Question about file seeking position

Question

My previous Question is about raw data reading and writing, but a new problem arised, it seems there is no ending....

The question is: the parameters of the function

Answer 1

The offset parameter of lseek is of type off_t. In 32-bit compilation environments, this type defaults to a 32-bit signed integer - however, if you compile with this macro defined before all system includes:

#define _FILE_OFFSET_BITS 64

...then off_t will be a 64-bit signed type.

For fseek, the fseeko function is identical except that it uses the off_t type for the offset, which allows the above solution to work with it too.