#include <stdio.h>

char *
alloc(size)
	int size;
{
	static char	*freebase;
	static int	nleft = 0;
	register char *cp;
	register int i;

	if (size > nleft) {
		freebase = (char *)sbrk((int)(i = size > 2048 ? size : 2048));
		if (freebase == (char *)-1) {
			return(NULL);
		}
		nleft = i - size;
	} else
		nleft -= size;
	cp = freebase;
	for (i = size; --i >= 0; )
		*cp++ = 0;
	freebase = cp;
	return (cp - size);
}