Avoiding echo -e
Why is printf better than echo?
What is the proper way of creating installation media from Ubuntu iso? This is the third time I've tried to install Ubuntu Server 14.04.03 64-bit on the same laptop, and each time it caused different problems.  Each time I wrote the same iso image to a USB flash drive by using a different application and OS.   Universal USB Installer (pendrivelinux.com) from Windows WinImage writer from Windows built-in image writer from Linux Mint 17.2    The iso image is the same in all three cases, the USB flash drive is the same, and the laptop is the same. However each time the installation of Ubuntu gave me different installation options. For example, the last time I installed Ubuntu, it didn't show all the packages to choose while installing (Basic Ubuntu server, etc.). I'm going to submit form using cURL, where some of the contents is come from other file, selected using sed  If param1 is line matching pattern from other file using sed, below command will works fine:  curl -d param1="$(sed -n '/matchpattern/p' file.txt)" -d param2=value2 http://example.com/submit   Now, go to the problem. I want show only text between 2 matching pattern excluding the matching pattern itself.  Lets say file.txt contains:  Bla bla bla firstmatch It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. secondmatch The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using 'Content here, content here', making it look like readable English.   Currently, lots of "beetween 2 matching pattern" sed command won't remove firstmatch and secondmatch.  I want the result to become:  It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. I have a WordPress website that I recently discovered had this error on the login page:     ERROR: Cookies are blocked due to unexpected output. For help, please   see this documentation or try the support forums.   I can only access the login page from wp-login.php, since /wp-admin/ displays a blank white page.  I've searched the web and tried many things with no success:   Removing ?&gt; and space at end of the functions.php Ensuring both functions.php and wp-config.php had no spaces at beginning or end of file Opening wp-config.php and functions.php in Notepad++ and converting to UTF-8 (people recommend 'without BOM' but that is only an option in the newest version of Notepad++ - I'm guessing UTF-8 does that now) I've set WP_DEBUG to true and have received no errors in debug.log,  except for 2 that relate to when I hadn't fully uploaded some files. That particular error mentioned nav-menu.php; this confirmed that it is reporting errors, just not related to my login issues I renamed each plugin folder with _tmp at the end to try and rule out any plugins causing the problem I also renamed the plugins folder to rule out all plugins at the same time   Given these things I've tried, and that I'm not receiving any PHP errors, what else could I try? What is the difference between AOSP and AOKP? How to iterate through the name of files in a folder Assume I have many TeX files. For the sake of simplicity, also asssume they are in a single folder or directory.  I want to input all files from within my main LaTeX document. Actually I can create a list of those files using C# in advance.  To enrich my view about LaTeX or TeX, could you tell me whether or not this job can be done only by using pure TeX or LaTeX? In the simple harmonic oscillator model, we talk about the angular frequency and I understand that this tells something about the instantaneous angular velocity of the object. For example, a simple pendulum. But what does this mean when we apply this concept to an object attached to a spring that behaves as a simple harmonic oscillator? There is no instantaneous circular motion for the object, so how can we relate the angular frequency to a system like this? Note: This is a canonical post created so that we can close the many similar questions as duplicates as discussed in .   We have created a logo for a client and they love it. We've already started preparing the materials that will feature the new logo.   However, after we had created the logo, we found a logo for another company that looks eerily similar. We did not intentionally create the new logo to look like the one of the other company, in fact we didn't even know it existed beforehand, but it does regardless.  What should we do? Is this plagiarism? Can our client use the logo we have created? Should they? Or do we need to come up with another logo that's more different? Helical motion of charged particle in external magnetic field TexShop will not compile without trashing aux files after every error I have a couple of LaTeX files with the same problem. If I produce an error, fix it, and then try to compile a pdf, I get the following error.  )Runaway argument? {{ ! File ended while scanning use of \@newl@ablel. &lt;inserted text&gt;                 \par l.90 \begin{document}   If I then click on the console or trash my .aux file, it compiles fine. Any thoughts on what is going on and how to prevent this annoying extra step? Java: Load class from string Lufthansa airline offers the &quot;Economy Flex&quot; fare. The listed advantages of this fare are:  Rebooking possible plus fare difference Refundable except 70 EUR plus fare difference  What does the &quot;plus fare difference&quot; mean? Imagine I buy a ticket for 200 €. Later I decide to cancel. They keep 70 Euro, so I get 130€ back. What's with the fare difference? Fare difference to what? As a comparison, the &quot;Economy classic&quot; states:  Rebooking: 70 EUR plus fare difference Refund not possible Why didn't the machine affect Bond in Spectre? Why "grand theft auto", not "grand auto theft"? There is a video game series called "Grand Theft Auto".  According to its :     The name of the series references the term used in the US for motor   vehicle theft.      [...]      Motor vehicle theft or, grand theft auto, is the criminal act of   stealing or attempting to steal a car (or any other motor vehicle).   I always wondered why this term sounds so strange.   Shouldn't it be "grand auto theft" or maybe "grand theft of auto" instead? Are there any other terms with strange words order and/or missing prepositions like this? Prime spectrums bijection but not homeomorphism I understand there is a method for solving simultaneous modular equations. For example; $$x = 2 \mod{3}$$ $$x = 3 \mod{5}$$ $$x = 2 \mod{7}$$ We find numbers equal to the product of every given modulo except one of them - giving $5 \cdot 7$, $3 \cdot 7$ and $3 \cdot 5$. We then find the multiplicative inverses of these numbers with modulo equal to the number missing from the product. The numbers found are then 2, 1 and 1 in this case. The value of x is then given by: $$x = 2 \cdot (5 \cdot 7) \cdot 2 + 3 \cdot (3 \cdot 7) \cdot 1 + 2 \cdot (3 \cdot 5) \cdot 1 = 233 = 23 \mod{3\cdot5\cdot7}$$  But I do not understand how this method correctly gives the value of $x$. I understand that the Chinese remainder theorem proves that there is a unique value of $0\le x \lt 3\cdot5\cdot7 \mod{3\cdot5\cdot7}$ but can someone please explain why this method finds this value of x? Visiting Russia as an Arab. Am I going to be hassled? Probability of student passing an exam There're $25$ tests, each with $2$ questions. There're total of $50$ different questions (the questions do not repeat). The student knows the answer of $44$ questions. To pass the exam, the student needs to correctly answer both questions on the first test he drew, or answer $1$ question from the test he drew first, and $1$ question from the test he drew second. (meaning he draws twice if he answers a question incorrectly on his first try)  What is the probability that the student will pass the exam?  I have never faced a problem like this one so any help is appreciated. I was thinking about approaching it "manually" with some applied combinatorics but I feel like there's a much easier way that I am not familiar with. Changes to "close as duplicate" (part deux) No, this is not a , nor is it a solicitation on  to backup or  and only a little bit about Where to backup and When to do it.  This is basically a strategy question: what, where and when all together. "How" is not really relevant: there are tons of back-up programs out there and they all do the same basic thing: make copies of data.  But the real question is: are these back-up programs making copies of the data important to you?  How should you install&amp;run Ubuntu while safeguarding your data?  There is no "one size fits all" when it comes to computers, Ubuntu versions or a backup strategy, therefore I've split this up into 5 basic user types with each their own answer:       (or you're running in UEFI mode!)   And as the above does not fit everyone, one for the impatient:   !    So click one of the above links and go to your user type!  P.S. If you're running a server farm and you've read this question so far, I'm sorry: this is about a single PC, not a network, nor a server farm. Do black holes have a moment of inertia? My question is in the title: Do black holes have a moment of inertia?  I would say that it is: $$I ~\propto~ M R_S^2,$$ where $R_S$ is the Schwarzschild radius, but I cannot find anything in the literature.