passing char buffer to functions and getting the size of the buffer

Question

I have set the buffer to size 100. I display the buffer in the main function where the buffer is declared. However, when I pass the buffer to the function and get the sizeof

Answer 1

What happens, is when you pass an array to a function, you only pass the address of the array in the memory, not the size of the array. What sizeof(buffer) is outputting in load_buffer() is the size of the pointer, which is four bytes.

The best way to keep the size of the buffer in the function is to change the function to:

void load_buffer(char *buffer, int length);

and the call to:

load_buffer(buffer, sizeof(buffer));

and then use length whenever you want the size of buffer.