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• Internet Explorer 8 + Deflate

  - by Andreas Bonini

  I have a very weird problem.. I really do hope someone has an answer because I wouldn't know where else to ask. I am writing a cgi application in C++ which is executed by Apache and outputs HTML code. I am compressing the HTML output myself - from within my C++ application - since my web host doesn't support mod_deflate for some reason. I tested this with Firefox 2, Firefox 3, Opera 9, Opera 10, Google Chrome, Safari, IE6, IE7, IE8, even wget.. It works with ANYTHING except IE8. IE8 just says "Internet Explorer cannot display the webpage", with no information whatsoever. I know it's because of the compression only because it works if I disable it. Do you know what I'm doing wrong? I use zlib to compress it, and the exact code is: /* Compress it */ int compressed_output_size = content.length() + (content.length() * 0.2) + 16; char *compressed_output = (char *)Alloc(compressed_output_size); int compressed_output_length; Compress(compressed_output, compressed_output_size, (void *)content.c_str(), content.length(), &compressed_output_length); /* Send the compressed header */ cout << "Content-Encoding: deflate\r\n"; cout << boost::format("Content-Length: %d\r\n") % compressed_output_length; cgiHeaderContentType("text/html"); cout.write(compressed_output, compressed_output_length); static void Compress(void *to, size_t to_size, void *from, size_t from_size, int *final_size) { int ret; z_stream stream; stream.zalloc = Z_NULL; stream.zfree = Z_NULL; stream.opaque = Z_NULL; if ((ret = deflateInit(&stream, CompressionSpeed)) != Z_OK) COMPRESSION_ERROR("deflateInit() failed: %d", ret); stream.next_out = (Bytef *)to; stream.avail_out = (uInt)to_size; stream.next_in = (Bytef *)from; stream.avail_in = (uInt)from_size; if ((ret = deflate(&stream, Z_NO_FLUSH)) != Z_OK) COMPRESSION_ERROR("deflate() failed: %d", ret); if (stream.avail_in != 0) COMPRESSION_ERROR("stream.avail_in is not 0 (it's %d)", stream.avail_in); if ((ret = deflate(&stream, Z_FINISH)) != Z_STREAM_END) COMPRESSION_ERROR("deflate() failed: %d", ret); if ((ret = deflateEnd(&stream)) != Z_OK) COMPRESSION_ERROR("deflateEnd() failed: %d", ret); if (final_size) *final_size = stream.total_out; return; }

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• How to provide default argument as this object?

  - by atch

  I would like to have declaration like this: void Date::get_days_name(const Date& = this) which I would understand that if no argument is provided use this object as an argument. For some reason in VS I'm getting err msg: 'Error 1 error C2355: 'this' : can only be referenced inside non-static member ' Any idea what I'm doing wrong?

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• Parsing numbers at PreviewTextInput

  - by Nitin Chaudhari

  I have a WPF application in which I have a hook at PreviewTextInput, through that I get the currently entered character and I have the string already entered. Given this I need to write the following function : bool ShouldAccept(char newChar,string existingText) existingText can be comma seperated valid numbers(including exponential) and it should just return false when invalid characters are pressed. My code(if else based) currently has a lot of flaws, I wanted to know if there is any smart way to do it.

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• MySQL doesn't use index in join query

  - by Kocsonya Laci

  I have two tables: comments(id(primary key), author, ip(index)) and visitors(id(primary key), date_time, ip(index)) I want to join them like that: SELECT visitors.date_time FROM comments LEFT JOIN visitors ON ( comments.ip = visitors.ip ) WHERE comments.author = 'author' LIMIT 10 It works, but very slow.. In EXPLAIN it shows that it doesn't use the index on the visitors table: id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE comments ref author author 78 const 9660 Using where 1 SIMPLE visitors ALL NULL NULL NULL NULL 8033 Any ideas? Thanks!

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• Win32 C/C++ Load Image from memory buffer

  - by Bruno

  I want to load a image (.bmp) file on a Win32 application, but I do not want to use the standard LoadBitmap/LoadImage from Windows API: I want it to load from a buffer that is already in memory. I can easily load a bitmap directly from file and print it on the screen, but this issue is making me stuck :( What I'm looking for is a function that works like this: HBITMAP LoadBitmapFromBuffer(char* buffer, int width, int height); Thanks.

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• Fundamental types

  - by smerlin

  I always thought the following types are "fundamental types", so i thought my anwser to this question would be correct, but surprisingly it got downvoted... Searching the web, i found this. So, IBM says aswell those types are fundamental types.. Well how do you interpret the Standard, are following types (and similar types), "fundamental types" according to the c++ standard ? unsigned int signed char long double long long long long int unsigned long long int

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• Parameter has no walue

  - by Simon

  string queryString = "SELECT SUM(skupaj_kalorij)as Skupaj_Kalorij " + "FROM (obroki_save LEFT JOIN users ON obroki_save.ID_uporabnika=users.ID)" + "WHERE users.ID= " + a.ToString() + " AND obroki_save.datum =?"; using (OleDbCommand cmd = new OleDbCommand(queryString,database)) { cmd.Parameters.Add("@datum", OleDbType.Char).Value = DateTime.Now.ToShortDateString(); } Why doesn't the parametr datum get the date value? (the value of at least one complex parameter has not been determined )

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• C# hash password create salt question

  - by 5YrsLaterDBA

  If I create salt by using something like this: public class User { private const int Hash_Salt_Length = 8; private byte[] saltBytes = new byte[Hash_Salt_Length]; public User() { RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider(); rng.GetNonZeroBytes(saltBytes); } .... } The saltBytes bytes array will be different for each session (restart the application). How can I check password to allow user login our application?

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• Getting Type mismatch for my function

  - by Sandy Williams

  I am getting an error message i.e. Type mismatch: 'EMXWEB_IE_LAUNCH' Line (1): "' ==============================================================================". the function is Option Explicit Public Function EMXWEB_IE_LAUNCH (dicArguments, sErrMsg) Dim strVersion Dim strExeVersion Dim WshShell Dim strEMXWebBrowserTitleBarText Dim ie Const strFunctionName = "EMXWEB_IE_LAUNCH" Set ie = CreateObject( "InternetExplorer.Application" ) ie.Navigate "www.google.com" ie.Visible=True End Function Could any one let me know where i am wrong and why i am getting this issue

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• Implementing default constructors

  - by James

  Implement the default constructor, the constructors with one and two int parameters. The one-parameter constructor should initialize the first member of the pair, the second member of the pair is to be 0. Overload binary operator + to add the pairs as follows: (a, b) + (c, d) = (a + c, b + d); Overload the - analogously. Overload the * on pairs ant int as follows: (a, b) * c = (a * c, b * c). Write a program to test all the member functions and overloaded operators in your class definition. You will also need to write accessor (get) functions for each member. The definition of the class Pairs: class Pairs { public: Pairs(); Pairs(int first, int second); Pairs(int first); // other members and friends friend istream& operator>> (istream&, Pair&); friend ostream& operator<< (ostream&, const Pair&); private: int f; int s; }; Self-Test Exercise #17: istream& operator (istream& ins, Pair& second) { char ch; ins ch; // discard init '(' ins second.f; ins ch; // discard comma ',' ins second.s; ins ch; // discard final '(' return ins; } ostream& operator<< (ostream& outs, const Pair& second) { outs << '('; outs << second.f; outs << ", " ;// I followed the Author's suggestion here. outs << second.s; outs << ")"; return outs; }

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• Dangling pointer

  - by viswanathan

  How can the below code result in a dangling pointer. { char *cPointer = malloc ( some constant number ); /* some code */ free ( cPointer ); cPointer = NULL; /* some code */ }

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• C++ vector and segmentation faults

  - by Headspin

  I am working on a simple mathematical parser. Something that just reads number = 1 + 2; I have a vector containing these tokens. They store a type and string value of the character. I am trying to step through the vector to build an AST of these tokens, and I keep getting segmentation faults, even when I am under the impression my code should prevent this from happening. Here is the bit of code that builds the AST: struct ASTGen { const vector<Token> &Tokens; unsigned int size, pointer; ASTGen(const vector<Token> &t) : Tokens(t), pointer(0) { size = Tokens.size() - 1; } unsigned int next() { return pointer + 1; } Node* Statement() { if(next() <= size) { switch(Tokens[next()].type) { case EQUALS : Node* n = Assignment_Expr(); return n; } } advance(); } void advance() { if(next() <= size) ++pointer; } Node* Assignment_Expr() { Node* lnode = new Node(Tokens[pointer], NULL, NULL); advance(); Node* n = new Node(Tokens[pointer], lnode, Expression()); return n; } Node* Expression() { if(next() <= size) { advance(); if(Tokens[next()].type == SEMICOLON) { Node* n = new Node(Tokens[pointer], NULL, NULL); return n; } if(Tokens[next()].type == PLUS) { Node* lnode = new Node(Tokens[pointer], NULL, NULL); advance(); Node* n = new Node(Tokens[pointer], lnode, Expression()); return n; } } } }; ... ASTGen AST(Tokens); Node* Tree = AST.Statement(); cout << Tree->Right->Data.svalue << endl; I can access Tree->Data.svalue and get the = Node's token info, so I know that node is getting spawned, and I can also get Tree->Left->Data.svalue and get the variable to the left of the = I have re-written it many times trying out different methods for stepping through the vector, but I always get a segmentation fault when I try to access the = right node (which should be the + node) Any help would be greatly appreciated.

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• C++: incorrect swapping of nodes in linked list

  - by Dragon

  I have 2 simple structures: struct Address { char city[255]; }; typedef Address* AddressPtr; struct Person { char fullName[255]; Address* address; Person* next; }; typedef Person* PersonPtr; The Person structure forms the Linked list where new elements are added to the beginning of the list. What I want to do is to sort them by fullName. At first I tried to swap links, but I lost the beginning of the list and as a result my list was sorted partially. Then I decided to sort list by swapping the values of nodes. But I get strange results. For a list with names: Test3, Test2, Test1, I get Test3, Test3, Test3. Here is my sorting code: void sortByName(PersonPtr& head) { TaskPtr currentNode, nextNode; for(currentNode = head; currentNode->next != NULL; currentNode = currentNode->next) { for(nextNode = currentNode->next; nextNode != NULL; nextNode = nextNode->next) { if(strcmp(currentNode->fullName, nextNode->fullName) > 0) { swapNodes(currentNode, nextNode); } } } } void swapNodes(PersonPtr& node1, PersonPtr& node2) { PersonPtr temp_node = node2; strcpy(node2->fullName, node1->fullName); strcpy(node1->fullName, temp_node->fullName); strcpy(node2->address->city, node1->address->city); strcpy(node1->address->city, temp_node->address->city); } After the sorting completion, nodes values are a little bit strange. UPDATED This is how I swapped links void swapNodes(PersonPtr& node1, PersonPtr& node2) { PersonPtr temp_person; AddressPtr temp_address; temp_person = node2; node2 = node1; node1 = temp_person; temp_address = node2->address; node2->address = node1->address; node1->address = temp_address; }

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• I want to trace logs using a Macro multi parameter always null. problem c++ windows

  - by sxingfeng

  I am using the following way to cout a function's time: #define TIME_COST(message, ...)\ char szMessageBuffer[2048] = {0};\ va_list ArgList;\ va_start(ArgList, message);\ vsprintf_s(szMessageBuffer, 2048, message, ArgList);\ va_end(ArgList); \ string strMessage(szMessageBuffer);\ CQLogTimer t(strMessage); // CQLogTimer is a self destructor,which will cout life time of its own and print szMessageBuffer. However when I use the macro this : void fun { TIME_COST("hello->%s", filePath); XXXXXX } The message generated always is hello-(null) Can Any one help? Many thanks!

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• How can I hash a string to an int using c++?

  - by zebraman

  I have to write my own hash function. If I wanted to just make the simple hash function that maps each letter in the string to a numerical value (i.e. a=1, b=2, c=3, ...), is there a way I can perform this hash on a string without having to first convert it to a c-string to look at each individual char? Is there a more efficient way of hashing strings?

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• How to initialise a struct-type in the initialisation list?

  - by M4design

  How can I initilise a structure in the constructor list? Say: struct St{int x, y}; class Foo { public: Foo(int a = 0, int b = 0) : /*here initilise st_foo out of a and b*/ {} private: const St st_foo; };

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• SQLite/iPhone read copyright symbol

  - by Marco A

  Hi All, I am having problems reading the copyright symbol from a sqlite db that I have for my App that I am developing. I import the information manually, ie, from an excel sheet. I have tried two ways of doing it and failed with both: 1) Tried replacing the copyright symbol with "\u00ae" (unicode combination) within excel and then importing the modified file. - Result: I get the combination of \u00ae as a part of the string, it doesnt detect the unicode combination. 2) Tried leaving as it is. Importing the excel with the copyright symbol. - Result: I get a symbol that is different from the copyright, its something like an AE put together.looks like this: Æ Heres my code how I read from DB: -(void) readCategoriesFromDatabase:(NSString *) rest_input { // Init the products Array categories = [[NSMutableArray alloc] init]; // Open the database from the users filessytem rest_input = [rest_input stringByAppendingString:@"'"]; NSString *newString; newString = [@"select distinct category from food where restaurant='" stringByAppendingString:rest_input]; const char *cat_sqlStatement = [newString UTF8String]; sqlite3_stmt *cat_compiledStatement; if(sqlite3_prepare_v2(database, cat_sqlStatement, -1, &cat_compiledStatement, NULL) == SQLITE_OK) { // Loop through the results and add them to the feeds array while(sqlite3_step(cat_compiledStatement) == SQLITE_ROW) { NSString *catName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(cat_compiledStatement,0)]; // Create a new product object with the data from the database Product *category = [[Product alloc] initWithName:catName]; // Add the product object to the respective Array [categories addObject:category]; [category release]; } sqlite3_finalize(cat_compiledStatement); } NSLog(@"Finished Accessing Database to gather Categories...."); } I open the DB with this function: -(void) checkAndCreateDatabase{ NSLog(@"Checking/Creating Database...."); NSFileManager *fileManager = [NSFileManager defaultManager]; success = [fileManager fileExistsAtPath:databasePath]; [fileManager removeFileAtPath:databasePath handler:nil]; NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName]; [fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil]; [fileManager release]; if (sqlite3_open([databasePath UTF8String], &database) != SQLITE_OK) { sqlite3_close(database); database = nil; } NSLog(@"Finished Checking/Creating Database...."); } Thanks to anything that can help me out.

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• How can I break if gdb is attached, but continue if it is not?

  - by Michael Anderson

  I have some debugging code that if executed while running with GBD attached should break the execution of the application, but if GDB is not running it should continue. The code I'm working with looks something like this in structure: try { if( some_complex_expression ) { gdb_should_berak_here(); do_some_stuff(); throw MyException(); } } catch( const MyException & e ) { handle_exception_and_continue(); } What should gdb_should_break_here be?

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• Jumping into argv?

  - by jth

  Hi, I`am experimenting with shellcode and stumbled upon the nop-slide technique. I wrote a little tool that takes buffer-size as a parameter and constructs a buffer like this: [ NOP | SC | RET ], with NOP taking half of the buffer, followed by the shellcode and the rest filled with the (guessed) return address. Its very similar to the tool aleph1 described in his famous paper. My vulnerable test-app is the same as in his paper: int main(int argc, char **argv) { char little_array[512]; if(argc>1) strcpy(little_array,argv[1]); return 0; } I tested it and well, it works: jth@insecure:~/no_nx_no_aslr$ ./victim $(./exploit 604 0) $ exit But honestly, I have no idea why. Okay, the saved eip was overwritten as intended, but instead of jumping somewhere into the buffer, it jumped into argv, I think. gdb showed up the following addresses before strcpy() was called: (gdb) i f Stack level 0, frame at 0xbffff1f0: eip = 0x80483ed in main (victim.c:7); saved eip 0x154b56 source language c. Arglist at 0xbffff1e8, args: argc=2, argv=0xbffff294 Locals at 0xbffff1e8, Previous frame's sp is 0xbffff1f0 Saved registers: ebp at 0xbffff1e8, eip at 0xbffff1ec Address of little_array: (gdb) print &little_array[0] $1 = 0xbfffefe8 "\020" After strcpy(): (gdb) i f Stack level 0, frame at 0xbffff1f0: eip = 0x804840d in main (victim.c:10); saved eip 0xbffff458 source language c. Arglist at 0xbffff1e8, args: argc=-1073744808, argv=0xbffff458 Locals at 0xbffff1e8, Previous frame's sp is 0xbffff1f0 Saved registers: ebp at 0xbffff1e8, eip at 0xbffff1ec So, what happened here? I used a 604 byte buffer to overflow little_array, so he certainly overwrote saved ebp, saved eip and argc and also argv with the guessed address 0xbffff458. Then, after returning, EIP pointed at 0xbffff458. But little_buffer resides at 0xbfffefe8, that`s a difference of 1136 byte, so he certainly isn't executing little_array. I followed execution with the stepi command and well, at 0xbffff458 and onwards, he executes NOPs and reaches the shellcode. I'am not quite sure why this is happening. First of all, am I correct that he executes my shellcode in argv, not little_array? And where does the loader(?) place argv onto the stack? I thought it follows immediately after argc, but between argc and 0xbffff458, there is a gap of 620 bytes. How is it possible that he successfully "lands" in the NOP-Pad at Address 0xbffff458, which is way above the saved eip at 0xbffff1ec? Can someone clarify this? I have actually no idea why this is working. My test-machine is an Ubuntu 9.10 32-Bit Machine without ASLR. victim has an executable stack, set with execstack -s. Thanks in advance.

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• Find the position of a string in an array of string with the GLib

  - by e1s

  Hello, I have an array of string, like: char **strings = {"str1", "str2"}; And i would like to know if there is a function in the glib to find the position of a string in this array. I guess i could just do g_strcmp0 in a for() loop, but there may be a better way to do it. Thanks

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• wireless profile saving problem please help me out

  - by Jayjitraj

  DATA_BLOB in; DATA_BLOB out; BYTE pin=(BYTE)"FIPL2"; DWORD din=strlen((char*)pin)+1; in.pbData = pin; in.cbData = din; if(CryptProtectData(&in,L"what is it",NULL,NULL,NULL,0,&out)) { BYTE *b=out.pbData; Now I want to convert it into hexadecimal to save as my wifi password so what should i do }

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• gcc optimization? bug? and its practial implication to project

  - by kumar_m_kiran

  Hi All, My questions are divided into three parts Question 1 Consider the below code, #include <iostream> using namespace std; int main( int argc, char *argv[]) { const int v = 50; int i = 0X7FFFFFFF; cout<<(i + v)<<endl; if ( i + v < i ) { cout<<"Number is negative"<<endl; } else { cout<<"Number is positive"<<endl; } return 0; } No specific compiler optimisation options are used or the O's flag is used. It is basic compilation command g++ -o test main.cpp is used to form the executable. The seemingly very simple code, has odd behaviour in SUSE 64 bit OS, gcc version 4.1.2. The expected output is "Number is negative", instead only in SUSE 64 bit OS, the output would be "Number is positive". After some amount of analysis and doing a 'disass' of the code, I find that the compiler optimises in the below format - Since i is same on both sides of comparison, it cannot be changed in the same expression, remove 'i' from the equation. Now, the comparison leads to if ( v < 0 ), where v is a constant positive, So during compilation itself, the else part cout function address is added to the register. No cmp/jmp instructions can be found. I see that the behaviour is only in gcc 4.1.2 SUSE 10. When tried in AIX 5.1/5.3 and HP IA64, the result is as expected. Is the above optimisation valid? Or, is using the overflow mechanism for int not a valid use case? Question 2 Now when I change the conditional statement from if (i + v < i) to if ( (i + v) < i ) even then, the behaviour is same, this atleast I would personally disagree, since additional braces are provided, I expect the compiler to create a temporary built-in type variable and them compare, thus nullify the optimisation. Question 3 Suppose I have a huge code base, an I migrate my compiler version, such bug/optimisation can cause havoc in my system behaviour. Ofcourse from business perspective, it is very ineffective to test all lines of code again just because of compiler upgradation. I think for all practical purpose, these kinds of error are very difficult to catch (during upgradation) and invariably will be leaked to production site. Can anyone suggest any possible way to ensure to ensure that these kind of bug/optimization does not have any impact on my existing system/code base? PS : When the const for v is removed from the code, then optimization is not done by the compiler. I believe, it is perfectly fine to use overflow mechanism to find if the variable is from MAX - 50 value (in my case).

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• functional, bind1st and mem_fun

  - by Neil G

  Why won't this compile? #include <functional> #include <boost/function.hpp> class A { A() { typedef boost::function<void ()> FunctionCall; FunctionCall f = std::bind1st(std::mem_fun(&A::process), this); } void process() {} }; Errors: In file included from /opt/local/include/gcc44/c++/bits/stl_function.h:712, from /opt/local/include/gcc44/c++/functional:50, from a.cc:1: /opt/local/include/gcc44/c++/backward/binders.h: In instantiation of 'std::binder1st<std::mem_fun_t<void, A> >': a.cc:7: instantiated from here /opt/local/include/gcc44/c++/backward/binders.h:100: error: no type named 'second_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h:103: error: no type named 'first_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h:106: error: no type named 'first_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h:111: error: no type named 'second_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h:117: error: no type named 'second_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h: In function 'std::binder1st<_Operation> std::bind1st(const _Operation&, const _Tp&) [with _Operation = std::mem_fun_t<void, A>, _Tp = A*]': a.cc:7: instantiated from here /opt/local/include/gcc44/c++/backward/binders.h:126: error: no type named 'first_argument_type' in 'class std::mem_fun_t<void, A>' In file included from /opt/local/include/boost/function/detail/maybe_include.hpp:13, from /opt/local/include/boost/function/detail/function_iterate.hpp:14, from /opt/local/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:47, from /opt/local/include/boost/function.hpp:64, from a.cc:2: /opt/local/include/boost/function/function_template.hpp: In static member function 'static void boost::detail::function::void_function_obj_invoker0<FunctionObj, R>::invoke(boost::detail::function::function_buffer&) [with FunctionObj = std::binder1st<std::mem_fun_t<void, A> >, R = void]': /opt/local/include/boost/function/function_template.hpp:913: instantiated from 'void boost::function0<R>::assign_to(Functor) [with Functor = std::binder1st<std::mem_fun_t<void, A> >, R = void]' /opt/local/include/boost/function/function_template.hpp:722: instantiated from 'boost::function0<R>::function0(Functor, typename boost::enable_if_c<boost::type_traits::ice_not::value, int>::type) [with Functor = std::binder1st<std::mem_fun_t<void, A> >, R = void]' /opt/local/include/boost/function/function_template.hpp:1064: instantiated from 'boost::function<R()>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not::value, int>::type) [with Functor = std::binder1st<std::mem_fun_t<void, A> >, R = void]' a.cc:7: instantiated from here /opt/local/include/boost/function/function_template.hpp:153: error: no match for call to '(std::binder1st<std::mem_fun_t<void, A> >) ()'

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• How to Read from LocalResources in class Global area

  - by Nasser Hajloo

  I have a class name xxxx and a resource whichthe class read from it to set some string. Everything is fine and nothing goes wrong. The problem is that I have some Constant Global String which I set them in global area like public partial class ExampleDocument : ClassBase { const string TheProblem = "I can not read this string from resources cause here Methods do not work"; #region Method ... #endregion } The question is, How to read this strings frrom Rersource File.

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• multi-thread access MySQL error

  - by user188916

  I have written a simple multi-threaded C program to access MySQL,it works fine except when i add usleep() or sleep() function in each thread function. i created two pthreads in the main method, int main(){ mysql_library_init(0,NULL,NULL); printf("Hello world!\n"); init_pool(&p,100); pthread_t producer; pthread_t consumer_1; pthread_t consumer_2; pthread_create(&producer,NULL,produce_fun,NULL); pthread_create(&consumer_1,NULL,consume_fun,NULL); pthread_create(&consumer_2,NULL,consume_fun,NULL); mysql_library_end(); } void * produce_fun(void *arg){ pthread_detach(pthread_self()); //procedure while(1){ usleep(500000); printf("producer...\n"); produce(&p,cnt++); } pthread_exit(NULL); } void * consume_fun(void *arg){ pthread_detach(pthread_self()); MYSQL db; MYSQL *ptr_db=mysql_init(&db); mysql_real_connect(); //procedure while(1){ usleep(1000000); printf("consumer..."); int item=consume(&p); addRecord_d(ptr_db,"test",item); } mysql_thread_end(); pthread_exit(NULL); } void addRecord_d(MYSQL *ptr_db,const char *t_name,int item){ char query_buffer[100]; sprintf(query_buffer,"insert into %s values(0,%d)",t_name,item); //pthread_mutex_lock(&db_t_lock); int ret=mysql_query(ptr_db,query_buffer); if(ret){ fprintf(stderr,"%s%s\n","cannot add record to ",t_name); return; } unsigned long long update_id=mysql_insert_id(ptr_db); // pthread_mutex_unlock(&db_t_lock); printf("add record (%llu,%d) ok.",update_id,item); } the program output errors like: [Thread debugging using libthread_db enabled] [New Thread 0xb7ae3b70 (LWP 7712)] Hello world! [New Thread 0xb72d6b70 (LWP 7713)] [New Thread 0xb6ad5b70 (LWP 7714)] [New Thread 0xb62d4b70 (LWP 7715)] [Thread 0xb7ae3b70 (LWP 7712) exited] producer... producer... consumer...consumer...add record (31441,0) ok.add record (31442,1) ok.producer... producer... consumer...consumer...add record (31443,2) ok.add record (31444,3) ok.producer... producer... consumer...consumer...add record (31445,4) ok.add record (31446,5) ok.producer... producer... consumer...consumer...add record (31447,6) ok.add record (31448,7) ok.producer... Error in my_thread_global_end(): 2 threads didn't exit [Thread 0xb72d6b70 (LWP 7713) exited] [Thread 0xb6ad5b70 (LWP 7714) exited] [Thread 0xb62d4b70 (LWP 7715) exited] Program exited normally. and when i add pthread_mutex_lock in function addRecord_d,the error still exists. So what exactly the problem is?

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