I made Ubuntu 14.04 (64bit) in my VM and I gave it 350gb of my 1tb HDD space and I did it fixed (not dynamically allocated) and i did it as a VDI and in my settings I set it to read the space as a SSD. I gave it 2 processors with 2000mb which is low so I was going to set up about 20gb of swap and swappiness of 50.  I was going to follow this guide to set up swap:    This is what I got:  oggie7797@oggie7797-VirtualBox:~$ sudo swapon -s [sudo] password for oggie7797:  Filename                Type        Size    Used    Priority /dev/sda5                               partition   2044924 14344   -1 oggie7797@oggie7797-VirtualBox:~$ free              total       used       free     shared    buffers     cached Mem:       2000792    1741236     259556      25060      13084     349624 -/+ buffers/cache:    1378528     622264 Swap:      2044924      14344    2030580 oggie7797@oggie7797-VirtualBox:~$    As you can see, it shows that I have swap even though this is a fresh install and all I have done is install Chrome-dev browser. So, now that I have given as much information that I can think to give I hope that someone can help me figure out how to either delete and create a fresh swap of my desired size or just simply edit this mysteriously preexisting swap to a larger size. Thanks in advance! :)
I have, by default, 250MB of swap space in Ubuntu, and I want to expand it to a larger size. I need 800MB, which I think will be enough to open several applications without having to hit the current limit of swap. I hope someone can help me.
Can I get individual man pages for the bash builtin commands? Is there anywhere you can download a manpage for every builtin commands?  I know you can just use help or man bash and search to find info about it, but I want them separated, so I can just do man read and get the read manpage. I'm using an unsigned repo in Ubuntu 16.04 from Debian multimedia:  deb http://www.deb-multimedia.org jessie main   To install deb-multimedia-keyring, I'm running:  apt-get update &amp;&amp; apt-get install deb-multimedia-keyring -y   This gives an error:  W: GPG error: http://www.deb-multimedia.org jessie InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5C808C2B65558117 E: The repository 'http://www.deb-multimedia.org jessie InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. How to keep the console window open in Visual C++? I'm starting out in Visual C++ and I'd like to know how to keep the console window.  For instance this would be a typical "hello world" application:   int _tmain(int argc, _TCHAR* argv[]) {     cout &lt;&lt; "Hello World";     return 0; }   What's the line I'm missing? If two limits don't exist, are we sure the limit of sum doesn't exist? This is a true/false question.     If the limits $$\lim_ {x\to a}\ f(x)\quad \text{ and }\quad  \lim_ {x\to a}\ g(x)$$ don't exist, limits $$\lim_ {x\to a}\ (f(x)+g(x))\quad \text{ and }\quad \lim_ {x\to a}\ (f(x)g(x))$$ don't exist also.   My idea is, that, because $$\lim_ {x\to a}\ (f(x)+g(x))=\lim_ {x\to a}\ f(x)+\lim_ {x\to a} g(x)$$ then the limits doesn't exist, correct? Integral $ \int_{-\infty}^{\infty}\frac{x^{2}}{\cosh\left(x\right)}\,{\rm d}x $ I need to compute the improper integral $$ \int_{-\infty}^{\infty}\frac{x^{2}}{\cosh\left(x\right)}\,{\rm d}x $$ using contour integration and possibly principal values.  Trying to approach this as I would normally approach evaluating an improper integral using contour integration doesn't work here, and doesn't really give me any clues as to how I should do it. This normal approach is namely evaluating the contour integral $$ \oint_{C}{\frac{z^2}{\cosh\left(z\right)}\mathrm{d}z} $$ using a semicircle in the upper-half plane centered at the origin, but the semicircular part of this contour integral does not vanish since $\cosh\left(z\right)$ has period $2\pi\mathrm{i}$ and there are infinitely-many poles of the integrand along the imaginary axis given by $-\pi\mathrm{i}/2 + 2n\pi\mathrm{i}$ and $\pi\mathrm{i}/2 + 2n\pi\mathrm{i}$ for $n \in \mathbb{Z}$. The residues of the integrand at these simple poles are $-\frac{1}{4}\mathrm{i}\pi^{2}\left(1 - 4n\right)^{2}$ and $\frac{1}{4}\mathrm{i}\left(4\pi n + \pi\right)^{2}$, so that even when we add up all of the poles, we have the sum $4\pi^{2}\mathrm{i}\sum_{n = 0}^{\infty}\,n$, which clearly diverges.  Any hints would be greatly appreciated. I'm trying to load a field value (machine name: field_theme_image) from a content of node value 3, in "page--front.tpl.php".  &lt;?php   $node=node_load(3);   print $node-&gt;field_theme_image[$node-&gt;language][0]['uri']; ?&gt;   Using the above code I'm not getting full URL value. Please see the image below. I can see the path value in Devel themer. Up to now I don't understand well what \null actually is and when we need it. I have only known that it can be used to create hypothetical anchors as follows.  \documentclass{article} \usepackage[a6paper,margin=2cm]{geometry} \parindent=0pt  \begin{document} \hfill xport \hfill\null\\ \null\hrulefill{} never \hrulefill\par \hrulefill{} dies. \hrulefill\par \hfill really? \hfill\null\par   \newpage \null \vfill \hfill The End \hfill\null \end{document}    What is \null and when do we need to use it? Why do \hrulefill and \hfill need starting \null when they follow \\ but not need \null when they follow \par? Why does \hfill always need ending \null but \hrulefill not need it? If a topology contains all infinite subsets, then it is the discrete topology I am solving question $8$ of exercises in section 1.1. of chapter 1 in "Topology without tears". The question reads as follows.     Let $X$ be an infinite set and $\tau$ be a topology on $X$. If every infinite subset of $X$ is in $\tau$, prove that $\tau$ is the discrete topology   My idea was to show that every singleton set is in the topology and thereby the topology is discrete.  Choose an infinite set $A$ from $X$ such that $A^c$ is also infinite. $A$ and $A^c$ belong to $\tau$ since they are infinite sets. Now consider any $x \in X$. Note that $A \cup \{x\}$ and $A^c \cup \{x\}$ belong to $\tau$ since they are infinite sets. Hence, their intersection which is nothing but $\{x\} \in \tau$ for every $x \in X$.  The problem I have is I don't know how to prove the first sentence in the previous paragraph. These are my line of thoughts to prove them.   If $X$ is a countably infinite set, then I can list the elements are let the odd numbered elements fall into $A$. This guarantees $A$ and $A^c$ are both infinite. If $X$ is uncountable, then I can choose a countably infinite subset and call it $A$.   Are the above arguments rigorous? I am not especially happy with my second argument of choosing a countably infinite subset from an uncountable set since I do not give an explicit procedure of constructing the set $A$.  Also, is there any other simpler way of answering the original question? Prove that $\left(1+\dfrac{1}{1^3}\right)\left(1+\dfrac{1}{2^3}\right)\cdots\left(1+\dfrac{1}{n^3}\right)&lt;3$   for all positive integers $n$   This problem is copied from Math Olympiad Treasures by Titu Andreescu and Bogdan Enescu.They start by stating that induction wouldn't directly work here since the right hand side stays constant while the left increases.They get rid of this problem by strengthening the hypothesis.$$\left(1+\dfrac{1}{1^3}\right)\left(1+\dfrac{1}{2^3}\right)\cdots\left(1+\dfrac{1}{n^3}\right)\le3-\dfrac{1}{n}$$ and then proceed by induction.  The problem is that I can't find a motivation for the above change.I mean,we could have subtracted a lot of things from the RHS but what should nudge us to try $\dfrac{1}{n}$?The rest of the proof is quite standard,but I can't see how I am supposed to have thought of it.Is it just experience?Or is it a standard technique?A little guidance and motivation will be appreciated. This is the PATH variable without sudo:  $ echo 'echo $PATH' | sh  /opt/local/ruby/bin:/usr/bin:/bin   This is the PATH variable with sudo:  $ echo 'echo $PATH' | sudo sh /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/X11R6/bin   As far as I can tell, sudo is supposed to leave PATH untouched. What's going on? How do I change this? (This is on Ubuntu 8.04).  UPDATE: as far as I can see, none of the scripts started as root change PATH in any way.  From man sudo:      To prevent command spoofing, sudo   checks ``.'' and ``'' (both denoting   current directory) last when searching   for a command in the user's PATH (if   one or both are in the PATH). Note,   however, that the actual PATH   environment variable is not modified   and is passed unchanged to the program   that sudo executes. Question regarding the Fibonacci sequence Given the Fibonacci sequence $(F_1, F_2,F_3, ...)$ how do I prove that if $m|n$ then $F_m|F_n$? Can this be proven with mathematical induction? Using Georeference information stored in tfwx (from ArcGIS) in QGIS? I have georeferenced some images (ArcGIS -> Update Georeferencing) which creates a *.tfwx file with the new parameters for georeferencing.   I renamed it to *.tfw but QGIS is not able to read the georeferencing information.   Does anybody has any useful tips how to fix this? How often do publishers sue researchers for copyright infringement for putting their articles on a personal website? I know that some publishers sometimes send copyright infringement emails to researchers putting their articles on a personal website. How often do publishers actually sue researchers for copyright infringement for putting their articles on a personal website? (assuming the authors didn't have the legal right to do so)  I am mostly interested in United States-based authors, but I am curious about other countries as well. How to create wifi hotspot in Ubuntu 17.10 What recourse do I have if I believe a moderator has abused their privileges? How to send text to Notepad in C#/Win32? I'm trying to use SendMessage to Notepad, so that I can insert written text without making Notepad the active window.  I have done something like this in the past using SendText, but that required giving Notepad focus.  Now, first I'm retrieving the Windows handle:  Process[] processes = Process.GetProcessesByName("notepad"); Console.WriteLine(processes[0].MainWindowHandle.ToString());   I've confirmed it's the right handle for Notepad, the same shown within Windows Task Manager.  [DllImport("User32.dll", EntryPoint = "SendMessage")] public static extern int SendMessage(int hWnd, int Msg, int wParam, int lParam);   From here, I haven't been able to get SendMessage to work in all my experimentation.  Am I going in the wrong direction? How can I determine the current brew package count? I tried to get the number of available brew packages by running  brew search | wc -l   but I don't know how accurate this really is. What do I need to take into account to get a more correct number?  PS: macports lists 19,889 packages online I would like to have my whole document showing a blank line (or space) between paragraphs and no indentation. I know how to do it line by line, but is there a way to change that with just one or a few lines at the beginning of the document? Like a package you can install, or a new command? How to access the Index Of A Generic.List By Reflection? ok, ive a class and i pass an object as property.  the object that i pass is a List&lt;X&gt;  in my class im trying to access the Object index by reflection BUT I CAN'T!!!   Example:  this class works i just wrote down the part i want to show you and i need help.  class MyClass {     private object _recordSet;     public object RecordSet     {         get { return _recordSet; }         set { _recordSet = value; }     }      public string Draw()     {         system.reflection.Assembly asem = system.reflection.Assembly.getAssembly(_dataSource.GetType());          object instance;          instance = asem.CreateInstance(_dataSource.GetType().UnderlyingSystemType.FullName);          //to access de Count of my List         int recordcount = int.Parse(_dataSource.GetType().GetProperty("Count").GetValue(_dataSource,null));          //i need to do a          for(int cont = 0; cont &lt; recordCount; cont++)         {             _dataSource[cont].Name; // &lt;-- THIS PART IS NOT WORKING!!! because i cant access the Index Directly.... WHAT TO DO!! ???         }     } } Why is torque a cross product? If I'm not wrong, torque is perpendicular to both the radius and force i. e. It is along the axis of rotation. Questions that arise are- why do we consider the length between the axis/point of rotation while calculating torque? More importantly why is torque a cross product?