Strange problem.

[Noodlez]

Code Select Expand


int loadfile(char path[255], char *data){
   FILE *pFile;
   char *buffer;
   int lSize;
   pFile = fopen(path,"rt");
   if(pFile!=NULL){
       fseek(pFile, 0, SEEK_END); /
       lSize = ftell(pFile);
       rewind(pFile);
       
       data = new char[lSize];
       if (data==NULL) return 2;
       fread(data,1,lSize,pFile);
       fclose(pFile);
       return 0;
   }
   return 1;
}


Best way to explain the problem:

Code Select Expand


char *strBuffer;
char strPath[255];
if(loadfile(strPath, strBuffer)){
   printf("File contents: %s\n",strBuffer);
}


When loadfile function is called, and I output the buffer within the function, the contents of the file are outputted. However, after calling the function, NULL will be displayed. This has had me stumped for 2 days, but I just don't see whats wrong.

Note: The example code is not the code used in my program, however they both do the exact same thing, so it shouldn't matter.

[Skywing]

strBuffer will be pointing to uninitialized data.  I think you meant to pass a char** instead of a char* judging from your code.

[Moonshine]

Yes, you'll need a reference to a pointer, or a pointer to a pointer like skywing said.  Or you could always initialize a buffer before the function call (which would require you to have a seperate GetFileSize() type function).

The easiest way to fix this is just change

int loadfile(char path[255], char *data); // Can't pass a pointer to a pointer using one *

to

int loadfile(char path[255], char *&data); // Use a reference to a pointer for easiness' sake (vs. pointer to a pointer)


Also note that you'll need to add a null terminator on the end of that buffer if you're dealing with strings (IIRC).

[Noodlez]

Awsome. Thanks Moon & Sky, it works now.