fread(3)

NAME

   fread, fwrite - binary stream input/output

SYNOPSIS

   #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

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

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

   For nonlocking counterparts, see unlocked_stdio(3).

RETURN VALUE

   On  success,  fread()  and  fwrite() return the number of items read or
   written.  This number equals the number of bytes transferred only  when
   size  is 1.  If an error occurs, or the end of the file is reached, the
   return value is a short item count (or zero).

   fread() does not distinguish between end-of-file and error, and callers
   must use feof(3) and ferror(3) to determine which occurred.

ATTRIBUTES

   For   an   explanation   of   the  terms  used  in  this  section,  see
   attributes(7).

   
   Interface          Attribute      Value   
   
   fread(), fwrite()  Thread safety  MT-Safe 
   

CONFORMING TO

   POSIX.1-2001, POSIX.1-2008, C89.

SEE ALSO

   read(2), write(2), feof(3), ferror(3), unlocked_stdio(3)

COLOPHON

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