FREAD

Section: MINTLIB LIBRARY FUNCTIONS (3)
Updated: 3 March 1993
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NAME

fread, fwrite - buffered binary input/output

SYNOPSIS

#include <stdio.h>

size_t fread (void *ptr, size_t size, size_t nitems, 
              FILE *stream);

size_t fwrite (const void *ptr, size_t size, size_t nitems,
               FILE *stream);

DESCRIPTION

fread reads, into a block pointed to by ptr, nitems items of data from the named input stream stream, where an item of data is a sequence of bytes (not necessarily terminated by a null byte) of length size. It returns the number of items actually read. fread stops reading if an end-of-file or error condition is encountered while reading from stream, or if nitems items have been read. fread leaves the file pointer in stream, if defined, pointing to the byte follow- ing the last byte read if there is one. fread does not change the contents of the file referred to by stream. fwrite writes at most nitems items of data from the block pointed to by ptr to the named output stream stream. It returns the number of items actually written. fwrite stops writing when it has written nitems items of data or if an error condition is encountered on stream. fwrite does not change the contents of the block pointed to by ptr. If size or nitems is non-positive, no characters are read or written and 0 is returned by both fread and fwrite.

RETURN VALUES

fread and fwrite return the number of elements read on success, 0 on failure.