Purchasing genuine Ubuntu
Is Ubuntu an open source software?
Is GTA Online cross-platform? Grand Theft Auto Online exists on five different platforms: XBox 360, PS3, XBox One, PS4, and PC. Do any of these play on the same servers, allowing people on differing platforms to play together? So i was reading about  on Wiki and I found a interesting thing written there .    It says that the S. radius of the universe is as big as the size of the universe?   How is this possible?  Since most the universe is empty space shouldn't the S. radius of our universe be significantly smaller then 13.7 light years? Tips to extend battery life for laptops and notebooks This question is present as a matter of historical interest.  While you are encouraged to help maintain its answers, please understand that "big list" questions are not generally allowed on Ask Ubuntu and will be closed per the .   It is possible to greatly extend the usage time of a laptop or netbook running on battery by disabling various services and installing various packages.   What tricks or tips do people have for getting an extra hour or two out of their batteries? I'm pulling items out of the DOM with jQuery and want to set a property on an object using the id of the DOM element.   Example  const obj = {}  jQuery(itemsFromDom).each(function() {   const element = jQuery(this)   const name = element.attr('id')   const value = element.attr('value')    // Here is the problem   obj.name = value })   If itemsFromDom includes an element with an id of "myId", I want obj to have a property named "myId". The above gives me name.  How do I name a property of an object using a variable using JavaScript? I did a dumb thing... I forgot that Ubuntu 10.04 (Lucid Lynx) switched to &nbsp;2 which puts a ton of *.mod files (kernel modules) in /boot/grub. I thought they were soundtrack files put there erroneously, and I moved them. Needless to say, the next reboot was traumatic. I was presented with something I had no memory of ever seeing... a 'grub rescue>' prompt.  With the help of  however, I was able to recover...   I discovered that GRUB rescue does not have 'cd', 'cp' or any other filesystem commands except its own variation of 'ls'. So first I had to find the partition with the /boot directory containing vmlinuz file and other boot image files... (approximation from memory of failed attempts, as well as blank lines for clarity, added 2014-07-10 by docsalvage)    grub rescue&gt;  ls   (hd0,4) (hd0,3) (hd0,2) (hd0,1)    grub rescue&gt;  ls (hd0,4)/boot ... some kind of 'not found' message  grub rescue&gt;  ls (hd0,3)/boot ... some kind of 'not found' message  grub rescue&gt;  ls (hd0,2)/boot ... grub ... initrd.img-2.6.32-33-generic ... vmlinuz-2.6.32-33-generic   I found a /boot directory containing the vmlinuz file vmlinuz-2.6.32-33-generic on partition (hd0,2). Then I manually booted from the 'grub rescue>' prompt. The following commands will...   Set the root to use the /boot directory on partition (hd0,2). Load kernel module linux. Set that module to use the kernel image vmlinuz-2.6.32-33-generic. Set initrd(initialize RAM disk) to use the image initrd.img-2.6.32-33-generic. Boot Linux.  grub rescue&gt;  set root=(hd0,2)/boot   grub rescue&gt;  insmod linux   grub rescue&gt;  linux (hd0,2)/boot/vmlinuz-2.6.32-33-generic root=/dev/sda2 grub rescue&gt;  initrd (hd0,2)/boot/initrd.img-2.6.32-33-generic   grub rescue&gt;  boot    This boots and crashes to the BusyBox prompt which DOES have some rudimentary filesystem commands. Then I moved the *.mod files back to the /boot/grub directory...  busybox&gt;  cd /boot   busybox&gt;  mv mod/* grub busybox&gt;  reboot  The reboot was successful, but that was a lot of work.   Is there an easier way? Show $d_{1}(x_{n},x)\rightarrow{0}$ if and only if $d_{2}(x_{n},x)\rightarrow{0}$. Let $X=(0,\infty)$. Define two metrics on $X$ by   $d_{1}(x,y)=|x-y|$ and   $d_{2}(x,y)=|x-y|+|\frac{1}{x}-\frac{1}{y}|$   for all $x, y \in{X}$.   Let $(x_{n})$ be a sequence in $X$ and $x\in{X}$.   Show  $d_{1}(x_{n},x)\rightarrow{0}$ if and only if $d_{2}(x_{n},x)\rightarrow{0}$.  Note: $d_{1}$ and $d_{2}$ are then said to be equivalent metrics on $X$.  Since $d_{1}$ and $d_{2}$ are equivalent metrics, will it be sufficient to show $c*d_{2}(x,y)\leq{d_{1}(x,y)}\leq{C*d_{2}(x,y)}$?  So far I have the following: $d_{1}(x,y)=|x-y|\leq{|x-y|+|\frac{1}{x}-\frac{1}{y}|}=d_{2}(x,y)$. Therefore, $d_{1}(x,y)\leq{C*d_{2}(x,y)}$ where $C=1$. Is there a $c$ that would satisfy the left-hand side of the inequality?  Any help would be appreciated. (this is not homework) How to detect when a variable changes value How can I easily detect when a variable changes value? I would like the execution of the program to break on the debugger whenever a specified variable changes value. Right now I'm using Eclipse's debugger. "Nobody want to go there," or "nobody wants to go there"? In English, the number 0 is treated as plural. It is then:   0 seconds 1 second    1.2 seconds   2 seconds     Shouldn't it be "nobody want to go there," instead of "nobody wants to go there"?  I also saw in TOEFL that "any __" should be used with a singular.  But I see it very common that it is a plural also.  Why is that?  (updated: example, "we don't have any apples any more" vs "If you get any apple, please let me know.") I would appreciate if someone could help me write the mathematical equation for the seasonal ARIMA (2,1,0) x (0,2,2) period 12. I'm a little confused with how to go about this. I would prefer an equation involving $Y_t , e_t, θ$ and $Θ$. com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure I know it is possible for a group $G$ to have normal subgroups $H, K$, such that $H\cong K$ but $G/H\not\cong G/K$, but I couldn't think of any examples with $G$ finite. What is an illustrative example? Prove that if $(ab)^i = a^ib^i \forall a,b\in G$ for three consecutive integers $i$ then G is abelian Today, comparing processors is obviously not just looking at the frequency and the number of cores.  When choosing a new PC, how do you compare processors? Is there some resource, like a site or something that does (not necessarily super-precise) processor comparisons?  Thanks. Please rate and comment. I want to improve; constructive criticism is highly appreciated. Please take style into account as well.  The following proof is solely based on vector space related axioms. Axiom names are italicised. They are defined in Wikipedia (see vector space article).  Vector spaces - Multiplying by zero scalar yields zero vector  \begin{array}{lrll} \text{Let} &amp; \dots &amp; \text{be} &amp; \dots \\ \hline &amp; F &amp;&amp; \text{a field.} \\ &amp; V &amp;&amp; \text{a vector space over $F$.} \\ &amp; 0 &amp;&amp; \text{an identity element of addition of $F$.} \\ &amp; \mathbf{0} &amp;&amp; \text{an identity element of addition of $V$.} \\ &amp; \mathbf{v} &amp;&amp; \text{an arbitrary vector in $V$.} \\ \end{array}  $$\text{Then, }0\mathbf{v} = \mathbf{0}.$$  Proof. We will denote by $1$ an identity element of scalar multiplication; we will denote by $(-\mathbf{v})$ an additive inverse of $\mathbf{v}$. \begin{align*} 0\mathbf{v} &amp;= 0\mathbf{v} + \mathbf{0}                     &amp;&amp; \text{by }\textit{Identity element of vector addition} \\ &amp;= 0\mathbf{v} + (\mathbf{v} + (-\mathbf{v}))   &amp;&amp; \text{by }\textit{Inverse elements of vector addition} \\ &amp;= (0\mathbf{v} + \mathbf{v}) + (-\mathbf{v})   &amp;&amp; \text{by }\textit{Associativity of vector addition} \\ &amp;= (0\mathbf{v} + 1\mathbf{v}) + (-\mathbf{v})  &amp;&amp; \text{by }\textit{Identity element of scalar multiplication} \\ &amp;= ((0 + 1)\mathbf{v}) + (-\mathbf{v})          &amp;&amp; \text{by }\textit{Distributivity of scalar multiplication (field addition)} \\ &amp;= ((1 + 0)\mathbf{v}) + (-\mathbf{v})          &amp;&amp; \text{by }\textit{Commutativity of field addition} \\ &amp;= (1\mathbf{v}) + (-\mathbf{v})                &amp;&amp; \text{by }\textit{Identity element of field addition} \\ &amp;= \mathbf{v} + (-\mathbf{v})                   &amp;&amp; \text{by }\textit{Identity element of scalar multiplication} \\ &amp;= \mathbf{0}                                   &amp;&amp; \text{by }\textit{Inverse elements of vector addition} \\ \end{align*} QED #!/bin/bash echo "$(curl -s -I https://google.com|grep Server)" abc   returns:  abcer: gws   and bash -x shows:    ++ grep Server ++ curl -s -I https://google.com ' abco 'Server: gws  abcer: gws   but    echo abc "$(curl -s -I https://google.com|grep Server)"`    returns  abc Server: gws   In other words, if I add text AFTER the curl command, it gets mangled, but it's ok if I add it before curl. What is happening? I cannot figure it out. How do I read an entire file into a std::string in C++? How do I read a file into a std::string, i.e., read the whole file at once?  Text or binary mode should be specified by the caller. The solution should be standard-compliant, portable and efficient. It should not needlessly copy the string's data, and it should avoid reallocations of memory while reading the string.  One way to do this would be to stat the filesize, resize the std::string and fread() into the std::string's const_cast&lt;char*&gt;()'ed data(). This requires the std::string's data to be contiguous which is not required by the standard, but it appears to be the case for all known implementations. What is worse, if the file is read in text mode, the std::string's size may not equal the file's size.  A fully correct, standard-compliant and portable solutions could be constructed using std::ifstream's rdbuf() into a std::ostringstream and from there into a std::string. However, this could copy the string data and/or needlessly reallocate memory.    Are all relevant standard library implementations smart enough to avoid all unnecessary overhead?  Is there another way to do it?  Did I miss some hidden Boost function that already provides the desired functionality?     void slurp(std::string&amp; data, bool is_binary) How to Draw 2 Functions In Tex Logitech SetPoint software button remapping My Logitech G5 Laser mouse has 9 buttons but it's SetPoint software only allows 5 of them to be used as "mouse buttons" and the remaining 4 can only be assigned special windows functions (Forward, Back, Cruise Up, etc) or Keystroke Assignments.  Many of the games I play will take up to 10 "MOUSE BUTTON" inputs for in-game actions but wont recognize the remaining 4 buttons even when assigned keystroke assignments.  Is there a way to make these last 4 buttons "Generic Buttons" as well as buttons 3,4,and 5? (1 is left click and 2 is right click).  My other question is if the above is not possible, maybe I can use AutoHotkey to remap keystrokes as assigned by my SetPoint software to mouse button commands?  If so how? How to reinstall PulseAudio (Ubuntu 12.04) Prove $\alpha \in R[[x]]$ is a unit iff $a_0 \in R$ is a unit Prove $\alpha \in R[[x]]$ is a unit iff $a_0 \in R$ is a unit.   $"\Rightarrow"$ suppose $\alpha \in R[[x]]$ is a unit, where $\alpha = \sum_{n=0}^{\infty} a_nx^n$  then there exists an inverse $\beta = \sum_{n=0}^{\infty} b_nx^n$   stuck at this spot,  $(\sum_{n=0}^{\infty} a_nx^n)(\sum_{n=0}^{\infty} b_nx^n) = \sum_{n=0}^{\infty}(\sum_{k=0}^{n}(a_kb_{n-k}))x^n$  A little mixed up on how this becomes $1 = \sum_{n=0}^{\infty}e_nx^n$ where $e_0 =1, e_{n&gt;0} = 0$ and why that would make $a_0b_0 = 1$ which would make $a_0 \in R$ a unit. I haven't tried the other direction yet.  EDIT  Maybe I get it, because we assumed this sum is a unit then its inverse exists and so the $x^0=1$ and all $a_ib_i=1$ thus $a_0b_0=1$ which gives $a_0$ is a unit in $R$