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 loca- tion 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 or written (i.e., not the number of characters). If an error 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, and callers must use feof(3) and ferror(3) to determine which occurred.
CONFORMING TO C89, POSIX.1-2001.
SEE ALSO read(2), write(2), feof(3), ferror(3), unlocked_stdio(3)
BSD MANPAGE 1996-05-17 FREAD(3)