-mate-desktop, ubuntu-budgie-desktop
Supported: 9m
Download-Size: 35.5 kB
APT-Manual-Installed: no
APT-Sources: http://in.archive.ubuntu.com/ubuntu eoan/main amd64 Packages
Description: IIO sensors to D-Bus proxy
 Industrial I/O subsystem is intended to provide support for devices
 that in some sense are analog to digital or digital to analog convertors
 .
 Devices that fall into this category are:
  * ADCs
  * Accelerometers
  * Gyros
  * IMUs
  * Capacitance to Digital Converters (CDCs)
  * Pressure Sensors
  * Color, Light and Proximity Sensors
  * Temperature Sensors
  * Magnetometers
  * DACs
  * DDS (Direct Digital Synthesis)
  * PLLs (Phase Locked Loops)
  * Variable/Programmable Gain Amplifiers (VGA, PGA)
 .
 Many ultrabooks ship with some of these devices. iio-sensor-proxy is
 intended to serve as a proxy, providing access to these devices through
 a D-Bus interface

pratap@i7-4770:~$


Given this started immediately after you replaced the CPU cooler, I can only point to a problem with the new CPU cooler (fan not running, bad contact with the CPU, lack of thermal paste, no liquid in a liquid cooling device, etc.) as the most likely source of the problem.


You can do this using terminal command:
ln -s filepath linkpath

You can also hold Shift + Ctrl and drag a file where you want to make a shortcut.
If you want executables then you need *.desktop file. Here is a link how to use it. Do not forget to add permissions for executing. If you want this shortcut to be shown in applications menu put desktop file in ~/.local/share/applications.


Ubuntu 16.04 fresh install, extremely slow

Problem solved by installing proprietary Nvidia graphics driver.

I noticed that Xorg process has been using 99.9 of CPU


Firstly, this is not the system cache.  The system cache is a cache that resides in memory and occupies physical memory that is not otherwise used by applications.

This is a .cache folder inside your home directory, so not system-wide at all.  You can, if you need the space, safely delete it (only a misbehaving program would die if you delete stuff it's put in ~/.cache).

To answer your question though, deja-dup is a backup tool provided by Ubuntu.  The cache probably helps it keep track of all the files in your backup sets.  It probably saves a fair bit of time re-generating this information each time the backup process starts.  Every file in your backup sets, it appears, has signatures stored in a cache.

5G does sound like a lot, though.  If you don't use deja-dup, or you don't care about it losing its cache and being a lot more slow next time it starts, you could delete it.


If you're using php5 in 18.04 then you won't be able to do it via

apt-get install php

since that installs php 7.2. If you're fine with that, then you're set. If you require php 5.6, you'll have to use ondrej/php repo which is outside of a default ubuntu repo. You can do that by adding the ppa:ondrej/php repo and then install php5.6. It should look something like this

sudo add-apt-repository ppa:ondrej/php
sudo apt-get update
sudo apt-get install php5.6

If you're suspecting php already is installed on the server, then you can do a few things to figure that out. This will show you what version is installed.

php --version

If you get a command not found, then chances are it is not installed. If it comes back with a version and you want to see where the bin is then you can run this to find it

which php

and that will give you the path to the file it's using. If you need to find if it's installed via apt (standard way to install)

sudo apt list --installed | grep php

and that will list all packages installed with php in their name.


Firefox slow at loading websites on Ubuntu 14.04

The update with Firefox version 43.0.4 seems to solved the problem.
Thanks everyone who helped :)


How to preserve custom configurations across reboots when using juju and maas?

The system config will happen in two places: in the commissioning phase, when the 'OS is installed', and in the charms that get deployed, when configuration can happen.

If the config your want is at the OS / hardware setup level, then look into commissioning scripts. If it's more related to the workload, look into a subordinate charm that you can deploy onto any machine to get the result you want.


Issue when try to access Windows 7 folder from Ubuntu 14.04 PC

Try going to the Connect to server on the Left side panel of nautilus and type in the address bar:
smb://XXX.XXX.XXX.XXX, Where X is the IP address of your Windows 7 PC on your local network. Works for Me. Don`t know why it happens though.

Also, you may want to change the settings from: let Windows manage to: use User accounts and passwords, in your sharing tab.


Codeblocks not running at all after installation

Something similar happend to me. The right thing to do is try for a full reinstalation.

$ sudo apt-get autoremove --purge codeblocks

This will delete all your configuration files and remove used packages along with codeblocks like codeblocks-common, etc.

If you install again, it'll run with no visible erros, but chances are it'll not install codeblocks-contrib due to version incompatibility if your packages are broken like mine was.
And trying to run codeblocks from will get you a "codeblocks: symbol lookup error"

The fix for me was to first, purge libcodeblocks0 which was broken for me

$ sudo apt-get remove --purge libcodeblocks0

Then install it again with

$ sudo apt-get update
$ sudo apt-get install codeblocks


How can you use Imagemagick crop to get first 100px from an image?

You need to add the information from which X and Y you want to start, otherwise Imagemagick will repeat the crop:

convert foo.png -gravity north -crop 1000x100+0+0 bar.png


Ubuntu 18.04: GUI not starting after fresh install

I do not know what caused this issue, but I fixed it by following some steps from Ubuntu Wiki. I had originally switched to lightdm but I had to switch back to gdm3 using sudo dpkg-reconfigure gdm3 for the following to work.
First I reinstalled xserver-xorg-video-ati. The package was already installed, but I ran the command anyways.
sudo apt-get install xserver-xorg-video-ati --reinstall

Then I had to create /etc/X11/xorg.conf and edit as as follows:
Section "Device"
    Identifier  "Card0"
    Driver      "radeon"
EndSection

Then after restarting the GUI was started.


The program 'iptables' is currently not installed

Credit to kraxor's comment on the original question:

You should try reinstalling iptables by executing the following command:

sudo apt-get --reinstall install iptables


Cannot install a downloaded flashplayer 11 application for linux

You do not need to download anything. You can run in terminal

sudo apt-get install flashplugin-installer

and flash will be installed.

Ubuntu is not Windows. In most of cases you do not need to download software from sites.


Removing Ubuntu 14.04 and re-install 12.04?

I would open the tray and reboot, preferably with alt-ctrl-del if possible. It should not take that long to load. But, if you have unlimit data, or even the .iso on a PC, you might want to try a fresh dvd, if that one shows signs of wear. I would completely understand if your on a machine with Rambus or something, but if you had it on your system, your system should be capable of loading the cd in a timely fashion.

getting a .iso of Precise can be done from:

http://releases.ubuntu.com/precise/

and it's the latest, so less time doing updates after install.


Slideshow of Image Folder whose files increase

I suggest that you use Eye of Gnome (Ubuntu package name: eog). I just tested Eye of Gnome version 3.10.2 under Ubuntu 14.04, and confirmed that it does successfully detect new images in a directory and incorporate them into a running slideshow.

Here's the bash script I used to test the functionality (requires ImageMagick):

#!/bin/bash

TEMPDIR=$(mktemp -d)

function deletetempdir {
  rm -rf "$TEMPDIR"
}

# Automatically remove slideshow directory on exit
trap deletetempdir EXIT

function makeimage {
  convert -size 500x100 xc:white -pointsize 72 \
          -draw "text 5,60 '$1'" $TEMPDIR/$2.png
}

makeimage One 1
makeimage Two 2

eog -s $TEMPDIR & # start EOG in slideshow mode

sleep 30

makeimage 'New image!' 3

sleep 30

kill $! # kill EOG

EOG will cycle between the two initial images for 30 seconds; at this point, the script creates a new image, which EOG adds automatically to the end of the slideshow.


Packages required for website deployment using apache on Ubuntu 20.04

To install the Apache server packages on Ubuntu 20.nn
sudo apt update

Then install the apache2 package
sudo apt install apache2

If you are have the firewall enabled list your firewall applications profiles..
sudo ufw app list

Which will give you something like..
Available applications:
  Apache
  Apache Full
  Apache Secure
  OpenSSH

Now choose which one you want Apache..
e.g.
sudo ufw allow Apache
Job done


Set the terminal title in a .desktop started application

Leave the Exec untouched and add those two lines on top of the script invoked by the XTERM:

test -x /usr/bin/xtitle || sudo apt-get install -y xtitle || exit 1
xtitle "My Title"


Cannon Point-LP CNVi [Wireless-AC] Device not working

I still can't comment so it's hard to ask clarifying questions. It looks like there were known issues with this WiFi card on Linux firmware version 20190628. AFAICT it was fixed upstream: https://bugzilla.kernel.org/show_bug.cgi?id=203315

I would suggest one of two possible lines of action. The first, is simply try the recently released 20.04 live CD and see if your WiFi works in that live environment. 20.04 will have a newer kernel than 19.10 did and so should include this firmware fix.

If for some reason that's not an option or does not work you can always install the backports iwlwifi kernel module via the command line:

sudo apt update
sudo apt install backport-iwlwifi-dkms

I'll be honest, I'm not sure the iwlwifi kernel module will actually help if it's a Linux firmware bug. So my recommendation would be to try and prefer the 20.04 live CD solution.


Laptop no longer wakes up from sleep when opened


I am not sure if I am interpreting your question correctly, but a few things to help test if you can in fact see your router from your server.
Because NetPlan now is the default manager, we can ignore /etc/resolv.conf, however to view or modify on Ubuntu you can set your DNS settings via /etc/resolv.conf as follows:
nameserver 127.0.0.53
options edns0
search internal-network.local

If you are using resolv and not Netplan, point this at your DNS provider (in this question, PiHole I surmise), and restart the service:
sudo systemctl status resolvconf.service

From here, you can then test to see if you can reach your router or DNS provider. If you simply ping the IP address of your destination (removing DNS from the equation) you should see if you can hit your L2 next-hop. You can find this out quite easily:
ip a | grep default

default via 192.168.0.1 dev eno2
default via 192.168.0.1 dev eno2 proto dhcp metric 100

(Noting your ranges will vary)
From there perform a basic ping -c 1 192.168.0.1 to ensure you have connectivity. From here you can start to validate that you have L2 network access.
Your Question

I get the feeling that the server cannot find the router

This is pretty open. If you've configured your DHCP leases (or your static routes correctly) then that should be fine. On your server, have a look at the netplan configuration and ensure you've set it correctly.
Run cat /var/lib/NetworkManager/internal... (noting the file is unique, use tab to auto-complete) to see your DHCP data:
# This is private data. Do not parse.
ADDRESS=192.168.0.9
NETMASK=255.255.255.0
ROUTER=192.168.0.1
SERVER_ADDRESS=192.168.0.1
T1=42600
T2=74550
LIFETIME=85200
DNS=8.8.8.8 8.8.4.4
DOMAINNAME=internal-network.local
CLIENTID=01b42e9933fa61

If you've got the correct information here (ROUTER, NETMASK and SERVER_ADDRESS) then your problem is something else. A simple ICMP ping will denote whether you've got access to your router. If you're in the same logical network (I'm going to guess you're on a convention /24 range (255.255.255.0/24)) then you should also be see your DNS setup without the requirement to route.

IP route show gives me no info at all. I get the feeling that the server can't find the router?

This will give you all the information you require. If your DNS server is not within the same broadcast domain,  you'll need to route to it. If this is in the same logical subnet then you should be able to abide by the default route on your box (an assumption is being made you have 1 logical NIC) - and even if not, as long as default knows how to route to $x you're fine.
The question here is does your server have the capacity to route via your router to the internet. Start by identifying your routers internal IP address and see if you can get to it - then, try an internet address:
m-(~)-(15 files, 1.5Mb)--> traceroute 1.1.1.1
traceroute to 1.1.1.1 (1.1.1.1), 64 hops max
  1   192.168.0.1  0.505ms  0.395ms  0.301ms
  2   58.162.26.2  1.810ms  1.904ms  1.923ms

The first hop is my router, and then out to the internet. If you've got dual NICs, you might want to add a route:
ip route add 1.1.1.1/32 via 192.168.0.1

Retest this single host and see if your route changes.


You can try this. Open the terminal and type:

gksu gedit /etc/systemd/logind.conf

Set these two lines to look like this:

HandleLidSwitch=suspend
HandleLidSwitchDocked=ignore

Save the file, reboot and test it under the two environments (docked and undocked).

If unacceptable results, change your power settings to "Do nothing" on the lid close event where you have it set to "Suspend" now. You shouldn't have to reboot to test your two environments again.


Problem with internet speed checking with speedtest --simple

Are you sure you're using the same driver for your network card? Are we talking about wifi or ethernet connection? Please post the results of the following command run in a terminal:  inxi -Fxzd


How do I get my EPG to come back on mythTV?

If your box stopped, crashed or you switched it off etc. - it is feasible one of the mythconverg tables got corrupted - in which case you need to run mysqlrepair

mysqlrepair -u mythtv -p mythconverg

It will ask you for a password - which you can find in the .mythtv/mysql.txt file.


This morning I booted the PC and it booted with one of my screens not working. Under the about Ubuntu it said 15.10.

I did a apt-get dist-upgrade and received errors about the software centre that has issues and some errors that I cant remember.

After some research I found that apparently there is also a bug in the distribution script which does not upgrade the kernel to 4.2 as well.

I started by apt-get -f install to fix issues with software centre. Rebooted and then apt-get clean and apt-get update. After this apt-get install linux-generic to upgrade the kernel. Rebooted and then apt-get update && apt-get dist-upgrade again to check if all is up to date and working. And yes it was.

Hope this info helps with similar issues.


Problem Configuring DNS on ubuntu server running as a virtual machine

After trying for hours and hours, I was finally able to solve the problem and get DNS working. The major problem was the settings of the virtual box machine. Earlier I wasn't paying much attention to them but as suggested by @abdulkadir(see comments), I spent time there and got the success.

network details

network: 192.168.2.0/24
gateway/router : 192.168.2.1

Here is the solution:

first of all network settings for dns server:

network settings on the client machine:

Interface file(DNS side):

named.conf.options file:

named.conf.local file:

forward zone file:

reverse zone file:

Interface file(client side)

This setup worked absolutely fine for me.
I would specifically like to mentions that I didn't make any changes to "resolv.conf", "hosts" or "hostnames" file. Some of the sources on the web were suggesting that.

Thanks.


libtxc-dxtn & libtxc-dxtn:i386 not found in ppa - 18.04 Bionic

You can compile it from sources
Sources are not maintained since 2 years
The code is hosted on freedesktops git infrastructure at: http://cgit.freedesktop.org/~mareko/libtxc_dxtn/

Here is how to compile the libtxc-dxtn library
Run those lines as USER

# required stuff
sudo apt-get install mesa-common-dev
# get source files
cd ~/
wget https://people.freedesktop.org/~cbrill/libtxc_dxtn/libtxc_dxtn-1.0.1.tar.gz
tar xvfz libtxc_dxtn-1.0.1.tar.gz
cd libtxc_dxtn-1.0.1
# start the job
./configure
make
sudo make install
# clean up sources (optional)
cd ..
rm -rf libtxc_dxtn-1.0.1 libtxc_dxtn-1.0.1.tar.gz


youtube-dl /usr/bin/env: ‘python’: No such file or directory

In Ubuntu 20.04, python3 is the installed default. The python variable is not set:

❯ which python
python not found

We can get around this by using python3 and which:

❯ python3 $(which youtube-dl) https://www.youtube.com/watch?v=0IE-CXNs6Sw
[youtube] 0IE-CXNs6Sw: Downloading webpage


If you want to set up name resolution inside a LAN i can think of 2 options:

1. Set up a DNS-server

Run: sudo apt-get install named on one of the servers, configure the DNS-server and point to that server by editing /etc/resolv.conf or using resolvconf if that's what you use.

2 . edit /etc/hosts

Simply edit this file and add the ip-address & desired name.
This has to be done on each machine individually.


This is most probably a bug and is reported here

Another solution you have is*  -
Type the following two commands

  cat /var/lib/update-notifier/user.d/data-downloads-failed
  cat /var/lib/update-notifier/user.d/data-downloads-failed-permanently

If any one of htem gives you the same error which you are getting then type
sudo rm /var/lib/update-notifier/user.d/data-downloads-failed

*i would suggest you not to use the commands & wait till the bug gets fixed.


new install of Ubuntu will not go past password login

If you want to uninstall Ubuntu and install another OS or reinstall Ubuntu, you can just put in the installation material of the OS (USB, CD etc.) Then before the booting of Ubuntu begins you use the pre-defined button(s) to go into BIOS. (They differ between computers so I can't tell what buttons they are, but in most cases it prints it on screen when you start your computer up. Or you can Google it.) Set the boot options so the computer boots your installation material before booting OS. From there, you can install the OS of your choosing.

However if you didn't mean to go back to Windows by saying "totally starting over" then I think instead of performing a reinstall you can simply use recovery mode following the instructions from here and get rid of your problem.

How you want to approach the situation is up to you.


I'm not sure what you had set up before, but you can output stderr and stdout to /dev/null, and disown the process:

command > /dev/null 2>&1 & disown

$ tail -f /var/log/messages > /dev/null 2>&1 & disown
[1] 12345
$

Do not confuse & and && here.  & runs the command in the background, while disown  'de-couples' the background from the terminal process a bit.  You can set up a BASH script, function, or alias to wrap your commands in something similar.


is there an IDE and compiler for c# in ubuntu?

If you already have experience with Visual Studio, your best bet is to use Mono. Mono is a Visual Studio equivalent for Linux, compatible with Visual Basic and C# code, a great thing for a beginner Ubuntu user that was a .Net programmer on Windows. Eclipse IDE is also a great and very powerful programming tool also compatible with C#. Both are available through the Ubuntu Software Center. If you are wanting a way to develop programs through a graphical interface quickly, your best bet is Quickly, also available through the software center. It uses python however, not C#. But it is very beginner-friendly and is the quickest way to start making apps for Ubuntu. Beyond that, do some searching in the software center and see if there's an alternative that you like better. Try Em all out, if you want. Hope that helps!
Some screenshots:

Mono:

Eclipse:

Quickly:

More information on developing for Ubuntu can be found at developer.ubuntu.com.


If I've installed an application both as a snap and via APT, how can I tell which one is currently running?

Call each one separately
You can start a specific version of an application by providing the full path name of the executable. Firefox, e.g., installed using APT will be launched by /usr/bin/firefox. The executables of snap applications are under /snap/bin/ so /snap/bin/firefox will launch the snap version.
Typing firefox will launch the APT version, because /usr/bin is listed earlier in the search path than /snap/bin in a default Ubuntu install. The default PATH is:
$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

When you simply type firefox, the system searches each of the consecutive directories (folders) until an executable with the name firefox is found. If the APT version is installed, it will find the executable in /usr/bin before searching /snap/bin, so the search will be stopped and that executable will be launched.
You can learn which executable will be launched with the command which.
$ which firefox
/usr/bin/firefox

You can learn which executables you have installed with the command whereis:
$ whereis firefox
firefox: /usr/bin/firefox /usr/lib/firefox /etc/firefox /snap/bin/firefox /usr/share/man/man1/firefox.1.gz

Here, both the APT and the snap version of firefox are installed.
Know which one is running
Running processes
The command ps ax lists all running processes. Thus:
ps ax | grep firefox

will list all processes with the name "firefox". The output includes the full pathname of the executable.
Creator of a specific window
It is also possible to identify the creator of a specific window, to learn whether the open window is from the APT or the snap version. However, this is rather complicated and not always reliable. See the Unix & Linux Stackexchange questions What process created this X11 window? and What process created this window with no PID associated?.


Thanks to the help of thp I resolved this.

Turns out I need to install version 3.6.1, which can be done from the .deb file here.

This now made ipod reappear as a device option, and after a reinstall of libgpod4 with sudo apt-get install --reinstall libgpod4 my ability to sync with ctrl+s was restored.

I also found that to enable the system tray icon for gpodder on Ubuntu 13.10 I need to manually install appindicator by sudo apt-get install python-appindicator.

Finally, gpodder --verbose also gave the error No module named eyed3 on my system, this can be resolved by changing eyed3.mp3 to eyeD3.mp3 everywhere in
/usr/lib/pymodules/python2.7/gpodder/sync.py.

Now gpodder luanches without error and I can sync my ipod again!

The only thing that seems to be missing is the ability to right-click and sync a single podcast to ipod.


How do I purge PHP 7, install PHP 5.6, and still get phpMyAdmin?

you may need to disable the proxy_fcgi apache module:

sudo a2dismod proxy_fcgi proxy; sudo service apache2 restart

1. Re-Install PHP 5.6

Actually is not required to remove php7.0, you can install php5.6 together ( also because you will have dependency problem with phpmyadmin package that required php7.0)

Assuming libapache2-mod-php is a suitable way to enable PHP in Apache for you, you can proceed in this way:

sudo add-apt-repository ppa:ondrej/php

sudo apt-get update

sudo apt-get install php7.0 php5.6 php5.6-mysql php-gettext php5.6-mbstring php-xdebug libapache2-mod-php5.6 libapache2-mod-php7.0


New message when rebooting from login screen: Authentication is required for rebooting the system while an application asked to inhibit it

You can get a list of all systemd inhibitors with this:

$ systemd-inhibit --list

     Who: rick (UID 1000/rick, PID 2358/unity-settings-)
    What: sleep
     Why: GNOME needs to lock the screen
    Mode: delay

     Who: rick (UID 1000/rick, PID 2358/unity-settings-)
    What: handle-power-key:handle-suspend-key:handle-hibernate-key
     Why: GNOME handling keypresses
    Mode: block

     Who: NetworkManager (UID 0/root, PID 1189/NetworkManager)
    What: sleep
     Why: NetworkManager needs to turn off networks
    Mode: delay

     Who: Unattended Upgrades Shutdown (UID 0/root, PID 1372/unattended-upgr)
    What: shutdown
     Why: Stop ongoing upgrades or perform upgrades before shutdown
    Mode: delay

     Who: rick (UID 1000/rick, PID 2358/unity-settings-)
    What: handle-lid-switch
     Why: Multiple displays attached
    Mode: block

5 inhibitors listed.

However the list doesn't change after you open a file for editing for example. You can use this instead:

$ dbus-send --print-reply --dest=org.gnome.SessionManager /org/gnome/SessionManager org.gnome.SessionManager.GetInhibitors

method return time=1573403207.555584 sender=:1.49 -> destination=:1.1853 serial=7743 reply_serial=2
   array [
   ]

$ gedit temp &

# Now type some text into gedit but don't save the file

$ dbus-send --print-reply --dest=org.gnome.SessionManager /org/gnome/SessionManager org.gnome.SessionManager.GetInhibitors

method return time=1573403241.678869 sender=:1.49 -> destination=:1.1855 serial=7747 reply_serial=2
   array [
      object path "/org/gnome/SessionManager/Inhibitor1727"
   ]

In the first instance there are no inhibitor locks. We edit a file in gedit and in the second instance a lock exists. However it doesn't actually tell us the name gedit.


I googled about the Default Keyring Application on Xubuntu and found out GNOME Keyring Manager daemon takes care of the password.

From here, found where GNOME Keyring stores its files. Then deleted those files and it asked for password a last time and now it is back to normal. No more asking for setting up of new password at each boot.

Deleting files stored in given folder did the work for me.

~/.local/share/keyrings

P.S.: I only deleted files not any folder(which weren't present there anyways.)


I can't set Xubuntu 13.04 to connect to the nearest access point

Actually, I am using Ubuntu, but I am pretty sure there must be something very similar to this on xubuntu:

Edit Network Connections -> choose the connection you do not want to connect to, click edit -> under the tab "General" uncheck the box "automatically connect to this network when it is available"

Repeat those steps for all connections you do not want your system to connect to.


Ubuntu 18.04 : how to use Lightning (Thunderbird calendar) in place of Gnome agenda?

I found an solution : there is an Thunderbird extension that does what I want.
EDS Calendar integration integrates calendars events with Gnome clock applet.
And there is nothing else to install, as evolution-data-server is already part of Ubuntu 18.04.
You only need to install v0.5 (last one is v0.5.1) to be compliant with Thunderbird v52.
Cool ! 8-)


Ubuntu freezing irregularly for unknown reason

With only 4G RAM, and 2G swap, it leads me to think that you've got a swap problem. We'll increase the /swapfile from 2G to 4G.
Note: Incorrect use of the dd command can cause data loss. Suggest copy/paste.
sudo swapoff -a           # turn off swap
sudo rm -i /swapfile      # remove old /swapfile

sudo dd if=/dev/zero of=/swapfile bs=1M count=4096

sudo chmod 600 /swapfile  # set proper file protections
sudo mkswap /swapfile     # init /swapfile
sudo swapon /swapfile     # turn on swap
free -h                   # confirm 4G RAM and 4G swap
reboot                    # reboot and verify operation


Same for me. I was forced to install juju-gui manually (xenial version):

juju deploy cs:juju-gui-142 --series xenial
juju expose juju-gui

Login info:

juju show-controller --show-password


Hmmm there are a lot reasons it might not work. Often, it's because of a quite complex reason.

What you can try:

Press the 'off' button on the laptop. Maybe it only works after pressing Ctrl+alt+F2.
Press Ctrl+Alt+F2 and then Ctrl+Alt+Del (this will reboot, but you can press the 'off' button while in the bios/boot screen, when it displays the Thinkpad logo). Sometimes, I have to do this more than once before rebooting actually happens.
If all else fails, you can press the 'off' button for ~5 seconds until the system goes down. This is basically the same as switching off the power, so not recommended, but sometimes it's the only thing that's left.

Note, Ctrl+Alt+Fx switches virtual terminals. You can go back to the graphical screen with Ctrl+Alt+F7.

This is probably too late, but I thought in case it happens again.


Correct way to set which clang binaries to use

You could probably create a symbolic link (symlink) in a directory that is already a part of both shells' PATH like /usr/local/bin, name it clang and link it to the actual binary in /usr/lib/llvm-3.6/bin or wherever it is:

sudo ln -s /usr/lib/llvm-3.6/bin/clang /usr/local/bin/

That way, the shell finds the link if you type cname, resolves it to the real file and runs that one. It links to the name of the file, so as long as the file name and location of the binary does not get changed, it's fine. You may even replace it with an updated version as long as it is not named differently.

The only alternative is to change your PATH variable.


But there is soution:

1) You can get this driver "redirfs,avflt,dazuko -- kernel 3.18 or lower" needed from here:

http://www.bondoffamily-net.com/~kinta-chan/techknow/DownLoad/DownLoad.html

2) Go to folder where you downloaded the driver:

sudo mv driver.tar /opt/COMODO/driver.tar

3) Then change directory

cd /opt/COMODO

4) Install it
sudo ./post_setup.sh
(Please be carefull at end of licence you NEED to accept with Y and then you can add email address, and choose Language 8)

5) Restart cmdavd
/etc/init.d/cmdavd restart

6) Reboot if must

7) RIGHT CLICK on System Tray icon and click

Antivirus Security Level
On Access

DONE!!!


Ubuntu 12.10 Dell/Broadcom BCM43142 driver install trouble

Please try:

sudo apt-get install --reinstall linux-headers-`uname -r`

Those backticks are on the left side of my US keyboard on the same key with ~. After the headers for your currently running kernel are reinstalled, try again:

sudo dpkg -i wire*.deb


can use c++ write custom qml plugins in ubuntu sdk

I just learned how to do this, and I wrote up what I learned here.  I'll repeat the basic ideas here.

Whichever C++ classes you wish to expose can be left mostly as is.  Any methods that you want exposed to QML need to be prefixed with Q_INVOKABLE in the header file.  To represent the plugin, you need a class that inherits from QQmlExtensionPlugin which has a registerTypes method that calls qmlRegisterType on each class to be exposed to QML.

The dialog you mention, was it this?

If so, then for "Command" put qmlscene and for "Arguments", -I <DIR> <QML>, where <DIR> is the directory containing the plugin directory (likely ., the project directory) and <QML> is your main .qml file.  Again, see my post for a more thorough explanation and a downloadable example.


Should `arm-none-eabi-gcc` include a `stdio.h`?

Well, that was easy. I just needed to install libnewlib-arm-none-eabi and now everything works. I guess that package is basically 'libc' for this compiler.


Disabling Secure Boot solved the problem.


How to do screencasting (desktop recording) with high quality audio and video?

The solution I like is to use SimpleScreenRecorder. Here's how I did it:

How to build and install latest SimpleScreenRecorder from git?

My solution turned out to be simple to follow once I got the help I needed. I hope others can follow the dev's git instructions now.

Here's more info on SSR:

Main page - SimpleScreenRecorder - Maarten Baert's website

SimpleScreenRecorder is a Linux program that I've created to record programs and games. There were already a few programs that could do this, but I wasn't 100% happy with any of them, so I created my own.

My original goal was to create a program that was just really simple to use, but as I was writing it I started adding more and more features, and the result is actually a pretty powerful program. It's 'simple' in the sense that it's easier to use than ffmpeg/avconv or VLC, because it has a straightforward user interface.

Features

Graphical user interface (Qt-based).
Faster than VLC and ffmpeg/avconv.
Records the entire screen or part of it, or records OpenGL applications directly (similar to Fraps on Windows).
Synchronizes audio and video properly (a common issue with VLC and ffmpeg/avconv).
Reduces the video frame rate if your computer is too slow (rather than using up all your RAM like VLC does).
Fully multithreaded: small delays in any of the components will never block the other components, resulting is smoother video and better performance on computers with multiple processors.
Pause and resume recording at any time (either by clicking a button or by pressing a hotkey).
Shows statistics during recording (file size, bit rate, total recording time, actual frame rate, ...).
Can show a preview during recording, so you don't waste time recording something only to figure out afterwards that some setting was wrong.
Uses libav/ffmpeg libraries for encoding, so it supports many different codecs and file formats (adding more is trivial).
Can also do live streaming (experimental).
Sensible default settings: no need to change anything if you don't want to.
Tooltips for almost everything: no need to read the documentation to find out what something does.


How to remove icons from ''all applications''?

Certain desktops come with a menu editor, in which you could remove the entries.

Else, open the directory .local/share/applications/ in a terminal or file browser and remove the .desktop files you don't need any longer.


How to find the final target of a daisy-chain of symbolic links?

Use readlink -e <linkfile>. See readlink's manpage for more info on its arguments.


There are some reasons :

The sound may be muted or has been set to zero value.

For this, check the right most corner and click on the sound icon and raise your sound volume.
The login sound could be disabled from the  Startup applications. It can be found in right most corner of your screen from where you logout.

For this, verify that a check sign is there on Gnome login sound.
Or if you changed something accidentally and don't know what you changed.

Then use this method:

Install dconf-tools  from software-center and then open it.

Go to org/ gnome/desktop/application/sound and then point your cursor to event-sounds. On the bottom of dconf editor, there is to set to default option, click on it and log out and login from your account.


Is there any user-friendly nurbs modelling software

I think Google Sketch Up works pretty well with wine: http://wiki.winehq.org/GoogleSketchup


How can I change or delete the shortcut to shade/roll up a window in Ubuntu 20.04?

The toggle-shade shortcut is not enabled by default and is not accessible using Keyboard Shortcuts.
In order to reset it to its default setting (no shortcut), you can run the following gsettings command:
gsettings reset org.gnome.desktop.wm.keybindings toggle-shaded

There is also a graphical way to reset it using dconf-editor:

Install dconf-editor using:
sudo apt install dconf-editor

Open dconf Editor.

Go to /org/gnome/desktop/wm/keybindings/toggle-shaded.

Enable Use default value.


Assuming, your file is in your Downloads folder, press Ctrl+Alt+T and type:

chmod +x ~/Downloads/jmf.bin

and start the installation with:

sudo ~/Downloads/jmf.bin

If your file is in your current folder

chmod +x jmf.bin

and start with

sudo ./jmf.bin

If your file contains brackets, eg. ( and/or ) than use double quotes for the filename

chmod +x "jmf(.bin)"

and start with

sudo "./jmf(.bin)"


There are problems with Wine and YnHub for a while now.

Since you have linux, why don't you use Verlihub or PtokaX instead? They are more robust and of course, YnHub has many connection problems even on Windows (not mentioning MANY security issues).

EDIT: Or other solution, you must create Virtual Machine with Windows installed and then use YnHub on Windows within virtual OS.

Edit: You may also use port forwarding from a your router to help you. Just create YnHub port to one that is higher than 1023 and then use port forwarding from outside port 511 to your internal YnHub port.


How are the various ulimit values for a process set?

If you have not changed the value of any resource shown by ulimit, it would use the default value which is what you see while running the shell built-in ulimit -a. Note that the system call inolved in getting the value is getrlimit(2).

Again if you need to change the value you need to use setrlimit(2) system call, ulimit does exactly this while setting a new resoure limit for processes.

The resource limits shown in ulimit are applied on individual processes, not users.

To set the new value for the number of open file descriptors (default is 1024) per process, you can use :

ulimit -n 512

Note that you can check the hard limit and soft limits with ulimit -Hn and ulimit -Sn respectively. You can decrease to any value and increase upto the hard limit.

To increase the limit beyond current hard limit (1024) you need to be root.

Note that you can not increase the value beyond kernel specified maximum.

Now there is a file /etc/security/limits.conf that is used by pam specifically pam_limits.so upon start of each user session, you can set values here to take permanent effect as ulimit set values only for the running session.

Although you need to set the values on this file on a user/group basis the limits are applicable on per process under that user/group apart from some items like maxsyslogins, maxlogins. /etc/security/limits.conf has sufficient description within the file to get you started.

Also check help ulimit, man 2 setrlimit to get more idea.


How do I allow a user access to one specific directory and its contents?

I am not sure but sudo chown -R a_user /var/www/site1 might work.

Or if you want any other users to access the directory and its content sudo -R chmod 744 /var/www/site1 might help.


Changing ownership of read-only file system

Remount the partition (or disc) but this time with rw (read, write) settings.
Should be something like this:

sudo mount -o rw,remount /"Untitled 1"


My computer has crashed after I tried to upgrade from 18.04 to 20.04

In general when the system fails during the upgrade, there is little chance for recovery. In my suggestion you have to make a clean installation of the Ubuntu 20.04 LTS.


How to access over WLAN usb external hard disks connected to my ubuntu desktop from my laptop or android tablet?

I have done similar using a Raspberry Pi and sharing content via MiniDLNA which is available in the standard Ubuntu repo's (sudo apt-get install minidlna).  It takes only a little configuration and then the installation of a DLNA player on your Android device.  It also works for streaming to TV's and Playstation3 (probably also XBox and other devices).

A fairly good guide for setting it up can be found here:

https://help.ubuntu.com/community/MiniDLNA


Multiseat stops working after upgrading from 18.04 to 20.04

I found a hacky workaround by switching to lightdm. Now everything works fine, except for the aesthetic of the logon screen.


How to display something in unity systray from a bash script

Indicator System Monitor

The closest method I've found to satisfy your requirements is (webupd8.org - Ubuntu appindicator that displays bash) that displays text on the Unity system tray / application indicator bar. The sample above comes from two bash scripts: multi-timer and display-auto-brightness.
Install and Configure Sysmonitor Indicator
You need to install indicator-sysmonitor from ppa:
sudo add-apt-repository ppa:fossfreedom/indicator-sysmonitor
sudo apt-get update
sudo apt-get install indicator-sysmonitor

Then run the gui and configure it with the script name that updates the system tray.
Sample scripts to output to system tray
Here are a few examples from the WebUpd8 link above:

Display the current CPU frequency for the first core:
echo $(grep "cpu MHz" /proc/cpuinfo | head -1 | cut -d ' ' -f3 | cut -d '.' -f1) MHz

Check if a website is up (smiley face) or down (sad face):
if wget -O /dev/null webupd8.org > /dev/null; then echo "☺"; else echo "☹"; fi


I use HP printers at work, and so far I have not come across a model the does not work out of the box with Linux, and we are talking 10-15 different models.


To first find the id of the device use:

xinput -list

From there find the name of the touch screen and then run:

xinput disable DEVICE

where DEVICE is the device name enclosed in quotes or its id.


You likely don't want to run a gradle task through Xvfb, but rather execute something within an X Windows Virtual Frame Buffer FROM a gradle task.

For example your gradle test task might do:

xvfb-run -a --server-args='-screen 0, 1024x768x24' google-chrome -start-maximized http://runMyLocalBrowserBasedTest > /dev/null &


if you are sure the problem is the conservation mode in the Lenovo Vintage.
if you are using Ubuntu then there is a gnome extension,charging-mode that allows you to monitor and switch between different charging modes. it worked for me on Lenovo Legion.
click here
if you are using something else there is a manual method
::::::::: Conservative mode commands ::::::::
from terminal
sudo su

write password
reading the current status:
cat /sys/bus/platform/drivers/ideapad_acpi/VPC2004:00/conservation_mode

enable Conservation mode:
echo 1  >  /sys/bus/platform/drivers/ideapad_acpi/VPC2004:00/conservation_mode

disable conservation mode:
echo 0  > /sys/bus/platform/drivers/ideapad_acpi/VPC2004:00/conservation_mode


Libkmod Error appearing when Ubuntu 14.04 starts

My problem is solved.
I removed the file iwlwifi.conf with the command line:

sudo rm /etc/modprobe.d/iwlwifi.conf

After restart, Ubuntu notified me that it had found a "critical error". I clicked Send Report and after 4 days an automatic update proceeded and everything works fine now.


First things first, we need to check your file system.

For 18.04 or newer...

boot to a Ubuntu Live DVD/USB
open a terminal window by pressing Ctrl+Alt+T
type sudo fdisk -l
identify the /dev/sdXX device name for your "Linux Filesystem"
type sudo fsck -f /dev/sdXX, replacing sdXX with the number you found earlier
repeat the fsck command if there were errors
type reboot

You have a very old BIOS...

sudo dmidecode -s bios-version shows that your current BIOS is version 1.10 from 2013.

Toshiba Satellite L50-A
PSKL8L-006002

The latest version can be downloaded at https://support.dynabook.com.

Please update your BIOS and see if it helps.


Yes, Ubuntu supports both "MSDOS"-style partition tables and GPT partition tables.

If Secure Boot is also enabled, and you want to install Ubuntu alongside Windows 8, see this question.

If you just want to install Ubuntu by itself, then you shouldn't have to do anything special, even if you have a GPT disk. See this generic installation question and these generic instructions.

Although this works most of the time, sometimes the GRUB boot loader will not be installed correctly. So if you cannot boot after installing, see this answer or the techniques presented here (they apply to this situation, even though this situation is not a recent installation of Windows).

Alternatively, if Ubuntu will be the only OS you want on your machine (or all the OSes you want on your machine will work without UEFI and GPT), then you may consider disabling EFI in your "BIOS" setup and creating an MS-DOS style partition table on your disk.


Mutlimedia Keys on Ubuntu 20.04 with Spotify

This is a common issue that people have with Spotify. Fortunately, there is a solution that works 95% of the time.
Follow these steps:

Get Spotify Gnome Integration from GitHub. This can be downloaded as a Zip file if you don't use Git.
(If you downloaded the Zip) Extract the archive.
(From the Terminal) Change to the directory that was created when extracting the Gnome integration files, for example:cd ~/Downloads/spotify-gnome
Copy some files using the following command:sudo install bin/spotify /usr/local/bin/

Note:
For this to work, you will need python-dbus on your computer. If you don't have this (or if you can't start Spotify anymore), it can be installed like this:
sudo apt-get install python-dbus

Restart Spotify. The media buttons should now work correctly.
Hope this helps


Could anyone be able to tell me why we use $ in the command echo "Start of report : $start" ?

It is a bash (and sh) feature. The text "$start" is replaced with the value of the variable called "start". In your script, the start variable is set to the output of the date command by the line start=$(date). Note that $(...) is a different shell feature from $....

For more complete information on the bash scripting language, see:

http://www.tldp.org/LDP/abs/html/


To go back to a previous version of the kernel and updates, when first booting up, select previous linux versions from the GRUB menu and choose the version you want to boot up with.


Wifi devices gone from the additional drivers list and Wifi stopped working

To purge the 'Additional Drivers' for wireless, please open a terminal and do:

sudo apt-get purge bcmwl-kernel-source

Reboot.


Installing Ubuntu onn SSD (2nd) and documents on hdd (main) on Dell Studio 1737

In order to make the system recognize your Ubuntu, you have to change the boot order in bios. After turning on your computer press either F2 or F12 (sometimes it Delete key)  and go to bios munu, in the "Boot" tab change boot order. It also could be in the advanced tab.

If you want to have your documents on your HDD. You just have to set your HOME PARTITION (/home) on that drive while installing Ubuntu.

In the picture you see a box named Mount Point. Its on Root Partition (/) by default. You can set root on SDD and after that select your HDD and click on + sign and from this box select /home.
That will do it.


Diplay information in Console at every boot

I assume you want the message displayed on a text console (you are not running a GUI) before the user logs in.
One of the simplest methods is to use the /etc/issue file or /etc/issue.d directory. The /etc/issue file contains the default text that is displayed on the console before login prompt. For example what I see on my text console is the following:
Ubuntu 20.04.2 LTS jarek-02 tty3

jarek-02 login:

The message in the top line comes from the /etc/issue file which has the following contents:
Ubuntu 20.04.2 LTS \n \l
<empty line>

\n is replaced by hostname of your machine, and \l is replaced by TTY name.
You can either replace the contents of /etc/issue with your own (but I guess it can be overwritten with a release upgrade, when release changes to 20.04.3 for example), or you can add another file by creating a directory /etc/issue.d and placing a file with an extension .issue there.
For example, when I created a file /etc/issue.d/01start.issue with the following contents:
<empty line>
Welcome to the server. The IP is: \4
<empty line>
<empty line>

the message on my text console looks like this:
Ubuntu 20.04.2 LTS jarek-02 tty3

Welcome to the server. The IP is: 192.168.15.100

jarek-02 login:

(\4 is replaced with the IPv4 address of your computer).
You can find more information in man agetty.


Can not resolve domains in wireguard network on xubuntu 20.04

Turns out my system was not up to date. A simple sudo apt update && sudo apt upgrade fixed all the issues. It's the basics ...


WSL2 apt update failing with errors using old-release sources

Ubuntu 18.04 LTS Bionic Beaver is not an old-releases. It is supported release.
So you have to replace the repo-lines by archive back.
Doing this programmatically is possible by executing:
sudo sed -i "s|old-releases.ubuntu.com/ubuntu bionic|archive.ubuntu.com/ubuntu bionic|g" /etc/apt/sources.list

And then run sudo apt-get update as usual.


Ubuntu 16.04 LTS black screen after login since updating packages with Software Updater

Today an update caused similar symptoms on my HTPC, which is an Intel NUC box running 16.04 LTS.

I could reach my Ubuntu box via VNC but my TV display via HDMI was always black.

I am working ok now after the following steps:

xrandr -q (to see my HDMI connections are not detected)

Tested my TV and HDMI cable with a laptop, all good.
Update my way past the issue

apt-get update
apt-get upgrade

The Update forward did not fix it, time to roll back...
What kernel package is the latest we are using?

dpkg --list | grep linux-image | more

It is 4.4.0-119 so lets get rid of it:

apt-get purge linux-image-4.4.0-119-generic
apt-get purge linux-headers-4.4.0-119-generic

Reboot to check

shutdown -r now

What is the current kernel we rolled back to?

uname -a

OK lets see if 4.4.0-97 fixed it?

xrandr -q

Nope, no HDMI still.
Lets make sure are packages are OK

dpkg --configure -a

Lets try update and upgrade again...

apt-get update
apt-get upgrade

Lets try a full power down

shutdown -h now

Now lets watch the BIOS screen come up on the TV when we power the NUC box on.
BIOS displays and Ubuntu is back on my TV.

The kernel I landed on that is working now is:
4.4.0-116-generic


Shortcut to switch between different keyboard layouts (languages)?

I believe there's no default shortcut. However, you can pick one.
The below screenshots are from Ubuntu 13.04, but 12.04 should be somewhat similar.

Click on the gears icon on the top right and go to System Settings.

Click on Keyboard Layout.

Click on Options....

Expand Key(s) to change layout and pick the key (combination) that you want to use to switch layouts.


I've had some success with installing linux on this laptop. The UEFI is 32-bit, and so I had to compile a 32-bit UEFI grub to boot. The wireless card in this laptop is also unsupported currently. It's supported in android, but not in the current Broadcom linux drivers.


Are you sure NetworkManager is installed? It should make most common network setups work out of the box. If it is, you can try nm-connection-editor to edit any specific data for your connection. Also look up the information nmcli gives you, especially nmcli general status or nmcli device <ethernet device name>. Come back here with any additional insight or information...


In terminal, type in sudo apt-get install --reinstall ubuntu-desktop to completely reinstall back to defaults.

To remove all compiz settings type rm  -rf ~/.compiz-1 ~/.config/compiz-1 in terminal, then logout and back in.


Kubuntu 16.04 + Bumblebee Failed to load module "mouse" (module does not exist, 0)

Please don't install any packages.

Just edit the file /etc/bumblebee/xorg.conf.nvidia to include the following screen-section to make bumblebee work:

Section "Screen"
  Identifier "Default Screen"
  Device "DiscreteNvidia"
EndSection

(To open the file for editing, run sudo kate /etc/bumblebee/xorg.conf.nvidia )

After a restart of bumblebee, it works properly.