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• A Newbie question regarding Software Development

  - by Sharif

  Hi, I'm going to complete my B.pharm (Hons.) degree and, you know, I don't have much knowledge about programing. I was wondering to build a software on my own. Could you guys tell me what to learn first for that? Is it too hard for a student of other discipline to build a software? Let me know please. The software I want to make is like a dictionary (or more specifically like "Physician's Desk Reference"). It should find the generic name, company name, indication, price etc. of a drug when I enter the brand name and vice versa. To build a software like that what programing language could help me most and what (and how many) language should I learn first? In my country, there is no practice of Community pharmacy (most of the pharmacy stores are run by unskilled people), that's why this type of thing could help them sell drugs. Would you please tell me what I'm to do and how tough it is? I'm very keen to learn programming. Thanks in advance NB: I started this post in ASKREDDIT section but it seems that was not the right place for poll type question, so I post it again in this section

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• How do I perform this MutliArray setup in Java?

  - by Andy Barlow

  I come from a PHP background and I'm just getting my teeth into some Java. I was wondering how I could implement the following in Java as simply as possible, just echoing the results to a terminal via the usual "System.out.print()" method. <?php $Results[0]['title'] = "No Country for Old Men"; $Results[0]['run_time'] = "122 mins"; $Results[0]['cert'] = "15"; $Results[1]['title'] = "Old School"; $Results[1]['run_time'] = "88 mins"; $Results[1]['cert'] = "18"; // Will basically show the above in order. foreach($Results as value) { echo $Results[$value]['title']; echo $Results[$value]['run_time']; echo $Results[$value]['cert']; } // Lets add some more as I need to do this in Java too $Results[2]['title'] = "Saving Private Ryan"; $Results[2]['run_time'] = "153 mins"; $Results[2]['cert'] = "15"; // Lets remove the first one as an example of another need $Results[0] = null; ?> I hear there are "list iterators" or something that are really good for rolling through data like this. Perhaps it could be implemented with that? A fully working .java file would be most handy in this instance, including how to add and remove items from the array like the above. P.S. I do plan on using this for an Android App in the distant future, so, hopefully it should all work on Android fine too, although, I imagine this sort of thing works on anything Java related :).

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• How to get a template tag to auto-check a checkbox in Django

  - by Daniel Quinn

  I'm using a ModelForm class to generate a bunch of checkboxes for a ManyToManyField but I've run into one problem: while the default behaviour automatically checks the appropriate boxes (when I'm editing an object), I can't figure out how to get that information in my own custom templatetag. Here's what I've got in my model: ... from django.forms import CheckboxSelectMultiple, ModelMultipleChoiceField interests = ModelMultipleChoiceField(widget=CheckboxSelectMultiple(), queryset=Interest.objects.all(), required=False) ... And here's my templatetag: @register.filter def alignboxes(boxes, cls): """ Details on how this works can be found here: http://docs.djangoproject.com/en/1.1/howto/custom-template-tags/ """ r = "" i = 0 for box in boxes.field.choices.queryset: r += "<label for=\"id_%s_%d\" class=\"%s\"><input type=\"checkbox\" name=\"%s\" value=\"%s\" id=\"id_%s_%d\" /> %s</label>\n" % ( boxes.name, i, cls, boxes.name, box.id, boxes.name, i, box.name ) i = i + 1 return mark_safe(r) The thing is, I'm only doing this so I can wrap some simpler markup around these boxes, so if someone knows how to make that happen in an easier way, I'm all ears. I'd be happy with knowing a way to access whether or not a box should be checked though.

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• What are the advantages of using J2EE over ASP.net?

  - by m_oLogin

  We are currently planning to launch a couple of internal web projects in the future. Our company's dev teams are mostly experienced in J2EE and have worked with it for years. Today, we have the choice of launching a couple of our projects on .net. I have checked out a couple of sources on the net, and it seems like the "J2EE vs ASP.net" combat brings out as much discord as the overseen "Apple vs Microsoft" or "Free Eclipse vs Visual Studio"... Nevertheless, I have been somewhat quite impressed with ASP.net's abilities to create great things with huge simplicity (for ex. asp.net ajax's demos). No more tons of xmls to play with, no more tons of frameworks to configure (we usually use the famous combo struts/spring/hibernate)... It just seemed to me that ASP.net had some good advantages over J2EE, but then again, I may speak by ignorance. What I want to know is this : What are the real advantages of using J2EE over ASP.net? Is there anything that cannot be done in ASP.net that can be done in J2EE? Once the frameworks are all in place and configured, is it faster to develop apps in J2EE than it is in .net? Are the applications generally easier to maintain in J2EE than in ASP.net? Is it worth it for some developpers to leave their J2EE knowledge on the side and move on to ASP.net if it does exactly the same thing?

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• How do I stop a routed event from triggering on specific places in XAML?

  - by cfouche

  I have the following situation: A stackpanel contains a number of elements, including some that are contained in a GroupBox. So something like this: <StackPanel x:Name="stackpanel" Background="White"> <TextBlock Text="TextBlock"/> <TextBlock Text="Another TextBlock"/> <!--plus a load of other elements and controls--> <GroupBox Header="GroupBoxHeader"> <TextBlock Text="Text inside GroupBox"/> </GroupBox> </StackPanel> I want a MouseDown in the stackpanel to trigger some Storyboard, so I've added an EventTrigger, like this: <EventTrigger RoutedEvent="Mouse.MouseDown" SourceName="stackpanel"> <BeginStoryboard Storyboard="{StaticResource OnMouseDown1}"/> </EventTrigger> This is almost right, but the thing is - I don't want the MouseDown to be picked up by the GroupBox's header or border, only by its content. In other words, I want the Storyboard to begin when someone does a mousedown on anything inside the StackPanel, except GroupBox headers and borders. Is there some way of doing this? (I've tried setting e.Handled to true on the GroupBox, but then its content doesn't pick up the mousedown anymore either.)

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• Multiple inequality conditions (range queries) in NoSQL

  - by pableu

  Hi, I have an application where I'd like to use a NoSQL database, but I still want to do range queries over two different properties, for example select all entries between times T1 and T2 where the noiselevel is smaller than X. On the other hand, I would like to use a NoSQL/Key-Value store because my data is very sparse and diverse, and I do not want to create new tables for every new datatype that I might come across. I know that you cannot use multiple inequality filters for the Google Datastore (source). I also know that this feature is coming (according to this). I know that this is also not possible in CouchDB (source). I think I also more or less understand why this is the case. Now, this makes me wonder.. Is that the case with all NoSQL databases? Can other NoSQL systems make range queries over two different properties? How about, for example, Mongo DB? I've looked in the Documentation, but the only thing I've found was the following snippet in their docu: Note that any of the operators on this page can be combined in the same query document. For example, to find all document where j is not equal to 3 and k is greater than 10, you'd query like so: db.things.find({j: {$ne: 3}, k: {$gt: 10} }); So they use greater-than and not-equal on two different properties. They don't say anything about two inequalities ;-) Any input and enlightenment is welcome :-)

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• Visual Studio breaks, and steps, but sometimes steps out

  - by James Wilkins

  Something very odd is going on. It's been going on for some time, but I've just ignored it up to now. I have both a Silverlight and WCF service in my solution, which shares .CS file between them (one project has a link to the file, which exists in the other project). While debugging the Silverlight app, pressing the F10 key steps through code as normal, and when I get to a method call which exists in the shared file (between the projects), and Press F11, it simply skips the method instead of stepping into it (and yes, the "Just My Code" option is not checked). If I put a breakpoint in the method I'm trying to get into, it works fine (as in the debugger will break on the line), but as soon as I step (F10) it exits the method (and with F11 [step into] also). Ok, on first thought, you might think it's to do with the link, but no, it isn't. I tried removing the link and using a copy instead, but the same thing happens. And no, it's not the debug symbols, I looked into that already. The method I'm trying to step through is static, and is in a non-static partial class, in a file shared by both projects. My guess: The same types and static methods exist in the WCF and Silverlight ... would the debugger get confused?

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• How To Share Information Between Django and Javascript?

  - by Randy

  So I am pretty new to both Django and Javascript (I am using JQuery) and I am wondering if I am doing a hack or if there are more slick ways to send client-side displayed database ids to the django server-side. Here is my process: I have a dataTable (http://datatables.net) that I am displaying rows of data by using the bProcessing option to use AJAX to retrieve records from the database. The URL in my urls.py is something like: url(r'^assets/activitylog/(?P<cid>.*)$', views.getActivityTable_ajax, name="activitylog_table"), and my dataTable ajax-relavant code is something like: "sAjaxSource": "/assets/activitylog/" + getIDFromHTML(), where the javascript function getIDFromHTML() grabs <cid> that is used by the Django view is simply: function getIDFromHTML(){ // Simply return the text in the #release_id div element from the HTML return $("#release_id").html(); }; This is the part that seems "hacky" to me. I am inserting into my template code the database id that I am using in the datatables URL (with display:none in the css) just so I can pass it back to the view. Most of this is necessitated because one cannot use django template tags in the javascript code unless the code is embedded into the HTML itself, which I am not (and will not) do. The only other thing that I have found is to change the URL to get rid of the parameter passed in to: url(r'^assets/activitylog', views.getActivityTable_ajax, name="activitylog_table"), and change the view code to: def getActivityTable_ajax(request): """Returns the activity for a given pid from HTTP GET ajax reqest""" pid = int(urlparse.urlparse(request.META['HTTP_REFERER']).path.split('/')[-1]) # rest of view code here... since the id that I need is on the end of this referer url. This way I don't have to monkey around with embedding the hidden database id into the HTML and passing it back to via ajax the the table population view code. Is it okay to use HTTP_REFERER in the request object in this manner? Am I going about this in the totally wrong way? Thanks in advance!

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• Deeply nested subqueries for traversing trees in MySQL

  - by nickf

  I have a table in my database where I store a tree structure using the hybrid Nested Set (MPTT) model (the one which has lft and rght values) and the Adjacency List model (storing parent_id on each node). my_table (id, parent_id, lft, rght, alias) This question doesn't relate to any of the MPTT aspects of the tree but I thought I'd leave it in in case anyone had a good idea about how to leverage that. I want to convert a path of aliases to a specific node. For example: "users.admins.nickf" would find the node with alias "nickf" which is a child of one with alias "admins" which is a child of "users" which is at the root. There is a unique index on (parent_id, alias). I started out by writing the function so it would split the path to its parts, then query the database one by one: SELECT `id` FROM `my_table` WHERE `parent_id` IS NULL AND `alias` = 'users';-- 1 SELECT `id` FROM `my_table` WHERE `parent_id` = 1 AND `alias` = 'admins'; -- 8 SELECT `id` FROM `my_table` WHERE `parent_id` = 8 AND `alias` = 'nickf'; -- 37 But then I realised I could do it with a single query, using a variable amount of nesting: SELECT `id` FROM `my_table` WHERE `parent_id` = ( SELECT `id` FROM `my_table` WHERE `parent_id` = ( SELECT `id` FROM `my_table` WHERE `parent_id` IS NULL AND `alias` = 'users' ) AND `alias` = 'admins' ) AND `alias` = 'nickf'; Since the number of sub-queries is dependent on the number of steps in the path, am I going to run into issues with having too many subqueries? (If there even is such a thing) Are there any better/smarter ways to perform this query?

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• [Cocoa] Placing an NSTimer in a separate thread

  - by ndg

  I'm trying to setup an NSTimer in a separate thread so that it continues to fire when users interact with the UI of my application. This seems to work, but Leaks reports a number of issues - and I believe I've narrowed it down to my timer code. Currently what's happening is that updateTimer tries to access an NSArrayController (timersController) which is bound to an NSTableView in my applications interface. From there, I grab the first selected row and alter its timeSpent column. From reading around, I believe what I should be trying to do is execute the updateTimer function on the main thread, rather than in my timers secondary thread. I'm posting here in the hopes that someone with more experience can tell me if that's the only thing I'm doing wrong. Having read Apple's documentation on Threading, I've found it an overwhelmingly large subject area. NSThread *timerThread = [[[NSThread alloc] initWithTarget:self selector:@selector(startTimerThread) object:nil] autorelease]; [timerThread start]; -(void)startTimerThread { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSRunLoop *runLoop = [NSRunLoop currentRunLoop]; activeTimer = [[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(updateTimer:) userInfo:nil repeats:YES] retain]; [runLoop run]; [pool release]; } -(void)updateTimer:(NSTimer *)timer { NSArray *selectedTimers = [timersController selectedObjects]; id selectedTimer = [selectedTimers objectAtIndex:0]; NSNumber *currentTimeSpent = [selectedTimer timeSpent]; [selectedTimer setValue:[NSNumber numberWithInt:[currentTimeSpent intValue]+1] forKey:@"timeSpent"]; } -(void)stopTimer { [activeTimer invalidate]; [activeTimer release]; }

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• Windows Azure: Creating a subdirectories inside the blob

  - by veda

  I wanted to create some subdirectories inside my blob. But it is not working out well Here is my code protected void ButUpload_click(object sender, EventArgs e) { // store upladed file as a blob storage if (uplFileUpload.HasFile) { name = uplFileUpload.FileName; // get refernce to the cloud blob container CloudBlobContainer blobContainer = cloudBlobClient.GetContainerReference("documents"); if (textbox.Text != "") { name = textbox.Text + "/" + name; } // set the name for the uploading files string UploadDocName = name; // get the blob reference and set the metadata properties CloudBlockBlob blob = blobContainer.GetBlockBlobReference(UploadDocName); blob.Metadata["FILETYPE"] = "text"; blob.Properties.ContentType = uplFileUpload.PostedFile.ContentType; // upload the blob to the storage blob.UploadFromStream(uplFileUpload.FileContent); } } What I did is that, If I have to create a sub directory, I will enter the name of the sub directory in the textbox. for example, if I need to create a file named "test.txt" inside the sub directory "files" Then, my textbox.text = files and uplFileUpload.FileName = test.txt Now I will concatenate them and upload to the blob.. But it is not working well.. I am getting just https://test.core.windows.net/documents/files/ I am not getting the entire thing I was expecting https://test.core.windows.net/documents/files/test.txt What am I doing wrong... How to create sub directories inside the blob.

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• Using Pastebin API in Node.js

  - by wiill

  I've been trying to post a paste to Pastebin in Node.js, but it appears that I'm doing it wrong. I'm getting a Bad API request, invalid api_option, however I'm clearly setting the api_option to paste like the documentation asks for. var http = require('http'); var qs = require('qs'); var query = qs.stringify({ api_option: 'paste', api_dev_key: 'xxxxxxxxxxxx', api_paste_code: 'Awesome paste content', api_paste_name: 'Awesome paste name', api_paste_private: 1, api_paste_expire_date: '1D' }); var req = http.request({ host: 'pastebin.com', port: 80, path: '/api/api_post.php', method: 'POST', headers: { 'Content-Type': 'multipart/form-data', 'Content-Length': query.length } }, function(res) { var data = ''; res.on('data', function(chunk) { data += chunk; }); res.on('end', function() { console.log(data); }); }); req.write(query); req.end(); console.log(query) confirms that the string is well encoded and that api_option is there and set to paste. Now, I've been searching forever on possible causes. I also tried setting the encoding on the write req.write(query, 'utf8') because the Pastebin API mentions that the POST must be UTF-8 encoded. I rewrote the thing over and over and re-consulted the Node HTTP documentation many times. I'm pretty sure I completely missed something here, because I don't see how this could fail. Does anyone have an idea of what I have done wrong?

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• Pseudo-quicksort time complexity

  - by Ord

  I know that quicksort has O(n log n) average time complexity. A pseudo-quicksort (which is only a quicksort when you look at it from far enough away, with a suitably high level of abstraction) that is often used to demonstrate the conciseness of functional languages is as follows (given in Haskell): quicksort :: Ord a => [a] -> [a] quicksort [] = [] quicksort (p:xs) = quicksort [y | y<-xs, y<p] ++ [p] ++ quicksort [y | y<-xs, y>=p] Okay, so I know this thing has problems. The biggest problem with this is that it does not sort in place, which is normally a big advantage of quicksort. Even if that didn't matter, it would still take longer than a typical quicksort because it has to do two passes of the list when it partitions it, and it does costly append operations to splice it back together afterwards. Further, the choice of the first element as the pivot is not the best choice. But even considering all of that, isn't the average time complexity of this quicksort the same as the standard quicksort? Namely, O(n log n)? Because the appends and the partition still have linear time complexity, even if they are inefficient.

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• scanf segfaults and various other anomalies inside while loop

  - by Shadow

  while(1){ //Command prompt char *command; printf("%s>",current_working_directory); scanf("%s",command);<--seg faults after input has been received. printf("\ncommand:%s\n",command); } I am getting a few different errors and they don't really seem reproducible(except for the segfault at this point .<). This code worked fine about 10 minutes ago, then it infinite looped the printf command and now it seg faults on the line mentioned above. The only thing I changed was scanf("%s",command); to what it currently is. If I change the command variable to be an array it works, obviously this is because the storage is set aside for it. 1) I got prosecuted about telling someone that they needed to malloc a pointer* (But that usually seems to solve the problem such as making it an array) 2) the command I am entering is "magic" 5 characters so there shouldn't be any crazy stack overflow. 3) I am running on mac OSX 10.6 with newest version of xCode(non-OS4) and standard gcc 4) this is how I compile the program: gcc --std=c99 -W sfs.c Just trying to figure out what is going on. Being this is for a school project I am never going to have to see again, I will just code some noob work around that would make my boss cry :) But for afterwards I would love to figure out why this is happening and not just make some fix for it, and if there is some fix for it why that fix works.

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• PHP Socket Server vs node.js: Web Chat

  - by Eliasdx

  I want to program a HTTP WebChat using long-held HTTP requests (Comet), ajax and websockets (depending on the browser used). Userdatabase is in mysql. Chat is written in PHP except maybe the chat stream itself which could also be written in javascript (node.js): I don't want to start a php process per user as there is no good way to send the chat messages between these php childs. So I thought about writing an own socket server in either PHP or node.js which should be able to handle more then 1000 connections (chat users). As a purely web developer (php) I'm not much familiar with sockets as I usually let web server care about connections. The chat messages won't be saved on disk nor in mysql but in RAM as an array or object for best speed. As far as I know there is no way to handle multiple connections at the same time in a single php process (socket server), however you can accept a great amount of socket connections and process them successive in a loop (read and write; incoming message - write to all socket connections). The problem is that there will most-likely be a lag with ~1000 users and mysql operations could slow the whole thing down which will then affect all users. My question is: Can node.js handle a socket server with better performance? Node.js is event-based but I'm not sure if it can process multiple events at the same time (wouldn't that need multi-threading?) or if there is just an event queue. With an event queue it would be just like php: process user after user. I could also spawn a php process per chat room (much less users) but afaik there are singlethreaded IRC servers which are also capable to handle thousands of users. (written in c++ or whatever) so maybe it's also possible in php. I would prefer PHP over Node.js because then the project would be php-only and not a mixture of programming languages. However if Node can process connections simultaneously I'd probably choose it.

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• div content margin pushing container

  - by jef2904

  Hi, Im running into an issue that's really baffleing me. I have a container that I want to apply a background to an postion it in the top right of the browser screen. The div inside has a top margin of 4em and this is pushing the container div here is the CSS #container { background: transparent url("../images/house-bg.png") top right no-repeat scroll; } #wrapper { background: #FFF; width: 960px; height: 600px; margin: 4em auto 0; border: 10px solid #C3CF21; -moz-border-radius: 20px; -webkit-border-radius: 20px; border-radius: 20px; -moz-box-shadow: 0 0 25px #444; -webkit-box-shadow: 0 0 25px #444; box-shadow: 0 0 25px #444; } and heres the HTML <div id="container"> <div id="wrapper"> <div id="header"> </div> <div id="main"> </div> </div> <div id="footer"> &copy; Copyright <?php echo date("Y");?> Company, Inc. </div> </div> I want the margin of the wrapper to be inside the container div instead of outside. I've tried multiple display properties and position properties to no avail. The only thing that fixes it is inserting an "&nbsp;" before the start of the #wrapper but theres got to be a CSS fix to this. Thanks in Advanced, Jorge

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• Something about Stream

  - by sforester

  I've been working on something that make use of streams and I found myself not clear about some stream concepts( you can also view another question posted by me at http://stackoverflow.com/questions/2933923/about-redirected-stdout-in-system-diagnostics-process ). 1.how do you indicate that you have finished writing a stream, writing something like a EOF? 2.follow the previous question, if I have written a EOF(or something like that) to a stream but didn't close the stream, then I want to write something else to the same stream, can I just start writing to it and no more set up required? 3.if a procedure tries to read a stream(like the stdin ) that no one has written anything to it, the reading procedure will be blocked,finally some data arrives and the procedure will just read till the writing is done,which is indicated by getting a return of 0 count of bytes read rather than being blocked, and now if the procedure issues another read to the same stream, it will still get a 0 count and return immediately while I was expecting it will be blocked since no one is writing to the stream now. So does the stream holds different states when the stream is opened but no one has written to it yet and when someone has finished a writing session? I'm using Windows the .net framework if there will by any thing platform specific. Thanks a lot!

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• SVN 409 conflict on commits and updates

  - by bhefny

  We have been using SVN for the past year now and when we migrated to an online server we started getting this error: Commit: Commit failed (details follow): File or directory 'x.php' is out of date; try updating resource out of date; try updating CHECKOUT of '/!svn/ver/491/x.php': 409 Conflict (http://svn.example.com) We are currently using SmartSVN 6.5 and we have also tested with RapidSVN & Syncro (but we can't use tortoise as we have a lot of Ubunutu users) at the begining I though this How do you fix an SVN 409 Conflict Error would help, but it didn't we are still facing the same error and it's even more absurd now. the main problem is that after you get the error, you can't shake it of. Updating doesn't solve, reverting doesn't solve. You are just stuck with the error. The only thing that could work is removing the file from SVN and adding your version but that would be against why we are using SVN in the first place This is our apache config (and yes autoversioning is ON) <Location /> DAV svn SVNPath /home/example/svn SVNAutoversioning on AuthType Basic AuthName "Access Restricted" AuthUserFile /home/example/svn-auth-file Require valid-user </Location> <Directory /> <Files ~ "^\.ht"> Order allow,deny Allow from all Satisfy All </Files> <Files ~ "^error_log"> Order allow,deny Allow from all Satisfy All </Files> </Directory> And here are some observation: We don't receive conflicts anymore, we just get this 409 conflict you can somehow avoid the error if you always update before committing When committing a modified file + a newly added file, you get the error. As if the added file incremented the version by one and then you are committing another file with a older version. Please advise, we are about to go insane

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• C++: parsing with simple regular expression or shoud I use sscanf?

  - by Helltone

  I need to parse a string like func1(arg1, arg2); func2(arg3, arg4);. It's not a very complex parsing problem, so I would prefer to avoid resorting to flex/bison or similar utilities. My first approch was to try to use POSIX C regcomp/regexec or Boost implementation of C++ std::regex. I wrote the following regular expression, which does not work (I'll explain why further on). "^" "[ ;\t\n]*" "(" // (1) identifier "[a-zA-Z_][a-zA-Z0-9_]*" ")" "[ \t\n]*" "(" // (2) non-marking "\[" "(" // (3) non-marking "[ \t]*" "(" // (4..n-1) argument "[a-zA-Z0-9_]+" ")" "[ \t\n]*" "," ")*" "[ \t\n]*" "(" // (n) last argument "[a-zA-Z0-9_]+" ")" "]" ")?" "[ \t\n]*" ";" Note that the group 1 captures the identifier and groups 4..n-1 are intended to capture arguments except the last, which is captured by group n. When I apply this regex to, say func(arg1, arg2, arg3) the result I get is an array {func, arg2, arg3}. This is wrong because arg1 is not in it! The problem is that in the standard regex libraries, submarkings only capture the last match. In other words, if you have for instance the regex "((a*|b*))*" applied on "babb", the results of the inner match will be bb and all previous captures will have been forgotten. Another thing that annoys me here is that in case of error there is no way to know which character was not recognized as these functions provide very little information about the state of the parser when the input is rejected. So I don't know if I'm missing something here... In this case should I use sscanf or similar instead? Note that I prefer to use C/C++ standard libraries (and maybe boost).

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• Connections hanging on read()

  - by viraptor

  Hi, Short version: I've got a strange issue with a server accepting TCP connections. Even though there are normally some processes waiting, at some volume of connections it hangs. Long version: The server is written in Perl and binds a $srv socket with the reuse flag and listen == 5. Afterwards, it forks into 10 processes with a loop of $clt=$srv->accept(); do_processing($clt); $clt->shutdown(2); The client written in C is also very simple - it sends some lines, then receives all lines available and does a shutdown(sockfd, 2); There's nothing async going on and at the end both send and receive queues are empty (as reported by netstat). Connections last only ~20ms. All clients behave the same way, are the same implementation, etc. Now let's say I'm accepting X connections from client 1 and another X from client 2. Processes still report that they're idle all the time. If I add another X connections from client 3, suddenly the server processes start hanging just after accepting. The first blocking thing they do after accept(); is while (<$clt>) ... - but they don't get any data (on the first try already). Suddenly all 10 processes are in this state and do not stop waiting. On strace, the server processes seem to hang on read(), which makes sense. There are loads of connections in TIME_WAIT state belonging to that server (~100 when the problem starts to manifest), but this might be a red herring. What could be happening here?

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• Request-local storage in ASP.NET (accessible to the code from IHttpModule implementation)

  - by IgorK

  I need to have some object hanging around between two events I'm interested in: PreRequestHandlerExecute (where I create an instance of my object and want to save it) and PostRequestHandlerExecute (where I want to get to the object). After the second event the object is not needed for my purposes and should be discarded either by storage or my explicit action. So the ideal context where my object should be stored is per request (with guaranteed no sharing issues when different threads are serving requests... or processes/servers :) ) Take into account that actual implementation I can do is being made from a HttpModule and is supposed to be a pluggable solution for already written web apps (so the option to provide some state using static/instance variables in Global.asax doesn't look good - I will have to modify Global.asax on every web application). Cache seems to be too broad for this use. I tried to see whether httpContext.Application (of type HttpApplicationState) is good for me or not, but cannot get whether it is exactly per HttpApplication instance or not (AFAIK you can have several instances of HttpApplications used on different threads and therefore serving several requests simultaneously - then using storage shared between threads will not work correctly; otherwise I would use it because one HttpApplication instance serves exactly one request at a time). Something could be done with storing state on the HttpModule instances if I know for sure that it's exactly bound 1-to-1 with every HttpApplication instance running (but again I need a proof that HttpApplication instance is 1-to-1 with my HttpModule's instance). Any valuable and reputable links on these topics are much appreciated... Would be great to find something particularly well-suited for per request situation (because otherwise I may end up with something ulgy... probably either some 'broader' scoped storage and some hacks to have different keys in the storage for different requests, OR using a thread-local thing and in this way commit to the theory that IIS/ASP.NET will not ever serve first event from one thread and the second event from the other thread and so on)

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• WinCE and PC USB communication

  - by sebeksd

  We are developing some device and we need to find good solution for one of needed functionality. Thing is that we need communicate WinCE 6.0 (ARM) and Windows on PC. Easiest way is of course COM port but in our case it is impossible (all serial ports are used on WinCE and we don't want to add one more). Second option is LAN but for us it is not the best option for few reasons. So there is third option we could use. USB to USB communication but how to do that ? Of course WinCE is USB Device and PC is USB Host so all hardware basics are meet. We could use Active sync but there are few problems with it: - WinCE 6.0 is not working with WMDC (drivers on device just crash after connecting device with PC) and I didn't find any solution for it so in this case we need to use WinXP on PC side (old ActiveSync) - we need to filter communication with active sync to only our application, no other non authorized software should be allowed (what I know this is imposible to obtain). So propably best way to do what we need is to communicate throug USB like standard COM (serial communication). The question is, how it could be made, are we need to write driver on WinCE and also a Driver on Windows (PC), or there are better solution? Maybe some driver for WinCE 6.0 that would emulate Virtual COM on PC side (and of course allow standard Read/Write to it on WinCE side) ? Could someone tell me if something like that exists ?

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• Proper way of naming your Java Google App Engine Project

  - by Saif Bechan

  I am starting out with Google's App Engine in Java. I have seen the tutorial video but I do not understand the naming of the project package. It is going to be a guestbook, that's why the name is guestbook, I understand that part. But after that I see package name. 1)Is that something you import into the project, or is is something you create. I have seen this a lot in projects, something like com.xxx.xxx. 2)How do you name this type of thing or is this an import. I have looked at another tutorial there they take the naming to a whole new level. The name of both the project and the package is de.vogella.gae.java.todo. 3)What does this mean in java terms. 4)Maybe one of you can help me with this specific project I want to start. I want to create a Google App project that for now only serves static files. I will leave the project empty and just put all my static files in the war directory of the project. I want the domain name to be mydomainstatic

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• How to scale a PHP application (servers, mysql, memcache)

  - by Stéphane Goetz

  Hi, I'm currently creating a website for a social project in switzerland. And before there is an overflow of user, I want to prepare the application to scale. I answered by myself many questions but some are left. I explain what I want to do. First at the beginnning, the Application will have only one server (short time) with DNS, PHP, Mysql, Data, and memcache. Second Then I will split them in two DNS, Mysql, memcache Data, PHP Third Here is the problem, I don't know how to do it exactly here to keep the application running well. I could do : Front : Load Balancer, memcache, DNS Web 1 : PHP, DATA Web 2 : PHP, DATA Mysql This would be the scheme, all PHP sessions are kept in the DB. BUT, how do I sync the data? do I run a Rsync to keep them up to date. do I put them on a separate disk (network disk) to be sure ? but in this case, how can I do in case of user uploads ? and if the website gets more success and we have to go on greater structures, would'nt it create some latency on updates ? or would it be a good thing to go directly to amazon's web services ? some infos I use codeigniter as Framework. I use linux as webserver (distribution not chosen now, but should be Debian) Thanks in advance for your answers.

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• A feeling that I'm not that good developer

  - by Karim

  Hi, Im having a strange feeling, but let me first introduce myself as a software developer. I started to program when I was still a kid, I had about 10 or 11 years. I really enjoy my work and never get bored from it. It's amazing how somebody could be paid for what he really likes to do and would be doing it anyway even for free. WHen I first started to program, I was feeling proud of what I was doing, each application I built was for me a success and after 2-3 year I had a feeling that I'm a coding guru. It was a nice feeling ;-) But the more I was in the field, the more types of software I started to develop I was starting to have a feeling that I'm completely wrong in that I'm guru. I felt that I'm not even a mediocre developer. Each new field I start to work on is giving me this feeling. Like when I once developed a device driver for a client, I saw how much I need to learn about device drivers. When I developed a video filter for an application, I saw how much do I still need to learn about DirectShow, Color Spaces, and all the theory behind that. The worst thing was when I started to learn algorithms. It was several years ago. I knew then the basic structures and algorithms like the sorting, some types of trees, some hashtables, strings etc.. and when I really wanted to learn a group of structures I learned about 5-6 new types and saw that in fact even this small group has several hundred subtypes of structures. It's depressing how little time people have in their lives to learn all this stuff. I'm now a software developer with about 10 years of experience and I still feel that I'm not a proficient developer when I think about things that others do in the industry. Is this normal what I'm experiencing or is it a sign of a destructive excessive ambition? Thanks in advance for any comments.

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