Java API for web scraping or web mining
What are the pros and cons of the leading Java HTML parsers?
Is past simple ever justified with 'by'? Can anyone shed some light on the following aspect?  By 5 PM I gave him the book.  By 5 PM I had given him the book.  In both the sentences the book was given before 5 PM and no later than 5 PM. But I can't understand then what the difference between them is. a Also is it right to use simple past with 'by' at all? If yes, then why and if not, then why is it incorrect to use simple past with 'by'? Helping someone climb I know this is kinda stupid but what is the word for "helping someone climb by allowing him to stand on your hands" (to allow him/her see above some wall or climb something)? Did Spike get his reflection back with his soul? How can I invert a 'clip' selection within TikZ? I wish to draw an arc for a reflex angle on the outside of a triangle with coordinates (A), (B) and (C).  If I wanted to draw the arc inside the triangle I could use something like  \begin{scope} \path[clip] (A) -- (B) -- (C) -- cycle; \draw (B) circle (2mm);    % this is the little angle marker \end{scope}   Is there a straightforward way to exclude the part of the circle that's in the triangle, as in the pseudo-code below?  \begin{scope} \path[magicalinverseclipcommand] (A) -- (B) -- (C) -- cycle; \draw (B) circle (2mm);    % this is the little angle marker \end{scope}   EDIT: Although I included the code above as a motivating example of what an inverse clip would do, I would prefer a general solution that works systematically with any closed path, and not just in the particular example of a triangle with a circle clipped out of it. Looking at my question, I realise this isn't clear, and I will be happy with the best solution to my particular problem, but wonder if there is a less ad hoc solution than those listed so far. How do I play Minecraft with people online, besides using a server? I have a directory with ~1M files and need to search for particular patterns. I know how to do it for all the files:  find /path/ -exec grep -H -m 1 'pattern' \{\} \;   The full output is not desired (too slow). Several first hits are OK, so I tried to limit number of the lines:  find /path/ -exec grep -H -m 1 'pattern' \{\} \; | head -n 5   This results in 5 lines followed by  find: `grep' terminated by signal 13   and find continues to work. This is well explained . I tried quit action:  find /path/ -exec grep -H -m 1 'pattern' \{\} \; -quit   This outputs only the first match.  Is it possible to limit find output with specific number of results (like providing an argument to quit similar to head -n)? Sharepoint 2010 - Deploy webpart as Feature scope = web Updating inherited property Creating a virtual microphone What are some examples of induction where the base case is difficult but the inductive step is trivial? According to :     ...proofs by mathematical induction   have two parts: the "base case" that   shows that the theorem is true for a   particular initial value such as n = 0   or n = 1 and then an inductive step   that shows that if the theorem is true   for a certain value of n, it is also   true for the value n + 1. The base   case is often trivial and is   identified as such, although there are   cases where the base case is difficult   but the inductive step is trivial.   What are some examples of proofs by induction where the base case is difficult but the inductive step is trivial? How does negation affect the use and understanding of "or" and "and" I'm trying to make more sense of how negation effects how a sentence is parsed and understood if and's and or's are used within them.  Pop quiz: You are trapped on a bus with a bomb going 50 MPH. You have a radio... (okay enough Keanu Reeves references) :-)  Let's say the bomb expert says "Don't cut the red or green wires." I think that means "Do not cut the wires colored red. Do not cut the wires colored green."  Now, let's say the bomb expert said on the radio "Do not cut the red and green wires", instead. Do I take that to mean:     "Do not cut the wires colored red. Do not cut the wires colored green."   OR     "Do not cut the wires whose insulation has red and green stripes." ?   OR     "It's okay to cut the wires colored red or the wires colored green, as long I don't cut one of each color."   Which meaning should I take if the radio breaks and I can't ask follow up questions? If a set is $F_\sigma$ and is of first category then it is a countable union of closed nowhere dense sets We say a set is $F_\sigma$ if it is a countable union of closed sets. We say a set is of first category if it is a countable union of nowhere dense sets.  The question is, if a set of $F_\sigma$ and of first category, is it true that this set is a countable union of closed nowhere dense sets. I have the following functional equation. Find all continuous functions $f:(-1,1) \to \mathbb R$ such that $$ f(x+y)=\frac{f(x) + f(y)}{1 - f(x)f(y)} $$ The first obvious solution is $f(x) \equiv 0$. Another one I guessed, it is $f(x) = \pm \tan x$. I suspect, that there are no more solutions. The problem is that I don't know how to prove that.  Since we have a rational equation, I have no idea how to make any substitutions in order to get expression for $\tan x$ (as it is not a rational expression).  P.S. I can also show that it is true that (a) $f(0) = 0$ (take $x=y=0$), and (b) $f(-x) = -f(x)$ (take $y=-x$).  Update: there is a solution of this problem also here: Collection was modified; enumeration operation may not execute I can't get to the bottom of this error, because when the debugger is attached, it does not seem to occur.  Collection was modified; enumeration operation may not execute  Below is the code. This is a WCF server in a Windows service. The method NotifySubscribers() is called by the service whenever there is a data event (at random intervals, but not very often - about 800 times per day). When a Windows Forms client subscribes, the subscriber ID is added to the subscribers dictionary, and when the client unsubscribes, it is deleted from the dictionary. The error happens when (or after) a client unsubscribes. It appears that the next time the NotifySubscribers() method is called, the foreach() loop fails with the error in the subject line. The method writes the error into the application log as shown in the code below. When a debugger is attached and a client unsubscribes, the code executes fine. Do you see a problem with this code? Do I need to make the dictionary thread-safe? [ServiceBehavior(InstanceContextMode=InstanceContextMode.Single)] public class SubscriptionServer : ISubscriptionServer {     private static IDictionary&lt;Guid, Subscriber&gt; subscribers;      public SubscriptionServer()     {                     subscribers = new Dictionary&lt;Guid, Subscriber&gt;();     }      public void NotifySubscribers(DataRecord sr)     {         foreach(Subscriber s in subscribers.Values)         {             try             {                 s.Callback.SignalData(sr);             }             catch (Exception e)             {                 DCS.WriteToApplicationLog(e.Message,                    System.Diagnostics.EventLogEntryType.Error);                  UnsubscribeEvent(s.ClientId);             }         }     }          public Guid SubscribeEvent(string clientDescription)     {         Subscriber subscriber = new Subscriber();         subscriber.Callback = OperationContext.Current.                 GetCallbackChannel&lt;IDCSCallback&gt;();          subscribers.Add(subscriber.ClientId, subscriber);                  return subscriber.ClientId;     }      public void UnsubscribeEvent(Guid clientId)     {         try         {             subscribers.Remove(clientId);         }         catch(Exception e)         {             System.Diagnostics.Debug.WriteLine(&quot;Unsubscribe Error &quot; +                      e.Message);         }     } } How does remittance work? How does it differ from direct money transfer? I have a bank account in Germany in which I receive my salary in Euros. I want to deposit a part of it in my Indian bank account for personal savings. My Indian bank account is in INR. As I see it, I have two options:   To use a remittance service that converts my Euros into INR and deposits in my account. I am not sure how it works. The service (which I know is reliable) I signed up for asks me to deposit Euros in a certain account ("funding") which will be converted to INR and deposited in my account. How does that work exactly? Use my bank's service to make a international bank transfer to my account. Is that even possible, given that my Indian account is in INR? Will I incur higher conversion fees and lower exchange rate?   In general, what are the pros and cons of each of the above methods? And are there any other methods? Is there any way to create a simple txt file without opening the terminal? Is there any way to create a text file without using the terminal at all? Integral Representation of the Zeta Function: $\zeta(s)=\frac1{\Gamma(s)}\int_{0}^\infty \frac{x^{s-1}}{e^x-1}dx$ How does one get from this $$\zeta(s)=\sum_{k=1}^{\infty}\frac1{k^s}$$ to the integral representation $$\zeta(s)=\frac1{\Gamma(s)}\int_{0}^\infty \frac{x^{s-1}}{e^x-1}dx$$ of the Riemann Zeta function?  I can see that it can be rewritten as  $$\Gamma(s)\zeta(s)=\int_{0}^\infty \frac{x^{s-1}}{e^x-1}dx$$ and the Gamma function as an integral yields  $$\zeta(s)\int_{0}^\infty \frac{x^{s-1}}{e^x}dx=\int_{0}^\infty \frac{x^{s-1}}{e^x-1}dx$$  But this approach does not work as the right integral does not converge.  So how does one go from the summation to the integral representation? What is the difference between a directory name that ends with a slash and one that does not? Is there any difference between a directory name such as  mydirectory   and  mydirectory/   I noticed this happens when I execute ls in some directories - some of the directory names have a slash and some don't. This is problematic because if I want to access a file contained in a directory, I may need to add a slash at the end:  vi $mydirectory"/"$myfile   or simply do   vi $mydirectory$myfile How to pronounce "Moderators's"? If I want to use the plural of &quot;moderator&quot; and also add the apostrophe plus S, how do I pronounce it? How do native speakers pronounce it?  Moderators = moderatorz Moderators's = moderatorziz or just moderatorz?  A sentence is:  &quot;I always thought that moderators's decisions seemed fairly arbitrary.&quot;   I guess moderatorziz is correct but it sounds weird to me. Do native speakers pronounce it as moderatorziz? I've been trying to solve the following problem:  Suppose that $f$ and $f&#39;$ are continuous functions on $\mathbb{R}$, and that $\displaystyle\lim_{x\to\infty}f(x)$ and $\displaystyle\lim_{x\to\infty}f&#39;(x)$ exist. Show that $\displaystyle\lim_{x\to\infty}f&#39;(x) = 0$.  I'm not entirely sure what to do. Since there's not a lot of information given, I guess there isn't very much one can do. I tried using the definition of the derivative and showing that it went to $0$ as $x$ went to $\infty$ but that didn't really work out. Now I'm thinking I should assume $\displaystyle\lim_{x\to\infty}f&#39;(x) = L \neq 0$ and try to get a contradiction, but I'm not sure where the contradiction would come from.   Could somebody point me in the right direction (e.g. a certain theorem or property I have to use?) Thanks