File.lastmodified() generates wrong date and month
Why is January month 0 in Java Calendar?
Problem about angle in isosceles triangle $ABC$ is an isosceles triangle, $AB=AC$, and $\measuredangle A=20^{\circ}$. For point $M$ on $AB$ and $N$ on $AC$, we have $AM=NC=BC$. Compute the  $\measuredangle BMN$.  In a similar problem (with only one point on one side) the key step was to construct an equilateral triangle on the other side. I tried using that in this problem too, but I didn't manage to solve it. #include&lt;iostream&gt; using namespace std;  class A  {    int a;    int b;    public:    void eat()    {       cout&lt;&lt;"A::eat()"&lt;&lt;endl;    } };  class B: public A {    public:    void eat()    {        cout&lt;&lt;"B::eat()"&lt;&lt;endl;     }  };  class C: public A {     public:    void eat()     {        cout&lt;&lt;"C::eat()"&lt;&lt;endl;     }  };  class D: public B, C {  };  int foo(A *ptr) {  ptr-&gt;eat();  } main() {  D obj; foo(&amp;(obj.B)); //error. How do i call with D's B part.  }   The above foo call is a compile time error.  I want to call foo with obj's B part without using virtual inheritance. How do i do that.   Also, in case of virtual inheritance, why the offset information need to be stored in the vtable. This can be determined at the compile time itself. In the above case, if we pass foo with D's object, at compile time only we can calculate the offset of D's A part. How can I release and renew my DHCP lease from Terminal? From the Terminal, how can I release and renew my DHCP lease?  Currently, I'm doing the following for the wireless interface, but I'm wondering if there's a better way:  sudo ifconfig en1 down sudo ifconfig en1 up   For the wired interface, replace en1 with en0. I tried the first experiment in chapter 5 in the Metafontbook: ran mf, typed \relax and drawdot (35,70); showit;.  This opened a window entitled Metafont, but containing nothing.  What's missing?  Using TeXlive 2020 on Linux. PS. After adding drawdot (65,70); showit; I see both dots. PS II. Which have now disappeared, after I changed window-manager workspace and back. PS III.  Typing showit; before the first drawdot opens a window and allows the first dot to be seen, but after having switched workspaces and back, I haven't found any way of bringing the picture back, short of drawing something more and showing it. Non abelian Lie group with abelian Lie algebra Can I travel to the UK unaccompanied on an accompanied child visa now that I am over 18? I got a visa with my mother when I was 17 years old. On it was stated "Not valid unless accompanied by my mother".    Can I travel to the UK alone now that I am 18? How can I output a list of all installed packages with installation date and additional information? Can I rephrase the sentence "Can you explain this word to me?" into "Can you explain me this word." Why does virtualbox only have 32-bit option, no 64-bit option on Windows 7? I have downloaded and installed the newest  for my Windows 7 (64-bit OS), but when I want to install 64-bit Linux, the New->Create Virtual Machine only displays 32-bit option, no 64-bit option. Could anyone give any clues about this issue? Thanks very much in advance! Proof of $a^n+b^n$ divisible by $a+b$ when $n$ is odd I am playing a bit around with Qgis 2.14.6 to understand how it deals with distance measurement.  I took a line-shapefile that I saved in 3 different coordinate systems (4326, 32642 and a national one that doesn't exist in Qgis yet).  Using 32642 and the national one, the length is quite similar (6442m vs. 6428m)  But using 4326 (unprojected WGS84), I get 8057m  In all cases, I just used the Field Calculator and introduced $length.  I was already positively surprised that the result using 4326 was in meters and not in degrees.  To calculate the distance on the dataset in 4326, I assume that Qgis does some kind of re-projection in the background. Does anyone know which one?   Shapefiles here if anyone wants to play around:   EDIT - adding more info after more tests  As you can see, now both my shapefile and the project are in EPSG:4326, so unprojected:    Here the rough measurement of my shapefile, with the Qgis measure tool:   When I use the field calculator, the preview gives me a value in degrees, while the result seems to be in meters:      This would mean that the function $length, like the measurement tool, always gives a result in meters, but using a very coarse approximation of the degrees => meters transformation:    Is this a bug? or should it really behave like this? I find it at best counter-intuitive (but maybe it's just me) and, at worse, completely misleading (it makes very little sense to use, everywhere on earth, the length of 1 degree at the Equator). Any input or opinion here? Should I open a bug report (at least for the inconsistency between the preview and the actual result)? Java: Cannot find symbol? React on global hotkey in a Java program on Windows/Linux/Mac? A Java6 application sits in the system tray. It needs to be activated using a hotkey (e.g. Super-G or Ctrl-Shift-L etc) and do something (e.g. showing an input box).  How do I do that on:   Windows (XP or Vista) OS/X Linux (Gnome or KDE) Running a caching DNS server on my LAN C# Mono - Low Level Keyboard Hook I'm using code that I found on the .  The only problem is it uses external DLL calls that don't work in mono.  I was wondering if anyone knew of a way to accomplish the same thing as that code, but will run in both Windows using .net, and Linux using mono?  Edit:  Clarifying what I'm trying to do: I'm making a .  The program sits in the system tray and when the user presses the hot-key, it will pop up all the gadgets.  So the program doesn't have focus, so typically it won't catch any keystrokes, so I'm using the low-level keyboard hook and I hook the two keys that the user defines as the hot-keys.  But I'm using a Windows DLL call for that, which doesn't work in Linux using mono.  So I'm wondering if there's a way to do the same thing, but will run in Linux using mono? Can I deduct a contribution to a traditional IRA if I am also contributing to a 401(k) in the same tax year? I'm looking for a shapefile containing an 1000m or 2000m UTM grid ("graticule"). All I was about to find on the web is a 10000m UTM grid (here: ) and I am aware that a 1000m UTM grid for the whole world might be quite big.  That's why I'm now wondering if and how it would be possible to generate such a shapefile for a part of the world. I would prefer to use open source tools like gdal. Others output formats than a shapefile might be ok too.   Has anyone an idea? For every vector space $V$ does there exist a linear functional $f$ ( a linear map from $V$ to $F$ the underlying field ) such that for some $ \vec v \in V$ , $f(\vec v) \ne 0$ ? If it does exist , can we prove the existence without the "axiom of choice " ? Is the existence equivalent to axiom of choice ? This may be a silly question, but I ask it still. If I have declared a shebang  #!/bin/bash    in the beginning of my_shell_script.sh, so do I always have to invoke this script using bash  [my@comp]$bash my_shell_script.sh   or can I use e.g.  [my@comp]$sh my_shell_script.sh   and my script determines the running shell using the shebang? Is it the same happening with ksh shell? I'm using AIX. Installing 2 versions of Ubuntu on same hard drive?