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  • After updating debian lenny, ps stops recognising my users

    - by William Coates
    Since upgrading my debian lenny box with apt-get, ps seems to be behaving strangely, and also if i run top i see under the user column the ids, not the names. whoami => foo ps -U foo => ERROR: User name does not exist. I get this output when I run "strace -e trace=open ps -U foo 2&1 | less", seems just this /usr/lib/libnss_compat.so.2 doesnt exist: open("/etc/mtab", O_RDONLY) = 3 open("/usr/lib/locale/locale-archive", O_RDONLY|O_LARGEFILE) = 3 open("/proc/self/stat", O_RDONLY) = 3 open("/proc/uptime", O_RDONLY) = 3 open("/etc/nsswitch.conf", O_RDONLY) = 4 open("/etc/ld.so.cache", O_RDONLY) = 4 open("/lib/libnss_compat.so.2", O_RDONLY)=4 open("/usr/lib/libnss_compat.so.2", O_RDONLY)=-1 ENOENT (No such file or directory) open("/proc/self/stat", O_RDONLY)= 4

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  • What does "cpuid level" mean?

    - by ogzylz
    For an example, I put just output from 1 core of a 16 core machine. What does the output mean by "cpuid level" of "6"? Also, what do "bogomips" of "5992.10" and "clflush size" of "64" mean? processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 6 model name : Intel(R) Xeon(TM) CPU 3.00GHz stepping : 8 cpu MHz : 2992.689 cache size : 4096 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 2 fpu : yes fpu_exception: yes cpuid level : 6 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl vmx cid cx16 xtpr lahf_lm bogomips : 5992.10 clflush size : 64 cache_alignment: 128 address sizes: 40 bits physical, 48 bits virtual power management:

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  • Passing array values in an HTTP request in .NET

    - by Zarjay
    What's the standard way of passing and processing an array in an HTTP request in .NET? I have a solution, but I don't know if it's the best approach. Here's my solution: <form action="myhandler.ashx" method="post"> <input type="checkbox" name="user" value="Aaron" /> <input type="checkbox" name="user" value="Bobby" /> <input type="checkbox" name="user" value="Jimmy" /> <input type="checkbox" name="user" value="Kelly" /> <input type="checkbox" name="user" value="Simon" /> <input type="checkbox" name="user" value="TJ" /> <input type="submit" value="Submit" /> </form> The ASHX handler receives the "user" parameter as a comma-delimited string. You can get the values easily by splitting the string: public void ProcessRequest(HttpContext context) { string[] users = context.Request.Form["user"].Split(','); } So, I already have an answer to my problem: assign multiple values to the same parameter name, assume the ASHX handler receives it as a comma-delimited string, and split the string. My question is whether or not this is how it's typically done in .NET. What's the standard practice for this? Is there a simpler way to grab the multiple values than assuming that the value is comma-delimited and calling Split() on it? Is this how arrays are typically passed in .NET, or is XML used instead? Does anyone have any insight on whether or not this is the best approach?

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  • Java Applet Deployment, ClassNotFoundException (primary class)

    - by Matt
    This is driving me up the wall. I have checked and rechecked spelling and paths. I have tried just about every combination of paths, including relative, absolute, and full http paths. I continue to get the following error when trying to load a Java applet: java.lang.ClassNotFoundException: AppletClient.class at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source) at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source) at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Exception: java.lang.ClassNotFoundException: AppletClient.class The HTML used to load the applet: <applet width="100" height="100" archive="applet/myapplet.jar, applet/applet_dependency.jar" code="AppletClient.class"> <param value="blahblah" name="username"> <param value="false" name="codebase_lookup"> </applet> The applet is in a relative directory, "applet", from the path of the current page. I have unzipped the jar file and can see AppletClient.class. Also, in the source of the project, it is spelled that way (casing and all). I have tried with/without the parameters. I have changed the names of the archive jars in the applet include tag just to see if I get a different error for bad file names (same error). I have manually done GETs on the jars to make sure the server is responding to the requests (it is). I have tried with and without the codebase tag, with all different varieties of paths (start getting bad "magic number" errors on those). I know that this error sometimes pops up when a dependency fails to load, so it can be misleading, but all dependencies are present, accounted for, and are fetchable via manual GETs. Between each and every attempt I always clear my cache in FireFox. These problems are reproduced in IE8 and Chrome as well. Per my Java Console from the browser, I am running Java Plug-in 1.6.0_20. This is from the same machine that I develop the applet on, which runs fine via Eclipse. Finally, I kicked on Fiddler2, and I don't see a single request for the jar files anywhere The host site is running from my Visual Studio debugger, so it's running on localhost. But I see the requests for all the other resources on Fiddler. Just... no Jars. ANYWHERE. I clear the log, cleared my browser cache, and did a ctrl-R refresh. And still, not a single Jar request on the Fiddler log. I even did a delayed write (with JS) of the applet tag after the page loaded, once all the Fiddler activity slowed down. The element gets written to the document (and I can see the 100x100 Java error window), but not a single request shows up on Fiddler. Any suggestions, before I go crawl into the corner and cry myself to sleep? EDIT: From the Java console, if I hit "l" (el) to "dump classloader list", I see something that looks like this: Live entry: key=http://localhost:55446/BaseWebSite/,http://localhost:55446/BaseWebSite/applet/myappliet.jar, http://localhost:55446/BaseWebSite/applet/applet_dependency.jar, refCount=1, threadGroup=sun.plugin2.applet.Applet2ThreadGroup[name=http://localhost:55446/BaseWebSite/-threadGroup,maxpri=4]

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  • VMware ESXi 4 On-Disk Data Deduplication - possible and supported?

    - by hurikhan77
    Environment: We are running multiple web, database, and application servers which usually share a pretty common installation (gentoo linux) and similar configuration in VMware ESXi 4. The differences are usually only some installed features or differing component versions. To create a new server, I usually choose the most similar (by features) running server, rsync a copy of it into freshly mounted filesystems, run grub, reconfigure and reboot. Problem: Over time this duplicates many on-disk data blocks which probably sums up to several 10's of gigabytes. I suppose if I could use a base system as template with the actual machines based on top of that, only writing changed blocks to some sort of "diff image", performance should improve (increased cache hit rate) and storage efficiency should increase (deduplicated storage space). This would be similar to what ESXi already supports for RAM deduplication (page sharing). Question: Is there any way to easily do this on ESXi 4? I already share the portage tree via NFS but this would not work for the rootfs.

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  • cant access site intermittent as i get site not available

    - by user61438
    i have a news site i check stuff for regularly.. once in a while i cant access it completely from my 5 different browsers and even from the command line, nslookup cant resolve, ping and tracert fails.. all not being able to resolve site name..the problem is specific to this.. i am told by the site support person that problem is that its cache on my machine or on ISP and I say thats not true because this site I access it 1-2-3 times a week from one browser only.. i only fire up the other ones in times of trouble..and when i have the problem even if i try on my secondary machines i still get the same problems.. when problem goes away all works well.... question is whats causing the intermittent dns/http problems... i don't believe this is something to do with my machine because probe disappears without me having done anything at all.

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  • clojure.algo.monad strange m-plus behaviour with parser-m - why is second m-plus evaluated?

    - by Mark Fisher
    I'm getting unexpected behaviour in some monads I'm writing. I've created a parser-m monad with (def parser-m (state-t maybe-m)) which is pretty much the example given everywhere (here, here and here) I'm using m-plus to act a kind of fall-through query mechanism, in my case, it first reads values from a cache (database), if that returns nil, the next method is to read from "live" (a REST call). However, the second value in the m-plus list is always called, even though its value is disgarded (if the cache hit was good) and the final return is that of the first monadic function. Here's a cutdown version of the issue i'm seeing, and some solutions I found, but I don't know why. My questions are: Is this expected behaviour or a bug in m-plus? i.e. will the 2nd method in a m-plus list always be evaluated if the first item returns a value? Minor in comparison to the above, but if i remove the call _ (fetch-state) from checker, when i evaluate that method, it prints out the messages for the functions the m-plus is calling (when i don't think it should). Is this also a bug? Here's a cut-down version of the code in question highlighting the problem. It simply checks key/value pairs passed in are same as the initial state values, and updates the state to mark what it actually ran. (ns monods.monad-test (:require [clojure.algo.monads :refer :all])) (def parser-m (state-t maybe-m)) (defn check-k-v [k v] (println "calling with k,v:" k v) (domonad parser-m [kv (fetch-val k) _ (do (println "k v kv (= kv v)" k v kv (= kv v)) (m-result 0)) :when (= kv v) _ (do (println "passed") (m-result 0)) _ (update-val :ran #(conj % (str "[" k " = " v "]"))) ] [k v])) (defn filler [] (println "filler called") (domonad parser-m [_ (fetch-state) _ (do (println "filling") (m-result 0)) :when nil] nil)) (def checker (domonad parser-m [_ (fetch-state) result (m-plus ;; (filler) ;; intitially commented out deliberately (check-k-v :a 1) (check-k-v :b 2) (check-k-v :c 3))] result)) (checker {:a 1 :b 2 :c 3 :ran []}) When I run this as is, the output is: > (checker {:a 1 :b 2 :c 3 :ran []}) calling with k,v: :a 1 calling with k,v: :b 2 calling with k,v: :c 3 k v kv (= kv v) :a 1 1 true passed k v kv (= kv v) :b 2 2 true passed [[:a 1] {:a 1, :b 2, :c 3, :ran ["[:a = 1]"]}] I don't expect the line k v kv (= kv v) :b 2 2 true to show at all. The first function to m-plus (as seen in the final output) is what is returned from it. Now, I've found if I pass a filler into m-plus that does nothing (i.e. uncomment the (filler) line) then the output is correct, the :b value isn't evaluated. If I don't have the filler method, and make the first method test fail (i.e. change it to (check-k-v :a 2) then again everything is good, I don't get a call to check :c, only a and b are tested. From my understanding of what the state-t maybe-m transformation is giving me, then the m-plus function should look like: (defn m-plus [left right] (fn [state] (if-let [result (left state)] result (right state)))) which would mean that right isn't called unless left returns nil/false. I'd be interested to know if my understanding is correct or not, and why I have to put the filler method in to stop the extra evaluation (whose effects I don't want to happen). Apologies for the long winded post!

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  • Exchange 2010 SP2 OWA performance

    - by Frederik Nielsen
    How do I increase performance in OWA 2010 SP2? I am running CAS on a seperate installation, which has 8GB RAM and 4 CPU cores - running virtualized in a vmware environment. However, the load times are pretty bad, so is there any way to improve those? I am thinking of installing a linux cache-stuff-server in front of the OWA, but will that work? And how should it be done? Allright, I "fixed" it - was just something temporary issue. Thanks for your replies

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  • ZFS SAS/SATA controller recommendations

    - by ewwhite
    I've been working with OpenSolaris and ZFS for 6 months, primarily on a Sun Fire x4540 and standard Dell and HP hardware. One downside to standard Perc and HP Smart Array controllers is that they do not have a true "passthrough" JBOD mode to present individual disks to ZFS. One can configure multiple RAID 0 arrays and get them working in ZFS, but it impacts hotswap capabilities (thus requiring a reboot upon disk failure/replacement). I'm curious as to what SAS/SATA controllers are recommended for home-brewed ZFS JBODs. In addition, how does battery-backed write cache (BBWC) play into the solution?

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  • .net IHTTPHandler Streaming SQL Binary Data

    - by Yisman
    Hello everybody I am trying to implement an ihttphandeler for streaming files. files may be tiny thumbnails or gigantic movies the binaries r stored in sql server i looked at a lot of code online but something does not make sense isnt streaming supposed to read the data piece by piece and move it over the line? most of the code seems to first read the whole field from mssql to memory and then use streaming for the output writing wouldnt it b more eficient to actually stream from disk directly to http byte by byte (or buffered chunks?) heres my code so far but cant figure out the correct combination of the sqlreader mode and the stream object and the writing system Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest context.Response.BufferOutput = False Dim FileField=safeparam(context.Request.QueryString("FileField")) Dim FileTable=safeparam(context.Request.QueryString("FileTable")) Dim KeyField=safeparam(context.Request.QueryString("KeyField")) Dim FileKey=safeparam(context.Request.QueryString("FileKey")) Using connection As New SqlConnection(ConfigurationManager.ConnectionStrings("Main").ConnectionString) Using command As New SqlCommand("SELECT " & FileField & "Bytes," & FileField & "Type FROM " & FileTable & " WHERE " & KeyField & "=" & FileKey, connection) command.CommandType = Data.CommandType.Text enbd using end using end sub please be aware that this sql command also returns the file extension (pdf,jpg,doc...) in the second field of the query thank you all very much

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  • Server 2012 R2 DNS Conditional forwarding not working reliably, possible caching issue?

    - by Matt
    I have a bit of a home lab setup with a domain controller that is acting as the DNS server for my network. For everything, it's working fine and forwards external DNS requests to my ISP. The household recently wanted to get Netflix going and it seemed a DNS option was better than a VPN to get around the region locking, so I signed up for unblock-us.com Since I have a Windows DNS server I thought I'd be clever and make use of conditional forwarders and added the Netflix domain to the list. Initially this worked well and all devices on the network could now access Netflix, however after about an hour going to the Netflix site would result in a page cannot be found. Doing an nslookup of Netflix.com from my PC resulted in it not returning any IP addresses. As a test, I deleted the Netflix domain from the DNS servers cache and things started working again - devices could get to the site again however the same thing happens again after around half an hour to an hour. Have I missed something here that's causing it to stop working?

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  • Does ASP.NET need to be configured for Full Trust to implement 'PageHandlerFactory' ?

    - by Kev
    Our hosting platform (running IIS6/ASP.NET 2.0) is configured to run under partial trust. In the machine wide web.config file we set the ASP.NET trust level to Medium (and lock to prevent overrides) and use a modified policy file. When trying to add a custom HttpHandler to handle .aspx requests for a website running in this configuration I get the following security exception: Security Exception Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your system administrator or change the application's trust level in the configuration file. Exception Details: System.Security.SecurityException: Request failed. Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: [SecurityException: Request failed.] System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase) +0 System.Reflection.Assembly.GetType(String name, Boolean throwOnError, Boolean ignoreCase) +42 System.Web.Compilation.CompilationUtil.GetTypeFromAssemblies(AssemblyCollection assembliesCollection, String typeName, Boolean ignoreCase) +172 System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) +291 System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase) +52 I'm using a class derived from PageHandlerFactory, for example: public class MyPageHandlerFactory : PageHandlerFactory { public override System.Web.IHttpHandler GetHandler(System.Web.HttpContext context, string requestType, string virtualPath, string path) { // CustomPageHandler derives from System.Web.UI.Page return new CustomPageHandler(); } } My web.config httpHandler configuration is as follow: <httpHandlers> <add verb="*" path="*.aspx" type="MyPageHandler.MyPageHandlerFactory" /> </httpHandlers> The documentation for PageHandlerFactory shows that PageHandlerFactory is decorated with the following attributes: [PermissionSetAttribute(SecurityAction.LinkDemand, Unrestricted = true)] [PermissionSetAttribute(SecurityAction.InheritanceDemand, Unrestricted = true)] public class PageHandlerFactory : IHttpHandlerFactory Does this mean that I need to set ASP.NET to run at Full Trust to be able to create my own PageHandlerFactory classes?

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  • problem writing xml to file with .net mvc - timeout?

    - by Mark
    Hey, so having an issue with writing out to an xml file. Works fine for single requests via the browser, but when I use something like Charles to perform 5-10 repeated requests concurrently several of them will fail. The trace simply shows a 500 error with no content inside, basically I think they start timing out waiting for write access or something... This method is inside my repository class, have also attempted to have repository instance as a singleton but doesn't appear to make any difference.. Any help would be much appreciated. Cheers public void Add(Request request) { try { XDocument requests; XmlReader xmlReader; using (xmlReader = XmlReader.Create(_requestsFilePath)) { requests = XDocument.Load(xmlReader); XElement xmlRequest = new XElement("request", new XElement("code", request.code), new XElement("date", request.date), new XElement("email", new XCData(request.email)), new XElement("name", new XCData(request.name)), new XElement("recieveOffers", request.recieveOffers) ); requests.Root.Element("requests").Add(xmlRequest); xmlReader.Close(); } requests.Save(_requestsFilePath); } catch (Exception ex) { HttpContext.Current.Trace.Warn("Error writing to file: "+ex); } }

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  • f12 and ctrl + f5 not working correctly

    - by ComatoseDuck
    When I came back to my work computer after being away for a week I found out when I try to clear the cache and refresh the page via ctrl + f5 (or just f5) I get the prompt "Type the Internet address of a document, and Internet Explorer will open it for you" with a drop down list in IE. When I try f5 in Chrome and FF it opens the "Open file" dialog box. When I try to f12 for Dev tools in IE, Chrome & FF it opens up the print dialog box. Why is this happening and what can I do to revert it back to the way it was?

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  • AMD Processors and the Windows Phone 8 Emulator

    - by Aj Patel
    I would madly appreciate it if anyone in this community would help me with my question. The background is that I want to develop Windows Phone 8 applications but both of my current computer processors do not have Hardware Virtualization & Second Level Address Translation that are needed to run the Emulator. I have my eyes on an AMD computer g7-2243us (I like it because it has 1600x900 screen res). I looked up this Link that shows that this computer's AMD processor (Next Gen AMD Quad-Core A8-4500M Accelerated 1.9GHz up to 2.8GHz 4MB L2 Cache Processor) supports AMD-V Hardware Virtualization. So, will this computer be able to run the emulator? Thank you so much for your answers. I'm pretty sure it will run the emulator, but I just want to make sure before spending $400. Thank You all So Much.

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  • Recover a deleted webpage

    - by rc
    Suppose, a blog or a nice article was hosted on a website and it got deleted or worse the website was brought down. How do you view that web page? I tried searching for the cached version in Google. But, looks like the content was deleted long ago and is not listed in the search results directly. There are annotations to the link from many other sites, but still the actual content is not fully available. Now, can anybody help me see this page... I am actually looking for http://effectize.com/become-coolest-programmer :) And, moreover, in addition to bookmarking a favorite link, is it possible to cache the content of the link as well for later reference in case it gets deleted? EDIT: Looks like a URL can be cached for future reference. Try: http://backupurl.com/

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  • Robocopy hiding folders on backup drives

    - by Neil Barnwell
    I have a backup batch file that uses Robocopy to backup my files: robocopy "C:\" "G:\Default\RoboCopyBackup\C" /XF Pagefile.sys /XD "System Volume Information" "Recycler" "Temporary Internet Files" "Installer Cache" "Temp" /E /R:1 /W:0 /TEE /XJ This should create a folder structure on the external backup drive like so: G:\Default\RoboCopyBackup\C\... However, G: appears totally empty. What is weird, is that the folders and files are there! If I type the above path into the address bar, I see all the files and folders! Can anyone help me work out why? I think it might be some NTFS-based ownership/permissions thing but I'm not sure.

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  • Downloading videos from a flash website

    - by Mimi
    There are those plugins that can capture flash videos from websites like Youtube and others. There's also the browsing cache which keeps the videos and I can copy them somewhere else and have them stored on my computer. I know of these, but how can I download a video from a website that (I think) is all flash because the address doesn't change wherever you navigate to and so it stays the same when you play a video that's on the website? No plugin I've tried (realplayer, ant video downloadr, IDM) have worked with it and nothing gets cached from that website.

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  • What hardware makes a good MongoDB Server ? Where to get it ?

    - by João Pinto Jerónimo
    Suppose you're on dell.com right now and you're buying a server to run your MongoDB database for your small startup. You will have to handle literally tens of thousands of writes and reads per minute (but small objects). Would you go for 2 processors ? Invest more on RAM ? I've heard (correct me if I'm wrong) MongoDB handles the most it can on the RAM and then flushes everything to the disk, in that case I should invest on a CPU with a large L2 cache, probably 40GB of RAM and a solid state drive.. right ? Would I be better off with a high end (~$11,309, 2 expensive processors, 96GB of RAM) server or 2x(~$6,419, 2 expensive processors, 12GB of RAM) servers ? Is Dell ok or do you have better sugestions ? (I'm outside the US, on Portugal)

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  • Apache unable to write to files and folders on Fedora 16

    - by mickburkejnr
    I've recently installed Fedora 16 on a new PC, and I'm intending to use it for developing my websites. I've set up Apache to host multiple development sites on the machine. Right now though, I am trying to install a PHP framework (Symfony2) and I'm unable to install it on to the web server. It comes back with an error saying that it's unable to write to the cache folder on the server. I have checked and modified the folder so that it is writeable, but still the error keeps being displayed? What am I doing wrong?

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  • In Nginx, can I handle both a location:url or a content-type: text/html response from memcached?

    - by Sean Foo
    I'm setting up an nginx - apache reverse proxy where nginx handles the static files and apache the dynamic. I have a search engine and depending on search parameter I either directly forward the user to the page they are looking for or provide a set of search results. I cache these results in memcached as key:/search.cgi?q=foo value: LOCATION:http://www.example.com/foo.html and key:/search.cgi?q=bar value: CONTENT-TYPE: text/html <html> .... .... </html> I can pull the "Content-type...." values out of memcached using nginx and send them to the user, but I can't quite figure out how to handle a returned value like "Location..." Can I?

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  • URL with no query parameters - How to distinguish.

    - by Broken Link
    Env: .NET 1.1 I got into this situation. Where I need to give a URL that someone could redirect them to our page. When they redirect they also need to tell us, what message I need to display on the page. Initially I thought of something like this. http://example.com/a.aspx?reason=100 http://example.com/a.aspx?reason=101 ... http://example.com/a.aspx?reason=115 So when we get this url based on 'reason' we can display different message. But the problem turns out to be that they can not send any query parameters at all. They want 15 difference URL's since they can't send query params. It doesn't make any sense to me to created 15 pages just to display a message. Any smart ideas,that have one URL and pass the 'reason' thru some means? EDIT: Options I'm thinking based on Answers Try HttpRequest.PathInfo or Second option I was thinking was to have a httphanlder read read the path like this - HttpContext.Request.Path based on path act. Ofcourse I will have some 15 entries like this in web.config. <add verb="*" path="reason1.ashx" type="WebApplication1.Class1, WebApplication1" /> <add verb="*" path="reason2.ashx" type="WebApplication1.Class1, WebApplication1" /> Does that look clean?

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  • Languages and VMs: Features that are hard to optimize and why

    - by mrjoltcola
    I'm doing a survey of features in preparation for a research project. Name a mainstream language or language feature that is hard to optimize, and why the feature is or isn't worth the price paid, or instead, just debunk my theories below with anecdotal evidence. Before anyone flags this as subjective, I am asking for specific examples of languages or features, and ideas for optimization of these features, or important features that I haven't considered. Also, any references to implementations that prove my theories right or wrong. Top on my list of hard to optimize features and my theories (some of my theories are untested and are based on thought experiments): 1) Runtime method overloading (aka multi-method dispatch or signature based dispatch). Is it hard to optimize when combined with features that allow runtime recompilation or method addition. Or is it just hard, anyway? Call site caching is a common optimization for many runtime systems, but multi-methods add additional complexity as well as making it less practical to inline methods. 2) Type morphing / variants (aka value based typing as opposed to variable based) Traditional optimizations simply cannot be applied when you don't know if the type of someting can change in a basic block. Combined with multi-methods, inlining must be done carefully if at all, and probably only for a given threshold of size of the callee. ie. it is easy to consider inlining simple property fetches (getters / setters) but inlining complex methods may result in code bloat. The other issue is I cannot just assign a variant to a register and JIT it to the native instructions because I have to carry around the type info, or every variable needs 2 registers instead of 1. On IA-32 this is inconvenient, even if improved with x64's extra registers. This is probably my favorite feature of dynamic languages, as it simplifies so many things from the programmer's perspective. 3) First class continuations - There are multiple ways to implement them, and I have done so in both of the most common approaches, one being stack copying and the other as implementing the runtime to use continuation passing style, cactus stacks, copy-on-write stack frames, and garbage collection. First class continuations have resource management issues, ie. we must save everything, in case the continuation is resumed, and I'm not aware if any languages support leaving a continuation with "intent" (ie. "I am not coming back here, so you may discard this copy of the world"). Having programmed in the threading model and the contination model, I know both can accomplish the same thing, but continuations' elegance imposes considerable complexity on the runtime and also may affect cache efficienty (locality of stack changes more with use of continuations and co-routines). The other issue is they just don't map to hardware. Optimizing continuations is optimizing for the less-common case, and as we know, the common case should be fast, and the less-common cases should be correct. 4) Pointer arithmetic and ability to mask pointers (storing in integers, etc.) Had to throw this in, but I could actually live without this quite easily. My feelings are that many of the high-level features, particularly in dynamic languages just don't map to hardware. Microprocessor implementations have billions of dollars of research behind the optimizations on the chip, yet the choice of language feature(s) may marginalize many of these features (features like caching, aliasing top of stack to register, instruction parallelism, return address buffers, loop buffers and branch prediction). Macro-applications of micro-features don't necessarily pan out like some developers like to think, and implementing many languages in a VM ends up mapping native ops into function calls (ie. the more dynamic a language is the more we must lookup/cache at runtime, nothing can be assumed, so our instruction mix is made up of a higher percentage of non-local branching than traditional, statically compiled code) and the only thing we can really JIT well is expression evaluation of non-dynamic types and operations on constant or immediate types. It is my gut feeling that bytecode virtual machines and JIT cores are perhaps not always justified for certain languages because of this. I welcome your answers.

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  • Am I using handlers in the wrong way?

    - by superexsl
    Hey, I've never used HTTP Handlers before, and I've got one working, but I'm not sure if I'm actually using it properly. I have generated a string which will be saved as a CSV file. When the user clicks a button, I want the download dialog box to open so that the user can save the file. What I have works, but I keep reading about modifying the web.config file and I haven't had to do that. My Handler: private string _data; private string _title = "temp"; public void AddData(string data) { _data = data; } public bool IsReusable { get { return false; } } public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/csv"; context.Response.AddHeader("content-disposition", "filename=" + _title + ".csv"); context.Response.Write(_data); context.Response.Flush(); context.Response.Close(); } And this is from the page that allows the user to download: (on button click) string dataToConvert = "MYCSVDATA...."; csvHandler handler = new csvHandler(); handler.AddData(dataToConvert); handler.ProcessRequest(this.Context); This works fine, but no examples I've seen ever instantiate the handler and always seem to modify the web.config. Am I doing something wrong? Thanks

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  • Can't see any YouTube videos

    - by André
    I have a problem with watching YouTube videos. It says: "An error occurred, please try again later". I've tried loading different videos and that's what it says to all the videos I try to watch. I've tried using another browser, clearing cache + cookies etc, but none of that really worked out. My operating system is Windows 7 Home Premium, I use Google Chrome as my browser. And the YouTube videos was able to be watched earlier. I suspect that it has something to do with the PC, since I've got YouTube working on my laptop earlier. Not sure if it still works on my laptop though. Hope I've given enough information for you to help me out with this problem. Feel free to ask if there's anything else you need to know. Anyone who can help me out?

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