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  • Get last n lines of a file with Python, similar to tail

    - by Armin Ronacher
    I'm writing a log file viewer for a web application and for that I want to paginate through the lines of the log file. The items in the file are line based with the newest item on the bottom. So I need a tail() method that can read n lines from the bottom and supports an offset. What I came up with looks like this: def tail(f, n, offset=0): """Reads a n lines from f with an offset of offset lines.""" avg_line_length = 74 to_read = n + offset while 1: try: f.seek(-(avg_line_length * to_read), 2) except IOError: # woops. apparently file is smaller than what we want # to step back, go to the beginning instead f.seek(0) pos = f.tell() lines = f.read().splitlines() if len(lines) >= to_read or pos == 0: return lines[-to_read:offset and -offset or None] avg_line_length *= 1.3 Is this a reasonable approach? What is the recommended way to tail log files with offsets?

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  • Experienced developer trying to get outsourcing contract with current client.

    - by Mike
    I work for a major bank as a contract software developer. I've been there a few months, and without exception this place has the worst software practices I've ever seen. The software my team makes has no formal testing, terrible code (not reusable, hard to read, etc), minimal documentation, no defined development process and an absolutely sickening amount of waste due to bureaucratic overhead. Part of my contract is to maintain a group of thousands of very poorly written batch jobs. When one of the jobs fails (read: crashes), it's a developers job to look at the source, figure out what's wrong, fix it, and check it in. There is no quality assurance process or auditing of the results whatsoever. Once the developer says "it works" a manager signs off and it goes into production. What's disturbing is that these jobs essentially grab market data and put it into a third-party risk management system, which provides the bank with critical intelligence. I've discovered the disturbing truth that this has been happening since the 90s and nobody really has evidence the system is getting the correct data! Without going into details, an issue arose on Friday that was so horrible I actually stormed out of the place. I was ready to quit, but I decided to just get out to calm my nerves and possibly go back Monday. I've been reflecting today on how to handle this. I have realized that, in probably less than 6 months, I could (with 2 other developers) remake a large component of this system. The new system would provide them with, as primary benefits, a maintainable codebase less prone to error and a solid QA framework. To do it properly I would have to be outside the bank, the internal bureaucracy is just too much. And moreover, I think a bank is fundamentally not a place that can make good software. This is my plan. Write a report explaining in depth all the problems with their current system Explain why their software practices fail and generate a tremendous amount of error and waste. Use this as the basis for claiming the project must be developed externally. Write a high level development plan, including what resources I will require Hand 1,2,3 to my manager, hopefully he passes it up the chain. Worst case he fires me, but this isn't so bad. Convinced Executive decides to award my company a contract for the new system I have 8 years experience as a software contractor and have delivered my share of successful software products, but all working in-house for small/medium sized companies. When I read this over, I think I have a dynamite plan. But since this is the first time doing something this bold so I have my doubts. My question is, is this a good idea? If you think not, please spare no detail.

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  • Good patterns for loose coupling in Java?

    - by Eye of Hell
    Hello. I'm new to java, and while reading documentation so far i can't find any good ways for programming with loose coupling between objects. For majority of languages i know (C++, C#, python, javascript) i can manage objects as having 'signals' (notification about something happens/something needed) and 'slots' (method that can be connected to signal and process notification/do some work). In all mentioned languages i can write something like this: Object1 = new Object1Class(); Object2 = new Object2Class(); Connect( Object1.ItemAdded, Object2.OnItemAdded ); Now if object1 calls/emits ItemAdded, the OnItemAdded method of Object2 will be called. Such loose coupling technique is often referred as 'delegates', 'signal-slot' or 'inversion of control'. Compared to interface pattern, technique mentioned don't need to group signals into some interfaces. Any object's methods can be connected to any delegate as long as signatures match ( C++Qt even extends this by allowing only partial signature match ). So i don't need to write additional interface code for each methods / groups of methods, provide default implementation for interface methods not used etc. And i can't see anything like this in Java :(. Maybe i'm looking a wrong way?

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  • Experiences with "language converters"?

    - by Friedrich
    I have read a few articles mentioning converters from one language to another. I'm a bit more than skeptical about the use of such kind of tools. Does anyone know or have experiences let's say about Visual Basic to Java or vs converters? Just one example to pick http://www.tvobjects.com/products/products.html, claims to be the "world leader" or so in that aspect, However if read this: http://dev.mysql.com/tech-resources/articles/active-grid.html There the author states: "The consensus of MySQL users is that automated conversion tools for MS Access do not work. For example, tools that translate existing Access applications to Java often result in 80% complete solutions where finishing the last 20% of the work takes longer than starting from scratch." Well we know we need 80% of the time to implement the first 80% functionality and another 80% of the time for the other 20 %.... So has anyone tried such tools and found them to be worthwhile?

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  • Python byte per byte XOR decryption

    - by neurino
    I have an XOR encypted file by a VB.net program using this function to scramble: Public Class Crypter ... 'This Will convert String to bytes, then call the other function. Public Function Crypt(ByVal Data As String) As String Return Encoding.Default.GetString(Crypt(Encoding.Default.GetBytes(Data))) End Function 'This calls XorCrypt giving Key converted to bytes Public Function Crypt(ByVal Data() As Byte) As Byte() Return XorCrypt(Data, Encoding.Default.GetBytes(Me.Key)) End Function 'Xor Encryption. Private Function XorCrypt(ByVal Data() As Byte, ByVal Key() As Byte) As Byte() Dim i As Integer If Key.Length <> 0 Then For i = 0 To Data.Length - 1 Data(i) = Data(i) Xor Key(i Mod Key.Length) Next End If Return Data End Function End Class and saved this way: Dim Crypter As New Cryptic(Key) 'open destination file Dim objWriter As New StreamWriter(fileName) 'write crypted content objWriter.Write(Crypter.Crypt(data)) Now I have to reopen the file with Python but I have troubles getting single bytes, this is the XOR function in python: def crypto(self, data): 'crypto(self, data) -> str' return ''.join(chr((ord(x) ^ ord(y)) % 256) \ for (x, y) in izip(data.decode('utf-8'), cycle(self.key)) I had to add the % 256 since sometimes x is 256 i.e. not a single byte. This thing of two bytes being passed does not break the decryption because the key keeps "paired" with the following data. The problem is some decrypted character in the conversion is wrong. These chars are all accented letters like à, è, ì but just a few of the overall accented letters. The others are all correctly restored. I guess it could be due to the 256 mod but without it I of course get a chr exception... Thanks for your support

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  • multiple calender in exchange web service

    - by user3559462
    i have multiple calender in my mailbox, i can retrieve only one calender that is main calnder folder using ews api 2.0, now i want whole list of calenders and appointments and meetings in that. like i have three calender one is main calnder 1.Calender(color-code:default) 2.Jorgen(color-code:pink) 3.Soren(color-code: yellow) i can retrieve all the values of main "Calnder", using the below code Folder inbox = Folder.Bind(service, WellKnownFolderName.Calendar); view.PropertySet = new PropertySet(BasePropertySet.IdOnly); // This results in a FindItem call to EWS. FindItemsResults<Item> results = inbox.FindItems(view); i = 1; m = results.TotalCount; if (results.Count() > 0) { foreach (var item in results) { PropertySet props = new PropertySet(AppointmentSchema.MimeContent,AppointmentSchema.ParentFolderId,AppointmentSchema.Id,AppointmentSchema.Categories,AppointmentSchema.Location); // This results in a GetItem call to EWS. var email = Appointment.Bind(service, item.Id, props); string iCalFileName = @"C:\export\appointment" +i ".ics"; // Save as .eml. using (FileStream fs = new FileStream(iCalFileName, FileMode.Create, FileAccess.Write)) { fs.Write(email.MimeContent.Content, 0, email.MimeContent.Content.Length); } i++; } now i want to get all the remaining calender schedules also, i am not able to get is Please help, need it urgently

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  • Unable to retrieve the complete description string of the event log record

    - by Santosh Pillai
    Hi All, I have an MFC application that reads and displays event log records using the ::ReadEventLog() API. The problem is with reading the "Description" message string of the event log record. The MFC application is unable to read the complete "Description" message string and displays only some part of it. However the Windows System Event Log Viewer reads and displays the complete "Description" message string correctly. I have ensured that my MFC application reads the entire "Description" message string by retrieving all the strings as provided by the "NumStrings" and "StringOffset" member variables of the EVENTLOGRECORD structure and merging all of them. Also as mentioned in MSDN my application loads the Source Name specific message library file (whose path is specified in the registry at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Application[SourceName]) that further contains additional message string information and merges it with the earlier read strings. I am still unable to get the entire "Description" message string. Please provide any help towards resolving the issue. Regards, Santosh.

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  • How to make a good programming interview?

    - by luckyluke
    I am doing interviews with from time to time to recruit some not bad people. And I really think I AM NOT doing to correct Job. I work in a company when We have to do a lot o DB programming, .NET programming, Java programming, so we need people who are open minded and not focused on a particular tech. Afterall language is a notation, You have to understand what is going under the hood. I ask people about their project, ask them some coding questions (believe me a SQL question involving a CROSS JOIN is hard), let them write some code, ask them about oo design, ask them how they update their knowledge, and stay up to date, do they have FUN when they code (at least sometimes). Hell I even give them a coding solution for home (3 hours max) to see how they think and code. And yet my hit rate at hiring junior member (those who live over the initial 3 months) is just about 33%. So my question, how do YOU make the good interviews, because I think my hit rate is to low? Do you have any best-practices(should be at least 60-70%)? p.s. And i noticed that: the best programmers are lazy, but motivated, just being lazy is not enough:) But people who write the best code are attentive to details:)

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  • Asp.net Custom user control button. How to stop multiple clicks by user.

    - by Laurence Burke
    I am trying to modify an open source Forum called YetAnotherForum.net in the project they have a custom user control called Yaf:ThemeButton. Now its rendered as an anchor with an onclick method in this code ThemeButton.cs using System; using System.Web.UI; using System.Web.UI.WebControls; namespace YAF.Controls { /// <summary> /// The theme button. /// </summary> public class ThemeButton : BaseControl, IPostBackEventHandler { /// <summary> /// The _click event. /// </summary> protected static object _clickEvent = new object(); /// <summary> /// The _command event. /// </summary> protected static object _commandEvent = new object(); /// <summary> /// The _attribute collection. /// </summary> protected AttributeCollection _attributeCollection; /// <summary> /// The _localized label. /// </summary> protected LocalizedLabel _localizedLabel = new LocalizedLabel(); /// <summary> /// The _theme image. /// </summary> protected ThemeImage _themeImage = new ThemeImage(); /// <summary> /// Initializes a new instance of the <see cref="ThemeButton"/> class. /// </summary> public ThemeButton() : base() { Load += new EventHandler(ThemeButton_Load); this._attributeCollection = new AttributeCollection(ViewState); } /// <summary> /// ThemePage for the optional button image /// </summary> public string ImageThemePage { get { return this._themeImage.ThemePage; } set { this._themeImage.ThemePage = value; } } /// <summary> /// ThemeTag for the optional button image /// </summary> public string ImageThemeTag { get { return this._themeImage.ThemeTag; } set { this._themeImage.ThemeTag = value; } } /// <summary> /// Localized Page for the optional button text /// </summary> public string TextLocalizedPage { get { return this._localizedLabel.LocalizedPage; } set { this._localizedLabel.LocalizedPage = value; } } /// <summary> /// Localized Tag for the optional button text /// </summary> public string TextLocalizedTag { get { return this._localizedLabel.LocalizedTag; } set { this._localizedLabel.LocalizedTag = value; } } /// <summary> /// Defaults to "yafcssbutton" /// </summary> public string CssClass { get { return (ViewState["CssClass"] != null) ? ViewState["CssClass"] as string : "yafcssbutton"; } set { ViewState["CssClass"] = value; } } /// <summary> /// Setting the link property will make this control non-postback. /// </summary> public string NavigateUrl { get { return (ViewState["NavigateUrl"] != null) ? ViewState["NavigateUrl"] as string : string.Empty; } set { ViewState["NavigateUrl"] = value; } } /// <summary> /// Localized Page for the optional link description (title) /// </summary> public string TitleLocalizedPage { get { return (ViewState["TitleLocalizedPage"] != null) ? ViewState["TitleLocalizedPage"] as string : "BUTTON"; } set { ViewState["TitleLocalizedPage"] = value; } } /// <summary> /// Localized Tag for the optional link description (title) /// </summary> public string TitleLocalizedTag { get { return (ViewState["TitleLocalizedTag"] != null) ? ViewState["TitleLocalizedTag"] as string : string.Empty; } set { ViewState["TitleLocalizedTag"] = value; } } /// <summary> /// Non-localized Title for optional link description /// </summary> public string TitleNonLocalized { get { return (ViewState["TitleNonLocalized"] != null) ? ViewState["TitleNonLocalized"] as string : string.Empty; } set { ViewState["TitleNonLocalized"] = value; } } /// <summary> /// Gets Attributes. /// </summary> public AttributeCollection Attributes { get { return this._attributeCollection; } } /// <summary> /// Gets or sets CommandName. /// </summary> public string CommandName { get { if (ViewState["commandName"] != null) { return ViewState["commandName"].ToString(); } return null; } set { ViewState["commandName"] = value; } } /// <summary> /// Gets or sets CommandArgument. /// </summary> public string CommandArgument { get { if (ViewState["commandArgument"] != null) { return ViewState["commandArgument"].ToString(); } return null; } set { ViewState["commandArgument"] = value; } } #region IPostBackEventHandler Members /// <summary> /// The i post back event handler. raise post back event. /// </summary> /// <param name="eventArgument"> /// The event argument. /// </param> void IPostBackEventHandler.RaisePostBackEvent(string eventArgument) { OnCommand(new CommandEventArgs(CommandName, CommandArgument)); OnClick(EventArgs.Empty); } #endregion /// <summary> /// Setup the controls before render /// </summary> /// <param name="sender"> /// </param> /// <param name="e"> /// </param> private void ThemeButton_Load(object sender, EventArgs e) { if (!String.IsNullOrEmpty(this._themeImage.ThemeTag)) { // add the theme image... Controls.Add(this._themeImage); } // render the text if available if (!String.IsNullOrEmpty(this._localizedLabel.LocalizedTag)) { Controls.Add(this._localizedLabel); } } /// <summary> /// The render. /// </summary> /// <param name="output"> /// The output. /// </param> protected override void Render(HtmlTextWriter output) { // get the title... string title = GetLocalizedTitle(); output.BeginRender(); output.WriteBeginTag("a"); output.WriteAttribute("id", ClientID); if (!String.IsNullOrEmpty(CssClass)) { output.WriteAttribute("class", CssClass); } if (!String.IsNullOrEmpty(title)) { output.WriteAttribute("title", title); } else if (!String.IsNullOrEmpty(TitleNonLocalized)) { output.WriteAttribute("title", TitleNonLocalized); } if (!String.IsNullOrEmpty(NavigateUrl)) { output.WriteAttribute("href", NavigateUrl.Replace("&", "&amp;")); } else { // string.Format("javascript:__doPostBack('{0}','{1}')",this.ClientID,"")); output.WriteAttribute("href", Page.ClientScript.GetPostBackClientHyperlink(this, string.Empty)); } bool wroteOnClick = false; // handle additional attributes (if any) if (this._attributeCollection.Count > 0) { // add attributes... foreach (string key in this._attributeCollection.Keys) { // get the attribute and write it... if (key.ToLower() == "onclick") { // special handling... add to it... output.WriteAttribute(key, string.Format("{0};{1}", this._attributeCollection[key], "this.blur();this.display='none';")); wroteOnClick = true; } else if (key.ToLower().StartsWith("on") || key.ToLower() == "rel" || key.ToLower() == "target") { // only write javascript attributes -- and a few other attributes... output.WriteAttribute(key, this._attributeCollection[key]); } } } // IE fix if (!wroteOnClick) { output.WriteAttribute("onclick", "this.blur();this.style.display='none';"); } output.Write(HtmlTextWriter.TagRightChar); output.WriteBeginTag("span"); output.Write(HtmlTextWriter.TagRightChar); // render the optional controls (if any) base.Render(output); output.WriteEndTag("span"); output.WriteEndTag("a"); output.EndRender(); } /// <summary> /// The get localized title. /// </summary> /// <returns> /// The get localized title. /// </returns> protected string GetLocalizedTitle() { if (Site != null && Site.DesignMode == true && !String.IsNullOrEmpty(TitleLocalizedTag)) { return String.Format("[TITLE:{0}]", TitleLocalizedTag); } else if (!String.IsNullOrEmpty(TitleLocalizedPage) && !String.IsNullOrEmpty(TitleLocalizedTag)) { return PageContext.Localization.GetText(TitleLocalizedPage, TitleLocalizedTag); } else if (!String.IsNullOrEmpty(TitleLocalizedTag)) { return PageContext.Localization.GetText(TitleLocalizedTag); } return null; } /// <summary> /// The on click. /// </summary> /// <param name="e"> /// The e. /// </param> protected virtual void OnClick(EventArgs e) { var handler = (EventHandler) Events[_clickEvent]; if (handler != null) { handler(this, e); } } /// <summary> /// The on command. /// </summary> /// <param name="e"> /// The e. /// </param> protected virtual void OnCommand(CommandEventArgs e) { var handler = (CommandEventHandler) Events[_commandEvent]; if (handler != null) { handler(this, e); } RaiseBubbleEvent(this, e); } /// <summary> /// The click. /// </summary> public event EventHandler Click { add { Events.AddHandler(_clickEvent, value); } remove { Events.RemoveHandler(_clickEvent, value); } } /// <summary> /// The command. /// </summary> public event CommandEventHandler Command { add { Events.AddHandler(_commandEvent, value); } remove { Events.RemoveHandler(_commandEvent, value); } } } } now that is just cs file its handled like this in the .ascx page of the actual website <YAF:ThemeButton ID="Save" runat="server" CssClass="yafcssbigbutton leftItem" TextLocalizedTag="SAVE" OnClick="Save_Click" /> now it is given an OnClick codebehind function that does some serverside function like this protected void Save_Click(object sender, EventArgs e) { //some serverside code here } now I have a problem with the user being able to click multiple times and firing that serverside function multiple times. I have added in the code as of right now an extra onclick="this.style.display='none'" in the .cs code but that is a ugly fix I was wondering if anyone would have a better idea of disabling the ThemeButton clientside?? pls any feedback if I need to give more examples or further explain the question thanks.

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  • Serializing MDI Winforms for persistency

    - by Serge
    Hello, basically my project is an MDI Winform application where a user can customize the interface by adding various controls and changing the layout. I would like to be able to save the state of the application for each user. I have done quite a bit of searching and found these: http://stackoverflow.com/questions/2076259/how-to-auto-save-and-auto-load-all-properties-in-winforms-c http://stackoverflow.com/questions/1669522/c-save-winform-or-controls-to-file Basically from what I understand, the best approach is to serialize the data to XML, however winform controls are not serializable, so I would have use surrogate classes: http://www.codeproject.com/KB/dotnet/Surrogate_Serialization.aspx Now, do I need to write a surrogate class for each of my controls? I would need to write some sort of a recursive algorithm to save all my controls, what is the best approach to do accomplish that? How would I then restore all the windows, should I use the memento design pattern for that? If I want to implement multiple users later, should I use Nhibernate to store all the object data in a database? I am still trying to wrap my head around the problem and if anyone has any experience or advice I would greatly appreciate it, thanks.

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  • [Java] Flood fill using a stack

    - by dafero
    Hello to everyone :), I am using the recursive Flood fill algorithm in Java to fill some areas of a image. With very small images it works fine, but when de image becomes larger the JVM gives me a Stack Over Flow Error. That's the reason why I have to reimplement the method using a Flood Fill with my own stack. (I read that's the best way to do it in these kind of cases) Can anyone explain me how to code it? (if you don't have the code at hand, with the pseudo-code of the algorithm will be fine) I've read a lot in the Internet but I haven't understood it very well. Thanks!

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  • Can't get max_post_size php variable set in lunar pages.

    - by Behrooz Karjooravary
    I need to increase max post size and upload size for php to use the audio module of drupal. I read this has to be set in php.ini. However I don't think I have access to that file in lunar pages. I also read it can also be set in .htaccess. However it doesn't change anything. I tried: php_value post_max_size "40M" php_value upload_max_filesize "40M" i also tried: php_value post_max_size 40M php_value upload_max_filesize 40M On localhost it says restart webserver. But this is not possible on shared host. Could that be the problem?

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  • Processing incoming email

    - by Mike Schots
    How do I programmatically read an incoming email with .NET. I need a method to take the content of email message (in this case XML) on a POP server and read it into my application. Ideally this could be solved by: .NET code that I can run as a background task on my webserver to process the email. A service that can POST the contents of the email to my webserver. Although I'm open to other options. EDIT: Copied from the "non-answer": Currently, we're looking at using the email accounts our hosting company provides. Our own mail server could potentially be an option, but its something the we'd need to contact the host about.

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  • java: how to get a string representation of a compressed byte array ?

    - by Guillaume
    I want to put some compressed data into a remote repository. To put data on this repository I can only use a method that take the name of the resource and its content as a String. (like data.txt + "hello world"). The repository is moking a filesystem but is not, so I can not use File directly. I want to be able to do the following: client send to server a file 'data.txt' server compress 'data.txt' into a compressed file 'data.zip' server send a string representation of data.zip to the repository repository store data.zip client download from repository data.zip and his able to open it with its favorite zip tool The problem arise at step 3 when I try to get a string representation of my compressed file. Here is a sample class, using the zip*stream and that emulate the repository showcasing my problem. The created zip file is working, but after its 'serialization' it's get corrupted. (the sample class use jakarta commons.io ) Many thanks for your help. package zip; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.zip.ZipEntry; import java.util.zip.ZipInputStream; import java.util.zip.ZipOutputStream; import org.apache.commons.io.FileUtils; /** * Date: May 19, 2010 - 6:13:07 PM * * @author Guillaume AME. */ public class ZipMe { public static void addOrUpdate(File zipFile, File ... files) throws IOException { File tempFile = File.createTempFile(zipFile.getName(), null); // delete it, otherwise you cannot rename your existing zip to it. tempFile.delete(); boolean renameOk = zipFile.renameTo(tempFile); if (!renameOk) { throw new RuntimeException("could not rename the file " + zipFile.getAbsolutePath() + " to " + tempFile.getAbsolutePath()); } byte[] buf = new byte[1024]; ZipInputStream zin = new ZipInputStream(new FileInputStream(tempFile)); ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFile)); ZipEntry entry = zin.getNextEntry(); while (entry != null) { String name = entry.getName(); boolean notInFiles = true; for (File f : files) { if (f.getName().equals(name)) { notInFiles = false; break; } } if (notInFiles) { // Add ZIP entry to output stream. out.putNextEntry(new ZipEntry(name)); // Transfer bytes from the ZIP file to the output file int len; while ((len = zin.read(buf)) > 0) { out.write(buf, 0, len); } } entry = zin.getNextEntry(); } // Close the streams zin.close(); // Compress the files if (files != null) { for (File file : files) { InputStream in = new FileInputStream(file); // Add ZIP entry to output stream. out.putNextEntry(new ZipEntry(file.getName())); // Transfer bytes from the file to the ZIP file int len; while ((len = in.read(buf)) > 0) { out.write(buf, 0, len); } // Complete the entry out.closeEntry(); in.close(); } // Complete the ZIP file } tempFile.delete(); out.close(); } public static void main(String[] args) throws IOException { final String zipArchivePath = "c:/temp/archive.zip"; final String tempFilePath = "c:/temp/data.txt"; final String resultZipFile = "c:/temp/resultingArchive.zip"; File zipArchive = new File(zipArchivePath); FileUtils.touch(zipArchive); File tempFile = new File(tempFilePath); FileUtils.writeStringToFile(tempFile, "hello world"); addOrUpdate(zipArchive, tempFile); //archive.zip exists and contains a compressed data.txt that can be read using winrar //now simulate writing of the zip into a in memory cache String archiveText = FileUtils.readFileToString(zipArchive); FileUtils.writeStringToFile(new File(resultZipFile), archiveText); //resultingArchive.zip exists, contains a compressed data.txt, but it can not //be read using winrar: CRC failed in data.txt. The file is corrupt } }

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  • AES decryption in Java - IvParameterSpec to big

    - by user1277269
    Im going to decrypt a plaintext with two keys. As you see in the picture were have one encrypted file wich contains KEY1(128 bytes),KEYIV(128 bytes),key2(128bytes) wich is not used in this case then we have the ciphertext. The error I get here is "Exception in thread "main" java.security.InvalidAlgorithmParameterException: Wrong IV length: must be 16 bytes long. but it is 64 bytes." Picture: http://i264.photobucket.com/albums/ii200/XeniuM05/bg_zps0a523659.png public class AES { public static void main(String[] args) throws Exception { byte[] encKey1 = new byte[128]; byte[] EncIV = new byte[256]; byte[] UnEncIV = new byte[128]; byte[] unCrypKey = new byte[128]; byte[] unCrypText = new byte[1424]; File f = new File("C://ftp//ciphertext.enc"); FileInputStream fis = new FileInputStream(F); byte[] EncText = new byte[(int) f.length()]; fis.read(encKey1); fis.read(EncIV); fis.read(EncText); EncIV = Arrays.copyOfRange(EncIV, 128, 256); EncText = Arrays.copyOfRange(EncText, 384, EncText.length); System.out.println(EncText.length); KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType()); char[] password = "lab1StorePass".toCharArray(); java.io.FileInputStream fos = new java.io.FileInputStream( "C://ftp//lab1Store"); ks.load(fos, password); char[] passwordkey1 = "lab1KeyPass".toCharArray(); PrivateKey Lab1EncKey = (PrivateKey) ks.getKey("lab1EncKeys", passwordkey1); Cipher rsaDec = Cipher.getInstance("RSA"); // set cipher to RSA decryption rsaDec.init(Cipher.DECRYPT_MODE, Lab1EncKey); // initalize cipher ti lab1key unCrypKey = rsaDec.doFinal(encKey1); // Decryps first key UnEncIV = rsaDec.doFinal(EncIV); //decryps encive byte array to undecrypted bytearray---- OBS! Error this is 64 BYTES big, we want 16? System.out.println("lab1key "+ unCrypKey +" IV " + UnEncIV); //-------CIPHERTEXT decryption--------- Cipher AESDec = Cipher.getInstance("AES/CBC/PKCS5Padding"); //---------convert decrypted bytearrays to acctual keys SecretKeySpec unCrypKey1 = new SecretKeySpec(unCrypKey, "AES"); IvParameterSpec ivSpec = new IvParameterSpec(UnEncIV); AESDec.init(Cipher.DECRYPT_MODE, unCrypKey1, ivSpec ); unCrypText = AESDec.doFinal(EncText); // Convert decrypted cipher bytearray to string String deCryptedString = new String(unCrypKey); System.out.println(deCryptedString); }

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  • How to implement Xml Serialization with inherited classes in C#

    - by liorafar
    I have two classes : base class name Component and inheritd class named DBComponent [Serializable] public class Component { private string name = string.Empty; private string description = string.Empty; } [Serializable] public class DBComponent : Component { private List<string> spFiles = new List<string>(); // Storage Procedure Files [XmlArrayItem("SPFile", typeof(string))] [XmlArray("SPFiles")] public List<string> SPFiles { get { return spFiles; } set { spFiles = value; } } public DBComponent(string name, string description) : base(name, description) { } } [Serializable] public class ComponentsCollection { private static ComponentsCollection instance = null; private List<Component> components = new List<Component>(); public List<Component> Components { get { return components; } set { components = value; } } public static ComponentsCollection GetInstance() { if (ccuInstance == null) { lock (lockObject) { if (instance == null) PopulateComponents(); } } return instance; } private static void PopulateComponents() { instance = new CCUniverse(); XmlSerializer xs = new XmlSerializer(instance.GetType()); instance = xs.Deserialize(XmlReader.Create("Components.xml")) as ComponentsCollection; } } } I want read\write from a Xml file. I know that I need to implement the Serialization for DBComponent class otherwise it will not read it.But i cannot find any simple article for that. all the articles that I found were too complex for this simple scenario. The Xml file looks like this: <?xml version="1.0" encoding="utf-8" ?> <ComponentsCollection> <Components> <DBComponent Name="Tenant Historical Database" Description="Tenant Historical Database"> <SPFiles> <SPFile>Setup\TenantHistoricalSP.sql</SPFile> </SPFiles> </DBComponent> <Component Name="Agent" Description="Desktop Agent" /> </Components> </ComponentsCollection> Can someone please give me a simple example of how to read this kind of xml file and what should be implemented ? Thanks Lior

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  • .NET 4: Process.Start using credentials returns empty output

    - by alexey
    I run an external program from ASP.NET: var process = new Process(); var startInfo = process.StartInfo; startInfo.FileName = filePath; startInfo.Arguments = arguments; startInfo.UseShellExecute = false; startInfo.RedirectStandardOutput = true; startInfo.RedirectStandardError = true; process.Start(); process.WaitForExit(); Console.Write("Output: {0}", process.StandardOutput.ReadToEnd()); Console.Write("Error Output: {0}", process.StandardError.ReadToEnd()); Everything works fine with this code: the external program is executed and process.StandardOutput.ReadToEnd() returns the correct output. But after I add these two lines before process.Start() (to run the program in the context of another user account): startInfo.UserName = userName; startInfo.Password = securePassword; The program is not executed and process.StandardOutput.ReadToEnd() returns an empty string. No exceptions are thrown. userName and securePassword are correct (in case of incorrect credentials an exception is thrown). How to run the program in the context of another user account?

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  • Dealing with UIImagePickerController to minimize memory useage

    - by Gordon Fontenot
    So, I have read the SO post on UIImagePickerController, UIImage, Memory and More, and I read the post on Memory Leak Problems with UIImagePickerController in iPhone. I have VASTLY increased my memory efficiency between these 2 posts, and I thank the OPs and the people that provided the answers. I just had a question on the answer provided in the Memory Leak question, which was (essentially): only have one instance of the controller throughout the programs runtime What would be the best way to go about this without causing memory leaks? Right now I am initiating it and releasing it on every use from within the view, and I am seeing exactly what the answer describes (Memory warnings and a crash after about 20 uses). Should I initiate the UIImagePickerController when I need it, but use a seperate class unrelated to the view to control it? How should I deal with releasing the controller if I do it this way?

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  • Generate number sequences with LINQ

    - by tanascius
    I try to write a LINQ statement which returns me all possible combinations of numbers (I need this for a test and I was inspired by this article of Eric Lippert). The method's prototype I call looks like: IEnumerable<Collection<int>> AllSequences( int start, int end, int size ); The rules are: all returned collections have a length of size number values within a collection have to increase every number between start and end should be used So calling the AllSequences( 1, 5, 3 ) should result in 10 collections, each of size 3: 1 2 3 1 2 4 1 2 5 1 3 4 1 3 5 1 4 5 2 3 4 2 3 5 2 4 5 3 4 5 Now, somehow I'd really like to see a pure LINQ solution. I am able to write a non LINQ solution on my own, so please put no effort into a solution without LINQ. My tries so far ended at a point where I have to join a number with the result of a recursive call of my method - something like: return from i in Enumerable.Range( start, end - size + 1 ) select BuildCollection(i, AllSequences( i, end, size -1)); But I can't manage it to implement BuildCollection() on a LINQ base - or even skip this method call. Can you help me here?

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  • WCF Callbacks often break

    - by cdecker
    I'm having quite some trouble with the WCF Callback mechanism. They sometimes work but most of the time they don't. I have a really simple Interface for the callbacks to implement: public interface IClientCallback { [OperationContract] void Log(string content); } I then implmenent that interface with a class on the client: [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession)] [ServiceContract] internal sealed class ClientCallback : IClientCallback { public void Log(String content){ Console.Write(content); } } And on the client I finally connect to the server: NetTcpBinding tcpbinding = new NetTcpBinding(SecurityMode.Transport); EndpointAddress endpoint = new EndpointAddress("net.tcp://127.0.0.1:1337"); ClientCallback callback= new ClientCallback(); DuplexChannelFactory<IServer> factory = new DuplexChannelFactory<IServer>(callback,tcpbinding, endpoint); factory.Open(); _connection = factory.CreateChannel(); ((ICommunicationObject)_connection).Faulted += new EventHandler(RecreateChannel); try { ((ICommunicationObject)_connection).Open(); } catch (CommunicationException ce) { Console.Write(ce.ToString()); } To invoke the callback I use the following: OperationContext.Current.GetCallbackChannel().Log("Hello World!"); But it just hangs there, and after a while the client complains about timeouts. Is there a simple solution as to why?

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  • Is there a disassembler + debugger for java (ala OllyDbg / SoftICE for assembler)?

    - by Ran Biron
    Is there a utility similar to OllyDbg / SoftICE for java? I.e. execute class (from jar / with class path) and, without source code, show the disassembly of the intermediate code with ability to step through / step over / search for references / edit specific intermediate code in memory / apply edit to file... If not, is it even possible to write something like this (assuming we're willing to live without hotspot for the debug duration)? Edit: I'm not talking about JAD or JD or Cavaj. These are fine decompilers, but I don't want a decompiler for several reasons, most notable is that their output is incorrect (at best, sometimes just plain wrong). I'm not looking for a magical "compiled bytes to java code" - I want to see the actual bytes that are about to be executed. Also, I'd like the ability to change those bytes (just like in an assembly debugger) and, hopefully, write the changed part back to the class file. Edit2: I know javap exists - but it does only one way (and without any sort of analysis). Example (code taken from the vmspec documentation): From java code, we use "javac" to compile this: void setIt(int value) { i = value; } int getIt() { return i; } to a java .class file. Using javap -c I can get this output: Method void setIt(int) 0 aload_0 1 iload_1 2 putfield #4 5 return Method int getIt() 0 aload_0 1 getfield #4 4 ireturn This is OK for the disassembly part (not really good without analysis - "field #4 is Example.i"), but I can't find the two other "tools": A debugger that goes over the instructions themselves (with stack, memory dumps, etc), allowing me to examine the actual code and environment. A way to reverse the process - edit the disassembled code and recreate the .class file (with the edited code).

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  • double_t in C99

    - by yCalleecharan
    Hi, I just read that C99 has double_t which should be at least wide as double. Does this imply that it gives more precision digits after the decimal place? More than the usual 15 digits for double?. Secondly, how to use it: Is only including #include enough? I read that one has to set the FLT_EVAL_METHOD to 2 for long double. How to do this? As I work with numerical methods, I would like maximum precision without using an arbitrary precision library. Thanks a lot...

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  • python duration of a file object in an argument list

    - by msw
    In the pickle module documentation there is a snippet of example code: reader = pickle.load(open('save.p', 'rb')) which upon first read looked like it would allocate a system file descriptor, read its contents and then "leak" the open descriptor for there isn't any handle accessible to call close() upon. This got me wondering if there was any hidden magic that takes care of this case. Diving into the source, I found in Modules/_fileio.c that file descriptors are closed by the fileio_dealloc() destructor which led to the real question. What is the duration of the file object returned by the example code above? After that statement executes does the object indeed become unreferenced and therefore will the fd be subject to a real close(2) call at some future garbage collection sweep? If so, is the example line good practice, or should one not count on the fd being released thus risking kernel per-process descriptor table exhaustion?

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  • iphone download several files

    - by Floo
    hi all !  In my app i need to download several plist.  to download a plist i use the NSURLconnection  in my code i use an UIAlertView with a UIActivityIndicator then when the download is finished i add a button to the alert to dismiss it.  To download the plist i use somewhere in my code an NSURL set to the adresse where the plist is, next i set a NSURLRequest with the url cache policy and a timeout interval.  Then i set my NSMutableData to the NSURL connection with a NSURLRequest.  In the delegate didReceiveData: i append data to my mutable data object, in the didFailWithError: i handle error. And finaly in the connectionDidFinishLoading  i serialize my data to a plist so i can write to file my plist, and release my alertview.  My problem is : how can i do if i have sevetal file to download because the connectionDidFinishLoading is called each time my NSURLConnection is finished but i want to release my UiAlert when everything is finished. But when the first plist is downloaded my code in the connectionDidFinishLoading will fire.  here is my code :  in the view did load :  // set the UiAlert in the view did load  NSURL *theUrl = [NSURL URLWithString:@"http://adress.com/plist/myPlist.plist"]; NSURLRequest *theRequest = [NSURLRequest requestWithURL:theUrl cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0]; self.plistConnection = [[ NSURLConnection alloc] initwithRequest:theRequest delegate:self startImmediatly:YES]; //plistConnection is a NSURLConnection - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {  [incomingPListData appendData:data]; } -(void)connection:(NSURLConnection *)connectionDidFailWithError:(NSError *)error { // handle error here  } -(void)connectionDidFinisloading:(NSURLConnection *) connection {  NSPropertyListFormat format; NSString *serialErrorString;  NSData *plist = [NSPropertyListSerialisation propertyListFromData:incomingPlistData mutabilityOption:NSPropertyListImmutable format:&format errorDescription:&serialErrorString]; if (serialErrorString) {//error} else { // create path and write plist to path} // change message and title of the alert so if i want todownload an another file  where do i put the request the connection and how can i tell the didFinishLoading to fire code when all my file are downloaded.  thanks to all

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  • Android: Streaming audio over TCP Sockets

    - by user299988
    Hi, For my app, I need to record audio from MIC on an Android phone, and send it over TCP to the other android phone, where it needs to be played. I am using AudioRecord and AudioTrack class. This works great with a file - write audio to the file using DataOutputStream, and read from it using DataInputStream. However, if I obtain the same stream from a socket instead of a File, and try writing to it, I get an exception. I am at a loss to understand what could possibly be going wrong. Any help would be greatly appreciated. EDIT: The problem is same even if I try with larger buffer sizes (65535 bytes, 160000 bytes). This is the code: Recorder: int bufferSize = AudioRecord.getMinBufferSize(11025, , AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT); AudioRecord recordInstance = new AudioRecord(MediaRecorder.AudioSource.MIC, 11025, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize); byte[] tempBuffer = new byte[bufferSize]; recordInstance.startRecording(); while (/*isRecording*/) { bufferRead = recordInstance.read(tempBuffer, 0, bufferSize); dataOutputStreamInstance.write(tempBuffer); } The DataOutputStream above is obtained as: BufferedOutputStream buff = new BufferedOutputStream(out1); //out1 is the socket's outputStream DataOutputStream dataOutputStreamInstance = new DataOutputStream (buff); Could you please have a look, and let me know what is it that I could be doing wrong here? Thanks,

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