size_t fwrite(const void *buf, size_t size, size_t count, FILE *fp)

	- prototype in stdio.h

	- writes  (count * size)  bytes to file stream "fp"
	- swapping parameters "size" and "count" can often provide more
	  exact feedback (exactly how many bytes were written)
	- returns number of data blocks actually written or a short count
	  on error

	- see  fopen()   fread()   setvbuf()