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  • Re-ordering C++ template functions

    - by DeadMG
    In C++, I have a certain template function that, on a given condition, calls a template function in another class. The trouble is that the other class requires the full definition of the first class to be implemented, as it creates the second class and stores them and manages them in similar fashions. The trouble is that naturally, they fall as one class, and thus have some tight interop, except that I need them to be two classes for threading reasons. A sort of, master for all threads, one child per thread, system. Any advice on how this can be implemented?

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  • Will these security functions be enough? (PHP)

    - by ggfan
    I am trying to secure my site so I don't have sql injections and xss scripting. Here's my code. //here's the from, for brevity, i just show a field for users to put firstname <form> <label for="first_name" class="styled">First Name:</label> <input type="text" id="first_name" name="first_name" value="<?php if (!empty($first_name)) echo $first_name; ?>" /><br /> //submit button etc </form> if (isset($_POST['submit'])) { //gets rid of extra whitesapce and escapes $first_name = mysqli_real_escape_string($dbc, trim($_POST['first_name'])); //check if $first_name is a string if(!is_string($first_name) { echo "not string"; } //then insert into the database. ....... } mysqli_real_espace_string: I know that this func escapes certain letters like \n \r, so when the data gets inputted into the dbc, it would have '\' next to all the escaped letters? --Will this script be enough to prevent most sql injections? just escaping and checking if the data is a string. For integers values(like users putting in prices), i just: is_numeric(). --How should I use htmlspecialchars? Should I use it only when echoing and displaying user data? Or should I also use this too when inputting data to a dbc? --When should I use strip_tags() or htmlspecialchars? SOO with all these function... if (isset($_POST['submit'])) { //gets rid of extra whitesapce and escapes $first_name = mysqli_real_escape_string($dbc, trim($_POST['first_name'])); //check if $first_name is a string if(!is_string($first_name) { echo "not string"; } //gets rid of any <,>,& htmlspecialchars($first_name); //strips any tags with the first name strip_tags($first_name) //then insert into the database. ....... } Which funcs should I use for sql injections and which ones should I use for xss?

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  • What is the best way to identify that a function returned and automatically do something with it?

    - by EpsilonVector
    I'm implementing user threads on a Linux 2.4 kernel (homework) and my threads are basically just functions running with their own execution context (for example: uthread_create(functionpointer, args)). I'm having a hard time figuring out how to catch the return value and have it ready to be returned when two threads join. I know where to get the value from (eax), but not how to identify that the function actually finished. There's something called atexit, but I've seen people advising against using it, so... what is the best way to discover that a function returned and do something about it?

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  • Difference between these two functions that find Palindromes....

    - by Moin
    I wrote a function to check whether a word is palindrome or not but "unexpectedly", that function failed quite badly, here it is: bool isPalindrome (const string& s){ string reverse = ""; string original = s; for (string_sz i = 0; i != original.size(); ++i){ reverse += original.back(); original.pop_back(); } if (reverse == original) return true; else return false; } It gives me "string iterator offset out of range error" when you pass in a string with only one character and returns true even if we pass in an empty string (although I know its because of the intialisation of the reverse variable) and also when you pass in an unassigned string for example: string input; isPalindrome(input); Later, I found a better function which works as you would expect: bool found(const string& s) { bool found = true; for (string::const_iterator i = s.begin(), j = s.end() - 1; i < j; ++i, --j) { if (*i != *j) found = false; } return found; } Unlike the first function, this function correctly fails when you give it an unassigned string variable or an empty string and works for single characters and such... So, good people of stackoverflow please point out to me why the first function is so bad... Thank You.

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  • Pass the current state of a function into another function in C/C++

    - by sand
    Is there a way to pass the current state of a function into another function in C/C++? I mean all the parameters and local variables by current state. For example: void funcA (int a, int b) { char c; int d, e; // Do something with the variables. // ... funcB(); // Do something more. } void funcB() { // funcB() should be able to access variables a,b,c,d & e // and any change in these variables reflect into funcA(). } The code is in bad shape if there is a need for funcB() kind of functions. But can it be achieved? This can help if someone is starting to re-factor a long method with multiple parameters.

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  • Accessing Sub functions /procedures from DPR or other function / procedure in Delphi

    - by HX_unbanned
    Hello, stackoverflowers :) As much I know - Subroutines are with Private access mode to its parent unction / procedure, right? Is there any way to access them from "outer-world" - dpr or other function / procedure in unit? Also - which way takes more calcualtion and space to compiled file? for example: function blablabla(parameter : tparameter) : abcde; procedure xyz(par_ : tpar_); begin // ... end; begin // ... end; procedure albalbalb(param : tparam) : www; begin xyz(par_ : tpar); // is there any way to make this function public / published to access it therefore enabling to call it this way? end; // all text is random. // also, is there way to call it from DPR in this manner? // in C++ this can be done by specifing access mode and/or using "Friend" class .. but in DELPHI?

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  • Using date functions in android application?

    - by rob
    Hi there, I am displaying some event data based on the todays event and a list of events in a week. Currently I am displaying all the events in form of list from the file, As the file contains out dated events as well but I want to display on the basis of today's date events and a week events then week after. In short I want to restrict the list on the basis of this and extract information. I know there is a class java.util containing Date class, but need some quick idea and help how can I do this? Can anyone quote example? Thanks

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  • Operators vs Functions in C/C++

    - by user356106
    Someone recently asked me the difference between a C++ standard operator (e.g. new,delete,sizeof) and function (e.g. tan,delete, malloc). By "standard" I mean those provided by default by the compiler suite, and not user defined. Below were the answers I gave, though neither seemed satisfactory. (1) An operator doesn't need any headers to be included to use it : E.g. you can have a call to new without including any headers. However, a function (say free() ) does need headers included, compulsorily. (2) An operator is defined as such (ie as a class operator) somewhere in the standard headers. A function isn't. Can you critique these answers and give me a better idea of the difference?

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  • Why is order important in moving from tab to tab programmatically (and new in 1.8.10

    - by Bruce
    Hi folks, Up until I updated to jquery-ui-1.8.10 (already using jQuery 1.5), the following code has worked as expected: case 'baseeditor': $('#tab1').html(responseText).fadeIn(500, function() { ... load the contents of the tab and stuff... }); $("#prolearn").tabs("select",1); break; case ... The tab is fueled and then focus is moved from tab0 (from where the ajax call is initiated) to tab1. Now, that code won't work, but this version does: case 'baseeditor': $("#prolearn").tabs("select",1); $('#tab1').html(responseText).fadeIn(500, function() { ... load the contents of the tab and stuff... }); break; case ... Can someone explain the difference - have I just been lucky getting away with my original version? Thanks/Bruce

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  • Linq Order By a subtable

    - by Michael
    Hello, My question is how to sort a Linq query by a sub table: Table Apps: - app_id - name Table AppStatus: - app_status_id - app_id - severity - status_date I would like to have a query with all the apps, sorted by the last status severity: app_id name 1 first 2 second 3 third app_status_id app_id severity status_date 1 1 5 12-4-2010 2 1 2 15-4-2010 3 2 7 10-4-2010 4 3 3 13-4-2010 Now i want it sorted like: app_id name 3 third 1 first 2 second Can anyone help me with a LINQ query for this. I tried the following already, but that didn't work: var apps = from apps in dc.Apps orderby apps.AppStatus.LastOrDefault().severity select apps;

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  • if with multiple conditions, order of execution

    - by markus
    Hi, In an if statement with multiple conditions is second executed if the outcome is clear after checking the first condition? example: if(i>0 && array[i]==0){ } If I swap the conditions a seg fault may occur for negative values of i but this way the memory debugger doesn't find a problem. Can I be sure that this works always or do have have to use nested if statements?

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  • do you call them functions, procedures or methods?

    - by lowlyintern
    consider a standard c# 'function' public void foo() { //some code } In c or c++ this is called a 'function' - even if taking no parameters and returning no value. In another language maybe it would be a 'procedure'. In object orientation speak it would be called a 'method' if a class member. What would be the correct term to use in c#?

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  • error_expected_primary expression before in. In functions

    - by user2975402
    Here is my code. I try to fix it and I always obtain the same error: expected primary expression before 'int'. in line 47, 55, 63, 80, 86. And I've already tried this program in small pieces before and it works. It doesn't marked that error. ` #include using namespace std; int add (int a, int b) { int r; r=a+b; return (r); } int ssub (int a, int b) { int r; r=a-b; return (r); } int mult(int a, int b) { int r; r=a*b; return (r); } int menu(int a, int b){ int r; char x; cout <<"What do you want to do: \na.Adding \n s. Substract \n m. Multiply. \n. e. Exit"<<endl; cin>>x; switch (x){ case 'a': cout << "Give a value for a"<<endl; cin>>a; cout <<"Give a value for b"<<endl; cin>>b; add (int a, int b); //aquí y en otras líneas me sale: expected primary expression before int. break; case 's': cout << "Give a value for a"<<endl; cin>>a; cout <<"Give a value for b"<<endl; cin>>b; ssub (int a, int b); break; case 'm': cout << "Give a value for a"<<endl; cin>>a; cout <<"Give a value for b"<<endl; cin>>b; mult (int a, int b); break; case 'e': x='e'; break; default: cout<<"Wrong choice. Run the program again and choose another letter"<<endl; break; } return r; } cout<<"The result is " << menu (int a, int b)<<endl; int main() { menu (int a, int b); return 0; } `

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  • Unit testing a functions whose purposes is side effects

    - by David
    How would you unit test do_int_to_string_conversion? #include <string> #include <iostream> void do_int_to_string_conversion(int i, std::string& s) { switch(i) { case 1: s="1"; break; case 2: s="2"; break; default: s ="Nix"; } std::cout << s << "\n"; } int main(int argc, char** argv){ std::string little_s; do_int_to_string_conversion(1, little_s); do_int_to_string_conversion(2, little_s); do_int_to_string_conversion(3, little_s); }

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  • R table column order when including the empty string

    - by Libo Cannici
    I have a series of value that include the empty string levels(mydata$phone_partner_products) "" "dont_know" "maybe_interesting" "not_interesting" "very_interesting" "very_not_interesting" If I make a frequencies table I get this table(mydata$phone_partner_products) dont_know maybe_interesting 3752 226 2907 not_interesting very_interesting very_not_interesting 1404 1653 1065 How can I reorder the columns in a more meaningful way? How can I rename the empty string "" level? Thank you a lot in advance.

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  • Rails 3 Order By Count on has_many :through

    - by goo
    I have an application where I can list Items and add tags to each Item. The models Items and Tags are associated like this: class Item < ActiveRecord::Base has_many :taggings has_many :tags, :through => :taggings end class Tagging < ActiveRecord::Base belongs_to :item belongs_to :tag end class Tag < ActiveRecord::Base has_many :taggings has_many :items, :through => :taggings end So, this many-to-many relationship allows me to set n tags for each Item, and the same tag can be used several times. I'd like to list all tags ordered by the number of items associated with this tag. More used tags, shows first. Less used, last. How can I do that? Regards.

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  • Templates, interfaces (multiple inheritance) and static functions (named constructors)

    - by fledgling Cxx user
    Setup I have a graph library where I am trying to decompose things as much as possible, and the cleanest way to describe it that I found is the following: there is a vanilla type node implementing only a list of edges: class node { public: int* edges; int edge_count; }; Then, I would like to be able to add interfaces to this whole mix, like so: template <class T> class node_weight { public: T weight; }; template <class T> class node_position { public: T x; T y; }; and so on. Then, the actual graph class comes in, which is templated on the actual type of node: template <class node_T> class graph { protected: node_T* nodes; public: static graph cartesian(int n, int m) { graph r; r.nodes = new node_T[n * m]; return r; } }; The twist is that it has named constructors which construct some special graphs, like a Cartesian lattice. In this case, I would like to be able to add some extra information into the graph, depending on what interfaces are implemented by node_T. What would be the best way to accomplish this? Possible solution I thought of the following humble solution, through dynamic_cast<>: template <class node_T, class weight_T, class position_T> class graph { protected: node_T* nodes; public: static graph cartesian(int n, int m) { graph r; r.nodes = new node_T[n * m]; if (dynamic_cast<node_weight<weight_T>>(r.nodes[0]) != nullptr) { // do stuff knowing you can add weights } if (dynamic_cast<node_position<positionT>>(r.nodes[0]) != nullptr) { // do stuff knowing you can set position } return r; } }; which would operate on node_T being the following: template <class weight_T, class position_T> class node_weight_position : public node, public node_weight<weight_T>, public node_position<position_T> { // ... }; Questions Is this -- philosophically -- the right way to go? I know people don't look nicely at multiple inheritance, though with "interfaces" like these it should all be fine. There are unfortunately problems with this. From what I know at least, dynamic_cast<> involves quite a bit of run-time overhead. Hence, I run into a problem with what I had solved earlier: writing graph algorithms that require weights independently of whether the actual node_T class has weights or not. The solution with this 'interface' approach would be to write a function: template <class node_T, class weight_T> inline weight_T get_weight(node_T const & n) { if (dynamic_cast<node_weight<weight_T>>(n) != nullptr) { return dynamic_cast<node_weight<weight_T>>(n).weight; } return T(1); } but the issue with it is that it works using run-time information (dynamic_cast), yet in principle I would like to decide it at compile-time and thus make the code more efficient. If there is a different solution that would solve both problems, especially a cleaner and better one than what I have, I would love to hear about it!

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  • c Pointer to pointer, or passing list to functions

    - by user361808
    Hi, I am new to c programming. Could anyone please tell me what's wrong with the following program? typedef struct Person_s { int age; char name[40]; } Person_t; int process_list(int *countReturned, Person_t **p_list) { Person_t *rowPtr=0; //the actual program will fethc data from DB int count =1; if(!((*p_list) = (Person_t *) malloc(sizeof(Person_t)))) { return -1; } rowPtr = *p_list; rowPtr[count-1].age =19; strcpy(rowPtr[count-1].name,"Prince Dastan"); *countReturned = count; return 0; } int main(int argc, char *argv[]) { Person_t *tmpPerson=0; Person_t **p_list=0; int *count=0; int i; process_list(count,p_list); tmpPerson = *p_list; for(i=0; i< *count; i++) { printf("Name: %s , age: %d\n",tmpPerson->name,tmpPerson->age); tmpPerson++; } //free(tmpPerson); return 0; }

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  • Need help with some functions and variables

    - by Doug
    function createXMLHTTP() { xmlhttp = =new XMLHttpRequest(); return xmlhttp; } I'm trying to create 3 instances of this, but it all has the same variable name which is xmlhttp. How can I dynamically create different variable names? I'm not sure if that's the right way to ask the question. I want to create like xmlhttp1, xmlhttp2, xmlhttp3, so then I can reference each one.

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  • Calling member functions dynamically

    - by user652511
    I'm pretty sure it's possible to call a class and its member function dynamically in Delphi, but I can't quite seem to make it work. What am I missing? // Here's a list of classes (some code removed for clarity) moClassList : TList; moClassList.Add( TClassA ); moClassList.Add( TClassB ); // Here is where I want to call an object's member function if the // object's class is in the list: for i := 0 to moClassList.Count - 1 do if oObject is TClass(moClassList[i]) then with oObject as TClass(moClassList[i]) do Foo(); I get an undeclared identifier for Foo() at compile. Clarification/Additional Information: What I'm trying to accomplish is to create a Change Notification system between business classes. Class A registers to be notified of changes in Class B, and the system stores a mapping of Class A - Class B. Then, when a Class B object changes, the system will call a A.Foo() to process the change. I'd like the notification system to not require any hard-coded classes if possible. There will always be a Foo() for any class that registers for notification. Maybe this can't be done or there's a completely different and better approach to my problem. By the way, this is not exactly an "Observer" design pattern because it's not dealing with objects in memory. Managing changes between related persistent data seems like a standard problem to be solved, but I've not found very much discussion about it. Again, any assistance would be greatly appreciated. Jeff

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  • Change div order in CSS or javascript

    - by Sam Holder
    say I have layout like so: <div id="main"> <div id="NormalContent"> {some content which is a fixed length list} </div> <div id="FeaturedContent"> {some content which may contain a long list} </div> </div> and I want to place FeaturedContent above NormalContent. Can I do this with CSS? I assume I can with Javascript?

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  • Basic string and value functions in Objective-C for iPhone

    - by David Maitland
    I have very little programming knowledge; only a fair bit in Visual Basic. How do I take a value from a text field, then do some simple math such as divide the value by two, then display it back to the user in the same field? In Visual Basic you could just do txtBoxOne.text = txtBoxOne.text / 2 I understand this question is more than one question and is very basic stuff, but I need to get my head out of Visual Basic and into where I should be :)

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