How do we make sense of this find command?
Understanding the -exec option of `find`
Limit of $\lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {n^2 +i} }$ Direct way leads to nowhere.  $$\lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {n^2 +i} } = \lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{n \sqrt {1 +\frac{i}{n^2}} } = $$  $$ = \lim_{n\rightarrow \infty} \frac{1}{n} \cdot \lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {1 +\frac{i}{n^2}} } = 0 \cdot \sum^{n}_{i=1} 1 = 0 \cdot n $$  So, I tried to apply squeeze theorem:  $$\lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{\sqrt {n^2 +i} } \leq \lim_{n\rightarrow \infty} \sum^{n}_{i=1} \frac{1}{n}  = 1$$  Could you help me to figure out the lower bound? Iteration over std::vector: unsigned vs signed index variable What is the correct way of iterating over a vector in C++?  Consider these two code fragments, this one works fine:  for (unsigned i=0; i &lt; polygon.size(); i++) {     sum += polygon[i]; }   and this one:  for (int i=0; i &lt; polygon.size(); i++) {     sum += polygon[i]; }   which generates warning: comparison between signed and unsigned integer expressions.  I'm new in the world of C++, so the unsigned variable looks a bit frightening to me and I know unsigned variables can be dangerous if not used correctly, so - is this correct? Where are the Stack Exchange data dumps? I see a lot of talk around here regarding the Stack Overflow public data dump.  Where is it? How can I play with it? Displaying layout marks in a document set with different layouts Is there any package that allows for the display of layout marks within a document where the layout changes several times throughout? I'm using the geometry facilities to issuing \newgeometry commands throughout my document, but it doesn't update the displayed layout and neither does the showframe package or the facilities of the memoir class.  EDIT: As Werner has pointed out, the showframe option of the geometry package displays correctly any updated page layout set by issuing \newgeometry commands.   My trouble came out of the fact that I'm issuing also \pagecolor commands and the page color seems to be hiding the layout lines typeset according to the geometry package. My confusion only worsened because the showframe package layout lines were not hidden by the page color (the package got the layout wrong on some pages, though). So, it all boils down to a conflict with the page color.   Even though I'm using geometry's showframe option for "debugging" ends, and I don't mind to have no page color at that stage of development, is it possible to override this problem and have at the same time both the page layout displayed by geometry as well as the page colored?   Btw, should I open a new question given that the problem is actually different from the originally posted one? Word for people who don't make their deadline Removable singularities and an entire function Function $f(z)$ is an entire function such that $$|f(z)| \le |z^{n}|$$ for $z \in \mathbb{C}$ and some $n \in \mathbb{N}$.  Show that the singularities of the function $$\frac {f(z)}{z^{n}}$$ are removable. What can be implied about the function $f(z)$ if moreover $f(1) = i$? Draw a far-reaching conclusion.  My attempt: If the singularities of $\frac {f(z)}{z^{n}}$ are removable, it is entire (not sure, need help with the justification) and bounded, so constant from Liouville's theorem, the constant value of the funcion is $i$, hence $f(z)=iz^{n}$.   But what about the $n$ here, is it arbitrary? Could somebody help me prove the removability of the singularities and suggest if my attempt is going the right way? Why does a find field value in one application show up in a the find field of another application? On my MacBook Pro I have found that several applications seem to share the value for a find.  For example, I searched 'applestackexchange' in Safari's unified address bar, then I switch to Xcode and click into a Find field.  The first word of my search in Safari then appears there.  iTerm2 and Sublime Text 2 also seem to participate in this sharing.  Running latest Mountain Lion on  a 2012 MBP. Windows registry entries for default explorer view Can I block incoming calls using wildcard patterns? Recently I have been getting a few unwanted telemarketing calls, all coming from the same source. Each number though is different at the end.  For instance, if the numbers to be blocked are:    123-4567 123-7642 123-8643   It would be convenient for the future to simply block with a wildcard, such as:   123-*   Is this at all possible? Integrating Knowledge into an existing website What is the non-parametric equivalent of a two-way ANOVA that can include interactions? Calculating $1+\frac13+\frac{1\cdot3}{3\cdot6}+\frac{1\cdot3\cdot5}{3\cdot6\cdot9}+\frac{1\cdot3\cdot5\cdot7}{3\cdot6\cdot9\cdot12}+\dots? $ I have Ubuntu 14.04 installed on my laptop. Can I clone the entire system with apps, settings, etc on a USB 3 pendrive, and then boot from that on other computers as a portable Ubuntu installation to take around with me?  I am trying a function that Timeshift has that's called "Clone the current system on another device". I've selected the pendrive as the target device. Timeshift was talking about this being bootable. But is it going to bootable on only this laptop, or on any system? For example, on an Intel Mac, or a Windows computer without the grub bootloader? Is that Timeshift function what I am looking for, or do I have to do something else?  Edit: The Timeshift clone failed to boot on the first system I tested it on. (A Dell Hackintosh that usually boots from USB just fine.) Using C++ library in C code I have a C++ library that provides various classes for managing data.  I have the source code for the library.  I want to extend the C++ API to support C function calls so that the library can be used with C code and C++ code at the same time.  I'm using GNU tool chain (gcc, glibc, etc), so language and architecture support are not an issue.  Are there any reasons why this is technically not possible?  Are there any gotcha's that I need to watch out for?  Are there resources, example code and/or documentation available regarding this?    Some other things that I have found out:   Use the following to wrap your C++ headers that need to be used by C code.     #ifdef __cplusplus extern "C" {   #endif   //   // Code goes here ...   //   #ifdef __cplusplus   } // extern "C"   #endif    Keep "real" C++ interfaces in separate header files that are not included by C.  Think  here.  Using #ifndef __cplusplus #error stuff helps here to detect any craziness. Careful of C++ identifiers as names in C code Enums varying in size between C and C++ compilers.  Probably not an issue if you're using GNU tool chain, but still, be careful. For structs follow the following form so that C does not get confused.  typedef struct X { ... } X  Then use pointers for passing around C++ objects, they just have to be declared in C as struct X where X is the C++ object.   All of this is courtesy of a friend who's a wizard at C++. How do I get a really wide tilde?  I need to cover at least  abcdefghijklmnopqrstuvwxyz  The \widetilde command does not work. Nor using \stackrel with \sim. Is it safe to delete the file Caches, in the Library of the Mac OS X Hard Drive?  It's a pretty big file, 3.56 GB, Caches reminds me of logs i don't need or browser cookies.   Is it safe to delete the folder "Caches"? Simple question, but one that I've been curious about...is there a functional difference between the following two commands?  String::class String.class   They both do what I expect -- that is to say they return Class -- but what is the difference between using the :: and the .?  I notice that on those classes that have constants defined, IRB's auto-completion will return the constants as available options when you press tab after :: but not after ., but I don't know what the reason for this is... notify-send not working under ssh I am a US citizen and have recently visted the UK  with simply a passport which allowed me to vist for 6months I have heard rumors that I am obligated to stay in the US for a Equal amount of time that I have visited the UK before I am able to return, but I am struggling tour no any proof of this obligation .. Am I missing somthing or is it simply not true Is time dilation an illusion? It is said that we can verify time dilation by flying a very accurate clock on a fast jet or spaceship and prove that it registers less time than the clocks on earth. However, the clocks on earth would be moving relative to the clock on the spaceship, and since time always dilates and never goes faster regardless of the direction of relative motion,  the clocks on earth should register less time than the clock on the spaceship.  Is this true? Whenever there is a fast-moving object such as a rocket do all clocks on earth really become slow?  If the rocket with the clock landed after moving at relativistic speed, would its clock and the earth's clock again show the same time since during its travel both appeared slow to each other?  Or is all this just an illusion, ie. the clocks just appear to be slow to each other but in actually run at normal speed, and neither is behind when the rocket actually lands?