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  • Render To Texture Using OpenGL is not working but normal rendering works just fine

    - by Franky Rivera
    things I initialize at the beginning of the program I realize not all of these pertain to my issue I just copy and pasted what I had //overall initialized //things openGL related I initialize earlier on in the project glClearColor( 0.0f, 0.0f, 0.0f, 1.0f ); glClearDepth( 1.0f ); glEnable(GL_ALPHA_TEST); glEnable( GL_STENCIL_TEST ); glEnable(GL_DEPTH_TEST); glDepthFunc( GL_LEQUAL ); glEnable(GL_CULL_FACE); glFrontFace( GL_CCW ); glEnable(GL_COLOR_MATERIAL); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST ); //we also initialize our shader programs //(i added some shader program functions for definitions) //this enum list is else where in code //i figured it would help show you guys more about my //shader compile creation function right under this enum list VVVVVV /*enum eSHADER_ATTRIB_LOCATION { VERTEX_ATTRIB = 0, NORMAL_ATTRIB = 2, COLOR_ATTRIB, COLOR2_ATTRIB, FOG_COORD, TEXTURE_COORD_ATTRIB0 = 8, TEXTURE_COORD_ATTRIB1, TEXTURE_COORD_ATTRIB2, TEXTURE_COORD_ATTRIB3, TEXTURE_COORD_ATTRIB4, TEXTURE_COORD_ATTRIB5, TEXTURE_COORD_ATTRIB6, TEXTURE_COORD_ATTRIB7 }; */ //if we fail making our shader leave if( !testShader.CreateShader( "SimpleShader.vp", "SimpleShader.fp", 3, VERTEX_ATTRIB, "vVertexPos", NORMAL_ATTRIB, "vNormal", TEXTURE_COORD_ATTRIB0, "vTexCoord" ) ) return false; if( !testScreenShader.CreateShader( "ScreenShader.vp", "ScreenShader.fp", 3, VERTEX_ATTRIB, "vVertexPos", NORMAL_ATTRIB, "vNormal", TEXTURE_COORD_ATTRIB0, "vTexCoord" ) ) return false; SHADER PROGRAM FUNCTIONS bool CShaderProgram::CreateShader( const char* szVertexShaderName, const char* szFragmentShaderName, ... ) { //here are our handles for the openGL shaders int iGLVertexShaderHandle = -1, iGLFragmentShaderHandle = -1; //get our shader data char *vData = 0, *fData = 0; int vLength = 0, fLength = 0; LoadShaderFile( szVertexShaderName, &vData, &vLength ); LoadShaderFile( szFragmentShaderName, &fData, &fLength ); //data if( !vData ) return false; //data if( !fData ) { delete[] vData; return false; } //create both our shader objects iGLVertexShaderHandle = glCreateShader( GL_VERTEX_SHADER ); iGLFragmentShaderHandle = glCreateShader( GL_FRAGMENT_SHADER ); //well we got this far so we have dynamic data to clean up //load vertex shader glShaderSource( iGLVertexShaderHandle, 1, (const char**)(&vData), &vLength ); //load fragment shader glShaderSource( iGLFragmentShaderHandle, 1, (const char**)(&fData), &fLength ); //we are done with our data delete it delete[] vData; delete[] fData; //compile them both glCompileShader( iGLVertexShaderHandle ); //get shader status int iShaderOk; glGetShaderiv( iGLVertexShaderHandle, GL_COMPILE_STATUS, &iShaderOk ); if( iShaderOk == GL_FALSE ) { char* buffer; //get what happend with our shader glGetShaderiv( iGLVertexShaderHandle, GL_INFO_LOG_LENGTH, &iShaderOk ); buffer = new char[iShaderOk]; glGetShaderInfoLog( iGLVertexShaderHandle, iShaderOk, NULL, buffer ); //sprintf_s( buffer, "Failure Our Object For %s was not created", szFileName ); MessageBoxA( NULL, buffer, szVertexShaderName, MB_OK ); //delete our dynamic data free( buffer ); glDeleteShader(iGLVertexShaderHandle); return false; } glCompileShader( iGLFragmentShaderHandle ); //get shader status glGetShaderiv( iGLFragmentShaderHandle, GL_COMPILE_STATUS, &iShaderOk ); if( iShaderOk == GL_FALSE ) { char* buffer; //get what happend with our shader glGetShaderiv( iGLFragmentShaderHandle, GL_INFO_LOG_LENGTH, &iShaderOk ); buffer = new char[iShaderOk]; glGetShaderInfoLog( iGLFragmentShaderHandle, iShaderOk, NULL, buffer ); //sprintf_s( buffer, "Failure Our Object For %s was not created", szFileName ); MessageBoxA( NULL, buffer, szFragmentShaderName, MB_OK ); //delete our dynamic data free( buffer ); glDeleteShader(iGLFragmentShaderHandle); return false; } //lets check to see if the fragment shader compiled int iCompiled = 0; glGetShaderiv( iGLVertexShaderHandle, GL_COMPILE_STATUS, &iCompiled ); if( !iCompiled ) { //this shader did not compile leave return false; } //lets check to see if the fragment shader compiled glGetShaderiv( iGLFragmentShaderHandle, GL_COMPILE_STATUS, &iCompiled ); if( !iCompiled ) { char* buffer; //get what happend with our shader glGetShaderiv( iGLFragmentShaderHandle, GL_INFO_LOG_LENGTH, &iShaderOk ); buffer = new char[iShaderOk]; glGetShaderInfoLog( iGLFragmentShaderHandle, iShaderOk, NULL, buffer ); //sprintf_s( buffer, "Failure Our Object For %s was not created", szFileName ); MessageBoxA( NULL, buffer, szFragmentShaderName, MB_OK ); //delete our dynamic data free( buffer ); glDeleteShader(iGLFragmentShaderHandle); return false; } //make our new shader program m_iShaderProgramHandle = glCreateProgram(); glAttachShader( m_iShaderProgramHandle, iGLVertexShaderHandle ); glAttachShader( m_iShaderProgramHandle, iGLFragmentShaderHandle ); glLinkProgram( m_iShaderProgramHandle ); int iLinked = 0; glGetProgramiv( m_iShaderProgramHandle, GL_LINK_STATUS, &iLinked ); if( !iLinked ) { //we didn't link return false; } //NOW LETS CREATE ALL OUR HANDLES TO OUR PROPER LIKING //start from this parameter va_list parseList; va_start( parseList, szFragmentShaderName ); //read in number of variables if any unsigned uiNum = 0; uiNum = va_arg( parseList, unsigned ); //for loop through our attribute pairs int enumType = 0; for( unsigned x = 0; x < uiNum; ++x ) { //specify our attribute locations enumType = va_arg( parseList, int ); char* name = va_arg( parseList, char* ); glBindAttribLocation( m_iShaderProgramHandle, enumType, name ); } //end our list parsing va_end( parseList ); //relink specify //we have custom specified our attribute locations glLinkProgram( m_iShaderProgramHandle ); //fill our handles InitializeHandles( ); //everything went great return true; } void CShaderProgram::InitializeHandles( void ) { m_uihMVP = glGetUniformLocation( m_iShaderProgramHandle, "mMVP" ); m_uihWorld = glGetUniformLocation( m_iShaderProgramHandle, "mWorld" ); m_uihView = glGetUniformLocation( m_iShaderProgramHandle, "mView" ); m_uihProjection = glGetUniformLocation( m_iShaderProgramHandle, "mProjection" ); ///////////////////////////////////////////////////////////////////////////////// //texture handles m_uihDiffuseMap = glGetUniformLocation( m_iShaderProgramHandle, "diffuseMap" ); if( m_uihDiffuseMap != -1 ) { //store what texture index this handle will be in the shader glUniform1i( m_uihDiffuseMap, RM_DIFFUSE+GL_TEXTURE0 ); (0)+ } m_uihNormalMap = glGetUniformLocation( m_iShaderProgramHandle, "normalMap" ); if( m_uihNormalMap != -1 ) { //store what texture index this handle will be in the shader glUniform1i( m_uihNormalMap, RM_NORMAL+GL_TEXTURE0 ); (1)+ } } void CShaderProgram::SetDiffuseMap( const unsigned& uihDiffuseMap ) { (0)+ glActiveTexture( RM_DIFFUSE+GL_TEXTURE0 ); glBindTexture( GL_TEXTURE_2D, uihDiffuseMap ); } void CShaderProgram::SetNormalMap( const unsigned& uihNormalMap ) { (1)+ glActiveTexture( RM_NORMAL+GL_TEXTURE0 ); glBindTexture( GL_TEXTURE_2D, uihNormalMap ); } //MY 2 TEST SHADERS also my math order is correct it pertains to my matrix ordering in my math library once again i've tested the basic rendering. rendering to the screen works fine ----------------------------------------SIMPLE SHADER------------------------------------- //vertex shader looks like this #version 330 in vec3 vVertexPos; in vec3 vNormal; in vec2 vTexCoord; uniform mat4 mWorld; // Model Matrix uniform mat4 mView; // Camera View Matrix uniform mat4 mProjection;// Camera Projection Matrix out vec2 vTexCoordVary; // Texture coord to the fragment program out vec3 vNormalColor; void main( void ) { //pass the texture coordinate vTexCoordVary = vTexCoord; vNormalColor = vNormal; //calculate our model view projection matrix mat4 mMVP = (( mWorld * mView ) * mProjection ); //result our position gl_Position = vec4( vVertexPos, 1 ) * mMVP; } //fragment shader looks like this #version 330 in vec2 vTexCoordVary; in vec3 vNormalColor; uniform sampler2D diffuseMap; uniform sampler2D normalMap; out vec4 fragColor[2]; void main( void ) { //CORRECT fragColor[0] = texture( normalMap, vTexCoordVary ); fragColor[1] = vec4( vNormalColor, 1.0 ); }; ----------------------------------------SCREEN SHADER------------------------------------- //vertext shader looks like this #version 330 in vec3 vVertexPos; // This is the position of the vertex coming in in vec2 vTexCoord; // This is the texture coordinate.... out vec2 vTexCoordVary; // Texture coord to the fragment program void main( void ) { vTexCoordVary = vTexCoord; //set our position gl_Position = vec4( vVertexPos.xyz, 1.0f ); } //fragment shader looks like this #version 330 in vec2 vTexCoordVary; // Incoming "varying" texture coordinate uniform sampler2D diffuseMap;//the tile detail texture uniform sampler2D normalMap; //the normal map from earlier out vec4 vTheColorOfThePixel; void main( void ) { //CORRECT vTheColorOfThePixel = texture( normalMap, vTexCoordVary ); }; .Class RenderTarget Main Functions //here is my render targets create function bool CRenderTarget::Create( const unsigned uiNumTextures, unsigned uiWidth, unsigned uiHeight, int iInternalFormat, bool bDepthWanted ) { if( uiNumTextures <= 0 ) return false; //generate our variables glGenFramebuffers(1, &m_uifboHandle); // Initialize FBO glBindFramebuffer(GL_FRAMEBUFFER, m_uifboHandle); m_uiNumTextures = uiNumTextures; if( bDepthWanted ) m_uiNumTextures += 1; m_uiTextureHandle = new unsigned int[uiNumTextures]; glGenTextures( uiNumTextures, m_uiTextureHandle ); for( unsigned x = 0; x < uiNumTextures-1; ++x ) { glBindTexture( GL_TEXTURE_2D, m_uiTextureHandle[x]); // Reserve space for our 2D render target glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexImage2D(GL_TEXTURE_2D, 0, iInternalFormat, uiWidth, uiHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL); glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + x, GL_TEXTURE_2D, m_uiTextureHandle[x], 0); } //if we need one for depth testing if( bDepthWanted ) { glFramebufferTexture2D(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, m_uiTextureHandle[uiNumTextures-1], 0); glFramebufferTexture2D(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT, GL_TEXTURE_2D, m_uiTextureHandle[uiNumTextures-1], 0);*/ // Must attach texture to framebuffer. Has Stencil and depth glBindRenderbuffer(GL_RENDERBUFFER, m_uiTextureHandle[uiNumTextures-1]); glRenderbufferStorage(GL_RENDERBUFFER, /*GL_DEPTH_STENCIL*/GL_DEPTH24_STENCIL8, TEXTURE_WIDTH, TEXTURE_HEIGHT ); glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, m_uiTextureHandle[uiNumTextures-1]); glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, m_uiTextureHandle[uiNumTextures-1]); } glBindFramebuffer(GL_FRAMEBUFFER, 0); //everything went fine return true; } void CRenderTarget::Bind( const int& iTargetAttachmentLoc, const unsigned& uiWhichTexture, const bool bBindFrameBuffer ) { if( bBindFrameBuffer ) glBindFramebuffer( GL_FRAMEBUFFER, m_uifboHandle ); if( uiWhichTexture < m_uiNumTextures ) glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + iTargetAttachmentLoc, m_uiTextureHandle[uiWhichTexture], 0); } void CRenderTarget::UnBind( void ) { //default our binding glBindFramebuffer( GL_FRAMEBUFFER, 0 ); } //this is all in a test project so here's my straight forward rendering function for testing this render function does basic rendering steps keep in mind i have already tested my textures i have already tested my box thats being rendered all basic rendering works fine its just when i try to render to a texture then display it in a render surface that it does not work. Also I have tested my render surface it is bound exactly to the screen coordinate space void TestRenderSteps( void ) { //Clear the color and the depth glClearColor( 0.0f, 0.0f, 0.0f, 1.0f ); glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); //bind the shader program glUseProgram( testShader.m_iShaderProgramHandle ); //1) grab the vertex buffer related to our rendering glBindBuffer( GL_ARRAY_BUFFER, CVertexBufferManager::GetInstance()->GetPositionNormalTexBuffer().GetBufferHandle() ); //2) how our stream will be split here ( 4 bytes position, ..ext ) CVertexBufferManager::GetInstance()->GetPositionNormalTexBuffer().MapVertexStride(); //3) set the index buffer if needed glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, CIndexBuffer::GetInstance()->GetBufferHandle() ); //send the needed information into the shader testShader.SetWorldMatrix( boxPosition ); testShader.SetViewMatrix( Static_Camera.GetView( ) ); testShader.SetProjectionMatrix( Static_Camera.GetProjection( ) ); testShader.SetDiffuseMap( iTextureID ); testShader.SetNormalMap( iTextureID2 ); GLenum buffers[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1 }; glDrawBuffers(2, buffers); //bind to our render target //RM_DIFFUSE, RM_NORMAL are enums (0 && 1) renderTarget.Bind( RM_DIFFUSE, 1, true ); renderTarget.Bind( RM_NORMAL, 1, false); //false because buffer is already bound //i clear here just to clear the texture to make it a default value of white //by doing this i can see if what im rendering to my screen is just drawing to the screen //or if its my render target defaulted glClearColor( 1.0f, 1.0f, 1.0f, 1.0f ); glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT ); //i have this box object which i draw testBox.Draw(); //the draw call looks like this //my normal rendering works just fine so i know this draw is fine // glDrawElementsBaseVertex( m_sides[x].GetPrimitiveType(), // m_sides[x].GetPrimitiveCount() * 3, // GL_UNSIGNED_INT, // BUFFER_OFFSET(sizeof(unsigned int) * m_sides[x].GetStartIndex()), // m_sides[x].GetStartVertex( ) ); //we unbind the target back to default renderTarget.UnBind(); //i stop mapping my vertex format CVertexBufferManager::GetInstance()->GetPositionNormalTexBuffer().UnMapVertexStride(); //i go back to default in using no shader program glUseProgram( 0 ); //now that everything is drawn to the textures //lets draw our screen surface and pass it our 2 filled out textures //NOW RENDER THE TEXTURES WE COLLECTED TO THE SCREEN QUAD //bind the shader program glUseProgram( testScreenShader.m_iShaderProgramHandle ); //1) grab the vertex buffer related to our rendering glBindBuffer( GL_ARRAY_BUFFER, CVertexBufferManager::GetInstance()->GetPositionTexBuffer().GetBufferHandle() ); //2) how our stream will be split here CVertexBufferManager::GetInstance()->GetPositionTexBuffer().MapVertexStride(); //3) set the index buffer if needed glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, CIndexBuffer::GetInstance()->GetBufferHandle() ); //pass our 2 filled out textures (in the shader im just using the diffuse //i wanted to see if i was rendering anything before i started getting into other techniques testScreenShader.SetDiffuseMap( renderTarget.GetTextureHandle(0) ); //SetDiffuseMap definitions in shader program class testScreenShader.SetNormalMap( renderTarget.GetTextureHandle(1) ); //SetNormalMap definitions in shader program class //DO the draw call drawing our screen rectangle glDrawElementsBaseVertex( m_ScreenRect.GetPrimitiveType(), m_ScreenRect.GetPrimitiveCount() * 3, GL_UNSIGNED_INT, BUFFER_OFFSET(sizeof(unsigned int) * m_ScreenRect.GetStartIndex()), m_ScreenRect.GetStartVertex( ) );*/ //unbind our vertex mapping CVertexBufferManager::GetInstance()->GetPositionTexBuffer().UnMapVertexStride(); //default to no shader program glUseProgram( 0 ); } Last words: 1) I can render my box just fine 2) i can render my screen rect just fine 3) I cannot render my box into a texture then display it into my screen rect 4) This entire project is just a test project I made to test different rendering practices. So excuse any "ugly-ish" unclean code. This was made just on a fly run through when I was trying new test cases.

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  • Initialize array in amortized constant time -- what is this trick called?

    - by user946850
    There is this data structure that trades performance of array access against the need to iterate over it when clearing it. You keep a generation counter with each entry, and also a global generation counter. The "clear" operation increases the generation counter. On each access, you compare local vs. global generation counters; if they differ, the value is treated as "clean". This has come up in this answer on Stack Overflow recently, but I don't remember if this trick has an official name. Does it? One use case is Dijkstra's algorithm if only a tiny subset of the nodes has to be relaxed, and if this has to be done repeatedly.

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  • Removing/Adding a specific variable from an object inside javascript array? [migrated]

    - by hustlerinc
    I have a map array with objects stuffed with variables looking like this: var map = [ [{ground:0, object:1}, {ground:0, item:2}, {ground:0, object:1, item:2}], [{ground:0, object:1}, {ground:0, item:2}, {ground:0, object:1, item:2}] ]; Now I would like to be able to delete and add one of the variables like item:2. 1) What would I use to delete specific variables? 2) What would I use to add specific variables? I just need 2 short lines of code, the rest like detecting if and where to execute I've figured out. I've tried delete map[i][j].item; with no results. Help appreciated.

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  • Doctrine Mssql uniqueidentifier isn't cast as char or nvarchar when retrieved from the database.

    - by Tres
    When I retrieve a record from the database which has a column of type "uniqueidentifier", Doctrine fills it with "null" rather than the unique id from the database. Some research and testing has brought this down to a PDO/dblib driver issue. When directly querying via PDO, null is returned in place of the unique id. For reference, http://trac.doctrine-project.org/ticket/1096, has a bit on this, however, it was updated 11 months ago with no comment for resolution. A way around this, as mentioned at http://bugs.php.net/bug.php?id=24752&edit=1, is to cast the column as a char. However, it doesn't seem Doctrine exposes the native field type outside of generating models which makes it a bit hard to detect uniqueidentifier types and cast them internally when building the sql query. Has anyone found a workaround for this?

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  • I need a simple Example of JNA which can map char * of c dll.

    - by Vikas Sharma
    I have one dll of cpp and i need to call its function which returns char*. Im using String in native Declaration but getting out put like ???? or some crap thing. I just want to knw that do i have to decode the String.i have already set my system property like System.setProperty("jna.encoding","UTF-8"); Im in big mess. Hope to get Some Positive replies from u guys. Thanks in Advance.. Cheers...!

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  • Casting a char to an unsigned short: what happens behind the scenes?

    - by hb
    Given this field: char lookup_ext[8192] = {0}; // Gets filled later And this statement: unsigned short *slt = (unsigned short*) lookup_ext; What happens behind the scenes? lookup_ext[1669] returns 67 = 0100 0011 (C), lookup_ext[1670] returns 78 = 0100 1110 (N) and lookup_ext[1671] returns 68 = 0100 0100 (D); yet slt[1670] returns 18273 = 0100 0111 0110 0001. I'm trying to port this to C#, so besides an easy way out of this, I'm also wondering what really happens here. Been a while since I used C++ regularly. Thanks!

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  • Why does C's "fopen" take a "const char *" as its second argument?

    - by Chris Cooper
    It has always struck me as strange that the C function "fopen" takes a "const char *" as the second argument. I would think it would be easier to both read your code and implement the library's code if there were bit masks defined in stdio.h, like "IO_READ" and such, so you could do things like: FILE* myFile = fopen("file.txt", IO_READ & IO_WRITE); Is there a programmatic reason for the way it actually is, or is it just historic? (i.e. "That's just the way it is.")

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  • casting BSTR as char* in a dll; different results depnding on VB/C# caller.

    - by Toby Wilson
    I have a dll function that takes BSTR parameters. These are casted as char* before being used for other things. When the dll is called from VB code this works fine. However, when it is called from C# code, only the first character is pointed to. Both of these are excel addIns for Pre-2007 and 2007+ versions of Office, which call into a faster C++ AddIn. They actually call it directly, not through Excel. The VB function declaration looks like this: Private Declare Function Test Lib "ExcelAddIn.xll" (ByVal param As String) As String The C# function declaration looks like this: [DllImport("ExcelAddIn.xll", CharSet=CharSet.Ansi)] [return:MarshalAs(UnmanagedType.BStr)] private static extern string Test([MarshalAs(UnmanagedType.BStr)] string param); When debugging the dll and watching the input BSTR values, they appear to be correct from both; just the C# one only casts the first character. Charset=CharSet.Unicode makes no difference. Any ideas anyone?

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  • is there a way to use cin.getline() without having to define a char array size before hand?

    - by zebraman
    Basically my task is having to sort a bunch of strings of variable length ignoring case. I understand there is a function strcasecmp() that compares cstrings, but doesn't work on strings. Right now I'm using getline() for strings so I can just read in the strings one line at a time. I add these to a vector of strings, then convert to cstrings for each call of strcasecmp(). Instead of having to convert each string to a cstring before comparing with strcasecmp(), I was wondering if there was a way I could use cin.getline() for cstrings without having a predefined char array size. Or, would the best solution be to just read in string, convert to cstring, store in vector, then sort?

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  • Any way to find out which line break char(s) to use in Javascript?

    - by Irro
    I'm trying to parse some text into a textarea control and at the same time replace all with ordinary line break chars. I have been able to do it in windows by replacing with CR (it didn't work with CRLF strangely enough, it gave me linebreak + empty space) but I'm afraid that this code won't work in Unix/Mac because they use LF for line break. Is there any way to use the system default line break char in javascript? Something similar to Environment.NewLine in .Net (I wasn't able to write backslash in this editor but I use /r for CR and /n for LF, replace / with backslash)

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  • Setting an empty default value for a char-column in MySQL?

    - by user281434
    Hi In phpMyAdmin I have a char(32) column that has no default value(ie. Default: None). When I try to insert data through a SQL query, it throws out an error saying that the column "doesn't have a default value". I need it to be empty, so instead I've just set it's default value as "As defined: " and then nothing in the value field. Is this a bad idea? And is it any better than simply throwing in an empty value for the column in the SQL query? Thanks for your time.

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  • Haskell: Left-biased/short-circuiting function

    - by user2967411
    Two classes ago, our professor presented to us a Parser module. Here is the code: module Parser (Parser,parser,runParser,satisfy,char,string,many,many1,(+++)) where import Data.Char import Control.Monad import Control.Monad.State type Parser = StateT String [] runParser :: Parser a -> String -> [(a,String)] runParser = runStateT parser :: (String -> [(a,String)]) -> Parser a parser = StateT satisfy :: (Char -> Bool) -> Parser Char satisfy f = parser $ \s -> case s of [] -> [] a:as -> [(a,as) | f a] char :: Char -> Parser Char char = satisfy . (==) alpha,digit :: Parser Char alpha = satisfy isAlpha digit = satisfy isDigit string :: String -> Parser String string = mapM char infixr 5 +++ (+++) :: Parser a -> Parser a -> Parser a (+++) = mplus many, many1 :: Parser a -> Parser [a] many p = return [] +++ many1 p many1 p = liftM2 (:) p (many p) Today he gave us an assignment to introduce "a left-biased, or short-circuiting version of (+++)", called (<++). His hint was for us to consider the original implementation of (+++). When he first introduced +++ to us, this was the code he wrote, which I am going to call the original implementation: infixr 5 +++ (+++) :: Parser a -> Parser a -> Parser a p +++ q = Parser $ \s -> runParser p s ++ runParser q s I have been having tons of trouble since we were introduced to parsing and so it continues. I have tried/am considering two approaches. 1) Use the "original" implementation, as in p +++ q = Parser $ \s - runParser p s ++ runParser q s 2) Use the final implementation, as in (+++) = mplus Here are my questions: 1) The module will not compile if I use the original implementation. The error: Not in scope: data constructor 'Parser'. It compiles fine using (+++) = mplus. What is wrong with using the original implementation that is avoided by using the final implementation? 2) How do I check if the first Parser returns anything? Is something like (not (isNothing (Parser $ \s - runParser p s) on the right track? It seems like it should be easy but I have no idea. 3) Once I figure out how to check if the first Parser returns anything, if I am to base my code on the final implementation, would it be as easy as this?: -- if p returns something then p <++ q = mplus (Parser $ \s -> runParser p s) mzero -- else (<++) = mplus Best, Jeff

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  • Wrapping a pure virtual method with multiple arguments with Boost.Python

    - by fallino
    Hello, I followed the "official" tutorial and others but still don't manage to expose this pure virtual method (getPeptide) : ms_mascotresults.hpp class ms_mascotresults { public: ms_mascotresults(ms_mascotresfile &resfile, const unsigned int flags, double minProbability, int maxHitsToReport, const char * unigeneIndexFile, const char * singleHit = 0); ... virtual ms_peptide getPeptide(const int q, const int p) const = 0; } ms_mascotresults.cpp #include <boost/python.hpp> using namespace boost::python; #include "msparser.hpp" // which includes "ms_mascotresults.hpp" using namespace matrix_science; #include <iostream> #include <sstream> struct ms_mascotresults_wrapper : ms_mascotresults, wrapper<ms_mascotresults> { ms_peptide getPeptide(const int q, const int p) { this->get_override("getPeptide")(q); this->get_override("getPeptide")(p); } }; BOOST_PYTHON_MODULE(ms_mascotresults) { class_<ms_mascotresults_wrapper, boost::noncopyable>("ms_mascotresults") .def("getPeptide", pure_virtual(&ms_mascotresults::getPeptide) ) ; } Here are the bjam's errors : /usr/local/boost_1_42_0/boost/python/object/value_holder.hpp:66: error: cannot declare field ‘boost::python::objects::value_holder<ms_mascotresults_wrapper>::m_held’ to be of abstract type ‘ms_mascotresults_wrapper’ ms_mascotresults.cpp:12: note: because the following virtual functions are pure within ‘ms_mascotresults_wrapper’: ... include/ms_mascotresults.hpp:334: note: virtual matrix_science::ms_peptide matrix_science::ms_mascotresults::getPeptide(int, int) const ms_mascotresults.cpp: In constructor ‘ms_mascotresults_wrapper::ms_mascotresults_wrapper()’: ms_mascotresults.cpp:12: error: no matching function for call to ‘matrix_science::ms_mascotresults::ms_mascotresults()’ include/ms_mascotresults.hpp:284: note: candidates are: matrix_science::ms_mascotresults::ms_mascotresults(matrix_science::ms_mascotresfile&, unsigned int, double, int, const char*, const char*) include/ms_mascotresults.hpp:109: note: matrix_science::ms_mascotresults::ms_mascotresults(const matrix_science::ms_mascotresults&) ... /usr/local/boost_1_42_0/boost/python/object/value_holder.hpp: In constructor ‘boost::python::objects::value_holder<Value>::value_holder(PyObject*) [with Value = ms_mascotresults_wrapper]’: /usr/local/boost_1_42_0/boost/python/object/value_holder.hpp:137: note: synthesized method ‘ms_mascotresults_wrapper::ms_mascotresults_wrapper()’ first required here /usr/local/boost_1_42_0/boost/python/object/value_holder.hpp:137: error: cannot allocate an object of abstract type ‘ms_mascotresults_wrapper’ ms_mascotresults.cpp:12: note: since type ‘ms_mascotresults_wrapper’ has pure virtual functions So I tried to change the constructor's signature by : BOOST_PYTHON_MODULE(ms_mascotresults) { //class_<ms_mascotresults_wrapper, boost::noncopyable>("ms_mascotresults") class_<ms_mascotresults_wrapper, boost::noncopyable>("ms_mascotresults", init<ms_mascotresfile &, const unsigned int, double, int, const char *,const char *>()) .def("getPeptide", pure_virtual(&ms_mascotresults::getPeptide) ) Giving these errors : /usr/local/boost_1_42_0/boost/python/object/value_holder.hpp:66: error: cannot declare field ‘boost::python::objects::value_holder<ms_mascotresults_wrapper>::m_held’ to be of abstract type ‘ms_mascotresults_wrapper’ ms_mascotresults.cpp:12: note: because the following virtual functions are pure within ‘ms_mascotresults_wrapper’: include/ms_mascotresults.hpp:334: note: virtual matrix_science::ms_peptide matrix_science::ms_mascotresults::getPeptide(int, int) const ... ms_mascotresults.cpp:24: instantiated from here /usr/local/boost_1_42_0/boost/python/object/value_holder.hpp:137: error: no matching function for call to ‘ms_mascotresults_wrapper::ms_mascotresults_wrapper(matrix_science::ms_mascotresfile&, const unsigned int&, const double&, const int&, const char* const&, const char* const&)’ ms_mascotresults.cpp:12: note: candidates are: ms_mascotresults_wrapper::ms_mascotresults_wrapper(const ms_mascotresults_wrapper&) ms_mascotresults.cpp:12: note: ms_mascotresults_wrapper::ms_mascotresults_wrapper() If I comment the virtual function getPeptide in the .hpp, it builds perfectly with this constructor : class_<ms_mascotresults>("ms_mascotresults", init<ms_mascotresfile &, const unsigned int, double, int, const char *,const char *>() ) So I'm a bit lost...

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  • How to use CFNetwork to get byte array from sockets?

    - by Vic
    Hi, I'm working in a project for the iPad, it is a small program and I need it to communicate with another software that runs on windows and act like a server; so the application that I'm creating for the iPad will be the client. I'm using CFNetwork to do sockets communication, this is the way I'm establishing the connection: char ip[] = "192.168.0.244"; NSString *ipAddress = [[NSString alloc] initWithCString:ip]; /* Build our socket context; this ties an instance of self to the socket */ CFSocketContext CTX = { 0, self, NULL, NULL, NULL }; /* Create the server socket as a TCP IPv4 socket and set a callback */ /* for calls to the socket's lower-level connect() function */ TCPClient = CFSocketCreate(NULL, PF_INET, SOCK_STREAM, IPPROTO_TCP, kCFSocketDataCallBack, (CFSocketCallBack)ConnectCallBack, &CTX); if (TCPClient == NULL) return; /* Set the port and address we want to listen on */ struct sockaddr_in addr; memset(&addr, 0, sizeof(addr)); addr.sin_len = sizeof(addr); addr.sin_family = AF_INET; addr.sin_port = htons(PORT); addr.sin_addr.s_addr = inet_addr([ipAddress UTF8String]); CFDataRef connectAddr = CFDataCreate(NULL, (unsigned char *)&addr, sizeof(addr)); CFSocketConnectToAddress(TCPClient, connectAddr, -1); CFRunLoopSourceRef sourceRef = CFSocketCreateRunLoopSource(kCFAllocatorDefault, TCPClient, 0); CFRunLoopAddSource(CFRunLoopGetCurrent(), sourceRef, kCFRunLoopCommonModes); CFRelease(sourceRef); CFRunLoopRun(); And this is the way I sent the data, which basically is a byte array /* The native socket, used for various operations */ // TCPClient is a CFSocketRef member variable CFSocketNativeHandle sock = CFSocketGetNative(TCPClient); Byte byteData[3]; byteData[0] = 0; byteData[1] = 4; byteData[2] = 0; send(sock, byteData, strlen(byteData)+1, 0); Finally, as you may have noticed, when I create the server socket, I registered a callback for the kCFSocketDataCallBack type, this is the code. void ConnectCallBack(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info) { // SocketsViewController is the class that contains all the methods SocketsViewController *obj = (SocketsViewController*)info; UInt8 *unsignedData = (UInt8 *) CFDataGetBytePtr(data); char *value = (char*)unsignedData; NSString *text = [[NSString alloc]initWithCString:value length:strlen(value)]; [obj writeToTextView:text]; [text release]; } Actually, this callback is being invoked in my code, the problem is that I don't know how can I get the data that the windows client sent me, I'm expecting to receive an array of bytes, but I don't know how can I get those bytes from the data param. If anyone can help me to find a way to do this, or maybe me point me to another way to get the data from the server in my client application I would really appreciate it. Thanks.

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  • Suggestions for duplicate file finder algorithm (using C)

    - by Andrei Ciobanu
    Hello, I wanted to write a program that test if two files are duplicates (have exactly the same content). First I test if the files have the same sizes, and if they have i start to compare their contents. My first idea, was to "split" the files into fixed size blocks, then start a thread for every block, fseek to startup character of every block and continue the comparisons in parallel. When a comparison from a thread fails, the other working threads are canceled, and the program exits out of the thread spawning loop. The code looks like this: dupf.h #ifndef __NM__DUPF__H__ #define __NM__DUPF__H__ #define NUM_THREADS 15 #define BLOCK_SIZE 8192 /* Thread argument structure */ struct thread_arg_s { const char *name_f1; /* First file name */ const char *name_f2; /* Second file name */ int cursor; /* Where to seek in the file */ }; typedef struct thread_arg_s thread_arg; /** * 'arg' is of type thread_arg. * Checks if the specified file blocks are * duplicates. */ void *check_block_dup(void *arg); /** * Checks if two files are duplicates */ int check_dup(const char *name_f1, const char *name_f2); /** * Returns a valid pointer to a file. * If the file (given by the path/name 'fname') cannot be opened * in 'mode', the program is interrupted an error message is shown. **/ FILE *safe_fopen(const char *name, const char *mode); #endif dupf.c #include <errno.h> #include <pthread.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include "dupf.h" FILE *safe_fopen(const char *fname, const char *mode) { FILE *f = NULL; f = fopen(fname, mode); if (f == NULL) { char emsg[255]; sprintf(emsg, "FOPEN() %s\t", fname); perror(emsg); exit(-1); } return (f); } void *check_block_dup(void *arg) { const char *name_f1 = NULL, *name_f2 = NULL; /* File names */ FILE *f1 = NULL, *f2 = NULL; /* Streams */ int cursor = 0; /* Reading cursor */ char buff_f1[BLOCK_SIZE], buff_f2[BLOCK_SIZE]; /* Character buffers */ int rchars_1, rchars_2; /* Readed characters */ /* Initializing variables from 'arg' */ name_f1 = ((thread_arg*)arg)->name_f1; name_f2 = ((thread_arg*)arg)->name_f2; cursor = ((thread_arg*)arg)->cursor; /* Opening files */ f1 = safe_fopen(name_f1, "r"); f2 = safe_fopen(name_f2, "r"); /* Setup cursor in files */ fseek(f1, cursor, SEEK_SET); fseek(f2, cursor, SEEK_SET); /* Initialize buffers */ rchars_1 = fread(buff_f1, 1, BLOCK_SIZE, f1); rchars_2 = fread(buff_f2, 1, BLOCK_SIZE, f2); if (rchars_1 != rchars_2) { /* fread failed to read the same portion. * program cannot continue */ perror("ERROR WHEN READING BLOCK"); exit(-1); } while (rchars_1-->0) { if (buff_f1[rchars_1] != buff_f2[rchars_1]) { /* Different characters */ fclose(f1); fclose(f2); pthread_exit("notdup"); } } /* Close streams */ fclose(f1); fclose(f2); pthread_exit("dup"); } int check_dup(const char *name_f1, const char *name_f2) { int num_blocks = 0; /* Number of 'blocks' to check */ int num_tsp = 0; /* Number of threads spawns */ int tsp_iter = 0; /* Iterator for threads spawns */ pthread_t *tsp_threads = NULL; thread_arg *tsp_threads_args = NULL; int tsp_threads_iter = 0; int thread_c_res = 0; /* Thread creation result */ int thread_j_res = 0; /* Thread join res */ int loop_res = 0; /* Function result */ int cursor; struct stat buf_f1; struct stat buf_f2; if (name_f1 == NULL || name_f2 == NULL) { /* Invalid input parameters */ perror("INVALID FNAMES\t"); return (-1); } if (stat(name_f1, &buf_f1) != 0 || stat(name_f2, &buf_f2) != 0) { /* Stat fails */ char emsg[255]; sprintf(emsg, "STAT() ERROR: %s %s\t", name_f1, name_f2); perror(emsg); return (-1); } if (buf_f1.st_size != buf_f2.st_size) { /* File have different sizes */ return (1); } /* Files have the same size, function exec. is continued */ num_blocks = (buf_f1.st_size / BLOCK_SIZE) + 1; num_tsp = (num_blocks / NUM_THREADS) + 1; cursor = 0; for (tsp_iter = 0; tsp_iter < num_tsp; tsp_iter++) { loop_res = 0; /* Create threads array for this spawn */ tsp_threads = malloc(NUM_THREADS * sizeof(*tsp_threads)); if (tsp_threads == NULL) { perror("TSP_THREADS ALLOC FAILURE\t"); return (-1); } /* Create arguments for every thread in the current spawn */ tsp_threads_args = malloc(NUM_THREADS * sizeof(*tsp_threads_args)); if (tsp_threads_args == NULL) { perror("TSP THREADS ARGS ALLOCA FAILURE\t"); return (-1); } /* Initialize arguments and create threads */ for (tsp_threads_iter = 0; tsp_threads_iter < NUM_THREADS; tsp_threads_iter++) { if (cursor >= buf_f1.st_size) { break; } tsp_threads_args[tsp_threads_iter].name_f1 = name_f1; tsp_threads_args[tsp_threads_iter].name_f2 = name_f2; tsp_threads_args[tsp_threads_iter].cursor = cursor; thread_c_res = pthread_create( &tsp_threads[tsp_threads_iter], NULL, check_block_dup, (void*)&tsp_threads_args[tsp_threads_iter]); if (thread_c_res != 0) { perror("THREAD CREATION FAILURE"); return (-1); } cursor+=BLOCK_SIZE; } /* Join last threads and get their status */ while (tsp_threads_iter-->0) { void *thread_res = NULL; thread_j_res = pthread_join(tsp_threads[tsp_threads_iter], &thread_res); if (thread_j_res != 0) { perror("THREAD JOIN FAILURE"); return (-1); } if (strcmp((char*)thread_res, "notdup")==0) { loop_res++; /* Closing other threads and exiting by condition * from loop. */ while (tsp_threads_iter-->0) { pthread_cancel(tsp_threads[tsp_threads_iter]); } } } free(tsp_threads); free(tsp_threads_args); if (loop_res > 0) { break; } } return (loop_res > 0) ? 1 : 0; } The function works fine (at least for what I've tested). Still, some guys from #C (freenode) suggested that the solution is overly complicated, and it may perform poorly because of parallel reading on hddisk. What I want to know: Is the threaded approach flawed by default ? Is fseek() so slow ? Is there a way to somehow map the files to memory and then compare them ?

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  • Variable declared with variable keyword in sql plus(oracle 9i)?

    - by Vineet
    I am trying to declare g_num ,number data type with size it gives an error but in case of varchar2,char it does not. variable g_name varchar2(5);//correct accept size for varchar 2 variable g_num number(23);//Gives an error " VAR[IABLE] [ <variable> [ NUMBER | CHAR | CHAR (n [CHAR|BYTE]) | VARCHAR2 (n [CHAR|BYTE]) | NCHAR | NCHAR (n) | NVARCHAR2 (n) | CLOB | NCLOB | REFCURSOR ] ]" Please suggest!

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  • Implement python replace() function without using regexp

    - by jwesonga
    I'm trying to rewrite the equivalent of the python replace() function without using regexp. Using this code, i've managed to get it to work with single chars, but not with more than one character: def Replacer(self, find_char, replace_char): s = [] for char in self.base_string: if char == find_char: char = replace_char #print char s.append(char) s = ''.join(s) my_string.Replacer('a','E') Anybody have any pointers how to make this work with more than one character? example: my_string.Replacer('kl', 'lll')

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  • Finding out the common / uncommon elements between two Arrays in PHP

    - by Veera
    Consider I have two arrays: $friends = Array('foo', 'bar', 'alpha'); $attendees = Array('foo', 'bar'); Now I need to populate a new array $nonattendees which contains only the elements which are in $friends array and not in $attendees array. i.e, $nonattendees array should be populated with 'alpha'. Is there any in built array operation available in PHP to achieve the above functionality or should I write my own for loops?

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  • How to wrap two unmannaged C++ functions into two managed C# functions?

    - by Gbps
    I've got two unmanaged C++ functions, Compress and Decompress. The arguments and returns go as followed: unsigned char* Compress (unsigned char*,int) unsigned char* Decompress (unsigned char*,int) Where all uchars are arrays of uchars. Could someone please help me lay out a way to convert these into managed C# code using the Byte[] array instead of unsigned char*? Thank you very much!

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  • zlib gzgets extremely slow?

    - by monkeyking
    I'm doing stuff related to parsing huge globs of textfiles, and was testing what input method to use. There is not much of a difference using c++ std::ifstreams vs c FILE, According to the documentation of zlib, it supports uncompressed files, and will read the file without decompression. I'm seeing a difference from 12 seconds using non zlib to more than 4 minutes using zlib.h This I've tested doing multiple runs, so its not a disk cache issue. Am I using zlib in some wrong way? thanks #include <zlib.h> #include <cstdio> #include <cstdlib> #include <fstream> #define LENS 1000000 size_t fg(const char *fname){ fprintf(stderr,"\t-> using fgets\n"); FILE *fp =fopen(fname,"r"); size_t nLines =0; char *buffer = new char[LENS]; while(NULL!=fgets(buffer,LENS,fp)) nLines++; fprintf(stderr,"%lu\n",nLines); return nLines; } size_t is(const char *fname){ fprintf(stderr,"\t-> using ifstream\n"); std::ifstream is(fname,std::ios::in); size_t nLines =0; char *buffer = new char[LENS]; while(is. getline(buffer,LENS)) nLines++; fprintf(stderr,"%lu\n",nLines); return nLines; } size_t iz(const char *fname){ fprintf(stderr,"\t-> using zlib\n"); gzFile fp =gzopen(fname,"r"); size_t nLines =0; char *buffer = new char[LENS]; while(0!=gzgets(fp,buffer,LENS)) nLines++; fprintf(stderr,"%lu\n",nLines); return nLines; } int main(int argc,char**argv){ if(atoi(argv[2])==0) fg(argv[1]); if(atoi(argv[2])==1) is(argv[1]); if(atoi(argv[2])==2) iz(argv[1]); }

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  • convert table of input values into 2D array or struct?

    - by Henry
    What's the easiest way to convert a table of values (2D grid like Excel), into a 2D array or struct in ColdFusion? Thought of using dot in the name and eval them to become struct, but AFAIK name attribute of input field can only contains alpha numeric and underscore, and first char must be an alpha char.

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  • Why do we have reinterpret_cast in C++ when two chained static_cast can do it's job?

    - by Nawaz
    Say I want to cast A* to char* and vice-versa, we have two choices (I mean, many of us think we've two choices, because both seems to work! Hence the confusion!): struct A { int age; char name[128]; }; A a; char *buffer = static_cast<char*>(static_cast<void*>(&a)); //choice 1 char *buffer = reinterpret_cast<char*>(&a); //choice 2 Both work fine. //convert back A *pA = static_cast<A*>(static_cast<void*>(buffer)); //choice 1 A *pA = reinterpret_cast<A*>(buffer); //choice 2 Even this works fine! So why do we have reinterpret_cast in C++ when two chained static_cast can do it's job? Some of you might think this topic is a duplicate of the previous topics such as listed at the bottom of this post, but it's not. Those topics discuss only theoretically, but none of them gives even a single example demonstrating why reintepret_cast is really needed, and two static_cast would surely fail. I agree, one static_cast would fail. But how about two? If the syntax of two chained static_cast looks cumbersome, then we can write a function template to make it more programmer-friendly: template<class To, class From> To any_cast(From v) { return static_cast<To>(static_cast<void*>(v)); } And then we can use this, as: char *buffer = any_cast<char*>(&a); //choice 1 char *buffer = reinterpret_cast<char*>(&a); //choice 2 //convert back A *pA = any_cast<A*>(buffer); //choice 1 A *pA = reinterpret_cast<A*>(buffer); //choice 2 Also, see this situation where any_cast can be useful: Proper casting for fstream read and write member functions. So my question basically is, Why do we have reinterpret_cast in C++? Please show me even a single example where two chained static_cast would surely fail to do the same job? Which cast to use; static_cast or reinterpret_cast? Cast from Void* to TYPE* : static_cast or reinterpret_cast

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  • Split string in C every white space

    - by redsolja
    I want to write a program in C that displays each word of a whole sentence (taken as input) at a seperate line. This is what i have done so far: void manipulate(char *buffer); int get_words(char *buffer); int main(){ char buff[100]; printf("sizeof %d\nstrlen %d\n", sizeof(buff), strlen(buff)); // Debugging reasons bzero(buff, sizeof(buff)); printf("Give me the text:\n"); fgets(buff, sizeof(buff), stdin); manipulate(buff); return 0; } int get_words(char *buffer){ // Function that gets the word count, by counting the spaces. int count; int wordcount = 0; char ch; for (count = 0; count < strlen(buffer); count ++){ ch = buffer[count]; if((isblank(ch)) || (buffer[count] == '\0')){ // if the character is blank, or null byte add 1 to the wordcounter wordcount += 1; } } printf("%d\n\n", wordcount); return wordcount; } void manipulate(char *buffer){ int words = get_words(buffer); char *newbuff[words]; char *ptr; int count = 0; int count2 = 0; char ch = '\n'; ptr = buffer; bzero(newbuff, sizeof(newbuff)); for (count = 0; count < 100; count ++){ ch = buffer[count]; if (isblank(ch) || buffer[count] == '\0'){ buffer[count] = '\0'; if((newbuff[count2] = (char *)malloc(strlen(buffer))) == NULL) { printf("MALLOC ERROR!\n"); exit(-1); } strcpy(newbuff[count2], ptr); printf("\n%s\n",newbuff[count2]); ptr = &buffer[count + 1]; count2 ++; } } } Although the output is what i want, i have really many black spaces after the final word displayed, and the malloc() returns NULL so the MALLOC ERROR! is displayed in the end. I can understand that there is a mistake at my malloc() implementation but i do not know what it is. Is there another more elegant - generally better way to do it? Thanks in advance.

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  • mysql timeout - c/C++

    - by user1262876
    Guys i'm facing a problem with this code, the problem is the timeout by timeout i mean the time it takes the program to tell me if the server is connected or not. If i use my localhost i get the answer fast, but when i connect to outside my localhost it takes 50sc - 1.5 min to response and the program frezz until it done. HOw can i fix the frezzing, or make my own timeout, like if still waiting after 50sc, tell me connection failed and stop? please use codes as help, becouse i would understand it better, thanks for any help i get PS: USING MAC #include "mysql.h" #include <stdio.h> #include <stdlib.h> // Other Linker Flags: -lmysqlclient -lm -lz // just going to input the general details and not the port numbers struct connection_details { char *server; char *user; char *password; char *database; }; MYSQL* mysql_connection_setup(struct connection_details mysql_details) { // first of all create a mysql instance and initialize the variables within MYSQL *connection = mysql_init(NULL); // connect to the database with the details attached. if (!mysql_real_connect(connection,mysql_details.server, mysql_details.user, mysql_details.password, mysql_details.database, 0, NULL, 0)) { printf("Conection error : %s\n", mysql_error(connection)); exit(1); } return connection; } MYSQL_RES* mysql_perform_query(MYSQL *connection, char *sql_query) { // send the query to the database if (mysql_query(connection, sql_query)) { printf("MySQL query error : %s\n", mysql_error(connection)); exit(1); } return mysql_use_result(connection); } int main() { MYSQL *conn; // the connection MYSQL_RES *res; // the results MYSQL_ROW row; // the results row (line by line) struct connection_details mysqlD; mysqlD.server = (char*)"Localhost"; // where the mysql database is mysqlD.user = (char*)"root"; // the root user of mysql mysqlD.password = (char*)"123456"; // the password of the root user in mysql mysqlD.database = (char*)"test"; // the databse to pick // connect to the mysql database conn = mysql_connection_setup(mysqlD); // assign the results return to the MYSQL_RES pointer res = mysql_perform_query(conn, (char*) "SELECT * FROM me"); printf("MySQL Tables in mysql database:\n"); while ((row = mysql_fetch_row(res)) !=NULL) printf("%s - %s\n", row[0], row[1], row[2]); // <-- Rows /* clean up the database result set */ mysql_free_result(res); /* clean up the database link */ mysql_close(conn); return 0; }

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  • How can I share dynamic data array between Applications?

    - by Ehsan
    Hi, I use CreateFileMapping, but this method was not useful,because only static structure can be shared by this method. for example this method is good for following structure: struct MySharedData { unsigned char Flag; int Buff[10]; }; but it's not good for : struct MySharedData { unsigned char Flag; int *Buff; }; would be thankful if somebody guide me on this, Thanks in advance!

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