This is what comes up in /var/log/mail.log.1. I have absolutely no idea the domain no-reverse-dns-configured.com is being read. Also the said IP has nothing to do with my server. I don't event imagine where to start looking.
I've seen a couple other questions with this error message but it seemed that the host and ip in question were ones the OP knew. These two are unrelated to my server.  Where and why is postfix generating this error?     Jul 24 17:42:14 email postfix/smtpd[32277]: warning: hostname kimtake.respectedopinion.com does not resolve to address 62.210.28.114   Jul 24 17:42:14 email postfix/smtpd[32277]: connect from unknown[62.210.28.114]   Jul 24 17:42:14 email postfix/smtpd[32277]: disconnect from unknown[62.210.28.114]
We all know that _spPageContextInfo is a very useful thing in Client side development. I need something equivalent of _spPageContextInfo in SPFX. Currently I am unable to use it directly from typescript. It gives error like     Can not find '_spPageContextInfo'   Finally, I have gone through the API documentation of  and  found . PageContext has dependence with . My qestion is: How to use PageContext? I need to use it my BaseService class. constructor of my class is:  constructor(private $http: ng.IHttpService, private $q: ng.IQService, serviceScope: ServiceScope) {     serviceScope.whenFinished(() =&gt; {       this.pageContext = new PageContext(serviceScope);       console.log(this.pageContext);     });   }   Inside the constructor serviceScope is undefined. I know the reason: As I am not injecting/initialising serviceScope anywhere like other angular services. So what is the approach of injecting/initialising serviceScope in angular service class? If $U$ is unitary operator then spectrum $\sigma(U)$ is contained inside the unit circle In a Hilbert space, let $U$ be a continuous operator which it unitary. Prove $\sigma (U)\subseteq \Bbb{S}^1$.   It is important for me to know how I am doing, and I didn't come by a clear explanation so it would be appreciated to have your correcting and guiding.  Attempt: $U^{*}U=UU^{*}=I$ and therefore $U^{-1}=U$. I have $$ \| U x \|^2 = \langle U x, U x \rangle = \langle U^* U x, x \rangle = \langle x, x \rangle = \|x\|^2 $$ and the same goes for $U^*$ and therefore $\| U \| = \| U^{-1} \| = 1$.   Looking at $U-\lambda$ I can take $$ -\lambda U(U^{-1}-{1\over \lambda}I) =U-\lambda I. $$ Clearly, for $\lambda \ne 0$, $-\lambda U$ is defined and is a linear operator. $(U^{-1}-{1\over \lambda}I)$ is invertible if $|\lambda|\ge 1$ and therefore $\sigma (A^{-1})=\sigma (A)\subseteq \{|z|\le1\}$. But from the RHS, $U-\lambda I$ is invertible if $|\lambda|\le 1$ and therefore $\sigma(A)\subseteq \Bbb{S}^1$. I have noticed my claims tend to have holes in them many times which I cannot spot. If it is substantially true, how can I make sure it is completely formal? Sometimes I need to write text and then pipe that text into another command. My usual workflow goes something like this:   vim # I edit and save my file as file.txt cat file.txt | pandoc -o file.pdf # pandoc is an example  rm file.txt   I find this cumbersome and seeking to learn bash scripting I'd like to make the process much simpler by writing a command which fires open an editor and when the editor closes pipe the output of the editor to stdout.  Then I'd be able to run the command as quickedit | pandoc -o file.pdf.   I'm not sure how this would work. I already wrote a function to automate this by following the exact workflow above plus some additions. It generates a random string to act as a filename and passes that to vim when the function is invoked. When the user exits vim by saving the file, the function prints the file to the console and then deletes the file.   function quickedit {     filename="$(cat /dev/urandom | env LC_CTYPE=C tr -cd 'a-f0-9' | head -c 32)"     vim $filename     cat $filename     rm $filename } # The problem: # =&gt; Vim: Warning: Output is not to a terminal   The problem I soon encountered is that when I do something like quickedit | command vim itself can't be used as an editor because all output is constrained to the pipe.   I'm wondering if there are any workarounds to this, so that I could pipe the output of my quickedit function. The suboptimal alternative is to fire up a separate editor, say sublime text, but I really want to stay in the terminal. Would a wormhole be able to move? Java: Why does if statement never resolve to true? DataGridTextColumn.IsReadOnly seems to be faulty How to prove this inequality $ x + \frac{1}{x} \geq 2 $ I was asked to prove that:   $$x + \frac{1}{x}\geqslant 2$$  for all values of $ x &gt; 0 $  I tried substituting random numbers into $x$ and I did get the answer greater than $2$. But I have a feeling that this is an unprofessional way of proving this. So how do I prove this inequality? I am considering purchasing a Mac for my godson who will be using it to run Blender 2.8.  I know very little about this program.  All I can find are requirements for a Mac that will run earlier versions of Blender.  Would someone please recommend a list of requirements for a Mac (or a link to a list of requirements) that I could use to find a model that can run 2.8?  Thank you in advance for all your help! Sincerely, M. Lap How to make skill use on investigations "important" but failure not derail the plot? Well guys, following previous recommendations here I was able to build a Horror Themed Savage Worlds campaign that has made my players excited. However they're still getting used to the style, as well as I am. In order for them to hurt the major evils of the adventures they have to find their Form (physical appearance, name), Truth (How the creature came to be) and Reason (What the creature wants to), so they have to do research, kill lesser creatures, and run away from the big baddie of the adventure as they seek what it is.  Well, this is my problem:  How can I make them use skills significantly?  I'm used to railroading my players, even with mysteries, and I don't know how to put their skills for significant use. An example is, they usually require Streetwise or Investigation to gather clues and such, however, I wonder what to do if they fail the roll... If they fail they're not supposed to find anything, so chances they never finish the adventure are well, high, that and I have no idea how to give them additional, interesting ways for them to find the truth. So do I give it no matter what they rolled? How do I make use of their skills important and not just busy-work without having a failure on a roll completely stop their progress in the investigation? When I'm not exploring fresh caves or lands in minecraft, I'm busy trying to find deposits of diamond, gold and iron deep in the earth. So far I've just been digging around just above bedrock on a whim to look for these rare minerals but I've started thinking that I should be taking a more controlled, efficient approach to mining.  What is the optimal mining strategy that yields the most rare minerals while minimizing blocks removed and time spent digging and traveling?  Edit: The existing answers are great for mining, but no one has addressed travel time to and from the mine which is usually ~60 blocks downward and incredibly tedious. Solutions? Questions can be closed or marked as duplicates.  What does it mean for a question to be &quot;closed&quot;? What does it mean for a question to be marked as a &quot;duplicate&quot;? Who can close a question? What are the reasons for closing a question ? Is closure the end of the road for a question? When are closed questions eligible for deletion?   Related        For more information, see &quot;&quot; in the . Evaluating this integral : $ \int \frac {1-7\cos^2x} {\sin^7x \cos^2x} dx $ The question :  $$ \int \frac {1-7\cos^2x} {\sin^7x \cos^2x} dx $$  I tried dividing by $\cos^2 x$ and splitting the fraction.  That turned out to be complicated(Atleast for me!)  How do I proceed now? Default behavior of "git push" without a branch specified How to use WPF Background Worker I try to import .obj files from this project:  - the files contain Polygon Mesh Data.  When I import the obj file into blender, the outliner shows a new mesh added, but nothing is visible in the 3D viewport:      Any help will be appreciated. How to launch a command on network connection/disconnection? I have a wifi connection that requires to authenticate using a web form once the wireless link is established. I know how to automate the authentication with a script that uses curl/.  But how can I ask Windows to call my script every time I connect to a particular network connection?  I would be also interested in receiving the name of the wireless profile or the ESSID on the command-line of my script. A mysterious app named &quot;10102&quot; shows up in my data usage. It bears only the standard Android app icon (the Bugdroid logo with a cube on its torso). From what the graph tells me, it has used 36 megabytes of data in the background and zero on the foreground. I think I haven't uninstalled anything for months. Is it malware? I haven't sideloaded anything and only authorized my laptop as a USB debugger. If it's malware, how do I remove it? I have no idea how to find its package name and 10102 isn't in the list of downloaded apps in settings. I'm running stock &amp; never-been-rooted Android 4.4.4 on Nexus 4. How to solve "permission denied" when using sudo with redirection in Bash? Listing, zebra effect and broken lines In , I've found one solution to produce a zebra effect for listing. Unfortunately, this only works if the lines are not broken. Is there a way to fix this?  Here is a code with an example showing the problem:  \documentclass[10pt,a4paper]{article}     \usepackage[utf8x]{inputenc}     \usepackage{ucs}     \usepackage[T1]{fontenc}     \usepackage{lmodern}     \usepackage[frenchb]{babel}     \usepackage[x11names, svgnames]{xcolor}     \usepackage{graphicx}     \usepackage{listings}     \usepackage{amsfonts}     \usepackage{amssymb}      \makeatletter         % Patch line number key to call line background macro         \lst@Key{numbers}{none}{%             \def\lst@PlaceNumber{\lst@linebgrd}%             \lstKV@SwitchCases{#1}%             {none&amp;\\%              left&amp;\def\lst@PlaceNumber{\llap{\normalfont                         \lst@numberstyle{\thelstnumber}\kern\lst@numbersep}\lst@linebgrd}\\%              right&amp;\def\lst@PlaceNumber{\rlap{\normalfont                         \kern\linewidth \kern\lst@numbersep                         \lst@numberstyle{\thelstnumber}}\lst@linebgrd}%             }{\PackageError{Listings}{Numbers #1 unknown}\@ehc}}          % New keys         \lst@Key{linebackgroundcolor}{}{%             \def\lst@linebgrdcolor{#1}%         }         \lst@Key{linebackgroundsep}{0pt}{%             \def\lst@linebgrdsep{#1}%         }         \lst@Key{linebackgroundwidth}{\linewidth}{%             \def\lst@linebgrdwidth{#1}%         }         \lst@Key{linebackgroundheight}{\ht\strutbox}{%             \def\lst@linebgrdheight{#1}%         }         \lst@Key{linebackgrounddepth}{\dp\strutbox}{%             \def\lst@linebgrddepth{#1}%         }         \lst@Key{linebackgroundcmd}{\color@block}{%             \def\lst@linebgrdcmd{#1}%         }           % Line Background macro         \newcommand{\lst@linebgrd}{%             \ifx\lst@linebgrdcolor\empty\else             \rlap{%                 \lst@basicstyle                 \color{-.}% By default use the opposite (`-`) of the current color (`.`) as background                 \lst@linebgrdcolor{%                 \kern-\dimexpr\lst@linebgrdsep\relax%                 \lst@linebgrdcmd{\lst@linebgrdwidth}{\lst@linebgrdheight}{\lst@linebgrddepth}%                 }%             }%             \fi         }     \makeatother      \lstset{ %    * Number for lines         numbers=left,                   % Where to put the line-numbers         numberstyle=\footnotesize,      % Size of the fonts used for the line-numbers         stepnumber=1,                   % Step between two numbers         numbersep=5pt,                  % How far the line-numbers are from the code % %    * Back returns for long lines         breaklines=true,                % Sets automatic line breaking         breakatwhitespace=false,        % Automatic breaks only happen at whitespace ?         breakindent=0pt,                % Space before the text of a break         postbreak=\mbox{                % Character used at the begining of a break             \rotatebox[y=0.9ex]{180}{\color{Red} $\Lsh$}%         },     }  \begin{document}  \begin{lstlisting}[language=Python,linebackgroundcolor={\ifodd\value{lstnumber}\color{gray}\fi}] for i in range(5): for i in range(5): for i in range(5): for i in range(5): for i in range(5): for i in range(5):     sum += i**3 print sum  print('Fin de la boucle...') \end{lstlisting}  \end{document} How to efficiently find positions of duplicates?