freebsd man page for fwrite

FREAD(3)						   BSD Library Functions Manual 						  FREAD(3)

NAME
     fread, fwrite -- binary stream input/output

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <stdio.h>

     size_t
     fread(void * restrict ptr, size_t size, size_t nmemb, FILE * restrict stream);

     size_t
     fwrite(const void * restrict ptr, size_t size, size_t nmemb, FILE * restrict stream);

DESCRIPTION
     The function fread() reads nmemb objects, each size bytes long, from the stream pointed to by stream, storing them at the location given by
     ptr.

     The function fwrite() writes nmemb objects, each size bytes long, to the stream pointed to by stream, obtaining them from the location given
     by ptr.

RETURN VALUES
     The functions fread() and fwrite() advance the file position indicator for the stream by the number of bytes read or written.  They return
     the number of objects read or written.  If an error occurs, or the end-of-file is reached, the return value is a short object count (or
     zero).

     The function fread() does not distinguish between end-of-file and error, and callers must use feof(3) and ferror(3) to determine which
     occurred.	The function fwrite() returns a value less than nmemb only if a write error has occurred.

SEE ALSO
     read(2), write(2)

STANDARDS
     The functions fread() and fwrite() conform to ISO/IEC 9899:1990 (``ISO C90'').

BSD
								   March 8, 1994							       BSD