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  • Parse an XML file

    - by karan@dotnet
    The following code shows a simple method of parsing through an XML file/string. We can get the parent name, child name, attributes etc from the XML. The namespace System.Xml would be the only additional namespace that we would be using. string myXMl = "<Employees>" + "<Employee ID='1' Name='John Mayer'" + "Address='12th Street'" + "City='New York' Zip='10004'>" + "</Employee>" + "</Employees>"; XmlDocument xDoc = new XmlDocument();xDoc.LoadXml(myXMl);XmlNodeList xNodeList = xDoc.SelectNodes("Employees/child::node()");foreach (XmlNode xNode in xNodeList){ if (xNode.Name == "Employee") { string ID = xNode.Attributes["ID"].Value; //Outputs: 1 string Name = xNode.Attributes["Name"].Value;//Outputs: John Mayer string Address = xNode.Attributes["Address"].Value;//Outputs: 12th Street string City = xNode.Attributes["City"].Value;//Outputs: New York string Zip = xNode.Attributes["Zip"].Value; //Outputs: 10004 }} Lets look at another XML: string myXMl = "<root>" + "<parent1>..some data</parent1>" + "<parent2>" + "<Child1 id='1' name='Adam'>data1</Child1>" + "<Child2 id='2' name='Stanley'>data2</Child2>" + "</parent2>" + "</root>"; XmlDocument xDoc = new XmlDocument();xDoc.LoadXml(myXMl);XmlNodeList xNodeList = xDoc.SelectNodes("root/child::node()"); //Traverse the entire XML nodes.foreach (XmlNode xNode in xNodeList) { //Looks for any particular nodes if (xNode.Name == "parent1") { //some traversing.... } if (xNode.Name == "parent2") { //If the parent node has child nodes then //traverse the child nodes foreach (XmlNode xNode1 in xNode.ChildNodes) { string childNodeName = xNode1.Name; //Ouputs: Child1 string childNodeData = xNode1.InnerText; //Outputs: data1 //Loop through each attribute of the child nodes foreach (XmlAttribute xAtt in xNode1.Attributes) { string attrName = xAtt.Name; //Outputs: id string attrValue = xAtt.Value; //Outputs: 1 } } }}  

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  • Problem with DNS

    - by dotNET
    Hey, I bought a new website, and the company gived me another free domain name, so when I asked for the socond they created it and they told me to change the DNS to look like the first one. It's been a week waiting for it to propagate, today when I type the url I got this error message : If you are the web site owner, it is possible you have reached this page because: * The IP address has changed. * There has been a server misconfiguration. * The site may have been moved to a different server. If you are the owner of this website and were not expecting to see this page, please contact your hosting provider. When I try to add the second domain to my cpanel (Addon domain) I get also another error : The addon domain “abcdef.com” has been created. An account with that login already exists. Do you have any ideas about this problem. Thanks. EDIT I tried to flush the DNS with ipconfig /flushdns, but It's not changing anything.

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  • Asp.net Session State Revisited

    - by karan@dotnet
    Every now and then I see doubts and queries which I believe is the most discussed topic in the .net environment - Asp.net Sessions. So what really are they, why are they needed and what does browser and .net do with it. These and some of the other questions I hope to answer with this post. Because of the stateless nature of the HTTP protocol there is always a need of state management in a web application. There are many other ways to store data but I feel Session state is amongst the most powerful one. The ASP.NET session state is a technology that lets you store server-side, user-specific data. Our web applications can then use data to process request from the user for which the session state was instantiated. So when does a session is first created? When we start a asp.net application a non-expiring cookie is created and its called as ASP.NET_SessionId. Basically there are two methods for this depending upon how you configure this setting in your config file. The session ID can be a part of cookie as discussed above(called as ASP.NET_SessionId) or it is embedded in the browser’s URL. For the latter part we have to set cookie-less session in our web.config file. These Session ID’s are 120-bit random number that is represented by 20-character string. The cookie will be alive until you close your browser. If you browse from one app to another within the same domain, then both the apps will use the same session ID to track the session state. Why reuse? so that you don’t have to create a new session ID for each request. One can abandon one particular Session by calling Session.Abandon() which will stop the page processing and clear out the session data. A subsequent page request causes a brand new session object to be instantiated. So what happened to my cookie? Well the session cookie is still there even when one Session.Abandon() is called and another session object is created. The Session.Abandon() lets you clear out your session state without waiting for session timeout. By default, this time-out is a 20-minute sliding expiration. This expiration is refreshed every time that the user makes a request to the Web site and presents the session ID cookie. The Abandon method sets a flag in the session state object that indicates that the session state should be abandoned. If your app does not have global.asax then your session cookie will be killed at the end of each page request. So you need to have a global.asax file and Session_Start() handler to make sure that the session cookie will remain intact once its issued after the first page hit. The runtime invokes global.asax’s Session_OnEnd() when you call Session.Abandon() or the session times out. The session manager stores session data in HttpCache with sliding expiration where this timeout can be configured in the <sessionState> of web.config file. When the timeout is up the HttpCache will remove the session state object. Sometimes we want particular pages not to time out as compared to other pages in our applications. We can handle this in two ways. First, we can set a timer or may be a JavaScript function that refreshes the page after fixed intervals of time. The only thing being the page being cached locally and then the request is not made to the server so to prevent that you can add this to your page: <%@ OutputCache Location="None" VaryByParam="None" %> Second approach is to move your page into its own folder and then add a web.config to that folder to control the timeout. Also not all pages in your application will need access to session state. For those pages that do not, you can indicate that session state is not needed and prevent session data from being fetched from the store in requests to these pages. You can disable the session state at page level like this:<%@ Page EnableSessionState="False" %>tbc…

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  • Install wireless driver for an HP ProBook 4525s

    - by dotNET
    Hey, I need to install the wifi driver to ubuntu. so I downloaded the driver from hp website but the extension is .rpm, so I need to convert him to .deb so I can install it on ubuntu. The problem is I don't have internet connection on ubuntu to do this : sudo apt-get install alien how can convert the driver on windows for example, or how can I do download alien and place it under my usb to install it after booting on ubuntu. Thanks UPDATE: It's an HP ProBook 4525s with this two drivers : Pilote LAN sans fil Ralink Pilote LAN sans fil Broadcom http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?prodNameId=4173724&lang=en&cc=fr&prodTypeId=321957&prodSeriesId=4173615&taskId=135

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  • Install HP driver in ubuntu

    - by dotNET
    Hey, I need to install the wifi driver to ubuntu. so I downloaded the driver from hp website but the extension is .rpm, so I need to convert him to .deb so I can install it on ubuntu. The problem is I don't have internet connection on ubuntu to do this : sudo apt-get install alien how can convert the driver on windows for example, or how can I do download alien and place it under my usb to install it after booting on ubuntu. Thanks

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  • Confused about my future. Doubt about .Net or Java way.

    - by dotNET
    I'm very confused about choosing the programming langage to follow in the next step of my life. I'm right now so familiar with C++, VB.NET and PHP, but to jump to a higher level I must choose between JEE(JSP, Servlets, JSF, Spring, EJB, Struts, Hibernate,...) and .NET(ASP.NET, C#). Because I cant learn them at the same time. And you realize that, when I mentioned JEE a lot of things comes to the head. In my personnal experience I prefere the .NET, but Java seems to be a better choice. believe me, i'm not writing a subjective topic. I just want to know what must I follow to get succes in my life. The question here is : Is there any things that can be done with Java, and cannot be done with .NET. Is there any chances that I can follow the uncounted number of frameworks that are always in developpement. ... (also something not said) ?

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  • htmltext of TextArea in Flex 3 disappears when embedding fonts!

    - by Ali Syed
    hello, I have textArea which gets the text through user input in runtime. User input comes through Richtexteditor so it is html I save the html text from Richtexteditor to textArea's htmltext property. everything seems to be fine! till I try to embed fonts!! (I need to embed fonts because I apply a fade effect to the TextArea.) With embedded fonts the text simply disappears! could you help me out here please! i am really desperate! Ali M Syed @font-face { src:local("Arial"); fontFamily: ArialEmbedded; } . . . body.setStyle("fontFamily", "ArialEmbedded"); body is TextArea

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  • Unable to connect: incorrect log on parameters Crystal report

    - by Brave ali Khatri
    I am using windows 7 ,SQL Server 2000 and VS 2008 / Crystal Report XI. i am getting Below Error when click on GetReport Button. Logon failed. Details: ADO Error Code: 0x Source: Microsoft OLE DB Provider for SQL Server Description: Login failed for user 'sa'. SQL State: 42000 Native Error: Error in File C:\Users\bahadur\AppData\Local\Temp\Total_Sales_Comparision {C4649F80-D1F7-4AED-A4B1-0B8EF83996C6}.rpt: Unable to connect: incorrect log on parameters. Blockquote MY C# Code is below ConnectionInfo crConnectionInfo = new ConnectionInfo(); crConnectionInfo.ServerName = "BRAVEALI-PC"; crConnectionInfo.DatabaseName = "SCM_TEST"; crConnectionInfo.UserID = "sa"; crConnectionInfo.Password = "myDB Password"; ReportDocument report = new ReportDocument(); report.Load(@"D:\Project's\SCM Reports\Total_Sales_Comparision.rpt"); report.SetParameterValue("@invcm_date_from", Convert.ToDateTime (TextBox4.Text)); report.SetParameterValue("@invcm_date_to", Convert .ToDateTime(TextBox5.Text)); CrystalReportViewer1.ReportSource = report; //CrystalReportViewer1.RefreshReport(); Regards Brave Ali

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  • AJAX TabContainer containing user controls

    - by Ali
    Hi all, Wondering if someone here can help. I have an AJAX tabcontainer which has a number of tabs and each tab contains a user control. When I add a new item from one of the tabs, it is not reflected in the user control in another tab unless a postback occurs. (e.g. the first tab has a listview where I add a new record and the second has a simple form which contains a drop-down which I expect to contain value added from first tab). How can I make the tabcontainer to refresh its tabs from a usercontrol? Any help will be most appreciated. Thanks, Ali

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  • Replace or recode several different values by a single value in an Excel file

    - by Ali
    Hi all, I have an Excel worksheet which contains data in several columns. For a specific column, I will need Excel to replace all values between, say 10 to 15, by the value 1 and values between 16 and 20 by the value 2 and so forth. I know how to do it for a single value; ie: I can replace value 10 by 1, 11 by 1 and so on. But this will be a tedious exercise. Are there some lines of codes that can execute this task? Thanks for your help. regards, Ali

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  • Python script repeated auto start up.

    - by Ali
    I am designing a python web app, where people can have an email sent to them on a particular day. So a user puts in his emai and date in a form and it gets stored in my database. My script would then search through the database looking for all records of todays date, retrive the email, sends them out and deletes the entry from the table. Is it possible to have a setup, where the script starts up automatically at a give time, say 1 pm everyday, sends out the email and then quits? If I have a continuously running script, i might go over the CPU limit of my shared web hosting. Or is the effect negligible? Ali

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  • ASP.Net GridView Sorting

    - by Ali Shafai
    I have a grid view with AllowSorting set to true. I get an event onsorting when a sortable header is clicked on. the handler has a parameter "GridViewSortEventArgs e" which has a SortDirection property on it. regardless of how many times you click on the same heading, the SortDirection is always Ascending. I think I'm missing something, like a way to tell the grid "now you are sorted based on column one and in ascending order", so that next time the grid sees a click on the "column one" heading, it decides to go descending. any help appreciated. Cheers, Ali

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  • SQL query to return a data that both creteria exist in one table

    - by Ali
    Dear all, I have a TWO tables of data with following fields table1=(ITTAG,ITCODE,ITDESC,SUPcode) table2=(ACCODE,ACNAME,ROUTE,SALMAN) this my customer master tables that contains my customer data such as customer code, customer name and so on... Every Route has a supervisor(table1=supcode) and I need to know supervisor name in my table which both supervisor name and code exist in one table. table1 has contain all names separated by ITTAG. for example, supervisor name's ITTAG='K' also salesamn name's ITTAG='S'. ITTAG ITCODE ITDESC SUPCODE ------ ------ ------ ------- S JT JOHN TOMAS TF K WK VIKI KOO NULL NOW THIS IS A RESULT WHICH I WANT ACCODE ACNAME ROUTE SALEMANNAME SUPERVISORNAME ------- ------ ------ ------------ --------------- IMC1010 ABC HOTEL 01 JOHN TOMAS VIKI KOO i hope this this information is sufficient to get the query.. Thanks Ali

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  • apache htaccess rewrite rules make redirection loop

    - by Ali
    Hi guys, Have a very strange problem with Apache .htaccess URL Rewriting and Redirection. Here's my setup: I have a zend application with a single point of entry (index.php) directly under my apache document root (call this the "public" folder). I also have all other public files (images, js, css, etc.) under the public folder. Here, I also have a wordpress blog under the "blog" folder. There's an empty test folder too The Problem When I go to mydomain.com/blog, I get redirected to http://www.theredpin.com/blog (correctly), then to http://www.theredpin.com/blog/ (just with an extra / at end), finally to http://theredpin.com/blog/ -- and we're back where we started. The loop continues. What I don't understand is why would wordpress try to remove the www? I'm guessing it's wordpress because my empty test folder acts just fine! PLEASE HELP. I"M REALLY DESPERATE :( Thank you very much Other things that happen: When I go to mydomain.com, i correctly get redirected to www.mydomain.com When I go to www.mydomain.com, i correctly stay where I am When I go to www.mydomain.com/test or mydomain.com/test, behaviour is correct. Setup So my .htaccess file does the following: If there's no www., then add it and do a 301 redirect. Here's the code I use RewriteCond %{HTTP_HOST} ^mydomain.com [NC] RewriteRule ^(.*)$ http://www.mydomain.com/$1 [L,R=301] If the request is NOT for a resource (image, etc.), or the blog, then load zend application by rewriting to index.php RewriteRule !((^blog(/)?.*$)|(.(js|ico|gif|jpg|jpeg|png|css|cur|JPG|html|txt))$) index.php Thanks again for all your help!!! Ali

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  • JQuery Thickbox - Can't get it to display

    - by Ali
    Hi All, I am using JQuery for the first time today. I can't make it to work (It simple doesnt show up). I want to display inline content using Thickbox (Eventually I will be displaying a PDF in an iframe). I have included all the javascript and css files etc. and referenced them as in code below. <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="JQueryLearning._Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>Untitled Page</title> <script src="Scripts/thickbox.js" type="text/javascript"></script> <script src="Scripts/thickbox-compressed.js" type="text/javascript"></script> <script src="Scripts/jquery-1.4.2.min.js" type="text/javascript"></script> <link href="App_Themes/Theme/Css/thickbox.css" rel="stylesheet" type="text/css" /> </head> <body> <form id="form1" runat="server"> <div> <a href="#TB_inline?height=50&width=300&inlineId=hiddenModalContent" title="Simple Demo" class="thickbox">Show hidden content.</a> <div id="hiddenModalContent" style="display: none;"> <div style="text-align: center;"> Hello ThickBox!</div> </div> </div> </form> </body> </html> Am I missing something? Thanks, Ali

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  • Cannot cause $(this).find("a").click(); to fire using JQuery

    - by Ali
    Hi Everyone, I have a small question which should be very easy for the jquery experts out there. I am trying to follow http://aspdotnetcodebook.blogspot.com/2010/01/page-languagec-autoeventwireuptrue.html to be able to perform an action on gridview row double click. I can redirect to another page fine (as shown in the example) but I cannot cause the $(this).find("a").click(); to fire. Below is my GridView markup. <asp:GridView ID="gvCustomers" runat="server" DataSourceID="odsCustomers" CssClass="datagrid" GridLines="None" AutoGenerateColumns="False" DataKeyNames="Customer_ID" PageSize="3" AllowPaging="True" AllowSorting="True" OnRowCommand="gvCustomers_RowCommand" OnRowDataBound="gvCustomers_RowDataBound"> <Columns> <asp:BoundField DataField="Customer_ID" HeaderText="ID" ReadOnly="true" Visible="false" /> <asp:BoundField DataField="Customer_FirstName" HeaderText="First Name" ReadOnly="true" /> <asp:BoundField DataField="Customer_LastName" HeaderText="Last Name" ReadOnly="true" /> <asp:BoundField DataField="Customer_Email" HeaderText="Email" ReadOnly="true" /> <asp:BoundField DataField="Customer_Mobile" HeaderText="Mobile" ReadOnly="true" /> <asp:TemplateField> <ItemTemplate> <asp:LinkButton ID="lnkButton" runat="server" CommandName="showVehicles" CommandArgument='<%# Eval("Customer_ID") %>' ></asp:LinkButton> </ItemTemplate> </asp:TemplateField> </Columns> <EmptyDataTemplate> Sorry No Record Found. </EmptyDataTemplate> </asp:GridView> I just cant make it work as the author has suggested: /* or you could have a hidden LinkButton in the row (Text="" or not set) that you could trigger. Make sure you set the CommandName="Something" and CommandArgument="RecordId" */ on the OnCommand of linkButton, I have my server side method which I would like to fire. Any ideas will be most apprecited. Thanks, Ali

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  • how to combine widget webapp framework with SEO-friendly CSS and JS files

    - by Ali
    Hi guys, I'm writing a webapp using Zend framework and a homebrew widget system. Every widget has a controller and can choose to render one of many views if it chooses. This really helps us modularize and reconfigure and reuse the widgets anywhere on the site. The Problem is that the views of each widget contain their own JS and CSS code, which leads to very messy HTML code when the whole page is put together. You get pockets of style and script tags everywhere. This is bad for a lot of different reasons as I'm sure you know, but it has a profound effect on our SEO as well. Several solutions that I've been able to come up with: Separate the CSS and JS of every view of every widget into its own file - this has serious drawbacks for load times (many more resources have to be loaded separately) and it makes coding very difficult as now you have to have 3-4 files open just to edit a widget. combine the all the widget CSS into a single file (same with JS) - would also lead to a massive load when someone enters the site, mixes up the CSS and the JS for all widgets so it's harder to keep track of them, and other problems that I'm sure you can think of. Create a system that uses method 1 (separate CSS and JS for every widget), when delivering the page, stitches all CSS and JS together. This obviously needs more processing time and of course the creation of such a system, etc. My Question is what you guys think of these solutions or if there are pre-existing solutions that you know of (or any tech that might help) solve this problem. I really appreciate all of your thoughts and comments!! Thanks guys, Ali

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  • Scala programming language for beginners, is it a legend?

    - by ali
    Hi every one, I am Ali from Saudi Arabia. undoubtedly, Scala is one of the best programming language for any programmer to learn, but there is "good" problems that is faced especially by beginners, and what seems frustrating that these problems won't solve soon, so as a beginner and on behalf of beginners let me raise these "objective" questions: 1- why scala has no effective and stable development platform, in fact, it suffers many problems with Eclipse, Netbeat, and Intellij. 2- although I have looked for a clear,easy, and understandable explanation of how to get started with Scala, but fortunately, there was no article or guide that deserves to spend the time I have spent to read it. nobody could tell you clear steps that fit you as a beginner who wants to start his"HELLO WORLD" with Scala, while all other languages have its "HELLO WORLD" guides and books. thank you for your time, be sure that you read notes below. 1- I have no experience in programming language before. 2- don't tell me "not to begin with scala", simply, because I will do. 3- OS is windows vista home premium. 4- I hate excuses, such as Scala is new language......etc

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  • Creating a top-down spaceship

    - by Ali
    I'm creating a top-down 2D space game in LIBGDX for android. When spaceship is going forward it will look like this: when it goes upward I want to change it's direction with a nice animation so it seems like a real spaceship. A between frame would be like this: I have rendered the spaceship in different Z axis degrees from ship0 to ship90. Calculating rotation on XY plane wouldn't be so hard, but I don't know how to calculate the rotation on Z axis so I can choose the right sprite to use.

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  • Ancillary Objects: Separate Debug ELF Files For Solaris

    - by Ali Bahrami
    We introduced a new object ELF object type in Solaris 11 Update 1 called the Ancillary Object. This posting describes them, using material originally written during their development, the PSARC arc case, and the Solaris Linker and Libraries Manual. ELF objects contain allocable sections, which are mapped into memory at runtime, and non-allocable sections, which are present in the file for use by debuggers and observability tools, but which are not mapped or used at runtime. Typically, all of these sections exist within a single object file. Ancillary objects allow them to instead go into a separate file. There are different reasons given for wanting such a feature. One can debate whether the added complexity is worth the benefit, and in most cases it is not. However, one important case stands out — customers with very large 32-bit objects who are not ready or able to make the transition to 64-bits. We have customers who build extremely large 32-bit objects. Historically, the debug sections in these objects have used the stabs format, which is limited, but relatively compact. In recent years, the industry has transitioned to the powerful but verbose DWARF standard. In some cases, the size of these debug sections is large enough to push the total object file size past the fundamental 4GB limit for 32-bit ELF object files. The best, and ultimately only, solution to overly large objects is to transition to 64-bits. However, consider environments where: Hundreds of users may be executing the code on large shared systems. (32-bits use less memory and bus bandwidth, and on sparc runs just as fast as 64-bit code otherwise). Complex finely tuned code, where the original authors may no longer be available. Critical production code, that was expensive to qualify and bring online, and which is otherwise serving its intended purpose without issue. Users in these risk adverse and/or high scale categories have good reasons to push 32-bits objects to the limit before moving on. Ancillary objects offer these users a longer runway. Design The design of ancillary objects is intended to be simple, both to help human understanding when examining elfdump output, and to lower the bar for debuggers such as dbx to support them. The primary and ancillary objects have the same set of section headers, with the same names, in the same order (i.e. each section has the same index in both files). A single added section of type SHT_SUNW_ANCILLARY is added to both objects, containing information that allows a debugger to identify and validate both files relative to each other. Given one of these files, the ancillary section allows you to identify the other. Allocable sections go in the primary object, and non-allocable ones go into the ancillary object. A small set of non-allocable objects, notably the symbol table, are copied into both objects. As noted above, most sections are only written to one of the two objects, but both objects have the same section header array. The section header in the file that does not contain the section data is tagged with the SHF_SUNW_ABSENT section header flag to indicate its placeholder status. Compiler writers and others who produce objects can set the SUNW_SHF_PRIMARY section header flag to mark non-allocable sections that should go to the primary object rather than the ancillary. If you don't request an ancillary object, the Solaris ELF format is unchanged. Users who don't use ancillary objects do not pay for the feature. This is important, because they exist to serve a small subset of our users, and must not complicate the common case. If you do request an ancillary object, the runtime behavior of the primary object will be the same as that of a normal object. There is no added runtime cost. The primary and ancillary object together represent a logical single object. This is facilitated by the use of a single set of section headers. One can easily imagine a tool that can merge a primary and ancillary object into a single file, or the reverse. (Note that although this is an interesting intellectual exercise, we don't actually supply such a tool because there's little practical benefit above and beyond using ld to create the files). Among the benefits of this approach are: There is no need for per-file symbol tables to reflect the contents of each file. The same symbol table that would be produced for a standard object can be used. The section contents are identical in either case — there is no need to alter data to accommodate multiple files. It is very easy for a debugger to adapt to these new files, and the processing involved can be encapsulated in input/output routines. Most of the existing debugger implementation applies without modification. The limit of a 4GB 32-bit output object is now raised to 4GB of code, and 4GB of debug data. There is also the future possibility (not currently supported) to support multiple ancillary objects, each of which could contain up to 4GB of additional debug data. It must be noted however that the 32-bit DWARF debug format is itself inherently 32-bit limited, as it uses 32-bit offsets between debug sections, so the ability to employ multiple ancillary object files may not turn out to be useful. Using Ancillary Objects (From the Solaris Linker and Libraries Guide) By default, objects contain both allocable and non-allocable sections. Allocable sections are the sections that contain executable code and the data needed by that code at runtime. Non-allocable sections contain supplemental information that is not required to execute an object at runtime. These sections support the operation of debuggers and other observability tools. The non-allocable sections in an object are not loaded into memory at runtime by the operating system, and so, they have no impact on memory use or other aspects of runtime performance no matter their size. For convenience, both allocable and non-allocable sections are normally maintained in the same file. However, there are situations in which it can be useful to separate these sections. To reduce the size of objects in order to improve the speed at which they can be copied across wide area networks. To support fine grained debugging of highly optimized code requires considerable debug data. In modern systems, the debugging data can easily be larger than the code it describes. The size of a 32-bit object is limited to 4 Gbytes. In very large 32-bit objects, the debug data can cause this limit to be exceeded and prevent the creation of the object. To limit the exposure of internal implementation details. Traditionally, objects have been stripped of non-allocable sections in order to address these issues. Stripping is effective, but destroys data that might be needed later. The Solaris link-editor can instead write non-allocable sections to an ancillary object. This feature is enabled with the -z ancillary command line option. $ ld ... -z ancillary[=outfile] ...By default, the ancillary file is given the same name as the primary output object, with a .anc file extension. However, a different name can be provided by providing an outfile value to the -z ancillary option. When -z ancillary is specified, the link-editor performs the following actions. All allocable sections are written to the primary object. In addition, all non-allocable sections containing one or more input sections that have the SHF_SUNW_PRIMARY section header flag set are written to the primary object. All remaining non-allocable sections are written to the ancillary object. The following non-allocable sections are written to both the primary object and ancillary object. .shstrtab The section name string table. .symtab The full non-dynamic symbol table. .symtab_shndx The symbol table extended index section associated with .symtab. .strtab The non-dynamic string table associated with .symtab. .SUNW_ancillary Contains the information required to identify the primary and ancillary objects, and to identify the object being examined. The primary object and all ancillary objects contain the same array of sections headers. Each section has the same section index in every file. Although the primary and ancillary objects all define the same section headers, the data for most sections will be written to a single file as described above. If the data for a section is not present in a given file, the SHF_SUNW_ABSENT section header flag is set, and the sh_size field is 0. This organization makes it possible to acquire a full list of section headers, a complete symbol table, and a complete list of the primary and ancillary objects from either of the primary or ancillary objects. The following example illustrates the underlying implementation of ancillary objects. An ancillary object is created by adding the -z ancillary command line option to an otherwise normal compilation. The file utility shows that the result is an executable named a.out, and an associated ancillary object named a.out.anc. $ cat hello.c #include <stdio.h> int main(int argc, char **argv) { (void) printf("hello, world\n"); return (0); } $ cc -g -zancillary hello.c $ file a.out a.out.anc a.out: ELF 32-bit LSB executable 80386 Version 1 [FPU], dynamically linked, not stripped, ancillary object a.out.anc a.out.anc: ELF 32-bit LSB ancillary 80386 Version 1, primary object a.out $ ./a.out hello worldThe resulting primary object is an ordinary executable that can be executed in the usual manner. It is no different at runtime than an executable built without the use of ancillary objects, and then stripped of non-allocable content using the strip or mcs commands. As previously described, the primary object and ancillary objects contain the same section headers. To see how this works, it is helpful to use the elfdump utility to display these section headers and compare them. The following table shows the section header information for a selection of headers from the previous link-edit example. Index Section Name Type Primary Flags Ancillary Flags Primary Size Ancillary Size 13 .text PROGBITS ALLOC EXECINSTR ALLOC EXECINSTR SUNW_ABSENT 0x131 0 20 .data PROGBITS WRITE ALLOC WRITE ALLOC SUNW_ABSENT 0x4c 0 21 .symtab SYMTAB 0 0 0x450 0x450 22 .strtab STRTAB STRINGS STRINGS 0x1ad 0x1ad 24 .debug_info PROGBITS SUNW_ABSENT 0 0 0x1a7 28 .shstrtab STRTAB STRINGS STRINGS 0x118 0x118 29 .SUNW_ancillary SUNW_ancillary 0 0 0x30 0x30 The data for most sections is only present in one of the two files, and absent from the other file. The SHF_SUNW_ABSENT section header flag is set when the data is absent. The data for allocable sections needed at runtime are found in the primary object. The data for non-allocable sections used for debugging but not needed at runtime are placed in the ancillary file. A small set of non-allocable sections are fully present in both files. These are the .SUNW_ancillary section used to relate the primary and ancillary objects together, the section name string table .shstrtab, as well as the symbol table.symtab, and its associated string table .strtab. It is possible to strip the symbol table from the primary object. A debugger that encounters an object without a symbol table can use the .SUNW_ancillary section to locate the ancillary object, and access the symbol contained within. The primary object, and all associated ancillary objects, contain a .SUNW_ancillary section that allows all the objects to be identified and related together. $ elfdump -T SUNW_ancillary a.out a.out.anc a.out: Ancillary Section: .SUNW_ancillary index tag value [0] ANC_SUNW_CHECKSUM 0x8724 [1] ANC_SUNW_MEMBER 0x1 a.out [2] ANC_SUNW_CHECKSUM 0x8724 [3] ANC_SUNW_MEMBER 0x1a3 a.out.anc [4] ANC_SUNW_CHECKSUM 0xfbe2 [5] ANC_SUNW_NULL 0 a.out.anc: Ancillary Section: .SUNW_ancillary index tag value [0] ANC_SUNW_CHECKSUM 0xfbe2 [1] ANC_SUNW_MEMBER 0x1 a.out [2] ANC_SUNW_CHECKSUM 0x8724 [3] ANC_SUNW_MEMBER 0x1a3 a.out.anc [4] ANC_SUNW_CHECKSUM 0xfbe2 [5] ANC_SUNW_NULL 0 The ancillary sections for both objects contain the same number of elements, and are identical except for the first element. Each object, starting with the primary object, is introduced with a MEMBER element that gives the file name, followed by a CHECKSUM that identifies the object. In this example, the primary object is a.out, and has a checksum of 0x8724. The ancillary object is a.out.anc, and has a checksum of 0xfbe2. The first element in a .SUNW_ancillary section, preceding the MEMBER element for the primary object, is always a CHECKSUM element, containing the checksum for the file being examined. The presence of a .SUNW_ancillary section in an object indicates that the object has associated ancillary objects. The names of the primary and all associated ancillary objects can be obtained from the ancillary section from any one of the files. It is possible to determine which file is being examined from the larger set of files by comparing the first checksum value to the checksum of each member that follows. Debugger Access and Use of Ancillary Objects Debuggers and other observability tools must merge the information found in the primary and ancillary object files in order to build a complete view of the object. This is equivalent to processing the information from a single file. This merging is simplified by the primary object and ancillary objects containing the same section headers, and a single symbol table. The following steps can be used by a debugger to assemble the information contained in these files. Starting with the primary object, or any of the ancillary objects, locate the .SUNW_ancillary section. The presence of this section identifies the object as part of an ancillary group, contains information that can be used to obtain a complete list of the files and determine which of those files is the one currently being examined. Create a section header array in memory, using the section header array from the object being examined as an initial template. Open and read each file identified by the .SUNW_ancillary section in turn. For each file, fill in the in-memory section header array with the information for each section that does not have the SHF_SUNW_ABSENT flag set. The result will be a complete in-memory copy of the section headers with pointers to the data for all sections. Once this information has been acquired, the debugger can proceed as it would in the single file case, to access and control the running program. Note - The ELF definition of ancillary objects provides for a single primary object, and an arbitrary number of ancillary objects. At this time, the Oracle Solaris link-editor only produces a single ancillary object containing all non-allocable sections. This may change in the future. Debuggers and other observability tools should be written to handle the general case of multiple ancillary objects. ELF Implementation Details (From the Solaris Linker and Libraries Guide) To implement ancillary objects, it was necessary to extend the ELF format to add a new object type (ET_SUNW_ANCILLARY), a new section type (SHT_SUNW_ANCILLARY), and 2 new section header flags (SHF_SUNW_ABSENT, SHF_SUNW_PRIMARY). In this section, I will detail these changes, in the form of diffs to the Solaris Linker and Libraries manual. Part IV ELF Application Binary Interface Chapter 13: Object File Format Object File Format Edit Note: This existing section at the beginning of the chapter describes the ELF header. There's a table of object file types, which now includes the new ET_SUNW_ANCILLARY type. e_type Identifies the object file type, as listed in the following table. NameValueMeaning ET_NONE0No file type ET_REL1Relocatable file ET_EXEC2Executable file ET_DYN3Shared object file ET_CORE4Core file ET_LOSUNW0xfefeStart operating system specific range ET_SUNW_ANCILLARY0xfefeAncillary object file ET_HISUNW0xfefdEnd operating system specific range ET_LOPROC0xff00Start processor-specific range ET_HIPROC0xffffEnd processor-specific range Sections Edit Note: This overview section defines the section header structure, and provides a high level description of known sections. It was updated to define the new SHF_SUNW_ABSENT and SHF_SUNW_PRIMARY flags and the new SHT_SUNW_ANCILLARY section. ... sh_type Categorizes the section's contents and semantics. Section types and their descriptions are listed in Table 13-5. sh_flags Sections support 1-bit flags that describe miscellaneous attributes. Flag definitions are listed in Table 13-8. ... Table 13-5 ELF Section Types, sh_type NameValue . . . SHT_LOSUNW0x6fffffee SHT_SUNW_ancillary0x6fffffee . . . ... SHT_LOSUNW - SHT_HISUNW Values in this inclusive range are reserved for Oracle Solaris OS semantics. SHT_SUNW_ANCILLARY Present when a given object is part of a group of ancillary objects. Contains information required to identify all the files that make up the group. See Ancillary Section. ... Table 13-8 ELF Section Attribute Flags NameValue . . . SHF_MASKOS0x0ff00000 SHF_SUNW_NODISCARD0x00100000 SHF_SUNW_ABSENT0x00200000 SHF_SUNW_PRIMARY0x00400000 SHF_MASKPROC0xf0000000 . . . ... SHF_SUNW_ABSENT Indicates that the data for this section is not present in this file. When ancillary objects are created, the primary object and any ancillary objects, will all have the same section header array, to facilitate merging them to form a complete view of the object, and to allow them to use the same symbol tables. Each file contains a subset of the section data. The data for allocable sections is written to the primary object while the data for non-allocable sections is written to an ancillary file. The SHF_SUNW_ABSENT flag is used to indicate that the data for the section is not present in the object being examined. When the SHF_SUNW_ABSENT flag is set, the sh_size field of the section header must be 0. An application encountering an SHF_SUNW_ABSENT section can choose to ignore the section, or to search for the section data within one of the related ancillary files. SHF_SUNW_PRIMARY The default behavior when ancillary objects are created is to write all allocable sections to the primary object and all non-allocable sections to the ancillary objects. The SHF_SUNW_PRIMARY flag overrides this behavior. Any output section containing one more input section with the SHF_SUNW_PRIMARY flag set is written to the primary object without regard for its allocable status. ... Two members in the section header, sh_link, and sh_info, hold special information, depending on section type. Table 13-9 ELF sh_link and sh_info Interpretation sh_typesh_linksh_info . . . SHT_SUNW_ANCILLARY The section header index of the associated string table. 0 . . . Special Sections Edit Note: This section describes the sections used in Solaris ELF objects, using the types defined in the previous description of section types. It was updated to define the new .SUNW_ancillary (SHT_SUNW_ANCILLARY) section. Various sections hold program and control information. Sections in the following table are used by the system and have the indicated types and attributes. Table 13-10 ELF Special Sections NameTypeAttribute . . . .SUNW_ancillarySHT_SUNW_ancillaryNone . . . ... .SUNW_ancillary Present when a given object is part of a group of ancillary objects. Contains information required to identify all the files that make up the group. See Ancillary Section for details. ... Ancillary Section Edit Note: This new section provides the format reference describing the layout of a .SUNW_ancillary section and the meaning of the various tags. Note that these sections use the same tag/value concept used for dynamic and capabilities sections, and will be familiar to anyone used to working with ELF. In addition to the primary output object, the Solaris link-editor can produce one or more ancillary objects. Ancillary objects contain non-allocable sections that would normally be written to the primary object. When ancillary objects are produced, the primary object and all of the associated ancillary objects contain a SHT_SUNW_ancillary section, containing information that identifies these related objects. Given any one object from such a group, the ancillary section provides the information needed to identify and interpret the others. This section contains an array of the following structures. See sys/elf.h. typedef struct { Elf32_Word a_tag; union { Elf32_Word a_val; Elf32_Addr a_ptr; } a_un; } Elf32_Ancillary; typedef struct { Elf64_Xword a_tag; union { Elf64_Xword a_val; Elf64_Addr a_ptr; } a_un; } Elf64_Ancillary; For each object with this type, a_tag controls the interpretation of a_un. a_val These objects represent integer values with various interpretations. a_ptr These objects represent file offsets or addresses. The following ancillary tags exist. Table 13-NEW1 ELF Ancillary Array Tags NameValuea_un ANC_SUNW_NULL0Ignored ANC_SUNW_CHECKSUM1a_val ANC_SUNW_MEMBER2a_ptr ANC_SUNW_NULL Marks the end of the ancillary section. ANC_SUNW_CHECKSUM Provides the checksum for a file in the c_val element. When ANC_SUNW_CHECKSUM precedes the first instance of ANC_SUNW_MEMBER, it provides the checksum for the object from which the ancillary section is being read. When it follows an ANC_SUNW_MEMBER tag, it provides the checksum for that member. ANC_SUNW_MEMBER Specifies an object name. The a_ptr element contains the string table offset of a null-terminated string, that provides the file name. An ancillary section must always contain an ANC_SUNW_CHECKSUM before the first instance of ANC_SUNW_MEMBER, identifying the current object. Following that, there should be an ANC_SUNW_MEMBER for each object that makes up the complete set of objects. Each ANC_SUNW_MEMBER should be followed by an ANC_SUNW_CHECKSUM for that object. A typical ancillary section will therefore be structured as: TagMeaning ANC_SUNW_CHECKSUMChecksum of this object ANC_SUNW_MEMBERName of object #1 ANC_SUNW_CHECKSUMChecksum for object #1 . . . ANC_SUNW_MEMBERName of object N ANC_SUNW_CHECKSUMChecksum for object N ANC_SUNW_NULL An object can therefore identify itself by comparing the initial ANC_SUNW_CHECKSUM to each of the ones that follow, until it finds a match. Related Other Work The GNU developers have also encountered the need/desire to support separate debug information files, and use the solution detailed at http://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html. At the current time, the separate debug file is constructed by building the standard object first, and then copying the debug data out of it in a separate post processing step, Hence, it is limited to a total of 4GB of code and debug data, just as a single object file would be. They are aware of this, and I have seen online comments indicating that they may add direct support for generating these separate files to their link-editor. It is worth noting that the GNU objcopy utility is available on Solaris, and that the Studio dbx debugger is able to use these GNU style separate debug files even on Solaris. Although this is interesting in terms giving Linux users a familiar environment on Solaris, the 4GB limit means it is not an answer to the problem of very large 32-bit objects. We have also encountered issues with objcopy not understanding Solaris-specific ELF sections, when using this approach. The GNU community also has a current effort to adapt their DWARF debug sections in order to move them to separate files before passing the relocatable objects to the linker. The details of Project Fission can be found at http://gcc.gnu.org/wiki/DebugFission. The goal of this project appears to be to reduce the amount of data seen by the link-editor. The primary effort revolves around moving DWARF data to separate .dwo files so that the link-editor never encounters them. The details of modifying the DWARF data to be usable in this form are involved — please see the above URL for details.

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