For practicing how grep works in Ubuntu terminal, I made one .txt file: '&quot;..asdf_-_-..34'&quot;&quot;'&quot;'&quot; jd8m***ns'''_**''x;';nn*?/...;   ++..++ ./,/;]_+))(+_)((*+_&quot;:|.&lt;&quot;{}+_)09+_):}.}-0_)  I wanted to match asjacent single and double quotes using grep -E -e '\'+\&quot;+' -e '\&quot;+\'+' But it is not giving desired output. Can anyone please help me with the same?
I am using gedit text editor with embedded terminal in ubuntu 12.04. I'm trying to search for some text using grep. I want to search for this line of code   'type' =&gt; 'select'   I tried:  grep -r '\'type\' =&gt; \'select\''  But grep didn't return any results.  So can someone kindly tell me how to search for the code above?
Movie/TV series with a scene of spiky, black goo growing out of a lab container? There was a scene from a sci-fi horror video, not animated, don't know if it's a movie or TV series, where there was this black goo in a glass container and some scientists were looking at it under a microscope.   The pitch black goo grew and grew so fast, eventually breaking out of the inner box and the scientists that were inside the "inner lab" were begging to get out but the scientists outside that inner lab refused to open the door. The black goo was spiky (had spikes).  It's not any of the "Alien" movies, "The Blob", "Life", or "The Thing". It's not vintage. It was made after 1990, I'm pretty sure. My tweets are not showing up in other people's mentions My replies are not showing up in other people's mentions. I tried tweeting several friends, my other accounts but my tweets just won't appear in their mentions? They do appear on my own Twitter page. It's been almost 24 hours now and it's pretty frustrating. How can I decode HTML characters in C#? I have email addresses encoded with HTML character entities. Is there anything in .NET that can convert them to plain strings? Is it possible for a foreigner to drive through (mainland) China in a foreign-registered car? Is it possible to drive through mainland China, for example for transit from Kazakhstan to Vietnam, as a non-Chinese citizen, in an own car/van/truck?  This is about an European Union citizen, trying to make a tourist trip overland by car from the EU to Vietnam. This is about a special (equipped with sleeping, cooking and other facilities) vehicle, that the owner intends to keep and use in Vietnam, so buying/renting a vehicle inside China and selling it before leaving is not an option - the question is about driving a specific vehicle the owner already has in the EU to Vietnam. getting new licence plates is OK, as long as it is allowed to put back the old ones when the vehicle gets back to the EU.  What legal issues are there with getting in an own car over China, and how to overcome them?  Is it possible to drive a car with EU licence plates through China, or would one have to get something like temporary Chinese plates? Is an EU driving licence valid? Are there any customs issues one has to know about, and how long one can keep a foreign motor vehicle in China without having to pay import taxes on it? This is a follow up question to my previous question  Let $k$ be a field and $V \subseteq \Bbb{A}^n$ and $W \subseteq \Bbb{A}^m$ be algebraic sets. Then it should be true that $I(V \times W ) = I(V) + I(W)$ where by $I(V)$ here we mean the extension of $I(V)k[x_1,\ldots,x_{m+n}]$. Now I believe I have proven this (see the proof at the bottom of my question) but when I look at Martin's answer , it is instead claimed that we  actually have  $$I(V \times W )= \sqrt{I(V) + I(W)},$$  and for $I(V) + I(W)$ to be a radical ideal we need $k$ to be algebraically closed.           My question is: What's going on here? I believe my claim is true even without the assumption that $k$ is algebraically closed.           Here's a proof user Sanchez told me of, which I have simplified:       First it is clear that we always have $I(V) + I(W) \subseteq I(V \times W)$. For the reverse inclusion consider a polynomial $f \in I(V \times W)$. Then we can always write $$f = \sum_{i=1}^n f_ig_i$$ where $f_i \in k[x_1,\ldots,x_n]$ and $g_i \in k[x_{n+1},\ldots,x_{m+n}]$. Now take any $b' \in W$. If for all $i$ we have $g_i(b') = 0$ then since $b'$ is arbitrary, $g_i \in I(W)$ for all $i$. Then $f \in I(W) \subseteq I(V ) + I(w)$ and we are done. Otherwise suppose there exists $b \in W$  and $i$ such that $g_i(b) \neq 0$. Then wlog we may suppose that  $g_1(b) \neq 0$.   Next, $\sum f_ig_i(b) = 0 $ on all of $V$ by assumption of $f \in I(V \times W)$. So $\sum f_i g_i(b) = p$ for some $p \in I(V)$. Now write $$f_1 = \frac{ p - g_2(b) f_2 + \ldots g_n(b)f_n}{g_1(b)}.$$  Substituting this for $f_1$ in $\sum f_ig_i$, followed by taking things mod $I(V)$ we get an  expression with only $n-1$ terms $\mod{I(V)}$. Continuing this process we will finally get an expression with $0$ terms $\mod{I(V)}$ so that $f \in I(V)$. This shows $I(V \times W) \subseteq I(V) + I(W)$ which completes the proof. Which of $\{J_0,J_1,J_2\}$ and $\{J_0,J_+,J_-\}$ is a generator for the Lie algebra $\mathfrak{su}(2)$? I have just started learning about Lie algebra in the context of quantum mechanics and got confused with this: Some sources say the generators are $J_0,J_1$ and $J_2$ and some use $J_0,J_+$ and $J_−$. Which set is correct? Or if both are correct what key concept am I missing here? My understanding is that if have certain commutation relations then we know that Lie Algebra is such and such. But if we have two such choices then this understanding falls apart? How do I figure out what is $\mathfrak{su}(2)$ Lie Algebra in general? I am a Pakistani national and need to transit through Dubai International Airport (DXB).  I am not planning to leave the airport and both of my flights (arrival and departure) are from Terminal 3.  I am pretty sure that I do not need transit visa at the DXB, however it is no where mentioned on any of their official website.   Can anyone please provide me such a link stating that transiting without leaving the airport does not require visa at DXB, as I need to use this link as a proof for a visa application?  Thanks Identifying pin numbers from PCB Detecting absolute motion inside a box This is not a contradiction and I know it is impossible but still consider a thought experiment by me and point out if something is wrong. See the following picture and then the explanation follows.    Rest frames are easy to understand. They are just for clarification. Lets move on to the moving frames. The velocity of the box is $0.1\ c$. Now a photon is emitted (I am not taking a light ray to avoid complication in discussion). After emission the box also moves a certain distance ahead. So the photon takes more than one second to reach the wall. But even the source moves that much distance ahead. When the light is reflected back, the source and the wall again move forward as the box is moving. But after reflection the wall has no role to play. We are concerned about the source. The source moves a certain distance ahead and therefore light takes less than one second to reach back. But the difference of the first case and the second case is not the same. To explain, I will give some equations.  Moving frame 1:  Velocity of the box: $0.1\ c = 30,000km/s$  Time taken by light to reach the wall $=\frac{330,000\ \text{km}}{300,000\ \text{kms}^{-1}}= 1.1s$  Distance moved ahead by the box from original position: $30,000\ \text{km}$  Moving frame 2:  distance moved ahead by the box from original position  $&gt;30,000\ \text{km}$ as the box also moves ahead after reflection.  let $d$ be the distance moved ahead by the box after reflection.  Time taken by light to reach the source: $\frac{270,000\ \text{km}\ -\ d}{300,000\ \text{kms}^{-1}} &lt;0.9s$  Therefore we see that this could possibly determine the absolute motion.  So in total we see that the light will take lesser time to reach the source. Please correct me if I am wrong and give your opinion why is it so.  EDIT 2 for clarification  The box is the compartment in space in which you are moving and I am calculating the time the light takes to reach back the source. I am not even adding velocities. Please correct me and tell me where did I add velocities. For clarification just let me give a simple example. Suppose person A is standing still and B is running towards a light source. Obviously he will see the light before person A even though the speed would be the same. So, what I am doing over here is not increasing the speed of light, but instead decreasing the distance to be covered by it. Is it possible to legally visit uninhabited islands in the Pacific for a couple of days/weeks like Robinson Crusoe Do you know any way how can I visit uninhabited islands in the Pacific (French Polynesia, Micronesia etc.) and stay there for a couple of days or weeks?  The only condition, these island (or islands) should have drinking water.  Could it be done legally or only illegally?  Does any company do such crazy things via plane or boat?  Any information is appreciated.  I am mostly interested in French Polynesia.  Boat or plane... that's not very important. I block everything Google, including Google APIs, as I don't like to to have Google tracking all of my usage on the Internet. Is there any way to use Stack Exchange without Google APIs?  I usually am browsing with Windows 7 and Firefox, but of course not Firefox with StackExchange. Past participle form of "exit"? Wheel going badly out of true on final tightening On two occasions (same wheel, loosened everything off and re-did the whole thing after the first time) as I've applied a final half turn to tighten the spokes round the wheel it's gone from being pretty laterally true (within about 0.5 mm) to badly out of true (probably a couple of mm or more out).  The simplest explanation would be that I've managed to mess up by missing spokes/over under-tightening some of them, but I'm fairly sure that's not the case.  What else could cause this?  This is a rear wheel with a fair amount of dish. I'm worried that I might be over-tightening. On both occasions I decided to do a final half turn as the non drive side seemed a little loose, but I was concerned the drive side might be over tight. Could this cause a sudden change in trueness?  I've got the wheel back to a reasonable state, but I'm no longer sure I have even tension in the spokes. If $a^3 =a$ for all $a$ in a ring $R$, then $R$ is commutative. Let $R$ be a ring, where $a^{3} = a$ for all $a\in R$. Prove that $R$ must be a commutative ring. Memory layout of a .NET array What is the memory layout of a .NET array?  Take for instance this array:  Int32[] x = new Int32[10];   I understand that the bulk of the array is like this:  0000111122223333444455556666777788889999   Where each character is one byte, and the digits corresponds to indices into the array.  Additionally, I know that there is a type reference, and a syncblock-index for all objects, so the above can be adjusted to this:  ttttssss0000111122223333444455556666777788889999         ^         +- object reference points here   Additionally, the length of the array needs to be stored, so perhaps this is more correct:  ttttssssllll0000111122223333444455556666777788889999         ^         +- object reference points here   Is this complete? Are there more data in an array?  The reason I'm asking is that we're trying to estimate how much memory a couple of different in-memory representations of a rather large data corpus will take and the size of the arrays varies quite a bit, so the overhead might have a large impact in one solution, but perhaps not so much in the other.  So basically, for an array, how much overhead is there, that is basically my question.  And before the arrays are bad squad wakes up, this part of the solution is a static build-once-reference-often type of thing so using growable lists is not necessary here. 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? Show $a^p \equiv a \mod 2p$ I've stucked at the following problem:  Let $p$ be an odd prime number. Show that for all $a\in\mathbb{Z}$  $$a^p \equiv a\ (\mathrm{mod}\ 2p)$$  How can I prove it? I know within Fermat's theorem that $a^p \equiv a\ \mathrm{mod}\ p$. "Knowledge of" vs. "knowledge on" How to help a toddler overcome the fear of water on head? I've read many years ago in books, that the brain has no nerves on it, and if someone was touching your brain, you couldn't feel a thing.  Just two days before now, I had a very bad migraine, due to a cold. It's become better now, but when I had it I felt my head was going to literally split in half, as the pain was literally coming from my brain.  So it lead me to the question: How come people can get headaches if the brain has no nerves?