there are two checks you can perform to check after it has been removed.

The first one checks that wubi has been uninstalled and this could leave gigbytes of information leftover (use the second check for left over data)

the second check is to open a partition manager and check that the partitoin for ubuntu is gone. you can press start and search partition to do this.

firstly i suggest pressing start, type in uninstall, and then click [Uninstall a program]

when it loads find Wubi within the list, click it and then click uninstall at the top, follow the instructions and restart to perform the check.

the next thing to do is just delete the partition.
like mentioned before, click start, type partiton and click the option labelled [create and format hard disk partitons] at this point remove any cd`s or usb drives and continue.

you will see at the bottom of the window that opens a row, on the left of that row will be the name of the hard disk eg (C:windows) and its normally the C drive unless you changed it. then right click the ubuntu partition (normally the third one along) and click delete partitoin, you can check your deleting the correct one by going into my computer and renaming your first windows partitoin, then re open the window, press f5 to refreash and the one thats renamed is the one you DONT delete. if you have any problems just comment or email me 2340k@live.co.uk


Configure error: could not find the zlib library

You need to install -dev package for zlib1g - it is named zlib1g-dev:

sudo apt-get install zlib1g-dev

and it will install zlib.pc file for pkg-config along with zlib.h header.


Security risk with scripts that write to /sys/class

What was actually said and its meaning
Quote from the linked post:

Set the permissions 755 owned by root. Then either edit your sudoers file to allow them to be run as root, or use chmod +s to set them SUID.
This sort of thing is considered a security risk, BTW, so make absolutely sure the permissions are set appropriately.

This talks about two cases:

setting script and allow it to be executed as root without prompting for password
setting SUID bit on scripts

What's the problem with scripts in general ? To paraphrase from Stephane Chazelaz's answer (which I strongly recommend reading), shell scripts  can be a problem if run either in web servers or when privileged script runs something else. To a regular user who just has desktop - that means in most cases destroyed system - maybe attacker injected rm -rf / somewhere - or computer being overtaking by malware and being a part of botnet to attack commercial servers. But for commercial servers, this can mean anything from client credit card information being stolen to systems destroyed causing loss of money because system is down and customers go somewhere else. So when something is said to be a security issue, you need to know what that means for you.  You also should know who could be your possible attacker - that defines  what sort of approach they can use to compromise your system, and for someone interested in your credit card information or conversation with people, they'll likely to go after network traffic rather than the script, which means they'll likely go with MITM attack rather than the script.
What can be the problem in your specific case ?

Your script executes 3 commands: echo $1 | tr, and cat. If attacker replaces cat or tr with malicious programs, it can mean either system destroyed, or leaking information every time you execute those commands. And because your script runs with root-level privilege - those commands also run with root level privilege. Since echo is a shell built-in, it's immune against attacks where /bin/echo is replaced  ( unless you run env echo instead - that will call /bin/echo).  Arguably, if you have someone capable of replacing system-level binaries, it means they already have root access, which is more important problem than just your script.

The scripts live in  /home/ioana/.config/i3/ with 0754 permissions. OK, that's fine. If your account is compromised attacker doesn't need root - they'll use your account to overwrite the script contents. What about permissions of the /home/ioana/.config/i3/ directory ?  Deleting a file requires having write permissions on the directory where file lives, so if you have another user on your system and they do not have write permissions on script itself, if they have permissions to write into directory they can delete the script (not really a security issue, but a mini-DoS for ships and giggles).

Another problem in theory can come from the command-line parameters. You have echo $1 | tr '[a-z]' '[A-Z]'. Say an attacker uses /*/*/*/*/../../../../*/*/*/*/../../../../*/*/*/* as $1 mentioned in Stephane's answer. The shell will need to convert those * into actual files,and all those expansions are expensive for CPU. That's a small way to make your computer lag, again mini-DoS.

In case you're running outdated version of bash, it can be vulnerable to arbitrary code injection via exporting functions - aka shellsock. So one could export a malicious function before running your prvileged script.

If an attacker is fond of animal cruelty, they can abuse cat

Of course, all these things can be combined with wget to download something else that's malicious on your computer and execute with root privileges.

In the end, the fact that you're operating on /sys/class/ type of directory isn't the problem. Problem lies with the level of what shell scripts can do and that shell scripts have mechanisms that aren't perfect. But let's not get overly paranoid. Like I said, if someone got access to your account (which has sudo privileges) or root account - that's enough of a concern already.
See also

Why is SUID disabled for shell scripts but not for binaries?


Overscanning picture problem using HDMI with Intel Graphics

Okay, if you haven't already tried these, check it out

xrandr --output HDMI-1 --set underscan on
xrandr --output HDMI-1 --set "underscan hborder" 40 --set "underscan vborder" 25

Another one I came across was this:

xrandr --output HDMI1 --transform 1.05,0,-35,0,1.05,-19,0,0,1


Mount usb to serial adapter CANBUS and can-utils ubuntu?

I know this is a very old thread. But it is still unanswered and while I was searching for a solution I stumbled upon this thread.

The solution to this problem is that slcand does not support this interface.
To use it anyway a mapper between the interface and socket can must be used.
This adapter can be found at https://github.com/alexmohr/usb-can

After install just run usbcan -s 500000 -d /dev/ttyUSB0


compute $a_1 + a_2x + ... + a_nx^{n - 1} (mod 10^9 + 7)$ using bash commands

You could do something like this:
# Get x from first line in the file
x=`head -n 1 input.txt`
echo x = $x
# Get number of lines in the file
n=`cat input.txt | wc -l`
((nn=n-2))
# We will loop over i starting with i=0 so then x_to_power_i starts at 1
x_to_power_i=1
sum=0
for i in `seq 0 $nn` ; do
    # Show what we have now
    echo i = $i x_to_power_i = $x_to_power_i
    # Get a_i value
    ((ii=i+2))
    a_i=`cat input.txt | head -n $ii | tail -n 1`
    echo a_i = $a_i
    # Calculate current term and add it to sum
    tmp=`echo "$sum + $a_i*$x_to_power_i" | bc -l`
    sum=$tmp
    echo sum = $sum
    # Update x_to_power_i for next i
    tmp=`echo "$x_to_power_i*$x" | bc -l`
    x_to_power_i=$tmp
done
# Show final result
echo Final sum = $sum

That's just the polynomial, ignored the "mod" thing as I don't understand what that means.
Anyway, you can do things like the above to avoid overflow, you pipe things to the bc command (bc - An arbitrary precision calculator language -- see man bc).
Edit: here is another variant, looping directly over file contents instead of using seq:
# Get x from first line in the file
x=`head -n 1 input.txt`
echo x = $x
# Get number of lines in the file
n=`cat input.txt | wc -l`
# Create a new file with all except first line
((nn=n-1))
tail -n $nn input.txt > tmpfile.txt
# We will loop over i starting with i=0 so then x_to_power_i starts at 1
x_to_power_i=1
sum=0
i=0
for a_i in `cat tmpfile.txt` ; do
    # Show what we have now
    echo i = $i x_to_power_i = $x_to_power_i
    echo a_i = $a_i
    # Calculate current term and add it to sum
    tmp=`echo "$sum + $a_i*$x_to_power_i" | bc -l`
    sum=$tmp
    echo sum = $sum
    # Update x_to_power_i for next i
    tmp=`echo "$x_to_power_i*$x" | bc -l`
    x_to_power_i=$tmp
((i=i+1))
done
# Show final result
echo Final sum = $sum


You should be able to
sudo modprobe alx
echo '1969 e0b1' | sudo tee /sys/bus/pci/drivers/alx/new_id
Then the ethernet should function so you can install the 4.8 kernel with

sudo apt-get install linux-generic-hwe-16.04

Reboot

If uname -a shows that you have x86_64 kernel you can download the following package using a computer with internet access

http://archive.ubuntu.com/ubuntu/pool/main/l/linux-hwe/linux-image-4.8.0-41-generic_4.8.0-41.44~16.04.1_amd64.deb

http://archive.ubuntu.com/ubuntu/pool/main/l/linux-hwe/linux-image-extra-4.8.0-41-generic_4.8.0-41.44~16.04.1_amd64.deb

http://archive.ubuntu.com/ubuntu/pool/main/l/linux-meta-hwe/linux-image-generic-hwe-16.04_4.8.0.41.12_amd64.deb

http://archive.ubuntu.com/ubuntu/pool/main/l/linux-hwe/linux-headers-4.8.0-41_4.8.0-41.44~16.04.1_all.deb

http://archive.ubuntu.com/ubuntu/pool/main/l/linux-meta-hwe/linux-headers-generic-hwe-16.04_4.8.0.41.12_amd64.deb

http://archive.ubuntu.com/ubuntu/pool/main/l/linux-meta-hwe/linux-generic-hwe-16.04_4.8.0.41.12_amd64.deb

Copy them to the Desktop of the Ubuntu computer, then in terminal

cd Desktop

sudo dpkg -i *.deb

It should install the 4.8 kernel files, reboot when finished


Will I have problems installing multiple desktop environments?

You won't have any problems installing multiple desktop environments. Nothing in the system will stop you from installing KDE, GNOME, Unity, Enlightenment, and all the others all at once (except for disk space).

However, desktop environments will often "argue" with each other and overwrite settings. For example, installing KDE on a system will very often break a Unity installation by overwriting GTK or similar properties. Similarly, installing Unity will break KDE most of the time.

Unfortunately for you, these incompatibilities are very hard to repair after they've happened, so this is a risk you must be willing to take with your system. If you want to explore different environments, I'd highly recommend you use VMs until such time as you find one you like. Then, install that one and only that one on your system.


How to install a gui for remote desktop on server 18.04?

Simple

Use this command:

$ sudo apt install ubuntu-desktop


Changing the system OS from windows XP to Ubuntu

Your specs are not good enough for latest Ubuntu. Even if you manage to install it somehow, you will not be able to expect good performance.

Lubuntu is recommended for your 1gb RAM PC.It is based on Ubuntu, uses the same repositories, but specially built for older and weaker machines.

Lubuntu site


How to run commands one after anther in shell script using gnu parallel

What you need is the && how George mentioned in the comment already.

&& means the next listed command will be run only if the previous command returned a exit value of 0. You can also use || if you want to run the next command only if the first one failed - or returned a value not being 0.

So for your case it would be:

time parallel -j 40 :::: filetoprocess.sh && time parallel -j 40 :::: filetoprocess2.sh

Which means it will run once the first command is successfully finished and won't run if the first one failed.

Try it out with

echo test 1 `sleep 2` && echo test 2 `sleep 2` && echo test 3 `sleep 2`


What problems to expect with Dell G5 15 5500 and how to solve them?

I'm sure that at least Ubuntu 18.04 LTS works with the Dell G5 15 5500. Because another version, the Dell G5 5500 came preinstalled with Ubuntu (see here), the same will go for this one. You can install it, it's 95% verified to work on your system.
Edit: About the RST situation, you should look here.


Open a terminal (Ctrl+Alt+T), and type the following:

sudo apt-get clean
sudo apt-get -f install
sudo dpkg --configure -a

Check if whatever you were installing (I'm guessing the Citrix client) is installed successfully. If not, try the following:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get --reinstall install icaclient


How can I make rhythmbox open maximised initially?

Alt + F2 and enter this: gconf-editor
apps > rhythmbox > plugins > status-icon
check window-visible

OR

Alt + F2 and enter this:

gconftool-2 --type bool --set /apps/rhythmbox/plugins/status-icon/window-visible true


Does a Linksys WMP110 Wireless Card work?

If Linksys WMP110 v1 is the desired card. It seems to be that the chipset-manufacturer is
Atheros Communications, Inc. Their wireless driver ath9k is opensource, so the card should work. As I see it uses the chipset AR5008 / AR5416. My wireless card is a TP-Link TL-WN951N, it uses the same chips and I have a bug with the ath9k driver.

For Linksys WMP110 v2 also exits a linux driver.


HDD spin down time is not working after sleep

Problem also exist on my desktop with 16.04. After some research I realized that I can force HDD to go sleep by hdparm -Y , but hdparm -S doesn't work.

My solution is:

Disable spin down time in gnome-disk-utility and other tools like
hdparm.conf
Install hd-idle. You can use this link for instructions on install and configure
Create new file at /lib/systemd/system-sleep e.g. hdidle with executable bit
Add following code:

#!/bin/sh
if [ "$2" = "suspend" ] || [ "$2" = "hybrid-sleep" ]; then
    case "$1" in
        post) hd-idle -i 0 -a sdb -i 60 -a sdc -i 60 ;;
    esac
fi

This will spin down the disk after 60s (edit it as you need). Change sdb and sdc accordingly.


The easiest way to install Ipython is with Anaconda.


How to merge free space into partion in ubuntu server?

1) You need to run gparted from Live CD/USB otherwise it can't unmount your Ubuntu partitions.

2) You can then resize the primary partition to include the free space behind it (2149MB).

The remaining 2 small free sections are parted's partitioning requirement I guess, you don't need to touch these.


Mount disk image for all users, even guest

The guest session is prevented to access it because of the default AppArmor setting. One way to fix it should be to open this file for editing:

sudo nano /etc/apparmor.d/abstractions/lightdm

find these lines:

owner /{,run/}media/ r,
owner /{,run/}media/** rmwlixk,  # we want access to USB sticks and the like

and remove the owner keyword so it looks like:

/{,run/}media/ r,
/{,run/}media/** rmwlixk,  # we want access to USB sticks and the like

But that would give the guest users access to all mounted stuff, which would defeat the security scheme. So I would rather add a new rule, so it looks something like this:

/{,run/}media/ r,
owner /{,run/}media/** rmwlixk,  # we want access to USB sticks and the like
/media/guest-** rmwlixk,


Hi Lucho this is the information I get

  *-network NO RECLAMADO
       descripción: Network controller
       producto: BCM43142 802.11b/g/n
       fabricante: Broadcom Corporation
       id físico: 0
       información del bus: pci@0000:07:00.0
       versión: 01
       anchura: 64 bits
       reloj: 33MHz
       capacidades: pm msi pciexpress cap_list
       configuración: latency=0
       recursos: memoria:b3200000-b3207fff
  *-network
       descripción: Ethernet interface
       producto: RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller
       fabricante: Realtek Semiconductor Co., Ltd.
       id físico: 0
       información del bus: pci@0000:08:00.0
       nombre lógico: eth0
       versión: 07
       serie: 2c:60:0c:db:ac:9c
       tamaño: 100Mbit/s
       capacidad: 100Mbit/s
       anchura: 64 bits
       reloj: 33MHz
       capacidades: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuración: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl8106e-1_0.0.1 06/29/12 ip=192.168.1.61 latency=0 link=yes multicast=yes port=MII speed=100Mbit/s
       recursos: irq:47 ioport:3000(size=256) memoria:b3004000-b3004fff memoria:b3000000-b3003fff memoria:90100000-9010ffff


I would expect timers to be corrected automatically but as you indicate this is not happening try:

systemctl stop apt-daily.timer
systemctl start apt-daily.timer


Is it possible to set display configuration programmatically on login time?

Assuming you are using LightDM,
Edit the config file at /usr/share/lightdm/lightdm.d/
Mine is 01_debian.conf, but I suspect yours will be 01_ubuntu.conf

Add: display-setup-script=xrandr --output HDMI1 --primary
replace HDMI1 with the name of the monitor you want to use.

Note: if the server doesn't have a custom setup for LightDM, the above line can be added to /etc/lightdm/lightdm.conf


Single bluetooth keyboard on multiple computers?

This is a common Bluetooth security feature to prevent from connecting to more than one device. Unless your Bluetooth keyboard is able to store more than one connection there is not much we can do about this.

Also see Bluetooth pairing and security on Wikipedia.


Ubuntu 14.04 VLC Subtitles - Will not attach (unable to drag/drop or upload while viewing)

You are confusing SRT and SFV.

SRT is a filename extension used for files containing subtitles in SubRip format. To my experience VLC automatically picks these up if you put them in the same directory as the video file.

SFV stands for simple file verification and is solely used in the warez scene.
Talking about warez is not allowed here as far as I know.

You should open the file with a text editor to verify that it really is a subtitle file format.


There is a utility called 'stress' you could use.


In the Ubuntu Software Center search for gnome-terminal.Then Install it.
Type in the Dash  gnome-terminal.That's it.


grub is only loaded after bios loads. So there must be ways to goto bios. Maybe your monitor starts too late. Please consult your motherboard manual to go to bios mode. Generally it's del key. Keep pressing it just after switching on the pc. Boot in win 8 and perform a startup repair.

or boot using ubuntu and use "boot-repair" program to repair both linux
 windows.


Desktop icons outside the monitor on second monitor (smaller one)

You are right that it uses a simple rectangle containing all monitors. That is the best solution currently available for Linux, but it introduces multiple bugs (across the board, not just in the window manager) whenever your arrangement does not fill up the desktop with actual screen space. I have used multiple monitors on Linux for about 6 years now, and the only good workaround I have found is to use the same resolution on all my monitors (in your case 1920x1080 is the recommended resolution for both monitors).


Shortcut for Resolution Change using NVIDIA

I'm pretty sure this feature is gone since Bullet Proof X. However:

You can create short cuts (System → Preferences → Keyboard Shortcuts) to change your resolution:

Have a look at System → Preferences → Monitors to see your available modes, in my case there are four, from 640×480 up to my native resolution
You can now use xrandr -s 0 to xrandr -s 3 to change to one of them.

It's not exactly the same as the old +/– business, but it works rather well.

To add a short cut, in the Keyboard Shortcut settings, click add, choose a name, like 'First Resolution', a command like xrandr -s 0, and hit Apply. Then click the short cut cell, where it says Disabled and press, for example, Ctrl+Shift+Alt+0 (my preference).

Note: this works on any graphics card, not just NVidia's.


can not login ubuntu 16.04 cycles loop with slow cursor buggy

I have had this happen to me, and this is what I did to fix the issue.
Check the permissions of .Xauthority
 ls -l .Xauthority
-rw------- 1 user user 153 Sep  2 15:50 .Xauthority

If it is showing root root, simply enter this:
sudo rm .Xauthority
touch .Xauthority
sudo chown user:user .Xauthority
sudo reboot

If you are still being bounced of your login screen and back, please try:
ls -l .ICEauthority
-rw------- 1 user user 153 Sep  2 15:50 .ICEauthority
If you are showing root root, then
sudo rm .ICEauthority
touch .ICEauthority
sudo chown user:user .ICEauthority


The md5sum for your file (Mathematica_10.0.0_LINUX.sh) should be 5c7712ee4eaccd607cea26a326db7c30 according to http://www.math.uri.edu/~alex/Mathematica/instructions.txt.

They don't provide the same version but you can download Mathematica_10.1.0_LINUX.sh from the same site (2015 version).

MD5 checksums:

1523e5ed52161e8bb3f55bd688e11f35  Mathematica_10.1.0_LINUX.sh


Non readable menu items in many apps like gimp, shutter

I was able to fix it by removing .gtkrc-2.0. All apps (gimp, inkscape) instantly restored their default styles.

rm -rf ~/.gtkrc-2.0


Why does host and bridge get an IP but not the virtual machine?

I am not an expert, but I think STP should be disabled in your bridge. It is disabled in mine. I don't have any ip address on my network interface list, the host ip address shows on the br0 interface:

doug@s15:~/idle/k56wtteo/idle$ ip a show enp3s0
3: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master br0 state UP group default qlen 1000
    link/ether f4:6d:04:65:2d:8e brd ff:ff:ff:ff:ff:ff
doug@s15:~/idle/k56wtteo/idle$ ip a show br0
4: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether f4:6d:04:65:2d:8e brd ff:ff:ff:ff:ff:ff
    inet 192.168.111.112/24 brd 192.168.111.255 scope global dynamic br0
       valid_lft 84590sec preferred_lft 84590sec

However, by bridge stuff does look like yours:

doug@s15:~/idle/k56wtteo/idle$ brctl show br0
bridge name     bridge id               STP enabled     interfaces
br0             8000.f46d04652d8e       no              enp3s0
                                                        vnet0

Does your VM definition specify to use the bridged interface? Example (/etc/libvirt/qemu/serv-ff.xml in this example (I think I read somewhere that you are using kvm)):

<interface type='bridge'>
  <mac address='52:54:00:27:1b:4e'/>
  <source bridge='br0'/>
  <model type='virtio'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
</interface>

If I look at the arp table of the my LAN i can see the VM:

doug@DOUG-64:~$ arp | grep serv-ff
serv-ff.smythies.com     ether   52:54:00:27:1b:4e   C                     enp2s0

And if I set tcpdump on the host monitoring the bridge interface, I can observe the VM quest ask for and get an IP address from my LAN via DHCP upon quest re-boot:

doug@s15:~/idle/k56wtteo/idle$ sudo tcpdump -tttt -n -i br0 port 67 and port 68
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on br0, link-type EN10MB (Ethernet), capture size 262144 bytes
2020-03-05 18:12:35.522302 IP 192.168.111.217.68 > 192.168.111.1.67: BOOTP/DHCP, Request from 52:54:00:27:1b:4e, length 265
2020-03-05 18:12:48.534782 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 52:54:00:27:1b:4e, length 291
2020-03-05 18:12:48.535118 IP 192.168.111.1.67 > 192.168.111.217.68: BOOTP/DHCP, Reply, length 300
2020-03-05 18:12:48.535243 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 52:54:00:27:1b:4e, length 303
2020-03-05 18:12:48.535460 IP 192.168.111.1.67 > 192.168.111.217.68: BOOTP/DHCP, Reply, length 300

And on the VM itself:

doug@serv-ff:~$ ip a show ens3
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 52:54:00:27:1b:4e brd ff:ff:ff:ff:ff:ff
    inet 192.168.111.217/24 brd 192.168.111.255 scope global dynamic ens3
       valid_lft 86044sec preferred_lft 86044sec
    inet6 fe80::5054:ff:fe27:1b4e/64 scope link
       valid_lft forever preferred_lft forever


Is it possible to use ubuntu as a windows local network server?

You can install Samba, a system that can share directories, printers and CDROM/DVDROM. Samba can even replace Active Directory, so your other computer users can authenticate on it. You can setup Samba so you have a public, freely available directory, have user-based home directories and shared directories, where the rights are based on their Linux credentials.

The main configuration file is smb.conf, which is usually located under /etc/samba, at least under Ubuntu. You can also use something like Webmin to manage your Samba configurations and shares from a web-based interface, instead of manually editing configuration files.

If you search on the net, you will find tons of free documentation on SAMBA.

You mainly have to install samba itself. enter the command:

sudo apt-get install samba-server


dpkg: unrecoverable fatal error, aborting:

Remove the mentioned files with

sudo rm /var/lib/dpkg/info/gir1.2-gdkpixbuf-2.0*

Then reinstall the package with

sudo apt-get install --reinstall gir1.2-gdkpixbuf-2.0

or

sudo dpkg -i --force-all /var/cache/apt/archives/gir1.2-gdkpixbuf-2.0*.deb


Chances are fairly high that the kernel version of Elementary OS is out-of-date. Updating to a more stable version of Ubuntu, such as 14.04, would be advisable. Once you've done that, have a look at the recommendations provided by Game Imps. They suggest running the xboxdrv command as such:

sudo xboxdrv --detach-kernel-driver

If this does not work, try removing your Bluetooth dongle and utilizing bluez with the 14.04 installation's kernel installed.

Your other, more costly, option, is to purchase a controller that supports Linux natively, such as the Logitech F710. This controller has out-of-the-box wireless support for most Linux distros, especially Ubuntu distributions, as it pairs not with Bluetooth, but with a dedicated USB 2.0 dongle (included with the controller).


How do I switch tabs in my terminal like I do in Chrome

Indeed, for one or another reason, this interface does not allow Ctrl+Tab to be set as a shortcut to move to the next tab. However, you can change the assignment using the tool dconf-editor.

Install dconf-editor, launch it and navigate to /org/gnome/terminal/legacy/keybindings/ and click the "next-tab" setting. Uncheck the "Use default value" checkmark and fill in <Control>Tab. Proceed in a similar way for "prev-tab".


Improving the quality of reduced website screenshots in GIMP

Sinc is broken.

Try this:

Figure out ratio between source image and final image (e.g. 1200px width to become 600px give you 2
Apply Gaussian blur with that value
Scale down with linear interpolation
Apply sharpening to your liking


Can I play Windows (Steam) games on Ubuntu?

You can install Ubuntu along side Windows and boot into either one when you turn on your computer. But that is beside the point. (You will probably NOT want to replace Windows if this is your first time installing Ubuntu.). Just select 'Install Ubuntu alongside Windows X' in the installer.

You can run Windows steam games on Linux through WINE. Though it will be a huge amount easier just running Linux Steam games on Ubuntu, it IS possible to run some of the windows games (though it may be slower). I think there are instructions here: https://developer.valvesoftware.com/wiki/Steam_under_Linux#Step_2:_installing_steam.

Basically you want to run this in a terminal (for Ubuntu 18.04+):

sudo apt-get install wine winetricks
winetricks steam

Note that for Ubuntu 16.04 and earlier, winetricks is a dependency of wine. You can do do this instead, and it'll be equivalent:

sudo apt-get install wine
winetricks steam


Bash script cannot run with keyboard shortcut

To add a script to a keyboard shortcut:

Unless the script is in $PATH (like ~/bin), use the full path to the script, don't use ~ or relative paths.
If you use full path, start (as always) with a slash, e.g.:

sh /home/username/script.sh

Your example doesn't :)
If your script is executable, just the full path will do:

/home/username/script.sh

if it isn't, use the preceding language, e.g.:

sh /home/username/script.sh

What is the issue in your examples

In the attempts you show, you either use incorrect paths (home/some_dir is not a valid directory without a starting slash), you use another path then you mean to (/script.sh refers to your root directory) or you use relative paths. None of them will work from a shortcut key.

The same rules apply to Startup Applications by the way.

EDIT

An additional issue in this case:

Your specific case; using an xdotool command in the script

From a comment, we found out the script you run uses an xdotool command, pressing keys:

#!/bin/bash
xdotool keydown Super key w
sleep 0.5
xdotool keyup Super

Virtually pressing keys from a shortcut key combination will practically always lead to key- clashes, since the keys you physically press, will be combined with the ones you virtually press.

What to do

One way to avoid the issue is to give your fingers the time to "leave" the keys, to avoid the real keystrokes to be combined with the virtual ones. Even then though, you need to release the shortcut after you pressed them. The script then becomes:

#!/bin/bash
# here we add a little break to give your fingers
# the opportunity to release the keys
sleep 0.5
xdotool keydown Super key w
sleep 0.5
xdotool keyup Super

Note

If you are still having the issue, increase the time in line 4 (and only press the shortcut key shortly)


Your hadoop-env.sh, stopall.sh, start-dfs.sh, stop-dfs.sh, start-all.sh, stop-all.sh will be in /usr/local/hadoop/conf.

You don't have to create any configuration files.


Getting a `Permission denied` error from mount when trying to chroot to Arch Linux

The problem looks like you haven't mounted any partition onto the /mnt, and are trying to pacstrap into the installation media itself. Re-check if you have not missed mounting a partition onto /mnt
    # mount /dev/sdxY /mnt
Then install the base packages, generate fstab, and then chroot to it.


Emerald missing close, maximize and minimize buttons when restoring window from maximized state

This not a proper answer. It's an unknown bug (which will not be fixed) Try a different theme. Try to compile emerald again from a different source. This happens only with Ubuntu. It is not to be seen in my Arch Linux box (I'm using the same theme as you with minor modifications). May be Compiz is responsible for this.


The tutorial is for Debian systems and of limited use for Ubuntu. In Ubuntu you need these commands in a terminal:

sudo sudo add-apt-repository ppa:ubuntu-audio-dev/alsa-daily
sudo apt-get update
sudo apt-get install alsa-hda-dkms
sudo reboot

And this:

  Sound was much better. Now has a level of contstant white noise in the
  background. On advice I also added the following to
  /etc/modprobe.d/alsa-base.conf, but made little difference to the
  background noise - so stay with it for now - sounds okay.

means this:

Edit the file /etc/modprobe.d/alsa-base.conf

sudo nano /etc/modprobe.d/alsa-base.conf

Finally, add this line:

options snd-hda-intel model=asus


Problem With Guest Additions in Ubuntu Server [Virtual Box]

Please use the fully updated current version of Ubuntu. There is no need to separate install of any kernel headers or any other packages, up-to date current Ubuntu is absolutely enough to install VirtualBox additions (I did it few times recently).


Nautilus remote server doesn't remember specific folder

There doesn't seem to be a way to do this as far as I'm seeing, I found a workaround so I'm just going to share that. If anyone has an actual solution I'd still like to hear it.

Opening Nautilus
Going to Connect to Server
Writing sftp://user@server/specific-folder
Add folder to bookmarks

The folder should now appear to the shortcuts on the left panel of nautilus.


Well, after much messing around (days of it - good job I'm retired)  I managed to sort out this mess.

Firstly, I'm seriously underwhelmed by the help I received from this forum.  I've only asked 3 questions (to deal with specific problems) and have only received limited help with one of them.  Ubuntu will only remain a niche system unless that changes.  A serious number of users appear to have audio problems similar to mine and few get any answers via this forum!

Eventually, after many attempts at fixing the problem, I reloaded 16.04 (rather than 18.04) in dev/sda8 and the audio problem went away.  An issue I hadn't reported was that the partition I was using for home (dev/sda7) was formatted in ntfs and I suspected there was a fundamental permissions issue around that. I eventually came across a thread about using ntfs with Ubuntu and managed to get the system to work, though not perfectly and it seemed that all directories had acquired root permissions. Eventually, I bit the bullet, backed up my home directory (and also copied it to my Win10 partition).  I then loaded a clean version of 18.04 to dev/sda8, reformatted dev/sda7 as ext4 and then set up dev/sda7 as home and copied the new 'clean' home to it.  I then carefully selected bits of my old home from within my Win10 partition and pulled them across to dev/sda7.  That way, I was able to restore all my original files and important settings such as my Firefox bookmarks and history and my Thunderbird email accounts, addresses, saved mail, etc. Permissions for all these files now show my username, rather than root.

I suspect this answer might not directly help anyone, but might give some clues to those with similar problems.  It looks like my gut instinct of permissions problems was correct and the results seem to bear this out.  Unfortunately, this issue was spread across 3 separate problem areas - audio, hdd file systems and permissions - something I didn't realise on my initial posting,


No sound device after update from 16.04 to 18.04

So, I solved it. Just wanted to leave the solution here, as someone else might encounter the same.
After some more hours of wresting with it, I turned my attention to pulseaudio, and executed the following:

rm -r ~/.config/pulse; pulseaudio -k

That actually failed with an error, so I was about to give up, but found a hint somewhere else that suggested running the following command:

pulseaudio -D

After doing so and rebooting the device list got properly populated and I was able to select a working device :).

Solved!


How to get an uniform look for Qt and GTK applications in xenial

Try deleting Trolltech.conf from ~/.config. This file contains the settings for qt4, including a list of available kde-styles. After upgrading the system it often breaks down for some reason.


append or remove file from tar and tar.gz

-d is not delete but diff.

From man tar:

 -d, --diff, --compare
       find differences between archive and file system

use --delete.

tar --delete -vf foo.tar IMG_1807.MOV

You cannot update a tar.gz file, see this and this.

Regarding your question how to extract to specific location:

You must follow the correct command line order. -C as an option goes before [pathname]. See man tar for more information. The following works:

tar -xvf foo.tar -C /path/to/destination IMG_1807.MOV


Screen tearing in Ubuntu with Nvidia/Intel graphics

Create /etc/X11/xorg.conf.d/20-intel.conf containing

Section "Device"
   Identifier  "Intel Graphics"
   Driver      "intel"
   Option      "TearFree"    "true"
EndSection

That should fix everything.

Source is https://wiki.archlinux.org/index.php/Intel_graphics#Tear-free_video

Note: This only works if you're using bumblebee.

Note from comments: Since 10.10 the config file directory is now /usr/share/X11/xorg.conf.d

Starting from Ubuntu 16.04 LTS * you can use the following script to switch between NVIDIA and INTEL's graphics cards and besides it corrects the video/screen tearing on INTELs environment: https://github.com/bauca/graphics-switcher


Trouble reinstalling ubuntu without removing other partitions on disk

Why don't you erase the hard drive and then install Ubuntu 16.04? If you have personal files you want to save already on the hard drive, just save them onto DVDs before you erase the hard drive. That's what I do.


Well then, LVM has a wrong idea of the size of sda1. Try:

sudo pvresize /dev/sda1


PPA package build fails but I can't figure out why?

Your application is trying to install during the build/compile process.  For Debian/Ubuntu packages, the idea is that the package builds and contains the binaries and rules for where to install them.  There are debian/PACKAGENAME.install files which you use to define where executables are installed.  That is of course assuming you have the binaries compiled and ready to move into their correct locations on disk when the package is installed.

Look towards the end of that file here:

make[2]: Entering directory `/build/buildd/konzolno-radio-1.0.3'
installing executable file to /usr/local/bin
install: cannot create regular file '/usr/local/bin/konzolno-radio': Permission denied
make[2]: *** [install] Error 1
make[2]: Leaving directory `/build/buildd/konzolno-radio-1.0.3'
make[1]: *** [override_dh_auto_install] Error 2
make[1]: Leaving directory `/build/buildd/konzolno-radio-1.0.3'
make: *** [binary] Error 2
dpkg-buildpackage: error: /usr/bin/fakeroot debian/rules binary gave error exit status 2

The problem you have is your package is trying to actually install the file to /usr/local/bin during compile.  That's what you're doing wrong, change your compiler rules to NOT install automatically.  You have to let dpkg do the installation of what goes where.


Wine and PlayOnLinux open game in wrong resolution

I just figured out the answer:

Pressing F4 changes the resolution for the desired (native) resolution for this game.

Running the game again confirmed the proper resolution is kept.


I want to use Ubuntu for developing my application - pl help

The mono project is a project for developing .NET applications on non-Microsoft operating systems. They appear to have visual basic support, but are better know for C#. I recommend looking into mono software.

Just because you develop applications on Linux doesn't mean your code has to be open-source, just as if you develop on Windows you can make your code open source. For more information on making (or getting involved in) open source projects, take a look at https://github.com/


Writing a Script to open files with faketime

Generally speaking, if you have a script and you want to pass the arguments through to another program, you have to add:
"$@"

onto the end. Like if I had a script to do an ls -l, it would look like this:
ls -l "$@"


How to temporarily block network access to root user?

You can set your firewall to block everything.

To Block All (For All Users Including Root):

sudo iptables -P INPUT DROP

sudo iptables -P OUTPUT DROP

sudo iptables -P FORWARD DROP

To Allow Again:

sudo iptables -P INPUT ACCEPT

sudo iptables -P OUTPUT ACCEPT

sudo iptables -P FORWARD ACCEPT


Opening a Window within an already open window (Quickly/Glade)

I'm doing this in my App also. I achieved it by doing something similar to the following:

In your main window get a reference to the widget you want to use as your parent.  It must be a derivative of GtkContainer (such as GtkBox).
In my instance I did something like the following in my class constructor:

self.itemAsMyContainer = self.builder.get_object("name_of_object_id")

I then used glade to create another, separate ui file with a GtkContainer derivative such (in my case GtkBox) as its top level object, and then modified its Class name in a similar way to how quickly does it. I then created a separate class for it in a similar way to _lib/Window.py in the quickly template.  Once that was done I could simply instantiate this new class and attach it to my referenced Container with a piece of code like:

self.my_sub_ui = MySexyGtkContainerSubClass()
self.itemAsMyContainer.pack_start(self.my_sub_ui)

I believe this same approach is possible with another window but you might have to unparent it.  See this question for more info on that here


installation error for brostrend ac3 wifi adapter

I suggest that you try this package instead; with a working internet connection by ethernet, tethered or whatever means possible:

sudo apt-get update
sudo apt-get install git
git clone https://github.com/bits3rpent/rtl8812AU_8821AU_linux.git
cd rtl8812AU_8821AU_linux
make
sudo make install
sudo modprobe rtl8812au


The problem is now resolved. Unfortunately, I am not sure how. The last thing I did was deleting the ~/.local/share/applications, but it had no menu-xdg.


install synaptic if not:- sudo apt-get install synaptic

Open synaptic package manager and search the app you want to delete then tick mark and and right click and select 'Mark for complete remove'.


Managed to sort it out with:

sudo apt install python3-click-package=0.4.43+16.04.20160203-0ubuntu2 gir1.2-click-0.4=0.4.43+16.04.20160203-0ubuntu2 libclick-0.4-0=0.4.43+16.04.20160203-0ubuntu2

I built that command step by step following the messages in the unmet dependencies...
Then I was able to fully remove the click package...

sudo apt purge click


The code from this branch of numpy appears to include a fix.
Here's a snippet and the relevant comments :

643         # XXX Hack to get numpy installable with easy_install.
644         # The problem is easy_install runs it's own setup(), which
645         # sets up distutils.core._setup_distribution. However,
646         # when our setup() runs, that gets overwritten and lost.
647         # We can't use isinstance, as the DistributionWithoutHelpCommands
648         # class is local to a function in setuptools.command.easy_install
649         if dist is not None and \
650                 repr(dist).find('DistributionWithoutHelpCommands') != -1:
651             return None
652         return dist

However, if you don't want to do that, try python3.1 setup.py install inside the directory where you extracted numpy.  That avoids the easy_install issue described in the code comments.


After opening a text-only virtual console by using the keyboard shortcut Ctrl+Alt+F3, as you have already done,  at the login: prompt type your username and press Enter.
At the Password: prompt type your user password and press Enter.
After you have logged in in the console type:

sudo systemctl start graphical.target

and press Enter to bring up your default purple login screen and then login to your Ubuntu desktop environment as usual.
If you get stuck in a login loop at the login screen due to a problem that occurred upgrading to Ubuntu 16.04, you can fix it by following the instructions in the answers to this question: Ubuntu gets stuck in a login loop.


If you are uncomfortable using the terminal (although I would never discourage anyone from using it and familiarizing him/her self with the terminal), you can also achieve the task using the GUI method below:

Open Network-Manager from the icon in the System Tray.
Select Edit Connections from the menu.
Select Wired/Wireless depending on your type of connection.
Double click on your particular connection.
Select IPv4 (you are in all probability not using IPv6).
Change the method to Automatic (DHCP) Addresses Only.
In the field provided for DNS servers, enter two DNS addresses separated by a comma. I would recommend trying Google's DNS servers at first.
Click Save.
Disconnect from your network and then reconnect to it.
Restart your browser to test your connection speed.

Thats it.


You are showing that you are new ;-) Regarding your concerns:

All you need to worry about backing up is your private data. You can copy those files over to a media to create a backup or setup our backup tool deja-dup to create automatic backups.
If you use server software on your machine (like apache or mysql) you also might consider backing up the config files for those.

For all other software, we have the official repositories. So why waste a DVD, USB stick or hard disc space to keep a copy that is available online or even on your installation media.

In Ubuntu, we have the additional drivers tab that holds all the drivers you ever need to take care of. Why do you need a backup if they are on the servers from Canonical? I can not think of a better place for them to be saved for me.

  I don't want to revert back to original factory settings state

Why is that a worry to you? The additional drivers tab holds both the original and proprietary driver and maybe a 3rd one. It might also hold a wireless driver. And that is it. It is always there for you if you want to switch graphics cards.

1 thing of advice for you: forget about how you do things in Windows. Linux does things in another way. That does not mean either way is wrong (just that the 2 operating systems came from different perspectives (Windows single user; Linux multi-user) and have had other thoughts about how to do things.

I hope I took away a lot (if not all) of your concerns. Join us in chat (20+ rep required ;) ) if you have questions. Happy Ubunting.


Trying to keep users in their home directory

Don't do it because there are some important files like /bin, /etc, /var which are necessary for normal users.

If you still want to, you just have to work a little bit with permissions.

Suppose you have the following users of your machine:

carla - the owner of her home directory
lisa - the owner of her home directory
root - the superuser

Now the most important thing is, change the permissions.

First open terminal:

sudo -s

chmod 700 /home/user

It will give no permission to other users on your home directory (/etc, /bin, etc.) and that is what you were asking for.

Because by default it is 755.

Type umask 077 (without sudo helpful in your case)

This will give future files or directories 700 permission.

If you want to check it is working, check through terminal. Don't do it through GUI desktop.


apt upgrade reporting in bytes and 10000+%

So in this peculiar case changing the source package location from https to http fixed the issue.


I have a Ralink Wireless Lan USB Adapter that I can't get to work no matter what I try

I know it's already answered but I found an easier solution. There's a PPA with the correct driver here: https://code.launchpad.net/~thopiekar/+archive/ubuntu/mt7601

So, all you have to do is type this on console:

apt-add-repository ppa:thopiekar/mt7601
apt update
apt install mt7601


libinput touchpad is always ON with Ubuntu 18.04

I found an Archlinux article about disabling the touchpad with xinput.
1. Get its name with xinput list.
2. Disable it with xinput disable <device name>.

For more information, see https://wiki.archlinux.org/index.php/Libinput#Disable_touchpad.


Disallow user from moving/renaming a directory?

Easiest is probably using chattr:

sudo mkdir /home/user/somedir
sudo chown root:root /home/user/somedir
sudo chattr +i /home/user/somedir


Missing opensslconf.h when compiling GIT

When the following dependency is installed lib64expat1-dev many packages are replaced, some of which were 64bit specific.

The problem here is that opensslconfig.h has been moved into a different directory as can be seen below:

$ find / -type f -name opensslconf.h
/usr/include/x86_64-linux-gnu/openssl/opensslconf.h

Where as the compiler is searching for this file inside of /usr/include for it.  So simply creating a symbolic link will correct this dependency.

$ cd /usr/include/openssl
$ ln -s /usr/include/x86_64-linux-gnu/openssl/opensslconf.h opensslconf.h


It might not be perfect, but you could use feh -p and examine the error messages generated.
To list all the unloadable images in /opt/images and below
feh -ur /opt/images

-u, --unloadable Don't display images.  Just print out their names if imlib2 can NOT successfully load them.  Returns false if at least one image was loadable.
-r, --recursive Recursively expand any directories in the commandline arguments to the content of those directories, all the way down to the bottom level.


Deleting Multiple Progressive Files Using Command Line

If you want to delete all the files in a directory with names like imageXXX.png, you won't have to use a for loop. You can use a wildcard like this rm image*.
Note-This will remove all the files in the current directory with names like imageXXXX


stdin and Commands

  On my understanding, any command that reads from standard input (i.e keyboard), that it gets its input from a file.

Effectively, yes. As I've discussed in my answer on What characterizes a file in Linux/Unix?, a file is any object on which you can execute standard operations such as read(), open(), write(), close(). stdin being represented via file descriptor 0 is effectively a file in that regard, and any command/process in Linux gets 3 standard file descriptors - stdin,stdout,stderr - when that process is started. What are the actual files behind those file descriptors ? The command doesn't care and shouldn't, as long as it can do operations on it.

  But echo command does not read and display the text_content.txt on the terminal. what's wrong here?

Now, command is free to do what it will with those file descriptors1. In case of echo it only deals with stdout and doesn't perform any action on stdin at all. So there's nothing wrong with the command itself.

< redirection will open() the file text_content.txt for reading, and it still will assign file descriptor ( for example 3 ) returned from open() call to file descriptor 0, and if a command is concerned with stdin - it will read from file descriptor 0 as if nothing happened.In fact, you will see that in action, if you run strace -f -e dup2,write,openat bash -c 'echo < text_content.txt

openat(AT_FDCWD, "/etc/passwd", O_RDONLY) = 3
dup2(3, 0)                              = 0
write(1, "\n", 1
)                       = 1
dup2(10, 0)                             = 0
+++ exited with 0 +++

Notice the dup2() system call. That's how file descriptor 3 (the file) is assigned/redirected. In sort of cp original copy syntax, dup2(3,0) makes a copy of file descriptor 3 to file descriptor 0, and they point to same file.

Notice also that write() output a newline to file descriptor 1. That's the default behavior. If we do strace -f -e dup2,write,openat bash -c 'echo FOO < /etc/passwd' here's what we will see

dup2(3, 0)                              = 0
write(1, "FOO\n", 4FOO
)                    = 4
dup2(10, 0)                             = 0
+++ exited with 0 +++

So again, nothing wrong here - redirections are performed properly and echo does its job of writing stuff to stdout which is file descriptor 1.

How to actually read a file

Now, lets address something else. How can we read a file in shell ? Well, for that there exists cat command, which accepts arguments, so you can do just cat file.txt. Can you do cat < file.txt ? Sure. But that means shell will have to do that dup2() call, whereas cat file.txt doesn't - so there's less unnecessary syscalls is what I'm saying.

In complex cases, such as when you need to perform an action on each line of the file, you would do

while IFS= read -r line || [ -n "$line" ]; do
    # command to process line variable here
done < /etc/passwd

Now, for the whole loop file descriptor 0 will be a copy of whatever file descriptor is returned from opening /etc/passwd.  Of course, if you can use cat or another specific command to the job of reading a file - do that. Shell is slow method and has a lot of pitfalls. See also, Why is using a shell loop to process text considered bad practice?

1. Some applications still might care about what they can do with stdin or detect if stdin is a file or pipeline. When stdin file descriptor is assigned as read-end of pipeline (which is also a file descriptor) the output is not seekable (meaning that application written in C or another language cannot use seek() syscall to quickly navigate to specific byte offset in a file). A good example of that is given in the question titled What is the difference between “cat file | ./binary” and “./binary < file”?

Sidenote: on Linux it's not exactly keyboard from where stdin gets its input. If you do

$ ls -l /proc/self/fd/0
lrwx------ 1 serg serg 64 Feb 23 16:45 /proc/self/fd/0 -> /dev/pts/0

you will see in the output that it is /dev/pts/0 terminal device to which stdin points initially. The terminal device then interfaces with keyboard, or it could as well be serial cable.

Additionally, if file is not very large, you could take advantage of bash's mapfile builtin to read lines into array:

mapfile  -t  < /etc/passwd
for i in "${MAPFILE[@]}"; do echo "$i"; done


Is installing Ubuntu on Mac as simple as installing on a generic PC?

It depends on which Mac you want and what version of Ubuntu you want to install on it. Take a look at https://help.ubuntu.com/community/MacBook for more information. There you can find exactly what works and what doesnt work on specific MacBooks


How to install playonlinux on Ubuntu 17.10?

You have an incompatible version of libcurl3 installed on your system. Probably you had a PPA or other unofficial software source added at some point in the past which provided this.

The solution is to downgrade libcurl3 to the correct version matching the other packages from the official repositories:

sudo apt install libcurl3=7.55.1-1ubuntu2

After that, you should be able to install playonlinux, as its dependency curl will no longer be blocked by a conflicting dependency version.


Main Menu keyboard navigation does not restart at the first typed letter. Is this a bug or a tweakable feature?

First, sorry for not quite answering your question, but it seems to me that there are other solutions that may fit your bill...

From what I gather, you want to quickly launch applications from the keyboard and you'd like to retain the "muscle memory" you acquired from the windows days :)

There are a couple of fantastic apps that do fulfill your first requirement, but may somewhat fail the second. However, from personal experience, after using these for a while I feel seriously handicapped on any computer without them:

Gnome-do (http://do.davebsd.com/) similar to Quicksilver on Mac OSX. Hit Win+Space and a window pops up that lets you type the first letters of any program installed, and then lauches it. Gnome-do is smart, so it learns your habits. It also has a large number of plugins -- it can post stuff on twitter, search the net etc..
Cardapio (https://launchpad.net/cardapio) a main menu replacement, which includes similar functionality as gnome-do -- quick search of apps etc (I think it's also similar to the start menu in Win 7).


Login loop 14.04 but guest account is accessible

I had the same problem. When I logged into my account via tty (by pressing ctrl+alt+F1, it said that there was an error in the ~/.profile file (I had been messing around in there).  After fixing the error I was able to log in.

Look for any error messages and try to fix them.


How to ignore multiple files and directories with grive?

Ignoring multiple directories can be done by using positive lookahead.
This regex ignores the directories "irrelevant" and "unnecessary":

grive --ignore '(?=^irrelevant$)|(?=^unnecessary$)'

The dry-run command I used for testing:

grive --dry-run --verbose --ignore '(?=^irrelevant$)|(?=^unnecessary$)' > output.txt 2>&1

The directories 'irrelevant' and 'unnecessary' were ignored while the file 'irrelevant1' was not. Hope this works for you.

Update (as of 2017-04-01): latest version of grive2 introduced .griveignore which is syntactically close to .gitignore.


How to install PixelAnnotationTool from Github?

Linux AppImage

This method describes the installation without building from source. Open a terminal and type

wget https://github.com/abreheret/PixelAnnotationTool/releases/download/v1.3.1/PixelAnnotationTool_x86_64_v1.3.1.AppImage

chmod +x PixelAnnotationTool_x86_64_v1.3.1.AppImage
./PixelAnnotationTool_x86_64_v1.3.1.AppImage& or open nautilus and double click PixelAnnotationTool_x86_64_v1.3.1.AppImage

Build and run on linux :

Instruction follows this link. The install the Qt5.9.1 IDE.

On Ubuntu, PixelAnnotationTool need this pacakage (OpenCV and Qt5.9.1):

sudo apt install build-essential cmake
sudo apt install mesa-common-dev
sudo apt install libopencv-dev python-opencv
wget http://download.qt.io/official_releases/qt/5.9/5.9.1/qt-opensource-linux-x64-5.9.1.run
chmod +x qt-opensource-linux-x64-5.9.1.run
./qt-opensource-linux-x64-5.9.1.run

To compile the application :

cd ..
mkdir x64
cd x64
cmake -DQT5_DIR=/path/to/Qt5.9.1/5.9.1/gcc_64/lib/cmake -G "Unix Makefiles" ..
make


How to change tab width in terminal in Ubuntu 10.04

You can set the tab width on any terminal to 4 (for example) by using the following command:

tabs -4

You can also set an explicit tablist. Consider looking at the man page.


When I plug in a USB microphone it also becomes the audio output (ie not working) Ubuntu20.04

find the profilename, use

pacmd list-cards | grep 'active profile'

Add the following to /etc/pulse/default.pa:

set-card-profile <cardindex> <profilename>

test it:

pactl set-card-profile <cardindex> <profilename>

alternative : use earcandy


Try pressing Ctrl + Alt + T, if a terminal appears type unity --replace. If that doesn't work try unity --reset and if that doesn't work either try sudo apt-get install --reinstall unity.

If Ctrl + Alt + T doesn't open a terminal try Ctrl + Alt + F1. To switch back to the graphical interface press Ctrl + Alt + F7.


How to always show some hidden files in Nautilus?

Perhaps you can use something like nautilus-hide?

sudo apt-get install nautilus-hide
nautilus -q

Project page: https://github.com/brunonova/nautilus-hide


Check out the official Ubuntu Touch wiki. The link you are looking for is the one on the wiki that says Get involved!.

Ubuntu Touch is no longer maintained as a core product by Canonical, however the Ubports community is continuing development.


Wiping Windows 7 with Ubuntu 14.04 installed

If all you want to do is delete your "data" (files, pictures, etc), then just do a meticulous cleanup of the folders in which W7 keeps this stuff (My Documents, My Pictures, etc). This will allow u to keep your current W7 installation (and all updates). If you wipe-out (re-format the W7 partition), and then re-install Windows 7, the Windows 7 installation process will MOST CERTAINLY wipe out grub2 bootloader and install the W7 bootloader in it's place. This is not a disaster and can be fixed fairly easily by booting to a Ubuntu live CD and re-installing grub2.


Black screen before boot animation Ubuntu 14.04

After googling for a while I managed to come to solution in a simple way. It won't remove black screen completely but now it only lasts for 2-3 secs and smoothly jumps to boot screen and you can enjoy your boot animation. To solve this I created splash file:

sudo gedit /etc/initramfs-tools/conf.d/splash

then type and save inside the file:

FRAMEBUFFER=y

choose and update your default.plymouth

sudo update-alternatives --config default.plymouth

sudo update-initramfs -u

sudo reboot

Done. Now it should look good and normal.


Can I Install Ubuntu first before installing Windows for dual boot

Though you can technically install Ubuntu and Windows in any order, I would highly recommend that you install Windows first.  This is because installing Windows on top of Ubuntu will likely result in messing up the MBR.  When that happens, it can be very difficult to boot into Ubuntu, because the Grub dual-boot menu might disappear.  It can be a little tricky recovering from that, which you can read all about here:

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

So if you have the opportunity to start from scratch, installing Windows first and Ubuntu second could potentially make your life MUCH easier.


How to install on a laptop w/o internet access?

You don't need to have Ubuntu on your PC. Download unetbootin, and make a bootable media from the downloaded ISO file. After that you can install it to the laptop.

Note: unetbootin is just one of the options.


VirtualBox - RTR3InitEx failed with rc=-1912 (rc=-1912)

Read This first!
Please note that this answer is intended to specifically solve the original poster's problem when typical solutions like running sudo /sbin/vboxconfig or removing virtualbox-dkms and installing dkms does not work.
Please first try these simple workarounds, these might help you right away.

It seems that your installation version of virtualbox is for 32-bit architecture while you are running 64-bit operation system which can be the cause of this problem.
My workaround would be to remove the installed version from PPA, and installing virtualbox from official repositories.
To remove virtualbox, run:
sudo apt autoremove --purge virtualbox*

After that make sure there is no other version installed on your system by:
dpkg -l 'virtualbox*' | grep ^i

You shouldn't get any output, also you can try to run virtualbox to make sure it's not installed.
Then remove all related PPAs from your sources.list and sources.list.d directory. ex:
mkdir ~/apt-tmp
sudo mv /etc/apt/sources.list.d/* ~/apt-tmp

Make sure there is nothing except official repositories sources in /etc/apt/sources.list.
And update your sources:
sudo apt update

Now we can search to see which versions are available to install:
apt-cache madison virtualbox | grep -iv sources

Which produces an output like this:
virtualbox | 5.0.32-dfsg-0ubuntu1.16.04.2 | http://mirrors.kernel.org/ubuntu xenial-updates/multiverse amd64 Packages
virtualbox | 5.0.18-dfsg-2build1 | http://mirrors.kernel.org/ubuntu xenial/multiverse amd64 Packages

Then I would install the last version mentioned in xenial-updates:
sudo apt install virtualbox=5.0.32-dfsg-0ubuntu1.16.04.2

Also sudo apt install virtualbox, would be fine, but I would go with the above command to make sure my desired version is going to be installed.
And after all, check that the correct version is installed.
From command line:
dpkg -l virtualbox* | grep ^i

ii  virtualbox                     5.0.32-dfsg-0ubuntu1.16.04.2 amd64        x86 virtualization solution - base binaries
ii  virtualbox-dkms                5.0.32-dfsg-0ubuntu1.16.04.2 all          x86 virtualization solution - kernel module sources for dkms
ii  virtualbox-qt                  5.0.32-dfsg-0ubuntu1.16.04.2 amd64        x86 virtualization solution - Qt based user interface

From GUI: to make sure correct version is running.
Help menu -> about virtualbox
Pay attention to green highlight


Kernel panic - unable to mount root fs after upgrade to 20.04

I had this on every or nearly every update from Ubuntu 19.10 to 20.04. No crazy old devices or anything, just plain VMs or bare metal with standard hardware.
So I'm wondering why they obviously didn't even test the happy path of a normal upgrade from 19.10 to 20.04, as it HAS to work on a fresh release, no excuses. "Wait for the first point release" is an advice for the LTS to LTS upgrade.

However, leasts-pain-solution for the people without USB-Sticks at hand is:

Hold SHIFT during boot to get GRUB menu (it will appear after the
first failed boot automatically, though)
Choose "Advanced options for Ubuntu"
Choose the older kernel in recovery mode (Linux 5.3.0-51-generic (recovery mode))
In the Recovery Menu, choose "dpkg - Repair broken packages"
After repair, reboot. Hold SHIFT again
Now choose "Advanced options for Ubuntu"/older Kernel again, this time WITHOUT recovery mode
System should now properly boot with GUI. uname -a will show the old kernel 5.3.0
Simply reboot again
System should now magically boot with GUI and the new 5.4.0 Kernel


Since you said you name your database "joomladb", you should use the same name when you grant permission to database user as in

GRANT ALL PRIVILEGES ON joomladb.* TO "joomla_admin"@"localhost"
IDENTIFIED BY "joomla_admin_password";


Win32 Disk Imager

Try the cloning tool Win32 Disk Imager. An old version, 0.9, works in Windows XP. See this links,

Win32 Disk Imager tutorial for cloning iso files

sourceforge.net/projects/win32diskimager/

  For Windows XP/Vista, please use v0.9 (in the files archive).

Rufus 2.18

Try an older version of Rufus. According to

github.com/pbatard/rufus/blob/master/ChangeLog.txt

Rufus version 2.18 works in Windows XP.

  Version 2.18 (2017.11.07)
      Ensure that the same drive is reselected on device refresh
      Add a cheat mode to cycle the USB port of currently selected device
      Make lookup for updatable .cfg file more generic (e.g. ESET SysRescue)
      Fix handling of multiextent ISOs (e.g. BlackArch Linux)
      Fix propagation of image decompression errors
      Update grub4dos to latest

IMPORTANT: THIS IS THE LAST RELEASE TO SUPPORT WINDOWS XP AND WINDOWS VISTA
SUBSEQUENT RUFUS RELEASES ARE *NO LONGER* COMPATIBLE WITH THESE PLATFORMS


If both hard drives are seprated but they are in one cpu than you are not gonna loose any data at all. But if you install ubuntu in 128 Giga u have to choose the something else option while installing than select \ bar in front of space where you want to install your OS. or you have one Hard Drive of 1TB then u have to choose very wisely. try this videos on youtube for more details (https://www.youtube.com/watch?v=G7ffzC4S0A4) (https://www.youtube.com/watch?v=X-DHaQLrBi8)


What Happens to Partition After Ubuntu Installation

If you set them as "do not use partition" they won't be touched at all.

If I remember correctly, you can still select a mount point for them, so that a line for each is added to your fstab file (this way they will be mounted automatically, e.g. set mount points to /myfiles1, /myfiles2).

Anyway, before you install Ubuntu, I'd suggest you back up your disk, if that is not possible, at least back up your Widows install, you never know when and if you will need it.


I just installed Debian on a platform with the same GPU and had a similar "what the heck" moment. I managed to make it slightly less horrible by telling the kernel to use an 8-bit screen mode by adding this to the GRUB_CMDLINE_LINUX:
video=1024x768-8

Lower resolutions were even faster, but 1024x768 was the sweet spot for me. This took it from maybe 35-40 seconds down to about 7-8 seconds.
As far as I can tell this should work equally well on Ubuntu. I'm using a 4.19 kernel and the video= option hasn't changed dramatically.


In the case of perl-base, dpkg is a Pre-Depends, not a Depends. What's Pre-Depends?

This field is like Depends, except that it also forces dpkg to complete installation of the packages named before even starting the installation of the package which declares the pre-dependency[...].
[...]
Pre-Depends should be used sparingly, preferably only by packages whose premature upgrade or installation would hamper the ability of the system to continue with any upgrade that might be in progress.

dpkg was, at one time, written in Perl (and parts of it still might be written in Perl, I haven't checked the source code). So if Perl got upgraded before dpkg, it might mess things up, and cause dpkg to stop functioning. So dpkg has to be installed/upgraded and configured before Perl. That's why it's a Pre-Depends.


Android emulator is not working on Linux because of libGL

Using system libstdc++ solves the issue

For example:

cd ~/Android/Sdk/tools
./emulator -avd Nexus_5X_API_27 -use-system-libs

If it works correctly, set the following variable in ~/.bashrc:

export ANDROID_EMULATOR_USE_SYSTEM_LIBS=1

Re-login or source ~.bashrc. You can then omit the -use-system-libs option:

./emulator -avd Nexus_5X_API_27

This method does not work when the emulator is called from Android Studio. Here is a workaround

Create a shell script android-studio.sh in a directory available in your PATH. For example ~/bin with the following contents:

#!/bin/bash
export ANDROID_EMULATOR_USE_SYSTEM_LIBS=1
~/Programs/android-studio/bin/studio.sh %f

and then update the launcher command in

~/.local/share/applications/jetbrains-studio.desktop

to point to ~/bin/android-studio.sh.


copy/move multiple files using cp/mv without using regular expressions

If you want to move or copy all of the files to the same directory, you can use the -t option of cp or mv, but this will mean that you have to type/supply each filename as an argument. It works in the following manner, with as many files as arguments as you like:

cp -t /destination/directory/ file1 file2 file3

or

mv -t /destination/directory/ file1 file2 file3

This is quite laborious, but typing the file names can be made easier using Bash's tab completion.

Alternatively the following bash script will find all the files in a directory, given as the first argument, and copy the selected files into the destination directory, given as the second argument.

It checks each file and asks whether you want to copy that file. At the end of file selection it shows a list of selected files and asks if you want to copy them to the destination directory:

#!/bin/bash
directory=$1
destination=$2
selected_files=()
for f in ${directory}/*
do
  if [[ -f $f ]]
  then
    while true
    do
      read -p "Would you like to copy ${f}? y/n: " choice
      case $choice in
        y|Y) selected_files+=("$f");
             break ;;
        n|N) echo "${f} will not be copied.";
             break ;;
        *) echo "Invalid choice, enter y/n: " ;;
      esac
    done
  fi
done
echo "The following files will be copied to ${destination}."
for file in "${selected_files[@]}"
do
  echo "$file"
done
while true
do
  read -p "Are these the correct files? y/n: " confirm
  case $confirm in
    y|Y) break ;;
    n|N) echo "Exiting filechooser"; exit 1 ;;
    *) echo "Invalid choice, enter y/n: " ;;
  esac
done
cp -t "$destination" "${selected_files[@]}"

Be warned that there's no error checking in this script about whether the destination directory exists, or that you've input the correct arguments.


It seems like you may run into a recognised problem - see this answer which explains how to progress when stuck at the initrafms prompt.


Send-Via-Bluetooth custom action on pcmanfm-qt

You can change the MimeType line into MimeTypes=*;!inode/directory;. Which allows any MimeType except the one of folders.

The file then should look like this:

[Desktop Entry]
Type=Action
Name[en]=Send-via-Blueman
Icon=bluetooth
Profiles=profile-zero;

[X-Action-Profile profile-zero]
Exec=blueman-sendto %F
Name[en]=Default profile
MimeTypes=*;!inode/directory;
SelectionCount==1


How to test what is causing a delay on user login?

Check the log files in the /var/log/lightdm/ directory.

Also if you have a modified /etc/lightdm/lightdm.conf file with a session-setup-script that can cause a delay.


Why isn't Ubuntu using the open-source AMD/ATI drivers?

fglrx is the closed-source driver!

Your steps in fact installed the AMD/ATI closed-source driver. The open-source one radeon is included by default with Ubuntu.

Please remove the fglrx drivers to "activate" the open-source one.


This is most likely due to bugs occurring on 15.04 and later version, the bugs itself has been reported to launchpad which you can see here https://bugs.launchpad.net/ubuntu/+source/runit/+bug/1448164.

This is because runit depends on upstart and Ubuntu have decides the move to systemd as the default init system in 15.04. To get rid of the error, you need to purge runit, git & git-all:

sudo apt-get purge runit
sudo apt-get purge git-all
sudo apt-get purge git
sudo apt-get autoremove
sudo apt update
sudo apt install git

https://askubuntu.com/a/771889/253251


Internet Download Manager for Ubuntu 16.04

IDM is windows based download manage and it does not offer for Linux.

You may try one of below alternative:
1. uGet
2. SteadyFlow
3. FlareGet
4. kGet
5. XDM(Xtreme Download Manager)

Please refer this url : http://www.linuxandubuntu.com/home/5-best-linux-download-managers


Having trouble booting ubuntu 12.04 desktop from usb in windows 7

When you create a live usb boot  make sure you follow these instructions, or using any other software you like, is extremely difficult to do it manually.

After doing that there is still a pitfall to reach, you have to configure you BIOS settings to allow you computer to boot from a USB drive, to do this, whe you computer is starting it shows a loading screen from you bios provider, that screen usually has a list of the key bindings, one for BIOS settings (f12, spr or other key) and other for Boot device options.

You can press the key associated with Boot device options and then select you USB drive or go to BIOS settings and look for boot options where I'm sure you can find something like boot device order or priority and set you USB drive over your hard drive.

After this is done, hopefully you will be allowed to boot from your USB, also, I think that's a great way to install Ubuntu, way more efficient than using a CD or DVD.


Repeat a command every x interval of time in terminal?

You can use  watch command, watch is used to run any designated command at regular intervals.

Open Terminal and type:

watch -n x <your command>

change x to be the time in seconds you want.

For more help using the watch command and its options, run man watch or visit this Link.

For example : the following will list, every 60s, on the same Terminal, the contents of the Desktop directory so that you can know if any changes took place:

watch -n 60 ls -l ~/Desktop


Alright - absolutely NOT a network expert and I don't care if you agree, or even know, the reason for my total, complete and absolute dislike of the ipv6. Trust that my feelings on the matter will not change.

Here is how I have beaten down the ipv6 proliferation on my network systems running ubuntu 16.04:

I'm not going to describe my initial attempts - such as ignoring it on my network interfaces, feeble attempts to not accept or forward it with iptables (tho I did learn a VERY nice tip regarding ipv6 and iptables). If you haven't already done those things then you shouldn't do any of my suggestions here IMSHO.

URLs I found useful (there are others, these have worked for me):

http://www.neuraldump.com/2016/11/how-to-disable-ipv6-in-ubuntu-16-04-xenial-xerus/#comment-22453
http://mindref.blogspot.com/2010/12/debian-disable-ipv6_22.html
http://crashmag.net/disable-ipv6-lookups-with-bind-on-rhel-or-centos

Initial Pass: Disable it using sysctl directives
 as user root create/edit (replace / with 'or') /etc/sysctl.d/99-idontlikeipv6.conf adding the following lines:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

Save the file then restart procps:

sudo service procps reload

Further down the spiral... (and why iptables just ain't enuf)

IPv6 and Linux Socket Listening (or how to tell if you have a problem)
most people concerned about security will, at a minimum, run a firewall of some sort. I did, and thought that iptables was the best thing ever for process protection without lots of overhead.

Then I learned local processes, which bind to IPv4 and IPv6, are not 'protected', or prevented from receiving, IPv6 traffic by ANY iptable directives, as iptables only affects/blocks IPv4 traffic.  To firewall IPv6 traffic you need to setup another rules file and load it via ip6tables. This is the file and load commands I used:

(as root) create/edit /etc/ip6tables.up.rules and add the following:
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT DROP [0:0]
COMMIT
load it up
sudo ip6tables-restore < /etc/ip6tables.up.rules
check how it's looking:
netstat -atunp

This will show you any processes listening on your local machine - you want to look for the tcp6 and udp6 lines. you can filter the netstat output to those lines with:

netstat -atunp | egrep "tcp6|udp6"

When I did this I saw things such as:

tcp6       0      0 :::10000                :::*                    LISTEN      2353/perl
tcp6       0      0 :::113                  :::*                    LISTEN      1399/oidentd
tcp6       0      0 :::631                  :::*                    LISTEN      6620/cupsd
tcp6       0      0 :::17500                :::*                    LISTEN      6834/dropbox
udp6       0      0 :::5353                 :::*                                7160/chrome
udp6       0      0 :::5353                 :::*                                1120/avahi-daemon:
udp6       0      0 :::57956                :::*                                1120/avahi-daemon:

along with still others. The rest of this is how I got rid of (some) them:

Look at netstat to see how you are doing. I still had a lot of things listening for IPv6 traffic. Processes like tomcat, apache2, rpcbind, cupsd, chrome...the list went on for a while. Disabling these each took a bit of investigation and work. I'll try to be brief.

apache2: modify apache file ports.conf (mine was in /etc/apache2) adding an ip address after each Listen directive, before each port, ':' delimiter. For example:
Listen 127.0.0.1:80

    Listen 127.0.0.1 443

tomcat/catalina: Modify the server.xml file under /conf adding an address directive into each connector clause, like:
< Connector
port="6969"
address="8.8.8.8"
redirectPort="8443"
postfix: modify the /etc/postfix/main.cf file line for net_protocols to read:
net_protocols = ipv4
bind9/named: locate your dns config file (might be several, you are on your own here) and add listen-on-v6 { none; }; close to/before/after a 'listen-on' directive. Mine was in /etc/bind/named.conf, some pages said to look/add it to a file called named.conf.options
cups (cupsd, cups-browserd): edit /etc/cups/cupsd.conf and change the port directive as follows (NOTE: buyer beware, you might enjoy what cups gets you, if so you won't want to fuk it up):
Port 127.0.0.1:631
sshd: depends on ssh server installed. I ran across two different ways to set this to only listed on ipv4 addresses.

edit /etc/ssh/sshd_config and have only 1 ListenAddress directive and give it a specific IPv4 address the 'any port' 0.0.0.0 value, like:
# ListenAddress ::
ListenAddress 4.4.4.4
Set the AddressFamily directive to inet (make sure only one AddressFamily directive is enabled)
# AddressFamily any
AddressFamily inet

ntp: edit /etc/default/ntp to have NTPD_OPTS start with -4, similar to:
NTPD_OPTS='-4 -g'
rpcbind (rpc.statd, rpc.mountd): comment out lines that start with tcp6 or udp6
avahi-daemon: I couldn't find any reason to allow it and it purged very easily... apt-get purge avahi-daemon
chrome - this one was controlled through the UI - the following URL was key to nerfing it's IPv6 trafficking:  https://unix.stackexchange.com/questions/187294/chromium-browser-pepperflashplugin-opening-listening-ports-on-0-0-0-05353
use chrome to navigate to URL chrome://flags/#device-discovery-notifications and use the select list to choose 'disable' (or disabled, can't remember). Disabling this so-called "device discovery" feature turns off listening of mDNS port 5353/tcp. You need to relaunch Chromium / Google Chrome to make this take effect.

To have these changes take affect reboot your machine. There's other ways, but I'm too damn tired to go into the details and rebooting will either give you a machine with IPv6 suckers and putters - OR it'll give you a whole new set of problems to worry about.

NOTE: Knowledge is power, with hands it can be a powerful weapon. You assume all responsibility for fking your systems up by following any of the things in my post. njoy

-wc


Try running "sudo update-grub" in a terminal. This should tell the bootloader to look for your Windows 7 partition and allow you to switch next time you boot up.


If I boot Ubuntu, restart and then Boot Windows, it will give an error in the boot loader

The answer to your problem is to disable Fast Boot on Windows 8.

To disable it -

All Control Panel items -> Power Options -> System Settings

Click on the 'Change settings that are currently unavailable' link to make the Shutdown options available and Untick the Turn on fast startup option.

The reason for this is explained below with content from this source.

Fast boot explained with an image:

During fast boot the system loads the hiberfile and does not use the files on the filesystem.

So the biggest problem, and the worst problem you can have on a computer, is data loss: if you create a shared NTFS data partition the hibernation may maintain the file structure so if you try to save a file from Linux into the NTFS partition it will get lost on Windows reboot as it only remembers the old file structure. See this Ubuntu Forums thread for more information.

In general: if a disc is mounted when using fast boot, Windows puts this disc and its content in a hiberfile. Any changes made to the system are gone when the hiberfile is restored. This includes mounted external discs. Ubuntu will refuse to mount a disc that has a hiberfile.

One of the bad messages you see in these topics is getting a "disc has errors" when booting Windows.


Best practice for shared directory on server (samba windows 10 clients)

Edit the samba configuration file.

sudo nano /etc/samba/smb.conf

Add this to the end of the file:

[Public Directory]
comment = Contents are read/write by all.
path = /home/user/directory-to-be-shared
read only = no
guest ok = yes
create mask = 0666
force create mode = 0666
directory mask = 0777
force directory mode = 0777

Then restart samba.

sudo service smbd restart

Notes:

The string within brackets (Public Directory in the example above)
is what users will see when accessing the shared folder from other
systems.
Files created within this directory by users on other systems will
be owned by nobody:nogroup, with read and write permissions for
owner, group, and other.
Directories created in this directory by users on other systems will
be owned by nobody:nogroup, with read, write, and directory traversal
permissions for owner, group, and other.
The masks and modes in the configuration file apply to files and
directories created by users on other systems. These masks and modes
are ignored when creating files as a user on the server. Or, to put it
another way, if you are user on the server, make sure that each file
and directory that you create within /home/user/directory-to-be-shared has 666 and 777 permissions respectively.
If you have enabled a firewall on the server, you will need to open
port 445 for tcp. For example, if you use ufw (uncomplicated
firewall) to configure the firewall:

sudo ufw allow in 445/tcp
sudo ufw reload
sudo ufw status verbose


Use sed:

sed "s/.*/'&','&'/" filename

s/foo/bar replaces foo by bar. .* matches the whole line, & in the replacement section inserts the whole match.


Is it possible to get a patch included in the current release? If so, how?

As Dobey mentioned, in order for a patch to be accepted into an already released version of Ubuntu, it must got through the Stable Release Update (SRU) process. The bar to entry for SRUs is quite high. A simple way to sum up the thinking behind the process might be: "The bug we know is better than the bug we don't know about." In practice, that means that only targeted bug fixes are allow and no changes that are too "intrusive."

There are a number of requirements that must be met in order to proceed with an SRU:

The bug is fixed in the current development release (i.e. quantal).
The bug report's description must be updated to include a justification for why the fix is needed in the stable release, a test case to reproduce the bug and verify it has been fixed, and a discussion of the fix's regression potential.
The Launchpad team ubuntu-sru should be subscribed to the bug report.
The package is then uploaded to release-proposed In order for this to happen, you will need to go through the sponsorship process (more info below).

After all that has occurred, the SRU team will verify that the package in -proposed resolves the bug. Then the package will be pushed into -updates after it passed a minimum aging period of 7 days.

Finding the right person

Your question hints at the fact that sometimes Launchpad seems like it is where patches go to die. Sadly, if you don't know the process it can feel like that, but I swear it's not really that bad. Luckily, the main thing you need to know is simple. Check out the sponsorship process for all the details and some hints, but the most important part is to subscribe the ubuntu-sponsors team to the bug report. That ensures that it will show up in the sponsorship queue and get looked at by an honest to god Ubuntu  developer.

If you need to talk something over in real time, #ubuntu-devel on Freenode IRC will do the trick. Check the channel topic for the current patch pilot. They're there to help you. If there's no pilot on duty, feel free to ask for help in the channel, but please be patient.

Getting everything ready to go

In order to make the process go as quickly as possible there are a few things to do.

Update the bug description to look like:

  [Impact]

  Here's an explanation of the impact of the bug on users and a
  justification for backporting the fix to the stable release

  [Test Case]

  Step
  By
  Step
  Instructions
  To Verify
  The Fix

  [Regression Potential]

  Here's a discussion of any potential for
  regressions.

  [Original Report]

  Every thing that used to be in the description is
  retained below.

Next, prepare your patches. Things will go much quicker if you provide debdiffs that take care of all the packaging bits rather than a patch against the upstream source. This includes using the packages patch system if it uses one. Luckily add-patch from ubuntu-dev-tools  can take care of that for you.

Let's walk through this. First grab the source and the patch in the bug report:

$ pull-lp-source compiz precise
$ wget https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/974242/+attachment/3141645/+files/fix-974242.patch

Now we'll add the patch to the source package:

$ cd compiz-0.9.7.8/
$ add-patch ../fix-974242.patch

This will add the patch to debian/patches and run dch prompting you to add a new entry to debian/changelog Adjust the entry to target proposed and increment the version number so that it will be below the next version uploaded to the development release. Like so:

compiz (1:0.9.7.8-0ubuntu1.1) precise-proposed; urgency=low

  * debian/patches/fix-974242.patch: [DESCRIBE CHANGES HERE]

 -- Your Name <you@example.com>  Mon, 11 Jun 2012 17:37:59 -0400

The file at debian/patches/fix-974242.patch also has some headers that you might want to edit:

## Description: add some description
## Origin/Author: add some origin or author
## Bug: bug URL

Now build your new source package:

$ debuild -S -us

And create the debdiff:

$ cd ..
$ debdiff compiz_0.9.7.8-0ubuntu1.dsc compiz_0.9.7.8-0ubuntu1.1.dsc > sru-for-lp-974242.debdiff

You can now attach the resulting debdiff file to your bug report.


How can I recover my files and my system after running rm -r /home/username?

If you lost some important data try to recover with 'testdisc'.
If no important data is lost and you can boot. Go to settings>Details>Users unlock and add another user with Administrative powers, set password and login again or reboot. Login as new user from there you can delete the previous user.

I wonder why you did it.


Execute Bash script at startup, but only once a day?

As Ubuntu uses Anacron by default, you already have this behaviour by putting the script into /etc/cron.daily. Check run-parts --test /etc/cron.daily to check if your script is picked up (importantly, no .sh extension and the +x bit set). See this wiki page and man anacron for more detailed information about why this will work for you.


Could you tell us what version of ubuntu you are using and if it is  32 or 64-bit please?

Also check if you downloaded the right driver. It should be the 290.10 Linux 32-bit/Linux 64-bit released on november 22nd 2011.


In case someone has the same problem:
I put gateway=192.168.1.254, this did not fix it.
Originally I checked "Use this connection only for the resources on its network" checkbox for IPv4. Checking it for Ipv6 too, solved it!


Have you thought about Latex?
There are different kinds of Latex software for Ubuntu. You could try out:
1. Kile
2. Texmaker
3. Lyx

But have a look into Latex. I'm sure it can help you out, and maybe become a good friend of yours.


If you would be able to identify the files, that you need,

You should be able to mount the partitions with file systems according to the following link, Mount dd image for my USB. kpartx is probably the best alternative.
When mounted, you can browse the file systems via the mountpoints and look for the files that you need.
The encryption is a complication, I have not tried to mount an image of an encrypted drive ...

If it is necessary to boot,

As suggested already in a comment, we don't think that you can boot from the image file. Instead

you can get a new drive, that is big enough,
and clone from the image file to the new drive.
If there is a GUID partition table, GPT, and the target drive size is different from the original one, the backup table at the end of the drive must be fixed with gdisk. This is done automatically by mkusb, so it is a good idea to clone with mkusb. Rename the image file to backup.img, to tell mkusb that it is an image file, not an iso file.
Replace the current drive with this new one and boot from it. Do not boot when both drives with installed systems are connected.


Your question indicates you no longer need Ubuntu on this machine and that space will be reclaimed for the use of windows XP.

You can eliminate the partitons from windows XP itself. As a precaution, take a backup of windows data before doing the steps.

Go to 'Settings -> Control Panel -> Administrative Tools -> Computer Management -> Storage -> Disk Management' from windows xp and simply delete and reformat the ext2/3/4 partitions which will be Linux partitions and create and format new windows partitions.

I assume the primary partition is windows XP and it is the one with boot flag.

Now you will need to fix MBR to remove grub and re-instate pure windows XP MBR.
Refer http://helpdeskgeek.com/how-to/fix-mbr-xp-vista/ (I personally did not use this in the past, but after reading it and remembering my past experience this documentation looks correct).

Now you should have PC without old Ubuntu.


Keyboard Layout Table – how to force update?

A cache of (compiled) keyboard layouts is kept in the /var/lib/xkb/ directory, in the various *.xkm files.  Perhaps deleting these files may help?  There is a README in that directory giving a bit more information.


My user can't SFTP to a dir even though it's a member of the group that has write permissions to it

Note that despite the name, vsftpd is NOT an SFTP server, it's a plain old FTP protocol server. SFTP is usually handled by the ssh daemon. So any config changes you do in vsftpd will not affect SFTP transfers.

The file will be owned by whoever uploaded the file. You may want to check your SFTP client's options for ownership and permission preservation (WinSCP in your case).

(btw I'm just reformatting the comments as an answer).


you are doing it wrong, you are trying to move a file inside / folder without root permissions

for you try getting your current directory by

pwd

and then try moving the files using

mv <folder to move> <destination>

try using relative locations ie:

mv /home/<user>/South_America /home/<user>/North_America/

for more information about the mv command type in the terminal

man mv

or

mv --help


I don't know know of any Maven repository managers packaged for Ubuntu, but Archiva and possibly others can certainly be deployed on Ubuntu.

Download the standalone version and extract it:

wget http://apache.osuosl.org//archiva/binaries/apache-archiva-1.3.5-bin.tar.gz
tar -xvzf apache-archiva-1.3.5-bin.tar.gz

To start it run:

./apache-archiva-1.3.5/bin/archiva start

It should then be available at http://localhost:8080/archiva

More advance documentation can be found in the System Administrators Guide to Apache Archiva.


What to do when nothing seems to fix Ubuntu 14.10 stuck after log in?

I am facing the same situation, frankly I don't have the time to go through the logs and fix it plus I am afraid I will ruin something again and I can't spare any time right now to reinstall Ubuntu and/or try any fix so I am dealing with it the following way.

What I am doing to get access to my machine after getting stuck on login page is the following:

1- After rebooting and landing on login page I go to a TTY (ctrl+alt+F1).

2- Login as my normal user.

3- kill lightdm running processes sudo killall -u lightdm

4- remove Xauthority file rm .Xauthority, the one under my normal user account i.e: ~myUsernameAccount/.Xauthority.

5- make sure no lightdm instance is still running with ps aux | grep lightdm

root      2412  0.0  0.0  89496  2600 tty1     S    16:59   0:00 sudo lightdm
root      2413  0.0  0.1 351608  4100 tty1     SLl  16:59   0:00 lightdm
root      2418  0.5  1.0 312932 39132 tty7     Ssl+ 16:59   1:57 /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
root      2491  0.0  0.1 188932  4700 tty1     Sl   16:59   0:00 lightdm --session-child 12 19
ash    8723  0.0  0.0  15944   916 tty1     S+   23:15   0:00 grep --color=auto lightdm

See in the previous output, lightdm is lunched as root so killall -u lightdm won't work, so I do the following: sudo kill 2412 2413 2418 2491, but if the system is just booted up then you will see lightdm instead of root and that command will work fine, (also notice that the last line is grep output command and is always shown so ignore it)

Now if you check ps aux | grep lightdm again the output should be something similar to this only:

  ash  8759  0.0  0.0  15940   912 tty1     S+   23:17   0:00 grep
  --color=auto lightdm

6- lunch lightdm again sudo lightdm&.

7- Switch to GUI (ctrl+alt+F7) again.

8- Login normally, it mat get you back to F1 TTY so again go to GUI using ctrl+alt+F7, wait for few seconds till the crash report is completed and I will be on my desktop.

P.s: using this method, you have to enter the system key everytime you do something that requires root privileges, for example: I can't edit network connections from the top panel directly, I have to call the networking from terminal using sudo, ...etc.

Ofcourse this is not a good practice at all, but I hope it will help someone to get around the problem for a little amount of time.


Yes perfectly safe (I accidentally did once and installed it back since I love unity)


How to install Window theme on Ubuntu without sudo privileges?

To install themes system-wide, you would place them in /usr/share/themes, and icon themes would go in /usr/share/icons.  But since you don't have root access, you can't write to those directories.

However, you can write files to your home directory.  GTK themes can also be placed in ~/.themes (and icons go in ~/.icons).  For example, if your username is "peter" you would place files in /home/peter/.themes.

These folders may not exist, and even if they do, you almost certainly won't be able to see them by default.  Open your home folder and press [Ctrl]+[H] to display dot files - files and folders which start with a dot - these are hidden files under Linux.  Now you should see several dot files, including stuff like .cache and .bash_logout.  Don't remove these; they're there (and hidden!) for a reason.  Instead, just right-click and Create New Folder and call it .themes.

Since you didn't specify the particular theme you're working with, I can't guide you on the exact structure they should be copied into the folder with.  Feel free to edit your post, or look around in /usr/share/themes and mimic the structure with your own .themes directory.

Good luck!


Repeater/Access Point with 2 WiFi interfaces very low bandwidth

You can try to set the rate of both cards.

Iwconfig wlan1 rate 54M fixed

Also, what kind of wifi cards and are you using a usb hub?


Ordinarally Raja would have the reason.
If it is on amazon cloud, you could set up another server, and attach the other server storage and change the config by hand.
You have to know the provider features. Perhaps there are ways. Many "dedicated servers" aren't trully that. Ask for your host support.

Or hire a whitehat pentester to try to do so if it is legal on your country. On my country is legal, as long as the servers is really yours.


The most efficient way is to use AtomicParsley and a bash 'for' loop. Install AtomicParsley on any version of Ubuntu as follows:

sudo apt-get install atomicparsley

Then change to the directory containing the m4a files and run the following:

for i in *.m4a
do
AtomicParsley "$i" --artwork cover.jpg --overWrite
done

And now your m4a files have the album art embedded and you can safely delete your album art image. This will work for all versions of Ubuntu...


Why is my RAID5 array smaller than expected?

There is a slight misunderstanding here. The size reported here is not the final, usable size of the RAID5 array, but the size of storage used from each device. See the description of the --size option:

-z, --size=
      Amount  (in  Kibibytes)  of space to use from each drive in RAID
      levels 1/4/5/6.  This must be a multiple of the chunk size,  and
      must  leave about 128Kb of space at the end of the drive for the
      RAID superblock.  If this is not specified (as  it  normally  is
      not)  the smallest drive (or partition) sets the size, though if
      there is a variance among the  drives  of  greater  than  1%,  a
      warning is issued.

This is exactly what you're seeing, including the warning.

  What do I need to do in order to get my largest drive as the parity and the 2 smaller drives added together as the capacity of the array?

That sounds like RAID4, not RAID5.


Unable to open file from Windows NTFS partition

I suspect that the arrows on these icons mean that they represent symlinks, or maybe placeholders from onedrive, considering the OneDrive-few path component. So try to locate the real file.

Also try detailed list view, or however it is called in your file manager. That may tell you the location that the symlink points to.


How can I fix internet connection issues on wsl2

I was having the same issue. As the comment above suggested I disabled IPv6 option for both, my wireless adapter and WSL Ethernet adapter.
Follow the steps:

Right click on your network icon, and click on Open Network and Internet settings
image
In the settings page look for Change adapter options under Advanced Network settings
img
On the next page you'll see a bunch of network adapters, for bluetooth, vpns, ethernet and for wifi.
If you use wifi, then disable IPv6 for wifi and wsl adapters.
Right click on the adapter and click Properties
In the pop up look for a checkbox specifying IPv6 connection, uncheck it. img

I was trying to comment at first then couldn't (less reputations).