How to get a pointer to the beginning of a file in C++

Question

Is it possible in C++ to somehow get a pointer to the beginning of an opened file so that it ( the pointer ) can be passed to the unix write function together with the size of the file?

Just to be clear: I want to pass the whole file to a write-like function - how do I do this?

Answer 1

sendfile() is specifically for this purpose on POSIX platforms when sending over the network, and the kernel handles the intricacies of doing it.

Answer 2

You can just mmap() the complete file, and then pass this pointer to write. You'll have to open it using the open(), not fopen() though.