If I run  grep "!" test.txt   it will show error     bash: !: event not found   Well, I know I actually should use grep '!'. But how to understand the above error?  I know ! is bash special character. According to .      Double quotes: "..." prevents some substitutions but allows others.   Every substitution that begins with a dollar sign $ is performed, as   is the legacy ... (backtick) command substitution. Backslash   escaping is also performed. No word splitting or filename expansion is   performed.   It doesn't mention that double quotes will affect !. Could somebody explain how does bash or grep interpret grep "!"? What is the "event"?
I tried to create a script by echo'ing the contents into a file, instead of opening it with a editor  echo -e "#!/bin/bash \n /usr/bin/command args"  &gt; .scripts/command   The output:     bash: !/bin/bash: event not found   I've isolated this strange behavior to the .  $ echo ! !    $ echo "!" bash: !: event not found  $ echo \#! #!  $ echo \#!/bin/bash bash: !/bin/bash: event not found    Why is bang causing this?   What are these "events" that bash refers to?     How do I get past this problem and print "#!/bin/bash" to the screen or my file?
How can I break on an unhandled exception in ASP.NET? When debugging an application in Visual Studio, there are 2 options for breaking on exceptions. Break as soon as an exception is thrown, and breaking only when an exception isn't caught. This works fine when developing desktop applications. However, when developing ASP.NET applications, all exceptions are eventually caught by the code in IIS.  Is it possible to disable this behavior, so that the debugger breaks when my ASP.Net application code fails to catch an exception?  Edit: Just to be clear, I don't want to break whenever an exception is thrown, as many times they are handled just fine by my code, and I don't want to stop on every exception. I only want to stop on the exceptions that aren't handled by my code.  Edit: This seems to not be an issue in Visual Studio 2008. In Visual Studio 2003, all exceptions were treated as user handled, because the ASP.NET runtime caught all the exceptions so as not to bring down the web server process. It seems that in Visual Studio 2008, this type of exception catching is not counted when checking for user-unhandled exceptions. I need to build a list of files present in a directory but also pass in a file containing a list of directories to exclude.  I've seen the below suggestion but I've had no luck with it when it comes to the type flag:  find $dir_name $(printf "! -name %s " $(cat $exclude_file))   Is there a way I can do it or will I need to create the entire list and then work through it removing ones that partially match ones in the exclude directory. I'll like to add this functionality to the autocomplete widget in Entityreference field to show node ID next to the titles in the dropdown list. The reason behind the idea is to differentiate between multiple nodes with same title.  Example:    This is a title (3) This is a title (2) This is a title (1)   I know the node ID is shown once a selection is made but I like to show it in the dropdown list in order to pick the right node quickly based on the node ID. Find all functions $f(x)$ such that $f\left(x^2+f(y)\right)$=$y+(f(x))^2$ Solving linear congruences by hand: modular fractions and inverses When I am faced with a simple linear congruence such as  $$9x \equiv 7 \pmod{13}$$ and I am working without any calculating aid handy, I tend to do something like the following:  "Notice" that adding $13$ on the right and subtracting $13x$ on the left gives: $$-4x \equiv 20 \pmod{13}$$  so that $$x \equiv -5 \equiv 8 \pmod{13}.$$  Clearly this process works and is easy to justify (apart from not having an algorithm for "noticing"), but my question is this: I have a vague recollection of reading somewhere this sort of process was the preferred method of C. F. Gauss, but I cannot find any evidence for this now, so does anyone know anything about this, or could provide a reference? (Or have I just imagined it all?)  I would also be interested to hear if anyone else does anything similar. Which queue for an unmarried EU/non-EU couple travelling through UK Immigration Control together? Possible to use draws from two distributions to get draw from distribution with density their product? Java code needs a system.out.println statement to run What is 'Currying'? I've seen references to curried functions in several articles and blogs but I can't find a good explanation (or at least one that makes sense!) I want to install Win Xp on my Ideapad Z 570 laptop but i always get blue screen with message with some drive related problem which asks me to run CHKDSK command. I tried with that but no luck. Is there any way i can install Win Xp with SP 2 ?  Edit: i searched across the sites and came to know there could be some Compatibility problems, and i could fix it by setting HDD mode to IDE; will it solve the problem? Is there a name for this layout? More numbers between $[0,1]$ or $[1,\infty)$? Gparted: move extended partition on the left I have some free disk space on the left of my ubuntu (sda5)  What is best solution to extend sda5 ?  I can    copy sda3 or sda5 with dd to bigger disk. delete sda3,5,swap create sda3,5,swap dd original partition.   Not sure how to do it properly.  May be there is a simpler solution. Book recommendation on the history of PDE/ODE? How do I grep for all non-ASCII characters? How to mount a remote (over SSH) directory to be available like a local directory (incl. in shell, not just in Gnome)? Algebraic closure of $\mathbb{C}(x)$ is isomorphic to $\mathbb{C}$ Let $x$ be transcendental over $\mathbb{C}$. Let $K$ be the algebraic closure of $\mathbb{C}(x)$. How to show that $K$ is isomorphic to $\mathbb{C}$? Beamer - Color of header foreground with AnnArbor theme I use beamer with the theme AnnArbor and colortheme whale.  I tried to use:  \setbeamercolor{section in head/foot}{fg=white, bg=blue}   or  \setbeamercolor{palette tertiary}{fg=white, bg=blue}   But for an unknown reason, the bg works but not the fg... The sections names stay black in the header.    EDIT : the problem comes from the hyperref package.  This code works well :  \documentclass{beamer} \usetheme{AnnArbor} \usecolortheme{whale} \setbeamercolor{frametitle}{fg=white,bg=blue}  \begin{document}     \section{Test 1}     \subsection{Test 1.1}     \begin{frame}         \frametitle{Test}     \end{frame} \end{document}   Whereas this one doesn't works :  \documentclass{beamer} \usetheme{AnnArbor} \usecolortheme{whale} \setbeamercolor{frametitle}{fg=white,bg=blue} \usepackage{hyperref} \hypersetup{     colorlinks=true,     linkcolor=black,     urlcolor=blue,     citecolor=gray,     frenchlinks=false,     pdfborder={0 0 0} }  \begin{document}     \section{Test 1}     \subsection{Test 1.1}     \begin{frame}         \frametitle{Test}     \end{frame} \end{document}   And that's pretty normal because of this line :  linkcolor=black, How to initialize a JavaScript Date to a particular time zone Prove that $\exp(x)>0$ using only formal definition of exp