/var/www owner for apache2 and ftp access

I'd recommend setting it to be owned by james:james.
Alternatively, you could leave it as root:root and requite sudo for anybody deploying files in there, but if you are directly working in the /var/www directory (rather than working somewhere else and pushing the files there) that may not be convenient, and it won't work with FTP either.
You can set the owner of /var/www to whatever you like, as long as the www-data user has read access.  You can achieve this by setting permissions to allow world read access (as is default).
By default, it is owned by root:root (not www-data as you state in the question).

For security, it is not a good idea to set it to be owned by www-data.  www-data is intended to be an unprivileged account which cannot write to any files, and can only read them.
Yes, occasionally you may need to give www-data the permission to write to a given file, but for security this should be strictly limited to those particular files, and precautions should be taken such as making sure no such files are executable as scripts by the web server (ie they are not in a location where they may be interpreted as PHP or CGI files), etc.

For security, it is an even worse idea to set the file permissions to world-writable (eg, 777).  Unprivileged users such as www-data should not be able to write to files in this directory.  The only people who need write access will be the people who are actually writing files in there.

The /var/www directory is intended to be yours to do with what you like.  It makes sense to set ownership to whichever account will be editing the files.  You can create a group for this purpose if you have multiple people, but in this case it's just you.
Note: if creating a group, create a new group.  Do not re-use the www-data group as that is intended to be an unprivileged group without write access to any files (as I explain above).

Too often I see people recommending adopting very bad security practices such as setting /var/www to be owned by www-data, or adding people to the www-data group in order to give that group editing privileges, or setting /var/www to be world-writable (eg 777).  By doing any of this you are potentially opening yourself up to significant security problems.


Gnome overview - how to remove applications from certain search keywords?

You can edit .desktop files located in /usr/share/applications/

From what I've found search is based on the Name, GenericName and Comment properties inside .desktop files, so by changing these properties you should be able to filter which apps are shown.

You can edit .desktop files in any text editor.


How can I make Onboard, the visual keyboard, open in Ubuntu on startup?

Open Gedit and type:

#!/bin/bash
# you can change the size of the window below (1000x300)
onboard -s 1000x300

Now save this file somewhere as filename.sh and open a terminal window. Navigate to this file location by using:

cd /home/user/blah/blah/../filename.sh

When you get there type in

sudo chmod a+x 'filename.sh'

(quotes are there for avoiding space character problems). Now you've made it an executable bash script. Open 'gnome-session-properties' from terminal and click on Add.

Name: Onboard
Command: "Browse to the file location"
Comment: Onboard on startup

Click add and you're done! Logout and login to see if it worked.


First, check the settings in the router. WPA2-AES is preferred; not any WPA and WPA2 mixed mode and certainly not TKIP. Second, if your router is capable of N speeds, you may have better connectivity with a channel width of 20 MHz in the 2.4 GHz band instead of automatic 20/40 MHz, although it is likely to affect N speeds. I also have better luck with a fixed channel, either 1, 6 or 11, rather than automatic channel selection. Also, be certain the router is not set to use N speeds only; auto B, G and N is preferred. After making these changes, reboot the router.

Next, I recommend that your regulatory domain be set explicitly. Check yours:

sudo iw reg get

If you get 00, that is a one-size-maybe-fits-all setting. Find yours here: http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2 Then set it temporarily:

sudo iw reg set IS

Of course, substitute your country code if not Iceland. Set it permanently:

gksudo gedit /etc/default/crda

Use nano or kate or leafpad if you don't have the text editor gedit.

Change the last line to read:

REGDOMAIN=IS

Proofread carefully, save and close the text editor.

Next, I'd set IPv6 to Ignore in Network Manager: http://docs.fedoraproject.org/en-US/Fedora/18/html/Installation_Guide/images/netconfig/network-connections-ipv6-ignore.png  This example is for ethernet, but you want wireless.

If these changes do not help, please try:

sudo modprobe -r ath9k
sudo modprobe ath9k nohwcrypt=1

If it helps, make it permanent:

sudo -i
echo "options ath9k nohwcrypt=1"  >>  /etc/modprobe.d/ath9k.conf
exit


This look like a confirmed bug.

Friends app crashes instantly when loading.

Steps to reproduce:
Run friends app from the terminal, or click the "Friends" logo in the dash.

Expected Behavior:
Friends app displays timeline.

Actual behavior:

Friends app never comes up. If run from the terminal, the "Segmentation Fault" message is seen.

See Friends app crashes on start

Source:Launchpad


Ubuntu Server 12 not spawning a serial ttyS0 when running on Xen

The answer to this problem is to provide an "entry" in /etc/init for the Xen required /dev/hvc0 serial console.

How to do this?

Either as root or using sudo commands, open a terminal and change to the /etc/init directory. Copy the file for tty1, that is /etc/init/tty1.conf to /etc/init/hvc0.conf. Then edit the new hvc0 file in your favorite text editor, replacing all occurrences of tty1 with hvc0. The next time you boot using Xen, your serial terminal should now work correctly. You should be able to log in to dom0 and use the command line, or by hitting Ctrl-a 3 times, switch to direct serial communication with the hypervisor.

Sincerely,

Segfaultreloaded


The cron runtime environment is quite different from the GUI runtime environment. Run
env | sort; set

in each environment, saving the results to a file.
If you arrange your ~/.bashrc appropriately you can preface your Python script with
#!/bin/bash
. $HOME/.bashrc
yourPythonScript

to set up your cron environment.
Read man -a crontab;man -a cron.


Netbeans doesn't load modules for regular users

I've just encountered exactly the same with Netbeans 8.0.1 (updating by running as sudo)

Changing the owner and group of some files in ~/.cache did the trick

sudo chown -R <user>:<group> ~/.cache/netbeans


The f is for "function indexes".
en = ethernet
p# = PCI bus number
s# = slot number
f# = function index

Added some resources: libvirt.org has a good explanation
waste.org says this about "f":

All devices have at least 1 function, function #0.  There are 8 possible functions per device, numbered 0-7.  Any device that has more than 1 function is called a multi-function device.  Multi-function devices, such as a combination modem+soundcard will usually have 2 uniquely addressable functions, numbered 0 and 1.

The function leads to the vendor and device id:

Every function of a device has 256 eight-bit registers.  Registers 0-3F are defined by the PCI specification and provide a wealth of information about the particular function.  Registers 40-FF are vendor defined and control the properties of the function itself.  Without vendor specific documentation, these registers should probably be left untouched.

Registers 0 and 1 are defined by the PCI spec as being the vendor ID.  The vendor ID is a 16bit value.
Registers 2 and 3 are the device ID

From pbhj's link in comments it leads to the source code:
Line 264+:
if (sscanf(sysname, "%x:%x:%x.%u", &domain, &bus, &slot, &func) != 4)
            return -ENOENT;

if (naming_scheme_has(NAMING_NPAR_ARI) &&
    is_pci_ari_enabled(names->pcidev))
        /* ARI devices support up to 256 functions on a single device ("slot"), and interpret the
         * traditional 5-bit slot and 3-bit function number as a single 8-bit function number,
         * where the slot makes up the upper 5 bits. */
        func += slot * 8;


To set up the correct mapping in HDMI 5.1 sound when the channels are configured incorrectly you should try the following in the command line

pulseaudio -k
gksu gedit /usr/share/pulseaudio/alsa-mixer/profile-sets/extra-hdmi.conf
Find the HDMI-surround section there in that file. Switch the incorrect speakers in channel-mapping and save the file.
Run speaker-test -c6 -twav
If it is still incorrect, go back to step 1.

Tested on Ubuntu 12.04 with an NVIDIA ION (zotac motherboard).


How to generate a strong key for SSH encryption?

The ssh connection is encrypted already. "Keys" are used for several things and yo are confusing the host keys with login (athentication).

The host keys are used to identify the server.

You can log in several ways, password, Kerberos, or keys.

See: http://bodhizazen.com/Tutorials/SSH_overview

http://www.openssh.com/


Will Canonical disable Amazon (and similar) lenses by default

If you ask me, I don't believe, that those features will be disabled in the future. For that reason they are there, and Canonical thinks they are convenient. Most users don't bother, or think they are positive.
If you don't think so, you might change distro. There are many good distros with another philosophy and not ALL Linux Distros have to say a loud NO to business. I think that's not fair.
Well, I uninstall those lenses and do also some other things to protect myself against advertising and data collection.


Copy music from Ubuntu 14.04 LTS to iPhone5s iOS 8.1

Banshee could be useful. You can install it with the following command line help.

sudo add-apt-repository ppa:banshee-team/ppa
sudo apt-get update
sudo apt-get install banshee

For more info, go for the ubuntu official documentation.


There is an app called caffeine that make sure this problem does not occur:

Step 1: Add the PPA

sudo add-apt-repository ppa:caffeine-developers/ppa

Step 2: Update package list

sudo apt update

Step 3: Install caffeine

sudo apt install caffeine


Deleting all files with filenames matching a pattern and size below a certain limit

Use the find command:

find /path/to/ -name '*.avi' -type f -size -100M -delete

Details:

/path/to/

This tells find to look for files in the /path/to/ directory and all its subdirectories.  If you want to start from the current directory, use . instead.
-name '*.avi'

This tells find to only look for files whose names end in .avi
-type f

This tells find to only look for regular files.  This excludes directories, pipes, sockets, etc.
-size -100M

This tells find to only look for files smaller than 100MB.  If you wanted to delete files larger than 100MB, then use +100M instead.
-delete

This tells find to delete the files matching the above criteria.

For safety, the first time you try this command, leave off the -delete.  This will return a list of files found:

    find /path/to/ -name '*.avi' -type f -size -100M

If the files found are the ones that you want to delete, then add back -delete.

Searching only the current directory and not its subdirectories

To limit recursion find into subdirectories, use the -maxdepth option:

find /path/to/ -maxdepth 1 -name '*.avi' -type f -size -100M -delete

To perform the above on the current directory:

find . -maxdepth 1 -name '*.avi' -type f -size -100M -delete


How to create an Ubuntu bootable USB drive in Mac OS X?

The quickest way I have found is to use UNetbootin.
I imagine it's not officially supported by Ubuntu but it does work for this purpose and as long as you have Refind installed you will be able to boot it.

Just as an aside, Refind will see the Stick as about 3 or 4 different bootable OS's due too Ubuntu having an EFI capable version of GRUB. For some reason when booting using syslinux and UNetbootin they do not work. Simply choose the penguin image instead of any of the 'Cubes'.


This seems to be an issue with a (fairly) recent version of Chrome.  Please see https://bbs.archlinux.org/viewtopic.php?id=211616 and https://bugs.chromium.org/p/chromium/issues/detail?id=576409

One poster mentioned that by downloading the current .deb file from chrome, and installing it using sudo apt-get ... that they were able to make Chrome work again, so I would suggest thatthis may fix your issue.


Realtek RTL8188CUS 802.11n WLAN Adapter Not connecting, keeps asking for password

There is an updated rtl8192xx driver available. Please get a temporary wired ethernet connection and do:

sudo apt-get install linux-backports-modules-cw-3.6-precise-generic

Reboot and tell us if the behavior has improved.


My system only see 8Gb instead of 12Gb memory, can you help me please?

You have one (or more) of these five issues...

Your BIOS is too old
You have incorrect spec DIMM sticks
You have the memory DIMMS installed into the incorrect slots
You may need to have similar DIMMS in all four slots
You have a defective motherboard

BIOS
MSI H55M-P31
You have BIOS version: V1.3, dated: 12/21/2009. BIOS version 1.A is available here.

Note: Confirm that I have the correct web page for your motherboard.
Note: Have good backups before updating the BIOS.
See https://storage-asset.msi.com/files/pdf/How_to_flash_the_BIOS.pdf and https://www.youtube.com/watch?v=LRyFMf0D9Lc for help.
Memory
Here is a page from the motherboard User Manual:

Your 4G DIMMS should be installed into slots DIMM1 and DIMM3.
Your 2G DImms should be installed into slots DIMM2 and DIMM4.
If that doesn't solve your problem, you'll have to get 4G DIMMS similar to the DIMMS installed in DIMM1 and DIMM3, and replace the 2G DIMMS. See the note below...

Update #1:
Have done items #1 and #3/4 and the problem persists. Suggest contacting MSI Support.
Update #2:
Install 4x4G RAM DIMMs, then,
Go to https://www.memtest86.com/ and download/run their free memtest to test your memory. Get at least one complete pass of all the 4/4 tests to confirm good memory. This may take many hours to complete.


What is the simplest way to backup a zfs file system to a second drive

Dissimilar disks are not an issue.
The easiest way is to use snapshots and zfs send | receive.

I can highly recommend sanoid / syncoid for automating this: https://github.com/jimsalterjrs/sanoid/


You are going to need Wine in order to install and run Windows software/games.

I will link you to the official WineHQ Wiki. It has all the information you need to install Wine.

Then is as simple as to install the software just like you would do in windows.

N.B : As pointed out by Byte Commander AGS has a bronze compatibility level, so you should expect issue installing/running this specific software.


File system has become read-only after updating to 15.04?

The solution was posted in the comments by @Lewis Lebentz Jul 26 at 15:00.

I'll paraphrase so anyone looking for the answer can find it here easily. But @Lewis should post the answer himself mark it as answered and you get due credit.

The solution:
Open a support ticket, ask Digital Ocean to mount the recovery ISO (It's a special ISO that only they can mount).

Choose 1 to mount the filesystem and the edit /etc/fstab.
Note: Use the console and run nano or vi /mnt/etc/fstab. Alternatively you can enable SSH and networking (in the recovery
options) to login with your terminal (see instruction) though I
havn't tried that myself.
Changed the UUID in there to the output of blkid, save.
Ask DO to remove the recovery disk. Restart and you should have access again!


Ubuntu Server 20.04.2 - How to hold MySQL to 5.7?

How I made it work thanks to Kulfy...
sudo nano /etc/apt/preferences.d/mysql

Added following code and saved.
Package: mysql-server
Pin: version 5.7*
Pin-Priority: 1001

Package: mysql-client
Pin: version 5.7*
Pin-Priority: 1001

Package: mysql-community-server
Pin: version 5.7*
Pin-Priority: 1001

Package: mysql-community-client
Pin: version 5.7*
Pin-Priority: 1001

Package: libmysqlclient-dev
Pin: version 5.7*
Pin-Priority: 1001

Now apt no longer annoys me with mysql 8.0 updates... Great!


Ubuntu appindicators extension which shows the system tray app icons in the top bar, fails to (properly) show some app icons (for example electron based app like Skype, Thunderbird with Firetray etc.).

As a workaround you may try any of the following extensions:

TopIcon: Shows legacy tray icons on top
TopIcons Plus: Same as above with more customisations like icon size, spacing etc.

Logout and login after activting the extension(s).


Adjust volume level of individual application

Open System settings and click Sound.

Chose the Applications tab.

Adjust individual applications.

Only the ones recently playing noises will show up. I don't know how permanent this change is.


You can try this PPA for installing gcc 4.7. Do note that it has packages only for 12.04 and not for 11.10.

Run the following commands in a terminal:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-4.7

Or, if you prefer a graphical way of installing a PPA, take a look at What are PPAs and how do I use them?.


Software to convert video to picture or video to .JPG to avoid taking screenshots by hand for many videos

The command line tool ffmpeg can disassemble a video in individual image files, and also can reassemble image files into a video. ffmpeg has a myriad of options allowing for a very high level of control, but that comes at a price of complexity and some learning curve.

For example, the following command will output an image every second:

ffmpeg -i input.mp4 -vf fps=1 out%d.png

The extension you provide, determines the file format you export. You can, if needed, provide extra options to control the graphical output yourself (i.e. change compression level, resolution, etc.)

Resulting images may then be further batch processed using Imagemagicks convert. For batch processing, you may prefer to use mogrify, which overwrites the original image file.


Does removing extra workspaces in Unity2d impact CPU or RAM performance?

With anything resembling modern hardware or more then 1 Gb of ram you are not going to notice a performance hit.

If you wish, run top in a terminal and add a work space. Top will show you the changes in ram and cup use. You will likely see a bit of a change as you add the workspace, or if you switch workspaces. Let it settle ;)

So yes it will use resources, but the affect on "performance" should be negligible.

If you do see a hit on performance, then you would have a bug, probably in the video driver / graphics card.


How can I copy files from/to USB drive containg a running live distro?

Yes, it is possible. Let's say you are running Ubuntu Live USB. You will have to know the name of the file in /dev that the kernel gave to your USB drive. Open a terminal and run the following command:
lsblk

It will list all the drives detected by the kernel and some information about them, such as their size. Find yours by looking at its size. It should be something like /dev/sdb1. Now run:
mount

This will list all the mount points and theirs respective devices. Find /dev/sdb1 (or whatever your USB drive is) in a line like /dev/sdb1 on /some/path. /some/path is our mount point. Open a file manager and type this path in the address bar. Press ENTER and you will be inside your USB root. Create a directory to put your files in, so they won't be confused with the live system's files.
EDIT: sorry if it was confusing to you. As an Arch Linux user I am used to do almost everything through command line. If you just open Nautilus, your USB drive should already be there, in the left bar. Just click it and you will be inside it. You can follow the command line method anyway to learn the "hardcore" way.


How do I get the latest logrotate, which isn't yet in the apt repositories?

One solution that I have used before is to just download the .deb package from a future release.  For logrotate, that would be this link.  From here, just select the architecture, and then the mirror to download from.
You can install it by using dpkg -i.  If you are concerned about doing this, you can extract the contents into a temporary directory and see if anything looks like it might conflict with something else.  For example:  dpkg-deb --extract <deb file>.
When you finally decide to install it, if there are dependencies, it will warn you about them.  (Of course, there is a list at the link above, as well.)  If the dependencies are already satisfied, then you're done.  If they are not, then you can decide whether you should manually download those or if you've gone too far and should stop.  A dependency that many other programs rely on will cause you more problems down the road.
Keep in mind that when you upgrade your system, you might want to remove it and put the old version back and let the system upgrade it itself.
I have done the above previously with programs that had very few (usually no) dependencies.


Ubuntu 16.04 window switcher not appearing

To fiz this add the simple full screen setting to the Sublime User Settings with:

"use_simple_full_screen": true


I can't seem to run/execute Minecraft.jar, please help

It seems to me that you're just not in the right folder. Run the following command:

cd ~/Downloads

You'll notice your prompt change to say something linethe following:

anas@localhost:Downloads$

This means that your terminal window is now pointing to your Downloads folder, and you can access files in that folder directly. Now, run your launcher command:

java -jar Minecraft.jar

Minecraft should start right up.

Linux is picky with directory structures in the terminal, especially when it comes to a relative path. For example, assuming you're in your home folder (~):

java -jar Minecraft.jar will attempt to launch Minecraft.jar in your current directory (or /home/anas/Minecraft.jar)
java -jar Downloads/Minecraft.jar will attempt to launch Minecraft.jar inside the Downloads subdirectory of the current directory (or /home/anas/Downloads/Minecraft.jar)
java -jar /home/anas/Downloads/Minecraft.jar will attempt to launch the jarfile at /home/anas/Downloads/Minecraft.jar exactly as written.


You can install pip using:
sudo apt-get install python-pip

django using
sudo apt-get install python-django

Tip to know the correct package name to install:
If you know what the package you are trying to install does, you can search its exact name using apt-cache search as follows:
apt-cache search pip | grep install

I grep it with install since I know pip is used to install python libraries, so "install" might be in the summary for pip.


The linked article only seems to indicate that an attacker can see what sectors are unused ( who cares? ) and complain about trim making recovering deleted files impossible ( having nothing to do with encryption ), so no, there is no security problem.

Writing to the whole SSD wears it out and kills its performance, so you don't want to do that.  Enabling trim may recover from that by effectively undoing your initial write, so that write is just a waste of time ( that shortens the life off the disk ).


Grub not loading installing ubuntu in a windows 10 laptop

I found this page helpfull when I faced the similar problem.You can try reinstalling grub from a live session (USB,CD) following the instructions in the given page.

http://howtoubuntu.org/how-to-repair-restore-reinstall-grub-2-with-a-ubuntu-live-cd
If you can log in to ubuntu using windows advanced options, then try reinstalling grub with simple commands like
sudo grub-install /dev/sdX    # Example: sudo grub-install /dev/sda use -f or --force if necessary


GUI for ubuntu server: xfce or xubuntu-desktop

Both are metapackages but xubuntu-desktop is a metapackage for much more stuff than the other one that is just for the desktop environment, xorg and few minor things.
You can read about the difference between a package and a metapackage here.
In short metapackage does not contain anything else than references and what matters is what metapackage refers to (metapackage claims to depend on them and asks that list to be installed).

So I guess your first option would not install anything. If you really want the minimal solution then go with xfce for which the correct command would be:

sudo apt-get install xfce4

Just add anything else one by one according to your needs. Also if you have xfce4 installed you can always expand your install with xubuntu-desktop that would just add lots of stuff.

You could also consider using Webmin or Zentyal for web based server management.


I was dealing with the same problem and foud the solution miself ;)

You need to go to privacy settings on your facebook account, at Ads, Apps and Websites ->Edit Settings->Apps you Use->Edit Settings  and Remove Ubuntu
go to System Settings and add again the facebook Online Account

and it will work


This is the download link for tkgate 1.8.0.
Extract and follow the README file for installation.

  INSTALLATION

  To install tkgate follow the steps below:

  0. Obtain and install tcl/tk 8.0 or later.

  1. cd to the directory in which you unpacked this distribution.

  2. Run the configuration script:

  ./configure

  The script will run a series of tests to discover properties of your environment and edit the config.h file. The specific properties that
  are tested are:

  O/S:             (FreeBSD, SunOS, Linux, other)
  Compiler:             (gcc or cc)
  Tcl/Tk Version:           (8.0jp, 8.2 or 8.0)
  Language support:         (Japanese/English or English Only)
  Grammar compiler:         (bison or yacc)
  Lexical analyizer:        (flex or lex)
  Test for required libs:       (-X11)
  Test for system-dependent libs:   (-xpg4, -ldl, -lsocket, -lnsl, -lm)
  Test for long long:       ("1" or "0")
  Test for optreset requirement:    ("1" or "0")
  Check OS name to determine signal() semantics: (handler disabled/reenabled on catch)

  The following actions are performed:

  config.h is edited to reflect the results of the tests above.
  Top-level makefile is built using xmkmf
  Subdirectory (src/common, src/tkgate, src/gsim, src/gmac) makefiles are built using xmkmf
  Include file links are built
  Dependencies are built.

  Normally the configuration will take place fully automatically, but if
  some components such as tcl/tk are in non-standard locations you may need to edit config.h and add the required directories to TKGATE_INCDIRS and TKGATE_LIBDIRS.

  3. Edit the file config.h to change the install directory locations if necessary.  By default, executables will be installed in "/usr/X11R6/bin", man pages in "/usr/X11R6/man/man1", and library files in "/usr/X11R6/lib/tkgate-1.6g". Do not edit any of the lines between the BEGIN-AUTO and END-AUTO lines as these will be automatically generated by the configure script.

  4. Edit the file "sitename.txt" to specify the name for the site. This name will appear on traces and circuit diagrams printed by TkGate.  The default name is "Earth" (probably correct for most users, but maybe a little unspecific). Users can also override the site name by editing their preferences.

  5. Compile TkGate using the command:

  make

  6. Install TkGate using the commands:

 make install
 make install.man

  If you don't have write access to the install directories, you can also run TkGate from the compilation directory which is used as a secondary home directory. You can also explicitly set the home directory by setting the enviornment variable TKGATE_HOME. The executable for tkgate will be in src/tkgate/tkgate.

  7. (optional) Set the protection on the file "tkgate-error.log" in the tkgate home directory to be publicly writable.  TkGate makes internal consistency checks and logs any problems to this file (these are potential problems with TkGate, not with the circuit being edited). If the file is unwritable, errors will be logged to the file of the same name in the current directory. Normally this file should have few or no entries.


Canon LBP and HP Laserjet 1020 say "Document Printed" but nothing prints

Do you have printer drivers installed?

My laserjet worked initially on ubuntu 11.10 but stopped working after an update. Then I started getting exactly the same kind of error you described and tried a few things before I got it working.

Try these commands.

hp-setup

This will help find and install the printer.

Then I used

system-config-printer

I found multiple installations for HP-Laserjet-1020 on my system.. tried printing test pages from all. I kept the printer profile that worked as default and deleted others.


What would be a good opensource software for graphing circles, circular regions, and regions bounded by curves and/or arcs?

I would use: gnuplot or a more simple graphical plotting program from the software centre, then I would use inkscape to do the filling and detail. I don't think there is an easier way to 'draw maths', vector drawing and mathematics doesn't really go well.

gnuplot has a learning curve, but there are some short and concise tutorials, and you can output the graphs as vectors drawings (eps) etc... or high res. what ever suits your needs.


Looking on their site for SBT, you are missing a space at the end of your deb line before the backslash.  And you only need one line:

deb http://dl.bintray.com/sbt/debian /

Hope this helps!


What is the use/purpose of the ca-certificates package?

I'm not certain what exactly you're asking, so I think perhaps it is a two parter.

Question 1: What is a ca-certificate?

Short:

It is a digital certificate that is used to verify the identity of 3rd parties, and encrypt data between you and said 3rd party.

Long:

A certificate authority (ca), is a trusted entity (like Comodo) that issues digital documents that can be used like a digital passport.  When we go to a website (like google.com), Google will send you their certificate.  Our browsers do a little magic with the ca-certificate, and either verify or reject the certificate provided by Google.

It also is used to process data back and forth between you and Google, so that it is encrypted in transit.  This helps stop people from watching your data move between you and Google.

It also helps you determine if someone is trying to scam you by pretending to be Google, your bank or other sites.

While not foolproof, it is by far much safer than plain text that can be read by almost anyone.

Further Reading:

http://searchsecurity.techtarget.com/definition/certificate-authority

Question 2: What is the ca-certificates package?

Short:

A deb package that contains certificates provided by the Certificate Authorities.

Long:

All digital certificates need to be updated, replaced and changed every now and then.  This package holds the updated versions of the ca-certificates that are common to everyone.

It simplifies the process of downloading certificates and importing them manually.

When you install the ca-certificates package, you also get an updater.

You can run it manually or add it to a cron job.  You can find more information in the links below.

Further Reading:

http://manpages.ubuntu.com/manpages/xenial/man8/update-ca-certificates.8.html
https://launchpad.net/ubuntu/xenial/+package/ca-certificates
https://launchpad.net/ubuntu/+source/ca-certificates/+changelog


How to restore the Unity greeter after installing and uninstalling xfce-desktop?

execute this command in terminal and choose your required greeter (display manager) :

sudo dpkg-configure lightdm

if it doesn't work try sudo dpkg-reconfigure lightdm


Transliteration from Greek to latin in spreadsheet

The Lingua::Translit perl-module seems to provide a workaround. To install just download and extract the tar.gz file. Then run in a terminal:

    perl Makefile.PL
    make
    make test
    make install

To use:

First convert the .ods file into csv (using libreoffice) and then:

translit  -i input.csv -t "ISO 843" -o transliterated.csv

PS: I will let this question open for a few weeks, as I am confident there are solutions out there that could be used directly from Libreoffice.


If you are on 11.04 type monitor on unity launcher

Then you will see your monitors like this

If you want to turned of the laptop screen and use the external one jsut select the laptop monitor and then click on Off radio button.  then click on apply

like this:

Now you have only the external monitor.

Update - Replying to the comment below.

You should remove  ~/.config/monitors.xml and try again.


You can specify multiple location directives that handle the requests differently:

upstream myapp1 {
    server 192.168.0.20; #RP1
}
upstream myapp2 {
    server 192.168.0.10; # some other machine?
}

server {
    listen 80;

    # server requests to myapp1 if there is no more specific match
    location / {
        proxy_pass http://myapp1;
        proxy_set_header Host $host;
    }

    # serve requests to this path from a different host
    location /foo/ {
        proxy_pass http://myapp2;
        proxy_set_header Host $host;
    }

    # serve requests to this path from the local disk
    location /this-server/ {
        root /var/www;
    }
}


Ctrl+f didn't worked for me. But shift+ctrl+f switches to fullscreen resolution.


No

At first glance you cannot have too much swap because you can see swap
as a way to increase RAM.  Actually it doesn't increase RAM, it just
pretends to: If you have 8 GB of real RAM and a swap space of, say, 24
GB configured, then your programs can allocate and use up to 8+24=32 GB
of memory which sounds good at first.

But

If you run applications that either have memory leaks or aren't really
made for running with 8 GB of memory (think of video editing, for
example), then these applications will start to use that swap space,
and swap is slow. The more swap space is actively in use by these
applications, the more the system is busy with just moving memory around
to and from the disk. This will drastically slow down the overall system's
responsiveness and lead to a bad user experience.

Eventually -- when swap space is exhausted -- some applications
will face an out-of-memory situation and be killed by the kernel's
OOM_Killer.

From wiki:

  The typical OOM case in modern computers happens when the operating
  system is unable to create any more virtual memory, because all of
  its potential backing devices have been filled.

Conclusion

Hence, one drawback of having too much swap space is: the more you
have, the later this OOM situation occurs and the longer you will have
to suffer from a lagging and unresponsive system.

Another apparent downside of course is wasting disk space but that might
not be so important nowadays.


A random action made it work (Rebooting my computer was not enough):

nautilus -q

No idea of what was the problem. It seems working now. I will set this anwser as fully solved after some hours of usage to test if this solution is definitive.


Most probably you are using key stored in some non-standard location and added to your gnome-keyring.

Using ssh -A santhosh@localhost will forward the connection to your agent and you will be able to use the same identity withing ssh session.

Other way would be to specify the identity file in your ~/.ssh/config:

Host github.com
  IdentityFile path/to/key


This binary takes much more space than its dynamic counterpart located in e2fsprogs, though

This means that this software is built static, so all its components are included into single deb-package. There are no dependencies for such package. This is because of the fact that binary is linked as static - it includes all possibly libraries in one file.
You can check package dependencies on https://packages.ubuntu.com/focal/e2fsck-static to confirm that it does not have any must-installed dependencies.


The issue was due to two optical devices being connected to CPU. Removing the other solved it.

Following commands might help:

sudo apt-get update
sudo apt-get upgrade
cat /proc/modules | grep usb
lsusb (This lists the devices connected to USB port.)


Can't log in to Samba PDC with domain account

You have not configured your server as a PDC - for a DC you need to set "domain master = yes". The setup of winbind and use of various other parameters is also not necessary on a DC.


Standard install procedure for PHP 5.3 without Suhosin?

Probably not. Suhosin is considered standard for PHP 5.3.

Using 5.3 without a hardening patch isn't recommended at all, and Suhosin is considered the de facto standard due to its binary compatibility.

Additionally, Precise is the last version running 5.3, so any version you upgrade to will have a fairly major future version of PHP. Since it sounds like you're on LTS releases, this may not be an issue for another year, but it will inevitably come into play.

If you still want to have 5.3 without Suhosin, you're very likely going to need to compile it yourself. It is possible to set it up so that apt/dpkg track dependencies (see this question for more details), but if apt sees you're running an older version of PHP than it has in the repos, it may try to update you, which will include Suhosin.

Alternatively, you could upgrade to 5.4, which has at least upstream standard repos without Suhosin. I think Ubuntu's repos have done the same and released 5.4 without Suhosin. At the very least, the Debian and Arch teams have declared Suhosin "upstream dead," so even if Ubuntu still has it, you should be able to pull straight from Debian, or possibly port the Arch one.


Apport is preventing me from upgrading my system, how do I fix it?

The best thing you can do is to remove the package (uninstall it) that is causing the problem, here some examples:

How to remove/install a package that is not fully installed?
How to uninstall plex from ubuntu (You're not having problems with plex, but the error message is the same, so it could be a good idea to have a look at it).

After removing the package that is causing the problem, you can update your system and finally re-install the package if required.

Hope this helps.


How do I get the update procedure to work?

Replace apt-get upgrade with apt-get dist-upgrade and try again if you like.


How can I override Byobu's distro logo not using statusrc config?

You can set text for the log at ~/.byobu/statusrc or /usr/share/byobu/status/statusrc

The latter will be used as defaults for all users.

I could change the default logo into "U " by this.

# Default: depends on the distro (which is either auto-detected, either set
# via $DISTRO)
#LOGO="\o/"
LOGO="U "

Setting "" does not work but " " can be used, instead.


Broadcom Hybrid Chipset Wifi Works Bluetooth Does Not

The Bluetooth Manager is often better than the default admin stuff:

https://apps.ubuntu.com/cat/applications/precise/blueman/


How do I re-enable disabled network notifications in GNOME Shell?

12.10 - Dconf
Run these commands:
gsettings set org.gnome.nm-applet disable-disconnected-notifications "false"
gsettings set org.gnome.nm-applet disable-connected-notifications "false"

Or open dconf-editor  and scroll down to org ▸ gnome ▸ nm-applet and uncheck disable-connected-notifications and disable-disconnected-notifications settings there.

11.10 and 12.04 - Gconf
gconf-editor  lets you edit the network manager notifications.
Scroll to / ▸ apps  ▸ nm-applet and uncheck disable-connected-notifications settings there.

Or the command line method:
gconftool -s /apps/nm-applet/disable-disconnected-notifications --type=bool false
gconftool -s /apps/nm-applet/disable-connected-notifications --type=bool false


Fresh Ubuntu 18.04 Overheating and Battery Problem

Laptop overheating can be many things.  If it is not high CPU usage then one possibility is that air circulation is not good.  If you use the laptop on a soft surface the airflow can be blocked.  I use a laptop cooler fan (which also is a kind of stand) but you could use something as simple as a tray or really anything that gives some room for air underneath.  The added fan usage might be what is causing your battery to drain faster.


I crash my system often.  How can i rollback to day one just like first installation in Ubuntu 10.04, 10.10, 11.04, 11.10?

At this point, you should backup any user data, and do a clean (format the disk partitions and everything) install of the version you want.

Next time, you could install a virtual machine like KVM or VirtualBox and do your testing in virtual machines. Or, install the TestDrive application from the Ubuntu software repository, which claims to download an .iso and run it in a virtual machine.


Where can I find a list of computers guaranteed to work with Ubuntu?

There is an ongoing QA effort for Laptops and Desktops in the Ubuntu Community - you can find that information here:

Old Ubuntu Laptop Reports and for everything 11.04 and onwards, Laptop Testing Site

You can find the reports for Lucid tested Laptops tests here: 10.04 Lucid Laptop Tests. The best course of action is to find a handful of laptops you're interested in then check the Reports on each.

If you feel compelled to help you can find more information at the Laptop Testing page.

Finally there is a detailed list of compatible systems on the Ubuntu Certification page.


Manual intervention required for booting - How do I automate this?

One part of the answer is from Acer saying 'if you are on BIOS 1.x, stay on 1.x'

A german Acer forum gave me the advice to do a low-level-format prior to installing the x64 version.
I have not tested this, as I'm back to 32bit (up and running smooth).


How do I close a pdf from Ubuntu command line?

fuser -k -TERM FILE

  Replace FILE with the name of the file in question.

Check the link below for a fuller description (and be aware this is a powerful/ dangerous command)

Source: Is there something like an “xdg-close” - opposite of xdg-open? on Unix & Linux


dualshock 3 controller vibrates constantly on usb

i have this issue with one of my ps3 controllers, but not another one. i am able to fix it by unplugging it from pc and plugging into ps3 for a few seconds, then plug back into pc. any time i unplug from pc, and plug back in, it will start vibrating again and i will need to redo procedure to fix again.


"Fatal Error, cannot install GRUB on disk" while installing Ubuntu

I'm not sure whether the GRUB installer was confused or if there was something screwy with the partition table on the OP's drive, but he was able to successfully complete the install by:

Physically removing the drive he did not want to install on from the system
Booting into the live envirnment in of the install media
Running this command to zero out the existing partition table/hanging EFI files/whatever that was on the first bit of his drive WARNING: do NOT run this unless unless you know what you're doing, or else you might destroy data on another drive that you wanted to leave alone! While /dev/sda was the correct target disk in Ziggy's case, it may not be for you!:

sudo dd if=/dev/zero of=/dev/sda bs=4M count=32

Rebooting
Installing using "Erase disk and install Ubuntu"


Authentication error while removing windows using os uninstaller

Ok first of all do Control+Alt+F1, this will put you in CLI (Command Line Interface) like DOS it will ask for your ubuntu login password the one you made while installing ubuntu or made another account afterwards (it needs root privileges) type the username hit enter type the password (it will show blank, you wont be able to see what password you typed) then run the following command: sudo apt update && sudo apt upgrade This shuold fix it if it does'nt try booting up from a ubuntu live cd/dvd or usb


Press Alt+F2 and type gksudo gparted then it will ask for your password and then it should run as root .


Maybe you are experiencing problem with gdm or ligthdm. Can you check their status.

service gdm status

Sometimes the display manager would have crashed, you can check this in /var/crash.  If you are running Ubuntu using VirtualBox try re-installing VBox tools.


This tool will show your current layout graphically:

gkbd-keyboard-display -g 1

This is the command used during setup for choosing your keyboard layout:

dpkg-reconfigure keyboard-configuration

But to make it auto-detect the keyboard, you need to change a setting in dpkg-reconfigure keyboard-configuration. I'm not sure what setting, though.

To change a setting, echo <packagename> <setting> <type> <value> | debconf-set-selections. For example:

echo "keyboard-configuration console-setup/ask_detect boolean true" | debconf-set-selections

Hopefully this helps you.


How to remove uninstalled wine app icons from unity dash?

I fixed it:

open terminal and cd ~/.local/share/applications.
ls -a and there were few wine-*** files and a folder wine.
now you can do a selective remove or; in my case; delete all those files using rm -rf wine*

Problem solved!

curtsy: https://askubuntu.com/a/71245/241969


Well, it could be anything, try running the whole session under strace, log it to a file to see where it might be hanging.


Why the need for a reboot with new HDD dock?

Well, you ask "Why you had to reboot to make sure the module is loaded". Lets remember that through Linux doesn't need reboot for most of operations there are still modules out in the wild that still doesn't behave correctly (I'm thinking about some VM software that if you don't restart it wouldn't work at all), with hardware sometimes it doesn't initialize correctly if isn't loaded at boot, etc.

Through you really trust Linux to comply with true Plug&Play, is difficult to really get all the hardware and corner cases such as yours. It would be interesting to see the dmesg output when you plugged the drive but I doubt you have it around anymore.


How do I update Oracle Java (JDK and JRE)

Now, you can use the Linux Uprising Java PPA, so you get updates automatically through the package manager. If you need the latest Oracle Java 12, you install it:

sudo add-apt-repository ppa:linuxuprising/java
sudo apt-get update
sudo apt-get install oracle-java12-installer
sudo update-alternatives --config java

Old solution - DISCONTINUED- does not work anymore

You can use the WebUpd8 Java PPA, so you get updates automatically through the package manager. If you need the latest Oracle Java 8, you install it:

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java8-installer
sudo update-java-alternatives -s java-8-oracle

Are PPAs safe to add to my system and what are some "red flags" to watch out for?

If you need the latest Oracle Java 6 (Outdated version), you install it too:

sudo apt-get install oracle-java6-installer

If you need the latest Oracle Java 7 (Outdated version), you install it too:

sudo apt-get install oracle-java7-installer

If you want test Oracle Java 9 early access builds, you can install it too:

sudo apt-get install oracle-java9-installer

To switch between different Java versions, you could use the following terminal command:

sudo update-alternatives --config java

Source:

Web Upd8: Install Oracle Java 7 in Ubuntu via PPA Repository
Web Upd8: Oracle Releases Critical Security Update For Java 7 (7U13) And Java 6 (6U39), PPA Updated
Web Upd8: Install Oracle Java 8 In Ubuntu Via PPA [JDK8]
Web Upd8: Oracle Java 8 (Stable) Released, Install it In Ubuntu
Web Upd8: Install Oracle Java 9 In Ubuntu, Linux Mint Or Debian Via PPA Repository [JDK9]


Please read the java 9 migration guide. Or see Replacements for deprecated JPMS modules with Java EE APIs.

Short version: use the reference implementation of JAX-WS.

<dependency>
  <groupId>com.sun.xml.ws</groupId>
  <artifactId>jaxws-ri</artifactId>
  <version>2.3.0</version>
  <type>pom</type>
</dependency>


Ethernet cable unplugged on Ubuntu 20.10 on Rasberry Pi 4

There are not LED indicating the cable is plugged in, I don't know if this is normal.

It's not. Probably your cable or ethernet port in either end is broken. Try with a different cable, and verify that connection to a different computer works.


how do tab groups work in ubuntu firefox

To use Tab Groups, press Ctrl+Shift+E.

I think a video will explain it better: http://www.youtube.com/watch?v=zU_MMUgEPes

You can also look at:

http://support.mozilla.org/en-US/kb/tab-groups-organize-tabs
http://www.youtube.com/watch?v=r9kR1Os1h1k#t=1m29s


mp4's can be easily edited using both kdenlive and openshot.

If you use kdenlive you may be in the need to have KDE's theme properly configured in order to avoid problems with the menus and other program's items while at work.

I personally prefer the usage of kdenlive.

Transcoding can also be done inside of both these NLES. Or by following one of this suggestions: How can I maximum compress video files?

Screenshots placed here for your convenience.

kdenlive

openshot

The properties of the mp4 file that I used for this screenshots:

Good luck!


Indicator-Power-Message: exiting: service couldn't acquire or lost ownership of busname

This seems a confirmed bug for Ubuntu . Please check https://bugs.launchpad.net/ubuntu/+source/indicator-power/+bug/1257251?comments=all

Try to reinstall it:

 sudo apt-get install --reinstall indicator-power


Problem with Radeon HD 6870 on Ubuntu 11.10

Catalyst may be the best driver for your card.
This should help "smooth" the video:
sudo apt-get install compizconfig-settings-manager

Run CompizConfig Settings Manager.
Click the OpenGL icon, then deselect the "Sync to VBlank" option.

Warning
This answer recommends the use of CompizConfig Settings Manager (ccsm). This is an advanced tool which has been known to
sometimes break users' desktops, even through ordinary use or
changing options which seem innocent enough. You are taking a risk by
following this answer or any advice recommending the use of CCSM. If
you do encounter problems, please see this question for
instructions on how to restore Unity.


I have problem with this error while reinstall mysql

try this

sudo apt-get remove --purge mysql-\*
sudo apt-get install mysql-server mysql-client


My $PATH variable is messed up. How to change it back?

How to permanently change $PATH variable?
A similar question has been answered before at How to add a directory to the PATH?
Where to make the change?
$PATH can be changed at various levels and for various situations. At the global level the $PATH is stored in /etc/environment. Changing this will alter the default $PATH set for all the users of the computer.
Personalized custom changes can be done in three places based on one's need.

To change the path of all login sessions change the path at /home/$USER/.profile.
To change the in bash shell sessions that are opened after login, such as the terminal window, change the path at /home/$USER/.bashrc.
To change the in GUI sessions that may be opened after login, such as a remote GUI shell, change the path at /home/$USER/.xsessionrc.

How to make the change?
Typically you add a new PATH statement or an export command like:
PATH="/path/to/dir:$PATH"

or
export PATH="/path/to/dir:$PATH"

Note these statements use the $PATH variable on the right hand side. This specific way off adding a new directory to the $PATH adds the new directory at the beginning of the existing $PATH variable.
Specific Case in the Question
Look for the files mentioned above:

/etc/environment
/home/$USER/.profile
/home/$USER/.bashrc
/home/$USER/.xsessionrc

to find exactly where the $PATH was modified by the improper installation of the software Stata. In this case modifications where made in /home/$USER/.bashrc.
From the comments, three export statements were added to /home/$USER/.bashrc:
export PATH=/Downloads/stata\ installation/stata:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
export PATH=/Downloads/stata\ installation/stata15:/Downloads/stata installation/stata

The first export statement adds the /Downloads/stata\ installation/stata in the beginning of the default $PATH.
The second export statement resets the $PATH to the default set for directories.
The second export statement tries set the $PATH to some Stata directories but misses the escape character \ before the space and messes up the /Downloads/stata installation/stata as only /Downloads/stata
Since Stata is not installed in this computer you don't need any of these modifications. You can comment all the export statements as:
#export PATH=/Downloads/stata\ installation/stata:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
#export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
#export PATH=/Downloads/stata\ installation/stata15:/Downloads/stata installation/stata

Note inserting the # in the beginning of each line marks them as comments. If everything works after commenting these export commands, you may delete them from the .bashrc file.
Commenting out or deleting these three lines will your bash session without these customization of $PATH variables. You will be using the defaults set in /etc/environment.
Hope this helps


How to open Nautilus at current command line directory?

You can type in the terminal:

cd /home/myUser/some/long/path/to/a/directory

and then:

nautilus .

The above command will open nautilus in the folder /home/myUser/some/long/path/to/a/directory (the period is the current directory)

Or in the Terminal just type:

nautilus /home/myUser/some/long/path/to/a/directory


I would look at going to the advanced welcome page options and playing with boot parameters as described here if possible.

If you’re running a nvidia card you may need to disable the nouvea drivers


No GUI shell in Ubuntu 16.04 after update - NVIDIA graphics card

for all the dummies like me:
first

sudo apt purge nvidia*

find out which graphics card you have with:

lspci | grep VGA

then look up which driver you need on nvidia.com
search for it in the repositories with

 sudo apt-cache search nvidia-*

(or add further numbers to shorten the list). Install it with

sudo apt install nvidia-YOURNUMBER

then

reboot


Update error while trying to install Spotify

Spelling mistake. :)

http://repository.spotify.com/dists/stabel/

should be:

http://repository.spotify.com/dists/stable/

You can actually test this in your very own web browser afterwards.


Asrock J4205 / Intel Apollo Lake will not install Ubuntu 16 / 17 (ASM1061 SATA optical DVD drive cd issue)

A partial answer, which might give others enough info to get their system working, or to give a fuller one if they have in depth knowledge of relevant hardware / linux boot process.

Worked out that next step in boot process might be initialisation of DVD drive, which I had connected to the ASM1061 sata socket (see note above)

Unfortunately the ASM1061 is allergic to (some?) optical drives - not sure if this is plain unsupported, bugs, incompatabilites or what.  Apparently some board / card blurbs warn about this in the small print. Mine didn't!
As above it didn't stop Win10 DVD booting, or sysrescue cd. BUT IT DOES CRASH BOOT OF UBUNTU SETUP, EVEN IF DRIVE IS JUST THERE, AND BOOT IS FROM A PERFECTLY OK USB STICK which is what foxed me for a while.

So easiest fix on this board is to swap sata cables about and connect DVD to SOC based controller, or not use it at all. There may be other options based on controller mode settings, or kernel parameters.

So now it boots and installs happily, just have to return my new hard drive because it has bad sectors and fails SMART :(  So can't comment on long term stability yet.

Further info in these threads:

Can I prevent an IDENTIFY PACKET DEVICE command to a specific device at boot?

Boot failure: failed: command IDENTIFY PACKET DEVICE


your issue looks similar to this; try to look at it and adapt for your problem. In the linked post, the problem is with linux-headers package


I can't connect to the internet using ethernet

After searching through the BIOS system I found a setting called "Integrated NIC" and it was disabled. So I enabled it and the internet started working.


Dropbox AppIndicator Menu broken in gnome-flashback

Can I fool Dropbox to believe it runs under Unity? Can I force "appindicator mode"?

Yes, you can! Experiments show that Dropbox (or related) looks for the environment variable XDG_CURRENT_DESKTOP, a freedesktop.org standard thing reflecting the name of the Desktop Environment in use. Set it to Unity and Dropbox turns sane. (I tried other sensible values, but the results were worse.)

There will be several ways to plant that variable on Dropbox. I chose to edit the command line interface script /usr/bin/dropbox from the nautilus-dropbox package to always overwrite this variable. Add this line after the imports. It will also work for "Start Dropbox on system startup":

os.environ['XDG_CURRENT_DESKTOP'] = 'Unity'


Resuming from hibernation shows a fuzzy "static" screen

What you are experiencing is a variation of this bug https://bugs.launchpad.net/unity/+bug/689831 however this person is using an Nvidia card. FUZxxl is correct that it seems to be a driver issue. Though I urge you to please visit the bug report, mark it as affecting you, and if you could please add any details that are specific to your own situation.


Though ext2fsd is more widely used tool for your purpose, but if you are really not comfortable with GUI it provides and learning curve associated with it, here is one alternative which meets your criteria though not as powerful as ext2fsd: Ext2Read

Ext2Read is an explorer like utility to explore ext2/ext3/ext4 files. It now supports LVM2 and EXT4 extents. It can be used to view and copy files and folders. It can recursively copy entire folders. It can also be used to view and copy disk and file

Link to project:

http://sourceforge.net/projects/ext2read/


Installing meson via pip3 install meson and rebooting gives me meson 0.48.2. Still no clue why it was reporting 0.44 when the apt version (0.47) was installed.


Why ubuntu software center doesn't have the latest version of softwares?

The default Repositories included with Ubuntu are maintained by Canonical and a few third-parties. They have to first evaluate all software and updates before they are allowed.

However that's why there are PPA Repositories that you can subscribe to. Most software developers maintain a PPA so users can get the latest updates as soon as they're available. You can usually find the PPA for a program by checking the Developer's webpage. Alternatively you can search http://Launchpad.net for a specific software.

Some developers don't provide a PPA however, and that's when you'll have to manually download the DEB install file each time there's an update and install from that.

Worst case, some devs only develop for Linux in general and you'll have to download a ZIP or TAR.GZ archive that contains install scripts or even just a self contained program for you to run.


Strange appearance of text/background in gedit

Just solved this issue after months of annoyance, by removing the line run_im xim from ~/.xinputrc thanks to the people commenting on Ubuntu's issue tracker at https://bugs.launchpad.net/ubuntu/+source/gedit/+bug/1620806

I have another line there for disabling the touch screen but that one is fine.

Now why would the setting of the input method handler affect the background redrawing, I can't even imagine.


How to add a package from a later version of an ubuntu?

Download the tar file from the below link and try installing the package. Seems to be working in my machine

https://tesseract-ocr.googlecode.com/archive/3.03-rc1.tar.gz

 ./configure
 make
 make install

Once you finished installing check the installed status using checkinstall command instead of make install


The -a option was removed 6(!) years ago in the upstream Debian package. It was never intended as a package system management option. It only purpose was to collect bug report in multible packages.
If this option worked as a fix for your issue, it was certainly not intended. The "advice" from FOSS seams more like a sledgehammer for the "failed to start session" issue. In most cases deleting the x-manager files in the user home is suffisant.


What is the difference between update-grub and update-grub2?

There is no difference.

Ubuntu 9.10 and later have GRUB2 installed, but sudo update-grub has still prevailed as the standard command.

sudo update-grub and sudo update-grub2 are equivalent, so it doesn't matter which one you run. /usr/sbin/update-grub2 is just a symbolic link to /usr/sbin/update-grub.

ek@Del:~$ ls -l `which update-grub update-grub2`
-rwxr-xr-x 1 root root 64 May 17 03:07 /usr/sbin/update-grub
lrwxrwxrwx 1 root root 11 May 17 03:22 /usr/sbin/update-grub2 -> update-grub

Actually, generally speaking sometimes one command can be a symbolic link of another, and yet they behave differently, because the executable checks how it was invoked (i.e., by what name) and behaves accordingly.

That is not the case for update-grub2 and update-grub though, which are both provided by packages like grub-pc that provide GRUB2. Furthermore, /usr/sbin/update-grub is actually just a short shell script that does most of its work through yet another command, and we can look at its complete 3-line source code (in Ubuntu 12.04) to see that the name used to invoke it is not checked:

#!/bin/sh
set -e
exec grub-mkconfig -o /boot/grub/grub.cfg "$@"

"$@" expands to all the command-line arguments passed after the name update-grub or update-grub2, but not that name itself. And this is the only place in the script that command-line syntax is checked at all.


(update to 14.04) unity is not loading after I login to the admin profile after upgrade

I had a similar problem, I solved it by switching in terminal (CTRL+ALT+F1) then removing the configuration file ~/.config/dconf/user like this :

(! this action will remove your gnome 3 settings !)

sudo service lightdm stop
rm ~/.config/dconf/user
sudo service lightdm start


How I can modify the "hibernate" option in the power menu

sudo gedit /etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla
Type in it-

  [Re-enable hibernate by default in upower]
    Identity=unix-user:*
    Action=org.freedesktop.upower.hibernate
    ResultActive=yes
  [Re-enable hibernate by default in logind]
    Identity=unix-user:*
    Action=org.freedesktop.login1.hibernate
    ResultActive=yes

Type sudo killall unity-panel-service
Now you have hibernate option enabled.

note: Don't type anything in place of *


How to rename multiple files in bash by changing year name

Assuming no spaces or funky characters in the file names, and all files are in one folder:

for f in DOWN* ; do echo mv "$f" "${f/1982/2040}" ; done

If the mv commands look ok to you, do it again without the echo.


Go to Settings → Keyboard shortcuts.

Go to System shortcuts section.

Click on the shortcut with name Show the overview and key combination Super+S.

Instead of adding anyother key binding to it just press Backspace and click on Set.

That's it, shortcut is disabled!!
Hope this helps :))


Add custom folder shortcuts to places list

The closest I've gotten is to add a folder to the bookmarks. Navigate into a directory and press CTRL+D then it'll get added to a "Bookmarks" sub-list below Places.

EDIT: On second glance, it is available from the "GEAR" menu on the upper-right corner of the window.


Installing Ubuntu, screen does not follow from instruction

You are unable to download updates during installation because your Ethernet cable or wireless is not connected.  You can take care of this and get updates after you've installed Ubuntu.  For now, you can proceed with the installation without installing updates.

You may not be seeing the "Erase disk and install Ubuntu" option because of the way your disk is formatted or partitioned.  These instructions will help you partition your disk correctly.

Note: These instructions assume you want to DELETE your ENTIRE disk.  All DATA on your disk will be LOST.  All existing operating systems on your disk will be lost.

Launch the installer.

Notice, I've disabled my network to simulate your situation.

Click Install Ubuntu

Because the network is disabled, the option to "Download updates..." is not available.

However, "Install third-party software..." is still available because the DVD already contains the necessary files. You can select this now, if you wish.

Click Continue

At this point, you sould see the following screen.

If you see this screen, select "Something else" option and click the Continue button.

If you don't see this screen, that's OK; just move on to the next step.

On the next screen, you will see your disk.  It will be listed as "/dev/XXX".

Select "/dev/XXX", and click the New Partition Table... button.

In the dialog that pops up, click the Continue button.

Now you will see your disk "/dev/XXX" again.

There will be free space listed underneath it (if it wasnt there before).

Select "free space", and click the + button.

A "Create Partition" dialog will appear.

In the Size field, enter 256 MB.
For the "Type for the new partition:", select "Primary".
For the "Location of the new partition:", make sure "Beginning of this space" is selected.
For the "Use as:" drop-down, select "Ext4 journaling file system".
For the "Mount point:" drop down, select "/boot".
Click the OK.

Once again, select "free space", and click the + button.

The "Create Partition" dialog will reappear.
In the Size field, enter the size of memory in your system in MB. It doesn't have to be exact. (Since I have 4GB of memory, I've selected 4096).  If you're unsure what to use, 8192 MB would be a good number to enter here.
For the "Type for the new partition:", select "Primary".
For the "Location of the new partition:", make sure "Beginning of this space" is selected.
For the "Use as:" drop-down, select "swap area".
Click the OK.

Once again, select "free space", and click the + button.

The "Create Partition" dialog will reappear.
In the Size field, leave the default value that appears.
For the "Type for the new partition:", select "Primary".
For the "Location of the new partition:", make sure "Beginning of this space" is selected.
For the "Use as:" drop-down, select "Ext4 journaling file system".
For the "Mount point:" drop down, select "/".
Click the OK.

Finally, your screen should look something like this.

Click the Install Now button.

A confirmation dialog will appear.

Click the Continue button.

At last you will see the following screen.

This is the same as step 8 in the Install Ubuntu instructions you have already been following, so you can continue the rest of the installation from there: https://tutorials.ubuntu.com/tutorial/tutorial-install-ubuntu-desktop#7


Store the passphrase of encrypted disk in /etc/crypttab encrypted

First, add a keyfile to each encrypted volume then, simply edit your crypttab [/etc/crypttab] to include your extra encrypted volumes.

Make a key:

  The keyfile can be of arbitrary content and size. We will generate a
  random temporary keyfile of 2048 bytes:

  dd if=/dev/urandom of=secretkey bs=512 count=4

Add a key

  cryptsetup luksAddKey /dev/sda2 secretkey

    Enter any LUKS passphrase:

    key slot 0 unlocked.

    Command successful.

Add to crypttab:

label      UUID=#       keyfile-location     luks


How do you override the browser CSS defaults?

This depends on the browser. On Firefox and Google Chrome, you can use the Stylish extension.

An example on Google Chrome:

Click the Stylish icon, and click Write Style for:

Add your desired CSS, name it, remove the Applies to specifier so that it applies to everything, and save it:

Effect:


"Gave up waiting for root device" while booting

I'm experiencing something similar after upgrading from 13.04 to 13.10.  I haven't solved it but can get it to boot by doing the following.

From the initframs prompt try typing "ls /dev/mapper" and see if your root volume is listed.  If it is not listed, try waiting 10 seconds and run ls again.

If it is now listed, type "exit" and it should now find the root device and boot.


How to get sound with KGS go server with 16.04 or higher?

Edit the file /etc/java-XX-openjdk/sound.properties with XX replaced by your Java version.
Add the following lines to the file:
javax.sound.sampled.Clip=com.sun.media.sound.DirectAudioDeviceProvider
javax.sound.sampled.Port=com.sun.media.sound.PortMixerProvider
javax.sound.sampled.SourceDataLine=com.sun.media.sound.DirectAudioDeviceProvider
javax.sound.sampled.TargetDataLine=com.sun.media.sound.DirectAudioDeviceProvider

Then play!


Why is this occuring? (MV missing operand when trying to make sh file executable)

You need to either give the mv command the full path to the file, or change your default directory to ~/Downloads before you issue the command you used.

sudo mv ~/Downloads/isorespin.sh /usr/local/bin

or

cd ~/Downloads
sudo mv  isorespin.sh /usr/local/bin


What is a " .desktop" file? How can I open it?

According to https://wiki.archlinux.org/index.php/desktop_entries:

The freedesktop Desktop Entry specification provides a standard for applications to integrate into a desktop environment. Desktop entries are the configuration files that describe how an application is launched and which data it can handle. They also configure how an application appears in a menu with an icon, which is subject to the related menu specification standard.
The most common desktop entries are the .desktop and .directory files. This article explains briefly how to create useful and standard compliant desktop entries. It is mainly intended for package contributors and maintainers, but may also be useful for software developers and others.


Can I restore files backed up by Deja Dup on a Ubuntu 16.04 to 18.04?

In principle, yes.
Very likely yes, but afaik this is not 100% guaranteed. You are backing up your data with an older version of Dejadup, you will be restoring it with a newer version. There is an (albeit very unlikely) chance that a newer version may have changed internal workings, and may be incompatible with your backup.
That chance is very, very little, though. One can trust that the developers of this backup tool will do everything possible to maintain compatibility with older backups. In addition, the backup tool uses standard and open formats for the storage of the backup, i.e., pgp encrypted content in standard tar archives. So even if the tool would change or go away, the standard long standing and well developed command line tools that can open these archives, certainly will remain available.
Still, I personally would feel saver making a direct copy of the files on a linux file system that supports linux file permissions. Then, you have the backup in files that can be directly copied. Plain copying of files and file attributes is guaranteed to work in a newer version of the operating system.


After clicking on "install" now , choose the third option which reads Something else. Select the partition (which is your new hard disk) , if the partition has not been created, create it by clicking Add button , set "mount point" to / and partition type to ext4 journal. I would recommend you to create one more partition as swap partition. Then select your ext4 partition and click install now. You are ready to go..!


My SSH tunnels get interrupted because the host machine falls asleep. Bug or Feature?

I havent tested this myself - but google revealed this possible answer (article from 'how-to-geek')

You can configure the ssh client to automatically send a protocol no-op code code every number of seconds so that the server won’t disconnect you. This is setting is sometimes referred to as Keep-Alive or Stop-Disconnecting-So-Much in other clients.

Global Configuration

Add the following line to the /etc/ssh/ssh_config file:

ServerAliveInterval 60

The number is the amount of seconds before the server with send the no-op code.

Current User Configuration

Add the following lines to the ~/.ssh/config file (create if it doesn’t exist)

Host *
  ServerAliveInterval 60

Make sure you indent the second line with a space.

Per-Host Configuration

If you only want to enable keep alive for a single server, you can add that into the ~/.ssh/config file with the following syntax:

Host *hostname.com
   ServerAliveInterval 60


Trying to upgrade from 14.04 LTS to 15.10, not working due to "broken packages"

As mentioned in the comment section, you need to run the following command and then post the errors if any:

sudo apt-get -f install

It should be noted that this is a real gutsy way to upgrade to a new version. I can't say that I don't do it myself as it does come with advantages but broken package management if at least temporary should be expected. If the above command doesn't work, post the errors and we will go from there.

It should also be noted that this may not be so easy as there is a transition to systemd that apt-get may not fully be able to handle.

Normally, you should run the following command to do the upgrade:

sudo do-release-upgrade -d

In a few weeks, 16.04 will be released and then you would run the following instead:

sudo do-release-upgrade

You may have to wait until then as this is the next LTS release and so an upgrade from 14.04 should be expected.

As always, possibly consider some sleep as things may seem more easy in the morning.


Why I have a dual boot menu at start-up?

It's not a "dual boot" menu, it's the GRUB menu. Normal. If you really want to hide it, run, in a terminal:

sudo nano /etc/default/grub

Put a # in front of every line that begins with GRUB_HIDDEN (there should be two of them) and do the same with GRUB_DEFAULT. Now change the GRUB_TIMEOUT so it looks like this:

GRUB_TIMEOUT=0

Hit Ctrl+O then Enter to save and Ctrl+X to exit. In the terminal, run

sudo update-grub

And GRUB menu should be hidden from now on.


Blank Screen after logged in (only desktop wallpaper showing)

If you have an AMD card, the clean install of 14.04.2 LTS has/had a bug where fglrx wouldn't play nice.

The fix I was told to do was download and use the clean install for 14.04 (not point release 2) and then update as needed.


Linux Kernel 3.10.17 upgrade in 12.04 64bit?

You can install any kernel you want. There is no problem on using one or multiple Kernels at a time. Updating to a new Kernel keeps you up-to-date with Security Patches, Stability Improvements, Updated Drivers, and New Kernel Functions.

The link you mentioned is talking about to install a latest kernel. But you can see that Kernel 3.10.17 is not the latest one. You can find that Kernel 3.11.6 is the latest stable release now.

As you can find that in every 2 weeks a new kernel is released. So it doesn't mean that you've to update kernels after every two weeks. :) What I suggest you to stick with the kernels which is running without any problem.

I'm using Ubuntu 12.04 LTS with Kernel 3.11 without any problem. But sometime you should consider the Kernel Mapping to your Ubuntu Version. For example following link lists out the mapping of different kernel to different version of OS (go to precise section):

Ubuntu to Mainline kernel version mapping

The link you provided is a nice tutorial, you can also also get a complete information of Kernel installing/removing from following link.

Kernel Mainline Builds

Following link illustrates how Ubuntu 12.04 LTS works actually. It illustates in very nice way, you would also like:

Ubuntu LTS Enablement Stack


Xfce4 Left Handed Touchpad Tap-Button Bug

This worked for me in Xubuntu:

Add the lines

synclient tapbutton1=3
synclient tapbutton2=1

in /etc/rc.local (somewhere above exit 0)

And then from the XFCE menu type "start"
You'll see the Session and Startup app.
Launch it
Click on the Application AutoStart tab
Click Add
then fill out the boxes
in the Command Box type /etc/rc.local
Save it


Having a list of paths, how can I filter out subdirectories of previously mentioned paths?

AWK

$ awk -F '/' 'oldstr && NR>1{ if($0!~oldstr"/"){print $0;oldstr=$0}};NR == 1{print $0;oldstr=$0}'  paths.txt
/proc
/run
/tmp
/home/bytecommander/ramdisk
/var/zomg
/var/zomgkthx
/zomg
/zomgkthx

The way this works is simple enough, but order of commands is significant. We start by recording what the first line is and printing it out. We go to following line and check if the next line contains previous text. If it does - we do nothing. If it doesn't - that's a different, new path.

The original approach was flawed and failed when there were adjacent paths with same leading substring, such as /var/zomg and /var/zomgkthx (Thanks to Chai T.Rex for pointing that out). The trick is to append "/" to old path to signify ending of it, thus breaking the substring. Same approach is used in python alternative below.

Python alternative

#!/usr/bin/env python
import sys,os

oldline = None
with open(sys.argv[1]) as f:
     for index,line in enumerate(f):
         path = line.strip()
         if index == 0 or not line.startswith(oldline):
             print(path)
             oldline = os.path.join(path,'')

Sample run:

$ ./reduce_paths.py paths.txt
/proc
/run
/tmp
/home/bytecommander/ramdisk
/var/zomg
/var/zomgkthx
/zomg
/zomgkthx

This approach is similar to awk-one. Idea is the same: record the first line, and keep printing and resetting the tracking variable only when we encounter line that doesn't have tracking variable as a starting substring.

Alternatively, once could use os.path.commonprefix() function as well.

#!/usr/bin/env python
import sys,os

oldline = None
with open(sys.argv[1]) as f:
     for index,line in enumerate(f):
         path = line.strip()
         if index == 0 or os.path.commonprefix([path,oldline]) != oldline:
             print(path)
             oldline = os.path.join(path,'')


How can I install a program in Ubuntu with .install extension?

Your installer tries to access an HTTP address via internet. The server on internet, where your installer tries to go to, replies with 301 Moved Permanently, which means that the file that installer tries to access has been moved and is no longer there.
The installer then quits as it does not find a file where it expects it.
Your installer wants the file http://www.mathworks.com//pi_install_agent_pi_R2015b_glnxa64, but it seems that it cannot handle 301 Moved Permanently response, which redirects it to https://www.mathworks.com/pi_install_agent_pi_R2015b_glnxa64. Maybe installer cannot handle HTTPS at all?


Enable password asterisks when run command sudo?

Run the following command in a Terminal:

sudo visudo

Scroll down to the line that looks like this

Defaults        env_reset

and change it to this:

Defaults        env_reset,pwfeedback

Press Ctrl+X to finish editing, Y to save changes, and Enter to exit.


How can I make Chromium open apt links with xdg-open?

I have downloaded Google Chrome 8.0.552.215

Then i installed the suggested extension from your link.

then i went to http://www.apturl.net/ i searched for avidemux for example.

I clicked on it and it started the apt manager. No problem.

I suggest check your google chrome version which would be the only different thing.

Tested with ubuntu 10.04, 10.10 and kubuntu 10.10

EDIT: Tried playdeb.net and getdeb.net. Both worked. Am using the chrome version i mention above. Let me know if you can work with this version just in case. Downloaded Google Chrome from http://www.google.com/chrome

EDIT2: Updated to 8.0.552.224. Still works. No problem here. Please confirm when you update how it went.


system crash while using dual operating system

If you want to install Ubuntu in dual-boot with Windows, the best way for a beginning user is:

Install Windows on a partition using 40% of your hard disk
Install Ubuntu on a partition using 40% of your hard disk
create a FAT32 partition of 10% of your hard disk
Leave the other 10% space free for now to allocate it later to wherever you will need it.

Then:

When you use Windows, use your Windows applications on your Windows files
When you use Ubuntu, use your Ubuntu Applications on your Ubuntu files.
When you need files accessible to both Ubuntu and Windows, store them on the FAT partition.

Never any problems!


Chrome and chromium refuse to run on ubuntu 20

OK, i will respond my own question. I found out that the problem was caused by a setting in /etc/security/limits.conf . I had limited the max memory to 8GB for my user ! It seems that chrome and chromium cannot run with less than 8GB ?? Which seems weird to me.... is this a "feature" or a "bug" in chromium ?


You USB drive is write protected.
You may find a small tab on the side of the device which you have perhaps inadvertently moved to set it to the locked position. Change the position of the slider to unlock it.


I believe the problem is with mtp-probe which is not able to recognize your camera as Media Transfer Protocol MTP device : mtp-probe: bus: 3, device: 3 was not an MTP device

I have the same problem with my Canon, Inc. Powershot S95 in Ubuntu 14.04 and used gphotofs for a work-around. In a terminal I did the following:

Install gphotofs:
$ sudo apt-get install gphotofs
then mount your camera, which I did under /tmp/camera
$ mkdir /tmp/camera/
$ gphotofs /tmp/camera/

That is it.

If gphotofs worked /tmp/camera/ should now be connected to your camera (check using either the terminal or nautilus). Lastly if you are using a photo manager like shotwell, use an `import from folder' option to access your pictures.

When you are finished importing your pictures you can unmount the camera folder:

$ fusermount -u /tmp/camera/


Ubuntu on 32-bit UEFI - optimal solution

I've installed 32-bit versions of Ubuntu on systems with 32-bit EFIs, including both an ancient 32-bit Mac Mini and an ASUS T100. I don't have detailed documentation on how to do it, but I provide an outline in my answer to this question:

32-Bit UEFI Boot Support

Either way you do it will involve significant hoop-jumping. My own preference is to stick with the bit depth of the EFI, unless you have a compelling reason to do otherwise.


Judging from your comments, you've removed Nautilus and as I explained in my comments, Nautilus is what manages the desktop (and wallpaper) in Ubuntu.

The easiest fix is just to reinstall Nautilus. You don't have to use it for anything but managing the desktop.

The harder route is getting Nemo to manage your desktop. This post seems to suggest that this is all that's required but I find it hard to believe:

gsettings set org.gnome.desktop.background show-desktop-icons false
gsettings set org.nemo.desktop show-desktop-icons true


Without seeing the exact CSS, it seems that the tables use different fonts. (Compare capital „B”s or „1”s for example.)

A few things you can try:

Try to specify the exact same font with pixel sizes in your CSS, and see if it makes a difference.
Use Firebug to inspect the dimensions / paddings of the input boxes. Use a CSS reset stylesheet to even out the browser differences.
Modify the layout to be able to accomodate a few pixel differences in font sizes.
Use tables for tabular data. If you had a table row for a team, the cells should not be misplaced vertically.

If you don't have access to the source code of the website, you still have options to modify the appearance.

The Stylish extension will modify the appearance (CSS) of the web sites (and according to the add-on page, even Firefox itself). By writing user style sheets, it is up to you to modify the look to your liking.
Greasemonkey on the other hand is a universal weapon to change anything on the web page (including the HTML structure) by using JavaScript. If you can code an algorithm for the problem, no one is going to stop you from changing the page the way you like it.

Another way to address the problem is to change the appearance or the theme you are using in your OS. GUI programs use the widgets of the operating system* to display buttons, checkboxes and input fields, etc.

So in most cases changing the theme will change the fonts / paddings / sizes of input boxes.

*) Not exactly that simple but the point is the widget appearance is borrowed by your browser. That's why it looks native.


You can emulate typing with the xdotool.

Install it using the command sudo apt-get install xdotool first.

Then you can make it emulate a single keystrokes like this:

xdotool key A
xdotool key space
xdotool key alt+F2
xdotool key X space plus space Y space equal space Z

Or you can tell it to emulate typing whole strings instead of single keys:

xdotool type 'I am typing words...'
xdotool type 'Never going to type with my fingers any more!'

Both on multiple keystrokes as well as on typing strings, you can specify a --delay option to control the delay between two keystrokes in milliseconds. The default is 12ms:

xdotool key --delay 500 X space plus space Y space equal space Z
xdotool type --delay 200 'I am typing words...'


How to dual boot windows 10 and Ubuntu 15.04 so that Ubuntu has a larger disk partition than windows

Using Defraggler to defragment will allow you to move the files Windows places at the end of its disk space to make all files contiguous at the beginning. After using Defraggler, you will then be able to make the Windows partition much smaller. https://www.piriform.com/defraggler/download

I have done this before, and it worked.


Is it possible to get dragging working on a Macbook multi-touch touch pad?

Thumb-down dragging in Ubuntu Maverick on newer Macbook( Pro)s is currently supported only by the new, currently non-configurable, but quite functional independently written "multitouch" X input driver from the mactel PPA.  (Canonical hasn't written utouch support for MB(P)s yet.)

From one of the official Macbook or MacBook Pro Maverick hardware support pages--

To enable the multitouch drivers, add the mactel ppa:

sudo add-apt-repository ppa:mactel-support && sudo apt-get update

Then run this in a console:

sudo apt-get install xf86-input-multitouch bcm5974-dkms

Then add this to the new file /usr/share/X11/xorg.conf.d/99-multitouch.conf (on Maverick and later) with the same permissions as the other files in the directory:

Section "InputClass"
    MatchIsTouchpad "true"
    Identifier "Multitouch Touchpad"
    Driver "multitouch"
EndSection

You can then get three-finger gestures working using mouse "buttons" 8, 9, 10, and 11 (use xev to view them) via imwheel (Ubuntu universe).  I'm going to finish that part another day, though xev is clearly showing the "press" of the "buttons" to indicate it's ready to be hooked up.

To see if this applies to your model, you should go to Ubuntu.com Help Community MacBook or MacBookPro page and find your system, or something close to it, for the Ubuntu version you are using (stick to the correct version!) in the grey box on the right at the top.  Currently, many of the systems have out-of-date or incomplete information.  However, Apple changes little between versions, so you'll be able to use information from almost any machine's page (read them all!).  The MacBook Pro 7,1 Maverick page has the most complete information for Maverick as far as I've seen, though the Maverick MBP 5,5, 5,3, and 6,2 pages also have info not found elsewhere that I needed.  That's where this information came from.

More info on PPAs:

Mactel wiki page
What are PPAs and how do I use them?


It should be a little easier than you've made it.

Instead of mounting the ISO as a separate disk, just start your newly created VM - the first thing it should do, is as for an ISO that contains the operating system which you can specify using a drop-down box.  The VM should then boot, mount and start loading from that.


Error installing nvidia driver manually.

The driver will not be able to load during the current xsession because the conflicting driver is in use. Erase all that stuff you wrote to the blacklist file and reboot for your changes to take effect.


How to install ownCloud in Ubuntu Server 12.04

You're on Installing Prerequisites For ownCloud according to this article. try updating or enabling your software sources in Software and Updates. (main, universe, resrticted, multiverse) also Canonical Partners in the PPA list and Independent.


Cannot install docker version 17.03.2 from Ubuntu Bionic 18.04 server?

You could also try using rancheros, and using the ubuntu console container, not the same though. I had the same issue, so here's what I did:

sudo apt install libltdl7
wget https://download.docker.com/linux/ubuntu/dists/xenial/pool/stable/amd64/docker-ce_17.03.2~ce-0~ubuntu-xenial_amd64.deb
sudo dpkg -i docker-ce_17.03.2~ce-0~ubuntu-xenial_amd64.deb


step 1

I assume that you have done successful tests with ping. traceroute and telnet.

With telnet somehost 80 the accessible of the http service should be ensured.

If this all works the problem should be a proxy problem.
Assuming that the non-ubuntu installations are working a misconfiguration of the proxy will be occurred locally in the ubuntu installations.

step 2

The failing telnet shows that the problem is below the application layer.
Ping is working?
May you check with nmap which ports are reachable?
May you check your local firewall rules with ufw status.

Resolution

  "firewall was disabled on all units, ping was working & nmap didn't show up anything abnormal. We tracked this down to a bug in the application layer which creates malformed packets and that led to our network abuse monitor intercepting HTTP requests & halting them. Nearly killed me finding that out! Thanks for your replies"


When installing a font package, you don't need to run fc-cache manually. In the past, this used to be done by a postinst script included in each font package, but now fontconfig installs a dpkg trigger that automatically regenerates the font cache whenever a new file is placed in /usr/share/fonts by any package.

So a Debian package for a font file, is extremely simple. You just need a debian/install file that places the font in the correct directory, like:

*.ttf usr/share/fonts/truetype/myfont

See the Debian font team's packaging policy wiki page for more information.


How to enable Gedit autosave files with name of current system Date and Time

There is a plugin available that will do the job.

Download "doublesave.zip" from here.
Extract the contents and copy doublesave.plugin and doublesave.py to ~/.local/share/gedit/plugins. If the folder does not exist, you will need to create it.
Also create ~/gedit-backups because the backup files will be stored here.
Open gedit and enable the Doublesave plugin: select Edit  ▸ Preferences ▸ Plugins ▸ [Name of Plugin] to enable the plugin.

From now on, each time you save a file in gedit while working, a timestamped backup is created in ~/gedit-backups.

It is also possible to tweak some things. For example, I've recently installed Dropbox and wanted to have gedit-backups in my Dropbox folder rather than in ~/home/user. And I preferred my timestamp to be %Y%m%d%H%M%S rather than %Y_%m_%d-%H_%M_%S.

To make both those changes, edit ~/.local/share/gedit/plugins/doublesave.py.

create a folder called gedit-backups in the desired location
open gedit, and untick the Doublesave plugin
exit gedit
delete  ~/.local/share/gedit/plugins/doublesave.pyc
edit  ~/.local/share/gedit/plugins/doublesave.py

look for

homedir = os.path.expanduser("~")+"/gedit-backups/"
commands.getoutput("mkdir "+homedir)

name = doc.get_short_name_for_display()

timestamp = datetime.now().strftime("%Y_%m_%d-%H_%M_%S")

ext = ".bak"
newFileName =  name+"-" + timestamp + ext
newpath = "\""+homedir + newFileName+"\""
command = "cp \""+source+"\" "+ newpath
print command
commands.getoutput(command)
commands.getoutput("chmod -w "+newpath)

change homedir = os.path.expanduser("~")+"/gedit-backups/" to what is required. I use homedir = os.path.expanduser("~")+"/Dropbox/gedit-backups/"
change the timestamp as needed. I changed "%Y_%m_%d-%H_%M_%S" to "%Y%m%d%H%M%S"
save the file
reopen gedit and reinstall the Doublesave plugin.


“Qml2Puppet” windows appearing in Qt Creator

Yes, annoying. I hope, soon, it is fixed. Waiting is annoying also?

Well, actually, I have a workaround on this. Fortunately, clicking on "design" tab launching qml2puppet executable located on /usr/bin.

By this mechanism, we can substitute the qml2puppet executable with our own script. The script will execute the real qml2puppet and beside, suppressing the "ilegal" windows.

Steps :

Rename qml2puppet into qml2puppet.bak

  sudo mv /usr/bin/qml2puppet /usr/bin/qml2puppet.bak

Make our executable script

Create file

  gksudo gedit /usr/bin/qml2puppet

Copy the full-script here into the script
Make it executable

  sudo chmod a+x /usr/bin/qml2puppet

Download script component for controlling windows : wmctrl

  sudo apt-get install wmctrl

Well done. Try it! When you face other problem following those step, you can comment below.


Plex media server and mount issues in Ubuntu 13.04

well the safest option is to always backup, secondly XBMC does a much better job at managing things like this, consider XBMC as an alternative


eth0 appears to be your ethernet, and it wouldn't have an ip address or mask if it wasn't connected. lo is just your loopback.

With those in mind, it appears that your wireless is not active. With your wireless working yesterday. It seems to be a module hasn't loaded. Here is what I recommend:

Try booting from a livecd, if your wireless works run this in terminal:
(you may have to add the universe repository)

  sudo apt-get install hwinfo

Then run the following:

  hwinfo --network

Find the wireless card. (wlan0)

Write down the "Driver Modules:" value. (r8192se_pci)

Boot back into Ubuntu and run this in terminal:

  sudo modprobe <modulename> Where  is the value from above.

(this is where I would start to find out the issue.


Can't understand difference between liblapack3 and liblapack3gf

You can think of a transitional package as a shortcut to another (desired) package. The transitional package does not contain anything but metadata that indicates that this package depends on the desired package so that the desired package will be installed when you will be trying to install the transitional package.

In you case as it says,

liblapack3gf - library of linear algebra routines 3 - shared version

As far as the description is concerned you are good to install liblapack3gf.

Whereas in other person's computer when he will try to install liblapack3gf, as it is a transitional package for liblapack3 - Library of linear algebra routines 3 - shared version the following will pop up:

The following extra packages will be installed:
   liblapack3


How to grep two numbers from the same line at different places using bash?

One possible way...

% grep 'solver.cpp:229' ExampleFile.txt | cut -d ' ' -f 3,6 | tr -d ','
2000 0.305721
2020 0.294722


NetGear WNA3100M Wireless adaptor (RTL8192CU) crashes Ubuntu 16.10 after update to latest kernel (4.8.0-41)

It appears that you have two, possibly conflicting drivers loaded. Let's blacklist one and see if there is any improvement. Please open a terminal and do:

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

Reboot and let us hear your report.


Does updating software on Ubuntu slow down the OS?

It depends on what packages you are installing, and how much your computer can take. Unless the software packages are using a lot of memory, or your hard drive isalmost completely full, updating software packages shouldn't slow your computer down.


How do I automate adding all entries in `/etc/hosts` to `~/.ssh/config` file?

IIUC, you could use awk:

awk '{print "Host " $1 "\nHostname " $2}' /etc/hosts


undefined reference to `XShmQueryVersion'

You need to tell the compiler what libraries to find the X11 functions in.  The core X functions like XOpenDisplay are in libX11, while extensions are in additional libraries - like libXext for XShmQueryVersion.

The direct way to tell your compiler to link with these libraries is via -l flags:

g++ myprogram.c -o program -lXext -lX11

Once you get to building larger software, with Makefiles & such, there are tools to help manage the flags for these libraries, and you might have something in your Makefile such as:

CFLAGS += `pkg-config --cflags x11 xext`
LIBS += `pkg-config --libs x11 xext`


The latest version of the Canon CAPT Driver is version 2.5 2.7. You can find information about the driver at the Canon CAPT Printer Driver for Linux Version 2.xx webpage. The link to download the driver is the red word Download at the bottom of the same webpage.

The instructions for installing the Canon CAPT Driver v2.6 in Ubuntu 14.04 are found at the Ubuntu Canon Capt Driver wiki under the Ubuntu 14.04 Install heading.


I have the same problem when using certain Belkin Wifi adapters since 10.10. I'm not sure what adapter you are using but the fix for me is below, I imagine the fix for your adapter may be similar but will specify a different driver.

Step #1:
In terminal type "sudo gedit /etc/modprobe.d/blacklist.conf"

Step #2:
add the line "blacklist rt2800usb" anywhere within. Feel free to add a #Description above it. Click save when done, and reboot.