FREAD(3) Linux Programmer's Manual FREAD(3)
fread, fwrite - binary stream input/output
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);
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.
For non-locking counterparts, see unlocked_stdio(3).
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.
The functions fread and fwrite conform to ANSI X3.159-1989 (``ANSI C'').
read(2), write(2), feof(3), ferror(3), unlocked_stdio(3)
BSD MANPAGE 1996-05-17 FREAD(3)