Timestamping each line of a file with a date taken from the file itself
update line based on previous line
Using the Terminal keybindings with bash on macOS I have been trying to learn the keyboard shortcuts for the shell on macOS, but when I tried using ALT+B, it did not work.  How do you discover, configure and use keybindings in the shell? Any cheatsheets would be helpful. What do the supercharges in extended supersymmetry do? What do the supercharges in  do?  In ${\cal N}=1$ supersymmetry there are a certain number of fermions and and equal number of bosons. You can transform all fermions to the bosons (and vice versa) in a 1 to 1 fashion using a single supercharge, $Q$.  So what happens when you have, for example, ${\cal N}=2$ supersymmetry with 8 supercharges? Since $Q$ is a generator of supersymmetry transformations, is it a linear combination of these supercharges that act on the particles? In which case could one particle be acted on by two separate linear combinations of $Q$? Or is it strictly one linear combination of $Q$ per fermion/boson?  Also, what does ${\cal N}$ mean physically? What difference does ${\cal N}=2$ have to ${\cal N}=1$ other than more supercharges? Or is that the only difference between the two theories? How to install Flash player on Ubuntu? Even though I have the latest Adobe Flash player 11.2 for Linux in Firefox -   - a particular online flash game still requests that I update to the latest flash player.  I've tried this online game on my laptop (Windows 8 with Flash Player 11.8) and it has no problems.  Is there a way to trick Ubuntu or this game into thinking Flash Player 11.8 is "installed"? How can I donate to Ubuntu without PayPal? When I wanted to download Ubuntu 12.10 from ubuntu.com, I was asked to make a donation. However, there is only a PayPal option to make the payment. But I don't use PayPal. Is there any other option to make the payment? Setting Low Disk Space Alerts on Windows Server 2008 OpenLayers 3: Cross-Origin Request Blocked: The Same Origin Policy disallows How do I assign the output of a command into an array? Left pedal coming loose On my bike, which I just built out of spare parts, the left pedal seems to constantly be coming loose. It seems to come out about 5m every time I ride ~10km.  It's an old cotter pin crank, and the pedal is a left pedal (there's an L stamped into the end of the screw that goes into the crank). The pedal has a crack in one side of the axle compartment, but I don't think that would affect it.  I thought that these pedals had left-hand threads so that the action of pedalling would work to tighten the screw? If so, why would this be happening, and is there anything I can do about it short of replacing the crank and pedal? I am a Saint Lucian and will be traveling to Manchester, UK soon about which I am a bit nervous.  Run Down:   I own a small business in my country (in the Caribbean), I have a certificate mentioning the details of the business from my Government. I pay rent in my country, but I do not have any loans (I hate owing). I pay life insurance in my country. I have a US B-1/B-2 visa (Visitor &amp; Business). I have visited the US once (last year November) on my US B-1/B-2 visa.   What I will be doing in the UK:   I plan to spend three months out of the six months which would be granted if I get leave to enter stamp. I plan to skydive in the first week and spend a few nights at an Airbnb. I plan to visit the Manchester Football Club stadium, I'm not the biggest of football fans but since I'm in Manchester, why not! I plan to do some more sightseeing and enjoy my time there. After the first week I will be staying with my female friend who owns an apartment for the rest of the time showing me around and helping me experience the UK lifestyle until June.   Why I'm leaving in June:   I am a WordPress enthusiast (I'm a Programmer) and WordCamp EU will be happening in France this year so I plan to fly from the UK to Paris where I will spend three days then take another flight from there to my country.   How my flights will be:   I will be taking a one-way Thomas Cook flight from my country to Manchester but will be purchasing my ticket for Manchester to France ahead of time so I could show Thomas Cook as well as Immigration that I don't plan to stay.   My concerns, could someone address them point by point please?:   I have a bank account but I just use it for collecting easy payments from my clients and pay for expenses. I store my savings in a credit union because of higher interest rates paid than the bank. When I applied for my US visa I showed a credit union statement showing my total balance. I'm seeing online that I should provide statements but these statements would look very bad since I my bank account is just for expenses... I mean it sometimes gets as low as $30 then, when my monthly earnings come in from clients, I withdraw savings to the credit union and leave what I need in the account for expenses. I read another post and it said people with bank statements showing poor spending might have difficulty but it's simply because the account is used for expenses not savings. For the later stages of my visit (after the first week) I will be staying with my friend. I will simply be staying with her to save on cost of Airbnbs for the next two months three weeks, even though they could be cheap, free is better right? I will be booking the Airbnb, skydiving and tours prior to traveling to the UK, will that help? Is my stay too long for staying with someone? I won't be depending on her for anything since I have my own funds...it's just convenient that she has a place where I could stay. If it is then I don't have a problem shortening my stay to 1-2 weeks and just head back to my country and take a separate flight to Paris in June.   I am nervous because I really want to visit the UK and see my friend, I am also not sure if the minimum amount of time that could be given to a visitor is six months? What if I get a round trip for two weeks and the Immigration officer gives me exactly two weeks stay, is that possible? Or is the minimum they could give six months?  Your help is very much appreciated, I want soon to try backpacking (nomad life) but I don't think my poor heart could take the stress of worrying about immigration :(  Update  Since people in the comments are asking about my relationship with the friend I plan to stay with even though she's from my country originally but now a UK citizens and we are simply friends. Custom hard edges in Blender Proving that if $A$ is a $8\times 8$ matrix over $\mathbb{R}$ and $A^3=A$, then $A$ is diagonalizable. If $A$ is a $8\times 8$ matrix over $\mathbb{R}$ and $A^3=A$ then prove that $A$ is diagonalizable.   I have got that the minimal polynomial of $A$ may be $x^3-x$ or $x$ or $x(x+1)$ or $x(x-1)$ in the 2nd case it is not possible in the 3rd and 4th cases the matrix will be the identity matrix or identity matrix multiplied by a scalar!  But I cannot reach any further. Why doesn't "its" have an apostrophe? I know that its is the possessive and it's is the contraction, and know when to use them.  But why doesn't the possessive have an apostrophe?   "The bear's eating a fish." [contraction] "The bear's coat is brown." [possessive] "It's eating a fish." [contraction] "Its coat is brown." [possessive] "One's eating a fish." [contraction] "One's coat is brown." [possessive]    lists the etymology as "From  +‎ ", and  says that this is actually the original form:     Originally written it's, and still deliberately spelled thus by some writers until early 1800s.   So what happened to the apostrophe?  When did people stop using it, and why did they?  It seems that it's as the possessive is more natural, as most people do this until they're taught that it is wrong (or even after).  Update: Online Etymology Dictionary has been updated to include two potential explanations:     The apostrophe came to be omitted, perhaps because it's already was established as a contraction of it is, or by general habit of omitting apostrophes in personal pronouns (hers, yours, theirs, etc.).   Can anyone back up either of these arguments?  The possessive one's still has the apostrophe, despite these. How can author deal with late reviews? Another problem I personally struggle with in peer-review publication process is the situation when review takes really, really, really long. The precise definition of "long" is probably very area-specific: for example a paper in Maths will probably took longer to review than one in Physics. Many well-established journals and major publishers, sadly, prefer not to specify the "rules of the game" precisely, particularly how long the review process should normally take. Fortunately, I quite often serve as a referee with the very same journals and know the amount of time I am given to write a review. Unfortunately, when I am an author, I do not observe these deadlines to be always met. For example, a notable U.S. publisher would ask a reviewer to send a review in 2 months; but in practice a first review of my paper once took as long as 8 months.  As a rule of thumb, I usually start writing to editors with questions about "the status of my paper" in X+1 months time, when X is a deadline time for a reviewer to submit a review. This strategy is not particularly successful &mdash; what I usually get is a recommendation to be more patient. Since there is no "official" deadline time announced, there is no formal ground for complaints here.  Of course, such delays lead to a whole bunch of funny situations, particularly if a preprint is put online (e.g., on arXiv) and the results are presented in some conferences. Follow-ups with no official paper to cite, grant applications in which you can not justify by a solid publication, good research but bad bibliometrics or CV, to name just a few.   Could you recommend an efficient way to deal with this problem? Any way to tell apart a CPU defect from a mainboard defect? What's the deepest reason why QCD bound states have integer charge? How to remove chromium-browser settings from Ubuntu 14.04? I have already gone through   and I'm really not getting why the solutions given there are not working for me.  What I'm doing is:   sudo apt-get purge chromium-browser   rm -rf ~/.config/chromium     Then reinstalling by running the following command:   sudo apt-get install chromium-browser    This must remove the settings of chromium-browser and do a fresh installation. The browser is uninstalling, but after being installed it is containing the previous settings, moreover it's not signing me out of even Gmail! Scheduling a team based activity with 10 different teams and X different games. Every team must meet each other ONCE but never twice, Hi there I am planning a ”Scavenger hunt”-like activity (I have no other words for this event), and I am having trouble creating the schedule.   The idea of this hunt/run/game/competition is that 10 teams will battle each other at X different mini games. The games on are team vs. team based, meaning that there will always be two teams on each post and one winner and one loser.  I require that every team fights every other team. Meaning that team 1 will have to meet team 2, 3, 4, 5, 6, 7, 8, 9, and 10, and team 2 will have to meet team 1, 3, 4, 5, 6, 7, 8, 9, 10 (and so forth). The amount of mini games must be so, that every team only meets the other teams ONCE each, but still they have to meet every team.  How many posts do I need to create, and how could I schedule the overall activity? (A table of rounds and teams would be much appreciated). Why doesn't this C++0x code call the move constructor? I created a custom module in drupal 8. And I am trying to add js and css file in  my_module.libraries.yml file using this   lrv_key:   version: 1.x   js:     js/lrv.js: {}        dependencies:       - core/jquery       - core/drupalSettings   css:     theme:       css/lrv.css: {}   But it doesnt work. After MiKTeX update: suddenly all fonts (incl. existing path-referenced ttf files) are not found by fontspec / LuaLaTeX anymore