Does logback have a NullAppender?
How to configure logback to skip logging messages from org.package.* with all levels below WARN?
Set keyboard caret position in html textbox Does anybody know how to move the keyboard caret in a textbox to a particular position?  For example, if a text-box (e.g. input element, not text-area) has 50 characters in it and I want to position the caret before character 20, how would I go about it?  This is in differentiation from this question:  , which requires jQuery. Can I access private members from outside the class without using friends? Disclaimer Yes, I am fully aware that what I am asking about is totally stupid and that anyone who would wish to try such a thing in production code should be fired and/or shot.  I'm mainly looking to see if can be done. Now that that's out of the way, is there any way to access private class members in C++ from outside the class?  For example, is there any way to do this with pointer offsets? (Naive and otherwise non-production-ready techniques welcome) Update As noted in the comments, I asked this question because I wanted to write a blog post on over-encapsulation (and how it affects TDD).  I wanted to see if there was a way to say &quot;using private variables isn't a 100% reliable way to enforce encapsulation, even in C++.&quot;  At the end, I decided to focus more on how to solve the problem rather than why it's a problem, so I didn't feature some of the stuff brought up here as prominently as I had planned, but I still left a link. At any rate, if anyone's interested in how it came out, here it is:   (I suggest reading it before you decide that I'm crazy). I have a simple 2-column layout with a footer that clears both the right and left div in my markup.  My problem is that I can't get the footer to stay at the bottom of the page in all browsers.  It works if the content pushes the footer down, but that's not always the case. Defer Parsing of Scripts this is my first time to try this "Defer Parsing" thing, and I don't really have an idea how to do it.    Using PageSpeed tool, I found out that one of the reason why my page is loading too slow (currently 92/100) are the scripts. And the PageSpeed suggested that I need to Defer Parsing all those scripts.  Is there anyone that can help me with this. Thanks. Cardinality of a set A is strictly less than the cardinality of the power set of A Mapping key combination with xmodmap I'm trying to achieve the following mapping keycode 135 = &lt;Ctrl-C&gt;  Is it possible to achieve this in some way? What is the direction of stack growth in most modern systems? I am preparing some training materials in C and I want my examples to fit the typical stack model.  What direction does a C stack grow in Linux, Windows, Mac OSX (PPC and x86), Solaris, and most recent Unixes? How do I prove if $\sup\{ (n!)^{1/n} | n \in\Bbb N\} = +\infty$?  I don't know how to properly explain it How does a lurker gain reputation to receive privilege for commenting? I have been reading Stack Exchange for years - mostly not logged in, and have never posted (this is my first). I'm simply not very talkative, and very good at googling.  Recently a few occasions have come up when I've wanted to comment on a question.  I wanted either to ask for, or provide, clarification which did not warrant a new answer.  How do I gain enough reputation to comment without:   asking questions which have already been answered or that I can figure out on my own, or posting my comment like as an answer (i.e. being  rude)? Can there be a notification for bounties started on questions you've asked or answered? Why is free will a widely discussed, established concept? Does this concept emerge from religious / spiritual doctrine? Why is there so much interest in this topic?  If a neural-network based AI machine with a certain high degree of complexity scores a perfect 100 every run in a turing test, have we not already refuted the idea of free will? In fact, let me extend this reasoning, if ANY machine scores a single point in a turing test (and not 100), have we not already disproved (or alternatively put in great doubt the existence of) free will? If we already created a machine that can master a certain degree of human interaction, have we not then demonstrated that human interaction is programmable? (given enough time for the creation of a complex or more appropriately elaborative neural system).   From the perspective of an external observer, such a machine would be qualitatively human although intrinsically quantitative behind a stream of 1's and 0's. It would exhibit a type of decision making indistinguishable from that of a human. Does this not reduce the type of decision making we understand to be "free will" to something quantitative, deterministic, materialist? Why is it so difficult to pull an immersed mug out of the water? We are using Nginx to serve static files on a development platform. As it is a development platform, we'd like to disable caching so that each change is propagated to the server. The configuration of the VHost is quite simple:  server {   server_name  static.server.local;   root /var/www/static;    ## Default location   location / {     access_log        off;     expires           0;     add_header        Cache-Control private;   }  }   When we access an HTML file (http://static.server.local/test.html), we have no issue: the server returns a code 304 Not Modified as long as the file is not changed, and a 200 OK response with the modified file when the file is changed. However, it seems to behave differently with a Javascript or a CSS file. Once the file is changed, we get a 200 OK response as expected, but with the old text. Is there an internal cache mechanism in Nginx that could explain this behaviour? Or some configuration that we should add?    As a side note, here is the header returned by Nginx when the file has been modified (it seems correct):  Accept-Ranges:bytes Cache-Control:max-age=0 private Connection:keep-alive Content-Length:309 Content-Type:text/css Date:Fri, 13 May 2011 14:13:13 GMT Expires:Fri, 13 May 2011 14:13:13 GMT Last-Modified:Fri, 13 May 2011 14:13:05 GMT Server:nginx/0.8.54   Edit After trying different settings with the expires directive and Cache-Controlheader, I made some further investigations. In fact, the server is installed on a VirtualBox guest Ubuntu, and data are read from a shared folder that is on the Mac OSX host. If the file is edited from an IDE (NetBeans) on the host, it seems that changes do not appear whereas if I edit it directly on the guest (using VIM), it is refreshed. The strange thing is it does not behave similarly with HTML files. Quite puzzling.  Edit 2 (ANSWER) Indeed, the origin of the issue was more on the VirtualBox side. Or rather a conflict between VirtualBox and the "sendfile" option of the server. This link  gave me the solution: switch the sendfile flag in the server configuration to off:  sendfile  off;   Hope this could also help other person using VirtualBox for development. :) There are some additional information on the . In the standard PrintDialog there are four values associated with a selected printer: Status, Type, Where, and Comment.  If I know a printer's name, how can I get these values in C# 2.0? How can I securely format a solid-state drive? Let $Q_8$ be the quaternion group. Show that $G/Z$ can never be isomorphic to $Q_8$, where $Z$ is the center of $G$. Hint: if $G/Z\cong Q_8$, show that $G$ has two abelian subgroups of index $2$.  I'm trying to prove the hint by looking at the canonical homomorphism $\pi:G\rightarrow G/Z$. Well, $Q_8$ has some abelian subgroups of index $2$, such as $H=\{1,-1,i,-i\}$, but that doesn't seem to map to abelian subgroups of index $2$ of $G$. (We know that $\pi(ab)=\pi(a)\pi(b)=\pi(b)\pi(a)=\pi(ba)$ for $a,b$ in $\pi^{-1}(H)$, but that only yields $aba^{-1}b^{-1}\in Z$, not $aba^{-1}b^{-1}=1$.) $X\sim\mathrm{Poisson}(\lambda_1 = 5)$ and $Y\sim\mathrm{Poisson}(\lambda_2 = 15)$. Let $Z = X + Y$ . Compute $\mathrm{Corr}(X, Z)$. With powershell get exactly the same application list as in Add/Remove programms Covariant derivative ambiguity I'm studying general relativity and am running into an ambiguity with the covariant derivative. The covariant derivative acting on a scalar is, in a co-ordinate basis, simply $$\nabla_X f = X^a \nabla_a f = X^a \partial_a f $$ whilst when acting on vectors or tensors, the covariant derivative includes extra terms involving the connection coefficients $\Gamma$. My problem is that I'm not sure what happens when the covariant derivative acts on the components of a vector. So the $X^a$ in the above expression are each scalar functions, and so when we write $\nabla_Y X^a$, do we assume the covariant derivative acts on $X^a$ as scalars, or do we include connection coefficient terms?  To clarify, consider $$ \nabla_X Y = X^a \nabla_a(Y^b e_b) = X^a (\nabla_a Y^b) e_b + X^a Y^b (\nabla_a e_b) = X^a (\partial_a Y^b) e_b + X^a Y^b \Gamma^c{}_{ba} e_c $$ As you can see, when the covariant derivative acts on the $Y^b$, it acts as a simple partial derivative, since the $Y^b$ are here considered functions premultiplying the vectors $e_b$.   However, in this equation from  page: $$(\nabla_X \nabla_Y Z)^a = X^c \nabla_c Y^b \nabla_b Z^a = X^c Y^b \nabla_c \nabla_b Z^a + (X^c \nabla_c Y^b) \nabla_b Z^a = (\nabla^2_{X,Y} Z)^a + (\nabla_{\nabla_X Y} Z)^a$$ When the covariant derivative acts on the $Y^b$ term it treats it like a vector.  What's going on here? Thanks. Why didn't the Seons change? In the book Elantris, the Reod was caused by a giant earthquake opening a chasm which changed the shape of all the Aons. The Seons, which are basically living Aons, were presumably unchanged, since nobody noticed the change, which should have been obvious on the simpler Aons.