NAME    [Toc]    [Back]

     fread, fwrite - binary stream input/output

SYNOPSIS    [Toc]    [Back]

     #include <stdio.h>

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

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

DESCRIPTION    [Toc]    [Back]

     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    [Toc]    [Back]

     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-offile
 is reached, the return value is a  short  object  count
(or zero).

     The  function  fread()  does not distinguish between end-offile 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    [Toc]    [Back]

     read(2), write(2)

STANDARDS    [Toc]    [Back]

     The  functions  fread()  and  fwrite()   conform   to   ANSI
X3.159-1989 (``ANSI
     C'').

OpenBSD      3.6                           March      8,     1994