What is the best way to download a list of stack exchange questions for offline browsing?
How do I backup my Stackexchange favorites for offline use?
Replace environment variables in a file with their actual values? Is there an easy way to substitute/evaluate environment variables in a file? Like let's say I have a file config.xml that contains:  &lt;property&gt;     &lt;name&gt;instanceId&lt;/name&gt;     &lt;value&gt;$INSTANCE_ID&lt;/value&gt; &lt;/property&gt; &lt;property&gt;     &lt;name&gt;rootPath&lt;/name&gt;     &lt;value&gt;/services/$SERVICE_NAME&lt;/value&gt; &lt;/property&gt;   ...etc. I want to replace $INSTANCE_ID in the file with the value of the INSTANCE_ID environment variable, $SERVICE_NAME with the value of the SERVICE_NAME env var. I won't know a priori which environment vars are needed (or rather, I don't want to have to update the script if someone adds a new environment variable to the config file). Thanks! The X button stopped working on one of my PS3 controllers. It's hardly through abuse, the controller isn't a year old and I don't play a lot.  The button doesn't stick, it presses like the others, only the system isn't aware that I'm using it. I tried resetting it with the tiny reset button in the back, to no avail.  What can I do? If two people want to buy a car together, would they go half on the car or halves. Example: Let's go half on this car or Let's go halves on this car? Grub rescue - error: unknown filesystem Using conditional statements in ArcGIS Field Calculator? I have seen some hypotheses that the recent series corporate actions and statements are a sign of SO/SE being in the process of being, or about to be, sold. Arguments cited include the corp statements being made in paywalled areas and addressed to an audience that seems very distinct from the community, the choice of CEO, the push for a 'service sector' flavour of tensely smiling hospitality, and surely some more I can't recall in a coherent form.   Just how plausible and implausible, and how founded or unfounded, is such a hypothesis? Is it, as far as people more knowledgeable either about business in general or about the specific case of SE/SO, strategically consistent or even outright connected with the corp's behaviour (and a likely cause thereof)? Crop jpeg into circular tikz node \documentclass[demo]{article} \usepackage{graphicx} \usepackage{tikz} \begin{document} \begin{tikzpicture} \node[circle,draw,inner sep=2cm]{\includegraphics{myimage.jpg}}; \end{tikzpicture} \end{document}   How do I modify the above code so that the included image is adapted to the circle shape and cropped of the exceeding parts?  I want to specify a shape (a circle) and then include an image respecting the given dimension and cropped. $\lim_{x \to 0} f(x)=\frac{\tan 3x}{\tan 2x}$ without L'Hospital I have a file as below:  mime PI Name: ISHO SUCCESS RATE RT, Value: 95.663826 scr  PI Name: RRC Access Failures due to UU, Value: 0.13394141 prog PI Name: RRC Access Failures due to UU, Value: 0.16077702 sch PI Name: RRC Access Failures due to UU, Value: 0.11781933   I want to remove text PI till Value:. I tried   sed '/&lt;PI&gt;/,/&lt;\/Value:&gt;/d'    Any help? Why the electric potential of Earth is zero? For a localized charge distribution the potential is set to zero far away from the charge distribution (at infinity)  Now, when grounding a conductor, i.e. connecting it to Earth, it is said that we are setting its potential to zero.   Why Earth's potential is zero? And if it is zero, is it zero even if the potential is still zero at infinity? Can US citizens go to Cuba freely and vice versa after the recent diplomatic relation restoration? A recent full diplomatic relation restoration between the US and Cuba took place, does that mean that US citizens can go to Cuba freely and vice versa? product distribution of two uniform distribution, what about 3 or more How do you keep user.config settings across different assembly versions in .net? The locus of the intersection point of two perpendicular tangents to a given ellipse For a given ellipse, find the locus of all points P for which the two tangents are perpendicular.   I have a trigonometric proof that the locus is a circle, but I'd like a pure (synthetic) geometry proof. El Captain update download doesn't continue after restarting the Mac I started to download the El Capitan upgrade, but then I shut down my computer. The day after I wanted to continue the download but in App Store it shows "Waiting..." and doesn't do anything. Also when I go to the updates section, it shows the button "Download" but it's inactive. Maybe someone can help me? I tried to find the download file in some directory to delete it and start over but I couldn't find it. How do I list all available shell builtin commands? We know bash supports number of  buitin commands  like:  $ type type cd help command type is a shell builtin cd is a shell builtin help is a shell builtin command is a shell builtin   I want to get list of all available shell builtin commands. How do I do that by command-line? Word for "reading carefully" Sometimes we read books rather quickly and don't give them much (or any) thought, so the action 'reading' does not necessarily imply that we have given enough thoughts to any book we read.   Is there a word that describes reading a book with great care; usually but necessarily slowly over a long period of time. How does a phonon cause two electrons to attract each other and form a cooper pair? We know that like charges repel each other. But my professor claimed that two electrons can attract each other as well. What he said was that due to screening an electron travelling at some speed won't repel another electron, but that they will, in some cases, attract each other due to weak phonon exchange. What does that mean? What is phonon exchange? Do two electrons really attract each other? Let $\alpha,\beta,\gamma$ be the roots of $x^3-3x^2+1 = 0$. Prove that $$\alpha^n+\beta^n+\gamma^n \equiv 4^n+5^n+(-6)^n \pmod{17}$$ where $n$ is an integer.   It sort of makes sense why they are congruent since we can say $x^3-3x^2+1 \equiv (x-4)(x-5)(x+6) \pmod{17}$, but since $\alpha,\beta,\gamma$ aren't integers, how do we prove this? How to show that $\lim \frac{1}{n} \sum_{i=1}^n \frac{1}{i}=0 $? Show that  $$\lim \frac{1}{n} \sum_{i=1}^n \frac{1}{i} =0 $$  I've proved that this sequence converges (it is bounded and decreasing). NOW, I need to find a sequence that is bigger than this one and goes to zero. Maybe something using geometric serie of 1/2  Thanks in advance!