How can I solve "Media change: please insert the disc labeled"?
"media change: please insert the disc labeled" when trying to install Ruby on Rails
How would I connect to a proxy on Ubuntu Studio? So I am running Ubuntu Studio on my laptop and what do I do to connect to a proxy? I search for proxy and in network settings their is no PROXY tab. What are key words in the tabs to look for? Is there any Stack Exchange site where I can ask others to recommend me good web sites for solving specific problems?  For example I would like to know if there is any URL shortening website that can allow me to define the url.  For example instead of http://bit.ly/1gX2dD0 I would like it to be http://bit.ly/superflow - if "superflow" is not available then I will invent another word.  I can imagine that such services are paid but I don't need the link to last more than one day, and maybe there is such a website. On the moderator , the tooltip will display the text used for voting on a question; this is incorrect.   Steps to reproduce:   Cast a vote for or against any candidate Undo that vote   At this point, the tooltip content is changed, at least for that candidate.  See screenshots:           As you can see, the message doesn't quite fit here; these are certainly not questions. Proving the identity $\sum_{k=1}^n {k^3} = \big(\sum_{k=1}^n k\big)^2$ without induction I recently proved that  $$\sum_{k=1}^n k^3 = \left(\sum_{k=1}^n k \right)^2$$  using mathematical induction.  I'm interested if there's an intuitive explanation, or even a combinatorial interpretation of this property. I would also like to see any other proofs. How do I type Arabic text in Photoshop? I want to type Arabic text in Photoshop, but the text appears disjointed and the letters do not connect at all. For example محمد appears as م ح م د.   I'm using Photoshop CS6 on OSX Mountain Lion. Disable Tabbing in Firefox 3, Chrome 4 and IE8? Tabbed Browsing may be nice for reading news sites in one sitting, but I still think they are a usability nightmare if you need to keep the page open for a long time, e.g., for testing it while developing or as a reference for something.  The nice thing about the Windows Taskbar (before Windows 7 ) is that it's easy and natural to remember where things are. I can have 30 tabs in it, but because I know what each one is, I know where I have to click to open something - it's the most efficient way of working I've encountered so far.  Sadly, Tabbed Browsing completely breaks this efficiency because it is not possible to specifically click on a tab in the taskbar, I have to click on the browser, search the tab and then click it, which means at least 2 clicks.  Long story, short question: Is there an extension or setting to completely disable tabbing on Firefox 3, Chrome 4 and Internet Explorer 8 and have one Window/Taskbar entry for each open page? I know that in Chrome I can just drag a tab out of a Window to create a new one, but if there is a general way, that would be easier.  Edit: IE8 conveniently offers an option for that: Tools - Options - Tabs - Enable Tabbed Browsing. Can I use a custom Splash screen? The default Splash screens are cool, but I'd like to add some of my own work to remind me of how awesome I am (no, not really).    Is it possible to customize/change the splash screen? I've begun cooking Asian food in the past year or so, and in many Korean and Chinese beef recipes, I see instructions to soak beef in water. Just plain water, not salt water or anything. And every recipe seems to have a different  time - from 5 minutes to like, multiple hours.  I inquired about this and was given various reasons for this step, including "to remove the blood (because it is simply undesirable", "To remove the blood, because it gives the meat a bad taste" or "To soften the beef".  I'm wondering:   Does soaking meat in water really remove that much blood? How much of a flavor component is blood and why would it give it a bad taste (especially since i've never soaked beef before and I've like the taste just fine)? What is the action of solute-free water on a piece of beef immersed in it? Can it really tenderise it to any degree, or is there any osmosis occurring or other such physical/chemical action? I have an application which is a relatively old. Through some minor changes, it builds nearly perfectly with Visual C++ 2008. One thing that I've noticed is that my "debug console" isn't quite working right. Basically in the past, I've use AllocConsole() to create a console for my debug output to go to. Then I would use freopen to redirect stdout to it. This worked perfectly with both C and C++ style IO.  Now, it seems that it will only work with C style IO. What is the proper way to redirect things like cout to a console allocated with AllocConsole()?  Here's the code which used to work:  if(AllocConsole()) {     freopen("CONOUT$", "wt", stdout);     SetConsoleTitle("Debug Console");     SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_RED); }   EDIT: one thing which occurred to me is that I could make a custom streambuf whose overflow method writes using C style IO and replace std::cout's default stream buffer with it. But that seems like a cop-out. Is there a proper way to do this in 2008? Or is this perhaps something that MS overlooked?  EDIT2: OK, so I've made an implementaiton of the idea I spelled out above. Basically it looks like this:  class outbuf : public std::streambuf { public:     outbuf() {         setp(0, 0);     }      virtual int_type overflow(int_type c = traits_type::eof()) {         return fputc(c, stdout) == EOF ? traits_type::eof() : c;     } };  int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) {     // create the console     if(AllocConsole()) {         freopen("CONOUT$", "w", stdout);         SetConsoleTitle("Debug Console");         SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_RED);       }      // set std::cout to use my custom streambuf     outbuf ob;     std::streambuf *sb = std::cout.rdbuf(&amp;ob);      // do some work here      // make sure to restore the original so we don't get a crash on close!     std::cout.rdbuf(sb);     return 0; }   Anyone have a better/cleaner solution than just forcing std::cout to be a glorified fputc? I have a table similar to this:  CREATE TABLE example (   id integer primary key,   name char(200),   parentid integer,   value integer);   I can use the parentid field to arrange data into a tree structure.  Now here's the bit I can't work out. Given a parentid, is it possible to write an SQL statement to add up all the value fields under that parentid and recurse down the branch of the tree ?  UPDATE: I'm using posgreSQL so the fancy MS-SQL features are not available to me. In any case, I'd like this to be treated as a generic SQL question.  BTW, I'm very impressed to have 6 answers within 15 minutes of asking the question! Go stack overflow! When I'm on my mod site I have my diamond dropdown:    But on Meta.SE and other sites, I have the StackBurger:    This doesn't show on my mod site, so I can't switch between sites easily. Are the PUT, DELETE, HEAD, etc methods available in most web browsers? I've seen a couple questions around here like , which mentions:     Unfortunately that same browser won't allow me to test HTTP PUT, DELETE, and to a certain degree even HTTP POST.   I've also heard that browsers support only GET and POST, from some other sources like:        However, a few quick tests in Firefox show that sending PUT and DELETE requests works as expected -- the XMLHttpRequest completes successfully, and the request shows up in the server logs with the right method. Is there some aspect to this I'm missing, such as cross-browser compatibility or non-obvious limitations? What's the last character in a file? I just read the answers to  and everyone said to delete the last character. My question is,  isn't the eof character the last one? Do muggleborns get their letter on their 11th birthday or the summer before they start Hogwarts? A lot of the fanfiction seems to like to give Hermione her letter in September to coincide with her birthday. That just doesn't seem very logical for the Statute of Secrecy, as you then have 10 out of every 12 10-year-old wizards and witches knowing about magic while finishing the school year (assuming even distribution of birthdays).   It seems to me that this is just asking at least one of them to brag about knowing magic and spill the secret.   Also this would mean that the poor kid born on 30 of August would only have 2 days to adjust to being magical before being shepherded off to a boarding school in the middle of nowhere.  From another point of view, getting such news on your birthday can screw up a lot of celebration plans.  Also, from rereading the memory from Dumbledore where he introduced magic to Tom, there is no mention of snow or even closeness to his birthday from the caretaker.  I believe this view came from the fact that Harry got his letter on his birthday but that piece of fanon seems to forget that letters were being sent up to at least a week or 2 beforehand (leading to the Dursleys hiding on a rock in the sea in the first place). Transparent text cut out of background How to Measure Luck vs Skill in Games? Label PGFPlot table points with coordinates I would like to label each plotted point with its x and y coordinate. I am able to label with a single one using the MWE below. I must avoid manually labeling each point since my actual table size is larger and will be changed out regularly. \documentclass{standalone}   \usepackage{tikz} \usepackage{pgfplots} \pgfplotsset{compat=1.16}  \begin{document}  \pgfplotstableread[col sep=&amp;,row sep=\\]{  x     &amp;  y     \\  0.940 &amp;  0.992 \\  0.992 &amp; -0.940 \\ -0.992 &amp;  0.940 \\ -0.940 &amp; -0.992 \\ }\mytable  \begin{tikzpicture}  \begin{axis}     \addplot+[only marks, nodes near coords]table[x=x,y=y,meta=x]{\mytable}; \end{axis}  \end{tikzpicture} \end{document}  which creates the following figure  The desired output is for each point to be labelled with both coordinates. For specific example the top left point would be labelled with &quot;(0.94, 0.992)&quot;. What was Stack Exchange 1.0? I've seen a few users mention that certain SE sites like  and  are unique, as they were originally created as Stack Exchange 1.0 sites.  As a fairly recent user, I don't know what Stack Exchange 1.0 was like. The current version of Stack Exchange is the only version I've ever known.   What was Stack Exchange 1.0? What changed between SE 1.0 and 2.0? Massive 404 attack with non existent URLs. How to prevent this? The problem is a whole load of 404 errors, as reported by Google Webmaster Tools, with pages and queries that have never been there. One of them is viewtopic.php, and I've also noticed a scary number of attempts to check if the site is a WordPress site (wp_admin) and for the cPanel login. I block TRACE already, and the server is equipped with some defense against scanning/hacking. However, this doesn't seem to stop. The referrer is, according to Google Webmaster, totally.me.  I have looked for a solution to stop this, because it isn't certainly good for the poor real actual users, let alone the SEO concerns.  I am using the Perishable Press mini black list (), a standard referrer blocker (for porn, herbal, casino sites), and even some software to protect the site (XSS blocking, SQL injection, etc). The server is using other measures as well, so one would assume that the site is safe (hopefully), but it isn't ending.  Does anybody else have the same problem, or am I the only one seeing this? Is it what I think, i.e., some sort of attack? Is there a way to fix it, or better, prevent this useless resource waste?  EDIT I've never used the question to thank for the answers, and hope this can be done. Thank you all for your insightful replies, which helped me to find my way out of this. I have followed everyone's suggestions and implemented the following:   a honeypot a script that listens to suspect urls in the 404 page and sends me an email with user agent/ip, while returning a standard 404 header a script that rewards legitimate users, in the same 404 custom page,  in case they end up clicking on one of those urls. In less than 24 hours I have been able to isolate some suspect IPs, all listed in Spamhaus. All the IPs logged so far belong to spam VPS hosting companies.   Thank you all again, I would have accepted all answers if I could. Can't install php5 on Ubuntu 16.04 so I've recently installed my first Ubuntu, to be precise, a daily build of 16.04, on my new laptop since the hardware was to new for 15.10. Now I'm in the process of setting it up and I want to install php5 and some extensions.  When I execute sudo apt-get install libapache2-mod-php5 I get the error message that there is no installation package available for php5 and libapache2.  The error message is in german, so I doubt that this would help, but anyways here it is. :-) E: For package »libapache2-mod-php5« existiert kein Installationskandidat.  Do I need to add a apt-get repository? Or what am I doing wrong?