fread

fread, fwrite - binary stream input/output

#include <stdio.h>
 I size_t fread(void * ptr , size_t  size , size_t  nmemb \
", FILE *" stream );
 I size_t fwrite(const void * ptr , size_t  size , size_t  nmemb ,
I               FILE * stream );

The function R fread () reads nmemb elements of data, each size bytes long, from the stream pointed to by R stream , storing them at the location given by R ptr .

The function R fwrite () writes nmemb elements of data, each size bytes long, to the stream pointed to by R stream , obtaining them from the location given by R ptr .

For non-locking counterparts, see unlocked_stdio(3).

R fread () and R 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).

R fread () does not distinguish between end-of-file and error, and callers must use feof(3) and ferror(3) to determine which occurred.

C89, POSIX.1-2001.

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