I'm trying to check if a machine is a ThinkPad or not using something like this:  sudo dmidecode | grep ThinkPad   I want the end result return true or false (or 1/0).   I'm thinking the solution might be something like this:  sudo dmidecode | grep -c ThinkPad | test xargs -gt 0   But I'm not sure how to properly use xargs here.
As a part of this script, I need to be able to check if the first argument given matches the first word of file. If it does, exit with an error message; if it doesn't, append the arguments to the file. I understand how to write the if statement, but not how to use grep within a script. I understand that grep will look something like this  grep ^$1 schemas.txt   I feel like this should be much easier than I am making it.  I'm getting an error "too many arguments" on the if statement. I got rid of the space between grep -q and then got an error binary operator expected.   if [ grep -q ^$1 schemas.txt ] then         echo "Schema already exists. Please try again"         exit 1 else         echo "$@" &gt;&gt; schemas.txt fi
I need two bib-like sections: a "References" giving works explicitly cited in my text, and a "Bibliography" (or "Further reading" if you prefer) giving everything from my bibfile that didn't already appear in "References". The first is of course completely standard, but the second... I'm stumped.  Further loose constraints: I'm somewhat committed to biblatex and the biblatex-apa style. But I'll happily accept an answer not related to them if there's any chance I can adapt it. Intuition of pdf of a continuous random variable What is the intuition behind the probability density function of a continuous random variable? Integrating it within two points provides the probability that is associated between two points, but if you plug a single value into $f(X=x)$, it outputs a value. What is the intuitive understanding of this value for a given x?   For example, in the above image, the value of the red curve at x=0 is 0.4. How can 0.4 be interpreted? This isn't a particularly major issue, but I've had this thing nagging me for a while. When looking at QGIS 3.4's global variables, user_full_name is assigned my given and surname, which includes a diaeresis (¨) somewhere in there. I can't seem to find any way to get QGIS to switch/adapt encoding and display the name correctly. The accented character gets switched to that ubiquitous black rhombus.  I looked for info on this behavior and found moderately similar issues like  and  but it's not exactly the same problem as it's not a geodata encoding issue but rather how QGIS deals with values pulled from the OS.  I have tried unchecking the Override system locale tickbox in Options|General as I prefer to use American English even though my OS is set to Canadian French. No effect to observe.  There's somewhat of a workaround right now which is to fix the name in the Project variable project_author as it is editable (it's filled with the offending global variable by default).  I'm curious to know, though, if someone has encountered this before and if there's a solution in QGIS. Let $g_n= {2^2}^n +1 $. Prove $g_0 · g_1 · · · g_{n−1} = g_{n} − 2$ Let $g_n= {2^2}^n +1 $. Prove $g_0 · g_1 · · · g_{n−1} = g_{n} − 2$.    I'm not sure how to start this proof, if it should be done algebraically or if I should try to use a proof by induction. How can I create an empty file from the command line? This is a follow-up to .  Suppose you want to denote vectors by upright bold letters; then \mathbf{u} works fine, except that if it's a Greek letter you have to use \boldsymbol{\omega} instead.  Question: Is it possible to define a generic vector command in LaTeX which automatically chooses between \mathbf and \boldsymbol, so that one can write just \vect{u} and \vect{\omega} without having to treat the Greek symbols specially by hand?  (Just to be clear: \newcommand{\vect}[1]{\boldsymbol{#1}} is no good in this situation, since \boldsymbol{u} gives bold italic instead of roman.) How are "Suggested Tags" chosen? After you've typed in a question, you get suggested tags that appear that look like this:        It appears that you need a minimum amount of characters ():     you must have entered a title (any length) and a minimum body length of 220 characters.   But other than that, how are the tags chosen? Is it:   A match of the title/body with other questions (taking the tags from those questions) A match of the title/body with tag excerpts (taking tags with overlap) A match of the title/body with tag wikis (taking tags with overlap) All of the Above None of the Above Other (please explain)   Some additional info from :  The suggested tags seem to only pop up on meta.so (they do not work on regular Stack Overflow, or on other SE sites).  While we're on the topic, why isn't this feature implemented network-wide? How do you factorise $x^3z - x^3y - y^3z + yz^3 + xy^3 - xz^3$? I'm trying to factorise $$ x^3z - x^3y - y^3z + yz^3 + xy^3 - xz^3 $$ into four linear factors.  By plugging it into WolframAlpha I've learned that it's $$-(x-y)(x-z)(y-z)(x+y+z)$$  My question is: what are the steps involved in factorising the expression? Is there a method I don't know about that I'd have access to with my limited maths?  Really appreciate any help! Similar to Lifepod 1993, but not it pgfplots - draw boxplot without outliers I am creating a boxplot with pgfplots, using the builtin statistics library. I load the input data from a table file.  \usepackage{pgfplots} \usepgfplotslibrary{statistics} ... \begin{tikzpicture} \begin{axis}[boxplot/draw direction=y]    \addplot+[boxplot] table[      col sep=tab,      x expr=\coordindex,      y=aColName] {aFileName}; \end{axis} \end{tikzpicture}   Is it possible to draw the plot without outliers? Or hide them? I don't want to pre-calculate the boxplot values by hand. Taskbar > File Explorer > Context Menu failing me So I have the latest version of Windows 10, and this is a new PC.  File Explorer is in the taskbar.  When I open the context menu (right-click) on it, I get the list of folders as seen in the picture.  When I right click on any of them, I get the blank black box you see in the picture.  If I click on any of the folders, such as Downloads or Update.  Nothing happens.  They don't open.  The only way to use it is to click on the actual File Explorer icon and then navigate from there.  I've tried uninstalling things (not that I have much installed since it's a fresh install) and I've tried scans, etc.  This only happens with File Explorer.  Everything else works fine.  I can't figure it out. Anyone can comment this ruby code? Recursively delete empty directories in Windows How to add citation for a whole paragraph? If I write a report and a whole paragraph is based on one source but not cited verbally it seems unnecessary to include the reference after every sentence:  Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua (source 1). Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat (source 1).  Now I found a Phd thesis that puts the reference after the last dot of the paragraph to indicate that it is based on this very source:  Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. (source 1)  Is this a common practice? Is it generally understood? What are other ways to add the reference for a whole paragraph? How do you improve Drupal performance? Drupal is fast at develop, but the performance is so poor.  It is hard to reach 50 request per second.  And there are so many SQL queries in a simple web page.  If you test the request time of a form submit in Drupal.org it will always take seconds to finish.  How do you improve the speed of your web site? The problem:  Assume $f: \mathbb{R} \rightarrow \mathbb{R}$ satisfies $|f(t) - f(x)| \leq |t - x|^2$ for all $t, x$. Prove $f$ is constant.  I believe I have some intuition about why this is the case; i.e. if $t$ and $x$ are very close, ($|t - x| = \epsilon$), then $\sqrt{\epsilon}$ will converge to 0, so $|f(t) - f(x)|$ will also converge to zero if you keep taking $t$ and $x$ closer and closer to each other. However, how do I formalize this argument? Thanks. I am trying to solve a variation on the .  In this scenario, someone is selecting coupons at random with replacement from n different possible coupons. However, the person is not selecting coupons one at a time, but instead, in batches.  Here's an example problem formulation: There are 100 distinct coupons. A person makes selections in 10-coupon batches at random (each coupon with replacement). What is the expected number of batches necessary to have selected 80 unique coupons?  I have been able to determine the expected number of selections necessary to have selected k unique coupons when selecting one at a time (much like Henry's ), but I'm a bit stumped as to how to go about solving it with this particular wrinkle.  Any tips/guidance would be greatly appreciated. What is the C# Using block and why should I use it? What is the purpose of the Using block in C#? How is it different from a local variable? How to create Mist in Blender Referencing subfigures in main caption (with \subfloat and \subref) I've used subfloat to include subfigures, with their relevant labels but with empty captions. what I'm going to do is to reference these figures with \subref in the main caption of the figure. But what I get is only ?? signs in the caption [main caption]. I can't figure out what's the problem. this is what I have:  \begin{figure} \centering \subfloat[][] { \includegraphics[scale=0.55]{signal} \label{signal_model} } \subfloat[][] { \includegraphics[scale=0.55]{amplitude} \label{amplitude_mod} } \caption{phase noise variability: \subref{signal model} some text \subref{amplitude_mod} some other text} \end{figure}