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  • Web Applications Development: Security practices for Application design

    - by Shyam
    Hi, As I am creating more web applications that are targeted for multiple users, I figured out that I have to start thinking about user management and security. At a glance and in my ideal world, all users belong to a group. Permissions and access is thus defined per group (and inherited by the users of that group). Logically, I have my group of administrators, which are identified with a level "7" (integer) clearance. A group of webusers have for example level "1". This in generally all works great for me, but I need some kind of list that I have to keep in mind how I secure my system, and some general practices. I am not looking for a specific environment; I want to learn the why's and how's. An example is privilege escalation. If someone would be able to "push" themselves inside a group with higher privileges, for example the Administration, how can I prevent this, or what measures should I take to have some sort of precaution? I don't like in that case to walk into a caveat. My question is basically: where can I find a good resource, list, policy, book that explains the security of web applications, the why's, the how's and readable if you don't have any experience in the realm of advanced security? I prefer a free resource, as I believe I couldn't be the first one who thought about this. Thank you for your answers, comments and feedback.

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  • Open an Emacs buffer when a command tries to open an editor in shell-mode

    - by Chris Conway
    I like to use Emacs' shell mode, but it has a few deficiencies. One of those is that it's not smart enough to open a new buffer when a shell command tries to invoke an editor. For example with the environment variable VISUAL set to vim I get the following from svn propedit: $ svn propedit svn:externals . "svn-prop.tmp" 2L, 149C[1;1H ~ [4;1H~ [5;1H~ [6;1H~ [7;1H~ ... (It may be hard to tell from the representation, but it's a horrible, ugly mess.) With VISUAL set to "emacs -nw", I get $ svn propedit svn:externals . emacs: Terminal type "dumb" is not powerful enough to run Emacs. It lacks the ability to position the cursor. If that is not the actual type of terminal you have, use the Bourne shell command `TERM=... export TERM' (C-shell: `setenv TERM ...') to specify the correct type. It may be necessary to do `unset TERMINFO' (C-shell: `unsetenv TERMINFO') as well.svn: system('emacs -nw svn-prop.tmp') returned 256 (It works with VISUAL set to just emacs, but only from inside an Emacs X window, not inside a terminal session.) Is there a way to get shell mode to do the right thing here and open up a new buffer on behalf of the command line process?

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  • .ico icons not showing up on Windows

    - by Ali
    I followed the The Qt Resource System guide and the .ico icons appear on Linux. The icons are not showing up on Windows when I try to run the applicaton from Qt Creator. I suspect a plugin issue based on Qt/C++: Icons not showing up when program is run under windows O.S but I failed to figure out what to do from the guide How to Create Qt Plugins. Is it a plugin issue or why aren't the icons showing up on Windows? If it is a plugin issue: How do I tell my applicaton where to find the qico.dll? Details of the environment: Works on: Kubuntu 12.04 LTS, Qt Creator 2.4.1 and Qt 4.7.4 (64 bit) Fails on: Windows XP SP2 32 bit, Qt Creator 2.4.1 and Qt 4.7.4 (32 bit) Everyting is at its default (as installed out of the box), I did not mess with the settings. resources.qrc <!DOCTYPE RCC><RCC version="1.0"> <qresource> <file>images/spreadsheet.ico</file> </qresource> </RCC> Also tried with <qresource prefix="/">. From the applicaton.pro RESOURCES += \ resources.qrc OTHER_FILES += \ images/spreadsheet.ico In the corresponding source file QIcon(":/images/spreadsheet.ico") I repeat: it works on Linux.

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  • Sql Server Replication: Snapshot vs Merge

    - by Zyphrax
    Background information Let's say I have two database servers, both SQL Server 2008. One is in my LAN (ServerLocal), the other one is on a remote hosting environment (ServerRemote). I have created a database on ServerLocal and have an exact copy of that database on ServerRemote. The database on ServerRemote is part of a web application and I would like to keep it's data up-to-date with the data in the database ServerLocal. ServerLocal is able to communicate with ServerRemote, this is one-way traffic. Communication from ServerRemote to ServerLocal isn't available. Current solution I thought it would be a nice solution to use replication. So I've made ServerLocal a publisher and subscriptions are pushed to the ServerRemote. This works fine, when a snapshot is transfered to ServerRemote the existing data will be purged and the ServerRemote database is once again an exact replica of the database on ServerLocal. The problem Records that exist on ServerRemote that don't exist on ServerLocal are removed. This doesn't matter for most of my tables but in some of my tables I'd like to keep the existing data (aspnet_users for instance), and update the records if necessary. What kind of replication fits my problem?

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  • PHP.ini Settings Are Ignored By PHP5.3.5 Running With Windows 7 And Apache 2.2.15

    - by Andy
    I did an install of PHP5.3.5 on Windows 7 Home Premium using the MSI installer download. I got it to overwrite a previous version of PHP5 in C:\php5\ When first testing it, the server failed to start. I fixed this by adding the path to PHP in the Apache2.2 httpd file where the installer had inserted 2 lines of coded pointing to the ini file directory and the PHP DLL but had left out the directory path. After doing this, the server starts ok and I can run phpinfo to view the PHP settings in my web browser on local host. In the phpinfo it states that the loaded configuration file is C:\php5\php.ini as expected. But if I make any changes to the settings, and reboot the server, none of the changes are reflected in phpinfo. Yes, I do refresh the browser window. If I rename the php.ini to something else to make it invisible phpinfo then correctly identifies that there is no php.ini file loaded. So the settings in php.ini are being ignored and some default settings are being used (but I have no idea where these are derived from). As far as I can tell, there are no other php.ini files on my computer. In phpinfo it states that the Configuration File (php.ini) Path is C:\Windows but this is the same as on a Windows XP computer that I work on. And in the windows folder I don't see any php.ini file. In the windows registry, there is no mention of PHP5, and the PATH environment variable starts with C:\php5\; So hopefully someone can suggest how I can get PHP5 to take notice of the C:\php5\php.ini settings. :)

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  • SQL Server job (stored proc) trace

    - by Jit
    Hi Friends, I need your suggestion on tracing the issue. We are running data load jobs at early morning and loading the data from Excel file into SQL Server 2005 db. When job runs on production server, many times it takes 2 to 3 hours to complete the tasks. We could drill down to one job step which is taking 99% of the total time to finish. While running the job step (stored procs) on staging environment (with the same production database restored) takes 9 to 10 minutes, the same takes hours on production server when it run at early morning as part of job. The production server always stuck up at the very job step. I would like to run trace on the very job step (around 10 stored procs run for each user in while loop within the job step) and collect the info to figure out the issue. What are the ways available in SQL Server 2005 to achieve the same? I want to run the trace only for these SPs and not for certain period time period on production server, as trace give lots of information and it becomes very difficult for me (as not being DBA) to analyze that much of trace information and figure out the issue. So I want to collect info about specific SPs only. Let me know what you suggest. Appreciate your time and help. Thanks.

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  • google maps api keys to be set webserver-wide, (as env var? inside apache?)

    - by ~knb
    I have a web site with many virtual hosts and each registered with several domain names (ending in .org, .de), site1.mysite.de, site2.mysite.org Then I have different templating systems based on several programming languages (perl and php) in use on the web server. The Google Maps Api requires a unique Google Maps api key for each vhost. I want to have something like a web-server wide variable $goomapkey that I can call from inside my code. In PHP code, Now I have a kludgy case-analysis solution like $domain = substr($_SERVER['SERVER_NAME'], -3); if (".de" == $domain){ //if ("xxxxxx" eq substr($ENV{SERVER_NAME}, 0, 5)){ // $gookey = "ABQIAAA..."; //} else { //site1.de $gookey = "ABQIAAAA1Js..."; //} } elseif ("dev" == substr($_SERVER['SERVER_NAME'], 0, 3)){ //dev.mysite.org $gookey = "ABQIAAAA1JsSb..."; } else { //www.mysite.org $gookey = "ABQIAAAA1JsS..."; //TODO: Add more keys for each virtual host, for my.machinename.de, IP-address based URL, ... } ... inside my php-based CMS. A non-ideal solution, because it is, php-only, and I still have to set it at several html templates inside the CMS, and there are too many cases. I want the google maps api key to be set by the apache web server who examines the request *early in the request loop before any php page template code is constructed and evaluated. is an environment variable a good solution? which technology should be used to set the $goomapkey variable? I'd prefer mod_perl2 Apache request handler, but the documentation is confusing (many API changes in the past ). Which Apache module could I use? Is there a built-in Apache module that does the same thing?

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  • Visual Studio 2010 Bootstrap Folder?

    - by Matma
    We currently run a VS2005 app/environment and im investigating upgrading to 2010. But before i can say yes its all good, go buy bossman... I have to confirm that a bootstrap for a thridparty driver install which is included on our installation cd can be used/included (its a usb security dongle so drivers MUST be included/setup for our app to run). It is in the list of available pre-reqs but i didnt put it in the vs2010 bootstrap folder so is this coming from my vs2005 install? or the fact that i had previously selected it in the installer and its saved/loaded that in vs2010? Either way its got a little error icon and says its not found so i get errors on build. I want to resolve this and have it in the list of available pre-reqs as we did for 2005. i.e. copy it to the C:\Program Files (x86)\Microsoft Visual Studio 8\SDK\v2.0\BootStrapper folder... But i cant seem to find where the bootstraps are for vs2010? does it not use them? Naturally ive searched the entire vs folder structure for appropriate files/folders but nothing? Where/How is this now done?

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  • Wicket application + Apache + mod_jk - AJP queues are filling up!

    - by nojyarg
    Dear community, We are having a Wicket-based Java application deployed in a production server cluster using Apache (2.2.3) with mod_jk (1.2.30) as load balancing component w/ sticky session and Jboss 5 as application container for the Java application. We are inconsistently seeing an issue in our production environment where our AJP queues between Apache and Jboss as shown in the JMX console fill up with requests to the point where the application server is no longer taking on any new requests. When looking at all involved system components (overall traffic, load db, process list db, load of all clustered application server nodes) nothing points towards a capacity issue which would explain why the calls are being stalled in the AJP queue. Instead all systems appear sufficiently idle. So far, our only remedy to this issue is to restart the appservers and the load balancer which only occasionally clears the AJP queues. We are trying to figure out why the queues are filling up to the point that no calls get returned to the end user although the system is not under a high load. Has anyone else experienced similar problems? Are there any other system metrics we should monitor that could explain the queuing behavior? Is this potentially a mod_jk issue? If so, is it advisable to swap mod_jk with mod_cluster to resolve the issue? Any advice is highly appreciated. If I can provide additional information for the sake of troubleshooting I would be more than willing to do so. /Ben

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  • why does setting stderr=subprocess.STDOUT fix a subprocess.check_output call?

    - by ShankarG
    I have a python script running on a small server that is called in three different ways - from within another python script, by cron, or by gammu-smsd (an SMS daemon with the wonderful mobile utility [gammu]). The script is for maintenance and contained the following kludge to measure used space on the system (presumably this is possible from within Python, but this was quick and dirty): reportdict['Used Space'] = subprocess.check_output(["df / | tail -1 | awk '{ print $5; }'"], shell=True)[0:-1] Oddly enough this line would only fail when the script was called by a shell script running from gammu-smsd. The line would fail with a CalledProcessError exception saying "returned exit status 2", even though the output attribute of the CalledProcessError object contained the correct output. The only command in the sequence of shell commands that would give such an error status would be awk, with status 2 indicating a fatal error. If the python script with this line was called by cron, by another python script, or from the command line, this line would work fine. I broke my head trying to fix the environment for the script, thinking this must be the problem. Finally though I put in stderr=subprocess.STDOUT, like so: reportdict['Used Space'] = subprocess.check_output(["df / | tail -1 | awk '{ print $5; }'"], stderr=subprocess.STDOUT, shell=True)[0:-1] This was a debug measure to help me figure out if some output was coming on stderr. But after this the script started working, even when called from gammu-smsd! Why might this be the case? I ask for future reference when using subprocess...

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  • Random problem connecting to MySQL

    - by CharlesLeaf
    Environment: RHEL 5 servers, MySQL 5.1.43, PHP 5.1.6 (using MySQLi). Currently only available within our internal VPN network. Servers ServerA: Webserver ServerB/C/D: Database server (1 master 2 slaves) The error (on ServerA) [Tue May 25 11:12:17 2010] [error] [client CLIENTIP] PHP Warning: mysqli::real_connect() [function.mysqli-real-connect]: (HY000/2003): Can't connect to MySQL server on 'ServerB' (4) in /home/**/Database.php on line 67, referer: [website] Problem description It appears that at completely random times, our website is unable to connect to one of the MySQL servers - usually the Master. Except for the forementioned error message, there is nothing to be found in any of the logs as far as I can see, and most of the times the connection is succesful and everything works as it should. It's just at completely random times, this error pops up. There's no firewall blocking any internal traffic, timeout value is 3 but it doesn't take 3 seconds before it fails to connect. With the default mysql client I can connect from ServerA to ServerB,C and D and haven't encountered a problem yet. Does anyone have a clue what I might be overlooking / could be the problem? Because I've run out of ideas myself.

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  • a way to use log4j pass values like java -DmyEnvVar=A_VALUE to my code

    - by raticulin
    I need to pass some value to enable certain code in may app (in this case is to optionally enable writing some stats to a file in certain conditions, but it might be anything generally). My java app is installed as a service. So every way I have thought of has some drawbacks: Add another param to main(): cumbersome as customers already have the tool installed, and the command line would need to be changed every time. Adding java -DmyEnvVar=A_VALUE to my command line: same as above. Set an environment variable: service should at least be restarted, and even then you must take care of what user is the service running under etc. Adding the property in the config file: I prefer not to have this visible on the config file so the user does not see it, it is something for debugging etc. So I thought maybe there is some way (or hack) to use log4j loggers to pass that value to my code. I have thought of one way already, although is very limited: Add a dummy class to my codebase com.dummy.DevOptions public class DevOptions { public static final Logger logger = Logger.getLogger(DevOptions.class); In my code, use it like this: if (DevOptions.logger.isInfoEnabled()){ //do my optional stuff } //... if (DevOptions.logger.isDebugEnabled()){ //do other stuff } This allows me to use discriminate among various values, and I could increase the number by adding more loggers to DevOptions. But I wonder whether there is a cleaner way, possibly by configuring the loggers only in log4j.xml??

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  • sql server - framework 4 - IIS 7 weird sort from db to page

    - by ila
    I am experiencing a strange behavior when reading a resultset from database in a calling method. The sort of the rows is different from what the database should return. My farm: - database server: sql server 2008 on a WinServer 2008 64 bit - web server: a couple of load balanced WinServer 2008 64 bit running IIS 7 The application runs on a v4.0 app pool, set to enable 32bit applications Here's a description of the problem: - a stored procedure is called, that returns a resultset sorted on a particular column - I can see thru profiler the call to the SP, if I run the statement I see correct sorting - the calling page gets the results, and before any further elaboration logs the rows immediately after the SP execution - the results are in a completely different order (I cannot even understand if they are sorted in any way) Some details on the Stored Procedure: - it is called by code using a SqlDatAdapter - it has also an output value (a count of the rows) that is read correctly - which sort field is to be used is passed as a parameter - makes use of temp tables to collect data and perform the desired sort Any idea on what I could check? Same code and same database work correctly in a test environment, 32 bit and not load balanced.

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  • retrieve image from gallery in android

    - by smsys
    I have created an Activity where i have a Button. By pressing the button an android Gallery opens. When i choose an image from the gallery it is shows it in an ImageView of my Activity but after choosing second time the following error occuring 01-13 17:55:25.323: ERROR/AndroidRuntime(14899): java.lang.OutOfMemoryError: bitmap size exceeds VM budget Here is the source code i am using: public class MyImage extends Activity { /** Called when the activity is first created. */ Gallery gallery; private Uri[] mUrls; String[] mFiles=null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); File images = Environment.getDataDirectory(); File[] imagelist = images.listFiles(); mFiles = new String[imagelist.length]; for(int i= 0 ; i< imagelist.length; i++) { mFiles[i] = imagelist[i].getAbsolutePath(); } mUrls = new Uri[mFiles.length]; for(int i=0; i < mFiles.length; i++) { mUrls[i] = Uri.parse(mFiles[i]); } Gallery g = (Gallery) findViewById(R.id.Gallery01); g.setAdapter(new ImageAdapter(this)); g.setFadingEdgeLength(40); } public class ImageAdapter extends BaseAdapter{ int mGalleryItemBackground; public ImageAdapter(Context c) { mContext = c; } public int getCount(){ return mUrls.length; } public Object getItem(int position){ return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent){ ImageView i = new ImageView(mContext); i.setImageURI(mUrls[position]); i.setScaleType(ImageView.ScaleType.FIT_XY); i.setLayoutParams(new Gallery.LayoutParams(260, 210)); return i; } private Context mContext; } }

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  • How do I distribute my slightly customized Linux in VirtualBox?

    - by goodrone
    Suppose I've got some Arch Linux installation which I'd like to distribute among students with (sometimes very) basic Linux knowledge to make them able to compile C programs in an environment very similar to that in the university. (Things like Cygwin or MinGW seem to be inappropriate here.) I also choose VirtualBox as a holder for the virtual system. The question is: how do I distribute it? I mean: installing VirtualBox on the target machine (if not still installed) uncompressing and copying my image file (.VDI) registering the image (so that VirtualBox could see it when launched) configuring the guest system in VirtualBox (network, memory, etc.) optionally installing PuTTY to simplify interfacing with the guest Linux Should I create an installer? Which one? Or just write some .BAT-scripts? (Target host system is Windows, mostly XP and Vista.) I definately don't want to have a webpage with screen shot explaining where to click and what to press, because it's boring. Additionaly, what will be the best (the most user-friendly) way to configure network when the guest Linux system is run for the first time?

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  • How to write an R function that evaluates an expression within a data-frame

    - by Prasad Chalasani
    Puzzle for the R cognoscenti: Say we have a data-frame: df <- data.frame( a = 1:5, b = 1:5 ) I know we can do things like with(df, a) to get a vector of results. But how do I write a function that takes an expression (such as a or a > 3) and does the same thing inside. I.e. I want to write a function fn that takes a data-frame and an expression as arguments and returns the result of evaluating the expression "within" the data-frame as an environment. Never mind that this sounds contrived (I could just use with as above), but this is just a simplified version of a more complex function I am writing. I tried several variants ( using eval, with, envir, substitute, local, etc) but none of them work. For example if I define fn like so: fn <- function(dat, expr) { eval(expr, envir = dat) } I get this error: > fn( df, a ) Error in eval(expr, envir = dat) : object 'a' not found Clearly I am missing something subtle about environments and evaluation. Is there a way to define such a function?

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  • JSR-299 (CDI) configuration at runtime

    - by nsn
    I need to configure different @Alternatives, @Decorators and @Injectors for different runtime environments (think testing, staging and production servers). Right now I use maven to create three wars, and the only difference between those wars are in the beans.xml files. Is there a better way to do this? I do have @Alternative @Stereotypes for the different environments, but even then I need to alter beans.xml, and they don't work for @Decorators (or do they?) Is it somehow possible to instruct CDI to ignore the values in beans.xml and use a custom configuration source? Because then I could for example read a system property or other environment variable. The application exclusively runs in containers that use Weld, so a weld-specific solution would be ok. I already tried to google this but can't seem to find good search terms, and I asked the Weld-Users-Forums, but to no avail. Someone over there suggested to write my own custom extension, but I can't find any API to actually change the container configuration at runtime. I think it would be possible to have some sort of @ApplicationScoped configuration bean and inject that into all @Decorators which could then decide themselves whether they should be active or not and then in order to configure @Alternatives write @Produces methods for every interface with multiple implementations and inject the config bean there too. But this seems to me like a lot of unnecessary work to essentially duplicate functionality already present in CDI?

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  • C#/.NET: FInd out whether a server exists, Query DNS for SVC records.

    - by TomTom
    Writing a cleint/Server tool I am tasked trying to find a server to connect to. I would love to make things as easy as possible for the user. As such, my idea is to: CHeck whether specific servers (coded by name) exist (like "mail.xxx" for a mail server, for example - my exampüle is not a mail server;) Query otherwise for DNS SVC records, allowing the admin to configure a server location for a specific serivce (that the client connects to). The result is that the user may have to enter only a domain name, possibly even not even that (using the registered standard domain of the computer in a LAN environment). Anyone ideas how: To find out whether a server exists and answers (i.e. is online) in the fastest way? TCP can take a long time if the server is not there. A UDP style ping sounds like a good idea to me. PING itself may be unavailable. Anyonw knows how to ask from withint .NET best for a SVC record in a specific (the default) domain?

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  • Static libraries in version-cross-compiled program

    - by Brian Postow
    I have a unix command line app (with big nasty makefile) that I'm trying to run on a mac. I am compiling it on a 10.6 system, with all of the appropriate libraries of course. The deployment environment is a 10.5 system, with no extra libraries. I compiled without -dynamic, and it appears to have static libraries, correctly. When I run it on the 10.6 system, it works. However, when I run it on the 10.5 system, I get: dyld: unknown required load command 0x80000022 I got this same error when I compiled things for the 10.6 system using the 10.5 xcode, so it looks like a version mis-match type problem. However, I used gcc-4.0, and $CFLAGS = -isysroot /Developer/SDKs/MacOSX10.5.sdk -mmacosx-version-min=10.5 so it SHOULD be set up for 10.5... any ideas? thanks Editing an ancient question: I have the exact same problem on a different computer. This time I am at 10.5.8, fully update, the same executable works on 10.6 still. Has anyone had any luck with this in the months since I asked this?

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  • GPG error occurs while using "deb file:/local-path-to-repo ..." in /etc/apt/sources.list

    - by Chandler.Huang
    I need to install packages within non-internet connection environment. My plan is to download dist structure from Internet and then add file path to /etc/apt/sources.list. So I download related structure includes ubunt/dists/precise, precise-backports, precise-proposed, precise-security, precise-updates from a ftp mirror server. And then I remove original source and add the following to my /etc/apt/sources.list. deb file:path-to-local-ubuntu-directory/ precise main restricted multiverse universe deb-src file:path-to-local-ubuntu-directory/ precise main restricted multiverse universe Then I got GPG error as following after apt-get update. root@openstack:/~# apt-get update Ign file: precise InRelease Get:1 file: precise Release.gpg [198 B] Get:2 file: precise Release [50.1 kB] Ign file: precise Release Get:3 file: precise/main TranslationIndex [3,761 B] Get:4 file: precise/multiverse TranslationIndex [2,716 B] Get:5 file: precise/restricted TranslationIndex [2,636 B] Get:6 file: precise/universe TranslationIndex [2,965 B] Reading package lists... Done W: GPG error: file: precise Release: The following signatures were invalid: BADSIG 0976EAF437D05B5 Ubuntu Archive Automatic Signing Key <[email protected]> I had tried use the following steps after google but in vain. sudo apt-get clean cd /var/lib/apt sudo mv lists lists.old sudo mkdir -p lists/partial sudo apt-get update Is there any way to resolve this? And why this error occurs? Thanks a lot.

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  • ASP.NET: Page HTML head rendering

    - by Fabian
    I've been trying to figure out the best way to custom render the <head> element of a pag to get rid of the extra line breaks which is caused by <head runat="server">, so its properly formatted. So far the only thing i've found which works is the following: protected override void Render(HtmlTextWriter writer) { StringWriter stringWriter = new StringWriter(); HtmlTextWriter htmlTextWriter = new HtmlTextWriter(stringWriter); base.Render(htmlTextWriter); htmlTextWriter.Close(); string html = stringWriter.ToString(); string newHTML = html.Replace("\r\n\r\n<!DOCTYPE", "<!DOCTYPE") .Replace("\r\n<html", "<html") .Replace("<title>\r\n\t", "<title>") .Replace("\r\n</title>", "</title>") .Replace("</head>", "\n</head>"); writer.Write(newHTML); } I define my had tag like Now i have 2 questions: How does the above code affect the performance (so is this viable in an production environment)? Is there a better way to do this, for example a method which i can override to just custom render the <head>? Oh yeah ASP.NET MVC is not an option.

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  • Haskell: Dealing With Types And Exceptions

    - by Douglas Brunner
    I'd like to know the "Haskell way" to catch and handle exceptions. As shown below, I understand the basic syntax, but I'm not sure how to deal with the type system in this situation. The below code attempts to return the value of the requested environment variable. Obviously if that variable isn't there I want to catch the exception and return Nothing. getEnvVar x = do { var <- getEnv x; Just var; } `catch` \ex -> do { Nothing } Here is the error: Couldn't match expected type `IO a' against inferred type `Maybe String' In the expression: Just var In the first argument of `catch', namely `do { var <- getEnv x; Just var }' In the expression: do { var <- getEnv x; Just var } `catch` \ ex -> do { Nothing } I could return string values: getRequestURI x = do { requestURI <- getEnv x; return requestURI; } `catch` \ex -> do { return "" } however, this doesn't feel like the Haskell way. What is the Haskell way?

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  • How can I compile .NET 3.5 C# code on a system without Visual Studio?

    - by JimEvans
    I have some C# code that uses some constructs specific to .NET 3.5. When you install the .NET Framework distribution, you get the C# compiler installed with it (csc.exe). Even if I specify the csc.exe in C:\Windows\Microsoft.NET\Framework\v3.5, I cannot compile the code on a computer with only the .NET Framework installed, but not Visual Studio. I am able to compile code that uses v2.0 constructs without difficulty. How can I accomplish this? Here is a sample that demonstrates my problem: using System; class Program { public static void Main() { // The MacOSX value to the PlatformID enum was added after // .NET v2.0 if (Environment.OSVersion.Platform == PlatformID.MacOSX) { Console.WriteLine("Found mac"); } Console.WriteLine("Simple program"); } } When compiling this code using csc.exe, I receive the following error: test.cs(9, 58): error CS0117: 'System.PlatformID' does not contain a definition for 'MacOSX' When executing csc.exe /? I receive the banner: Microsoft (R) Visual C# 2008 Compiler version 3.5.21022.8 for Microsoft (R) .NET Framework version 3.5 Copyright (C) Microsoft Corporation. All rights reserved.

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  • Continuous build infrastructure recommendations for primarily C++; GreenHills Integrity

    - by andersoj
    I need your recommendations for continuous build products for a large (1-2MLOC) software development project. Characteristics: ClearCase revision control Approx 80% C++; 15% Java; 5% script or low-level Compiles for Green Hills Integrity OS, but also some windows and JVM chunks Mostly an embedded system; also includes some UI pieces and some development support (simulation tools, config tools, etc...) Each notional "version" of the deliverable includes deployment images for a number of boards, UI machines, etc... (~10 separate images; 5 distinct operating systems) Need to maintain/track many simultaneous versions which, notably, are built for a variety of different board support packages Build cycle time is a major issue on the project, need support for whatever features help address this (mostly need to manage a large farm of build machines, I guess..) Operates in a secure environment (this is a gov't program) (Edited to add: This is a classified program; outsourcing the build infrastructure is a non-starter.) Interested in any best practices or peripheral guidance you might offer. The build automation issues is one of several overlapping best practices that appear to be missing on the program, but try to keep your answers focused on build infrastructure piece and observations directly related. Cost is not an object. Scalability and ease of retrofitting onto an existing infrastructure are key. JA

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  • Android Java writing text file to sd card

    - by Paul
    I have a strange problem I've come across. My app can write a simple textfile to SD card and sometimes it works for some people but not for others and I have no idea why. Some people it force closes if they put some characters like "..." in it and such. I cannot seem to reproduce it as I've had no troubles but this is the code that handles it. Can anyone think of something that may lead to problems or a better to way to do it? public void generateNoteOnSD(String sFileName, String sBody){ try { File root = new File(Environment.getExternalStorageDirectory(), "Notes"); if (!root.exists()) { root.mkdirs(); } File gpxfile = new File(root, sFileName); FileWriter writer = new FileWriter(gpxfile); writer.append(sBody); writer.flush(); writer.close(); Toast.makeText(this, "Saved", Toast.LENGTH_SHORT).show(); } catch(IOException e) { e.printStackTrace(); importError = e.getMessage(); iError(); } }

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