[SOLVED] malloc() not allocating enough space

malloc() not allocating enough space

Hello here is my problem

FILE *sourcefile;

if ((sourcefile = fopen(argv[1],"r")) == NULL)  //Opens File
{
    printf("Error: Could not open %s\n",argv[1]);
    return 0;
}

fseek(sourcefile, 0 , SEEK_END);  // Sets file pointer at the end of the file
unsigned int fSize = ftell(sourcefile); // Determines file size by the position of file pointer
fseek(sourcefile, 0 , SEEK_SET); // Sets file pointer at the start of the file

char *buffer = (char *) malloc(fSize); 

if (buffer == NULL)
{
    printf("Error: Not enough system memory\n");
    return 0;
}

printf("%d\n",sizeof(buffer));
printf("%d\n",fSile);

fread (buffer,1,fSize,sourcefile);
fclose (sourcefile);

My code is simply opening a file and loading its contents into memory. The problem is, when I use

char *buffer = (char *) malloc(fSize)

it allocates only 4 bytes and not the full size of the file (i.e. 25 bytes when opening a simple txt with a small sentence). When I print the sizes of buffer and fSize at the end, I get 4 and 25 respectively, so fSize is correct. Any idea why this is happening?

Thanks,

Solution

sizeof(buffer) should be 4 bytes on a 32-bit platform. It is a pointer pointing to the buffer that malloc allocated. There is no way to query it for the size of the buffer.