Memory Managing C - c++

Question

I wrote a function, using the C header stdio.h that returns content of a file (text or html). Can anyone please go through it and suggest if I have done the memory management efficiently. I shall be so pleased to hear better suggestions that I can improve my codes.
char *getFileContent(const char *filePath)
{
//Prepare read file
FILE *pReadFile;
long bufferReadSize;
char *bufferReadFileHtml;
size_t readFileSize;
char readFilePath[50];
sprintf_s(readFilePath, "%s", filePath);
pReadFile = fopen (readFilePath, "rb");
if (pReadFile != NULL)
{
// Get file size.
fseek (pReadFile , 0 , SEEK_END);
bufferReadSize = ftell (pReadFile);
rewind (pReadFile);
// Allocate RAM to contain the whole file:
bufferReadFileHtml = (char*) malloc (sizeof(char) * bufferReadSize);
if (bufferReadFileHtml != NULL)
{
// Copy the file into the buffer:
readFileSize = fread (bufferReadFileHtml, sizeof(char), bufferReadSize, pReadFile);
if (readFileSize == bufferReadSize)
{
return bufferReadFileHtml;
} else {
char errorBuffer[50];
sprintf_s(errorBuffer, "Error! Buffer overflow for file: %s", readFilePath);
}
} else {
char errorBuffer[50];
sprintf_s(errorBuffer, "Error! Insufficient RAM for file: %s", readFilePath);
}
fclose (pReadFile);
free (bufferReadFileHtml);
} else {
char errorBuffer[50];
sprintf_s(errorBuffer, "Error! Unable to open file: %s", readFilePath);
}
}

Answer 1

This looks like a C program, not a C++ program. While it will compile using most C++ compilers, it doesn't take advantage of any C++ features (e.g. new/new[], delete/delete[], explicit casting, stream operators, strings, nullptr etc.)
Your code almost looks like a safe C function, although I think sprintf_s is a Microsoft-only function, and thus probably won't compile using GCC, Clang, Intel, etc. as it isn't a part of the standard.
Your function should also return a value at all times. Turn compiler warnings on to catch these kinds of things; they make debugging a lot easier :)

Answer 2

There's not much to be said without knowing how you will be using the buffer you've created. Here are some possible considerations:
1) When you are reading the file into a buffer, your processor is doing nothing else for this program. It might be better to read and begin analyzing the already read portion in parallel.
2) If you need really fast-efficient-low memory file IO, consider converting your program to a state machine and forget about the buffer altogether.
3) If you don't really have a very demanding application, you are killing yourself by writing in C. C#, python, etc-- almost any other language has better string manipulation libraries.
Btw, you should use snprintf for portability and safety, as others have pointed out.