In C I have this enum:  enum {     STAR_NONE =     1 &lt;&lt; 0, // 1     STAR_ONE =      1 &lt;&lt; 1, // 2     STAR_TWO =      1 &lt;&lt; 2, // 4     STAR_THREE =    1 &lt;&lt; 3  // 8 };   Why is 1 &lt;&lt; 3 equal to 8 and not 6?
I've been attempting to learn C in my spare time, and other languages (C#, Java, etc.) have the same concept (and often the same operators) ...   What I'm wondering is, at a core level, what does bit-shifting (&lt;&lt;, &gt;&gt;, &gt;&gt;&gt;) do, what problems can it help solve, and what gotchas lurk around the bend? In other words, an absolute beginner's guide to bit shifting in all its goodness.
If you try to execute a program that is not installed you will get a message  The program 'x' is currently not installed. You can install it by typing:  sudo apt-get install x   and instead of offering you to install the program for you, you have to type the actual command. How can this behavior be changed? I wonder about the Adjustments to Cost Basis after a wash sale occur. Considering this  ( from marketwatch.com) where someone: On 1 Dec, 2018 used an amount of money in his account to buy 100 shares of XYZ Co., for $2000 (to make it simple , let's say 1 Feb, 2019 to turn all the transactions into the same year) On 1 Apr, 2019 he sells the shares for $1200, and incurred a loss of 800$. On 10 Apr, 2019 he bought back 100 shares for $1300, and had a wash sale. The 800$ loss gets added to the cost basis of this transaction( and the basis becomes $2100) Now, If on 13 Apr 2019, he sold 100 shares for $1400; I'm pretty sure that the realized Gain/Loss record of this transaction would show something like this: &quot; XYZ Co. shares  100 , Proceeds $1400 , Cost basis  $2100(adjusted), Short-term Gain/Loss  -$700 &quot;. So, even though the Gain/Loss shows a negative number, he still got an actual profit of $100 from this sale, right? How to dump a man page? Spice containers purchase  I'm planning on upgrading my spice storage. Reading some advice online (e.g. , and ) I came to the conclusion that spice containers should:   Not be exposed to direct sunlight and high temperatures Be airtight   Which means that either you store it inside of some closed cupboard/wardrobe/room or you have containers which do block light and are in a relatively shady place. And the containers need to be airtight.  Available solutions  I've been browsing for some containers available online in my country and the 2 most sensible options I've seen are these:       The problem  The first one is hermetic (it has some rubber around the lid) but it's clear glass. The other one does not have the rubber, just a regular twist-off lid, but it's amber glass.  It'll be hard for me to find any space inside of cupboards to store all of my spices (I need at least 30), so I'd rather buy amber glass container, which I believe will effectively block the sunlight, even when kept on the counter. But I can't find any hermetic amber-glass containers, only ones with regular lid.  The question  Is that regular twist-off lid enough to keep spices airtight and fresh? Or should I focus on buying a hermetic container (like the one in clear glass). I could then for example paint them black to block the sunlight. Isolate OSX Dock per Space How can I make it so that each space has its own isolated dock?  Basically what I'm looking for is:   The dock in one space should not show the icon of an app that was open in another space. If I have the same program open in two different spaces, clicking on the icon in one space should not go to the app in the other space.   Is this possible natively, or with a third party program? If $$Y=\sum_{i=1}^{N}X_i^2$$ where $X_i \sim \mathcal{N}(0,\sigma^2)$, i.e. all $X_i$ are i.i.d. normal random variables of zero mean with same variances, then $$Y \sim \Gamma\left(\frac{N}{2},2\sigma^2\right).$$  I know the chi-squared distribution is a special case of the gamma distribution, but could not derive the chi-squared distribution for random variable $Y$. Any help, please? How can a distribution have infinite mean and variance? It would be appreciated if the following examples could be given:   A distribution with infinite mean and infinite variance. A distribution with infinite mean and finite variance. A distribution with finite mean and infinite variance.  A distribution with finite mean and finite variance.   It comes from me seeing these unfamiliar terms (infinite mean, infinite variance) used in an article I am reading, googling and reading a thread on the , and not finding it a sufficiently clear explanation. I also haven't found any explanations in any of my own textbooks. sort but keep header line at the top I am getting output from a program that first produces one line that is a bunch of column headers, and then a bunch of lines of data. I want to cut various columns of this output and view it sorted according to various columns. Without the headers, the cutting and sorting is easily accomplished via the -k option to sort along with cut or awk to view a subset of the columns. However, this method of sorting mixes the column headers in with the rest of the lines of output. Is there an easy way to keep the headers at the top? I know that electromagnetic waves induce electric currents in conductors and that's the basis for radio, wi-fi etc.  I also know that light is also an electromagnetic wave. So, can light induce a current in a conductor (like a metal wire? or a coil?). And, if the answer is yes, is the same visible for other high-frequency waves (X-rays, gamma)?  I heard about the photoelectric effect, but it seems related to the particle theory of light (photons transferring their energy to electrons).  So, do high-frequency electromagnetic waves generate electric currents? Is it possible to measure them? Is the skin effect relevant here? What Sci-Fi book (1987 or older) had Aliens conquer earth and made Humans their slaves? I have been trying to recall the title of a book I read about 25 years ago (1987), I have tried to find it again a couple of times over the years without any luck.    The story takes place on earth, which has been invaded and conquered by aliens.  The humans have become servants or slaves.  One of the primary human characters is the human servant of an alien leader.  If I remember correctly, the aliens are much bigger than humans, I keep thinking of horses or elephants for some reason with regard to the aliens.  At the end, somehow the human slaves have forced the aliens to abandon their conquest of earth, but I don't remember exactly why.  I think it was something to do with simply refusing to be obedient, which the aliens could not comprehend, but I'm not sure about that.  I think the book ends with the alien leader (and the rest of the aliens) blasting off from earth in a rocket.  Does anyone recognize what book I'm referring to?  Thanks for any help! "Is the same" or "are the same"? Which is the correct one?     On average, the polyunsaturated fat content in one teaspoon of the olive oil and canola oil is the same        On average, the polyunsaturated fat content in one teaspoon of the olive oil and canola oil are the same GPU Rendering causing strange lines When I render using my r9 390 graphics card, weird lines are appearing over the render. This problem has just started happening recently, as a few days ago I was rendering the same scene without the lines appearing. I don't believe I've changed any settings in Blender and the below scene is from a new file, so render settings should be default.   Rendering using my CPU is fine:   The only thing I can think that has changed is I recently updated my card to the latest drivers. Playing games with it is still fine and the card is quite new so I wouldn't think it's a problem with the card itself. For a specific package, can I find out why it is installed?  So, can I see or it's manually installed, or that it is installed as a dependency of another package? Or that it is installed as part of the distro? Word for lights on police cars, etc Changing "index.php" Within The Address How can we prove charge invariance under Lorentz Transformation? Checking if a number is a Fibonacci or not? The standard way (other than generating up to $N$) is to check if $(5N^2 + 4)$ or $(5N^2 - 4)$ is a perfect square.  What is the mathematical logic behind this? Also, is there any other way for checking the same? This is NOT an installation problem question. I've had both op sys working fine side-by-side for a couple of weeks now. I'm using Ubunutu 12.04 64-bit.  This morning when I tried to switch from Win8 to Ubuntu, it just rebooted into Win8. No grub screen whatsoever. This is the 3rd machine I've had dual-booting &amp; have never seen this, but then Win8 is a 1st for me &amp; has thrown some pretty awesome blocks in the path to get to here. Atrocious op sys...  I'm assuming the ASUS updater did this yesterday. (ASUS R503U)  So, do I just put the Ubuntu disk in &amp; reinstall grub? How to select JSF components using jQuery? How to find and replace using sed on records starting with Specific number