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Search found 756 results on 31 pages for 'malloc'.

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  • Setting the first two bytes of a block of memory

    - by idealistikz
    Suppose I have a block of memory as such: void *block = malloc(sizeof(void *) + size); How do I set the first two bytes of the block as NULL or have it point somewhere? I do not want to simply assign 'block' to NULL or to another pointer because I want to access the rest of the memory I malloc'ed.

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  • How to create factories with attr_accesible?

    - by regedarek
    How to deal with factories and attr_accessible? My example: # model class SomeModel attr_accessible :name, full_name, other_name end #spec require 'spec_helper' describe "test" do it do create(:some_model, name: "test name", user: User.first) #factory end end #error ruby(17122,0x12a055000) malloc: *** error for object 0x8: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug I think the error is because user_id is not in attr_accesible atributes

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  • How to tell where I am in an array with pointer arythmetic?

    - by klez
    In C, I have declared a memory area like this: int cells = 512; int* memory = (int*) malloc ((sizeof (int)) * cells); And I place myself more or less in the middle int* current_cell = memory + ((cells / 2) * sizeof (int)); My question is, while I increment *current_cell, how do I know if I reached the end of the allocated memory area?

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  • C: reading file and populating struct

    - by deostroll
    Hi, I have a structure with the following definition: typedef struct myStruct{ int a; char* c; int f; } OBJECT; I am able to populate this object and write it to a file. However I am not able to read the char* c value in it...while trying to read it, it gives me a segmentation fault error. Is there anything wrong with my code: //writensave.c #include "mystruct.h" #include <stdio.h> #include <string.h> #define p(x) printf(x) int main() { p("Creating file to write...\n"); FILE* file = fopen("struct.dat", "w"); if(file == NULL) { printf("Error opening file\n"); return -1; } p("creating structure\n"); OBJECT* myObj = (OBJECT*)malloc(sizeof(OBJECT)); myObj->a = 20; myObj->f = 45; myObj->c = (char*)calloc(30, sizeof(char)); strcpy(myObj->c, "This is a test"); p("Writing object to file...\n"); fwrite(myObj, sizeof(OBJECT), 1, file); p("Close file\n"); fclose(file); p("End of program\n"); return 0; } Here is how I am trying to read it: //readnprint.c #include "mystruct.h" #include <stdio.h> #define p(x) printf(x) int main() { FILE* file = fopen("struct.dat", "r"); char* buffer; buffer = (char*) malloc(sizeof(OBJECT)); if(file == NULL) { p("Error opening file"); return -1; } fread((void *)buffer, sizeof(OBJECT), 1, file); OBJECT* obj = (OBJECT*)buffer; printf("obj->a = %d\nobj->f = %d \nobj->c = %s", obj->a, obj->f, obj->c); fclose(file); return 0; }

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  • Memory leak when application loads in iPhone

    - by iPhoneDev
    I have a navigation based template, when I run my application using Instruments, the very first memory leak comes under: Leak Object: Malloc 128 bytes Responsible Library: CoreGraphics Responsible Frame: open_handle_to_dylib_path I don't know where this leak is coming from and how remove this. If it's a default leak, then I think I don't need to worry about it. But if it's not then I have to find a way to remove the leak.

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  • C99 variable length automatic array performance

    - by aaa
    Is there significant cpu/memory overhead associated with using automatic arrays with g++/Intel on 64-bit x86 linux platform? int function(int N) { double array[N]; overhead compared to allocating array before hand (assuming function is called multiple times) overhead compared to using new overhead compared to using malloc The range of N may be from 1kb to 16kb roughly, stack overrun is not a problem.

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  • Whats the easiest way to convert a long in C to a char*?

    - by dh82
    What is the clean way to do that in C? wchar_t* ltostr(long value) { int size = string_size_of_long(value); wchar_t *wchar_copy = malloc(value * sizeof(wchar_t)); swprintf(wchar_copy, size, L"%li", self); return wchar_copy; } The solutions I came up so far are all rather ugly, especially allocate_properly_size_whar_t uses double float base math.

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  • Missing part of the image when taking screenshot while supporting Retina Display

    - by Spaft
    I'm currently working on enabling support for retina display for my game. In the game, we have a feature that the user can take screenshot. We are using these part of code we found online a while ago and it's working fine when we are not supporting retina display: CCDirector* director = [CCDirector sharedDirector]; CGSize size = [director winSizeInPixels]; //Create buffer for pixels GLuint bufferLength = size.width * size.height * 4; GLubyte* buffer = (GLubyte*)malloc(bufferLength); //Read Pixels from OpenGL glReadPixels(0, 100, size.width, size.height, GL_RGBA, GL_UNSIGNED_BYTE, buffer); //Make data provider with data. CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, buffer, bufferLength, NULL); //Configure image int bitsPerComponent = 8; int bitsPerPixel = 32; int bytesPerRow = 4 * size.width; CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB(); CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault; CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault; CGImageRef iref = CGImageCreate(size.width, size.height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent); uint32_t* pixels = (uint32_t*)malloc(bufferLength); CGContextRef context = CGBitmapContextCreate(pixels, size.width, size.height, 8, size.width * 4, CGImageGetColorSpace(iref), kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big); CGContextTranslateCTM(context, 0, size.height); CGContextScaleCTM(context, 1.0f, -1.0f); switch (director.deviceOrientation) { case CCDeviceOrientationPortrait: break; case CCDeviceOrientationPortraitUpsideDown: CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(180)); CGContextTranslateCTM(context, -size.width, -size.height); break; case CCDeviceOrientationLandscapeLeft: CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(-90)); CGContextTranslateCTM(context, -size.width, 0); break; case CCDeviceOrientationLandscapeRight: CGContextRotateCTM(context, CC_DEGREES_TO_RADIANS(90)); CGContextTranslateCTM(context, size.width * 0.5f, -size.height); break; } CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, size.width, size.height), iref); UIImage *outputImage = [UIImage imageWithCGImage:CGBitmapContextCreateImage(context)]; //Dealloc CGDataProviderRelease(provider); CGImageRelease(iref); CGContextRelease(context); free(buffer); free(pixels); return outputImage; But when we enabled retina display in cocos 0.99.5. This functionality is a little messed up since it will miss a little left part of the image while the high is still correct. So I'm wondering if there is anything wrong with the code or am I doing anything wrong here? Thank you in advance for any reply!

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  • Yet another Memory Leak Issue (memory is still gone when program terminates)- C program on SLES

    - by user1426181
    I run my C program on Suse Linux Enterprise that compresses several thousand large files (between 10MB and 100MB in size), and the program gets slower and slower as the program runs (it's running multi-threaded with 32 threads on a Intel Sandy Bridge board). When the program completes, and it's run again, it's still very slow. When I watch the program running, I see that the memory is being depleted while the program runs, which you would think is just a classic memory leak problem. But, with a normal malloc()/free() mismatch, I would expect all the memory to return when the program terminates. But, most of the memory doesn't get reclaimed when the program completes. The free or top command shows Mem: 63996M total, 63724M used, 272M free when the program is slowed down to a halt, but, after the termination, the free memory only grows back to about 3660M. When the program is rerun, the free memory is quickly used up. The top program only shows that the program, while running, is using at most 4% or so of the memory. I thought that it might be a memory fragmentation problem, but, I built a small test program that simulates all the memory allocation activity in the program (many randomized aspects were built in - size/quantity), and it always returns all the memory upon completion. So, I don't think that's it. Questions: Can there be a malloc()/free() mismatch that will lose memory permanently, i.e. even after the process completes? What other things in a C program (not C++) can cause permanent memory loss, i.e. after the program completes, and even the terminal window closes? Only a reboot brings the memory back. I've read other posts about files not being closed causing problems, but, I don't think I have that problem. Is it valid to be looking at top and free for the memory statistics, i.e. do they accurately describe the memory situation? They do seem to correspond to the slowness of the program. If the program only shows a 4% memory usage, will something like valgrind find this problem?

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  • Hot to get rid of memory allocations/deallocations in swig wrappers?

    - by Dmitriy Matveev
    I want to use swig for generation of read-only wrappers for a complex object. The object which I want to wrap will always be existent while I will read it. And also I will only use my wrappers at the time that object is existent, thus I don't need any memory management from SWIG. For following swig interface: %module test %immutable; %inline %{ struct Foo { int a; }; struct Bar { int b; Foo f; }; %} I will have a wrappers which will have a lot of garbage in generated interfaces and do useless work which will reduce performance in my case. Generated java wrapper for Bar class will be like this: public class Bar { private long swigCPtr; protected boolean swigCMemOwn; protected Bar(long cPtr, boolean cMemoryOwn) { swigCMemOwn = cMemoryOwn; swigCPtr = cPtr; } protected static long getCPtr(Bar obj) { return (obj == null) ? 0 : obj.swigCPtr; } protected void finalize() { delete(); } public synchronized void delete() { if (swigCPtr != 0) { if (swigCMemOwn) { swigCMemOwn = false; testJNI.delete_Bar(swigCPtr); } swigCPtr = 0; } } public int getB() { return testJNI.Bar_b_get(swigCPtr, this); } public Foo getF() { return new Foo(testJNI.Bar_f_get(swigCPtr, this), true); } public Bar() { this(testJNI.new_Bar(), true); } } I don't need 'swigCMemOwn' field in my wrapper since it always will be false. All code related to this field will also be useless. There are also unnecessary logic in native code: SWIGEXPORT jlong JNICALL Java_some_testJNI_Bar_1f_1get(JNIEnv *jenv, jclass jcls, jlong jarg1, jobject jarg1_) { jlong jresult = 0 ; struct Bar *arg1 = (struct Bar *) 0 ; Foo result; (void)jenv; (void)jcls; (void)jarg1_; arg1 = *(struct Bar **)&jarg1; result = ((arg1)->f); { Foo * resultptr = (Foo *) malloc(sizeof(Foo)); memmove(resultptr, &result, sizeof(Foo)); *(Foo **)&jresult = resultptr; } return jresult; } I don't need these calls to malloc and memmove. I want to force swig to resolve both of these problems, but don't know how. Is it possible?

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  • depth first search graph by using linked list

    - by programmerwannabe
    im using mac book and i cannot read the text file using this code. moreover, can you guys please add function(graph is connected?, and is this graph tree?) inputA.txt consist 1 2 1 6 1 5 2 3 2 6 3 4 3 6 4 5 4 6 5 6 #include <stdio.h> #include <memory.h> #include <stdlib.h> #define MAX 10 #define TRUE 1 #define FALSE 0 typedef struct Graph{ int vertex; struct Graph* link; } g_node; typedef struct graphType{ int x; int visited[MAX]; g_node* adjList_H[MAX]; } graphType; typedef struct stack{ int data; struct stack* link; } s_node; s_node* top; void push(int item){ s_node* n=(s_node*)malloc(sizeof(s_node)); n->data = item; n->link = top; top = n; } int pop(){ int item; s_node* n=top; if(top == NULL){ puts("\nstack is empty!\n"); return 0; } else { item = n-> data; top = n->link; free(n); return item; } } void createGraph(graphType* g){ int v; g->x = 1; for(v=1 ; v < MAX ; v++){ g -> visited[v] = FALSE; g -> adjList_H[v] = NULL; } } void insertVertex(graphType* g, int v){ if(((g->x)) > MAX){ puts("\n it has been overed the number of vertex\n"); return ; } g -> x++; } void insertEdge(graphType* g, int u, int v){ g_node* node; if(u >= g -> x || v >= g -> x){ puts("\n no vertex in the graph\n"); return ; } node = (g_node*)malloc(sizeof(g_node)); node -> vertex = v; node -> link = g -> adjList_H[u]; g-> adjList_H[u] = node; } void print_adjList(graphType* g){ int i; g_node *p; for(i=1 ; i<g -> x ; i++){ printf("\n\t\t vertex %d adjacency list ", i); p = g -> adjList_H[i]; while(p){ printf("-> %d", p-> vertex); p = p-> link; } } } void DFS_adjList(graphType* g, int v) { g_node* w; top = NULL; push(v); g->visited[v] = TRUE; printf(" %d", v); while(top != NULL){ w=g->adjList_H[v]; while(w){ if (!g->visited[w->vertex]){ push(w->vertex); g->visited[w->vertex] = TRUE; printf(" %d", w->vertex); v = w->vertex; w=g->adjList_H[v]; } else w= w->link; } v = pop(); } } int main (int argc, const char * argv[]) { FILE *fp; char mychar; char arr[][2]={0, }; int j, k; int i; graphType *G9; G9 = (graphType*)malloc(sizeof(graphType)); createGraph(G9); for(i=1; i<7 ; i++) insertVertex(G9, i); fp = fopen("inputD.txt", "r"); for(j = 0 ; j< 10 ; j++){ for(k = 0 ; k < 2 ; k++){ mychar = fgetc(fp); if(mychar = EOF){ j=10; break; } else if(mychar == ' ') continue; else if(mychar <= '9' || mychar >= '1'){ arr[j][k] = mychar; printf("%d%d", arr[i][k]); } } } insertEdge(G9, 1, 2); insertEdge(G9, 1, 6); insertEdge(G9, 1, 5); insertEdge(G9, 2, 3); insertEdge(G9, 2, 6); insertEdge(G9, 3, 4); insertEdge(G9, 3, 6); insertEdge(G9, 4, 5); insertEdge(G9, 4, 6); insertEdge(G9, 5, 6); insertEdge(G9, 6, 5); insertEdge(G9, 6, 4); insertEdge(G9, 5, 4); insertEdge(G9, 6, 3); insertEdge(G9, 4, 3); insertEdge(G9, 6, 2); insertEdge(G9, 3, 2); insertEdge(G9, 5, 1); insertEdge(G9, 6, 1); insertEdge(G9, 2, 1); printf("\n graph adjacency list "); print_adjList(G9); printf("\n \n//////////////////////////////////////////////\n\n depth fist search >> "); DFS_adjList(G9, 1); return 0; }

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  • Problem intialising 2D array

    - by TeeJay
    Ok, so I have a 2D Array that is initialised with values from a file (format: x y z). My file reads in the values correctly but when adding the z value to the matrix/2DArray, I run into a segfault and I have no idea why. It is possibly incorrect use of pointers? I still don't quite have the hang of them yet. This is my intialiser, works fine, even intialises all "z" values to 0. int** make2DArray(int rows, int columns) { int** newArray; newArray = (int**)malloc(rows*sizeof(int*)); if (newArray == NULL) { printf("out of memory for newArray.\n"); } for (int i = 0; i < rows; i++) { newArray[i] = (int*)malloc(columns*sizeof(int)); if (newArray[i] == NULL) { printf("out of memory for newArray[%d].\n", i); } } //intialise all values to 0 for (int i = 0; i < rows; i++) { for (int j = 0; j < columns; j++) { newArray[i][j] = 0; } } return newArray; } This is how I call the initialiser (and problem function). int** map = make2DArray(rows, columns); fillMatrix(&map, mapFile); And this is the problem code. void fillMatrix(int*** inMatrix, FILE* inFile) { int x, y, z; char line[100]; while(fgets(line, sizeof(line), inFile) != NULL) { sscanf(line, "%d %d %d", &x, &y, &z); *inMatrix[x][y] = z; } } From what I can gather through the use of ddd, the problem comes when y gets to 47. The map file has a max "x" value of 47 and a max "y" value of 63, I'm pretty sure I haven't got the order mixed up, so I don't know why the program is segfault-ing? I'm sure it's some newbie mistake...

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  • allocating "unmanaged" memory in c#

    - by Blitzz
    Hi, I'm writting a program in c# that uses a C++ library, and for some reason I need to allocate an unmanaged buffer to pass it to the lib. Is there a way to do this in c# ? Basically I would just need to do a malloc in C#... Thanks

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  • matrix multiplication with MPI [on hold]

    - by user3695701
    I'm working on an assignment on matrix multiplication with MPI. A*B=C. the requirement is that B should be vertically partitioned. Here's what I intend to do: broadcast matrix A to all processes and scatter B into several slices with each slice containing n/p columns. The following code only works when the number of process(p) is 1. when p1(say 2), I got [cluster2:21080] *** Process received signal *** [cluster2:21080] Signal: Segmentation fault (11) [cluster2:21080] Signal code: Address not mapped (1) [cluster2:21080] Failing at address: (nil) [cluster2:21080] [ 0] /lib/libpthread.so.0(+0xf8f0) [0x7f49f38108f0] [cluster2:21080] [ 1] /lib/libc.so.6(memcpy+0xe1) [0x7f49f35024c1] [cluster2:21080] [ 2] /usr/lib/libmpi.so.0(ompi_convertor_unpack+0x121)[0x7f49f47c88e1] [cluster2:21080] [ 3] /usr/lib/openmpi/lib/openmpi/mca_pml_ob1.so(+0x8a26) [0x7f49f0dcea26] [cluster2:21080] [ 4] /usr/lib/openmpi/lib/openmpi/mca_btl_tcp.so(+0x662c) [0x7f49efce462c] [cluster2:21080] [ 5] /usr/lib/libopen-pal.so.0(+0x1ede8) [0x7f49f42e0de8] [cluster2:21080] [ 6] /usr/lib/libopen-pal.so.0(opal_progress+0x99) [0x7f49f42d5369] [cluster2:21080] [ 7] /usr/lib/openmpi/lib/openmpi/mca_pml_ob1.so(+0x5585) [0x7f49f0dcb585] [cluster2:21080] [ 8] /usr/lib/openmpi/lib/openmpi/mca_coll_tuned.so(+0xcc01) [0x7f49eeeb1c01] [cluster2:21080] [ 9] /usr/lib/openmpi/lib/openmpi/mca_coll_tuned.so(+0x266c) [0x7f49eeea766c] [cluster2:21080] [10] /usr/lib/openmpi/lib/openmpi/mca_coll_sync.so(+0x1388) [0x7f49ef0c0388] [cluster2:21080] [11] /usr/lib/libmpi.so.0(MPI_Bcast+0x10e) [0x7f49f47d025e] [cluster2:21080] [12] ./out(main+0x259) [0x401571] [cluster2:21080] [13] /lib/libc.so.6(__libc_start_main+0xfd) [0x7f49f3498c8d] [cluster2:21080] [14] ./out() [0x400f29] [cluster2:21080] *** End of error message *** Can someone help me? Thanks. //matrices A and B //double* A =(double *)malloc(n*n*sizeof(double)); //double* B =(double *)malloc(n*n*sizeof(double)); //code initializing A,B... //n is the size of the matrix //p is the number of processes //myrank is the rank of calling process MPI_Init (&argc, &argv); MPI_Comm_rank(MPI_COMM_WORLD, &myrank); MPI_Comm_size(MPI_COMM_WORLD, &p); //broadcast A to all processes MPI_Bcast (A, n*n, MPI_DOUBLE, 0, MPI_COMM_WORLD); MPI_Datatype tmp_type, col_type; // extract a slice from B MPI_Type_vector(n, num_of_col_per_slice, n, MPI_DOUBLE, &tmp_type); // position of the first (0) and each next (stride * sizeof(double) ) slice MPI_Type_create_resized(tmp_type, 0, n * sizeof(double), &col_type); MPI_Type_commit(&col_type); //scatter a slice of B to each process MPI_Scatter(B, 1, col_type, B+myrank*n/p, n * n/p, MPI_DOUBLE, 0, MPI_COMM_WORLD); //use blas function to calculate A*sliceOfB and store the resulting slice to C cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, n, n/p, n, 1.0, A, n, B+myrank*n/p, n, 0.0, C+myrank*n/p, n); //gather all those resulting slices into C MPI_Gather (C+myrank*n/p, n*n/p, MPI_DOUBLE, C, n*n/p, MPI_DOUBLE, 0, MPI_COMM_WORLD);

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  • Indexing with pointer C/C++

    - by Leavenotrace
    Hey I'm trying to write a program to carry out newtons method and find the roots of the equation exp(-x)-(x^2)+3. It works in so far as finding the root, but I also want it to print out the root after each iteration but I can't get it to work, Could anyone point out my mistake I think its something to do with my indexing? Thanks a million :) #include <stdio.h> #include <math.h> #include <malloc.h> //Define Functions: double evalf(double x) { double answer=exp(-x)-(x*x)+3; return(answer); } double evalfprime(double x) { double answer=-exp(-x)-2*x; return(answer); } double *newton(double initialrt,double accuracy,double *data) { double root[102]; data=root; int maxit = 0; root[0] = initialrt; for (int i=1;i<102;i++) { *(data+i)=*(data+i-1)-evalf(*(data+i-1))/evalfprime(*(data+i-1)); if(fabs(*(data+i)-*(data+i-1))<accuracy) { maxit=i; break; } maxit=i; } if((maxit+1==102)&&(fabs(*(data+maxit)-*(data+maxit-1))>accuracy)) { printf("\nMax iteration reached, method terminated"); } else { printf("\nMethod successful"); printf("\nNumber of iterations: %d\nRoot Estimate: %lf\n",maxit+1,*(data+maxit)); } return(data); } int main() { double root,accuracy; double *data=(double*)malloc(sizeof(double)*102); printf("NEWTONS METHOD PROGRAMME:\nEquation: f(x)=exp(-x)-x^2+3=0\nMax No iterations=100\n\nEnter initial root estimate\n>> "); scanf("%lf",&root); _flushall(); printf("\nEnter accuracy required:\n>>"); scanf("%lf",&accuracy); *data= *newton(root,accuracy,data); printf("Iteration Root Error\n "); printf("%d %lf \n", 0,*(data)); for(int i=1;i<102;i++) { printf("%d %5.5lf %5.5lf\n", i,*(data+i),*(data+i)-*(data+i-1)); if(*(data+i*sizeof(double))-*(data+i*sizeof(double)-1)==0) { break; } } getchar(); getchar(); free(data); return(0); }

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  • Accessing char* after assigning its value C

    - by iSight
    Hi, I have assign the value of a member variable as under: myValue = (char*)malloc(strlen(inValue) * sizeof(char)); strcpy(mValue, inValue); while assigning it the value was proper as(taking printf output): http://www.w3.org/2001/XMLSchema But, when i get its value after wards i get it as: http://www.w3.org/2001/XMLSchema(! What could be the problem for this issue

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  • storing characters in char data type C language

    - by iSight
    Hi, I can store string of few length in char data type. But when it exceeds its capacity what can be the alternative way to store string. I am using char data type. void setString(char* inPoints) { if (strcmp(mPoints, inPoints)!= ZERO) { if (mPoints) { free(mPoints); } mPoints = (char*)malloc((strlen(inPoints) + 1) * sizeof(char)); strcpy(mPoints, inPoints); } }

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  • implicit declaration of

    - by gcc
    int i=0; char **mainp; for(i=0;i<2;++i) { mainp[i]=malloc(sizeof(char)*200); if(!scanf("%[^#],#",mainp[i])) break; if(i<2) scanf("%[^#],#",mainp[i]); } why does gcc send me that warnings warning: implicit declaration of function ‘scanf’ warning: incompatible implicit declaration of built-in function ‘scanf’ warning: ‘mainp’ may be used uninitialized in this function

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  • "Implicit declaration" warning

    - by gcc
    For this code: int i=0; char **mainp; for(i=0;i<2;++i) { mainp[i]=malloc(sizeof(char)*200); if(!scanf("%[^#],#",mainp[i])) break; if(i<2) scanf("%[^#],#",mainp[i]); } GCC emits the warnings: warning: implicit declaration of function ‘scanf’ warning: incompatible implicit declaration of built-in function ‘scanf’ warning: ‘mainp’ may be used uninitialized in this function And I get a segmentation fault at runtime

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