I am sorry if the question is already repeated as i did not find suitable answer in stack overflow.  I have written a code for automatic sending of email when the count should be less than 20.  The code seems to compile and run in Eclipse. but when i try to run in the Linux terminal I am getting an error     Can any of you help me?
I am getting a NoClassDefFoundError when I run my Java application.  What is typically the cause of this?
Why should I use an Initialization Vector (IV) when I have unique keys? I took a look at  but my question is not the same.  I have unique keys encrypting each plaintext (in CBC mode, AES-256) and I do not use a key to encrypt more than one plaintext. Is it insecure to use null IVs in this case? If it is insecure, why? Is infinite scrolling justifiable? Recently I've noticed a new trend in user interfaces. Facebook and Twitter do this, and I've come across it on other random, less famous sites. However, to keep things simple, I'll just use Facebook as an example.  When you first log into Facebook, you are presented with a "News Feed" that has a certain amount of posts from your friends. The feed extends down past the bottom of the viewport.  Then, when you scroll down, to see the feeds "below the fold", at some point as you move downward, it loads in more items. Apparently, this is called "infinite scrolling".  On my computer, this often causes my position in the feed to jump while I'm in the action of scrolling, which is really annoying.  What's particularly egregious about this UI concept is that there is footer information at the bottom of the page. I advertise on Facebook, and use the link at the bottom of the page to get to the advertisement management interface.  Because of this incremental load feature I'm describing, I often scroll down to the bottom to get to the link I want, when I reach the bottom of the page, it will suddenly load in new data, pushing the footer down again, and I have to scroll down again.  This whole thing seems completely pointless to me. What's the upside? A Facebook page is near a megabyte of data, so saving the few extra kilobytes of feed data for when the user scrolls down is just not worth it.  What's wrong with a link that just says "show more"?  Since this additional data retrieval thing seems to happen as soon as I start scrolling even a little anyway, why not just load that data in the first place?  To me this minor annoyance reeks of some engineers concept of a "neat trick" that does not have any actual appreciable upside.  Or am I wrong about that? Is there an advantage that I'm not seeing? Am I the only one who thinks it's stupid? Do some people like it? Drupal 7. Custom module. I have a content type 'RFI' with a handful of fields I created with Drupal UI. I want a user to: fill out a form &amp; click submit while drupal: saves fields to database, creates a new node of 'RFI' and populates the fields of the node with the content provided by the form's corresponding fields.  From what I understand:  Build a form with fields (taking from the 'DBTNG examples' module just for clarity):  function rfi_build_form($form, &amp;$form_state) { $form = array();  $form['add'] = array( '#type'  =&gt; 'fieldset', '#title' =&gt; t('Add a person entry'), ); $form['add']['name'] = array( '#type'  =&gt; 'textfield', '#title' =&gt; t('Name'), '#size'  =&gt; 15, ); $form['add']['surname'] = array( '#type'  =&gt; 'textfield', '#title' =&gt; t('Surname'), '#size'  =&gt; 15, ); $form['add']['age'] = array( '#type'  =&gt; 'textfield', '#title' =&gt; t('Age'), '#size'  =&gt; 5, '#description' =&gt; t("Values greater than 127 will cause an exception. Try it - it's a    great example why exception handling is needed with DTBNG."), ); $form['add']['submit'] = array( '#type'  =&gt; 'submit', '#value' =&gt; t('Add'), ); return $form; }   Here the form fields are saved to database with database API.  function rfi_build_submit($form, &amp;$form_state) { global $user;  // Save the submitted entry. $entry = array( 'name'    =&gt; $form_state['values']['name'], 'surname' =&gt; $form_state['values']['surname'], 'age'     =&gt; $form_state['values']['age'], 'uid'     =&gt; $user-&gt;uid, ); $return = dbtng_example_entry_insert($entry); if ($return) { drupal_set_message(t("Created entry @entry", array('@entry' =&gt; print_r($entry, TRUE)))); } }   Now here is how I know how to create a node of RFI type. How do I take the values of the fields above [name], [surname], [age] and have them related to corresponding fields in my content type?  function rfi_build_type($form, &amp;$form_state){ $node = new stdClass(); $node-&gt;type = 'rfi'; $node-&gt;name = ''; $node-&gt;surname = ''; $node-&gt;age = ''; $node-&gt;language = 'en'; $node-&gt;uid = 1; node_save($node); }   I was thinking that since the fields have been saved already, that I could use a database query to get these values, but intuition tells me I'm overlooking something.  Thank you! Show that the cardinality of $\mathbb N$ is the same as the cardinality of $\mathbb N \times \mathbb N$ Show that $| \mathbb N | = | \mathbb N \times \mathbb N |$, i.e., the cardinality  of $\mathbb N$ is the same as the cardinality of $\mathbb N \times \mathbb N$.   How do I show it using the Fundamental Theorem of Arithmetic and the Schröder–Bernstein Theorem? How to customize MacBooks' keyboard? I spilled a juice on my MacBook-Pro keyboard. Consequently, some keys like 2, esc and tab don't work anymore on my keyboard.   Is there anyway to change those disabled keys with combination of some other keys, like Fn,Ctrl, Option+ something, using an app or a command? Why is it sensical for a proposition with a false antecedent to validate to true? If I open up many tabs in Chrome, the Tabs start to shrink. This is usually a normal behavior if the tabs would use the whole availible space, BUT in my case the tabs shrink too much. They don't use up the whole availible space anymore, but only go until somwhere at three quarters of the window. The more tabs I open, the larger the availible space gets until it reaches a maximum. This strikes me as somewhat not so normal.  Another funny thing is, if I use a second Monitor to extend my Desktop, Tabs will be smaller on the second Desktop and will only fill half the availible space from the beginning. For example right now I have 6 tabs open, which fill out approximately half the availible space. If I open more tabs, only the tab size reduces. This has not been like that when I first installed the browser.  This is what it looks like:    Is there any solution for this?   I hereby explicitly mean NO extensions. I found enough extensions to handle tabs. I just want them to behave normally without any of those tab-extensions. Re-Installing Chrome does NOT work, I tried that. RC4 , Is it possible to find the key if we know the plaintext and ciphertext? Is it possible to find the key if we know the plaintext and ciphertext with RC4. How should I write the algorithm? Typesetting annuity and life-insurance symbols in ConTeXt How do I typeset annuity and life-insurance symbols, actuarial notation in ConTeXt. I see there are packages available but not for ConTeXt.    Thanks I wrote a Table Valued Function in Microsoft SQL Server 2008 to take a comma delimited column in a database to spit out separate rows for each value.  Ex: "one,two,three,four" would return a new table with only one column containing the following values:  one two three four   Does this code look error prone to you guys? When I test it with   SELECT * FROM utvf_Split('one,two,three,four',',')    it just runs forever and never returns anything. This is getting really disheartening especially since there are no built in split functions on MSSQL server (WHY WHY WHY?!) and all the similar functions I've found on the web are absolute trash or simply irrelevant to what I'm trying to do.  Here is the function:  USE *myDBname* GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER FUNCTION [dbo].[utvf_SPlit] (@String VARCHAR(MAX), @delimiter CHAR)  RETURNS @SplitValues TABLE (     Asset_ID VARCHAR(MAX) NOT NULL )  AS BEGIN             DECLARE @FoundIndex INT             DECLARE @ReturnValue VARCHAR(MAX)              SET @FoundIndex = CHARINDEX(@delimiter, @String)              WHILE (@FoundIndex &lt;&gt; 0)             BEGIN                   DECLARE @NextFoundIndex INT                   SET @NextFoundIndex = CHARINDEX(@delimiter, @String, @FoundIndex+1)                   SET @ReturnValue = SUBSTRING(@String, @FoundIndex,@NextFoundIndex-@FoundIndex)                   SET @FoundIndex = CHARINDEX(@delimiter, @String)                   INSERT @SplitValues (Asset_ID) VALUES (@ReturnValue)             END              RETURN END Why is AES resistant to known-plaintext attacks? At least it's my understanding that AES isn't affected by known-plaintext. Is it immune to such an attack, or just resistant? Does this vary for chosen-plaintext? Tracking down where disk space has gone on Linux? When administering Linux systems I often find myself struggling to track down the culprit after a partition goes full. I normally use du / | sort -nr but on a large filesystem this takes a long time before any results are returned.  Also, this is usually successful in highlighting the worst offender but I've often found myself resorting to du without the sort in more subtle cases and then had to trawl through the output.  I'd prefer a command line solution which relies on standard Linux commands since I have to administer quite a few systems and installing new software is a hassle (especially when out of disk space!) I am trying to achieve something like this:     This image is linked from .  also provides a solution and seems simpler. Both answers deal with the algorithmicx package however. I am interested in the solution for the algorithm2e package.   I read the documentation of the algorithm2e package but didn't find an answer.   How can I achieve the colored effect?  EDIT:  Here is sample code to create a minimum working example.  \documentclass{article}  \usepackage[ruled]{algorithm2e} % http://www.ctan.org/pkg/algorithm2e  \begin{document}  \begin{algorithm}[h]  \caption{Evolutionary algorithm}   initialize population \;  \For( \emph{Evolutionary loop}){$g := 1$ to $G_{max}$}  {     do things \;     evolve population \;  }  celebrate \; \end{algorithm}  \end{document} Infinite distinct factorizations into irreducibles for an element Consider the factorization into irreducibles of $6$ in $\mathbb{Z}[\sqrt{-5}]$. We have $6=2 \times 3$ and  $6=(1+\sqrt{-5}) \times (1-\sqrt{-5})$, i.e. $2$ distinct factorizations. And,  $$6^2=3 \times 3\times2\times2$$ $$=(1+\sqrt{-5}) \times (1-\sqrt{-5}) \times (1+\sqrt{-5}) \times (1-\sqrt{-5})$$ $$=(1+\sqrt{-5}) \times (1-\sqrt{-5})\times3\times2.$$ More generally, $6^n$ will have $n+1$ distinct factorizations into irreducibles in $\mathbb{Z}[\sqrt{-5}]$ by a simple combinatorial argument. But, can we construct a ring in which there exists an element that has an infinite number of distinct factorizations into irreducibles? To make life harder, can we construct an extension of $\mathbb{Z}$ in which this happens? I have been thinking about this for a while and have managed to find no foothold.. Any help is appreciated. If we set $A$ and $B$. Assuming that there exist an injective map from $A$ to $B$ and an injective map from $B$ to $A$. How to prove that there is a bijection between $A$ and $B$. Command "find -name" must be enclosed in quotes or it doesn't work. Why is that? Expected value as a function of quantiles? I was wondering where there is a general formula to relate the expected value of a continuous random variable as a function of the quantiles of the same r.v. The expected value of r.v. $X$ is defined as: $E(X) = \int x dF_X(x) $ and quantiles are defined as :  $Q^p_X = \{x : F_X(x) = p \} =F_X^{-1}(p) $ for $p\in(0,1)$.  Is there for instance a function function $G$ such that:  $E(X) = \int_{p\in(0,1)} G(Q^p_X) dp $ Output of Logistic Regression Prediction Opposite of caregiver I want to write a book about the unfair expectations of a caregiver. A caregiver refers to somebody to looks after somebody else.  What is the term for that 'somebody else'.  'Patient' doesn't seem all encompassing. How can we get rid of misspelled and unused (or "zombie") tags? During the re-tagging of questions, tags sometimes become orphaned from existing questions.  Are these zombie tags ever removed from the ?  What if a tag is misspelled and needs to be removed? How do we get rid of it?