I am unable to install git on my ubuntu 12.10 system. I followed-  sudo add-apt-repository ppa:git-core/ppa sudo apt-get update sudo apt-get install git-core   sudo apt-get update gives me the error-  Err http://security.ubuntu.com quantal-security/main amd64 Packages   404  Not Found Err http://security.ubuntu.com quantal-security/restricted amd64 Packages   404  Not Found Err http://security.ubuntu.com quantal-security/universe amd64 Packages   404  Not Found Err http://security.ubuntu.com quantal-security/multiverse amd64 Packages   404  Not Found  Err http://archive.ubuntu.com quantal-updates/main amd64 Packages   404  Not Found Err http://archive.ubuntu.com quantal-updates/restricted amd64 Packages   404  Not Found Err http://archive.ubuntu.com quantal-updates/universe amd64 Packages   404  Not Found Err http://archive.ubuntu.com quantal-updates/multiverse amd64 Packages   404  Not Found  Err http://archive.ubuntu.com quantal/main amd64 Packages   404  Not Found Err http://archive.ubuntu.com quantal/restricted amd64 Packages   404  Not Found Err http://archive.ubuntu.com quantal/universe amd64 Packages   404  Not Found Err http://archive.ubuntu.com quantal/multiverse amd64 Packages   404  Not Found   Then some failed to fetch errors and finally-  E: Some index files failed to download. They have been ignored, or old ones used instead.   When I run sudo apt-get install git, I get-  Building dependency tree        Reading state information... Done The following extra packages will be installed:   git-man liberror-perl Suggested packages:   git-daemon-run git-daemon-sysvinit git-doc git-el git-arch git-cvs git-svn   git-email git-gui gitk gitweb The following NEW packages will be installed:   git git-man liberror-perl 0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded. Need to get 6,800 kB/6,824 kB of archives. After this operation, 15.3 MB of additional disk space will be used. Do you want to continue [Y/n]? y WARNING: The following packages cannot be authenticated!   liberror-perl git-man git Install these packages without verification [y/N]? y Err http://archive.ubuntu.com/ubuntu/ quantal/main git-man all 1:1.7.10.4-1ubuntu1   404  Not Found Err http://archive.ubuntu.com/ubuntu/ quantal/main git amd64 1:1.7.10.4-1ubuntu1   404  Not Found Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/g/git/git-man_1.7.10.4-1ubuntu1_all.deb  404  Not Found Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/g/git/git_1.7.10.4-1ubuntu1_amd64.deb  404  Not Found E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?   I have just set up ubuntu and this is the first I tried installing. Please help.
Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc
Repeat String - Javascript During the end credit scene of Spider-Man: Far from Home, we see that,      Nick Fury and Maria Hill are two Skrulls, Talos and (presumably) his wife.   And we also see that,      Nick Fury is in a spaceship like structure, presumably away from Earth.   So that begs the question,      How long has Talos been impersonating Nick Fury? Is it since the events of Captain Marvel or since Avengers: Endgame or sometime in between? Drupal out of the box comes with a page (which is the default homepage) that is assigned to the node path.  How do I avoid users reach it, and redirect them to the actual homepage of the site? Easy way to write contents of a Java InputStream to an OutputStream I was surprised to find today that I couldn't track down any simple way to write the contents of an InputStream to an OutputStream in Java. Obviously, the byte buffer code isn't difficult to write, but I suspect I'm just missing something which would make my life easier (and the code clearer).  So, given an InputStream in and an OutputStream out, is there a simpler way to write the following?  byte[] buffer = new byte[1024]; int len = in.read(buffer); while (len != -1) {     out.write(buffer, 0, len);     len = in.read(buffer); } launchd plist format for running a command at a specific time on a weekday I am using Selenium 2/WebDriver for automation. I have a table and am trying to select a row in it. When the test runs, I can see the row become highlighted as if it is clicked, but then immediately I get the "org.openqa.selenium.StaleElementReferenceException: Element is no longer attached to the DOM" error and the test fails.  The code is the following:  @Test public void rowSelection() throws Exception {     SeleniumHelper helper = new SeleniumHelper();     action = new SeleniumActionHelper(driver);      helper.login();      String testUrl = navigateToUrl("option/listOptions.xhtml");     driver.get(testUrl);      WebElement table = findElementById("tableSection:dataTableWrapped_data");     List&lt;WebElement&gt; allRows = table.findElements(By.tagName("tr"));     for (WebElement row : allRows)         {             List&lt;WebElement&gt; cells = row.findElements(By.tagName("td"));             for (WebElement cell : cells)             {                 WebElement listName = cell.findElement(By.xpath("./* [text()='body_build']"));                 listName.click();             }         } }   I have put a Thread.sleep(2000) in front and after the listName.click() action, but neither has helped. Any help would be greatly appreciated. What are tag badges? How do they work? /dev/tcp not found When I try to run the following command:  echo -e "GET / HTTP/1.1\n\n" | /dev/tcp/74.125.225.19/80   I get the following error message:  bash: /dev/tcp/74.125.225.19/80: No such file or directory   The following command works perfectly, so the problem involves how I'm using /dev/tcp:  echo -e "GET / HTTP/1.1\n\n" | nc 74.125.225.19 80   I'm in Ubuntu 13.04, so the capability should be on my system. What am I doing wrong? What are the rules for using /dev/tcp properly? How can I set cron to run certain commands every one and a half hours? -I'm not a religious person so this is not a denial. I'm just trying to understand the most fundamental topic about Universe.  -I know the Big Bang cosmological model is not a law but it's a theory.  -I'm a non-Native English speaker so please let me know if the question is not clear for you.  -This question came to my mind after watching When should you use struct and not class in C#? My conceptual model is that structs are used in times when the item is merely a collection of value types.  A way to logically hold them all together into a cohesive whole.  I came across these rules :   A struct should represent a single value. A struct should have a memory footprint less than 16 bytes. A struct should not be changed after creation.   Do these rules work? What does a struct mean semantically? How to properly write multiple authors in bibtex file? I use  to store all articles I need and bibtex4word add-on (in MS Word) to maintain the reference list. So, I would like to know how to properly fill the "author" field in Jabref with multiple authors to appear them correct in the reference list.  For example, I've got the article with several authors:      E. Orti, J.L. Bredas, C. Clarisse   And I would like them to appear in this manner. But instead I get this:     C. C. E. Orti, J. L. Bredas Command and Conquer 3 exeption in exception handler I have command and conquer 3 from Origin, but when I try to start it, I get the 'exception in exception handler' error and the game exits.   I've tried the Origin launcher fix as well as -runver to make the game run a different version (although this just says that it can't find any version). I run Windows 10 (I know, experimental) but this game worked at one point, and then stopped working suddenly - there wasn't even an update in between.   I suspect that it's got to do with Origin, but any help would be appreciated. The difference between two periodic functions converges to zero, is this two functions identical? If $f(x)$ and $g(x)$ are two periodic functions, that is, $f(x+T_1)=f(x)$ and $g(x+T_2)=g(x)$ for every $x \in \Bbb R$. Now that $\displaystyle\lim_{x\to\infty}(f(x)-g(x))=0$.  Conjecture: $f(x) \equiv g(x)$. Error - SqlDateTime overflow. Must be between 1/1/1753 12:00:00 AM and 12/31/9999 11:59:59 PM Choice of $q$ in Baby Rudin's Example 1.1 First, my apologies if this has already been asked/answered.  I wasn't able to find this question via search.  My question comes from Rudin's "Principles of Mathematical Analysis," or "Baby Rudin," Ch 1, Example 1.1 on p. 2.  In the second version of the proof, showing that sets A and B do not have greatest or lowest elements respectively, he presents a seemingly arbitrary assignment of a number $q$ that satisfies equations (3) and (4), plus other conditions needed to show that $q$ is the right number for the proof.  As an exercise, I tried to derive his choice of $q$ so that I may learn more about the problem.  If we write equations (3) as $q = p - (p^2 - 2)x$, we can write (4) as   $$ q^2 - 2 = (p^2 - 2)[1 - 2px + (p^2 - 2)x^2]. $$  Here, we need a rational $x &gt; 0$, chosen such that the expression in $[...]$ is positive.  Using the quadratic formula and the sign of $(p^2 - 2)$, it can be shown that we need   $$ x \in \left(0, \frac{1}{p + \sqrt{2}}\right) \mbox{ for } p \in A, $$  or, for $p \in B$, $x &lt; 1/\left(p + \sqrt{2}\right)$ or $x &gt; 1/\left(p - \sqrt{2}\right)$.  Notice that there are MANY solutions to these equations! The easiest to see, perhaps, is letting $x = 1/(p + n)$ for $n \geq 2$.  Notice that Rudin chooses $n = 2$ for his answer, but it checks out easily for other $n$.  The Question:  Why does Rudin choose $x = 1/(p + 2)$ specifically?  Is it just to make the expressions work out clearly algebraically?  Why doesn't he comment on his particular choice or the nature of the set of solutions that will work for the proof?  Is there a simpler derivation for the number $q$ that I am missing? I've often come across posts on forums or other websites where you see people joking in such a manner about running/logging in as root as if it's something awful and everyone ought to know about it. However, there isn't much that a search reveals on the matter.   It may be widely known to Linux experts, but I really don't know why. I remember always running as root when I first tried Linux years ago (Redhat and Mandrake) and don't remember running into any problems because of that.   There are actually some distros that have a bright red background with alert signs all over it as wallpaper for the root user (SuSe?). I still use the "Administrator" account for regular use on my Windows installation and haven't ever run into any problems there either. If I seem tired, can I say: "I haven't slept last night"? If not, why have I been told that we use present perfect for actions that have present effects? I'm looking for some sample code that will sort the list items in an HTML list by alphabetical order.  Can anyone help?  Here is a sample list for people to work with:  &lt;ul class="alphaList"&gt;     &lt;li&gt;apples&lt;/li&gt;     &lt;li&gt;cats&lt;/li&gt;     &lt;li&gt;bears&lt;/li&gt; &lt;/ul&gt; How come unpolarized light does not undergo destructive interference?