Why do some Linux shell scripts use exec to run commands?
reason for exec in wrapper scripts
Is any quotient of a Euclidean domain by a prime ideal a Euclidean domain? Let $R$ be a Euclidean domain, i.e., a ring with a norm $N : R \rightarrow \mathbb N$ such that for any $a,b\in R$ with $b\not=0$, we may write $a = qb + r$ for some $q,r \in R$ with $N(r) &lt; N(b)$. Let $I$ be a prime ideal of $R$, so $R/I$ is a domain. Must $R/I$ in fact be a Euclidean domain?   I know that this is true if we replace "Euclidean domain" with "PID", and false if we replace it with "UFD", so there is no clear intuition to be gained from similar concepts. My first attempts at a proof was to borrow a construction from analysis and define a norm on $R/I$ by  $N(a + I) = \inf\{N(a+i) : i\in I\}$  but this didn't really get me anywhere.   So, this fact true? If so, how can I prove it? If not, whats a counterexample? Where can I get Blender test builds? I know that  provides downloads for official releases. I see on forums that people use newer versions of Blender. Where can I get newer version of Blender (nightly builds, alpha versions... etc). I didn't know how to solve this problem.  How to prove $$\sum_{n=0}^{\infty}\sin(e\pi n!)$$ converges? adding @2x to src above certain resolution on none retina devices I'm running into this weird problem with Google spreadsheets: if the cells have comments on them and I sort the spreadsheet, the rows sort but the comments stay in the same position, and don't move with the cells they're attached to.  In other words, the cells look like this:  A C  &lt;-- comment on this cell B   and then I sort by this column:  A B  &lt;-- comment remains on this cell (stays in position) C  &lt;-- comment should have remained attached to this cell   This means that sorting is completely broken and I can't use it at all, because I clearly need the cell comments to stay with the cell they're attached to.  Is this a bad bug in Google Spreadsheets, or am I missing something here? I wrote a DLL in .NET and I want to access it in VBScript. I don't want to add it to the assembly directory.   Is there a way to point too the DLL and create an instance of it? How do I find the common ratio of a geometric sequence? A geometric sequence has its first term equal to $12$ and its fourth term equal to $-96$.   How do I find the common ratio? And find the sum of the first $14$ terms Basic photo editing on OS X I need to edit a photo on my Mac. I wish to take two photos and paste them together to create one that's larger, containing both. I couldn't figure out how to do this with iPhoto.   For Windows you have Paint.NET.    For Linux you have Kolourpaint.   What would be the equivalent on OS X?  Please note that it must be of quality both in code and in UI. I wouldn't want to install buggyware on my Mac. Whether the players killed a mage and got his spellbook(s) or they met with a nice wizard who let him or her learn a spell from his spellbook, can a player prepare a spell from a spellbook that isn't his or hers?  I'm asking because the PHB p. 114 says:     [...] Preparing a new list of wizard spells requires time spent studying your spellbook and memorizing the incantations and gestures you must make to cast the spell: at least 1 minute per spell level for each spell on your list.    emphasis mine   Further, the block on the left as a Copying a Spell into the Book ("the" Book as in "your" Book, since it appears in the block titled Your Spellbook), which explains how you can copy a spell from one book to another, assuming the book is from a stranger, it cost more and takes more time. It actually says:     [...] deciphering the unique system of notation used by the system of notation of the wizard who wrote it. [...]   It continues saying that you have to learn the various parts of the spell (verbose, material, gesture.)  This makes it sounds like a wizard would have a really hard time to prepare a spell from another's spellbook. Is that the case? Is it mandatory to have published papers while applying for PhD? I've heard from people saying that while applying for PhD, you need to have past experience in researching something and should have international publications. I was like more concentrated towards practical experience and have't had any publications. If I am aspiring to do PhD and want to apply, it would be impossible if such a criteria exists! I have just started learning Japanese Mahjong and I am a bit lost as to why this hand failed.  I did several pons and chis over the course of a hand, having a total of three open melds (one set and two sequences).  Apart from these I had an incomplete bamboo sequence of II and III as well as a pair of dragons, therefore I was on a single wait for I or IV bamboo stick tile. When the IV tile appeared in one of the discards of other players, I was given a choice to do another chi and declare another open meld, but I couldn't win with a ron. Why was that?  Am I wrong that winning by ron guarantees a single needed yaku to win a hand, just like Closed Tsumo does?  After declaring the chi I was offered with, my hand was left with a single pair of tiles, one of which I had to discard.  Eventually the round finished with a draw.  Why couldn't I win this hand with a ron on the IV bamboo tile, and why was I given only the choice of chi instead? Maximum number of edges in a bipartite graph Prove that for a bipartite graph $G$ on $n$ vertices the number of edges in $G$ is at most $\frac{n^2}{4}$.     I used induction on $n$.    Induction hypothesis: Suppose for a bipartite graph with less than $n$ vertices the result holds true.    Now take a bipartite graph on $n$ vertices.Let $x,y$ be two vertices in $G$ where an edge exist between $x$ and $y$. Now remove these two vertices from $G$ and consider this graph $G'$. $G'$ has at most ${(n-2)^2}\over4$. Add these two vertices back.  Then the number of edges $G$ can have is at most    $$|E(G')|+d(x)+d(y)-1$$   My question is in my proof I took $d(x) + d(y) \le n$, where $d(x)$ denotes the degree of vertex $x$.  Can I consider $d(x)+d(y) \leq n$? I thought the maximum number of edges is obtained at the situation $K_{\frac n 2,\frac n 2}$ Interpreting coefficient in a linear regression model with categorical variables I will give my examples with R calls. First a simple example of a linear regression with a dependent variable 'lifespan', and two continuous explanatory variables.  data.frame(height=runif(4000,160,200))-&gt;human.life human.life$weight=runif(4000,50,120) human.life$lifespan=sample(45:90,4000,replace=TRUE) summary(lm(lifespan~1+height+weight,data=human.life))  Call: lm(formula = lifespan ~ 1 + height + weight, data = human.life)  Residuals: Min       1Q   Median       3Q      Max  -23.0257 -11.9124  -0.0565  11.3755  23.8591   Coefficients:              Estimate Std. Error t value Pr(&gt;|t|)     (Intercept) 63.635709   3.486426  18.252   &lt;2e-16 *** height       0.007485   0.018665   0.401   0.6884     weight       0.024544   0.010428   2.354   0.0186 *   --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1   Residual standard error: 13.41 on 3997 degrees of freedom Multiple R-squared: 0.001425,   Adjusted R-squared: 0.0009257  F-statistic: 2.853 on 2 and 3997 DF,  p-value: 0.05781   In order to find the estimate of 'lifespan' when the value of 'weight' is 1, I add (Intercept)+height=63.64319  Now what if I have a similar data frame, but one where one of the explanatory variables is categorical?  data.frame(animal=rep(c("dog","fox","pig","wolf"),1000))-&gt;animal.life animal.life$weight=runif(4000,8,50) animal.life$lifespan=sample(1:10,replace=TRUE) summary(lm(lifespan~1+animal+weight,data=animal.life))  Call: lm(formula = lifespan ~ 1 + animal + weight, data = animal.life)  Residuals: Min      1Q  Median      3Q     Max  -4.7677 -2.7796 -0.1025  3.1972  4.3691   Coefficients:             Estimate Std. Error t value Pr(&gt;|t|)     (Intercept) 5.565556   0.145851  38.159  &lt; 2e-16 *** animalfox   0.806634   0.131198   6.148  8.6e-10 *** animalpig   0.010635   0.131259   0.081   0.9354     animalwolf  0.806650   0.131198   6.148  8.6e-10 *** weight      0.007946   0.003815   2.083   0.0373 *   --- Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1   Residual standard error: 2.933 on 3995 degrees of freedom Multiple R-squared: 0.01933,    Adjusted R-squared: 0.01835  F-statistic: 19.69 on 4 and 3995 DF,  p-value: 4.625e-16   In this case, to find the estimate of 'lifespan' when the value of 'weight' is 1, should I add each of the coefficients for 'animal' to the intercept: (Intercept)+animalfox+animalpig+animalwolf? Or what is the proper way to do this?  Thanks Sverre How to change folders color? How do i change the folders colors? i am using this icon theme   and there are several folders. like black, gray, purple, orange(which is the default), yellow, green, red, blue, brown and lightblue  How can i use any of them? for example have a blue folder called "family" in images and another right beside that have a purple folder called "others".  Basically why have he created all those folders with different colors? Solve for $A,B$: $\mathrm{LCM}(A,B)=168$, $\mathrm{HCF(A,B)}=12$ Absolutely continuity and Lipschitz-like continuity I'm trying to figure out if the following is true or false:  Let $\mu$ and $\nu$ be finite measures on Borel subsets of $[0,1]$,and $\nu \ll \mu$ ($\nu$ is absolutely cts with respect to $\mu$). Does there exist always a $C \in \mathbb{R}$ such that $\forall A \subseteq [0,1]$ that is Borel, we have $\nu(A)$ $\lt$ $C \mu (A)$.  The Radon-Nykodym theorem seems to almost suggest that is true, if I knew it was bounded, then I could say $\nu (A) \le \int_{A} g \ d\mu \le \int_{A} C \ d\mu \le C\mu (A)$, where $C$ is the bound. However, I don't know if it is bounded and in fact, I could take an unbounded function that is still integrable on $[0,1]$, such as $\frac{1}{\sqrt x}$.  I can't even be sure if it is true or false.   Thank you! Capture characters from standard input without waiting for enter to be pressed Can a creature's sacrifice benefit be taken when it is sacrificed to Eldrazi Monument? Log of products to sum of logs MAC addresses in JavaScript I know that we can get the MAC address of a user via IE (ActiveX objects).  Is there a way to obtain a user's MAC address using JavaScript?