I'm pretty new to Ubuntu. I just want to open the most common ports namely   FTP (port 20 TCP/UDP) HTTP (port 80 TCP/UDP) SMTP (port 25 TCP) ETC   I've tried all the ways in iptables, ufw, and gufw.  In the end, it still remains unchanged with the same error:  Connection refused.  I can't even access the home page on HTTP port: 80 from the other device.
My SoulSeek client Nicotine+ checks my open ports during initial configuration and promts that the one port number it needs is closed, cutting me off frmo about 50% of the users. Is there anyway I can open that particular port for the application to use?  RUnning ubuntu desktop 13.04. I have not manually installed any firewalls, but not sure if its included in the default installation.
Working with objects created with Activator.CreateInstance Math mode macro in TeXstudio I want to set up a macro in TeXstudio for math mode which displays $*$ and places the cursor at position *. So far I have tried using $%|$ but upon triggering, this macro does not allow text insertion at the placeholder.  EDIT: The method above works fine if the macro shortcut is set to the default Shift+F1. However, changing the shortcut to another combination, as I would like to do, seems to be the cause of the problem. When I try to create a reaction from chemmacros/reactions I got the following error. I dunno what I am missing. Please help. Thank you.     line 11: Undefined control sequence. \end   line 11: Missing number, treated as zero. \end   line 11: Missing number, treated as zero. \end     Minimum Working Example    \documentclass[12pt,a4paper]{article} \usepackage{chemmacros} \chemsetup{modules={reactions}} \begin{document} \begin{reaction}     A + B -&gt; C \end{reaction} \end{document} I have a bunch of Spring beans which are picked up from the classpath via annotations, e.g.  @Repository("personDao") public class PersonDaoImpl extends AbstractDaoImpl implements PersonDao {     // Implementation omitted }   In the Spring XML file, there's a  defined:  &lt;bean id="propertyConfigurer"    class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"&gt;     &lt;property name="location" value="/WEB-INF/app.properties" /&gt; &lt;/bean&gt;    I want to inject one of the properties from app.properites into the bean shown above. I can't simply do something like   &lt;bean class="com.example.PersonDaoImpl"&gt;     &lt;property name="maxResults" value="${results.max}"/&gt; &lt;/bean&gt;   Because PersonDaoImpl does not feature in the Spring XML file (it is picked up from the classpath via annotations). I've got as far as the following:  @Repository("personDao") public class PersonDaoImpl extends AbstractDaoImpl implements PersonDao {      @Resource(name = "propertyConfigurer")     protected void setProperties(PropertyPlaceholderConfigurer ppc) {     // Now how do I access results.max?      } }   But it's not clear to me how I access the property I'm interested in from ppc? $M= \{ A \in Mat_{2 \times 2}{\mathbb{R}}| \det(A)=1 \}$ is homeomorphic to $S^{1} \times \mathbb{R}^{2}$ How to report issues with the mobile SE application How to extract code of .apk file which is not working? Proving which QM interpretation is correct Let's assume that the existence of gravitons is theoretically proven or they are detected by LHC could one interpretaion be proven correct? Plotting the function $f(x)=x^{1/3}$ defined for any real number $x$ gives us:   Since $f$ is a function, for any given $x$ value it maps to a single y value (and not more than one $y$ value, because that would mean it's not a function as it fails the vertical line test). This function also has a vertical tangent at $x=0$.   My question is: how can we have a function that also has a vertical tangent? To get a vertical tangent we need 2 vertical points, which means that we are not working with a "proper" function as it has multiple y values mapping to a single $x$. How is it possible for a "proper" function to have a vertical tangent?  As I understand, in the graph I pasted we cannot take the derivative of x=0 because the slope is vertical, hence we cannot see the instantaneous rate of change of x to y as the y value is not a value (or many values, which ever way you want to look at it). How is it possible to have a perfectly vertical slope on a function? In this case I can imagine a very steep curve at 0.... but vertical?!? I can't wrap my mind around it. How can we get a vertical slope on a non vertical function? I used to find color codes which I want to use for texts or background colors on htmls with color edit tool of MS paint which pre-installed on Windows. But now I use Mac instead of Windows. How can I find color codes with Mac? Is an software like MS paint pre-installed on Mac? CPU Die temperatures reaches 90° C, is that normal? How to dismiss the Windows 8.1 Upgrade banner? For f continuous on $[0,1]$, show that there exist points $\alpha_k$ such that $\sum \limits_{k=1}^n \frac{1}{f'(\alpha_k)} = n $ Suppose that $f$ is continous on $[0,1]$ , differentiable on $(0,1)$ , and $f(0)=0$ and  $f(1)=1$.For every integer $n$ show  that there must exist $n$ distinct points $\alpha_1,\alpha_2\cdots,\alpha_n$ in that interval so that    $\sum \limits_{k=1}^n \frac{1}{f'(\alpha_k)} = n $   Is it theorem or i can show it with basic differentiation knowledge .Please give me hint . Probability that a k digit number does not contain certain digits How do I print an IFrame from javascript in Safari/Chrome Can someone please help me out with printing the contents of an IFrame via a javascript call in Safari/Chrome.  This works in firefox:  $('#' + id)[0].focus(); $('#' + id)[0].contentWindow.print();   this works in IE:  window.frames[id].focus(); window.frames[id].print();   But I can't get anything to work in Safari/Chrome.  Thanks  Andrew What's the term for design ala "object.method1().method2().method3()"? What's the term for this design?  object.method1().method2().method3()   ..when all methods return *this?  I found the term for this a while ago, but lost it meanwhile. I have no clue how to search for this on google :) Also if anyone can think of a better title for the question, feel free to change it.  Thanks  Update-Gishu: After reading about it, I feel that your question is misleading w.r.t. code snippet provided.. (Feel free to rollback)  Method Chaining  object.method1().method2().method3()   Fluent Interfaces  private void makeFluent(Customer customer) {         customer.newOrder()                 .with(6, "TAL")                 .with(5, "HPK").skippable()                 .with(3, "LGV")                 .priorityRush();     } Flattening a shallow list in Python How to setup a restricted SFTP server on Ubuntu? I would like to know how to set up root, sudo, sftp-only user accounts which won't be required public key authentication at log in. I would also like to know how to set up sftp-only users' home directories where they can't access upper level other directories. Like the title said, I want to install Celestia. I already downloaded the packages  and then, I tried all the things that I found on some posts (also, they're outdated, cause the last one is for Ubuntu 16.04) but nothing works.  How can I install it on Ubuntu 18.04.1? how to fill intersection of 2 shapes in latex tikz package I have to fill a specific region as given in the following figure.  The code I have written is   \begin{tikzpicture}  \draw (0,0) rectangle (10,10);  \draw (3.5,3.5) circle (5) node {A};  \end{tikzpicture}   Now, how to fill the intersecting area (area of circle overlapping the square)