Why can't I sys_write from a pointer to stack memory, using int 0x80?
What happens if you use the 32-bit int 0x80 Linux ABI in 64-bit code?
White stains and stainless steel cookware I know this question has been asked before in some form or another, but I can't seem to find a definitive answer. I've looked on SA, chowhound, martha stewart, about.com, etc., and answers seem to vary. Answers that I've seen vary from using vinegar to washing using special stainless steel soaps (which I'm not very keen on using) to only using soft sponges and hot water.   The one thing I always do is wash my stainless steel with warm soapy water and a soft sponge. If there's burned food stuck on the cookware, I scrape it off with a wood pot scraper (lightly, of course). And I always dry with a soft cloth immediately after washing. Yet I still get stains!  I'd like to get a general consensus on how to prevent those white and rainbow colored stains as well as minimizing corrosion. I'm stuck with this integral  $\int\frac {\cos^4x}{\sin^3x} dx$    which I rewrote as  $\int \csc^3x \cos^4xdx$  then after using the half angle formula twice for $\cos^4x$ I got this  $\frac 14\int \csc^3x (1+\cos(2x))(1+\cos(2x))dx$   then after solving those products I got these integrals  $\frac 14 \{\int \csc^3xdx+2\int \csc^3x \cos(2x)dx + \int \csc^3x \cos^2(2x)dx\}$  I do know how to solve the $\int \csc^3xdx$ one but I'm totally lost on the other ones, any tips/help/advice would be highly appreciated! thanks in advance guys! How to get an enum value from a string value in Java? Say I have an enum which is just public enum Blah {     A, B, C, D }  and I would like to find the enum value of a string, for example &quot;A&quot; which would be Blah.A. How would it be possible to do this? Is the  the method I need? If so, how would I use this? A hard problem on exponential integration Suppose $a : [0 , 1] \to \Bbb R$ is an infinitely smooth function. For $\lambda\ge1$, define $$F(\lambda) := \lambda \int_0^1 e^{\lambda t} a(t) \, dt.$$ If $\sup_{\lambda\ge1}|F(\lambda)|\lt\infty$, then $a$ is the identically zero function. Below are the some results I have derived:   Derivatives of any order of $a$ vanishes at $t = 1.$ For any $\delta\lt1$, $a(t)$ has a zero in the open interval $(\delta , 1).$  The same is true for all the derivatives of $a(t)$. This tells us that the $n^\text{th}$ derivative of $a$ has infinitely many distinct zeros for all natural $n$. If $a$ is analytic, then I can show that $a(t)\equiv 0.$ If $a(t)\ge0$ on $[0 , 1]$, then it is obvious that $a\equiv 0.$   I would appreciate any hint.  Actually $(1)$ and $(3)$ follows from $(2)$. For $(2)$, suppose that $a(1)\gt0$ (the case that $a(1)\lt0$ can be argued in the same way as the following), then there exists $\delta\lt1$ such that $a(t)$ is strictly positive on $I = [1-\delta , 1]$. Then write $F(\lambda) = \lambda\int_0^{1-\delta}e^{\lambda t}a(t)dt + \lambda\int_{1-\delta}^1e^{\lambda t}a(t)dt$. Now there exists $c\gt0$ such that $a(t)&gt;c$ on $I$ since $I$ is compact, so that the second term is bounded below by $c (e^{\lambda}-e^{\lambda(1-\delta)})$. But the first term is only $O(e^{\lambda(1-\delta)})$, so this contradicts the fact that $F(\lambda)$ is bounded. Morever, using the same idea and integration by parts, one can see that $n^{th}$ derivative of $a$ must vanish at $1$. We are using Nginx to serve static files on a development platform. As it is a development platform, we'd like to disable caching so that each change is propagated to the server. The configuration of the VHost is quite simple:  server {   server_name  static.server.local;   root /var/www/static;    ## Default location   location / {     access_log        off;     expires           0;     add_header        Cache-Control private;   }  }   When we access an HTML file (http://static.server.local/test.html), we have no issue: the server returns a code 304 Not Modified as long as the file is not changed, and a 200 OK response with the modified file when the file is changed. However, it seems to behave differently with a Javascript or a CSS file. Once the file is changed, we get a 200 OK response as expected, but with the old text. Is there an internal cache mechanism in Nginx that could explain this behaviour? Or some configuration that we should add?    As a side note, here is the header returned by Nginx when the file has been modified (it seems correct):  Accept-Ranges:bytes Cache-Control:max-age=0 private Connection:keep-alive Content-Length:309 Content-Type:text/css Date:Fri, 13 May 2011 14:13:13 GMT Expires:Fri, 13 May 2011 14:13:13 GMT Last-Modified:Fri, 13 May 2011 14:13:05 GMT Server:nginx/0.8.54   Edit After trying different settings with the expires directive and Cache-Controlheader, I made some further investigations. In fact, the server is installed on a VirtualBox guest Ubuntu, and data are read from a shared folder that is on the Mac OSX host. If the file is edited from an IDE (NetBeans) on the host, it seems that changes do not appear whereas if I edit it directly on the guest (using VIM), it is refreshed. The strange thing is it does not behave similarly with HTML files. Quite puzzling.  Edit 2 (ANSWER) Indeed, the origin of the issue was more on the VirtualBox side. Or rather a conflict between VirtualBox and the "sendfile" option of the server. This link  gave me the solution: switch the sendfile flag in the server configuration to off:  sendfile  off;   Hope this could also help other person using VirtualBox for development. :) There are some additional information on the . Do I really need to replace my helmet every 2-3 years if it hasn't been in a crash? Infinitely differentiable function with given zero set? new finding by Minev et al. seems to suggest that transitions between atomic states are not instantaneous, but continuous processes wherein a superposition smoothly adjusts from favoring one state to another (if I understand it correctly). The authors also claim to be able to catch a system "mid-jump" and reverse it. Popular articles are  and .  I am curious if this finding rules out any interpretations of QM. It seems to generally go against the Copenhagen attitude, which describes measurements as collapsing physical systems into a definite classical state. The popular articles indeed claim that the founders of QM would have been surprised by the new finding.  The link with the asterisk mentions that something called "quantum trajectories theory" predicts what was observed. Is this an interpretation, or a theory? And are they implying that other interpretations/theories don't work? Security Review - CRUD/FLS Checks for every SOQL Query I know this sounds like a standard question, so please bear with me.  Recently our Security Reviews fail due to CRUD/FLS violations. The highlighted codelines include almost every SOQL Query in the application.  Our approach is usually as follows:   In case of displaying data on VF pages we either use sObjects fields or use the platform methods to check the accessibility of the fields In case of domain logic triggered by the user (e.g. by clicking a button on a VF page) we have a helper class that checks every field to be updated before doing the DML operation.   Up until recently this approach has worked fine (and passed pervious Security Reviews). As mentioned above the latest Security Review results seem to require us to check every field in a SOQL query for accessibility even if it is never displayed back to the user.    Let's suppose the following program flow as an example:   Query an object with some fields Perform some modification on said fields Perform an update on the sObject to save the modification using a helper class which checks for the required CUD/FLS rights for the modified fields   As I see it there is no need for checking field accessibility in step 1 in that case (since nothing is displayed back to the user and the dml operation is already protected). Is that correct or am I missing something? So is it really required to do an accessibility check for every SOQL Query in the code?  Another question would be how to handle background operations in that case like data purging. These have either to be running in system mode (which causes issues during the Security Review) or require the job to be started by a user with the appropriate access rights (which can be error prone and is not that user friendly). Is there any best practice regarding that.  Unfortunately I could not find a question targeting exactly that issue. Most of the questions I have found are related to how to perform that check (like  or ). So please apologize in case the question was already answered (I would really appreciate a link to the answer then).    Thanks for your time and help.  Mathias Time Dilation When In Orbit Imagine a space ship orbiting the sun at near relativistic speeds, when compared to Earth (say from the reference frame of the sun) there would be x amount of time dilation.  This would mean people on the ship could live for 100's of Earth years.  My question is what would happen if a second ship flew directly away from the Sun and back (ignoring acceleration) at the same speed the orbiting ship is travelling, would the time dilation for the ship that travels in a straight line be the same as that moving in a circle?  The reason I ask is that I was imagining a scenario where intergalactic travel is possible as time dilation means even a journey of light years only ages the crew a fraction of that time, with space stations orbiting certain star systems at similar speeds so that people that don't work on ships can live a similar length of time. I understand that time dilation is all linked to a certain reference frame but working with a reference frame of the sun what would the time dilation be for the different objects taking different paths but at the same speed relative to the sun? If the ship docked back with the space station would they both say the same amount of time had passed? What is an alternative to execfile in Python 3? It seems they canceled in Python 3 all the easy way to quickly load a script by removing execfile()   Is there an obvious alternative I'm missing? I have used the package nomencl. In my code I have incorporated the \nomenclature as well. But when I compile, it is not showing me any results. My code is :  \documentclass[pdftex,12pt,a4paper]{report} \usepackage{nomencl} \makenomenclature \begin{document} ---page numbering and other things included----- \include{symbols} -----others--- \end{document}   symbols.tex  \chapter*{NOTATIONS} \addcontentsline{toc}{chapter}{Notations} \nomenclature{$G_e$}{Equivalent Shear Modulus} \printnomenclature   Shall I use \nomenclature while explaining the chapter. Will It give me the same results? like  \documentclass[pdftex,12pt,a4paper]{report} \usepackage{nomencl} \makenomenclature \begin{document} ---page numbering and other things included----- \include{symbols} \include{chap3-calculate_w} -----others--- \end{document}   symbols.tex  \chapter*{NOTATIONS} \addcontentsline{toc}{chapter}{Notations} \printnomenclature   chap3-calculate_w.tex  \chapter{SETTLEMENT RESPONSE OF GEOSYNTHETIC REINFORCED GRANULAR FILL SOFT SOIL} \label{chap:W} \section{INTRODUCTION} In this thesis, the methodology to determine an  Equivalent single layer shear modulus \nomenclature{$G_e$}{Equivalent Shear Modulus},$G_e$ value for a...etc   I am not getting the output in both these. Can someone help me with this? What can $E=mc^2$ do? In the famous equation , the variables stand for:     $E$ is energy, $m$ is mass, and $c$ is the speed of light (in vacuum).   And I understand the equation fairly but limited in knowing in its effects/outputs in reality, honestly.   Some example? Could anybody please give me some sort of examples in real world which are done by this equation? How can I disable a tab inside a TabControl? Is there a way to disable a tab in a ? AttributeError: MapDocObject: Unable to save on mxd.save/saveACopy? I'm trying to use arcpy to save an .mxd and am having an issue.  It doesn't matter if I use mxd.save or mxd.saveACopy I get the same error.  I know it doesn't look like I am doing anything w/ it here, but it's just a portion of my code:  import arcpy import arcpy.mapping as map arcpy.env.overwriteOutput = True  env.workspace = r"C:\MGIS\FinalProject2.gdb     mxd = map.MapDocument(r"C:\MGIS\Finalproject2.mxd") df = map.ListDataFrames(mxd)[0]  for df in map.ListDataFrames(mxd): df.scale = 2000000  #Add layers into map document addLayer = map.Layer(OKXcounties) addLayer1 = map.Layer(contourLabelText) addLayer2 = map.Layer(contoursClipLyr) addLayer3 = map.Layer(clipOKXLyr) map.AddLayer(df, addLayer, "AUTO_ARRANGE") map.AddLayer(df, addLayer1, "AUTO_ARRANGE") map.AddLayer(df, addLayer2, "AUTO_ARRANGE") map.AddLayer(df, addLayer3, "AUTO_ARRANGE")  # Add contour Labels for lyr in map.ListLayers(mxd):     if lyr.name == "contourLabelText":         lyr.showLabels = True     if lyr.name == "Contour Features":         lyr.transparency = 100  mxd.saveACopy(mxd)   I get the following error:   Traceback (most recent call last):   File "C:\Python26\ArcGIS10.0\Lib\site-packages\pythonwin\pywin\framework\scriptutils.py", line 312, in RunScript     exec codeObject in __main__.__dict__   File "C:\MGIS\geog485\FinalProject2\mxdtest.py", line 7, in &lt;module&gt;     mxd.saveACopy(mxd)   File "C:\Program Files\ArcGIS\Desktop10.0\arcpy\arcpy\utils.py", line 181, in fn_     return fn(*args, **kw)   File "C:\Program Files\ArcGIS\Desktop10.0\arcpy\arcpy\_mapping.py", line 668, in saveACopy     self._arc_object.saveACopy(file_name) AttributeError: MapDocObject: Unable to save.  Check to make sure you have write access to the specified file and that there is enough space on the storage device to hold your document.   Space is not the issue, I have 60 GB of free space and I've checked the windows properties of the .mxd file.  Read-only box is unchecked and I've "allowed" all permissions for all groups:    Does anyone have any idea how if this is a bug or how I can fix this?  I'm using ArcInfo 10.0 SP4. Some issues with timezones in PHP have been in the back of my mind for a while now, and I was wondering if there are better ways to handle it than what I'm currently doing.  All of the issues revolve around reformating database stored dates:  When dealing with a site that has to support multiple timezones (for users), to normalize the timezone offest of stored timestamps I always store it with the server timezone using the CURRENT_TIMESTAMP attribute or the NOW() function.   This way I don't have to consider what timezone was set for PHP when the timestamp was entered (since PHP time functions are timezone aware). For each user, according to his preference I set the timezone somewhere in my bootstrap file using:  date_default_timezone_set($timezone);   When I'm looking to format dates with the php date() function, some form of conversion has to take place since MySQL currently stores timestamp in the format Y-m-d H:i:s. With no regard to timezone, you could simply run:  $date = date($format,strtotime($dbTimestamp));   The problem with this is that date() and strtotime() are both timezone aware functions, meaning that if the PHP timezone is set differently from the server timezone, the timezone offset will apply twice (instead of once as we would like).  To deal with this, I usually retrieve MySQL timestamps using the UNIX_TIMESTAMP() function which is not timezone aware, allowing my to apply date() directly on it - thereby applying the timezone offset only once.  I don't really like this 'hack' as I can no longer retrieve those columns as I normally would, or use * to fetch all columns (sometimes it simplifies queries greatly). Also, sometimes it's simply not an option to use UNIX_TIMESTAMP() (especially when using with open-source packages without much abstraction for query composition).  Another issue is when storing the timestamp, when usage of CURRENT_TIMESTAMP or NOW() is not an option - storing a PHP generated timestamp will store it with the timezone offset which I would like to avoid.  I'm probably missing something really basic here, but so far I haven't been able to come up with a generic solution to handle those issues so I'm forced to treat them case-by-case. Your thoughts are very welcome Algebraic Property inherited by a "lift"? Suppose $K$ is a field, and $K\subset E$ is an algebraic extension, and $K\subset F$ is any extension.  Suppose that $L$ is some field which contains both $F$ and $E$ as subfields.  I want to show that $FE$ (the smallest subfield of $L$ containing both $F$ and $E$) is algebraic over $F$.  Lang mentions that the result is true because an element remains algebraic under lifting, but I can't prove the claim with this.  I interpret his comment to mean that if $x\in E$ is algebraic over $K$, then $x\in FE$ is algebraic over $F$.  This is certainly true.    But this doesn't seem enough if I start with any element of $FE$. 3rd iterate of a continuous function equals identity function I often need to view on the canvas the (selected or not) features from the current active vector layer.  In this situation, I only need to view something on the canvas, without doing anything on the canvas itself (so, the active window is always the Attribute Table).  This is what I usually do:   Open the Attribute Table for the current active layer; Select the first feature; Press Ctrl+P button (i.e. the "Pan map to the selected row" button); Minimize the Attribute Table; View something on the canvas for the current feature; Go to the first step until needed.   Is there a way (a method, a shortcut) for directly browsing every feature on the canvas without the needing of going backwards and forwards with the Attribute Table? I mean, something like a "next" button?  (I may use the workaround of splitting the windows of the Attribute Table and of the canvas within the monitor, or also docking the Atrribute Table, but I would like to work on the full QGIS window).    EDIT I saw that my question was casted as a duplicate of  question. The two questions are very similiar, but I think it should be left as open for two reasons:   the related duplicated question doesn't have an accepted answer; my question is slightly different because I'm looking for the possibility of displaying only the selected features (and the @Joseph's , that I marked as accepted, answers well to my request). Probability of Obtaining the Roots in a Quadratic Equation by Throwing a Die Three Times