how to reverse the words in a string but not characters in C Programming
Efficiently reverse the order of the words (not characters) in an array of characters
I just installed a new Ubuntu Server 18.04. I set my hostname hostnamectl set-hostname ****.openbayou.biz and I set /etc/hosts:  127.0.0.1 localhost [ip address] ****.openbayou.biz hostname # The following lines are desirable for IPv6 capable hosts [ip6 address] *****.openbayou.biz hostname ::1     localhost ip6-localhost ip6-loopback ff02::1 ip6-allnodes ff02::2 ip6-allrouters   I also installed OSSEC to monitor for new files, errors and changes to my server and I'm now getting these alerts:  Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-  0001, retrying transaction with reduced feature level UDP.`   It's now repeating itself:  systemd-resolved[3195]: message repeated 4 times: [ Server returned error  NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction  with reduced feature level UDP.]   I've looked online for a solution and nobody is reporting this issue. How can you smooth the edge between two materials? I have created this with cycles:  But the edge between the glowing and non glowing materials is very sharp. The material was manually applied to faces in edit mode. Is there any way I can smooth the edge between them in cycles? Given that the sequence $(v,Av,A^2v,...,A^nv)$ is linearly dependent (1), $A_{n \times n}$, over $\mathbb{F^n}$ prove that scalars $c_0,c_1,..,c_n$ exist (such that not all of them are zeroes) such that the matrix $M=c_0I+c_1A+..+c_nA^n$ is singular.    First I'm not sure how (*) can be used here exactly. We can say that the sequence $(c_0I,c_1A,..,c_nA^n)$ resembles the sequence (1) where $v=I$. But here we have scalar $c_i$ so it's not exactly the same sequence.   Maybe I could say that the sequence $(c_0I,c_1A,..,c_nA^n)$ is linearly dependent because it has $n+1$ elements while over $dim\mathbb{F^n}=n$ $\quad$(2).  Intuitively I understand that suppose we sum all the matrices $c_iA^i$ and then in the last sum operation we get to some $c_jA^j$ and if it's a linear combination of other matrices then we can have such a $c_j$ that: $$ c_oI+\sum_{i=1}^{n-1} c_iA^i+c_jA^j=0 $$ But I don't think this is enough to prove. How to add a class to a given element? Is there a word or phrase for someone who works hard at night and does not sleep? All the words or phrases I know for people who stay up at night merely describe the habit of not sleeping (e.g.: a night owl or insomniac)  I am looking for a word or phrase with an emphasis on working hard at night. These people work are different from insomniacs because they have no problem sleeping but they refuse sleep to work. They are different from night owl because they wake up early in the morning.  To give more context, suppose a nurse with kids who has a normal day life like most people and takes care of the kids but also works most nights in a hospital. Show that $n-m$ is a multiple of 9 when $n$ and $m$ have same digits I have just proved the divisibility rule for 3 and 9.  Let $n\in\mathbb{N}$. Let $m$ be a number that appears when you shuffle the digits in $n$. Show that $n-m$ is a multiple of 9.  Can anyone offer some help? Creation of entangled electrons Using OR comparisons with IF statements When using IF statements in Python, you have to do the following to make the "cascade" work correctly.  if job == "mechanic" or job == "tech":         print "awesome" elif job == "tool" or job == "rock":         print "dolt"   Is there a way to make Python accept multiple values when checking for "equals to"? For example,  if job == "mechanic" or "tech":     print "awesome" elif job == "tool" or "rock":     print "dolt" Why do prisms work (why is refraction frequency dependent)? It is well known that a  can "split light" by separating different frequencies of light:    Many sources state that the reason this happens is that the  is different for different frequencies.  This is known as .  My question is about why dispersion exists.  Is frequency dependence for refraction a property fundamental to all waves?  Is the effect the result of some sort of non-linearity in response by the refracting material to electromagnetic fields?  Are there (theoretically) any materials that have an essentially constant, non-unity index of refraction (at least for the visible spectrum)? "Back" and "Install Now" buttons grayed out in 14.04 installer The "Back" and "Install Now" buttons are grayed out in the 14.04 installer. How do I restore them? Asking feedback/rating for a mobile app? Fig.1: A typical prompt, asking user for feedback/rating in iOS Background Any serious smartphone users must have seen a message similar to Fig.1 above at least once. Variations of such prompt include: &quot;Please give us 5 star ratings if you love this app!&quot;, &quot;Rate us :)&quot;, &quot;Your rating helps improve this app!&quot;, etc. Basically, Fig.1 asks user to leave a (nice) feedback/rating for the app on its AppStore(or equivalents).  The Shorter Question  When and how often should a mobile app user be asked to leave a feedback/ratings?   The Longer Question #1. Which User-statistics? What are the significant user's behavioral statistics that should be based on to generate Fig.1? For example:  Number of runs since install/reinstall of the application Time elapsed since current application run Time elapsed since first application run Time elapsed since first application install Certain events (e.g. after certain number of stages are cleared for a game app)  #2. When to Ask? If multiple user-statistics are chosen to be calculated to generate Fig.1, specifically how should the user-statistics satisfy the condition of the event? For example:  Form a unified equation (e.g. X^2+Y^2=Z^2) with all significant user-statistics partaken fairly to trigger the event. Create (multiple of) &quot;absolute&quot; event triggers (e.g. every 10th app run; elapsing 2 hours since current application run). Both of the two. Generate Fig.1 whichever comes true first. Neither of the two. &quot;There's a better way!&quot;  #3. How often? What would be the optimal min/max frequency of Fig.1 generation? By optimal, I mean users are not to be bothered too much, yet developers gain maximum output of great feedbacks from users? #4. &quot;Don't bother me again :(&quot; Should users have an option to opt-out from receiving Fig.1 at all? #5. Universal User-statistics for All Mobile Apps? Should apps under different categories be based on different user-statistics? There are significant differences in size and type of user-statistics in apps under different categories. For example, a &quot;Flashlight&quot; app is not typically run for one hour straight, while a music/movie streaming app may be run for over one hour. #6. &quot;This app does not need more feedback.&quot; Should every app of all kinds of user base ask this message? If any, should any mobile app stop generating Fig.1 when target conditions are met (e.g. downloads count, active user count, feedback count)? #7. Feedback/Rating Before Deletion Should users be asked to leave a feedback before deleting as seen in Fig.2 below? Users are more likely to leave very critical review on app deletion, but this kind of feedback will be very helpful for the developers to strengthen their app's weakness for next version release.                                                                                                 Fig.2: Asking user for rating before app deletion Ubuntu 18.04 hangs on booting with message "started user manager for uid 120" on Asus 1015PX I installed Ubuntu 18.04 amd64 desktop on Asus Eeepc 1015px, but it hangs on booting. The last message is 'Started User Manager for UID 120'.  I managed to boot up in recovery mode and finished the installation with 'sudo apt-get upgrade', but nothing has changed.  Does anybody know how I can tackle it?  Thanks in advance, Newton. I saw this movie a while back. I don't remember how it starts, but from where I remember watching it, it may have not been too far from the start. Apparently, Earth has been conquered by some alien empire or something and humanity are basically cavemen being used as slaves. From what I remember, the main antagonist alien is seen taking one of the slaves to a room where a machine is used on him to make him smart; this is apparently a big no-no so the main antagonist and his sidekick have to keep it quiet. The idea was that by making one of the slaves smart, it could increase the work output of the others. Apparently the antagonist is using the slaves on Earth to gather gold bullion  which is apparently still very valuable to the aliens but he's doing it illegally (not the slave labor; that's apparently ok). The protagonist who had the machine used on him becomes the intermediary between the slaves and the aliens and begins teaching the other slaves. I remember him teaching them mathematics and I remember him saying that it was universally accepted (I think he may have been referring to algebra or trigonometry). At some point he becomes aware that they are slaves and organizes a plan to free not only his fellow slaves but the Earth. Some escape and find an old museum which has old flight simulators, and shows that humanity wasn't always a slave race and that it may have been modern times in which Earth was invaded (i.e. no lasers or starships). I think they also find Fort Knox as there is a huge collection of gold bricks and weapons. The protagonist comes up with a plan to destroy some sort of teleporter the aliens use to transport stuff to and from Earth, however that alone wont be enough as they could fight back, which will be bad for humanity, which is still undeveloped. So the plan also includes using the teleporter before destroying it to to transport and detonate a nuclear warhead on the alien home world which apparently cripples any attempt to immediately send a fleet but also as a show of strength. After executing their plan, the main antagonist is captured by the humans and as an insult is locked in a cage surrounded by the gold he sought. If I recall correctly the place is set to detonate as to destroy the precocious gold and that will be used against the aliens should they mobilize a fleet in the future (i.e. attack us and we destroy Earth's supply of gold). The antagonist's side kick for some reason I remember as a big black man from whom the antagonist had removed his hand at some point and also apparently the antagonist was cruel to him. After the antagonist is locked up, he is trying to appeal to his sidekick's loyalty, however the sidekick takes the humans' side, I'm also getting an image that apart from treating him kindly the sidekick's missing hand was restored. I know how to define a package or a class, but how do I make it available (to myself) at all times?  Say I have the package file commonstuff.sty (or myprettyclass.cls), that I want to be able to include in any .tex file I create on my computer. Where do I put it? Do I need to run some installer on it, or is it enough to keep it in a certain folder?  Note: I know I can just place it in the same folder as the .tex file, but that's not what I'm after here. I'm looking for a way to "install" the package centrally on my computer. What is the 64-bit Firefox Beta PPA? Choosing colors appropriately for red-green colorblindness I want a green for "correct answer" and a red for "wrong answer". My current choice is rgb(144, 238, 144) for the green and rgb(250, 128, 114) for the red. (See wikilearner.net/wiki for the colours in action.)  I have been told that these colors are very close in contrast, making it difficult for a person with red-green color-blindness. What would be a better choice? I uploaded a pre-print of an article on arXiv 1 year ago. The article was accepted in SCI journal and currently available online. However, I found a typo mistake in one equation and want to add more discussion related one figure (On researchgate I am receiving a lot of queries regarding that figure). Should i upload a new version of pre-print on arXiv? (How citations will work in this case? as arxiv version is more advanced compare to Journal version) OrI may upload a short document on arXiv as an errata/correction with extra discussion?Or I may address errata and discussion in online page of journal? Actually this journal allows the registered users to comment and start discussion related to published article. The Civilization series of games is famous for having a way to play by e-mail. This allows people to take a long time on their turn without holding up the other players, as you do in a real-time game. Yet, I can not find any method to play by e-mail in the game menus. Does it exist? If so, how do you do it? When trying to add a bit more detail to a related , I realized I don't know how to specify which one of the available Bash word types to execute. According to help type there are five word types:   alias keyword function builtin file   It's possible for a word to have several types (true is just an example; a more commonly overridden word would be cd):  $ type -a true true is a shell builtin true is /bin/true   How do you force the execution of a specific synonym? So far, in order of precedence:   alias: This is a special case since it has precedence over all the other synonyms. Forcing this would only be useful when the command should fail if the alias is not defined.  $   keyword:  $   function:  $   builtin:  $ builtin true  file:  $ command true $ $(which true) $ /bin/true    :   Quoting a word excludes aliases and keywords. That is,  $ 'true'   will run only the function, builtin or file. Intuition behind the definition of a measurable set