I have use Nmap -a to view all open ports on my laptop. However, I noticed that the states are different. Some have ESTABLISHED, some LISTENING and some were stateless. What do they mean?
I use netstat to check my port status.  I was wondering what's the difference between port status LISTENING, TIME_WAIT, CLOSE_WAIT, FIN_WAIT1 and ESTABLISHED?
Add new alias to Gmail without SMTP (forwarding-only address) I used to be able to go to Accounts and Import → Add another email address you own and add an email account that's only a forwarding address. That is, it's not a mailbox and I don't have SMTP access to it.  Gmail would send me a confirmation email to that address, I'd confirm it's mine, and done. Now it only gives me the option to add SMTP credentials.  Did they stop supporting the previous method? Is there any other way I can get that option back? If Anakin Skywalker didn't get what he wanted as a Sith (to save Padmé), why was he still a Sith? In the prequels, the primary reason Anakin was willing to become  is because he wanted to save Padmé;     ANAKIN: I will do whatever you ask.       PALPATINE: Good.       ANAKIN: Just help me save Padme's life. I can't live without her. If she dies, I don't know what I will do.      PALPATINE: To cheat death is a power only one has achieved, but if we work together, I know we can discover the secret.       ANAKIN kneels before PALPATINE.       ANAKIN: I pledge myself to your teachings. To the ways of the Sith.   Given that he didn't manage to save her, why did he still become a Sith? Do I need a RHEL subscription to install packages? A vessel is filled with liquid,3 parts of which are water and 5 parts syrup.How much of the mixture must be drawn off and replaced with water so that the mixture may be half water and half syrup?  What is the best possible way to solve this question? How to calculate stays against 90/180 visa rules? Some destinations have a "90/180 rule" which says you can come and go but you must not spend over 90 days out of any 180 days in the area.  concerns this rule.  At least Schengen and Turkey have this rule, probably depending on where the traveller is from and what kind of visa they apply for.  Maybe I'm a dummy but I've always had a lot of trouble trying to add up how many days I've spent in such places when I've entered and left several times over recent months.  Is there an easy way to do this I'm missing or is it difficult for everybody? I'm guessing something based on counting backwards from the end date might be the trick?  Maybe you know of an app or website that can do this for you. Differences between Verb + to be + adjectives and Verb + adjective Does the pilot of a rocket ship experience an asymptotic approach to the speed of light? A question has recently come up that goes beyond my knowledge of special relativity.  Suppose a pilot has his foot on the gas pedal of a rocket ship and keeps it applied to achieve a constant acceleration, and he has a magical engine that can maintain the thrust needed to accomplish such acceleration even as the vehicle acquires mass.  He measures his acceleration at periodic intervals and sums it up as he goes.  Observers perceive the rocket to increase in speed and gradually approach the speed of light (but never reach it). Two possibilities are being debated for what the pilot observes, and my preference is for the first:   Time dilation gives him the impression that the summation of his readings are approaching light speed at a constant rate, but there is an asymptote involved here even in the inertial frame such that he never actually perceives himself to reach, let alone exceed, $c$, because time slows down to a crawl (as seen from the reference frame) before this can happen. Although to observers he is only approaching $c$, it is possible for the summation of the measurements on his accelerometer to indicate that he has surpassed $c$ and is now traveling faster than light.  From the reference frame he is approaching $c$ and his instruments in the inertial frame tell him that he has surpassed it.   I assume (1) is true beyond a doubt?  If so, is there a straightforward explanation for this? I observe the following strange characters ^@ in syslog at the time when my machine freezes.  Then i have to hardboot my machine.  What could be wrong any ideas?  Oct 12 12:20:52 nanak-P570WM anacron[1074]: Normal exit (1 job run) ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@  Oct 12 12:24:28 nanak-P570WM kernel: imklog 5.8.11, log source = /proc/kmsg started. Oct 12 12:24:28 nanak-P570WM rsyslogd: [origin software="rsyslogd" swVersion="5.8.11" x-pid="543" x-info="http://www.rsyslog.com"] start How do I find out which folder an app is in in iOS 11? In older versions of iOS, if I searched for an app with Spotlight, it would tell me which folder the app was in. (E.g., this feature still works on my iPad, which is running iOS 9, but not on my iPod Touch, which is running iOS 11.)  This feature seems to have been removed at some point. When I search for an app under iOS 11 using Spotlight, it will find the app and let me run it, but it doesn't tell me which folder it is in.  How can I find out which folder an app is in now? System.FinalException: Record is read-only: Trigger.updateCompetitors: line 24 I am writing a trigger to get all the Opportunity competitors into a field on Opportunity, however, getting an error while testing it.  Error: updateCompetitors: execution of AfterUpdate caused by: System.FinalException: Record is read-only: Trigger.updateCompetitors: line 24  Can you please check the below code and suggest me what's wrong with this?  trigger updateCompetitors on Opportunity(after insert, after update){    List&lt;Opportunity&gt; OppIds = new List&lt;Opportunity&gt;();     for (Opportunity opp: trigger.new){         OppIds.add(opp);     }  List&lt;OpportunityCompetitor&gt; oppComps = new List&lt;OpportunityCompetitor&gt;();  oppComps= [select id, CompetitorName, Strengths, Weaknesses from OpportunityCompetitor where OpportunityId in: Trigger.newMap.keySet()];  List&lt;Opportunity&gt; OppstoUpdate = new List&lt;Opportunity&gt;();   for (Opportunity opp: OppIds){     String allcomps = null;      if( oppComps.size()&gt;0 ) {       for (integer i = 0; i &lt; oppComps.size(); i++){          allcomps = allcomps + oppComps[i].CompetitorName+',';       }     }    opp.OpportunityCompetitors__c = allcomps;    OppstoUpdate.add(opp);  }    update OppstoUpdate; } Show rigorously that the sum of integrals of $f$ and of its inverse is $bf(b)-af(a)$ Suppose $f$ is a continuous, strictly increasing function defined on a closed interval $[a,b]$ such that $f^{-1}$ is the inverse function of $f$. Prove that,   $$\int_{a}^bf(x)dx+\int_{f(a)}^{f(b)}f^{-1}(x)dx=bf(b)-af(a)$$   A high school student or a Calculus first year student will simply, possibly, apply change of variable technique, then integration by parts and he/she will arrive at the answer without giving much thought into the process. A smarter student would probably compare the integrals with areas and conclude that the equality is immediate.  However, I am an undergrad student of Analysis and I would want to solve the problem "carefully". That is, I wouldn't want to forget my definitions, and the conditions of each technique. For example, while applying change of variables technique, I cannot apply it blindly; I must be prudent enough to realize that the criterion to apply it includes continuous differentiability of a function. Simply with $f$ continuous, I cannot apply change of variables technique.  Is there any method to solve this problem rigorously? One may apply the techniques of integration (by parts, change of variables, etc.) only after proper justification.  The reason I am not adding any work of mine is simply that I could not proceed even one line since I am not given $f$ is differentiable. However, this seems to hold for non-differentiable functions also.  I would really want some help. Pictorial proofs and/or area arguments are invalid. I'm trying to run this command in the terminal:  sudo apt install software-properties-common   This is the error message I get:  E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable)   E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend),     is another process using it? it seems my bash-completion got corrupted. Every time I try to use command substitution, for example when I type  ls $(ls Deskto&lt;Tab&gt;   ..result is..  ls $(ls Desktobash unexpected eof while looking for matching ")".   I tried removing my .bashrc file and cp /etc/skel/bashrc ~/ to get a new one. That works until I add something into my new bashrc. Even when I do echo '#" &gt;&gt; ./.bashrc it breaks again. Removing my bash_aliases did not help either.  Also sudo apt-get install --reinstall bash-completion did not do the trick.  However there are some threads about similar problem, nothing works.  ANY hint will be greatly appreciated! :) Preview Breaks with Invalid Tag Name [tag:+] In the formatted preview for Questions &amp; Answers, typing a tag link with an invalid tag name "crashes" the preview. As soon as you type the following the preview stops updating and an error can be observed in the Javascript console.   [tag:+]   Observed in Safari 7 and Chrome 31.   seems related to the business rule of not allowing certain characters in tags, but it sounds like a different bug. When A and B are positively related variables, can they have opposite effect on their outcome variable C? A is positively related to B.  C is the outcome of A and B, but the effect of A on C is negative and the effect of B on C is positive.  Can this happen? I'm using soul to letterspace headings in a Hungarian document and compiling it with lualatex.  For some reason soul drops some of the accented letters at the end of a word, but not all. In the example below, only ő and ű are affected:  \documentclass{minimal} \usepackage{fontspec} \setmainfont[Ligatures = TeX]{TeX Gyre Pagella} \usepackage{soul} \begin{document} \noindent \so{áll llá ÁLL LLÁ}\\ \so{íll llí ÍLL LLÍ}\\ \so{űll llű ŰLL LLŰ}\\ \so{őll llő ŐLL LLŐ}\\ \so{üll llü ÜLL LLÜ}\\ \so{öll llö ÖLL LLÖ}\\ \so{úll llú ÚLL LLÚ}\\ \so{óll lló ÓLL LLÓ}\\ \so{éll llé ÉLL LLÉ} \end{document} I've got a bunch of files named with a the pattern 99 - DescriptiveName.txt and I'd like to remove the number from the front so I just have DescriptiveName.txt.  How can I do this? Can I do it from the command line or is there a utility that can do this? How do I add PHP code/file to HTML(.html) files? Visit the UK with Schengen tourist short-stay visa I'm Russian, and I have touristic  Schengen short stay visa. I want to know, can I stay for some period in UK without getting UK visa, or it is not possible (I heard about 36 hours free of visa staying or something like that) Passing list to viewparams variables in GeoServer SQL views? I have a sql view which take only one parameter, but this parameter is a list, and a need to know how can i pass this parameter in the url  Here is my sql view  SELECT * FROM shop WHERE id IN %list%   When I put the default value for %list% as (1, 2 ,3) as example, the layer preview works and show the shopa with the default ids,  but when I try this in the url  viewparams=list:(1,2,3)   does not work.   I already tried other things like   viewparams=list:"1,2,3"   but nothing works.  Does anyone know how to do this?