Preload most-used piece of software I tried an in-memory Linux distro and I was shocked by how fast it was.  Is there is a way to always cache in memory some (user specified) software like the file explorer so that you can benefit of that speed without having to preload the whole system in the memory (unfeasible if it's your main desktop because there would be not enough memory)
Lots of ram. How to use it? My PC has 8 Gb of ram. Is there any way to make ubuntu use most of it? I mean rarely drop caches and keep once opened programms in ram longer, preload apps on boot, etc.
How to get a tool that can only break specific blocks and has a name? So, right now I'm using this:  /give @p minecraft:diamond_pickaxe 1 0 {CanDestroy:[minecraft:stone]}   But I need one that also has the Name value. Anyone know this one? Custom URL Hack - anybody know how can i find the fields IDs from "User" object? I'm new in custom URL hacking.  I am trying to write a custom URL in a custom button. It is suppose to clone the User record, and while doing so, I want some user fields to be cleared. However, I need help identifying those fields IDs (e.g. Email, Name, etc).  How can i refer these fields when writing the custom URL code? In "Tasksel" how do I select a package? I found a video on YouTube that shows someone using the command tasksel from the server's boot menu after a fresh install of Ubuntu Server. Simple enough it looked like, but when I go to the options I want to choose for installation it has no information on how to select them, and when I click Enter on one of them it takes me back to the command prompt.  So how do I make a selection of the items listed under tasksel?  I have tried Shift++ to add, but no luck. Anyone know?  I want to install Ubuntu Desktop, as Ubuntu GNOME GUI is not an option in the listing for Ubuntu 17.10 Server. Trigonometry Olympiad problem: Evaluate $1\sin 2^{\circ} +2\sin 4^{\circ} + 3\sin 6^{\circ}+\cdots+ 90\sin180^{\circ}$ Find the value of   $$1\sin 2^{\circ} +2\sin 4^{\circ} + 3\sin 6^{\circ}+\cdots+ 90\sin180^{\circ}$$   My attempt  I converted the $\sin$ functions which have arguments greater than $90^\circ$ to $\cos$ but I have gone no where with it!  I also tried using double angle formula for the angles which are even. Slit screen and wave-particle duality In a double-slit experiment, interference patterns are shown when light passes through the slits and illuminate the screen. So the question is, if one shoots a single photon, does the screen show interference pattern? Or does the screen show only one location that the single photon particle is at? banner set interval How do I suppress stderr warning messages from a command inside command substitution? touch ~/deleted/$(echo "directory_"$(readlink -f foo)|tr '/' '\') 2&gt; /dev/null   where foo is a directory  It's reading the full pathname of foo and creating it as a file replacing all '/' with '\' and putting a directory_ in front so the directory  /home/test/foo would create a file directory_\home\test\foo  It does exactly what I want except a warning keeps printing tr: warning: an unescaped backslash at end of string is not portable   a. I don't know what that means b. I would like it to not show  I tried to redirect stderr to /dev/null but it doesn't work. How do I suppress it? Functional Analysis: The rank of an operator detemines if it's a compact operator. How to reset Kali linux root password No margins for Winter Bash popup When opting out the Winter Bash the top bar popup related to snowflake looks like this for me:    Is it intentional that there are no horizontal margins for popup content? CSV rows to Polyline with OGR I'm not sure if I can complete this operation in one step - but someone might be able to help me.  My input file is a csv file with PointID, x, y, z and LineID columns.  I'm looking to combine all rows with the same LineID into Polyline25D using ogr2ogr with a virtual datasource (VRT file).  I can get a MultiPoint output, but can't work out how to combine multiple rows (if it's at all possible).   Alternatively, could someone help me with a python script to combine the x, y, z fields into WKT?  Input Example :  pointid y   x   z   lineid 1   320589.01   1815258.73  423.78  1 2   320573.49   1815256.71  425.04  1 3   320557.42   1815252.40  425.86  1 4   320541.64   1815248.71  426.19  1 5   320529.37   1815247.01  427.18  1 1   320588.78   1815259.35  423.43  2 2   320573.06   1815257.09  424.66  2 3   320557.00   1815253.09  425.06  2 4   320541.79   1815249.54  425.78  2 5   320529.14   1815247.74  426.22  2 6   320516.78   1815245.02  426.84  2 1   320588.62   1815260.10  423.44  3 2   320572.59   1815258.42  424.65  3 3   320556.21   1815255.29  425.13  3 4   320540.73   1815252.19  425.80  3 5   320529.02   1815248.37  426.20  3 Universal extractors With an  of archive/compression file formats, is there a single free/open-source command line tool to rule them all? Perhaps something with a consistent / unified set of flags? (note my  friendly )  I once run into a set of aliases meant to largely simplify the task of compressing/de-compressing files with bindings to tar and other utils, but I can't find this anymore.  Update: How can I configure something like atool to not use unzip to extract zip files (which apparently can't handle files larger than 4GB) and to use gunzip instead?  $ aunpack large_file.zip error:  Zip file too big (greater than 4294959102 bytes) Archive:  large_file.zip warning [large_file.zip]:  1491344848 extra bytes at beginning or within zipfile   (attempting to process anyway) error [large_file.zip]:  start of central directory not found;   zipfile corrupt.   (please check that you have transferred or created the zipfile in the   appropriate BINARY mode and that you have compiled UnZip properly) aunpack: unzip ...: non-zero return-code Have we ever observed two drosophila lineages that evolved reproductive isolation in labs? Background  The standard definition of species refers to the concept of . If two lineages are found to be reproductively isolated, then we consider these two lineages to belong to different species. My question concerns evolved reproductive isolation in Drosophila sp. following labs due to experimental evolution.  Question  Have we ever demonstrated that two Drosophila sp. lineages that could initially interbreed (in nature or in labs) evolved through artificial selection (and drift and mutations) in labs to finally not be able to interbreed anymore either due pre- or post- zygotic isolation (see )? Or, in other words, have we ever demonstrated that two drosophila lineages evolved to become different species (reproductive isolation definition) in labs experiments?  If not, have we ever observed some partial reproductive isolation such as inbreeding depression for example?    Note: This question is motivated by @LotusBiology that could not receive the answers she/he was waiting for because he/she failed to ask questions that are possibly answerable! So I wanted to ask this question that somehow addresses  question he/she asked (now on-hold)  For more information about the concept of species, please have a look at Can Metamagic be used in Item Creation? What are the limits? One of my players has recently obtained the Craft Wondrous Item feat. In an attempt to prepare for what he may build I want to know the specific limits of Wondrous Items.  I know that someone can create an item for which they do not meet the prerequisites by adding +5 to the spellcraft DC, and that assistance is a thing.  Can someone use meta-magic when crafting a non-specific wondrous item?  Example: Amulet of Empowered Fire-Ball.  If so, can they use meta-magic feats they do not know, substituting for +5 DC?  Can the Spell Level exceed 9 for these items, as long as they add +5 for not meeting the CL requirements, and make the higher check?  Example: Amulet of Maximized Empowered Still Silent Disintigrate. Finding all software packages in Debian that provide a particular alternative The Debian distribution has the . From the Wiki:     The Debian alternatives system creates a way for several programs that   fulfill the same or similar functions to be listed as alternative   implementations that are installed simultaneously but with one   particular implementation designated as the default. For example many   systems have several text editors installed at the same time. The vi   program is a classic example of an editor that has many   implementations such as nvi, elvis, vim, etc. but which one should be   designated as the default?   In general, there are multiple packages in Debian that provide a particular alternative. How does one obtain a complete list of all such packages that exist in the Debian repositories? Let us use the vi alternative as an example.  NOTE: Doing such a query against the list of installed packages is easy, but that is not what this question asks. Prove that $f'(a)=\lim_{x\rightarrow a}f'(x)$. Let $f$ be a real-valued function continuous on $[a,b]$ and differentiable on $(a,b)$. Suppose that $\lim_{x\rightarrow a}f'(x)$ exists. Then, prove that $f$ is differentiable at $a$ and $f'(a)=\lim_{x\rightarrow a}f'(x)$.    It seems like an easy example, but a little bit tricky. I'm not sure which theorems should be used in here.    ==============================================================  Using @David Mitra's advice and @Pete L. Clark's notes I tried to solve this proof. I want to know my proof is correct or not.  By MVT, for $h&gt;0$ and $c_h \in (a,a+h)$ $$\frac{f(a+h)-f(a)}{h}=f'(c_h)$$ and $\lim_{h \rightarrow 0^+}c_h=a$.    Then $$\lim_{h \rightarrow 0^+}\frac{f(a+h)-f(a)}{h}=\lim_{h \rightarrow 0^+}f'(c_h)=\lim_{h \rightarrow 0^+}f'(a)$$   But that's enough? I think I should show something more, but don't know what it is. How to find the smallest $n$ such that $n^a\equiv 1 \pmod p$ Why not use tables for layout in HTML? It seems to be the  that tables should not be used for layout in HTML.   Why?  I have never (or rarely to be honest) seen good arguments for this. The usual answers are:   It's good to But this is a fallacious argument; . I guess it's true that using the table element for layout has little to do with tabular data. So what? Does my boss care? Do my users care?Perhaps me or my fellow developers who have to maintain a web page care... Is a table less maintainable? I think using a table is  than using divs and CSS.By the way... why is using a div or a span good separation of content from layout and a table not? Getting a good layout with only divs often requires a lot of nested divs. Readability of the codeI think it's the other way around. Most people understand HTML, few understand CSS. It's better for SEO not to use tablesWhy? Can anybody show some evidence that it is? Or a statement from Google that tables are discouraged from an SEO perspective? Tables are slower.An extra tbody element has to be inserted. This is peanuts for modern web browsers. Show me some benchmarks where the use of a table significantly slows down a page. A layout overhaul is easier without tables, see .Most web sites that need an upgrade need new content (HTML) as well. Scenarios where a new version of a web site only needs a new CSS file are not very likely. Zen Garden is a nice web site, but a bit theoretical. Not to mention its  of CSS.   I am really interested in good arguments to use divs + CSS instead of tables. On the number divisors of a number Let $d(n)$ be the number divisors of a natural number $n$. Now let $m$ be a natural number. Find least natural number $n$ such that $d(n)=m$.  Thank you In which Comic Book series is Batman actually Thomas Wayne? I've heard people say that there is a series of comics where Batman is actually Thomas Wayne instead of his son, Bruce.   Where can I find this? What is the series called?