How do you turn lists with multiple characters into strings?
Why is it string.join(list) instead of list.join(string)?
Redirect Restricted Page to 404 Is there a way to show a 404 page if the current logged in user does not have the right clearance to view the page? I am looking for a PHP method, something like  if( !current_user_can('administrator') ) { show_404(); exit(); }   I have thought about using a redirect, but I would like to keep the url the same. Let $A$ be a $3\times 4$ and $b$ be a $3\times 1$ matrix with integer entries.Suppose that the system $Ax=b$ has a complex solution. Then which of the following are true? (CSIR December 2014)         $Ax=b$ has an integer solution.    $Ax=b$ has a rational solution.   The set of real solutions to $Ax=0$ has a basis consisting of rational solutions.   If $b$ is not equal to zero then $A$ has positive rank.      Is it possible to say that 1 and 2 are true as $Ax=b$ has a complex solution? If not  what we have to understand from the statement "the system $Ax=b$ has a complex solution " ? What about 3 and 4  ? Exposing database IDs - security risk? I am looking for a driver for the TP-Link AC600 Archer T2U Nano, on Kubuntu 18.04 (kernel version 4.15.0-51-generic).   I already tried different drivers, none of them worked. Can Windows use a Linux shell instead of cmd? Swing's KeyListener and multiple keys pressed at the same time How can we connect a PHP script to MS Access (.mdb) file?  I tried by including following PHP code:  $db_path = $_SERVER['DOCUMENT_ROOT'] . '\WebUpdate\\' . $file_name . '.mdb'; $cfg_dsn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" . $db_path; $odbcconnect = odbc_connect($cfg_dsn, '', '');   But it failed and I received following error message:   Warning: odbc_connect() [function.odbc-connect]: SQL error: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified, SQL state IM002 in SQLConnect in C:\web\WebUpdate\index.php on line 41 How do I read image files directly from a zip without extracting to disk? After a brief discussion with @MonicaCellio (In the comment) - It has come to my attention that perhaps I chose the wrong words to describe my original idea (In the edit history). When I wrote "social features" I was actually suggesting an alternative way to for users to share their knowledge using a new type of post and articles and not just by questions and answers.   The basics of my idea was to allow users to write articles on topics relevant to the community on the SE websites just as any answer posted is expected  to be too. Allowing users to write their own content (I.E posts/articles/etc..) will be granted as a privilege for advanced users so that not anyone could write stupid things, users that will write content must be established and well-familiar with the rules of SE.   I know anyone can start a blog, but it's require frequent maintenance and content updates, while writing on SE ensure that it addressed to a large, well-established community, with a similar fields of interest.  Posts writing will follow the same guidelines as asking and answering questions does, but it will provide an alternative for users that are mostly answering specific questions, as a new method to contribute to the community.   By writing, one may also reveal more about their personality, wit, way of thinking, ETC. That's when the "social" takes place - You'll also have "authors" and not just "users" you can remember by their catchy name, but people that you can remember by the field of interest they are writing content about.   They key points will be:    Users will be able write rich content with advanced WYSIWYG HTML editor, content that doesn't require a question to answer, but that is still relevant to the SE website it is writing on. Users will be able to Upvote/Downvote other users posts. Posts will be listed on their author profile, so it will not just show the activity, but additional layer of user generated content. Popular posts with high reputation could be associated to tags making the information of tags richer with user generated content Users will be able to include links in answers not only to other questions, but also to posts. User will be able to comment on post to allow the author to correct and improve it. It will improve the interaction and offline discussions (Which are prohibited when it come to long discussions on questions and answers). I believe that users will be happy to share their own tutorials, tips and tricks - Because they are already doing so when answering questions, but before the can start, they'll have to earn enough reputation to ensure that only high profile users will be able to write high profile content, and not just any rubbish. It will provide another type of method for voting and getting earning reputation Users will be able to include content in their CVs on SO Jobs.  Opportunity to earn some new badges.   So it's a Mega feature request and it require some detailed design work, but I do think that it will invite a new type of activity for users on SO (and the rests of the sites of-course). WPF DataGrid : CanContentScroll property causing odd behavior Surface integral of a scalar over a unit cube. Evaluate the following integral $$\iint_S (x+y+z) \, dS$$  where $S$ is the surface of the cube $[0,1] \times [0,1] \times [0,1]$  Honestly, I don't know what to do. All I know is that you have to evaluate the integral for each of the 6 surfaces of the cube. The normals for them I can do and the equations of the planes, but other than that I couldn't do much.  Can someone break it down for me, please?  PS: No divergence theorem yet for me. Terminal not displaying colors for directory listings I don't know why my bash session doesn't show colors. I have tried Terminal as well as iTerm.  I have tried:   ls -G Setting export CLICOLOR=1 and export LSCOLORS=GxFxCxDxBxegedabagaced Using different themes such as solarized and something else   The versions of my software are:   bash: GNU bash, version 3.2.51(1)-release (x86_64-apple-darwin13) osx: 10.9.2   I have Homebrew installed  I don't know what other information might be helpful. I spend a lot of time on the shell, this problem is becoming very annoying :)  edit: in terminal preferences, I have 'Declare terminal as: xterm-256color' and 'Display ANSI colors' along with 'Use bright colors for bold text' Word for romantic partner you are living with but not married to I'm learning C#, so I made a little C# program that says Hello, World!, then compiled it with mono-csc and ran it with mono:  $ mono-csc Hello.cs $ mono Hello.exe Hello, World!   I noticed that when I hit TAB in bash, Hello.exe was marked executable. Indeed, it runs by just a shell loading the filename!   Hello.exe is not an ELF file with a funny file extension:  $ readelf -a Hello.exe readelf: Error: Not an ELF file - it has the wrong magic bytes at the start $ xxd Hello.exe | head -n1 00000000: 4d5a 9000 0300 0000 0400 0000 ffff 0000  MZ..............   MZ means it's a Microsoft Windows statically linked executable. Drop it onto a Windows box, and it will (should) run.  I have wine installed, but wine, being a compatibility layer for Windows apps, takes about 5x as long to run Hello.exe as mono and executing it directly do, so it's not wine that runs it.  I'm assuming there's some mono kernel module installed with mono that intercepts the exec syscall/s, or catches binaries that begin with 4D 5A, but lsmod | grep mono and friends return an error.   What's going on here, and how does the kernel know that this executable is special?    Just for proof it's not my shell working magic, I used  (aka sh) to run it and it still runs natively.    Here's the program in full, since a commenter was curious:  using System;  class Hello {   /// &lt;summary&gt;   ///   The main entry point for the application   /// &lt;/summary&gt;   [STAThread]   public static void Main(string[] args) {     System.Console.Write("Hello, World!\n");   } } Why didn't (or did) I or some other user get a hat although the requirements were (or weren't) fulfilled? During Winter Bash, users can earn hats. But sometimes it seems that a hat was awarded even though its requirements weren't (yet) met, or vice versa.  What could be the reason for this? Limit of $\frac{\log(n!)}{n\log(n)}$ as $n\to\infty$. (exercise from Tao's analysis book) Proof of a lemma relating to power set of X I'm stuck at one exercise from chapter of sets from Terence Tao's analysis book. I need to proof the lemma:  Lemma: Let $X$ be a set. Then the set $\{Y : Y \:\text{is a subset of}\: X\}$ is a set.  Note: The set $\{Y : Y \:\text{is a subset of}\: X\}$ is known as the power set of $X$, defined as  $2^X $  I can understand why the lemma is true, but I have no clue how to prove it. Furthermore, the author gave a hint that I found very confusing, it follows:  Hint: start with the set $\{0, 1\}^X$ and apply the replacement axiom, replacing each function $f$ with the object $f^{-1}(\{1\})$. "It is they who lied" or "it is them who lied?" Which is the correct usage of the third person, plural pronoun?     It is they who lied.   It is them who lied. What is the historic present tense? I learned that the historical present may be used to create an effect of immediacy in narratives. I have a question about the historic present tense. Why don't we use the progressive tense instead of the simple present tense?   ※My English skill is poor, so my question might sound rude. But I don't mean to offend anyone. I'd be glad if someone could reply to my question. What does outputting to /dev/null accomplish in bash scripts?