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  • How to separate sets of numbers onto separate lines

    - by Fred
    About the script: The script below will create 300 sets of random characters. What is presently happening, is that it creates them but shows them all on one line, in one big chunk. With all the searching and testing I've done to try and achieve this, I have had no success. I would like to know which code and where to put it, so that each SET (300) of 15 characters long, will show and be saved to file. Here is my script: <?php function GetID($x){ $characters = array_merge(range('A','Z'),range('a','z'),range(2,9)); shuffle($characters); for($x=0;$x<=299;$x++){ } for (; strlen($ReqID)<$x;){ $ReqID .= $characters[mt_rand(0, count($characters))]; } return $ReqID; } $ReqID .= GetID(5); $ReqID .= "-"; $ReqID .= GetID(5); $ReqID .= "-"; $ReqID .= GetID(5); echo $ReqID; $fh = fopen("file.txt","a+"); fwrite($fh, ("$ReqID")."\n"); fclose($fh); ?>

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  • Best practices for encrypting continuous/small UDP data

    - by temp
    Hello everyone, I am having an application where I have to send several small data per second through the network using UDP. The application need to send the data in real-time (no waiting). I want to encrypt these data and insure that what I am doing is as secure as possible. Since I am using UDP, there is no way to use SSL/TLS, so I have to encrypt each packet alone since the protocol is connectionless/unreliable/unregulated. Right now, I am using a 128-bit key derived from a passphrase from the user, and AES in CBC mode (PBE using AES-CBC). I decided to use a random salt with the passphrase to derive the 128-bit key (prevent dictionary attack on the passphrase), and of course use IVs (to prevent statistical analysis for packets). However I am concerned about few things: Each packet contains small amount of data (like a couple of integer values per packet) which will make the encrypted packets vulnerable to known-plaintext attacks (which will result in making it easier to crack the key). Also, since the encryption key is derived from a passphrase, this will make the key space way less (I know the salt will help, but I have to send the salt through the network once and anyone can get it). Given these two things, anyone can sniff and store the sent data, and try to crack the key. Although this process might take some time, once the key is cracked all the stored data will be decrypted, which will be a real problem for my application. So my question is, what is the best practices for sending/encrypting continuous small data using a connectionless protocol (UDP)? Is my way the best way to do it? ...flowed? ...Overkill? ... Please note that I am not asking for a 100% secure solution, as there is no such thing. Cheers

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  • Java Concurrency in practice sample question

    - by andy boot
    I am reading "Java Concurrency in practice" and looking at the example code on page 51. This states that if a thread has references to a shared object then other threads may be able to access that object before the constructor has finished executing. I have tried to put this into practice and so I wrote this code thinking that if I ran it enough times a RuntimeException("World is f*cked") would occur. But it isn't doing. Is this a case of the Java spec not guaranting something but my particular implementation of java guaranteeing it for me? (java version: 1.5.0 on Ubuntu) Or have I misread something in the book? Code: (I expect an exception but it is never thrown) public class Threads { private Widgit w; public static void main(String[] s) throws Exception { while(true){ Threads t = new Threads(); t.runThreads(); } } private void runThreads() throws Exception{ new Checker().start(); w = new Widgit((int)(Math.random() * 100) + 1); } private class Checker extends Thread{ private static final int LOOP_TIMES = 1000; public void run() { int count = 0; for(int i = 0; i < LOOP_TIMES; i++){ try { w.checkMe(); count++; } catch(NullPointerException npe){ //ignore } } System.out.println("checked: "+count+" times out of "+LOOP_TIMES); } } private static class Widgit{ private int n; private int n2; Widgit(int n) throws InterruptedException{ this.n = n; Thread.sleep(2); this.n2 = n; } void checkMe(){ if (n != n2) { throw new RuntimeException("World is f*cked"); } } } }

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  • Find all ways to insert zeroes into a bit pattern

    - by James
    I've been struggling to wrap my head around this for some reason. I have 15 bits that represent a number. The bits must match a pattern. The pattern is defined in the way the bits start out: they are in the most flush-right representation of that pattern. So say the pattern is 1 4 1. The bits will be: 000000010111101 So the general rule is, take each number in the pattern, create that many bits (1, 4 or 1 in this case) and then have at least one space separating them. So if it's 1 2 6 1 (it will be random): 001011011111101 Starting with the flush-right version, I want to generate every single possible number that meets that pattern. The # of bits will be stored in a variable. So for a simple case, assume it's 5 bits and the initial bit pattern is: 00101. I want to generate: 00101 01001 01010 10001 10010 10100 I'm trying to do this in Objective-C, but anything resembling C would be fine. I just can't seem to come up with a good recursive algorithm for this. It makes sense in the above example, but when I start getting into 12431 and having to keep track of everything it breaks down.

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  • Save Xml in an Excel cell value causes ComException

    - by mas_oz2k1
    I am trying to save an object (Class1) as string in a cell value. My issue is that from time to time I have a ComException: HRESULT: 0x8007000E (E_OUTOFMEMORY) (It is kind of random but I have not identified any particular pattern yet) when I write the value into a cell. Any ideas will be welcome For illustration purposes: Let Class1 be the class to be converted to an Xml string. (Notice that I removed the xml declaration at the start of the string to avoid having the preamble present- non printable character) <Class1 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" <ElementID HL690375</ElementID </Class1" Class1 myClass = new Class1(); this class is converted to a string s. s= ConvertObjectToXmlString(myClass); then s is assigned to a cell Range r = Application.ActiveCell; r.Value2 = s; Note: (1) If the string is too big, I limit it to 32000 chars and split the string in chunks of 32000 chars and save the chunks in multiple cells. (2) I do not to quote the string before adding to a cell. Do I need to? If so how it can be done? (3) All object contents are English. (4) C# code sample will be great but VB.net code is OK.

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  • Extract history from Korn shell

    - by Luc
    I am not happy about the history file in binary format of the Korn shell. I like to "collect" some of my command lines, many of them actually, and for a long time. I'm talking about years. That doesn't seem easy in Korn because the history file is not plain text so I can't edit it, and a lot of junk is piling up in it. By "junk" I mean lines that I don'twant to keep, like 'cat' or 'man'. So I added these lines to my .profile: fc -ln 1 9999 ~/khistory.txt source ~/loghistory.sh ~/khistory.txt loghistory.sh contains a handful of sed and sort commands that gets rid of a lot of the junk. But apparently it is forbidden to run fc in the .profile file. I can't login whenever I do, the shell exits right away with signal 11. So I removed that 'fc -l' line from my .profile file and added it to the loghistory.sh script, but the shell still crashes. I also tried this line in my .profile: strings ~/.sh_history ~/khistory.txt source ~/loghistory.sh That doesn't crash, but the output is printed with an additional, random character in the beginning of many lines. I can run 'fc -l' on the command line, but that's no good. I need to automate that. But how? How can I extract my ksh history as plain text? TIA

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  • How to (kindly) ask your users to upgrade from IE6?

    - by nickf
    It's no secret at all that IE6 has been a major roadblock to the advancement of the web over the last few years. I couldn't count the number of hours I've spent bashing my head against a wall trying to fix or debug IE6 issues. The way I see it, there are two types of IE6 user. a) the poor corporate schmoe whose IT department doesn't want to upgrade in case something breaks, and b) the mums and dads of the world who think the internet is the blue E on their desktop (and I don't mean that in a nasty way). There's probably a couple of people who know about all the other browsers, but still choose to run IE6. They get what they deserve, IMO. Anyway, getting to the point, I'd say that 90% of my IE6-using visitors are in the the mums and dads category - they're not stupid, they just don't know WHY they should upgrade to IE7 or Firefox or whatever. How do I educate these people without pissing them off? Is there a nice and friendly website I can direct these people to, which explains the reasons for upgrading in plain language? Any mention of "security" or "web standards" I think would just come across as scary. I've just seen http://www.whatbrowser.org which seems to fit the bill nicely. It explains in very basic terms: what a web browser is why you'd want to upgrade it how old your current browser is (subtle hint to those with a 9 year old browser) ..aaaand it's in 22 languages. It's from Google but displays no bias (it links to Firefox, Chrome, Opera, Safari, Internet Explorer displayed in a random order).

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  • Is sending a hashed password over the wire a security hole?

    - by Ubiquitous Che
    I've come across a system that is in use by a company that we are considering partnering with on a medium-sized (for us, not them) project. They have a web service that we will need to integrate with. My current understanding of proper username/password management is that the username may be stored as plaintext in the database. Every user should have a unique pseudo-random salt, which may also be stored in plaintext. The text of their password must be concatenated with the salt and then this combined string may be hashed and stored in the database in an nvarchar field. So long as passwords are submitted to the website (or web service) over plaintext, everything should be just lovely. Feel free to rip into my understanding as summarized above if I'm wrong. Anyway, back to the subject at hand. The WebService run by this potential partner doesn't accept username and password, which I had anticipated. Instead, it accepts two string fields named 'Username' and 'PasswordHash'. The 'PasswordHash' value that I have been given does indeed look like a hash, and not just a value for a mis-named password field. This is raising a red flag for me. I'm not sure why, but I feel uncomfortable sending a hashed password over the wire for some reason. Off the top of my head I can't think of a reason why this would be a bad thing... Technically, the hash is available on the database anyway. But it's making me nervous, and I'm not sure if there's a reason for this or if I'm just being paranoid.

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  • struct and rand()

    - by teoz
    I have a struct with an array of 100 int (b) and a variable of type int (a) I have a function that checks if the value of "a" is in the array and i have generated the array elements and the variable with random values. but it doesn't work can someone help me fix it? #include <stdio.h> #include <stdlib.h> #include <time.h> typedef struct { int a; int b[100]; } h; int func(h v){ int i; for (i=0;i<100;i++){ if(v.b[i]==v.a) return 1; else return 0; } } int main(int argc, char** argv) { h str; srand(time(0)); int i; for(i=0;0<100;i++){ str.b[i]=(rand() % 10) + 1; } str.a=(rand() % 10) + 1; str.a=1; printf("%d\n",func(str)); return 0; }

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  • List iterator not dereferencable?

    - by Roderick
    Hi All I get the error "list iterator not dereferencable" when using the following code: bool done = false; while (!_list_of_messages.empty() && !done) { // request the next message to create a frame // DEBUG ERROR WHEN NEXT LINE IS EXECUTED: Counted_message_reader reader = *(_list_of_messages.begin()); if (reader.has_more_data()) { _list_of_frames.push_back(new Dlp_data_frame(reader, _send_compressed_frames)); done = true; } else { _list_of_messages.pop_front(); } } (The line beginning with "Counted_message_reader..." is the one giving the problem) Note that the error doesn't always occur but seemingly at random times (usually when there's lots of buffered data). _list_of_messages is declared as follows: std::list<Counted_message_reader> _list_of_messages; In the surrounding code we could do pop_front, push_front and size, empty or end checks on _list_of_messages but no erase calls. I've studied the STL documentation and can't see any glaring problems. Is there something wrong with the above code or do I have a memory leak somewhere? Thanks! Appreciated!

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  • Playing craps, asking and printing

    - by Angelo Mejia
    How do I ask the amount of games of craps someone wants to play and print the number of wins as a result of n number of games? Also How do I make a table in the main method using the previous methods I have? A table like this but shows the results: Percent Wins Games Experiment Number 1 2 3 4 5 6 7 8 9 10 100 1000 10000 100000 1000000 public class CrapsAnalysis { public static int rollDie( int n) { return (int)(Math.random()*n) + 1 ; } public static int rollDice( ) { int die1 ; int die2 ; die1 = rollDie(6) ; die2 = rollDie(6) ; return die1 + die2 ; } public static boolean playOneGame( ) { int newDice ; //repeated dice rolls int roll ; //first roll of the dice int playerPoint = 0 ; //player point if no win or loss on first roll newDice = rollDice() ; roll = rollDice() ; if (roll == 7 || roll == 11) return true; else if (roll == 2 || roll == 3 || roll == 12) return false; else { playerPoint = roll; newDice = rollDice(); do { newDice = rollDice(); } while (newDice != playerPoint || newDice != 7) ; if (newDice == 7) return false; else return true; } } public static int playGames ( int n ) { int numWon = 0; for (int i = 1; i <= n; i++) if(playOneGame()) numWon++; return numWon; } public static void main(String[] args) { //Don't know how to ask and print out the results of the number of wins depending on the n number of games played } }

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  • WSACONNREFUSED when connecting to server

    - by Robert Mason
    I'm currently working on a server. I know that the client side is working (I can connect to www.google.com on port 80, for example), but the server is not functioning correctly. The socket has socket()ed, bind()ed, and listen()ed successfully and is on an accept loop. The only problem is that accept() doesn't seem to work. netstat shows that the server connection is running fine, as it prints the PID of the server process as LISTENING on the correct port. However, accept never returns. Accept just keeps running, and running, and if i try to connect to the port on localhost, i get a 10061 WSACONNREFUSED. I tried looping the connection, and it just keeps refusing connections until i hit ctrl+c. I put a breakpoint directly after the call to accept(), and no matter how many times i try to connect to that port, the breakpoint never fires. Why is accept not accepting connections? Has anyone else had this problem before? Known: [breakpoint0] if ((new_fd = accept(sockint, NULL, NULL)) == -1) { throw netlib::error("Accept Error"); //netlib::error : public std::exception } else { [breakpoint1] code...; } breakpoint0 is reached (and then continued through), no exception is thrown, and breakpoint1 is never reached. The client code is proven to work. Netstat shows that the socket is listening. If it means anything, i'm connecting to 127.0.0.1 on port 5842 (random number). The server is configured to run on 5842, and netstat confirms that the port is correct.

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  • Android: Capturing the return of an activity.

    - by Chrispix
    I have a question regarding launching new activities. It boils down to this. I have 3 tabs on a view A) contains gMap activity B) camera activity C) some random text fields. Requirement is that the application runs in Portrait mode. All 3 tabs work as expected w/ the exception of the Camera Preview Surface (B). It is rotated 90 degrees. They only way to make it correct is to set the app to landscape which throws all my tabs around, and is pretty much unworkable. My solution is this : replace my camera activity with a regular activity that is empty w/ the exception of Intent i = new Intent(this,CameraActivity.class); startActivity(i); This launches my CameraActivity. And that works fine. I had to do a linear layout and include 3 images that look like real tabs, so I can try and mimic the operation of the tabs while rotating the screen to landscape and keep the visuals as portrait. The user can click one of the images(buttons) to display the next tab. This is my issue. It should exit my 'camera activity' returning to the 'blank activity' in a tab, where it should be interpreted to click the desiered tab from my image. The main thing is, when it returns, it returns to a blank (black) page under a tab (because it is 'empty'). How can I capture the return event back to the page that called the activity, and then see what action they performed? I can set an onclicklistener where I can respond to the fake tabs (images) being clicked to exit out of the camera activity. On exit, the tab should update so that is where you return. any Suggestions? Thanks,

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  • Implement a threading to prevent UI block on a bug in an async function

    - by Marcx
    I think I ran up againt a bug in an async function... Precisely the getDirectoryListingAsync() of the File class... This method is supposted to return an object containing the lists of files in a specified folder. I found that calling this method on a direcory with a lot of files (in my tests more than 20k files), after few seconds there is a block on the UI until the process is completed... I think that this method is separated in two main block: 1) get the list of files 2) create the array with the details of the files The point 1 seems to be async (for a few second the ui is responsive), then when the process pass from point 1 to point 2 the block of the UI occurs until the complete event is dispathed... Here's some (simple) code: private function checkFiles(dir:File):void { if (dir.exists) { dir.addEventListener( FileListEvent.DIRECTORY_LISTING, listaImmaginiLocale); dir.getDirectoryListingAsync(); // after this point, for the firsts seconds the UI respond well (point 1), // few seconds later (point 2) the UI is frozen } } private function listaImmaginiLocale( event:FileListEvent ):void { // from this point on the UI is responsive again... } Actually in my projects there are some function that perform an heavy cpu usage and to prevent the UI block I implemented a simple function that after some iteration will wait giving time to UI to be refreshed. private var maxIteration:int = 150000; private function sampleFunct(offset:int = 0) :void { if (offset < maxIteration) { // do something // call the recursive function using a timeout.. // if the offset in multiple by 1000 the function will wait 15 millisec, // otherwise it will be called immediately // 1000 is a random number for the pourpose of this example, but I usually change the // value based on how much heavy is the function itself... setTimeout(function():void{aaa(++offset);}, (offset%1000?15:0)); } } Using this method I got a good responsive UI without afflicting performance... I'd like to implement it into the getDirectoryListingAsync method but I don't know if it's possibile how can I do it where is the file to edit or extend.. Any suggestion???

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  • How to maintain ComboBox.SelectedItem reference when DataSource is resorted?

    - by Dave
    This really seems like a bug to me, but perhaps some databinding gurus can enlighten me? (My WinForms databinding knowledge is quite limited.) I have a ComboBox bound to a sorted DataView. When the properties of the items in the DataView change such that items are resorted, the SelectedItem in my ComboBox does not keep in-sync. It seems to point to someplace completely random. Is this a bug, or am I missing something in my databinding? Here is a sample application that reproduces the problem. All you need is a Button and a ComboBox: public partial class Form1 : Form { private DataTable myData; public Form1() { this.InitializeComponent(); this.myData = new DataTable(); this.myData.Columns.Add("ID", typeof(int)); this.myData.Columns.Add("Name", typeof(string)); this.myData.Columns.Add("LastModified", typeof(DateTime)); this.myData.Rows.Add(1, "first", DateTime.Now.AddMinutes(-2)); this.myData.Rows.Add(2, "second", DateTime.Now.AddMinutes(-1)); this.myData.Rows.Add(3, "third", DateTime.Now); this.myData.DefaultView.Sort = "LastModified DESC"; this.comboBox1.DataSource = this.myData.DefaultView; this.comboBox1.ValueMember = "ID"; this.comboBox1.DisplayMember = "Name"; } private void saveStuffButton_Click(object sender, EventArgs e) { DataRowView preUpdateSelectedItem = (DataRowView)this.comboBox1.SelectedItem; // OUTPUT: SelectedIndex = 0; SelectedItem.Name = third Debug.WriteLine(string.Format("SelectedIndex = {0:N0}; SelectedItem.Name = {1}", this.comboBox1.SelectedIndex, preUpdateSelectedItem["Name"])); this.myData.Rows[0]["LastModified"] = DateTime.Now; DataRowView postUpdateSelectedItem = (DataRowView)this.comboBox1.SelectedItem; // OUTPUT: SelectedIndex = 2; SelectedItem.Name = second Debug.WriteLine(string.Format("SelectedIndex = {0:N0}; SelectedItem.Name = {1}", this.comboBox1.SelectedIndex, postUpdateSelectedItem["Name"])); // FAIL! Debug.Assert(object.ReferenceEquals(preUpdateSelectedItem, postUpdateSelectedItem)); } }

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  • On Disk Substring index

    - by emeryc
    I have a file (fasta file to be specific) that I would like to index, so that I can quickly locate any substring within the file and then find the location within the original fasta file. This would be easy to do in many cases, using a Trie or substring array, unfortunately the strings I need to index are 800+ MBs which means that doing them in memory in unacceptable, so I'm looking for a reasonable way to create this index on disk, with minimal memory usage. (edit for clarification) I am only interested in the headers of proteins, so for the largest database I'm interested in, this is about 800 MBs of text. I would like to be able to find an exact substring within O(N) time based on the input string. This must be useable on 32 bit machines as it will be shipped to random people, who are not expected to have 64 bit machines. I want to be able to index against any word break within a line, to the end of the line (though lines can be several MBs long). Hopefully this clarifies what is needed and why the current solutions given are not illuminating. I should also add that this needs to be done from within java, and must be done on client computers on various operating systems, so I can't use any OS Specific solution, and it must be a programatic solution.

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  • Shuffle Two NSMutableArray independently

    - by Superman
    I'm creating two NSMutableArray in my viewDidLoad, I add it in a NSMutableDictionary. When I tried shuffling it with one array, It is okay. But the problem is when Im shuffling two arrays independently its not working,somehow the indexes got mixed up. Here is my code for my array (I have two of these): self.items1 = [NSMutableArray new]; for(int i = 0; i <= 100; i++) { NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES); NSString *documentsDir = [paths objectAtIndex:0]; NSString *savedImagePath = [documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:@"[Images%d.png", i]]; if([[NSFileManager defaultManager] fileExistsAtPath:savedImagePath]){ self.container = [[NSMutableDictionary alloc] init]; [container setObject:[UIImage imageWithContentsOfFile:savedImagePath] forKey:@"items1"]; [container setObject:[NSNumber numberWithInt:i] forKey:@"index1"]; [items1 addObject:container]; } } NSLog(@"Count : %d", [items1 count]); [items1 enumerateObjectsUsingBlock:^(id object, NSUInteger index, BOOL *stop) { NSLog(@"%@ images at index %d", object, index); }]; then my shuffle code(Which I tried duplicating for the other array,but not working also): srandom(time(NULL)); NSUInteger count = [items1 count]; for (NSUInteger i = 0; i < count; ++i) { int nElements = count - i; int n = (random() % nElements) + i; [items1 exchangeObjectAtIndex:i withObjectAtIndex:n]; } How am I going to shuffle it using above code (or if you have other suggestions) with two arrays? Thanks My other problem is when I tries subclassing the class for the shuffle method or either use the above code, their index mixed. For example: Object: apple, ball, carrots, dog Indexes: 1 2 3 4 but in my View when shuffled: Object: carrots, apple, dog, balle Indexes: 2 4 1 3

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  • Finding a list of indices from master array using secondary array with non-unique entries

    - by fideli
    I have a master array of length n of id numbers that apply to other analogous arrays with corresponding data for elements in my simulation that belong to those id numbers (e.g. data[id]). Were I to generate a list of id numbers of length m separately and need the information in the data array for those ids, what is the best method of getting a list of indices idx of the original array of ids in order to extract data[idx]? That is, given: a=numpy.array([1,3,4,5,6]) # master array b=numpy.array([3,4,3,6,4,1,5]) # secondary array I would like to generate idx=numpy.array([1,2,1,4,2,0,3]) The array a is typically in sequential order but it's not a requirement. Also, array b will most definitely have repeats and will not be in any order. My current method of doing this is: idx=numpy.array([numpy.where(a==bi)[0][0] for bi in b]) I timed it using the following test: a=(numpy.random.uniform(100,size=100)).astype('int') b=numpy.repeat(a,100) timeit method1(a,b) 10 loops, best of 3: 53.1 ms per loop Is there a better way of doing this?

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  • Am I encrypting my passwords correctly in ASP.NET

    - by Nick
    I have a security class: public class security { private static string createSalt(int size) { //Generate a random cryptographic number RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider(); byte[] b = new byte[size]; rng.GetBytes(b); //Convert to Base64 return Convert.ToBase64String(b); } /// <summary> /// Generate a hashed password for comparison or create a new one /// </summary> /// <param name="pwd">Users password</param> /// <returns></returns> public static string createPasswordHash(string pwd) { string salt = "(removed)"; string saltAndPwd = string.Concat(pwd, salt); string hashedPwd = FormsAuthentication.HashPasswordForStoringInConfigFile( saltAndPwd, "sha1"); return hashedPwd; } } This works fine, but I am wondering if it is sufficient enough. Also, is this next block of code better? Overkill? static byte[] encrInitVector = new byte[] { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; static string encrKey = "(removed)"; public static string EncryptString(string s) { byte[] key; try { key = Encoding.UTF8.GetBytes(encrKey.Substring(0, 8)); DESCryptoServiceProvider des = new DESCryptoServiceProvider(); byte[] inputByteArray = Encoding.UTF8.GetBytes(s); MemoryStream ms = new MemoryStream(); CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(key, encrInitVector), CryptoStreamMode.Write); cs.Write(inputByteArray, 0, inputByteArray.Length); cs.FlushFinalBlock(); return Convert.ToBase64String(ms.ToArray()); } catch (Exception e) { throw e; }

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  • Copy constructor called even when returning by reference?

    - by Johnyy
    Hi, I am testing the return of local objects by reference. My original test went well but something else happens unexpected. #include <iostream> using namespace std; class MyInt { public: MyInt(int i){ value = new int(i); } ~MyInt(){ delete value; } int getValue(){ return *value; } MyInt(const MyInt &b){ cout<<"Copy"<<endl; } private: int* value; }; MyInt& returnref(){ MyInt a(10); cout<<"Returning from returnref()"<<endl; return a; } int main(){ MyInt a = returnref(); cout<<a.getValue()<<endl; return 0; } My console prints "Returning from ..." then "Copy" then a random value. My understanding of pass by reference is that it does not need to make any copy. Why is it not doing what I expected?

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  • JAVA MySql multiple word search

    - by user1703849
    i have a database in MySql that has a name column in it which contains several words(description). I am connected to database with java through eclipse. I have a search, that returns results if only name field contains one word. id: name: info: type: 1 balloon big red balloon big 2 house expensive beautiful luxury 3 chicken wings deep fried wings tasty these are just random words but as an example my search can only see ex. balloon and then show info, but if i type chicken wings, it does nothing. so it possible somehow to search from columns with multiple words? this is my search code below import java.io.*; import java.sql.*; import java.util.*; class Search { public static void main(String[] args) { Scanner inp``ut = new Scanner(System.in); try { Connection con = DriverManager.getConnection( "jdbc:mysql://example/mydb", "user", "password"); Statement stmt = (Statement) con.createStatement(); System.out.print("enter search: "); String name = input.next(); String SQL = "SELECT * FROM menu where name LIKE '" + name + "'"; ResultSet rs = stmt.executeQuery(SQL); while (rs.next()) { System.out.println("Name: " +rs.getString("name")); System.out.println("Description: " + rs.getString("info") ); System.out.println("Price: " + rs.getString("Price")); } } catch (Exception e) { System.out.println("ERROR: " + e.getMessage()); } } }

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  • My python program always brings down my internet connection after several hours running, how do I debug and fix this problem?

    - by Shane
    I'm writing a python script checking/monitoring several server/websites status(response time and similar stuff), it's a GUI program and I use separate thread to check different server/website, and the basic structure of each thread is using an infinite while loop to request that site every random time period(15 to 30 seconds), once there's changes in website/server each thread will start a new thread to do a thorough check(requesting more pages and similar stuff). The problem is, my internet connection always got blocked/jammed/messed up after several hours running of this script, the situation is, from my script side I got urlopen error timed out each time it's requesting a page, and from my FireFox browser side I cannot open any site. But the weird thing is, the moment I close my script my Internet connection got back on immediately which means now I can surf any site through my browser, so it must be the script causing all the problem. I've checked the program carefully and even use del to delete any connection once it's used, still get the same problem. I only use urllib2, urllib, mechanize to do network requests. Anybody knows why such thing happens? How do I debug this problem? Is there a tool or something to check my network status once such situation occurs? It's really bugging me for a while... By the way I'm behind a VPN, does it have something to do with this problem? Although I don't think so because my network always get back on once the script closed, and the VPN connection never drops(as it appears) during the whole process.

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  • no more hitcollision at 1 life

    - by user1449547
    So I finally got my implementation of lives fixed, and it works. Now however when I collide with a ghost when I am at 1 life, nothing happens. I can fall to my death enough times for a game over. from what i can tell the problem is that hit collision is not longer working, because it does not detect a hit, I do not fall. the question is why? update if i kill myself fast enough it works, but if i play for like 30 seconds, it stops the hit collision detection on my ghosts. platforms and springs still work. public class World { public interface WorldListener { public void jump(); public void highJump(); public void hit(); public void coin(); public void dying(); } public static final float WORLD_WIDTH = 10; public static final float WORLD_HEIGHT = 15 * 20; public static final int WORLD_STATE_RUNNING = 0; public static final int WORLD_STATE_NEXT_LEVEL = 1; public static final int WORLD_STATE_GAME_OVER = 2; public static final Vector2 gravity = new Vector2(0, -12); public Hero hero; public final List<Platform> platforms; public final List<Spring> springs; public final List<Ghost> ghosts; public final List<Coin> coins; public Castle castle; public final WorldListener listener; public final Random rand; public float heightSoFar; public int score; public int state; public int lives=3; public World(WorldListener listener) { this.hero = new Hero(5, 1); this.platforms = new ArrayList<Platform>(); this.springs = new ArrayList<Spring>(); this.ghosts = new ArrayList<Ghost>(); this.coins = new ArrayList<Coin>(); this.listener = listener; rand = new Random(); generateLevel(); this.heightSoFar = 0; this.score = 0; this.state = WORLD_STATE_RUNNING; } private void generateLevel() { float y = Platform.PLATFORM_HEIGHT / 2; float maxJumpHeight = Hero.hero_JUMP_VELOCITY * Hero.hero_JUMP_VELOCITY / (2 * -gravity.y); while (y < WORLD_HEIGHT - WORLD_WIDTH / 2) { int type = rand.nextFloat() > 0.8f ? Platform.PLATFORM_TYPE_MOVING : Platform.PLATFORM_TYPE_STATIC; float x = rand.nextFloat() * (WORLD_WIDTH - Platform.PLATFORM_WIDTH) + Platform.PLATFORM_WIDTH / 2; Platform platform = new Platform(type, x, y); platforms.add(platform); if (rand.nextFloat() > 0.9f && type != Platform.PLATFORM_TYPE_MOVING) { Spring spring = new Spring(platform.position.x, platform.position.y + Platform.PLATFORM_HEIGHT / 2 + Spring.SPRING_HEIGHT / 2); springs.add(spring); } if (rand.nextFloat() > 0.7f) { Ghost ghost = new Ghost(platform.position.x + rand.nextFloat(), platform.position.y + Ghost.GHOST_HEIGHT + rand.nextFloat() * 3); ghosts.add(ghost); } if (rand.nextFloat() > 0.6f) { Coin coin = new Coin(platform.position.x + rand.nextFloat(), platform.position.y + Coin.COIN_HEIGHT + rand.nextFloat() * 3); coins.add(coin); } y += (maxJumpHeight - 0.5f); y -= rand.nextFloat() * (maxJumpHeight / 3); } castle = new Castle(WORLD_WIDTH / 2, y); } public void update(float deltaTime, float accelX) { updatehero(deltaTime, accelX); updatePlatforms(deltaTime); updateGhosts(deltaTime); updateCoins(deltaTime); if (hero.state != Hero.hero_STATE_HIT) checkCollisions(); checkGameOver(); checkFall(); } private void updatehero(float deltaTime, float accelX) { if (hero.state != Hero.hero_STATE_HIT && hero.position.y <= 0.5f) hero.hitPlatform(); if (hero.state != Hero.hero_STATE_HIT) hero.velocity.x = -accelX / 10 * Hero.hero_MOVE_VELOCITY; hero.update(deltaTime); heightSoFar = Math.max(hero.position.y, heightSoFar); } private void updatePlatforms(float deltaTime) { int len = platforms.size(); for (int i = 0; i < len; i++) { Platform platform = platforms.get(i); platform.update(deltaTime); if (platform.state == Platform.PLATFORM_STATE_PULVERIZING && platform.stateTime > Platform.PLATFORM_PULVERIZE_TIME) { platforms.remove(platform); len = platforms.size(); } } } private void updateGhosts(float deltaTime) { int len = ghosts.size(); for (int i = 0; i < len; i++) { Ghost ghost = ghosts.get(i); ghost.update(deltaTime); if (ghost.state == Ghost.GHOST_STATE_DYING && ghost.stateTime > Ghost.GHOST_DYING_TIME) { ghosts.remove(ghost); len = ghosts.size(); } } } private void updateCoins(float deltaTime) { int len = coins.size(); for (int i = 0; i < len; i++) { Coin coin = coins.get(i); coin.update(deltaTime); } } private void checkCollisions() { checkPlatformCollisions(); checkGhostCollisions(); checkItemCollisions(); checkCastleCollisions(); } private void checkPlatformCollisions() { if (hero.velocity.y > 0) return; int len = platforms.size(); for (int i = 0; i < len; i++) { Platform platform = platforms.get(i); if (hero.position.y > platform.position.y) { if (OverlapTester .overlapRectangles(hero.bounds, platform.bounds)) { hero.hitPlatform(); listener.jump(); if (rand.nextFloat() > 0.5f) { platform.pulverize(); } break; } } } } private void checkGhostCollisions() { int len = ghosts.size(); for (int i = 0; i < len; i++) { Ghost ghost = ghosts.get(i); if (hero.position.y < ghost.position.y) { if (OverlapTester.overlapRectangles(ghost.bounds, hero.bounds)){ hero.hitGhost(); listener.hit(); } break; } else { if(hero.position.y > ghost.position.y) { if (OverlapTester.overlapRectangles(hero.bounds, ghost.bounds)){ hero.hitGhostJump(); listener.jump(); ghost.dying(); score += Ghost.GHOST_SCORE; } break; } } } } private void checkItemCollisions() { int len = coins.size(); for (int i = 0; i < len; i++) { Coin coin = coins.get(i); if (OverlapTester.overlapRectangles(hero.bounds, coin.bounds)) { coins.remove(coin); len = coins.size(); listener.coin(); score += Coin.COIN_SCORE; } } if (hero.velocity.y > 0) return; len = springs.size(); for (int i = 0; i < len; i++) { Spring spring = springs.get(i); if (hero.position.y > spring.position.y) { if (OverlapTester.overlapRectangles(hero.bounds, spring.bounds)) { hero.hitSpring(); listener.highJump(); } } } } private void checkCastleCollisions() { if (OverlapTester.overlapRectangles(castle.bounds, hero.bounds)) { state = WORLD_STATE_NEXT_LEVEL; } } private void checkFall() { if (heightSoFar - 7.5f > hero.position.y) { --lives; hero.hitSpring(); listener.highJump(); } } private void checkGameOver() { if (lives<=0) { state = WORLD_STATE_GAME_OVER; } } }

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  • Is it "right" to translate error messages?

    - by Iraklis
    This is somehow subjective depending on the target translation language, but bear with me for a sec. I have recently been involved in a translation project. The goal was to translate the strings of an MVC framework to the Greek language. 70% of the language strings of the framework where translated, however 30% where intentionally left out. The decision was that we will not translate error messages aimed towards the developer of the application. The reasoning behind this (in short) was: are aimed towards designers/programmers. Programmers ( and even designers :) ) should have a basic understanding of English, at least enough so they can search on it on Google if they do not know what it means. (racist?) are aimed towards the developer and in a perfect world should not be displayed to the end user of the application as they concern the inner workings of the web application itself. i.e "You must set the database name in your database config file." and perhaps most importantly, they make the life of the developer harder when he tries to get more information/help regarding the error. For example the above error yields 8 results in Google (in quotes), whereas its Greek translation yields exactly 0. I know that this depends on the popularity of the target translation language and the application itself. For example I'm guessing that there are is vast amount of documentation regarding German SAP error messages (i know, i know, SAP IS German, but you get the point), as opposed to Greek Error Messages documentation regarding random application X which has about 500 installations worldwide. So to summarize: When you develop language translation packs for your applications do you translate error messages? Do you only do for predominant languages like English/Spanish/German/French? Or do you live them intact? I'm not looking for the "right" or "correct" answer, I'm looking for a "best-practices" answer, or if this problem is defined in any "official" standard/policy that you have had experience with.

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  • LNK2019 Against CArray Add, GetAt, GetSize, all includes are present

    - by David J
    I'm having some issues trying to Compile a DLL, but I just can't see where this linking error is coming from. My LNK2019 is: Exports.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: int __thiscall CArray<struct HWND__ *,struct HWND__ *>::Add(struct HWND__ *)" (__imp_?Add@? $CArray@PAUHWND__@@PAU1@@@QAEHPAUHWND__@@@Z) referenced in function "int __stdcall _Disable(struct HWND__ *,long)" (?_Disable@@YGHPAUHWND__@@J@Z) Disable(...) is... static BOOL CALLBACK _Disable(HWND hwnd, LPARAM lParam) { CArray<HWND, HWND>* pArr = (CHWndArray*)lParam; if(::IsWindowEnabled(hwnd) && ::IsWindowVisible(hwnd)) { pArr->Add(hwnd); ::Enable(hwnd, FALSE); } } This is the first function in Exports.cpp; right above it is #include <afxtempl.h> I have the Windows 7.1 SDK installed (and have tried reinstalling both that and VS2010). The exact same project compiles perfectly fine on other machines, so it can't be the code itself.. I've spent countless errors researching, which led to desperate attempts of just changing random values in the solution file, including different Windows headers, etc. My last resort is getting to be just reinstalling the OS completely (assuming it's actually a problem with the Windows SDK being incorrect or something). Any suggestions at all would be a huge help. EDIT: I've added /showIncludes on the cpp giving issues, and I do see afxtempl.h being included. It's being included multiple times due to other headers including it, but it is there (and it is from the same directory every time): 1> Note: including file: C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\atlmfc\include\afxtempl.h

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