Its just a problem with installing the printer from Epson using the configure printer program. It just freezes half way through instillation.    I've been working on this problem or ages now I've tried everything from un-installing Software centre and Configure Printer programs. Each time it just stalls, then when I look in Software centre i can see packages half way installed. I've ran every script I can get my hands on.  What is the command to find what the problem/error is? It started when I accidentally rebooted half way through its original install   Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) E: Unable to lock directory /var/lib/apt/lists/  once I clear this problem it occurs again when I try and Install the printer.
I just installed Ubuntu 13.10, and I can't configure my wi-fi Epson TX430W printer.  Using the Settings-&gt;Printers interface, I can detect the printer. When I click add, I briefly see a "Searching for drivers" dialog. It dissapears, and then I'm left with the printer forever in "Installing" status.  If I close the window and reopen Printers, it doesn't show up on the list.  How can I solve, or at least diagnose the problem?
I'm trying to align a legend inside a table caption, so that the colons are vertically aligned. I can do it with the align ambient outside of the caption, but if I use the same code inside the caption the pdf won't compile (I use LuaTeX to compile). I'm using the package caption.  EDIT: i want something like this:    for which i've written this code:  \begin{align} \begin{split} a : {} &amp; the~first~letter~of~the~alphabet \\ b : {} &amp; the~second~one \\ and : {} &amp; so~on \end{split} \end{align}   There might be a more elegant way... but i don't know it.  Anyway, I can't do it inside the caption, that's why i'm stuck. The statement is:     In a commutative ring with 1, every proper ideal is contained in a maximal ideal.   and we prove it using Zorn's lemma, that is, $I$ is an ideal, $P=\{I\subset  A\mid A\text{ is an ideal}\} $, then by set inclusion, every totally ordered subset has a bound, then $P$ has a maximal element $M$.  My question is why $M$ must contain $I$? How does one type Chinese in LaTeX? Emacs text-scale-adjust causes line numbers column to incrementally shrink and disappear I've set up emacs to display line numbers (global-linum-mode 1), and it works until I start enlarging the text via text-scale-adjust    The line numbers column starts to shrink, and disappears entirely after a few increments. When it has fully disappeared, further increments have no more effect on the left edge.    Is this a know issue? Is there a workaround?    Using GNU Emacs 23.1.1 in Ubuntu 10.04. Is it acceptable to use "Just wondering" as a question? I often find myself writing sentences such as: "I am wondering if the landlord replied to you yet?"  And I always end up removing the question mark and rephrasing the sentence. In speech it is easy to inflect such a sentence so as to infer that it is a question, but in reality "I am wondering" is a statement and I feel it should not have a question mark when written down.  So is it acceptable to use "I am wondering" as a question? How to show that there is an element of order $51$ in the multiplicative group $(Z/103Z)^∗.$  I can't use Cauchy's theorem since $51$ is not prime. Trying to find vehicles which are free between 2 variable dates Faculty positions: What to say in a statement on diversity? Is there a way to prevent those pesky .DS_Store files from being ever created? Is there a way (eg. a binary hack into Finder) to stop it from creating .DS-Stores on LOCAL Volumes?   I am using Leopard, therefore these don't work:    (requires Lion)  (requires Snow Leopard)   Also,  slows down my computer. What resolution should a large format artwork for print be? How can I create a new extensible symbol? Given an arbitrary thin vertical symbol, can I create a new math delimiter from it (and if so, how)?   Edit: Ideally, I would like to be able to create an extensible symbol, either built out an existing normal symbol, or even made from scratch.  Edit 2: I am pretty sure that what I am after is an explanation of how to create a .tfm file for an extensible symbol (which Werner's answer describes the general structure of, but not how to make one).    For example, let's say I wanted to use the \dagger () or \wr () symbol as a delimiter, and write expressions like    \[\left\ldagger \sum_{n=1}^\infty a_n \right\rdagger\]   where the symbol scaled appropriately. Would there be any distinction between declaring a symmetric delimiter (like \vert), as opposed to one that has inherently different "left" and "right" versions like [ and ]?  Now, even being unaware of the inner workings of TeX, I imagine that there has to be lots of information in the fonts for how a delimiter is to be scaled in different situations, and if I try to make my own delimiter, this information won't be present. Would I need to get deep into FontForge or equivalent to achieve my custom delimiters, or is there an easier way? Cleanest way to toggle a boolean variable in Java? Is there a better way to negate a boolean in Java than a simple if-else?  if (theBoolean) {     theBoolean = false; } else {     theBoolean = true; } I've been interested in non-standard analysis recently. I was reading up on it and noticed the following interesting comment on the , right after giving an example of a nonstandard differentiation:     The use of the standard part in the definition of the derivative is a rigorous alternative to the traditional practice of neglecting the square of an infinitesimal quantity... the typical method from Newton through the 19th century would have been simply to discard the $dx^2$ term.   I've never heard anything like this before, and really find it fascinating that Newton's method was to define the relation $dx^2 = 0$. If we actually formalize the above structure by taking $\mathbb{R}$ and adjoining an element $dx^2 = 0$ to it, we get the "dual numbers," isomorphic to the quotient ring $\mathbb{R}[x]/x^2$. I'd seen some things about how this algebra plays into automated differentiation algorithms for some computer software systems, but I've never heard anything about Newton directly working in this algebra. So I have a few questions:   Does anyone have more historical information on the way that Newton performed differentiation, and its relation to the dual numbers? Does anyone know how effectively real analysis can be formalized with the dual numbers? Does the resulting system play nice enough to develop all of the important modern results? If we start with $\mathbb{C}[x]/x^2$ instead, can we likewise develop complex analysis?   Since this idea is so simple, I'm very curious how powerful it is. I'm also curious if it has any major drawbacks too, since I'm not sure why anyone would mess with the foundational baggage involved in defining the hyperreals if this simple 2-dimensional real algebra could really do the trick. Can my commander ever not be my commander? Once and for all: Is there anything that can possibly be done to my commander that would cause it to cease being my commander?    All of these questions ask the same thing, but aren't general enough to be marked as a duplicate.      Is a commander still a commander if it gets turned into a forest?     Is a commander still a commander if it gets turned face down? Updating inherited property How can I monitor the memory usage? I have used top to see the memory usage at the moment. But I would like to monitor the memory usage over a period of time. E.g start monitoring and then execute a few commands, and final stop the monitoring and see how much memory that have been used during the period.  How can I do this on Ubuntu Server?  I guess I could start a cronjob every 5th second or so, and invoke a command that log the current memory usage in a textfile. But what command should I use to get the current memory usage in a format that is easy to log to a text file? I am under DDoS. What can I do? This is a  about DoS and DDoS mitigation.   I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth.  Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too!  This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own.  Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case.  It also goes away after a few hours.  Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening?  Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed.  As soon as I started it up again, this happened again and it crashed again.  How is that similar, and what can I do about it? Redefining \listoffigures and \listoftables as tables How do you address unknown peers in email? This is one bit of academic etiquette I'm not sure about. When I write to another researcher, a peer (we're both professors). I've never exchanged with before and never met him but I know of him (and he probably knows of me).  Erring on the side of formality, I write to him “Dear professor Mortimer”. I sign with my first name, because that's how I've always signed my emails (there's a formal signature block below, with full name and contact details) and I think it indicates a willingness to be called by my first name (which I prefer, but I don't want to force people one way or the other).  Is that going to be well received? Will people take the hint? Or should I just start using first names from the start? (it does sound weird to write “dear Philipp” to someone you don't know) I'm running CentOS 7.0 build 1503. I'm trying to search for commands I don't know the name of by searching the man descriptions for multiple keywords using AND (e.g. search for a command containing the both words "create" and "group" in the description).  So I came across the command apropos (which is an alias for man -k). The default behaviour when given multiple keywords is to return any command matching any of the keywords, which isn't what I want. According to the man page the option -a specifies using AND, to return matches only when all words match.  But this isn't what I'm seeing in practice, so I need some help here - e.g. using Centos 7, if I do:  apropos create user   I see a huge list of commands, seemingly matching any command with create or user in the description, as expected. Noting the list includes an entry for the command 'useradd (8) - create a new user...'.  If I do:  apropos -a create user   I only get 2 commands (environ and open). This is what I'm confused by - I would expect it to return the command 'useradd (8) - create a new user', because i can see from the previous search that command does contain those words in the description. Also the 2 returned commands don't obviously seem to be anything about creating users. What am I doing wrong? I'm sure it's something embarrassingly obvious, for that I apologise in advance.  Thanks