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  • Retrieving multiple rows from a loop-created form... Stuck.

    - by hangston
    Let me start by saying that I'm new to PHP, but I'm here to learn and would really appreciate your help. I use the following code to pull in data and create a form. This creates up to 40 lines for a user to fill out. Each line consists of the same information: Description, Amount, and Frequency. The remainder of the information needed is generated by the database. (See hidden fields) <?php $row = 0; do { $optid = $row_options['option_id']; echo "<tr>\n\t<td>" . htmlentities($row_options['option']) . "</td>\n"; echo "\t<td>" . "<input name='description' type='text' size='40' maxlength='120'/>" . "</td>\n"; echo "\t<td>" . "<input name='option_id' type='hidden' value='$optid' />$<input name='amount' type='text' size='10' maxlength='7'/>" . "</td>\n"; echo "\t<td>" . "<select name='assisted_frequency'> <option value='Monthly'>Monthly</option> <option value='Weekly'>Weekly</option> <option value='Daily'>Daily</option> <option value='Hourly'>Hourly</option> <option value='One-Time'>One-Time</option> </select>" . "</td>\n</tr>\n"; $array[$row] = array( $arraydesc[$row] = $_POST['description'], $arrayamto[$row] = $_POST['amount'], $arrayoptid[$row] = $optid, $arrayfreq[$row] = $_POST['frequency'], ); $row ++; } while ($row_options = mysql_fetch_assoc($options)); $counter = $row - 1; ?> I'm having troubles retrieving the information that the user inputs. My intent is to loop through each row after the user has input their information, then upload the mix of my database information and the user's information into another database. For example, the user would see, albeit prettier: form1 Option 1: description [input box] amount [input box] frequency [option box] Option 2: description [input box] amount [input box] frequency [option box] Option 3: description [input box] amount [input box] frequency [option box] Option 4: description [input box] amount [input box] frequency [option box] submit Upon submitting the form above, I'm using a query similar to the following to input the data into the database: for($row=0; $row<=$counter; $row++){ $insertSQL2 = sprintf("INSERT INTO table (option_id, amount, description, frequency) VALUES (%s, %s, %s, %s)", GetSQLValueString($arrayoptid[$row], "int"), GetSQLValueString($arrayamto[$row], "int"), GetSQLValueString($arraydesc[$row], "text"), GetSQLValueString($arrayfreq[$row], "text")); // code to submit query } I've tried for, foreach, arrays (what feels like the everything I know) to post each row (row by row) into the database. I either get just the last row of data, or no data at all. I also worry that the [$row] technique is adding characters to my data. What is the best way to retrieve each row of the user's inputs, then upload this data (row by row) into the database? Also, I would really appreciate your suggestions for improving my coding technique and the approach I'm taking.

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  • Make file Linking issue Undefined symbols for architecture x86_64

    - by user1035839
    I am working on getting a few files to link together using my make file and c++ and am getting the following error when running make. g++ -bind_at_load `pkg-config --cflags opencv` -c -o compute_gist.o compute_gist.cpp g++ -bind_at_load `pkg-config --cflags opencv` -c -o gist.o gist.cpp g++ -bind_at_load `pkg-config --cflags opencv` -c -o standalone_image.o standalone_image.cpp g++ -bind_at_load `pkg-config --cflags opencv` -c -o IplImageConverter.o IplImageConverter.cpp g++ -bind_at_load `pkg-config --cflags opencv` -c -o GistCalculator.o GistCalculator.cpp g++ -bind_at_load `pkg-config --cflags opencv` `pkg-config --libs opencv` compute_gist.o gist.o standalone_image.o IplImageConverter.o GistCalculator.o -o rungist Undefined symbols for architecture x86_64: "color_gist_scaletab(color_image_t*, int, int, int const*)", referenced from: _main in compute_gist.o ld: symbol(s) not found for architecture x86_64 collect2: ld returned 1 exit status make: *** [rungist] Error 1 My makefile is as follows (Note, I don't need opencv bindings yet, but will be coding in opencv later. CXX = g++ CXXFLAGS = -bind_at_load `pkg-config --cflags opencv` LFLAGS = `pkg-config --libs opencv` SRC = \ compute_gist.cpp \ gist.cpp \ standalone_image.cpp \ IplImageConverter.cpp \ GistCalculator.cpp OBJS = $(SRC:.cpp=.o) rungist: $(OBJS) $(CXX) $(CXXFLAGS) $(LFLAGS) $(OBJS) -o $@ all: rungist clean: rm -rf $(OBJS) rungist The method header is located in gist.h float *color_gist_scaletab(color_image_t *src, int nblocks, int n_scale, const int *n_orientations); And the method is defined in gist.cpp float *color_gist_scaletab(color_image_t *src, int w, int n_scale, const int *n_orientation) { And finally the compute_gist.cpp (main file) #include <stdio.h> #include <stdlib.h> #include <string.h> #include "gist.h" static color_image_t *load_ppm(const char *fname) { FILE *f=fopen(fname,"r"); if(!f) { perror("could not open infile"); exit(1); } int width,height,maxval; if(fscanf(f,"P6 %d %d %d",&width,&height,&maxval)!=3 || maxval!=255) { fprintf(stderr,"Error: input not a raw PPM with maxval 255\n"); exit(1); } fgetc(f); /* eat the newline */ color_image_t *im=color_image_new(width,height); int i; for(i=0;i<width*height;i++) { im->c1[i]=fgetc(f); im->c2[i]=fgetc(f); im->c3[i]=fgetc(f); } fclose(f); return im; } static void usage(void) { fprintf(stderr,"compute_gist options... [infilename]\n" "infile is a PPM raw file\n" "options:\n" "[-nblocks nb] use a grid of nb*nb cells (default 4)\n" "[-orientationsPerScale o_1,..,o_n] use n scales and compute o_i orientations for scale i\n" ); exit(1); } int main(int argc,char **args) { const char *infilename="/dev/stdin"; int nblocks=4; int n_scale=3; int orientations_per_scale[50]={8,8,4}; while(*++args) { const char *a=*args; if(!strcmp(a,"-h")) usage(); else if(!strcmp(a,"-nblocks")) { if(!sscanf(*++args,"%d",&nblocks)) { fprintf(stderr,"could not parse %s argument",a); usage(); } } else if(!strcmp(a,"-orientationsPerScale")) { char *c; n_scale=0; for(c=strtok(*++args,",");c;c=strtok(NULL,",")) { if(!sscanf(c,"%d",&orientations_per_scale[n_scale++])) { fprintf(stderr,"could not parse %s argument",a); usage(); } } } else { infilename=a; } } color_image_t *im=load_ppm(infilename); //Here's the method call -> :( float *desc=color_gist_scaletab(im,nblocks,n_scale,orientations_per_scale); int i; int descsize=0; //compute descriptor size for(i=0;i<n_scale;i++) descsize+=nblocks*nblocks*orientations_per_scale[i]; descsize*=3; // color //print descriptor for(i=0;i<descsize;i++) printf("%.4f ",desc[i]); printf("\n"); free(desc); color_image_delete(im); return 0; } Any help would be greatly appreciated. I hope this is enough info. Let me know if I need to add more.

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  • .NET Windows Service with timer stops responding

    - by Biri
    I have a windows service written in c#. It has a timer inside, which fires some functions on a regular basis. So the skeleton of my service: public partial class ArchiveService : ServiceBase { Timer tickTack; int interval = 10; ... protected override void OnStart(string[] args) { tickTack = new Timer(1000 * interval); tickTack.Elapsed += new ElapsedEventHandler(tickTack_Elapsed); tickTack.Start(); } protected override void OnStop() { tickTack.Stop(); } private void tickTack_Elapsed(object sender, ElapsedEventArgs e) { ... } } It works for some time (like 10-15 days) then it stops. I mean the service shows as running, but it does not do anything. I make some logging and the problem can be the timer, because after the interval it does not call the tickTack_Elapsed function. I was thinking about rewrite it without a timer, using an endless loop, which stops the processing for the amount of time I set up. This is also not an elegant solution and I think it can have some side effects regarding memory. The Timer is used from the System.Timers namespace, the environment is Windows 2003. I used this approach in two different services on different servers, but both is producing this behavior (this is why I thought that it is somehow connected to my code or the framework itself). Does somebody experienced this behavior? What can be wrong? Edit: I edited both services. One got a nice try-catch everywhere and more logging. The second got a timer-recreation on a regular basis. None of them stopped since them, so if this situation remains for another week, I will close this question. Thank you for everyone so far. Edit: I close this question because nothing happened. I mean I made some changes, but those changes are not really relevant in this matter and both services are running without any problem since then. Please mark it as "Closed for not relevant anymore".

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  • Can MySQL reasonably perform queries on billions of rows?

    - by haxney
    I am planning on storing scans from a mass spectrometer in a MySQL database and would like to know whether storing and analyzing this amount of data is remotely feasible. I know performance varies wildly depending on the environment, but I'm looking for the rough order of magnitude: will queries take 5 days or 5 milliseconds? Input format Each input file contains a single run of the spectrometer; each run is comprised of a set of scans, and each scan has an ordered array of datapoints. There is a bit of metadata, but the majority of the file is comprised of arrays 32- or 64-bit ints or floats. Host system |----------------+-------------------------------| | OS | Windows 2008 64-bit | | MySQL version | 5.5.24 (x86_64) | | CPU | 2x Xeon E5420 (8 cores total) | | RAM | 8GB | | SSD filesystem | 500 GiB | | HDD RAID | 12 TiB | |----------------+-------------------------------| There are some other services running on the server using negligible processor time. File statistics |------------------+--------------| | number of files | ~16,000 | | total size | 1.3 TiB | | min size | 0 bytes | | max size | 12 GiB | | mean | 800 MiB | | median | 500 MiB | | total datapoints | ~200 billion | |------------------+--------------| The total number of datapoints is a very rough estimate. Proposed schema I'm planning on doing things "right" (i.e. normalizing the data like crazy) and so would have a runs table, a spectra table with a foreign key to runs, and a datapoints table with a foreign key to spectra. The 200 Billion datapoint question I am going to be analyzing across multiple spectra and possibly even multiple runs, resulting in queries which could touch millions of rows. Assuming I index everything properly (which is a topic for another question) and am not trying to shuffle hundreds of MiB across the network, is it remotely plausible for MySQL to handle this? UPDATE: additional info The scan data will be coming from files in the XML-based mzML format. The meat of this format is in the <binaryDataArrayList> elements where the data is stored. Each scan produces = 2 <binaryDataArray> elements which, taken together, form a 2-dimensional (or more) array of the form [[123.456, 234.567, ...], ...]. These data are write-once, so update performance and transaction safety are not concerns. My naïve plan for a database schema is: runs table | column name | type | |-------------+-------------| | id | PRIMARY KEY | | start_time | TIMESTAMP | | name | VARCHAR | |-------------+-------------| spectra table | column name | type | |----------------+-------------| | id | PRIMARY KEY | | name | VARCHAR | | index | INT | | spectrum_type | INT | | representation | INT | | run_id | FOREIGN KEY | |----------------+-------------| datapoints table | column name | type | |-------------+-------------| | id | PRIMARY KEY | | spectrum_id | FOREIGN KEY | | mz | DOUBLE | | num_counts | DOUBLE | | index | INT | |-------------+-------------| Is this reasonable?

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  • Java consistent synchronization

    - by ring0
    We are facing the following problem in a Spring service, in a multi-threaded environment: three lists are freely and independently accessed for Read once in a while (every 5 minutes), they are all updated to new values. There are some dependencies between the lists, making that, for instance, the third one should not be read while the second one is being updated and the first one already has new values ; that would break the three lists consistency. My initial idea is to make a container object having the three lists as properties. Then the synchronization would be first on that object, then one by one on each of the three lists. Some code is worth a thousands words... so here is a draft private class Sync { final List<Something> a = Collections.synchronizedList(new ArrayList<Something>()); final List<Something> b = Collections.synchronizedList(new ArrayList<Something>()); final List<Something> c = Collections.synchronizedList(new ArrayList<Something>()); } private Sync _sync = new Sync(); ... void updateRunOnceEveryFiveMinutes() { final List<Something> newa = new ArrayList<Something>(); final List<Something> newb = new ArrayList<Something>(); final List<Something> newc = new ArrayList<Something>(); ...building newa, newb and newc... synchronized(_sync) { synchronized(_sync.a) { _synch.a.clear(); _synch.a.addAll(newa); } synchronized(_sync.b) { ...same with newb... } synchronized(_sync.c) { ...same with newc... } } // Next is accessed by clients public List<Something> getListA() { return _sync.a; } public List<Something> getListB() { ...same with b... } public List<Something> getListC() { ...same with c... } The question would be, is this draft safe (no deadlock, data consistency)? would you have a better implementation suggestion for that specific problem? update Changed the order of _sync synchronization and newa... building. Thanks

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  • StreamWriter appends random data

    - by void
    Hi I'm seeing odd behaviour using the StreamWriter class writing extra data to a file using this code: public void WriteToCSV(string filename) { StreamWriter streamWriter = null; try { streamWriter = new StreamWriter(filename); Log.Info("Writing CSV report header information ... "); streamWriter.WriteLine("\"{0}\",\"{1}\",\"{2}\",\"{3}\"", ((int)CSVRecordType.Header).ToString("D2", CultureInfo.CurrentCulture), m_InputFilename, m_LoadStartDate, m_LoadEndDate); int recordCount = 0; if (SummarySection) { Log.Info("Writing CSV report summary section ... "); foreach (KeyValuePair<KeyValuePair<LoadStatus, string>, CategoryResult> categoryResult in m_DataLoadResult.DataLoadResults) { streamWriter.WriteLine("\"{0}\",\"{1}\",\"{2}\",\"{3}\"", ((int)CSVRecordType.Summary).ToString("D2", CultureInfo.CurrentCulture), categoryResult.Value.StatusString, categoryResult.Value.Count.ToString(CultureInfo.CurrentCulture), categoryResult.Value.Category); recordCount++; } } Log.Info("Writing CSV report cases section ... "); foreach (KeyValuePair<KeyValuePair<LoadStatus, string>, CategoryResult> categoryResult in m_DataLoadResult.DataLoadResults) { foreach (CaseLoadResult result in categoryResult.Value.CaseLoadResults) { if ((LoadStatus.Success == result.Status && SuccessCases) || (LoadStatus.Warnings == result.Status && WarningCases) || (LoadStatus.Failure == result.Status && FailureCases) || (LoadStatus.NotProcessed == result.Status && NotProcessedCases)) { streamWriter.Write("\"{0}\",\"{1}\",\"{2}\",\"{3}\",\"{4}\"", ((int)CSVRecordType.Result).ToString("D2", CultureInfo.CurrentCulture), result.Status, result.UniqueId, result.Category, result.ClassicReference); if (RawResponse) { streamWriter.Write(",\"{0}\"", result.ResponseXml); } streamWriter.WriteLine(); recordCount++; } } } streamWriter.WriteLine("\"{0}\",\"{1}\"", ((int)CSVRecordType.Count).ToString("D2", CultureInfo.CurrentCulture), recordCount); Log.Info("CSV report written to '{0}'", fileName); } catch (IOException execption) { string errorMessage = string.Format(CultureInfo.CurrentCulture, "Unable to write XML report to '{0}'", fileName); Log.Error(errorMessage); Log.Error(exception.Message); throw new MyException(errorMessage, exception); } finally { if (null != streamWriter) { streamWriter.Close(); } } } The file produced contains a set of records on each line 0 to N, for example: [Record Zero] [Record One] ... [Record N] However the file produced either contains nulls or incomplete records from further up the file appended to the end. For example: [Record Zero] [Record One] ... [Record N] [Lots of nulls] or [Record Zero] [Record One] ... [Record N] [Half complete records] This also happens in separate pieces of code that also use the StreamWriter class. Furthermore, the files produced all have sizes that are multiples of 1024. I've been unable to reproduce this behaviour on any other machine and have tried recreating the environment. Previous versions of the application didn't exhibite this behaviour despite having the same code for the methods in question. EDIT: Added extra code.

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  • Is this a SEO SAFE anchor link

    - by Mayhem
    so... Is this a safe way to use internal links on your site.. By doing this i have the index page generating the usual php content section and handing it to the div element. THE MAIN QUESTION: Will google still index the pages using this method? Common sense tells me it does.. But just double checking and leaving this here as a base example as well if it is. As in. EXAMPLE ONLY PEOPLE The Server Side if (isset($_REQUEST['page'])) {$pageID=$_REQUEST['page'];} else {$pageID="home";} if (isset($_REQUEST['pageMode']) && $_REQUEST['pageMode']=="js") { require "content/".$pageID.".php"; exit; } // ELSE - REST OF WEBSITE WILL BE GENERATED USING THE page VARIABLE The Links <a class='btnMenu' href='?page=home'>Home Page</a> <a class='btnMenu' href='?page=about'>About</a> <a class='btnMenu' href='?page=Services'>Services</a> <a class='btnMenu' href='?page=contact'>Contact</a> The Javascript $(function() { $(".btnMenu").click(function(){return doNav(this);}); }); function doNav(objCaller) { var sPage = $(objCaller).attr("href").substring(6,255); $.get("index.php", { page: sPage, pageMode: 'js'}, function(data) { ("#siteContent").html(data).scrollTop(0); }); return false; } Forgive me if there are any errors, as just copied and pasted from my script then removed a bunch of junk to simplify it as still prototyping/white boarding the project its in. So yes it does look a little nasty at the moment. REASONS WHY: The main reason is bandwidth and speed, This will allow other scripts to run and control the site/application a little better and yes it will need to be locked down with some coding. -- FURTHER EXAMPLE-- INSERT PHP AT TOP <?php // PHP CODE HERE ?> <html> <head> <link rel="stylesheet" type="text/css" href="style.css" /> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="scripts.js"></script> </head> <body> <div class='siteBody'> <div class='siteHeader'> <?php foreach ($pageList as $key => $value) { if ($pageID == $key) {$btnClass="btnMenuSel";} else {$btnClass="btnMenu";} echo "<a class='$btnClass' href='?page=".$key."'>".$pageList[$key]."</a>"; } ?> </div><div id="siteContent" style='margin-top:10px;'> <?php require "content/".$pageID.".php"; ?> </div><div class='siteFooter'> </div> </div> </body> </html>

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  • Android , Read in binary data and write it to file

    - by Shpongle
    Hi all , Im trying to read in image file from a server , with the code below . It keeps going into the exception. I know the correct number of bytes are being sent as I print them out when received. Im sending the image file from python like so #open the image file and read it into an object imgfile = open (marked_image, 'rb') obj = imgfile.read() #get the no of bytes in the image and convert it to a string bytes = str(len(obj)) #send the number of bytes self.conn.send( bytes + '\n') if self.conn.sendall(obj) == None: imgfile.flush() imgfile.close() print 'Image Sent' else: print 'Error' Here is the android part , this is where I'm having the problem. Any suggestions on the best way to go about receiving the image and writing it to a file ? //read the number of bytes in the image String noOfBytes = in.readLine(); Toast.makeText(this, noOfBytes, 5).show(); byte bytes [] = new byte [Integer.parseInt(noOfBytes)]; //create a file to store the retrieved image File photo = new File(Environment.getExternalStorageDirectory(), "PostKey.jpg"); DataInputStream dis = new DataInputStream(link.getInputStream()); try{ os =new FileOutputStream(photo); byte buf[]=new byte[1024]; int len; while((len=dis.read(buf))>0) os.write(buf,0,len); Toast.makeText(this, "File recieved", 5).show(); os.close(); dis.close(); }catch(IOException e){ Toast.makeText(this, "An IO Error Occured", 5).show(); } EDIT: I still cant seem to get it working. I have been at it since and the result of all my efforts have either resulted in a file that is not the full size or else the app crashing. I know the file is not corrupt before sending server side. As far as I can tell its definitely sending too as the send all method in python sends all or throws an exception in the event of an error and so far it has never thrown an exception. So the client side is messed up . I have to send the file from the server so I cant use the suggestion suggested by Brian .

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  • choosing an image locally from http url and serving that image without a server round trip

    - by serverman
    Hi folks I am a complete novice to Flash (never created anything in flash). I am quite familiar with web applications (J2EE based) and have a reasonable expertise in Javascript. Here is my requirement. I want the user to select (via an html form) an image. Normally in the post, this image would be sent to server and may be stored there to be served later. I do not want that. I want to store this image locally and then serve it via HTTP to the user. So, the flow is: 1. Go to the "select image url":mywebsite.com/selectImage Browse the image and select the image This would transfer control locally to some code running on the client (Javascript or flash), which would then store the image locally at some place on the client machine. Go to the "show image url": mywebsite.com/showImage This would eventually result in some client code running on the browser that retrieves the image and renders it (without any server round trips.) I considered the following options: Use HTML5 local storage. Since I am a complete novice to flash, I looked into this. I found that it is fairly straightforward to store and retrieve images in javascript (only strings are allowed but I am hoping storing base64 encoded strings would work at least for small images). However, how do I serve the image via http url that points to my server without a server round trip? I saw the interesting article at http://hacks.mozilla.org/category/fileapi/ but that would work only in firefox and I need to work on all latest browsers (at least the ones supporting HTML5 local storage) Use flash SharedObjects. OK, this would have been good - the only thing is I am not sure where to start. Snippets of actionscripts to do this are scattered everywhere but I do not know how to use those scripts in an actual html page:) I do not need to create any movies or anything - just need to store an image and serve it locally. If I go this route, I would also use it to store other "strings" locally. If you suggest this, please give me the exact steps (could be pointers to other web sites) on how to do this. I would like to avoid paying for any flash development environment software ideally:) Thank you!

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  • Casting between variant and bstr_t causing inconsisten crash in Windows 2008

    - by user58470
    We have a C# application, calling a simple C++ wrapper class, that then calls an existing C++ DLL. The C++ code is all VC++ 6.0. We are getting inconsistent behaviour, but the crash, when it happens, always happens within the C++ wrapper DLL, and always in the same spot (have confirmed using painful logging statements). It never happens on any environment except on Windows 2008, so we suspect some bad-but-not-fatal memory trashing is going on that somehow Windows 2008 is being more mindful of. Here's the relevant code, if anyone has any ideas on why this might be crashing it would be much appreciated. We've been tearing our hair out for a few days and project timelines are slipping all for the want of being able to return a simple string back to C#... I've been told we've tried setting the VARIANT vresult using VariantInit, and clearing it when we are done with VariantClear, but that didn't help. // JobMgrDll.cpp : Defines the entry point for the DLL application. // #include "stdafx.h" #include "JobMgrDll.h" #include "jobmgr.h" CString gcontext; CString guser; CString ghost; CString glog; JOBMGRDLL_API int nJobMgrDll=0; extern "C" JOBMGRDLL_API char* perform_billcalc(char* cmd, char* context, char* user,char* host,BSTR* log,int* loglen) { char* result = new char[1000]; memset(result,0,999); result[999] = '\0'; bstr_t bt_command = cmd; UUID uuid = __uuidof(BRLib::Rules); VARIANT vresult; char *p_rv; gcontext = context; guser = user; ghost = host; write_log("execute_job"); p_rv = execute_job(uuid, "none", bt_command, &vresult); write_log("DONE execute_job"); CString message; write_log ("Intializing bstr_t with variant"); // WE ALWAYS GET HERE bstr_t res(vresult); //message.Format("%s result = %s",p_rv,res); //write_log(message); write_log("copying Result"); // WE DON'T ALWAYS GET HERE, BUT SOMETIMES WE DO strcpy(result,(char*)res); write_log(CString(result)); *loglen = glog.GetLength(); *log = glog.AllocSysString(); return result; } Again, any ideas much, much appreciated.

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  • How would you structure your entity model for storing arbitrary key/value data with different data t

    - by Nathan Ridley
    I keep coming across scenarios where it will be useful to store a set of arbitrary data in a table using a per-row key/value model, rather than a rigid column/field model. The problem is, I want to store the values with their correct data type rather than converting everything to a string. This means I have to choose either a single table with multiple nullable columns, one for each data type, or a set of value tables, one for each data type. I'm also unsure as to whether I should use full third normal form and separate the keys into a separate table, referencing them via a foreign key from the value table(s), or if it would be better to keep things simple and store the string keys in the value table(s) and accept the duplication of strings. Old/bad: This solution makes adding additional values a pain in a fluid environment because the table needs to be modified regularly. MyTable ============================ ID Key1 Key2 Key3 int int string date ---------------------------- 1 Value1 Value2 Value3 2 Value4 Value5 Value6 Single Table Solution This solution allows simplicity via a single table. The querying code still needs to check for nulls to determine which data type the field is storing. A check constraint is probably also required to ensure only one of the value fields contains non-nulll data. DataValues ============================================================= ID RecordID Key IntValue StringValue DateValue int int string int string date ------------------------------------------------------------- 1 1 Key1 Value1 NULL NULL 2 1 Key2 NULL Value2 NULL 3 1 Key3 NULL NULL Value3 4 2 Key1 Value4 NULL NULL 5 2 Key2 NULL Value5 NULL 6 2 Key3 NULL NULL Value6 Multiple-Table Solution This solution allows for more concise purposing of each table, though the code needs to know the data type in advance as it needs to query a different table for each data type. Indexing is probably simpler and more efficient because there are less columns that need indexing. IntegerValues =============================== ID RecordID Key Value int int string int ------------------------------- 1 1 Key1 Value1 2 2 Key1 Value4 StringValues =============================== ID RecordID Key Value int int string string ------------------------------- 1 1 Key2 Value2 2 2 Key2 Value5 DateValues =============================== ID RecordID Key Value int int string date ------------------------------- 1 1 Key3 Value3 2 2 Key3 Value6 How do you approach this problem? Which solution is better? Also, should the key column be separated into a separate table and referenced via a foreign key or be should it be kept in the value table and bulk updated if for some reason the key name changes?

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  • Howoto get id of new record after model.save

    - by tonymarschall
    I have a model with the following db structure: mysql> describe units; +------------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------+----------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | name | varchar(128) | NO | | NULL | | | created_at | datetime | NO | | NULL | | | updated_at | datetime | NO | | NULL | | +------------+----------+------+-----+---------+----------------+ 7 rows in set (0.00 sec) After creating a new record an saving i can not get the id of the record. 1.9.3p194 :001 > unit = Unit.new(:name => 'test') => #<Unit id: nil, name: "test", created_at: nil, updated_at: nil> 1.9.3p194 :002 > unit.save (0.2ms) BEGIN SQL (0.3ms) INSERT INTO `units` (`created_at`, `name`, `updated_at`) VALUES ('2012-08-31 23:48:12', 'test', '2012-08-31 23:48:12') (144.6ms) COMMIT => true 1.9.3p194 :003 > unit.inspect => "#<Unit id: nil, name: \"test\", created_at: \"2012-08-31 23:48:12\", updated_at: \"2012-08-31 23:48:12\">" # unit.rb class Unit < ActiveRecord::Base attr_accessible :name end # migration class CreateUnits < ActiveRecord::Migration def change create_table :units do |t| t.string :name, :null => false t.timestamps end end end Tried this with other models and have the same result (no id). Data is definitily saved and i can get data with Unit.last Another try with Foo.id = nil # /var/www# rails g model Foo name:string invoke active_record create db/migrate/20120904030554_create_foos.rb create app/models/foo.rb invoke test_unit create test/unit/foo_test.rb create test/fixtures/foos.yml # /var/www# rake db:migrate == CreateFoos: migrating ===================================================== -- create_table(:foos) -> 0.3451s == CreateFoos: migrated (0.3452s) ============================================ # /var/www# rails c Loading development environment (Rails 3.2.8) 1.9.3p194 :001 > foo = Foo.new(:name => 'bar') => #<Foo id: nil, name: "bar", created_at: nil, updated_at: nil> 1.9.3p194 :002 > foo.save (0.2ms) BEGIN SQL (0.4ms) INSERT INTO `foos` (`created_at`, `name`, `updated_at`) VALUES ('2012-09-04 03:06:26', 'bar', '2012-09-04 03:06:26') (103.2ms) COMMIT => true 1.9.3p194 :003 > foo.inspect => "#<Foo id: nil, name: \"bar\", created_at: \"2012-09-04 03:06:26\", updated_at: \"2012-09-04 03:06:26\">" 1.9.3p194 :004 > Foo.last Foo Load (0.5ms) SELECT `foos`.* FROM `foos` ORDER BY `foos`.`id` DESC LIMIT 1 => #<Foo id: 1, name: "bar", created_at: "2012-09-04 03:06:26", updated_at: "2012-09-04 03:06:26">

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  • How to fix this Speech Recognition wicked bug?

    - by aF
    I have this code in my C# project: public void startRecognition(string pName) { presentationName = pName; if (WaveNative.waveInGetNumDevs() > 0) { string grammar = System.Environment.GetEnvironmentVariable("PUBLIC") + "\\SoundLog\\Presentations\\" + presentationName + "\\SpeechRecognition\\soundlog.cfg"; if (File.Exists(grammar)) { File.Delete(grammar); } executeCommand(); /// Create an instance of SpSharedRecoContextClass which will be used /// to interface with the incoming audio stream recContext = new SpSharedRecoContextClass(); // Create the grammar object recContext.CreateGrammar(1, out recGrammar); //recContext.CreateGrammar(2, out recGrammar2); // Set up dictation mode //recGrammar2.SetDictationState(SpeechLib.SPRULESTATE.SPRS_ACTIVE); //recGrammar2.SetGrammarState(SPGRAMMARSTATE.SPGS_ENABLED); // Set appropriate grammar mode if (File.Exists(grammar)) { recGrammar.LoadCmdFromFile(grammar, SPLOADOPTIONS.SPLO_STATIC); //recGrammar.SetDictationState(SpeechLib.SPRULESTATE.SPRS_INACTIVE); recGrammar.SetGrammarState(SPGRAMMARSTATE.SPGS_ENABLED); recGrammar.SetRuleIdState(0, SPRULESTATE.SPRS_ACTIVE); } /// Bind a callback to the recognition event which will be invoked /// When a dictated phrase has been recognised. recContext.Recognition += new _ISpeechRecoContextEvents_RecognitionEventHandler(handleRecognition); // System.Windows.Forms.MessageBox.Show(recContext.ToString()); // gramática compilada } } private static void handleRecognition(int StreamNumber, object StreamPosition, SpeechLib.SpeechRecognitionType RecognitionType, SpeechLib.ISpeechRecoResult Result) { string temp = Result.PhraseInfo.GetText(0, -1, true); _recognizedText = ""; // System.Windows.Forms.MessageBox.Show(temp); // System.Windows.Forms.MessageBox.Show(recognizedWords.Count.ToString()); foreach (string word in recognizedWords) { if (temp.Contains(word)) { // System.Windows.Forms.MessageBox.Show("yes"); _recognizedText = word; } } } This codes generates a dll that I use in another application. Now, the wicked bug: - when I run the startRecognition method in the beginning of the execution of the other application, this codes works very well. But when I run it some time after the beginning, this codes works but the handleRecognition method is never called. I see that the words are recognized because they appear on the Microsoft Speech Recognition app, but the handler method is never called. Do you know what's the problem with this code? NOTE: this project has some code that is allways being executed. Might that be the problem? Because the other code is running it doesn't allow it to this to run?

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  • Retreiving multiple rows from a loop-created form... Stuck.

    - by hangston
    Hi All, Let me start by saying that I'm new to PHP, but I'm here to learn and would really appreciate your help. I use the following code to pull in data and create a form. This creates up to 40 lines for a user to fill out. Each line consists of the same information: Description, Amount, and Frequency. The remainder of the information needed is generated by the database. (See hidden fields) <?php $row = 0; do { $optid = $row_options['option_id']; echo "<tr>\n\t<td>" . htmlentities($row_options['option']) . "</td>\n"; echo "\t<td>" . "<input name='description' type='text' size='40' maxlength='120'/>" . "</td>\n"; echo "\t<td>" . "<input name='option_id' type='hidden' value='$optid' />$<input name='amount' type='text' size='10' maxlength='7'/>" . "</td>\n"; echo "\t<td>" . "<select name='assisted_frequency'> <option value='Monthly'>Monthly</option> <option value='Weekly'>Weekly</option> <option value='Daily'>Daily</option> <option value='Hourly'>Hourly</option> <option value='One-Time'>One-Time</option> </select>" . "</td>\n</tr>\n"; $array[$row] = array( $arraydesc[$row] = $_POST['description'], $arrayamto[$row] = $_POST['amount'], $arrayoptid[$row] = $optid, $arrayfreq[$row] = $_POST['frequency'], ); $row ++; } while ($row_options = mysql_fetch_assoc($options)); $counter = $row - 1; ?> I'm having troubles retrieving the information that the user inputs. My intent is to loop through each row after the user has input their information, then upload the mix of my database information and the user's information into another database. For example, the user would see, albeit prettier: form1 Option 1: description [input box] amount [input box] frequency [option box] Option 2: description [input box] amount [input box] frequency [option box] Option 3: description [input box] amount [input box] frequency [option box] Option 4: description [input box] amount [input box] frequency [option box] submit Upon submitting the form above, I'm using a query similar to the following to input the data into the database: for($row=0; $row<=$counter; $row++){ $insertSQL2 = sprintf("INSERT INTO table (option_id, amount, description, frequency) VALUES (%s, %s, %s, %s)", GetSQLValueString($arrayoptid[$row], "int"), GetSQLValueString($arrayamto[$row], "int"), GetSQLValueString($arraydesc[$row], "text"), GetSQLValueString($arrayfreq[$row], "text")); // code to submit query } I've tried for, foreach, arrays (what feels like the everything I know) to post each row (row by row) into the database. I either get just the last row of data, or no data at all. I also worry that the [$row] technique is adding characters to my data. What is the best way to retrieve each row of the user's inputs, then upload this data (row by row) into the database? Also, I would really appreciate your suggestions for improving my coding technique and the approach I'm taking. Thank you, Hangston

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  • Can I have a workspace that is both a git workspace and a svn workspace?

    - by Troy
    I have checked out now a local working copy of a codebase that lives in an svn repo. It's a big Java project that I use Eclipse to develop in. Eclipse of course builds everything on the fly, in it's own way with all the binaries ending up in [project root]/bin. That's perfectly fine with me, for development, but when the build runs on the build server, it looks quite a lot different (maven build, binaries end up in a different directory structure, etc). Sometimes I need to recreate the build server environment on my local development system to debug the build or what have you, so I usually end up downloading an entirely new working copy into a new workspace and running the build from there (prevents cluttering my development workspace with all the build artifacts and dirtying up the working copy). Of course sometimes I'm interested in running the full build on code that I don't want to check in yet, so I will manually copy over the "development" workspace onto the "build" workspace. Besides taking a lot of extra time copying a lot of files that I don't actually need (just overlaying the new over the old), this also screws up my svn metadata, meaning that I can't check in changes from that "build workspace" working copy, and I often end up having to re-download the code to get it back into a known state. So I'm thinking I make my svn working copy a local git repo, then "check out" the in-development code from the svn working copy/git master, into the local build workspace. Then I can build, revert my changes, have all the advantages of a version controlled working copy in the build workspace. Then if I need to make changes to the build, push those back into the git master (which is also a svn working copy), then check them into the main svn repo. |-------------| |main svn repo| <------- |---------------------| |-------------| |svn working copy | <------- |--------------------| | (svn dev workspace/ | | non-svn-versioned | | git master) | | build workspace | |---------------------| | (git working copy) | |--------------------| Just switching everything to git would obviously be better, but, big company, too many people using svn, too costly to change everything, etc. We're stuck with svn as the main repo for now. BTW, I know there is a maven plugin for Eclipse and everything, I'm mainly interested to know if there is a way to maintain a workspace that is both a git working copy and an svn working copy. Actually any distributed version control system would probably work (hg possibly?). Advice? How does everybody else handle this situation of having a to manage both a "development" build process and a "production" build process?

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  • How to fix this Speech Recognition on C# wicked bug?

    - by aF
    Hello, I have this code in my C# project: public void startRecognition(string pName) { presentationName = pName; if (WaveNative.waveInGetNumDevs() > 0) { string grammar = System.Environment.GetEnvironmentVariable("PUBLIC") + "\\SoundLog\\Presentations\\" + presentationName + "\\SpeechRecognition\\soundlog.cfg"; if (File.Exists(grammar)) { File.Delete(grammar); } executeCommand(); /// Create an instance of SpSharedRecoContextClass which will be used /// to interface with the incoming audio stream recContext = new SpSharedRecoContextClass(); // Create the grammar object recContext.CreateGrammar(1, out recGrammar); //recContext.CreateGrammar(2, out recGrammar2); // Set up dictation mode //recGrammar2.SetDictationState(SpeechLib.SPRULESTATE.SPRS_ACTIVE); //recGrammar2.SetGrammarState(SPGRAMMARSTATE.SPGS_ENABLED); // Set appropriate grammar mode if (File.Exists(grammar)) { recGrammar.LoadCmdFromFile(grammar, SPLOADOPTIONS.SPLO_STATIC); //recGrammar.SetDictationState(SpeechLib.SPRULESTATE.SPRS_INACTIVE); recGrammar.SetGrammarState(SPGRAMMARSTATE.SPGS_ENABLED); recGrammar.SetRuleIdState(0, SPRULESTATE.SPRS_ACTIVE); } /// Bind a callback to the recognition event which will be invoked /// When a dictated phrase has been recognised. recContext.Recognition += new _ISpeechRecoContextEvents_RecognitionEventHandler(handleRecognition); // System.Windows.Forms.MessageBox.Show(recContext.ToString()); // gramática compilada } } private static void handleRecognition(int StreamNumber, object StreamPosition, SpeechLib.SpeechRecognitionType RecognitionType, SpeechLib.ISpeechRecoResult Result) { string temp = Result.PhraseInfo.GetText(0, -1, true); _recognizedText = ""; // System.Windows.Forms.MessageBox.Show(temp); // System.Windows.Forms.MessageBox.Show(recognizedWords.Count.ToString()); foreach (string word in recognizedWords) { if (temp.Contains(word)) { // System.Windows.Forms.MessageBox.Show("yes"); _recognizedText = word; } } } This codes generates a dll that I use in another application. Now, the wicked bug: - when I run the startRecognition method in the beginning of the execution of the other application, this codes works very well. But when I run it some time after the beginning, this codes works but the handleRecognition method is never called. I see that the words are recognized because they appear on the Microsoft Speech Recognition app, but the handler method is never called. Do you know what's the problem with this code? Thanks in advance :D

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  • Not sure what happens to my apps objects when using NSURLSession in background - what state is my app in?

    - by Avner Barr
    More of a general question - I don't understand the workings of NSURLSession when using it in "background session mode". I will supply some simple contrived example code. I have a database which holds objects - such that portions of this data can be uploaded to a remote server. It is important to know which data/objects were uploaded in order to accurately display information to the user. It is also important to be able to upload to the server in a background task because the app can be killed at any point. for instance a simple profile picture object: @interface ProfilePicture : NSObject @property int userId; @property UIImage *profilePicture; @property BOOL successfullyUploaded; // we want to know if the image was uploaded to out server - this could also be a property that is queryable but lets assume this is attached to this object @end Now Lets say I want to upload the profile picture to a remote server - I could do something like: @implementation ProfilePictureUploader -(void)uploadProfilePicture:(ProfilePicture *)profilePicture completion:(void(^)(BOOL successInUploading))completion { NSUrlSession *uploadImageSession = ..... // code to setup uploading the image - and calling the completion handler; [uploadImageSession resume]; } @end Now somewhere else in my code I want to upload the profile picture - and if it was successful update the UI and the database that this action happened: ProfilePicture *aNewProfilePicture = ...; aNewProfilePicture.profilePicture = aImage; aNewProfilePicture.userId = 123; aNewProfilePicture.successfullyUploaded = NO; // write the change to disk [MyDatabase write:aNewProfilePicture]; // upload the image to the server ProfilePictureUploader *uploader = [ProfilePictureUploader ....]; [uploader uploadProfilePicture:aNewProfilePicture completion:^(BOOL successInUploading) { if (successInUploading) { // persist the change to my db. aNewProfilePicture.successfullyUploaded = YES; [Mydase update:aNewProfilePicture]; // persist the change } }]; Now obviously if my app is running then this "ProfilePicture" object is successfully uploaded and all is well - the database object has its own internal workings with data structures/caches and what not. All callbacks that may exist are maintained and the app state is straightforward. But I'm not clear what happens if the app "dies" at some point during the upload. It seems that any callbacks/notifications are dead. According to the API documentation- the uploading is handled by a separate process. Therefor the upload will continue and my app will be awakened at some point in the future to handle completion. But the object "aNewProfilePicture" is non existant at that point and all callbacks/objects are gone. I don't understand what context exists at this point. How am I supposed to ensure consistency in my DB and UI (For instance update the "successfullyUploaded" property for that user)? Do I need to re-work everything touching the DB or UI to correspond with the new API and work in a context free environment?

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  • Trying to reinvent the wheel of StackOverflow to have a good learning experience. Need some suggesti

    - by Legend
    I want to learn and am not able to do it unless I have a real "mission" to complete. SO is my favorite and I can't imagine a better experience than actually recreating it but not in ASP. I'd like to use PHP+MySQL+jQuery. So far, I have been a self-taught programmer but I would like to master one paradigm that forces you to adhere to the standards. For instance, recently, jQuery forced me to use some "rules". The plugins were supposed to be written in a particular way and that's it. When I started off, everything seemed like Greek and Latin but when I finished a very small plugin, I felt really happy because it forced me to program in a certain way. I am looking for something like this only in a larger project. I've heard a lot about MVC and all but I am confused about the various frameworks out there. Zend seems awesome but looks heavy at the same time and also requires you to have a lot more control over the web-server whereas CakePHP is a good and a fast framework that needs only little control. Do I use one of these or just write my own MVC? I have the following goals: Goals: Site should be fast - I know this depends on my coding skills but I will learn on my way. The framework itself should not slow me down) Setting up the site should not require you to use command-line - This requirement is ok during development. But some frameworks like Symphony require you to initialize certain things through command-line Should support pluggable modules - For instance, if I want to be able to use the FCK editor, I should be able to organize things in a good way. Should be possible to extend - For instance, SO is mainly a Q&A site but I should be able to logically extend it into an Idea Management System (optional but I'm curious). This goes more into code re-usability I guess. I am comfortable with MySQL so I should be done with database design etc. with some serious effort. As for PHP, I can write code on my own but haven't really used any frameworks that much. jQuery, I started off recently and love it. I would be glad if someone can guide me during these initial steps. Precisely, when designing something like SO, I have the following questions: Do I use a framework? If yes, should it be MVC? If MVC, which one is a good and a scalable one? (I'd love something like jQuery that will not die anytime soon) How do I balance the functionality? The same logic can sometimes be made server centric or client centric. (more Ajax?). Is it a good idea to make a heavy javascript site considering the recent advances on client-side JS processing? Just in case anyone is wondering, I am not interested in commercializing any of this. I need a reason to learn something :)

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  • What is the most idiomatic way to emulating Perl's Test::More::done_testing?

    - by DVK
    I have to build unit tests for in environment with a very old version of Test::More (perl5.8 with $Test::More::VERSION being '0.80') which predates the addition of done_testing(). Upgrading to newer Test::More is out of the question for practical reasons. And I am trying to avoid using no_tests - it's generally a bad idea not catching when your unit test exits prematurely - say due to some logic not executing when you expected it to. What is the most idiomatic way of running a configurable amount of tests, assuming no no_tests or done_testing() is used? Details: My unit tests usually take the form of: use Test::More; my @test_set = ( [ "Test #1", $param1, $param2, ... ] ,[ "Test #1", $param1, $param2, ... ] # ,... ); foreach my $test (@test_set) { run_test($test); } sub run_test { # $expected_tests += count_tests($test); ok(test1($test)) || diag("Test1 failed"); # ... } The standard approach of use Test::More tests => 23; or BEGIN {plan tests => 23} does not work since both are obviously executed before @tests is known. My current approach involves making @tests global and defining it in the BEGIN {} block as follows: use Test::More; BEGIN { our @test_set = (); # Same set of tests as above my $expected_tests = 0; foreach my $test (@tests) { my $expected_tests += count_tests($test); } plan tests = $expected_tests; } our @test_set; # Must do!!! Since first "our" was in BEGIN's scope :( foreach my $test (@test_set) { run_test($test); } # Same sub run_test {} # Same I feel this can be done more idiomatically but not certain how to improve. Chief among the smells is the duplicate our @test_test declarations - in BEGIN{} and after it. Another approach is to emulate done_testing() by calling Test::More->builder->plan(tests=>$total_tests_calculated). I'm not sure if it's any better idiomatically-wise.

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  • How do I use JDK 7 on Mac OSX?

    - by Yko
    OK. This is a newbie question but I can't figure it out... I would like to use the WatchService API as mentioned in this link: http://download.oracle.com/javase/tutorial/essential/io/notification.html After reading around, I found out that WatchService is part of the NIO class which is scheduled for JDK 7. So, it is in beta form. It's fine. http://jdk7.java.net/download.html has the JDK which I downloaded and extracted. I got a bunch of folders. I don't know what to do with them. Then, I read around some more and found that some nice group of people created JDK 7 as a binary so someone like me can install it easily. It is called Open JDK: http://code.google.com/p/openjdk-osx-build/ So, I downloaded the .dmg file and instal it. Then I open "Java Preference" and see that OpenJDK7 is available. So, now I feel that I can start trying out WatchService API. From the tutorial in the first link, the author gave a .java file to test it out first and make sure that it is running. Here is the link to the file: http://download.oracle.com/javase/tutorial/essential/io/examples/WatchDir.java So, I boot up Eclipse (actually I use STS) and create a new Java project and choose JaveSE-1.7 in the "use an execution environment JRE:". Under the src folder, I copy pasted the WatchDir.java file. And I still see tons of squiggly red lines. All the "import.java.nio.*" are all red and I cannot run it as a Java app. If you read this far, thanks a lot. So, now... What do I need to do? Thanks. EDIT: I actually did not pursue using Java 7 but there are a lot of interest in it and it seems like people keep answering this question. What should I do to make it more relevant to people who search for it? Let me know by PMing me. Thanks.

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  • HTML/JS/CSS issue getting bigger by itself

    - by Azzyh
    Here's the picture to begin with. I have this check box, that when you check, then with jQuery toggle(); it hides that you see in first half of the picture (#writeComment) and shows #SCtryVOTE (what you see in the other half picture, to the right). Now i dont know why but of some reason it expands when its checked, why i dont know, is it because it needs more place than it have or? how do i make this work without having problems when its checked. Here's coding: $('#tryout').click(function () { $('#writeComment').toggle(!$(this).attr('checked')); $('#SCtryVOTE').toggle($(this).attr('checked')); }); the js jquery script part, heres the table and divs HTML part: <input type="checkbox" id="tryout"> <table align="center" width="400" cellpadding="0" cellspacing="1" id="theBoxer"> <tr style="background: #686868;"> <td align="center" valign="top" width="70" height="25" style="border:1px #FFF solid;">Opret</td> <td align="center" valign="top" width="70" height="25" style="border:1px #FFF solid;">Opret</td> </td> </tr> <tr> <td align="left" valign="top" width="70" height="112" style=""> TEST </td> <td align="left" valign="top" width="70" height="112" style=""> <div id="writeComment"> Smid en kommentar:<br> <form action="javascript:DoInsert()" method="post"> <textarea id="kommentar" name="kommentar"></textarea><br /> <input type="hidden" name="fID" id="fID" value="<? echo $_GET["id"]; ?>"> <input type="submit" name="Submit" value="Sæt ind!"> </form> </div> <div id="SCtryVOTE" style="display: none;"> <form onsubmit="if (!this.comment.cleared) clearContents( document.getElementById('comment') ); return true;" action="javascript:DoSCInsert()" method="post"> <textarea onfocus=" javascript:clearContents(this); this.cleared=true;" rows="5" cols="40" id="comment" name="comment" <?php if($vis["username"] == $pusername) { echo "DISABLED"; } ?>>Tryk for at skrive. Skal være detaljeret og grundet.</textarea> <br>Ja: <input type="radio" value="Y" id="SCvoteY" name="vote"></input> Nej: <input type="radio" id="SCvoteN" value="N" name="vote"> </input> <input type="submit" id="SCstem" name="Submit" value="Stem!"> </form> </div> Maybe you need the CSS part too for these two boxes: #writeComment{ position: relative; left: 5px; top: 10px; } #SCtryVOTE{ position: relative; left: 5px; top: 10px; }

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  • Device drivers and Windows

    - by b-gen-jack-o-neill
    Hi, I am trying to complete the picture of how the PC and the OS interacts together. And I am at point, where I am little out of guess when it comes to device drivers. Please, don´t write things like its too complicated, or you don´t need to know when using high programming laguage and winapi functions. I want to know, it´s for study purposes. So, the very basic structure of how OS and PC (by PC I mean of course HW) is how I see it is that all other than direct CPU commands, which can CPU do on itself (arithmetic operation, its registers access and memory access) must pass thru OS. Mainly becouse from ring level 3 you cannot use in and out intructions which are used for acesing other HW. I know that there is MMIO,but it must be set by port comunication first. It was not like this all the time. Even I am bit young to remember MSDOS, I know you could access HW directly, becouse there ws no limitation, no ring mode. So you could to write string to diplay use wheather DOS function, or directly acess video card memory and write it by yourself. But as OS developed, there is no longer this possibility. But it is fine, since OS now handles all the HW comunication, and frankly it more convinient and much more safe (I would say the only option) in multitasking environment. So nowdays you instead of using int instructions to use BIOS mapped function or DOS function you call dll which internally than handles everything you don´t need to know about. I understand this. I also undrstand that device drivers is the piece of code that runs in ring level 0, so it can do all the HW interactions. But what I don´t understand is connection between OS and device driver. Let´s take a example - I want to make a sound card make a sound. So I call windows API to acess sound card, but what happens than? Does windows call device drivers to do so? But if it does call device driver, does it mean, that all device drivers which can be called by winAPI function, must have routines named in some specific way? I mean, when I have new sound card, must its drivers have functions named same as the old one? So Windows can actually call the same function from its perspective? But if Windows have predefined sets of functions requored by device drivers, that it cannot use new drivers that doesent existed before last version of OS came out. Please, help me understand this mess. I am really getting mad. Thanks.

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  • Is 4-5 years the “Midlife Crisis” for a programming career?

    - by Jeffrey
    I’ve been programming C# professionally for a bit over 4 years now. For the past 4 years I’ve worked for a few small/medium companies ranging from “web/ads agencies”, small industry specific software shops to a small startup. I've been mainly doing "business apps" that involves using high-level programming languages (garbage collected) and my overall experience was that all of the works I’ve done could have been more professional. A lot of the things were done incorrectly (in a rush) mainly due to cost factor that people always wanted something “now” and with the smallest amount of spendable money. I kept on thinking maybe if I could work for a bigger companies or a company that’s better suited for programmers, or somewhere that's got the money and time to really build something longer term and more maintainable I may have enjoyed more in my career. I’ve never had a “mentor” that guided me through my 4 years career. I am pretty much blog / google / self taught programmer other than my bachelor IT degree. I’ve also observed another issue that most so called “senior” programmer in “my working environment” are really not that senior skill wise. They are “senior” only because they’ve been a long time programmer, but the code they write or the decisions they make are absolutely rubbish! They don't want to learn, they don't want to be better they just want to get paid and do what they've told to do which make sense and most of us are like that. Maybe that’s why they are where they are now. But I don’t want to become like them I want to be better. I’ve run into a mental state that I no longer intend to be a programmer for my future career. I started to think maybe there are better things out there to work on. The more blogs I read, the more “best practices” I’ve tried the more I feel I am drifting away from “my reality”. But I am not a great programmer otherwise I don't think I am where I am now. I think 4-5 years is a stage that can be a step forward career wise or a step out of where you are. I just wanted to hear what other have to say about what I’ve mentioned above and whether you’ve experienced similar situation in your past programming career and how you dealt with it. Thanks.

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  • How can I obtain the IPv4 address of the client?

    - by Dr Dork
    Hello! I'm prepping for a simple work project and am trying to familiarize myself with the basics of socket programming in a Unix dev environment. At this point, I have some basic server side code setup to listen for incoming TCP connection requests from clients after the parent socket has been created and is set to listen... int sockfd, newfd; unsigned int len; socklen_t sin_size; char msg[]="Test message sent"; char buf[MAXLEN]; int st, rv; struct addrinfo hints, *serverinfo, *p; struct sockaddr_storage client; char ip[INET6_ADDRSTRLEN]; . . //parent socket creation and listen code omitted for simplicity . //wait for connection requests from clients while(1) { //Returns the socketID and address of client connecting to socket if( ( newfd = accept(sockfd, (struct sockaddr *)&client, &len) ) == -1 ){ perror("Accept"); exit(-1); } if( (rv = recv(newfd, buf, MAXLEN-1, 0 )) == -1) { perror("Recv"); exit(-1); } struct sockaddr_in *clientAddr = ( struct sockaddr_in *) get_in_addr((struct sockaddr *)&client); inet_ntop(client.ss_family, clientAddr, ip, sizeof ip); printf("Receive from %s: query type is %s\n", ip, buf); if( ( st = send(newfd, msg, strlen(msg), 0)) == -1 ) { perror("Send"); exit(-1); } //ntohs is used to avoid big-endian and little endian compatibility issues printf("Send %d byte to port %d\n", ntohs(clientAddr->sin_port) ); close(newfd); } } I found the get_in_addr function online and placed it at the top of my code and use it to obtain the IP address of the client connecting... // get sockaddr, IPv4 or IPv6: void *get_in_addr(struct sockaddr *sa) { if (sa->sa_family == AF_INET) { return &(((struct sockaddr_in*)sa)->sin_addr); } return &(((struct sockaddr_in6*)sa)->sin6_addr); } but the function always returns the IPv6 IP address since thats what the sa_family property is set as. My question is, is the IPv4 IP address stored anywhere in the data I'm using and, if so, how can I access it? Thanks so much in advance for all your help!

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  • How can I enable a debugging mode via a command-line switch for my Perl program?

    - by Michael Mao
    I am learning Perl in a "head-first" manner. I am absolutely a newbie in this language: I am trying to have a debug_mode switch from CLI which can be used to control how my script works, by switching certain subroutines "on and off". And below is what I've got so far: #!/usr/bin/perl -s -w # purpose : make subroutine execution optional, # which is depending on a CLI switch flag use strict; use warnings; use constant DEBUG_VERBOSE => "v"; use constant DEBUG_SUPPRESS_ERROR_MSGS => "s"; use constant DEBUG_IGNORE_VALIDATION => "i"; use constant DEBUG_SETPPING_COMPUTATION => "c"; our ($debug_mode); mainMethod(); sub mainMethod # () { if(!$debug_mode) { print "debug_mode is OFF\n"; } elsif($debug_mode) { print "debug_mode is ON\n"; } else { print "OMG!\n"; exit -1; } checkArgv(); printErrorMsg("Error_Code_123", "Parsing Error at..."); verbose(); } sub checkArgv #() { print ("Number of ARGV : ".(1 + $#ARGV)."\n"); } sub printErrorMsg # ($error_code, $error_msg, ..) { if(defined($debug_mode) && !($debug_mode =~ DEBUG_SUPPRESS_ERROR_MSGS)) { print "You can only see me if -debug_mode is NOT set". " to DEBUG_SUPPRESS_ERROR_MSGS\n"; die("terminated prematurely...\n") and exit -1; } } sub verbose # () { if(defined($debug_mode) && ($debug_mode =~ DEBUG_VERBOSE)) { print "Blah blah blah...\n"; } } So far as I can tell, at least it works...: the -debug_mode switch doesn't interfere with normal ARGV the following commandlines work: ./optional.pl ./optional.pl -debug_mode ./optional.pl -debug_mode=v ./optional.pl -debug_mode=s However, I am puzzled when multiple debug_modes are "mixed", such as: ./optional.pl -debug_mode=sv ./optional.pl -debug_mode=vs I don't understand why the above lines of code "magically works". I see both of the "DEBUG_VERBOS" and "DEBUG_SUPPRESS_ERROR_MSGS" apply to the script, which is fine in this case. However, if there are some "conflicting" debug modes, I am not sure how to set the "precedence of debug_modes"? Also, I am not certain if my approach is good enough to Perlists and I hope I am getting my feet in the right direction. One biggest problem is that I now put if statements inside most of my subroutines for controlling their behavior under different modes. Is this okay? Is there a more elegant way? I know there must be a debug module from CPAN or elsewhere, but I want a real minimal solution that doesn't depend on any other module than the "default". And I cannot have any control on the environment where this script will be executed...

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