update attempt to clarify more, using an example, does the following shell commands:  SHELLVARIABLE="1st line, 2nd line, 3rd line, "  printf '%s' "$SHELLVARIABLE"   generate this output:   1st line,&lt;newline&gt;2nd line,&lt;newline&gt;3rd line,&lt;newline&gt;   &lt;newline&gt; being the character 0x0a / \n?  Original question formulation  What is the correct (POSIX-confirm) way to store a newline character 0x0a (aka known by its commen c style escap \n) into a shell variable.  I want to make sure that doing the following:  SHELLVARIABLE=" "   is, not merely working by chance but instead is indeed the correct way.  Since POSIX's  is perfectly capable of producing a newline character (i.e. printf '\n', or printf '%b' '\0012') I first attempted a more explicit (? or correct?) form:  SHELLVARIABLE="$(printf '\n')"   though a tempting approach, does not work. As the according to , command substitution (i.e. via $() and ` `) shall remove     sequences of one or more newlines at the end of the substitution.   Note: Asking to store a single trailing newline into a shell variable is only to abstract the more general use case (i indeed seek answer to) that is how to store a string into POSIX shell variable which ends with the newline character.
I'm trying to set an RSA key as an environment variable which, as a text file, contains newline characters.  Whenever I attempt to read from the file and pass it into an environment variable, it will just stop at the newline character on the first line. How can I prevent this?
I often use  to keep my sentences gender neutral. Many of my friends (none of them are native speakers), however, consider this to be grammatically incorrect, and suggest me not to use it in formal English exams.  My questions are:   Is singular they widely accepted in English speaking countries such as America and Britain? Is it formal enough to be used in formal situations, such as a public speech? Is it casual enough to be used in informal situations, such as gossiping among friends? I know the so-called textbook definition of unit tests and integration tests.  What I am curious about is when it is time to write unit tests... I will write them to cover as many sets of classes as possible.  For example, if I have a Word class, I will write some unit tests for the Word class.  Then, I begin writing my Sentence class, and when it needs to interact with the Word class, I will often write my unit tests such that they test both Sentence and Word... at least in the places where they interact.  Have these tests essentially become integration tests because they now test the integration of these 2 classes, or is it just a unit test that spans 2 classes?  In general, because of this uncertain line, I will rarely actually write integration tests... or is my using the finished product to see if all the pieces work properly the actual integration tests, even though they are manual and rarely repeated beyond the scope of each individual feature?  Am I misunderstanding integration tests, or is there really just very little difference between integration and unit tests? I have to prove by induction that $$\sum_{r=0}^{n}\begin{pmatrix}n \\ r \end{pmatrix}=2^k$$, using the identity $\begin{pmatrix}n \\ r-1 \end{pmatrix}+\begin{pmatrix}n \\ r \end{pmatrix}=\begin{pmatrix}n+1 \\ r \end{pmatrix}$. I'm fine with everything except the inductive step, where I only managed to get as far as $$\sum_{r=0}^{k+1}\begin{pmatrix}n \\ r \end{pmatrix}= \sum_{r=0}^{k}\begin{pmatrix}n \\ r \end{pmatrix}+\begin{pmatrix}n \\ k+1 \end{pmatrix}$$ I tried to then use the identity and substitute $\begin{pmatrix}n \\ r \end{pmatrix}=\begin{pmatrix}n+1 \\ r \end{pmatrix}-\begin{pmatrix}n \\ r-1 \end{pmatrix}$ but all this did was just take me around in a circle. I also couldn't substitute $2^k$ for $\sum_{r=0}^{k}\begin{pmatrix}n \\ r \end{pmatrix}$ since this didn't properly simplify to give $2^{k+1}$. However, I think that I have to obtain the expression $\sum_{r=0}^{k}\begin{pmatrix}n \\ r \end{pmatrix}$ since it simplifies to $2^{k+1}$. But I've not been able to obtain this in anyway so I'm wondering if anyone can guide in what I need to or what direction I need to take to complete the inductive step. Can a self-complementary graph on 100 vertices have precisely one vertex of degree 50? What could be the reason, that private keys are not unlocked? Since I updated to Ubuntu 17.10 a while ago, my private keys – the which I use for example to access my server via ssh – are not unlocked programmatically after login anymore.    My understanding is, that usually the seahorse client should take care of this, by asking you whether or not to store the key's password when typing them in for the first time.  My first guess was, that seahorse-daemon wasn't running for some reason, but it is:  user@Zeus:~$ ps aux | grep seahorse user    19170  0.0  0.1 432636 26564 ?        Ss   00:07   0:00 seahorse-daemon   My second guess was, that for some reason I have to delete all related passwords stored in seahorse under »Passwords->login«:    I was hoping to force the client to ask me again and then storing them again. But this didn't help either. The client does not pop up to ask me...  Then I found this question, which could be related, but did not help me:    As the management of other passwords work as expected (for example passwords for nautilus, Chromium, Nextcloud etc.) I assume the problem has to do something with ssh-agent...  Can anybody hint me in the right directions, how to solve this problem? Has anything changed in the way how GNOME handles passwords? Maybe some new fancy program failed being installed during the upgrade process?   UPDATE When I add the private key to the authentication agent again with:  ssh-add ~/.ssh/id_rsa   and try to log in, I will be asked to unlock the key only once, after that the key gets unlocked programmatically. But this works only until the next reboot. After a fresh start, I have to add the key again... I have a question that is highly similar to this one:  However, I'm not sure how to do this when fractional powers are involved. I understand that the answer involving the binomial theorem shows this for fractions too, but I'm not sure how to go through the mechanics of it all. For example, when trying to differentiate $\sqrt{ax+b}$, I get to   $$ \lim_{h \rightarrow 0}  \frac{\sqrt{a(x+h)+b} - \sqrt{ax+b}}{h} $$  then can't get the $h$ to cancel out. I think this involves algebraic manipulation of some sort, but can't figure it out.  Thanks Determining if an Object is of primitive type I have an Object[] array, and I am trying to find the ones that are primitives. I've tried to use Class.isPrimitive(), but it seems I'm doing something wrong:  int i = 3; Object o = i;  System.out.println(o.getClass().getName() + ", " +                    o.getClass().isPrimitive());   prints java.lang.Integer, false.  Is there a right way or some alternative? I installed Ubuntu alongside Windows but I did not disable secure boot as someone told me it could cause problems with boot loader. So when installation finished and I rebooted, the system went straight into Windows. I went to Ubuntu IRC Support and they told me to turn off the secure boot and reinstall Ubuntu. I did that but my system still boot into windows.  This is a picture of partitions on my system:    This is my first Ubuntu install on my new laptop. I followed everdaylinux guide to install it and I used something else option. When do we not put a comma before "because"? In what situation do you put a comma before "because"?   And, when do you not put a comma before "because"?   I've always assumed that you put a comma, because the clause introduced by "because" will always be independent, because it cannot stand on its own, because it wouldn't make sense on its own.   Is this the case? Could you think of an example where it doesn't take a comma? 18.04 on MSI GE63 - boot hangs at 'Loading initial ramdisk' without `acpi=off` What is the command to open the shutdown dialog? I would like to use a gesture to shutdown/restart my computer and I need to know the command that launches the shutdown dialog: What are the alternatives to OS X's Spotlight? Why must a singularity form inside a black hole? android expandablelistview how to set space between groups items I am trying to change the page size in the QGIS 3.0 Composer but I am not able to see the Composition tab.  I have right clicked an empty space in the toolbar but did not see anything about composition.  I am using Windows 7.  I tried looking at the QGIS docs but they are still in testing. How to hook into the CPT's title placeholder? I want to change the default placeholder text in my Custom Post Type title field. This isn't possible while registering a new post type.  The following screenshot describes it. I don't want to award a bounty if I feel that the user hasn't answered the question in the right fashion. How do I prevent it? How to successfully put a bibliography in a report on TexShop? I'm trying to put a bibliography in my LaTeX document, but I get various errors when I run it in BibTeX (saying no \citation found etc.), and no bibliography is printed in the PDF when I typeset it in LaTeX. My code reads as follows:  \documentclass[12pt]{report} ... \usepackage{biblatex} \addbibresource{SUSYBib.bib} ... \begin{document} ...\cite{1}... ...\cite{2}... \nocite{*} \printbibliography \end{document}   And my .bib file reads as  @book{1, title={The Schrödinger Equation}, author={F. A. Berezin, M. A. Shubin}, year={1983}, publisher={Moscow State University, Moscow}, pages={57-59} } @book{2, title={An Introduction to Measure Theory}, author={Terence Tao}, year={2011}, publisher={American Mathematical Society}, pages={91} } Is it possible to understand the One Piece storyline by watching the movies only? How does Linux handle multiple consecutive path separators (/home////username///file)? I'm working on a python script that passes file locations to an scp subprocess. That's all fine, but I'm in a situation where I may end up concatenating a path with a filename such that there's a double '/ in the path. I know that bash doesn't care if you have multiple file separators, but I'm wondering how exactly that is rectified. Is it bash that strips extra /s or does it really not matter ever?  I ask because it will save me several lines of code to check for extra /s while concatenating. I know it's not a big deal, but I'm curious as well. I have a bash script that has the line cd //usr (instead of cd /usr), which seems to imply there might be a significance to using multiple /s in a path