resetting git path after clean install
Why is Git not found after installing OS X Lion?
How can I type special symbols on my Android device like ☺ or ♥ as a regular character? Can we have a black hole without a singularity? Assuming we have a sufficiently small and massive object such that it's escape velocity is greater than the speed of light, isn't this a black hole? It has an event horizon that light cannot escape, time freezes at this event horizon, etc. However this object is not a singularity.  If a large star's mass were compressed to the size of, say, a proton, it would certainly have these properties but it would still not be a singularity as a proton does have volume.  The reason "physics breaks down" at singularities is because we cannot divide by zero, but as long as the proton-sized object has volume, physics won't "break down", yet we still have an event horizon and an object that is invisible (but not undetectable) from the outside.  I have read the answers to  related question. I'm not sure if they don't address my specific question or if I don't understand the answers. In .NET, the  is used in a lot of places throughout the .NET base class libraries. Implementing it properly is especially important to find items quickly in a collection or when determining equality.  Is there a standard algorithm or best practice on how to implement GetHashCode for my custom classes so I don't degrade performance? How to make files protected? How to make some file that contains crucial data protected? For instance, suppose I have some files that are important, is there any method or strategy to make these kind of file more protected on Ubuntu? I even want to make some files ask for a password whenever someone tries to open it. Does it affect the version of Ubuntu in terms of security policy? May I use any encryption algorithm externally? Regards. Gapless superconductivity I don't understand what is meant by &quot;gapless superconductors&quot;. As far as I know, the superconducting gap is necessairy for both zero resistance and the Meissner effect, the two hallmarks of superconductivity. So, what does it mean to have gapless superconductivity and how does it work? Thanks in advance, Greetings Should I install graphics card drivers from Windows Update? I have a Xonar DX (CMI8788 driver) 7.1 surround sound card installed on my Ubuntu 11.10 system.   I want to use the outputs of the card as 4 separate stereo outputs and I am struggling with ALSA to get it to work.  This is my asound.conf:  #/etc/asound.conf pcm_slave.eightchannels {         pcm "hw:0,0"            # or "hw:1,0" for the second card         channels 8 } pcm.stereo1 {         type plug         slave.pcm {                 type dshare                 ipc_key 87882222                 slave eightchannels                 bindings [ 2 3 ]         } } pcm.stereo2 {         type plug         slave.pcm {                 type dshare                 ipc_key 87882222                 slave eightchannels                 bindings [ 4 5 ]         } } pcm.stereo3 {         type plug         slave.pcm {                 type dshare                 ipc_key 87882222                 slave eightchannels                 bindings [ 6 7 ]         } } pcm.stereo4 {         type plug         slave.pcm {                 type dshare                 ipc_key 87882222                 slave eightchannels                 bindings [ 0 1 ]         } }   This is my aplay -l output:  $ aplay -l **** List of PLAYBACK Hardware Devices **** card 0: DX [Xonar DX], device 0: Multichannel [Multichannel]   Subdevices: 1/1   Subdevice #0: subdevice #0 card 0: DX [Xonar DX], device 1: Digital [Digital]   Subdevices: 1/1   Subdevice #0: subdevice #0 card 1: Intel [HDA Intel], device 0: ALC662 rev1 Analog [ALC662 rev1 Analog]   Subdevices: 1/1   Subdevice #0: subdevice #0 card 1: Intel [HDA Intel], device 1: ALC662 rev1 Digital [ALC662 rev1 Digital]   Subdevices: 1/1   Subdevice #0: subdevice #0   This is my aplay -L output:   The system seems to completely ignore my configuration. However, I am sure that the config is used, because when i insert a random string at the top, i get a parsing error.  Any help is greatly appreciated. equal size numerator and denominator I am trying to size the numerator and denominator of the below equation so that they are equal in size.  I have not had much luck suggestions are appreciated.  \begin{equation} \sum_{i=1}^{n} \frac{\frac{cf_{n}}{(1+i)^n}} {\displaystyle\sum_{i=1}^{n}\frac{cf_n}{(1+i)^n}} , n_{i} \end{equation} Update SQL Server table with local data How to add a vertical line to a plot How can I prevent SQL injection in PHP? If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening? Accessing inherited variable from templated parent class Consider the following code:  template&lt;class T&gt; class Foo { public:   Foo() { a = 1; }  protected:   int a; };  template&lt;class T&gt; class Bar : public Foo&lt;T&gt; { public:   Bar() { b = 4; };    int Perna(int u);  protected:   int b;  };  template&lt;class T&gt; int Bar&lt;T&gt;::Perna(int u)  {    int c = Foo&lt;T&gt;::a * 4; // This works   return (a + b) * u;    // This doesn't }   g++ 3.4.6, 4.3.2 and 4.1.2 give error   test.cpp: In member function `int Bar&lt;T&gt;::Perna(int)': test.cpp:25: error: `a' was not declared in this scope   g++ 2.96 and MSVC 6, 7, 7.1, 8 and 9 accept it, as do (at least) older Intel and SGI c++ compilers.   Do the new Gnu C++ compiler obey the standard or not? If they do, what is the rationale behind that inheriting class is not able to see a protected inherited member variable?  Also, if there's  int A() { return a; }    in Foo, I get error  test.cpp:25: error: there are no arguments to A that depend on a template parameter, so a declaration of A must be available test.cpp:25: error: (if you use -fpermissiveâ, G++ will accept your code, but allowing the use of an undeclared name is deprecated)   when I try to use it in a member function of Bar. I find that curious as well: Bar inherits Foo, so I think it's obvious that A() in scope of Bar is Foo::A(). "Seen" status is earlier than the user's last post I posted what I think is a clever answer to:    But then I noticed the question was posted a while ago on Mar 2.  I wanted to see what the chance of the user logging back in and seeing my answer, but the  says the user was seen on Feb 19.  I thought this was supposed to be the date they last logged in? How could they have asked a question on Mar 2 if they haven't logged in since February?  Thanks Multiple vs single field capture for phone number form input Working on a form dealing with phone numbers, I've seen two methods to capture user input .   In past practices example 2 (image below) has proved effective in controlling phone number lengths on forms.   However with responsive in mind it would seem example 1 is considered a more popular pattern on forms. I've researched both patterns with the findings below.     Example 1  Pros   1 input = less taps on mobile device 1 input = less coding   Cons   could be difficult to control phone number format (1-555-555-5555, +22444455555, and etc)   Example 2  Pros   easier to control phone format reduced user error   Cons   3 inputs = more taps on mobile device more inputs = more coding   Both inputs have pros and cons and I'm not such which method would provide the best user experience for responsive environments. Can anyone share some insight or provide a better way to use phone number inputs? Theorem environment with hanging indentation I would like to define a theorem environment with custom layout. In particular, I want the body of the theorem to be indented, like this  Text body. Text body. Text body.  Theorem 1 (Pythagoras).     Let a,b,c the sides of a rectangular triangle.     Without loss of generality, we assume that  a&lt;b&lt;c .     Then, the following equality holds:            a^2 + b^2 = c^2  More text. And even more text.   This is similar to the quote environment, I believe.  How can I do this?  Preferably, I would like to use the existing \newtheorem command, but that's not mandatory. E: Could not get lock /var/lib/dpkg/lock-frontend - open (11: Resource temporarily unavailable) Backup of clients' directory to Windows Server 2008 Who is the Community user? I see the  on the user page.  It seems to edit posts sometimes.  What is it? And why has it downvoted over 1800 times? See also: Version: Ubuntu 16.04  I have used it some weeks, but now it gives me this message when I'm trying to install software and update or upgrade:  Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable) /var/lib/apt/lists/ locked   followed by this:    .  and another error:  ** (appstreamcli:4560): WARNING **: Exception: Unable to get write lock on /var/cache/app-info/xapian/default: already locked   What should I do? "not a valid identifier" when I do "export $PATH" When I run export $PATH in bash, I get the error not a valid identifier. Why?