FREAD(3) Linux Programmer's Manual 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 elements 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 elements of data, each size bytes
long, to the stream pointed to by stream, obtaining them from the loca-
tion given by ptr.
For non-locking counterparts, see unlocked_stdio(3).
RETURN VALUE
fread and fwrite return the number of items successfully read(2,n,1 builtins) or writ-
ten (i.e., not the number of characters). If an error(8,n) occurs, or the
end-of-file is reached, the return value is a short item count (or
zero).
fread does not distinguish between end-of-file and error(8,n), and callers
must use feof(3) and ferror(3) to determine which occurred.
CONFORMING TO
The functions fread and fwrite conform to ANSI X3.159-1989 (``ANSI
C'').
SEE ALSO
read(2,n,1 builtins)(2), write(1,2)(2), feof(3), ferror(3), unlocked_stdio(3)
BSD MANPAGE 1996-05-17 FREAD(3)