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• C-x C-c not working in Emacs 23.1

  - by mahesh

  I am using Emacs 23.1 with Cygwin but when I try to exit by pressing C-x C-c it says C-x C-g is undefined and I am not able to exit.

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• How to make a Shell Script create a copy and terminate itself?

  - by ricedragon

  So far I used trap " call function" 2 fucntion { ./test.sh exit } but it never reaches the exit line and a whole bunch of process piles up any one got any idea? I tried & (bg) but i need to be able to keep doing it , the bg only allows me to do it once The point of it is when i type ctrl C it should terminate the original test.sh but it should also call itself before terminating hence create a new process.

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• Batch file to check the size and print the outout

  - by OraR

  I am trying to make a batch file and that would check the size of f1.txt file and if the size is 1118 then no changes will be displayed if not the file has been changed. @ECHO OFF set maxbytesize=1118 set "filename=f1.txt" for %%A in (%filename%) do echo.Size of "%%A" is %%~zA bytes if %%~zA==%maxbytesize% ( echo "No Changes" pause >nul exit ) echo "Changes" pause >nul exit Please can someone let me know any possible guidelines for the above. Thanks.

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• How LINQ to Object statements work

  - by rajbk

  This post goes into detail as to now LINQ statements work when querying a collection of objects. This topic assumes you have an understanding of how generics, delegates, implicitly typed variables, lambda expressions, object/collection initializers, extension methods and the yield statement work. I would also recommend you read my previous two posts: Using Delegates in C# Part 1 Using Delegates in C# Part 2 We will start by writing some methods to filter a collection of data. Assume we have an Employee class like so: 1: public class Employee { 2: public int ID { get; set;} 3: public string FirstName { get; set;} 4: public string LastName {get; set;} 5: public string Country { get; set; } 6: } and a collection of employees like so: 1: var employees = new List<Employee> { 2: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 3: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 4: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 5: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" }, 6: }; Filtering We wish to  find all employees that have an even ID. We could start off by writing a method that takes in a list of employees and returns a filtered list of employees with an even ID. 1: static List<Employee> GetEmployeesWithEvenID(List<Employee> employees) { 2: var filteredEmployees = new List<Employee>(); 3: foreach (Employee emp in employees) { 4: if (emp.ID % 2 == 0) { 5: filteredEmployees.Add(emp); 6: } 7: } 8: return filteredEmployees; 9: } The method can be rewritten to return an IEnumerable<Employee> using the yield return keyword. 1: static IEnumerable<Employee> GetEmployeesWithEvenID(IEnumerable<Employee> employees) { 2: foreach (Employee emp in employees) { 3: if (emp.ID % 2 == 0) { 4: yield return emp; 5: } 6: } 7: } We put these together in a console application. 1: using System; 2: using System.Collections.Generic; 3: //No System.Linq 4:  5: public class Program 6: { 7: [STAThread] 8: static void Main(string[] args) 9: { 10: var employees = new List<Employee> { 11: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 12: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 13: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 14: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" }, 15: }; 16: var filteredEmployees = GetEmployeesWithEvenID(employees); 17:  18: foreach (Employee emp in filteredEmployees) { 19: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 20: emp.ID, emp.FirstName, emp.LastName, emp.Country); 21: } 22:  23: Console.ReadLine(); 24: } 25: 26: static IEnumerable<Employee> GetEmployeesWithEvenID(IEnumerable<Employee> employees) { 27: foreach (Employee emp in employees) { 28: if (emp.ID % 2 == 0) { 29: yield return emp; 30: } 31: } 32: } 33: } 34:  35: public class Employee { 36: public int ID { get; set;} 37: public string FirstName { get; set;} 38: public string LastName {get; set;} 39: public string Country { get; set; } 40: } Output: ID 2 First_Name Jim Last_Name Ashlock Country UK ID 4 First_Name Jill Last_Name Anderson Country AUS Our filtering method is too specific. Let us change it so that it is capable of doing different types of filtering and lets give our method the name Where ;-) We will add another parameter to our Where method. This additional parameter will be a delegate with the following declaration. public delegate bool Filter(Employee emp); The idea is that the delegate parameter in our Where method will point to a method that contains the logic to do our filtering thereby freeing our Where method from any dependency. The method is shown below: 1: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 2: foreach (Employee emp in employees) { 3: if (filter(emp)) { 4: yield return emp; 5: } 6: } 7: } Making the change to our app, we create a new instance of the Filter delegate on line 14 with a target set to the method EmployeeHasEvenId. Running the code will produce the same output. 1: public delegate bool Filter(Employee emp); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: var employees = new List<Employee> { 9: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 10: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 11: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 12: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 13: }; 14: var filterDelegate = new Filter(EmployeeHasEvenId); 15: var filteredEmployees = Where(employees, filterDelegate); 16:  17: foreach (Employee emp in filteredEmployees) { 18: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 19: emp.ID, emp.FirstName, emp.LastName, emp.Country); 20: } 21: Console.ReadLine(); 22: } 23: 24: static bool EmployeeHasEvenId(Employee emp) { 25: return emp.ID % 2 == 0; 26: } 27: 28: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 29: foreach (Employee emp in employees) { 30: if (filter(emp)) { 31: yield return emp; 32: } 33: } 34: } 35: } 36:  37: public class Employee { 38: public int ID { get; set;} 39: public string FirstName { get; set;} 40: public string LastName {get; set;} 41: public string Country { get; set; } 42: } Lets use lambda expressions to inline the contents of the EmployeeHasEvenId method in place of the method. The next code snippet shows this change (see line 15).  For brevity, the Employee class declaration has been skipped. 1: public delegate bool Filter(Employee emp); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: var employees = new List<Employee> { 9: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 10: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 11: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 12: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 13: }; 14: var filterDelegate = new Filter(EmployeeHasEvenId); 15: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 16:  17: foreach (Employee emp in filteredEmployees) { 18: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 19: emp.ID, emp.FirstName, emp.LastName, emp.Country); 20: } 21: Console.ReadLine(); 22: } 23: 24: static bool EmployeeHasEvenId(Employee emp) { 25: return emp.ID % 2 == 0; 26: } 27: 28: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 29: foreach (Employee emp in employees) { 30: if (filter(emp)) { 31: yield return emp; 32: } 33: } 34: } 35: } 36:  The output displays the same two employees.  Our Where method is too restricted since it works with a collection of Employees only. Lets change it so that it works with any IEnumerable<T>. In addition, you may recall from my previous post,  that .NET 3.5 comes with a lot of predefined delegates including public delegate TResult Func<T, TResult>(T arg); We will get rid of our Filter delegate and use the one above instead. We apply these two changes to our code. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: var employees = new List<Employee> { 7: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 8: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 9: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 10: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 11: }; 12:  13: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 14:  15: foreach (Employee emp in filteredEmployees) { 16: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 17: emp.ID, emp.FirstName, emp.LastName, emp.Country); 18: } 19: Console.ReadLine(); 20: } 21: 22: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 23: foreach (var x in source) { 24: if (filter(x)) { 25: yield return x; 26: } 27: } 28: } 29: } We have successfully implemented a way to filter any IEnumerable<T> based on a  filter criteria. Projection Now lets enumerate on the items in the IEnumerable<Employee> we got from the Where method and copy them into a new IEnumerable<EmployeeFormatted>. The EmployeeFormatted class will only have a FullName and ID property. 1: public class EmployeeFormatted { 2: public int ID { get; set; } 3: public string FullName {get; set;} 4: } We could “project” our existing IEnumerable<Employee> into a new collection of IEnumerable<EmployeeFormatted> with the help of a new method. We will call this method Select ;-) 1: static IEnumerable<EmployeeFormatted> Select(IEnumerable<Employee> employees) { 2: foreach (var emp in employees) { 3: yield return new EmployeeFormatted { 4: ID = emp.ID, 5: FullName = emp.LastName + ", " + emp.FirstName 6: }; 7: } 8: } The changes are applied to our app. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: var employees = new List<Employee> { 7: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 8: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 9: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 10: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 11: }; 12:  13: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 14: var formattedEmployees = Select(filteredEmployees); 15:  16: foreach (EmployeeFormatted emp in formattedEmployees) { 17: Console.WriteLine("ID {0} Full_Name {1}", 18: emp.ID, emp.FullName); 19: } 20: Console.ReadLine(); 21: } 22:  23: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 24: foreach (var x in source) { 25: if (filter(x)) { 26: yield return x; 27: } 28: } 29: } 30: 31: static IEnumerable<EmployeeFormatted> Select(IEnumerable<Employee> employees) { 32: foreach (var emp in employees) { 33: yield return new EmployeeFormatted { 34: ID = emp.ID, 35: FullName = emp.LastName + ", " + emp.FirstName 36: }; 37: } 38: } 39: } 40:  41: public class Employee { 42: public int ID { get; set;} 43: public string FirstName { get; set;} 44: public string LastName {get; set;} 45: public string Country { get; set; } 46: } 47:  48: public class EmployeeFormatted { 49: public int ID { get; set; } 50: public string FullName {get; set;} 51: } Output: ID 2 Full_Name Ashlock, Jim ID 4 Full_Name Anderson, Jill We have successfully selected employees who have an even ID and then shaped our data with the help of the Select method so that the final result is an IEnumerable<EmployeeFormatted>.  Lets make our Select method more generic so that the user is given the freedom to shape what the output would look like. We can do this, like before, with lambda expressions. Our Select method is changed to accept a delegate as shown below. TSource will be the type of data that comes in and TResult will be the type the user chooses (shape of data) as returned from the selector delegate. 1:  2: static IEnumerable<TResult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) { 3: foreach (var x in source) { 4: yield return selector(x); 5: } 6: } We see the new changes to our app. On line 15, we use lambda expression to specify the shape of the data. In this case the shape will be of type EmployeeFormatted. 1:  2: public class Program 3: { 4: [STAThread] 5: static void Main(string[] args) 6: { 7: var employees = new List<Employee> { 8: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 9: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 10: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 11: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 12: }; 13:  14: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 15: var formattedEmployees = Select(filteredEmployees, (emp) => 16: new EmployeeFormatted { 17: ID = emp.ID, 18: FullName = emp.LastName + ", " + emp.FirstName 19: }); 20:  21: foreach (EmployeeFormatted emp in formattedEmployees) { 22: Console.WriteLine("ID {0} Full_Name {1}", 23: emp.ID, emp.FullName); 24: } 25: Console.ReadLine(); 26: } 27: 28: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 29: foreach (var x in source) { 30: if (filter(x)) { 31: yield return x; 32: } 33: } 34: } 35: 36: static IEnumerable<TResult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) { 37: foreach (var x in source) { 38: yield return selector(x); 39: } 40: } 41: } The code outputs the same result as before. On line 14 we filter our data and on line 15 we project our data. What if we wanted to be more expressive and concise? We could combine both line 14 and 15 into one line as shown below. Assuming you had to perform several operations like this on our collection, you would end up with some very unreadable code! 1: var formattedEmployees = Select(Where(employees, emp => emp.ID % 2 == 0), (emp) => 2: new EmployeeFormatted { 3: ID = emp.ID, 4: FullName = emp.LastName + ", " + emp.FirstName 5: }); A cleaner way to write this would be to give the appearance that the Select and Where methods were part of the IEnumerable<T>. This is exactly what extension methods give us. Extension methods have to be defined in a static class. Let us make the Select and Where extension methods on IEnumerable<T> 1: public static class MyExtensionMethods { 2: static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 3: foreach (var x in source) { 4: if (filter(x)) { 5: yield return x; 6: } 7: } 8: } 9: 10: static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 11: foreach (var x in source) { 12: yield return selector(x); 13: } 14: } 15: } The creation of the extension method makes the syntax much cleaner as shown below. We can write as many extension methods as we want and keep on chaining them using this technique. 1: var formattedEmployees = employees 2: .Where(emp => emp.ID % 2 == 0) 3: .Select (emp => new EmployeeFormatted { ID = emp.ID, FullName = emp.LastName + ", " + emp.FirstName }); Making these changes and running our code produces the same result. 1: using System; 2: using System.Collections.Generic; 3:  4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: var employees = new List<Employee> { 10: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 11: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 12: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 13: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 14: }; 15:  16: var formattedEmployees = employees 17: .Where(emp => emp.ID % 2 == 0) 18: .Select (emp => 19: new EmployeeFormatted { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: } 23: ); 24:  25: foreach (EmployeeFormatted emp in formattedEmployees) { 26: Console.WriteLine("ID {0} Full_Name {1}", 27: emp.ID, emp.FullName); 28: } 29: Console.ReadLine(); 30: } 31: } 32:  33: public static class MyExtensionMethods { 34: static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 35: foreach (var x in source) { 36: if (filter(x)) { 37: yield return x; 38: } 39: } 40: } 41: 42: static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 43: foreach (var x in source) { 44: yield return selector(x); 45: } 46: } 47: } 48:  49: public class Employee { 50: public int ID { get; set;} 51: public string FirstName { get; set;} 52: public string LastName {get; set;} 53: public string Country { get; set; } 54: } 55:  56: public class EmployeeFormatted { 57: public int ID { get; set; } 58: public string FullName {get; set;} 59: } Let’s change our code to return a collection of anonymous types and get rid of the EmployeeFormatted type. We see that the code produces the same output. 1: using System; 2: using System.Collections.Generic; 3:  4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: var employees = new List<Employee> { 10: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 11: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 12: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 13: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 14: }; 15:  16: var formattedEmployees = employees 17: .Where(emp => emp.ID % 2 == 0) 18: .Select (emp => 19: new { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: } 23: ); 24:  25: foreach (var emp in formattedEmployees) { 26: Console.WriteLine("ID {0} Full_Name {1}", 27: emp.ID, emp.FullName); 28: } 29: Console.ReadLine(); 30: } 31: } 32:  33: public static class MyExtensionMethods { 34: public static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 35: foreach (var x in source) { 36: if (filter(x)) { 37: yield return x; 38: } 39: } 40: } 41: 42: public static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 43: foreach (var x in source) { 44: yield return selector(x); 45: } 46: } 47: } 48:  49: public class Employee { 50: public int ID { get; set;} 51: public string FirstName { get; set;} 52: public string LastName {get; set;} 53: public string Country { get; set; } 54: } To be more expressive, C# allows us to write our extension method calls as a query expression. Line 16 can be rewritten a query expression like so: 1: var formattedEmployees = from emp in employees 2: where emp.ID % 2 == 0 3: select new { 4: ID = emp.ID, 5: FullName = emp.LastName + ", " + emp.FirstName 6: }; When the compiler encounters an expression like the above, it simply rewrites it as calls to our extension methods.  So far we have been using our extension methods. The System.Linq namespace contains several extension methods for objects that implement the IEnumerable<T>. You can see a listing of these methods in the Enumerable class in the System.Linq namespace. Let’s get rid of our extension methods (which I purposefully wrote to be of the same signature as the ones in the Enumerable class) and use the ones provided in the Enumerable class. Our final code is shown below: 1: using System; 2: using System.Collections.Generic; 3: using System.Linq; //Added 4:  5: public class Program 6: { 7: [STAThread] 8: static void Main(string[] args) 9: { 10: var employees = new List<Employee> { 11: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 12: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 13: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 14: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 15: }; 16:  17: var formattedEmployees = from emp in employees 18: where emp.ID % 2 == 0 19: select new { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: }; 23:  24: foreach (var emp in formattedEmployees) { 25: Console.WriteLine("ID {0} Full_Name {1}", 26: emp.ID, emp.FullName); 27: } 28: Console.ReadLine(); 29: } 30: } 31:  32: public class Employee { 33: public int ID { get; set;} 34: public string FirstName { get; set;} 35: public string LastName {get; set;} 36: public string Country { get; set; } 37: } 38:  39: public class EmployeeFormatted { 40: public int ID { get; set; } 41: public string FullName {get; set;} 42: } This post has shown you a basic overview of LINQ to Objects work by showning you how an expression is converted to a sequence of calls to extension methods when working directly with objects. It gets more interesting when working with LINQ to SQL where an expression tree is constructed – an in memory data representation of the expression. The C# compiler compiles these expressions into code that builds an expression tree at runtime. The provider can then traverse the expression tree and generate the appropriate SQL query. You can read more about expression trees in this MSDN article.

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• Scripting with the Sun ZFS Storage 7000 Appliance

  - by Geoff Ongley

  The Sun ZFS Storage 7000 appliance has a user friendly and easy to understand graphical web based interface we call the "BUI" or "Browser User Interface".This interface is very useful for many tasks, but in some cases a script (or workflow) may be more appropriate, such as:Repetitive tasksTasks which work on (or obtain information about) a large number of shares or usersTasks which are triggered by an alert threshold (workflows)Tasks where you want a only very basic input, but a consistent output (workflows)The appliance scripting language is based on ECMAscript 3 (close to javascript). I'm not going to cover ECMAscript 3 in great depth (I'm far from an expert here), but I would like to show you some neat things you can do with the appliance, to get you started based on what I have found from my own playing around.I'm making the assumption you have some sort of programming background, and understand variables, arrays, functions to some extent - but of course if something is not clear, please let me know so I can fix it up or clarify it.Variable Declarations and ArraysVariablesECMAScript is a dynamically and weakly typed language. If you don't know what that means, google is your friend - but at a high level it means we can just declare variables with no specific type and on the fly.For example, I can declare a variable and use it straight away in the middle of my code, for example:projects=list();Which makes projects an array of values that are returned from the list(); function (which is usable in most contexts). With this kind of variable, I can do things like:projects.length (this property on array tells you how many objects are in it, good for for loops etc). Alternatively, I could say:projects=3;and now projects is just a simple number.Should we declare variables like this so loosely? In my opinion, the answer is no - I feel it is a better practice to declare variables you are going to use, before you use them - and given them an initial value. You can do so as follows:var myVariable=0;To demonstrate the ability to just randomly assign and change the type of variables, you can create a simple script at the cli as follows (bold for input):fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("Number of projects is: %d\n",projects.length);("." to run)> projects=152;("." to run)> printf("Value of the projects variable as an integer is now: %d\n",projects);("." to run)> .Number of projects is: 7Value of the projects variable as an integer is now: 152You can also confirm this behaviour by checking the typeof variable we are dealing with:fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> projects=152;("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> .var projects is of type objectvar projects is of type numberArraysSo you likely noticed that we have already touched on arrays, as the list(); (in the shares context) stored an array into the 'projects' variable.But what if you want to declare your own array? Easy! This is very similar to Java and other languages, we just instantiate a brand new "Array" object using the keyword new:var myArray = new Array();will create an array called "myArray".A quick example:fishy10:> script("." to run)> testArray = new Array();("." to run)> testArray[0]="This";("." to run)> testArray[1]="is";("." to run)> testArray[2]="just";("." to run)> testArray[3]="a";("." to run)> testArray[4]="test";("." to run)> for (i=0; i < testArray.length; i++)("." to run)> {("." to run)>    printf("Array element %d is %s\n",i,testArray[i]);("." to run)> }("." to run)> .Array element 0 is ThisArray element 1 is isArray element 2 is justArray element 3 is aArray element 4 is testWorking With LoopsFor LoopFor loops are very similar to those you will see in C, java and several other languages. One of the key differences here is, as you were made aware earlier, we can be a bit more sloppy with our variable declarations.The general way you would likely use a for loop is as follows:for (variable; test-case; modifier for variable){}For example, you may wish to declare a variable i as 0; and a MAX_ITERATIONS variable to determine how many times this loop should repeat:var i=0;var MAX_ITERATIONS=10;And then, use this variable to be tested against some case existing (has i reached MAX_ITERATIONS? - if not, increment i using i++);for (i=0; i < MAX_ITERATIONS; i++){ // some work to do}So lets run something like this on the appliance:fishy10:> script("." to run)> var i=0;("." to run)> var MAX_ITERATIONS=10;("." to run)> for (i=0; i < MAX_ITERATIONS; i++)("." to run)> {("." to run)>    printf("The number is %d\n",i);("." to run)> }("." to run)> .The number is 0The number is 1The number is 2The number is 3The number is 4The number is 5The number is 6The number is 7The number is 8The number is 9While LoopWhile loops again are very similar to other languages, we loop "while" a condition is met. For example:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n",counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Counter is 10Loop has ended and Counter is 11So what do we notice here? Something has actually gone wrong - counter will technically be 11 once the loop completes... Why is this?Well, if we have a loop like this, where the 'while' condition that will end the loop may be set based on some other condition(s) existing (such as the counter has reached 10) - we must ensure that we  terminate this iteration of the loop when the condition is met - otherwise the rest of the code will be followed which may not be desirable. In other words, like in other languages, we will only ever check the loop condition once we are ready to perform the next iteration, so any other code after we set "isTen" to be true, will still be executed as we can see it was above.We can avoid this by adding a break into our loop once we know we have set the condition - this will stop the rest of the logic being processed in this iteration (and as such, counter will not be incremented). So lets try that again:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>            break;("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n", counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Loop has ended and Counter is 10Much better!Methods to Obtain and Manipulate DataGet MethodThe get method allows you to get simple properties from an object, for example a quota from a user. The syntax is fairly simple:var myVariable=get('property');An example of where you may wish to use this, is when you are getting a bunch of information about a user (such as quota information when in a shares context):var users=list();for(k=0; k < users.length; k++){     user=users[k];     run('select ' + user);     var username=get('name');     var usage=get('usage');     var quota=get('quota');...Which you can then use to your advantage - to print or manipulate infomation (you could change a user's information with a set method, based on the information returned from the get method). The set method is explained next.Set MethodThe set method can be used in a simple manner, similar to get. The syntax for set is:set('property','value'); // where value is a string, if it was a number, you don't need quotesFor example, we could set the quota on a share as follows (first observing the initial value):fishy10:shares default/test-geoff> script("." to run)> var currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> set('quota','30G');("." to run)> run('commit');("." to run)> currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> .Current Quota is: 0Current Quota is: 32212254720This shows us using both the get and set methods as can be used in scripts, of course when only setting an individual share, the above is overkill - it would be much easier to set it manually at the cli using 'set quota=3G' and then 'commit'.List MethodThe list method can be very powerful, especially in more complex scripts which iterate over large amounts of data and manipulate it if so desired. The general way you will use list is as follows:var myVar=list();Which will make "myVar" an array, containing all the objects in the relevant context (this could be a list of users, shares, projects, etc). You can then gather or manipulate data very easily.We could list all the shares and mountpoints in a given project for example:fishy10:shares another-project> script("." to run)> var shares=list();("." to run)> for (i=0; i < shares.length; i++)("." to run)> {("." to run)>    run('select ' + shares[i]);("." to run)>    var mountpoint=get('mountpoint');("." to run)>    printf("Share %s discovered, has mountpoint %s\n",shares[i],mountpoint);("." to run)>    run('done');("." to run)> }("." to run)> .Share and-another discovered, has mountpoint /export/another-project/and-anotherShare another-share discovered, has mountpoint /export/another-project/another-shareShare bob discovered, has mountpoint /export/another-projectShare more-shares-for-all discovered, has mountpoint /export/another-project/more-shares-for-allShare yep discovered, has mountpoint /export/another-project/yepWriting More Complex and Re-Usable CodeFunctionsThe best way to be able to write more complex code is to use functions to split up repeatable or reusable sections of your code. This also makes your more complex code easier to read and understand for other programmers.We write functions as follows:function functionName(variable1,variable2,...,variableN){}For example, we could have a function that takes a project name as input, and lists shares for that project (assuming we're already in the 'project' context - context is important!):function getShares(proj){        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                printf("Discovered share: %s\n",shares[i]);        }        run('done'); // exit selected project}Commenting your CodeLike any other language, a large part of making it readable and understandable is to comment it. You can use the same comment style as in C and Java amongst other languages.In other words, sngle line comments use://at the beginning of the comment.Multi line comments use:/*at the beginning, and:*/ at the end.For example, here we will use both:fishy10:> script("." to run)> // This is a test comment("." to run)> printf("doing some work...\n");("." to run)> /* This is a multi-line("." to run)> comment which I will span across("." to run)> three lines in total */("." to run)> printf("doing some more work...\n");("." to run)> .doing some work...doing some more work...Your comments do not have to be on their own, they can begin (particularly with single line comments this is handy) at the end of a statement, for examplevar projects=list(); // The variable projects is an array containing all projects on the system.Try and Catch StatementsYou may be used to using try and catch statements in other languages, and they can (and should) be utilised in your code to catch expected or unexpected error conditions, that you do NOT wish to stop your code from executing (if you do not catch these errors, your script will exit!):try{  // do some work}catch(err) // Catch any error that could occur{ // do something here under the error condition}For example, you may wish to only execute some code if a context can be reached. If you can't perform certain actions under certain circumstances, that may be perfectly acceptable.For example if you want to test a condition that only makes sense when looking at a SMB/NFS share, but does not make sense when you hit an iscsi or FC LUN, you don't want to stop all processing of other shares you may not have covered yet.For example we may wish to obtain quota information on all shares for all users on a share (but this makes no sense for a LUN):function getShareQuota(shar) // Get quota for each user of this share{        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","----");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}Running Scripts Remotely over SSHAs you have likely noticed, writing and running scripts for all but the simplest jobs directly on the appliance is not going to be a lot of fun.There's a couple of choices on what you can do here:Create scripts on a remote system and run them over sshCreate scripts, wrapping them in workflow code, so they are stored on the appliance and can be triggered under certain circumstances (like a threshold being reached)We'll cover the first one here, and then cover workflows later on (as these are for the most part just scripts with some wrapper information around them).Creating a SSH Public/Private SSH Key PairLog on to your handy Solaris box (You wouldn't be using any other OS, right? :P) and use ssh-keygen to create a pair of ssh keys. I'm storing this separate to my normal key:[geoff@lightning ~] ssh-keygen -t rsa -b 1024Generating public/private rsa key pair.Enter file in which to save the key (/export/home/geoff/.ssh/id_rsa): /export/home/geoff/.ssh/nas_key_rsaEnter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /export/home/geoff/.ssh/nas_key_rsa.Your public key has been saved in /export/home/geoff/.ssh/nas_key_rsa.pub.The key fingerprint is:7f:3d:53:f0:2a:5e:8b:2d:94:2a:55:77:66:5c:9b:14 geoff@lightningInstalling the Public Key on the ApplianceOn your Solaris host, observe the public key:[geoff@lightning ~] cat .ssh/nas_key_rsa.pub ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc= geoff@lightningNow, copy and paste everything after "ssh-rsa" and before "user@hostname" - in this case, geoff@lightning. That is, this bit:AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc=Logon to your appliance and get into the preferences -> keys area for this user (root):[geoff@lightning ~] ssh [email protected]: Last login: Mon Dec  6 17:13:28 2010 from 192.168.0.2fishy10:> configuration usersfishy10:configuration users> select rootfishy10:configuration users root> preferences fishy10:configuration users root preferences> keysOR do it all in one hit:fishy10:> configuration users select root preferences keysNow, we create a new public key that will be accepted for this user and set the type to RSA:fishy10:configuration users root preferences keys> createfishy10:configuration users root preferences key (uncommitted)> set type=RSASet the key itself using the string copied previously (between ssh-rsa and user@host), and set the key ensuring you put double quotes around it (eg. set key="<key>"):fishy10:configuration users root preferences key (uncommitted)> set key="AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc="Now set the comment for this key (do not use spaces):fishy10:configuration users root preferences key (uncommitted)> set comment="LightningRSAKey" Commit the new key:fishy10:configuration users root preferences key (uncommitted)> commitVerify the key is there:fishy10:configuration users root preferences keys> lsKeys:NAME     MODIFIED              TYPE   COMMENT                                  key-000  2010-10-25 20:56:42   RSA    cycloneRSAKey                           key-001  2010-12-6 17:44:53    RSA    LightningRSAKey                         As you can see, we now have my new key, and a previous key I have created on this appliance.Running your Script over SSH from a Remote SystemHere I have created a basic test script, and saved it as test.ecma3:[geoff@lightning ~] cat test.ecma3 script// This is a test script, By Geoff Ongley 2010.printf("Testing script remotely over ssh\n");.Now, we can run this script remotely with our keyless login:[geoff@lightning ~] ssh -i .ssh/nas_key_rsa root@fishy10 < test.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Testing script remotely over sshPutting it Together - An Example Completed Quota Gathering ScriptSo now we have a lot of the basics to creating a script, let us do something useful, like, find out how much every user is using, on every share on the system (you will recognise some of the code from my previous examples): script/************************************** Quick and Dirty Quota Check script ** Written By Geoff Ongley            ** 25 October 2010                    **************************************/function getUserQuota(usr){        run('select ' + usr);        var username=get('name');        var usage=get('usage');        var quota=get('quota');        var usage_g=usage / 1073741824; // convert bytes to gigabytes        var quota_g=quota / 1073741824; // as above        var quota_percent=0        if (quota > 0)        {                quota_percent=(usage / quota)*(100/1);        }        printf("    %20s        %8.2f           %8.2f           %d%%\n",username,usage_g,quota_g,quota_percent);        run('done'); // done with this selected user}function getShareQuota(shar){        //printf("DEBUG: selecting share %s\n", shar);        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","--------");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}function getShares(proj){        //printf("DEBUG: selecting project %s\n",proj);        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                share=shares[j];                getShareQuota(share);        }        run('done'); // exit selected project}function getProjects(){        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                var project=projects[i];                getShares(project);        }        run('done'); // exit context for all projects}getProjects();.Which can be run as follows, and will print information like this:[geoff@lightning ~/FISHWORKS_SCRIPTS] ssh -i ~/.ssh/nas_key_rsa root@fishy10 < get_quota_utilisation.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Project: another-project  SHARE: and-another                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                 geoffro            0.05            0.00        0%                   Billy            0.10            0.00        0%                    root            0.00            0.00        0%            testing-user            0.05            0.00        0%  SHARE: another-share                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                 geoffro            0.05            0.49        9%            testing-user            0.05            0.02        249%                   Billy            0.10            0.29        33%  SHARE: bob                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%  SHARE: more-shares-for-all                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                   Billy            0.10            0.00        0%            testing-user            0.05            0.00        0%                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%                 geoffro            0.05            0.00        0%  SHARE: yep                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                   Billy            0.10            0.01        999%            testing-user            0.05            0.49        9%                 geoffro            0.05            0.00        0%Project: default  SHARE: Test-LUN    SKIPPING Test-LUN - This is NOT a NFS or CIFs share, not looking for users  SHARE: test-geoff                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                 geoffro            0.05            0.00        0%                    root            3.18           10.00        31%                    uucp            0.00            0.00        0%                  nobody            0.59            0.49        119%^CKilled by signal 2.Creating a WorkflowWorkflows are scripts that we store on the appliance, and can have the script execute either on request (even from the BUI), or on an event such as a threshold being met.Workflow BasicsA workflow allows you to create a simple process that can be executed either via the BUI interface interactively, or by an alert being raised (for some threshold being reached, for example).The basics parameters you will have to set for your "workflow object" (notice you're creating a variable, that embodies ECMAScript) are as follows (parameters is optional):name: A name for this workflowdescription: A Description for the workflowparameters: A set of input parameters (useful when you need user input to execute the workflow)execute: The code, the script itself to execute, which will be function (parameters)With parameters, you can specify things like this (slightly modified sample taken from the System Administration Guide):          ...parameters:        variableParam1:         {                             label: 'Name of Share',                             type: 'String'                  },                  variableParam2                  {                             label: 'Share Size',                             type: 'size'                  },execute: ....};  Note the commas separating the sections of name, parameters, execute, and so on. This is important!Also - there is plenty of properties you can set on the parameters for your workflow, these are described in the Sun ZFS Storage System Administration Guide.Creating a Basic Workflow from a Basic ScriptTo make a basic script into a basic workflow, you need to wrap the following around your script to create a 'workflow' object:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function() {// (basic script goes here, minus the "script" at the beginning, and "." at the end)}};However, it appears (at least in my experience to date) that the workflow object may only be happy with one function in the execute parameter - either that or I'm doing something wrong. As far as I can tell, after execute: you should only have a basic one function context like so:execute: function(){}To deal with this, and to give an example similar to our script earlier, I have created another simple quota check, to show the same basic functionality, but in a workflow format:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function () {        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                run('select ' + projects[i]);                shares=list('filesystem');                printf("Project: %s\n", projects[i]);                for(j=0; j < shares.length; j++)                {                        run('select ' +shares[j]);                        try                        {                                run('users');                                printf("  SHARE: %s\n", shares[j]);                                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","-------");                                users=list();                                for(k=0; k < users.length; k++)                                {                                        run('select ' + users[k]);                                        username=get('name');                                        usage=get('usage');                                        quota=get('quota');                                        usage_g=usage / 1073741824; // convert bytes to gigabytes                                        quota_g=quota / 1073741824; // as above                                        quota_percent=0                                        if (quota > 0)                                        {                                                quota_percent=(usage / quota)*(100/1);                                        }                                        printf("    %20s        %8.2f   %8.2f   %d%%\n",username,usage_g,quota_g,quota_percent);                                        run('done');                                }                                run('done'); // exit user context                        }                        catch(err)                        {                        //      printf("    %s is a LUN, Not looking for users\n", shares[j]);                        }                        run('done'); // exit selected share context                }                run('done'); // exit project context        }        }};SummaryThe Sun ZFS Storage 7000 Appliance offers lots of different and interesting features to Sun/Oracle customers, including the world renowned Analytics. Hopefully the above will help you to think of new creative things you could be doing by taking advantage of one of the other neat features, the internal scripting engine!Some references are below to help you continue learning more, I'll update this post as I do the same! Enjoy...More information on ECMAScript 3A complete reference to ECMAScript 3 which will help you learn more of the details you may be interested in, can be found here:http://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262,%203rd%20edition,%20December%201999.pdfMore Information on Administering the Sun ZFS Storage 7000The Sun ZFS Storage 7000 System Administration guide can be a useful reference point, and can be found here:http://wikis.sun.com/download/attachments/186238602/2010_Q3_2_ADMIN.pdf

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• ASM programming, how to use loop?

  - by chris

  Hello. Im first time here.I am a college student. I've created a simple program by using assembly language. And im wondering if i can use loop method to run it almost samething as what it does below the program i posted. and im also eager to find someome who i can talk through MSN messanger so i can ask you questions right away.(if possible) ok thank you .MODEL small .STACK 400h .data prompt db 10,13,'Please enter a 3 digit number, example 100:',10,13,'$' ;10,13 cause to go to next line first_digit db 0d second_digit db 0d third_digit db 0d Not_prime db 10,13,'This number is not prime!',10,13,'$' prime db 10,13,'This number is prime!',10,13,'$' question db 10,13,'Do you want to contine Y/N $' counter dw 0d number dw 0d half dw ? .code Start: mov ax, @data ;establish access to the data segment mov ds, ax mov number, 0d LetsRoll: mov dx, offset prompt ; print the string (please enter a 3 digit...) mov ah, 9h int 21h ;execute ;read FIRST DIGIT mov ah, 1d ;bios code for read a keystroke int 21h ;call bios, it is understood that the ascii code will be returned in al mov first_digit, al ;may as well save a copy sub al, 30h ;Convert code to an actual integer cbw ;CONVERT BYTE TO WORD. This takes whatever number is in al and ;extends it to ax, doubling its size from 8 bits to 16 bits ;The first digit now occupies all of ax as an integer mov cx, 100d ;This is so we can calculate 100*1st digit +10*2nd digit + 3rd digit mul cx ;start to accumulate the 3 digit number in the variable imul cx ;it is understood that the other operand is ax ;AND that the result will use both dx::ax ;but we understand that dx will contain only leading zeros add number, ax ;save ;variable <number> now contains 1st digit * 10 ;---------------------------------------------------------------------- ;read SECOND DIGIT, multiply by 10 and add in mov ah, 1d ;bios code for read a keystroke int 21h ;call bios, it is understood that the ascii code will be returned in al mov second_digit, al ;may as well save a copy sub al, 30h ;Convert code to an actual integer cbw ;CONVERT BYTE TO WORD. This takes whatever number is in al and ;extends it to ax, boubling its size from 8 bits to 16 bits ;The first digit now occupies all of ax as an integer mov cx, 10d ;continue to accumulate the 3 digit number in the variable mul cx ;it is understood that the other operand is ax, containing first digit ;AND that the result will use both dx::ax ;but we understand that dx will contain only leading zeros. Ignore them add number, ax ;save -- nearly finished ;variable <number> now contains 1st digit * 100 + second digit * 10 ;---------------------------------------------------------------------- ;read THIRD DIGIT, add it in (no multiplication this time) mov ah, 1d ;bios code for read a keystroke int 21h ;call bios, it is understood that the ascii code will be returned in al mov third_digit, al ;may as well save a copy sub al, 30h ;Convert code to an actual integer cbw ;CONVERT BYTE TO WORD. This takes whatever number is in al and ;extends it to ax, boubling its size from 8 bits to 16 bits ;The first digit now occupies all of ax as an integer add number, ax ;Both my variable number and ax are 16 bits, so equal size mov ax, number ;copy contents of number to ax mov cx, 2h div cx ;Divide by cx mov half, ax ;copy the contents of ax to half mov cx, 2h; mov ax, number; ;copy numbers to ax xor dx, dx ;flush dx jmp prime_check ;jump to prime check print_question: mov dx, offset question ;print string (do you want to continue Y/N?) mov ah, 9h int 21h ;execute mov ah, 1h int 21h ;execute cmp al, 4eh ;compare je Exit ;jump to exit cmp al, 6eh ;compare je Exit ;jump to exit cmp al, 59h ;compare je Start ;jump to start cmp al, 79h ;compare je Start ;jump to start prime_check: div cx; ;Divide by cx cmp dx, 0h ;reset the value of dx je print_not_prime ;jump to not prime xor dx, dx; ;flush dx mov ax, number ;copy the contents of number to ax cmp cx, half ;compare half with cx je print_prime ;jump to print prime section inc cx; ;increment cx by one jmp prime_check ;repeat the prime check print_prime: mov dx, offset prime ;print string (this number is prime!) mov ah, 9h int 21h ;execute jmp print_question ;jumps to question (do you want to continue Y/N?) this is for repeat print_not_prime: mov dx, offset Not_prime ;print string (this number is not prime!) mov ah, 9h int 21h ;execute jmp print_question ;jumps to question (do you want to continue Y/N?) this is for repeat Exit: mov ah, 4ch int 21h ;execute exit END Start

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• Run web.py as daemon.

  - by mamcx

  I have a simple web.py program to load data. In the server I don't want to install apache or any webserver. I try to put it as a background service with http://www.jejik.com/articles/2007/02/a_simple_unix_linux_daemon_in_python/ And subclassing: (from http://www.jejik.com/files/examples/daemon.py) class Daemon: def start(self): """ Start the daemon """ ... PID CHECKS.... # Start the daemon self.daemonize() self.run() #My code class WebService(Daemon): def run(self): app.run() if __name__ == "__main__": if DEBUG: app.run() else: service = WebService(os.path.join(DIR_ACTUAL,'ElAdministrador.pid')) if len(sys.argv) == 2: if 'start' == sys.argv[1]: service.start() elif 'stop' == sys.argv[1]: service.stop() elif 'restart' == sys.argv[1]: service.restart() else: print "Unknown command" sys.exit(2) sys.exit(0) else: print "usage: %s start|stop|restart" % sys.argv[0] sys.exit(2) However, the web.py software not load (ie: The service no listen) If I call it directly (ie: No using the daemon code) work fine.

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• Invalid argument when calling linux splice()

  - by benny wallace

  Hi I wanted to try out the splice syscall. I have this function - it should copy content of one file to another: static void test_splice( int in, int out ) { int i = 0, rcvd = 0; int filedes[2]; off_t off = 0; if ( pipe( filedes ) < 0 ) { perror( "Kicha pipe" ); exit( EXIT_FAILURE ); } for ( i = 0; i < NUMLOOPS; ++i ) { if ( ( rcvd = splice( in, NULL, filedes[1], NULL, BUFSIZE, SPLICE_F_MORE | SPLICE_F_MOVE ) ) < 0 ) { perror( "splice" ); exit( EXIT_FAILURE ); } if ( splice( filedes[0], NULL, out, NULL, rcvd, SPLICE_F_MORE | SPLICE_F_MOVE ) < 0 ) { perror( "splice" ); exit( EXIT_FAILURE ); } } } The second call to splice in first iteration returns EINVAL ( invalid argument from perror ) everytime - what could be the reason?

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• Using ret with FASM on Win32

  - by Jon Purdy

  I'm using SDL with FASM, and have code that's minimally like the following: format ELF extrn _SDL_Init extrn _SDL_SetVideoMode extrn _SDL_Quit extrn _exit SDL_INIT_VIDEO equ 0x00000020 section '.text' public _SDL_main _SDL_main: ccall _SDL_Init, SDL_INIT_VIDEO ccall _SDL_SetVideoMode, 640, 480, 32, 0 ccall _SDL_Quit ccall _exit, 0 ; Success, or ret ; failure. With the following quick-and-dirty makefile: SOURCES = main.asm OBJECTS = main.o TARGET = SDLASM.exe FASM = C:\fasm\fasm.exe release : $(OBJECTS) ld $(OBJECTS) -LC:/SDL/lib/ -lSDLmain -lSDL -LC:/MinGW/lib/ -lmingw32 -lcrtdll -o $(TARGET) --subsystem windows cleanrelease : del $(OBJECTS) %.o : %.asm $(FASM) $< $@ Using exit() (or Windows' ExitProcess()) seems to be the only way to get this program to exit cleanly, even though I feel like I should be able to use retn/retf. When I just ret without calling exit(), the application does not terminate and needs to be killed. Could anyone shed some light on this? It only happens when I make the call to SDL_SetVideoMode().

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• Ret Failure with SDL using FASM on Win32

  - by Jon Purdy

  I'm using SDL with FASM, and have code that's minimally like the following: format ELF extrn _SDL_Init extrn _SDL_SetVideoMode extrn _SDL_Quit extrn _exit SDL_INIT_VIDEO equ 0x00000020 section '.text' public _SDL_main _SDL_main: ccall _SDL_Init, SDL_INIT_VIDEO ccall _SDL_SetVideoMode, 640, 480, 32, 0 ccall _SDL_Quit ccall _exit, 0 ; Success, or ret ; failure. With the following quick-and-dirty makefile: SOURCES = main.asm OBJECTS = main.o TARGET = SDLASM.exe FASM = C:\fasm\fasm.exe release : $(OBJECTS) ld $(OBJECTS) -LC:/SDL/lib/ -lSDLmain -lSDL -LC:/MinGW/lib/ -lmingw32 -lcrtdll -o $(TARGET) --subsystem windows cleanrelease : del $(OBJECTS) %.o : %.asm $(FASM) $< $@ Using exit() (or Windows' ExitProcess()) seems to be the only way to get this program to exit cleanly, even though I feel like I should be able to use retn/retf. When I just ret without calling exit(), the application does not terminate and needs to be killed. Could anyone shed some light on this? It only happens when I make the call to SDL_SetVideoMode().

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• How do I get a Mac ".command" file to automatically quit after running a shell script?

  - by LOlliffe

  In my shell script, my last lines are: ... echo "$l" done done exit I have Terminal preference set to "When the shell exits: Close the window". In all other cases, when I type "exit" or "logout", in Terminal, the window closes, but for this ".command" file (I can double-click on my shell script file, and the script runs), instead of closing the window, while the file's code says "exit", what shows on the screen is: ... $l done logout [Process completed] ...and the window remains open. Does anyone know how to get a shell script to run, and then just automatically quit the Terminal window on completion? Thanks!

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• three out of five file streams wont open, i believe its a problem with my ifstreams.

  - by user320950

  #include<iostream> #include<fstream> #include<cstdlib> #include<iomanip> using namespace std; int main() { ifstream in_stream; // reads itemlist.txt ofstream out_stream1; // writes in items.txt ifstream in_stream2; // reads pricelist.txt ofstream out_stream3;// writes in plist.txt ifstream in_stream4;// read recipt.txt ofstream out_stream5;// write display.txt int wrong=0; in_stream.open("ITEMLIST.txt", ios::in); // list of avaliable items if( in_stream.fail() )// check to see if itemlist.txt is open { wrong++; cout << " the error occured here0, you have " << wrong++ << " errors" << endl; cout << "Error opening the file\n" << endl; exit(1); } else{ cout << " System ran correctly " << endl; out_stream1.open("ITEMLIST.txt", ios::out); // list of avaliable items if(out_stream1.fail() )// check to see if itemlist.txt is open { wrong++; cout << " the error occured here1, you have " << wrong++ << " errors" << endl; cout << "Error opening the file\n"; exit(1); } else{ cout << " System ran correctly " << endl; } in_stream2.open("PRICELIST.txt", ios::in); if( in_stream2.fail() ) { wrong++; cout << " the error occured here2, you have " << wrong++ << " errors" << endl; cout << "Error opening the file\n"; exit (1); } else{ cout << " System ran correctly " << endl; } out_stream3.open("PRICELIST.txt", ios::out); if(out_stream3.fail() ) { wrong++; cout << " the error occured here3, you have " << wrong++ << " errors" << endl; cout << "Error opening the file\n"; exit (1); } else{ cout << " System ran correctly " << endl; } in_stream4.open("display.txt", ios::in); if( in_stream4.fail() ) { wrong++; cout << " the error occured here4, you have " << wrong++ << " errors" << endl; cout << "Error opening the file\n"; exit (1); } else{ cout << " System ran correctly " << endl; } out_stream5.open("display.txt", ios::out); if( out_stream5.fail() ) { wrong++; cout << " the error occured here5, you have " << wrong++ << " errors" << endl; cout << "Error opening the file\n"; exit (1); } else{ cout << " System ran correctly " << endl; }

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• Java: Checking contents of char variable with if condition

  - by Troy

  Hello, I have a char variable that is supposed to contain either a Y,y,n or N character, I want to test if it does not contain it, then display an error message and exit the program. This is the code I am using; if (userDecision != 'Y' || userDecision != 'y' || userDecision != 'n' || userDecision != 'N') { System.out.println("Error: invalid input entered for the interstate question"); System.exit(0); } Irregardless of what is in the variable it always returns true and executes the command to exit the program, what am I doing wrong?

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• stuck in while loop python

  - by user1717330

  I am creating a chat server in python and got quite far as a noob in the language. I am having 1 problem at the moment which I want to solve before I go further, but I cannot seem to find how to get the problem solved. It is about a while loop that continues.. in the below code is where it goes wrong while 1: try: data = self.channel.recv ( 1024 ) print "Message from client: ", data if "exit" in data: self.channel.send("You have closed youre connection.\n") break except KeyboardInterrupt: break except: raise When this piece of code get executed, on my client I need to enter "exit" to quit the connection. This works as a charm, but when I use CTRL+C to exit the connection, my server prints "Message from client: " a couple of thousand times. where am I going wrong?

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• BASH: Checking for environment variables

  - by Hamza

  Hi folks, I am trying to check the value of an environment variable and depending on the value do certain things and it works fine as long as the variable is set. When it isn't though I get a whole bunch of errors (as BASH is trying to compare the string I specify with an undefined variable, I guess) I tried implementing an extra check to prevent it happening but no luck. The block of code I am using is: #!/bin/bash if [ -n $TESTVAR ] then if [ $TESTVAR == "x" ] then echo "foo" exit elif [ $TESTVAR == "y" ] then echo "bar" exit else echo "baz" exit fi else echo -e "TESTVAR not set\n" fi And this the output: $ export TESTVAR=x $ ./testenv.sh foo $ export TESTVAR=y $ ./testenv.sh bar $ export TESTVAR=q $ ./testenv.sh baz $ unset TESTVAR $ ./testenv.sh ./testenv.sh: line 5: [: ==: unary operator expected ./testenv.sh: line 9: [: ==: unary operator expected baz My question is, shouldn't 'unset TESTVAR' nullify it? It doesn't seem to be the case... Thanks.

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• Python: Control timeout length

  - by skylarking

  I have code similar to the following running in a script: try: s = ftplib.FTP('xxx.xxx.xxx.xxx','username','password') except: print ('Could not contact FTP serer') sys.exit() IF the FTP site is inaccessible, the script almost seems to 'hang' ... It is taking about 75 seconds on average before sys.exit() appears to be called... I know the 75 seconds is probably very subjective, and dependent on the system this runs on...but is there a way to have python just try this once, and if unsucessful, to exit immediately? The platform I am using for this is Mac OS X 10.5/python 2.5.1.

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• Assigning two strings together getting Access Read Violation

  - by Jay Bell

  I am trying to pass a string to a class mutator and set the private member to that string here is the code that is sending the string void parseTradePairs(Exchange::Currency *curr, std::string *response, int begin, int exit) { int start; int end; string temp; string dataResponse; CURL *tempCurl; initializeCurl(tempCurl); int location = response->find("marketid", begin); if(location <= exit) { start = location + 11; begin = response->find("label", start); end = begin - start - 3; findStrings(start, end, temp, response); getMarketInfo(tempCurl, temp, dataResponse); curr->_coin->setExch(temp); // here is the line of code that is sending the string dataResponse >> *(curr->_coin); curr->_next = new Exchange::Currency(curr, curr->_position + 1); parseTradePairs(curr->_next, response, begin, exit); } } and here is the mutator within the coin class that is receiving the string and assigning it to _exch void Coin::setExch(string exch) { _exch = exch; } I have stepped through it and made sure that exch has the string in it. "105" but soon as it hits _exch = exch; I get the reading violation. I tried passing as pointer as well. I do not believe it should go out of scope. and the string variable in the class is initialized to zero in the default constructor but again that should matter unless I am trying to read from it instead of writing to it. /* defualt constructor */ Coin::Coin() { _id = ""; _label = ""; _code= ""; _name = ""; _marketCoin = ""; _volume = 0; _last = 0; _exch = ""; } Exchange::Exchange(std::string str) { _exch = str; _currencies = new Currency; std::string pair; std::string response; CURL *curl; initializeCurl(curl); getTradePairs(curl, response); int exit = response.find_last_of("marketid"); parseTradePairs(_currencies, &response, 0, exit); } int main(void) { CURL *curl; string str; string id; Coin coin1; initializeCurl(curl); Exchange ex("cryptsy"); curl_easy_cleanup(curl); system("pause"); return 0; } class Exchange { public: typedef struct Currency { Currency(Coin *coin, Currency *next, Currency *prev, int position) : _coin(coin), _next(next), _prev(prev), _position(position) {} Currency(Currency *prev, int position) : _prev(prev), _position(position), _next(NULL), _coin(&Coin()){} Currency() : _next(NULL), _prev(NULL), _position(0) {} Coin *_coin; Currency *_next; Currency *_prev; int _position; }; /* constructor and destructor */ Exchange(); Exchange(std::string str); ~Exchange(); /* Assignment operator */ Exchange& operator =(const Exchange& copyExchange); /* Parse Cryptsy Pairs */ friend void parseTradePairs(Currency *curr, std::string *response, int begin, int exit); private: std::string _exch; Currency *_currencies; }; here is what i changed it to to fix it. typedef struct Currency { Currency(Coin *coin, Currency *next, Currency *prev, int position) : _coin(coin), _next(next), _prev(prev), _position(position) {} Currency(Currency *prev, int position) : _prev(prev), _position(position), _next(NULL), _coin(&Coin()){} Currency() { _next = NULL; _prev = NULL; _position = 0; _coin = new Coin(); } Coin *_coin; Currency *_next; Currency *_prev; int _position; };

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• Java application return codes

  - by doele

  I have a Java program that processes one file at a time. This Java program is called from a wrapper script which logs the return code from the Java program. There are 2 types of errors. Expected errors and unexpected errors. In both cases I just need to log them. My wrapper knows about 3 different states. 0-OK, 1-PROCESSING_FAILED, 2- ERROR. Is this a valid approach? Here is my approach: enum ReturnCodes {OK,PROCESSING_FAILED,ERROR}; public static void main(String[] args) { ... proc.processMyFile(); ... System.exit(ReturnCodes.OK.ordinal()); } catch (Throwable t) { ... System.exit(ReturnCodes.ERROR.ordinal()); } private void processMyFile() { try { ... }catch( ExpectedException e) { ... System.exit(ReturnCodes.PROCESSING_FAILED.ordinal()); } }

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• Unable to make the session state request to the session state server

  - by Angry_IT_Guru

  For about 4-5 months now, I seem to be having this sporadic issue--mainly during our busiest time of the day between 10:30-11:45AM, where all my Windows 2003 web servers in a Microsoft NLB cluster start throwing session state server errors. A sample error is below. System.Web.HttpException: Unable to make the session state request to the session state server. Please ensure that the ASP.NET State service is started and that the client and server ports are the same. If the server is on a remote machine, please ensure that it accepts remote requests by checking the value of HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\aspnet_state\Parameters\AllowRemoteConnection. If the server is on the local machine, and if the before mentioned registry value does not exist or is set to 0, then the state server connection string must use either 'localhost' or '127.0.0.1' as the server name. at System.Web.SessionState.OutOfProcSessionStateStore.MakeRequest(StateProtocolVerb verb, String id, StateProtocolExclusive exclusiveAccess, Int32 extraFlags, Int32 timeout, Int32 lockCookie, Byte[] buf, Int32 cb, Int32 networkTimeout, SessionNDMakeRequestResults& results) at System.Web.SessionState.OutOfProcSessionStateStore.SetAndReleaseItemExclusive(HttpContext context, String id, SessionStateStoreData item, Object lockId, Boolean newItem) at System.Web.SessionState.SessionStateModule.OnReleaseState(Object source, EventArgs eventArgs) at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) Now I'm using ASP.NET State service on a centralized back-end Windows 2003 server that all servers communicate to. I was originally using SQL Server state for a couple years as well prior to having this issue. The problem with SQL wqas that when the issue occurred, it created a blocking situation which essentially impacted all users across all servers. The product company recommended that I use the standard ASP.NET State service as that was what they technically supported. Why this would make a difference is beyond me -- but I had no choice but to try it! I have attempted to create multiple application pools, adding additional servers, chaning TCP/IP timeout from 20 to 30 seconds, and even calling Microsoft ASP.NET product support, with very little success. I even recommended that they review whether they are using read-only session state instead of read/write per page request -- as I understand that this basically causes every page to make round-trips to state server even if state isn't being used on the page. Unfortunately, the application is developed by our product company and they insist that it is something with my environment because other clients do not have these sort of issues. However, I've talked to other clients and they tell me when they've seen issues like they, they've basically had to create another web farm. This issue almost seems like I've simply reached some architectural limit within the application... Microsoft's position on the issue is that the session state needs to be reduced and the returncode being reported back from the state server indicates buffers are full. To better understand the scope of issues (rather than wait for customers to call and complain), I installed ELMAH and configured it to send me e-mails when unhandled exceptions occur. I basically get 500-1000 e-mails during the time period of high activity! If any one has any other ideas I could try or better ways to troubleshoot, I'd appreciate it.

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• How to stop Apache from crashing my entire server?

  - by CyberShadow

  I maintain a Gentoo server with a few services, including Apache. It's fairly low-end (2GB of RAM and a low-end CPU with 2 cores). My problem is that, despite my best efforts, an over-loaded Apache crashes the entire server. In fact, at this point I'm close to being convinced that Linux is a horrible operating system that isn't worth anyone's time looking for stability under load. Things I tried: Adjusting oom_adj for the root Apache process (and thus all its children). That had close to no effect. When Apache was overloaded it would bring the system to a grind, as the system paged out everything else before it got to kill anything. Turning off swap. Didn't help, it would unload memory paged to binaries of processes and other files on /, thus causing the same effect. Putting it in a memory-limited cgroup (limited to 512 MB of RAM, 1/4th of the total). This "worked", at least in my own stress tests - except the server keeps crashing under load (basically stalling all other processes, inaccessible via SSH, etc.) Running it with idle I/O priority. This wasn't a very good idea in the end, because it just caused the system load to climb indefinitely (into the thousands) with almost no visible effect - until you tried to access an unbuffered part of the disk. This caused the task to freeze. (So much for good I/O scheduling, eh?) Limiting the number of concurrent connections to Apache. Setting the number too low caused web sites to become unresponsive due to most slots being occupied with long requests (file downloads). I tried various Apache MPMs without much success (prefork, event, itk). Switching from prefork/event+php-cgi+suphp to itk+mod_php. This improved performance, but didn't solve the actual problem. Switching I/O schedulers (cfq to deadline). Just to stress this out: I don't care if Apache itself goes down under load, I just want the rest of my system to remain stable. Of course, having Apache recover quickly after a brief period of intensive load would be great to have, but one step at a time. Right now I am mostly dumbfounded by how can humanity, in this day and age, design an operating system where such a seemingly simple task (don't allow one system component to crash the entire system) seems practically impossible - or at least, very hard to do. Please don't suggest things like VMs or "BUY MORE RAM". Some more information gathered with a friend's help: The processes hang when the cgroup oom killer is invoked. Here's the call trace: [<ffffffff8104b94b>] ? prepare_to_wait+0x70/0x7b [<ffffffff810a9c73>] mem_cgroup_handle_oom+0xdf/0x180 [<ffffffff810a9559>] ? memcg_oom_wake_function+0x0/0x6d [<ffffffff810aa041>] __mem_cgroup_try_charge+0x32d/0x478 [<ffffffff810aac67>] mem_cgroup_charge_common+0x48/0x73 [<ffffffff81081c98>] ? __lru_cache_add+0x60/0x62 [<ffffffff810aadc3>] mem_cgroup_newpage_charge+0x3b/0x4a [<ffffffff8108ec38>] handle_mm_fault+0x305/0x8cf [<ffffffff813c6276>] ? schedule+0x6ae/0x6fb [<ffffffff8101f568>] do_page_fault+0x214/0x22b [<ffffffff813c7e1f>] page_fault+0x1f/0x30 At this point, the apache memory cgroup is practically deadlocked, and burning CPU in syscalls (all with the above call trace). This seems like a problem in the cgroup implementation...

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• Unable to make the session state request to the session state server.

  - by Angry_IT_Guru

  For about 4-5 months now, I seem to be having this sporadic issue--mainly during our busiest time of the day between 10:30-11:45AM, where all my Windows 2003 web servers in a Microsoft NLB cluster start throwing session state server errors. A sample error is below. System.Web.HttpException: Unable to make the session state request to the session state server. Please ensure that the ASP.NET State service is started and that the client and server ports are the same. If the server is on a remote machine, please ensure that it accepts remote requests by checking the value of HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\aspnet_state\Parameters\AllowRemoteConnection. If the server is on the local machine, and if the before mentioned registry value does not exist or is set to 0, then the state server connection string must use either 'localhost' or '127.0.0.1' as the server name. at System.Web.SessionState.OutOfProcSessionStateStore.MakeRequest(StateProtocolVerb verb, String id, StateProtocolExclusive exclusiveAccess, Int32 extraFlags, Int32 timeout, Int32 lockCookie, Byte[] buf, Int32 cb, Int32 networkTimeout, SessionNDMakeRequestResults& results) at System.Web.SessionState.OutOfProcSessionStateStore.SetAndReleaseItemExclusive(HttpContext context, String id, SessionStateStoreData item, Object lockId, Boolean newItem) at System.Web.SessionState.SessionStateModule.OnReleaseState(Object source, EventArgs eventArgs) at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) Now I'm using ASP.NET State service on a centralized back-end Windows 2003 server that all servers communicate to. I was originally using SQL Server state for a couple years as well prior to having this issue. The problem with SQL wqas that when the issue occurred, it created a blocking situation which essentially impacted all users across all servers. The product company recommended that I use the standard ASP.NET State service as that was what they technically supported. Why this would make a difference is beyond me -- but I had no choice but to try it! I have attempted to create multiple application pools, adding additional servers, chaning TCP/IP timeout from 20 to 30 seconds, and even calling Microsoft ASP.NET product support, with very little success. I even recommended that they review whether they are using read-only session state instead of read/write per page request -- as I understand that this basically causes every page to make round-trips to state server even if state isn't being used on the page. Unfortunately, the application is developed by our product company and they insist that it is something with my environment because other clients do not have these sort of issues. However, I've talked to other clients and they tell me when they've seen issues like they, they've basically had to create another web farm. This issue almost seems like I've simply reached some architectural limit within the application... Microsoft's position on the issue is that the session state needs to be reduced and the returncode being reported back from the state server indicates buffers are full. To better understand the scope of issues (rather than wait for customers to call and complain), I installed ELMAH and configured it to send me e-mails when unhandled exceptions occur. I basically get 500-1000 e-mails during the time period of high activity! If any one has any other ideas I could try or better ways to troubleshoot, I'd appreciate it.

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• JAVA image transfer problem

  - by user579098

  Hi, I have a school assignment, to send a jpg image,split it into groups of 100 bytes, corrupt it, use a CRC check to locate the errors and re-transmit until it eventually is built back into its original form. It's practically ready, however when I check out the new images, they appear with errors.. I would really appreciate if someone could look at my code below and maybe locate this logical mistake as I can't understand what the problem is because everything looks ok :S For the file with all the data needed including photos and error patterns one could download it from this link:http://rapidshare.com/#!download|932tl2|443122762|Data.zip|739 Thanks in advance, Stefan p.s dont forget to change the paths in the code for the image and error files package networks; import java.io.*; // for file reader import java.util.zip.CRC32; // CRC32 IEEE (Ethernet) public class Main { /** * Reads a whole file into an array of bytes. * @param file The file in question. * @return Array of bytes containing file data. * @throws IOException Message contains why it failed. */ public static byte[] readFileArray(File file) throws IOException { InputStream is = new FileInputStream(file); byte[] data=new byte[(int)file.length()]; is.read(data); is.close(); return data; } /** * Writes (or overwrites if exists) a file with data from an array of bytes. * @param file The file in question. * @param data Array of bytes containing the new file data. * @throws IOException Message contains why it failed. */ public static void writeFileArray(File file, byte[] data) throws IOException { OutputStream os = new FileOutputStream(file,false); os.write(data); os.close(); } /** * Converts a long value to an array of bytes. * @param data The target variable. * @return Byte array conversion of data. * @see http://www.daniweb.com/code/snippet216874.html */ public static byte[] toByta(long data) { return new byte[] { (byte)((data >> 56) & 0xff), (byte)((data >> 48) & 0xff), (byte)((data >> 40) & 0xff), (byte)((data >> 32) & 0xff), (byte)((data >> 24) & 0xff), (byte)((data >> 16) & 0xff), (byte)((data >> 8) & 0xff), (byte)((data >> 0) & 0xff), }; } /** * Converts a an array of bytes to long value. * @param data The target variable. * @return Long value conversion of data. * @see http://www.daniweb.com/code/snippet216874.html */ public static long toLong(byte[] data) { if (data == null || data.length != 8) return 0x0; return (long)( // (Below) convert to longs before shift because digits // are lost with ints beyond the 32-bit limit (long)(0xff & data[0]) << 56 | (long)(0xff & data[1]) << 48 | (long)(0xff & data[2]) << 40 | (long)(0xff & data[3]) << 32 | (long)(0xff & data[4]) << 24 | (long)(0xff & data[5]) << 16 | (long)(0xff & data[6]) << 8 | (long)(0xff & data[7]) << 0 ); } public static byte[] nextNoise(){ byte[] result=new byte[100]; // copy a frame's worth of data (or remaining data if it is less than frame length) int read=Math.min(err_data.length-err_pstn, 100); System.arraycopy(err_data, err_pstn, result, 0, read); // if read data is less than frame length, reset position and add remaining data if(read<100){ err_pstn=100-read; System.arraycopy(err_data, 0, result, read, err_pstn); }else // otherwise, increase position err_pstn+=100; // return noise segment return result; } /** * Given some original data, it is purposefully corrupted according to a * second data array (which is read from a file). In pseudocode: * corrupt = original xor corruptor * @param data The original data. * @return The new (corrupted) data. */ public static byte[] corruptData(byte[] data){ // get the next noise sequence byte[] noise = nextNoise(); // finally, xor data with noise and return result for(int i=0; i<100; i++)data[i]^=noise[i]; return data; } /** * Given an array of data, a packet is created. In pseudocode: * frame = corrupt(data) + crc(data) * @param data The original frame data. * @return The resulting frame data. */ public static byte[] buildFrame(byte[] data){ // pack = [data]+crc32([data]) byte[] hash = new byte[8]; // calculate crc32 of data and copy it to byte array CRC32 crc = new CRC32(); crc.update(data); hash=toByta(crc.getValue()); // create a byte array holding the final packet byte[] pack = new byte[data.length+hash.length]; // create the corrupted data byte[] crpt = new byte[data.length]; crpt = corruptData(data); // copy corrupted data into pack System.arraycopy(crpt, 0, pack, 0, crpt.length); // copy hash into pack System.arraycopy(hash, 0, pack, data.length, hash.length); // return pack return pack; } /** * Verifies frame contents. * @param frame The frame data (data+crc32). * @return True if frame is valid, false otherwise. */ public static boolean verifyFrame(byte[] frame){ // allocate hash and data variables byte[] hash=new byte[8]; byte[] data=new byte[frame.length-hash.length]; // read frame into hash and data variables System.arraycopy(frame, frame.length-hash.length, hash, 0, hash.length); System.arraycopy(frame, 0, data, 0, frame.length-hash.length); // get crc32 of data CRC32 crc = new CRC32(); crc.update(data); // compare crc32 of data with crc32 of frame return crc.getValue()==toLong(hash); } /** * Transfers a file through a channel in frames and reconstructs it into a new file. * @param jpg_file File name of target file to transfer. * @param err_file The channel noise file used to simulate corruption. * @param out_file The name of the newly-created file. * @throws IOException */ public static void transferFile(String jpg_file, String err_file, String out_file) throws IOException { // read file data into global variables jpg_data = readFileArray(new File(jpg_file)); err_data = readFileArray(new File(err_file)); err_pstn = 0; // variable that will hold the final (transfered) data byte[] out_data = new byte[jpg_data.length]; // holds the current frame data byte[] frame_orig = new byte[100]; byte[] frame_sent = new byte[100]; // send file in chunks (frames) of 100 bytes for(int i=0; i<Math.ceil(jpg_data.length/100); i++){ // copy jpg data into frame and init first-time switch System.arraycopy(jpg_data, i*100, frame_orig, 0, 100); boolean not_first=false; System.out.print("Packet #"+i+": "); // repeat getting same frame until frame crc matches with frame content do { if(not_first)System.out.print("F"); frame_sent=buildFrame(frame_orig); not_first=true; }while(!verifyFrame(frame_sent)); // usually, you'd constrain this by time to prevent infinite loops (in // case the channel is so wacked up it doesn't get a single packet right) // copy frame to image file System.out.println("S"); System.arraycopy(frame_sent, 0, out_data, i*100, 100); } System.out.println("\nDone."); writeFileArray(new File(out_file),out_data); } // global variables for file data and pointer public static byte[] jpg_data; public static byte[] err_data; public static int err_pstn=0; public static void main(String[] args) throws IOException { // list of jpg files String[] jpg_file={ "C:\\Users\\Stefan\\Desktop\\Data\\Images\\photo1.jpg", "C:\\Users\\Stefan\\Desktop\\Data\\Images\\photo2.jpg", "C:\\Users\\Stefan\\Desktop\\Data\\Images\\photo3.jpg", "C:\\Users\\Stefan\\Desktop\\Data\\Images\\photo4.jpg" }; // list of error patterns String[] err_file={ "C:\\Users\\Stefan\\Desktop\\Data\\Error Pattern\\Error Pattern 1.DAT", "C:\\Users\\Stefan\\Desktop\\Data\\Error Pattern\\Error Pattern 2.DAT", "C:\\Users\\Stefan\\Desktop\\Data\\Error Pattern\\Error Pattern 3.DAT", "C:\\Users\\Stefan\\Desktop\\Data\\Error Pattern\\Error Pattern 4.DAT" }; // loop through all jpg/channel combinations and run tests for(int x=0; x<jpg_file.length; x++){ for(int y=0; y<err_file.length; y++){ System.out.println("Transfering photo"+(x+1)+".jpg using Pattern "+(y+1)+"..."); transferFile(jpg_file[x],err_file[y],jpg_file[x].replace("photo","CH#"+y+"_photo")); } } } }

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• Creating a dynamic proxy generator – Part 1 – Creating the Assembly builder, Module builder and cach

  - by SeanMcAlinden

  I’ve recently started a project with a few mates to learn the ins and outs of Dependency Injection, AOP and a number of other pretty crucial patterns of development as we’ve all been using these patterns for a while but have relied totally on third part solutions to do the magic. We thought it would be interesting to really get into the details by rolling our own IoC container and hopefully learn a lot on the way, and you never know, we might even create an excellent framework. The open source project is called Rapid IoC and is hosted at http://rapidioc.codeplex.com/ One of the most interesting tasks for me is creating the dynamic proxy generator for enabling Aspect Orientated Programming (AOP). In this series of articles, I’m going to track each step I take for creating the dynamic proxy generator and I’ll try my best to explain what everything means - mainly as I’ll be using Reflection.Emit to emit a fair amount of intermediate language code (IL) to create the proxy types at runtime which can be a little taxing to read. It’s worth noting that building the proxy is without a doubt going to be slightly painful so I imagine there will be plenty of areas I’ll need to change along the way. Anyway lets get started…   Part 1 - Creating the Assembly builder, Module builder and caching mechanism Part 1 is going to be a really nice simple start, I’m just going to start by creating the assembly, module and type caches. The reason we need to create caches for the assembly, module and types is simply to save the overhead of recreating proxy types that have already been generated, this will be one of the important steps to ensure that the framework is fast… kind of important as we’re calling the IoC container ‘Rapid’ – will be a little bit embarrassing if we manage to create the slowest framework. The Assembly builder The assembly builder is what is used to create an assembly at runtime, we’re going to have two overloads, one will be for the actual use of the proxy generator, the other will be mainly for testing purposes as it will also save the assembly so we can use Reflector to examine the code that has been created. Here’s the code: DynamicAssemblyBuilder using System; using System.Reflection; using System.Reflection.Emit; namespace Rapid.DynamicProxy.Assembly {     /// <summary>     /// Class for creating an assembly builder.     /// </summary>     internal static class DynamicAssemblyBuilder     {         #region Create           /// <summary>         /// Creates an assembly builder.         /// </summary>         /// <param name="assemblyName">Name of the assembly.</param>         public static AssemblyBuilder Create(string assemblyName)         {             AssemblyName name = new AssemblyName(assemblyName);               AssemblyBuilder assembly = AppDomain.CurrentDomain.DefineDynamicAssembly(                     name, AssemblyBuilderAccess.Run);               DynamicAssemblyCache.Add(assembly);               return assembly;         }           /// <summary>         /// Creates an assembly builder and saves the assembly to the passed in location.         /// </summary>         /// <param name="assemblyName">Name of the assembly.</param>         /// <param name="filePath">The file path.</param>         public static AssemblyBuilder Create(string assemblyName, string filePath)         {             AssemblyName name = new AssemblyName(assemblyName);               AssemblyBuilder assembly = AppDomain.CurrentDomain.DefineDynamicAssembly(                     name, AssemblyBuilderAccess.RunAndSave, filePath);               DynamicAssemblyCache.Add(assembly);               return assembly;         }           #endregion     } }   So hopefully the above class is fairly explanatory, an AssemblyName is created using the passed in string for the actual name of the assembly. An AssemblyBuilder is then constructed with the current AppDomain and depending on the overload used, it is either just run in the current context or it is set up ready for saving. It is then added to the cache.   DynamicAssemblyCache using System.Reflection.Emit; using Rapid.DynamicProxy.Exceptions; using Rapid.DynamicProxy.Resources.Exceptions;   namespace Rapid.DynamicProxy.Assembly {     /// <summary>     /// Cache for storing the dynamic assembly builder.     /// </summary>     internal static class DynamicAssemblyCache     {         #region Declarations           private static object syncRoot = new object();         internal static AssemblyBuilder Cache = null;           #endregion           #region Adds a dynamic assembly to the cache.           /// <summary>         /// Adds a dynamic assembly builder to the cache.         /// </summary>         /// <param name="assemblyBuilder">The assembly builder.</param>         public static void Add(AssemblyBuilder assemblyBuilder)         {             lock (syncRoot)             {                 Cache = assemblyBuilder;             }         }           #endregion           #region Gets the cached assembly                  /// <summary>         /// Gets the cached assembly builder.         /// </summary>         /// <returns></returns>         public static AssemblyBuilder Get         {             get             {                 lock (syncRoot)                 {                     if (Cache != null)                     {                         return Cache;                     }                 }                   throw new RapidDynamicProxyAssertionException(AssertionResources.NoAssemblyInCache);             }         }           #endregion     } } The cache is simply a static property that will store the AssemblyBuilder (I know it’s a little weird that I’ve made it public, this is for testing purposes, I know that’s a bad excuse but hey…) There are two methods for using the cache – Add and Get, these just provide thread safe access to the cache.   The Module Builder The module builder is required as the create proxy classes will need to live inside a module within the assembly. Here’s the code: DynamicModuleBuilder using System.Reflection.Emit; using Rapid.DynamicProxy.Assembly; namespace Rapid.DynamicProxy.Module {     /// <summary>     /// Class for creating a module builder.     /// </summary>     internal static class DynamicModuleBuilder     {         /// <summary>         /// Creates a module builder using the cached assembly.         /// </summary>         public static ModuleBuilder Create()         {             string assemblyName = DynamicAssemblyCache.Get.GetName().Name;               ModuleBuilder moduleBuilder = DynamicAssemblyCache.Get.DefineDynamicModule                 (assemblyName, string.Format("{0}.dll", assemblyName));               DynamicModuleCache.Add(moduleBuilder);               return moduleBuilder;         }     } } As you can see, the module builder is created on the assembly that lives in the DynamicAssemblyCache, the module is given the assembly name and also a string representing the filename if the assembly is to be saved. It is then added to the DynamicModuleCache. DynamicModuleCache using System.Reflection.Emit; using Rapid.DynamicProxy.Exceptions; using Rapid.DynamicProxy.Resources.Exceptions; namespace Rapid.DynamicProxy.Module {     /// <summary>     /// Class for storing the module builder.     /// </summary>     internal static class DynamicModuleCache     {         #region Declarations           private static object syncRoot = new object();         internal static ModuleBuilder Cache = null;           #endregion           #region Add           /// <summary>         /// Adds a dynamic module builder to the cache.         /// </summary>         /// <param name="moduleBuilder">The module builder.</param>         public static void Add(ModuleBuilder moduleBuilder)         {             lock (syncRoot)             {                 Cache = moduleBuilder;             }         }           #endregion           #region Get           /// <summary>         /// Gets the cached module builder.         /// </summary>         /// <returns></returns>         public static ModuleBuilder Get         {             get             {                 lock (syncRoot)                 {                     if (Cache != null)                     {                         return Cache;                     }                 }                   throw new RapidDynamicProxyAssertionException(AssertionResources.NoModuleInCache);             }         }           #endregion     } }   The DynamicModuleCache is very similar to the assembly cache, it is simply a statically stored module with thread safe Add and Get methods.   The DynamicTypeCache To end off this post, I’m going to create the cache for storing the generated proxy classes. I’ve spent a fair amount of time thinking about the type of collection I should use to store the types and have finally decided that for the time being I’m going to use a generic dictionary. This may change when I can actually performance test the proxy generator but the time being I think it makes good sense in theory, mainly as it pretty much maintains it’s performance with varying numbers of items – almost constant (0)1. Plus I won’t ever need to loop through the items which is not the dictionaries strong point. Here’s the code as it currently stands: DynamicTypeCache using System; using System.Collections.Generic; using System.Security.Cryptography; using System.Text; namespace Rapid.DynamicProxy.Types {     /// <summary>     /// Cache for storing proxy types.     /// </summary>     internal static class DynamicTypeCache     {         #region Declarations           static object syncRoot = new object();         public static Dictionary<string, Type> Cache = new Dictionary<string, Type>();           #endregion           /// <summary>         /// Adds a proxy to the type cache.         /// </summary>         /// <param name="type">The type.</param>         /// <param name="proxy">The proxy.</param>         public static void AddProxyForType(Type type, Type proxy)         {             lock (syncRoot)             {                 Cache.Add(GetHashCode(type.AssemblyQualifiedName), proxy);             }         }           /// <summary>         /// Tries the type of the get proxy for.         /// </summary>         /// <param name="type">The type.</param>         /// <returns></returns>         public static Type TryGetProxyForType(Type type)         {             lock (syncRoot)             {                 Type proxyType;                 Cache.TryGetValue(GetHashCode(type.AssemblyQualifiedName), out proxyType);                 return proxyType;             }         }           #region Private Methods           private static string GetHashCode(string fullName)         {             SHA1CryptoServiceProvider provider = new SHA1CryptoServiceProvider();             Byte[] buffer = Encoding.UTF8.GetBytes(fullName);             Byte[] hash = provider.ComputeHash(buffer, 0, buffer.Length);             return Convert.ToBase64String(hash);         }           #endregion     } } As you can see, there are two public methods, one for adding to the cache and one for getting from the cache. Hopefully they should be clear enough, the Get is a TryGet as I do not want the dictionary to throw an exception if a proxy doesn’t exist within the cache. Other than that I’ve decided to create a key using the SHA1CryptoServiceProvider, this may change but my initial though is the SHA1 algorithm is pretty fast to put together using the provider and it is also very unlikely to have any hashing collisions. (there are some maths behind how unlikely this is – here’s the wiki if you’re interested http://en.wikipedia.org/wiki/SHA_hash_functions)   Anyway, that’s the end of part 1 – although I haven’t started any of the fun stuff (by fun I mean hairpulling, teeth grating Relfection.Emit style fun), I’ve got the basis of the DynamicProxy in place so all we have to worry about now is creating the types, interceptor classes, method invocation information classes and finally a really nice fluent interface that will abstract all of the hard-core craziness away and leave us with a lightning fast, easy to use AOP framework. Hope you find the series interesting. All of the source code can be viewed and/or downloaded at our codeplex site - http://rapidioc.codeplex.com/ Kind Regards, Sean.

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• Using the Data Form Web Part (SharePoint 2010) Site Agnostically!

  - by David Jacobus

  Originally posted on: http://geekswithblogs.net/djacobus/archive/2013/10/24/154465.aspxAs a Developer whom has worked closely with web designers (Power users) in a SharePoint environment, I have come across the issue of making the Data Form Web Part reusable across the site collection! In SharePoint 2007 it was very easy and this blog pointed the way to make it happen: Josh Gaffey's Blog. In SharePoint 2010 something changed! This method failed except for using a Data Form Web Part that pointed to a list in the Site Collection Root! I am making this discussion relative to a developer whom creates a solution (WSP) with all the artifacts embedded and the user shouldn’t have any involvement in the process except to activate features. The Scenario: 1. A Power User creates a Data Form Web Part using SharePoint Designer 2010! It is a great web part the uses all the power of SharePoint Designer and XSLT (Conditional formatting, etc.). 2. Other Users in the site collection want to use that specific web part in sub sites in the site collection. Pointing to a list with the same name, not at the site collection root! The Issues: 1. The Data Form Web Part Data Source uses a List ID (GUID) to point to the specific list. Which means a list in a sub site will have a list with a new GUID different than the one which was created with SharePoint Designer! Obviously, the List needs to be the same List (Fields, Content Types, etc.) with different data. 2. How can we make this web part site agnostic, and dependent only on the lists Name? I had this problem come up over and over and decided to put my solution forward! The Solution: 1. Use the XSL of the Data Form Web Part Created By the Power User in SharePoint Designer! 2. Extend the OOTB Data Form Web Part to use this XSL and Point to a List by name. The solution points to a hybrid solution that requires some coding (Developer) and the XSL (Power User) artifacts put together in a Visual Studio SharePoint Solution. Here are the solution steps in summary: 1. Create an empty SharePoint project in Visual Studio 2. Create a Module and Feature and put the XSL file created by the Power User into it a. Scope the feature to web 3. Create a Feature Receiver to Create the List. The same list from which the Data Form Web Part was created with by the Power User. a. Scope the feature to web 4. Create a Web Part extending the Data Form Web a. Point the Data Form Web Part to point to the List by Name b. Point the Data Form Web Part XSL link to the XSL added using the Module feature c. Scope The feature to Site i. This is because all web parts are in the site collection web part gallery. So in a Narrative Summary: We are creating a list in code which has the same name and (site Columns) as the list from which the Power User created the Data Form Web Part Using SharePoint Designer. We are creating a Web Part in code which extends the OOTB Data Form Web Part to point to a list by name and use the XSL created by the Power User. Okay! Here are the steps with images and code! At the end of this post I will provide a link to the code for a solution which works in any site! I want to TOOT the HORN for the power of this solution! It is the mantra a use with all my clients! What is a basic skill a SharePoint Developer: Create an application that uses the data from a SharePoint list and make that data visible to the user in a manner which meets requirements! Create an Empty SharePoint 2010 Project Here I am naming my Project DJ.DataFormWebPart Create a Code Folder Copy and paste the Extension and Utilities classes (Found in the solution provided at the end of this post) Change the Namespace to match this project The List to which the Data Form Web Part which was used to make the XSL by the Power User in SharePoint Designer is now going to be created in code! If already in code, then all the better! Here I am going to create a list in the site collection root and add some data to it! For the purpose of this discussion I will actually create this list in code before using SharePoint Designer for simplicity! So here I create the List and deploy it within this solution before I do anything else. I will use a List I created before for demo purposes. Footer List is used within the footer of my master page. Add a new Feature: Here I name the Feature FooterList and add a Feature Event Receiver: Here is the code for the Event Receiver: I have a previous blog post about adding lists in code so I will not take time to narrate this code: using System; using System.Runtime.InteropServices; using System.Security.Permissions; using Microsoft.SharePoint; using DJ.DataFormWebPart.Code; namespace DJ.DataFormWebPart.Features.FooterList { /// <summary> /// This class handles events raised during feature activation, deactivation, installation, uninstallation, and upgrade. /// </summary> /// <remarks> /// The GUID attached to this class may be used during packaging and should not be modified. /// </remarks> [Guid("a58644fd-9209-41f4-aa16-67a53af7a9bf")] public class FooterListEventReceiver : SPFeatureReceiver { SPWeb currentWeb = null; SPSite currentSite = null; const string columnGroup = "DJ"; const string ctName = "FooterContentType"; // Uncomment the method below to handle the event raised after a feature has been activated. public override void FeatureActivated(SPFeatureReceiverProperties properties) { using (SPWeb spWeb = properties.GetWeb() as SPWeb) { using (SPSite site = new SPSite(spWeb.Site.ID)) { using (SPWeb rootWeb = site.OpenWeb(site.RootWeb.ID)) { //add the fields addFields(rootWeb); //add content type SPContentType testCT = rootWeb.ContentTypes[ctName]; // we will not create the content type if it exists if (testCT == null) { //the content type does not exist add it addContentType(rootWeb, ctName); } if ((spWeb.Lists.TryGetList("FooterList") == null)) { //create the list if it dosen't to exist CreateFooterList(spWeb, site); } } } } } #region ContentType public void addFields(SPWeb spWeb) { Utilities.addField(spWeb, "Link", SPFieldType.URL, false, columnGroup); Utilities.addField(spWeb, "Information", SPFieldType.Text, false, columnGroup); } private static void addContentType(SPWeb spWeb, string name) { SPContentType myContentType = new SPContentType(spWeb.ContentTypes["Item"], spWeb.ContentTypes, name) { Group = columnGroup }; spWeb.ContentTypes.Add(myContentType); addContentTypeLinkages(spWeb, myContentType); myContentType.Update(); } public static void addContentTypeLinkages(SPWeb spWeb, SPContentType ct) { Utilities.addContentTypeLink(spWeb, "Link", ct); Utilities.addContentTypeLink(spWeb, "Information", ct); } private void CreateFooterList(SPWeb web, SPSite site) { Guid newListGuid = web.Lists.Add("FooterList", "Footer List", SPListTemplateType.GenericList); SPList newList = web.Lists[newListGuid]; newList.ContentTypesEnabled = true; var footer = site.RootWeb.ContentTypes[ctName]; newList.ContentTypes.Add(footer); newList.ContentTypes.Delete(newList.ContentTypes["Item"].Id); newList.Update(); var view = newList.DefaultView; //add all view fields here //view.ViewFields.Add("NewsTitle"); view.ViewFields.Add("Link"); view.ViewFields.Add("Information"); view.Update(); } } } Basically created a content type with two site columns Link and Information. I had to change some code as we are working at the SPWeb level and need Content Types at the SPSite level! I’ll use a new Site Collection for this demo (Best Practice) keep old artifacts from impinging on development: Next we will add this list to the root of the site collection by deploying this solution, add some data and then use SharePoint Designer to create a Data Form Web Part. The list has been added, now let’s add some data: Okay let’s add a Data Form Web Part in SharePoint Designer. Create a new web part page in the site pages library: I will name it TestWP.aspx and edit it in advanced mode: Let’s add an empty Data Form Web Part to the web part zone: Click on the web part to add a data source: Choose FooterList in the Data Source menu: Choose appropriate fields and select insert as multiple item view: Here is what it look like after insertion: Let’s add some conditional formatting if the information filed is not blank: Choose Create (right side) apply formatting: Choose the Information Field and set the condition not null: Click Set Style: Here is the result: Okay! Not flashy but simple enough for this demo. Remember this is the job of the Power user! All we want from this web part is the XLS-Style Sheet out of SharePoint Designer. We are going to use it as the XSL for our web part which we will be creating next. Let’s add a web part to our project extending the OOTB Data Form Web Part. Add new item from the Visual Studio add menu: Choose Web Part: Change WebPart to DataFormWebPart (Oh well my namespace needs some improvement, but it will sure make it readily identifiable as an extended web part!) Below is the code for this web part: using System; using System.ComponentModel; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using Microsoft.SharePoint; using Microsoft.SharePoint.WebControls; using System.Text; namespace DJ.DataFormWebPart.DataFormWebPart { [ToolboxItemAttribute(false)] public class DataFormWebPart : Microsoft.SharePoint.WebPartPages.DataFormWebPart { protected override void OnInit(EventArgs e) { base.OnInit(e); this.ChromeType = PartChromeType.None; this.Title = "FooterListDF"; try { //SPSite site = SPContext.Current.Site; SPWeb web = SPContext.Current.Web; SPList list = web.Lists.TryGetList("FooterList"); if (list != null) { string queryList1 = "<Query><Where><IsNotNull><FieldRef Name='Title' /></IsNotNull></Where><OrderBy><FieldRef Name='Title' Ascending='True' /></OrderBy></Query>"; uint maximumRowList1 = 10; SPDataSource dataSourceList1 = GetDataSource(list.Title, web.Url, list, queryList1, maximumRowList1); this.DataSources.Add(dataSourceList1); this.XslLink = web.Url + "/Assests/Footer.xsl"; this.ParameterBindings = BuildDataFormParameters(); this.DataBind(); } } catch (Exception ex) { this.Controls.Add(new LiteralControl("ERROR: " + ex.Message)); } } private SPDataSource GetDataSource(string dataSourceId, string webUrl, SPList list, string query, uint maximumRow) { SPDataSource dataSource = new SPDataSource(); dataSource.UseInternalName = true; dataSource.ID = dataSourceId; dataSource.DataSourceMode = SPDataSourceMode.List; dataSource.List = list; dataSource.SelectCommand = "" + query + ""; Parameter listIdParam = new Parameter("ListID"); listIdParam.DefaultValue = list.ID.ToString( "B").ToUpper(); Parameter maximumRowsParam = new Parameter("MaximumRows"); maximumRowsParam.DefaultValue = maximumRow.ToString(); QueryStringParameter rootFolderParam = new QueryStringParameter("RootFolder", "RootFolder"); dataSource.SelectParameters.Add(listIdParam); dataSource.SelectParameters.Add(maximumRowsParam); dataSource.SelectParameters.Add(rootFolderParam); dataSource.UpdateParameters.Add(listIdParam); dataSource.DeleteParameters.Add(listIdParam); dataSource.InsertParameters.Add(listIdParam); return dataSource; } private string BuildDataFormParameters() { StringBuilder parameters = new StringBuilder("<ParameterBindings><ParameterBinding Name=\"dvt_apos\" Location=\"Postback;Connection\"/><ParameterBinding Name=\"UserID\" Location=\"CAMLVariable\" DefaultValue=\"CurrentUserName\"/><ParameterBinding Name=\"Today\" Location=\"CAMLVariable\" DefaultValue=\"CurrentDate\"/>"); parameters.Append("<ParameterBinding Name=\"dvt_firstrow\" Location=\"Postback;Connection\"/>"); parameters.Append("<ParameterBinding Name=\"dvt_nextpagedata\" Location=\"Postback;Connection\"/>"); parameters.Append("<ParameterBinding Name=\"dvt_adhocmode\" Location=\"Postback;Connection\"/>"); parameters.Append("<ParameterBinding Name=\"dvt_adhocfiltermode\" Location=\"Postback;Connection\"/>"); parameters.Append("</ParameterBindings>"); return parameters.ToString(); } } } The OnInit method we use to set the list name and the XSL Link property of the Data Form Web Part. We do not have the link to XSL in our Solution so we will add the XSL now: Add a Module in the Visual Studio add menu: Rename Sample.txt in the module to footer.xsl and then copy the XSL from SharePoint Designer Look at elements.xml to where the footer.xsl is being provisioned to which is Assets/footer.xsl, make sure the Web parts xsl link is pointing to this url: Okay we are good to go! Let’s check our features and package: DataFormWebPart should be scoped to site and have the web part: The Footer List feature should be scoped to web and have the Assets module (Okay, I see, a spelling issue but it won’t affect this demo) If everything is correct we should be able to click a couple of sub site feature activations and have our list and web part in a sub site. (In fact this solution can be activated anywhere) Here is the list created at SubSite1 with new data It. Next let’s add the web part on a test page and see if it works as expected: It does! So we now have a repeatable way to use a WSP to move a Data Form Web Part around our sites! Here is a link to the code: DataFormWebPart Solution

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• Overview of SOA Diagnostics in 11.1.1.6

  - by ShawnBailey

  What tools are available for diagnosing SOA Suite issues? There are a variety of tools available to help you and Support diagnose SOA Suite issues in 11g but it can be confusing as to which tool is appropriate for a particular situation and what their relationships are. This blog post will introduce the various tools and attempt to clarify what each is for and how they are related. Let's first list the tools we'll be addressing: RDA: Remote Diagnostic Agent DFW: Diagnostic Framework Selective Tracing DMS: Dynamic Monitoring Service ODL: Oracle Diagnostic Logging ADR: Automatic Diagnostics Repository ADRCI: Automatic Diagnostics Repository Command Interpreter WLDF: WebLogic Diagnostic Framework This overview is not mean to be a comprehensive guide on using all of these tools, however, extensive reference materials are included that will provide many more details on their execution. Another point to note is that all of these tools are applicable for Fusion Middleware as a whole but specific products may or may not have implemented features to leverage them. A couple of the tools have a WebLogic Scripting Tool or 'WLST' interface. WLST is a command interface for executing pre-built functions and custom scripts against a domain. A detailed WLST tutorial is beyond the scope of this post but you can find general information here. There are more specific resources in the below sections. In this post when we refer to 'Enterprise Manager' or 'EM' we are referring to Enterprise Manager Fusion Middleware Control. RDA (Remote Diagnostic Agent) RDA is a standalone tool that is used to collect both static configuration and dynamic runtime information from the SOA environment. RDA is generally run manually from the command line against a domain or single server. When opening a new Service Request, including an RDA collection can dramatically decrease the back and forth required to collect logs and configuration information for Support. After installing RDA you configure it to use the SOA Suite module as decribed in the referenced resources. The SOA module includes the Oracle WebLogic Server (WLS) module by default in order to include all of the relevant information for the environment. In addition to this basic configuration there is also an advanced mode where you can set the number of thread dumps for the collections, log files, Incidents, etc. When would you use it? When creating a Service Request or otherwise working with Oracle resources on an issue, capturing environment snapshots to baseline your configuration or to diagnose an issue on your own. How is it related to the other tools? RDA is related to DFW in that it collects the last 10 Incidents from the server by default. In a similar manner, RDA is related to ODL through its collection of the diagnostic logs and these may contain information from Selective Tracing sessions. Examples of what it currently collects: (for details please see the links in the Resources section) Diagnostic Logs (ODL) Diagnostic Framework Incidents (DFW) SOA MDS Deployment Descriptors SOA Repository Summary Statistics Thread Dumps Complete Domain Configuration RDA Resources: Webcast Recording: Using RDA with Oracle SOA Suite 11g Blog Post: Diagnose SOA Suite 11g Issues Using RDA Download RDA How to Collect Analysis Information Using RDA for Oracle SOA Suite 11g Products [ID 1350313.1] How to Collect Analysis Information Using RDA for Oracle SOA Suite and BPEL Process Manager 11g [ID 1352181.1] Getting Started With Remote Diagnostic Agent: Case Study - Oracle WebLogic Server (Video) [ID 1262157.1] top DFW (Diagnostic Framework) DFW provides the ability to collect specific information for a particular problem when that problem occurs. DFW is included with your SOA Suite installation and deployed to the domain. Let's define the components of DFW. Diagnostic Dumps: Specific diagnostic collections that are defined at either the 'system' or product level. Examples would be diagnostic logs or thread dumps. Incident: A collection of Diagnostic Dumps associated with a particular problem Log Conditions: An Oracle Diagnostic Logging event that DFW is configured to listen for. If the event is identified then an Incident will be created. WLDF Watch: The WebLogic Diagnostic Framework or 'WLDF' is not a component of DFW, however, it can be a source of DFW Incident creation through the use of a 'Watch'. WLDF Notification: A Notification is a component of WLDF and is the link between the Watch and DFW. You can configure multiple Notification types in WLDF and associate them with your Watches. 'FMWDFW-notification' is available to you out of the box to allow for DFW notification of Watch execution. Rule: Defines a WLDF Watch or Log Condition for which we want to associate a set of Diagnostic Dumps. When triggered the specified dumps will be collected and added to the Incident Rule Action: Defines the specific Diagnostic Dumps to collect for a particular rule ADR: Automatic Diagnostics Repository; Defined for every server in a domain. This is where Incidents are stored Now let's walk through a simple flow: Oracle Web Services error message OWS-04086 (SOAP Fault) is generated on managed server 1 DFW Log Condition for OWS-04086 evaluates to TRUE DFW creates a new Incident in the ADR for managed server 1 DFW executes the specified Diagnostic Dumps and adds the output to the Incident In this case we'll grab the diagnostic log and thread dump. We might also want to collect the WSDL binding information and SOA audit trail When would you use it? When you want to automatically collect Diagnostic Dumps at a particular time using a trigger or when you want to manually collect the information. In either case it can be readily uploaded to Oracle Support through the Service Request. How is it related to the other tools? DFW generates Incidents which are collections of Diagnostic Dumps. One of the system level Diagonstic Dumps collects the current server diagnostic log which is generated by ODL and can contain information from Selective Tracing sessions. Incidents are included in RDA collections by default and ADRCI is a tool that is used to package an Incident for upload to Oracle Support. In addition, both ODL and DMS can be used to trigger Incident creation through DFW. The conditions and rules for generating Incidents can become quite complicated and the below resources go into more detail. A simpler approach to leveraging at least the Diagnostic Dumps is through WLST (WebLogic Scripting Tool) where there are commands to do the following: Create an Incident Execute a single Diagnostic Dump Describe a Diagnostic Dump List the available Diagnostic Dumps The WLST option offers greater control in what is generated and when. It can be a great help when collecting information for Support. There are overlaps with RDA, however, DFW is geared towards collecting specific runtime information when an issue occurs while existing Incidents are collected by RDA. There are 3 WLDF Watches configured by default in a SOA Suite 11g domain: Stuck Threads, Unchecked Exception and Deadlock. These Watches are enabled by default and will generate Incidents in ADR. They are configured to reset automatically after 30 seconds so they have the potential to create multiple Incidents if these conditions are consistent. The Incidents generated by these Watches will only contain System level Diagnostic Dumps. These same System level Diagnostic Dumps will be included in any application scoped Incident as well. Starting in 11.1.1.6, SOA Suite is including its own set of application scoped Diagnostic Dumps that can be executed from WLST or through a WLDF Watch or Log Condition. These Diagnostic Dumps can be added to an Incident such as in the earlier example using the error code OWS-04086. soa.config: MDS configuration files and deployed-composites.xml soa.composite: All artifacts related to the deployed composite soa.wsdl: Summary of endpoints configured for the composite soa.edn: EDN configuration summary if applicable soa.db: Summary DB information for the SOA repository soa.env: Coherence cluster configuration summary soa.composite.trail: Partial audit trail information for the running composite The current release of RDA has the option to collect the soa.wsdl and soa.composite Diagnostic Dumps. More Diagnostic Dumps for SOA Suite products are planned for future releases along with enhancements to DFW itself. DFW Resources: Webcast Recording: SOA Diagnostics Sessions: Diagnostic Framework Diagnostic Framework Documentation DFW WLST Command Reference Documentation for SOA Diagnostic Dumps in 11.1.1.6 top Selective Tracing Selective Tracing is a facility available starting in version 11.1.1.4 that allows you to increase the logging level for specific loggers and for a specific context. What this means is that you have greater capability to collect needed diagnostic log information in a production environment with reduced overhead. For example, a Selective Tracing session can be executed that only increases the log level for one composite, only one logger, limited to one server in the cluster and for a preset period of time. In an environment where dozens of composites are deployed this can dramatically reduce the volume and overhead of the logging without sacrificing relevance. Selective Tracing can be administered either from Enterprise Manager or through WLST. WLST provides a bit more flexibility in terms of exactly where the tracing is run. When would you use it? When there is an issue in production or another environment that lends itself to filtering by an available context criteria and increasing the log level globally results in too much overhead or irrelevant information. The information is written to the server diagnostic log and is exportable from Enterprise Manager How is it related to the other tools? Selective Tracing output is written to the server diagnostic log. This log can be collected by a system level Diagnostic Dump using DFW or through a default RDA collection. Selective Tracing also heavily leverages ODL fields to determine what to trace and to tag information that is part of a particular tracing session. Available Context Criteria: Application Name Client Address Client Host Composite Name User Name Web Service Name Web Service Port Selective Tracing Resources: Webcast Recording: SOA Diagnostics Session: Using Selective Tracing to Diagnose SOA Suite Issues How to Use Selective Tracing for SOA [ID 1367174.1] Selective Tracing WLST Reference top DMS (Dynamic Monitoring Service) DMS exposes runtime information for monitoring. This information can be monitored in two ways: Through the DMS servlet As exposed MBeans The servlet is deployed by default and can be accessed through http://<host>:<port>/dms/Spy (use administrative credentials to access). The landing page of the servlet shows identical columns of what are known as Noun Types. If you select a Noun Type you will see a table in the right frame that shows the attributes (Sensors) for the Noun Type and the available instances. SOA Suite has several exposed Noun Types that are available for viewing through the Spy servlet. Screenshots of the Spy servlet are available in the Knowledge Base article How to Monitor Runtime SOA Performance With the Dynamic Monitoring Service (DMS). Every Noun instance in the runtime is exposed as an MBean instance. As such they are generally available through an MBean browser and available for monitoring through WLDF. You can configure a WLDF Watch to monitor a particular attribute and fire a notification when the threshold is exceeded. A WLDF Watch can use the out of the box DFW notification type to notify DFW to create an Incident. When would you use it? When you want to monitor a metric or set of metrics either manually or through an automated system. When you want to trigger a WLDF Watch based on a metric exposed through DMS. How is it related to the other tools? DMS metrics can be monitored with WLDF Watches which can in turn notify DFW to create an Incident. DMS Resources: How to Monitor Runtime SOA Performance With the Dynamic Monitoring Service (DMS) [ID 1368291.1] How to Reset a SOA 11g DMS Metric DMS Documentation top ODL (Oracle Diagnostic Logging) ODL is the primary facility for most Fusion Middleware applications to log what they are doing. Whenever you change a logging level through Enterprise Manager it is ultimately exposed through ODL and written to the server diagnostic log. A notable exception to this is WebLogic Server which uses its own log format / file. ODL logs entries in a consistent, structured way using predefined fields and name/value pairs. Here's an example of a SOA Suite entry: [2012-04-25T12:49:28.083-06:00] [AdminServer] [ERROR] [] [oracle.soa.bpel.engine] [tid: [ACTIVE].ExecuteThread: '1' for queue: 'weblogic.kernel.Default (self-tuning)'] [userId: ] [ecid: 0963fdde7e77631c:-31a6431d:136eaa46cda:-8000-00000000000000b4,0] [errid: 41] [WEBSERVICE_PORT.name: BPELProcess2_pt] [APP: soa-infra] [composite_name: TestProject2] [J2EE_MODULE.name: fabric] [WEBSERVICE.name: bpelprocess1_client_ep] [J2EE_APP.name: soa-infra] Error occured while handling a post operation[[ When would you use it? You'll use ODL almost every time you want to identify and diagnose a problem in the environment. The entries are written to the server diagnostic log. How is it related to the other tools? The server diagnostic logs are collected by DFW and RDA. Selective Tracing writes its information to the diagnostic log as well. Additionally, DFW log conditions are triggered by ODL log events. ODL Resources: ODL Documentation top ADR (Automatic Diagnostics Repository) ADR is not a tool in and of itself but is where DFW stores the Incidents it creates. Every server in the domain has an ADR location which can be found under <SERVER_HOME>/adr. This is referred to the as the ADR 'Base' location. ADR also has what are known as 'Home' locations. Example: You have a domain called 'myDomain' and an associated managed server called 'myServer'. Your admin server is called 'AdminServer'. Your domain home directory is called 'myDomain' and it contains a 'servers' directory. The 'servers' directory contains a directory for the managed server called 'myServer' and here is where you'll find the 'adr' directory which is the ADR 'Base' location for myServer. To get to the ADR 'Home' locations we drill through a few levels: diag/ofm/myDomain/ In an 11.1.1.6 SOA Suite domain you will see 2 directories here, 'myServer' and 'soa-infra'. These are the ADR 'Home' locations. 'myServer' is the 'system' ADR home and contains system level Incidents. 'soa-infra' is the name that SOA Suite used to register with DFW and this ADR home contains SOA Suite related Incidents Each ADR home location contains a series of directories, one of which is called 'incident'. This is where your Incidents are stored. When would you use it? It's a good idea to check on these locations from time to time to see whether a lot of Incidents are being generated. They can be cleaned out by deleting the Incident directories or through the ADRCI tool. If you know that an Incident is of particular interest for an issue you're working with Oracle you can simply zip it up and provide it. How does it relate to the other tools? ADR is obviously very important for DFW since it's where the Incidents are stored. Incidents contain Diagnostic Dumps that may relate to diagnostic logs (ODL) and DMS metrics. The most recent 10 Incident directories are collected by RDA by default and ADRCI relies on the ADR locations to help manage the contents. top ADRCI (Automatic Diagnostics Repository Command Interpreter) ADRCI is a command line tool for packaging and managing Incidents. When would you use it? When purging Incidents from an ADR Home location or when you want to package an Incident along with an offline RDA collection for upload to Oracle Support. How does it relate to the other tools? ADRCI contains a tool called the Incident Packaging System or IPS. This is used to package an Incident for upload to Oracle Support through a Service Request. Starting in 11.1.1.6 IPS will attempt to collect an offline RDA collection and include it with the Incident package. This will only work if Perl is available on the path, otherwise it will give a warning and package only the Incident files. ADRCI Resources: How to Use the Incident Packaging System (IPS) in SOA 11g [ID 1381259.1] ADRCI Documentation top WLDF (WebLogic Diagnostic Framework) WLDF is functionality available in WebLogic Server since version 9. Starting with FMw 11g a link has been added between WLDF and the pre-existing DFW, the WLDF Watch Notification. Let's take a closer look at the flow: There is a need to monitor the performance of your SOA Suite message processing A WLDF Watch is created in the WLS console that will trigger if the average message processing time exceeds 2 seconds. This metric is monitored through a DMS MBean instance. The out of the box DFW Notification (the Notification is called FMWDFW-notification) is added to the Watch. Under the covers this notification is of type JMX. The Watch is triggered when the threshold is exceeded and fires the Notification. DFW has a listener that picks up the Notification and evaluates it according to its rules, etc When it comes to automatic Incident creation, WLDF is a key component with capabilities that will grow over time. When would you use it? When you want to monitor the WLS server log or an MBean metric for some condition and fire a notification when the Watch is triggered. How does it relate to the other tools? WLDF is used to automatically trigger Incident creation through DFW using the DFW Notification. WLDF Resources: How to Monitor Runtime SOA Performance With the Dynamic Monitoring Service (DMS) [ID 1368291.1] How To Script the Creation of a SOA WLDF Watch in 11g [ID 1377986.1] WLDF Documentation top

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