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FREAD(P)		   POSIX Programmer's Manual		      FREAD(P)

NAME
       fread - binary input

SYNOPSIS
       #include <stdio.h>

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

DESCRIPTION
       The  fread() function shall read into the array pointed to by ptr up to
       nitems elements whose size is specified by  size	 in  bytes,  from  the
       stream pointed to by stream.  For each object, size calls shall be made
       to the fgetc() function and the results stored, in the order  read,  in
       an array of unsigned char exactly overlaying the object. The file posi‐
       tion indicator for the stream (if defined) shall	 be  advanced  by  the
       number  of  bytes  successfully read. If an error occurs, the resulting
       value of the file position indicator for the stream is unspecified.  If
       a partial element is read, its value is unspecified.

       The fread() function may mark the st_atime field of the file associated
       with stream for update. The st_atime field shall be marked  for	update
       by  the	first  successful  execution  of  fgetc(),  fgets(), fgetwc(),
       fgetws(), fread(), fscanf(),  getc(),  getchar(),  gets(),  or  scanf()
       using stream that returns data not supplied by a prior call to ungetc()
       or ungetwc().

RETURN VALUE
       Upon successful completion, fread() shall return the number of elements
       successfully  read  which  is  less than nitems only if a read error or
       end-of-file is encountered. If size  or	nitems	is  0,	fread()	 shall
       return  0  and  the  contents  of the array and the state of the stream
       remain unchanged. Otherwise, if a read error occurs, the error  indica‐
       tor  for the stream shall be set,    and errno shall be set to indicate
       the error.

ERRORS
       Refer to fgetc() .

       The following sections are informative.

EXAMPLES
   Reading from a Stream
       The following example reads a single element from the  fp  stream  into
       the array pointed to by buf.

	      #include <stdio.h>
	      ...
	      size_t bytes_read;
	      char buf[100];
	      FILE *fp;
	      ...
	      bytes_read = fread(buf, sizeof(buf), 1, fp);
	      ...

APPLICATION USAGE
       The ferror() or feof() functions must be used to distinguish between an
       error condition and an end-of-file condition.

       Because of possible differences in element length  and  byte  ordering,
       files  written  using  fwrite() are application-dependent, and possibly
       cannot be read using fread() by a different application or by the  same
       application on a different processor.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       feof() , ferror() , fgetc() , fopen() , getc() , gets() , scanf() , the
       Base Definitions volume of IEEE Std 1003.1-2001, <stdio.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),	The  Open  Group  Base
       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
       event of any discrepancy between this version and the original IEEE and
       The Open Group Standard, the original IEEE and The Open Group  Standard
       is  the	referee document. The original Standard can be obtained online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group		     2003			      FREAD(P)
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