Detect if executable file is on user's PATH
How can I check if a program exists from a Bash script?
How to delay or slowly loop commands? I found 11 questions like this on gamingSE already, but none of them have proper and up-to-date answers. So I'm creating this Q&amp;A:  How do you either activate a command x seconds/minutes/hours/… in the future or every x seconds/minutes/… in a loop?  Repeating command blocks and ticking functions execute 20 times per second, redstone is  in many situations and most of the extremely fancy solutions, like falling blocks in cobwebs, have broken over time or are needlessly complicated. I am trying to route a pic32 chip to a  chip and having a bit of a hard time getting all 17 address lines and all 8 data lines connected. I am trying to tie the first 16 address pins to portB pins 0-15 and the data pins to portD 0-7.  After thinking about it for a while I realized that I am probably making my life more difficult by trying to line up rb0 with a0, rb1 with a1, etc. All I really want to be able to do is write a 16 bit value to portB and have the majority of the address loaded and ready. If I make pin assignments based on ease of routing, the logical address will be different between the mcu and the ram, but it should at least be consistent. Since nothing else needs to communicate with the RAM, I don't think it will be a problem if the mcu asks for address 0x101 and the RAM gives it address 0x110.   However, I wonder if it is a good idea. If there is some structure internal to the RAM designed to make sequential reads more efficient, or something like that, then I may want to go to the trouble of routing them 1:1. The pins arrangement on both chips fees somewhat random to me, so it would make it a lot easier on me if I could ignore the particular numbers. Is there any good reason why I should or should not do that? Square root of Positive Definite Matrix What is the probability that a shuffled standard deck of 52 cards has no two cards of the same rank together ?  I am unable to get a handle on this problem, and wonder whether there is an analytical solution ? Does DTIME(O(n)) = REGULAR? Currently, when someone suggests an edit, they are unable to keep track of it without watching reputation levels or constantly refreshing the page. What I would like is a notification, that shows up like the notification where someone has edited your question, that shows whether a suggested edit has been approved or rejected after the last vote is cast. This way, the community can be notified when their edit has been rejected/approved, while focusing their efforts on another question/answer. How does one get the MinionPro \qoppa? Since I have switched to the 2014 texlive, one issue is not working: the character \qoppa. The command is defined in polutonikogreek in babel. It is an archaic greek letter, but was used also in classic times for the number 90.  The glyph is available in the cmr font and in MinionPro and in the beautiful MinionMath font of Johannes Küster. I want the latter. In MinionPro/MinionMath, it is unicode character 03d9 (formerly u+03DE, it recently changed, as it turns out), see   How do I get the glyph into latex? I tried  \def\testqoppa{\begingroup\fontfamily{MinionPro}\fontencoding{LGR}\selectfont\char19\endgroup}   and   \def\testqoppab{\begingroup\fontfamily{minionmath}\fontencoding{LGR}\selectfont\char19\endgroup}   But all this gives the cmr glyph, because latex complains  LaTeX Font Warning: Font shape `LGR/MinionPro/m/n' undefined LaTeX Font Warning: Font shape `LGR/minionmath/m/n' undefined (Font)              using `LGR/cmr/m/n' instead on input line 571.   This seems like a beginner error from my side. Can somebody help me to get it right? I need \qoppa only in two places, so a nasty trick is also sufficient. The MinionMath font is installed and is working for all other purposes. Here is an extract of the .cls file:  \usepackage[fullfamily,textlf, opticals, swash, onlytext]{MinionPro} \usepackage[extraops,textcomp,withamsmath,amssymb]{minionmath} \usepackage{amsmath}             \usepackage{minionamsmath} \usepackage[polutonikogreek,greek,latin,french,italian,german,british]{babel} What is the difference between: Rooting, Jailbreak, ROM, Mod, etc.? Roast duck vs. roasted duck How do I separate hydraulic disc brake pads after pulling the brake while the wheel is off? Are these gerund sentences grammatically correct? I bought this book titled 2 Hari Taklukan Grammar, written by Edward Rahardian in Bahasa (Indonesian language) and mostly talk about gerund and infinitive. And these are some examples of the gerund sentences that I found.        His mother suggested having lunch before we leave.     I will try studying harder.     The car needs washing.     Your hair needs washing.     My teacher disliked me coming late.        Somehow those words sound unnatural for me because I've never heard those in daily conversations. As a learner, I only get exposed with English by watching TV series and any other entertainment resources.  So in my thought, they sound more natural like this:        His mother suggested to have lunch before we leave.     I will try to study harder.     The car needs to be washed.     Your hair needs to be washed.     My teacher disliked me to come late.       Are those sentences in the first group grammatically correct? And, is it normal for one to say them in normal/daily conversations? Proving the identity $\sum_{k=1}^n {k^3} = \big(\sum_{k=1}^n k\big)^2$ without induction Can not find the tag library descriptor for “http://java.sun.com/jsp/jstl/core” What characters are valid in a Java class name? What other rules govern Java class names (for instance, Java class names cannot begin with a number)? How can I display only the unique values in one column in Excel? Is there a way to display the unique values in a column ONLY?  Example:   AAPL AAPL AAPL AAPL AKAM AMZN AMZN AMZN AMZN AMZN AMZN  Expected result:   AAPL AKAM AMZN  I have already done a sort for multiple factors, and the first match for each is the best match.  I'm not sure if this is a vlookup or something else. An example of a norm which can't be generated by an inner product I realize that every inner product defined on a vector space can give rise to a norm on that space.  The converse, apparently is not true.  I'd like an example of a norm which no inner product can generate. $ \tan 1^\circ \cdot \tan 2^\circ \cdot \tan 3^\circ \cdots \tan 89^\circ$ How can I find the following product using elementary trigonometry?     $$ \tan 1^\circ \cdot \tan 2^\circ \cdot \tan 3^\circ \cdots \tan 89^\circ.$$   I have tried using a substitution, but nothing has worked. Is this NPN transistor AND logic gate practical? Mean Squared Error (MSE) of parameter $p$ in binomial distribution: intuition Reading JSON from a file?