FREAD

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUES
SEE ALSO
STANDARDS

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 location given by ptr.

RETURN VALUES

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.

SEE ALSO

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

STANDARDS

The functions fread and fwrite conform to ANSI C3.159-1989 (‘‘ANSI C’’).