$ cat Makefile clean:     find . -print0 | grep -z pattern | tee &gt;\(tr '\0' '\n' &gt; /dev/tty\) | xargs -0 rm $ make clean /bin/sh: /dev/tty): Permission denied   Previous question:
I often find  syntax very helpful, e.g. process substitution like in diff &lt;(sort file1) &lt;(sort file2).  Is it possible to use such Bash commands in a Makefile? I'm thinking of something like this:  file-differences:     diff &lt;(sort file1) &lt;(sort file2) &gt; $@   In my GNU Make 3.80 this will give an error since it uses the shell instead of bash to execute the commands.
If $|a| = 12, |b| = 22$ and $\langle a \rangle\cap \langle b\rangle \ne e$, prove that $a^6 = b^{11}$ Is there any way to bring an egg to its natural state (not boiled) after you cook it? This is probably a stupid question, but I'm curious now after I opened the refrigerator looking for eggs to make a cake and there was only one and it was cooked. Is there any way to undo that, whether at home or an industrial way? How to integrate PHP forum system with new Django website Note: This is not the same as , which is about the moderator tool. I am talking about the flag history page that is accessible through the user profile at .  I tend to have a pretty good hit rate for flags, well above 90% helpful on several sites. I also semi-regularly review the flag history page, both to see the status of any outstanding flags as well as see how flags I raised have been handled. Particularly, whenever a flag of mine is declined, I look over the post I raised the flag against with this new information in mind, to try to determine if I should change my flagging behavior in some way to better match the specific site's scope.  However, comment flags are difficult in this regard. Most often, there is only a binary status: helpful or declined. Helpful comment flags nearly always lead to the comment being deleted, so that obviously could present a bit of a problem, but that's not really relevant because a helpful flag means you should just keep doing what you've been doing. Declined comment flags, on the other hand, usually mean the comment is kept. It's the declined comment flags that I want to learn more about. But there's no way to!  All the flag says is which post it was on, how I flagged a comment, that I was the one to raise the flag (which frankly is rather useless information when you are already looking at your own flags summary), when the flag was raised and whether it's pending, helpful or declined. In a very few cases the moderator handling the flag may leave a helpful return comment.  This can get even more confusing if I raise multiple flags in quick succession against comments on the same question including any answers to it, because they basically all get bundled together.  Even in the case of a declined flag where the comment remains, there is no way to find your way back to the specific comment you flagged! Thus it is very difficult to recognize the error of your ways. Because comment flags (with few exceptions) are handled by diamond moderators only, the lack of feedback about which comment's flag was declined means it's easy to keep wasting the moderators' time without even intending to do so.  Hence my feature request: add a link to the specific comment that the specific flag was raised against, ideally only if that comment remains. How do you print the current month, day and year using awk and date? I can't seem to grab the month, day and year using   awk '{print $2, $3, $6}' date    Does anyone know how to? Scenario (Ubuntu 16.04):  I compile and run a C program (with -g, I get the traditional Segmentation Fault (core dumped), and then (of course) there is no mythical "core" file to be found. Some digging says to modify /proc/sys/kernel/core_pattern with a command to the effect of: echo '|tee /home/me/my_core_folder/my_core_file' | sudo tee /proc/sys/kernel/core_pattern, and after doing this, I stop getting (core dumped) and start only getting the plain Segmentation Fault. I try things like gdb ./program_object_file.out core.pid which obviously doesn't exist (I was getting desperate), and of course try the plain gdb ./a.out followed by (gdb) core core.pid and variants of the commands where I spam the tab key desperately trying to get auto-completion to get me to where I need to be.  Question:  Is there a generalized way I can get to core dumps? I recognize that every machine that I touch seems to have a Michael Bay's Transformers-esque ability to reconfigure hardware and software such that no device I own can be expected to work normally out-of-the-box. Is there a simple algorithm/recipe I can follow to locate core dumps on my own machine as well as on other peoples' machines? I always find myself tutoring friends on stuff like this after no small amount of  work to get things working for myself and it would be nice to be able to run a command or something to get core files dumped to the directory which the executable was run from... is there any way to do this that should work on most (I would settle for "some") Linux/Unix machines? How can I list all the printable ASCII characters in the terminal? How do I call one constructor from another in Java? Is it possible to call a constructor from another (within the same class, not from a subclass)? If yes how? And what could be the best way to call another constructor (if there are several ways to do it)? How do you make the shapefile a Read-only so the client can not make any edits using 10.2.2 ArcGIS.  It is not within a geodatabase, just a stand alone shapefile.  I am using Windows 8 When reviewing Suggested Edits on Stack Overflow, I often come across "fixed formatting" suggestions that use  to place emphasis on certain keywords, but isn't actual code.  For example:     I am having a difficult time with a background task in iOS. The problem I seem to be facing is that iOS is silently terminating the App if my background task runs for too long. What can I do to increase time iOS will wait for my background task to complete?   Gets edited to:     I am having a difficult time with a background task in iOS. The problem I seem to be facing is that iOS is silently terminating the App if my background task runs for too long. What can I do to increase time iOS will wait for my background task to complete?   This seems like an invalid use of an inline code span because, well, it isn't code, and it is distracting. There are a    of these edits being made. Often enough they get approved, which reinforces the behavior.  Is this a valid use of inline code spans? If not, should it be edited and corrected? Should edits suggesting these changes be rejected? I constantly stay up to date with each new release of Blender, but this means my preferences are wiped clean each time. How do I export/import these preferences to avoid loosing my carefully crafted set up each time? I am preparing a book for publication which contains the following passage:     Stromberg in Religious Liberalism in Eighteenth-Century England   (1954) noted that 'the critical moment in the emergence of a positive   spirit of reform...consisted in the awareness of evil as being social   and remediable. It begins about 1750.'   My proof reader (my wife) has picked this out suggesting it should be the past tense. However if I say It began about 1750 it seems to convey too much certainty about the exact date. I just want to convey an impression of it being something which emerges in the mid-eighteenth century. I believe use of the present tense is the way to go.   But what is this artifice called, this use of the present to convey mild uncertainty? Execute managebean method from javascript onload event Ubuntu 14.04, problem when install gstreamer1.0-libav, unmet dependencies Suddenly my Ubuntu stopped playing video. When I open a video, the player suggests that I install  gstreamer1.0-libav. However, it fails to install.  I tried installing it manually, here is the error message:  $ sudo apt-get install gstreamer1.0-libav Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  gstreamer1.0-libav : Depends: libavcodec54 (&gt;= 6:9.1-1) but it is not going to be installed or                                libavcodec-extra-54 (&gt;= 6:9.13) but it is not going to be installed                       Depends: libavformat54 (&gt;= 6:9.1-1) but it is not going to be installed E: Unable to correct problems, you have held broken packages. So what I have right now is something like this:  PropertyInfo[] info = obj.GetType().GetProperties(BindingFlags.Public);   where obj is some object.  The problem is some of the properties I want aren't in obj.GetType() they're in one of the base classes further up.  If I stop the debugger and look at obj, the I have to dig through a few "base" entries to see the properties I want to get at.  Is there some binding flag I can set to have it return those or do I have to recursively dig through the Type.BaseType hierarchy and do GetProperties on all of them? I am an international student in the US (important as my stay in US is tied to my student visa, issued to attend my current university).  I joined as a grad student in the MS CS program in one of the okayish public universities (ranked ~50 on QS/US news). I joined in Fall '18 and am still in my first semester. I took all the so-called "difficult" courses, but I find them very trivial (considering my undergrad was from a very good university). I am very disappointed with the curriculum and feel the coursework is not at all rigorous for a grad-school.  I might sound super arrogant, but I feel out-of-place when I talk to other students and hear them cringe about how hard the courses are, or how they don't have enough time to finish assignments within the deadlines as I find all of the coursework very trivial and feel that the assignments are a joke.   Fortunately, I am working with one of the best profs the university has to offer on a very impactful project and the research is going great. But that's the only plus point I see from sticking around.  My aim from grad school is to get research experience and join one of the Big 4s or upcoming CS unicorn startups. I cannot see myself joining one of the Big-Ns after graduating since the students from this school rarely bag a Google/Fb/unicorn startup job.  Since December is the Fall'19 admissions deadline, I am thinking about reapplying to those top 10 CS schools which I couldn't get into last year (probably because of my poor undergrad GPA).   On the other hand, since every CS company just asks leetcode-style questions in interviews, I can just be super good at it and try to nail whatever interview I get without wasting another year and then doing the same.  I'm not really interested in any kind of credit transfer either since I would like to start fresh in a more rigorous curriculum.  I'm not sure if switching schools would be a wise decision and could really use some advice from the community here.  PS :  Probably related -   Posting with a dummy account for anonymity. Let $been(x,y)$ denote "person x has been to place y."   Express “Every person has been to 2 or more places” using quantifiers and $been(x, y)$.  This one is completely stumping me. I'm sure that I haven't come across this kind of concept before, and can't wrap my head around how I would approach it. I suspect the quantifiers should be $∀x$, $∀y$, and that it may involve negating the statement "every person has been to one or zero places," but that's as far as I can manage to go. Any help greatly appreciated. Show that the condition number of an invertible matrix must be at least 1. What matrices have  condition number equal to 1.  If someone could help me with this and give an explanation that would be very helpful. I do not know where to start I'm reading  and I'm trying to understand the proof under "Degeneracy in One Dimension".  Here's what it says:     Considering a one-dimensional quantum system in a potential $V(x)$ with degenerate states $|\psi_1\rangle$ and $|\psi_2\rangle$ corresponding to the same energy eigenvalue $E$, writing the time-independent Schrödinger equation for the system:       $$-\frac{\hbar^2}{2m}\frac{ \partial^2\psi_1}{ \partial x^2} + V\psi_1 =E\psi_1$$       $$-\frac{\hbar^2}{2m}\frac{ \partial^2\psi_2}{ \partial x^2} + V\psi_2 =E\psi_2$$   Multiplying the first equation by $\psi_2$ and the second by $\psi_1$ and subtracting one from the other, we get:       $$\psi_1\frac{d^2}{d x^2}\psi_2-\psi_2\frac{d^2}{d x^2}\psi_1=0$$   Integrating both sides       $$\psi_1\frac{\partial \psi_2}{\partial x}-\psi_2\frac{\partial \psi_1}{\partial x}=constant$$   In case of well-defined and normalizable wave functions, the above constant vanishes, provided both the wave functions vanish at at least one point, and we find: $\psi_1(x)=c\psi_2(x)$ where $c$ is, in general, a complex constant. So, the two degenerate wave functions are not linearly independent. For bound state eigenfunctions, the wave function approaches zero in the limit $x\to\infty$ or $x\to-\infty$, so that the above constant is zero and we have no degeneracy.   Here are the parts I don't understand:   How does integrating $\psi_1\frac{d^2}{d x^2}\psi_2-\psi_2\frac{d^2}{d x^2}\psi_1=0$ yield $\psi_1\frac{\partial \psi_2}{\partial x}-\psi_2\frac{\partial \psi_1}{\partial x}=constant$.  Without having explicit formulas for $\psi_1(x)$ and $\psi_2(x)$, how do we just apparently pull them both out of the integral? I don't understand how the constant in the last equation vanishes just because $\psi_1$ and $\psi_2$ vanish at infinity. Even if it does vanish, how does that imply $\psi_1=c\psi_2$? What's the meaning of a set to the power of another set?