How to locate exactly that executable, which will be run if it's name entered in command line?
Why not use "which"? What to use then?
Yes, I'm really sure I want to delete that post Attempting to delete questions on the mobile site on iOS causes two notification messages asking me to confirm the deletion, which it shouldn't do.  I haven't really looked into it, but it may just be that the handlers from full.js and mobile.js are both being triggered, as there seems to be the flash of the error dialog indicating something went wrong on the supposed second AJAX request when the response from the first triggers a page reload.  You can see this happening by following the method calls; the mobile view first calls   StackExchange.question.init() -&gt; StackExchange.question.fullInit()   -&gt; StackExchange.vote.init()     -&gt; u()    ...where u() sets a delegated click handler on  $("div.post-menu *[id^='delete-post-'], table.flagged-posts *[id^='delete-post-']")   ...that calls .preventDefault() on the event, but doesn't block other handlers from firing.  It then later calls StackExchange.mobile.init(), which in turn calls the method J() that sets up a similar handler directly on $(".delete-post").  Since both handlers get triggered, there's two confirmation dialogs, and two attempts to delete the post. The extra handler in mobile.js seems unnecessary, so just removing it would appear to be the easy fix to the problem. Constant term in Lagrangian Why can we always drop any constant term in a Lagrangian density in quantum field theory?  This issue is somehow related to the constant term being some kind of cosmological constant.  Can you please explain this issue? From what time I've spent with threads in Java, I've found these two ways to write threads:  With implements Runnable:  public class MyRunnable implements Runnable {     public void run() {         //Code     } } //Started with a "new Thread(new MyRunnable()).start()" call   Or, with extends Thread:  public class MyThread extends Thread {     public MyThread() {         super("MyThread");     }     public void run() {         //Code     } } //Started with a "new MyThread().start()" call   Is there any significant difference in these two blocks of code ? Integration of the cardinal sine It is said that the integral of the cardinal sine is $1$. How do I integrate the cardinal sine? $$ \int_{-\infty}^{\infty} \frac{\sin(a)}{a} \, {\rm d} a $$ Can a hotel kick you out if you let an unregistered guest share a room with you? How to catch creation of DOM elements and manipulate them with jQuery I've installed Xcode and MacPorts on a brand new mid-2013 MacBook Air, but MacPorts doesn't work, saying that it cannot find anything.  mba:~ cnst$ sudo port install wget Warning: The Command Line Tools for Xcode don't appear to be installed; most ports will likely fail to build. Warning: See http://guide.macports.org/chunked/installing.xcode.html for more information. ---&gt;  Computing dependencies for wgetError: Unable to execute port: can't read "build.cmd": Failed to locate 'make' in path: '/opt/local/bin:/opt/local/sbin:/bin:/sbin:/usr/bin:/usr/sbin' or at its MacPorts configuration time location, did you move it? mba:~ cnst$   And, indeed, there is no make or clang in the path, but it is definitely installed, though:  mba:~ cnst$ find /Applications -name "clang" -or -name "make" /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang /Applications/Xcode.app/Contents/Developer/usr/bin/make mba:~ cnst$   Why is there no make or clang in the path?  Why MacPorts doesn't work?  I notice that  mentions that you have to install something from ADC, Apple Command Line Developer Tools, but ADC doesn't work since last Thursday or Friday due to their security breach, so, the developer tools are nowhere to be found.  What's the proper solution here? In Revenge of the Sith, after first being Force-choked by Anakin and then given births to Luke and Leia, Padme Amidala eventually lost her life on Polis Massa. We later, however, see her in the funeral procession on Naboo. The question is, how did she get there?    I mean, whoever delivered her there must have faced a lot of difficult questions, not just from her family but also from both the people and the authorities, since she was the former queen of the planet. Whoever it was, he could not have been just somebody, because it most certainly must not have been an easy task. It most likely was not any of the Jedi, since the world was probably half full of Palpatine's collaborators who would have immediately given them away.  So, who was it? And how was it carried out, in practice? Prepositional Phrase - confused - at or in Let's meet in the morning  or at the morning.  in the afternoon or at the afternoon.  in the night or at the night.  in the park or at the park.  working in the background or at the background. How resilient is Ubuntu to repeated "power-off" shutdowns? My company is considering the use of Ubuntu as an OS for use on a hardware device.     It would be installed on compact flash drive - apparently this is not standard flash drive but a specific type of memory that is supposed to "cope" with immediate power shutdown (I am not sure how this is achieved but they are supposedly a "high end" card).    The units that would be run using Ubuntu are the type of units that will not be gracefully shutdown - the power cable would be removed and that is that.     Can anybody give me some advice on the potential problems that can occur? Is Ubuntu a good system that can deal with this kind of power outage and reboot successfully on next startup?     I realise that nothing is unbreakable, but is it a commonly used OS for an embedded setup? Is it asking for trouble to use Ubuntu in this kind of environment? How do you evaluate this integral $\int \frac{6x^{3}+7x^2-12x+1}{\sqrt{x^2+4x+6}}dx$ $$\int \frac{6x^{3}+7x^2-12x+1}{\sqrt{x^2+4x+6}}dx$$  I have met this complex integral today, how do you evaluate this? Can you do this in more steps?  Is this an elliptic integral? I don't know how to evaluate this integral at all. Center image element in parent div apt: how to be sure that a specific package gets installed/updated from specific repository and not from the default one? In how many ways can a number be expressed as a sum of consecutive numbers? All the positive numbers can be expressed as a sum of one, two or more consecutive positive integers. For example $9$ can be expressed in three such ways, $2+3+4$, $4+5$ or simply  $9$. In how many ways can a number be expressed as a sum of consecutive numbers?  In how many ways can this work for $65$?  Here, for $9$ answer is $3$, for $10$ answer is $3$, for $11$ answer is $2$. Let $\alpha = \frac{1+\sqrt{-19}}{2}$. Let $A = \mathbb Z[\alpha]$. Let's assume that we know that its invertibles are $\{1,-1\}$. During an exercise we proved that:     Lemma: If $(D,g)$ is a Euclidean domain such that its invertibles are $\{1,-1\}$, and $x$ is an element of minimal degree among the elements that are not invertible, then $D/(x)$ is isomorphic to $\mathbb Z/2\mathbb Z$ or $\mathbb Z/3\mathbb Z$.   Now the exercise asks:     Prove that $A$ is not a Euclidean Domain.   Everything hints to an argument by contradiction: let $(A, d)$ be a ED and $x$ an element of minimal degree among the non invertibles we'd like to show that $A/(x)$ is not isomorphic to $\mathbb Z/2\mathbb Z$ or $\mathbb Z/3\mathbb Z$.  How do we do that? My problem is that, since I don't know what this degree function looks like, I don't know how to choose this $x$!  I know that the elements of $A/(x)$ are of the form $a+(x)$, with $a$ of degree less than $x$ or zero. By minimality of $x$ this means that $a\in \{0, 1, -1\}$. Now I'm lost: how do we derive a contradiction from this? I'm trying to find the derivative of $\sin^{-1}(x)$. I know the steps that lead to $\frac{1}{\sqrt{1-x^2}}$, however I don't understand why the following reasoning leads to a wrong answer.  Because  $$\frac{d}{dx}f^{-1}(x) = \frac{1}{f'(f^{-1}(x))} $$  If we plug in for $f(x) = \sin(x)$, and because $\frac{d}{dx}\sin(x) = \cos(x)$ we get  $$\frac{d}{dx}\sin^{-1}(x) = \frac{1}{\cos(\sin^{-1}(x))} $$  Since $\sin(x) = \cos(x-\frac{\pi}{2})$, we can state that $\sin^{-1}(x) = \cos^{-1}(x-\frac{\pi}{2})$. (I suspect this is what is wrong)  Thus,  $$\frac{d}{dx}\sin^{-1}(x) = \frac{1}{\cos(\cos^{-1}(x-\frac{\pi}{2}))}$$  Then, by the definition of inverse function, we have  $$\frac{d}{dx}\sin^{-1}(x) = \frac{1}{x - \frac{\pi}{2}}$$ Powering NiChrome wire from battery I'm looking to power nichrome wire from battery. The problem I ran into is that desired length/width of the wire has very small resistance ~ 8 Ohm.  Several kinds of batteries I've tested have internal resistance much higher then that, which leads to wire staying cold and battery getting hot.  Is there any way to increase current drawn from the battery? Some kind of amplifier maybe?  Edit:    1.2V(rechargable) and 1.5V one, while not getting hot itself did not provide enough power to heat the wire. 3V did not provide enough power, even stacking 3 of them in series, only provided about 1V of voltage on the wire, and not enough amperage to heat the wire. 9V battery did provide enough amperage to heat the wire, but at the same time got very hot very quickly itself.   PS. I was wondering if  might work for this purpose? Should there be a comma in 'a 30-day, money-back guarantee'? With all the various races in the federation, how do the humans manage to dominate it? How to decide whether missing values are MAR, MCAR, or MNAR I have a large proteomics dataset. In the rows I have the proteins , and in the rows I have the samples.The dataset contains a lot of missing values.  I would like to know I can find out whether missing values are MAR, MCAR, or MNAR, and how I can decide the best imputation technique. Kind regards.