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  • What is the equivalent of REGEXP_SUBSTR in mysql?

    - by KandadaBoggu
    I want to extract a word from a string column of a table. description =========================== abc order_id: 2 xxxx yyy aa mmm order_id: 3 nn kk yw Expected result set order_id =========================== 2 3 Table will at most have 100 rows, text length is ~256 char and column always has one order_id present. So performance is not an issue. In Oracle, I can use REGEXP_SUBSTR for this problem. How would I solve this in MySQL?

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  • simple question on C

    - by lego69
    I have this snippet of the code char *str = “123”; if(str[0] == 1) printf("Hello\n"); why I can't receive my Hello thanks in advance! how exactly compiler does this comparison if(str[0] == 1)?

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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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  • 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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  • Flex: Constant strings in metadata

    - by Daniel Engmann
    I have something like public class Controller { [Observer("fetchEmployeesEvent")] public function fetchEmployees() : void { //doSomething } } and I want something like public class Controller { public static const FETCH_EMPLOYEES_EVENT : String = "fetchEmployeesEvent"; [Observer(FETCH_EMPLOYEES_EVENT)] public function fetchEmployees() : void { //doSomething } } My problem is that only the first code snippet works. Flex seems to ignore the constant FETCH_EMPLOYEES_EVENT in the metadata-tag. My question is: Is it somehow possible to use constant strings in metadata?

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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++ memcpy problem :(

    - by Simon
    Hey all :) I have a problem my src pointer of memcpy is pointing wrong. unsigned char* lpBuffer is a buffer that contains my bytes, i checked with olly. The code: IMAGE_DOS_HEADER iDOSh; memcpy(&iDOSh,lpBuffer,sizeof(iDOSh)); The problem is that lpBuffer points wrong, output from debugger is dest = 002859E8 RIGHT src = 000001D8 FALSE src is pointing invalid :( i have no idea why Thanks for reading

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  • Java NoSuchElementException using scanner.nextInt()

    - by othnin
    I am trying to read in a pgm file (512x512 array) and when I read in a larger file I get the error: java.util.NoSuchElementException on reading element (3,97). I have created a much smaller file to read (23x23) and it reads fine. Is there a size limit? I have checked the file and confirmed that there is an int for the value: This appears to be the line it crashes at: fileArray[row][col] = scan.nextInt(); Here is the file: import java.util.Scanner; import java.io.*; public class FileReader { public static void main(String[] args) throws IOException { String fileName = "lena.pgma"; int width, height, maxValue; FileInputStream fileInputStream = null; fileInputStream = new FileInputStream(fileName); Scanner scan = new Scanner(fileInputStream); // Discard the magic number scan.nextLine(); // Discard the comment line scan.nextLine(); // Read pic width, height and max value width = scan.nextInt(); System.out.println("Width: " + width); height = scan.nextInt(); System.out.println("Heigth: " + height); maxValue = scan.nextInt(); fileInputStream.close(); // Now parse the file as binary data FileInputStream fin = new FileInputStream(fileName); DataInputStream dis = new DataInputStream(fin); // look for 4 lines (i.e.: the header) and discard them int numnewlines = 4; while (numnewlines > 0) { char c; do { c = (char)(dis.readUnsignedByte()); } while (c != '\n'); numnewlines--; } // read the image data int[][] fileArray = new int[height][width]; for (int row = 0; row < height; row++) { for (int col = 0; col < width; col++) { fileArray[row][col] = scan.nextInt(); System.out.print("(" + row + " ," + col +"): " + fileArray[row][col]+ " "); } System.out.println(); } dis.close(); } } any advise would be appreciated.

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  • Writing a managed wrapper for unmanaged (C++) code - custom types/structs

    - by Bobby
    faacEncConfigurationPtr FAACAPI faacEncGetCurrentConfiguration( faacEncHandle hEncoder); I'm trying to come up with a simple wrapper for this C++ library; I've never done more than very simple p/invoke interop before - like one function call with primitive arguments. So, given the above C++ function, for example, what should I do to deal with the return type, and parameter? FAACAPI is defined as: #define FAACAPI __stdcall faacEncConfigurationPtr is defined: typedef struct faacEncConfiguration { int version; char *name; char *copyright; unsigned int mpegVersion; unsigned long bitRate; unsigned int inputFormat; int shortctl; psymodellist_t *psymodellist; int channel_map[64]; } faacEncConfiguration, *faacEncConfigurationPtr; AFAIK this means that the return type of the function is a reference to this struct? And faacEncHandle is: typedef struct { unsigned int numChannels; unsigned long sampleRate; ... SR_INFO *srInfo; double *sampleBuff[MAX_CHANNELS]; ... double *freqBuff[MAX_CHANNELS]; double *overlapBuff[MAX_CHANNELS]; double *msSpectrum[MAX_CHANNELS]; CoderInfo coderInfo[MAX_CHANNELS]; ChannelInfo channelInfo[MAX_CHANNELS]; PsyInfo psyInfo[MAX_CHANNELS]; GlobalPsyInfo gpsyInfo; faacEncConfiguration config; psymodel_t *psymodel; /* quantizer specific config */ AACQuantCfg aacquantCfg; /* FFT Tables */ FFT_Tables fft_tables; int bitDiff; } faacEncStruct, *faacEncHandle; So within that struct we see a lot of other types... hmm. Essentially, I'm trying to figure out how to deal with these types in my managed wrapper? Do I need to create versions of these types/structs, in C#? Something like this: [StructLayout(LayoutKind.Sequential)] struct faacEncConfiguration { uint useTns; ulong bitRate; ... } If so then can the runtime automatically "map" these objects onto eachother? And, would I have to create these "mapped" types for all the types in these return types/parameter type hierarchies, all the way down until I get to all primitives? I know this is a broad topic, any advice on getting up-to-speed quickly on what I need to learn to make this happen would be very much appreciated! 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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  • Endianness conversion and g++ warnings

    - by SuperBloup
    I've got the following C++ code : template <int isBigEndian, typename val> struct EndiannessConv { inline static val fromLittleEndianToHost( val v ) { union { val outVal __attribute__ ((used)); uint8_t bytes[ sizeof( val ) ] __attribute__ ((used)); } ; outVal = v; std::reverse( &bytes[0], &bytes[ sizeof(val) ] ); return outVal; } inline static void convertArray( val v[], uint32_t size ) { // TODO : find a way to map the array for (uint32_t i = 0; i < size; i++) for (uint32_t i = 0; i < size; i++) v[i] = fromLittleEndianToHost( v[i] ); } }; Which work and has been tested (without the used attributes). When compiling I obtain the following errors from g++ (version 4.4.1) || g++ -Wall -Wextra -O3 -o t t.cc || t.cc: In static member function 'static val EndiannessConv<isBigEndian, val>::fromLittleEndianToHost(val)': t.cc|98| warning: 'used' attribute ignored t.cc|99| warning: 'used' attribute ignored || t.cc: In static member function 'static val EndiannessConv<isBigEndian, val>::fromLittleEndianToHost(val) [with int isBigEndian = 1, val = double]': t.cc|148| instantiated from here t.cc|100| warning: unused variable 'outVal' t.cc|100| warning: unused variable 'bytes' I've tried to use the following code : template <int size, typename valType> struct EndianInverser { /* should not compile */ }; template <typename valType> struct EndianInverser<4, valType> { static inline valType reverseEndianness( const valType &val ) { uint32_t castedVal = *reinterpret_cast<const uint32_t*>( &val ); castedVal = (castedVal & 0x000000FF << (3 * 8)) | (castedVal & 0x0000FF00 << (1 * 8)) | (castedVal & 0x00FF0000 >> (1 * 8)) | (castedVal & 0xFF000000 >> (3 * 8)); return *reinterpret_cast<valType*>( &castedVal ); } }; but it break when enabling optimizations due to the type punning. So, why does my used attribute got ignored? Is there a workaround to convert endianness (I rely on the enum to avoid type punning) in templates?

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  • a multi-component truth table for assembly

    - by Malfist
    Can someone help me convert this C if statement into something assembly can understand? if((plain>='a' && plain<='x') || (plain>='A' && plain <='X')){ code = plain+2; } plain is a char, which for assembly is stored in the al register. Any help would be appreciated.

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  • Using a macro for fstream file input as part of a class

    - by vette982
    I have a class that processes a file, and as part of the constructor with one argument I want to input a file using fstream. I basically want it do something like this class someClass{ public: someClass(char * FILENAME) { fstream fileToProcess; fileToProcess.open(<FILENAME>, fstream::in | fstream::out | fstream::app); } }; I want to pass the filename in as an argument to the class constructor, and then the class someClass will access it with fstream.

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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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  • What is an overloaded operator in c++?

    - by Jeff
    I realize this is a basic question but I have searched online, been to cplusplus.com, read through my book, and I can't seem to grasp the concept of overloaded operators. A specific example from cplusplus.com is: // vectors: overloading operators example #include <iostream> using namespace std; class CVector { public: int x,y; CVector () {}; CVector (int,int); CVector operator + (CVector); }; CVector::CVector (int a, int b) { x = a; y = b; } CVector CVector::operator+ (CVector param) { CVector temp; temp.x = x + param.x; temp.y = y + param.y; return (temp); } int main () { CVector a (3,1); CVector b (1,2); CVector c; c = a + b; cout << c.x << "," << c.y; return 0; } from http://www.cplusplus.com/doc/tutorial/classes2/ but reading through it I'm still not understanding them at all. I just need a basic example of the point of the overloaded operator (which I assume is the "CVector CVector::operator+ (CVector param)"). There's also this example from wikipedia: Time operator+(const Time& lhs, const Time& rhs) { Time temp = lhs; temp.seconds += rhs.seconds; if (temp.seconds >= 60) { temp.seconds -= 60; temp.minutes++; } temp.minutes += rhs.minutes; if (temp.minutes >= 60) { temp.minutes -= 60; temp.hours++; } temp.hours += rhs.hours; return temp; } from "http://en.wikipedia.org/wiki/Operator_overloading" The current assignment I'm working on I need to overload a ++ and a -- operator. Thanks in advance for the information and sorry about the somewhat vague question, unfortunately I'm just not sure on it at all.

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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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  • How does one smooth an image used as a control skin?

    - by kevmoo
    I'm embedding an image like this: [Embed(source="/tool_deleteUp.png")] private static const c_deleteButton_styleUp:Class; I'm using it like this: _removeButton = new Button(); _removeButton.setStyle('upSkin', c_deleteButton_styleUp); When I rotate the button, the image doesn't scale smoothly. I know the tricks one uses to scale an image loaded in an Image control, but I'm banging my head against a wall trying to figure out how to do it here. Help!

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  • Why is a c++ reference considered safer than a pointer?

    - by anand.arumug
    When the c++ compiler generates very similar assembler code for a reference and pointer, why is using references preferred (and considered safer) compared to pointers? I did see Difference between pointer variable and reference variable in C++ which discusses the differences between them. EDIT-1: I was looking at the assembler code generated by g++ for this small program: int main(int argc, char* argv[]) { int a; int &ra = a; int *pa = &a; }

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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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  • sending and receiving with sockets in java?

    - by Darksole
    I am working on sending and receiving from clients and servers in java, and am stumped at the moment. the client socket is to contact a server at “localhost” port 4321. The client will receive a string from the server and alternate spelling the contents of this string with the server. For example, given the string “Bye Bye”, the client (which always begins sending the first letter) sends “B”, receives “y”, sends “e”, receives “ ”, sends “B”, receives “y”, sends “e”, and receives “done!”, which is the string that either client or server will send after the last letter from the original string is received. After “done!” is transmitted, both client and server close their communications. How would i go about getting the first string and then going back and forth sending and reciving letters that make the string, and when finished either send or get done!? import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintWriter; import java.net.Socket; import java.net.UnknownHostException; import java.util.Scanner; public class Program2 { public static void goClient() throws UnknownHostException, IOException{ String server = "localhost"; int port = 4321; Socket socket = new Socket(server, port); InputStream inStream = socket.getInputStream(); OutputStream outStream = socket.getOutputStream(); Scanner in = new Scanner(inStream); PrintWriter out = new PrintWriter(outStream, true); String rec = ""; if(in.hasNext()){ rec = in.nextLine(); } char[] array = new char[rec.length()]; for(int i = 0; i < rec.length(); i++){ array[i] = rec.charAt(i); } while(in.hasNext()){ for(int x = 0; x < array.length + 1; x+=2){ String str = in.nextLine(); str = Character.toString(array[x]); out.println(str); } in.close(); socket.close(); } } }

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