For char * varable, how to view its value in debug mode - c++

Question

I composed below code to readback binary files by VC2017. In debug mode, I like to see the values in "buffer". but I could not see readable values.
my questions are:
how can I view the readable result?
I did "sizeof(buffer)", it returned 4, which was less than what I expected. I expected the buffer to be same size and the file size. why?
Thank you very much for enlightening me.
char* read_back(const char* filename)
{
FILE* pFile;
long lSize;
char* buffer;
pFile = fopen(filename, "rb");
if (pFile == NULL)
{
fputs("File error", stderr);
exit(1);
}
fseek(pFile, 0, SEEK_END);
lSize = ftell(pFile);
rewind(pFile); // set file pos at the begining
// copy the file into the buffer:
buffer = (char*)malloc(sizeof(char)*lSize);
size_t result = fread(buffer, 1, lSize, pFile);
if (result != lSize)
{
fputs("Reading error", stderr);
exit(3);
}
fclose(pFile);
return buffer;
}

Answer 1

Here's how to do your code in C++ (not the C code that you actually have)
#include <fstream>
#include <sstream>
#include <string>
std::string read_back(const char* filename)
{
std::ifstream file(filename, std::ios_base::binary);
std::ostringstream buffer;
buffer << file.rdbuf();
return buffer.str();
}
It returns a std::string not a char* but that's a good thing, because you don't have the issue of remembering to have to free the allocated memory.
As has been explained you misunderstand how pointers and sizeof work. Avoid pointers, they're hard.