Why doesn't grep remove lines of terminal output from find command by default?
Why doesn't grep using pipe work here?
Is there always an equilibrium point in space for gravity? .Net 'Any Framework' configuration How can I stop iPhone prompting me to setup Apple Pay in Settings? Can I find out which tags I have created? This would be interesting to know.  The tags could be highlighted on the users page for example. Parallel evaluation produces wrong result Some people say that mass increases with speed, some people say that the mass of an object is independent of its speed.  I understand how some (though not many) things in physics are a matter of interpretation based on one's definitions. But I can't get my head around how both can be 'true' is any sense of the word.  Either mass increases or it doesn't, right?  Can't we just measure it, and find out which 'interpretation' is right? e.g.: (in some sophisticated way) heat up some particles in a box and measure their weight?  ------------------------------  UPDATE  Right, so I've got two identical containers, each with identical amounts of water, each on identical weighing scales, and each in the same g field. If one container has hotter water, will the reading on its scale be larger than the other? If the answer is yes, and g is constant, does this mean that the m in w=mg has got bigger? $1+x+\ldots+x^n$ perfect square Let $p$ be the polynomial $p(x)=1+x+\ldots+x^n$. For which couples $(a, n)\in\mathbb{N}^2$, $p(a)$ is a perfect square? I'm particularly interested in $p(3)$. Dark age of universe when all fusion process ceases? Some say we live in the golden age of the universe because there exits countless number of stars that shines in the dark universe. As the supply of gas for star formation is steadily being exhausted, it is estimated that star formation will cease in 100 trillion years.  Question: Will there be a day that the universe becomes completly dark when all the stars burn out? Does all the cooled bodies eventually collide due to gravitational forces? Will black holes eventually dominate the universe? I'm trying to merge two directory trees that have many common elements but also each have elements that are only present in one of the two trees. The main issue I am having is that when mv encounters two sub-directories with the same relative paths it either keeps the source (with -f) or the destination (with -n) but I can't make it take the union of both sub-directories. I could of course use rsync with --remove-source-files but this will actually copy the data and then delete the old files as opposed to a true move. The two directory trees contain several hundred GB of data and are both on same partition so I would love to do a true move if possible for the sake of time.   Right now I have find * -type file -exec mv -n {} /destination/{} but this only moves  files from the source to the destination when the target directory already exists. I can preface this command with something like mv -n * /destination/ but this only brings over the top level directories. Is there any way to do this in a single line? I could  always write a script to check if the directory exists before copying the file but this seems like such a basic task, it seems like there should be an easier way. Why did the command ":(){ :|: & };:" make my system lag so badly I had to reboot? Do not run this command to 'test' it unless you are prepared for a crash and/or force-rebooting your system.  I was in my Virtualbox running 12.04 trying to compile an app, and while waiting I happened to chance upon a forum where a comment said:   Try :(){ :|: &amp; };:  Fun, too, and doesn't need root.  Without thinking, I ran it in my gnome-terminal. It made my 12.04(in Virtualbox) lag so badly, I had to shut it down. My question is what does this command do?   :(){ :|: &amp; };: Show that the Sorgenfrey line does not have a countable basis. Is save data from previous Dragon Age games used in Inquisition? Does Dragon Age Inquisition make use of save data from previous games in the series?  If so, what benefits does this provide? How to distribute the objects on a sphere evenly? I want to replicate this mesh -    I think the best way is using a particle system of cubes. So I need to create a sphere of simple circles. It is necessary that in each circle the vertices are at equal distance from each other. But I don't know how to create those circles. Change HTML Produced by wp_list_comments() I am developing a WordPress theme for which I would like each comment's timestamp wrapped in in a &lt;span&gt; element for the sake of styling it with CSS rules. However,  as I use it in my theme's comments.php template does not seem to provide options to alter the HTML produced:  &lt;ol class="comment-list"&gt;     &lt;?php         wp_list_comments( array(             'style'       =&gt; 'ol',             'format'      =&gt; 'html5',             'short_ping'  =&gt; true,         ) );     ?&gt; &lt;/ol&gt;   which produces timestamps as such:  &lt;time datetime="2015-12-21T19:09:49+00:00"&gt; december 21st,  2015 on 19:09 &lt;/time&gt;   How can I alter the function's output to include a &lt;span&gt;element around each &lt;time&gt; element without altering core files?  I've tried looking at my theme's functions.php, as well as WordPress wp-includes/comment.php and wp-includes/comment-template.php. None of them deal with the actual tag structure of the comment timestamps generated by wp_list_comments(), so there was nothing there for me to play with. so i have a 30A disconnect available for use at a customer site for running 2 5HP motors ( at 480V)  the only question i have though is if the line is sized for a 10HP motor would both the 5HP motors need additional fuse protection?   Or could i get away without having addtional fuses protecting the motors ? How to prove that we are living in a 3+1D world? how can I add an overlapped anchor in both overlapped paths automatically Can you create images like this:    when you have something like  0 = green (#54ff00) 1 = white (#ffffff) 2 = red   (#ff0000) 3 = blue  (#0048ff)  Image (Python list of integers defined above): [[2,0,0,0,0,0,0],  [0,3,0,0,0,0,0],  [0,3,2,1,1,0,0],  [0,3,2,2,2,1,1],  [0,3,2,0,0,1,0],  [0,0,0,0,0,1,0],  [0,0,0,0,0,1,0]]   with TikZ?  How far I got  The following MWE defines all colors, produces a grid of the correct size (though the size is determined by hand):  \documentclass[varwidth=true, border=2pt]{standalone} \usepackage{tikz} \usepackage{xcolor}  \begin{document}     \newcommand\n{7}     \definecolor{green}{HTML}{54FF00}     \definecolor{wite}{HTML}{FFFFFF}     \definecolor{red}{HTML}{FF0000}     \definecolor{blue}{HTML}{0048FF}     \begin{tikzpicture}         \foreach \x in {1,...,\n}{             \foreach \y in {1,...,\n}{                 \begin{scope}[shift={(\x,\y)}]                   \draw [fill=green] (0,0) rectangle (1,1);                 \end{scope}             }         }     \end{tikzpicture} \end{document}   Of course, I could simpy make a lot of adjusted                   \begin{scope}[shift={(\x,\y)}]                   \draw [fill=green] (0,0) rectangle (1,1);                 \end{scope}   but I've wondered if this can (with reasonable effort) be done in TikZ / LaTeX.  My problem is giving TikZ the color array. I don't have any idea how to do this. I only know two types of looks in TikZ:  \foreach \x in {0,1,2,3,4,5}{...} \foreach \number in {1,...,\n}{...}   I have never seen a nested over a 2D-array. All I have seen so far were 1D-Arrays of tuples (with fixed tuple size). If the sum of $n$ cubes is zero, then the sum must be no larger than $\frac n3$. I am trying to write a script that will delete all comments and everything in between inside C files in my current directory. I've been using sed, and this is what I have so far:   sed -i '/ * [^()] */d' *.c  This works when the comments are on the same line as an asterisk or backslash.   However it doesn't work when there is a commented line without a slash or asterisk.   I know sed goes line by line, I just don't know how to tell it to keep deleting until it sees a */.