How can I add a universal keybinding for a program?
Override iTunes "media" keys (play, pause, etc) for Spotify?
Generating a unique machine id Why did the command ":(){ :|: & };:" make my system lag so badly I had to reboot? Do not run this command to 'test' it unless you are prepared for a crash and/or force-rebooting your system.  I was in my Virtualbox running 12.04 trying to compile an app, and while waiting I happened to chance upon a forum where a comment said:   Try :(){ :|: &amp; };:  Fun, too, and doesn't need root.  Without thinking, I ran it in my gnome-terminal. It made my 12.04(in Virtualbox) lag so badly, I had to shut it down. My question is what does this command do?   :(){ :|: &amp; };: Why isn't this sudo mv operation with wildcard working? How should we handle downvote retaliation? Changing an element's ID with jQuery I need to change an element's ID using jQuery.    Apparently these don't work:  jQuery(this).prev("li").attr("id")="newid" jQuery(this).prev("li")="newid"   I found out that I can make it happen with the following code:  jQuery(this).prev("li")show(function() {     this.id="newid"; });   But that doesn't seem right to me. There must be a better way, no? Also, in case there isn't, what other method can I use instead of show/hide or other effects? Obviously I don't want to show/hide or affect the element every time, just to change its ID.  (Yep, I'm a jQuery newbie.)  Edit I can't use classes in this case, I must use IDs. Display View counts of Questions in Mobile version I often use Stack Exchange sites from my smartphone. It works great, but I always have to switch to full version to see view counts of a question. Can you please add it? There's plenty of space on question page for it to place. I request community to suggest a location. How does a cell phone charger work? I have studied that there is a transformer which steps down the ac voltage after then bridge rectifier to convert into ac to dc and then given to filter, this is what I have learnt in books, but when I open a mobile charger I couldn't figure it out how it actually works? File permissions and saving Let's say you open a file on which you have write permission. Meanwhile you change permissions and remove write permission while you still have the file open in some editor.  What will happen if you edit and save it? In QGIS, I have been learning a few expressions to style my trail maps but still know little and am stumped on what to use to filter my symbol data. I am showing Parking locations on my map. I use a marker symbol as a background element, so I can do callouts. I created a data field and added values to display beside this symbol a number that references a list of parking addresses in the book's text. All good except if the field has no number to display, it is NULL, it does not display my marker symbol. I need to filter this, so it does show even when there is no value in the field. Find the sum of finite series $S=\sum_{k=1}^{2015}{(-1)^{\frac{k(k+1)}{2}}}k$ Find the sum $\sum_{n=1}^{\infty} \frac{\ln n}{n(n- \ln n)}$ Find the following sum : $\sum_{n=1}^{\infty} \frac{\ln n }{n(n- \ln n)}$  I couldn't find any way to solve.   I just want a hint, how to initiate? Probability that the sum of 6 dice rolls is even How to switch between low latency and generic kernels? "invalid EFI file path" while booting Windows durbinWatsonTest() in R for non time-series data I am trying to understand whether the Durbin-Watson test is meaningful at all when applied to regression data that have no temporal order (eg. blood pressure ~ bodyMassIndex + exercise).   I would say no, as the autocorrelation should obviously vary with the order of the subjects (which is random), but I wonder whether the durbinWatsonTest in R involves a bootstrapping of the data, where order of the bootstrapping data is shuffled each time, and then perhaps an average autocorrelation is computed over the bootstrapping samples (but then again, shouldn't this average autocorrelation be zero for randomly sampled data?).  On the other hand, the value of the statistics seems to be quite stable over multiple runs of the function, so I am even more confused...  I came across it in Andy Field's book "Discovering Statistics with R", where it is used is an example with non-time series data, although in another, more recent book of the same author ("Adventures in Statistics") it does say that the test is applicable only to time series data. Show $\sin x = bx$ has at least 3 real solutions. Show $\sin x=bx$ has at least 3 real solutions for every $b$, where $-\dfrac{2}{3 \pi} &lt; b &lt; \dfrac{2}{\pi}$.   Some useful facts I am trying to use:  Intermediate value theorem: If $f$ is a continuous real-valued function on $[a,b]$ and $d \in \mathbb{R}$ satisfies $f(a)&lt; d&lt; f(b)$, then there exists a point $c$ in $(a,b)$ such that $f(c) = d$.   Corollary: If $f$ is a continuous real-valued function on $[a,b]$, then $f([a,b])$ is a closed interval. Can I use SPI for asynchronous serial output? I need a second serial async output channel on the MSP430G2553 and would like to use the SPI USCI to do this.  Is the USCI SPI baud rate stable enough to do this at 300 baud, 2400 baud or 9600 baud? I am currently using the 8 MHz clock.  Is there any other option that can save me from bit-banging?  My current thinking for 300 bd Tx is as follows:   set prescaler to 26666 LSB first load byte into Txbuf load 0x7F into Txbuf to generate stop and start bits repeat 2-3 send final stop bits 0xFF   It might also be possible to send ten bits of data on other members of the MSP430 family that contains a SPI.  Thanks for your responses. What is the difference between display: inline and display: inline-block? What is approximate error of Pythagorean Theorem vs. Haversine Formula in measuring distances on sphere at various scales? Many people when first trying to calculate distances between two longitude / latitude pairs  ask if Pythagorean theorem works as an appropriate distance function.  Most often people answer "no, the Pythagorean theorem only works on a 2D Euclidean plane." Rarely, however, do people mention the effect of scale and location on the sphere on how inaccurate the Pythagorean theorem is.  The basic idea being at very small scales, the surface of a sphere looks very much like a plane. At very large scales, it distances along the surface are more curved and therefore the difference between the incorrect Pythagorean Theorem and the correct Haversine Formula is greater.  Does anyone know a formula or rule of thumb that tells you the difference between the two distance measures based on the scale of the distance you are trying to measure?   I think having this explicitly would help in:   explaining why the Pythagorean Theorem isn't perfect; and in letting people who are looking for more "rough" distances know when Pythagoras actually will serve their purposes. Is acceleration relative in relativity? Suppose a box A is moving relative to a Box B, then by time dilation equation if I take 1 sec passed for an observer in A then for an observer in B will be little longer. Now if I suppose that the box B is moving while A is stationary under the same condition, then by the time dilation equation time passed in B must be shorter than A. How is this issue resolved? In the twin paradox problem my book says that it's due to acceleration, but in my opinion acceleration is relative (please correct me if I'm wrong), but here it is not the case.