fread

size_t

fread(void *buf, size_t size, size_t count, FILE *fp)

#include <stdio.h>
#include <string.h>
#include "local.h"

size_t
fread(void *buf, size_t size, size_t count, FILE *fp)
{
	size_t resid;
	char *p;
	int r;
	size_t total;

	/*
	 * The ANSI standard requires a return value of 0 for a count
	 * or a size of 0.  Peculiarily, it imposes no such requirements
	 * on fwrite; it only requires fread to be broken.
	 */
	if ((resid = count * size) == 0)
		return (0);
	if (fp->_r < 0)
		fp->_r = 0;
	total = resid;
	p = buf;
	while (resid > (r = fp->_r)) {
		(void)memcpy((void *)p, (void *)fp->_p, (size_t)r);
		fp->_p += r;
		/* fp->_r = 0 ... done in __srefill */
		p += r;
		resid -= r;
		if (__srefill(fp)) {
			/* no more input: return partial result */
			return ((total - resid) / size);
		}
	}
	(void)memcpy((void *)p, (void *)fp->_p, resid);
	fp->_r -= resid;
	fp->_p += resid;
	return (count);
}