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
